Process induced alignment of gold nano-rods (GNRs) in thermoplastic polymer composites with tailored optical properties

Publication date: 10 February 2017
Source:Polymer, Volume 110
Author(s): Devon A. Boyne, Alice M. Savage, Mark H. Griep, Frederick L. Beyer, Joshua A. Orlicki
Manipulation of the electronic and optical properties of plasmonic nanomaterials offers unique and exciting opportunities for several fields including opto-electronics, bio-medical engineering and photovoltaics. In particular, gold nanorods (GNR) represent a class of plasmonic nanomaterials that provide tunable optical properties from the visible to the near infrared regime. Herein, we have developed a highly effective method to prepare polymer nanocomposites (PNCs) doped with GNR additives utilizing extrusion and injection molding. A key outcome is that the process is amenable to scalable manufacturing and can produce highly reproducible PNCs with excellent optical properties. The resultant PNCs display good particle dispersion, minimal aggregation and a high retention of the optical properties as confirmed by UV-Vis spectroscopy and transmission electron microscopy. The nano-additives are incorporated into different thermoplastics to demonstrate the versatility of this method for different matrices and to demonstrate stability over the extrusion processing temperature range (235–335 °C). Furthermore, the tractability of this method is demonstrated by incorporating GNRs with different morphologies (aspect ratio, stabilizing layer, etc.). Finally, partial flow-induced alignment is demonstrated, the degree of which is modulated by the length and monodispersity of the GNR nano-additive. Ultimately, we report an optimized methodology to produce high quality GNR-PNCs with tailorable optical properties that can be adapted for scalable manufacturing.

Graphical abstract

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Amphiphilic silsesquioxane nanoparticles by hydrolytic condensation of Y-shaped triethoxysilanes having hydroxyl and fluoroalkyl groups: Synthesis, self-assembly, and surface properties

Publication date: 10 February 2017
Source:Polymer, Volume 110
Author(s): Ryo Koizumi, Tetsuya Kimura, Kazuhiro Nakabayashi, Hideharu Mori
Two Y-shaped molecules combining two dissimilar (hydrophilic and hydrophobic) units with a reactive triethoxysilane moiety were synthesized by Michael addition reaction of (aminopropyl)triethoxysilane with 2-hydroxyethyl acrylate (HEA), followed by the addition of 2,2,2-trifluoroethyl acrylate (TFEA) or 1H,1H,5H-octafluoropentyl acrylate (OFPA). Hydrolytic condensations of the Y-shaped triethoxysilane precursors proceeded as homogeneous systems in acetone in presence of the acidic catalyst to afford amphiphilic silsesquioxane nanoparticles (SQ-NPs) having hydroxyl and fluoroalkyl groups (HEA/TFEA-SQ and HEA/OFPA-SQ). Scanning force microscope (SFM), X-ray diffraction (XRD), and size-exclusion chromatography (SEC) measurements indicated the formation of nanoparticles (average particle diameter is about 2.0 nm) with reasonable molecular weights and low dispersities (Mn = 5100-5400, Mw/Mn = 1.22–1.36) without aggregation. Characteristic assembled structures and surface properties of the amphiphilic SQ-NPs in different solvents were also evaluated. Flexible self-standing films were obtained from the amphiphilic SQ-NPs without any additional compounds, which are due to intermolecular hydrogen bondings.

Graphical abstract

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Polygonum multiflorum Radix extract protects human foreskin melanocytes from oxidative stress in vitro and potentiates hair follicle pigmentation ex vivo

Abstract

Objective

To examine the ability of an extract from traditional Chinese medicine, Polygonum multiflorum Radix, to protect melanocyte viability from oxidative stress, a key mechanism in the initiation and progression of hair greying.

Methods

To assess the antioxidant capacity of Polygonum multiflorum Radix extract, primary human foreskin melanocytes were treated with a commercially available Polygonum multiflorum Radix extract added to culture medium and exposed to hydrogen peroxide (H₂O₂), using intracellular reactive oxygen species concentrations and glutathione/protein ratios as endpoints. To improve solubility for cosmetic uses, a new Polygonum multiflorum Radix extract was derived. As hair graying is the consequence of melanocyte disappearance in an oxidative stress environment, we checked if the anti-oxidant capacity of the new Polygonum multiflorum Radix extract could preserve melanocyte viability in response to H₂O₂-induced oxidative stress, and preserve pigmentation within ex vivo human hair follicles.

Results

In vitro treatment of primary human foreskin melanocytes with traditional available Polygonum multiflorum Radix extract resulted in decreased intracellular ROS accumulation in response to H₂O₂ exposure with a concomitant preservation of glutathione to protein ratio, consistent with a protective response against H₂O₂ exposure and demonstrating the promise of this extract for protecting melanocytes against oxidative stress. Melanocytes treated with the improved Polygonum multiflorum Radix extract exhibited attenuated H₂O₂-induced cell death, demonstrating a clear cytoprotective effect. Treatment of ex vivo human hair follicles with the improved Polygonum multiflorum Radix extract resulted in a higher level of melanin compared to vehicle-treated controls, demonstrating an ex vivo protective effect on hair pigmentation.

Conclusion

Polygonum multiflorum Radix extract protects in vitro primary human foreskin melanocytes from the deleterious effects of H₂O₂-exposure and improves pigmentation within ex vivo human hair follicles, demonstrating the utility of Polygonum multiflorum Radix extract as a potential active ingredient for the protection of melanocytes against premature death. This data provides in vitro mechanistic evidence consistent with existing in vivo studies for the use of Polygonum multiflorum Radix extract as a strategy for the prevention of oxidative-stress induced hair greying, in line with traditional Polygonum multiflorum Radix uses.

This article is protected by copyright. All rights reserved.

http://ift.tt/2jIOaf3

Neural Representations of Belief Concepts: A Representational Similarity Approach to Social Semantics

The present experiment identified neural regions that represent a class of concepts that are independent of perceptual or sensory attributes. During functional magnetic resonance imaging scanning, participants viewed names of social groups (e.g. Atheists, Evangelicals, and Economists) and performed a one-back similarity judgment according to 1 of 2 dimensions of belief attributes: political orientation (Liberal to Conservative) or spiritualism (Spiritualist to Materialist). By generalizing across a wide variety of social groups that possess these beliefs, these attribute concepts did not coincide with any specific sensory quality, allowing us to target conceptual, rather than perceptual, representations. Multi-voxel pattern searchlight analysis was used to identify regions in which activation patterns distinguished the 2 ends of both dimensions: Conservative from Liberal social groups when participants focused on the political orientation dimension, and spiritual from Materialist groups when participants focused on the spiritualism dimension. A cluster in right precuneus exhibited such a pattern, indicating that it carries information about belief-attribute concepts and forms part of semantic memory—perhaps a component particularly concerned with psychological traits. This region did not overlap with the theory of mind network, which engaged nearby, but distinct, parts of precuneus. These findings have implications for the neural organization of conceptual knowledge, especially the understanding of social groups.

http://ift.tt/2iLPkaB

Long-term usability and bio-integration of polyimide-based intra-neural stimulating electrodes

Publication date: April 2017
Source:Biomaterials, Volume 122
Author(s): S. Wurth, M. Capogrosso, S. Raspopovic, J. Gandar, G. Federici, N. Kinany, A. Cutrone, A. Piersigilli, N. Pavlova, R. Guiet, G. Taverni, J. Rigosa, P. Shkorbatova, X. Navarro, Q. Barraud, G. Courtine, S. Micera
Stimulation of peripheral nerves has transiently restored lost sensation and has the potential to alleviate motor deficits. However, incomplete characterization of the long-term usability and bio-integration of intra-neural implants has restricted their use for clinical applications. Here, we conducted a longitudinal assessment of the selectivity, stability, functionality, and biocompatibility of polyimide-based intra-neural implants that were inserted in the sciatic nerve of twenty-three healthy adult rats for up to six months. We found that the stimulation threshold and impedance of the electrodes increased moderately during the first four weeks after implantation, and then remained stable over the following five months. The time course of these adaptations correlated with the progressive development of a fibrotic capsule around the implants. The selectivity of the electrodes enabled the preferential recruitment of extensor and flexor muscles of the ankle. Despite the foreign body reaction, this selectivity remained stable over time. These functional properties supported the development of control algorithms that modulated the forces produced by ankle extensor and flexor muscles with high precision. The comprehensive characterization of the implant encapsulation revealed hyper-cellularity, increased microvascular density, Wallerian degeneration, and infiltration of macrophages within the endoneurial space early after implantation. Over time, the amount of macrophages markedly decreased, and a layer of multinucleated giant cells surrounded by a capsule of fibrotic tissue developed around the implant, causing an enlargement of the diameter of the nerve. However, the density of nerve fibers above and below the inserted implant remained unaffected. Upon removal of the implant, we did not detect alteration of skilled leg movements and only observed mild tissue reaction. Our study characterized the interplay between the development of foreign body responses and changes in the electrical properties of actively used intra-neural electrodes, highlighting functional stability of polyimide-based implants over more than six months. These results are essential for refining and validating these implants and open a realistic pathway for long-term clinical applications in humans.



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In vivo imaging of β-galactosidase stimulated activity in hepatocellular carcinoma using ligand-targeted fluorescent probe

Publication date: April 2017
Source:Biomaterials, Volume 122
Author(s): Eun-Joong Kim, Rajesh Kumar, Amit Sharma, Byungkwon Yoon, Hyun Min Kim, Hyunseung Lee, Kwan Soo Hong, Jong Seung Kim
Development of targeted, selective, and noninvasive fluorescent probes for in vivo visualization of tumor-associated overexpressed enzymes are highly anticipated for cancer diagnosis and therapy. Herein, we developed a noninvasive fluorescent probe (DCDHF-βgal) for the sensitive detection, and in vivo visualization of β-galactosidase in hepatocyte HepG2 cells and its xenograft model. As a model system for in vivo targeted imaging, DCDHF-βgal possessing galactose unit selectively target hepatocyte and monitor the β-galactosidase activity with deep tissue penetration, and low background interference. DCDHF-βgal was activated by intracellular β-galactosidases as the driving force for the release of NIR fluorophore, thereby exhibiting ratiometric optical response. Initial fluorescence emission measured at 615 nm was changed to fluorescence at 665 nm upon activation of DCDHF-βgal with β-galactosidase. Ratiometric fluorescence detection of β-galactosidase was also observed in hepatocellular carcinoma cells and tumor xenograft. The noninvasive in vivo optical imaging facilitated by targeted and enzyme-activated imaging agent would be useful in various biomedical and diagnostic applications.



