Oncogene addiction in non-small cell lung cancer: focus on ROS1 inhibition

Publication date: Available online 12 March 2017
Source:Cancer Treatment Reviews
Author(s): Francesco Facchinetti, Giulio Rossi, Emilio Bria, Jean-Charles Soria, Benjamin Besse, Roberta Minari, Luc Friboulet, Marcello Tiseo
Detection of molecular aberrations driving the biology and the clinical behavior of advanced non-small cell lung cancer (NSCLC) allows the adoption of specific therapeutic strategies dramatically impacting disease courses. Among these, ROS1 rearrangements are present in1-2% of lung adenocarcinomas. Thanks to similarities between ALK and ROS1 oncogenes, lessons inferred from ALK can be applied to ROS1-positive NSCLC; nevertheless, disparities exist between diseases mastered by these two fusion genes. In the absence of more common genetic alterations detected in NSCLC (e. g. EGFR and KRAS mutations, ALK gene fusions), seeking for ROS1 rearrangements is crucial. Dedicated molecular diagnostics should be standardized, hopefully relying upon practical and efficient algorithms, comprehending immunohistochemistry and fluorescence in situ hybridisation. The major clinical impact exerted by crizotinib represents the main reason for which not even a sole ROS1-positive tumor should be undetected. The recent approval of the inhibitor by both American and European health agencies would hopefully boost the widespread testing for ROS1, eventually increasing the absolute number of positive cases, potential further source of information regarding molecular and clinical resistance. In vitro and clinical evidence have already been generated concerning crizotinib resistance and strategies to maintain patients under specific driver-inhibition are being successfully developed. Gathering data concerning diagnostics, preclinical evidence, clinical practice and ongoing studies, the present review depicts the current scenario of ROS1 inhibition in NSCLC.



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Clinical Thyroidology for the Public – Highlighted Article

From Clinical Thyroidology for the Public: There are clear effects of thyroid hormone on the heart. Some clinical studies have shown an increased risk of heart disease and death in patients with hypothyroidism, both mild and overt. Read More….

The post Clinical Thyroidology for the Public – Highlighted Article appeared first on American Thyroid Association.

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Structural, rheological and nutraceutical potential of β-glucan from barley and oat

Publication date: Available online 12 March 2017
Source:Bioactive Carbohydrates and Dietary Fibre
Author(s): Asima Shah, Adil Gani, F.A. Masoodi, Shoib M. Wani, Bilal Ahmad Ashwar
β-glucan in oat and barley were characterized by FT-IR spectroscopy, size-exclusion chromatography and purity estimation by Megazyme β-glucan assay kit. Oat and barley β-glucan had average molecular weights of 2.0×103kDa and 1.79 ×10³kDa, respectively. Rheological analysis suggested that β-glucan consisted of interchain aggregations and showed shear thinning behavior as revealed from Herschel-Bulkely model and frequency sweep. Antioxidant activity was evaluated by three complementary assays. Oat β- glucan showed increased DPPH scavenging activity, reducing power, and protection against DNA damage than barley β-glucan. Further, the antiproliferative potential of β-glucan was tested against three human cancer cell lines using MTT assay (3- (4,5-dimethylthiazol-2-yl)−2,5-diphenyltetrazolium bromide). β-glucan exhibited dose dependent cancer cell growth inhibition with oat β-glucan being more potent than barley β-glucan. This study demonstrates that barley and oat beta glucans hold nutraceutical potential of importance for functional food development and human health in general.

Graphical abstract

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Genetics of coronary artery disease: discovery, biology and clinical translation

The past decade has seen tremendous progress in understanding the genetic architecture of coronary artery disease (CAD). Khera and Kathiresan review research efforts that have improved our understanding of the genetic drivers of CAD, and discuss the promises and challenges of integrating genetic information into routine clinical practice.

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Transplant genetics and genomics

Advances in genetics and genomics have transformed the field of organ transplantation. Here, the authors review the role of genetic dissimilarities between donor and recipient in transplant tolerance and rejection, and how the identification of genetic variants that predict adverse transplant outcomes can be used for personalized medicine.

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Integration site selection by retroviruses and transposable elements in eukaryotes

Next-generation sequencing has facilitated the study of how transposable elements and retroviruses select their diverse genomic sites of integration, and revealed integration site preferences that range from specific nucleotide sequences to particular chromatin states. The authors review the various mechanisms of integration site selection in eukaryotes, as well as the molecular and cellular determinants that guide this process.

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A paperless office – what does it mean?

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Letter re: Radiation shielding in dentistry: an update

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Corrigendum

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Comment: ‘Radiation shielding in dentistry: an update’

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Continuing Professional Development Quiz

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Continuing Professional Development Calendar

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Issue Information - TOC and JEB

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Heritability of brain activity related to response inhibition: A longitudinal genetic study in adolescent twins

Publication date: Available online 12 March 2017
Source:International Journal of Psychophysiology
Author(s): Andrey P. Anokhin, Simon Golosheykin, Julia D. Grant, Andrew C. Heath
The ability to inhibit prepotent but context- or goal-inappropriate responses is essential for adaptive self-regulation of behavior. Deficits in response inhibition, a key component of impulsivity, have been implicated as a core dysfunction in a range of neuropsychiatric disorders such as ADHD and addictions. Identification of genetically transmitted variation in the neural underpinnings of response inhibition can help to elucidate etiological pathways to these disorders and establish the links between genes, brain, and behavior. However, little is known about genetic influences on the neural mechanisms of response inhibition during adolescence, a developmental period characterized by weak self-regulation of behavior. Here we investigated heritability of ERPs elicited in a Go/No-Go task in a large sample of adolescent twins assessed longitudinally at ages 12, 14, and 16. Genetic analyses showed significant heritability of inhibition-related frontal N2 and P3 components at all three ages, with 50 to 60% of inter-individual variability being attributable to genetic factors. These genetic influences included both common genetic factors active at different ages and novel genetic influences emerging during development. Finally, individual differences in the rate of developmental changes from age 12 to age 16 were significantly influenced by genetic factors. In conclusion, the present study provides the first evidence for genetic influences on neural correlates of response inhibition during adolescence and suggests that ERPs elicited in the Go/No-Go task can serve as intermediate neurophysiological phenotypes (endophenotypes) for the study of disinhibition and impulse control disorders.



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Improving the impact strength of Poly(lactic acid) (PLA) in fused layer modeling (FLM)

Publication date: 7 April 2017
Source:Polymer, Volume 114
Author(s): Lu Wang, William M. Gramlich, Douglas J. Gardner
Polylactic acid (PLA) is one of the most popular thermoplastics for fused deposition modeling (FDM). Attributed to its semi-crystalline nature, the relation between printing parameters and properties are more complicated than amorphous thermoplastics like acrylonitrile-butadiene-styrene (ABS). This study was designed to investigate two printing parameters, layer height (0.2 and 0.4 mm) and plate temperature (30 and 160 °C) on the Izod impact strength of printed PLA. X-ray diffraction (XRD) analysis confirmed the existence of α crystals in parts printed from 160 °C-plate temperature and α′ crystals in those printed at 30 °C-plate temperature. Parts printed with a 160 °C (plate temperature) had higher crystallinity. Polarized optical microscope (POM) observations illustrated that the plate temperature of 160 °C and layer height of 0.2 mm induced higher crystallinity, smaller crystals and interfacial crystal bands. The Izod impact strength of printed PLA at higher plate temperature was up to 114% higher than injection molded PLA made using conventional molding parameters.

Graphical abstract

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Structure, Synthesis and Biological Properties of the Pentacyclic Guanidinium Alkaloids

Publication date: Available online 12 March 2017
Source:Bioorganic & Medicinal Chemistry
Author(s): Yunlong Shi, Yasamin Moazami, Joshua G. Pierce
The pentacyclic guanidinium alkaloids (PGAs) are a family of marine natural products that possess a polycyclic guanidine-containing core and a long alkyl chain tethered spermidine-derived tail that is rarely observed in other natural products. These natural products exhibit potent activities on a wide range of organisms and therefore have attracted the attention of many synthetic chemists; however, the structure-activity relationships and mechanisms of action of PGAs remain largely elusive. Herein we summarize the structure, synthesis, toxicity and mechanisms of action of PGAs and highlight their potential as chemical probes and/or therapeutic leads.

Graphical abstract

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Radiosurgery for intracranial meningiomas: A systematic review and meta-analysis

Publication date: Available online 12 March 2017
Source:Critical Reviews in Oncology/Hematology
Author(s): Valentina Pinzi, Elena Biagioli, Anna Roberto, Francesca Galli, Michele Rizzi, Federica Chiappa, Greta Brenna, Laura Fariselli, Irene Floriani
BackgroundRadiosurgery(RS), both in single and multiple sessions, have been performed for intracranial meningiomas. Different aspects are still controversial on this field. The aim of this systematic review is to summarize the current literature on long-term efficacy and safety of RS for meningiomas.MethodsOnline databases were searched for studies published until April 2015. The primary outcomes were disease control and progression-free-survival(PFS). The secondary outcomes were symptom control and radiation-induced toxicity.ResultsThe estimate of disease control rate ranged from 87.0% to 100.0% at 5 years and from 67.0% to 100.0% at 10 years. The PFS rate ranged 78.0%–98.9% and 53.1%–97.2% at 5 and 10 years, respectively. The overall symptom control was 92.3%, the overall toxicity was 8.1%.ConclusionsRS can be considered a safe and effective treatment. Efforts are needed in standardizing the definition of local and symptom control and toxicity in order to properly compare different treatment schedules.



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A novel SERS-based magnetic aptasensor for prostate specific antigen assay with high sensitivity

Publication date: 15 August 2017
Source:Biosensors and Bioelectronics, Volume 94
Author(s): Kang Yang, Yongjun Hu, Ning Dong, Guichi Zhu, Tingfeng Zhu, Ningjing Jiang
The accurate and highly sensitive detection of prostate specific antigen (PSA) is particularly important, especially for obese men and patients. In this report, we present a novel aptamer-based surface-enhanced Raman scattering (SERS) sensor that employs magnetic nanoparticles (MNPs) core-Au nanoparticles (AuNPs) satellite assemblies to detect PSA. The high specific biorecognition between aptamer and PSA caused the dissolution of the core-satellite assemblies, thus the concentration of functionalized AuNPs (signal probes) existing in the supernatant was on the rise with the continual addition of PSA. The aptamer-modified MNPs were used as supporting materials and separation tools in the present sensor. With the assistance of magnet, the mixture was removed from the supernatant for the concentration effects. It was found that the corresponding SERS signals from the supernatant were in direct correlation to PSA concentrations over a wide range and the limit of detection (LOD) was as low as 5.0pg/mL. Excellent recovery was also obtained to assess the feasibility of this method for human serum samples detection. All of these results show a promising application of this method. And this novel sensor can be used for the accurate and highly sensitive detection of PSA in clinic samples in the future.



