4,603 research outputs found

    Ballistic nanofriction

    Full text link
    Sliding parts in nanosystems such as Nano ElectroMechanical Systems (NEMS) and nanomotors, increasingly involve large speeds, and rotations as well as translations of the moving surfaces; yet, the physics of high speed nanoscale friction is so far unexplored. Here, by simulating the motion of drifting and of kicked Au clusters on graphite - a workhorse system of experimental relevance -- we demonstrate and characterize a novel "ballistic" friction regime at high speed, separate from drift at low speed. The temperature dependence of the cluster slip distance and time, measuring friction, is opposite in these two regimes, consistent with theory. Crucial to both regimes is the interplay of rotations and translations, shown to be correlated in slow drift but anticorrelated in fast sliding. Despite these differences, we find the velocity dependence of ballistic friction to be, like drift, viscous

    HMC05, Herbal Formula, Inhibits TNF- α

    Get PDF
    Vascular inflammation has been implicated in the progression of cardiovascular diseases such as atherosclerosis. In the present study, we found that HMC05, an extract from eight different herbal mixtures, dose-dependently inhibited tumor necrosis factor-α (TNF-α)-induced adhesion of monocytes to endothelial cells. Such inhibitory effect of HMC05 correlated with suppressed expression of monocyte chemoattractant protein-1, CC chemokine receptor 2, vascular cell adhesion molecule-1 and intercellular cell adhesion molecule-1. In addition, HMC05 significantly inhibited production of reactive oxygen species (ROS) and nuclear factor (NF)-κB activation by TNF-α. Those inhibitory effects of HMC05 (1–10 μg mL−1) on the TNF-α-induced inflammatory event was similar to those of berberine (1–10 μM), which is a major component of HMC05 and one of herbal compounds known to have vasorelaxing and lipid-lowering activities. However, berberine significantly reduced the viability of HUVECs in a time- and concentration-dependent manner. In contrast, HMC05 (1–10 μg ml−1) did not affect the cell viability for up to 48 h treatment. In conclusion, we propose that HMC05 may be a safe and potent herbal formula against vascular inflammation, and its action may be attributable to the inhibition of ROS- and NF-κB-dependent expression of adhesion molecules and chemokines

    Violência autoinfligida por intoxicação exógena em um serviço de urgência e emergência

    Get PDF
    RESUMO Objetivo Analisar as violências autoinfligidas por intoxicação exógena notificadas em um serviço de saúde. Métodos Estudo epidemiológico, retrospectivo e analítico realizado em um serviço de urgência e emergência do município de Teresina, Piauí. Procedeu-se nos meses de janeiro e fevereiro de 2015, mediante análise de todos os casos de violência autoinfligida por intoxicação exógena notificados no Sistema de Informação de Agravos de Notificação, no período de 2009 a 2014. O teste qui-quadrado de Pearson foi utilizado na análise. Resultados Foram notificadas 277 vítimas de violência autoinfligida por intoxicação exógena, sendo que 10,5% morreram por suicídio. Houve associação entre o óbito e as variáveis idade, escolaridade, zona de ocorrência e tipo de exposição, assim como entre o tipo de exposição e a quantidade de agentes utilizados. Conclusão Os resultados fornecem subsídios para a definição de estratégias de prevenção considerando os grupos vulneráveis e a complexidade dos fatores associados à violência autoinfligida

    A Phenome-Based Functional Analysis of Transcription Factors in the Cereal Head Blight Fungus, Fusarium graminearum

    Get PDF
    Fusarium graminearum is an important plant pathogen that causes head blight of major cereal crops. The fungus produces mycotoxins that are harmful to animal and human. In this study, a systematic analysis of 17 phenotypes of the mutants in 657 Fusarium graminearum genes encoding putative transcription factors (TFs) resulted in a database of over 11,000 phenotypes (phenome). This database provides comprehensive insights into how this cereal pathogen of global significance regulates traits important for growth, development, stress response, pathogenesis, and toxin production and how transcriptional regulations of these traits are interconnected. In-depth analysis of TFs involved in sexual development revealed that mutations causing defects in perithecia development frequently affect multiple other phenotypes, and the TFs associated with sexual development tend to be highly conserved in the fungal kingdom. Besides providing many new insights into understanding the function of F. graminearum TFs, this mutant library and phenome will be a valuable resource for characterizing the gene expression network in this fungus and serve as a reference for studying how different fungi have evolved to control various cellular processes at the transcriptional level

    Should a colon cancer screening decision aid include the option of no testing? A comparative trial of two decision aids

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>An important question in the development of decision aids about colon cancer (CRC) screening is whether to include an explicit discussion of the option of not being screened. We examined the effect of including or not including an explicit discussion of the option of deciding not to be screened in a CRC screening decision aid on subjective measures of decision aid content; interest in screening; and knowledge.</p> <p>Methods</p> <p>Adults ages 50–85 were assigned to view one of two versions of the decision aid. The two versions differed only in the inclusion of video segments of two men, one of whom decided against being screened. Participants completed questionnaires before and after viewing the decision aid to compare subjective measures of content, screening interest and intent, and knowledge between groups. Likert response categories (5-point) were used for subjective measures of content (eg. clarity, balance in favor/against screening, and overall rating), and screening interest. Knowledge was measured with a three item index and individual questions. Higher scores indicated favorable responses for subjective measures, greater interest, and better knowledge. For the subjective balance, lower numbers were associated with the impression of the decision aid favoring CRC screening.</p> <p>Results</p> <p>57 viewed the "with" version which included the two segments and 49 viewed the "without" version. After viewing, participants found the "without" version to have better subjective clarity about benefits of screening ("with" 3.4, "without" 4.1, <it>p </it>< 0.01), and to have greater clarity about downsides of screening ("with" 3.2, "without" 3.6, <it>p </it>= 0.03). The "with" version was considered to be less strongly balanced in favor of screening. ("with" 1.8, "without" 1.6, <it>p </it>= 0.05); but the "without" version received a better overall rating ("with" 3.5, "without" 3.8, <it>p </it>= 0.03). Groups did not differ in screening interest after viewing a decision aid or knowledge.</p> <p>Conclusion</p> <p>A decision aid with the explicit discussion of the option of deciding not to be screened appears to increase the impression that the program was not as strongly in favor of screening, but decreases the impression of clarity and resulted in a lower overall rating. We did not observe clinically important or statistically significant differences in interest in screening or knowledge.</p
    • …
    corecore