Optimizing the Thermomechanical Process of Nickel-Based ODS Superalloys by an Efficient Method

Thermo-mechanical process of nickel-based oxide dispersion strengthened (ODS) superalloys is critical to produce desired components. In this study, an efficient method of consolidating powder is introduced to optimize the preparation process, microstructure and properties of nickel-based ODS superalloys. The influences of consolidation temperature, strain rate and ball milling time on the hardness of nickel-based superalloys were studied. The relationship among process, microstructure and hardness was established, the nanoparticles strengthening and grain boundary strengthening in nickel-based ODS superalloys were discussed. The results indicate that long ball milling time, moderately low consolidation temperature and high strain rates are beneficial to improving properties of nickel-based superalloys. Moreover, dispersion strengthening of nanoparticles and grain boundary strengthening play important roles in enhancing nickel-based ODS superalloys.     

国有医疗机构的产权特征、存在问题与改革

该应用现代产权经济学理论，结合医疗服务市场的特点，分析国有医疗机构的产权特征和存在问题，并探讨其改革思路。     

中西医结合治疗卵巢储备功能减退患者成功妊娠二例并文献复习

卵巢储备功能减退（diminished ovarian reserve,DOR）是卵巢因素所致不孕症的主要原因之一,西医临床治疗方法主要依赖于口服提高卵巢储备功能的药物、人工激素周期替代疗法和辅助生殖技术助孕,中医运用补肾健脾法治疗DOR具有不良反应少、疗效持久、治疗手段多样化等优势。报告2例在常规西医治疗基础上应用中医补肾健脾法综合治疗DOR患者成功妊娠的情况,强调个体化中西医结合治疗方案对于解决疑难病证的重要性,为临床应用中医药治疗DOR患者提供证据。     

Point-of-Care Tests for Rapid Detection of Porcine Epidemic Diarrhea Virus: A Systematic Review and Meta-Analysis

The timely and accurate diagnosis of porcine epidemic diarrhea virus (PEDV) infection is crucial to reduce the risk of viral transmission. Therefore, the objective of this review was to evaluate the overall diagnostic accuracy of rapid point-of-care tests (POCTs) for PEDV. Studies published before 7 January 2022 were identified by searching PubMed, EMBASE, Springer Link, and Web of Science databases, using subject headings or keywords related to point of care and rapid test diagnostic for PEDV and PED. Two investigators independently extracted data, rated risk of bias, and assessed the quality using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. The bivariate model and the hierarchical summary receiver operating characteristic (HSROC) model were used for performing the meta-analysis. Threshold effect, subgroup analysis, and meta-regression were applied to explore heterogeneity. Of the 2908 records identified, 24 eligible studies involving 3264 specimens were enrolled in the meta-analysis, including 11 studies on evaluation of lateral flow immunochromatography assay (ICA)-based, and 13 on nucleic acid isothermal amplification (NAIA)-based POCTs. The overall pooled sensitivity, specificity and diagnostic odds ratio (DOR) were 0.95 (95% CI: 0.92–0.97), 0.96 (95% CI 0.88–0.99) and 480 (95% CI 111–2074), respectively; for ICA-based POCTs and the corresponding values for NAIA-based, POCTs were 0.97 (95% CI 0.94–0.99), 0.98 (95% CI 0.91–0.99) and 1517 (95% CI 290–7943), respectively. The two tests showed highly comparable and satisfactory diagnostic performance in clinical utility. These results support current recommendations for the use of rapid POC tests when PEDV is suspected.     

