Test and Microstructural Analysis of a Steel Slag Cement-Based Material Using the Response Surface Method

In this study, the silica fume replacement rate, fly ash replacement rate, and curing temperature were regarded as the independent variables, and the compressive and flexural strengths were regarded as the response values. The response surface method was used to construct the response surface polynomial regression model and obtain the optimal preparation parameters of a steel slag cement-based gel slurry (SCGS). The univariate and multivariate effects on the SCGS’s strength were investigated via analysis of variance and a three-dimensional surface model, and the hydration products and strength development law were characterized via scanning electron microscopy and X-ray diffraction. The actual compressive strengths at 3 and 28 d of age were 31.78 and 53.94 MPa, respectively, which were close to the predicted values (32.59 and 55.81 MPa, respectively), demonstrating that the optimized strengths were accurate and reliable. Further, the hydration reaction rate of SiO₂ in the silica fume and the physical filling effect of the inert components of fly ash and steel slag under the optimal parameters were the key factors for the early strength of the material. Moreover, continuous C₃S hydration in steel slag and the continuous excitation of the volcanic ash properties of fly ash were important factors for the later strength.     

Optimization of the assembly efficiency for lidamycin chromophore bound to its apoprotein: a case study using orthogonal array

Objective Lidamycin (LDM) can be dissociated to an apoprotein (LDP) and an active enediyne chromophore (AE).The detached AE can reassemble with its LDP‐containing fusion protein to endow the latter with potent antitumor activity.However,the reassembly of AE with LDP is affected by several factors.Our aim was to optimize the assembly efficiency of the AE with a LDP‐containing fusion protein and investigate the influence of several factors on the assembly efficacy.Methods A method based on RP‐HPLC was develop...     

农村妇儿肺通气功能免疫水平的配对分析

用配对比较的方法,探讨厨房位置和燃料不同对农村妇儿肺通气功能免疫水平的影响规律,结果是家庭月耗煤多的妇儿FEV1.0％、儿童唾液溶菌酶、血清IgG含量偏低;炉灶置宅内耗煤多的家庭儿童IgA含量偏高。说明合理布局厨房位置、设置排烟道及精选燃料,可大大改善室内空气质量,保护妇儿健康。     

葡萄球菌肠毒素A脂质体不良反应的初步研究

目的：观察葡萄球菌肠毒素A(staphylococcal enterotoxin A，SEA)脂质体的不良反应。方法：用逆相蒸发法制备SEA脂质体(L-SEA)，静脉注射L-SEA，用ELISA法检测小鼠血浆中细胞因子肿瘤坏死因子-α（TNF-α）、γ-干扰素(IFN-γ)的水平，并观察L—SEA对新西兰大白兔血压、呼吸及体温的影响。结果：L-SEA组小鼠血浆中细胞因子水平较游离SEA组显著降低，对新西兰大白兔血压、呼吸及体温的影响也明显低于游离SEA组。结论：L-SEA可以显著降低SEA的不良反应，其机制可能是L—SEA能减少血浆中细胞因子的产生。     

Arthroscopic Intra‐Articular Repair of the Torn Subscapularis Tendon with Single Anterior Portal,Single Suture Anchor,and X‐Shaped Fixation Technique

Subscapular tendon plays an important role in shoulder joint function. With the advance of magnetic resonance imaging technology and the popularization of arthroscopic shoulder surgery, subscapularis tears have been increasingly detected. However, reduction and fixation of subscapular tendon tears appears to be technically challenging. This study aims to describe an arthroscopic intra‐articular X‐shaped fixation technique: a procedure of subscapularis tendon repair performed with the aid of a suture passer using only a single anterior portal and a single suture anchor. By incorporating the advantages of a single anterior working portal for anchor placement and tear repair, this technique provides an easier way to use suture lasso and make knots in a limited working space, and the whole procedure is minimally invasive with a short learning curve. This technique has been applied in patients with subscapularis tears involving no intraoperative or postoperative complications. Our technology offers a valuable new treatment option for subscapularis tears.     

基础医学实验课程体系的建立与实践

目的探讨基础医学实验课程新体系的建立及实践效果。方法新的基础医学实验课程体系融合了20多门基础医学课程的实验内容,构建了人体形态学、人体功能学、显微结构学、病原生物学、细胞与分子生物学5个实验教学模块,将实验内容分3个层次设置,对实验教学方法和考核方式等进行了创新。结果基础医学实验教学课程新体系的建立,在实验教学实践中取得了显著的效果。结论新体系全面提高了实验教学水平和学生的综合素质。     

Underlying mechanisms of saphenous vein graft stenosis after coronary artery bypass caused by clipping of the side branches: an experimental study

