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Σάββατο 30 Ιουνίου 2018
Scholar : Chemistry and Ecology, Volume 34, Issue 7, August 2018 is now available online on Taylor & Francis Online
FAAH inhibition attenuates TLR3-mediated hyperthermia, nociceptive- and anxiety-like behaviour in female rats
Source:Behavioural Brain Research, Volume 353
Author(s): Lisa E. Flannery, Daniel M. Kerr, David P. Finn, Michelle Roche
Aberrant activation of toll-like receptor (TLR)s results in persistent and prolonged neuroinflammation and has been implicated in the pathogenesis and exacerbation of psychiatric and neurodegenerative disorders. TLR3 coordinates the innate immune response to viral infection and recent data have demonstrated that inhibiting fatty acid amide hydrolase (FAAH), the enzyme that primarily metabolizes anandamide, modulates TLR3-mediated neuroinflammation. However, the physiological and behavioural consequences of such modulation are unknown. The present study examined the effect of URB597, a selective FAAH inhibitor, on neuroinflammation, physiological and behavioural alterations following administration of the TLR3 agonist and viral mimetic poly I:C to female rats. URB597 attenuated TLR3-mediated fever, mechanical and cold allodynia, and anxiety-like behaviour in the elevated plus maze and open field arena. There was no effect of URB597 on TLR3-mediated decreases in body weight and no effect in the sucrose preference or forced swim tests. URB597 attenuated the TLR3-mediated increase in the expression of CD11b and CD68, markers of microglia/macrophage activation. In summary, these data demonstrate that enhancing FAAH substrate levels suppresses TLR3-mediated microglia/macrophage activation and associated changes in fever, nociceptive responding and anxiety-related behaviour. These data provide further support for FAAH as a novel therapeutic target for neuroinflammatory disorders.
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Maternal stress during pregnancy induces depressive-like behavior only in female offspring and correlates to their hippocampal Avp and Oxt receptor expression
Source:Behavioural Brain Research, Volume 353
Author(s): M. Schmidt, K. Braun, C. Brandwein, A.C. Rossetti, S. Guara Ciurana, M.A. Riva, M. Deuschle, J. Bock, P. Gass, N. Gröger
The majority of studies examining the consequences of prenatal stress in rodent models analyze pups having been raised by their biological mother, i.e. the female which experienced stress during her pregnancy. To test whether pregnancy stress changes maternal behavior and thereby - in addition to stress exposure in utero – influences behavior and brain function of offspring, we implemented a fostering model, in which mouse pups that were not stressed in utero, are raised by dams which were exposed to stress during their pregnancy. We found that dams, which were stressed during pregnancy (PS foster dams), unexpectedly displayed slightly more active and passive light time nursing compared to unstressed dams (CON foster dams). Adult male offspring which were raised by a PS foster dam showed significantly less anxiety-like behavior compared to males raised by a CON foster dam, whereas adult female offspring which were raised by PS foster dams displayed increased depressive-like behavior as a tendency. Since the arginine vasopressin receptor 1a (AvpR1a) and the structurally related oxytocin receptor (OxtR) are both closely related to stress-responsiveness, anxiety and depression, mRNA expression of these genes were assessed in the hippocampus of adult male and female offspring. No significant differences in mRNA expression of both receptor types were observed, however, in female offspring of PS foster dams maternal licking/grooming correlated positively with AvpR1a and negatively with OxtR mRNA expression.These findings indicate that stress during pregnancy does not reduce, but slightly increase maternal behavior, which might lead to sex-specific behavioral outcomes and changes in hippocampal AvpR1a and OxtR mRNA expression in adult offspring.
https://ift.tt/2KwAfDn
Scholar : These new articles for Astropolitics are available online
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Physiological Functions of Nedd4-2: Lessons from Knockout Mouse Models
Publication date: Available online 29 June 2018
Source:Trends in Biochemical Sciences
Author(s): Jantina A. Manning, Sharad Kumar
Protein modification by ubiquitination plays a key evolutionarily conserved role in regulating membrane proteins. Nedd4-2, a ubiquitin ligase, targets membrane proteins such as ion channels and transporters for ubiquitination. This Nedd4-2-mediated ubiquitination provides a crucial step in controlling the membrane availability of these proteins, thus affecting their signaling and physiological outcomes. In one well-studied example, Nedd4-2 fine-tunes the physiological function of the epithelial sodium channel (ENaC), thus modulating Na+ reabsorption by epithelia to maintain whole-body Na+ homeostasis. This review summarizes the key signaling pathways regulated by Nedd4-2 and the possible implications of such regulation in various pathologies.
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Quality Control in the Endoplasmic Reticulum: Crosstalk between ERAD and UPR pathways
Publication date: Available online 29 June 2018
Source:Trends in Biochemical Sciences
Author(s): Jiwon Hwang, Ling Qi
Endoplasmic reticulum (ER)-associated degradation (ERAD) and the unfolded protein response (UPR) are two key quality-control machineries in the cell. ERAD is responsible for the clearance of misfolded proteins in the ER for cytosolic proteasomal degradation, while UPR is activated in response to the accumulation of misfolded proteins. It has long been thought that ERAD is an integral part of UPR because expression of many ERAD genes is controlled by UPR; however, recent studies have suggested that ERAD has a direct role in controlling the protein turnover and abundance of IRE1α, the most conserved UPR sensor. Here, we review recent advances in our understanding of IRE1α activation and propose that UPR and ERAD engage in an intimate crosstalk to define folding capacity and maintain homeostasis in the ER.
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Ultrasensitive detection of trypsin activity and inhibitor screening based on the electron transfer between phosphorescence copper nanocluster and cytochrome c
Publication date: 1 November 2018
Source:Talanta, Volume 189
Author(s): Shiyu Zhang, Can Chen, Xiaofei Qin, Qianchen Zhang, Jinhua Liu, Jixin Zhu, Yongqian Gao, Lin Li, Wei Huang
Trypsin, as one of important proteases, is specific for catalyzing the hydrolysis of peptide and ester bonds containing lysine and arginine residues at the C-terminus. The level of trypsin in biological fluids can serve as a reliable and specific diagnostic biomarker for pancreatic function and its pathological changes. Herein, we demonstrate the application of phosphorescent Cu NCs for trypsin detection for the first time depending on the electron transfer between Cu NCs and cyt c. Cyt c and Cu NCs were selected as the quencher and the fluorophore, respectively. Cu NCs could bind to the positively charged cyt c through electrostatic and hydrophobic interactions, and the phosphorescence of Cu NCs was efficiently quenched by the metal-containing heme of cyt c. In the presence of trypsin, cyt c was digested, thus phosphorescence of Cu NCs remained. Therefore, a new and continuous phosphorescence assay for the detection of trypsin activity and its inhibitor screening was established. The plot of relative fluorescence versus trypsin concentration obtains a good linear detection range from 0 to 20 ng/mL (R2 = 0.9657), and a detection limit of 2 ng/mL, which is much lower than 20 ng/mL of the sensor in buffer solution because of urine amplifying the phosphorescence signal of Cu NCs based on the FRET strategy. This assay still has been successfully applied to trypsin inhibitor screening, demonstrating its potential application in drug discovery.
Graphical abstract
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Mimicking peroxidase activity of Co2(OH)2CO3-CeO2 nanocomposite for smartphone based detection of tumor marker using paper-based microfluidic immunodevice
Publication date: 1 November 2018
Source:Talanta, Volume 189
Author(s): Negar Alizadeh, Abdollah Salimi, Rahman Hallaj
We present a paper-based microfluidic colorimetric immunosensor for the detection of carcinoembryonic antigen (CEA), using Co2(OH)2CO3-CeO2 nanocomposite with extraordinary intrinsic peroxidase like activity. The morphology and composition of the nanocomposite characterized with Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) techniques. The proposed immunosensor facilely fabricated by loading mixture of ionic liquid and chitosan functionalized primary antibodies (Ab1) on the surface of paper. Compared to traditional paper based immunodevice, when ionic liquid was used the nonspecific binding protein from the paper surface was more effectively removed. Secondary antibodies (Ab2) were stacked on the surface of the carboxylated Co2(OH)2CO3-CeO2 nanocomposite. The immunosensor response was obtained by a color change resulting from Co2(OH)2CO3-CeO2 nanocomposite catalyzing the oxidation of 3,3′,5,5′-tetramethyl benzidine in the presence of H2O2. The colorimetric sensing was accomplished on the paper, using smartphone for taking a photo and then analyzing the colors with an installed application. Detection of CEA was performed by this method with a linear range from 0.002 to 75.0 ng mL−1 and a detection limit of 0.51 pg mL−1. In this paper we developed simple, cost-effective and portable design for sensitive immunoassay and point-of-care diagnostics of cancer marker.
Graphical abstract
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Bioluminescent SNP genotyping technique: Development and application for detection of melanocortin 1 receptor gene polymorphisms
Publication date: 1 November 2018
Source:Talanta, Volume 189
Author(s): Eugenia E. Bashmakova, Vasilisa V. Krasitskaya, Alexander A. Bondar, Ekaterina N. Eremina, Eugene V. Slepov, Ruslan A. Zukov, Ludmila A. Frank
SNP genotyping based on the reaction of specific primer extension with the following bioluminescent detection of its products was shown to be potentially applicable for biomedical exploration. The paper describes its elaboration and first application in extensive biomedical research concerning MC1R gene variants' frequency and associations with clinical characteristics in melanoma patients of Eastern Siberia (Krasnoyarsk region, Russia). Polymorphisms rs 1805007 (R151C), rs 1805008 (R160W), and rs 1805009 (D294H) were detected in 174 DNA samples from patients with histologically proved diagnosis of cutaneous melanoma and in 200 samples from healthy individuals. All the results on bioluminescent SNP genotyping were confirmed by Sanger sequencing. Some features characteristic of the population were found, i.e. melanoma is mostly associated with R160W or R151C while variant D294H is extremely rare; simultaneous carriage of any two investigated variants is also strongly associated with melanoma; R151C is associated with ulceration and consequently the disease course is more aggressive, etc.The design of the technique allows fast evaluation of any known diagnostically important SNP frequencies and associations across population.
