期刊：
Journal of Applied Polymer Science,2011年122(5):3248-3254 ISSN：0021-8995
通讯作者：
Liu, Yanfei
作者机构：
[Liu, Yanfei; Huang, Kelong; Liu, Suqin] Cent South Univ, Sch Chem & Chem Engn, Changsha 410083, Hunan, Peoples R China.;[Peng, Dongming] Hunan Univ Chinese Med, Sch Pharm, Changsha 410208, Hunan, Peoples R China.;[Liu, Zhenbao] Chinese Acad Med Sci, Inst Biomed Engn, Tianjin 300192, Peoples R China.;[Liu, Zhenbao] Peking Union Med Coll, Tianjin 300192, Peoples R China.
通讯机构：
[Liu, Yanfei] C;Cent South Univ, Sch Chem & Chem Engn, Changsha 410083, Hunan, Peoples R China.
关键词：
drug delivery systems;functionalization of polymers;microencapsulation;polycarbonates
摘要：
A novel biodegradable aliphatic polycarbonate, poly(propylene carbonate maleate) (PPCMA) was synthesized by terpolymerization of carbon dioxide, propylene oxide, and maleic anhydride (MA), using a polymer supported bimetallic complex as catalyst. The utility of PPCMA to encapsulate and control the release of drug pazufloxacin mesilate (PZFX), via microcapsules, was investigated. PPCMA microcapsules containing PZFX were elaborated by solvent evaporation method based on the formation of double W/O/W emulsion. The manufacturing parameters such as the volume ratio of V(PPCMA) : V(PZFX), the concentration of stabilizer gelatin in outer aqueous phase played major roles on microcapsule characters, and were altered to optimize the process parameters. The PPCMA-PZFX microcapsules were obtained with smooth and spherical surface under optimum condition, the mean diameter of microcapsules was similar to 2 mu m, and the drug loading and drug encapsulation efficiency of the microcapsules were 22.9 +/- 1.05% and 82.1 +/- 2.03%, respectively. PZFX released from PPCMA microcapsules was found to reach 89.8 +/- 2.89% after 36d in a pH 7.4 phosphate-buffered solution, and the release profile obeyed the Higuchi equation. The results suggest that the new polymer PPCMA provides an alternative to degradable matrix polymers for long-term sustained releasing drug delivery systems. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 122: 3248-3254, 2011
摘要：
A further chemical investigation of the plant Rubus corchorifolius L. f., collected in Hunan Province, afforded two new ent-kauranoids 6 and 7. Their structures were elucidated by various spectroscopic methods.
摘要：
In order to resolve the problem of data packets losing abruptly in opportunistic networks, a fault-tolerant transfer algorithm based on interweaving code is proposed. The algorithm includes two parts: one is used by nodes sending data and another is used by receiving nodes to recover lost data. When the packets are sent, interweaving idea is used to disperse the packets. When the packets are received, interpolation method is used to recover the sequence of lost packets based on the strong autocorrelation of transferred packet. Then, interpolation method is used to recover lost data.
摘要：
One new tirucallane-type triterpenoid, alianthusaltinin A (1), one new C29 sterone, alianthaltone A (2), and 12 known compounds have been isolated from the stem bark of Ailanthus altissima. The structures of new compounds were identified by means of spectroscopic methods. Compound 3 was isolated from natural sources for the first time, and compounds 4, 5, and 9 were isolated from this plant for the first time.
摘要：
It is well-known for AdaBoost to select out the optimal weak classifier with the least sample-weighted error rate, which might be suboptimal for minimizing the naive error rate.In OtBoost, a two-stage weak classifier selection approach based on adaptive boosting framework is applied to minimize both the sample-weighted error rate and the optimal-thresholded class-weighted error rate.
