一种具有抗肿瘤活性胆酸衍生物的合成新方法

以胆酸为原料, 使之与甲醇反应, 得到胆酸甲酯(2). 2采用PCC(氯铬酸吡啶)氧化得到脱氢胆酸甲酯(3), 3在CoCl2存在的条件下通过NaBH4的化学选择性还原得到7α-羟基-3,12-二氧代胆酸甲酯(4). 对4的抗肿瘤活性试验表明该化合物对Sk-Hep-1(肝癌)和H-292(肺癌)细胞株具有中等程度的细胞毒性.     

α-萜品烯马来酰亚胺基酰腙衍生物的合成及杀菌活性研究

以α-蒎烯为原料,在质子酸催化下发生Wagner-Meerwein重排得到α-萜品烯,再与马来酸酐发生Diels-Alder环加成反应得到α-萜品烯马来酸酐(3),然后与水合肼反应制备N-氨基-α-萜品烯马来酰亚胺(4).在冰醋酸催化下,4与各种取代苯甲醛反应,合成得到17个新型α-萜品烯马来酰亚胺基酰腙化合物5a～5q.初步探索了合成条件,并利用元素分析,1H NMR,13C NMR,LC-MS,FT-IR等多种手段对目标产物作了分析表征.初步的生物活性测试表明,大部分化合物具有一定的杀菌活性,其中4-羟基-3-甲氧基苯基-α-萜品烯马来酰亚胺基酰腙(5n)在浓度为50 mg/L时对苹果轮纹病菌、花生褐斑病菌和番茄早疫病菌的抑制率分别达91%,83.3%和76.7%.     

Inhibition of LPS-induced no production in RAW264.7 cell lines: synthesis and molecular modeling of α-ketophosphonates of febuxostat

In an effort to develop novel anti-inflammatory agents, we synthesized phosphorylated derivatives of febuxostat using various phosphates/phosphonites by Michaelis-Arbuzov reaction. Their inhibitory activity on nitric oxide (NO) production, reactive oxygen species (ROS) production and cytotoxicity were evaluated using lipopolysaccharide (LPS) activated macrophages RAW264.7 assay, flow-cytometry analysis and MTT method respectively. Some of these compounds showed potent inhibition of NO and ROS production without obvious cytotoxicity. Furthermore, docking simulations were performed to positional compounds 3g, 3h, 3i and 3j into the COX-2 active site to determine the probable binding model. Physicochemical parameters revealed that most of the compounds possessed drug-like properties.     

不同基体改进剂对电感耦合等离子体质谱法测量血清中甲胎蛋白的影响

血清中甲胎蛋白(AFP)的准确测量对于癌症的临床诊断和治疗具有重要意义.电感耦合等离子体质谱法(ICP-MS)具有灵敏度高、检出限低、多元素同时检测等优点,但用于血清中低丰度蛋白的检测时,检出限常不及荧光检测法,因此,提高ICP-MS免疫分析测量低丰度蛋白质时的灵敏度具有重要意义.本研究发现,增强液能很大程度增加Eu信号强度,选取醋酸、醇类、EDTA三类有机试剂模拟增强液来探索增强机理.结果表明:酸性体系能增加目标元素在基体中的稳定性,减少其在管壁的吸附;碳原子或分子容易接受电子提高Eu的电离效率;EDTA能与金属离子结合,减少吸附,但同时EDTA与其它金属结合引入更多的干扰,从而使空白信号增大,5％ HAc既能满足酸性要求也能满足含碳量要求,作为基体时铕的灵敏度最高,同时也不影响空白信号.因此选择5％ HAc作为解离液,并应用于人血清中甲胎蛋白含量的测定,线性范围为1～600 μg/L,检出限为0.57 μg/L,采用基体改进ICP-MS测量人血清中AFP的含量与TRFIA测量结果一致,且精密度要优于TRFIA的测量结果.     