Graphical abstract
https://ift.tt/2KwjJmR
A novel air-assisted liquid-liquid microextraction based on in-situ phase separation for the HPLC determination of bisphenols migration from disposable lunch boxes to contacting water
Publication date: 1 November 2018
Source:Talanta, Volume 189
Author(s): Qinghua Zhou, Zanhui Jin, Jia Li, Bin Wang, Xiuzhen Wei, Jinyuan Chen
In this study, a novel air-assisted liquid-liquid microextraction (AALLME) method was developed for the HPLC determination of bisphenols migration from disposable plastic lunch box to contacting water. The AALLME was carried out in commercially-available medical plastic syringes with low-density extraction solvent (n-octanol), and the reaction of NaHCO3 and HCl was introduced to simultaneously induce the in-situ phase separation and salt effect. After the AALLME processes, the upper organic phase was pushed into the end of syringes (narrow tube) by moving the piston so that it could be readily collected for the HPLC analysis. The factors including the type and volume of extraction solvent, NaHCO3 addition and extraction cycles were optimized. Under the optimal conditions, the limits of detection (LODs) for target bisphenols were evaluated to be 0.2–0.7 μg L−1, and good linearities with correlation coefficients higher than 0.9955 were obtained. The recoveries for target bisphenols ranged from 80% to 106%, with the relative standard deviations (RSDs) of 4.4–14.1%. The proposed method was successfully applied to investigate the migration of bisphenols from the disposable plastic lunch boxes to the contacting water, revealing that compared to the conventional water-bath heating, the microwave heating could induce the significant migration of bisphenols in a much shorter time.
Graphical abstract
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Increasing the structural energy dissipation of laminated fibre composite materials by delamination control
Publication date: 15 October 2018
Source:Materials & Design, Volume 156
Author(s): M. Kuhtz, A. Hornig, J. Richter, M. Gude
In this paper an approach to increase the energy absorption capacity of laminated composites is investigated. The interlaminar interfaces of two different composite materials, a 2/2 twill weave of glass fibre reinforced polypropylene and a plain weave of carbon reinforced epoxy, are modified. Perforated, non adhesive polytetrafluorethylene (PTFE-) foils were interleaved between the composite layers leading to different interlaminar contact area (ICA) set-ups. The energy absorption capacity, impact resistance as well as the damage and failure behaviour, especially delamination, are evaluated in Charpy drop weight experiments. Based on the resulting force-displacement-response, initiation and propagation energies as well as the ductility index are evaluated. High speed camera imaging is used to correlate failure phenomena to structural response. It can be shown, that the failure behaviour of textile reinforced composites is significantly influenced by the interface modification concept. As a result, the delamination initiation and propagation is enhanced with lower ICA leading to higher energy absorption capacity on the one hand and higher propagation-to-initiation-energy-ratio on the other hand. Consequently, the already high energy absorption capacity of composite materials can be further increased up to 65% while the ductility index rises up to ten times.
Graphical abstract
https://ift.tt/2NcG4I6
Mapping of axial plastic zone for roller bearing overloads using neutron transmission imaging
Publication date: 15 October 2018
Source:Materials & Design, Volume 156
Author(s): A. Reid, I. Martinez, M. Marshall, T. Minniti, S. Kabra, W. Kockelmann, T. Connolley, M. Mostafavi
Premature failure of wind turbine gearbox bearings is an ongoing concern for industry, with sudden overload events potentially contributing towards raceway damage, significantly hindering performance. Subsurface stresses generated along a line contact cause material yielding, and a probable crack initiation site. Currently, the ability to study subsurface plastic zone evolution using non-destructive techniques is limited. Neutron Bragg edge imaging is a novel technique, allowing for two-dimensional mapping of the Bragg edge broadening parameter, indicative of bulk plastic deformation. An experiment on the ENGIN-X strain scanning instrument, at the ISIS neutron source, UK, was setup for Bragg edge transmission imaging, to measure the effect of in situ loading on the raceway of a bearing, scaled-down from a traditional wind turbine gearbox bearing. Results demonstrate a strong correlation between load and the Bragg edge width, and allow for future experimental development in studying, not only the effect of overloads on fatigue life, but also the use of neutron imaging for evaluating plastic deformation in engineering components.
Graphical abstract
https://ift.tt/2z2MCpQ
Enhancement of hardness, modulus and fracture toughness of the tetragonal (Fe,Cr)2B and orthorhombic (Cr,Fe)2B phases with addition of Cr
Publication date: 15 October 2018
Source:Materials & Design, Volume 156
Author(s): Jonathan Lentz, Arne Röttger, Felix Großwendt, Werner Theisen
This study analyzes the influence of Cr content on hardness H, elastic modulus E and fracture toughness KIC of the M2B boride by means of nanoindentation experiments. Additionally, properties of the Fe3(C,B) phase are determined. Samples of the M2B phase are casted and microstructurally characterized by means of scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction. At a Cr content higher than 14.7 atom% the M2B phase transforms from tetragonal into orthorhombic structure. The tetragonal M2B type possesses an optimum of H (21 ± 1 GPa), E (373 ± 6) GPa and KIC (3.5 ± 0.7 MPam) at 4–5 atom% Cr. The hardness, modulus and toughness of the orthorhombic M2B phase increase with Cr content and reach values of H = 27 ± 0.7 GPa, E = 473 ± 9 of and KIC = 3.26 ± 0.8 MPam at maximal investigated Cr content of 55 atom%. The hardness of the M2B phases decreases around 2.3–3.2 GPa as a function of indentation depth, which is known as the indentation size effect. Hardness and fracture toughness of M2B phase outperform conventionally used M7C3 carbides and are similar to MC-carbides. Findings can be used in novel alloying approaches in order to optimize the performance and reduce cost of tool steels.
Graphical abstract
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Thermal and tensile properties of diamondene at finite temperature: A molecular dynamics study
Publication date: 15 October 2018
Source:Materials & Design, Volume 156
Author(s): Jiao Shi, Kun Cai, Yi Min Xie
Diamondene can be formed by compressing two or more layers of graphene. As a sp2/sp3 orbital hybridized two-dimensional material, its physical properties are different from either graphene or diamond. This new material is ultrahard on a SiC substrate. Here, we focus on the thermal stability and the basic mechanical properties of diamondene without passivation. We used molecular dynamics calculations to show that diamondene has isotropic thermal expansion at temperature below 280 K. At room temperature, it is unstable. When stretched along the armchair direction, diamondene has a maximum elastic strain that is higher than 0.17. It then experiences further plastic deformation before collapse. However, when stretched along the zigzag direction, the maximum elastic strain is higher than 0.3, e.g., 0.318 at 250 K. The ribbon collapses soon after the strain exceeds the critical value. Hence, diamondene has an elastic-brittle property along the zigzag direction. This excellent elasticity is significant for applications of diamondene in a flexible device.
Graphical abstract
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Polymer-metal-polymer (PMP) multilayer transparent electrode for organic optoelectronics
Publication date: 15 October 2018
Source:Materials & Design, Volume 156
Author(s): Vikas Sharma, Himanshu Sharma, Rishi Vyas, Kanupriya Sachdev
Metal embedded polymer hybrid materials have found a niche of applications in energy and display domain. Herein, we report results of investigations on Polystyrene-Silver-Polystyrene (PAP) multilayer structure (<100 nm) exhibiting promising electrical and optical properties useful for the organic transparent electrode. Polystyrene and silver layers were obtained by spin coating and DC sputtering, respectively. Ag layer thickness was varied (4 nm to 30 nm) to optimize optical and electronic properties. Highest average transparency towards visible light was measured ≥70% for 8 nm thick Ag layered PAP structure whereas a minimum value of resistivity 6.03E−5 Ω was obtained for 12 nm thick Ag layer which implies the formation of the uniform continuous layer at this thickness. The study is supplemented with the characterization to prove smooth top layer which is required for growth of secondary layers (FESEM), chemical state of the trilayer (XPS measurement), uniformity in the chemical composition of the trilayer (Depth profiling) and structural properties (X-Ray diffraction and Raman spectroscopy). The importance of the present investigation lies in the synthesis process which is easy, low cost and allows tuning of optoelectronic properties of TCE as required by the application.
