大尺寸均匀有耗球电磁散射的算法

给出了一种用于计算大尺寸均匀有耗球电磁散射的算法，克服了直接利用Ｍｉｅ理论递堆公式在大尺寸时数值解的不确定性，在直接利用Ｍｉｅ理论递推公式适用的大尺寸范围内其数值数与直接利用Ｍｉｅ理论递推公式计算的数值解精度相当。     

Identification of metabolites of Danggui Buxue Tang in rat urine by liquid chromatography coupled with electrospray ionization time‐of‐flight mass spectrometry

A method coupling liquid chromatography with electrospray ionization time‐of‐flight mass spectrometry (LC/ESI‐TOF/MS) has been developed for rapid and sensitive analysis of rat urinary metabolite profile of Danggui Buxue Tang (DBT), a well‐known Chinese herbal formula. After oral administration of DBT, urine samples were collected during 0–24 h, and then pretreated by solid‐phase extraction. A total of 68 compounds including 13 parent compounds and 55 metabolites were detected in the drug‐containing urines compared with blank urines. The total analytical time was less than 20 min. Metabolites of DBT were identified using dynamic adjustment of the fragmentor voltage to produce structure‐relevant fragment ions. By using this approach, the mass accuracy of precursor and fragment ions was typically within ±5 ppm of the theoretical values, and enabled the identification of 43 metabolites including 27 isoflavanoid and 16 phthalide metabolites. Our results indicated that glucuronidation and sulfation were the major metabolic pathways of isoflavonoids, while glutathione conjugation, glucuronidation and sulfation were the main metabolic pathways of phthalides. No saponin‐related metabolites were detected. The results of the present study provided important structural information relating to the metabolism of DBT. Furthermore, this work demonstrated the potential of the LC/ESI‐TOF/MS approach for identification of metabolites from Chinese herbal medicines in urine. Copyright © 2009 John Wiley & Sons, Ltd.     

偏二甲肼渗透管标准物质的制备及其均匀性稳定性研究

以精馏和光解纯化工艺获得的高纯偏二甲肼为原料,制备了渗透率范围为0.5-30μg/min的偏二甲肼渗透管标准物质.经过均匀性、稳定性检验,结果表明:该标准物质均匀性、稳定性良好,为航天作业环境中各类快速检测仪的监控准确性提供了判定依据.     

Three New Apianen lactones Compounds from Dioscorea Cirrhosa Lour

Dioscorea Cirrhosa Laour. which is a species of the Dioscorea, grows abundantly in southern and eastern China. Its roots are used in Chinese medicine as a remedy for various diseases, especially use for tumours and cancers. These results have prompted a search for its chemical constituents. Continuing out previous work,further studies on the constituents of the drug yielded three new compounds along with three known compounds in the EtOAc Fr of EtOH extraction.     

Effects of delayed recovery and nonuniform transmission on the spreading of diseases in complex networks

We investigate the effects of delaying the time to recovery (delayed recovery) and of nonuniform transmission on the propagation of diseases on structured populations. Through a mean-field approximation and large-scale numerical simulations, we find that postponing the transition from the infectious to the recovered states can largely reduce the epidemic threshold, therefore promoting the outbreak of epidemics. On the other hand, if we consider nonuniform transmission among individuals, the epidemic threshold increases, thus inhibiting the spreading process. When both mechanisms are at work, the latter might prevail, hence resulting in an increase of the epidemic threshold with respect to the standard case, in which both ingredients are absent. Our findings are of interest for a better understanding of how diseases propagate on structured populations and to a further design of efficient immunization strategies.     

Ultrafast photo-induced turning of magnetization and its relaxation dynamics in GaMnAs

We report that,by linearly polarized pumping of different wavelengths,Kerr transients appear at zero magnetic field only in the case when GaMnAs samples are initialized at 3 K by first applying a 0.8 Tesla field and then returning to zero field.We find that,instead of magnetization precession,the near-band gap excitation induces a coherent out-of-plane turning of magnetization,which shows very long relaxation dynamics with no precession.When photon energy increases,the peak value of the Kerr transient incre...     

可聚合手性酰胺类单体的合成

以S-(+)-1-甲基环己乙胺或S-(-)-1-甲基苯乙胺为手性源,分别与甲基丙烯酰氯和10-十一烯酰氯酰胺化合成了4个典型的可聚合手性酰胺类单体,其结构经NMR,IR和元素分析表征。     

CO_2 Adducts of the Amino and Imino Groups Studied by ~1HNMR and ~(13)CNMR

When isolating 1,4-dideoxy-1,4-imino-D-arabinitol using Dowex 1(2 (OH- form) or CM-Sephadex C-25 (NH4+ form), we found another compound always accompanied with it. It was apparent that the two compounds had similar structures from their 1HNMR and 13CNMR in D2O (Fig. 1). At first, we guessed the two compounds were isomerides. But when acid was added into the solution of the two compounds, the signals for the minor compound disappeared.Figure 1 13CNMR of 1,4-dideoxy-1,4-imino-D-arabin…     

Determination of Chloride 3-Methyl-9-(2-oxa-2λ5-2H-1,3,2-oxazaphosphorine-2-cyclohexyl)-3,6,9-triazaspiro [5.5] undecane (SLXM-2) in Rats by LC: Application to a Pharmacokinetic Study

A novel and simple liquid chromatographic (LC) method was developed for quantification of a new anticancer compound, chloride 3-methyl-9-(2-oxa-2λ5-2H-1,3,2-oxazaphosphorine-2-cyclohexyl)-3,6,9-triazaspiro [5.5] undecane (SLXM-2) in rat plasma. The present method used protein precipitation for extraction of SLXM-2 from rat plasma. Separation was carried out on a reversed-phase C₁₈ column (150 mm × 4.6 mm i.d., 5 μm). The mobile phases consisted of acetonitrile and 2 mM sodium dodecyl sulfate (SDS) (24:76, v/v). The flow rate was 1.0 mL min^?1. A diode-array detector (DAD) was used and the column effluent was monitored at 192 nm. Regression equations revealed good linear relationship between the peak area and the concentration. The correlation coefficient was 0.9996. The relative standard deviations (RSD) of the precision and accuracy were <9.0% (intra-day) and <6.1% (inter-day), respectively. The recovery and stability were found satisfactory during the study. The method was successfully applied for the pharmacokinetic study of SLXM-2 in rats. After a single dose (400 mg kg^?1) of SLXM-2 was given to rats by intravenous injection, the half-life of SLXM-2 was 0.304 h, the area under the plasma concentration–time curve was 673.1 μg h mL^?1 and the maximal plasma concentration was 1534.9 ± 185.8 μg mL^?1.