壳聚糖絮凝法处理刺五加提取液的研究

目的：采用絮凝剂壳聚糖用于刺五加浸提液的澄清。方法：对絮凝条件进行了优化,并同醇沉的效果做了比较,做了经济核算。结果：最佳的絮凝条件：壳聚糖加入量为28．6mL/L,温度为30℃,pH为5．36。结论：壳聚糖絮凝法不仅澄清效果很好,而且经济实用,可代替醇沉法用于刺五加提取液的澄清。     

Prevention of adhesion of rabbit knee joint with chitosan：an experimental study

Ｐｒｅｖｅｎｔｉｏｎｏｆａｄｈｅｓｉｏｎｏｆｒａｂｂｉｔｋｎｅｅｊｏｉｎｔｗｉｔｈｃｈｉｔｏｓａｎ：ａｎｅｘｐｅｒｉｍｅｎｔａｌｓｔｕｄｙＹｅＧｅｎｍａｏ（叶根茂）；ＨｏｕＣｈｕｎｌｉｎ（侯春林）（ＤｅｐａｒｔｍｅｎｔｏｆＯｒｔｈｏｐａｅｄｉｃｓ，Ｃ...     

壳聚糖纳米粒介导的PIK3CA基因干扰对胃癌细胞侵袭转移能力的影响

目的观察PIK3CA siRNA-壳聚糖纳米粒子处理胃癌细胞BGC823后,胃癌细胞BGC823侵袭能力的变化,研究壳聚糖纳
米粒子介导PIK3CA干扰在抑制胃癌侵袭转移中的应用价值。方法使用壳聚糖包被PIK3CA siRNA制备纳米粒子,纳米粒子
粒径在350 nm。用其处理胃癌细胞,通过western blot及PCR检测PIK3CA沉默情况,并通过Transwell实验观察细胞侵袭性的
变化。结果PIK3CA siRNA-壳聚糖纳米粒子可显著下调胃癌细胞BGC823中PIK3CA的表达（P<0.01）,并且可明显抑制胃癌
细胞的侵袭性（P<0.001）。结论通过壳聚糖纳米粒子介导的PIK3CA基因干扰可以显著降低胃癌细胞的侵袭能力。
     

慢性胃炎湿证患者舌苔脱落细胞的检测分析

目的探讨舌苔脱落细胞在慢性胃炎湿证患者诊断中的应用价值。方法对脾虚证及脾胃湿热证、寒湿中阻证共67例及18例正常人进行舌苔脱落细胞的检测。结果各组舌苔脱落细胞的构成比均以角化细胞为主,其次为角化前细胞和完全角化细胞,最后为中层细胞。较之正常人,脾虚证组的角化细胞明显减少,而角化前细胞及中层细胞明显增多（P〈0．01）。各证型组及正常人,除脾胃湿热证组外,各组舌推片都以背景清晰,分布均匀为主,有少量炎症细胞浸润,炎症细胞的分布呈脾虚、正常人、寒湿中阻及脾胃湿热的递增趋势。结论慢性胃炎湿证患者舌苔脱落细胞的检测为中医辨证提供了更为可靠的客观依据。     

Investigation of Friction and Wear Behavior of Cast Aluminum Alloy Piston Skirt with Graphite Coating Using a Designed Piston Skirt Test Apparatus

A piston skirt friction and wear apparatus that simulates the contact and the relative motion of piston and cylinder liner in a real engine has been designed and constructed. With this apparatus, the friction and wear behavior of a cast aluminum alloy piston with a graphite coating under different loads was studied, and the effectiveness of the apparatus was confirmed. The total wear of the piston skirt was higher under a higher load, and the upper part of the skirt surface (around the height of the piston pin) was worn more severely. The wear mechanisms were studied and, based on the test results and surface analyses, three main wear modes were believed to occur in the wear process of the piston skirt: abrasive, adhesive, and fatigue wear. The effects of skirt profile design, coating, and surface texturing on the friction and wear behavior of the piston skirt can be investigated well using the proposed apparatus, which can truly reflect actual working conditions and is useful to improve the tribological performances of piston skirts.     

