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21.
Current evidence on the effects of continuous positive airway pressure (CPAP) on cardiac mechanics in patients with obstructive sleep apnea (OSA) is based on a few single studies. The authors investigated this topic through a meta‐analysis of speckle tracking echocardiography (STE) studies that provided data on left ventricular (LV) and right ventricular (RV) mechanics as assessed by global longitudinal strain (GLS). The PubMed, OVID‐MEDLINE, and Cochrane library databases were systematically analyzed to search English‐language review papers published from inception to January 31, 2022. Studies were identified by crossing the following terms: “obstructive sleep apnea”, “sleep quality”, “sleep disordered breathing”, “continuous positive airway pressure therapy”, “noninvasive ventilation”, “left ventricular hypertrophy”, “systolic dysfunction”, “global longitudinal strain”, “left ventricular mechanics”, “right ventricular mechanics”, “echocardiography” and “STE echocardiography”. The meta‐analysis, including a total of 337 patients with OSA from nine studies (follow‐up 2–24 months) showed a significant GLS improvement in both LV and RV after CPAP, standard mean difference (SMD) being 0.51±0.08, CI:0.36–0.66, p = .0001 and 0.28±0.07, CI:0.15–0.42, p = .0001), respectively. Corresponding SMD values for LV ejection fraction (LVEF) and tricuspid annular plane systolic excursion (TAPSE) were 0.20±0.06, CI:0.08–0.33, p = .001 and 0.08±0.06, CI: ‐0.04/0.20, p = .21. Our meta‐analysis suggests that: I) CPAP treatment exerts beneficial effects on biventricular function in patients with OSA; II) the assessment of cardiac mechanics by STE should be routinely recommended for monitoring cardiac function in this setting, due to limitations of conventional echocardiography in evaluating biventricular performance.  相似文献   
22.
This paper analyses the characteristics of the mechanical behavior of a trussed steel and concrete box beam under bending conditions based on the structural stressing state theory and the numerical shape function method. Firstly, the parametric generalized strain energy density was introduced to characterize the structural stressing state of trussed steel stud concrete box girders, and the strain energy density sum was plotted. Then the Mann-Kendall criterion was used to discriminate the leap point of the curve change and to redefine the structural failure load. By analyzing the strain and displacement, the existence of a sudden change in the structural response during the load-bearing process was again demonstrated. Afterwards, the numerical shape function method was used to extend the strain data, and further in-depth analyses of strain/stress fields and internal forces were carried out to show in detail the working characteristics of each under load. Through an in-depth analysis from different angles, the rationality of updating the failure load was verified. Finally, the effects of different structure parameters on the evolution of the structural stresses of the members were analyzed in a transversal comparison. The analysis results of the stress state of a steel-concrete truss structure reveal the working behavior characteristics of a steel-concrete truss structure from a new angle, which provides a reference for the design of a steel-concrete truss structure in the future.  相似文献   
23.
目的:探讨超声弹性成像比值在评估隐睾下降固定术后睾丸功能恢复的应用价值。方法:纳入2018年6月~2020年12月在本院行单侧隐睾下降固定术的患儿43例为观察对象,分为术前组和术后组。所有患儿均在术前及术后6个月采集血清抑制素B水平、双侧睾丸体积、睾丸中部组织(C)比外周组织(P)的SR-C/P、SR-C(对)/C(患)和SR-P(对)/P(患)。对照组为50例相应年龄段的体检儿童,测得相应数据作为对照。分析比较各组间的数据差异。结果:术前组和对照组、术前组和术后组的患侧睾丸体积差异有统计学意义(P<0.05)。术前组和对照组、术前组和术后组的血清抑制素B水平差异有统计学意义(P<0.05)。术前组和对照组、术前组和术后组的SR(患)-C/P,以及术前组的SR(对)-C/P和SR(患)-C/P比较,差异均有统计学意义(P<0.05)。术后组的SR-C(对)/C(患)和SR-P(对)/P(患)比较,差异有统计学意义(P<0.05)。结论:隐睾下降固定术后患侧睾丸体积增加,且中部组织硬度明显降低,与外周组织对比度增加,与血清抑制素B水平相关性良好。超声弹性SR法可初...  相似文献   
24.
Background: The purpose of this study was to measure and compare the strain levels in the peri-implant bone as generated by the blade-like implant (BLI) and the screw-type implant (STI) with two different internal connections (hexagonal and conical) and with a 1:1 and 2:1 crown/implant (C/I) ratio. Methods: The implants (BLI and STI) were placed into sawbones according to the manufacturer’s protocol. Two strain gauges, horizontal and vertical to the implant axis, were placed around each implant on the bone surface 1 mm from the cervical part. Each implant was loaded by a material testing machine at a force of 100 N. Micro-strains (με) generated in the surrounding bone were measured by a strain gauge and recorded. Results: Recorded micro-strains were not significant in both the insertion and loading phases (p < 0.0625). The average recorded micro-strain values were lower in the horizontal dimension of STI with hexagonal connection when the C/I ratio was 2:1 compared with BLI, 210 με and 443 με, respectively. Conclusion: Within the limitations of this study, implant design, implant-abutment connection and C/I ratio did not influence strain values in bone and there is no statistically significant effect of these parameters on bone.  相似文献   
25.