Synthesis and Anticancer Activity of Bagasse Xylan/Resveratrol Graft-Esterified Composite Nanoderivative

Biomass materials are high-quality raw materials for the preparation of natural, green and highly active functional materials due to their rich active groups, wide sources and low toxicity. Bagasse xylan (BX) and resveratrol (Res) were used as raw materials to introduce ethylene glycol dimethacrylate (EGDMA) via grafting reaction to obtain the intermediate product BX/Res-g-EGDMA. The intermediate was esterified with 3-carboxyphenylboronic acid (3-CBA) to obtain the target product 3-CBA-BX/Res-g-EGDMA. The BX/Res-composite-modified nanoderivative with antitumor activity was synthesized with the nanoprecipitation method. The effects of the reaction conditions on the grafting rate (G) of BX/Res-g-EGDMA and the degree of substitution (DS) of 3-CBA-BX/Res-g-EGDMA were investigated using single-factor experiments. The results showed that under the optimized process conditions, G and DS reached 142.44% and 0.485, respectively. The product was characterized with FTIR, XRD, TG-FTC, ¹H NMR and SEM, and its anticancer activity was simulated and tested. The results showed that 3-CBA-BX/Res-g-EGDMA had a spherical structure with an average particle size of about 100 nm and that its crystalline structure and thermal stability were different from those of the raw materials. In addition, 3-CBA-BX/Res-g-EGDMA showed the best docking activity with 2HE7 with a binding free energy of −6.3 kJ/mol. The inhibition rate of 3-CBA-BX/Res-g-EGDMA on MGC80-3 (gastric cancer cells) reached 36.71 ± 4.93%, which was 18 times higher than that of BX. Therefore, this material could be a potential candidate for biomedical applications.     

Thermodynamic and Kinetic Binding Behaviors of Human Serum Albumin to Silver Nanoparticles

A nanoparticle, under biological milieu, is inclined to be combined with various biomolecules, particularly protein, generating an interfacial corona which provides a new biological identity. Herein, the binding interaction between silver nanoparticles (AgNPs) and human serum albumin (HSA) was studied with transmission electron microscopy (TEM), circular dichroism (CD), and multiple spectroscopic techniques. Due to the ground state complex formed mainly through hydrophobic interactions, the fluorescence titration method proved that intrinsic fluorescence for HSA was probably statically quenched by AgNPs. The complete thermodynamic parameters were derived, indicating that the interaction between HSA and AgNPs is an entropy-driven process. Additionally, synchronous fluorescence and CD spectrum results suggested the conformational variation it has upon binding to AgNPs and the α-helix content has HSA visibly decreased. The kinetic experiments proved the double hysteresis effect has in HSA’s binding to the AgNPs surface. Moreover, the binding has between HSA and AgNPs follows the pseudo-second-order kinetic characteristic and fits the Freundlich model for multilayer adsorption. These results facilitate the comprehension about NPs’ underlying biological effects under a physiological environment and promote the secure applications of NPs biologically and medically.     

内窥镜在脑神经外科手术中的应用(附40例报告)

脑内窥镜手术是近年微创伤神经外科的一个重要发展方向.本文报告应用CT引导立体定向技术,施行脑内窥镜手术40例.包括脑肿瘤切除25例,脑囊肿摘除5例,脑内异物摘除4例.脑脓肿摘除3例,脉络丛烧的治疗脑积水2例,脑内寄生虫取出1例.病变均位于脑深部或重要功能区,其中鞍区18例、大脑半球8例、基底节区6例、侧脑室内5例、小脑半球3例.手术有效率97.5%(术后1月).术后无昏迷、偏瘫、颅内感染等严重并发症.本文介绍了内窥镜的手术方法,对于如何术中应用激光及防治并发症等问题进行了讨论.     

小鼠肺、肝和肾间质树突状细胞的形态与组织分布

目的:了解小鼠肺、肝和肾间质树突状细胞的形态与分布特点。方法:电镜形态学观察及表面分子CD11c、CD205与共刺激分子CD80、CD86和MHC-Ⅱ类分子免疫组织化学标记,观察研究C57BL/6小鼠肺、肝和肾间质树突状细胞的形态和分布特点。结果:间质树突状细胞具有特征性的胞质突起,广泛分布于肺、肝与肾间质中,数量较少,大部分处于非成熟状态,低表达CD205、CD80、CD86和MHC-Ⅱ类分子。结论:间质树突状细胞是脏器免疫微环境的重要组成部分和免疫前哨细胞。