药物中磺酸酯类基因毒性杂质研究进展

该文概述了近10年来有关药物中基因毒性杂质监管指南的完善历程与相关检测方法的研究进展。介绍了基因毒性杂质从早期的完全避免到目前的阶段化毒理学关注阈值（TTC）的风险控制理念以及各主流监管机构的具体要求。作为一类重要的基因毒性杂质,磺酸酯主要来源于磺酸及衍生物与低级醇（如甲醇、乙醇、异丙醇等）之间发生的副反应,具有化学结构类型多样化的特点。该文较为详尽地介绍了磺酸酯的形成机理和文献所采用的液相色谱法和气相色谱法,并对色谱方法的选择、预处理方式、衍生化方法及相应痕量水平的灵敏度和回收率等进行了评述。由此期望为合理控制药物中磺酸酯类基因毒性杂质,为保证药物的质量安全性提供有益的指导意见。     

Anti-Colon Cancer Activity of Dietary Phytochemical Soyasaponin I and the Induction of Metabolic Shifts in HCT116

Dietary phytochemicals play an important role in the prevention and treatment of colon cancer. It is reported that group B of soyasaponin, derived from dietary pulses, has anti-colonic effects on some colon cancer cell lines. However, it is uncertain which specific soybean saponins play a role. In our study, as one of the group B soyasaponin, the anti-colon cancer activity of soyasaponins I (SsI) was screened, and we found that it had the inhibitory effect of proliferation on colon cancer cell lines HCT116 (IC₅₀ = 161.4 μM) and LoVo (IC₅₀ = 180.5 μM), but no effect on HT29 between 0–200 μM. Then, nine potential targets of SsI on colon cancer were obtained by network pharmacology analysis. A total of 45 differential metabolites were identified by metabolomics analysis, and the KEGG pathway was mainly enriched in the pathways related to the absorption and metabolism of amino acids. Finally, molecular docking analysis predicted that SsI might dock with the protein of DNMT1, ERK1. The results indicated that the effect of SsI on HCT116 might be exerted by influencing amino acid metabolism and the estrogen signaling pathway. This study may provide the possibility for the application of SsI against colon cancer.     

光伏型光电探测器的激光软损伤机制

 对激光辐照功率密度高于探测器饱和阈值而低于其破坏阈值（中等功率的激光）时光伏型光电探测器的软损伤进行了理论研究,提出了一种新机制。当激光辐照功率密度超过探测器的饱和阈值以后,载流子的带间跃迁达到深度饱和,在半导体内产生热载流子且热载流子的温度高于晶格的温度,从而导致了光伏型光电探测器的电压输出信号随着辐照光功率密度的增加而下降直到零压输出的现象。对激光辐照下光伏型HgCdTe探测器的输出信号进行了模拟计算,结果表明,辐照光功率密度处于一定范围内探测器的输出信号随着辐照光功率密度的增加而逐步下降,甚至接近于零,与实验结果相符合。     

6-氯吡啶-3-亚甲基取代杂环化合物的合成

以2-氯-5-氯甲基吡啶、苯基哌嗪、1-苯基-3-甲基-2-吡唑酮为原料,通过3条路线合成了6个新的6-氯吡啶-3-亚甲基取代杂环化合物,其结构经1H NMR,MS和元素分析表征.     

离子色谱法测定蔬菜中硝酸盐

应用离子色谱法代替原用的镉还原法(即国标法)测定了蔬菜中硝酸根。离子色谱法的应用使测定的选择性、准确性、精密度和速度得到改善。蔬菜样品经捣碎,用自制的活性碳柱脱色和用微孔膜过滤等步骤的预处理后所得溶液即可进行离子色谱测定。所用色谱柱为IonpacAS14A-3C阴离子分离柱,淋洗液为Na2CO3和NaHCO3的混合溶液,洗出液中的NO3-经转化为游离酸(HNO3)后用电导检出器测定其导电率。在量程为30μS和进样液(50μL)中NO3-浓度在1.0~32.5 mg.L-1的范围内,NO3-离子峰高的积分值与进样液中NO3-浓度之间呈线性关系。用含不同浓度NO3-离子的3种蔬菜按方法测定以检验其精密度,所求得RSD值(n=6)在0.7%~5.6%之间。经检验,方法的测定结果与镉还原法的结果之间无显著差异。     

High-Temperature and Low-Frequency Acoustic Energy Absorption by a Novel Porous Metamaterial Structure

In this paper,we propose a novel porous metamaterial structure with an improved acoustic energy absorption performance at high-temperature and in the low-freque...     

