Research on Dynamic Compressive Performance and Failure Mechanism Analysis of Concrete after High Temperature and Rapid Cooling

To investigate the dynamic compressive properties of concrete after high temperature and rapid cooling, an experimental study was carried out by considering five temperatures and four strain rates. The coupling effect of high temperature and strain rate on concrete damage morphology and mechanical parameters was comparatively analyzed. The main conclusions are as follows: the compressive damage morphology of concrete is affected by strain rate development trends of significant variability under different temperature conditions. As the strain rate increases, the compressive stress and elastic modulus of concrete are gradually increased. As the temperature increases, the increase in compressive stress is gradually reduced by the strain rate. For the temperatures of 20 °C and 800 °C, the increase in compressive stress by the strain rate is 38.69% and 7.78%, respectively. Meanwhile, SEM and CT scanning technology were applied to examine the mechanism of the effect of high temperature and strain rate on the mechanical properties of concrete from the microscopic perspective, and the corresponding constitutive model was proposed.     

Using a two-step method of surface mechanical attrition treatment and calcium ion implantation to promote the osteogenic activity of mesenchymal stem cells as well as biomineralization on a β-titanium surface

Surface treatment is known as a very efficient measure by which to modulate the surface properties of biomaterials in terms of grain structure, topography, roughness and chemistry to determine the osseointegration of implants. In this work, a two-step method of surface modification was employed to impart high osteogenic activity and biomineralization capacity on a Ti–25Nb–3Mo–2Sn–3Zr alloy (a type of β-titanium named TLM). The preliminary surface mechanical attrition treatment (SMAT) refined the average grain size from 170 ± 19 μm to 74 ± 8 nm in the TLM surface layer and promoted the surface to be much rougher and more hydrophilic. The subsequent Ca-ion implantation did not change the surface roughness and topography obviously, but enhanced the surface wettability of the SMAT-treated TLM alloy. The in vitro evaluations of the adhesion, proliferation, osteogenic genes (RUNX2, ALP, BMP-2, OPN, OCN and COL-I) and protein (ALP, OPN, OCN and COL-I) expressions, as well as extracellular matrix (ECM) mineralization of mesenchymal stem cells (MSCs) revealed that the initial SMAT-treated sample significantly enhanced the adhesion and osteogenic functions of MSCs compared to an untreated TLM sample, and the subsequent introduction of Ca ions onto the SMAT-derived nanograined sample further promotes the MSC adhesion, proliferation, osteo-differentiation and ECM mineralization due to the adsorption of more proteins such as laminin (Ln), fibronectin (Fn) and vitronectin (Vn) on the surface, as well as the increase in extracellular Ca concentrations. In addition, the biomineralization capacity of the samples was also evaluated by soaking them in simulated bodily fluid (SBF) at 37 °C for 28 days, and the results showed that the Ca-ion implanted sample significantly boosted the deposition of Ca and P containing minerals on its surface, which was associated with the generation of more Ti–OH groups on the surface after ion implantation. The combination of the SMAT technique and Ca-ion implantation thus endowed the TLM alloy with outstanding osteogenic and biomineralization properties, providing a potential means for its future use in the orthopedic field.

Combination of the SMAT technique and Ca-ion implantation produced a β-titanium alloy with a bioactive surface layer, which was proved to effectively promote the osteogenic activity of MSCs and Ca–P mineral deposition in vitro.     

Efficacy analysis of Cheng’s GIRAFFE reconstruction after proximal gastrectomy for adenocarcinoma of esophagogastric junction

ObjectiveReconstruction of the digestive tract for adenocarcinoma of esophagogastric junction (AEG) is in dispute. This study evaluated Cheng’s gastric tube interposition esophagogastrostomy with reconstruction of His angle and fundus (Cheng’s GIRAFFE anastomosis) in laparoscopic/open proximal gastrectomy for Siewert type II AEG, which was performed at Zhejiang Cancer Hospital and the First Affiliated Hospital of Zhejiang Chinese Medical University. Here, we discuss the preliminary results of gastric emptying and anti-reflux.MethodsFrom a retrospective database, 74 patients with advanced Siewert type II AEG underwent curative proximal gastrectomy with GIRAFFE anastomosis, and their gastric emptying and anti-reflux outcomes were evaluated by the Reflux Disease Questionnaire (RDQ) score, nuclide gastric emptying, 24-h impedance-pH monitoring and gastroscopy.ResultsSeventy-four patients successfully completed proximal partial gastrectomy with Cheng’s GIRAFFE esophagogastric anastomosis. RDQ score six months after the operation was 2.2±2.5. Results of nuclide gastric emptying examinations showed that the gastric half-emptying time was 67.0±21.5 min, the 1-h residual rate was (52.2±7.7)%, the 2-h residual rate was (36.4±5.1)%, and the 3-h residual rate was (28.8±3.6)%; 24-h impedance-pH monitoring revealed that the mean DeMeester score was 5.8±2.9. Reflux esophagitis was observed by gastroscopy in 7 patients six months after surgery.ConclusionsCheng’s GIRAFFE anastomosis is safe and feasible for Siewert type II AEG.     

