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1.
γ-Tocotrienol and sesamin are phytochemicals that display potent anticancer activity. Since sesamin inhibits the metabolic degradation of tocotrienols, studies were conducted to determine if combined treatment with sesamin potentiates the antiproliferative effects of γ-tocotrienol on neoplastic mouse (+ SA) and human (MCF-7 and MDA-MB-231) mammary cancer cells. Results showed that treatment with γ-tocotrienol or sesamin alone induced a significant dose-responsive growth inhibition, whereas combination treatment with these agents synergistically inhibited the growth of + SA, MCF-7 and MDA-MB-231 mammary cancer cells, while similar treatment doses were found to have little or no effect on normal (mouse CL-S1 and human MCF-10A) mammary epithelial cell growth or viability. However, sesamin synergistic enhancement of γ-tocotrienol-induced anticancer effects was not found to be mediated from a reduction in γ-tocotrienol metabolism. Rather, combined treatment with subeffective doses of γ-tocotrienol and sesamin was found to induce G1 cell cycle arrest, and a corresponding decrease in cyclin D1, CDK2, CDK4, CDK6, phospho-Rb, and E2F1 levels, and increase in p27 and p16 levels. Additional studies showed that the antiproliferative effect of combination treatment did not initiate apoptosis or result in a decrease in mammary cancer cell viability. Taken together, these findings indicate that the synergistic antiproliferative action of combined γ-tocotrienol and sesamin treatment in mouse and human mammary cancer cells is cytostatic, not cytotoxic, and results from G1 cell cycle arrest.  相似文献   

2.
ABSTRACT

Litter decomposition plays a critical role in both nutrient cycling and the interspecific relationships between tree species. In this study, leaf litter from Robinia pseudoacacia was mixed with litter from 10 other species, this mixture was then ground and incubated in soil. The soil indexes (i.e., quantity of microbes, activities of enzymes, and chemical properties) were analyzed to study the effects of litter decomposition on soil properties and the interaction between the litters. If mixed separately with Larix principis-rupprechtii or Betula platyphylla, R. pseudoacacia litter exerted synergistic effects on the activities of most enzymes. The mixed litters of R. pseudoacacia and Pinus sylvestris var. mongolica or Ulmus pumila exerted synergistic effects on the soil available P. With regard to the soil properties as a whole, the mixed litters of R. pseudoacacia and B. platyphylla, Pinus tabulaeformis, P. sylvestris var. mongolica, or L. principis-rupprechtii exerted synergistic effects on soil during their decomposition. However, the mixed litters of R. pseudoacacia and Populus simonii, Quercus liaotungensis, U. pumila, or Caragana microphylla did not. This indicated that R. pseudoacacia mixed with the litter of other needle-leaf tree species benefits the development and regeneration of soil and thus can be used for sustainable forest management.  相似文献   

3.
对江西高安等16个县、市林区的马尾松毛虫用溴氰菊酯、氰戊菊酯和氯氰菊酯用点滴法进行毒力测定,结果表明,江西林区马尾松毛虫对溴氰菊酯的耐药力有明显提高,其中高安、贵溪林区马尾松毛虫的抗数达到了低抗水平,马尾松毛虫对氰戊菊酯和氯氰菊酯尚未产生抗性,室内用以上3种拟除虫菊酯与增效磷(SV1)按1:0.5、1:1、1:3、1:5T 1:10的比例混配,用点滴法对马尾松毛虫进行毒力测定,结果表明,增效磷与拟除虫菊酯混配有明显的增效作用,并且随着SV1比例的提高,增效作用增强,用4种拟除虫菊酯杀虫剂(2.5%溴氰菊酯、20% 酯、2.5%三氟氰菊酯和10%氯氰菊酯)加增效磷按不同混配比进行林间防马尾松毛虫试验,结果表明,增效与拟除虫菊酯杀虫剂混配有极显著的增效作用,林间防治松毛虫以溴氰菊酯+SV1(1:5)、氰戊菊酯+SV1(1:3-1:5)、三氟氰氯菊酯+SV1(1:3-1:5)以及氯氰菊酯+SV1(1:5)稀释8000倍效果最佳。  相似文献   

