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51.
千层塔中三萜成分的研究 总被引:5,自引:0,他引:5
前曾报道自千层塔[Huperzia serrata Thunb.(Trev)=Lycopodium serratum Thunb(Trev.)]中分得具有胆碱酯酶抑制活性的新生物碱——石杉碱甲、石杉碱乙、甲基石杉碱乙及已知生物碱8-deoxyserratinine,serratinine,lycodoline及lycoclavine。为进一步阐明该植物的化学成分,我们对其三萜成分进行了研究。从浙江安吉产的千层塔植物中分到六个石松三萜,其中一个为新化合物,经下述方法推定为serratenediol-21-acetate(Ⅰ)。另五 相似文献
52.
本文报道我国西南产麻黄——丽江麻黄Ephedra likiangensis Florin、匍枝丽江麻黄E.likiangensis f.mairei(Florin)C.Y.Cheng、藏麻黄E.saxatilis Royle ex Florin、山岭麻黄E.gerardiana Wall、垫状山岭麻黄E.gerardiana Var.congesta C.Y.Cheng、矮麻黄E.minuta Florin和异株矮麻黄E.minuta var.dioeca C.Y.Cheng,以及形态组织特征较特殊的宁夏产斑子麻黄E.lepidosperma C.Y.Cheng、新疆产窄膜麻黄E.lomatolepis Schrenk,西藏产西藏中麻黄E.intermedia var.tibetica Stapf的生药形态组织学研究结果。并根据对国产麻黄的生药形态组织学的系统研究结果,分别编写了各种国产麻黄(包括13种3变种1变型)的生药性状和生药显微特征检索表。 相似文献
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55.
微球给药系统的工艺优化研究 总被引:8,自引:2,他引:8
目的 :阐述微球制备工艺中的优化技术。方法 :检索近年来国内外文献并进行整理和归纳。结果 :单因素设计、正交设计、均匀设计、因子设计是目前微球工艺中常用的优化方法。结论 :通过上述方法优化微球的制备工艺 ,可在一定条件下达到经济、高效的目的 ,更理想的优化技术尚有待研究 相似文献
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Margaret Wrensch Ph.D. Shanna Swan Ph.D. Peter J. Murphy Ph.D. Jane Lipscomb Ph.D. Kathleen Claxton M.A. David Epstein M.A. 《Archives of environmental & occupational health》2013,68(4):210-216
We recently concluded that exposure to solvent-contaminated drinking water was an unlikely explanation for observed excesses of adverse pregnancy outcomes during 1980–1981 in the Los Paseos neighborhood of Santa Clara County, California, because these excesses were not observed in an adjacent exposed area. The validity of this conclusion depends on the assumption that the two areas had comparable exposure. Using quantitative methods to model movement of the solvent leak plume and water flow within the distribution system, we estimated that women with adverse outcomes were no more likely to have received contaminated water than women with normal live births. These results strengthen the conclusion that exposures to water from the contaminated well were not responsible for the excess of adverse outcomes observed in the Los Paseos area. 相似文献
58.
Cory P. Daignault Edwin L. Palmer James A. Scott John S. Swan Gilbert H. Daniels 《Nuclear Medicine and Molecular Imaging》2015,49(3):217-222
A Schmorl’s node is a common incidental finding encountered during radiologic imaging. Despite the vertebral body being a common site of metastatic disease, a lytic lesion adjacent to an endplate with typical imaging features can often confidently be called a Schmorl’s node. This is a case report of a patient with a single well-defined FDG-avid papillary thyroid carcinoma metastasis to the spine that had imaging findings characteristic of a Schmorl’s node on CT and MRI. This case is important to consider as it demonstrates that the imaging characteristics of metastatic disease and Schmorl’s nodes can overlap. 相似文献
59.
Harold S. Javitz Janet Brigham Christina N. Lessov-Schlaggar Ruth E. Krasnow & Gary E. Swan 《Addiction (Abingdon, England)》2009,104(6):1027-1035
Aim To examine whether Rasch modeling would yield a unidimensional withdrawal sensitivity measure correlating with factors associated with successful smoking cessation.