Graphical abstract
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Παρασκευή 29 Ιουνίου 2018
Parvalbumin Interneurons Shape Neuronal Vulnerability in Blunt TBI
https://ift.tt/2IDXEBb
Spreading of Tau Pathology in Sporadic Alzheimer’s Disease Along Cortico-cortical Top-Down Connections
https://ift.tt/2Kzw2lR
Effects of perineural invasion in prostate needle biopsy on tumor grade and biochemical recurrence rates after radical prostatectomy
Publication date: July 2018
Source:The Kaohsiung Journal of Medical Sciences, Volume 34, Issue 7
Author(s): Serdar Celik, Ozan Bozkurt, Omer Demir, Ozgur Gurboga, Burcin Tuna, Kutsal Yorukoglu, Guven Aslan
To predict local invasive disease before retropubic radical prostatectomy (RRP), the correlation of perineural invasion (PNI) on prostate needle biopsy (PNB) and RRP pathology data and the effect of PNI on biochemical recurrence (BR) were researched. For patients with RRP performed between 2005 and 2014, predictive and pathologic prognostic factors were assessed. Initially all and D'Amico intermediate-risk group patients were comparatively assessed in terms of being T2 or T3 stage on RRP pathology, positive or negative for PNI presence on PNB and positive or negative BR situation. Additionally the effect of PNI presence on recurrence-free survival (RFS) rate was investigated. When all patients are investigated, multivariate analysis observed that in T3 patients PSA, PNB Gleason score (GS) and tumor percentage were significantly higher; in PNI positive patients PNB GS, core number and tumor percentage were significantly higher and in BR positive patients PNB PNI positivity and core number were significantly higher compared to T2, PNI negative and BR negative patients, separately (p < 0.05). When D'Amico intermediate-risk patients are evaluated, for T3 patients PSA and PNB tumor percentage; for PNI positive patients PNB core number and tumor percentage; and for BR positive patients PNB PNI positivity were significantly higher compared to T2, PNI negative and BR negative patients, separately (p < 0.05). Mean RFS in the whole patient group was 56.4 ± 4.2 months for PNI positive and 96.1 ± 5.7 months for negative groups. In the intermediate-risk group, mean RFS was 53.7 ± 5.1 months for PNI positive and 100.3 ± 7.7 months for negative groups (p < 0.001). PNI positivity on PNB was shown to be an important predictive factor for increased T3 disease and BR rates and reduced RFS.
https://ift.tt/2IC3Hq7
Simplified scoring system for prediction of mortality in acute suppurative cholangitis
Publication date: July 2018
Source:The Kaohsiung Journal of Medical Sciences, Volume 34, Issue 7
Author(s): Barış Doğu Yıldız, Sabri Özden, Barış Saylam, Fahri Martlı, Mesut Tez
Our objective in this study was to identify the factors contributing to mortality in acute suppurative cholangitis which could be tested easily in every emergency clinic. This is a retrospective study enrolling 104 patients with acute suppurative cholangitis. Demographic and laboratory data were collected for analysis. In univariant analysis red cell distribution width, total bilirubin level, intensive care unit admission was identified as statistically significant (p < 0.05) to predict mortality. Three variables were statistically significant in multivariate analysis: total bilirubin level equal to or more than 6.9 mg/dl, red cell distribution width equal to or more than 14.45%, and admission to intensive care unit. We found a new scoring system for prediction of mortality in acute suppurative cholangitis utilizing only three variables. This would serve as a simplified, rapid way to direct patients for advanced interventions instead of wasting time with more complicated and time consuming multi-variable scoring systems.
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Influence of tidal volume on ventilation distribution and oxygenation during one-lung ventilation
Publication date: July 2018
Source:The Kaohsiung Journal of Medical Sciences, Volume 34, Issue 7
Author(s): Wei Wang, Mei-Ying Xu, Jing-Xiang Wu, Zhan-Qi Zhao
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Instructions to Authors
Publication date: July 2018
Source:The Kaohsiung Journal of Medical Sciences, Volume 34, Issue 7
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Checklist
Publication date: July 2018
Source:The Kaohsiung Journal of Medical Sciences, Volume 34, Issue 7
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Authorship and conflict statements
Publication date: July 2018
Source:The Kaohsiung Journal of Medical Sciences, Volume 34, Issue 7
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Publication date: July 2018
Source:The Kaohsiung Journal of Medical Sciences, Volume 34, Issue 7
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Publication date: July 2018
Source:The Kaohsiung Journal of Medical Sciences, Volume 34, Issue 7
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Effectiveness of robo-assisted lower limb rehabilitation for spastic patients: A systematic review
Source:Biosensors and Bioelectronics, Volume 117
Author(s): Divya Shakti, Lini Mathew, Neelesh Kumar, Chitra Kataria
BackgroundThough many rehabilitative treatments are available for treatment of spasticity, thus the effectiveness of different robo-rehabilitative devices needs to be evaluated through a systematic review.ObjectiveThe objective of this study is to focuses on the efficacy of Robot assistive rehabilitation device for the removal of spasticity from the lower limb of Spastic patients.Data SourcessourcesPubMed, Web of Sciences, EMBASE (Excerpta Medical database), CDSR (Cochrane database of systematic reviews), Scopus, IEEE Xplore, Wiley online library, MEDLINE (OvidSP), Science Direct, Springer Link were from January 1980 to September 2017Data ExtractionextractionSeventy-one publications from eleven databases published were selected using keywords Ankle foot, spasticity, robotic rehabilitation, efficacy of robotics and Ankle foot rehabilitation. The review is narrowed down to twenty-six articles which were selected for they focused on effects of Robot assistive rehabilitation device quantitatively.ResultA quantitative study from analyzing 26 studies comprising of 786 subjects is carried out. The major outcome of the effectiveness of the robot assistive therapy for the movement of ankle and functioning of gait is deduced. As the used protocols and treatment procedures vary, made comparative study complex or impracticable.ConclusionRobo-rehabilitation possesses an ability to provide unified therapy protocols with greater ease in comparison to conventional therapies. They continuously prove to be irreplaceable assistant devices when it comes to providing excellent treatment in terms of improvement from this study. Though many mechatronic devices are available but the devices for treatment of early stage rehabilitation of stroke patients is very limited.
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A DNA nanostructured aptasensor for the sensitive electrochemical detection of HepG2 cells based on multibranched hybridization chain reaction amplification strategy
Source:Biosensors and Bioelectronics, Volume 117
Author(s): Dabin Chen, Duanping Sun, Zhiru Wang, Weiwei Qin, Liang Chen, Ledu Zhou, Yuanqing Zhang
Sensitive detection of cancer cells is beneficial to the early diagnosis of cancer and individual treatment. In the present study, a DNA nanostructured aptasensor was used for the sensitive electrochemical detection of human liver hepatocellular carcinoma cells (HepG2) based on multibranched hybridization chain reaction amplification strategy. We established a well-designed platform by immobilizing DNA tetrahedron, a three-dimensional DNA nanostructure, on the gold electrode to capture HepG2 cells more specifically and efficiently. Meanwhile, functional hybrid nanoprobes consisted of MIL-101@AuNPs (Au nanoparticles), numerous hemin/G-quadruplex DNAzyme from multibranched hybridization chain reaction, and natural horseradish peroxidase (HRP) was designed. The hybrid nanoprobes possessed the functions of specific discernment and enzymatic signal amplification simultaneously. With the help of nanoprobes, HepG2 cells were recognized and captured to form a DNA tetrahedron-cell-nanoprobe sandwich-like structure on the electrode surface. The lower detection limit of this established cytosensor is 5 cells per ml. Moreover, it delivered a broad detection range from 102 to 107 cells per ml. The results revealed that the as-proposed cytosensor may be utilized as a powerful tool for early diagnosis of cancer in the future.
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An approach to the heating dynamics of residues from greenhouse-crop plant biomass originated by tomatoes ( Solanum lycopersicum , L.)
Abstract
The most representative of greenhouse-crop plant biomass residues of tomatoes (Solanum lycopersicum L.) were selected for this study by using X-ray fluorescence spectrometry (XRF) and X-ray powder diffraction (XRD). The heating dynamics in air in the 600–1150 °C range of these residues for the production of renewable energy and the resultant ashes have been investigated. A total of 11 elements were determined by XRF in the biomass ashes and some minor elements. The content of alkaline elements and chlorides decreased as increasing heating temperature and disappeared at 1150 °C. Alkaline salts, NaCl and KCl, were volatilized by heating since 800 °C. The total contents of S and P in the biomass ashes were associated to CaSO4, and a complex phosphate identified by XRD. CaCO3 present at 600 °C was decomposed to CaO with disappearance at 1000 °C. By heating, new silicates were formed by solid-state reactions in the biomass residue. The minor elements have been found in a relative proportion lower than 0.9 wt.% and they characterized the obtained ashes, with potential use as micronutrients.
https://ift.tt/2KwXBZG
Predicting early death in older adults with cancer
Source:European Journal of Cancer, Volume 100
Author(s): Rabia Boulahssass, Sebastien Gonfrier, Jean -Marc Ferrero, Marine Sanchez, Véronique Mari, Olivier Moranne, Cyrielle Rambaud, Francine Auben, Jean -Michel Hannoun levi, Jean -Marc Bereder, Isabelle Bereder, Patrick Baque, Jean Michel Turpin, Anne-Claire Frin, Delphine Ouvrier, Delphine Borchiellini, Remy Largillier, Guillaume Sacco, Jerome Delotte, Cyprien Arlaud, Daniel Benchimol, Matthieu Durand, Ludovic Evesque, Abakar Mahamat, Gilles Poissonnet, Jérôme Mouroux, Jérôme Barriere, Emmanuel Benizri, Thierry Piche, Joel Guigay, Eric Francois, Olivier Guerin
BackgroundPredicting early death after a comprehensive geriatric assessment (CGA) is very difficult in clinical practice. The aim of this study was to develop a scoring system to estimate risk of death at 100 days in elderly cancer patients to assist the therapeutic decision.MethodsThis was a multicentric, prospective cohort study approved by an ethics committee. Elderly cancer patients aged older than 70 years were enrolled before the final therapeutic decision. A standardised CGA was made before the treatment decision at baseline. Within 100 days, event (death), oncologic and geriatric data were collected. Multivariate logistic regression was used to select the risk factors for the overall population. Score points were assigned to each risk factor using the β coefficient. Internal validation was performed by a bootstrap method. Calibration was assessed with the Hosmer–Lemeshow goodness of fit test and accuracy with the mean c-statistic.FindingsOne thousand fifty patients (mean age: 82 years) joined the study from April 2012 to December 2014. The independent predictors were metastatic cancers (odds ratio [OR] 2.5; 95% confidence interval [CI], [1.7–3.5] p<0 .001); gait speed<0.8 m/s (OR 2.1; 95% CI [1.3–3.3] p=0.001); Mini Nutritional Assessment (MNA) < 17 (OR 8; 95% CI; [3.7–17.3] p<0.001), MNA ≤23.5 and ≥ 17 (OR 4.4; 95% CI, [2.1–9.1) p<0.001); performance status (PS) > 2 (OR 1.7; 95% CI, [1.1–2.6)] p=0.015) and cancers other than breast cancer (OR 4; 95% CI, [2.1–7.9] p<0.001). We attributed 4 points for MNA<17, 3 points for MNA between ≤23.5 and ≥ 17, 2 points for metastatic cancers, 1 point for gait speed <0.8 m/s, 1 point for PS > 2 and 3 points for cancers other than breast cancer. The risk of death at 100 days was 4% for 0 to 6 points, 24% for 7 to 8 points, 39% for 9 to 10 points and 67% for 11 points.InterpretationTo our knowledge, this is the first score which estimates early death in elderly cancer patients. The system could assist in the treatment decision for elderly cancer patients.
