悬浮液气-液界面二元胶体颗粒的漂浮组装机理

提出一种在悬浮液气-液界面漂浮组装亚微米单分散聚苯乙烯(PS)微球和纳米SiO2颗粒二元胶粒晶体的新方法, 并系统研究了漂浮组装机理. 研究表明, 聚苯乙烯微球和二氧化硅两种胶体颗粒在悬浮液气-液界面的漂浮组装是以PS微球的组装为主导的. 在一定PS微球相浓度范围内, 悬浮液中PS 微球与SiO2颗粒的初始体积配比基本不影响PS微球有序组装的形成. PS微球粒径在150-500 nm时易于形成有序排列, 较小或较大粒径的PS微球难以形成有序排列. SiO2颗粒的组装是一种以PS微球为“基底”的沉积过程. 二元胶粒晶体中SiO2颗粒的体积分数由其在混合悬浮液中的相浓度所决定.     

HPLC study of tissue distribution of loganin in rats

A rapid, sensitive and selective high performance liquid chromatography (HPLC) method was developed and validated for determination of loganin in rat tissues. Samples were prepared based on a simple protein precipitation. Separation of loganin was achieved on a reversed-phase C(18) column (250 x 4.6 mm, 5 microm) with a mobile phase consisting of acetonitrile and water (16:84, v/v) at a flow rate of 1.0 mL/min. The detection wavelength was set at 236 nm and the temperature of the column was kept at 30 degrees C. The method was applied to study tissue distribution of loganin in rats after a single administration of loganin at a dose of 20 mg/kg. The highest level was observed in kidney, then in stomach, lung and small intestine. The lowest level was found in brain. The peak levels were attained at 90 min in most tissues. It was indicated that kidney was the major distribution tissue of loganin in rats, and that loganin had difficulty in crossing the blood-brain barrier. It was also found there was no long-term accumulation of loganin in rat tissues.     

Cardiovascular effects of mycelium extract of Ganoderma lucidum: inhibition of sympathetic outflow as a mechanism of its hypotensive action

In an effort to understand the mechanism of cardiovascular actions of Ganoderma lucidum which was cultivated in Korea, the mycelium was isolated for a large-scale culture. Water extract of the mycelia was evaluated for its cardiovascular activity in anesthetized rabbits and rats. The left femoral artery and vein were cannulated for the measurement of arterial pressure and subsequent delivery of drugs. The left kidney was exposed retroperitoneally and a branch of the renal nerve was used to integrate renal efferent or afferent nerve activities. The extract decreased systolic and diastolic blood pressure, which was accompanied by an inhibition of renal efferent sympathetic nerve activity. The extract did not decrease heart rate in these animals, although there was clear hypotension in the extract dose dependent manner. This suggests that the hypotension induced by the treatment of the extract was secondary to the primary effect of the extract in the central nerve system, which suppressed the sympathetic outflow. Therefore we concluded that the mechanism of hypotensive action of Ganoderma lucidum was due to its central inhibition of sympathetic nerve activity.     

Determination of nitrite by inhibition of the chemiluminescence of acriflavine in a flow-injection assembly

The indirect determination of nitrite was performed with a flow-injection assembly on the basis of the inhibition of the analytical output obtained in a luminometer by oxidation of acriflavine. The acriflavine solution merged with the nitrite and the resulting mixture was injected into a pure water stream. This solution merged with the oxidant solution (potassium permanganate in sulfuric acid medium) and the resulting chemiluminiscence was affected (inhibited) by the presence of nitrite after reaction with the aminoacridine. The method was applicable over the range 10-800 microg l(-1) of nitrite with a correlation coefficient of 0.9960. The relative standard deviation was 1.4% and the throughput was 76 samples h(-1). The influence of foreign substances was also tested. A solid-phase reactor, filled with Amberlite IRA-900, was inserted in the assembly for the on-line preconcentration of nitrite; the analytical output resulted in an increase of up to 11.5-fold. The method was applied to the determination of nitrites in residual waters, industrial formulations and soil samples.     

思密达治疗口腔溃疡的临床观察

1998年8月－1999年3月采用思密达治疗口腔溃疡32例，并与红霉素（含强的松，维生素B2）治疗口腔溃疡30例比较，结果表明，治疗4天后，思密达组显效率75．00％，总有效率100．0％，而红霉素组显效率6．67％，总有效率40．0％，提示思密达治疗口腔溃疡有较好的临床效果。     

转动弹量热计的建立及对氯苯甲酸热值测定

元素有机物要达到完全的燃烧应当在转动弹量热计中进行,这种量热计与静止弹量热计比较有许多优点。首先,转动的结果起到了对弹液的搅拌作用,使弹内各部分溶液的浓度很快达到平衡。其次,促进了燃烧过程中某些副反应的进行,从而短期获得稳定的反应终态,使燃烧热测量的精度显著提高。     