4.
本文论述了我国合成樟脑的生产概况及制订同家标准的必要性,介绍了英、美、苏、日、德、法等六国合成樟脑的现行质量标准(一个工业标准,六个药典标准)。较详细地论述了合成樟脑质量测定方法的试验研究,经过比较、综合,最后提出了我国合成樟脑国家标准各项质量指标(包括测试方法)的具体建议。  相似文献   

5.
Transpiration from a hawthorn (Crataegus monogyna L.) dominated hedgerow in southern England was measured continuously over two growing seasons by the sap flow technique. Accompanying measurements of structural parameters, microclimate and leaf stomatal and boundary layer conductances were used to establish the driving factors of hedgerow transpiration. Observed transpiration rates, reaching peak values of around 8 mm day(-1) and a seasonal mean of about 3.5 mm day(-1), were higher than those reported for most other temperate deciduous woodlands, except short-rotation coppice and wet woodlands. The high rates were caused by the structural and physiological characteristics of hawthorn leaves, which exhibited much higher stomatal and boundary-layer conductances than those of the second-most abundant woody species in the hedgerow, field maple (Acer campestre L.). Only in the hot summer of 2003 did stomatal conductance, and thus transpiration, decrease substantially. The hedgerow canopy was always closely coupled to the atmosphere. Hedgerow transpiration equaled potential evaporation (calculated by the Priestley-Taylor formula) in 2003 and exceeded it in 2004, which meant that a substantial fraction of the energy (21% in 2003 and more than 37% in 2004) came from advection. Hedgerow canopy conductance (g(c)), as inferred from the sap flow data by inverting the Penman-Monteith equation, responded to solar radiation (R(G)) and vapor pressure deficit (D). Although the response to R(G) showed no systematic temporal variation, the response to D, described as g(c)(D) = g(cref) - mln(D), changed seasonally. The reference g(c) depended on leaf area index and the ratio of -m/g(cref) on long-term mean daytime D. A model is proposed based on these observations that predicts canopy conductance for the hawthorn hedge from standard weather data.  相似文献   

6.
Inhibition of Trypanosoma cruzi growth by medical plant extracts   总被引:4,自引:0,他引:4  
This study describes the screening of extracts obtained from 18 plants and two fungi used in the Chinese and Mediterranean traditional medicines on epimastigote forms of Trypanosoma cruzi. The extracts were tested against epimastigote of T. cruzi Bra C15C2 clone in vitro at 27 degrees C and at a concentration of 250 microg/ml in axenic culture. Angelica dahurica, A. pubescens, A. sinensis, Astragalus membranaceus, Coptis chinensis, Haplophyllum hispanicum, Phellodendron amurense, Poria cocos, Ranunculus sceleratus and Scutellaria baicalensis showed significant effects against the parasite with a percentage of growth inhibition between 20 and 100%. C. chinensis and R. sceleratus showed the greatest activity with IC(50) values of 1.7 microg/ml for C. chinensis and 10.7 microg/ml for R. sceleratus. These activities are greater than that of allopurinol. C. chinesis and R. sceleratus extracts did not show cytotoxic effects on rat polimorphonuclear cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and lactic dehydrogenase assays. These results allowed us to suggest that R. sceleratus and C. chinensis could be a source of new compounds clinically active against T. cruzi.  相似文献   