https://ift.tt/2NeRTxw
Training for Medical Oncologists on Shared Decision‐Making About Palliative Chemotherapy: A Randomized Controlled Trial
AbstractBackground.Systemic treatment for advanced cancer offers uncertain and sometimes limited benefit, while the burden can be high. This study examines the effect of shared decision‐making (SDM) training for medical oncologists on observed SDM in standardized patient assessments.Materials and Methods.A randomized controlled trial comparing training with standard practice was conducted. Medical oncologists and oncologists‐in‐training (n = 31) participated in a video‐recorded, standardized patient assessment at baseline (T0) and after 4 months (T1, after training). The training was based on a four‐stage SDM model and consisted of a reader, two group sessions (3.5 hours each), a booster session (1.5 hours), and a consultation card. The primary outcome was observed SDM as assessed with the Observing Patient Involvement scale (OPTION12) coded by observers blinded for arm. Secondary outcomes were observed SDM per stage, communication skills, and oncologists' satisfaction with communication.Results.The training had a significant and large effect on observed SDM in the simulated consultations (Cohen's f = 0.62) and improved observed SDM behavior in all four SDM stages (f = 0.39–0.72). The training improved oncologists' information provision skills (f = 0.77), skills related to anticipating/responding to emotions (f = 0.42), and their satisfaction with the consultation (f = 0.53).Conclusion.Training medical oncologists in SDM about palliative systemic treatment improves their performance in simulated consultations. The next step is to examine the effect of such training on SDM in clinical practice and on patient outcomes.Implications for Practice.Systemic treatment for advanced cancer offers uncertain and sometimes limited benefit, while the burden can be high. Hence, applying the premises of shared decision‐making (SDM) is recommended. SDM is increasingly advocated based on the ethical imperative to provide patient‐centered care and the increasing evidence for beneficial patient outcomes. Few studies examined the effectiveness of SDM training in robust designs. This randomized controlled trial demonstrated that SDM training (10 hours) improves oncologists' performance in consultations with standardized patients. The next step is to examine the effect of training on oncologists' performance and patient outcomes in clinical practice.
https://ift.tt/2KuRHIy
Developing a Roadmap for Interventional Oncology
AbstractInterventional oncology uses image‐guided procedures to enhance cancer care. Today, this specialty plays an increasingly critical role in cancer diagnosis (e.g., biopsy), cancer therapy (e.g., ablation or embolization), and cancer symptom palliation (e.g., nephrostomies or biliary drainages). Although the number of procedures and technical capabilities has improved over the last few years, challenges remain. In this article we discuss the need to advance existing procedures, develop new ones, and focus on several operational aspects that will dictate future interventional techniques to enhance cancer care, particularly by accelerating drug development and improving patient outcomes.Implications for Practice.Interventional oncology is vital for cancer diagnosis, therapy, and symptom palliation. This report focuses on current interventional procedures and techniques with a look toward future improvements that will improve cancer care and patient outcomes.
https://ift.tt/2NdnXl5
Fear of Mastectomy Associated with Delayed Breast Cancer Presentation Among Ghanaian Women
AbstractBackground.Breast cancer is the leading cause of cancer mortality among women globally. Most women in Ghana present with advanced stage disease. The aim of this study is to characterize sociocultural factors associated with delayed presentation.Materials and Methods.Qualitative study (grounded theory, constant comparative method) using individual in‐depth interviews with breast cancer patients seen at the Korle Bu Teaching Hospital in Accra, Ghana. Interviews were conducted in English and three local languages. We achieved theoretical saturation with 31 participants.Results.The mean length of delay reported by patients was approximately 1 year. Five recurrent themes were related to delayed presentation: (a) Women with a confirmed breast cancer diagnosis delay treatment because of the fear of mastectomy due to self and societal stigma; (b) role of the church as a social support system given the societal stigma associated with breast cancer; (c) study participants expressed some awareness of breast cancer, but with varying depths of breast cancer knowledge encompassing both myths and misconceptions about breast cancer; (d) most patients present late because they do not associate a "painless" breast lump with possible breast malignancy; and (e) delayed presentation linked to significant financial burden associated with breast cancer treatment.Conclusion.Despite current efforts to increase breast cancer awareness, the fear of mastectomy remains one of the main reasons for delayed presentation. Successful breast cancer education programs will need to be framed within the broader sociocultural dimensions of femininity that address some of the stigma associated with mastectomy reported in the Ghanaian context.Implications for Practice.Most women in Ghana present with advanced‐stage disease. The aim of this study was to characterize sociocultural factors associated with delayed presentation. Although several quantitative studies have been conducted on delays in presentation in sub‐Saharan Africa (SSA), this study is one of the few to identify fear of mastectomy as a reason for delayed presentation. Anecdotal data from current clinical experiences in SSA suggest that this is still an issue that has not been adequately reported and addressed in most SSA countries. The research results presented here will hopefully guide health providers and national organizations in designing breast cancer education programs in Ghana and other parts of SSA.
https://ift.tt/2KynGrm
Occlusion, temporomandibular disorders, and orofacial pain: An evidence-based overview and update with recommendations
Source:The Journal of Prosthetic Dentistry
Author(s): Michael J. Racich
This paper presents an overview of dental disciplines involved in the treatment of orofacial pain, temporomandibular disorders (TMD), and occlusion and provides an evidence-based contemporary update of their interrelationships. English language peer-reviewed articles were identified using PubMed. Key words bruxism, implants, occlusion, orofacial pain, orthodontics, prosthodontics, restorative dentistry, and TMD were used.
https://ift.tt/2IAkkCt
Replacement of maxillary incisor crowns over discolored substrates in a single visit with a CAD-CAM system and lithium silicate ceramic
Source:The Journal of Prosthetic Dentistry
Author(s): Gustavo Dartora, Pedro Henrique Wentz Tretto, Rodrigo Varella de Carvalho, Atais Bacchi
Discolored substrates constitute a challenge to the esthetics of the definitive restoration. Because of technique sensitivity, the generally prolonged treatment time is a drawback to both the patient and the dentist. The technique described presents the replacement of ceramic maxillary incisors crowns over discolored substrates in a single visit by using a milling machine. Translucent blocks of a lithium silicate ceramic reinforced with zirconium dioxide particles were used. Intraoral scans of the trial restorations and of the tooth preparations were performed. The crown parameters were defined in the software. Ceramic blocks were milled in the presintered phase and characterized. The crowns were cemented at the end of the appointment with excellent esthetics.
https://ift.tt/2KkkzY9
Comparison of marginal fit between CAD-CAM and hot-press lithium disilicate crowns
Source:The Journal of Prosthetic Dentistry
Author(s): Eran Dolev, Yoli Bitterman, Avi Meirowitz
Statement of problemHot-pressing and computer-aided design and computer-aided manufacturing (CAD-CAM) are major techniques for the fabrication of lithium disilicate crowns. They exhibit different accuracies regarding marginal fit, an important factor in restoration survival. However, studies comparing the marginal fit of different fabrication methods are lacking.PurposeThe purpose of this in vitro study was to compare the marginal discrepancy (MD) and absolute marginal discrepancy (AMD) of lithium disilicate crowns produced by the hot-press and CAD-CAM techniques.Material and methodsThirty (30) typodont teeth were divided into 2 groups. Fifteen teeth were scanned with the CEREC Omnicam intraoral scanner, and crowns were fabricated with the CEREC MC XL chairside CAD-CAM milling unit from IPS e.max CAD blocks. Fifteen typodont teeth were sent to a dental laboratory, and lithium disilicate crowns were fabricated from IPS e.max press ingots using the hot-press technique. The 30 crowns were cemented and then sectioned with a precision saw. The MD and AMD were measured for each crown with a light microscope. One-way ANOVA was conducted to analyze significant differences in crown marginal fit between the fabrication systems (α=.05).ResultsFor the CAD-CAM technique, the mean values of the AMD measurements were 115 μm, and for the hot-press technique, 130 μm. The MD measurements were 87 μm for the CAD-CAM technique and 90 μm for the hot-press technique. One-way ANOVA revealed no significant differences between the fabrication methods regarding marginal fit (P>05).ConclusionsNo significant differences were found between the fabrication methods tested. Both the CAD-CAM and hot-press techniques for producing monolithic lithium disilicate crowns produced MD values of less than 120 μm, within the clinically acceptable range.
