Study on the Design,Preparation, and Performance Evaluation of Heat-Resistant Interlayer-Polyimide-Resin-Based Neutron-Shielding Materials

Polymers have an excellent effect in terms of moderating fast neutrons with rich hydrogen and carbon, which plays an indispensable role in shielding devices. As the shielding of neutrons is typically accompanied by the generation of γ-rays, shielding materials are developed from monomers to multi-component composites, multi-layer structures, and even complex structures. In this paper, based on the typical multilayer structure, the integrated design of the shield component structure and the preparation and performance evaluation of the materials is carried out based on the design sample of the heat-resistant lightweight polymer-based interlayer. Through calculation, the component structure of the polymer-based materials and the three-layer thickness of the shield are obtained. The mass fraction of boron carbide accounts for 11% of the polymer-based material. Since the polymer-based material is the weak link of heat resistance of the multilayer shield, in terms of material selection and modification, the B₄C/TiO₂/polyimide molded plate was prepared by the hot-pressing method, and characterization analysis was conducted for its structure and properties. The results show that the ball milling method can mix the materials well and realize the uniform dispersion of B₄C and TiO₂ in the polyimide matrices. Boron carbide particles are evenly distributed in the material. Except for Ti, the other elemental content of the selected areas for mapping is in good agreement with the theoretical values of the elemental content of the system. The prepared B₄C/TiO₂/polyimide molded plate presents excellent thermal properties, and its glass transition temperature and initial thermal decomposition temperature are as high as 363.6 °C and 572.8 °C, respectively. In addition, the molded plate has good toughness performs well in compression resistance, shock resistance, and thermal aging resistance, which allows it to be used for a long time under 300 °C. Finally, the prepared materials are tested experimentally on an americium beryllium neutron source. The experimental results match the simulation results well.     

脑卒中后吞咽障碍患者“互联网+延续护理”实施障碍的质性研究

目的 了解脑卒中后吞咽障碍患者“互联网+延续护理”实施障碍因素,为针对性干预提供参考。方法 以理论域框架为指导制定访谈提纲,对25名医护技人员进行半结构式访谈,运用主题分析法分析资料、提炼主题（障碍因素）。结果 提炼出医护技人员缺乏劳动价值获得感、缺乏自我效能感,患者吞咽障碍康复行为欠佳等14个主题（障碍因素）,分别归属为社会/职业角色和身份,能力信念,记忆、注意力与决策过程,环境与资源以及社会影响5个理论域。结论 脑卒中后吞咽障碍患者“互联网+延续护理”实施的障碍因素较多,应针对障碍因素进行干预,创造有利条件为患者提供持续的高品质康复护理。     

脊柱侧凸患者的肺功能评价

对１０５例脊柱侧凸患者的肺功能进行检测和分析。结果表明，脊柱侧凸可引起限制型的肺通气功能障碍，肺功能减退与畸形的严重程度呈显著负相关；上胸段曲度对肺功能影响最大，下胸段曲度次之，腰段曲度影响甚微；侧凸类型对肺功能影响不明显。     

Correlation of oxygen free radical items between blood and kidney of chronic renal failure rat

Ｃｏｒｒｅｌａｔｉｏｎｏｆｏｘｙｇｅｎｆｒｅｅｒａｄｉｃａｌｉｔｅｍｓｂｅｔｗｅｅｎｂｌｏｏｄａｎｄｋｉｄｎｅｙｏｆｃｈｒｏｎｉｃｒｅｎａｌｆａｉｌｕｒｅｒａｔ￥ＹｕａｎＦａｈｕａｎ（袁发焕）；ＬｉａｏＬｉｓｈｅｎｇ（廖立生）（Ｄｅｐａｒｔｍｅｎｔｏ...     

Protective effect of glutamine-enriched early enteral nutrition on intestinal mucosal barrier injury after liver transplantation in rats

Background

The effect of glutamine-enriched early enteral nutrition (Gln-EEN) on intestinal mucosal barrier injury after liver transplantation (LT) remains uncertain.

Methods

The Wistar-to-Wistar rat LT model was used to explore the protective effect of Gln-EEN. Morphologic changes of intestinal mucosa, levels of intestinal malondialdehyde and secretory immunoglobulin (sIgA), plasma endotoxin, D-lactic acid, serum tumor necrosis factor-α (TNF-α), rates of bacterial translocation, and expression of intestinal nuclear factor-κB, TNF-α, and intercellular adhesion molecule-1 were determined.