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In vivo near-infrared imaging and phototherapy of tumors using a cathepsin B-activated fluorescent probe

Publication date: April 2017
Source:Biomaterials, Volume 122
Author(s): Xiaoqiang Chen, Dayoung Lee, Sungsook Yu, Gyoungmi Kim, Songyi Lee, Yejin Cho, Haengdueng Jeong, Ki Taek Nam, Juyoung Yoon
The development of multifunctional reagents for simultaneous specific near-infrared (NIR) imaging and phototherapy of tumors is of great significance. This work describes the design of a cathepsin B-activated fluorescent probe (CyA-P-CyB) and its applications as an NIR imaging probe for tumor cells and as a phototherapy reagent for tumors. In vitro experiments demonstrated that CyA-P-CyB was activated via the cleavage of a peptide linker by cathepsin B in tumor cells to produce fluorescence in the NIR region based on a FRET mechanism. MTT assays showed that the phototoxicity of CyA-P-CyB toward cells depended on the activity of cathepsin B, and the probe exhibited specific phototoxicity toward tumor cells. CyA-P-CyB was also successfully applied to the in vivo imaging and phototherapy of tumors. Histological analysis indicated that CyA-P-CyB had no cytotoxic effects on seven mouse tissues (lung, liver, heart, kidney, pancreas, spleen and brain) after the CyA-P-CyB treatment and laser irradiation.

Graphical abstract

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Tuning physical properties and BMP-2 release rates of injectable hydrogel systems for an optimal bone regeneration effect

Publication date: April 2017
Source:Biomaterials, Volume 122
Author(s): Bo-Bae Seo, Jeong-Tae Koh, Soo-Chang Song
For a substance to be used as a drug delivery carrier and tissue inducible material for a target disease, its drug release rate and physical properties should be optimized to facilitate the healing process. We developed multi-tunable hydrogel systems with various physical properties and release behaviors to determine the optimal conditions for bone regeneration. Five injectable poly(phosphazene) hydrogels were developed with different types and amounts of anionic side-chains. The five polymer hydrogels showed considerably different in vitro and in vivo performances for sol-gel phase transition, dissolution/degradation, water uptake, and pore size. Furthermore, bone morphogenetic protein-2 (BMP-2) was loaded into the polymer hydrogels by forming nano-sized ionic-complexes with each polymer. The five types of nanocomplex hydrogels showed completely different BMP-2 release rates. By administering each nanocomplex hydrogel to mouse calvarial, we identified the most adapted nanocomplex hydrogel system for effective bone regeneration. The BMP-2 release rate was the most important factor in effective bone regeneration. Finally, the bone regeneration effect of the optimized hydrogel system was investigated in a critical-sized calvarial defect model.



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Tailoring polymeric hybrid micelles with lymph node targeting ability to improve the potency of cancer vaccines

Publication date: April 2017
Source:Biomaterials, Volume 122
Author(s): Qin Zeng, Hanmei Li, Hao Jiang, Jiao Yu, Ying Wang, Huan Ke, Tao Gong, Zhirong Zhang, Xun Sun
It has been widely accepted that lymph nodes (LNs) are critical targets of cancer vaccines and particles sized between 10 and 100 nm with a neutral or negative surface charge are preferred for lymphatic transfer after subcutaneous or intradermal injection. However their limited uptake by antigen presenting cells (APCs) and inadequate retention within LNs undoubtedly restrains their strength on activating T cell immunity. Here, we address this issue by tailoring the physicochemical properties of polymeric hybrid micelles (HMs), which are self-assembled from two amphiphilic diblock copolymers, poly-(ethylene glycol) phosphorethanolamine (PEG-PE) and polyethylenimine-stearic acid conjugate (PSA) via hydrophobic and electrostatic interactions. We successfully encapsulate melanoma antigen peptide Trp2 and Toll-like receptor-9 (TLR-9) agonist CpG ODN into HMs with a size of sub-30 nm. Their surface characteristics which are found closely related to their in vivo kinetics can be modulated by simply adjusting the molar ratio of PEG-PE and PSA. Our results demonstrated the optimized HMs with an equal mol of PEG-PE and PSA can potently target proximal LNs where their cargos are efficiently internalized by DCs. Furthermore, HMs mediated Trp2/CpG delivery system greatly expands antigen specific cytotoxic T lymphocytes (CTLs) and offers a strong anti-tumor effect in a lung metastatic melanoma model.



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Whatsapp: Improvement tool for surgical team communication

We read the article by Sidhoum et al. entitled "WhatsApp: Improvement tool for surgical team communication" with interest and commend them for highlighting strategies to improve communication within the surgical team.1

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Hypoxia and host pathogen responses

Publication date: Available online 20 January 2017
Source:Microbes and Infection
Author(s): Sarah R. Walmsley, Jan Rupp




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Semi-automatic 3D morphological reconstruction of neurons with densely branching morphology: application to retinal AII amacrine cells imaged with multi-photon excitation microscopy

Publication date: Available online 20 January 2017
Source:Journal of Neuroscience Methods
Author(s): Bas-Jan Zandt, Are Losnegård, Erlend Hodneland, Margaret Lin Veruki, Arvid Lundervold, Espen Hartveit
BackgroundAccurate reconstruction of the morphology of single neurons is important for morphometric studies and for developing compartmental models. However, manual morphological reconstruction can be extremely time-consuming and error-prone and algorithms for automatic reconstruction can be challenged when applied to neurons with a high density of extensively branching processes.New methodWe present a procedure for semi-automatic reconstruction specifically adapted for densely branching neurons such as the AII amacrine cell found in mammalian retinas. We used whole cell recording to fill AII amacrine cells in rat retinal slices with fluorescent dyes and acquired digital image stacks with multi-photon excitation microscopy. Our reconstruction algorithm combines elements of existing procedures, with segmentation based on adaptive thresholding and reconstruction based on a minimal spanning tree. We improved this workflow with an algorithm that reconnects neuron segments that are disconnected after adaptive thresholding, using paths extracted from the image stacks with the Fast Marching method.ResultsBy reducing the likelihood that disconnected segments were incorrectly connected to neighboring segments, our procedure generated excellent morphological reconstructions of AII amacrine cells.Comparison with existingmethods Reconstructing an AII amacrine cell required about 2hrs computing time, compared to 2–4days for manual reconstruction. To evaluate the performance of our method relative to manual reconstruction, we performed detailed analysis using a measure of tree structure similarity (DIADEM score), the degree of projection area overlap (Dice coefficient), and branch statistics.ConclusionsWe expect our procedure to be generally useful for morphological reconstruction of neurons filled with fluorescent dyes.



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Controlling Tumor Progression with Cyclophosphamide, Vincristine, and Dacarbazine Treatment Improves Survival in Patients with Metastatic and Unresectable Malignant Pheochromocytomas/Paragangliomas

Abstract

Evidence has not been established to support that combination chemotherapy with cyclophosphamide, vincristine, and dacarbazine (CVD) improves survival in patients with malignant pheochromocytoma and paraganglioma (M-PPGL). To investigate the efficacy of CVD for this disease, we retrospectively analyzed data of 23 patients with metastatic and unresectable M-PPGL (mean age, 41.7 ± 15.4 years) who received at least 2 cycles of this regimen. The follow-up period after initiation of CVD ranged from 0.3 to 13.7 years, with a median of 3.3 years. CVD therapy achieved a complete tumor response (CR) in 1 patient (4%), a partial response (PR) in 5 (22%), stable disease (SD) in 5 (22%), and progressive disease (PD) in 13 (52%), respectively. All of the responders (CR and PR) but 6% of the non-responders (SD and PD) showed substantial biochemical improvement. The progression-free survival period in the responders was significantly longer than in the non-responders (p < 0.01). Although the overall survival and survival after the diagnosis of M-PPGL were longer in the responders than the non-responders, the difference was not statistically significant (p = 0.08). The progression-free and overall survival period were significantly longer in the non-progression group (CR, PR, and SD) than in the progression group (PD) (1.7 ± 3.3 vs. 0.3 ± 0.3 years, p < 0.01, and 4.6 ± 3.6 vs. 2.0 ± 3.7 years, p = 0.01, respectively). It is therefore suggested that CVD chemotherapy could be useful in controlling tumor progression and improving survival in patients with metastatic and progressive M-PPGL.

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Gadolinium Contrast Enhancement Improves Confidence in Diagnosing Recurrent Soft Tissue Sarcoma by MRI

Publication date: Available online 20 January 2017
Source:Academic Radiology
Author(s): Shinn-Huey S. Chou, Daniel S. Hippe, Amie Y. Lee, Kurt Scherer, Jack A. Porrino, Darin J. Davidson, Felix S. Chew, Alice S. Ha
Rationale and ObjectivesTo determine how utilization of postgadolinium magnetic resonance imaging (MRI) influenced reader accuracy and confidence at identifying postoperative soft tissue sarcoma (STS) recurrence among readers with various levels of expertise.Materials and MethodsThis retrospective study was institutional review board approved and Health Insurance Portability and Accountability Act compliant. Postoperative MRI from 26 patients with prior STS resection (13 patients with confirmed recurrence, 13 without recurrence) was reviewed. Four blinded readers of varying expertise (radiology resident, fellow, attending, and orthopedic oncologist) initially evaluated only the precontrast images and rated each MRI for recurrence on a 5-point confidence scale. Assessment was repeated with the addition of contrast-enhanced sequences. Diagnostic accuracy based on confidence ratings was evaluated using the area under the receiver operating characteristic curve (AUC). Changes in confidence ratings were calculated using Wilcoxon signed-rank test.ResultsAll readers demonstrated good diagnostic accuracy both with and without contrast-enhanced images (AUC >0.98 for each reader). When contrast-enhanced images were made available, the resident recorded improved confidence with both assigning (P = 0.031) and excluding recurrence (P = 0.006); the fellow showed improved confidence only with assigning recurrence (P = 0.015); and the surgeon showed improved confidence in excluding recurrence (P = 0.003). The addition of contrast-enhanced images did not significantly influence the diagnostic confidence of the attending radiologist.ConclusionsDiagnostic accuracy of MRI was excellent in evaluating postoperative STS recurrence, and reader confidence improved depending on expertise when postgadolinium imaging was included in the assessment.



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Radiological characterization of the ancient Roman tuff-pozzolana underground quarry in Orvieto (Italy): A natural laboratory to revisit the interactions between radionuclides and aerosols

Publication date: March 2017
Source:Journal of Environmental Radioactivity, Volume 168
Author(s): C. Nuccetelli, R. Trevisi, F. Leonardi, M. Ampollini, F. Cardellini, S. Tonnarini, K. Kovler, C. Vargas Trassiera
Orvieto (Italy) has a large network of underground tunnels quarried to extract tuff and pozzolana by Etruscans and Romans. One of these tunnels was chosen as natural laboratory to compare different radiation measurement and dose assessment methods. Indeed, tuff and pozzolana are very rich in natural radioactivity and are interesting from the radiation protection point of view since they are still used as building materials. In order to characterize this site an in situ experimental procedure was followed. It consisted in measurements carried out with different instruments: two portable gamma ray spectrometers, two gamma dose rate meters, two radon monitors and one two channel working level monitor. Samples of tuff and pozzolana stones were also collected to be measured with gamma spectrometry in laboratory. Due to the high content of ²³⁸U, ²³²Th (more than 200 Bq kg⁻¹ for both radionuclides) and ⁴⁰K (more than 2000 Bq kg⁻¹) of tuff and pozzolana, elevated levels of exposure to natural radioactivity were found: indeed, with different instruments and approach, a gamma dose rate of about 1 μGy h⁻¹ and an average radon concentration of about 10,000 Bq m⁻³, with a Potential Alpha Energy Concentration (PAEC) of 288 MeV cm⁻³, were measured. The radiological characteristics of Orvieto underground quarry make it a perfect site for "in field" intercomparisons of different measurement and dose assessment methods.



