Aim To establish a LC-MS method for determining the concentration of nifedipine in human plasma and to evaluate the pharmacokinetic characteristics of nifedipine sustained-release tablets. Methods A XB-C18 (5 μm, 4....Aim To establish a LC-MS method for determining the concentration of nifedipine in human plasma and to evaluate the pharmacokinetic characteristics of nifedipine sustained-release tablets. Methods A XB-C18 (5 μm, 4.6 mm ×150 mm) column and a mobile phase of methanol: 0.01 mol·L^-1ammonium acetate (60:40, V/V) were used to separate nifedipine, the detections was accuracy under atmosperic pressure electronic spray ionization (AP-ESI) mode and ion mass spectrum (m/z) of 314.9 [M+H]^+ for nifedipine, and 320.8 [M+H]^+ for lorazepam (Internal Standard, IS). Results The linear range of nifedipine was 0.3 - 80 ng·mL^-1 ( r = 0.9997), and the limit of quantitation (LOQ) was 0.3 ng·mL^-1. The nifedipine pharmacokinetic parameters after a single dose of 20 mg nifedipine sustained-release tablets test (T) or reference (R) were as the followings, t1/2 (6.73 ± 2.00) h and (7.04 ± 2.18) h, Tmax (4.28 ± 0.70) h and (4.48 ± 0.70) h, Cmax(39.66 ± 10.58) ng·mL^-1 and (40.19 ± 10.97) ng·mL^-1, AUC0-36 (391.63 ± 108.55) ng·mL^-1·h and (387.57 ± 121.51) ng·mL^-1·h, and AUC0-∞ (408.28 ± 121.16) ng·mL^-1·h and (406.15 ± 133.13) ng·mL^-1·h. The relative bioavailability of nifedipine sustained-release tablets (test) was (103.02 ± 13.93) %. Conclusion LC-MS method for the determination of concentrations of nifedipine in human plasma was sensitive and accurate, and could be used in nifedipine bioavailability and pharmacokinetic studies.展开更多
A new compound (1) named as winchic acid and eight known ones were isolated from the stem barks of Winchia colophylla A. DC. (collected in Xishuangbanna, Yunnan Province of China). The new compound 1 was identified as...A new compound (1) named as winchic acid and eight known ones were isolated from the stem barks of Winchia colophylla A. DC. (collected in Xishuangbanna, Yunnan Province of China). The new compound 1 was identified as 3beta-hydroxy-27-(4-hydroxy-3-methoxy-E-cinnamoyloxy)-lup-20(29)-en-28-oic acid on the basis of 1D and 2D NMR experiments. The eight known compounds were determined to be lupenone, lupenyl acetate, betulinic acid, alpha-amyrin acetate, ursolic acid, ptiloepoxide, beta-amyrin and cycloeucalenol, respectively.展开更多
Two new isoflavones (8, 3'-dihydroxy-7,4'-dimethoxyisoflavone, odoratin-7-0-[3-D-glu-copyranoside) and four known isoflavones (formononetin, 7,3'-dihydroxy-8,4'-dimethoxyisoflavone, calycosin, calycosi...Two new isoflavones (8, 3'-dihydroxy-7,4'-dimethoxyisoflavone, odoratin-7-0-[3-D-glu-copyranoside) and four known isoflavones (formononetin, 7,3'-dihydroxy-8,4'-dimethoxyisoflavone, calycosin, calycosin-7-0-(3-D-glucopyranoside) were isolated from the roots of Astragalus mem-branaceus (Fisch.) Bunge. Their structures were established by spectral analysis.展开更多
In this paper, the resources of Codonopsis convolvulacea subsp. Vinciflora in 13 counties of Tibet were investigated and analyzed by field investigation, sample point-sample set-sample survey, market investigation and...In this paper, the resources of Codonopsis convolvulacea subsp. Vinciflora in 13 counties of Tibet were investigated and analyzed by field investigation, sample point-sample set-sample survey, market investigation and expert visit. The results showed that among the 13 counties, the distribution area of C. convolvulacea ranked as Gongbujiangda County 〉 Zuogong County 〉 Milin County 〉 Mozhugongka County 〉 Lang County 〉 Duilongdeqing County 〉 Chayu County=Jiali County= Mangkang County=Dingqing County=Baqing County=Suo County=Nimu County. The Gongbujiangda County showed the largest distribution, while Zuogong County and Milin County showed relatively small distribution. Chayu County, Jiali County, Mangkang County, Dingqing County, Baqing County, Suo County and Nimu County showed no distribution. The average plant dry weight C. convolvulacea ranked as Duilongdeqing County 〉 Lang County, Gongbujiangda County 〉Milin County 〉Chayu County =Jiali County =Zuogong County =Mangkang County =Dingqing County =Baqing County=Suo County=Mozhugongka County=Nimu County. Among them, Duilongdeqing County showed the largest average plant dry weight. The average plant dry weight of C. convolvulacea in Chayu County, Jiali County, Zuogong County, Mangkang County, Dingqing