慢性心力衰竭的CT表现

目的:探讨慢性心力衰竭的CT表现。材料和方法:回顾性分析28例慢性心力衰竭的CT表现。结果:左心室增大16例、右心室增大8例、左心房增大6例、右心房增大4例,左、右心房增大3例,肺水肿24例、胸腔积液25例、肺动脉扩张3例、升主动脉扩张5例和冠状动脉钙化7例。左心衰CT示肺水肿、左心室扩大和胸腔积液。右心衰CT示右心室扩大、主肺动脉扩张和胸腔积液。全心衰竭CT示左右心室扩大,肺水肿和双侧胸腔积液。结论:CT可显示心脏各房室扩大、大动脉扩张、肺水肿、胸腔和心包积液以及冠状动脉钙化,为诊断原发心脏疾病及慢性心力衰竭提供重要依据。     

GeneXpert MTB/RIF系统对结核病诊断价值的回顾性分析

目的 回顾性分析GeneXpert MTB/RIF结核分枝杆菌鉴定对结核病诊断的应用价值.方法 收集2020年1-5月进行GeneXpert MTB/RIF结核分枝杆菌鉴定的住院患者669例,与抗酸染色镜检、结核菌素试验、结核分枝杆菌免疫球蛋白(Ig)G抗体检测、罗氏培养法、结核分枝杆菌基因(TB-DNA)扩增检测、γ-干扰素释放(IGRA)试验的检测结果进行对比分析,评估灵敏度、特异度、阳性预测值、阴性预测值等指标.结果 GeneX-pert MTB/RIF试验的灵敏度为53.98％,与IGRA试验(83.33％)和结核菌素试验(38.89％)比较,差异无统计学意义(P>0.05),但高于结核分枝杆菌IgG抗体检测(13.33％)、TB-DNA扩增检测(25.93％)和抗酸染色镜检(8.11％),差异有统计学意义(P<0.05).GeneXpert MTB/RIF试验的特异度为99.64％,与罗氏培养法(100.00％)、TB-DNA扩增检测(100.00％)、抗酸染色镜检(99.64％)比较,差异无统计学意义(P>0.05),但高于IGRA试验(51.72％)、结核菌素试验(66.67％)和结核分枝杆菌IgG抗体检测(80.39％),差异有统计学意义(P<0.05).结论 GeneXpert MTB/RIF试验具有较高的灵敏度和特异度,可作为结核病确诊依据.     

Statistical planning in confirmatory clinical trials with multiple treatment groups,multiple visits,and multiple endpoints

ABSTRACT

Multiplicity issues can be multidimensional: A confirmatory clinical trial may be designed to have efficacy assessed with two or more primary endpoints, for multiple dose groups, and at several post-baseline visits. Controlling for multiplicity in this situation is challenging because there can be a hierarchy with respect to some but not all measurements. If the higher dose is considered more efficacious, multiplicity approach may evaluate the higher dose with higher priority through a fixed sequential testing framework for dose assessments in combination with a Hochberg approach for endpoints. The lower dose is only assessed when the higher dose has significant results, which reduces the power for detecting signals in the lower dose group. However, in some instances the higher dose may associate with tolerability or safety concerns that preclude regulatory approval. A real confirmatory clinical trial with such challenges is provided as an illustrative example. We discuss closed testing procedures based on multi-way averages of comparisons for this complex multiplicity situation through illustrative case analyses and a simulation study. Such strategies manage the higher dose and the lower dose with equal priority, and they enable evaluation of the multiple endpoints at multiple visits collectively with power being reasonably high.     

3种不同材料修复无髓年轻第一恒磨牙的临床研究

目的:比较三种材料修复无髓年轻第一恒磨牙的临床效果.方法:275颗无髓并大面积牙体组织缺损的年轻第一恒磨牙分为3组,1组(93颗)采用树脂充填;2组(90颗)采用E-max高嵌体修复;3组(92颗)采用VITA enamic高嵌体修复;在修复后按照改良USPHS标准评价各组修复效果.结果:6个月随访:3组修复体修复效果...     

Rho and ROCK signaling in VEGF-induced microvascular endothelial hyperpermeability

OBJECTIVES: Vascular endothelial growth factor (VEGF) plays an important role in the regulation of microvascular permeability under various physiological and pathological conditions. The authors tested the hypothesis that the small GTPase Rho and its downstream effector ROCK (Rho-associated coiled-coil-containing protein kinase) mediate VEGF-induced increases in venular permeability. They also investigated myosin light chain (MLC) phosphorylation and actin polymerization, two well-characterized targets of the Rho-ROCK pathway that are implicated in the regulation of endothelial barrier function. METHODS: The apparent permeability coefficient of albumin (P(a)) was measured in intact isolated porcine coronary venules and in cultured coronary venular endothelial cell (CVEC) monolayers. RhoA activation was determined using a Rhotekin-agarose pull down assay. MLC phosphorylation was evaluated by immunoblotting with phospho-specific antibodies, and endothelial cellular F-actin was viewed using fluorescence microscopy. RESULTS: VEGF increased P(a) in both isolated coronary venules and CVEC monolayers. The hyperpermeability response occurred in a similar time course to that of Rho activation, MLC phosphorylation, and actin stress fiber formation. Selective blockage of ROCK with Y27632 dose-dependently inhibited VEGF-induced venular hyperpermeability. Moreover, inhibition of either Rho with exoenzyme C3 or ROCK with Y-27632 attenuated VEGF-induced increases in permeability, MLC phosphorylation, and actin-stress fiber formation in CVEC monolayers. CONCLUSIONS: Collectively, these findings suggest that the Rho-ROCK signal pathway contributes to VEGF-induced hyperpermeability. Myosin light-chain phosphorylation and actin stress fiber formation occur concomitantly with the increase in permeability upon VEGF stimulation.     

