共查询到20条相似文献，搜索用时 890 毫秒
1.
Identification of Rhodiola species by using RP-HPLC 总被引：2，自引：0，他引：2
INTRODUCTION The roots of Rhodiola species, one of the im-portant traditional Chinese herbal medicines, have anti-viral (Sun et al., 1993), anti-tumor (Wang et al., 1992), anti-ageing (Yi et al., 1992), anti-oxygen de-ficiency, anti-radiation (Luo et al., 1996) effects and other pharmacological properties (Xu et al., 2000). Ten Rhodiola species distribute in the Tianshan Mountains areas of China. Biologically active com-pounds content in the roots has large variation and the value of… 相似文献
2.
LEE Sang Hun LEE Kunwoo 《浙江大学学报(A卷英文版)》2006,7(9):1535-1543
INTRODUCTION 3D CAD systems for the feature-based B-rep solid models (Choi et al., 2002; Kim et al., 2003; 2005; Koo and Lee, 2002; Lee et al., 2004; Lee, 2005a) are becoming more suitable for CAD when compared with the conventional polygon-based mul- tiresolution modelling in computer graphics (Cignoni et al., 1998; Schr?der et al., 1992). As illustrated in Fig.1b, the object of the feature-based multiresolution modelling is a solid model where the suppressed ob- jects are form feat… 相似文献
3.
INTRODUCTION Epoxide hydrolases (EHs) play a key role in the transformation and metabolism of xenobiotics in bio-systems (Armstrong, 1987). The enzymes are found ubiquitously in various organisms, including mammals, plants, insects and microorganisms, etc. (Argiriadi et al., 1999). In the human body, EHs are found in organs such as the liver, lung, heart, brain, breast tissue, kidneys, and are associated with various diseases, including emphysema, pregnancy-induced hypertension, acute r… 相似文献
4.
Optimization of fermentation conditions for P450 BM-3 monooxygenase production by hybrid design methodology 总被引：1，自引：0，他引：1
INTRODUCTION P450 enzymes are found throughout nature and can catalyze the oxidation of various chemicals (Ortiz de Montellano, 1995). Because of their important roles in these processes, numerous systems have been developed for the expression of P450s in vitro (Helvig and Capdevila, 2000; Nakamura et al., 2001; Deeni, 2001). But P450 enzymes fermentation levels in the microbial system are too low to catalyze the reactions for industrial preparations. Therefore, it is necessary to impr… 相似文献
5.
Homoharringtonine induces apoptosis of endothelium and down-regulates VEGF expression of K562 cells 总被引：1，自引：0，他引：1
INTRODUCTION Homoharringtonine (HHT) is a cephalotoxin alkaloid with anti-leukemic activity and had been used successfully in the treatment of acute and chronic myeloid leukemias (O払rien et al., 1995; 1999; Feldman et al., 1992). The principal mecha-nism of action by HHT is the inhibition of protein synthesis in a dose- and time-dependent manner by binding to ribosome and inhibiting polypeptide chain elongation (Tujebajeva et al., 1989; Zhou et al., 1995). HHT had been shown to indu… 相似文献
6.
YU Ling-min ZHU Chang-chun FAN Xin-hui QI Li-jun YAN Wen 《浙江大学学报(A卷英文版)》2006,7(11):1956-1960
INTRODUCTION The richness of fundamental phenomena and the potential applications in nano-technologies has ar- oused rapidly growing interest in nano-dimensional materials. Quasi-one-dimensional (1D) nano-semi- conductors in the form of nanowires and nanoribbons have recently been successfully fabricated in many laboratories and by many methods (Wu et al., 2004; Yang et al., 2005; Gan et al., 2004; Soumitra et al., 2006). To synthesize CdS nanowires, people have developed a series of sy… 相似文献
7.
INTRODUCTION Piezoelectric symmetric structures always play an important role in the use of piezoelectric materials (Olesiak and Pyryev, 1995; Ding et al., 2003; Wu et al., 2003). To improve the durability of this kind of piezoelectric structures, functionally gradient piezo- electric materials (FGPM) have been developed and used to produce these devices such as sensors and actuators (Hauke et al., 2000; Zhu et al., 1995). For the case when a rectangular plate made of function- ally gr… 相似文献
8.