https://ift.tt/2KuO7OC
A digital technique for fabricating an interim implant-supported fixed prosthesis immediately after implant placement in patients with complete edentulism
Source:The Journal of Prosthetic Dentistry
Author(s): Ji-Hyeon Oh, Xueyin An, Seung-Mi Jeong, Byung-Ho Choi
The conversion of a denture into an interim implant-supported, screw-retained restoration has become the standard method for immediate interim restoration in patients with complete edentulism. The most critical steps of the denture conversion process are the creation of appropriate denture access holes to prevent displacement of the denture by the interim cylinders and removal of the denture flanges to facilitate both good esthetics and accessibility for oral hygiene after the denture is connected to the interim cylinders. This article presents a digital technique for designing and fabricating an interim implant-supported, fixed prosthesis for edentulous patients. The interim prosthesis has cylinder access holes that are digitally prefabricated and a denture flange part that is designed to be easily sectioned. This technique facilitates more straightforward and efficient immediate restoration for edentulous patients after implant placement.
https://ift.tt/2KzeNkD
Retentive strength and marginal discrepancies of a ceramic-reinforced calcium phosphate luting agent: An in vitro pilot study
Publication date: Available online 29 June 2018
Source:The Journal of Prosthetic Dentistry
Author(s): Rishabh P. Acharya, Steven M. Morgano, Allyn C. Luke, Saul Weiner
Statement of problemInformation on the properties of a relatively new luting agent with a unique formulation (ceramic-reinforced calcium phosphate) is limited.PurposeThe purpose of this in vitro study was to compare the retentive strengths and marginal discrepancies of a ceramic-reinforced calcium phosphate luting agent (CM) with a self-adhesive resin luting agent (RX) and to determine and compare the mode of failure of dislodged cemented copings.Material and methodsForty extracted human molar teeth were prepared to receive zirconia copings. After cementation, the specimens were divided into 4 subgroups (n=10): CM A (axial loading), CM OA (off-axis loading), RX A (axial loading), and RX OA (off-axis loading). For each subgroup, 9 of the specimens received experimental treatment (thermocycling and dynamic loading), and the tenth received no experimental treatment. Eight copings were pulled off in a universal testing machine (MTS Insight; MTS). The ninth specimen was treated experimentally but was not pull tested. The marginal discrepancy and the dentin interface of the specimens that were not pull tested were analyzed with scanning electron microscopy and energy dispersion spectroscopy. The mode of failure of the dislodged copings was also subjectively evaluated.ResultsThe mean retentive strengths were 5.92 MPa for CM A, 5.81 MPa for CM OA, 5.75 MPa for RX A, and 5.69 MPa for RX OA. The marginal discrepancy recorded for both CM and RX ranged from 30 to 45 μm, (mean, 36 ±4.6 μm). Energy dispersion spectroscopy analysis showed the presence of calcium, phosphorus, silicon, and aluminum for the CM marginal discrepancy and the presence of aluminum in the dentinal tubules adjacent to the CM. Calcium and phosphorus were detected in lesser amounts adjacent to the RX marginal discrepancy. The mode of failure for CM was primarily adhesive to the tooth preparation, and, for RX, the failure mode was predominantly adhesive to the coping.ConclusionsCM had statistically significantly higher mean retentive strength compared with RX. Subgroups loaded axially had statistically significantly higher retentive strengths compared with those loaded off axis.
https://ift.tt/2KzuZPD
Use of finite element analysis for the assessment of biomechanical factors related to pain sensation beneath complete dentures during mastication
Source:The Journal of Prosthetic Dentistry
Author(s): Jaroslaw Żmudzki, Grzegorz Chladek, Piotr Malara
Statement of problemThe pain commonly suffered by denture wearers during mastication is not documented in the objective biomechanical criteria for the pressure pain threshold.PurposeThe purpose of this finite element analysis study was to determine whether the pressures developed beneath a removable mandibular complete denture during mastication would exceed the average pressure pain threshold in patients for whom the denture foundation had an acceptable load-bearing capacity.Material and methodsA patient with an acceptable load-bearing denture foundation was modeled with finite element analysis. The denture/mucosa interface was modeled as a sliding or detaching interface. A convex mandibular residual ridge, resilient mucosa, and denture were modeled in computer-aided design (CAD) software using curves and cross sections. A unilateral vertical occlusal load of 100 N was assumed only for model verification, and an oblique mastication load of 141 N was assumed for simulated mastication with balanced articulation. The nonworking-side occlusal contact was simulated in 2 situations: prompt nonworking-side occlusal contact and delayed nonworking-side occlusal contact by setting an initial distance of 0.1 mm or 1 mm between the denture and a flat solid above the nonworking side.ResultsThe denture was held to the mucosa under vertical force and a maximum pressure of 203 kPa. The denture was tilted under an oblique mastication load and achieved stability through nonworking-side occlusal contact. This means that the denture was supported not only by the denture foundation but also by the nonworking-side occlusal contact and had a downwardly directed stabilizing reaction force. The denture was weakly supported on the delayed nonworking-side occlusal contact compared with the prompt nonworking-side occlusal contact and weakly supported on the denture foundation. In delayed nonworking-side occlusal contact, the pressure beneath the denture was 783 kPa (>pressure pain threshold) compared with 484 kPa (<pressure pain threshold) in prompt nonworking-side occlusal contact. Despite the lower reaction force of the foundation in delayed nonworking-side occlusal contact, the pressure beneath the denture increased, indicating a reduction in the load transfer area due to the inclined position of the denture. Friction on the mucosal surface was over 14-fold higher for the delayed nonworking-side occlusal contact.ConclusionsThe pressure beneath a removable mandibular complete denture exceeded the average pressure pain threshold and was supported with a large slide, which produced friction. Although the value of the load on the occlusal side did not change, the pressure under the denture increased and the force of nonworking-side occlusal contact decreased because of increasing distance to nonworking-side occlusal contact.
https://ift.tt/2Kjj9x4
Adhesive evaluation of three types of resilient denture liners bonded to heat-polymerized, autopolymerized, or CAD-CAM acrylic resin denture bases
Source:The Journal of Prosthetic Dentistry
Author(s): Jung Eun Choi, Tracey E. Ng, Chloe K.Y. Leong, Hansol Kim, Pu Li, John Neil Waddell
Statement of problemLevels of bond strength between different types of resilient denture liner materials bonded to different denture base acrylic resins, CAD-CAM acrylic resins in particular, have not been well reported.PurposeThe purpose of this study was to measure the tensile bond strength and durability of various combinations of 3 different resilient denture liners bonded to 3 different poly(methyl methacrylate) denture base materials.Material and methodsThe tensile bond strength of 3 resilient denture liners, namely Ufi Gel SC, Silagum-Comfort, and Vertex Soft, combined with heat-polymerized (Vertex Rapid Simplified), autopolymerized (Vertex Self-Curing), and computer-aided design and computer-aided manufacturing (CAD-CAM) (IvoBase CAD) denture base resins were tested by using a universal testing machine (total N=138). Half of the specimens were thermocycled between 5°C and 55°C for 1500 cycles before testing. After testing, modes of failure and interface surfaces were examined using light microscopy and scanning electron microscopy, respectively. Thermogravimetric analysis was carried out to analyze the differences in content between the 3 different denture base acrylic resins.ResultsThe mean tensile bond strength values ranged from 0.36 ±0.1 MPa to 1.51 ±0.46 MPa. CAD-CAM denture base materials showed the lowest range of bond strength when coupled to resilient denture liners (0.36 to 0.42 MPa). No statistically significant differences (P=.74) were found in bond strength between the thermocycled (0.71 ±0.23 MPa) and non-thermocycled groups (0.74 ±0.21 MPa). Silicone-based resilient denture liners exhibited the highest tensile strength with each type of denture resin. All 3 types of failure modes (adhesive, cohesive, and mixed modes) were observed.ConclusionsSilicone-based resilient denture liners produced the highest tensile bond strength to all denture bases tested. Resilient denture liners bonded to CAD-CAM denture bases produced the weakest tensile bond strengths. Thermocycling did not produce statistically significant differences in tensile bond strength of the resilient denture liners to the denture base resins.
https://ift.tt/2IDO2q8
Osteogenesis ability of CAD-CAM biodegradable polylactic acid scaffolds for reconstruction of jaw defects
Source:The Journal of Prosthetic Dentistry
Author(s): Mohamed H. Helal, Hebatullah D. Hendawy, Rowan A. Gaber, Nourhan R. Helal, Moustafa N. Aboushelib
Statement of problemReconstruction of alveolar bony defects is difficult using grafting materials in a powder form. A biodegradable scaffold material might simplify the procedure.PurposeThe purpose of this in vivo study was to evaluate osteogenesis ability of a biodegradable CAD-CAM–fabricated polylactic acid (PLA) scaffold enriched with calcium phosphate salts including hydroxyapatite (HA) and beta tricalcium phosphate (β-TCP) used to reconstruct mandibular defects in a dog model.Material and methodsSurgical defects were made bilaterally in the mandible of male beagle dogs. Computerized tomography images were obtained for determination of the 3-dimensional shape of the defects after 3 months of healing. Porous PLA scaffolds were fabricated by milling custom-made CAD-CAM blocks into the desired shape. After milling, half of the scaffolds were prepared by filling the pores of the scaffolds by a mixture of HA and β-TCP. Scaffolds were inserted in the mandibular defects bilaterally. After a healing time of 8 weeks, the bone-scaffold interface was analyzed histomorphometrically to detect the amount of new bone formation. Stained histological sections were examined using a computer software and depth of new bone formation was assessed (n=14, α=.05).ResultsHistomorphometric analysis revealed that enriched scaffolds with calcium phosphates had significantly (t=4.4, P<.001) higher amounts of new bone formation (1.3 ±0.33 mm) compared with the controls (0.7 ±0.39 mm). Average new bone growth in enriched scaffolds was 1.3 mm while almost half this value was observed in uncoated scaffolds, 0.7 mm.ConclusionsWithin the limitations of this animal study, HA and β-TCP enhanced osteogenesis ability of CAD-CAM–fabricated PLA scaffolds.