County, Baqing County, Suo County, Mozhugongka County and Nimu County was all 0 g. The order of biomass of C. convolvulacea in the 13 counties was Mozhugongka County 〉Duilongdeqing County 〉 Lang County 〉 Gongbujiangda County 〉Milin County 〉Zuogong County 〉Dingqing County =Jiali County=Mangkang County=Chayu County=Nimu County=Suo County=Baqing County. Mozhugongka County showed the largest biomass, while the biomass of C. convolvulacea in Dingqing County, Jiali County, Mangkang County, Chayu County, Nimu County, Suo County and Baqing County was all 0 t. The reserve of C. convolvulacea is determined by distribution area habitat and its own growth. In the 13 counties, the reserve of C. convolvulacea ranked as Gongbujiangda County 〉Mozhugongka County 〉 Lang County 〉Zuogong County 〉Milin County 〉Duilongdeqing County 〉Dingqing County=Jiali County=Mangkang County=Chayu County=Nimu County=Suo County=Baqing County. The reserve of C. convolvulacea was biggest in Gongbujiangda County and was relatively small in Dingqing County, Jiali County, Mangkang County, Chayu County, Nimu County, Suo County and Baqing County. Targeting at the problems existing in the utilization of C. convolvulacea, some suggestions are put forward, such as establishment of reserve for medicinal plant ecological industry, artificial cultivation, renewing concept and rational exploitation and utilization. In this paper, the resource characteristics and sustainable utilization of Tibetan medicinal plants were studied so as to provide a theoretical basis for the rational development and utilization of C. convolvulacea in the region.展开更多
[Objective] The research aimed to screen Streptomyces hygroscopicus strains with high production of agricultural antibiotics. [ Method] A strain of S. hygroscopicus was screened from the soil of Hainan Island. After n...[Objective] The research aimed to screen Streptomyces hygroscopicus strains with high production of agricultural antibiotics. [ Method] A strain of S. hygroscopicus was screened from the soil of Hainan Island. After natural screening and consecutive ultraviolet induced mutation twice, S6-7 strain was obtained as the original strain then treated by UV irradiation and streptomycin resistance screening, and finally rescreened through shake-flask fermentation. [Result] 7 better strains were selected by primary screening from 62 single colonies which were picked out randomly. After 3 generations of consecutive cultivation on slant media and rescreening, 5 strains presented obvious forward mutation. The forward mutation rate reached 8.06%, and the largest production increasing rate came up to 25.11%. [Conclusion] By combining streptomycin resistance screening and conventional ultraviolet induced mutation, both the antibiotic-producing capacity and forward mutation screening efficiency of the original strain were greatly enhanced.展开更多
[ Objective ] The aim of this study is to clone and analyze the actin gene from Rehmannia glutinosa. [ Method ] Degenerate primers were designed according to the conserved regions of actin sequences of Rehmannia gluti...[ Objective ] The aim of this study is to clone and analyze the actin gene from Rehmannia glutinosa. [ Method ] Degenerate primers were designed according to the conserved regions of actin sequences of Rehmannia glutinosa and its similar species, RT-PCR was next conducted to amplify the actin gene from Rehmannia glutinosa. [ Result] The amplified fragment is 724 bp and correspondingly 240 amino acids. The BLAST results indicate that the homology between the amplified fragment and other higher plants for aetin gene sequences and amino acid are more than 80% and 90%, respectively, suggesting that the amplified fragment is the actin gene of Rehmannia glutinosa. [ Conclusion] Phylogenetic analysis shows that the actin gene of Rehmannia glutinosa has an intimate genetic relationship with actin7 gene of Nicotiana tabacum.展开更多