7.
遭遇台风0613号袭击之后,日本山口市的许多乔木和灌木出现叶尖和叶缘甚至整叶黄化和坏死的症状。同一竹林林分中既有黄化叶片也有坏斑叶片。本文用非破坏、非接触的RGB图像分析法研究了这一现象。研究表明,室内拍摄的黄化竹单叶图像的G/R值与叶绿素计(SPAD)值之间呈紧密的正相关,平方回归相关系数0.961;与坏死斑面积率之间呈反逻辑斯蒂函数关系,平方回归相关系数0.958。用RGB图像分析法不仅可以估测叶片的黄化程度而且可也估测叶片的坏死斑面积。研究还发现,光线差异较大时拍摄的图片,相同叶片的G/L值的方差小于G/R值的方差值,尤其是绿色叶片。与G/R相比,黄化叶片的G/L值得到了与SPAD更紧密的相关性。室外拍摄的竹林冠分析表明,光线差别较大的图像G/L值与林分距海岸的距离的相关性也高于G/R值。  相似文献   

8.
云南昭通坝区降雨侵蚀力R指标的初步研究   总被引:2,自引:0,他引:2  
以云南昭通坝区昭鲁河新泉水文站1969~1978年10年的观测资料为基础,分析计算了各种降雨参数的单因子和复合因子,分别与土壤流失量之间的相关关系。结果表明,适合于昭通坝区的降雨侵蚀力R指标为ΣE·I15。根据不同组合形式与土壤流失量的相关系数r值进行评价,原通用土壤流失方程式中,降雨侵蚀力R指标也基本适用于昭通坝区。昭通坝区年平均R值为18414,在1年中R值主要分布于5~10月。  相似文献   

9.
In order to decrease the soil nutrient loss in young planted Chinese fir (Cunningharnia lanceolata (Lamb.) Hook.) forestland and to investigate the impact of young Chinese fir plantation intercropped with crops on soil quality, a field experiment was set up in the mid-subtropics of China in 1998. The effects of growing crops in combination with young Chinese fir on soil properties were evaluated by measuring physico-chemical, microbiological and biochemical parameters five years after the beginning of this experiment. Three treatments were selected in the experiment, i.e., Chinese fir plantation intercropped with peanut (Arachis hypogaea L.) -wheat (Triticum aestivum L.) cropping sequence (C-P/W); Chinese fir plantation intercropped with maize (Zea mays L.)-wheat cropping sequence (C-M/W) and only Chinese fir plantation (Control). Soils were sampled at the 0–10 cm depth in 2003. The increases in soil nutrients (especially with respect to soil available nutrients), soil microbial biomass C (SMBC), microbial quotient (MQ), soil basal respiration (SBR), microbe numbers and enzyme activities and slight decrease in metabolic quotient (qCO2) as well as melioration in soil structure and humus quality were observed in tree-crop combinations compared with sole plantation of Chinese fir, although the differences were not always statistically significant. In addition, the evidence obtained from this study also suggests that Chinese fir-crop combination can promote the growth of young Chinese fir. Therefore, growing crops in combination with young Chinese fir can be considered a good forest management practice, helping to limit the gradual depletion of soil nutrients and, at the same time, to some degree controlling the degradation of planted Chinese fir forestland.  相似文献   

10.
Cui CB  Liu HB  Gu JY  Gu QQ  Cai B  Zhang DY  Zhu TJ 《Fitoterapia》2007,78(3):238-240
Bioassay-guided fractionation of the ethyl acetate extract from the fermentation broth of marine-derived Streptomyces albogriseolus A2002 led to the isolation of echinosporin (1) and 7-deoxyechinosporin (2). Compound 1 inhibited the proliferation of tsFT210, K562 and HCT-15 cancer cells (IC(50) 91.5 microM, 25.1 microM and 247 microM respectively) and 2 showed the same effect on K562 cells (IC(50) 143 microM). Flow cytometric analysis suggested that 1 and 2 exert their anti-proliferative effects on those cells through inhibiting cell cycle at the G(2)/M phase and inducing apoptosis.  相似文献   

11.
采用正交试验方法 ,对过磷酸钙、菜籽饼粉及复合肥不同的施肥水平影响杉木种子出苗情况进行了效果对比试验。结果表明 :混合施用过磷酸钙与复合肥的处理组合均能促进杉木种子出苗 ,最佳组合为每hm2 混合施用 75 0kg过磷酸钙及 375kg复合肥 ,出苗率比对照高出 30 3%。  相似文献   