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Soil-soil solution distribution coefficient of soil organic matter is a key factor for that of radioiodide in surface and subsurface soils

Publication date: April 2017
Source:Journal of Environmental Radioactivity, Volumes 169–170
Author(s): Yusuke Unno, Hirofumi Tsukada, Akira Takeda, Yuichi Takaku, Shun'ichi Hisamatsu
We investigated the vertical distribution of the soil–soil-solution distribution coefficients (Kd) of ¹²⁵I, ¹³⁷Cs, and ⁸⁵Sr in organic-rich surface soil and organic-poor subsurface soil of a pasture and an urban forest near a spent-nuclear-fuel reprocessing plant in Rokkasho, Japan. Kd of ¹³⁷Cs was highly correlated with water-extractable K⁺. Kd of ⁸⁵Sr was highly correlated with water-extractable Ca²⁺ and SOC. Kd of ¹²⁵I⁻ was low in organic-rich surface soil, high slightly below the surface, and lowest in the deepest soil. This kinked distribution pattern differed from the gradual decrease of the other radionuclides. The thickness of the high-¹²⁵I⁻Kd middle layer (i.e., with high radioiodide retention ability) differed between sites. Kd of ¹²⁵I⁻ was significantly correlated with Kd of soil organic carbon. Our results also showed that the layer thickness is controlled by the ratio of Kd-OC between surface and subsurface soils. This finding suggests that the addition of SOC might prevent further radioiodide migration down the soil profile. As far as we know, this is the first report to show a strong correlation of a soil characteristic with Kd of ¹²⁵I⁻. Further study is needed to clarify how radioiodide is retained and migrates in soil.



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Editorial board

Publication date: March 2017
Source:Journal of Environmental Radioactivity, Volume 168





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Special issue: Naturally radioactivity in construction

Publication date: March 2017
Source:Journal of Environmental Radioactivity, Volume 168
Author(s): Konstantin Kovler, Wouter Schroeyers




http://ift.tt/2jJ0JaM

Concentrations of 226Ra, 232Th and 40K in industrial kaolinized granite

Publication date: March 2017
Source:Journal of Environmental Radioactivity, Volume 168
Author(s): Nataša Todorović, Jan Hansman, Dušan Mrđa, Jovana Nikolov, Richárd Kardos, Miodrag Krmar
Activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K in 120 kaolinized granite samples imported in Serbia from the Motajica mine, Bosnia and Herzegovina, were measured. The ²²⁶Ra concentration ranged from 61 to 319 Bq kg⁻¹, the ²³²Th from 44 to 272 Bq kg⁻¹, and the ⁴⁰K from 590 to 1470 Bq kg⁻¹. The frequency distribution of ⁴⁰K concentrations was near-Gaussian, where those of ²²⁶Ra and ²³²Th were right-skewed. In 6 samples, the gamma index, I, was higher than 2, which exceeds the exemption dose criterion (0.3 mSv y⁻¹). The absorbed dose rate and annual effective doses for workers in the ceramic industries in Serbia who worked with kaolinized granite were below levels of concern.



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Radon exhalation study of manganese clay residue and usability in brick production

Publication date: March 2017
Source:Journal of Environmental Radioactivity, Volume 168
Author(s): Tibor Kovács, Amin Shahrokhi, Zoltán Sas, Tamás Vigh, János Somlai
The reuse of by-products and residue streams is an important topic due to environmental and financial aspects. Manganese clay is a residue of manganese ore processing and is generated in huge amounts. This residue may contain some radionuclides with elevated concentrations. In this study, the radon emanation features and the massic exhalation rate of the heat-treated manganese clay were determined with regard to brick production. From the manganese mud depository, 20 samples were collected and after homogenization radon exhalation characteristics were determined as a function of firing temperatures from 100 to 750 °C. The major naturally occurring radionuclides ⁴⁰K, ²²⁶Ra and ²³²Th concentrations were 607 ± 34, 52 ± 6 and 40 ± 5 Bq kg⁻¹, respectively, comparable with normal clay samples. Similar to our previous studies a strong correlation was found between the internal structure and the radon emanation. The radon emanation coefficient decreased by ∼96% from 0.23 at 100 °C to 0.01 at 750 °C. The massic radon exhalation rate of samples fired at 750 °C reduced by 3% compared to samples fired at 100 °C. In light of the results, reusing of manganese clay as a brick additive is possible without any constraints.



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Radiological characterization and evaluation of high volume bauxite residue alkali activated concretes

Publication date: March 2017
Source:Journal of Environmental Radioactivity, Volume 168
Author(s): Tom Croymans, Wouter Schroeyers, Pavel Krivenko, Oleksandr Kovalchuk, Anton Pasko, Mikael Hult, Gerd Marissens, Guillaume Lutter, Sonja Schreurs
Bauxite residue, also known as red mud, can be used as an aggregate in concrete products. The study involves the radiological characterization of different types of concretes containing bauxite residue from Ukraine. The activity concentrations of radionuclides from the ²³⁸U, ²³²Th decay series and ⁴⁰K were determined for concrete mixture samples incorporating 30, 40, 50, 60, 75, 85 and 90% (by mass) of bauxite residue using gamma-ray spectrometry with a HPGe detector. The studied bauxite residue can, from a radiological point of view using activity concentration indexes developed by Markkanen, be used in concrete for building materials and in road construction, even in percentages reaching 90% (by mass). However, when also occupational exposure is considered it is recommended to incorporate less than 75% (by mass) of Ukrainian bauxite residue during the construction of buildings in order to keep the dose to workers below the dose criterion used by Radiation Protection (RP) 122 (0.3 mSv/a). Considering RP122 for evaluation of the total effective dose to workers no restrictions are required for the use of the Ukrainian bauxite residue in road construction.



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Alkali-activated concrete with Serbian fly ash and its radiological impact

Publication date: March 2017
Source:Journal of Environmental Radioactivity, Volume 168
Author(s): Cristina Nuccetelli, Rosabianca Trevisi, Ivan Ignjatović, Jelena Dragaš
The present paper reports the results of a study on different types of fly ash from Serbian coal burning power plants and their potential use as a binder in alkali-activated concrete (AAC) depending on their radiological and mechanical properties. Five AAC mixtures with different types of coal burning fly ash and one type of blast furnace slag were designed. Measurements of the activity concentrations of ⁴⁰K, ²²⁶Ra and ²³²Th were done both on concrete constituents (fly ash, blast furnace slag and aggregate) and on the five solid AAC samples. Experimental results were compared by using the activity concentration assessment tool for building materials - the activity concentration index I, as introduced by the EU Basic Safety Standards (CE, 2014). All five designed alkali-activated concretes comply with EU BSS screening requirements for indoor building materials. Finally, index I values were compared with the results of the application of a more accurate index - I(ρd), which accounts for thickness and density of building materials (Nuccetelli et al., 2015a). Considering the actual density and thickness of each concrete sample index - I(ρd) values are lower than index I values.As an appendix, a synthesis of main results concerning mechanical and chemical properties is provided.



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Radiological and material characterization of high volume fly ash concrete

Publication date: March 2017
Source:Journal of Environmental Radioactivity, Volume 168
Author(s): I. Ignjatović, Z. Sas, J. Dragaš, J. Somlai, T. Kovács
The main goal of research presented in this paper was the material and radiological characterization of high volume fly ash concrete (HVFAC) in terms of determination of natural radionuclide content and radon emanation and exhalation coefficients. All concrete samples were made with a fly ash content between 50% and 70% of the total amount of cementitious materials from one coal burning power plant in Serbia. Physical (fresh and hardened concrete density) and mechanical properties (compressive strength, splitting tensile strength and modulus of elasticity) of concrete were tested. The radionuclide content (²²⁶Ra, ²³²Th and ⁴⁰K) and radon massic exhalation of HVFAC samples were determined using gamma spectrometry. Determination of massic exhalation rates of HVFAC and its components using radon accumulation chamber techniques combined with a radon monitor was performed. The results show a beneficial effect of pozzolanic activity since the increase in fly ash content resulted in an increase in compressive strength of HVFAC by approximately 20% for the same mass of cement used in the mixtures. On the basis of the obtained radionuclide content of concrete components the I -indices of different HVFAC samples were calculated and compared with measured values (0.27–0.32), which were significantly below the recommended 1.0 index value. The prediction was relatively close to the measured values as the ratio between the calculated and measured I-index ranged between 0.89 and 1.14. Collected results of mechanical and radiological properties and performed calculations clearly prove that all 10 designed concretes with a certain type of fly ash are suitable for structural and non-structural applications both from a material and radiological point of view.



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Congenital Toxoplasmosis

Publication date: Available online 20 January 2017
Source:Pediatric Neurology
Author(s): Rahul Guha, Lauren Miley, Madison Aspiri, Radhika Dhamija




http://ift.tt/2jhaolv

Quantitative proteomics analysis reveals the tolerance of Mirabilis jalapa L. to petroleum contamination

Abstract

Petroleum is not only an important energy resource but is also a major soil pollutant. To gain better insight into the adaptability mechanism of Mirabilis jalapa to petroleum-contaminated soil, the protein profiles of M. jalapa root were investigated using label-free quantitative proteomics technique. After exposing to petroleum-contaminated soil for 24 h, 34 proteins significantly changed their protein abundance and most of the proteins increased in protein abundance (91.18%). Combined with gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses as well as data from previous studies, our results revealed that M. jalapa enhanced tolerance to petroleum by changing antioxidation and detoxification, cell wall organization, amino acid and carbohydrate metabolism, transportation and protein process, and so on. These metabolism alterations could result in the production and secretion of low molecular carbohydrate, amino acid, and functional protein, which enhanced the bioavailability of petroleum and reducing the toxicity of the petroleum. Taken together, these results provided novel information for better understanding of the tolerance of M. jalapa to petroleum stress.

http://ift.tt/2iKNZAY

Modification of the 137 Cs, 90 Sr, and 60 Co transfer to wheat plantlets by NH 4 + fertilizers

Abstract

Inorganic fertilizers are used as agricultural countermeasures intended to inhibit the soil to plant transfer of radionuclides after a radioactive fallout. Two NH₄⁺ fertilizers, diammonium phosphate (DAP) and NPK, were applied to soil contaminated with a mixture of radionuclides to analyze whether they modify the transfer of ¹³⁷Cs, ⁹⁰Sr, and ⁶⁰Co and stable elements (K, Na, Ca, and Mg) to wheat plantlets grown under controlled laboratory conditions. DAP introduced NH₄⁺ in the soil, which can increase ¹³⁷Cs transfer, while NPK also introduced K⁺, which can decrease it. The application of DAP increased the accumulation of ¹³⁷Cs in wheat plantlets with increasing application rate, so did the ¹³⁷Cs/K in plantlets. Regarding the NPK application, the ¹³⁷Cs increased in all treatments, but at maximum rate, the available K introduced by the fertilizer was probably able to partially satisfy the nutritional requirements of the wheat plantlet and the ¹³⁷Cs decreased relative to the recommended rate. The ¹³⁷Cs/K ratio in plantlet decreased with increasing NPK rates. The transfer of ⁹⁰Sr increased with increasing DAP rate and only at the maximum NPK rate. The ⁶⁰Co transfer only increased at the maximum application rates for DAP and NPK. These modifications should be considered when using these fertilizers as agricultural countermeasures.

