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Hydrophobicity, the spontaneous segregation of oil and water, can be modified by surfactants. The way this modification occurs is studied at the oil-water interface for a range of alkanes and two ionic surfactants. A liquid interfacial monolayer, consisting of a mixture of alkane molecules and surfactant tails, is found. Upon cooling, it freezes at T(s), well above the alkane's bulk freezing temperature, T(b). The monolayer's phase diagram, derived by surface tensiometry, is accounted for by a mixtures-based theory. The monolayer's structure is measured by high-energy X-ray reflectivity above and below T(s). A solid-solid transition in the frozen monolayer, occurring approximately 3 °C below T(s), is discovered and tentatively suggested to be a rotator-to-crystal transition.  相似文献   
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The immune balance in patients with rheumatoid arthritis (RA), a disease characterized by TH1 dominance, treated by the preferred combined anti-tumor necrosis factor (anti-TNF) and methotrexate (MTX) therapy was evaluated by assessing the chemokine and cytokine receptors as well as apoptosis induction. A meta-analysis of combined therapy by TNF blockers and MTX in 15 RA patients, MTX monotherapy in 20 RA patients, and 11 diagnosed but untreated RA patients was performed by assessing several immune markers in the whole lymphocyte population, as well as in specific CD4 cells, by both flow cytometry and image analysis. A significant downregulation of CXCR3 and IL-12 receptors (both TH1 markers) and a significant increase in the chemokine receptor CCR4 and, to a lesser extent, IL-4R (both TH2 markers) were found; a particularly marked increase was found in patients treated by combined therapy. This phenomenon was pronounced in CD4 cells and was accompanied by a high proportion of apoptotic cells. The therapeutic effect of MTX and TNF blockers may be due to apoptosis induction in lymphocytes infiltrating from the inflammation site and restoring the TH1/TH2 balance.  相似文献   
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The Balb/c mouse strain shows quantitative deficits of sociability and is behaviorally-hypersensitive to MK-801 (dizocilpine), a noncompetitive NMDA receptor antagonist. D-Serine (560mg/kg, intraperitoneally), a full agonist for the obligatory glycine co-agonist binding site on the NMDA receptor, increased the amount of time Balb/c mice spend in a compartment containing the enclosed social stimulus mouse and the amount of time Balb/c mice spend exploring (sniffing) an inverted cup containing the enclosed social stimulus mouse in a standard sociability apparatus. These effects of D-serine on the impaired sociability of the Balb/c mouse strain were not due to a "nonspecific" effect on locomotor activity; importantly, the locomotor activity of the Balb/c mouse strain decreases in the presence of an enclosed or freely-moving social stimulus mouse. The data suggest that dimensions of the impaired sociability of the Balb/c mouse strain may be improved by targeted NMDA receptor agonist interventions.  相似文献   
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Simulation is revolutionizing medical education, certification, and ongoing professional development. Simulation encompasses a variety of technologies as well as nontechnical approaches to improve individual psychomotor skills, group effectiveness, and systems processes, all without direct risk to patients. Simulation-enhanced learning experiences, addressing learning objectives based on the needs of the individual or the group and following the principles of adult education, can be used to ensure consistent and comprehensive learning opportunities, thereby creatively complementing didactic and clinical learning experiences. Pockets of simulation expertise are already present in the field of otolaryngology; more will develop as these exciting and important innovations blossom.  相似文献   
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