Effect of consumption of green and black tea on the level of various enzymes in rats

Summary Drinking of both green and black tea as the only liquid ingested resulted in significant decreases in the activity of transketolase in whole blood of rats both before and after the in vitro addition, of thiamin diphosphate. Liver transketolase activity was decreased only by green tea. Mucosal transketolase activity was not affected by either type of tea. The activity of lactate dehydrogenase (LDH) was not affected by either type of tea, while whole blood LDH was decreased by both green and black tea. Neither tea had any affect on mucosal alkaline phosphatase, but thiamin diphosphatase activity was decreased by both teas. An increase in liver total thiamin resulted from the drinking of both types of tea.     

两步法合成尼群地平的工艺改进

3 -硝基苯甲醛在酸催化剂作用下 ,与乙酰乙酸乙酯用生成纯 3-硝基苄叉基乙酰乙酸乙酯。该物质再与 β -氨基巴豆酸甲酯作用 ,在苄胺类复合催化剂作用下生成高纯度的尼群地平。杂质总含量小于 0 .5 % ;其中二甲酯对称物含量小于 0 .2 %。二乙酯对称物含量小于 0 .1%。     

r-排列非递归生成算法及应用

提出一种利用回溯法生成r-排列的算法.该算法使用栈和队列,并引入标记已选元素的方法,避免了回溯时的重复选择.生成的r-排列具有分组和对称性,且符合字典序.此算法也能生成全排列.利用该算法提出了r-组合生成算法,分析了它们的时间和空间复杂度,并介绍了r-排列和r-组合算法在任务安排问题中的应用.     

Zoeal stages of Hiplyra variegata (Rüppell, 1830) (Crustacea: Brachyura: Leucosiidae) reared in the laboratory and collected from plankton at Al-Kharrar creek,central Red Sea

The zoeal stages of Hiplyra variegata are described and illustrated for the first time. Zoea I was obtained from an ovigerous female, and the zoea II and zoea III stages were captured in the plankton (their identity was confirmed by rearing some of them from earlier stages). Comparisons are made with the only other species of the genus of which larvae are known, i.e. H. platycheir. The presence of a lateral spine on the carapace of zoea I is one of the most important characters that can be used for easy recognition of H. variegata. It is important to note that the third zoea of H. variegata has four small spines at each posterolateral margin of the carapace, in contrast to three spines in other species.     

不同条件下铱负载催化剂性能的比较研究

To discuss the potential role of iridium (Ir) nanoparticles loaded under atmospheric and high pressures, we prepared a series of catalysts with the same active phase but different contents of 10wt%, 20wt%, and 30wt% on gamma-alumina for decomposition of hydrazine. Under atmospheric pressure, the performance of the catalyst was better when 30wt% of the Ir nanoparticles was used with chelating agent that had greater selectivity of approximately 27%. The increase in the reaction rate from 175 to 220 h?1 at higher Ir loading (30wt%) was due to a good dispersion of high-number active phases rather than an agglomeration surface. As a satisfactory result of this investigation at high pressure, Ir catalysts with different weight percentages showed the same stability against crushing and activity with a characteristic velocity of approximately 1300 m/s.     

Optimization of cultural conditions for thermostable β-1,3-1,4-glucanase production by Bacillus subtilis ZJF-IA5

The optimization of cultural conditions for β-glucanase production by Bacillus subtilis ZJF-1A5 was investigated in flask trials. Temperature had great effect on β-glucanasc production which maximized atoptimal temperature of 37℃ and decreased significantly when temperature was over 37℃ . Charge quantity affected β-glucanasc production significantly. Adding oxygen vector N-dodecanc or acetic ether benefited β-glucanasc production, but it depended on the concentration and charge quantity. The results of fractional factorialdesign showed that age and size of inoculum and shaking speed were the key factors affecting β-glueanase production and the cultivation time span to reach the highest β-glucanasc activity. The optimal cultural conditionsfor p-glucanase production obtained with CCD were as follows: inoculum age and size (16 h, 3.82% (v/v)),shaking speed 210 r/rain, charge quantity of 30 mL in 250 mL flask and initial pH 7.0, cultured at 37℃ for 50 h. Repeated experimental results accorded with those predicted by a second-order polynomial model. The amount of p-glucanase, a-amylase and neutral protease produced by B subtills ZJF-1A5 was associated partially with cell growth. Those three enzymes‘ activities increased following the cell growth and increased signifi-cantly when cells entered the stationary phase.     

Large-scale traveling ionospheric disturbances observed by GPS receivers in Antarctica

The paper examines the propagation direction and velocity of largescale traveling ionospheric disturbances (LSTIDs) during extreme geomagnetic storms in the 23rd solar cycle (e.g., October 2003 and No-vember 2003 storms) using GPS observations. In the analysis, the time delay between the vertical total electron content (VTEC) structures at Scott Base, McMurdo, Davis and Casey GPS stations and the distance between these stations were the main parameters in the determination of LSTIDs propagation speed and di...