Design The psychometric Rasch modeling approach was applied to estimate an underlying latent construct (withdrawal sensitivity) in retrospective responses from 1644 smokers who reported quitting for 3 or more months at least once.
Setting Web-based, passcode-controlled self-administered computerized questionnaire.
Participants Randomly selected convenience sample of 1644 adult members of an e-mail invitation-only web panel drawn from consumer databases.
Measurements Lifetime Tobacco Use Questionnaire, assessing tobacco use across the life-span, including demographics and respondent ratings of the severity of withdrawal symptoms experienced in respondents' first and most recent quit attempts lasting 3 or more months.
Findings Rasch-modeled withdrawal sensitivity was generally unidimensional and was associated with longer periods of smoking cessation. One latent variable accounted for 74% of the variability in symptom scores. Rasch modeling with a single latent factor fitted withdrawal symptoms well, except for increased appetite, for which the fit was marginal. Demographic variables of education, gender and ethnicity were not related to changes in sensitivity. Correlates of greater withdrawal sensitivity in cessation attempts of at least 3 months included younger age at first quit attempt and indicators of tobacco dependence.
Conclusion The relationship between tobacco dependence symptoms and Rasch-model withdrawal sensitivity defines further the relationship between sensitivity and dependence. The findings demonstrate the utility of modeling to create an individual-specific sensitivity measure as a tool for exploring the relationships among sensitivity, dependence and cessation. 相似文献
Design The psychometric Rasch modeling approach was applied to estimate an underlying latent construct (withdrawal sensitivity) in retrospective responses from 1644 smokers who reported quitting for 3 or more months at least once.
Setting Web-based, passcode-controlled self-administered computerized questionnaire.
Participants Randomly selected convenience sample of 1644 adult members of an e-mail invitation-only web panel drawn from consumer databases.
Measurements Lifetime Tobacco Use Questionnaire, assessing tobacco use across the life-span, including demographics and respondent ratings of the severity of withdrawal symptoms experienced in respondents' first and most recent quit attempts lasting 3 or more months.
Findings Rasch-modeled withdrawal sensitivity was generally unidimensional and was associated with longer periods of smoking cessation. One latent variable accounted for 74% of the variability in symptom scores. Rasch modeling with a single latent factor fitted withdrawal symptoms well, except for increased appetite, for which the fit was marginal. Demographic variables of education, gender and ethnicity were not related to changes in sensitivity. Correlates of greater withdrawal sensitivity in cessation attempts of at least 3 months included younger age at first quit attempt and indicators of tobacco dependence.
Conclusion The relationship between tobacco dependence symptoms and Rasch-model withdrawal sensitivity defines further the relationship between sensitivity and dependence. The findings demonstrate the utility of modeling to create an individual-specific sensitivity measure as a tool for exploring the relationships among sensitivity, dependence and cessation. 相似文献
60.
The epidemiology of hyperuricaemia and gout in Taiwan aborigines 总被引:4,自引:1,他引:4
To determine the prevalence of hyperuricaemia, gout and gout-related
factors in Central Taiwan Atayal aborigines, 342 subjects over 18 yr old
were interviewed and examined. A questionnaire was designed to screen for
signs and symptoms of gout and gout-related risk factors. Serum uric acid,
triglyceride and creatinine were measured in all subjects. The prevalence
of hyperuricaemia was 41.4% and that of gout 11.7% in aborigines. The uric
acid level was 7.9+/-1.7 mg/dl in males and 5.7+/-1.5 in females, and
differed significantly under age 70 yr (P < 0.001). Significantly
increased triglyceride, creatinine and alcoholism was found in gouty
patients compared with non-gouty patients. In 40 cases with gout, 54% had
tophi and 35% of their first- degree relatives had gout. The high
prevalence of hyperuricaemia and gout in Taiwan Atayal aborigines, a
significant family predisposition, increased creatinine level and
alcoholism suggest multiple factors affecting the hyperuricaemia.
相似文献