胶质细胞源性神经营养因子对培养的胚鼠脑室下区神经干细胞表达Pitx3及酪氨酸羟化酶的影响

目的:观察胶质细胞源性神经营养因子(GDNF)对培养的胚鼠脑室下区(SVZ)神经干细胞(NSCs)表达Pitx3、酪氨酸羟化酶(TH)的影响。方法:取胚鼠SVZ组织,进行细胞培养。分为GDNF NSCs共培养组和NSCs单独培养对照组。用Pitx3、TH、Pitx3/TH免疫荧光单标和双标及Nestin免疫组化法进行检测。结果:共培养组5 d时形成神经球,10 d时球体积不断增大,12 d后开始贴壁生长,并向四周伸出突起并开始分化。对照组神经球明显少于共培养组。14 d共培养组Pitx3、TH、Pitx3/TH阳性细胞明显高于对照组。结论:GDNF能上调SVZ区NSCs表达Pitx3和TH,诱导NSCs向多巴胺(DA)能神经元分化。     

发现于炎症区域分子1在实验性大鼠肺纤维化组织中的表达及意义

目的研究发现于炎症区域分子1(FIZZ1)在大鼠肺纤维化组织中的表达及意义。方法 10只SpragueDawley大鼠随机分为模型组和对照组,每组5只。大鼠采用气管内注入博来霉素(5 mg·kg-1)的方法复制大鼠肺纤维化模型(模型组);采用气管内注入生理盐水(1.25 mL·kg-1)的方法制造阴性对照(对照组)。第28天处死大鼠,肺组织病理切片行苏木精-伊红染色,Ashcroft评分评定大鼠肺组织纤维化的严重程度;免疫组织化学方法检测大鼠FIZZ1和转化生长因子-β1(TGF-β1)的表达。结果模型组大鼠肺纤维化程度较对照组严重,Ashcroft评分比较差异有统计学意义(P<0.01);模型组大鼠FIZZ1和TGF-β1表达水平较对照组升高,差异有统计学意义(P<0.01)。结论 FIZZ1在肺纤维化发病机制中起重要作用,可能与TGF-β1的高表达有关。     

Substituting Resistance Spot Welding with Flexible Laser Spot Welding to Join Ultra-Thin Foil of Inconel 718 to Thick 410 Steel

This paper investigated various aspects of replacing existing micro-resistance spot welding (micro-RSW) with micro-laser spot welding for joining Inconel 718 thin foils to thick 410 steel stack-up to allow faster, non-contact joining together with flexibility in spot positioning and removal of tip dressing required for RSW electrodes. The joint quality was evaluated based on the mechanical strength, microstructural characteristics and joint strength at elevated temperature as these joints are often used for high-temperature applications. Experimental investigations were performed using micro-RSW and micro-laser spot welding to obtain the 90° peel and lap shear specimens, each comprising four spots. The obtained strength from laser joints was significantly higher than that of micro-RSW joints due to larger weld nugget formation and interface width. The process map for obtaining good quality welds was also identified, and about a 17% reduction in joint strength was obtained when welded specimens were subjected to elevated temperature (i.e., 500 °C) in comparison with room temperature. This reduction was compensated for using the flexibility of laser welding to add two extra spots. The overall performance of the micro-laser spot welds was found to be better than the micro-RSW considering joint strength, flexibility in placing the spots and time to produce the welds.     

川芎嗪对成年大鼠局灶性脑缺血后海马齿状回细胞增殖的作用

目的 观察川芎嗪对成年大鼠局灶性脑缺血后海马齿状回颗粒下区（SGZ）细胞增殖的作用。方法 线栓法制作大鼠左侧大脑中动脉阻塞模型，术后2h腹腔注射川芎嗪（80mg／kg，1次／d），术后4h腹腔注射BrdU（50mg／kg，1次／d），分别于缺血7、14、21d采用免疫组织化学染色观察海马SGZ BrdU阳性细胞数。结果 脑缺血7d，缺血同侧SGZ BrdU阳性细胞较假手术组明显增多，14d达峰值，21d减少（P〈0．01）。川芎嗪组7d时，缺血同侧SGZ BrdU阳性细胞亦明显增多，并随着缺血时间延长明显增加：与缺血模型组比较，川芎嗪组7、14和21d，缺血同侧SGZ BrdU阳性细胞数均增加显著（P〈0．01），至21d仍保持高水平。结论 川芎嗪对成年大鼠局灶性脑缺血后海马SGZ的细胞增殖可能有持续促进作用。     

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.     

