The pharmacokinetical study of plant alkaloid tetrandrine with a simple HPLC method in rabbits     

Jiang XH  Yang JQ  Li N  Wang H  Zhou QX 《Fitoterapia》2011,82(6):878-882

A simple HPLC method was developed to quantify rabbit plasma tetrandrine (Tet) with propranolol (Pro) as internal standard. Based on the established method Tet and Pro were eluted at 7.1 and 12.0 min, respectively. It was shown that the concentration-time data of Tet fit the classical two-compartment model, no matter the drug was administered intravenously or orally to rabbits. The values of AUC_0 → ∞, clearance (Cl_0 → ∞), volume of distribution (Vd), and elimination half-life (t_1/2β) of Tet were 59861.149 ± 26962.196 μg/L ? min, 0.503 ± 0.173 L/min/kg, 179 ± 76.185 L/kg, and 283.808 ± 162.937 min for intravenous injection of 5 mg/kg, or 18986.217 ± 7462.308 μg/L ? min, 0.805 ± 0.267 L/min/kg, 110.284 ± 94.176 L/kg, and 732.919 ± 847.32 min for gavage administration of 10 mg/kg , respectively. The results indicate that Tet displays a limited absorption in intestinal tract, even though it has a favorable pharmacokinetic profile after oral or intravenous administration.  相似文献   

Metabolism mediated interaction of α-asarone and Acorus calamus with CYP3A4 and CYP2D6     

Pandit S  Mukherjee PK  Ponnusankar S  Venkatesh M  Srikanth N 《Fitoterapia》2011,82(3):369-374

The present study was aimed to investigate the possible interaction of the standardized extract of Acorus calamus (AC) with Cytochrome P450 enzyme, quantitative determination of the α-asarone in the AC rhizome was performed by RP-HPLC method. In vitro interaction of the plant extract was evaluated by CYP450-carbon monoxide complex (CYP450-CO) assay. Effect on individual isoforms such as CYP3A4 and CYP2D6 isozymes were analyzed through fluorescence product formation and respective IC₅₀ values were determined. CYP450-CO assay showed moderate interaction potential. Extract showed higher IC₅₀ values (46.84 ± 1.83-32.99 ± 2.21 μg/ml) comparing to the standard inhibitors and lower IC₅₀ value than α-asarone (65.16 ± 2.37-42.15 ± 2.45 μg/ml).  相似文献   

Accuracy of the Rotfinder instrument in detecting decay on Norway spruce (Picea abies) trees     

Jonàs Oliva  Carmen RomeraloJan Stenlid 《Forest Ecology and Management》2011,262(8):1378-1386

Rotfinder is a non-destructive decay-sensing apparatus based on resistance measurements in standing trees. The accuracy of Rotfinder in detecting decay was evaluated in 500 standing trees in three Norway spruce (Picea abies) plots. Trees were measured at three heights, 0.30, 0.66 and 1.30 m. Sections were later inspected for the presence of decay and reaction zones. Inspected trees were mostly infected by Heterobasidion annosum and showed a large variation in the amount of decay present, ranging from 0.1% to 88.0% of the section. Correctly and incorrectly classified trees were compared in terms of ion and element concentration, density and moisture. Measurements at stump level (0.30 m) were more accurate than measurements at breast height (1.30 m) where the reaction zone and decay columns showed lower moisture content. The accuracy of Rotfinder increased when trees with small decay columns were regarded as ‘non-decayed’. When only trees with more than 15% of the section decayed were regarded as ‘decayed’, Rotfinder had an accuracy of 0.86 when performing assessments at stump level. False negatives, as opposed to true positives, corresponded to trees with smaller and drier decay columns, drier reaction zones and lower K⁺ (potassium) concentration in the decay column. False positives corresponded to trees with large sapwood and high sodium content in the sapwood. Rotfinder represents an alternative to the standard method of using increment core observations to assess decay in living trees.  相似文献   

Comparison of Forest Inventory and Analysis surveys, basal area models, and fitting methods for the aspen forest type in Minnesota     

John M. Zobel  Alan R. EkThomas E. Burk 《Forest Ecology and Management》2011,262(2):188-194

