Light-responsive polyurethanes: classification of light-responsive moieties,light-responsive reactions,and their applications

Stimuli responsiveness has been an attractive feature of smart material design, wherein the chemical and physical properties of the material can be varied in response to small environmental change. Polyurethane (PU), a widely used synthetic polymer can be upgraded into a light-responsive smart polymer by introducing a light-sensitive moiety into the polymer matrix. For instance, azobenzene, spiropyran, and coumarin result in reversible light-induced reactions, while o-nitrobenzyl can result in irreversible light-induced reactions. These variations of light-stimulus properties endow PU with wide ranges of physical, mechanical, and chemical changes upon exposure to different wavelengths of light. PU responsiveness has rarely been reviewed even though it is known to be one of the most versatile polymers with diverse ranges of applications in household, automotive, electronic, construction, medical, and biomedical industries. This review focuses on the classes of light-responsive moieties used in PU systems, their synthesis, and the response mechanism of light-responsive PU-based materials, which also include dual- or multi-responsive light-responsive PU systems. The advantages and limitations of light-responsive PU are reviewed and challenges in the development of light-responsive PU are discussed.

A comprehensive review of the advances of light-responsive PU in diverse ranges of medical and industrial applications. The review outlined the classes of light-responsive moieties, responsive mechanisms, and synthetic methods of light-responsive PU.     

氯胺酮复合雷米芬太尼用于腹部手术的麻醉

目的 观察小剂量氯胺酮复合雷米芬太尼用于腹部手术的麻醉效果。方法 ASAⅠ或Ⅱ级择期手术病人60例,随机均分为芬太尼组（F组）、雷米芬太尼组（R组）和雷米芬太尼复合氯胺酮组（RK组）。依据病人对手术刺激的反应强度调节用药量。观察术中循环功能、麻醉苏醒及停药后的不良反应。结果 R组在气管插管、切皮、麻醉维持期间平均动脉压及心率显著低于F组与RK组。RK组在麻醉维持期间平均动脉压及心率低于F组。RK组病人术毕呼吸恢复时间（7．2±3．6）min、呼唤睁眼时间（10．1±3．4）rain、拔管时间（12．9±7．1）min、定向力恢复时间（14．9±4．6）min,均比F组明显缩短,与R组差异无统计学意义。RK组苏醒期质量优于R组和F组。结论 小剂量氯胺酮复合雷米芬太尼用于腹部手术麻醉时,术中循环稳定,术后苏醒迅速,小剂量氯胺酮可提高雷米芬太尼术后恢复质量。     

Recent development and application of virtual screening in drug discovery: an overview

Virtual screening, especially the structure-based virtual screening, has emerged as a reliable, cost-effective and time-saving technique for the discovery of lead compounds. Here, the basic ideas and computational tools for virtual screening have been briefly introduced, and emphasis is placed on aspects of recent development of docking-based virtual screening, scoring functions in molecular docking and ADME/Tox-based virtual screening in the past three years (2000 to 2003). Moreover, successful examples are provided to further demonstrate the effectiveness of virtual screening in drug discovery.     

口服胰岛素毫微球的体外释药及对糖尿病大鼠的降血糖作用

为研制一种生物利用度较高而降血作用时间短的口服INS制剂。制备了胰岛素聚氰基丙烯酸烷基酯毫微球(INS-NP)。其平均粒径为252.4nm,胰岛素的结合率为70.1%±2.3%。INS-NP的体外释药符合双指数函数式,酸性介质中释放更快。Wistar大鼠po不同剂量的INS-NP和胰岛素溶液(INS-SOL),结果显示10u·kg^-1和20u·kg^-1的INS-NP可显著降低血糖,但两个剂量间无显著性差异而INS SOL无降糖作用。用曲线上面积比较poINS-NP和scINS-SOL后的降糖作用,结果前者的相对生物利用度为7.58%。在血糖下降的时间范围内,体外释药的百分率与降糖速率间有一定相关性。     

从 Janus激酶 2/信号转导和转录激活因子 3信号通路探讨牛磺酸对 Aβ25-35所致神经干细胞损伤的保护作用

目的探讨牛磺酸对 Aβ25-35损伤神经干细胞( neural stem cells,NSCs)的保护作用,并初步阐明其作用机制。方法研究自 2019年 3—11月通过 Aβ25-35损伤实验室提取的神经干细胞模型,探讨牛磺酸和 Janus激酶 2/信号转导和转录激活因子3该(JAK2/STAT3)的作用关系。从出生 48 h内的 C57BL/6乳鼠海马区提取 NSCs,以 25 μmol/L浓度 Aβ25-35诱导 NSCs,建立体外阿尔茨海默病( Alzheimer’s disease,AD)样 NSCs模型( AD-NSCs),并利用不同浓度的牛磺酸共同孵育,分为对照组、模型组( 25 μmol/L)、 Aβ25-35+牛磺酸 5 mmol组、 Aβ25-35+牛磺酸 10 mmol组、 Aβ25-35+牛磺酸 15 mmol组及 Aβ25-35+牛磺酸 20 mmol组,共六组。     