http://ift.tt/2k9E1Fb

Dissipation and phytoremediation of polycyclic aromatic hydrocarbons in freshly spiked and long-term field-contaminated soils

Abstract

Pot experiments were used to compare the dissipation and phytoremediation effect of alfalfa (Medicago sativa L.) for polycyclic aromatic hydrocarbons (PAHs) in a freshly spiked soil and two field-contaminated soils with different soil organic carbon (SOC) contents (Anthrosols, 1.41% SOC; Phaeozems, 8.51% SOC). In spiked soils, the dissipation rates of phenanthrene and pyrene were greater than 99.5 and 94.3%, respectively, in planted treatments and 95.0 and 84.5%, respectively, in unplanted treatments. In field-contaminated Anthrosols, there were limited but significant reductions of 10.2 and 15.4% of total PAHs in unplanted and planted treatments, respectively. In field-contaminated Phaeozems, there were no significant reductions of total PAHs in either unplanted or planted treatments. A phytoremediation effect was observed for the spiked soils and the Anthrosols, but not for the Phaeozems. The results indicated that laboratory tests with spiked soils cannot reflect the real state of field-contaminated soils. Phytoremediation efficiency of PAHs in field-contaminated soils was mainly determined by the content of SOC. Phytoremediation alone has no effect on the removal of PAHs in field-contaminated soils with high SOC content.

http://ift.tt/2iKNZ3W

I know you can see me: social ATTENTION influences BODILY self-awareness

Publication date: Available online 19 January 2017
Source:Biological Psychology
Author(s): Nesrine Hazem, Nathalie George, Matias Baltazar, Laurence Conty
It has recently been demonstrated that eye contact influences bodily self-awareness. Here, we investigated if the belief of being the target of another person's attention may also induce such influence. We created videos of an individual wearing two different pairs of sunglasses. We manipulated the participants to believe that they were in on-line connection with the individual and that one of the pairs of sunglasses was obstructed so that the individual could not see them through it. We demonstrated that the perception of an individual wearing see-through sunglasses, as compared to obstructed sunglasses or a low-level baseline condition, led to a greater correlation between the participants' rating of the intensity of their bodily reactions and their skin conductance response to emotional pictures. This shows that the belief to be watched by another social agent increases bodily self-awareness and further suggests that such belief is embedded in direct gaze perception.



http://ift.tt/2k9zC5b

On the neural mechanisms underlying the protective function of retroactive cuing against perceptual interference: Evidence by event-related potentials of the EEG

Publication date: Available online 20 January 2017
Source:Biological Psychology
Author(s): Daniel Schneider, Anna Barth, Stephan Getzmann, Edmund Wascher
This EEG study investigated the protective effect of retroactive attentional focusing on working memory. To this effect, we used a visuo-spatial working memory task and presented block-wise distractor displays after working memory contents had been updated by means of a retroactive cue (retro-cue). Retroactive attention attenuated the interfering effect of distractors on memory precision. The reduction of working memory load by means of a selective retro-cue was reflected by a decline of a negative slow wave over parietal sites. Posterior N1 to the distractor was reduced following a selective retro-cue compared to a neutral retro-cue condition, most notably at left hemispheric sites. P3b referred to the distractor was suppressed completely only following a selective retro-cue. This suggests that focusing on only a subset of visuo-spatial information represented in working memory releases cognitive resources for preventing the in-depth processing of subsequently irrelevant visual events, thereby inhibiting their transfer into working memory.



http://ift.tt/2k9AUxj

Soft tissue substitutes in non-root coverage procedures: a systematic review and meta-analysis

Abstract

Objectives

The present systematic review compared the effectiveness of soft tissue substitutes (STSs) and autogenous free gingival grafts (FGGs) in non-root-coverage procedures to increase keratinized tissue (KT) width around teeth.

Materials and methods

Included studies fulfilled the following main eligibility criteria: (a) preclinical in vivo or human controlled trials using FGG as control, (b) non-root-coverage procedures, and (c) assessment of KT width. Meta-analysis was performed on the gain in KT width (primary outcome variable) and several secondary variables.

Results

Eight human trials with short observation time evaluating five different STSs were identified. FGG yielded consistently significantly (p < 0.001) larger increase in KT width irrespective whether the comparison regarded an acellular matrix or a tissue-engineered STS. Further, FGG yielded consistently ≥2 mm KT width postoperatively, while use of STS did not, in the few studies reporting on this outcome. On the other hand, STSs resulted in significantly better aesthetic outcomes and received greater patient preference (p < 0.001).

Conclusions

Based on relatively limited evidence, in non-root-coverage procedures, FGG (1) resulted consistently in significantly larger increase in KT width compared to STS and (2) yielded consistently ≥2 mm KT width postoperatively, while STSs did not. STSs yielded significantly better aesthetic outcomes, received greater patient preference, and appeared safe.

Clinical relevance

Larger and more predictable increase in KT width is achieved with FGG, but STSs may be considered when aesthetics is important. Clinical studies reporting relevant posttreatment outcomes, e.g., postop KT width ≥2 mm, on the long-term (>6 months) are warranted.

http://ift.tt/2iKpOST

Xenobiotic transporters and kidney injury

Publication date: Available online 20 January 2017
Source:Advanced Drug Delivery Reviews
Author(s): Blessy George, Dahea You, Melanie S. Joy, Lauren M. Aleksunes
Renal proximal tubules are targets for toxicity due in part to the expression of transporters that mediate the secretion and reabsorption of xenobiotics. Alterations in transporter expression and/or function can enhance the accumulation of toxicants and sensitize the kidneys to injury. This can be observed when xenobiotic uptake by carrier proteins is increased or efflux of toxicants and their metabolites is reduced. Nephrotoxic chemicals include environmental contaminants (halogenated hydrocarbon solvents, the herbicide paraquat, the fungal toxin ochratoxin, and heavy metals) as well as pharmaceuticals (certain beta-lactam antibiotics, antiviral drugs, and chemotherapeutic drugs). This review explores the mechanisms by which transporters mediate the entry and exit of toxicants from renal tubule cells and influence the degree of kidney injury. Delineating how transport proteins regulate the renal accumulation of toxicants is critical for understanding the likelihood of nephrotoxicity resulting from competition for excretion or genetic polymorphisms that affect transporter function.

Graphical abstract

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Mitteilungen der Deutschen Gesellschaft für Kieferorthopädie

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Trends in Patient Safety of Intact Abdominal Aortic Aneurysm Repair: German Registry Data on 36,594 Procedures

Publication date: Available online 19 January 2017
Source:European Journal of Vascular and Endovascular Surgery
Author(s): M. Trenner, B. Haller, M. Storck, B. Reutersberg, M.A. Kallmayer, H.-H. Eckstein
Objective/BackgroundThe study aim was to determine whether patient safety for non-ruptured abdominal aortic aneurysm (nrAAA) repair has changed between 1999 and 2010 in a large German cohort.MethodsThe data source was the prospective quality assurance registry of the German Vascular Society from 1999 to 2010. Patient characteristics, surgical techniques (open aortic repair [OAR], endovascular aortic repair [EVAR]), procedural time and outcomes, including the length of hospital stay (LOS), were analysed using the Cochran–Armitage test for binary parameters and Spearman's correlation coefficient for quantitative parameters.ResultsA total of 36,594 operations (23,037 OAR, 13,557 EVAR) for infrarenal nrAAA in 201 hospitals in Germany were investigated. Patients' mean age increased from 69.6 to 72.0 years (p < .001). The rate of patients with American Society of Anesthesiologists scores of 3 or 4 increased (p < .001). Use of EVAR increased (1999: 16.7%; 2010: 62.7%; p < .001), and since 2009, EVAR has been more frequently used than OAR. The overall in hospital mortality decreased from 3.1% in 1999 to 2.3% in 2010 (p < .001). There were no temporal trends for mortality rates for EVAR (p = .233) or OAR (p = .281) when considered separately. Cardiac (1999: 8.1%; 2010: 5.1%; p < .001) and pulmonary (1999: 7.8%; 2010: 4.8%; p < .001) complications decreased. The rate of post-operative renal failure increased (1999: 3.6%; 2010 4.1%; p = .017), without increasing the rate of patients needing dialysis (1999: 1.7%; 2010: 1.7%; p = .171). The median LOS decreased from 17 days in 1999 to 10 days in 2010 (p < .001).ConclusionThis study shows significantly improved post-procedural in hospital outcomes and decreased use of resources for nrAAA repair. This trend can probably be attributed to the implementation of EVAR as a standard technique, but some trends could also possibly be explained by a change in the remuneration system. The main limitation of the registry is the lack of internal and external validation. However, in hospital patient safety for AAA repair seems to have improved significantly in the participating hospitals.



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A Multicentre Trial of Patient specific Rehearsal Prior to EVAR: Impact on Procedural Planning and Team Performance

Publication date: Available online 20 January 2017
Source:European Journal of Vascular and Endovascular Surgery
Author(s): L. Desender, I. Van Herzeele, M. Lachat, J. Duchateau, C. Bicknell, J. Teijink, J. Heyligers, F. Vermassen
ObjectivePatient specific rehearsal (PsR) prior to endovascular aneurysm repair (EVAR) enables the endovascular team to practice and evaluate the procedure prior to treating the real patient. This multicentre trial aimed to evaluate the utility of PsR prior to EVAR as a pre-operative planning and briefing tool.Material and methodsPatients with an aneurysm suitable for EVAR were randomised to pre-operative or post-operative PsR. Before and after the PsR, the lead implanter completed a questionnaire to identify any deviation from the initial treatment plan. All team members completed a questionnaire evaluating realism, technical issues, and human factor aspects pertinent to PsR. Technical and human factor skills, and technical and clinical success rates were compared between the randomised groups.Results100 patients were enrolled between September 2012 and June 2014. The plan to visualise proximal and distal landing zones was adapted in 27/50 (54%) and 38/50 (76%) cases, respectively. The choice of the main body, contralateral limb, or iliac extensions was adjusted in 8/50 (16%), 17/50 (34%), and 14/50 (28%) cases, respectively. At least one of the abovementioned parameters was changed in 44/50 (88%) cases. For 100 EVAR cases, 199 subjective questionnaires post-PsR were completed. PsR was considered to be useful for selecting the optimal C-arm angulation (median 4, IQR 4-5) and was recognised as a helpful tool for team preparation (median 4, IQR 4-4), to improve communication (median 4, IQR 3-4), and encourage confidence (median 4, IQR 3-4). Technical and human factor skills and technical and initial clinical success rates were similar between the randomisation groups.ConclusionPsR prior to EVAR has a significant impact on the treatment plan and may be useful as a pre-operative planning and briefing tool. Subjective ratings indicate that this technology may facilitate planning of optimal C-arm angulation and improve non-technical skills. Trial registration: URL://www.clinicaltrials.gov. Unique identifier: NCT01632631.