Aim To establish a new and sensitive HPLC-MS method for the determination ofzolmitriptan in human plasma and study the pharmacokinetics of zolmitriptan in healthy volunteers.Methods A single oral dose of 5 mg of zolmi...Aim To establish a new and sensitive HPLC-MS method for the determination ofzolmitriptan in human plasma and study the pharmacokinetics of zolmitriptan in healthy volunteers.Methods A single oral dose of 5 mg of zolmitriptan tablet was given to 20 healthy male volunteers.After dosing, blood samples were collected for a period of 24 h, and zolmitriptan concentration inplasma was analyzed by HPLC-MS. Results The plasma concentration-time course fitted well atwo-compartment open model with a lag time, giving the following pharmacokinetic parameters: T_(max)1.60 ± 0.24 h, C_(max) 9.73 ± 1.43 ng·mL^(-1). T_(1/2α)1.72±0.46 h, T_(1/2β) 4.52 + 0.97 h,and AUC_(0-t) 55.59 ± 5.12 ng·mL^(-1)·h. Conclusion The improved analytical method forzolmitriptan is rapid, sensitive and suitable for application to pharmacokinetic studies and routinedetermination of numerous samples.展开更多
Researches on pharmacological action and drug development of Periplane- ta americana have demonstrated that it has wide medicinal value, low side effects and rich resources, having good application prospects in medici...Researches on pharmacological action and drug development of Periplane- ta americana have demonstrated that it has wide medicinal value, low side effects and rich resources, having good application prospects in medicine field. This article reviewed the researches on pharmacological action and clinical application of Periplaneta americana in order to provide references for the further research and devel- opment of Periplaneta americana medicines.展开更多
Aim To study fuel dispersion in fuel air explosive(FAE) and computational ways of fuel dispersion velocity in the near area. Methods\ The dispersion process of fuel in FAE was analyzed by the use of results measured ...Aim To study fuel dispersion in fuel air explosive(FAE) and computational ways of fuel dispersion velocity in the near area. Methods\ The dispersion process of fuel in FAE was analyzed by the use of results measured with KODAK EKTAPRO EM Motion Analyzer and setting up mechanical models. Results\ Computational methods for fuel dispersion velocity in the acceleration stage is given and taken as a base for the study of fuel dispersion in the intermediate and the far area. Conclusion\ When the fuel flow velocity is higher than that of the explosion gas in the center cavity, the fuel divides with the explosion gas and its velocity of flow reaches a maximum. The acceleration stage ends at that time. The fuel dispersion velocity at this time is the initial conditions for numeral analyses of dispersion process in the intermediate and far areas.展开更多
[ObJective] The research aimed to determine the geographic distribution map of system of Rana dybowskii. [Method] Four morphologic indices (body length, body weight, forelimb length, hindlimb length) of eight geogra...[ObJective] The research aimed to determine the geographic distribution map of system of Rana dybowskii. [Method] Four morphologic indices (body length, body weight, forelimb length, hindlimb length) of eight geographical populations of R.dybowskii which naturally distribute in Changhai Mountain and Xiaoxing'an Mountain were measured. Measure results were variance analyzed and cluster analyzed. [Result] Variance analysis showed: the genetic branching among the Dongfanghong male population( belongs to Wandashan) and Xiaoxing'an Mountain male population and Changbai Mountain male population were significantly different (P〈0.05) ; the genetic branching between the Hebei female population (belongs to Xiaoxing'an Mountain) and Changbai Mountain female population was significantly different (P〈0.05 ). Cluster analysis showed : male R.dybowskii can be divided into three groups : the first group included Quanyang, Tianbei, Chaoyang and Ddkouqin, the second group included Tieli and Anshan, the third group included Dongfanghong; and the female R. dybowskii can be divided into three groups : the first group included Quanyang and Chaoyang, the second group included Tianbei and Dakouqin, the third group included Hebei. [Condusion] The paper deduced that the Sanjiang Plain was the geographical origin center ofR. dybowskii which radiated to Changbai Mountain and Xiaoxing'an Mountain along the adverse current of Songhua River basin, therefore, the current distribution pattern of R. dybowskii was formed.展开更多