Construction of the Skeleton of Phthalascidin, Mechanism of the Formation of the Key Tricyclic Lactam Intermediate

Phthalascidin is a structurally simplified version of Et-743, which is a potent anti-tumor marine natural product isolated from Ecteinascidia turbinata. Its antiproliferative activity is greater than that of the agents taxol, camptothecin, adriamycin, mitomycin C, cisplatin, bleomycin, and etoposide by 1-3 orders of magnitude. An elegant synthesis of Et-743 and phthalascidin has been reported by E. J. Corey and co-workers1,2. As part of our continuing program, we have also engaged in dev…     

LC Evaluation of Intestinal Transport of Praziquantel

Praziquantel (PZQ) is a highly lipophilic drug with low aqueous solubility. Despite this, it is well absorbed from the gastrointestinal tract. In this study, a simple LC method was developed and validated, in order to monitor the concentration of PZQ in TC-199 buffer in vitro, in the rat everted gut sac absorption model. PZQ was analyzed by a reversed-phase LC method with an isocratic mobile phase containing acetonitrile and water in the proportions 45:55. The flow-rate was 1 mL min⁻¹ and PZQ was determined by measuring absorbance at 215 nm, at 25 °C. The method was found to be specific, as none of the components of TC-199 or intestinal sac artefacts interfered with the drug peak. Recovery was within acceptable statistical limits. The limit of detection was 0.54 μg mL⁻¹ and the limit of quantitation was 1.63 μg mL⁻¹. The calibration curve was found to be linear in the concentration range of 10–90 μg mL⁻¹ PZQ. The proposed method was found to be rapid and selective and hence can be applied in the monitoring of the absorption of PZQ in in vitro everted gut sac absorption studies.

     

导数测量技术在气相色谱信号处理中的应用

介绍了导数测量技术在气相色谱信号处理中的应用。导数-气相色谱的热导检测器对苯的灵敏度和敏感度分别达到270kV·L/kg和0.3μg／L。与可分辨导数色谱峰相对应的常规色谱峰最小分离度为2．8。在被测组分质量浓度为8．1～810g／L的范围内,导数峰上峰高、下峰高、总峰高、峰面积均与质量浓度呈线性关系,其线性相关系数分别为0．9911,0．9982,0．9960和0.9991。     

Solubility and some properties of aqueous solutions of fullerenol-d and composition of crystal hydrates

Method of isothermal saturation in ampules was used to study the solubility of fullerenol in distilled water in the temperature range 20–80°C and to determine the composition of its equilibrium crystal hydrates. The pycnometric technique was employed to examine how the density depends of the concentration of fullerenol solutions and the average molar and partial molar volumes of the components in solution at 25°C was calculated. The method of refractometry was used to study the dependence of the refractive index on the concentration of fullerenol solutions and the specific refraction of the solutions was calculated.     

Distribution of 67Ga-citrate in 3'-methyl-4-dimethylaminoazobenzene-induced hepatoma of rats

The distribution of 67Ga-citrate in the hepatoma of rat induced by 3'-methyl-4-dimethylaminoazobenzene was studied. 67Ga uptake ratio resected specimen, autoradiography and histological specimen were compared each other. 67Ga uptake ratio of the tumor was increased 1.6 to 7.2 times (average 4.4) to control group. Regardless of the size of the tumor, macroautoradiographically observed distribution of 67Ga-citrate in the hepatoma was higher in the peripheral zone than in the central zone. Histologically the degeneration of tumor cell was low or absent in the peripheral zone of tumor, whereas it was intense in the central zone. 67Ga-citrate was highly accumulated in the zone which the degeneration was low or absent. We, however, could not demonstrate the site where 67Ga-citrate was incorporated.     

比对法在计量标准考核验证中的应用探讨

为探讨比对法在计量标准考核验证中的可行性,将5家实验室分别对同一分度吸量管的检定结果进行比对,同时采用具有溯源性的传递比较法进一步验证比对法的可靠性。验证结果显示,采用比对法和传递比较法对被考核实验室的验证结果一致,说明采用比对法对检定结果的验证是有效的、可行的。     