肺癌患者外周血调节性T细胞的检测及意义

目的探讨肺癌患者外周血CD4 CD25 调节T细胞水平的变化及其意义。方法采用流式细胞术检测68例肺癌患者外周血CD4 CD25 调节T细胞水平,并进行分层分析。结果肺癌组外周血CD4 CD25 调节T细胞水平(28.6±9.24)%,明显高于30例健康对照组CD4 CD25 T细胞水平(11.12±3.32)%(P<0.01)。进一步分层分析显示:随肺癌进展,外周血CD4 CD25 T细胞水平显著升高,进展期尤其明显[Ⅰ Ⅱ期:(19.52±3.32),n=22;Ⅲ期:(27.28±8.26)☆%,n=25,P<0.01;Ⅳ期:(32.31±15.63)%,n=21,P<0.01]。结论肺癌患者外周血CD4 CD25 调节T细胞水平明显高于正常,且与肿瘤的发生发展密切相关。去除这群细胞可能有效诱导肿瘤免疫,为肿瘤治疗提供一种新的方法。     

Synthesis of W-modified CeO2/ZrO2 catalysts for selective catalytic reduction of NO with NH3

In this paper, a series of tungsten–zirconium mixed binary oxides (denoted as W_mZrO_x) were synthesized via co-precipitation as supports to prepare Ce_0.4/W_mZrO_x catalysts through an impregnation method. The promoting effect of W doping in ZrO₂ on selective catalytic reduction (SCR) performance of Ce_0.4/ZrO₂ catalysts was investigated. The results demonstrated that addition of W in ZrO₂ could remarkably enhance the catalytic performance of Ce_0.4/ZrO₂ catalysts in a broad temperature range. Especially when the W/Zr molar ratio was 0.1, the Ce_0.4/W_0.1ZrO_x catalyst exhibited the widest active temperature window of 226–446 °C (NO_x conversion rate > 80%) and its N₂ selectivity was almost 100% in the temperature of 150–450 °C. Moreover, the Ce_0.4/W_0.1ZrO_x catalyst also exhibited good SO₂ tolerance, which could maintain more than 94% of NO_x conversion efficiency after being exposed to a 100 ppm SO₂ atmosphere for 18 h. Various characterization results manifested that a proper amount of W doping in ZrO₂ was not only beneficial to enlarge the specific surface area of the catalyst, but also inhibited the growth of fluorite structure CeO₂, which were in favor of CeO₂ dispersion on the support. The presence of W was conducive to the growth of a stable tetragonal phase crystal of ZrO₂ support, and a part of W and Zr combined to form W–Zr–O_x solid super acid. Both of them resulted in abundant Lewis acid sites and Brønsted acid sites, enhancing the total surface acidity, thus significantly improving NH₃ species adsorption on the surface of the Ce_0.4/W_0.1ZrO_x catalyst. Furthermore, the promoting effect of adding W on SCR performance was also related to the improved redox capability, higher Ce³⁺/(Ce³⁺ + Ce⁴⁺) ratio and abundant surface chemisorbed oxygen species. The in situ DRIFTS results indicated that nitrate species adsorbed on the surface of the Ce_0.4/W_0.1ZrO_x catalyst could react with NH₃ due to the activation of W. Therefore, the reaction pathway over the Ce_0.4/W_0.1ZrO_x catalyst followed both Eley–Rideal (E–R) and Langmuir–Hinshelwood (L–H) mechanisms at 250 °C.

Interaction of W with Zr improved NH₃-SCR performance via enhancing redox and surface acidity.     

计算机辅助药物设计技术在雄激素受体动态机制探讨和药物发现中的研究进展

雄激素受体（androgen receptor,AR）是男性前列腺癌的重要治疗靶标之一。计算机辅助药物设计（computer-aided drug design,CADD）技术在药物结合机制和新药开发中发挥日益重要的作用。利用计算机构建AR及其配体的复合物体系,研究动态机制,有助于为靶向AR的药物提供重要设计思路。综述了CADD技术在AR动态机制探讨和药物发现中的研究进展。     

中药为主治疗脊柱结核性截瘫209例疗效观察

目的:探讨中药为主治疗脊柱结核性截瘫的临床疗效。方法:对脊柱结核性截瘫患者209例采用启瘫复原胶囊、灭痨复骨丸、托毒散胶囊为主,并辅以西药治疗。结果:临床治愈195例,有效11例,无效3例,总有效率98．56％。结论:中药对脊柱结核性截瘫临床疗效肯定,值得推广应用。     

分子动力学模拟和机器学习结合在药物设计领域的应用

近年来,传统计算机辅助药物分子设计(computer-aided drug molecular design,CADD)和人工智能技术的融合为创新药物发现带来新的契机。分子动力学模拟(molecular dynamics simulation,MD)是CADD中一项不可或缺的经典技术,作为一种强大的模拟计算方法,常常用来研究靶标和药物之间相互作用的动态过程;机器学习(machine learning,ML)作为一种数据驱动的建模方法,正在被广泛应用于药物发现的各个阶段。MD和ML内在互补的特性,为两者的有机结合提供了诸多可能。一方面,ML可以用来分析MD中产生的海量、高维结构动态信息,通过特征提取、降维等策略,识别关键状态和构象,阐明生物体系动态演变背后的潜在机制;另一方面,MD产生的包含结构动态信息的数据可以用于ML模型训练,提高模型对靶标-药物体系热力学性质和动力学性质的预测精度。因此,MD和ML的有效结合在基于结构的药物设计领域的应用具有重要意义。