移行区指数作为良性前列腺增生的预测指标

目的：探讨经直肠超声(TRUS)测量的前列腺移行区与国际前列腺症状评分(IPSS)、最大尿流率(Qmax)及残余尿量(PVR)之间的关系，以及移行区指数(TZI)在评估良性前列腺增生(BPH)中的价值。方法：286例BPH患者进行IPSS评分、Qmax及PVR测量，TRUS测量前列腺体积(TPV)及移行区体积(TZV)，计算移行区指数(TZI=TZV／TPV)。结果：TPV与IPSS(r=0．092，P＞0．05)、Qmax(r=-0．125，P＞0．05)、PVR(r=0．426，P＞0．001)之间均无显著相关性;TZV与IPSS(r=0．385，P＜0．01)、Qmax(r＝-0．412，P＜0．001)、PVR(r=0．426，P＜0．001)之间有显著相关性。TZI与IPSS(r=0．436，P＜0．001)、Qmax(r=-0．534，P＜0．001)、PVR(r=0．528，P＜0．001)之间有显著相关性。TZI＞0．50的患者与TZI＜0．50的患者相比，IRSS、Qmax及PVR差异有显著性(P＜0．01)。结论：移行区指数与BPH的症状相关，且可有效评估梗阻的严重程度。     

一种在体标记成体大鼠室管膜/室下区细胞的方法

目的 研究正常成体大鼠侧脑室注射DiI标记室管膜/室下区(SVZ)细胞的方法.方法 50只雄性SD大鼠随机分为5组,每组10只,均接受2 g/L的 DiI 10 μL右侧脑室注射.采用H33258染色和激光共聚焦显微镜检测DiI注射后6 h、12 h、24 h、36 h和48 h时左侧脑室壁的标记细胞以及标记组织厚度.结论 右侧脑室DiI注射后24 h,DiI标记细胞位于左侧脑室的室管膜层; DiI注射后48 h,DiI标记细胞限定于左侧室的管膜层和室下区.此外,左侧室管膜/中隔室下区(SVZspt)和室管膜/神经节隆起的生后对应物(SVZge)部位荧光标记组织的厚度分别在DiI注射12 h和24 h后维持于稳定水平,而且,在相应各时间点上,室管膜/SVZge部位荧光标记组织的厚度都厚于室管膜/SVZspt部位(P＜0.05).结论 2 g/L 的DiI 10 μL注射于正常大鼠侧脑室后24～48 h,可能仅标记室管膜/室下区细胞.     

不同程度近视患者SMILE术后有效光学区的研究

目的：探究不同程度近视患者飞秒激光小切口角膜基质透镜取出术(SMILE)术后有效光学区(EOZ)的变化情况及其影响因素。

方法：回顾性研究。选择2019-10/2020-10于南昌大学附属眼科医院接受SMILE手术且术前光学区直径设计为6.5mm的近视患者50例92眼。根据术前等效球镜度数(SE)进行分组，低度近视组：-0.50D-6.00D 12例22眼。收集3组患者术前，术后3mo裸眼视力、最佳矫正视力、SE、光学区直径、角膜Q值及高阶像差。

结果：低、中及高度近视组患者术后3mo EOZ分别为5.07±0.69、5.08±0.43、4.50±0.58mm； 角膜Q值分别为0.22±0.17、0.57±0.34、0.63±0.73，三组间比较差异均有统计学意义(P<0.05)。三组患者术后EOZ直径均低于术前的6.5mm预计光学区(P<0.001)。三组患者术后角膜总高阶像差、球差、垂直彗差比较有差异(P<0.05)。SMILE术后EOZ直径与术前SE、剩余角膜基质床厚度均呈正相关(r=0.357、0.275，均P<0.05)，与中央角膜切削深度、术后角膜Q值均呈负相关(r=-0.316、-0.353，均P<0.05)，术后3mo角膜球差变化量与EOZ变化量成负相关(r=-0.336，P<0.05)。

结论：SMILE术后EOZ均低于术前预计光学区，且术前SE越高，术后光学区越小，术后角膜球差增加越多。另外，角膜切削深度、剩余角膜基质床厚度、角膜非球面性改变均可影响术后EOZ大小。