636 research outputs found
How confined lubricants diffuse during shear
The translational diffusion of a fluorescent dye embedded at a dilute concentration in a confined fluid was compared at rest and during shear. The fluid, octamethylcyclotetrasiloxane (OMCTS), was confined between step-free muscovite mica to thickness 3-4 layers. Fluorescence correlation spectroscopy showed that the time scales of intensity-intensity autocorrelation functions were essentially the same during shear and at rest, except they were faster during shear by a factor of 2 to 5. This dynamical probe of how liquids order in molecularly thin films fails to support the hypothesis that shear produced a melting transition.open242
Interferon-inducible protein SCOTIN interferes with HCV replication through the autolysosomal degradation of NS5A
Hepatitis C virus (HCV) utilizes autophagy to promote its propagation. Here we show the autophagy-mediated suppression of HCV replication via the endoplasmic reticulum (ER) protein SCOTIN. SCOTIN overexpression inhibits HCV replication and infectious virion production in cells infected with cell culture-derived HCV. HCV nonstructural 5A (NS5A) protein, which is a critical factor for HCV RNA replication, interacts with the IFN-beta-inducible protein SCOTIN, which transports NS5A to autophagosomes for degradation. Furthermore, the suppressive effect of SCOTIN on HCV replication is impaired in both ATG7-silenced cells and cells treated with autophagy or lysosomal inhibitors. SCOTIN does not affect the overall flow of autophagy; however, it is a substrate for autophagic degradation. The physical association between the transmembrane/proline-rich domain (TMPRD) of SCOTIN and Domain-II of NS5A is essential for autophagosomal trafficking and NS5A degradation. Altogether, our findings suggest that IFN-beta-induced SCOTIN recruits the HCV NS5A protein to autophagosomes for degradation, thereby restricting HCV replication.1110Ysciescopu
Confining Potential when a Biopolymer Filament Reptates
Using single-molecule fluorescence imaging, we track Brownian motion perpendicular to the contour of tightly entangled F-actin filaments and extract the confining potential. The chain localization presents a small-displacement Hookean regime followed by a large amplitude regime where the effective restoring force is independent of displacement. The implied heterogeneity characterized by a distribution of tube width is modeled.open271
Intravenous Vitamin C administration reduces fatigue in office workers: a double-blind randomized controlled trial
<p>Abstract</p> <p>Background</p> <p>Studies of the efficacy of vitamin C treatment for fatigue have yielded inconsistent results. One of the reasons for this inconsistency could be the difference in delivery routes. Therefore, we planned a clinical trial with intravenous vitamin C administration.</p> <p>Methods</p> <p>We evaluated the effect of intravenous vitamin C on fatigue in office workers. A group of 141 healthy volunteers, aged 20 to 49 years participated in this randomized, double-blind, controlled clinical trial. The trial group received 10 grams of vitamin C with normal saline intravenously, while the placebo group received normal saline only. Since vitamin C is a well-known antioxidant, oxidative stress was measured. Fatigue score, oxidative stress, and plasma vitamin C levels were measured before intervention, and again two hours and one day after intervention. Adverse events were monitored.</p> <p>Results</p> <p>The fatigue scores measured at two hours after intervention and one day after intervention were significantly different between the two groups (p = 0.004); fatigue scores decreased in the vitamin C group after two hours and remained lower for one day. Trial also led to higher plasma vitamin C levels and lower oxidative stress compared to the placebo group (p < 0.001, p < 0.001, respectively). When data analysis was refined by dividing each group into high-baseline and low-baseline subgroups, it was observed that fatigue was reduced in the lower baseline vitamin C level group after two hours and after one day (p = 0.004). The same did not hold for the higher baseline group (p = 0.206).</p> <p>Conclusion</p> <p>Thus, intravenous vitamin C reduced fatigue at two hours, and the effect persisted for one day. There were no significant differences in adverse events between two groups. High dose intravenous vitamin C proved to be safe and effective against fatigue in this study.</p> <p>Trial Registration</p> <p>The clinical trial registration of this trial is <url>http://ClinicalTrials.gov</url><a href="http://www.clinicaltrials.gov/ct2/show/NCT00633581">NCT00633581</a>.</p
Importância dos Saca-Rabos (Herpestes Ichneumon) como Reservatório de Mycobacterium avium subsp. paratuberculosis. Deteção por Técnicas Tradicionais e Moleculares
Poster apresentado nas IV Jornadas de Genética, realizadas na UTAD, Vila Real, nos dias 1,2 e 3 de Março de 2012.Os saca-rabos (Herpestes ichneumon) também conhecidos por mangustos, são carnívoros diurnos selvagens que juntamente com a geneta (Genetta genetta) representam os exemplares da família Viverridae em Portugal. É uma espécie cinegética de caça menor que se alimenta de coelhos, roedores, aves, cobras, insectos e ovos.
Neste estudo colheram-se amostras de 8 animais mortos por atropelamento e em ações de controlo de predadores, durante os anos de 2010 e 2011, nos concelhos de Idanha-a-Nova e Penamacor do distrito de Castelo Branco. As amostras colhidas foram fígado, pulmão, baço, intestino, rim, gânglio mesentérico, retrofaríngeo, mediastínico, amígdalas e fezes. As amostras foram submetidas à técnica de PCR e a cultura microbiológica em meios específicos.
Em três saca-rabos (37,5%) detectou-se Mycobacterium avium subsp. paratuberculosis (Map) através da técnica de biologia molecular. Dois eram machos e um era fêmea. Map foi confirmado também em cultura nos dois machos. Sete saca-rabos (87,5%) apresentaram bactérias álcool-ácido resistentes compatíveis com Map em esfregaços de diferentes tecidos, quando corados pelo método de Ziehl-Neelsen.
Estes resultados preliminares confirmam os saca-rabos como reservatório de Map no nosso país. Atualmente, estão a ser desenvolvidos mais estudos para a avaliação dos saca-rabos na dinâmica da infeção de Map em mamíferos selvagens
Photodynamic Therapy for Subretinal New Vessels
Photodynamic therapy (PDT) involves the induction of endothelial cell death or occlusion of blood vessels. On the basis of this mechanism of action, PDT is used in the treatment of predominant classic choroidal neovascularization (CNV), if the classic component is over 50%, and in myopic CNV. This study describes 2 cases of distinctive, abnormal, large, subretinal new vessels that are thought to have originated from the choroids. Diminishment of the new vessels was observed following treatment with PDT
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