孕酮诱导的蜕膜蛋白Depp在哺乳细胞株的转染表达与定位

目的 将孕酮诱导的蜕膜蛋白Depp基因构建到pCDGFP表达载体中,分析其在哺乳细胞株中的表达和定位情况.方法 用PCR方法扩增Depp全长序列,插入真核表达载体pCDGFP中,将构建好的质粒转染至COS7细胞,在荧光显微镜下观察其细胞定位;转染至HEK 293T细胞,提取总蛋白,利用GFP抗体进行Western bl...     

A Study on the Relationships between Water Film Thickness,Fresh Properties,and Mechanical Properties of Cement Paste Containing Superfine Basalt Powder (SB)

In this paper, the effect of a newly developed superfine basalt powder (SB) on the fresh and mechanical properties of cement paste was studied. The concept of water film thickness (WFT) was cited to explain the influence of SB on fresh and mechanical properties and related mathematical model formulas were established. In addition, the relationship between the fresh properties and mechanical properties of paste was also explored. The results indicated that SB can improve the segregation resistance and cohesiveness. The maximum improvement rate relative to the control cement paste was 75.4% and 50.4%, respectively. The 5% SB and 10% SB reduced the fluidity in the range of 4.1–68.7% but increased the early and late compressive strength in the range of 1.2–25.7% compared to control cement paste under different water/cementitious materials (W/CM) ratios. However, the influence of 20% SB on fluidity and compressive strength was opposite to the above behavior, and the increase rate and decrease rate were 1.8–11.8% and 1.1–13.9% respectively. The WFT was the most important factor that determined the compressive strength, rheological parameters, and flow parameters of paste containing SB, while the substitute content of SB and WFT together determined the bleeding rate and cohesiveness. Among them, the correlation between bleeding rate and WFT increased with time. The empirical mathematical models between WFT, fresh properties, and compressive strength were established and verified by other mineral admixtures, which were successfully extended and applied to the entire field of cement-based materials.     

Degradation Mechanism and Numerical Simulation of Pervious Concrete under Salt Freezing-Thawing Cycle

In order to explore the occurrence area of pervious concrete freeze-thaw deterioration, the mass loss, strength deterioration, ultrasonic longitudinal wave velocity and dynamic elastic modulus attenuation of pervious concrete under freeze-thaw cycles were measured, and a prediction model of freeze-thaw damage was established. The mechanical properties of hardened cement pastes with the same W/C ratio under freeze-thaw cycles were also measured. Mercury intrusion porosimetry (MIP) was used to measure the pore structure characteristic parameters and pore size distribution changes of cement paste under freeze-thaw cycle, and the microstructure evolution of interfacial transition zone (ITZ) of paste and aggregate was observed by SEM scanning electron microscopy. Finally, a pervious concrete model was established by DEM to analyze the relationship between the number of freeze-thaw cycles and the mesoscopic parameters. The results indicated that the quality, strength and dynamic elastic modulus of pervious concrete deteriorate to different degrees under the conditions of water freezing and salt freezing. The damage sensitivity and strength loss of freeze-thaw damage is greater than the dynamic elastic modulus loss, which is greater than mass loss. In the pervious concrete paste which underwent 100 freeze-thaw cycles, the pore structure and macro strength had no obvious change, and hardened paste and the aggregate-interface-generated defects increased with the increase in freezing and thawing times, indicating that the deterioration of pervious concrete performance under freeze-thaw cycles was closely related to the deterioration of the interface strength of the aggregate and hardened paste. The pervious concrete model established by DEM can accurately simulate the change of the compressive modulus and the strength of pervious concrete during freeze-thaw cycles.     

胸外科储备人才培养的初步探究

本研究以广州医科大学临床医学南山班为基础,成立以兴趣为导向的胸外科学习协作组。实施以早临床、早科研、英语培优计划、以胸外科协作组为核心的多学科诊疗（multiple disciplinary team,MDT）学习协作、裸眼3D胸腔镜系统下加速临床技能培训、新媒体微信公众号运营下推送科研进展培养科研思维等手段对入选学生进行全方位培养。2013至2017级共10位本科生招募进胸外科学习协作组,招募组员在临床技能、科研、升学方面都显示出一定的优势。说明将部分胸外科临床教学与科研思维的培养提前下沉至本科生教育,可以为胸外科储备人才的培养做铺垫,将来可以制定更加详细和个性化的方案因材施教。