Development of an isocratic HPLC method for catechin quantification and its application to formulation studies

The aim of this study was to develop a simple, rapid and accurate isocratic HPLC analytical method to qualify and quantify five catechin derivatives, namely (+)-catechin (C), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), (-)-epicatechin (EC) and (-)-epigallocatechin gallate (EGCG). To validate the analytical method, linearity, repeatability, intermediate precision, sensitivity, selectivity and recovery were investigated. The five catechin derivatives were completely separated by HPLC using a mobile phase containing 0.1% TFA in Milli-Q water (pH 2.0) mixed with methanol at the volume ratio of 75:25 at a flow rate of 0.8ml/min. The method was shown to be linear (r(2)>0.99), repeatable with instrumental precision<2.0 and intra-assay precision<2.5 (%CV, percent coefficient of variation), precise with intra-day variation<1 and inter-day variation<2.5 (%CV, percent coefficient of variation) and sensitive (LOD<1μg/mL and LOQ<3μg/mL) over the calibration range for all five derivatives. Derivatives could be fully recovered in the presence of niosomal formulation (recovery rates>91%). Selectivity of the method was proven by the forced degradation studies, which showed that under acidic, basic, oxidation temperature and photolysis stresses, the parent drug can be separated from the degradation products by means of this analytical method. The described method was successfully applied in the in vitro release studies of catechin-loaded niosomes to manifest its utility in formulation characterization. Obtained results indicated that the drug release from niosomal formulations was a biphasic process and a diffusion mechanism regulated the permeation of catechin niosomes.     

竹子内源激素HPLC测定方法改良

为了同时测定竹子中的玉米素,ZT),赤霉素(GA3)、异戊烯基腺嘌呤(2-ip)、6-卞氨腺嘌呤(6-BA)、吲哚-3-乙酸(IAA)、脱落酸(ABA)和吲哚-3-丁酸(IBA),对HPLC法测定的洗脱程序进行分段优化.结果表明,分段洗脱方式的效果最佳:0～10 min,流速0.8 mL·min-1,甲醇-1%乙酸溶液体积比为4:6;10～10.5 min,体积比增大至5:5,流速增大至1.5 mL·min-1(均以线性模式变化):10.5 min,流速1.5 mL·min-1,体积比5:5,运行18 min.7种内源激素的分离效果好,峰面积与含量之间呈线性关系,加标回收率达到95.5～104.2%.     

Effects of the plant alkaloid thaliblastine on non-cross-resistant and sensitive human leukemia cells in relation with reversal of acquired anthracycline resistance

Thaliblastine exhibits dose dependent cytotoxic effect on HL-60, HL-60/DOX, RHE and HD-MY-2 leukemia cells. Additionally, typical for apoptosis oligonucleosomal DNA fragmentation could be detected in leukemia cells treated with thaliblastine. Moreover, an MDR-phenotype reversing effect of thaliblastine was also identified.     

用HPLC测定松墨天牛体内的保幼激素

用反相高效液相色谱法检测了松墨天牛1～5龄幼虫、蛹和成虫体内的保幼激素(JH)滴度，检测到JH3和JH2，未检测到JH1。松墨天牛体内的JH3及JH2滴度变化随虫龄的增大而呈下降趋势，5龄幼虫的滴度最小，与蛹和成虫含量接近。     

不同植物、同种植物不同组织部位中白藜芦醇含量变化研究

白藜芦醇已被列为抗心血管病，抗癌最有前途的药物之一。本研究用高效液相色谱法测定虎杖、辣蓼、显齿蛇葡萄、葡萄、何首乌5种植物中的白藜芦醇的含量。结果表明：这5种植物中以虎杖根中白藜芦醇含量最高，同种植物不同组织部位中白藜芦醇含量差异较大。     

塞罕坝野生植物资源研究与保护

调查和分析了塞罕坝野生植物生存现状,指出现在塞罕坝由于旅游开发以及气候变化等因素,野生植物的生存空间受到了挑战。并在此基础上对如何保护塞罕坝野生植物资源提出了看法,要依据植物的生长规律、生活习性、濒危成度等进行分类保护。     

