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Oral appliances for the treatment of obstructive sleep apnea (OSA) produce either mandibular or tongue protrusion, and are thought to enlarge the upper airway (UA). We used videoendoscopy to measure UA cross-sectional area (CSA) and shape in the hypopharynx, oropharynx, and velopharynx during various stages of active mandibular and tongue protrusion during wakefulness in 10 patients with OSA and nine control subjects. Measurements were made in the supine position at end-tidal expiration, and were normalized to the CSA in the normal bite position. Airway shape was expressed as the anteroposterior/lateral (AP/L) diameter ratio. There were no differences between OSA patients and controls in the effects of mandibular and tongue protrusion on UA caliber. Both mandibular and tongue protrusion increased CSA in the hypopharynx and oropharynx (p < 0.001), whereas only tongue protrusion increased CSA in the velopharynx (p < 0.001). Tongue protrusion caused a greater increase in oropharyngeal and velopharyngeal CSA than did mandibular protrusion (p < 0.05). Mandibular protrusion caused a greater increase in CSA in the hypopharynx than in the oropharynx or velopharynx (p < 0.05). Obese patients had a larger relative increase in oropharyngeal CSA with mandibular and tongue protrusion than did subjects of normal weight. Tongue protrusion increased the AP/L diameter ratio in the oropharynx and velopharynx (p < 0.001), and mandibular protrusion did so to a lesser extent in the oropharynx (p < 0.01), resulting in a more circular airway shape. We conclude that mandibular and tongue protrusion increase the CSA and alter the shape of the UA during wakefulness.  相似文献   
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The membrane protein syntaxin participates in several protein-protein interactions that have been implicated in neurotransmitter release. To probe the physiological importance of these interactions, we microinjected into the squid giant presynaptic terminal botulinum toxin C1, which cleaves syntaxin, and the H3 domain of syntaxin, which mediates binding to other proteins. Both reagents inhibited synaptic transmission yet did not affect the number or distribution of synaptic vesicles at the presynaptic active zone. Recombinant H3 domain inhibited the interactions between syntaxin and SNAP-25 that underlie the formation of stable SNARE complexes in vitro. These data support the notion that syntaxin-mediated SNARE complexes are necessary for docked synaptic vesicles to fuse.  相似文献   
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本文针对在进行空调系统冷热源方案优选时存在复杂性、模糊性和不确定性的问题,提出了一种基于离差最大化与灰色关联耦合的空调冷热源优选模型。模型依据方案在评价指标下各属性值之间的差异进行客观赋权,根据各方案与理想中最佳方案之间的关联度大小进行方案优选决策。通过在某工程项目空调冷热源优选中的应用,表明其计算简单、结果令人满意。  相似文献   
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Television texts around the world increasingly feature female characters who resist or reformulate conventional gender roles. This trend seems to defy expectations that the concentration of media ownership leads to a conservative, homogeneous flow of popular imagery. Such an apparent contradiction can be explained by close analysis of the strategies, operations, and discourse of culture industries in the neo-network era of satellite and cable media. This era is paradoxically characterized by corporate conglomeration and by strategies of flexibility and decentralization. Consequently, media firms actually benefit for the transnational circulation of multiple and alternative representations of feminine desire. Although this does not necessarily democratize media, in most societies it significantly expands the range of feminine imagery available in popular culture.  相似文献   
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The Association for Professionals in Infection Control and Epidemiology, Inc (APIC), is a multidisciplinary, voluntary, international organization of professionals who practice infection control and the application of epidemiology in all health settings. APIC is an international leader in prevention and control of infection transmission.  相似文献   
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