A novel technique of three-dimensional reconstruction segmentation and analysis for sliced images of biological tissues 总被引：5，自引：0，他引：5
INTRODUCTION The past decades witnessed unprecedented ad-vances in the imaging science fields(Yelbuz et al.,2002;Campagnola et al.,2002;Sharpe et al.,2002).The technique of3D image reconstruction andanalysis plays a significant role in the basic researchof life science,which developed from2D imageprocessing but provides more information than2Dimage,and has rapidly expanded to molecular andcellular field(Guo et al.,1995;Trehan et al.,2003).Despite the rapid development of the new field,… 相似文献
9.
ZHANG Xiu-yan RUAN Hui MU Lin HE Guo-qing TANG Xing-jun CHEN Qi-he 《浙江大学学报(A卷英文版)》2006,7(11):1948-1955
INTRODUCTION Enzymes are efficient and specific biocatalysts widely used in food industries, but their application in industrial process often involves special properties not found in natural source enzymes. In order to ob- tain desirable enzymes, in the past ten years, scientists have developed rational (Kurth et al., 1998; Mouratou et al., 1999; DeSantis et al., 1999) and irrational de- sign methods (Babbitt and Gerlt, 1997; O’Brien and Herschlag, 1999) to improve the enzyme propert… 相似文献
10.
SIMOVSKI C.R VIITANEN A.J. TRETYAKOV S.A 《浙江大学学报(A卷英文版)》2006,7(1):29-33
INTRODUCTION The waveguide properties of linear arrays (chains) of silver nano-particles at optical frequencies are well known (Krenn et al., 1997; 1999; Tretyakov and Viitanen, 2000; Girard et al., 1994; Weber and Ford, 2004). Silver spheres and ellipsoids can support forward or backward waves along the chain depend- ing on their polarization state and the eigenfrequency (Krenn et al., 1999; Tretyakov and Viitanen, 2000; Girard et al., 1994; Weber and Ford, 2004). At com- paratively … 相似文献
11.
尘螨是强烈的过敏原之一,可引起尘螨性哮喘、过敏性鼻炎、过敏性皮炎。1992年我们对张家口医学院居民家中的枕和褥上的尘土进行了尘螨检查,发现尘螨阳性率为10.96％(8户/73户),与国内其他省市报告比较有显著性差异,原因可能与张家口气侯干燥、寒冷、少雨,不利于尘螨的孳生有关。 相似文献
12.
为了解河北省青年对尘螨过敏情况,对张家口医学院1993级新生1017名作了尘螨皮肤点刺实验,结果显示尘螨皮肤点刺试验阳性率在不同性别、地区间无统计学上的差异。 相似文献
13.
Prapassorn Bussaman Chirayu Sa-Uth Paweena Rattanasena Angsumarn Chandrapatya 《Journal of Zhejiang University. Science. B》2012,13(4):261-266
Xenorhabdus bacterium has been used as a biological control agent against Luciaphorus sp., a mushroom mite endemic in Thailand. To develop an effective formulation of Xenorhabdus stokiae, treatments using different parts of X. stokiae isolate PB09 culture, including whole cell suspension, cell-free supernatant, and crude cell extract, were performed. The
results show that different parts of X. stokiae isolate PB09 culture could induce variable effects on mite mortality and fecundity. Application with cell-free supernatant
of X. stokiae culture resulted in both the highest mite mortality rate [(89.00±3.60)%] and the lowest mite fecundity [(41.33±23.69) eggs/gravid
female]. Whole cell suspension of X. stokiae isolate PB09 culture was found to be slightly less effective than its cell-free supernatant, suggesting that X. stokiae was more likely to release its metabolites with acaricidal activities to the surrounding culture media. Crude cell extract
of X. stokiae was not effective against mites. Cell-free supernatant of X. stokiae isolate PB09 was the most effective biological control agent and it could be conveniently used in future formulations instead
of live bacteria. 相似文献
14.