灵芪胶囊对H22荷瘤小鼠p53和bcl-2蛋白表达的影响

目的：探讨灵芪胶囊对H22荷瘤小鼠的抑瘤作用及其抑瘤作用机制。方法：采用体内实验法,于无菌条件下抽取传代7d、生长良好的H22荷瘤小鼠腹水,无菌0．9％氯化钠溶液1：3稀释（约含瘤细胞2×10^6／ml）,按0．2ml／7,接种于消毒后的小鼠右前肢腋部皮下,制成肿瘤模型,灌胃给药灵芪胶囊11d后,称取小鼠体重,脱椎处死小鼠,取脾脏及胸腺称重并计算胸腺指数和脾脏指数。用免疫组化法检测各组凋亡相关基因突变型p53和bcl-2基因的表达。结果：灵芪胶囊在明显抑制肿瘤生长的同时不降低体重,在一定剂量对荷瘤动物的免疫器官指数无明显影响;灵芪胶囊三个剂量组突变型p53基因和bcl-2基N的表达均低于模型组。结论：灵芪胶囊对H22荷瘤小鼠有明显抑瘤作用,其机制可能与抑制突变型p53基N和bcl-2基因表达有关。     

妇科恶性肿瘤的时辰化疗进展

目的介绍近年来适用于妇科恶性肿瘤化疗的药物涉及时辰方案设计的研究成果,方法通过搜集并整理近年来国内外时辰化疗的相关临床和临床前试验的相关文献结果与结论应用时辰化疗理论,改进妇科肿瘤患者化疗方案和给药时间,可以有效降低化疗药物的毒副作用,较常规治疗具有优势,但不同人群、不同种族间的时辰依赖性是否存在差异,有待于进一步研究、     

损伤控制外科及加速康复外科理念在腹腔镜胃癌根治术中的应用

目的探讨损伤控制外科及加速康复外科理念在腹腔镜胃癌根治术中的应用价值。方法回顾性分析2013年2月-2014年2月实施腹腔镜胃癌根治术280例的临床资料,140例采用损伤控制外科及加速康复外科治疗方法作为观察组,140例采用传统治疗方法作为对照组,比较两组患者术后肛门通气时间、术后住院时间、住院费用和术后并发症发生情况。结果与对照组比较,观察组术后肛门通气早、术后住院时间短、住院费用降低（P〈0.05）,并不增加手术相关并发症的发生率（P〉0.05）。结论损伤控制外科及加速康复外科理念用于腹腔镜胃癌患者安全可行、有效,可加速患者的术后康复过程,与传统方法比较具有一定的优势,值得临床推广应用。     

奥扎格雷纳米结构脂质载体包封率的测定方法

目的:建立奥扎格雷纳米结构脂质载体(ozagrel-loaded nanostructured lipid carriers,OZ-NLC)包封率的测定方法。方法:分别采用超滤法、葡聚糖凝胶柱层析法、超速离心法分离游离药物,以紫外分光光度法测定奥扎格雷的含量,计算包封率。结果:超滤法和葡聚糖凝胶柱层析法可有效分离OZ-NLC与游离药物,两种方法的平均回收率分别为98.31%和97.15%,平均包封率为59.21%和61.11%。结论:葡聚糖凝胶柱层析法操作简便,结果可靠,重现性好,故选择该方法测定OZ-NLC的包封率。     

国产头孢三嗪对金葡菌,大肠杆菌及绿脓杆菌超微结构影响的观察

本文采用负染和超薄切片技术在电镜下的观察,研究了国产头孢三嗪在高浓度下和亚最低抑菌浓度下对金葡菌、大肠杆菌和绿脓杆菌超微结构的作用。结果显示,10MIC的头孢三嗪作用3小时即可导致细菌发生不可逆性改变,出现细胞膜皱缩,胞质稀疏,细胞膜连续性丧失,甚至细胞破裂,解体死亡。经Sub-MIC的头孢三嗪作用后,金葡菌呈现菌体增大,横膈增宽;而大肠杆菌和绿脓杆菌则表现为菌体增长和菌丝体形成,胞内出现大小不一的空泡,电子密度下降.本研究证实了头孢三嗪为一杀菌类抗生素;提示本药对细菌的形态学改变,主要由于和PBP_3结合所致。     

内生真菌SEF15927对截短侧耳素的微生物羟化研究

目的 研究植物内生真菌SEF15927对截短侧耳素的转化作用.方法 利用液体培养生长细胞对截短侧耳素进行生物转化.发酵液经乙酸乙酯萃取和硅胶柱层析分离获得一个羟化产物.运用质谱和核磁共振光谱鉴定结构.结果 转化产物为2-羟基截短侧耳素.结论 植物内生真菌SEF15927为一具有高转化率的截短侧耳素羟化菌株,