143 research outputs found

    Improving Electrical Properties of Polypropylene/GNP composites Using Compatibilizer and Solvent-Assisted Melt Blending

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    Over the past few years, polymer products have become essential to our lives. Many people may think that polymers are simply plastics, however, that is just the tip of the iceberg. Polymer products are used in food, sport, medical, and technological industries. There have been numerous applications in all these areas, but in the technological industry, electronic devices, in particular, are affected by electrostatic discharge (ESD) generated by friction during handling, packaging, or transportation. This requires the use of antistatic packaging, a special package that has low electrical resistivity in order to avoid electron accumulation. This study is an attempt to address this knowledge gap by use of compatibilizer approach & filler system to deliver high value improvements to microinjection molded parts

    Impact of doping on the performance of p-type Be-doped Al0.29 Ga0.71As Schottky diodes

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    The effects of changing the acceptors concentration on the electrical characteristics of Au/Ti on Be-doped Al0.29Ga0.71As Schottky contact have been investigated in the temperature range of 100–400 K. Using three devices with three different doping levels, the barrier height (ΩB), ideality factor (n) and series resistance (RS) for each diode were evaluated using both thermionic emission (TE) theory and Cheung's method. Our experimental results showed that the sample with a moderate doping concentration of 3×1016 cm-3 has the best performance, including ideality factor of 1.25 and rectification ratio of 2.24×103 at room temperature. All samples showed an abnormal behavior of reducing ΩB and increasing n with increase of temperature. This behavior was attributed, in case of low concertation samples, to barrier inhomogeneity and was explained by assuming a Gaussian distribution of barrier heights at the interface. While for the heavily doped sample, such non-ideal manner was ascribed with tunneling through the field emission (FE) mechanism

    The Potential of Parsley Polyphenols and Their Antioxidant Capacity to Help in the Treatment of Depression and Anxiety: An In Vivo Subacute Study

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    Depression and anxiety are major mental health problems in all parts of the world. These illnesses are associated with a number of risk factors, including oxidative stress. Psychotropic drugs of a chemical nature have demonstrated several side effects that elevated the impact of those illnesses. Faced with this situation, natural products appear to be a promising alternative. The aim of this study was to evaluate the anxiolytic and antidepressant effects of the Petroselinum sativum polyphenols in vivo, as well as its correlated antioxidant properties in vitro. Anxiolytic activity of the extract (50 and 100 mg/kg) was evaluated using the open field and the light-dark chamber tests, while the antidepressant activity was evaluated using the forced swimming test. The antioxidant activity of the extract was evaluated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical test and the FRAP (iron-reducing capacity) test. The phenolic extract showed very powerful anxiolytic and antidepressant-like effects, especially at a dose of 100 mg/kg, decreasing the depressive behavior in mice (decreased immobility time) and also the anxiolytic behavior (tendency for discovery in the center and illuminated areas) better even than those of paroxetine and bromazepam (classic drugs) concomitant with those results the extract also showed an important antioxidant capacity. These preliminary results suggest that Petroselinum sativum exhibits anxiolytic and antidepressant potential for use as a complement or independent phytomedicine to treat depression and anxiety

    An Insight into the Anxiolytic and Antidepressant-Like Proprieties of Carum carvi L. and Their Association with Its Antioxidant Activity

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    Depression and anxiety are widespread illnesses whose consequences on patients’ social and professional lives are becoming ever more dangerous and severe. The study’s objective is to explore the antidepressant-like and anxiolytic activity of the polyphenolic extract of Carum carvi L. as well as its antioxidant power as they were recently associated. The predictive antidepressant activity was evaluated using the forced swimming and tail suspension test in mice, a preclinical behavioral model widely used to determine the efficacy of antidepressant drugs. As for anxiolytic-like activity, two models were used, namely the light/dark chamber test to measure the animal’s degree of anxiety and the open field test to evaluate both anxiolytic and locomotor activity. The tests results indicate a remarkable antidepressant and anxiolytic-like effect after oral administration of the polyphenolic fraction of C. carvi and interesting antioxidant property. In the extract it has been confirmed the presence of 6 molecules belonging to polyphenols, identified with HPLC analysis. This study confirms and encourages the traditional use of the extract and appeals to further studies to understand its action mechanism

    An Insight into the Anxiolytic and Antidepressant-Like Proprieties of Carum carvi L. and Their Association with Its Antioxidant Activity

    Get PDF
    Depression and anxiety are widespread illnesses whose consequences on patients’ social and professional lives are becoming ever more dangerous and severe. The study’s objective is to explore the antidepressant-like and anxiolytic activity of the polyphenolic extract of Carum carvi L. as well as its antioxidant power as they were recently associated. The predictive antidepressant activity was evaluated using the forced swimming and tail suspension test in mice, a preclinical behavioral model widely used to determine the efficacy of antidepressant drugs. As for anxiolytic-like activity, two models were used, namely the light/dark chamber test to measure the animal’s degree of anxiety and the open field test to evaluate both anxiolytic and locomotor activity. The tests results indicate a remarkable antidepressant and anxiolytic-like effect after oral administration of the polyphenolic fraction of C. carvi and interesting antioxidant property. In the extract it has been confirmed the presence of 6 molecules belonging to polyphenols, identified with HPLC analysis. This study confirms and encourages the traditional use of the extract and appeals to further studies to understand its action mechanism