期刊：
Journal of Chemical Physics,2011年134(8):084103 ISSN：0021-9606
通讯作者：
Liu, Shubin
作者机构：
[Huang, Ying] Hunan Univ Chinese Med, Sch Pharm, Changsha 410208, Hunan, Peoples R China.;[Liu, Shubin] Univ N Carolina, Ctr Res Comp, Chapel Hill, NC 27599 USA.;[Zhong, Ai-Guo] Taizhou Coll, Dept Chem, Linhai 317000, Zhejiang, Peoples R China.;[Yang, Qinsong] PT TSG Chem, Bekasi 17520, Indonesia.
通讯机构：
[Liu, Shubin] U;Univ N Carolina, Ctr Res Comp, Chapel Hill, NC 27599 USA.
关键词：
density functional theory;isomerism;molecular moments;organic compounds
摘要：
The anomeric effect (the tendency of heteroatomic substituents adjacent to a heteroatom within the cyclohexane ring to prefer the axial orientation instead of the sterically less hindered equatorial position) is traditionally explained through either the dipole moment repulsion or the hyperconjugation effect. In this work, by employing our recent work in density functional steric analysis, we provide a novel two-component explanation, which is consistent with the common belief in chemistry that the effect has a stereoelectronic origin. With alpha-D-glucopyranose as the prototype, we systematically explore its conformational space and generate 32 isomers, leading to a total of 80 axial-equatorial conformation pairs. The energy difference analysis of these pairs shows that while statistically speaking the tendency is valid, the anomeric effect is not always true and can be violated. Three energy components, exchange-correlation, classical electrostatic, and density functional steric, are found to be directly proportional to the total energy difference between axial and equatorial isomers. We also found that the total dipole moment change, not the hyperconjugation effect, is a reasonable indicator of the total energy difference. However, all these correlations alone are not strong enough to provide a compellingly convincing explanation for the general validity of the effect. With the help of strong correlations between energy components, an explanation with two energy components, steric and electrostatic, was proposed in this work. We show that the axial-equatorial energy difference in general, with the anomeric effect as a special case, is dictated by two factors of the stereoelectronic origin, steric hindrance and classical electrostatic interactions, synchronously working together. Another explanation in terms of exchange-correlation and electrostatic interactions has also been obtained in this work. (C) 2011 American Institute of Physics. [doi:10.1063/1.3555760]
期刊：
Journal of Hazardous Materials,2010年179(1-3):742-747 ISSN：0304-3894
通讯作者：
Xiao, Xiaohe
作者机构：
[Kong, Weijun; Liu, Wei; Xiao, Xiaohe; Li, Xing-Feng; Zhao, Yanling; Jin, Cheng; Zhang, Ping] 302 Mil Hosp China, China Mil Inst Chinese Mat Med, Beijing 100039, Peoples R China.;[Kong, Weijun; Li, Zulun] Chengdu Univ Tradit Chinese Med, Coll Pharm, Chengdu 611137, Peoples R China.;[Liu, Wei] Jiangxi Univ Tradit Chinese Med, Coll Pharm, Nanchang 330004, Peoples R China.;[Li, Xing-Feng] Hunan Univ Tradit Chinese Med, Coll Pharm, Changsha 410208, Peoples R China.
通讯机构：
[Xiao, Xiaohe] 3;302 Mil Hosp China, China Mil Inst Chinese Mat Med, Beijing 100039, Peoples R China.
关键词：
Bile acid derivative;MANOVA;Microcalorimetry;PCA;S. aureus
摘要：
The effects of two bile acid derivatives, cholic acid (CA) and deoxycholic acid (DCA) on Staphylococcus aureus (S. aureus) growth were investigated and compared by microcalorimetry coupled with multiple analytical methods. The heat power (HP)-time curves of S. aureus growth affected by CA and DCA were studied by similarity analysis (SA), respectively. Then the quantitative thermo-kinetic parameters obtained from these curves were investigated by the multivariate analysis of variance (MANOVA) and principal component analysis (PCA). By analyzing the two main parameters, growth rate constant k(2) of the second exponential phase and the heat power P-2 of the second highest peak, together with the minimum inhibitory concentration (MIC) values of 10 mu g/mL for CA and 20 mu g/mL for DCA, it could be concluded that the antibacterial effect of CA was stronger than that of DCA. The existence of alpha-OH at C-7 position of steroid nucleus of bile acid derivatives enhanced the hydrophilicity of compound CA and its inhibitory effect on S. aureus. This study provides a useful method and idea to accurately evaluate the antibacterial effects of bile acid derivatives, which provides some references for screening out new antibacterial agents with high efficacy and low toxicity. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.