Betulin, which is a medicinal pentacyclic triterpene, is abundant in the bark of white birch (Betula platyphlly). The bark of birch was collected at Tayuan Forest Farm of Jiagedaqi, Heilongjiang Province in September ...Betulin, which is a medicinal pentacyclic triterpene, is abundant in the bark of white birch (Betula platyphlly). The bark of birch was collected at Tayuan Forest Farm of Jiagedaqi, Heilongjiang Province in September 2000. Supercritical fluid extraction (SFE) that is a new separation technology has been used for the processing pharmaceutical and natural products. In this paper, the extraction of betulin from the bark of birch by supercritical CO2 extraction was studied. The authors investigated and analyzed a few parameters such as modifier dosage, extraction pressure and extraction temperature. The optimal extrac-tion conditions showed that the modifier dosage used for per gram bark powder was 1.5 mL, the extraction pressure was at 20 Mpa, and the extraction temperature was at 55 C. The velocity of flow of liquid CO2 was at 10 kg/h. The pressure and tem-perature in separation vessel were at 5.5 Mpa and 50 C, respectively.展开更多
At present, the excessive application of traditional chemical pesticides, serious pesticide residue pollution and destruction of the ecological balance in China have become important factors affecting the quality and ...At present, the excessive application of traditional chemical pesticides, serious pesticide residue pollution and destruction of the ecological balance in China have become important factors affecting the quality and safety of medicinal material. Biological pesticides are rapidly developed due to their characteristics of high efficiency, low toxicity and residue. This study aimed to introduce the specific property of biological pesticides, review the classification of biological pesticides and their application in medicinal plants, analyze the problems in the production and utilization process of biological pesticides, and forecast the developmental prospect.展开更多
On the basis of extensive literature search, the species, ingredients, pharmacology, clinical applications, ecological value and cultivation techniques of Scirpus tabemaemontani Gmel have been reviewed, to provide sci...On the basis of extensive literature search, the species, ingredients, pharmacology, clinical applications, ecological value and cultivation techniques of Scirpus tabemaemontani Gmel have been reviewed, to provide scientific data for further research & development.展开更多
Aster souliei Franch, (Compositae) is a. herbaceous plant distributed innorth China. It has been used in folk medicine as antipyretic, detoxicant, expectorant andantitussive. In an effort to find biologically active c...Aster souliei Franch, (Compositae) is a. herbaceous plant distributed innorth China. It has been used in folk medicine as antipyretic, detoxicant, expectorant andantitussive. In an effort to find biologically active components from Chinese medicinal plants ' ,we have examined the aerial parts of this herb, leading to the isolation of a clerodane-typediterpene, 18, 19-dihydroxy-5α, 10β-neo-cleroda-3, 13 (l4)-dien-16, 15-butenolide (1). In thispaper we report the structural elucidation, and the antitumor and antibacterial activities of thiscompound. It was found that 1 possesses moderate cytotoxicity against human leukemia cells (HL-60)and activity against microorganisms.展开更多
文摘Aim To establish a LC-MS method for determining the concentration of nifedipine in human plasma and to evaluate the pharmacokinetic characteristics of nifedipine sustained-release tablets. Methods A XB-C18 (5 μm, 4.6 mm ×150 mm) column and a mobile phase of methanol: 0.01 mol·L^-1ammonium acetate (60:40, V/V) were used to separate nifedipine, the detections was accuracy under atmosperic pressure electronic spray ionization (AP-ESI) mode and ion mass spectrum (m/z) of 314.9 [M+H]^+ for nifedipine, and 320.8 [M+H]^+ for lorazepam (Internal Standard, IS). Results The linear range of nifedipine was 0.3 - 80 ng·mL^-1 ( r = 0.9997), and the limit of quantitation (LOQ) was 0.3 ng·mL^-1. The nifedipine pharmacokinetic parameters after a single dose of 20 mg nifedipine sustained-release tablets test (T) or reference (R) were as the followings, t1/2 (6.73 ± 2.00) h and (7.04 ± 2.18) h, Tmax (4.28 ± 0.70) h and (4.48 ± 0.70) h, Cmax(39.66 ± 10.58) ng·mL^-1 and (40.19 ± 10.97) ng·mL^-1, AUC0-36 (391.63 ± 108.55) ng·mL^-1·h and (387.57 ± 121.51) ng·mL^-1·h, and AUC0-∞ (408.28 ± 121.16) ng·mL^-1·h and (406.15 ± 133.13) ng·mL^-1·h. The relative bioavailability of nifedipine sustained-release tablets (test) was (103.02 ± 13.93) %. Conclusion LC-MS method for the determination of concentrations of nifedipine in human plasma was sensitive and accurate, and could be used in nifedipine bioavailability and pharmacokinetic studies.