    Brucella and Osteoarticular Cell Activation: Partners in Crime

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    Osteoarticular brucellosis is the most common presentation of human active disease although its prevalence varies widely. The three most common forms of osteoarticular involvement are sacroiliitis, spondylitis, and peripheral arthritis. The molecular mechanisms implicated in bone damage have been recently elucidated. B. abortus induces bone damage through diverse mechanisms in which TNF-α and the receptor activator of nuclear factor kappa-B ligand (RANKL)-the natural modulator of bone homeostasis are involved. These processes are driven by inflammatory cells, like monocytes/macrophages, neutrophils, Th17 CD4+ T, and B cells. In addition, Brucella abortus has a direct effect on osteoarticular cells and tilts homeostatic bone remodeling. These bacteria inhibit bone matrix deposition by osteoblasts (the only bone cells involved in bone deposition), and modify the phenotype of these cells to produce matrix metalloproteinases (MMPs) and cytokine secretion, contributing to bone matrix degradation. B. abortus also affects osteoclasts (cells naturally involved in bone resorption) by inducing an increase in osteoclastogenesis and osteoclast activation; thus, increasing mineral and organic bone matrix resorption, contributing to bone damage. Given that the pathology induced by Brucella species involved joint tissue, experiments conducted on synoviocytes revealed that besides inducing the activation of these cells to secrete chemokines, proinflammatory cytokines and MMPS, the infection also inhibits synoviocyte apoptosis. Brucella is an intracellular bacterium that replicates preferentially in the endoplasmic reticulum of macrophages. The analysis of B. abortus-infected synoviocytes indicated that bacteria also replicate in their reticulum suggesting that they could use this cell type for intracellular replication during the osteoarticular localization of the disease. Finally, the molecular mechanisms of osteoarticular brucellosis discovered recently shed light on how the interaction between B. abortus and immune and osteoarticular cells may play an important role in producing damage in joint and bone.Fil: Giambartolomei, Guillermo Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Arriola Benitez, Paula Constanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Delpino, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; Argentin

    The Transition between Telomerase and ALT Mechanisms in Hodgkin Lymphoma and Its Predictive Value in Clinical Outcomes

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    International audienceBackground: We analyzed telomere maintenance mechanisms (TMMs) in lymph node samples from HL patients treated with standard therapy. The TMMs correlated with clinical outcomes of patients. Materials and Methods: Lymph node biopsies obtained from 38 HL patients and 24 patients with lymphadenitis were included in this study. Seven HL cell lines were used as in vitro models. Telomerase activity (TA) was assessed by TRAP assay and verified through hTERT immunofluorescence expression; alternative telomere lengthening (ALT) was also assessed, along with EBV status. Results: Both TA and ALT mechanisms were present in HL lymph nodes. Our findings were reproduced in HL cell lines. The highest levels of TA were expressed in CD30−/CD15− cells. Small cells were identified with ALT and TA. Hodgkin and Reed Sternberg cells contained high levels of PML bodies, but had very low hTERT expression. There was a significant correlation between overall survival (p < 10−3), event-free survival (p < 10−4), and freedom from progression (p < 10−3) and the presence of an ALT profile in lymph nodes of EBV+ patients. Conclusion: The presence of both types of TMMs in HL lymph nodes and in HL cell lines has not previously been reported. TMMs correlate with the treatment outcome of EBV+ HL patients

    A novel mechanical cleavage method for synthesizing few-layer graphenes

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    A novel method to synthesize few layer graphene from bulk graphite by mechanical cleavage is presented here. The method involves the use of an ultrasharp single crystal diamond wedge to cleave a highly ordered pyrolytic graphite sample to generate the graphene layers. Cleaving is aided by the use of ultrasonic oscillations along the wedge. Characterization of the obtained layers shows that the process is able to synthesize graphene layers with an area of a few micrometers. Application of oscillation enhances the quality of the layers produced with the layers having a reduced crystallite size as determined from the Raman spectrum. Interesting edge structures are observed that needs further investigation

    Effects of small interfering RNAs targeting fascin on human esophageal squamous cell carcinoma cell lines

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    <p>Abstract</p> <p>Background</p> <p>Fascin induces membrane protrusions and cell motility. Fascin overexpression was associated with poor prognosis, and its downregulation reduces cell motility and invasiveness in esophageal squamous cell carcinoma (ESCC). Using a stable knockdown cell line, we revealed the effect of fascin on cell growth, cell adhesion and tumor formation.</p> <p>Methods</p> <p>We examined whether fascin is a potential target in ESCC using <it>in vitro </it>and <it>in vivo </it>studies utilizing a specific siRNA. We established a stable transfectant with downregulated fascin from KYSE170 cell line.</p> <p>Results</p> <p>The fascin downregulated cell lines showed a slower growth pattern by 40.3% (p < 0.01) and detachment from collagen-coated plates by 53.6% (p < 0.01), compared to mock cells, suggesting that fascin plays a role in cell growth by maintaining cell adhesion to the extracellular matrix. <it>In vivo</it>, the tumor size was significantly smaller in the tumor with fascin knockdown cells than in mock cells by 95% at 30 days after inoculation.</p> <p>Conclusions</p> <p>These findings suggest that fascin overexpression plays a role in tumor growth and progression in ESCC and that cell death caused by its downregulation might be induced by cell adhesion loss. This indicates that targeting fascin pathway could be a novel therapeutic strategy for the human ESCC.</p
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