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Fluorescent nanoprobe for in-vivo ratiometric imaging of endogenous hydrogen peroxide resulted from drug-induced organ damages

Publication date: 15 August 2017
Source:Biosensors and Bioelectronics, Volume 94
Author(s): Jin Peng, Xianfeng Hou, Fang Zeng, Shuizhu Wu
Drug-induced organ damages have been considered as a grave problem regarding public health; hence effective method for in vivo detection of drug-induced organ damages is of great significance. Herein we developed a ratiometric fluorescent nanoprobe (NPs-A), which was prepared by loading the probe molecules into phospholipid bilayer, for assaying hydrogen peroxide (H2O2, an organ damage biomarker) level in vivo. The photophysical behavior of the probe molecule depends on the electron-withdrawing ability of the group at the 6- position of anthracene ring, on which the recognition moiety for hydrogen peroxide (dicarbonyl coupled with nitrophenyl, referred to as nitrophenyl-dicarbonyl) was introduced. Upon the reaction of the probe with H2O2, nitrophenyl-dicarbonyl group transforms into carboxyl group, and due to the variation of the electron-withdrawing ability of the 6th substituent, the fluorescent properties of the probe molecule alters accordingly, thus ensuring the ratiometric detection for H2O2 with high selectivity with the detection limit of 0.49μM. In addition, the nanoprobe (NPs-A) was applied for cell and in vivo imaging applications; and the results indicate that it can detect and track the level of H2O2 in living cells and to monitor and spatially map endogenous H2O2 levels in a drug-induced organ damage model of zebrafish.

Graphical abstract

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Patterns of age related changes for phosphodiesterase type-10A in comparison with dopamine D2/3 receptors and sub-cortical volumes in the human basal ganglia: A PET study with 18F-MNI-659 and 11C-raclopride with correction for partial volume effect

Publication date: 15 May 2017
Source:NeuroImage, Volume 152
Author(s): Patrik Fazio, Martin Schain, Ladislav Mrzljak, Nahid Amini, Sangram Nag, Nabil Al-Tawil, Cheryl J. Fitzer-Attas, Juliana Bronzova, Bernhard Landwehrmeyer, Cristina Sampaio, Christer Halldin, Andrea Varrone
Phosphodiesterase 10A enzyme (PDE10A) is an important striatal target that has been shown to be affected in patients with neurodegenerative disorders, particularly Huntington´s disease (HD). PDE10A is expressed on striatal neurones in basal ganglia where other known molecular targets are enriched such as dopamine D2/3 receptors (D2/3 R). The aim of this study was to examine the availability of PDE10A enzyme in relation with age and gender and to compare those changes with those related to D2/3 R and volumes in different regions of the basal ganglia. As a secondary objective we examined the relative distribution of D2/3 R and PDE10A enzyme in the striatum and globus pallidus. Forty control subjects (20F/20M; age: 44±11y, age range 27–69) from an ongoing positron emission tomography (PET) study in HD gene expansion carriers were included. Subjects were examined with PET using the high-resolution research tomograph (HRRT) and with 3T magnetic resonance imaging (MRI). The PDE10A radioligand ¹⁸F-MNI-659 and D2/3 R radioligand ¹¹C-raclopride were used. The outcome measure was the binding potential (BPND) estimated with the two-tissue compartment model (¹⁸F-MNI-659) and the simplified reference tissue model (¹¹C-raclopride) using the cerebellum as reference region. The PET data were corrected for partial volume effects. In the striatum, PDE10A availability showed a significant age-related decline that was larger compared to the age-related decline of D2/3 R availability and to the age-related decline of volumes measured with MRI. In the globus pallidus, a less pronounced decline of PDE10A availability was observed, whereas D2/3 R availability and volumes seemed to be rather stable with aging. The distribution of the PDE10A enzyme was different from the distribution of D2/3 R, with higher availability in the globus pallidus. These results indicate that aging is associated with a considerable physiological reduction of the availability of PDE10A enzyme in the striatum. Moreover as result of the analysis, in the striatum for both the molecular targets, we observed a gender effect with higher BPND the female group.



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Spinal cord grey matter segmentation challenge

Publication date: 15 May 2017
Source:NeuroImage, Volume 152
Author(s): Ferran Prados, John Ashburner, Claudia Blaiotta, Tom Brosch, Julio Carballido-Gamio, Manuel Jorge Cardoso, Benjamin N. Conrad, Esha Datta, Gergely Dávid, Benjamin De Leener, Sara M. Dupont, Patrick Freund, Claudia A.M. Gandini Wheeler-Kingshott, Francesco Grussu, Roland Henry, Bennett A. Landman, Emil Ljungberg, Bailey Lyttle, Sebastien Ourselin, Nico Papinutto, Salvatore Saporito, Regina Schlaeger, Seth A. Smith, Paul Summers, Roger Tam, Marios C. Yiannakas, Alyssa Zhu, Julien Cohen-Adad
An important image processing step in spinal cord magnetic resonance imaging is the ability to reliably and accurately segment grey and white matter for tissue specific analysis. There are several semi- or fully-automated segmentation methods for cervical cord cross-sectional area measurement with an excellent performance close or equal to the manual segmentation. However, grey matter segmentation is still challenging due to small cross-sectional size and shape, and active research is being conducted by several groups around the world in this field. Therefore a grey matter spinal cord segmentation challenge was organised to test different capabilities of various methods using the same multi-centre and multi-vendor dataset acquired with distinct 3D gradient-echo sequences. This challenge aimed to characterize the state-of-the-art in the field as well as identifying new opportunities for future improvements. Six different spinal cord grey matter segmentation methods developed independently by various research groups across the world and their performance were compared to manual segmentation outcomes, the present gold-standard. All algorithms provided good overall results for detecting the grey matter butterfly, albeit with variable performance in certain quality-of-segmentation metrics. The data have been made publicly available and the challenge web site remains open to new submissions. No modifications were introduced to any of the presented methods as a result of this challenge for the purposes of this publication.



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A Rapid Quantification of Binocular Misalignment without Recording Eye Movements: Vertical and Torsional Alignment Nulling

Publication date: Available online 12 March 2017
Source:Journal of Neuroscience Methods
Author(s): Kara H. Beaton, Mark J. Shelhamer, Dale C. Roberts, Michael C. Schubert
BackgroundSmall, innate asymmetries between the left and right otolith organs can cause ocular misalignment with symptoms that include double vision and motion sickness. Additionally, ocular misalignment affects nearly 5% of the US population. We have developed a portable, non-invasive technology that uses subjective perception of binocular visual signals to estimate relative binocular alignment.New Method and ResultsThe Vertical Alignment Nulling (VAN) and Torsional Alignment Nulling (TAN) tests ask subjects to view one red and one blue line on a tablet computer while looking through color-matched red and blue filters so that each eye sees only one of the lines. Subjects align the red and blue lines, which are initially vertically offset from one another during VAN or rotated relative to one another during TAN, until they perceive a single continuous line. Ocular misalignments are inferred from actual offsets in the final line positions. During testing, all binocular visual cues are eliminated by employing active-matrix organic light-emitting diode (AMOLED) technology and testing in darkness. VAN and TAN can accurately account for visual offsets induced by prisms, and test-retest reliability is excellent, with resolution better than many current standard clinical tests.Comparison with Existing Method(s)VAN and TAN tests are similar to the clinical Lancaster red-green test. However, VAN and TAN employ inexpensive, hand-held hardware that can be self-administered with results that are quickly quantifiable.ConclusionsVAN and TAN provide simple, sensitive, and quantitative measures of binocular positioning alignment that may be useful for detecting subtle abnormalities in ocular positioning.



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Grilling enhances antidiarrheal activity of Terminalia bellerica Roxb. fruits

Publication date: 18 April 2017
Source:Journal of Ethnopharmacology, Volume 202
Author(s): Garima Pandey, Shyam Sundar Gupta, Anil Bhatia, O.P. Sidhu, A.K.S. Rawat, Ch V. Rao
Ethnopharmacological relevanceTerminalia bellerica Roxb. fruits are rich in a variety of biologically active ingredients. Tharu and Buksa tribes of Udham Singh Nagar, Uttarakhand, India use grilled fruits of Terminalia bellerica as an effective cure for diarrheaAim of the studyWe validated the ethnobotanical claim by comparing the antidiarrheal effect of grilled fruits (GF) with dried fruits (DF).Materials and methodsThe 50% ethanolic extracts of GF and DF were successively fractionated; the antioxidant and bacterial inhibition activity were studied using DPPH free radical scavenging, anti-lipid peroxidation and broth dilution method respectively. Difference in metabolites of ethyl acetate fractions of GF and DF was analyzed using GC-MS, gallic acid content was determined through HPTLC. Further the in-vivo antidiarrheal effect of ethyl acetate fractions of DF and GF was studied on castor oil induced diarrhea model.ResultsThe ethyl acetate fractions showed potential DPPH free radical scavenging (IC50 11.13µg/ml in DF and 8.56µg/ml in GF), anti-lipid peroxidation and antibacterial activity. The non-targeted metabolic profiling showed higher content of tartaric acid, valeric acid, gallic acid, succinic acid, oxalic acid, malonic acid, malic acid, 1,2,3 trisbenzene, uridine and 11-eicosenoic acid in GF. The HPTLC results indicated that gallic acid content was 2.8 (±0.14) and 4.92 (±0.28) mg/g while ellagic acid content was 4.7 (±0.32) and 4.45 (±0.45) mg/g dry powder in DF and GF respectively. According to in vivo antidiarrheal activity DF and GF (100mg/kg oral) inhibited diarrhea by 41.87% and 71.72% respectively.ConclusionGrilling significantly altered the levels of metabolites in T. bellerica fruits which could be responsible for its increased therapeutic potential.