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Temporal detection and analysis of guideline interactions

Publication date: Available online 20 January 2017
Source:Artificial Intelligence in Medicine
Author(s): Luca Anselma, Luca Piovesan, Paolo Terenziani
BackgroundClinical practice guidelines (CPGs) are assuming a major role in the medical area, to grant the quality of medical assistance, supporting physicians with evidence-based information of interventions in the treatment of single pathologies. The treatment of patients affected by multiple diseases (comorbid patients) is one of the main challenges for the modern healthcare. It requires the development of new methodologies, supporting physicians in the treatment of interactions between CPGs. Several approaches have started to face such a challenging problem. However, they suffer from a substantial limitation: they do not take into account the temporal dimension. Indeed, practically speaking, interactions occur in time. For instance, the effects of two actions taken from different guidelines may potentially conflict, but practical conflicts happen only if the times of execution of such actions are such that their effects overlap in time.ObjectivesWe aim at devising a methodology to detect and analyse interactions between CPGs that considers the temporal dimension.MethodsIn this paper, we first extend our previous ontological model to deal with the fact that actions, goals, effects and interactions occur in time, and to model both qualitative and quantitative temporal constraints between them. Then, we identify different application scenarios, and, for each of them, we propose different types of facilities for user physicians, useful to support the temporal detection of interactions.ResultsWe provide a modular approach in which different Artificial Intelligence temporal reasoning techniques, based on temporal constraint propagation, are widely exploited to provide users with such facilities. We applied our methodology to two cases of comorbidities, using simplified versions of CPGs.ConclusionWe propose an innovative approach to the detection and analysis of interactions between CPGs considering different sources of temporal information (CPGs, ontological knowledge and execution logs), which is the first one in the literature that takes into account the temporal issues, and accounts for different application scenarios.



http://ift.tt/2jImfwv

Generation of human islet-specific regulatory T cells by TCR gene transfer

Publication date: Available online 20 January 2017
Source:Journal of Autoimmunity
Author(s): Caroline M. Hull, Lauren E. Nickolay, Megan Estorninho, Max W. Richardson, James L. Riley, Mark Peakman, John Maher, Timothy I.M. Tree
Based on the success in animal models of type 1 diabetes (T1D), clinical trials of adoptive regulatory T cell (Treg) therapy are underway using ex vivo expanded polyclonal Tregs. However, pre-clinical data also demonstrate that islet-specific Tregs are more potent than polyclonal Tregs at reversing T1D. Translation of this approach into man will require methods to generate large populations of islet-specific Tregs which, to date, has proved to be a major hurdle. Here we demonstrate the feasibility of lentiviral-mediated T cell receptor (TCR) gene transfer to confer antigen specificity on polyclonal human Tregs. Targeting has been achieved using TCRs isolated from human islet-specific and viral-specific CD4⁺ T cell clones. Engineered T cells demonstrated expression of ectopically-delivered TCRs, resulting in endowment of cognate antigen-specific responses. This enabled antigen-specific suppression at increased potency compared to polyclonal Tregs. However, cells transduced with islet-specific TCRs were less responsive to cognate antigen than viral-specific TCRs, and in some cases, required additional methods to isolate functional antigen-specific Tregs. This study demonstrates the potential of TCR gene transfer to develop islet-specific Treg therapies for effective treatment of T1D, but also highlights that additional optimisation may be required to achieve its full potential.



http://ift.tt/2k9eFqY

Expansion of CD11b+Ly-6C+ myeloid-derived suppressor cells (MDSCs) driven by galectin-9 attenuates CVB3-induced myocarditis

Publication date: March 2017
Source:Molecular Immunology, Volume 83
Author(s): Yingying Zhang, Mengying Zhang, Xueqin Li, Zongsheng Tang, Ling He, Kun Lv
Galectin-9 is known to play a role in the modulation of innate and adaptive immunity to ameliorate CVB3-induced myocarditis. In the present study, we found that galectin-9 induced the expansion of CD11b⁺Ly-6C⁺ myeloid-derived suppressor cells (MDSCs) in the heart from CVB3-infected mice. Adoptive transfer of CD11b⁺Ly-6C⁺ MDSCs significantly alleviated myocarditis accompanied by increased Th2 and Treg frequency and anti-inflammatory cytokines expression in the heart tissue. Moreover, Ly6C⁺ MDSCs, but not Ly6G⁺ cells, expressed Arg-1 and NOS2, and suppressed CD4⁺ T cell proliferation in vitro in an Arg-1-dependent mechanism; an event that was reversed with treatment of either an Arg-1 inhibitor or addition of excess l-arginine. Furthermore, Ly6C⁺ MDSCs co-expressed higher levels of F4/80, Tim-3, and IL-4Rα, and had the plasticity to up-regulate NOS2 or Arg-1 in response to IFN-γ or IL-4 treatment. The present results indicate that galectin-9 expands CD11b⁺Ly-6C⁺ MDSCs to ameliorate CVB3-induced myocarditis.



http://ift.tt/2iTLTd4

IL-12 and IL-23 modulate plasticity of FoxP3+ regulatory T cells in human Leprosy

Publication date: March 2017
Source:Molecular Immunology, Volume 83
Author(s): Mohd Tarique, Chaman Saini, Raza Ali Naqvi, Neena Khanna, Alpana Sharma, D.N. Rao
Leprosy is a bacterial disease caused by M. leprae. Its clinical spectrum reflects the host's immune response to the M. leprae and provide an ideal model to investigate the host pathogen interaction and immunological dysregulation. Tregs are high in leprosy patients and responsible for immune suppression of the host by producing IL-10 and TGF-β cytokines. In leprosy, plasticity of Tregs remain unstudied. This is the first study describing the conversion of Tregs into Th1-like and Th17-like cells using in vitro cytokine therapy in leprosy patients. Peripheral blood mononuclear cells from leprosy patients were isolated and stimulated with M. leprae antigen (MLCwA), rIL-12 and rIL-23 for 48h. Expression of FoxP3 in CD4⁺CD25⁺ Tregs, intracellular cytokines IFN-γ, TGF-β, IL-10 and IL-17 in Tregs cells were evaluated by flow cytometry (FACS) after stimulation. rIL-12 treatment increases the levels of pStat4 in Tregs and IFN-γ production. In the presence of rIL-23, pStat3⁺ and IL-17A⁺ cells increase. rIL-12 and r—IL-23 treatment downregulated the FoxP3 expression, IL-10 and TGF-β production by Tregs and enhances the expression of co-stimulatory molecules (CD80, CD86). In conclusion rIL-12 converts Tregs into IFN-γ producing cells through STAT-4 signaling while rIL-23 converts Tregs into IL-17 producing cells through STAT-3 signaling in leprosy patients. This study may helpful to provide a new avenue to overcome the immunosuprression in leprosy patients using in vitro cytokine.



http://ift.tt/2jIBGo7

The protection effects of (1E,6E)-1,7-diphenylhepta-1,6-diene-3,5-dione, a curcumin analogue, against operative liver injury in rats

Publication date: 30 March 2017
Source:European Journal of Pharmaceutical Sciences, Volume 100
Author(s): Xiaowei Chi, Dan Yu, Peijing Li, Qianfeng Lu, Wenjiao Jiang, Kun Hao
The relationship between the chemistry characteristic and the hepatoprotective effects of (1E,6E)-1,7-diphenylhepta-1,6-diene-3,5-dione (DDD), a curcumin analogue, in operative liver injury rats was investigated to reveal the mechanism of hepatic protection effects of DDD. DDD (1.2–4.8mmol/kg) was administrated 10min before reperfusion phase in hepatic ischemia-reperfusion injury (IRI) rats. DDD (4.8mmol/kg) administrated 10min before ischemia and N-acetylcysteine (NAC) (4.8mmol/kg) administrated 10min before reperfusion were included for comparative studies. The plasma liver enzyme activities, histopathological indices and markers of lipid peroxide were determined to evaluate the hepatic protection effects. Effects of DDD on succinate dehydrogenase (SDH) activity were also investigated. DDD showed dose-dependent hepatocyte protections when administrated 10min before reperfusion stages in hepatic IRI rats. DDD showed almost equivalent hepatoprotective effects when administrated 10min before ischemia phase demonstrating that DDD acted on the reperfusion stages selectively against the hepatic IRI, instead of ischemia phase. NAC was not effective against hepatic IRI when treated 10min before reperfusion because of the higher pKa of NAC. In additional, DDD had no effect on the SDH both in hepatic IRI rats and in mitochondria. In conclusion, DDD had dose-dependent hepatocyte protections in the reperfusion stages in hepatic IRI rats, while the observed hepatocyte protections of DDD did not involve SDH activities. β-Diketone structures of DDD were crucial for the hepatocyte protections. The abilities of DDD to clear up the unsaturated aldehydes related with the enolate nucleophilicity and the pKa. DDD might be a promising candidate to treat hepatic IRI.

Graphical abstract

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Characterization, pharmacokinetics and tissue distribution of chlorogenic acid-loaded self-microemulsifying drug delivery system

Publication date: 30 March 2017
Source:European Journal of Pharmaceutical Sciences, Volume 100
Author(s): Li Chen, Chang-shun Liu, Qing-zhen Chen, Sen Wang, Yong-ai Xiong, Jing Jing, Jia-jia Lv
The purpose of this study was to develop a self-microemulsifying drug delivery system (SMEDDS) to improve the oral bioavailability of Chlorogenic acid (CA), an important bioactive compound from Lonicerae Japonicae Flos with poor permeability. SMEDDS was prepared and characterized by self-emulsifying rate, morphological observation, droplet size determination, stability, in vitro release, in vivo bioavailability and tissue distribution experiments. Results shown that the SMEDDS of CA has a high self-emulsifying rate (>98%) in the dissolution media, and its microemulsion exhibits small droplet size (16.37nm) and good stability. In vitro release test showed a complete release of CA from SMEDDS in 480min. After oral administration in mice, significantly enhanced bioavailability of CA was achieved through SMEDDS (249.4% relative to the CA suspension). Interestingly, SMEDDS significantly changed the tissue distribution of CA and showed a better targeting property to the kidney (2.79 of the relative intake efficiency). It is suggested that SMEDDS improves the oral bioavailability of CA may mainly through increasing its absorption and slowing the metabolism of absorbed CA via changing its distribution from the liver to the kidney. In conclusion, it is indicated that SMEDDS is a promising carrier for the oral delivery of CA.

Graphical abstract

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Engineering hot-melt extruded solid dispersion for controlled release of hydrophilic drugs

Publication date: 30 March 2017
Source:European Journal of Pharmaceutical Sciences, Volume 100
Author(s): Shuli Zhang, Xuan Meng, Zheng Wang, Aiping Fan, Guocheng Wang, Yanjun Zhao, Yu Tang
It is often challenging to precisely manipulate the release behavior of hydrophilic drugs that is believed to be crucial for a satisfactory therapeutic outcome. The aim of this work was to regulate the dissolution of hydrophilic drug from hot-melt extruded solid dispersion via rational screening of the pore-forming agents. Venlafaxine hydrochloride and Compritol® 888 ATO was selected as the model drug and carrier excipient, respectively. Hydrophilic polyethylene glycol (PEG 6000) and polyvinylpyrolidone (PVP K30) were chosen as the transient pore-forming agents. The X-ray diffraction and thermal analysis showed that both drug and carrier existed in the crystalline form. Both types of polymers could generate pores upon dissolution test and the drug release rate was proportionally correlated to the pore-forming agent content. The mathematical modelling showed that the Ritger-Peppas model gave the best fit to the release curves, which demonstrates a diffusion-dominant release mechanism. The scanning electron microscopy and mercury intrusion porosimetry analysis proved that PVP K30 could generate large pores with low porosity, but PEG 6000 produced smaller pores with relatively high porosity. The in vivo pharmacokinetics study in rat revealed that solid dispersions containing either PEG 6000 or PVP K30 (both at 2.5%, w/w) exhibited an elevated bioavailability compared to the commercial product, Effexor® XR. The current work implied that rational screening of transient pore-forming polymer in solid dispersion could be a robust approach for controlling hydrophilic drug release.

