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21.
The problem of poor reproducibility of scientific findings has received much attention over recent years, in a variety of fields including psychology and neuroscience. The problem has been partly attributed to publication bias and unwanted practices such as p-hacking. Low statistical power in individual studies is also understood to be an important factor. In a recent multisite collaborative study, we mapped brain anatomical left–right asymmetries for regional measures of surface area and cortical thickness, in 99 MRI datasets from around the world, for a total of over 17,000 participants. In the present study, we revisited these hemispheric effects from the perspective of reproducibility. Within each dataset, we considered that an effect had been reproduced when it matched the meta-analytic effect from the 98 other datasets, in terms of effect direction and significance threshold. In this sense, the results within each dataset were viewed as coming from separate studies in an “ideal publishing environment,” that is, free from selective reporting and p hacking. We found an average reproducibility rate of 63.2% (SD = 22.9%, min = 22.2%, max = 97.0%). As expected, reproducibility was higher for larger effects and in larger datasets. Reproducibility was not obviously related to the age of participants, scanner field strength, FreeSurfer software version, cortical regional measurement reliability, or regional size. These findings constitute an empirical illustration of reproducibility in the absence of publication bias or p hacking, when assessing realistic biological effects in heterogeneous neuroscience data, and given typically-used sample sizes. 相似文献
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目的:研究孤立性肺结节(SPN)胸腔镜术前CT引导下双弹簧圈精准标记定位的应用价值。方法:回顾分析43例SPN胸腔镜术前定位病例资料,包括双弹簧圈组22例,Hook-wire定位组21例。统计双弹簧圈定位的术中、术后并发症,衔接期时间以及作楔形切除所用时间,并将两组结果进行对比分析。结果:两组病例定位均取得成功;双弹簧圈组的气胸发生率(9.0%),肺出血发生率(9.0%),胸痛发生率(9.0%)均低于Hook-wire组,其中肺出血发生率与Hook-wire组比较,差异有统计学意义(P<0.01);衔接时间双弹簧圈组(15.38±8.32)h长于Hook-wire组(4.21±3.29)h,差异有统计学意义(P<0.05);作楔形切除所用时间双弹簧圈组(21.01±7.14)min与Hook-wire组(18.22±5.18)min差异无统计学意义(P>0.05)。结论:采用双微弹簧圈进行SPN胸腔镜手术前精准标记定位安全可靠、效果良好,与Hook-wire定位比较并发症发生率更低,并可获得更长的衔接期,具有较高的应用价值。 相似文献
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目的:检测非小细胞肺癌(NSCLC)组织中闭合蛋白(Occludin)的表达水平及其临床意义。方法:应用免疫组织化学方法检测73例NSCLC组织及其配对正常肺组织中Occludin蛋白表达水平,分析Occludin蛋白的表达差异及其与临床病理参数的相关性。结果:Occludin蛋白在肿瘤组织中的阳性表达率显著低于配对正常肺组织(P<0.05)。Occludin蛋白的表达水平与患者性别、肿瘤大小、淋巴结转移、组织学类型、Ki-67表达水平显著相关。结论:Occludin蛋白表达下调与NSCLC细胞的增殖、转移能力相关,在肿瘤进展中发挥重要作用。 相似文献
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目的:探讨不同温度、速度肠内营养(enteral nutrition,EN)液输注对患者胃肠道并发症的影响.方法:将240例进行EN的患者根据使用加温营养泵与否,分为观察组与对照组,各120例.同时将观察组再根据营养泵给液速度,分为01、02、03 3组,对照组也根据以上方法,分为C1、C2、C3 3组,每组40例.01、C1组EN泵给液速度为60-70 mL/h,02、C2组EN泵给液速80-100 mL/h,03、C3组EN泵给液速度为110-120 mL/h.观察各组患者胃肠道并发症的发生情况.结果:观察组与对照组在胃肠道并发症发生率、胃潴留发生情况、EN时间方面比较差异有统计学意义;同时,不同的输注速度在上述方面比较差异有统计学意义.结论:通过使用加温营养泵,温度控制在37℃-40℃,且输注速度在80-100 mL/h时可有效减少胃肠道并发症的发生,达到临床满意的效果,值得临床推广应用. 相似文献
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Man-Qing Liu Min Zhao Wen-Hua Kong Jin-Song Peng Fang Wang Hong-Yan Qiu Ze-Rong Zhu Li Tang Ming Sang Jian-Guo Wu Wen-Zhe Ho Wang Zhou 《Medicine》2015,94(46)
A number of cellular microRNAs (miRNAs) have been identified to have the ability to inhibit HIV-1 replication. In this study, we examined the impact of combination antiretroviral therapy (cART) on the expression of HIV-1 restriction miRNAs in peripheral blood mononuclear cells of HIV-1–infected men who have sex with men (MSM). Compared with male healthy donors, HIV-infected MSM had significantly lower levels of 9 HIV-1 restriction miRNAs. The treatment of HIV-1–infected MSM with cART, however, failed to restore the levels of these miRNAs in peripheral blood mononuclear cells. These observations suggest that the suppression of the cellular restriction miRNAs by HIV-1 may attribute to the virus latency during cART. 相似文献
27.
Spherical MCM-48 mesoporous sieve co-doped with vanadium and iron was successfully synthesized via one-step hydrothermal method. The material was characterized by X-ray diffraction (XRD), nitrogen adsorption-desorption isotherms, inductively coupled plasma (ICP), scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance UV-vis spectra, and X-ray photoelectron spectra (XPS) techniques. Results indicated that the V-Fe-MCM-48 showed an ordered 3D cubic mesostructure with spherical morphology, narrow pore size distribution and high specific surface area. Most of vanadium and iron atoms existing as tetrahedral V4+ and Fe3+ species were co-doped into the silicate framework. The particle sizes of V-Fe-MCM-48 were smaller and the specific area was much higher than those of of V-MCM-48. Additionally, the synthesized V-Fe-MCM-48 exhibited improved hydrothermal stability compared with the pure MCM-48. 相似文献
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A homogenization-based five-step multi-scale finite element (FsMsFE) simulation framework is developed to describe the time-temperature-dependent viscoelastic behavior of 3D braided four-directional composites. The current analysis was performed via three-scale finite element models, the fiber/matrix (microscopic) representative unit cell (RUC) model, the yarn/matrix (mesoscopic) representative unit cell model, and the macroscopic solid model with homogeneous property. Coupling the time-temperature equivalence principle, multi-phase finite element approach, Laplace transformation and Prony series fitting technology, the character of the stress relaxation behaviors at three scales subject to variation in temperature is investigated, and the equivalent time-dependent thermal expansion coefficients (TTEC), the equivalent time-dependent thermal relaxation modulus (TTRM) under micro-scale and meso-scale were predicted. Furthermore, the impacts of temperature, structural parameters and relaxation time on the time-dependent thermo-viscoelastic properties of 3D braided four-directional composites were studied. 相似文献