Graphical abstract

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Thyroid High-Impact Articles

FREE ACCESS through March 24, 2017
Read now:

Latest Impact Factor: 3.784
The Official Journal of: American Thyroid Association

2017 Guidelines of the American Thyroid Association for the Diagnosis and Management of Thyroid Disease During Pregnancy and the Postpartum
Erik K. Alexander, Elizabeth N. Pearce, Gregory A. Brent, Rosalind S. Brown, Herbert Chen, Chrysoula Dosiou, William A. Grobman, Peter Laurberg, John H. Lazarus, Susan J. Mandel, Robin P. Peeters, Scott Sullivan

Consanguinity and the Risk of Hashimoto's Thyroiditis
Raja Y. Zaghlol, Alireza Haghighi, Motasem M. Alkhayyat, Othman F. Theyab, Amal M. Owaydah, Mu'taz M. Massad, Mohammad A. Atari, Ayman A. Zayed

Response to Therapy Status Is an Excellent Predictor of Pregnancy-Associated Structural Disease Progression in Patients Previously Treated for Differentiated Thyroid Cancer
Luba Rakhlin, Stephanie Fish, R. Michael Tuttle

Can an Educational Intervention Improve Iodine Nutrition Status in Pregnant Women? A Randomized Controlled Trial
Parisa Amiri, Najmeh Hamzavi Zarghani, Pantea Nazeri, Fazlollah Ghofranipour, Mehrdad Karimi, Atieh Amouzegar, Parvin Mirmiran, Fereidoun Azizi

Stimulation of Thyroid Function by Human Chorionic Gonadotropin During Pregnancy: A Risk Factor for Thyroid Disease and a Mechanism for Known Risk Factors
Tim I.M. Korevaar, Yolanda B. de Rijke, Layal Chaker, Marco Medici, Vincent W.V. Jaddoe, Eric A. P. Steegers, Theo J. Visser, Robin P. Peeters

Biochemical Markers Reflecting Thyroid Function in Athyreotic Patients on Levothyroxine Monotherapy
Mitsuru Ito, Akira Miyauchi, Mako Hisakado, Waka Yoshioka, Akane Ide, Takumi Kudo, Eijun Nishihara, Minoru Kihara, Yasuhiro Ito, Kaoru Kobayashi, Akihiro Miya, Shuji Fukata, Mitsushige Nishikawa, Hirotoshi Nakamura, Nobuyuki Amino

The post Thyroid High-Impact Articles appeared first on American Thyroid Association.

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hOCT1 gene expression predict for optimal response to Imatinib in Tunisian patients with chronic myeloid leukemia

Abstract

Purpose

Imatinib mesylate (IM) is considered as a highly effective therapy for chronic myeloid leukemia (CML) patients. However, a minority of patients fail to achieve optimal response due to impaired bioavailability of IM. The human organic cation transporter 1 (OCT1; SLC22A1) has been reported to be the main influx transporter involved in IM uptake into CML cells. Genetic variants and/or hOCT1 expression changes may influence IM response. In this study, we aimed to investigate the impact of both hOCT1 polymorphisms located in exon 7 and hOCT1 mRNA levels on the clinical outcome in CML patients.

Methods

hOCT1 expression profile was determined using the quantitative real-time polymerase chain reaction in 69 CML patients treated with IM (35 responders to IM patients and 34 IM-resistant patients), while genotyping of 69 cases and 51 controls for hOCT1 polymorphisms was performed by direct sequencing after amplification of exon7.

Results

Our results showed that the hOCT1 gene was significantly downregulated in the samples of the IM-resistant group when compared with the IM-responder group (p = 0.0211). Moreover, sequencing data show an association in all cases between the SNP 408V>M (g.1222G>A) and an intronic 8 bp (base pairs) insertion of GTAAGTTG (rs36056065) at the 3′ end of exon 7. The genotype and allele distribution of the different SNPs did not differ significantly between the two groups of patients.

Conclusions

hOCT1 mRNA expression may serve as a clinical biomarker of response to imatinib and could be useful to predict IM therapy outcome of CML patients.

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Commentary on “Regional Versus Local Anaesthesia for Haemodialysis Arteriovenous Fistula Formation: A Systematic Review and Meta-analysis”

Publication date: Available online 11 March 2017
Source:European Journal of Vascular and Endovascular Surgery
Author(s): J.H.M. Tordoir




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Toe Pressure and Toe Brachial Index are Predictive of Cardiovascular Mortality, Overall Mortality, and Amputation Free Survival in Patients with Peripheral Artery Disease

Publication date: Available online 11 March 2017
Source:European Journal of Vascular and Endovascular Surgery
Author(s): J.-E. Wickström, M. Laivuori, E. Aro, R.T. Sund, O. Hautero, M. Venermo, J. Jalkanen, H. Hakovirta
Objective/BackgroundPeripheral haemodynamic parameters are used to assess the presence and severity of peripheral artery disease (PAD). The prognostic value of ankle brachial index (ABI) has been thoroughly delineated. Nonetheless, the relative usefulness of ankle pressure (AP), ABI, toe pressure (TP), and toe brachial index (TBI) in assessing patient outcome has not been investigated in a concurrent study setting. This study aimed to resolve the association of all four non-invasive haemodynamic parameters in clinically symptomatic patients with PAD with cardiovascular mortality, overall mortality, and amputation free survival (AFS).MethodsIn total, 732 symptomatic patients with PAD admitted to the Department of Vascular Surgery for conventional angiography at Turku University Hospital, Turku, Finland, between January 2009 and August 2011 were reviewed retrospectively. Demographic factors, cardiovascular mortality, all-cause mortality, and above foot level amputations were obtained and assessed in relation to AP, ABI, TP, and TBI by means of Kaplan–Meier life tables and a multivariate Cox regression model.ResultsThe haemodynamic parameter that was associated with poor 36 month general outcome was TP < 30 mmHg. Univariate Cox regression analysis of stratified values showed that TP and TBI associated significantly with mortality. In multivariate analysis both TP and TBI were associated with a significant risk of death. For TP < 30 mmHg and TBI < 0.25 the risk of cardiovascular mortality was hazard ratio [HR] 2.84, 95% confidence interval [CI] 1.75–4.61 [p<.001]; HR 3.68, 95% CI 1.48–9.19 [p=.050], respectively; all-cause mortality (HR 2.05, 95% CI 1.44–2.92 [p<.001]; HR 2.53, 95% CI 1.35–4.74 [p=.040], respectively); and amputation or death (HR 2.13, 95% CI 1.52–2.98 [p<.001]; HR 2.46, 95% CI 1.38–4.40 [p=.050], respectively)...ConclusionAmong non-invasive haemodynamic measurements and pressure indices both TP and TBI appear to be associated with cardiovascular and overall mortality and AFS for patients with PAD presenting symptoms of the disease.



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Effect of laser-assisted scaling and root planing on the expression of pro-inflammatory cytokines in the gingival crevicular fluid of patients with chronic periodontitis: A systematic review

Publication date: June 2017
Source:Photodiagnosis and Photodynamic Therapy, Volume 18
Author(s): Sergio Varela Kellesarian, Vanessa Ros Malignaggi, Hasham Abdullah Majoka, Abdulaziz A. Al-Kheraif, Tammy Varela Kellesarian, Georgios E. Romanos, Fawad Javed
BackgroundThe aim of the present systematic review was to assess the efficacy of laser-assisted (low level laser therapy [LLLT], high intensity laser therapy [HILT], or antimicrobial photodynamic therapy [aPDT]) scaling and root planing (SRP) compared with SRP alone on the expression of inflammatory cytokines in the gingival crevicular (GCF) of patients with chronic periodontitis (CP).MethodsIn order to address the focused question: "What is the efficacy of SRP with and without laser and/or aPDT on the expression of pro-inflammatory cytokines in the GCF of patients with CP?" an electronic search without time or language restrictions was conducted up to and including February 2017 in indexed databases using various key words.ResultsTwenty-two randomized control trials were included in the present systematic review. Nine studies and six studies assessed the efficacy of LLLT and HILT, as adjunct to SRP, respectively. Seven studies assessed the efficacy of aPDT as adjunct to SRP on down-regulating the expression of pro-inflammatory cytokines in the GCF among patients with CP. The outcomes of the studies included based upon the reduction in the levels of pro-inflammatory cytokines were inconsistent.ConclusionThe role of laser-assisted SRP on the expression of pro-inflammatory cytokines in the GCF of patients with CP remains unclear. Further long term and well-designed randomized clinical trials are needed in this regard.



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Real-time quantitative reverse transcription-PCR analysis of expression stability of Aggregatibacter actinomycetemcomitans fimbria-associated gene in response to photodynamic therapy

Publication date: June 2017
Source:Photodiagnosis and Photodynamic Therapy, Volume 18
Author(s): Maryam Pourhajibagher, Abbas Monzavi, Nasim Chiniforush, Mohammad Moein Monzavi, Shaghayegh Sobhani, Sima Shahabi, Abbas Bahador
BackgroundAggregatibacter actinomycetemcomitans is an etiological agent of both chronic and aggressive periodontitis. Dissemination of A. actinomycetemcomitans from the oral cavity and initiation of systemic infections has led to new approaches for treatment being needed. In this study, a series of experiments presented investigated the effect of methylene blue (MB)-mediated antimicrobial photodynamic therapy (aPDT) on cell viability and expression of fimbria-associated gene (rcpA) in A. actinomycetemcomitans.Materials and methodsTo determine the dose-depended effects of aPDT, A. actinomycetemcomitans ATCC 33384 strain photosensitized with MB was irradiated with diode laser following bacterial viability measurements. Cell-surviving assay and expression ratio of rcpA were assessed by colony forming unit and real-time quantitative reverse transcription-PCR (qRT-PCR) assays, respectively.ResultsIn the current study, MB-mediated aPDT using 100μg/mL showed significant reduction in A. actinomycetemcomitans growth when compared to the control (P<0.05). Sub-lethal dose of aPDT against A. actinomycetemcomitans was 25μg/mL MB at fluency of 93.75J/cm². Sub-lethal dose of aPDT could lead to about four-fold suppression of expression of rcpA.ConclusionHigh doses of MB-mediated aPDT could potentially exhibit antimicrobial activity, and the expression of rcpA as an important virulence factor of this strain is reduced in cells surviving aPDT with MB. So, aPDT can be a valuable tool for the treatment of A. actinomycetemcomitans infections.