The Forest Inventory and Analysis (FIA) unit of the U.S. Forest Service has collected, compiled, and made available plot data from three measurement periods (identified as 1977, 1990, and 2003, respectively) within Minnesota. Yet little if any research has compared the relative utility of these datasets for developing empirical yield models. This paper compares these and other subdatasets in the context of fitting a basal area (B) yield model to plot data from the aspen (Populus tremuloides Michx.) forest type. In addition, several models and fitting methods are compared for their applicability and stability over time. Results suggest that the three parent datasets, along with their subdatasets, provide very similar three parameter B yield model prediction capability, but as model complexity increases, variability in coefficient estimates increases between datasets. The absence of data for older aspen stands and the inherent noise within B data prevented the exact determination of an overall best model. However, the model B = b₁S^b₂(1 − exp( − b₃A)) with site index (S) and stand age (A) as predictors was found consistently among the highest in precision and stability. Additionally, nonlinear least squares and nonlinear mixed-effects fitting procedures produced similar model fits, but the latter is preferred for its potential to improve model projections. The results indicate little practical difference between datasets from different time periods and different sizes when used for fitting the models. Additionally, these results will likely extend to other states or regions with similar remeasurement data on aspen and other forest types, thus facilitating the development of other ecological models focused on forest management.  相似文献   

武陵山区女儿寨森林小流域地表水环境评价     

黄忠良  周小玲  常明庆  王平 《湖南林业科技》2011,38(5):22-26,38

以武陵山区女儿寨森林小流域5个水质监测断面的监测结果为依据,以总氮、总磷、高锰酸盐指数、氨氮作为评价指标,运用综合指数法、模糊数学评价法和灰色关联分析法对其地表水环境进行综合评价.结果表明,源头水、山洞出水口、二级出水口上、二级出水口下和总出水口的水质分别可以达到《地表水环境质量标准》(GB 3838-2002)中的Ⅲ...  相似文献   

生态公益林补偿标准确定的问题、方法与建议     

雍慧熊峰  潘磊王晓荣  王尊一 《湖北林业科技》2011,(6):46-50

生态公益林补偿是生态公益林建设的一项重要内容,如何合理有效地确立生态公益林补偿标准,是解决区域经济发展与生态环境保护矛盾关键。笔者在查阅文献的基础上,概括了我国现有生态补偿标准现状以及存在的主要问题,并对生态公益林补偿标准确定的影响因素和主要方法进行了总结和阐述,最后对如何完善生态补偿标准确定提出几点建议。  相似文献   

谈应用CoreldrawX3软件绘制林业工程作业设计图方法     

裴智能  马协春 《湖北林业科技》2011,(5):69-70

新形势下林业制图既要图面整洁、美观大方,又要高效、简单,手工制图已不符合现代林业发展要求,正逐渐被淘汰。笔者对应用CorelDrawX3绘制林业工程作业设计图的方法和技巧,包括图框绘制、小班勾绘、着色、求积以及绘图成果打印等进行了详细介绍,容易掌握、色彩丰富、制图效率高。CorelDrawX3是绘制林业工程设计图的实用...  相似文献   

西双版纳国家级自然保护区森林干扰因素及其干扰度评价     

杨忠兴  尹五元  艾建林 《福建林业科技》2011,38(3)

通过对西双版纳国家级自然保护区人为干扰现状分析,采用相对值法评价森林干扰度。评价结果显示:西双版纳国家级自然保护区森林干扰度值为6.48,勐腊、尚勇、勐养、勐仑、曼搞子保护区的森林干扰程度值分别为6.38、6.87、6.44、6.49、6.23;干扰程度总体处于"轻度干扰"状态。  相似文献   

SPOT5遥感影像在林业二类调查中的应用     

吴胜义  赵强国  石昊楠 《福建林业科技》2011,38(3)

采用ERDAS IMAGINE图像处理软件,对青海省互助县境内的北山林场的SPOT5遥感影像进行处理,包括原始数据导入、正射纠正、影像融合、波段组合、影像增强等处理过程以及数字正射影像图(DOM)的制作。探讨SPOT5遥感影像在林业二类调查中的应用处理方法及SPOT5影像的应用前景。经现地验证,以SPOT5遥感卫星影像为底图,通过人机交互目视解译方法区划判读小班能满足林业二类调查的需要,该影像数据能作为1∶10000专题图制作的基础数据。  相似文献   

北京地区乔木郁闭度测量研究     

李飞飞  吕国玮  刘涛  李方方  杨胜天 《林业资源管理》2011,(1)

比较了国内外已有的乔木郁闭度测量方法的优缺点,在样点法特别是观测管法的基础上,以北京延庆地区乔木林为对象,对郁闭度的激光测量进行了研究。实验改进了观察管法,对在野外测量乔木林郁闭度时精确测量所需样点数进行了研究,可以为野外快速、简洁、精确地测量乔木林郁闭度提供新的方法与参考。  相似文献