BackgroundSaphenous veins are regular bypass conduits selected in non-left anterior descending artery (LAD) coronary artery bypass graft (CABG) surgery. Despite the technical errors, acute thrombosis, intimal hyperplasia and arteriosclerosis which could lead to saphenous vein graft (SVG) failure, the metal-clipping-related SVG failure is unique and rare. This study was conducted to investigate the clinical and underlying mechanisms of the metal-clipping-related SVG failure.MethodsWe collected 6 typical cases of the metal-clipping-related SVG failure in 41 patients who were diagnosed graft stenosis by coronary angiograph after CABG in the Department of Cardiology, Beijing Anzhen Hospital, from January 2020 to September 2021. Furthermore, we built an in vitro model to verify the identical intravascular ultrasound (IVUS) pattern of metal clip.ResultsThere were 6 in 41 cases of SVG stenosis caused by clipping of the side branches. We found that the stenosis of SVG caused by metal clipping mostly occurred at the corner and multipole clipping points. In this situation, great resistance could be felt when pushing the instruments through the stenosis and crystallized cholesterol was rarely caught by the distal protection device. We verified the similar IVUS pattern of metal clip at the side-branches of SVG in vitro.ConclusionsThe metal-clipping-related stenosis may lead to SVG failure. The stenosis of SVG caused by metal clipping mostly occurred at the corner and multipole clipping points. IVUS showed great modality for clarification.     

Deep Cryogenic Treatment Characteristics of a Deformation-Processed Cu-Ni-Co-Si Alloy

This paper investigated the influence of deep cryogenic treatments (DCT) on the tensile strength, elongation to fracture and conductivity of a deformation-processed Cu-Ni-Co-Si alloy. The tensile properties were measured using a mechanical testing machine. The conductivity was evaluated using a low-resistance tester. The microstructure and precipitated phases were analyzed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), an energy dispersive spectrometer (EDS) and an X-ray diffractometer (XRD). The tensile strength, elongation to fracture and conductivity of the Cu-1.34Ni-1.02Co-0.61Si alloy before and after cold rolling at 47% reduction increased with increasing DCT time and tended to be stable at about 36 h. The microstructure became more uniform after the DCT. The grain size was refined and was smallest after DCT for 48 h. The DCT promoted the precipitation of the solid solution elements Ni, Co and Si from the Cu matrix to form many fine and evenly distributed 20–70 nm spherical second-phase particles in the grains and grain boundaries.     

人体内肺癌细胞Ku80蛋白含量与顺铂化疗敏感性的关系研究

目的探讨患者体内肺癌细胞Ku80蛋白含量与其对顺铂敏感性的相关性。方法收集肺癌患者胸腔积液中的肺癌细胞进行体外原代培养,通过传代进行纯化和扩增后进行实验。体外药敏试验采用CCK-8法测定肺癌细胞对顺铂的敏感性,获得各样本的半数抑制浓度(IC50)。利用Western blot法测定各样本细胞内Ku80蛋白含量。分析Ku80蛋白含量与顺铂敏感性的相关性。结果非小细胞肺癌(NSCLC)组IC50为(4.40±3.39)mg/L,小细胞肺癌(SCLC)组IC50为(1.02±0.54)mg/L,二者比较差异有统计学意义(P0.001)。NSCLC组Ku80蛋白相对含量为0.80±0.45,而SCLC组为0.48±0.25,二组之间比较差异有统计学意义(P0.05)。通过相关性分析得到肺癌患者Ku80含量与IC50呈正相关(r=0.618,P0.001)。结论 NSCLC患者Ku80基因表达高于SCLC患者,可能与NSCLC对化疗敏感性差有关。肺癌细胞Ku80蛋白含量与其对顺铂敏感性呈负相关。Ku80蛋白含量可作为预测肺癌患者以铂类为基础的化疗敏感性的候选指标。     

超声引导与触脉结合在桡动脉穿刺置管中的应用

目的 评估超声引导结合传统触脉定位行桡动脉穿刺置管的临床效果.方法 选取解放军第四一一医院准备择期手术患者60例,ASA Ⅰ或Ⅱ级,年龄32 ～ 87岁,采用数字表法随机分为U、C2组,每组30人.U组:采用传统触脉定位结合超声引导下穿刺置管;C组:采用传统触脉盲探法穿刺置管.记录2组患者定位及准备时间、置管成功时间、一次成功率、总成功率、穿刺次数、失败率及血肿并发症发生率.结果 与传统触脉定位法相比,传统触脉定位结合超声引导法置管成功时间显著缩短(P＜0.01),一次成功率显著提高(P＜0.01),穿刺次数显著减少(P＜0.01).结论 超声引导与触脉结合下行桡动脉穿刺置管,穿刺时间短,一次成功率高,并发症发生率低,安全可靠.