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Nuclear medicine for photodynamic therapy in cancer: planning, monitoring and nuclear PDT

Publication date: Available online 12 March 2017
Source:Photodiagnosis and Photodynamic Therapy
Author(s): Dris Kharroubi Lakouas, Damien Huglo, Serge Mordon, Maximilien Vermandel
Photodynamic therapy (PDT) is a modality with promising results for the treatment of various cancers. PDT is increasingly included in the standard of care for different pathologies. This therapy relies on the effects of light delivered to photosensitized cells. At different stages of delivery, PDT requires imaging to plan, evaluate and monitor treatment. The contribution of molecular imaging in this context is important and continues to increase. In this article, we review the contribution of nuclear medicine imaging in oncology to PDT for planning and therapeutic monitoring purposes. Several solutions have been proposed to plan PDT from nuclear medicine imaging. For instance, photosensitizer biodistribution has been evaluated with a radiolabeled photosensitizer or with conventional radiopharmaceuticals on positron emission tomography. The effects of PDT delivery have also been explored with specific SPECT or PET radiopharmaceuticals to evaluate the effects on cells (apoptosis, necrosis, proliferation, metabolism) or vascular damage. Finally, the synergy between photosensitizers and radiopharmaceuticals has been studied considering the Cerenkov effect to activate photosensitized cells.



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Methylene blue, curcumin and ion pairing nanoparticles effects on photodynamic therapy of MDA-MB-231 breast cancer cell

Publication date: Available online 12 March 2017
Source:Photodiagnosis and Photodynamic Therapy
Author(s): Reza Hosseinzadeh, Khatereh Khorsandi
PurposeThe aim of current study was to use methylene blue-curcumin ion pair nanoparticles and single dyes as photosensitizer for comparison of photodynamic therapy (PDT) efficacy on MDA-MB-231 cancer cells, also various light sources effect on activation of photosensitizer (PS) was considered.MethodIon pair nanoparticles were synthesized using opposite charge ions precipitation and lyophilized. The PDT experiments were designed and the effect of PSs and light sources (Red LED (630nm; power density: 30mWcm⁻²) and blue LED (465nm; power density: 34mWcm⁻²)) on the human breast cancer cell line were examined. The effect of PS concentration (0–75μg.mL⁻¹), incubation time, irradiation time and light sources, and priority in irradiation of blue or red lights were determined.ResultsThe results show that the ion pairing of methylene blue and curcumin enhance the photodynamic activity of both dyes and the cytotoxicity of ion pair nanoparticles on the MDA-231 breast cancer cell line. Blue and red LED light sources were used for photo activation of photosensitizers. The results demonstrated that both dyes can activate using red light LED better than blue light LED for singlet oxygen producing.ConclusionNano scale ion pair precipitating of methylene blue-curcumin was enhanced the cell penetrating and subsequently cytotoxicity of both dyes together.



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Diagnosis of occlusal caries lesions in deciduous molars by coherent light scattering pattern speckle

Publication date: Available online 12 March 2017
Source:Photodiagnosis and Photodynamic Therapy
Author(s): Silvia Regina Garcia Olivan, Alessandro Melo Deana, Marcelo Mendes Pinto, Ravana Angelini Sfalcin, Kristianne Porta Santos Fernandes, Raquel Agnelli Mesquita-Ferrari, Renato Araujo Prates, Sandra Kalil Bussadori
BackgroundIn this study is presented the correlation between laser speckle images and detection of incipient caries lesions by changing the microstructure of the surface of tooth enamel.MethodsWe used 30 healthy deciduous molar teeth collected from the Biobank Human Teeth, Faculty of Dentistry, University of São Paulo who had carious lesions induced by the pH cycling method. The samples were evaluated for the diagnosis of caries by twomethodsICDAS and speckle pattern of coherent light scattering after 5, 10 and 15days and the results were statistically analyzed using α=0.05 significance level.ResultsA significant difference was observed between the image of the speckle scattering of healthy and injured areas within the 3 study groups, but not when comparing the three groups, showing us that it is an innovative technique that needs further study, but can be used as a diagnostic method for the detection of early caries lesions.ConclusionIt can be concluded that the analysis of scattering speckle pattern is a diagnostic technique that provides information on the microstructure of the surface of tooth enamel which has sensitivity for detection of incipient caries lesions.



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Effect of 5-aminolevulinic acid photodynamic therapy on keratinocyte proliferation and apoptosis in condyloma acuminatum

Publication date: Available online 11 March 2017
Source:Photodiagnosis and Photodynamic Therapy
Author(s): Guangwen Yin, Ke Sha, Bingjie Cai, Fangfang Li, Xuyang Li, Xianxian Xia, Xinxin Pan
BackgroundThe effect of 5-aminolevulinic acid photodynamic therapy on keratinocyte proliferation and apoptosis in condyloma acuminatum tissues was evaluated.MethodsAn immunohistochemical method and TdT-mediated dUTP nick end labeling were performed to detect the positive expression of the keratinocyte proliferation-related gene Ki-67 and apoptosis, respectively, in condyloma acuminatum tissues.ResultsOf 52 cases, 44 showed positive expression of Ki-67 in condyloma acuminatum keratinocytes before the treatment, with a positive expression rate of 84.62% (44/52), an expression strength of mostly ++ − +++, and a Ki-67 proliferation index of 80.25±5.07%. After treatment, 22 cases showed positive expression of Ki-67 in condyloma acuminatum keratinocytes, with a positive expression rate of 42.31% (22/52), an expression strength of mostly −−++, and a proliferation index of 42.67±3.06%. The differences in the positive expression rate, expression strength, and proliferation index in the before- and after-treatment groups were statistically significant (χ²=20.070, P<0.001). For visible apoptotic cells in condyloma acuminatum keratinocytes before the 5-aminolevulinic acid photodynamic treatment, the expression strength was mostly+−++, and the average apoptotic index was 13.94±2.35%; after treatment, the expression strength was mostly ++ − +++, and the average apoptotic index was 73.88±7.65%; the difference in the apoptotic index between the before and after treatment groups was statistically significant (P<0.001).Conclusion5-Aminolevulinic acid photodynamic therapy can inhibit the proliferation and promote the apoptosis of keratinocytes, and represents an effective mechanism for treating condyloma acuminatum.



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The significance of closed kinematic chains to biological movement and dynamic stability

Publication date: Available online 12 March 2017
Source:Journal of Bodywork and Movement Therapies
Author(s): Stephen Levin, Susan Lowell de Solórzano, Graham Scarr
Closed kinematic chains (CKCs) are widely used in mechanical engineering because they provide a simple and efficient mechanism with multiple applications, but they are much less appreciated in living tissues. Biomechanical research has been dominated by the use of lever models and their kinematic analysis, which has largely ignored the geometric organization of these ubiquitous and evolutionary-conserved systems, yet CKCs contribute substantially to our understanding of biological motion.Closed-chain kinematics couple multiple parts into continuous mechanical loops that allow the structure itself to regulate complex movements, and are described in a wide variety of different organisms, including humans. In a biological context, CKCs are modular units nested within others at multiple size scales as part of an integrated movement system that extends throughout the organism and can act in synergy with the nervous system, where present. They provide an energy-efficient mechanism that enables multiple mechanical functions to be optimized during embryological development and increases evolutionary diversity.



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18F-FDG PET/CT in initial staging and treatment response evaluation in a patient with thymoma

Publication date: Available online 11 March 2017
Source:Revista Española de Medicina Nuclear e Imagen Molecular
Author(s): L. Uslu-Beşli, Y. Akın, T.F. Çermik




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A model to relate wind tunnel measurements to open field odorant emissions from liquid area sources

Publication date: May 2017
Source:Atmospheric Environment, Volume 157
Author(s): F. Lucernoni, L. Capelli, V. Busini, S. Sironi
Waste Water Treatment Plants are known to have significant emissions of several pollutants and odorants causing nuisance to the near-living population. One of the purposes of the present work is to study a suitable model to evaluate odour emissions from liquid passive area sources. First, the models describing volatilization under a forced convection regime inside a wind tunnel device, which is the sampling device that typically used for sampling on liquid area sources, were investigated. In order to relate the fluid dynamic conditions inside the hood to the open field and inside the hood a thorough study of the models capable of describing the volatilization phenomena of the odorous compounds from liquid pools was performed and several different models were evaluated for the open field emission. By means of experimental tests involving pure liquid acetone and pure liquid butanone, it was verified that the model more suitable to describe precisely the volatilization inside the sampling hood is the model for the emission from a single flat plate in forced convection and laminar regime, with a fluid dynamic boundary layer fully developed and a mass transfer boundary layer not fully developed. The proportionality coefficient for the model was re-evaluated in order to account for the specific characteristics of the adopted wind tunnel device, and then the model was related with the selected model for the open field thereby computing the wind speed at 10 m that would cause the same emission that is estimated from the wind tunnel measurement furthermore, the field of application of the proposed model was clearly defined for the considered models during the project, discussing the two different kinds of compounds commonly found in emissive liquid pools or liquid spills, i.e. gas phase controlled and liquid phase controlled compounds. Lastly, a discussion is presented comparing the presented approach for emission rates recalculation in the field, with other approaches possible, i.e. the ones relying on the recalculation of the wind speed at the emission level, instead of the wind speed that would cause in the open field the same emission that is measured with the hood.



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Changes in Circulating Peptide YY and Ghrelin Are Associated With Early Smoking Relapse

Publication date: Available online 12 March 2017
Source:Biological Psychology
Author(s): Andrine M. Lemieux, Mustafa al'Absi
Ghrelin and peptide YY (PYY) during ad libitum smoking have been associated with decreased reported craving (ghrelin) and increased positive affect (PYY), and higher baseline ghrelin levels predicted subsequent increased risk of smoking relapse. The current study assessed PYY and ghrelin during ad libitum smoking and again after the initial 48hours of a smoking cessation attempt. The data compared smokers who abstained for 28days (n=37), smokers who relapsed (n=54), and nonsmokers (n=37). Plasma samples and subjective measures assessing craving and mood were collected at the beginning of each session. Results showed that relapsers experienced greater levels of distress (ps <.01). While nonsmokers and abstainers showed no change in ghrelin across the initial 48h, relapsers declined (p <.01). With PYY relapsers increased (p <.05) across the early abstinent phase. PYY and ghrelin may be useful predictors of relapse, specifically in reference to early withdrawal.



