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Acta Chromatographica
Authors:
Zhaojun Sheng
,
Ruhan Ye
,
Siyuan Ge
,
Chenggang Wang
,
Xuetao Xu
,
Guangwen Zhang
, and
Ping Luo

An efficient and convenient reversed-phase high-performance liquid chromatography method has been developed and validated for the quantitative determination of cholic acid bulk drugs and their related impurities. Chromatographic separation was performed on a YMC-Pack ODS-AQ column (250 mm × 4.6 mm, S-5 μm, 12 nm), and the mobile phase consisted of acetonitrile, methanol, and diluted formic acid solution (pH 2.5) at a flow rate of 1.0 mL/min. The analytes were monitored using a refractive index detector at 30 °C, and the column temperature was 30 °C. Under the above chromatographic conditions, the method has good specificity and specified impurities can be effectively separated. The proposed method is found to have linearity in the 2.0–80.0 μg/mL concentration range with correlation coefficients of not less than 0.9999. The compounds analyzed in the solutions are stable for at least 7 days, and spike recoveries for all specified impurities range from 91.3% to 109.3% with relative standard deviations (RSDs) not more than 7.3%. The limit of detection and the limit of quantification for the analytes are 0.060 μg/mL and 2.0 μg/mL, respectively. The proposed method can be applied in the quality control assay of cholic acid bulk drugs, with the advantages of simplicity, accuracy, robustness, good selectivity, and high sensitivity.

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Abstract  

Fenton’s reagent was employed to synthesize glyoxalic acid from glyoxal. The reaction conditions were optimized in a semi-batch reactor. The mechanism and kinetics of the reaction were proposed.

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The objective of this study was to establish and optimize high-performance thin-layer chromatography (HPTLC) analysis of gatifloxacin and related substances by the method of design of experiment (DOE). First, preliminary screening of 22 solvents was performed using uniform design (UD) to establish the developing solvent proposed to be optimized. The optimal proportions of components in the developing solvent were established by using central composite design (CCD) to establish and validate HPTLC analysis of gatifloxacin and related substances. Using DOE, it was found that the optimal proportions (by volume) of components in the developing solvent in the HPTLC analytical method were methanol-1,2-dichloroethane-concentrated ammonia solution-acetonitrile (2.8:7.2:0.5:0.5, v/v). Methodological validation showed that the established HPTLC method could separate gatifloxacin and 8 related substances with similar structures effectively. In particular, impurity pairs with the greatest separation difficulty (due to their similar polarities and dipole moments), e.g., impurity #3 (8-fluorogatifloxacin) and impurity #8 (gatifloxacin 2-methylpiperazine), impurity #3, and substance #9 (gatifloxacin), could also be separated effectively. The HPTLC method was simple, accurate, reliable, and suitable for rapid qualitative analysis of gatifloxacin and related substances in routine tests. Additionally, the analytical results presented here may provide useful supplemental information on the current reversed phase high-performance liquid chromatography (RP-HPLC) method, especially in terms of the mechanism of normal-phase separation.

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Scientometrics
Authors:
Jia Zheng
,
Zhi-Yun Zhao
,
Xu Zhang
,
Dar-Zen Chen
,
Mu-Hsuan Huang
,
Xiao-Ping Lei
,
Ze-Yu Zhang
, and
Yun-Hua Zhao

Abstract

Since China adopted Open-Up and Reformed Policy for global collaboration, China's science and technology have experienced an astounding growth. Papers and patents encompass valuable scientific and technological (S&T) information and collaborative efforts. This article studies China's international S&T collaboration from the perspective of paper and patent analysis. The results show that China's total papers and patents have continuously increased from 2004 to 2008, the papers and patents resulting from China's international collaboration also present a steady growth. However, there is a decline in the share of international collaboration papers and patents with a certain range due to the rapid independent R&D. China's international scientific collaboration (ISC) is broadly distributed over many countries, the USA being the most important ISC partners. China's international technological collaboration (ITC) is mainly carried out with USA and Taiwan, and Taiwan has been the most significant ITC partner of when taking countries’ patent output into account. Besides, ISC shows a continuous raise of Chinese papers’ citation. Even the countries with a small amount of papers and ISC with China, exert a positive influence on the impact of citation of Chinese papers as well. However, ITC does not always play an active role in the improvement of citation impact of Chinese patents.

