Joinability of Particulate Reinforced Alumix 231 Based Composite Materials Produced by Powder Metallurgy Route

In the present study, weldability of Alumix 231 based composite materials reinforced with Al₂O₃ and B₄C and produced by powder metallurgy route is investigated. Various amounts of (0, 5, 10, and 15% wt.)Al₂O₃ and B₄C powders are added to the pre-alloyed Alumix 231 (Al—2.5% Cu—0.5% Mg—14% Si) powders separately and then mixed in a three-dimensional mixer for 45 min. Powders are compacted and sintered in an argon atmosphere at 640°C for 4 h. Produced blocks are welded by the Tungsten Inert Gas (TIG) welding at 25 V, 197 A and 14 l/min shielded gas flow in commercially pure argon atmosphere. Macro- and microexamination together with some mechanical properties of the welded area are studied. The results show that, although high amount of particles resulted in a decrease in the density, these composite materials can still be welded by the TIG welding method successfully.Исследуется свариваемость произведённых методом порошковой металлургии композитных материалов на основе Alumix 231, армированных Al₂O₃ и B₄C. Различные количества (0, 5, 10 и 15 масс.%) порошков Al₂O₃ и B₄C по отдельности добавлялись в предварительно сплавленные порошки Alumix 231 (Al—2,5% Cu—0,5% Mg—14% Si), а затем перемешивались в трёхмерном миксере в течение 45 минут. Затем порошки прессовались и спекались в атмосфере аргона при 640°C в течение 4 часов. Полученные блоки сваривались вольфрамовой сваркой в атмосфере инертного газа при 25 В, 197 А и потоке инертного газа в 14 л/мин в атмосфере технически чистого аргона. Были проведены макро- и микроисследования некоторых механических свойств сварной зоны. Их результаты показали, что, хотя оказалось большое количество частиц с пониженной плотностью, эти композитные материалы могут быть успешно сварены методом вольфрамовой сварки в атмосфере инертного газа.Досліджується зварюваність вироблених методою порошкової металургії композитних матеріялів на основі Alumix 231, армованих Al₂O₃ і B₄C. Різні кількості (0, 5, 10 і 15 мас.% ) порошків Al₂O₃ і B₄C окремо додавалися у попередньо стоплені порошки Alumix 231 (Al—2,5% Cu—0,5% Mg—14% Si), а потім перемішувалися в тривимірному міксері впродовж 45 хвилин. Потім порошки пресувалися та спікалися в атмосфері арґону при 640°C впродовж 4 годин. Одержані блоки зварювалися вольфрамовим зваренням в атмосфері інертного газу при 25 В, 197 А та потоці інертного газу у 14 л/хв. в атмосфері технічно чистого арґону. Було виконано макро- та мікродослідження деяких механічних властивостей зварної зони. їх результати показали, що, хоча виявилася велика кількість частинок зі зниженою густиною, ці композитні матеріяли можуть бути успішно зварені методою вольфрамового зварювання в атмосфері інертного газу

Biological Evaluation and Phytochemical Profiling of Some Lichen Species

Lichens are a symbiotic relationship between a fungus and a photosynthetic partner. Chemical characterization and bioactive potentials (antiproliferative, antioxidant, and antibacterial) of five lichen species (Evernia prunastri, Platismatia glauca, Pseudevernia furfuracea, Ramalina fastigiata, and Ramalina farinacea) were assessed. Five lichen metabolites (usnic acid, atranorin, stictic acid, evernic acid, and fumarprotocetraric acid) were analyzed by HPLC-DAD. E. prunastri was noteworthy evernic acid source. Antiproliferative activity was evaluated using human breast adenocarcinoma (MCF-7) and human hepatocellular carcinoma (HepG2/C3A) cell lines. The strongest activity was observed for P. glauca against HepG2/C3A, while the only lichen species that induced cytotoxicity against MCF-7 cell line was P. furfuracea. The highest antioxidant activity was also obtained with P. furfuracea. E. prunastri and R. farinaceae had the highest phenolic and flavonoid contents, respectively. Antibacterial activities of the extracts were determined against ten pathogenic bacteria. The most effective antibacterial agent was methanol extract of R. fastigiata. Our findings have revealed the pharmaceutical potentials of tested lichen species

Portable Microfluidic Integrated Plasmonic Platform for Pathogen Detection

Timely detection of infectious agents is critical in early diagnosis and treatment of infectious diseases. Conventional pathogen detection methods, such as enzyme linked immunosorbent assay (ELISA), culturing or polymerase chain reaction (PCR) require long assay times, and complex and expensive instruments, which are not adaptable to point-of-care (POC) needs at resource-constrained as well as primary care settings. Therefore, there is an unmet need to develop simple, rapid, and accurate methods for detection of pathogens at the POC. Here, we present a portable, multiplex, inexpensive microfluidic-integrated surface plasmon resonance (SPR) platform that detects and quantifies bacteria, i.e., Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) rapidly. The platform presented reliable capture and detection of E. coli at concentrations ranging from ∼105 to 3.2 × 107 CFUs/mL in phosphate buffered saline (PBS) and peritoneal dialysis (PD) fluid. The multiplexing and specificity capability of the platform was also tested with S. aureus samples. The presented platform technology could potentially be applicable to capture and detect other pathogens at the POC and primary care settings. © 2015, Nature Publishing Group. All rights reserved