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Pulmonary injury associated with radiation therapy – Assessment, complications and therapeutic targets

Publication date: May 2017
Source:Biomedicine & Pharmacotherapy, Volume 89
Author(s): Rasmi Rajan Radha, Guruvayoorappan Chandrasekharan
Pulmonary injury is more common in patients undergoing radiation therapy for lungs and other thoracic malignancies. Recently with the use of most-advanced technologies powerful doses of radiation can be delivered directly to tumor site with exquisite precision. The awareness of technical and clinical parameters that influence the chance of radiation induced lung injury is important to guide patient selection and toxicity minimization strategies. At the cellular level, radiation activates free radical production, leading to DNA damage, apoptosis, cell cycle changes, and reduced cell survival. Preclinical research shows the potential for therapies targeting transforming growth factor-β (TGF-B), Toll like receptor (TLRs), Tumour necrosis factor-alpha (TNF-alpha), Interferon gamma (IFN-γ) and so on that may restore lung function. At present Amifostine (WR-2721) is the only approved broad spectrum radioprotector in use for patients undergoing radiation therapy. Newer techniques also offer the opportunity to identify new biomarkers and new targets for interventions to prevent or ameliorate these late effects of lung damage.

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Dopaminergic modulation of reward-guided decision making in alcohol-preferring AA rats

Publication date: 30 May 2017
Source:Behavioural Brain Research, Volume 326
Author(s): Ville Oinio, Pia Bäckström, Johanna Uhari-Väänänen, Atso Raasmaja, Petteri Piepponen, Kalervo Kiianmaa
R**esults from animal gambling models have highlighted the importance of dopaminergic neurotransmission in modulating decision making when large sucrose rewards are combined with uncertainty. The majority of these models use food restriction as a tool to motivate animals to accomplish operant behavioral tasks, in which sucrose is used as a reward. As enhanced motivation to obtain sucrose due to hunger may impact its reward-seeking effect, we wanted to examine the decision-making behavior of rats in a situation where rats were fed ad libitum. For this purpose, we chose alcohol-preferring AA (alko alcohol) rats, as these rats have been shown to have high preference for sweet agents. In the present study, AA rats were trained to self-administer sucrose pellet rewards in a two-lever choice task (one pellet vs. three pellets). Once rational choice behavior had been established, the probability of gaining three pellets was decreased over time (50%, 33%, 25% then 20%). The effect of d-amphetamine on decision making was studied at every probability level, as well as the effect of the dopamine D1 receptor agonist SKF-81297 and D2 agonist quinpirole at probability levels of 100% and 25%. d-Amphetamine increased unprofitable choices in a dose-dependent manner at the two lowest probability levels. Quinpirole increased the frequency of unprofitable decisions at the 25% probability level, and SKF-82197 did not affect choice behavior. These results mirror the findings of probabilistic discounting studies using food-restricted rats. Based on this, the use of AA rats provides a new approach for studies on reward-guided decision making.



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Characterization of facet joint cartilage properties in the human and interspecies comparisons

Publication date: Available online 11 March 2017
Source:Acta Biomaterialia
Author(s): Siobhan A. O'Leary, Jarrett M. Link, Eric O. Klineberg, Jerry C. Hu, Kyriacos A. Athanasiou
The facet joint, a synovial joint located on the posterior-lateral spine, is highly susceptible to degenerative changes and plays a significant role in back-related morbidities. Despite its significance, the facet is rarely studied and thus current treatment strategies are lacking. This study aimed to characterize, for the first time, the properties of human, pig, monkey, and rabbit lumbar facet cartilage providing much-needed design criteria for tissue engineering approaches. In this study, where possible, the facet's morphological, histological, mechanical, and biochemical properties were evaluated. Comparisons between the properties of the inferior and superior facet surfaces, as well as among spinal levels were performed within each species. In addition, interspecies comparisons of the properties were determined. The human facet joint was found to be degenerated; 100% of joint surfaces showed signs of pathology and approximately 71% of these were considered to be grade 4. Joint morphology varied among species, demonstrating that despite the mini-pig facet being closest to the human in terms of width and length, it was far more curved than the human or any of the other species. No notable differences were found in the mini-pig, monkey, and rabbit mechanical and biochemical properties, suggesting that these species, despite morphological differences, may serve as suitable animal models for studying structure-function relationships of the human facet joint. The characterization data reported in this study may increase our understanding of this ill-described joint as well as provide the foundation for the development of new treatments such as tissue engineering.Statement of significanceThis work provides the first comprehensive description of the properties of lumbar facet joint cartilage. Importantly, this work establishes that histological, biochemical, and mechanical properties are comparable between bipedal and quadrupedal animals, helping to guide future selection of appropriate animal models. This work also suggests that the human facet joint is highly susceptible to pathology. The mechanical properties of facet cartilage, found to be inferior to those of other synovial joints, provide a greater understanding of the joint's structure-function relationships as well as the potential etiology of facet joint pathology. Lastly, this work will serve as the foundation for the development of much-needed facet joint treatments, especially those based on tissue engineering approaches.

Graphical abstract

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Effect of hydrogel elasticity and ephrinB2-immobilized manner on Runx2 expression of human mesenchymal stem cells

Publication date: Available online 12 March 2017
Source:Acta Biomaterialia
Author(s): Hiroyuki Toda, Masaya Yamamoto, Hiroshi Uyama, Yasuhiko Tabata
The objective of this study is to design the manner of ephrinB2 immobilized onto polyacrylamide (PAAm) hydrogels with varied elasticity and evaluate the effect of hydrogels elasticity and the immobilized manner of ephrinB2 on the Runx2 expression of human mesenchymal stem cells (hMSC). The PAAm hydrogels were prepared by the radical polymerization of acrylamide (AAm), and N,N'-methylenebisacrylamide (BIS). By changing the BIS concentration, the elasticity of PAAm hydrogels changed from 1 to 70 kPa. For the bio-specific immobilization of ephrinB2, a chimeric protein of ephrinB2 and Fc domain was immobilized onto protein A-conjugated PAAm hydrogels by making use of the bio-specific interaction between the Fc domain and protein A. When hMSC were cultured on the ephrinB2-immobilized PAAm hydrogels with varied elasticity, the morphology of hMSC was of cuboidal shape on the PAAm hydrogels immobilized with ephrinB2 compared with non-conjugated ones, irrespective of the hydrogels elasticity. The bio-specific immobilization of ephrinB2 enhanced the level of Runx2 expression. The expression level was significantly high for the hydrogels of 3.6 and 5.9 kPa elasticity with bio-specific immobilization of ephrinB2 compared with other hydrogels with the same elasticity. The hydrogels showed a significantly down-regulated RhoA activity. It is concluded that the Runx2 expression of hMSC is synergistically influenced by the hydrogels elasticity and their immobilized manner of ephrinB2 immobilized.Statement of SignificanceDifferentiation fate of mesenchymal stem cells (MSC) is modified by biochemical and biophysical factors, such as elasticity and signal proteins. However, there are few experiments about combinations of them. In this study, to evaluate the synergistic effect of them on cell properties of MSC, we established to design the manner of Eph signal ligand, ephrinB2, immobilized onto polyacrylamide hydrogels with varied elasticity. The gene expression level of an osteogenic maker, Runx2, was enhanced by the immobilized manner, and significantly enhanced for the hydrogels of around 4 kPa elasticity with bio-specific immobilization of ephrinB2. This is the novel report describing to demonstrate that the Runx2 expression of MSC is synergistically influenced by the hydrogels elasticity and their manner of ephrinB2 immobilized.

Graphical abstract

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Neurotoxicity of the steroidal alkaloids tomatine and tomatidine is RIP1 kinase- and caspase-independent and involves the eIF2α branch of the endoplasmic reticulum

Publication date: Available online 12 March 2017
Source:The Journal of Steroid Biochemistry and Molecular Biology
Author(s): Daniela Correia da Silva, Paula B. Andrade, Patrícia Valentão, David M. Pereira
Steroidal alkaloids are a class of natural products that occur in several species of the Solanaceae family. In the case of tomato plant (Lycopersicon esculentum Mill.), tomatine and its aglycone, tomatidine, are the most representative molecules. These steroidal alkaloids have already shown several potentially useful biological activities, from anticancer to anti-inflammatory or antibacterial. In this work, the toxicity of these molecules in neuronal cells, namely in the neuroblastoma cell line SH-SY5Y, was assessed, emphasis being given to the cellular mechanisms underlying the effects observed.The results show that tomatine/tomatidine-induced cell death is caspase- and RIP1 kinase-independent, as cell death is not prevented by the pan-caspase inhibitor Z-VAD.fmk or by RIP1 inhibitor necrostatin-1. Analysis of Ca²⁺ levels using the fluorescent probe Fura-2/AM indicates that both tomatine and tomatidine have a marked effect upon Ca²⁺ homeostasis by increasing cytosolic Ca²⁺, an event that might be associated with their effect upon the endoplasmic reticulum. We show that the toxicity of these molecules require the PERK/eIF2α branch of the unfolded protein response, but not the IRE1α branch. Given the role of the endoplasmic reticulum in proteostasis, the ability of these molecules to inhibit the proteasome was also evaluated. Tomatine was able to inhibit the chymotrypsin-like catalytic core of purified human 20S proteasome, as shown by its ability to prevent degradation of the fluorogenic substrate Suc-Leu-Leu-Val-Tyr-AMC, thus suggesting that interference with proteostasis can be responsible for the toxicity of these steroidal alkaloids. This study is relevant as it sheds a light regarding the toxicity of molecules present in one of the most consumed plants worldwide.

Graphical abstract

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Potential Prevention By Oral DHEA Of Superficial Tears In Elderly Atrophy Skin

Publication date: Available online 12 March 2017
Source:The Journal of Steroid Biochemistry and Molecular Biology
Author(s): Harry W. Daniell




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Heavy metal bioaccumulation in two passerines with differing migration strategies

Publication date: 15 August 2017
Source:Science of The Total Environment, Volume 592
Author(s): Zoë Cooper, Robert Bringolf, Robert Cooper, Kathy Loftis, Albert L. Bryan, James A. Martin
Various anthropogenic activities have resulted in concentration of heavy metals and contamination of surrounding environments. Historically, heavy metal contamination at the Savannah River Site (SRS) in South Carolina has resulted from accidental releases of stored waste generated from nuclear weapon production in the early 1950s. Songbirds inhabiting and using resources from these areas have the potential to bioaccumulate metals but there is limited information on metal concentration levels in areas suspected of contamination as well as uncontaminated sites. Nonlethal tissues samples from avian blood and feathers provide a reliable approach for determining the bioavailability of these pollutants (As, Cd, Cr, Cu, Hg, Ni, Pb, Se, and Zn). The objectives of this study were to survey terrestrial heavy metal contamination at the SRS on potentially bioavailable contaminated (PBC) sites through blood and feather samples from resident Northern Cardinals (Cardinalis cardinalis) and migratory Great Crested Flycatchers (Myiarchus crinitus) and quantify sex-specific concentrations within species. Samples were collected in April to June of 2016. Cardinals had lower blood concentrations of Hg (β=−0.17, 85% CL=−0.26, −0.09) and Se (β=−0.33, 85% CL=−0.50, −0.16) than flycatchers. Cr feather concentrations were less in cardinals (β=−1.46, 85% CL=−2.44, −0.49) and all feathers of both species from reference locations had significantly less Zn (β=−67.92, 85% CL=−128.71, −7.14). Results indicate flycatchers were exposed to differing heavy metal levels during feather formation on their wintering grounds as compared to their recent exposure (through bloods samples) on their breeding grounds. Sex of individuals did not have a significant impact on bioaccumulation in either species. Overall, metal concentration levels in both species indicate minimal risk for acute toxicity; however, there is limited research on wild passerine populations with similar concentration levels. Therefore, further research on reproductive success of these birds should be explored.