Graphical abstract

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Environmental and ecological risk of heavy metals in the marine sediment from Dakhla Bay, Morocco

Abstract

Heavy metal assessment in Dakhla Bay (Atlantic coast) was carried out using different environmental and ecological indices. Heavy metal concentrations were measured using ICP–AES and were compared with consensus-based sediment quality guidelines. The distribution of heavy metal concentrations varies for the three groups: (i) lead distribution is dominated by its associations with copper and chromium. These elements have the same source, most probably related to anthropogenic activities. (ii) Nickel, zinc and cobalt are associated with aluminium and iron indicating their terrigenous origin (natural content), and (iii) cadmium concentration is related to upwelling currents. This paper systematically studied the distributions and pollution levels of heavy metals in sediment in the coastal areas in Dakhla Bay, which is of scientific significance, to discuss the changing rules and the affecting factors of the harmful heavy metals and can be adopted for reference to other coastal areas.

http://ift.tt/2jFgCiq

Monitoring nutrients fate after digestate spreading in a short rotation buffer area

Abstract

One of the main sources of reactive nitrogen pollution is animal manure. The disposal of digestate (material remaining after the anaerobic digestion of a biodegradable feedstock) in agricultural soils could solve both the problems of soil fertilization and waste removal, but the fate of digestate in the environment must be assessed carefully before its massive utilization. To investigate whether digestate could be safely employed as a soil fertilizer, an agricultural field located in Monastier di Treviso (Northern Italy) and characterized by the presence of low hydraulic conductivity clay soils, was selected to be amended with bovine digestate. The experimental site was intensively monitored by a three-dimensional array of probes recording soil water content, temperature, and electrical conductivity, to solve the water and bulk mass fluxes in the unsaturated zone. High-resolution soil coring allowed the characterization of soil water composition over two hydrological years. Chloride, found in high concentrations in the digestate, was used as environmental tracer to track the fate of the percolating water. The study concluded that digestate could be confidently employed in short rotation buffer areas at an average rate of 195 ± 26 kg-N/ha/year in low hydraulic conductivity soils not affected by diffuse fracturing during dry periods.

http://ift.tt/2jFhdkc

Oxidation of danofloxacin by free chlorine—kinetic study, structural identification of by-products by LC–MS/MS and potential toxicity of by-products using in silico test

Abstract

In this study, we aimed to investigate the kinetics and the mechanism of reaction of the fluoroquinolone antibacterial danofloxacin (DANO) by free available chlorine (FAC) during water chlorination process. Kinetic study was thus performed at pH 7.2, 20 °C in the presence of an excess of total chlorine. Under these experimental conditions, a second-order reaction rate constant (first-order relative to DANO concentration and first-order relative to FAC concentration) was evaluated to k~1446 M⁻¹ s⁻¹. Five degradation products were identified at different reaction times. Their structures were investigated by using fragmentations obtained at different CID collision energies in MS/MS experiments. Moreover, the toxicity of the proposed structures was predicted by using T.E.S.T. program. The results indicated that all by-products may have a developmental toxicity. The oral rat LD₅₀ concentration was predicted to be lower than that of DANO. Furthermore, two degradation compounds presented a concentration level for fathead minnow LC₅₀ (96 h) lower than that of DANO and presented toxicity for the marine animals.

http://ift.tt/2kb7jr8

Screening of inorganic and organic contaminants in floodwater in paddy fields of Hue and Thanh Hoa in Vietnam

Abstract

In the rainy season, rice growing areas in Vietnam often become flooded by up to 1.5 m water. The floodwater brings contaminants from cultivated areas, farms and villages to the rice fields resulting in widespread contamination. In 2012 and 2013, the inorganic and organic contaminants in floodwater was investigated in Thanh Hoa and Hue. Water samples were taken at 16 locations in canals, paddy fields and rivers before and during the flood. In total, 940 organic micro-pollutants in the water samples were determined simultaneously by GC-MS method with automatic identification and quantification system (AIQS), while ICP-MS was used for determination of ten trace elements in the samples. The concentrations of 277 organic micro-pollutants and ten elements (As, Cu, Cd, Cr, Co, Pb, Zn, Fe, Mn, Al) ranged from 0.01 to 7.6 μg L⁻¹ and 0.1 to 3170 μg L⁻¹, respectively, in the floodwater. Contaminants originated from industrial sources (e.g. PAH) were detected at low concentrations, ranged from 0.01 to 0.18 μg L⁻¹, while concentrations of pollutants originated from domestic sources (e.g. sterols, pharmaceuticals and personal care products and pesticides) were ranged from 0.01 to 2.12 μg L⁻¹. Isoprocarb had the highest detection frequency of 90%, followed by isoprothiolane (88%) and fenobucarb (71%). The results indicated that contaminants in floodwater come from untreated wastewater from villages, and the agricultural activities are the major sources of increased pesticides resuspended in the floodwater in this study.

http://ift.tt/2iR3pie

Microbial changes linked to the accelerated degradation of the herbicide atrazine in a range of temperate soils

Abstract

Accelerated degradation is the increased breakdown of a pesticide upon its repeated application, which has consequences for the environmental fate of pesticides. The herbicide atrazine was repeatedly applied to soils previously untreated with s-triazines for >5 years. A single application of atrazine, at an agriculturally relevant concentration, was sufficient to induce its rapid dissipation. Soils, with a range of physico-chemical properties and agricultural histories, showed similar degradation kinetics, with the half-life of atrazine decreasing from an average of 25 days after the first application to <2 days after the second. A mathematical model was developed to fit the atrazine-degrading kinetics, which incorporated the exponential growth of atrazine-degrading organisms. Despite the similar rates of degradation, the repertoire of atrazine-degrading genes varied between soils. Only a small portion of the bacterial community had the capacity for atrazine degradation. Overall, the microbial community was not significantly affected by atrazine treatment. One soil, characterised by low pH, did not exhibit accelerated degradation, and atrazine-degrading genes were not detected. Neutralisation of this soil restored accelerated degradation and the atrazine-degrading genes became detectable. This illustrates the potential for accelerated degradation to manifest when conditions become favourable. Additionally, the occurrence of accelerated degradation under agriculturally relevant concentrations supports the consideration of the phenomena in environmental risk assessments.

http://ift.tt/2jgPa76

Monitoring pharmaceuticals and personal care products in reservoir water used for drinking water supply

Abstract

In this work, the presence of selected emerging contaminants has been investigated in two reservoirs, La Fe (LF) and Rio Grande (RG), which supply water to two drinking water treatment plants (DWTPs) of Medellin, one of the most populated cities of Colombia. An analytical method based on solid-phase extraction (SPE) of the sample followed by measurement by liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS) was developed and validated for this purpose. Five monitoring campaigns were performed in each reservoir, collecting samples from 7 sites (LF) and 10 sites (RG) at 3 different depths of the water column. In addition, water samples entering in the DWTPs and treated water samples from these plans were also analysed for the selected compounds. Data from this work showed that parabens, UV filters and the pharmaceutical ibuprofen were commonly present in most of the reservoir samples. Thus, methyl paraben was detected in around 90% of the samples collected, while ibuprofen was found in around 60% of the samples. Water samples feeding the DWTPs also contained these two compounds, as well as benzophenone at low concentrations, which was in general agreement with the results from the reservoir samples. After treatment in the DWTPs, these three compounds were still present in the samples although at low concentrations (<40 ng/L), which evidenced that they were not completely removed after the conventional treatment applied. The potential effects of the presence of these compounds at the ppt levels in drinking water are still unknown. Further research is needed to evaluate the effect of chronic exposure to these compounds via consumption of drinking water.

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Bioelectrochemical anaerobic sewage treatment technology for Arctic communities

Abstract

This study describes a novel wastewater treatment technology suitable for small remote northern communities. The technology is based on an enhanced biodegradation of organic carbon through a combination of anaerobic methanogenic and microbial electrochemical (bioelectrochemical) degradation processes leading to biomethane production. The microbial electrochemical degradation is achieved in a membraneless flow-through bioanode–biocathode setup operating at an applied voltage below the water electrolysis threshold. Laboratory wastewater treatment tests conducted through a broad range of mesophilic and psychrophilic temperatures (5–23 °C) using synthetic wastewater showed a biochemical oxygen demand (BOD₅) removal efficiency of 90–97% and an effluent BOD₅ concentration as low as 7 mg L⁻¹. An electricity consumption of 0.6 kWh kg⁻¹ of chemical oxygen demand (COD) removed was observed. Low energy consumption coupled with enhanced methane production led to a net positive energy balance in the bioelectrochemical treatment system.

http://ift.tt/2jF7L04

Variation in accumulation and translocation of di- n -butyl phthalate (DBP) among rice ( Oryza sativa L.) genotypes and selection of cultivars for low DBP exposure

Abstract

Di-n-butyl phthalate (DBP) is a typical endocrine-disrupting chemical with higher detection frequency and concentration in agricultural soil (particularly in paddy-field soil of Guangdong Province) of China. In this study, a greenhouse experiment was conducted to investigate variation in uptake and accumulation of DBP by 20 rice cultivars and to screen low DBP-accumulating cultivars. DBP concentrations in plants varied greatly with rice cultivars, growth stages, and tissues. The highest DBP concentrations in both roots and shoots were observed at the ripening stage, with concentrations 2–100-fold higher than those at tillering, jointing, and flowering stages. At the ripening stage, DBP concentrations decreased in the order of leaf > root > stem > grain, and significant differences of DBP concentrations were observed among various rice cultivars. Moreover, the magnitude of variation in DBP concentrations among various cultivars was greater in stems and grains than in roots and leaves. The translocation factors of DBP from roots to stems and from shoots to grains were <1.0, and those from stems to leaves were almost >1.0. Overall, cultivars Yuxiangyouzhan, Jinnongsimiao, Tianyou 122, and Wuyou 380 accumulated relatively lower DBP in grains, resulting in lower DBP exposure. The DBP uptake and translocation pathways in rice require further investigation.

