Laser-Processed PEN with Au Nanowires Array: A Biocompatibility Assessment

Although many noble metals are known for their antibacterial properties against the most common pathogens, such as Escherichia coli and Staphylococcus epidermidis, their effect on healthy cells can be toxic. For this reason, the choice of metals that preserve the antibacterial effect while being biocompatible with health cells is very important. This work aims to validate the effect of gold on the biocompatibility of Au/Ag nanowires, as assessed in our previous study. Polyethylene naphthalate (PEN) was treated with a KrF excimer laser to provide specific laser-induced periodic structures. Then, Au was deposited onto the modified PEN via a vacuum evaporation method. Atomic force microscopy and scanning electron microscopy revealed the dependence of the surface morphology on the incidence angle of the laser beam. A resazurin assay cytotoxicity test confirmed safety against healthy human cells and even cell proliferation was observed after 72 h of incubation. We have obtained satisfactory results, demonstrating that monometallic Au nanowires can be applied in biomedical applications and provide the biocompatibility of bimetallic Au/AgNWs.     

Hematites Precipitated in Alkaline Precursors: Comparison of Structural and Textural Properties for Methane Oxidation

Hematite (α-Fe₂O₃) catalysts prepared using the precipitation methods was found to be highly effective, and therefore, it was studied with methane (CH₄), showing an excellent stable performance below 500 °C. This study investigates hematite nanoparticles (NPs) obtained by precipitation in water from the precursor of ferric chloride hexahydrate using precipitating agents NaOH or NH₄OH at maintained pH 11 and calcined up to 500 °C for the catalytic oxidation of low concentrations of CH₄ (5% by volume in air) at 500 °C to compare their structural state in a CH₄ reducing environment. The conversion (%) of CH₄ values decreasing with time was discussed according to the course of different transformation of goethite and hydrohematites NPs precursors to magnetite and the structural state of the calcined hydrohematites. The phase composition, the size and morphology of nanocrystallites, thermal transformation of precipitates and the specific surface area of the NPs were characterized in detail by X-ray powder diffraction, transmission electron microscopy, infrared spectroscopy, thermal TG/DTA analysis and nitrogen physisorption measurements. The results support the finding that after goethite dehydration, transformation to hydrohematite due to structurally incorporated water and vacancies is different from hydrohematite α-Fe₂O₃. The surface area SBET of Fe₂O₃_NH-70 precipitate composed of protohematite was larger by about 53 m²/g in comparison with Fe₂O₃_Na-70 precipitate composed of goethite. The oxidation of methane was positively influenced by the hydrohematites of the smaller particle size and the largest lattice volume containing structurally incorporated water and vacancies.     

虚拟新闻系统的自动化设计研究

虚拟新闻丰富了战略对抗演习的表现手段,提高了参演人员的沉浸感。针对目前该系统以人工操作方式为主和自动化程度较低的现状,提出将现代汉语文本的词语切分技术引进到该系统,研究了自动分词过程中字典库的设计、分词的方法、虚拟新闻系统中自动分词的特点和详细的算法等问题。改进后的系统在战略对抗演习中进行了应用。对改进后和改进前的实验对比分析表明,现代汉语文本的词语切分技术能够缩短虚拟新闻的生成时间,提高整个系统的自动化程度。     

镀银编织铜丝与铜层微电阻点焊接头组织与性能研究

研究了0.1 mm镀银编织铜丝与0.07 mm厚度超薄纯铜层微电阻点焊接头的微观组织和力学性能,分析了不同参数对接头力学性能的影响,采用扫描电子显微镜对典型接头的微观组织结构特征进行了分析。结果表明,当焊接热量足够时,焊点接头主要为钎焊－熔焊混合连接机制,其形成过程中经历银元素润湿铺展、银元素扩散、铜元素熔化和金属凝固四个过程;焊点连接面处组织致密,存在铜银两相与单富铜相构成连接界面形态,后者焊点微观组织结构含有熔焊的特征;试验所用参数范围内,焊点的最大抗剪力可达45 N,焊接时间与焊接电流均在一定的范围内对焊点性能影响较大,当电阻产热达到饱和区间,焊点抗剪切性能变化不大。     

Synthesis,In Vitro,and Computational Studies of PTP1B Phosphatase Inhibitors Based on Oxovanadium(IV) and Dioxovanadium(V) Complexes

One of the main goals of recent bioinorganic chemistry studies has been to design and synthesize novel substances to treat human diseases. The promising compounds are metal-based and metal ion binding components such as vanadium-based compounds. The potential anticancer action of vanadium-based compounds is one of area of investigation in this field. In this study, we present five oxovanadium(IV) and dioxovanadium(V) complexes as potential PTP1B inhibitors with anticancer activity against the MCF-7 breast cancer cell line, the triple negative MDA-MB-231 breast cancer cell line, and the human keratinocyte HaCaT cell line. We observed that all tested compounds were effective inhibitors of PTP1B, which correlates with anticancer activity. [VO(dipic)(dmbipy)]·2 H₂O (Compound 4) and [VOO(dipic)](2-phepyH)·H₂O (Compound 5) possessed the greatest inhibitory effect, with IC₅₀ 185.4 ± 9.8 and 167.2 ± 8.0 nM, respectively. To obtain a better understanding of the relationship between the structure of the examined compounds and their activity, we performed a computer simulation of their binding inside the active site of PTP1B. We observed a stronger binding of complexes containing dipicolinic acid with PTP1B. Based on our simulations, we suggested that the studied complexes exert their activity by stabilizing the WPD-loop in an open position and limiting access to the P-loop.     

基于一体化实验系统的水雷声干扰器研究

提出了主要用于干扰水雷平台声呐的声干扰器.为了提高水面舰艇在未来水声对抗作战中的隐蔽性和生存能力,在分析应用调频信号宽带大功率干扰特性的基础上,以工控机、数据采集卡PCI6110E、适配器构成的一体化实验系统作为硬件平台,在VC 的环境下开发出了干扰器系统.经过消声水池系统联调、海上实验和理论分析,取得了预期的效果,表明系统能在一定程度上提高舰船反水雷作战能力.     

改进型SIRT法进行电磁波CT反演应用研究

利用声波、地震波CT中广泛应用的SIRT法对BPT法进行改进,用“dij／li”替换“dij”作为第i条射线在第j个网格中的权值,使那些较小的dij（dij=li）在传统的BPT法中权值微小,而在改进型BPT法中却有最大的权值,用其计算结果作为CT反演计算的初值,同时将BPT法融合到SIRT法中去,使射线与网格符合“近则优”的原则,称之为改进型SIRT法,能起到有效地压制野外资料的外界干扰影响。该方法于电磁波CT在生产实践应用中取得显著成效。     

马来酸单酯稀土包覆硅灰石改性PA6的研究

采用马来酸单酯稀土(RETM)对硅灰石表面进行包覆后用于尼龙6(PA6)的改性,研究了RETM对改性PA6的拉伸强度、缺口冲击强度、耐磨损性能、吸水性及成型收缩率等的影响。结果表明,与硅烷偶联剂包覆处理的硅灰石相比,采用RETM包覆处理的硅灰石改性PA6时硅灰石的分散均匀性较好,改性PA6的拉伸强度、缺口冲击强度、耐磨损性能都得到了提高,吸水率及成型收缩率显著降低。     

新闻纸的白度、色度与不透明度

本文通过对目前新闻纸市场上新闻纸的白度、色度和不透明度的调查，结合本厂的实践提出了对新闻纸的ISO白度、CIE白度、L^＊、a^＊、b^＊值和不透明度的合理控制范围。