https://ift.tt/2KzeN47
Retention force and deformation of an innovative attachment model for mini-implant–retained overdentures
Source:The Journal of Prosthetic Dentistry
Author(s): Mariana L.C. Valente, Marcos V.W. Shimano, José A.M. Agnelli, Andréa C. dos Reis
Statement of problemThe gradual loss of retention and the need for periodic replacement of attachment-system components are the most frequent complications in implant-supported overdentures.PurposeThe purpose of this in vitro study was to develop a new attachment system for overdentures with polymeric materials and compare its retention and deformation with a conventional O-ring attachment system.Material and methodsA matrix with 2 mini-implants with ball abutments was used to simulate the mandibular border during a fatigue resistance test. A total of 60 polyacetal (n=20), polytetrafluoroethylene (n=20), and conventional O-ring (n=20) attachments were captured in pairs with acrylic resin and subjected to 3625 insertion and removal cycles, simulating 30 months of overdenture use. The internal and external deformations of the attachments were assessed using an optical stereomicroscope. One-way ANOVA and the Tukey honestly significant difference tests were used for statistical evaluation (α=.05).ResultsThe polyacetal attachment system showed the highest retention (P<.001), followed by the O-ring and polytetrafluoroethylene attachments. The O-ring attachments exhibited the lowest deformation (P<.001), and the polyacetal attachments had the highest internal deformation (P<.001).ConclusionsThe newly developed polyacetal attachment model increased the retention of mini-implant–retained overdentures, and despite the deformation experienced, the retention period appears to be better than that of conventional systems.
https://ift.tt/2Kz7uGv
Accuracy of 3-dimensional computer-aided manufactured single-tooth implant definitive casts
Publication date: Available online 29 June 2018
Source:The Journal of Prosthetic Dentistry
Author(s): Michele Buda, Manuel Bratos, John A. Sorensen
Statement of problemThe integration of the digital workflow into routine prosthodontic practice for single-tooth implant surgery and fixed prosthesis fabrication has occurred at a remarkable pace in the last 5 years. With the greater demands of esthetics and precision, the definitive implant analog cast must ensure accurate implant positioning as well as an accurate relationship to adjacent teeth.PurposeThe purpose of this in vitro study was to evaluate the accuracy of the 3-dimensional (3D) implant position of definitive casts produced by 3D printing and analog technology.Material and methodsA master patient model was created from a dentate typodont. The maxillary left central incisor was removed, and a Straumann RC implant was positioned for a screw-retained prosthesis. A laboratory scanner with an accuracy of 5 μm was used for all scanning. A scanbody was connected to the master model implant and scanned to create a master patient file, which served as the control master patient for all comparisons. The two 3D printing systems used for this study were the Statasys Objet500 (group OBJ), an industrial Polyjet production system, and the Formlabs Formlab 2 (group FORM), a budget SLA Vat system. In addition, a conventional gypsum cast (group GYP) with an implant analog was made with elastomeric impression material. With a sample size of 10 per group, each gypsum cast and 2 printed group casts were scanned with the D2000 laboratory scanner 5 times per cast. Convince software (3Shape) was used for 3D analysis to calculate accuracy. The following variables were measured: implant analog vertical displacement, horizontal displacement of implant platform and apex, degree of tilting in the vertical axis, and rotational position change around the vertical axis. Means and standard deviations were calculated for trueness. One-way ANOVA and the post hoc t test with Bonferroni correction were used to investigate any significant differences among the experimental groups (α=.05).ResultsFor vertical displacement of the implant body, group OBJ had the lowest value of –30 ±24 μm. The values obtained for OBJ and FORM were significantly different from that obtained for GYP (P<.05). For horizontal displacement of the implant shoulder, Group OBJ had the lowest value, 85 ±12 μm, and the difference among these groups was significantly different (P<.05). The value for horizontal displacement of the implant apex was 123 ±25 μm for group OBJ and not significantly different from that obtained for group GYP (136 ±40 μm) but significantly different from that obtained for group FORM (326 ±54 µm). Also, the analysis of implant body tilting in the vertical axis showed significant differences between the values obtained for groups GYP and OBJ and between the values obtained for groups OBJ and FORM. With regard to implant rotational position change around the vertical axis, the values obtained for the gypsum cast and group FORM were not statistically different from those obtained for the master patient control model (P>.05). However, the implant orientation of group OBJ was significantly different from the orientation of groups GYP and FORM (P<.05). The actual clinical relevance of these printing system discrepancies is yet to be determined because the level of clinical acceptable discrepancy in the x, y, and z vectors is still undefined.ConclusionsThis study showed statistically significant differences in accuracy among the implant analog cast fabrication systems; however; the level of clinical acceptable discrepancy is still undefined. Although further research is needed, this study supports the conclusion that the Polyjet industrial printing system was more accurate than the conventional implant analog gypsum cast.
https://ift.tt/2KgUOYu
Comparison of user satisfaction and image quality of fixed and mobile camera systems for 3-dimensional image capture of edentulous patients: A pilot clinical study
Source:The Journal of Prosthetic Dentistry
Author(s): Irena Sailer, Shiming Liu, Roland Mörzinger, Marcel Lancelle, Thabo Beeler, Markus Gross, Chenglei Wu, Vincent Fehmer, Murali Srinivasan
Statement of problemAn evaluation of user satisfaction and image quality of a novel handheld purpose-built mobile camera system for 3-dimensional (3D) facial acquisition is lacking.PurposeThe purpose of this pilot clinical study was to assess and compare the effectiveness between a handheld mobile camera system designed for facial acquisition and a fixed static camera arrangement by comparing the time effectiveness and the operator and participant preference for the 2 techniques of image capture.Material and methodsCompletely edentulous participants (n=12: women=7, men=5; mean age: 74.6 years) were included in this pilot study. Images were captured with and without the prostheses in situ while maintaining "serious" and "full-smile" facial expressions. Images were captured using a mobile and a static system. The working times for the participant installation and image captures were recorded. Operator and participant perceptions of the entire experience were recorded by using visual analog scale questionnaires. Nonparametric tests were used for statistical analyses (α=.05).ResultsThe installation time was significantly shorter for the mobile system (static=24 ±13 seconds; mobile=10 ±10 seconds), but the differences in the image capture times were not statistically significant (static: 29 ±5 seconds; mobile: 40 ±18 seconds). Operator preference was in favor of the mobile system with regard to working time (P=.002), difficulty in using (installation: P=.002; handling: P=.045), and camera weight (P=.002); however, they preferred the static arrangement for image quality (P=.003) and comfort (P=.013). The participants rated the entire photographic experience favorably, and 10 of 12 participants preferred the static camera over the mobile one.ConclusionsDespite the complexity of the installation, the static system was evaluated better for image quality; the mobile system was easier in installation and handling. The operators preferred the mobile system, and the participants preferred the static system.
https://ift.tt/2IAk1HP
Load-bearing capacity of simulated Locator-retained overdenture system
Source:The Journal of Prosthetic Dentistry
Author(s): Mona Gibreel, Lippo V.J. Lassila, Timo O. Närhi, Leila Perea-Lowery, Pekka K. Vallittu
Statement of problemAcrylic resin overdenture bases usually fracture because of stress concentrations at the area of the abutments.PurposeThe purpose of this study was to evaluate the reinforcing effect of bidirectional woven electrical glass (E-glass) fiber weaves with a different number of layers and different locations on the load-bearing capacity of simulated Locator-retained overdenture specimens.Material and methodsTest specimens with a centrally located metal housing for a Locator stud attachment were fabricated from autopolymerizing acrylic resin (polymethylmethacrylate based) and reinforced with bidirectional woven E-glass fiber layers. The control group specimens were fabricated without fiber reinforcement. The 2L group had 2 layers of E-glass fiber weaves and was divided according to the fiber location within the specimens as follows: 2L-A subgroup with 2 fiber layers above the metal housing; 2L-N subgroup with 2 fiber layers adjacent to the housing; and 2L-A+2L-N subgroup with 2 fiber layers above and 2 fiber layers adjacent to the housing. The 4L group had 4 layers of E-glass fiber weaves and was divided according to the fiber location as follows: 4L-A subgroup with 4 fiber layers above the housing; 4L-N subgroup with 4 fiber layers adjacent to the housing; and 4L-A+4L-N subgroup with 4 fiber layers above and 4 fiber layers adjacent to the housing. Dry specimens were submitted to a 3-point static loading test, and the mean flexural strength, flexural modulus, and strain values were analyzed with 1-way ANOVA and Tukey post hoc tests (α=.05). Two-way ANOVA was conducted to detect the influence of the number and location of the reinforcing layers (α=.05).ResultsThe results revealed a significant difference (P<.001) in flexural strength values between the control group (92.4 ±14 MPa) and the 2 subgroups, 4L-A (116 ±7.3 MPa) and 4L-A+4L-N (117.1 ±6 MPa), with a significant effect only from the number of the reinforcing layers (P<.001) and not the location (P=.153). No significant differences were found with flexural modulus (P=.195) and strain values (P=.174) among the tested groups.ConclusionsThe load-bearing capacity of a Locator-retained overdenture can be significantly increased by placing 4 layers of bidirectional woven E-glass fiber weaves either only above the metal housing or in both locations above and adjacent to the metal.