Results

After LT, intestinal mucosa was damaged seriously. At 12, 24, and 48 hours posttransplantation, levels of intestinal sIgA were decreased; levels of malondialdehyde, endotoxin, D-lactic acid, and TNF-α, the ratio of bacterial translocation, and the expression of intestinal nuclear factor-κB, TNF-α, and intercellular adhesion molecule-1 all were increased. However, changes in earlier-mentioned parameters in recipients treated with Gln-EEN were attenuated remarkably at 24 to 48 hours.

Conclusions

Our data show that Gln-EEN is a potent protectant against intestinal mucosal barrier injury after LT.     

Oral uracil‐tegafur plus leucovorin vs fluorouracil bolus plus leucovorin for advanced colorectal cancer: a meta‐analysis of five randomized controlled trials

Aim The aim of this study was to evaluate systematically the efficacy and safety of oral uracil‐tegafur (UFT) plus leucovorin (LV) compared with infusional fluorouracil (5‐FU) plus LV for advanced colorectal cancer. Method Eligible studies were identified from Medline, Embase and the Cochrane Library. The end‐points included overall survival and overall tumour response rate, and toxicity including leucopenia, febrile neutropenia, stomatitis/mucositis and diarrhoea. Results Five randomized controlled trials were identified. Pooled data demonstrated no difference in overall survival between the oral UFT plus LV regimen and the 5‐FU bolus plus LV regimen [hazard ratio 1.013; 95% confidence interval (CI) 0.911–1.127].The fixed‐effect pooled estimate for overall tumour response rate showed no significant difference between the two regimens (relative risk 0.893; 0.672–1.187). Grade 3–4 leucopenia [odds ratio (OR) 0.126; 955 CI 0.048–0.326], grade 1–4 leucopenia (OR 0.089; 95% CI 0.067–0.119) and grade1–4 febrile neutropenia (OR 0.020; 95% CI 0.004–0.102) were significantly less prominent in the oral UFT regimens. For nonhaematological toxicities, grade 3–4 stomatitis/mucositis (OR 0.075; 95% CI 0.039–0.146), grade 3–4 infection (OR 0.484; 95% CI 0.310–0.758), grade 1–4 infection (OR 0.672; 95% CI 0.547–0.826, P < 0.001), grade 1–4 diarrhoea (OR 0.743; 95% CI 0.626–0.881) were also less likely to happen in patients in the oral UFT plus LV regimen, while there was no significant difference between the two treatment regimens with respect to grade 1–4 stomatitis/mucositis (OR 0.278; 95% CI 0.053–1.456) and grade 3–4 (OR 1.174; 95% CI 0.983–1.403) diarrhoea. Conclusion Oral UFT or 5‐FU bolus combined with LV results in similar overall survival and tumour response rates for advanced colorectal cancer. The former treatment regimen is greatly superior in terms of toxicity, especially haematological toxicity.     

酶处理急性分离技术用于研究果蝇成虫中枢神经细胞钾电流

目的 建立急性分离果蝇成虫中枢神经细胞技术,并记录分析其钾电流。方法 取S、R或H品系果蝇成虫3—5只,分离出果蝇脑组织。胶原酶消化处理后,加入10％的胎牛血清果蝇培养基终止酶反应。巴氏吸管吹打,细胞悬液静置1h后用于电生理实验。全细胞电压钳记录并分析其外向钾电流。结果 酶消化法成功急性分离出果蝇成虫中枢神经细胞。85％以上为Ⅱ型神经细胞,少部分为Ⅰ型和Ⅲ型神经细胞。记录到快失活与持续复合型、慢失活型、快失活和持续型四种全细胞钾电流。结论 本技术可成功急性分离三品系果蝇成虫中枢神经细胞,并记录到四种钾电流。     

骨质疏松与类风湿关节炎

类风湿关节炎和骨质疏松在我国都属于常见病和多发病,而二者之间又有着非常重要的联系。但是目前临床上还没有一个广泛应用的药物可以同时对两者都产生很好的治疗效果。为了进一步了解骨质疏松和类风湿关节炎的关系,将来能够找到更好的治疗药物,笔者从流行病学、发病机制以及治疗方法等方面分别进行了论述。