Graphical abstract

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Dielectric and electrical characteristics of mechanically synthesized Ni-Zn ferrite nanoparticles

Publication date: 25 June 2017
Source:Journal of Alloys and Compounds, Volume 708
Author(s): A. Hajalilou, H. Mohamed Kamari, K. Shameli
Ni-Zn ferrite nanoparticles were synthesized via mechanical activation of Zn, NiO and Fe2O3 powders in a high energy planetary ball mill. The 30 h-milled samples in argon, oxygen and air atmospheres were pressed in pellet and toroid shape form and were sintered from 500 °C to 900 °C with 100 °C increments. The X-ray diffraction patterns results indicated a single phase Ni-Zn ferrite formation with a cubic-spinel structure in all the samples sintered at 500 °C. The milling atmosphere had a key role in the synthesis, microstructure and properties of the samples in such a way that this effect sustained even after the completion of sintering process. Thus, the main goal of this study is to scrutinize the effect of sintering temperature in the 30-h-milled samples in different atmospheres on DC electrical resistivity and dielectric behavior of Ni-Zn ferrite samples. The results indicated that although electrical resistivity decreased, dielectric behaviors, i.e. constant, loss and tanδ increased with increase in sintering temperature. The milled samples in argon had the highest resistivity of 1.2 × 10⁶ Ωcm at 500 °C, and lowest dielectric constant and loss (∼4.67 × 10² and 1.7 at 300 K and frequency 10⁶ MHz, respectively) compared to other samples owing to more homogeneity and smaller average crystallite size, making them a good candidate for high frequency applications. X-ray photoelectron spectroscopy (XPS) revealed the presence of metal ions in their proper valence in the Ni-Zn ferrite crystal structure. Noticeably, a variation in the binding energy for the milled samples in different atmospheres is attributed to the changes in surroundings of Fe³⁺ and Zn²⁺/or Ni²⁺, due to non-equilibrium distribution of cations in tetrahedral and octahedral sites, which is further confirmed by the XRD patterns.



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Promotion effect of ZnO on the photocatalytic activity of coupled Al2O3-Nd2O3-ZnO composites prepared by the sol − gel method in the degradation of phenol

Publication date: 5 July 2017
Source:Applied Catalysis B: Environmental, Volume 208
Author(s): J.E. Casillas, F. Tzompantzi, S.G. Castellanos, G. Mendoza-Damián, R. Pérez-Hernández, A. López-Gaona, A. Barrera
The photocatalytic activity of coupled Al2O3-Nd2O3-ZnO composites (Al-Nd-Zn-x; where x=0.8, 1.2, 2.0, 5.0, and 15.0wt% of ZnO) prepared by the sol-gel method was studied in the photo-degradation of phenol in aqueous medium. The Al-Nd-Zn-x composites were characterized by physical adsorption of N2, XRD, TEM, SEM, Raman, UV–vis, XPS and fluorescence spectroscopies. Al-Nd-Zn-x composites with ZnO concentration in the range 0.8–2.0wt% showed high efficiency to photo-convert phenol and mineralize dissolved organic carbon to CO2with UV light irradiation. The Al-Nd-Zn-1.2 composite was the material with the highest efficacy to photodegradate phenol in aqueous medium photo-converting about 90.0% of phenol and mineralizing 75.0% of dissolved organic carbon after 3h of UV light. It is proposed that the intimate contact between Al2O3, Nd2O3 and ZnO phases of the coupled Al-Nd-Zn-x composites are beneficial characteristics for the separation of the photogenerated charge carriers in order to decrease the recombination rate of photogenerated electron-hole pairs. These Al-Nd-Zn-x composites are characterized by a high BET specific surface area and a bimodal pore size distribution which are excellent characteristics for the adsorption and diffusion of phenol molecules to the active sites resulting in enhanced photocatalytic properties for the degradation of phenol in aqueous medium.

Graphical abstract

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Mania is an extension of depression from the perspective of neuronal plasticity – evaluation of our hypothesis through the affective spectrum

Publication date: Available online 11 March 2017
Source:Medical Hypotheses
Author(s): Naoto Omata, Tomoyuki Mizuno, Hiyori Matsumoto, Hironori Mitsuya, Kayo Mita, Yasushi Kiyono, Yuji Wada




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Chemotherapy in combination with cytokine-induced killer cell transfusion: An effective therapeutic option for patients with extensive stage small cell lung cancer

Publication date: May 2017
Source:International Immunopharmacology, Volume 46
Author(s): Jianmin Huang, Quancheng Kan, Lan, Xuan Zhao, Zhen Zhang, Shuangning Yang, Hong Li, Liping Wang, Li Xu, Zhe Cheng, Yi Zhang
Background and aims: In the past decade of clinical studies, the combination of chemotherapy with cytokine induced killer (CIK) cell transfusion has confirmed a promised efficacy in several types of cancer. CIK cells are a mixture of T lymphocytes, generated from peripheral blood mononuclear cells induced by multiple cytokines. This study was aimed to evaluate the clinical efficacy of chemotherapy combined with CIK- cell therapy in patients with extensive stage small cell lung cancer (ES SCLC). Patients and Methods: Forty four patients with ES SCLC were enrolled in this study. All the patients received treatment from Oct 2010 to Sep 2013 in the First Affiliated Hospital of Zhengzhou University. Included patients were equally divided into 2 groups according to the treatment strategies. Patients in the combined treatment group received chemotherapy combined with CIK-cell transfusion and patients in the control group received chemotherapy alone. The short-term effects, overall survival (OS), progress free survival (PFS) and therapy-related adverse events were analyzed retrospectively. Results: Short-term efficacy evaluation indicated that the total response rates in the combined treatment group and control group were 40.9% (9/22) and 9.1% (2/22), respectively. There was a significant difference between the two groups (p=0.0339). Furthermore, the PFS of the combined treatment group was significantly longer than that of the control group (8 vs. 4months, P=0.005). No severe side effect was observed after transfusion of CIK cells. Conclusion: These results indicated that chemotherapy combined with CIK-cell immunotherapy might provide a safe and effective treatment for patients with ES SCLC.



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Cellular Interactions of The Phosphorylated Form of AKT in Prostate Cancer

Publication date: Available online 11 March 2017
Source:Human Pathology
Author(s): Kai H. Hammerich, Anna Frolov, Rile Li, Michael Ittmann, Gustavo E. Ayala
Phospho-Akt (P-Akt1) promotes proliferation and increased survival in vitro and plays an important role in prostate cancer (PCa) progression as well as the prediction of the probability of recurrence. In this study, the goal was to demonstrate the involvement and impact of P-Akt1 on cellular interactions, biomechanisms and pathways in PCa. Tissue microarrays from 640 PCa patients were immunostained with various antibodies. Ki67 was used to measure proliferation index and Tunnel for apoptotic index. Increased expression of P-Akt1 was associated with an increased proliferation, but inversely correlated with apoptotic index. Higher levels of P-Akt1 are associated with both higher levels of cytoplasmic p27 and higher levels of nuclear p27, suggesting an involvement in both cytoplasmic entrapment and phosphorylation of p27. P-Akt1 expression significantly correlated with nuclear and cytoplasmic staining of FHKR and GSK. The strongest correlations were found with the -P forms of both, suggesting enzyme kinetics in the latter. Here, phosphorylation is the principal method of FHKR and GSK inactivation. P-Akt1 correlated with NFkB, suggesting a role in the inhibition through phosphorylation of NFkB. The results of the current study are unique due to the scope of the markers and the size of the population used. In vitro and in vivo derived information of P-Akt1 and its downstream effectors demonstrate significant involvement in PCa. Our data suggests that PCa uses multiple mechanisms to regulate this pathway and substantiates the concept of redundancy in cancer pathway regulation. Consequently, new hypothesis driven studies can be derived from this information.



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Sex Steroid Receptor Expression in Idiopathic Pulmonary Fibrosis

Publication date: Available online 11 March 2017
Source:Human Pathology
Author(s): Mitra Mehrad, Humberto E. Trejo Bittar, Samuel A Yousem
Usual interstitial pneumonia (UIP) is characterized by progressive scarring of the lungs and is associated with high morbidity and mortality despite therapeutic interventions. Sex steroid receptors have been demonstrated to play an important role in chronic lung conditions; however, their significance is unknown in patients with UIP. We retrospectively reviewed 40 idiopathic UIP cases for the expression of hormonal receptors. Forty cases including 10 normal lung, 10 cryptogenic organizing pneumonia (COP), 10 idiopathic organizing diffuse alveolar damage (DAD), 7 hypersensitivity pneumonitis (HP) and 3 nonspecific interstitial pneumonitis (NSIP) served as controls. Immunohistochemistry for estrogen receptor alpha (ER-α), progesterone receptor (PR) and androgen receptor (AR) was performed in all groups. Expression of these receptors was assessed in four anatomic/pathologic compartments: alveolar and bronchiolar epithelium, arteries/veins, fibroblastic foci/airspace organization, and old scar. All UIPs (100%) stained positive for PR in myofibroblasts in the scarred areas, while among the control cases only one NSIP case stained focally positive and the rest were negative. PR was positive in myocytes of the large-sized arteries within the fibrotic areas in 31 cases (77.5%). PR was negative within the alveolar and bronchial epithelium, airspace organization and center of fibroblastic foci, however, weak PR positivity was noted in the peripheral fibroblasts of the fibroblastic foci where they merged with dense fibrous connective tissue scar. All UIP and control cases were negative for AR and ER-α. This is the first study to show the expression of PR within the established fibrotic areas of UIP, indicating that progesterone may have profibrotic effects in UIP patients. Hormonal therapy by targeting PR could be of potential benefit in patients with UIP/IPF.