https://ift.tt/2KrZWZl
In vitro retention of prefabricated and individually formed posts: A pilot study
Source:The Journal of Prosthetic Dentistry
Author(s): Ivana Parčina Amižić, Ivana Miletić, Anja Baraba, Yuwei Fan, Dan Nathanson
Statement of problemData on the retention of individually formed fiber-reinforced composite posts (everStick) cemented with self-adhesive cement are lacking.PurposeThe purpose of this in vitro study was to investigate the pull-out strength of 2 different fiber-reinforced composite posts (prefabricated and individually formed) cemented into extracted teeth with self-adhesive resin cement.Material and methodsThirty extracted single-rooted human teeth were decoronated, endodontically treated, and prepared with post spaces of equal length. Prepared specimens were divided into 2 groups (n=15 each) based on the type of post: commercially prefabricated fiber posts (GC) and individually formed resin posts (using GC reinforcing fibers). Self-adhesive resin cement (G-CEM LinkAce; GC) was used to cement all posts. Each post was held with moderate pressure, and root surfaces were light polymerized for 20 seconds (650 mW/cm2). After cementation, the specimens were stored in saline solution for 30 days. Treated teeth were kept in water for 24 hours before pull-out testing parallel to the longitudinal axis of the posts. Data were analyzed using the Student t test (α=.05) and the coefficient of variance as the ratio of the standard deviation to the mean.ResultsThe mean pull-out retention strength was 185.7 ±61.2 N for the prefabricated fiber posts and 98.9 ±56.5 N for the individually formed fiber posts (P=.026).ConclusionsThe prefabricated fiber posts exhibited significantly higher retention forces than the individually formed posts.
https://ift.tt/2Kxc1ZI
Digital workflow to rehabilitate worn dentition on a non-hinge simulated patient
Source:The Journal of Prosthetic Dentistry
Author(s): Ramtin Sadid-Zadeh, Anthony Alexander
This report describes the complete mouth rehabilitation of worn dentition by using a digital workflow on a non-hinge simulated patient. A dentiform was used to simulate a patient with loss of occlusal vertical dimension. Physical diagnostic waxing along with a digital workflow was then used to re-establish the occlusal vertical dimension at the interim and definitive restoration stages.
https://ift.tt/2KoE9m8
Combination of digital photographs for the identification of the screw-access hole of cement-retained implant restorations
Source:The Journal of Prosthetic Dentistry
Author(s): Konstantinos Michalakis, Hiroshi Hirayama
https://ift.tt/2IDNCA4
Should the restoration of adjacent implants be splinted or nonsplinted? A systematic review and meta-analysis
Publication date: Available online 29 June 2018
Source:The Journal of Prosthetic Dentistry
Author(s): Victor E. de Souza Batista, Fellippo R. Verri, Cleidiel A.A. Lemos, Ronaldo S. Cruz, Hiskell F.F. Oliveira, Jéssica M.L. Gomes, Eduardo P. Pellizzer
Statement of problemThe decision to splint or to restore independently generally occurs during the planning stage, when the advantages and disadvantages of each clinical situation are considered based on the proposed treatment. However, clinical evidence to help clinicians make this decision is lacking.PurposeThe purpose of this systematic review and meta-analysis was to assess the marginal bone loss, implant survival rate, and prosthetic complications of splinted and nonsplinted implant restorations.Material and methodsThis study was designed according to the Cochrane criteria for elaborating a systematic review and meta-analysis and adopted the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Also, this review was registered at the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42017080162). An electronic search in the PubMed/MEDLINE, Cochrane Library, and Scopus databases was conducted up to November 2017. A specific clinical question was structured according to the population, intervention, comparison, outcome (PICO) approach. The addressed focused question was "Should the restoration of adjacent implants be splinted or nonsplinted?" The meta-analysis was based on the Mantel-Haenszel and inverse variance methods to assess the marginal bone loss, implant survival, and prosthetic complications of splinted and nonsplinted implant restorations.ResultsNineteen studies were selected for qualitative and quantitative analyses. A total of 4215 implants were placed in 2185 patients (splinted, 2768; nonsplinted, 1447); the mean follow-up was 87.8 months (range=12-264 months). Quantitative analysis found no significant differences between splinted and nonsplinted restorations for marginal bone loss. The assessed studies reported that 75 implants failed (3.4%), of which 24 were splinted (99.1% of survival rate) and 51 were nonsplinted (96.5% of survival rate). Quantitative analysis of all studies showed statistically significant higher survival rates for splinted restorations than for nonsplinted restorations. Ceramic chipping, screw loosening, abutment screw breakage, and soft tissue inflammation were reported in the selected studies. The quantitative analysis found no statistically significant difference in the prosthetic complications of splinted and nonsplinted restorations.ConclusionsWithin the limitations of this systematic review and meta-analysis, it was concluded that there was no difference in the marginal bone loss and prosthetic complications of splinted and nonsplinted implant restorations; this is especially true for restorations in the posterior region. However, splinted restorations were associated with decreased implant failure.
https://ift.tt/2Kz02OO
Fracture resistance and 2-body wear of 3-dimensional–printed occlusal devices
Publication date: Available online 29 June 2018
Source:The Journal of Prosthetic Dentistry
Author(s): Anna-Maria Lutz, Rüdiger Hampe, Malgorzata Roos, Nina Lümkemann, Marlis Eichberger, Bogna Stawarczyk
Statement of problemPolymeric material for 3-dimensional printing can be used to fabricate occlusal devices. However, information about fracture resistance and wear is scarce.PurposeThe purpose of this in vitro study was to investigate the fracture resistance and 2-body wear of 3-dimensional–printed (3DP) (FotoDent splint; Dreve Dentamid GmbH), milled polymethylmethacrylate (CAM) (Temp Basic; Transpa 95H16, Zirkonzahn GmbH), and conventionally fabricated polymethylmethacrylate (CAST) (Castdon; Dreve Dentamid GmbH) occlusal devices.Material and methodsA total of 96 occlusal devices were prepared according to the 3 different manufacturing techniques 3DP, CAM, and CAST (n=32). For each manufacturing technique, specimens were further divided into initial fracture resistance tests (n=16) and artificial aging in the mastication simulator (50 N, 37°C) with 2-body wear followed by fracture resistance tests (n=16). The fracture resistance was determined using a universal testing machine (1 mm/min). The wear was measured after 20 000 and 120 000 mastication cycles with the replica technique, mapped with a laser scanner, and quantified in R software. Data were analyzed using a 2-way ANOVA followed by a 1-way ANOVA with Scheffé or Games-Howell post hoc tests, repeated measures ANOVA with corrected Greenhouse-Geisser P values, and the Levene, Mann-Whitney, and paired t tests (α=.05).ResultsCAM presented higher initial fracture resistance than 3DP or CAST (P<.001). After mastication simulation, CAM followed by 3DP showed higher fracture resistance than CAST (P<.001). Mastication simulation decreased the fracture resistance for CAM and CAST (P<.001) but not for 3DP (P=.78). Three-dimensional–printed occlusal devices showed the highest material volume loss, followed by CAM and the lowest in CAST (P<.001).ConclusionsThree-dimensional–printed occlusal devices showed lower wear resistance and lower fracture resistance than those milled or conventionally fabricated. Therefore, only short-term application in the mouth is recommended. Further developments of occlusal device material for 3-dimensional printing are necessary.
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In vivo biocompatibility of an interim denture resilient liner containing antifungal drugs
Source:The Journal of Prosthetic Dentistry
Author(s): Juliana Hotta, Gustavo Pompermeier Garlet, Tania Mary Cestari, Jozely Francisca Mello Lima, Vinícius Carvalho Porto, Vanessa Migliorini Urban, Karin Hermana Neppelenbroek
Statement of problemAntifungal agents incorporated into interim denture resilient liners have been suggested as an adjunct treatment for denture stomatitis (DS). However, before applying this protocol to humans, biocompatibility analysis of such drugs in animal models is required.PurposeThe purpose of this animal study was to evaluate the in vivo biocompatibility of an interim resilient liner modified with minimum inhibitory concentrations (MICs) of antifungal drugs for Candida albicans biofilm.Material and methodsSixty Wistar rats were divided into 6 groups (n=5): PC=positive control/no protocol; IOD (intraoral device)=rats using an acrylic resin palatal device (PD); Tru=rats using a PD relined with Trusoft; and Ny (nystatin), Chx (chlorhexidine diacetate), and Ke (ketoconazole) groups=rats using a PD relined with Trusoft + drug MICs. The rats were sacrificed at 7 or 14 days of trial. Histopathological qualitative analysis was performed by comparing photomicrographs of histological sections of the intermolar region. Morphological changes in the epithelium and keratin were quantitatively analyzed by computerized planimetry, and data were analyzed by using 2-way ANOVA and the Tukey HSD test (α=.05).ResultsQuantitative analysis showed that only PD containing Ke significantly decreased the thickness and area of the keratin compared with the other groups (P<.001), which showed no differences between each other (P>.05). These results agreed with those of qualitative analysis.ConclusionsIncorporation of MICs of Ny and Chx in Trusoft did not induce histopathological changes in the rat palatal mucosa, suggesting the in vivo biocompatibility of this DS treatment.
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Digital workflow for the design and additively manufacture of a splinted framework and custom tray for the impression of multiple implants: A dental technique
Source:The Journal of Prosthetic Dentistry
Author(s): Wenceslao Piedra Cascón, Marta Revilla-León
This article describes a step-by-step digital protocol for the design and fabrication, through additive manufacturing, of a splinted framework and a custom tray for the impression of a complete-arch prosthesis supported by multiple implants. The protocol presented uses open source software to control the thicknesses of the custom tray, splinting material, and impression material during the procedure, reducing laboratory and chairside time and costs.