A pH-independent electrochemical aptamer-based biosensor supports quantitative,real-time measurement in vivo

The development of biosensors capable of achieving accurate and precise molecular measurements in the living body in pH-variable biological environments (e.g. subcellular organelles, biological fluids and organs) plays a significant role in personalized medicine. Because they recapitulate the conformation-linked signaling mechanisms, electrochemical aptamer-based (E-AB) sensors are good candidates to fill this role. However, this class of sensors suffers from a lack of a stable and pH-independent redox reporter to support their utility under pH-variable conditions. Here, in response, we demonstrate the efficiency of an electron donor π-extended tetrathiafulvalene (exTTF) as an excellent candidate (due to its good electrochemical stability and no proton participation in its redox reaction) of pH-independent redox reporters. Its use has allowed improvement of E-AB sensing performance in biological fluids under different pH conditions, achieving high-frequency, real-time molecular measurements in biological samples both in vitro and in the bladders of living rats.

An electrochemical aptamer-based sensor, enabling in vivo measurements of drug concentrations directly in the bladder of living rats under pH-variable conditions, was developed employing a π-extended tetrathiafulvalene (exTTF) as redox reported.     

高强高性能混凝土高温爆裂机理研究进展

高强高性能混凝土已得到广泛应用,然而高温或火灾下的性能衰减与爆裂成为制约其应用的瓶颈问题,高温爆裂破坏机理尚不清楚. 该文对国内外高温或火灾下高强高性能混凝土爆裂机理的研究进行综述,阐述了蒸汽压、热应力、热开裂3 种热爆裂机理及其影响因素,分析了目前研究存在的困难与挑战. 提出建立一个以蒸汽压致爆机理为主,热应力和热开裂机理为辅的多因素耦合的爆裂模型来定量分析高强高性能混凝土的高温爆裂机理.     

钾离子响应型单分散智能凝胶微球制备与表征

采用沉淀共聚反应成功地制备出了温敏单体N-异丙基丙烯酰胺(NIPAM)和具有钾离子识别能力的苯并-18-冠-6-丙烯酰胺(BCAm)交联共聚的P(NIPAMc-o-BCAm)凝胶微球。采用动态激光光散射(DLS)方法研究了凝胶微球的温敏及钾离子响应特性。实验结果表明,P(NIPAM-co-BCAm)凝胶微球具有很好的单分散性和温敏特性,并且在33℃的5mM钾离子溶液中,其水化直径比在纯水中显著增大,显示出了离子响应性。     

含钢率对GFRP管-钢骨混凝土组合构件抗冲击性能的影响

为了研究含钢率对GFRP（glass fiber reinforced polymer）管-钢骨混凝土组合构件抗冲击性能的影响,建立15个组合构件的数值模型,在验证模型正确的基础上,通过分析典型构件的冲击全过程、截面弯矩发展以及破坏时应变分布规律,研究构件在侧向冲击荷载作用下的破坏模式;通过分析构件冲击力时程曲线、侧移时程曲线以及能量变化情况,探究含钢率对不同长细比构件抗冲击性能的影响。结果表明：与未配置钢骨的构件相比,GFRP管-钢骨混凝土构件的抗冲击承载力提高了7%~134%,侧向位移减小了13%~68%。在侧向冲击荷载作用下,构件的破坏模式以弯曲破坏为主,同时伴随着GFRP管和混凝土冲击区域的局部破坏,抗弯刚度是影响构件抗冲击性能的主要因素之一。构件的抗冲击承载力随着含钢率的增高而提高,随着构件长细比的增大而降低。含钢率相差1.5%时,截面惯性矩较大的窄翼缘型钢对构件的抗冲击性能更有利。对于长细比大于20的构件,钢骨耗能是组合构件总能耗的主要组成部分。