固相萃取-高效液相色谱法测定5种防腐木材中戊唑醇

采用高效液相色谱法测定防腐木材中戊唑醇含量,选择樟子松、南方松、赤松、花旗松和杉木作为试材,分别采用阴、阳离子固相萃取柱进行样品前处理。得出:阴离子固相萃取柱适合南方松和杉木的样品前处理,阳离子固相萃取柱适合樟子松、赤松、花旗松的样品前处理。并进行了精密度分析,验证了方法的准确性。     

三峡地区高山乡土造林树种选择研究

自上世纪70年代以来,大老岭林场开展了北亚热带三峡地区高山造林树种生态调查[1]。依据调查结果:1981年选择玉兰、银鹊、鹅掌秋、鄂枫杨、漆树、大叶杨、山桐子、桦榛、白辛、檫木、珙桐、香椿、亮叶桦、水曲柳等阔叶乡土树种和油松、华山松、落叶松、柳杉等针叶乡土树种开展栽培试验研究。通过各树种成活率、保存率及生长量26 a(2004)调查表明:26 a(2004)生现实遗传增益银鹊比11个阔叶树种材积提高26.8%,比其它10个阔叶树种材积提高32.0%;日本柳杉比4个针叶树种材积提高36.5%,比其它3个针叶树种材积提高48.8%。银鹊,日本柳杉最适宜三峡山区生长,营造银鹊、日本柳杉工业用材林,可大力提高新造林分生产力,现实遗传增益15%以上,取得较好的经济、社会和生态效益。     

HPLC法检测桔皮中橙皮甙的稳定性研究

以高效液相色谱法检测方法,对橙皮甙的稳定性进行了初步研究。结果表明：橙皮甙的耐光、耐热性能好,在碱性较强的条件下稳定存在,pH值为12时,其在溶液中的溶解度最大。     

The critical rotational speed of circular saw: simple measurement method and its practical implementations

Operation safety during sawing operations as well as dimensional accuracy and surface roughness depend on circular saw dynamic features among other factors such as circular saw blade accuracy and static/dynamic properties of the machine tool. Manufacturers of saw blades have an obligation to mark tools with a value stating the maximum allowed rotational speed for each saw. However, in some cases the value indicated on the saw corresponds to the critical rotational speed or is dangerously close to this critical value. Saw operation at the critical rotational speed is inadvisable and may result in serious injury or depreciation of product quality. This report outlines a simple methodology for evaluation of circular saw critical rotational speed. The assessment was conducted with a camera vision technique on the basis of an impulse test. Results are compared with theoretically calculated critical rotational speeds and the marks on saw blades.     

优良园林绿化树种小叶榄仁引种培育试验初报

在普洱市景谷县永平镇进行优良园林绿化树种一小叶榄仁的引种栽培研究,通过时其繁殖技术、栽培技术、生长情况、生物及生态学特性的全面总结,认为小叶榄仁可作为优良的园林绿化树种在云南省广大热区推广种植。     

上海延中绿地植物应用形式的初步研究

采取典型实地调查的方法对上海市延中绿地植物应用形式进行了研究分析。结果表明,延中绿地在植物的选择和应用上具有3个方面的突出特点：一是植物种类丰富,重视对本土植物的应用和植物专类园建设;二是注重色叶植物的应用和乔灌草植物的搭配,延中绿地近200种植物中,乔木占32．6％、灌木占28．3％、多年生草本植物占32％,色叶植物在感觉园和自然生态园中均有较高的比例;三是植物、水、建筑有机的结合,体现了“蓝”与“绿”的主题,应用形式多样,充分展示了植物的多样化。     

广州市公园附生植物造景分析

在对附生植物概念及其特征分析的基础上,结合对广州市10个公园的调查、分析,从附生植物造景的角度挖掘附生植物在园林应用中的潜力。结果显示,广州市公园的附生植物共有36种,隶属于16科32属,其中以蕨类、天南星科、兰科植物为主。附生植物应用方式可以分为树干附生、枯木附生、墙体附生、悬垂附生、山石附生和其他应用方式。因此,可在园林建设中通过增加优良种类的应用数量和提高应用频率、丰富附生植物的应用方式、驯化观赏价值高的乡土植物等途径来提高附生植物的种类多样性和景观多样性。     