Study on Corrosion Resistance and Conductivity of TiMoN Coatings with Different Mo Contents under Simulated PEMFC Cathode Environment

TiMoN coatings with different Mo contents on a SS316L substrate are deposited by using closed field unbalanced magnetron sputtering ion plating (CFUMSIP) technology to enhance the corrosion resistance and durability of stainless steel (SS) bipolar plates (BPs) in proton exchange membrane fuel cell (PEMFC) during the start-up/shut-down process. The electrochemical test results illustrate that TiMoN-4A coating has extremely good corrosion resistance compared to other coatings. The potentiostat polarization (+0.6 V_SCE) tests indicate that the corrosion current density (I_corr) of TiMoN-4A coating is 5.22 × 10⁻⁷A cm⁻², which meets the department of energy 2020 targets (DOE, ≤1 × 10⁻⁶ A cm⁻²). Otherwise, TiMoN-4A coating also exhibits the best corrosion resistance and stability in potentiostatic polarization, electrochemical impedance spectroscopy (EIS), and high potential (+1.2V_SCE) polarization tests. The interfacial contact resistance (ICR) measurement results show that TiMoN-4A coating has the minimum ICR of 9.19 mΩ·cm², which meets the DOE 2020 targets (≤10 mΩ·cm²).     

系列水溶性壳聚糖衍生物的抑菌性能研究

目的 检测壳聚糖水溶性衍生物羧甲基壳聚糖、水溶性低分子壳聚糖、氨基葡萄糖盐酸盐、壳寡糖等对金黄色葡萄球菌的抑菌活性。方法采用营养肉汤稀释法，测定壳聚糖衍生物对金黄色葡萄球菌的最小抑菌浓度，从而评价它们各自的抑菌能力。结果羧甲基壳聚糖、水溶性低分子壳聚糖、氨基葡萄糖盐酸盐对金黄色葡萄球菌的最小抑菌值分别为10，0，2．5，12．5mg／ml（样品溶液pH值均为7．2），其中水溶性低分子壳聚糖的抑菌能力最强，而壳寡糖在此条件下，对金黄色葡萄球菌则没有抑菌性。结论除壳寡糖外，大多壳聚糖对金黄色葡萄球菌的生长有不同程彦的棚制作用。     

兔非穿透性滤过手术联合壳聚糖膜植入的远期效果

目的:观察壳聚糖膜在动物非穿透性滤过手术(NPFS)中应用的组织反应以及远期降眼压效果。方法:壳聚糖膜来源于雪蟹壳。选取标准新西兰白兔22只44眼,雌雄兼用,单眼行NPFS(非穿透性滤过手术)联合壳聚糖膜植入作为实验组(A组),另眼单纯行NPFS作为对照组(B组)。术后观察眼压、炎症反应、结膜滤泡。并分别于1,4,12,28,36,40,48wk取标本行组织学检查。结果:术前两组眼压无显著性差异(P>0.05)。不同时间点两组术后眼压与术前眼压相比均有显著性差异(P<0.01),不同时间点两组之间术后眼压相比均有显著性差异(P<0.01)。超声生物显微镜检查:术后不同时间点两组均维持手术腔隙。A组术后36wk植入物部分吸收,植入材料有断裂现象。B组手术处可见组织间隙存在,但较手术早期减压腔隙减小。组织学检查:两组术后中性粒细胞数无显著性差异(P>0.05),成纤维细胞和嗜酸性细胞数有显著性差异(P<0.01)。术区总胶原纤维及Ⅰ、Ⅲ型胶原纤维含量有显著性差异(P<0.01)。结论:壳聚糖作为非穿透性滤过手术的植入材料有良好的组织相容性、有一定抑制纤维组织增生的作用,能够有效维持滤过,降眼压效果满意。     

Local Electrochemical Corrosion Properties of a Nano-SiO2/MAO Composite Coating on an AM60B-Mg Alloy

In order to improve the corrosion resistance of the automotive AM60B-Mg alloy, a nano-SiO₂/MAO composite coating was prepared on the surface of the alloy. The electrochemical properties were studied in an 80 °C corrosion environment using potentiodynamic polarization tests. Local Electrochemical Impedance Spectroscopy (LEIS) was used to study the corrosion mechanisms of coating defect zone. The microstructure and phase of the samples were observed by confocal laser microscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD). Macroscopic electrochemical test results showed that the impedance of the nano-SiO₂/MAO coating was much higher than that of the MAO coating, by about 433 times. Local electrochemical test results showed that the minimum impedance of the nano-SiO₂/MAO coating was 1–2 orders of magnitude higher than the maximum impedance of the MAO coating. The defective SiO₂/MAO coating still had high corrosion resistance compared to the defective MAO coating. A physical model of local corrosion mechanisms was proposed.     

Antimicrobial second skin using copper nanomesh

The functional support and advancement of our body while preserving inherent naturalness is one of the ultimate goals of bioengineering. Skin protection against infectious pathogens is an application that requires common and long-term wear without discomfort or distortion of the skin functions. However, no antimicrobial method has been introduced to prevent cross-infection while preserving intrinsic skin conditions. Here, we propose an antimicrobial skin protection platform copper nanomesh, which prevents cross-infectionmorphology, temperature change rate, and skin humidity. Copper nanomesh exhibited an inactivation rate of 99.99% for Escherichia coli bacteria and influenza virus A within 1 and 10 min, respectively. The thin and porous nanomesh allows for conformal coating on the fingertips, without significant interference with the rate of skin temperature change and humidity. Efficient cross-infection prevention and thermal transfer of copper nanomesh were demonstrated using direct on-hand experiments.