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Longitudinal and radial permeability analysis of additively manufactured porous scaffolds: Effect of pore shape and porosity

Publication date: 15 May 2017
Source:Materials & Design, Volume 122
Author(s): H. Montazerian, M. Zhianmanesh, E. Davoodi, A.S. Milani, M. Hoorfar
While in practice cell ingrowth in scaffolds mostly occurs radially, the recent literature has mainly emphasized on modeling permeability under unidirectional flows. In this article, we attempt to introduce the radial flow direction as another important factor for scaffold internal architecture design, and thereby show its trade-off with the conventionally studied longitudinal permeability. To this end, a set of computational models is developed for different lattice and triply periodic minimal surface-based geometries to predict the corresponding structure-property relationships with respect to different porosity levels. Also, permeability is experimentally investigated for different values of porosity through 3D-printing of the selected critical structures as identified by the numerical models; namely Hexagonal and Rhombic Dodecahedron. Relative to the longitudinal permeability, the normalized radial permeability is shown to change by −51.2% and 39.4% for Hexagonal and Rhombic Dodecahedron, respectively, implying the necessity of including radial permeability as a more realistic computational tool for the design of scaffold pore architecture. Moreover, the permeability-porosity relationship was developed through both the power law as well as the Kozeny-Carman models and the effects of experimental conditions on the permeability values were discussed.

Graphical abstract

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Intrinsic dead layer effects in relaxed epitaxial BaTiO3 thin film grown by pulsed laser deposition

Publication date: 15 May 2017
Source:Materials & Design, Volume 122
Author(s): Y. Gagou, J. Belhadi, B. Asbani, M. El Marssi, J.-L. Dellis, Yu. I. Yuzyuk, I.P. Raevski, J.F. Scott
Epitaxial BaTiO3 (BT) thin film of about 400nm thickness was grown on LaSr0.5Co0.5O3 (LSCO) coated (001)MgO using pulsed laser deposition. Ferroelectric properties of the BT thin film in Pt/BT/LSCO/MgO heterostructure capacitor configuration were investigated. Dynamic P-E hysteresis loops at room temperature showed ferroelectric behavior with Ps=32μC/cm², Pr=14μC/cm² and EC=65kV/cm. Static C-V measurements confirmed reversible switching with a coercive field EC=15kV/cm. Basing on a model taking into account an interface dead-layer we show that the capacitance-voltage "butterfly" loops imply only 25% switching of dipoles that inferred from dynamic polarization-field loops (~4 and ~16kV/cm, respectively). Dielectric permittivity as a function of temperature revealed a first-order ferroelectric-to-paraelectric (FE-PE) phase transition in the BT film characterized by a maximum at TC~130°C. The very large (~126K at 1kHz) difference between TC and the extrapolated Curie-Weiss temperature T0 is attributed to the dead-layer effects.

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A combined electron backscattered diffraction and visco-plastic self-consistent analysis on the anisotropic deformation behavior in a Mg-Gd-Y alloy

Publication date: 15 May 2017
Source:Materials & Design, Volume 122
Author(s): Jie Sun, Li Jin, Shuai Dong, Jie Dong, Zhenyan Zhang, Fenghua Wang, Wenjiang Ding, Alan A. Luo
The anisotropic mechanical properties of Mg alloys are critical in the application. In this paper, the anisotropic deformation behavior of extruded and aged Mg-Gd-Y alloys was studied by using electron backscatter diffraction (EBSD) analysis and visco-plastic self-consistent (VPSC) modeling. The results show that the activation of extension twinning was not the main reason for the mechanical anisotropy in the extruded Mg-Gd-Y alloy. Because twinning activity is very low during deformation. VPSC results show that the anisotropic deformation behavior in the extruded Mg-Gd-Y alloy is caused by various behavior of slip activity. The higher strength in sample during tension along transversal direction (TD) is caused by the more activation of prismatic slip. Furthermore, β' precipitates in the aged Mg-Gd-Y alloy can inhibit basal slip effectively. The CRSS of basal slip (90MPa) is very close to that of prismatic slip (100MPa) which leads to a better strength symmetry in Mg-Gd-Y alloy after aging treatment.

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Effect of the flyer material on the interface phenomena in aluminium and copper explosive welds

Publication date: 15 May 2017
Source:Materials & Design, Volume 122
Author(s): G.H.S.F.L. Carvalho, R. Mendes, R.M. Leal, I. Galvão, A. Loureiro
The effect of physical and mechanical properties of three different flyers on the interface phenomena of partially overlapped explosive welds, using the same base plate material, was studied. Flyers of Copper Cu-DHP and aluminium alloy 6082 (tempers T6 and O) were welded to AA6082-T6 base plates. The morphology of the weld interface is strongly influenced by the physical and mechanical properties of the flyer. In the interface of the aluminium welds, the use of a flyer of lower hardness and yield strength than the base plate results in asymmetrical waves, with bigger amplitude and smaller wavelength than the weld series of similar temper, and higher mechanical properties. The copper-aluminium welds presented flat interfaces, mainly because of the significant differences in melting temperature and density between the copper flyer and the aluminium base plate. Considering these results and analysing several dissimilar welds carried out by other authors it was found that when the product of density and melting temperature ratios between the flyer and the base plate exceeds a certain value, there is no formation of waves at the interface of the metals. Furthermore, for the Cu-Al welds, the CuAl2 (θ) intermetallic phase was formed on the bond zone.

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Experimental characterization and modelling of the elastic properties of direct compounded compression molded carbon fibre/polyamide 6 long fibre thermoplastic

Publication date: 15 May 2017
Source:Materials & Design, Volume 122
Author(s): Matthew Bondy, Pascal Pinter, William Altenhof
Characterization of 9% to 25% weight fraction compression molded carbon fibre LFT-D polyamide-6 was completed with orientations of 0°, ±45°, and 90°. A key finding is that tensile stiffness/strength and flexural stiffness were higher in the +45° direction compared to −45° (tensile modulus: 20%, strength: 10%, flexural modulus: 8%). Correspondingly, engineering strain at failure for uniaxial tensile tests was 18% lower in the +45° direction. This is hypothesized to be the result of fibre orientation asymmetry in the compression molding charge. Fibre orientation was measured by CT, fibre length was measured by matrix incineration/optical microscopy, and micromechanics models were employed to model elastic characteristics. An effectiveness was established for each process configuration by comparing the experimental modulus to the Generalized Self Consistent model. For the 0° direction, this effectiveness is approximately 90%. However, fibre length is more critical for the specimen geometry studied in the ±45° and 90° directions and this effectiveness is much lower (approximately 70%). Measurements of fibre length by an industrial partner without experience with direct compounding yielded data, that when input into the micromechanics models, poorly predicted mechanical characteristics for 0°. A length measurement methodology yielding accurate data is critical in modelling basic mechanical properties.

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Puncture position on wind turbine blades and arc path evolution under lightning strikes

Publication date: 15 May 2017
Source:Materials & Design, Volume 122
Author(s): Jiangyan Yan, Qingmin Li, Zixin Guo, Yufei Ma, Guozheng Wang, Li Zhang, Joseph D. Yan
Wind turbine blades are easy to get lightning strikes, which is calling more and more attention in recent years. Impulse voltage was applied on different blade structures and materials to study the puncture position distribution and the arc path inside the blade chamber. The experimental results reflected that most puncture points were located in the sandwich structure and thinner glass fiber cover. There was no obvious connection between puncture position, voltage polarities, and voltage peak values as to the experiment in this paper. However, the surface moisture and the experimental electrode position had significant influence for the puncture position. Arc paths inside the blade chamber considering different puncture positions were also studied. It can be concluded from the experiments that the arc usually consisted of surface-arc part and the air-arc part, in which the length of each part varied with the puncture position, voltage peak values and polarities. The research findings revealed the weak areas on typical blade and as well as the possible arc paths inside the sealed chamber, which will offer guidance for the lightning protection design of blade materials and the whole structure.

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Design, fabrication and characterization of composite piezoelectric ultrafine fibers for cochlear stimulation

Publication date: 15 May 2017
Source:Materials & Design, Volume 122
Author(s): Carlos Mota, Massimiliano Labardi, Luisa Trombi, Laura Astolfi, Mario D'Acunto, Dario Puppi, Giuseppe Gallone, Federica Chiellini, Stefano Berrettini, Luca Bruschini, Serena Danti
Sensorineural hearing loss, primed by dysfunction or death of hair cells in the cochlea, is the main cause of severe or profound deafness. Piezoelectric materials work similarly to hair cells, namely, as mechano-electrical transducers. Polyvinylidene fluoride (PVDF) films have demonstrated potential to replace the hair cell function, but the obtained piezoresponse was insufficient to stimulate effectively the auditory neurons. In this study, we reported on piezoelectric nanocomposites based on ultrafine PVDF fibers and barium titanate nanoparticles (BTNPs), as a strategy to improve the PVDF performance for this application. BTNP/PVDF fiber meshes were produced via rotating-disk electrospinning, up to 20/80 weight composition. The BTNP/PVDF fibers showed diameters ranging in 0.160–1.325μm. Increasing collector velocity to 3000rpm improved fiber alignment. The piezoelectric β phase of PVDF was well expressed following fabrication and the piezoelectric coefficients increased according to the BTNP weight ratio. The BTNP/PVDF fibers were not cytotoxic towards cochlear epithelial cells. Neural-like cells adhered to the composite fibers and, upon mechanical stimulation, showed enhanced viability. Using BTNP filler for PVDF matrices, in the form of aligned ultrafine fibers, increased the piezoresponse of PVDF transducers and favored neural cell contact. Piezoelectric nanostructured composites might find application in next generation cochlear implants.