THE OPERATION METHOD OF ULTRA-LOW-VOLUME SPRAYING WITH AIRPLANE

BRIEFINTRoDUCTIONGcncralSituationTheultra-low-volumesprayingwithairPlaneisanewinter-nationaltechniqueofsprayingPesticidealler6o's.lthasbeencontinousllydevelopingand..improving.ItisthemethodofusingsPeCialoiledpesticideandsprayingdireetlyPeshcideonthesdriceofcropsbytheequipmentofultra-low-volumesprayingontheairplane.lnChina.itwastheAgri-ForestryMinis-try'whoorgnizedtostUdymakingthiskindofequipment.Itwasinl975thatthesampleequipmentwasproducedandexperimented.NowitisusedalloverChinaItis…     

Toward sustainable harvesting of Africa's largest medicinal plant export (Prunus africana): a case study in Tanzania

Global demand for treating prostate disorders with Prunus africana bark extract has made P. africana Africa's largest medicinal plant export. Unsustainable harvesting practices can lead to local extirpations of this multipurpose tree. Survey research targeting P. africana harvesters in a Tanzania forest reserve revealed that 78% of them used unsustainable harvesting practices. This research focused on establishing a socioeconomic profile of the harvesters, the profitability of their business operations, and identifying the factors that influence their selection of harvesting practices. Results indicate that harvesters have above-national-average education, double the average family size, and generate income exceeding government's minimum wages. Large family size and high earning potential imply increased future harvesting activity. Logistic regression results indicate that education and training level could predict the likelihood that a harvester would use unsustainable harvesting practices. Local- and district-level government organisations could implement a resource assessment as a basis to design and implement harvesting schedules and ensure that the harvesters receive appropriate training, regardless of their education level.     

Analysis of information used in the management of plant genetic resources: a case study from northwestern Mato Grosso,Brazil

Evaluation and monitoring are critical to agroforestry (AFS) project management, especially if they aim to contribute to use and conservation of biodiversity and plant genetic resources. A methodology to analyze information used in decision-making processes was developed and applied in a biodiversity conservation project in the Brazilian Amazon. Quality of information gathered at landscape, AFS, species (Bactris gasipaes Kunth, both wild and cultivated varieties) and genetic diversity levels in three dimensions was analyzed. The information at the landscape level was good, while that in the organizational-institutional and socio-economic dimensions was acceptable; information gaps were serious in the genetic-ecological dimension. Ecological and economic functionality assessment based on indicators built upon reported administrative actions suggests that information related to conservation played a greater role in decision-making and management than information associated with use and development. The application of the methodology proved instrumental for enhancing efficacy of decision-making within an adaptive management approach to plant genetic resources use and conservation.     

台州市植物多样性保护的现状分析及解决对策

对台州市植物多样性的现状、环境条件进行了分析,并结合台州实际提出了植物多样性保护的几点措施。     

Traditional mule logging method in Hyrcanian Forest: a study of the impact on forest stand and soil

We inventoried plant regeneration and soil compaction along mule trails to evaluate damage to forest stands and regeneration follow-ing mule hauling before and after operations in Kheyrud Forest in the...     

作业成本法在森工企业中的应用研究初探

作业成本法作为一种先进的成本管理方法已经在各行各业广泛应用和研究,但还未在森工企业进行研究和应用。本文针对目前森工企业存在的问题,指出作业成本法在森工企业实施的必要性,同时结合作业成本法自身的含义和特点,说明作业成本法在森工企业具体应用过程,为森工企业进行成本核算提供指导。     

森林火灾生态效益损失评估方法探讨

通过以一起森林火灾为例，针对森林生态效益的内涵，进行了森林生态效益损失的评估。量化了因火灾造成森林生态效益损失的货币值，并进行了一些森林生态效益损失评估方法的初步探讨。