The functional support and advancement of our body while preserving the inherent naturalness is one of the ultimate goals of bioengineering (1–4). A functional layer is placed on the skin to complement the intrinsic biological and interactive functions (5, 6) and to add functions that do not yet exist (7–9). During use, the second skin layer should completely exploit its function and underlay skin functions without deforming the skin or interfering with the skin’s external interaction. Materials and structures need to be conformal and mechanically similar to the skin to minimize the distortion of natural sensations and movements. In addition, the air and heat transfer on the skin must be unimpeded to obtain a natural and comfortable wear fit (10).Body protection that requires common and long-term wear is an application in which both functionality and naturalness are important. As the outermost layer connecting our body to the environment, the skin is exposed to physical damage, hazardous chemicals, and infectious pathogens (11, 12). Therefore, we add a protective layer on the skin that blocks or filters out external contaminants. This entails the isolation and accumulation of biochemical compounds, which can lead to self-contamination and the subsequent cross-contamination/infection by interacting with other objects. In contrast to chemical contamination, which is not self-reproductive, the biological contamination of infectious microbes, such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a considerable issue to be addressed.By containing an antimicrobial material on the surface of the skin protective layer, cross-infection can be prevented in the long term. Unlike temporary rinsing or disinfection, the use of antibacterial or antiviral substances such as chemical or natural disinfectants and metal nanomaterials inhibits the growth of microorganisms on the surface (13–17). These materials are embedded in a complete covering polymer layer, such as gloves (18, 19), to isolate and protect both the inner and outer surfaces from the infection. To add breathability to the textile especially for the mask (13, 20, 21), many antibacterial fibers have been developed based on these materials. Moreover, various skin-attachable platforms with antimicrobial properties have been developed for convenient usage in daily lives. Antimicrobial nanofibers with conformal attachment to the skin have been developed for drug delivery, wound healing (22, 23), and electrophysiology (24, 25). In addition, stretchable and antibacterial hydrogels have been developed to allow more natural skin movement in wound-healing applications (26–28).However, there has been no practical skin protective solution to prevent cross-infection while preserving intrinsic skin conditions such as surface morphology, thermal transfer, and skin humidity. The thickening of the additional skin layer frequently results in a significant modification of the surface morphology, heat transfer, and the corresponding sensation. Thin layers have limited performance in terms of antimicrobial duration and speed. The skin coverage of polymer or hydrogel film blocks the transfer of air, moisture, and heat. In addition, the antimicrobial performance is focused on the skin side rather than the external side that affects cross-infection. Voids owing to the stiffness of the film or fiber and morphological differences compared to the skin further limit conformality, heat transfer, and water/air permeability (29).Here, we propose an antimicrobial skin protection platform copper nanomesh, which prevents cross-infection while minimizing modification of intrinsic skin properties such as interfacial morphology, temperature change rate, and skin humidity. The thin thickness and porous structure of the nanomesh allow conformal attachment to the fingertips, regardless of the mechanical and structural variations of the fingerprints, nails, and interfaces. To impart antimicrobial properties, copper, one of the most well-known antimicrobial (nano)materials (30–33), was coated with maintaining the nanomesh structure (copper nanomesh, from here onward). The measured inactivation rates of copper nanomesh against Escherichia coli bacteria and influenza virus A (H1N1) were 99.99% within 1 min and 10 min, respectively. It was found that the nanomesh structure contributed to the acceleration of bacterial inactivation compared to the copper film. Furthermore, it exhibited high biocompatibility with the skin cells and stable antibacterial performance even after long-term use (more than 6 h), including water immersion (more than 1 h).In addition, we investigated the naturalness of the copper nanomesh compared to that of the copper film and conventional gloves. As confirmed using the artificial skin and fingerprint recognition, the proposed copper nanomesh exhibited a higher conformability compared to that of the copper film. The copper nanomesh showed a high hydrophobicity to block external contaminants in solution while having high gas permeability and maintaining the skin humidity in a safe range. Additionally, the insertion of copper nanomesh did not affect the temperature change rate, which is important to maintain the sensation and comfort fit of the skin. Finally, the copper nanomesh was compared to the glove by wearing on our hands and interacting with various real-life objects. Using the proposed copper nanomesh, we successfully achieved an effective prevention of cross-infection and less-hindered thermal recognition of objects.