Electrocatalytic conversion of carbon dioxide (CO2) into specific renewable fuels is an attractive way to mitigate the greenhouse effect and solve the energy crisis. AunCu100-n/C alloy nanoparticles (AunCu100−n/C NPs) with tunable compositions, a highly active crystal plane and a strained lattice were synthesized by the thermal solvent co-reduction method. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) results show that AunCu100−n/C catalysts display a subtle lattice strain and dominant (111) crystal plane, which can be adjusted by the alloy composition. Electrochemical results show that AunCu100−n/C alloy catalysts for CO2 reduction display high catalytic activity; in particular, the Faradaic efficiency of Au75Cu25/C is up to 92.6% for CO at −0.7 V (vs. the reversible hydrogen electrode), which is related to lattice shrinkage and the active facet. This research provides a new strategy with which to design strong and active nanoalloy catalysts with lattice mismatch and main active surfaces for CO2 reduction reaction.  相似文献   
26.
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has lasted for two years and caused millions of infections and deaths in humans. Although the origin of SARS-CoV-2 infection in humans remains unknown, infection in animals has been frequently reported in varieties of animals all over the world. Both experimental and natural infections of SARS-CoV-2 in different animal species provide useful information on viral host range and pathogenicity. As the pandemic continues to evolve, SARS-CoV-2 infection in animals will be expanding. In this review, we summarized SARS-CoV-2 testing and infection in animals as well as SARS-CoV-2 strains and transmission in animals. Current data showed that at least 18 different animal species tested positive for SARS-CoV-2. These 18 animal species belong to pet, captive, farmed, and wild animals. Fifteen of the eighteen animal species were known to be positive for the Delta variant and ten animal species were infected with two different types of variants. Human-to-animal, animal-to-animal, and animal-to-human transmission events were suggested in different outbreaks involved in animal infection with SARS-CoV-2. Continued testing, immunization, and surveillance are warranted.  相似文献   
27.
目的:研究视网膜母细胞瘤细胞株VEGFR-3的表达,探讨视网膜母细胞瘤自身增殖的机制.方法:选择Rb50细胞株,通过S-P免疫组化法、RT-PCR法及PCR产物琼脂糖凝胶电泳等方法,研究Rb50细胞株VEGFR-3的表达情况.结果:S-P免疫组化法呈阳性结果,表明Rb50细胞株有VEGFR-3的表达,RT-PCR产物琼脂糖凝胶电泳表明Rb50细胞株有较高水平VEGFR-3 mRNA的存在.结论:视网膜母细胞瘤细胞株有VEGFR-3的表达,表明VEGFR信息通路对视网膜母细胞瘤生长、浸润的影响,除了与促进肿瘤血管及淋巴管新生,改善肿瘤组织微环境相关外,还与促进肿瘤细胞自身增殖有关.  相似文献   
28.
目的从医学生理角度探讨多媒体教学对大学生视、听功能的影响。方法依据眼疲劳及耳疲劳的主要症状自行设计调查表,对2004级、2005级临床医学专业应用多媒体教学的班级进行调查分析。结果2004级、2005级均有部分学生报告有眼疲劳及耳疲劳症状。2004级2个班眼疲劳及耳疲劳发生情况对比各项指标差异无显著性;2005级2个班眼疲劳及耳疲劳发生情况对比各项指标差异也无显著性;2004级与2005级眼疲劳及耳疲劳发生情况对比,5项指标差异具有显著性,5项指标差异不具有显著性。结论多媒体教学对大学生视、听功能的影响不容忽视,要采取积极的预防措施。  相似文献   
29.
目的 构建稳定敲低MYH10基因的COS-7细胞株。方法 在293TX细胞中进行病毒的包装,用获得的高效价慢病毒感染COS-7细胞,通过免疫印迹和荧光显微镜,检测病毒感染后COS-7细胞MYH10蛋白表达的变化。结果 在构建的两种重组质粒中,MYH10-lentiviral shRNA-2在转染后表现出明显的干扰作用,感染后能明显下调COS-7细胞的MYH10蛋白表达。结论 病毒感染的COS-7细胞可明显抑制COS-7细胞内源MYH10的表达,说明了稳定敲低MYH10基因的COS-7细胞株的建立,为进一步研究MYH10在相关疾病中的功能奠定了基础。  相似文献   
30.
以卫生部颁布规范为基础进行我院抗菌药物管理信息系统设计和实施,并在此基础上结合医院信息系统和应用环境,实现了相应的信息系统功能及配套具备消息机制平台和抗菌药物控制细化扩展功能。经过近1年使用,建立了整合医院信息资源的平台,并利用其中的扩展功能为抗菌药物进一步深入管控做出了有益的探索。  相似文献   
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