新型藤黄酸衍生物的合成及其抗肿瘤活性

以藤黄酸(1)为原料,分别与HBr和有机胺反应,合成了9个新型的藤黄酸衍生物(2~6),其结构经1HNMR,MS和HR-MS表征。采用MTT法测定了2~6对人结肠腺癌细胞(RKO)、人肝癌细胞(HepG-2)和人卵巢腺癌细胞(OVCAR-3)的体外抗肿瘤活性。结果表明,藤黄酸(N-丙基对甲苯磺酰胺)酯3,藤黄酸(N-丙基苯丙酰胺)酯4和N-色胺藤黄酰胺6b的抗肿瘤活性显著高于1;33-羟基转位藤黄酸2的抗肿瘤活性则大大降低。     

高效液相色谱-电喷雾串联质谱法测定畜禽粪便中四环素类抗生素

建立了高效液相色谱-电喷雾串联质谱法(HPLC-MS/MS)测定畜禽粪便中四环素类抗生素的分析方法。样品经甲醇-乙酸-水(体积比6∶3∶1)溶液提取,OASIS HLB小柱净化后,采用Waters Symmetry C18色谱柱(150×3.9mm,5μm)进行分离,以0.3%甲酸水溶液-0.3%甲酸乙腈溶液梯度洗脱,电喷雾正离子模式多反应监测(MRM)模式定量分析。在优化的色谱条件下,四环素、土霉素和金霉素在0.05~1.0mg/L范围内具有良好的线性,其检出限分别为0.025、0.084、0.098mg/kg;样品回收率为80%~103%。实验结果表明,该方法较液相色谱法具有更高的准确性和灵敏度,可满足畜禽粪便中四环素类抗生素残留的检测要求。     

基于新型氨基酸描述符SVICE对肽类药物进行QSAR研究

采用20种天然氨基酸的47个information indices描述符、33个connectivity indices描述符和44个eigenvalue-based indices描述符分别进行主成分分析,得出一种新的氨基酸描述符-SVICE.将其分别对三肽血管收缩素转化酶(ACE)、抗菌十八肽(AMP)、苦味活性二肽(BTT)序列表征后,建立结构与活性的SMR-MLR模型,并采用内外部双重验证的方法检验模型的稳定性.所建模型相关统计参量如下:复相关系数(Rcum2)、留一法(LOO)交互校验复相关系数(RCV2)和外部样本校验复相关系数(Qext2)分别为0.988,0.964,0.985;0.990,0.970和0.855;0.949,0.887,0.830.结果表明,运用SVICE描述符建立的MLR模型拟合、预测能力均较好,能较好解释肽类药物的活性与结构间的关系从而为新的强活性肽类药物的分子设计和改造提供了指导.     

污染物甲胺为电子给体可见光下Pt/ZnIn2S4光催化制氢

用水热法制备了ZnIn2S4固溶体,并通过XRD和UV-vis漫反射光谱进行了表征.研究了一甲胺、二甲胺和三甲胺为给电子体,在Pt/ZnIn2S4上的可见光光催化制氢及自身的降解反应.3种甲胺都能显著提高光催化分解水制氢活性,同时自身得到很好的降解.电子给体的放氢活性顺序为:TMADMAMMA.通过红外衰减全反射(ATR-IR)法检测电子给体在ZnIn2S4表面的吸附行为,吸附强度大小依次为MMADMATMA.光催化活性与分子结构和在催化剂表面的吸附行为有关.3种污染物浓度对放氢活性的影响都符合Langmuir-Hinshelwood动力学模型.讨论了可能的化学反应机理.     

毛细管气相色谱法测定工作场所空气中3种多环芳烃

采用毛细管气相色谱法测定工作场所空气中3种多环芳烃(萘、萘烷和四氢化萘)的含量。样品采用活性炭管采集,二硫化碳解吸20min,用DB-FFAP毛细管气相色谱柱分离,火焰离子检测器检测。3种多环芳烃在一定的质量浓度范围内与其峰面积呈线性关系,方法的检出限(3S/N)在0.05~0.5 mg·L-1之间。以空白样品为基体进行加标回收试验,所得回收率在89.3%~97.5%之间,测定值的相对标准偏差(n=6)在2.2%~5.4%之间。     

CO2/H2S corrosion behavior of tubular steel SM 80SS in Cl−-containing solution in the absence or presence of Ca2+ and Mg2+

CO₂/H₂S corrosion behavior of tubular steel SM 80SS have been investigated utilizing electrochemical measurement technology, weight loss test, scanning electron microscope (SEM) and X-ray diffraction (XRD). The results showed that temperature increased the corrosion rate and changed the corrosion mechanism of tubular steel SM 80SS. Cl^? quickened the anodic dissolution and increased the corrosion rate of tubular steel SM 80SS. Furthermore, the addition of Ca²⁺ and Mg²⁺ resulted in the corrosion products changing from crystalline FeCO₃ to amorphous Fe(Ca,Mg)(CO₃)₂ and serious corrosion under scale of tubular steel SM 80SS.     

共晶含能材料研究进展

共晶是不同种类的分子(两种或两种以上)通过氢键等分子间相互作用,形成具有特定结构和性能的多组分分子晶体,不同含能材料形成共晶可以有效改善炸药的感度、安全性等性能。针对目前高能炸药的改性需求,共晶在含能材料领域中的应用具有巨大的潜力。综述了共晶的形成原理及生长特性,总结了常见共晶的制备方法和表征方法,评述了含能材料共晶的研究现状和发展前景。     

A density functional theory study of gold clusters supported on layered double hydroxides

The geometrical structure and electronic properties of a series of Au _N (N = 1–8) clusters supported on a Mg²⁺, Al³⁺-containing layered double hydroxides (MgAl–LDH) are investigated using density functional theory. The Au clusters are supported on two typical crystal faces of the LDH platelet, the basal {0001} and the lateral $ \{ 10\,\bar{1}\,0\} $ crystal face, respectively, corresponding to the top and edge site of monolayer MgAl–LDH lamella for the sake of simplicity. It is revealed that an increase in the charge transfer from the LDH lamella to the Au _N clusters at the edge site rather than clusters on the top surface, demonstrating a preferential adsorption for Au _N clusters at the edge of LDH lamella. Moreover, the calculated adsorption energy of the Au _N clusters on the LDH lamella increases with the cluster size, irrespective of the adsorption site. The investigation on the interaction between O₂ and Au _N clusters on the LDH lamella is further carried out for understanding the catalytic oxidation properties of the LDH-supported Au catalyst. The formation of reactive O₂ ^? species, a necessary prerequisite in catalytic oxidation of CO, by O₂ bridging two Au atoms of Au _N clusters indicates that the LDH-supported Au catalyst has the required characteristics of a chemically active gold catalyst in CO oxidation.