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1.
Tympanic membranes (TM) that have healed spontaneously after perforation present abnormalities in their structural and mechanical properties; i.e., they are thickened and abnormally dense. These changes result in a deterioration of middle ear (ME) sound transmission, which is clinically presented as a conductive hearing loss (CHL). To fully understand the ME sound transmission under TM pathological conditions, we created a gerbil model with a controlled 50% pars tensa perforation, which was left to heal spontaneously for up to 4 weeks (TM perforations had fully sealed after 2 weeks). After the recovery period, the ME sound transmission, both in the forward and reverse directions, was directly measured with two-tone stimulation. Measurements were performed at the input, the ossicular chain, and output of the ME system, i.e., at the TM, umbo, and scala vestibuli (SV) next to the stapes. We found that variations in ME transmission in forward and reverse directions were not symmetric. In the forward direction, the ME pressure gain decreased in a frequency-dependent manner, with smaller loss (within 10 dB) at low frequencies and more dramatic loss at high frequency regions. The loss pattern was mainly from the less efficient acoustical to mechanical coupling between the TM and umbo, with little changes along the ossicular chain. In the reverse direction, the variations in these ears are relatively smaller. Our results provide detailed functional observations that explain CHL seen in clinical patients with abnormal TM, e.g., caused by otitis media, that have healed spontaneously after perforation or post-tympanoplasty, especially at high frequencies. In addition, our data demonstrate that changes in distortion product otoacoustic emissions (DPOAEs) result from altered ME transmission in both the forward and reverse direction by a reduction of the effective stimulus levels and less efficient transfer of DPs from the ME into the ear canal. This confirms that DPOAEs can be used to assess both the health of the cochlea and the middle ear.  相似文献   
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AIDS and Behavior - Transactional sex increases HIV risk among adolescent girls and young women (AGYW). Understanding the individual and dyadic nature of transactional sex may provide evidence for...  相似文献   
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目的 探讨集束化干预策略联合闭环管理模式对ICU多重耐药菌感染的防控效果。方法选取2020年1~12月EICU住院患者275例作为对照组,实施常规管理;2021年1~10月EICU住院患者239例作为观察组,在常规管理基础上实施集束化干预策略联合闭环管理。结果实施后,观察组多重耐药菌感染发生率明显低于对照组;患者住院日显著低于对照组,4项护理措施执行率(隔离标识、手卫生、环境消毒、医务人员相关知识知晓)、病原学送检率显著高于对照组(均P<0.05)。结论集束化干预联合信息化闭环管理可有效降低EICU多重耐药菌感染发生率。  相似文献   
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Obesogens are a subset of endocrine disruptor chemicals (EDCs) that cause obesity. The typical EDC 4-nonylphenol (4-NP) has been identified as an obesogen. However, the in vitro effects of 4-NP on adipogenesis remain unclear. In this study, 3T3-L1 preadipocytes and C3H/10T1/2 mesenchymal stem cells (MSCs) were used to investigate the influence of 4-NP on adipogenesis. The differentiation protocols for 3T3-L1 preadipocytes and C3H/10T1/2 MSCs took 8 and 12 days, respectively, beginning at Day 0. In differentiated 3T3-L1 preadipocytes, 20 μM 4-NP decreased cell viability on Days 4 and 8. Exposure to 4-NP inhibited triglyceride (TG) accumulation and adipogenic marker expression on Days 0–8, but the inhibitory effects were weaker on Days 2–8. The protein expression of pSTAT3 or STAT3 decreased on Days 0–8 and 2–8. Conversely, 4-NP promoted TG accumulation and the adipogenic marker expression in C3H/10T1/2 adipocytes. The opposing effects were attributed to physiological differences between the two cell lines. The 3T3-L1 preadipocytes are dependent on mitotic clonal expansion (MCE) to drive differentiation, while C3H/10T1/2MSCs and human preadipocytes are not. Additionally, 4-NP downregulated β-catenin expression in C3H/10T1/2 adipocytes. Accordingly, we hypothesized that 4-NP promotes adipogenesis. The role of the canonical Wnt pathway in the promotion of adipogenesis by 4-NP requires further validation. This study provides new insights into the mechanisms and appropriate risk management of 4-NP.  相似文献   
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目的:医疗服务价格改革对完善医疗服务合理定价,合理体现医务人员劳务价值,提高医务人员薪酬水平具有重要意义。方法:基于利益传导的视角,以医务人员劳务价值的体现为中介,采用定量研究方法,实证检验医疗服务价格对医务人员薪酬水平的影响。结果:医疗费用规模对医务人员薪酬水平有着显著的正向影响,但在门诊医疗和住院医疗二者间存在异质性,主要体现在劳务价值在医疗费用中的差异方面。结论:应持续深化医疗服务价格改革,提高医务人员薪酬水平。  相似文献   
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我国最新居民致残和致死调查报告显示,卒中发病率高居首位,虽然近几年卒中致死率较前下降,但是因为疾病的致残性及后续康复带来的巨大社会支出,对卒中的探索及相关研究依然刻不容缓。急性缺血性卒中(acute ischemic stroke,AIS)占所有卒中的85%,醒后卒中(wake-up stroke,WUS)又占其中的20%左右。因在睡眠中发病,故具体发病时间不详。事实上,很多患者疾病发生在醒来前的很短时间,但治疗上却错失了溶栓或血管内治疗的机会,最终导致预后不良。目前针对WUS发病时间的研究越来越多,其中通过影像学手段推测WUS的发病时间指导其治疗尤为热门。本文对WUS的近期影像学研究进展作一综述。  相似文献   
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