文摘A new compound (1) named as winchic acid and eight known ones were isolated from the stem barks of Winchia colophylla A. DC. (collected in Xishuangbanna, Yunnan Province of China). The new compound 1 was identified as 3beta-hydroxy-27-(4-hydroxy-3-methoxy-E-cinnamoyloxy)-lup-20(29)-en-28-oic acid on the basis of 1D and 2D NMR experiments. The eight known compounds were determined to be lupenone, lupenyl acetate, betulinic acid, alpha-amyrin acetate, ursolic acid, ptiloepoxide, beta-amyrin and cycloeucalenol, respectively.
基金This project is supported by National Center of New Drug Research,Science and Technology Committee and Educational Committee of Shanghai.
文摘Two new isoflavones (8, 3'-dihydroxy-7,4'-dimethoxyisoflavone, odoratin-7-0-[3-D-glu-copyranoside) and four known isoflavones (formononetin, 7,3'-dihydroxy-8,4'-dimethoxyisoflavone, calycosin, calycosin-7-0-(3-D-glucopyranoside) were isolated from the roots of Astragalus mem-branaceus (Fisch.) Bunge. Their structures were established by spectral analysis.
基金Supported by the Fourth National Census of Traditional Chinese Medicine Resources(20120716-540000)Program for Research on Humanities and Social Sciences in Colleges and Universities of Tibet Autonomous Region(sk2015-34)Construction Project for Tibet Characteristic Agriculture and Animal Husbandry Resources R&D Collaborative Innovation Center(2014-2015)~~
文摘In this paper, the resources of Codonopsis convolvulacea subsp. Vinciflora in 13 counties of Tibet were investigated and analyzed by field investigation, sample point-sample set-sample survey, market investigation and expert visit. The results showed that among the 13 counties, the distribution area of C. convolvulacea ranked as Gongbujiangda County 〉 Zuogong County 〉 Milin County 〉 Mozhugongka County 〉 Lang County 〉 Duilongdeqing County 〉 Chayu County=Jiali County= Mangkang County=Dingqing County=Baqing County=Suo County=Nimu County. The Gongbujiangda County showed the largest distribution, while Zuogong County and Milin County showed relatively small distribution. Chayu County, Jiali County, Mangkang County, Dingqing County, Baqing County, Suo County and Nimu County showed no distribution. The average plant dry weight C. convolvulacea ranked as Duilongdeqing County 〉 Lang County, Gongbujiangda County 〉Milin County 〉Chayu County =Jiali County =Zuogong County =Mangkang County =Dingqing County =Baqing County=Suo County=Mozhugongka County=Nimu County. Among them, Duilongdeqing County showed the largest average plant dry weight. The average plant dry weight of C. convolvulacea in Chayu County, Jiali County, Zuogong County, Mangkang County, Dingqing County, Baqing County, Suo County, Mozhugongka County and Nimu County was all 0 g. The order of biomass of C. convolvulacea in the 13 counties was Mozhugongka County 〉Duilongdeqing County 〉 Lang County 〉 Gongbujiangda County 〉Milin County 〉Zuogong County 〉Dingqing County =Jiali County=Mangkang County=Chayu County=Nimu County=Suo County=Baqing County. Mozhugongka County showed the largest biomass, while the biomass of C. convolvulacea in Dingqing County, Jiali County, Mangkang County, Chayu County, Nimu County, Suo County and Baqing County was all 0 t. The reserve of C. convolvulacea is determined by distribution area habitat and its own growth. In the 13 counties, the reserve of C. convolvulacea ranked as Gongbujiangda County 〉Mozhugongka County 〉 Lang County 〉Zuogong County 〉Milin County 〉Duilongdeqing County 〉Dingqing County=Jiali County=Mangkang County=Chayu County=Nimu County=Suo County=Baqing County. The reserve of C. convolvulacea was biggest in Gongbujiangda County and was relatively small in Dingqing County, Jiali County, Mangkang County, Chayu County, Nimu County, Suo County and Baqing County. Targeting at the problems existing in the utilization of C. convolvulacea, some suggestions are put forward, such as establishment of reserve for medicinal plant ecological industry, artificial cultivation, renewing concept and rational exploitation and utilization. In this paper, the resource characteristics and sustainable utilization of Tibetan medicinal plants were studied so as to provide a theoretical basis for the rational development and utilization of C. convolvulacea in the region.