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A convenient method was developed for simultaneous determination of 11 preservatives in cosmetics and pharmaceuticals. Matrix solid-phase dispersion had been optimized as the sample pretreatment technology, using Florisil as a dispersant, anhydrous sodium sulfate as a dehydrant, formic acid as an additive, and n-hexane and ethyl acetate as eluents successively, and followed by gas chromatography–flame ionization detection on a TR-5 capillary column. Experimental results showed that 11 preservatives were baseline separated within 22 min. Good linearities were observed in the concentration range of 0.53–250 μg/mL for all analytes, and there were also minor differences. All correlation coefficients (r) were more than 0.995. The average recoveries at 3 levels of spiked samples ranged from 80% to 124% with 0.9–12% intra-day RSD and 1.8–12% inter-day RSD. The limits of detection were less than 0.18 μg/mL for all analytes. Besides, there was no obvious matrix effect on the analytes. The conclusion was that the developed method was simple, cheap, accurate, precise, and environment-friendly, in addition to existing little matrix effects. It could be recommended to determine 11 preservatives individually or in any their combinations to not only in liquid and gel cosmetics but also in liquid medicine and ointment.

Open access
Scientometrics
Authors:
Jia Zheng
,
Zhi-yun Zhao
,
Xu Zhang
,
Dar-zen Chen
,
Mu-hsuan Huang
,
Xiao-ping Lei
,
Ze-yu Zhang
,
Yun-hua Zhao
, and
Run-sheng Liu

Abstract

Patents are the manifestation of the industry's research and development (R&D) endeavor; therefore, this paper studies the industry evolution of and key technologies in China from the perspective of patent analysis. Patents in six types of industries, including Chemical (excluding Drugs), Computers and Communications, Drugs and Medical, Electrical and Electronics (E&E), Mechanical, and Others are analyzed in this study. Findings from the analysis show a steady increase of US granted utility patents in China as well as percentage of these patents in the world over the period between 2003 and 2008. All the above industries in China have been growing rapidly during this period, which is very different from the global industry development. Despite the rapid development, the citation rates of these patents have been low, reflecting a need for improvement in the quality of patents and R&D performance for these six industries in China in order to exert more influence in the industry world. The analysis on patents also reveals China's industry distribution to be similar to the global industry distribution, with the exception of E&E industry which weights over one third of the total patents in technologies. The E&E industry is also the field with largest economic growth which rises more rapidly after 2006 with a sudden increase of patents in USPC 361. Detailed tracking of the key technology evolution reveals that 90% of the newly issued patents in USPC 361 after 2006 are owned by Foxconn Technology Co., Ltd, pointing to an unbalanced R&D environment in China's E&E industry sector. By providing the insight into the evolution of China's industrial and technological development through the perspective of patent analysis, this paper hopes to provide an objective statistic reference for future policy directions and academic researches.

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Application of microcalorimetry and chemometric analysis

Effects evaluation of angle and nail animal drugs on Bacillus subtilis growth

Journal of Thermal Analysis and Calorimetry
Authors:
Xiaoyan Xing
,
Yanling Zhao
,
Weijun Kong
,
Yanwei Zhong
,
Dan Yan
,
Ping Zhang
,
Yumei Han
,
Lei Jia
,
Cheng Jin
, and
Xiaohe Xiao

Abstract

In this study, microcalorimetry combined with chemometric analysis was used to investigate the effects of angle and nail animal valuable drugs on Bacillus subtilis (B. subtilis) growth. The power–time curves of the growth metabolism of B. subtilis affected by Cornu Cervi Pantotrichum, Cornu Cervi Elaphi, Cornu Saigae Tataricae, cornu caprae hircus, Cornu Bubali, Squama Manis, and Carapax Trionycis were determined using a thermal activity monitor (TAM) air isothermal microcalorimeter, ampoule mode, at 37 °C. By analyzing these curves and some quantitative parameters using principal component analysis, the effects of the seven animal drugs on B. subtilis could be quickly evaluated from the change of the two main parameters, the maximum heat-flow power P m 2 and total heat output Q t: Cornu Saigae Tataricae, cornu caprae hircus, Cornu Bubali, Squama Manis, and Carapax Trionycis inhibited the growth of B. subtilis, while Cornu Cervi Pantotrichum and Cornu Cervi Elaphi promoted the growth of B. subtilis. Further, the result of hierarchical clustering analysis showed that the drugs which promoted the growth of B. subtilis gathered in one cluster, the other drugs which inhibited the growth of B. subtilis gathered in the other cluster. All these illustrated that the internal characteristics of the seven animal drugs were different though they had similar resources and these drugs could be well clustered according the effects of them on B. subtilis growth with the help of chemometric methods. This study provided an useful idea of the combination of microcalorimetry and chemometric analysis for studying the effects of drugs on organisms.