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Tunable bandgap and spin-orbit coupling by composition control of MoS2 and MoOx (x=2 and 3) thin film compounds

Publication date: 15 May 2017
Source:Materials & Design, Volume 122
Author(s): S. Erfanifam, S.M. Mohseni, L. Jamilpanah, M. Mohammadbeigi, P. Sangpour, S.A. Hosseini, A. Iraji Zad
We report on the MoS2 and MoOx (x=2 and 3) composite thin layers, electrodeposited, onto a Florine doped Tin Oxide (FTO) substrate. Our results show a change in relative content of these compounds in different thicknesses ranging from ∼20 to 540nm. This change in the relative content at different thicknesses leads to a change in optical and electrical properties including bandgap and the type of semiconductivity. A sharp transition from p to n-type of semiconductivity is observed by scanning tunneling spectroscopy measurements. We find that the spin-orbit interaction of Mo 3d electrons in the MoS2 and MoO3 enhances by significant reduction of the MoO3 content in thicker layers.

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Stress-strain curve measurements of aluminum alloy and carbon steel by unconstrained-type high-pressure torsion testing

Publication date: 15 May 2017
Source:Materials & Design, Volume 122
Author(s): Yasuhiro Yogo, Masatoshi Sawamura, Noritoshi Iwata, Nobuyuki Yukawa
In measurements of stress-strain (SS) curves, it is difficult to achieve a large strain, i.e., 5 (500%), which is introduced in actual metal forming processes. Recently, a constrained-type high-pressure torsion test was applied and allowed measurement of the SS curve up to a strain of 10. However, the testing method cannot be used for steel specimens, because a compression pressure of over 3GPa has to be applied to a specimen via the dies, which leads to brakeage of the dies due to the stress concentration. Therefore, an unconstrained-type high-pressure torsion was applied for measurement of the SS curves of carbon steel. With this method, the rotation angle of the upper die and torque curve could be measured without breakage of the dies. After development of the methodology to convert the rotation angle-torque curve to a SS curve, the SS curves of an aluminum alloy and carbon steel were measured. The validity of the measured SS curves was examined by comparing the SS curves measured by the compression test, the constrained and unconstrained-type high-pressure torsion test. It was also confirmed that the difference of the unconstrained-type high-pressure torsion test was less than 10% compared to the other methods.

Graphical abstract

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Mechanical and microstructural characterization of alkali sulfate activated high volume fly ash binders

Publication date: 15 May 2017
Source:Materials & Design, Volume 122
Author(s): Akash Dakhane, Shannon Tweedley, Siva Kailas, Robert Marzke, Narayanan Neithalath
This paper presents a detailed characterization of cementitious blends containing high volumes of fly ash, activated using pH-neutral alkali sulfates. It is shown that this methodology, while resulting in a clinker factor reduction of 70%, provides requisite early-age strengths while compromising the 28-day strengths by only 30–40% as compared to plain OPC mixtures. The early age heat release for blends containing Class F fly ash is reduced by about 50% as compared to the straight OPC mixture. The overall pore volume increases with sulfate addition for the Class C fly ash based binder while it decreases when Class F fly ash is used, indicating the beneficial effect of the sulfate activation process in conjunction with a low calcium fly ash. The differences in reaction product constitution are brought out using thermal analysis and FTIR spectroscopy. ²⁹Si NMR spectroscopy coupled with Gaussian spectral deconvolution on Class F fly ash-OPC blends provides valuable information on the changes in Qⁿ(mAl) structures with addition of sodium sulfate, indicating the changes in the reaction products. From a durability perspective, Class F fly ash-based binders are found to be less susceptible to external or internal forms of sulfate attack as compared to plain OPC or the corresponding unactivated mixtures.

Graphical abstract

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Exfoliation of layered zirconium phosphate nanoplatelets by melt compounding

Publication date: 15 May 2017
Source:Materials & Design, Volume 122
Author(s): Lei Chen, Dazhi Sun, Jin Li, Guangdao Zhu
A melt compounding method to achieve the exfoliation of layered zirconium phosphate (ZrP) nanoplatelets was presented in this work. ZrP nanoplatelets were first intercalated by diglycolamine (DGA) to increase the interlayer distance and functionality. In the next melt compounding process, the cyclic anhydrides of maleic anhydride grafted polyolefin elastomers (POE-g-MA) reacted with the hydroxyls in DGA-ZrP. Subsequently, the long polyolefin chains of POE-g-MA intercalated into the interlayer of ZrP smoothly and exfoliated the nanoplatelets successfully. ZrP nanoplatelets with various sizes were fully exfoliated in POE-g-MA matrices. The modulus of elasticity of POE-g-MA was improved by the incorporation of ZrP nanoplatelets and further increased if the nanoplatelets are exfoliated. The ductility of ZrP/POE-g-MA compounds also became better, if ZrP nanoplatelets were first intercalated by DGA and then exfoliated, especially for the smaller nanoplatelets. Our work provides a general method to prepare polymer nanocomposites containing exfoliated ZrP nanoplatelets in a large scale.

Graphical abstract

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Mechanical properties of 3D printed polymeric cellular materials with triply periodic minimal surface architectures

Publication date: 15 May 2017
Source:Materials & Design, Volume 122
Author(s): Diab W. Abueidda, Mete Bakir, Rashid K. Abu Al-Rub, Jörgen S. Bergström, Nahil A. Sobh, Iwona Jasiuk
In this paper, three types of triply periodic minimal surfaces (TPMS) are utilized to create novel polymeric cellular materials (CM). The TPMS architectures considered are Schwarz Primitive, Schoen IWP, and Neovius. This work investigates experimentally and computationally mechanical properties of these three TPMS-CMs. 3D printing is used to fabricate these polymeric cellular materials and their base material. Their properties are tested to provide inputs and serve as validation for finite element modeling. Two finite deformation elastic/hyperelastic-viscoplastic constitutive models calibrated based on the mechanical response of the base material are used in the computational study of the TPMS-CMs. It is shown that the specimen size of the TPMS-CMs affect their mechanical properties. Moreover, the finite element results agree with the results obtained experimentally. The Neovius-CM and IWP-CM have a similar mechanical response, and it is found that they have higher stiffness and strength than the Primitive-CM.

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The influence of flow rates on the dynamic degradation behaviour of porous magnesium under a simulated environment of human cancellous bone

Publication date: 15 May 2017
Source:Materials & Design, Volume 122
Author(s): Amir Putra Md Saad, Rabiatul Adibah Abdul Rahim, Muhamad Noor Harun, Hasan Basri, Jaafar Abdullah, Mohammed Rafiq Abdul Kadir, Ardiyansyah Syahrom
This study analyses the effect of different flow rates on the degradation behaviour of porous magnesium for bone scaffold applications. A simulated boundary of bone marrow movement induced by various physiological activities was considered with a variation in flow rate in the experimental process, also known as a dynamic immersion test. Three types of porous magnesium (30%, 41%, and 55%) were immersed in simulated body fluid (SBF) for 24, 48, and 72h. The results show that the relative weight loss and mechanical properties of the porous magnesium significantly degraded by 68% and 95%, respectively, at increasing flow rates together with an increase in immersion period and porosity.

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Etched nickel microspheres catalyze methanol oxidation and in situ TEM observation of nickel microcrystal coalescence

Publication date: 15 May 2017
Source:Materials & Design, Volume 122
Author(s): Lei Zhao, Zhihuan Xi, Lijun Zhao
Here, nickel microspheres (Ni) were prepared by a solvothermal method, and then they were etched by Fe³⁺ ions in glycerol at 363K to realize surface-nanocrystallization. By surface-nanocrystallization on Ni, the reactivity of Ni can be improved and its magnetic properties can be maintained at their usual rate, which are important for the potential application of Ni as a magnetic catalyst. In this paper, the etched nickel microspheres (NiE) as a catalyst of methanol oxidation not only show high peak of current densities but also can be easily fixed on and cleaned out of electrode owing to their excellent soft magnetic property. Moreover, an interesting phenomenon is that coalescence phenomenon on micron-scale NiE happened after irradiation of electron beam due to their high reactivity and varied structures.

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The Effect Of Cart On Pituitary Hormones Release From Cultured Pituitary Cells

Publication date: Available online 11 March 2017
Source:Peptides
Author(s): M. Chmielowska, B. Baranowska, E. Wolinska-Witort, L. Martynska, M. Kalisz, A. Litwiniuk, W. Bik
Cocaine and Amphetamine -Regulated Transcript (CART) is widely expressed in the central nervous system and in several endocrine organs. CART is an important factor in the regulation of energy homeostasis. The aim of the study was to assess the role of CART in physiological response of pituitary cells in a course of starvation. The pituitary cells harvested from starved and fed ad libitum male rats were cultured for 48hours and treated with: 0.1 nM, 1 nM, 10 nM or 100 nM doses of CART. The medium was collected after 60minutes and stored at -70°C until samples were further assayed for: LH, FSH, PRL, GH, TSH and ACTH. We revealed that in cultures of pituitary cells collected from fasted rats the basal levels of the examined hormones were reduced. Incubation of pituitary cells of non-starved rats with any dose of CART reduced the concentration of LH and TSH, while the levels of the other hormones were decreased after administration only specific doses of CART. In cells of fasted rats no change in the concentration of gonadotrophins was observed. The PRL level was increased only in the 1 nM dose of CART, while the 10 nM and 100 nM CART doses markedly enhanced GH and TSH. Moreover, administration of 1nM, 10 nM and 100 nM of CART to cultured cells of fasted rats resulted in a significant rise of the ACTH.Our results indicate that CART can directly affect the physiological release of PRL, ACTH, TSH and GH in pituitary cells of starved animals. Moreover, CART did not alter the LH and FSH suppression level, which is correlated with food deprivation. This data stays in contrast with the already proposed role of CART as an anorexigenic hypothalamic factor.



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Structure-activity studies on polymyxin derivatives carrying three positive charges only reveal a new class of compounds with strong antibacterial activity

Publication date: Available online 11 March 2017
Source:Peptides
Author(s): Martti Vaara, Timo Vaara, Jonathan M. Tyrrell
Recent years have brought in an increased interest to develop improved polymyxins. The currently used polymyxins, i.e. polymyxin B and colistin (polymyxin E) are pentacationic lipopeptides that possess a cyclic heptapeptide part with three positive charges, a linear "panhandle" part with two positive charges, and a fatty acyl tail. Unfortunately, their clinical use is shadowed by their notable nephrotoxicity. We have previously developed a polymyxin derivative NAB739 which lacks the positive charges in the linear part. This derivative is better tolerated than polymyxin B in cynomolgus monkeys and is, in contrast to polymyxin B, excreted into urine in monkeys and rats. Here we have conducted further structure-activity relationship (SAR) studies on 17 derivatives with three positive charges only. We discovered a remarkably antibacterial class, as exemplified by NAB815, that carries two positive charges only in the cyclic part.



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