三种方法提取八角茴香精油及其抗菌活性研究 总被引：1，自引：0，他引：1
八角茴香精油及其单体成分具有多种生物活性,广泛应用于食品防腐领域.本文采用三种方法提取八角茴香精油,比较得出最优提取方法,并以大肠杆菌、金黄色葡萄球菌、枯草杆菌等作为供试菌种,对精油的抗菌效果、精油抗菌的稳定性进行了研究.结果表明,采用水蒸气蒸馏法提取八角茴香精油的最佳条件为:原料粉碎程度40目,料液比为1∶10,蒸馏2h,得率为9.194%;采用超临界CO2萃取法提取八角茴香精油的最佳条件为:压力为2000PSI、温度为30℃、萃取2.5h,得率为4.5%.乙醇回流法提取八角茴香精油最佳工艺条件为:料液比为1:10(g/mL),回流次数为3,回流时间为3h,得率最高可达34.52%;乙醇浸提法提取八角茴香精油最佳条件为:料液比1∶20(g/mL),浸提时间3h,粉碎程度60目,最高得率为20.38%.精油对大肠杆菌的抑制效果最好,其次是酵母. 相似文献
15.
短毛独活精油提取及抑菌作用研究 总被引：3，自引：0，他引：3
张知侠 《咸阳师范学院学报》2007,22(2):33-34
用石油醚提取获得短毛独活精油,采用生长速率法测试短毛独活精油的杀菌活性。结果表明:短毛独活精油对12种供试真菌均具有不同程度的抑菌作用,其中对小麦纹枯病菌的抑制率最强,达到100%;其次是油菜菌核病菌、辣椒疫霉病菌,达到80%以上;而对玉米大斑病菌、稻瘟病菌的抑制率相对较低。 相似文献
16.
Phytoremediation effectiveness and remediation costs are driving factors of this project. Full utilization of plant resources after their being used for phytoremediation is an unsolved problem. GC/MS technique was used to investigate the volatiles of the flowers from Elsholtzia argyi (PFE1: Purple Flower Elsholtzia) and their variation 相似文献
17.
Volatile constituents in the flowers of Elsholtzia argyi and their variation： a possible utilization of plant resources after phytoremediation 总被引：2，自引：0，他引：2
Phytoremediation effectiveness and remediation costs are driving factors of this project. Full utilization of plant resources after their being used for phytoremediation is an unsolved problem. GC/MS technique was used to investigate the volatiles of the flowers from Elsholtzia argyi (PFE 1 : Purple Flower Elsholtzia) and their variation (WFE: White Flower Elsholtzia),naturally growing in Pb/Zn mined area, and Elsholtzia argyi (PFE2: Purple Flower Elsholtzia), naturally growing in Jiuxi uncontaminated agriculture soil. Seventeen compounds constituting 86.88% of total essential oils were identified in PFE1, with 2,6-octadienoic acid,3,7-dimethyl-methyl ester being the main constituent (63.30%). Sixteen compounds accounting for 95.32% of total essential oils were identified in WFE, with caryophyllene being the main component (55.02%). Compared to PFE1, PFE2 contained lower level of 2,6-octadienoic acid,3,7-dimethyl-methyl ester (31.76%), which was the main constituent in the total essential oils of PFE2. Caryophyllene is the main ingredient of flavor. Elsholtzia ketone was identified in all the three Elsholtzia plants. It can be concluded that the selected Elsholtzia argyi plants can be exploited on their versatile uses as fragrances and antiseptics due to the perfume ingredient and antibacterial components existing in their essential oils. 相似文献
18.
采用水蒸气蒸馏法从茵陈中提取挥发油,用气相色谱-质谱联用(GC-MS)法测定并分析其化学成分,用归一化法测定其相对含量,结果鉴测出茵陈挥发油含有42个成分,占挥发油总成份的83.2%。 相似文献
19.
A major longitudinal study of runaway and homeless youth resulted in the establishment of a safe house in Calgary. In order to further knowledge building and research in this field, users of the facility are routinely asked to fill out an intake form, and consent is obtained for the use of the information for research purposes. Data collected during the first fourteen months of its operation have now been analyzed. Results are compared to the original survey data to determine which youth are using the facility and which are being missed. Interesting similarities and differences are described and discussed. 相似文献
20.
倪晋权 《马钢职工大学学报》2014,(1):8-10
将电除尘器改为布袋除尘器。结果表明,改进后的竖炉布袋除尘器,设备运行基本稳定,除尘效果良好,在竖炉炉顶使用布袋除尘器,开创了国内竖炉生产使用布袋除尘器的先河。 相似文献