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Abstract

Splenic lymphocytes play an important role in host acute or chronic diseases. The abnormality of these cells in the spleens of humans might lead to some riskful diseases for human. Hence, in this study, the effects of two ginsenosides Rg1 and Rb1 on splenic lymphocytes growth were studied by microcalorimetry. Some qualitative and quantitative information, such as the metabolic power-time curves, growth rate constant k, maximum heat-output power of the exponential phase P max, total heat output Q t of splenic lymphocytes were obtained to present the effects of Rg1 and Rb1 on these cells. The values of k, P max, and Q t from the thermogenic growth curves of splenic lymphocytes were found to increase in the presence of Rg1, while the change was adverse for Rb1, illustrating that Rg1 had promotion effect and Rb1 had inhibitory effect on splenic lymphocytes growth and these promotion or inhibitory effects were enhanced with increasing the concentration of the two compounds, respectively. The microcalorimetric results were confirmed by MTT assay for determining the MTT optical density (OD) value and [3H] Thymidine incorporation assay ([3H]-TdR) for determining the count per minute (cpm) value: Rg1 could increase the MTT OD value and the cpm value of [3H]-TdR incorporation into splenic lymphocytes, and these values were increased with increasing the concentration of this compound, while Rb1 had the adverse results. The structure–activity relationships showed that the glucopyranoside and hydroxyl groups at the dammarane-type mother nucleus skeleton might play a crucial role for the opposing effects of the two ginsenosides on splenic lymphocytes. Compared with the other two assay methods, the microcalorimetric method provided more useful and reliable information for quickly and objectively evaluating the effects of drugs or compounds on the living cells, which would be a highly promising analytical tool for the characterization of the biological process and the estimation of the drugs’ efficiency.

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Abstract

In this study, the activities of four ginsenosides Rc, Re, Rd, and Rf on splenic lymphocytes growth were studied by microcalorimetry. Some qualitative and quantitative information, such as the metabolic power–time curves, growth rate constant k, maximum heat-output power of the exponential phase P max and the corresponding appearance peak time t max, total heat output Q t, and promotion rate R p of splenic lymphocytes growth affected by the four ginsenosides were calculated. In accordance with thermo-kinetic model, the corresponding quantitative relationships of k, P max, t max, Q t, R p, and c were established. Also, the median effective concentration (EC50) was obtained by quantitative analysis. Based on both the quantitative quantity–activity relationships (QQAR) and EC50, the sequence of promotion activity was Rc > Re > Rd > Rf. The analysis of structure–activity relationships showed that the number, type, and position of sugar moieties on the gonane steroid nucleus had important influences on the promotion activity of Rc, Re, Rd, and Rf on splenic lymphocytes growth. Microcalorimetry can be used as a useful tool for determining the activity and studying the quantity–activity relationship of drugs on cell.

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Scientometrics
Authors:
Yuan Wang
,
Ruimin Ma
,
Tianhao Tang
,
Xia Liu
,
Ping Xie
,
Jianxin Wang
,
Jianxiang Liu
,
Haideng Zhou
, and
Siwei Zhang

Abstract

This article explores a method of evaluating the comprehensive competitiveness of American universities in Bridge Engineering, which is beneficial for students’ picking up an ideal university for further study in America. Making use of ESI database, SCI database and EI database as well as the ranking of American universities from U.S. News and World Report, the author evaluates the comprehensive competitiveness of American universities in Bridge Engineering, and then develops the ranking of comprehensive competitiveness of American universities in Bridge Engineering specialty. From the ranking, the author reaches the conclusion that American universities such as University of Illinois-Urbana-Champaign and Georgia Institute of Technology and so on, have comparatively higher international influence and competitiveness in the field of Bridge Engineering.

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