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Regulated partitioning of fixed carbon ( 14 C), sodium (Na + ), potassium (K + ) and glycine betaine determined salinity stress tolerance of gamma irradiated pigeonpea [ Cajanus cajan (L.) Millsp]

Abstract

Soil salinity is a major constraint that limits legume productivity. Pigeonpea is a salt sensitive crop. Seed gamma irradiation at a very low dose (2.5 Gy) is known to enhance seedling establishment, plant growth and yield of cereals and other crops. The present study conducted using two genetically diverse varieties of pigeonpea viz., Pusa-991 and Pusa-992 aimed at establishing the role of pre-sowing seed gamma irradiation at 0, 0.0025, 0.005, 0.01, 0.02, 0.05 and 0.1 kGy on plant growth, seed yield and seed quality under salt stress at 0, 80 and 100 mM NaCl (soil solution EC equivalent 1.92, 5.86 and 8.02 dS/m, respectively) imposed right from the beginning of the experiment. Changes in carbon flow dynamics between shoot and root and concentration of osmolyte, glycine betaine, plant uptake and shoot and root partitioning of Na⁺ and K⁺ and activity of protein degrading enzyme protease were measured under the combined effect of gamma irradiation and salt stress. Positive affect of pre-sowing exposure of seed to low dose of gamma irradiation (<0.01 kGy) under salt stress was evident in pigeonpea. Pigeonpea variety, Pusa-992 showed a better salt tolerance response than Pusa-991 and that the radiated plants performed better than the unirradiated plants even at increasing salinity level. Seed yield and seed protein and iron content were also positively affected by the low dose gamma irradiation under NaCl stress. Multiple factors interacted to determine physiological salt tolerance response of pigeonpea varieties. Gamma irradiation caused a favourable alteration in the source-sink (shoot-root) partitioning of recently fixed carbon (¹⁴C) under salt stress in pigeonpea. Gamma irradiation of seeds prior to sowing enhanced glycine betaine content and reduced protease activity at 60-day stage under various salt stress regimes. Lower partitioning of Na⁺and relatively higher accumulation of K⁺ under irradiation treatment was the other important determinants that differentiated between salt-tolerant and salt-susceptible variety of pigeonpea. The study provides evidence and physiological basis for exploring exploitation of pre-sowing exposure of seeds with low-dose gamma ray for enhancing the salt tolerance response of crop plants.

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Mitteilungen der Deutschen Gesellschaft für Kieferorthopädie

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A zeolitic imidazolate framework based nanoporous carbon as a novel fiber coating for solid-phase microextraction of pyrethroid pesticides

Publication date: 1 May 2017
Source:Talanta, Volume 166
Author(s): Shuaihua Zhang, Qian Yang, Xiumin Yang, Wenchang Wang, Zhi Li, Lihong Zhang, Chun Wang, Zhi Wang
A high-surface-area nanoporous carbon (NPC) has been successfully synthesized by using the metal-organic framework ZIF-90 as both the template and precursor together with furfuryl alcohol as a secondary carbon source. The prepared ZIF-90 templated NPC (ZIF-90-NPC) was then coated onto a stainless steel wire by a simple physical adhesion approach to prepare solid-phase microextraction (SPME) fiber. By coupling the ZIF-90-NPC coated fiber-based SPME with gas chromatography-microelectron capture detection (GC-μECD), the developed method gave a large enhancement factor (984-2869), low limit of detection (0.1–0.5ngg⁻¹) and good linearity (0.3–50ngg⁻¹) for the determination of some pyrethroid pesticides (bifenthrin, fenpropathrin, cyhalothrin, permethrin, cyfluthrin, flucythrinate, fenvalerate and deltamethrin) from different fruits and vegetables. The relative standard deviations (RSDs) for six replicate extractions of the pyrethroids by the ZIF-90-NPC coated fiber ranged from 4.3% to 8.0%. The recoveries of the spiked pyrethroids (5ngg⁻¹ and 20ngg⁻¹) from fruit and vegetable samples were in the range of 88.0–104.0% and 86.0–103.5% with the RSDs ranging from 4.8% to 12.9% and 5.0–10.8%, respectively. Besides, the ZIF-90-NPC coated fiber was stable enough for 100 extraction cycles without a significant loss of extraction efficiency. The method was successfully applied to the determination of the pyrethroids in fruit and vegetable samples.

Graphical abstract

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p-Aminothiophenol-coated CdSe/ZnS quantum dots as a turn-on fluorescent probe for pH detection in aqueous media

Publication date: 1 May 2017
Source:Talanta, Volume 166
Author(s): Dong Li, Hu Xu, Dan Li, Yuhong Wang
Since controlling hydrogen ion concentration (i.e. pH) is fairly important in various fields, developing a facile pH detection method is highly desired. Owing to the superior optical properties, semiconductor quantum dots (QDs) have been developed as a promising alternative for organic fluorophores in fluorescence analysis. In this study, a hydrophilic p-aminothiophenol (pATP) capped CdSe/ZnS QDs (denoted as pATP-QDs) as a selective "turn-on" fluorescence probe for pH in aqueous media is reported. The pATP-QDs probe easily obtained via ligand exchange are characterized by various analytic techniques including ultraviolet-visible, fourier transform infrared, fluorescence, time-resolved fluorescence spectroscopies, and transmission electron microscope etc. pATP-QDs exhibits weak fluorescence since pATP acts as an effective hole trapper. As an organic base, pATP easily binds to proton and the formation of pATP-H⁺ complex alters the energetic position of HOMO for pATP, which enables pATP-QDs unfavorable for the effective hole transfer. Thus, the QDs photoluminescence (PL) was switched on. PL "off-on" mode, high PL quantum yield of QDs as well as extremely high stability of pATP-H⁺ complex (logKs =7.47) enables pATP-QDs to exhibit an excellent pH detection performance. Under optimal conditions, the present probe exhibits a good linear relationship between fluorescence response and pH values in pH range 3.2–6.0. Furthermore, the present probe exhibits a high selectivity for proton over other common cations and has been successfully used for pH detection in real water samples.

Graphical abstract

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Magnetic/non-magnetic argan press cake nanocellulose for the selective extraction of sudan dyes in food samples prior to the determination by capillary liquid chromatograpy

Publication date: 1 May 2017
Source:Talanta, Volume 166
Author(s): Yassine Benmassaoud, María J. Villaseñor, Rachid Salghi, Shehdeh Jodeh, Manuel Algarra, Mohammed Zougagh, Ángel Ríos
Two methods for the determination of Sudan dyes (Sudan I, Sudan II, Sudan III and Sudan IV) in food samples, by solid phase extraction - capillary liquid chromatography, are proposed. Both methods use nanocellulose (NC) extracted from bleached argan press cake (APC), as a nano-adsorbent recycled from an agricultural waste material. One of the methods involves the dispersion of NC in food sample extracts, along with the waste and eluents being separated by centrifugation. In the other method, NC was modified by magnetic iron nanoparticles before using it in the extraction of Sudan dyes. The use of a magnetic component in the extraction process allows magnetic separation to replace the centrifugation step in a convenient and economical way. The two proposed methods allows the determination of Sudan dye amounts at the 0.25–2.00µgL⁻¹ concentration range. The limit of detections, limit of quantifications and standard deviations achieved were lower than 0.1µgL⁻¹, 0.20µgL⁻¹ and 3.46% respectively, when using NC as a nano-adsorbent, and lower than 0.07µgL⁻¹, 0.23µgL⁻¹ and 2.62%, respectively, with the magnetic nanocellulose (MNC) was used. Both methods were applied to the determination of Sudan dyes in barbeque and ketchup sauce samples, obtaining recoveries between 93.4% and 109.6%.

Graphical abstract

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The fabrication of carbon nanotubes array-based electrochemical chiral sensor by electrosynthesis

Publication date: 1 May 2017
Source:Talanta, Volume 166
Author(s): Hong Zhu, Fengxia Chang, Zhiwei Zhu
How to align the single-walled carbon nanotubes (SWCNTs) onto the electrode vertically and to control their density and orientation are still a major challenge. Theoretically, properly selected chiral SWCNTs can discriminate enantiomers through their different dielectric response to the adsorption of chiral species, few reports can confirm this theoretic model. Herein, we presented a new strategy to fabricate SWCNTs array-based electrochemical chiral sensor. Carboxylated chiral SWCNTs were vertically attached to the oxidized glass carbon electrode with ethylenediamine as a linker by electrosynthesis. The electrode surface was characterized with atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS). The practicability of the sensor was validated by chirally recognizing 3,4-dihydroxyphenylalanine as a model molecule. We found that both the highly ordered standing of SWCNTs and the application of square wave voltammetry (SWV) amplified the intrinsic chirality of chiral SWCNTs.

Graphical abstract

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A method for the analysis of sugars in biological systems using reductive amination in combination with hydrophilic interaction chromatography and high resolution mass spectrometry

Publication date: 1 May 2017
Source:Talanta, Volume 166
Author(s): Sami Bawazeer, Ali Muhsen Ali, Aliyah Alhawiti, Abedawn Khalaf, Colin Gibson, Jonans Tusiimire, David G. Watson
Separation of sugar isomers extracted from biological samples is challenging because of their natural occurrence as alpha and beta anomers and, in the case of hexoses, in their pyranose and furanose forms. A reductive amination method was developed for the tagging of sugars with the aim of it becoming part of a metabolomics work flow. The best separation of the common hexoses (glucose, fructose, mannose and galactose) was achieved when ²H5-aniline was used as the tagging reagent in combination with separation on a ZICHILIC column. The method was used to tag a range of sugars including pentoses and uronic acids. The method was simple to perform and was able to improve both the separation of sugars and their response to electrospray ionisation. The method was applied to the profiling of sugars in urine where a number of hexose and pentose isomers could be observed. It was also applied to the quantification of sugars in post-mortem brain samples from three control samples and three samples from individuals who had suffered from bipolar disorder.

Graphical abstract

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Determination of N-nitrosodiethanolamine in cosmetic products by reversed-phase dispersive liquid-liquid microextraction followed by liquid chromatography

Publication date: 1 May 2017
Source:Talanta, Volume 166
Author(s): Alberto Chisvert, Juan L. Benedé, María Peiró, Isabel Pedrón, Amparo Salvador
A new analytical method for the determination of N-nitrosodiethanolamine (NDELA), a very harmful compound not allowed in cosmetic products, is presented. The method is based on a new approach of dispersive liquid–liquid microextraction (DLLME) useful for extraction of highly polar compounds, called reversed-phase DLLME (RP-DLLME), followed by liquid chromatography–ultraviolet/visible (LC-UV/Vis) determination. The variables involved in the RP-DLLME process were studied to provide the best enrichment factors. Under the optimized conditions, a mixture of 750µL of acetone (disperser solvent) and 125µL of water (extraction solvent) was rapidly injected into 5mL of toluene sample solution. The extracts were injected into the LC-UV/Vis system using ammonium acetate 0.02M as mobile phase. After chromatographic separation, the eluate passed throughout a photolysis unit in order to convert NDELA to nitrite, and then it was merged with a flow stream of Griess Reagent and passed throughout a post-column reactor at 50°C to derivatize nitrite into an azo-dye, which was finally measured spectrophotometrically at 540nm. The method was successfully validated showing good linearity, an enrichment factor of 31.5±0.9, limits of detection and quantification of 1.1 and 3.6ngmL⁻¹, respectively, and a good repeatability (RSD <8%). Finally, the proposed analytical method was applied to the determination of NDELA in commercial cosmetic samples of different nature, specifically three lipophilic creams and a hydrophilic shower gel, with good relative recovery values (87 – 117%) thus showing that matrix effects are negligible. These results were compared with those obtained by applying the ISO 10130 official method, which uses the same detection approach. It was concluded that a great improvement in the sensitivity was achieved, whereas the use of organochlorine solvents is avoided and therefore it can be considered as a greener approach.

