Mechanical Reinforcement in Nylon 6 Nanocomposite Fiber Incorporated with Dopamine Reduced Graphene Oxide

The emergence of graphene-based polymer composite fibers provides a new opportunity to study the high-performance and functional chemical fibers. In this work, we have developed an efficient and convenient method with polydopamine (PDA) to functionalize and reduce graphene oxide (GO) simultaneously, and the modified graphene nanosheets can obtain uniform dispersion and strong interfacial bonding in nylon 6 (PA6). Furthermore, the reinforced PA6 composite fibers were prepared through mixing PDA-rGO into the PA6 polymer matrix and then melt spinning. The functional modification was characterized by surface analysis and structural testing including SEM, TEM, FTIR, and Raman. When the addition amount of the modified GO was 0.15 wt%, the tensile strength and Young’s modulus of the composite fiber reached 310.4 MPa and 462.3 MPa, respectively. The results showed a meaningful reinforcement with an effect compared to the pure nylon 6 fiber. Moreover, the composite fiber also exhibited an improved crystallinity and thermal stability, as measured by DSC and TGA.     

老年人呼吸机相关性肺炎的危险因素及病原学分析

目的研究老年人呼吸机相关性肺炎（VAP）的病原学和预后情况。方法选择老年科行呼吸机治疗的患者92例,采用回顾性队列研究方法,分析临床资料、病原菌构成、耐药性情况。结果VAP组和无VAP组之间的性别、呼吸末正压,是否服用H：受体阻滞剂、利尿剂、糖皮质激素,是否经口气管插管,是否气管插管后改气管切开等情况均差异无统计学意义（P〉0．05）;而两组患者的年龄、慢性阻塞性肺疾病（COPD）病程、白蛋白、机械通气时间、抗生素连续使用情况、是否昏迷等方面均差异有统计学意义（P〈0．05）。VAP患者的呼吸道分泌物培养分离出109株细菌,其中革兰阴性茵74株（67．89％）,革兰阳性茵22株（20．18％）,真茵13株（11．93％）。氨苄青霉素和头孢唑林对铜绿假单胞菌、鲍曼不动杆菌、肺炎克雷伯杆菌、大肠埃希菌及葡萄球菌属的耐药率较高,在70％-100％之间;而庆大霉素和丁胺卡那霉素对以上病原菌的耐药率较低,在19％-42％之间;泰能对以上病原菌的耐药率更低,在5％～22％之间。结论年龄、COPD病程、白蛋白、机械通气时间、抗生素连续使用天数、抗生素舍用种类、是否气管切开及是否昏迷均是发生VAP的危险因素,革兰阴性菌是VAP的主要病原茵,合理应用抗生素对VAP具有重要的防治意义。     

心脑血管疾病用药不良反应与药品品种关系的聚类分析

目的寻找心脑血管疾病用药的不良反应与药品品种间聚类关系,促进临床安全合理用药。方法运用数据挖掘技术中的两阶段聚类算法对药品的严重不良反应与药品品种间的关系进行聚类分析。结果由聚类结果可知,在使用心脑血管疾病用药时,出现的严重和新的严重不良反应为肝功能异常、肾功能异常、呼吸困难、横纹肌溶解,导致这些严重不良反应的药物有受体类药物、钙离子拮抗剂、降低胆固醇类药物。结论在选择心脑血管疾病用药时,受体类药物、钙离子拮抗剂、降低胆固醇类药物应慎用、少用,尽量避免严重的不良反应发生。     

The upregulated intestinal folate transporters direct the uptake of ligand-modified nanoparticles for enhanced oral insulin delivery

Transporters are traditionally considered to transport small molecules rather than large-sized nanoparticles due to their small pores. In this study, we demonstrate that the upregulated intestinal transporter (PCFT), which reaches a maximum of 12.3-fold expression in the intestinal epithelial cells of diabetic rats, mediates the uptake of the folic acid-grafted nanoparticles (FNP). Specifically, the upregulated PCFT could exert its function to mediate the endocytosis of FNP and efficiently stimulate the traverse of FNP across enterocytes by the lysosome-evading pathway, Golgi-targeting pathway and basolateral exocytosis, featuring a high oral insulin bioavailability of 14.4% in the diabetic rats. Conversely, in cells with relatively low PCFT expression, the positive surface charge contributes to the cellular uptake of FNP, and FNP are mainly degraded in the lysosomes. Overall, we emphasize that the upregulated intestinal transporters could direct the uptake of ligand-modified nanoparticles by mediating the endocytosis and intracellular trafficking of ligand-modified nanoparticles via the transporter-mediated pathway. This study may also theoretically provide insightful guidelines for the rational design of transporter-targeted nanoparticles to achieve efficient drug delivery in diverse diseases.     

Generative Design and Integrated 3D Printing Manufacture of Cross Joints

The integrated process of design and fabrication is invariably of particular interest and important to improve the quality and reduce the production cycle for structural joints, which are key components for connecting members and transferring loads in structural systems. In this work, using the generative design method, a pioneering idea was successfully realized to attain a reasonable configuration of the cross joints, which was then consecutively manufactured using 3D printing technology. Firstly, the initial model and generation conditions of a cross joint were constructed by the machine learning-based generative design algorithm, and hundreds of models were automatically generated. Then, based on the design objective and cost index of the cross joint, three representative joints were selected for further numerical analysis to verify the advantages of generative design. Finally, 3D printing was utilized to produce generative joints; the influences of printing parameters on the quality of 3D printing are further discussed in this paper. The results show that the cross joints from the generative design method have varied and innovative configurations and the best static behaviors. 3D printing technology can enhance the accuracy of cross joint fabrication. It is viable to utilize the integrated process of generative design and 3D printing to design and manufacture cross joints.     

Strained Lattice Gold-Copper Alloy Nanoparticles for Efficient Carbon Dioxide Electroreduction

Electrocatalytic conversion of carbon dioxide (CO₂) into specific renewable fuels is an attractive way to mitigate the greenhouse effect and solve the energy crisis. Au_nCu_100-n/C alloy nanoparticles (Au_nCu_100−n/C NPs) with tunable compositions, a highly active crystal plane and a strained lattice were synthesized by the thermal solvent co-reduction method. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) results show that Au_nCu_100−n/C catalysts display a subtle lattice strain and dominant (111) crystal plane, which can be adjusted by the alloy composition. Electrochemical results show that Au_nCu_100−n/C alloy catalysts for CO₂ reduction display high catalytic activity; in particular, the Faradaic efficiency of Au₇₅Cu₂₅/C is up to 92.6% for CO at −0.7 V (vs. the reversible hydrogen electrode), which is related to lattice shrinkage and the active facet. This research provides a new strategy with which to design strong and active nanoalloy catalysts with lattice mismatch and main active surfaces for CO₂ reduction reaction.