Measuring vertebrate telomeres: applications and limitations

Telomeres are short tandem repeated sequences of DNA found at the ends of eukaryotic chromosomes that function in stabilizing chromosomal end integrity. In vivo studies of somatic tissue of mammals and birds have shown a correlation between telomere length and organismal age within species, and correlations between telomere shortening rate and lifespan among species. This result presents the tantalizing possibility that telomere length could be used to provide much needed information on age, ageing and survival in natural populations where longitudinal studies are lacking. Here we review methods available for measuring telomere length and discuss the potential uses and limitations of telomeres as age and ageing estimators in the fields of vertebrate ecology, evolution and conservation

Salicylic acid functionalized silica-coated magnetite nanoparticles for solid phase extraction and preconcentration of some heavy metal ions from various real samples

A method for the preconcentration of trace heavy metal ions in environmental samples has been reported. The presented method is based on the sorption of Cu(II), Cd(II), Ni(II) and Cr(III) ions with salicylic acid as respective chelate on silica-coated magnetite nanoparticles. Prepared adsorbent was characterized by XRD, SEM, BET and FT-IR measurements. The metals content of the sorbed complexes are eluted using 4.0 mL of 1.0 mol L-1 nitric acid. The influences of the analytical parameters including pH, amount of solid phase and condition of eluting solution, the effects of matrix ions on the retention of the analytes were examined. The accuracy and precision of suggested method were tested by analyzing of certified reference materials. The detection limits (3Sb/m, N = 8) for Cu(II), Cd(II), Ni(II) and Cr(III) ions are 0.22, 0.11, 0.27 and 0.15 μg L-1, respectively, and the maximum preconcentration factor is 200. The method was successfully applied to the evaluation of these trace and toxic metals in various waters, foods and other samples

ADAM33 gene silencing by promoter hypermethylation as a molecular marker in breast invasive lobular carcinoma

<p>Abstract</p> <p>Background</p> <p>ADAM33 protein is a member of the family of transmembrane glycoproteins composed of multidomains. ADAM family members have different activities, such as proteolysis and adhesion, making them good candidates to mediate the extracellular matrix remodelling and changes in cellular adhesion that characterise certain pathologies and cancer development. It was reported that one family member, <it>ADAM23</it>, is down-regulated by promoter hypermethylation. This seems to correlate with tumour progression and metastasis in breast cancer. In this study, we explored the involvement of ADAM33, another ADAM family member, in breast cancer.</p> <p>Methods</p> <p>First, we analysed <it>ADAM33 </it>expression in breast tumour cell lines by RT-PCR and western blotting. We also used 5-aza-2'-deoxycytidine (5azadCR) treatment and DNA bisulphite sequencing to study the promoter methylation of ADAM33 in breast tumour cell lines. We evaluated ADAM33 methylation in primary tumour samples by methylation specific PCR (MSP). Finally, <it>ADAM33 </it>promoter hypermethylation was correlated with clinicopathological data using the chi-square test and Fisher's exact test.</p> <p>Results</p> <p>The expression analysis of <it>ADAM33 </it>in breast tumour cell lines by RT-PCR revealed gene silencing in 65% of tumour cell lines. The corresponding lack of ADAM33 protein was confirmed by western blotting. We also used 5-aza-2'-deoxycytidine (5-aza-dCR) demethylation and bisulphite sequencing methodologies to confirm that gene silencing is due to <it>ADAM33 </it>promoter hypermethylation. Using MSP, we detected <it>ADAM33 </it>promoter hypermethylation in 40% of primary breast tumour samples. The correlation between methylation pattern and patient's clinicopathological data was not significantly associated with histological grade; tumour stage (TNM); tumour size; ER, PR or ERBB2 status; lymph node status; metastasis or recurrence. Methylation frequency in invasive lobular carcinoma (ILC) was 76.2% compared with 25.5% in invasive ductal carcinoma (IDC), and this difference was statistically significant (p = 0.0002).</p> <p>Conclusion</p> <p><it>ADAM33 </it>gene silencing may be related to the discohesive histological appearance of ILCs. We suggest that <it>ADAM33 </it>promoter methylation may be a useful molecular marker for differentiating ILC and IDC.</p

Cardiovascular imaging 2010 in the International Journal of Cardiovascular Imaging

Cardiovascular Aspects of Radiolog

An analysis-ready and quality controlled resource for pediatric brain white-matter research

We created a set of resources to enable research based on openly-available diffusion MRI (dMRI) data from the Healthy Brain Network (HBN) study. First, we curated the HBN dMRI data (N = 2747) into the Brain Imaging Data Structure and preprocessed it according to best-practices, including denoising and correcting for motion effects, susceptibility-related distortions, and eddy currents. Preprocessed, analysis-ready data was made openly available. Data quality plays a key role in the analysis of dMRI. To optimize QC and scale it to this large dataset, we trained a neural network through the combination of a small data subset scored by experts and a larger set scored by community scientists. The network performs QC highly concordant with that of experts on a held out set (ROC-AUC = 0.947). A further analysis of the neural network demonstrates that it relies on image features with relevance to QC. Altogether, this work both delivers resources to advance transdiagnostic research in brain connectivity and pediatric mental health, and establishes a novel paradigm for automated QC of large datasets

Platelet monoamine oxidase activity predicts alcohol sensitivity and voluntary alcohol intake in rhesus monkeys

Platelet monoamine oxidase B (MAO-B) has been proposed to be a biological marker for the properties of monoamine systems, with low activity being associated with vulnerability for high scores on personality traits such as sensation seeking, monotony avoidance, and impulsiveness, as well as for vulnerability for alcoholism. In the present study, platelet MAO-B activity was analysed in 78 rhesus macaques, and its relation to voluntary alcohol intake and behaviours after intravenous alcohol administration was observed