Graphical abstract

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A novel electrochemical biosensor based on polyadenine modified aptamer for label-free and ultrasensitive detection of human breast cancer cells

Publication date: 1 May 2017
Source:Talanta, Volume 166
Author(s): Kun Wang, Meng-Qi He, Fu-Heng Zhai, Rong-Huan He, Yong-Liang Yu
Simple, rapid, sensitive, and specific detection of cancer cells plays a pivotal role in the diagnosis and prognosis of cancer. A sandwich electrochemical biosensor was developed based on polyadenine (polydA)-aptamer modified gold electrode (GE) and polydA-aptamer functionalized gold nanoparticles/graphene oxide (AuNPs/GO) hybrid for the label-free and selective detection of breast cancer cells (MCF-7) via a differential pulse voltammetry (DPV) technique. Due to the intrinsic affinity between multiple consecutive adenines of polydA sequences and gold, polydA modified aptamer instead of thiol terminated aptamer was immobilized on the surface of GE and AuNPs/GO. The label-free MCF-7 cells could be recognized by polydA-aptamer and self-assembled onto the surface of GE. The polydA-aptamer functionalized AuNPs/GO hybrid could further bind to MCF-7 cells to form a sandwich sensing system. Characterization of the surface modified GE was carried out by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) using Fe(CN)6^3-/4- as a redox probe. Under the optimized experimental conditions, a detection limit of 8 cellsmL⁻¹ (3σ/slope) was obtained for MCF-7 cells by the present electrochemical biosensor, along with a linear range of 10–10⁵ cellsmL⁻¹. By virtue of excellent sensitivity, specificity and repeatability, the present electrochemical biosensor provides a potential application in point-of-care cancer diagnosis.

Graphical abstract

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Magnetic mixed hemimicelles dispersive solid-phase extraction based on ionic liquid-coated attapulgite/polyaniline-polypyrrole/Fe3O4 nanocomposites for determination of acaricides in fruit juice prior to high-performance liquid chromatography-diode array detection

Publication date: 1 May 2017
Source:Talanta, Volume 166
Author(s): Xiaoling Yang, Kexin Qiao, Fang Liu, Xiaoling Wu, Miyi Yang, Jing Li, Haixiang Gao, Sanbing Zhang, Wenfeng zhou, Runhua Lu
In this research, a novel method using magnetic mixed hemimicelles dispersive solid-phase extraction (MMHDSPE) based on C16mimBr-coated attapulgite/polyaniline-polypyrrole/Fe3O4 (ATP/PANI-PPY/Fe3O4) nanocomposites were investigated for enrichment and separation of three acaricides in fruit juice. In this method, we combined the simplicity and speed of dispersive solid-phase extraction, the advantages of mixed hemimicelles and the facility of the phase separation of the magnetic nanoparticles to develop a simple, rapid, sensitive, and effective method for detecting target analytes from the juice samples. ATP/PANI-PPY/Fe3O4 nanocomposites were successfully synthesized using a one-pot method. The as-prepared nanocomposite sorbents were characterized by Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The experimental factors affecting the extraction efficiency including the sorbent type, amount of ATP/PANI-PPY/Fe3O4 nanocomposites, volume of ILs, sonication time, pH, and desorption conditions were optimized. Under the optimal conditions, good linearity was observed for all target analytes, with correlation coefficients (r²) ranging from 0.9994 to 0.9999; the limits of detection (LOD) were in the range of 0.16–0.57μgL⁻¹, and the recoveries of analytes using the proposed method ranged between 88.67% and 95.10%. The sorbents exhibited excellent repeatability in the range of 1.83–4.24% in extracting the three target analytes. In addition, the intra-day and inter-day precision values were found to be in the range of 0.19–6.24% and 2.23–8.36%, respectively. The method was successfully applied to analyze fruit juice samples by rapid preconcentration of acaricides.

Graphical abstract

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Molecularly imprinted solid phase extraction method for simultaneous determination of seven nitroimidazoles from honey by HPLC-MS/MS

Publication date: 1 May 2017
Source:Talanta, Volume 166
Author(s): Xiu-Chun Guo, Zhao-Yang Xia, Hai-Hui Wang, Wen-Yi Kang, Li-Ming Lin, Wen-Qing Cao, Hong-Wei Zhang, Wen-Hui Zhou
In this work, a selective sample cleanup procedure that combined molecular imprinting technique with solid phase extraction was developed for the simultaneous extraction of the seven nitroimidazoles (NMZs) from honey samples. The molecular imprinting polymers for NMZs were prepared through bulk polymerization method using 2-methyl-5-nitroimidazole as template molecule, methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the cross linking agent. The obtained molecular imprinting polymers showed high affinity to template molecule and was used as selective sorbent for simultaneously selective extraction of the seven NMZs from honey matrix. An off-line molecularly imprinted solid phase extraction (MISPE) method followed by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS-MS) for simultaneous determination of the seven NMZs from honey samples was also established. The proposed method was validated at 1.0, 2.0 and 10.0μg/kg, obtaining recoveries in the range of 79.7–110%, with repeatability and interday precision values (expressed as relative standard deviation) ≤11.4% and ≤15.2%, respectively. Limits of quantification for different NMZs were 1.0μg/kg, which were always below the minimum required performance limits established by the European Community Reference Laboratories (Commission Decision 2002/657/EC). It was demonstrated that this proposed MISPE-HPLC-MS-MS method could be applied to direct determination of NMZs from honey samples.

Graphical abstract

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Comparison of sensitivity to artificial spectral errors and multivariate LOD in NIR spectroscopy – Determining the performance of miniaturizations on melamine in milk powder

Publication date: 1 May 2017
Source:Talanta, Volume 166
Author(s): Raphael Henn, Christian G. Kirchler, Maria-Elisabeth Grossgut, Christian W. Huck
This study compared three commercially available spectrometers – whereas two of them were miniaturized – in terms of prediction ability of melamine in milk powder (infant formula). Therefore all spectra were split into calibration- and validation-set using Kennard Stone and Duplex algorithm in comparison. For each instrument the three best performing PLSR models were constructed using SNV and Savitzky Golay derivatives. The best RMSEP values were 0.28g/100g, 0.33g/100g and 0.27g/100g for the NIRFlex N-500, the microPHAZIR and the microNIR2200 respectively. Furthermore the multivariate LOD interval [LODmin, LODmax] was calculated for all the PLSR models unveiling significant differences among the spectrometers showing values of 0.20g/100g – 0.27g/100g, 0.28g/100g – 0.54g/100g and 0.44g/100g – 1.01g/100g for the NIRFlex N-500, the microPHAZIR and the microNIR2200 respectively. To assess the robustness of all models, artificial introduction of white noise, baseline shift, multiplicative effect, spectral shrink and stretch, stray light and spectral shift were applied. Monitoring the RMSEP as function of the perturbation gave indication of robustness of the models and helped to compare the performances of the spectrometers.Not taking the additional information from the LOD calculations into account one could falsely assume that all the spectrometers perform equally well which is not the case when the multivariate evaluation and robustness data were considered.

Graphical abstract

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Application of 2D-HPLC coupled with principal component analysis to study an industrial opiate processing stream

Publication date: 1 May 2017
Source:Talanta, Volume 166
Author(s): Paul G. Stevenson, Niki K. Burns, Stuart D. Purcell, Paul S. Francis, Neil W. Barnett, Fiona Fry, Xavier A. Conlan
Principal component analysis (PCA) loading plots were used to elucidate key differences between two-dimensional high performance liquid chromatography (2D-HPLC) fingerprint data from samples collected from stages along the Papaver somniferum industrial process chemistry workflow. Data reduction was completed using a 2D-HPLC peak picking approach as a precursor to chemometric analysis. Using comparisons of the final stages of product extraction as an example, PCA analysis of characteristic 2D-HPLC fingerprints accounted for 84.9% of variation between the two sample sets measured in triplicate, with 64.7% explained by PC1. Loadings plots of PC1 on each sample set identified where the significant changes were occurring and normalised bubble plots provided an indication of the relative importance of each of these changes. These findings highlight 2D-HPLC with appropriate chemometric analysis as a useful tool for the exploration of bioactive molecules within biomass.

Graphical abstract

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Effects of polyphenol compounds melanin on NAFLD/NASH prevention

Publication date: April 2017
Source:Biomedicine & Pharmacotherapy, Volume 88
Author(s): Natalia Belemets, Nazarii Kobyliak, Oleksandr Virchenko, Tetyana Falalyeyeva, Tsyryuk Olena, Petro Bodnar, Oleksiy Savchuk, Tetyana Galenova, Martin Caprnda, Luis Rodrigo, Lubomir Skladany, Delian Delev, Radka Opatrilova, Peter Kruzliak, Tetyana Beregova, Lyudmyla Ostapchenko
BackgroundOne of the pathogenic mechanisms of the progression non-alcoholic liver disease (NAFLD) to nonalcoholic steatohepatitis (NASH) is the accumulation of reactive oxygen species (ROS). So, antioxidant therapy is necessary for successful treatment of the liver injury. We have paid attention to melanin produced by yeast Nadsoniella nigra strain X-1 as novel antioxidant and anti-inflammatory agents with low toxicity. In current study we aimed to investigate the preventive effect of melanin on the monosodium glutamate (MSG) induced NAFLD model in rats.MethodsThe study was carried out on 45 Wistar rats that were divided into 3 groups: intact, MSG- and MSG+melanin groups (n=15 in each group). Newborn rats of MSG- and MSG+melanin groups were administered with MSG (4mg/g, 8μl/g, subcutaneously) at 2nd–10th days of life. Since the age of 1 month, rats of MSG-group were treated with water (0.25ml/100g), rats of MSG+melanin groups—with melanin (1mg/kg) dissolved in water (0.25ml/100g).Introductionhad been performed intermittently (two-week courses alternated with two-week breaks) for 3 months. In 4-month rats anthropometrical parameters and visceral adipose tissue (VAT) mass were estimated. To assess morphological changes in liver we used NAS (NAFLD activity score). The content of pro-inflammatory cytokines (interleukin (IL)-1β, IL-12Bp40, interferon (INF)-γ) and anti-inflammatory cytokines (IL-4, IL-10, tumor growth factor (TGF)-β) were measured by ELISA.ResultsWe found significantly lower total score (1.0±0.19 vs 3.33±0.36, p<0.001), degree of steatosis (0.73±0.18 vs 1.80±0.17, p<0.001) and manifestation of lobular inflammation (0.27±0.11 vs 1.20±0.17, p<0.001) due to NAFLD activity score in MSG+melanin group compared to MSG-obesity. NASH we confirmed only in 33.3% of rats with MSG-obesity that was significantly higher than after melanin (6.7%) administration (p=0.033). Melanin administration reduce amount of visceral fat on 44.5% (p<0.001) as compared to MSG-obesity group. Melanin reduced the content of IL-1β in rat serum and restored the level of anti-inflammatory cytokines (IL-10, TGF-β) to the control values.ConclusionThus, the administration of melanin can prevent development of NAFLD/NASH in rats with MSG-induced obesity and can be considered as possible novel therapeutic agents but further studies to confirm its action needed.



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