作者：
Research on a novel ant colony optimization algorithm
会议名称：
The Sixth International Symposium on Neural Networks (ISNN2009)
会议时间：
2009-09-30到2009-10-01
会议地点：
wuhan
会议论文集名称：
The Sixth International Symposium on Neural Networks
摘要：
Abstract In this paper, an adaptive optimization system is established. In order to improve the
global ability of basic ant colony algorithm, a novel ant colony algorithm which is based on
adaptively adjusting pheromone decay parameter has been proposed, and it has been
作者机构：
[Wu Yan-shu; Zhang Qian; Jin Cheng; Xiao Xiao-he; Yan Dan] 302 Mil Hosp China, PLA Inst Chinese Mat Med, Beijing 100039, Peoples R China.;[Wu Yan-shu; Zhang Qian; Wang Jian] Chengdu Univ Tradit Chinese Med, Coll Pharm, Chengdu 611137, Peoples R China.;[Jiao Yi] Hunan Univ Tradit Chinese Med, Coll Pharm, Changsha 410002, Hunan, Peoples R China.;[Du Xiao-xi] State Food & Drug Adm, Ctr Drug Evaluat, Beijing 100038, Peoples R China.
通讯机构：
[Xiao Xiao-he] 3;302 Mil Hosp China, PLA Inst Chinese Mat Med, Beijing 100039, Peoples R China.
作者机构：
[张平松; 吴荣新] School of Earth Science and Environmental Engineering, Anhui University of Science and Technology, Huainan, Anhui 232001, China;[刘盛东] School of Resources and Geosciences, China University of Mining and Technology, Xuzhou, Jiangsu 221008, China
通讯机构：
School of Earth Science and Environmental Engineering, Anhui University of Science and Technology, China
期刊：
JOURNAL OF PHYSICAL CHEMISTRY A,2008年112(2):305-311 ISSN：1089-5639
通讯作者：
Xiao, Xiaoming
作者机构：
[Rong, Chunying; Xiao, Xiaoming; Liu, Shubin; Huang, Ying] Hunan Normal Univ, Coll Chem & Chem Engn, Changsha 410081, Hunan, Peoples R China.;[Huang, Ying] Hunan Univ Tradit Chinese Med, Sch Pharm, Changsha 410007, Hunan, Peoples R China.;[Zhong, Aiguo] Taizhou Coll, Dept Chem, Linhai 317000, Zhejiang, Peoples R China.;[Liu, Shubin] Univ N Carolina, Renaissance Comp Inst, Chapel Hill, NC 27599 USA.
通讯机构：
[Xiao, Xiaoming] H;Hunan Normal Univ, Coll Chem & Chem Engn, Changsha 410081, Hunan, Peoples R China.
摘要：
Porphyrin and pincer complexes are both important categories of compounds in biological and catalytic systems. The idea to combine them is computationally investigated in this work. By employment of density functional theory (DFT), conceptual DFT, and time-dependent DFT approaches, structure, spectroscopy, and reactivity properties of porphyrin pincers are systematically studied for a selection of divalent metal ions. We found that the porphyrin pincers are structurally and spectroscopically different from their precursors and are more reactive in electrophilic and nucleophilic reactions. A few quantitative linear/exponential relationships have been discovered between bonding interactions, charge distributions, and DFT chemical reactivity indices. These results are implicative in chemical modification of hemoproteins and understanding chemical reactivity in heme-containing and other biologically important complexes and cofactors.