基金Supported by Basic Research Fund for Central Nonprofit Institutes(Agro-environmental Protection Institute of Ministry of Agriculture)~~
文摘[Objective] The research aimed to screen Streptomyces hygroscopicus strains with high production of agricultural antibiotics. [ Method] A strain of S. hygroscopicus was screened from the soil of Hainan Island. After natural screening and consecutive ultraviolet induced mutation twice, S6-7 strain was obtained as the original strain then treated by UV irradiation and streptomycin resistance screening, and finally rescreened through shake-flask fermentation. [Result] 7 better strains were selected by primary screening from 62 single colonies which were picked out randomly. After 3 generations of consecutive cultivation on slant media and rescreening, 5 strains presented obvious forward mutation. The forward mutation rate reached 8.06%, and the largest production increasing rate came up to 25.11%. [Conclusion] By combining streptomycin resistance screening and conventional ultraviolet induced mutation, both the antibiotic-producing capacity and forward mutation screening efficiency of the original strain were greatly enhanced.
基金National Natural Science Foundation of China (No 30472155)Beijing Natural Science Foundation (No 5062035)~~
文摘[ Objective ] The aim of this study is to clone and analyze the actin gene from Rehmannia glutinosa. [ Method ] Degenerate primers were designed according to the conserved regions of actin sequences of Rehmannia glutinosa and its similar species, RT-PCR was next conducted to amplify the actin gene from Rehmannia glutinosa. [ Result] The amplified fragment is 724 bp and correspondingly 240 amino acids. The BLAST results indicate that the homology between the amplified fragment and other higher plants for aetin gene sequences and amino acid are more than 80% and 90%, respectively, suggesting that the amplified fragment is the actin gene of Rehmannia glutinosa. [ Conclusion] Phylogenetic analysis shows that the actin gene of Rehmannia glutinosa has an intimate genetic relationship with actin7 gene of Nicotiana tabacum.
文摘Aim To establish a new and sensitive HPLC-MS method for the determination ofzolmitriptan in human plasma and study the pharmacokinetics of zolmitriptan in healthy volunteers.Methods A single oral dose of 5 mg of zolmitriptan tablet was given to 20 healthy male volunteers.After dosing, blood samples were collected for a period of 24 h, and zolmitriptan concentration inplasma was analyzed by HPLC-MS. Results The plasma concentration-time course fitted well atwo-compartment open model with a lag time, giving the following pharmacokinetic parameters: T_(max)1.60 ± 0.24 h, C_(max) 9.73 ± 1.43 ng·mL^(-1). T_(1/2α)1.72±0.46 h, T_(1/2β) 4.52 + 0.97 h,and AUC_(0-t) 55.59 ± 5.12 ng·mL^(-1)·h. Conclusion The improved analytical method forzolmitriptan is rapid, sensitive and suitable for application to pharmacokinetic studies and routinedetermination of numerous samples.
基金Supported by the National Natural Science Foundation of China(30560181)the Major Project of Yunnan Province(2008IF012)~~
文摘Researches on pharmacological action and drug development of Periplane- ta americana have demonstrated that it has wide medicinal value, low side effects and rich resources, having good application prospects in medicine field. This article reviewed the researches on pharmacological action and clinical application of Periplaneta americana in order to provide references for the further research and devel- opment of Periplaneta americana medicines.