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Comparison of fit accuracy of pressed lithium disilicate inlays fabricated from wax or resin patterns with conventional and CAD-CAM technologies
Source:The Journal of Prosthetic Dentistry
Author(s): Foudda R. Homsy, Mutlu Özcan, Marwan Khoury, Zeina A.K. Majzoub
Statement of problemThe use of resin patterns to produce partial coverage restorations is poorly documented.PurposeThe purpose of this in vitro study was to compare the marginal and internal fit accuracy of lithium disilicate glass-ceramic inlays obtained from wax or resin patterns and fabricated with digital and conventional techniques.Material and methodsA dentoform mandibular first molar was prepared for a mesio-occlusal ceramic inlay. Six groups of 15 inlays were obtained by conventional impression and manual wax (group CICW) or resin patterns (group CICR); conventional impression, laboratory scanning of the stone die, CAD-CAM milled wax (group CIDW), or polymethylmethacrylate (PMMA) blocks (group CIDR); and scanning of the master preparation with an intraoral scanner, CAD-CAM milled wax (group DSDW), or PMMA blocks (DSDR). The same design was applied to produce the wax and PMMA patterns in the last 4 groups. The replica technique was used to measure marginal and internal fit under stereomicroscopy. Mixed-model ANOVA was applied to assess differences according to the techniques, materials, and discrepancy location (α=.05).ResultsThe results demonstrated significant effects of the technique (P<.001), material (P=.009), and discrepancy location (P<.001) on fit measurements. Marginal discrepancy was only affected by the technique (P<.001), with the digital approaches yielding the smallest marginal discrepancy (23.5 ±3.6 μm), followed by the conventional digital techniques (31.1 ±5.6 μm) and finally by the conventional (42.8 ±7.2 μm) techniques. Internal fit was significantly influenced only by the material with lower discrepancy in wax (75.2 ±9.0 μm) than in resin patterns (84.7 ±15.1 μm). The internal discrepancy was significantly larger than the marginal discrepancy in all groups (P<.001).ConclusionsInlays generated from conventional wax and resin patterns tend to show higher marginal discrepancies than conventional digital and full digital patterns. Wax and resin materials yield similar marginal fit accuracies irrespective of the impression/manufacturing technique. Better internal fit was shown in wax than in resin patterns, regardless of the technique.
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Seeing-and Nursing-Our Power.
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What RNs Can Do to Improve the Health of Their Communities.
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Simulation in Nursing Education.
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Joint Commission Issues Alert Addressing Violence Against Health Care Workers.
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Ireland Proposes Promising Model for Nurse Staffing.
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NewsCAP: The American Heart Association issues corrections to 2018 stroke guidelines.
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The Impact of Legalization of Medical and Recreational Marijuana.
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NewsCAP: Soldiers in the U.S. Army who deploy within six months of an earlier deployment are at higher risk for suicide.
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NewsCAP: Each year an estimated 600 to 1,600 newborns fall or are dropped while in the hospital.
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NewsCAP: Study finds that NPs, physicians, and physician assistants (PAs) in the VA system provide comparable diabetes management.
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NewsCAP: The WHO releases Consolidated Guideline on Sexual and Reproductive Health and Rights of Women Living with HIV .
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Can You Be Fired for Taking a Sick Day?.
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Reducing Fall Risk in Older Adults.
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Promoting Drug Safety in Older Adults.
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New HIV Drug Treats Patients Unresponsive to Other Therapies.
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Biomedical applications of functional peptides in nano-systems
Publication date: September 2018
Source:Materials Today Chemistry, Volume 9
Author(s): Lei Rong, Si-Yong Qin, Chi Zhang, Yin-Jia Cheng, Jun Feng, Shi-Bo Wang, Xian-Zheng Zhang
During the past decades, functionalized nano-systems were believed in holding the bright future of the nanomaterials in biomedical applications. Due to their excellent biocompatibility, biodegradation capability, and biological activity, functional peptides have been vastly used solitary or employed as functional components in nano-systems for disease treatments. This review focuses on the recent advances on the use of functional peptides as a toolbox to construct various delivery nano-systems for tumor treatments. Arising from the special function contributed to the nano-systems, the functional peptides are mainly divided into three groups, cell-targeting peptides (CTPs), cell-penetrating peptides (CPPs), and environment-sensitive peptides. Within each group, their usage in both organic and inorganic systems is discussed. In particular, strategies used to generate promising therapeutic nano-systems for efficient tumor treatment are also highlighted.
Graphical abstract
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Identification of loci where DNA methylation potentially mediates genetic risk of type 1 diabetes
Source:Journal of Autoimmunity
Author(s): Jody Ye, Tom G. Richardson, Wendy L. McArdle, Caroline L. Relton, Kathleen M. Gillespie, Matthew Suderman, Gibran Hemani
The risk of Type 1 Diabetes (T1D) comprises both genetic and environmental components. We investigated whether genetic susceptibility to T1D could be mediated by changes in DNA methylation, an epigenetic mechanism that potentially plays a role in autoimmune diabetes. From enrichment analysis, we found that there was a common genetic influence for both DNA methylation and T1D across the genome, implying that methylation could be either on the causal pathway to T1D or a non-causal biomarker of T1D genetic risk. Using data from a general population comprising blood samples taken at birth (n = 844), childhood (n = 846) and adolescence (n = 907), we then evaluated the associations between 64 top GWAS single nucleotide polymorphisms (SNPs) and DNA methylation levels at 55 non-HLA loci. We identified 95 proximal SNP-cytosine phosphate guanine (CpG) pairs (cis) and 1 distal SNP-CpG association (trans) consistently at birth, childhood, and adolescence. Combining genetic co-localization and Mendelian Randomization analysis, we provided evidence that at 5 loci, ITGB3BP, AFF3, PTPN2, CTSH and CTLA4, DNA methylation is potentially mediating the genetic risk of T1D mainly by influencing local gene expression.
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Removal of bisphenol A by Fe-impregnated activated carbons
Abstract
A commercial wood-based activated carbon and the oxidized counterpart were impregnated with iron. The two Fe-impregnated carbons were prepared and characterized for their iron content, textural characteristics, surface chemistry, and their performance for bisphenol A adsorption. Batch adsorption experiments were conducted to study the effect of pH, ionic strength, kinetics, and thermodynamic equilibrium. Equilibrium adsorption data were described by both Langmuir and Freundlich isotherms. The iron impregnated activated carbon and the oxidized impregnated activated carbon presented maximum adsorption capacities of 785.65 and 469.78 mg/g, respectively, while adsorption followed second-order rate kinetics for both impregnated carbons. According to the thermodynamic parameters (ΔΗο, ΔSo, ΔGo), the adsorption is a spontaneous, exothermic, and physical process. Fenton-driven experiments conducted at different molar ratios of [H2O2]/[BPA] showed efficient degradation of BPA in spent Fe-impregnated carbons up to 82–95%, with traces of hydroxylated products.
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S olubilization of insoluble zinc compounds by zinc solubilizing bacteria (ZSB) and optimization of their growth conditions
Abstract
In this research, the optimum growth conditions for two zinc solubilizing bacteria (ZSB) have been studied for their potential application as bioinoculants to overcome Zn unavailability in soils. For this purpose, a laboratory-scale experiment was carried out to evaluate the zinc solubilizing ability of 80 plant growth promoting bacteria (PGPB) strains isolated from the rhizosphere of barley and tomato plants. To select effective ZSB, isolates were evaluated on Tris-mineral medium supplemented separately with zinc oxide, zinc carbonate, and zinc phosphate at a concentration of 0.1%. Two strains (Agrobacterium tumefaciens and Rhizobium sp.) were selected, based on a clear halo zone around their colonies in the solid medium supplemented with zinc oxide after 10 days of incubation at 29 °C. Results of solubilization at different pH values showed that these strains had solubilization activity in the range of pH 8–10 while no solubilization was observed at pH 6 and 7. The maximum Zn solubilization values were noted at pH 9: 51.4 mg L−1 (Agrobacterium tumefaciens) and 72.1 mg L−1 (Rhizobium sp). According to findings, bacterial growth was affected by different NaCl concentrations under in vitro condition. The salt concentration required for 50% inhibition of absorbance was 2.11 and 2.27% NaCl for Agrobacterium tumefaciens and Rhizobium sp., respectively. The maximum bacterial growth was observed at about 0.8% NaCl concentration.
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Evaluating the effect of biochar addition on the anaerobic digestion of swine manure: application of Py-GC/MS
Abstract
The anaerobic digestion process of swine manure was studied when char was used as supplement for improving performance. The use of pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) was proposed for assessing the organic matter degradation. The assessment on biogas production was carried out using samples of swine manure (SM) supplemented with char in one case and pre-treated by microwave irradiation in the other. This experimental set-up allows for the comparison of the biological degradation observed under these two different configurations and therefore aids in understanding the effect of char particles on the process. Results showed similar performance for both systems, with an average improvement of 39% being obtained in methane production when compared to the single digestion of SM. The analysis of digestate samples by Fourier transform infrared (FTIR) spectroscopy and Py-GC/MS showed improved degradation of proteins, with the Py-GC/MS technique also capable of identifying an increase in microbial-derived material when char was added, therefore highlighting the relevant role of carbon conductive particles on biological systems. Py-GC/MS along with the use of FTIR spectroscopy has proven to be useful tools when evaluating anaerobic digestion.
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Publication date: September 2017 Source: Free Radical Biology and Medicine, Volume 110 Author(s): Lucía Fernández-del-Río, Anish Nag, Elen...
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Abstract Noise pollution is a major factor of environmental complaints in many cities, which has significant impacts on human health. As a...