Ti/α-PbO2/β-PbO2电极电化学降解2-氯酚

采用电化学沉积法在Ti基底上制备了复合电极Ti/α-PbO2/β-PbO2,扫描电镜结果表明电极呈现由β-PbO2小晶体组成的菜花状微观形貌.所制电极在电化学降解环境污染物2-氯酚时表现出较高的电催化效率、较好的电极稳定性和较长的电极寿命.用正交实验优化了电化学降解2-氯酚的实验条件.在最优的实验条件(2-氯酚初始浓度50 mg/L,电解质0.1 mol/L Na2SO4,温度35oC,阳极电流密度20 mA/cm2)下电化学降解180 min后,2-氯酚的去除率达100%.动力学结果表明, Ti/α-PbO2/β-PbO2电极上2-氯酚的电化学氧化符合准一级动力学过程.     

First-principles study on the origin of optical transitions to be associated with F colour centers for PbWO4 crystals

The electronic structures of PbWO₄ crystals containing F type color centers with the lattice structure optimized are studied within the framework of the fully relativistic self-consistent Direc–Slater theory, using a numerically discrete variational (DV-Xα) method. The calculated results show that F and F⁺ centers have donor energy level in forbidden band. Their optical transition energy are 1.84 eV, 2.21 eV, respectively, which corresponds to the 680 nm, 550 nm absorption bands. It predicts that the 680 nm, 550 nm absorption bands originate form the F and F⁺ centers in PbWO₄ crystals.     

α-苯甲胺基-β-(3-吲哚基)-丙酸甲酯的合成

以L-色氨酸为原料经过4步得到α-苯甲胺基-β-(3-吲哚基)-丙酸甲酯,它是一种具有潜在的抗肿瘤活性的吲哚二酮哌嗪化合物的中间体,首先通过“酰氯法”合成L-色氨酸甲酯盐酸盐,再脱去盐酸,与苯甲醛发生缩合反应形成希夫碱,最后选择性还原,得目的产物,得率54.9%.     

α-Fe裂纹的分子动力学研究

通过分子动力学方法，模拟了α-Fe裂纹的单轴拉伸实验中的形变过程.研究了不同晶体取向裂纹的形变特点和断裂机理，观察到各种形变现象，如位错形核和发射，位错运动，堆垛层错或孪晶的形成，纳米空洞的形成与连接等.计算结果表明，裂纹扩展是塑性过程和弹性过程相结合的过程，其中塑性过程表现为由裂尖发射的位错导致的原子切变行为，而弹性过程的发生则是由无位错区中的原子断键所导致.同时还研究了α-Fe裂纹的形变特点和断裂机理与温度场和应力场的依赖关系.     

Cross sections for (d–t) neutron interaction with germanium isotopes

The cross sections for (n,x)$(n,x)$ reactions with Ge isotopes were measured at (d–t) neutron energies around 14 MeV with the activation technique using metal discs of natural composition. Calculations of detector efficiency, incident neutron spectrum and correction factors were performed with the Monte Carlo technique (MCNP4C code). Cross sections data are presented for ⁷⁰Ge(n,2n$n,2n$)⁶⁹Ge, ⁷⁴Ge(n,α$n,\alpha$)^71mZn, ⁷⁶Ge(n,2n$n,2n$)^75(m + g)Ge, ⁷⁰Ge(n,p$n,p$)⁷⁰Ga and ⁷²Ge(n,2n$n,2n$)^71gGe reactions. The cross section results for ⁷²Ge(n,2n$n,2n$)^71gGe reaction were reported for the first time. Some other cross sections were obtained with higher precision, including the ⁷⁰Ge(n,p$n,p$)⁷⁰Ga reaction. Theoretical calculations of excitation functions were performed with the TALYS-1.0 code and compared with the experimental cross section values. Data were included in the EXFOR database.     

CaWO4晶体中F型色心电子结构的研究

运用相对论的密度泛函离散变分法(DV-Xα)研究了CaWO₄晶体中F型色心的电子结构. 计算结果表明，F和F⁺心在禁带中引入了新的施主能级；分析了晶体内可能存在的光学跃迁模式，并通过过渡态的方法计算了F，F⁺心跃迁到导带底的能量分别为1.92eV和2.42eV. 因此，从理论上推断了F和F⁺心在CaWO₄晶体中可能引起650nm和515nm的吸收，由此说明CaWO₄晶体中650nm和515nm吸收带起源于晶体中的F和F⁺心. 关键词： 4晶体')" href="#">CaWO₄晶体 +心')" href="#">F和F⁺心 DV-Xα