文摘Aim To study fuel dispersion in fuel air explosive(FAE) and computational ways of fuel dispersion velocity in the near area. Methods\ The dispersion process of fuel in FAE was analyzed by the use of results measured with KODAK EKTAPRO EM Motion Analyzer and setting up mechanical models. Results\ Computational methods for fuel dispersion velocity in the acceleration stage is given and taken as a base for the study of fuel dispersion in the intermediate and the far area. Conclusion\ When the fuel flow velocity is higher than that of the explosion gas in the center cavity, the fuel divides with the explosion gas and its velocity of flow reaches a maximum. The acceleration stage ends at that time. The fuel dispersion velocity at this time is the initial conditions for numeral analyses of dispersion process in the intermediate and far areas.
文摘[ObJective] The research aimed to determine the geographic distribution map of system of Rana dybowskii. [Method] Four morphologic indices (body length, body weight, forelimb length, hindlimb length) of eight geographical populations of R.dybowskii which naturally distribute in Changhai Mountain and Xiaoxing'an Mountain were measured. Measure results were variance analyzed and cluster analyzed. [Result] Variance analysis showed: the genetic branching among the Dongfanghong male population( belongs to Wandashan) and Xiaoxing'an Mountain male population and Changbai Mountain male population were significantly different (P〈0.05) ; the genetic branching between the Hebei female population (belongs to Xiaoxing'an Mountain) and Changbai Mountain female population was significantly different (P〈0.05 ). Cluster analysis showed : male R.dybowskii can be divided into three groups : the first group included Quanyang, Tianbei, Chaoyang and Ddkouqin, the second group included Tieli and Anshan, the third group included Dongfanghong; and the female R. dybowskii can be divided into three groups : the first group included Quanyang and Chaoyang, the second group included Tianbei and Dakouqin, the third group included Hebei. [Condusion] The paper deduced that the Sanjiang Plain was the geographical origin center ofR. dybowskii which radiated to Changbai Mountain and Xiaoxing'an Mountain along the adverse current of Songhua River basin, therefore, the current distribution pattern of R. dybowskii was formed.
文摘Betulin, which is a medicinal pentacyclic triterpene, is abundant in the bark of white birch (Betula platyphlly). The bark of birch was collected at Tayuan Forest Farm of Jiagedaqi, Heilongjiang Province in September 2000. Supercritical fluid extraction (SFE) that is a new separation technology has been used for the processing pharmaceutical and natural products. In this paper, the extraction of betulin from the bark of birch by supercritical CO2 extraction was studied. The authors investigated and analyzed a few parameters such as modifier dosage, extraction pressure and extraction temperature. The optimal extrac-tion conditions showed that the modifier dosage used for per gram bark powder was 1.5 mL, the extraction pressure was at 20 Mpa, and the extraction temperature was at 55 C. The velocity of flow of liquid CO2 was at 10 kg/h. The pressure and tem-perature in separation vessel were at 5.5 Mpa and 50 C, respectively.
基金Supported by "Twelfth Five-Year" National Technology Support Program(2011BAI-06B01)~~
文摘At present, the excessive application of traditional chemical pesticides, serious pesticide residue pollution and destruction of the ecological balance in China have become important factors affecting the quality and safety of medicinal material. Biological pesticides are rapidly developed due to their characteristics of high efficiency, low toxicity and residue. This study aimed to introduce the specific property of biological pesticides, review the classification of biological pesticides and their application in medicinal plants, analyze the problems in the production and utilization process of biological pesticides, and forecast the developmental prospect.
文摘On the basis of extensive literature search, the species, ingredients, pharmacology, clinical applications, ecological value and cultivation techniques of Scirpus tabemaemontani Gmel have been reviewed, to provide scientific data for further research & development.
文摘Aster souliei Franch, (Compositae) is a. herbaceous plant distributed innorth China. It has been used in folk medicine as antipyretic, detoxicant, expectorant andantitussive. In an effort to find biologically active components from Chinese medicinal plants ' ,we have examined the aerial parts of this herb, leading to the isolation of a clerodane-typediterpene, 18, 19-dihydroxy-5α, 10β-neo-cleroda-3, 13 (l4)-dien-16, 15-butenolide (1). In thispaper we report the structural elucidation, and the antitumor and antibacterial activities of thiscompound. It was found that 1 possesses moderate cytotoxicity against human leukemia cells (HL-60)and activity against microorganisms.