电感耦合等离子体原子发射光谱法测定钒铁中8个杂质元素含量和方法精密度的验证

提出了电感耦合等离子体原子发射光谱法(ICP-AES)测定钒铁中硅、磷、铝、锰、镍、铬、铜、钛共8个杂质元素含量的方法。钒铁样品(0.5000g),先后加入50%(体积分数)硝酸溶液20mL及50%(体积分数)盐酸溶液10mL,在100℃左右加热溶解,溶解过程中应注意保持溶液体积在25mL左右。将溶液过滤并置于200mL容量瓶中作为母液留用。将滤纸及不溶物一并移入铂坩埚中,置于马弗炉中,先于250℃灰化20min,稍冷后加入无水碳酸钠和硼酸(质量比2∶1)组成的混合熔剂0.3g,升温至950℃融熔15min。冷却,用体积比1∶10的盐酸溶液10mL浸出熔块,将此溶液与上述母液合并并加水定容至200mL。此溶液供ICP-AES在仪器工作条件下进行分析。绘制校准曲线时,加入纯铁和五氧化二钒作为基体,以消除基体干扰,然后加入上述8种元素的标准溶液,并按上述溶液最终稀释体积条件和仪器工作条件制作曲线(R大于0.999)。为验证所提出的分析方法的测定数据的精密度,约请了10个实验室对8个不同含量水平的钒铁样品对方法作协同试验,按GB/T 6379.2-2004所规定的方法求算了重复性标准偏差Sr和重复性限r,以及再现性标准偏差SR和再现性限R,并求得所测定的8种元素在各自的测定范围内的r与w之间和R与w之间的函数关系,说明该方法有较好的稳定性和准确性,而且证明此方法是可行的。     

吸附等温线的插值方法的研究

关于用函数形式确切地描述吸附等温线已有不少研究.沈中和等认为,难于找到适合各种形状吸附等温线的理想函数形式,建议采用线性插值.但线性插值显然会使计算结果带来额外偏差.Buchner等和Zingales等曾提出用函数平滑或拟合整个吸附等温线,但此法受所选函数形式的限制并存在拟合误差,无法如实描绘某些吸附等     

Investigation of the tautomeric equilibrium of some phenylazonaphthols

The tautomeric equilibrium of phenylazonaphthols was investigated by the HMO method and by IR spectroscopy. It was found that in the case of 4-phenylazo-1-naphthol the thermodynamic stability of the tautomers was approximately the same, in the case of 1-phenylazo-2-naphthol the naphthoquinone hydrazone tautomer was substantially more stable.     

全自动凯氏定氮仪测定化肥中的含氮量

建立全自动凯氏定氮仪检测化肥中氮含量的分析方法。称取总氮量在0.03~0.3 g范围的样品,经消解仪消解及全自动凯氏定氮仪碱化蒸馏,以硼酸为接收液,用0.15~0.20 mol/L的盐酸标准溶液进行自动滴定。该方法加标回收率为99.0%~101.5%,测定结果的相对标准偏差小于1.0%(n=6)。与国标GB/T 8527–2010法测定结果无显著性差异,全自动凯式定氮仪法的准确度、精密度均优于国标方法,而且所用试剂少、分析时间短,满足实验室快速检测大批量化肥中含氮量的需要。     

离子色谱仪检定及整机性能不确定度评定

介绍电导检测器离子色谱检定方法。采用氯离子标准物质,使用泵流量设定值误差、流量稳定性、基线噪声、基线漂移、最小检测浓度、线性相关性、整机性能定性定量重复性等参数对离子色谱仪进行检定。同时用5 μg/mL氯离子为检测离子,结合JJF 1059.1–2012 《测量不确定度评定与表示》对整机性能不确定度来源进行考察。结果表明:在置信区间为95%时(包含因子k=2),氯离子的质量浓度为(4.94±0.35)μg/mL。经不确定度分析,标准工作曲线拟合引入的不确定度最大,其次是样品的重复随机测试过程。     

1,1,3,3-四(全氟己基乙基)二锡氧烷二聚体在环氧化合物开环反应中的催化作用

采用氟碳-有机溶剂两相催化体系,考察了1,1,3,3-四(全氟己基乙基)二锡氧烷二聚体(1)在环氧化合物开环反应中的催化作用.结果表明,催化剂(1)在氟碳-有机溶剂两相体系中使环氧苯乙烯和甲醇的开环反应产率高达95%,¹³CNMR谱表明,开环反应的区域选择性为100%.在氟碳-有机溶剂两相催化体系中以一锅法制备了3-苯基丙酸2-甲氧基-2-苯乙醇酯,收率高,方法简便,催化剂几乎可以定量回收循环使用.     

支气管肺炎患儿血清锌、铜含量分析

对支气管肺炎患儿200例，健康儿童200例，进行了血清锌，铜含量测定。结果显示，支气管肺炎患儿的血清锌含量降低。血清铜含量升高，提示微量元素与人体疾病关系密切。锌是儿童发育所需的重要物质。对健康儿童来说，它可能较恒定。可以反映儿童的免疫机能和发育水平。     

Determination of the purity of methyl nitrite

The purity of methyl nitrite prepared by the esterification of methanol with aqueous nitrous acid was determined by absorbing gaseous samples in solutions of acidic potassium permanganate and hydriodic acid. Nitrate formed in the oxidation reaction was determined by steam distillation, and iodomethane formed in hydriodic acid was determined by gas-liquid chromatography. The method was used to evaluate purification procedures.