12.
13.
植物抗氧化剂的研究概况与发展趋势   总被引:12,自引:2,他引:12  
植物抗氧化剂及其有关活性成分主要有黄酮类化合物、植物多酚、酚酸类化合物、维生素、活性多糖、酶、蛋白质和氨基酸等类型,在生物体内通过电子转移、络合金属离子、联合抗氧化作用和影响基因表达等机理起作用,在食品、医药、保健品和化妆品等方面将有广泛应用。提出应在原料筛选、提取分离方法的创新,多组分协同作用机理和抗氧化活性成分的构效关系等方面深入研究。  相似文献   

14.
《Forest Pathology》1995,25(2):125-128
Books reviwed in this article: Kegler , H. Friedt , W. (Hrsg.): Resistenz von Kulturpflanzen gegen pflanzenpathogene Viren . Adams , W. T.; Strauss , S. H.; Copes , D. L.; Griffin , A. R. (eds): Population Genetic of Forest Trees . Jalkanen , R.; Aalto , T.; Lahti , M.-L. (eds): Forest pathological research in northern forests with a special reference to abiotic stress factors . Fleming , T. H.; Estrada , A. (eds): Frugivory and Seed Dispersal: Ecological and Evolutionary Aspects . Strouts , R. G.; Winter , T. G.: Diagnosis of Ill-Health in Trees . Shigo , A. L.: Tree Anatomy .  相似文献   

15.
Effects of needle water potential (Psi(l)) on gas exchange of Scots pine (Pinus sylvestris L.) grown for 4 years in open-top chambers with elevated temperature (ET), elevated CO(2) (EC) or a combination of elevated temperature and CO(2) (EC + ET) were examined at a high photon flux density (PPFD), saturated leaf to air water vapor pressure deficit (VPD) and optimal temperature (T). We used the Farquhar model of photosynthesis to estimate the separate effects of Psi(l) and the treatments on maximum carboxylation efficiency (V(c,max)), ribulose-1,5-bisphosphate regeneration capacity (J), rate of respiration in the light (R(d)), intercellular partial pressure of CO(2) (C(i)) and stomatal conductance (G(s)). Depression of CO(2) assimilation rate at low Psi(l) was the result of both stomatal and non-stomatal limitations on photosynthetic processes; however, stomatal limitations dominated during short-term water stress (Psi(l) < -1.2 MPa), whereas non-stomatal limitations dominated during severe water stress. Among the nonstomatal components, the decrease in J contributed more to the decline in photosynthesis than the decrease in V(c,max). Long-term elevation of CO(2) and temperature led to differences in the maximum values of the parameters, the threshold values of Psi(l) and the sensitivity of the parameters to decreasing Psi(l). The CO(2) treatment decreased the maximum values of V(c,max), J and R(d) but significantly increased the sensitivity of V(c,max), J and R(d) to decreasing Psi(l) (P < 0.05). The effects of the ET and EC + ET treatments on V(c,max), J and R(d) were opposite to the effects of the EC treatment on these parameters. The values of G(s), which were measured simultaneously with maximum net rate of assimilation (A(max)), declined in a curvilinear fashion as Psi(l) decreased. Both the EC + ET and ET treatments significantly decreased the sensitivity of G(s) to decreasing Psi(l). We conclude that, in the future, acclimation to increased atmospheric CO(2) and temperature could increase the tolerance of Scots pine to water stress.  相似文献   

16.
北半球高卢蜜环菌的遗传多样性与分子鉴定   总被引:6,自引:0,他引:6  
从北美、欧洲和中国收集23个高卢密环菌菌株,PCR扩增其rDNA的IGS和ITS区域,用AluI,HaeIII,HinfI和TagI四种限制性内切酶进行酶切,同时结合随机扩增微卫生(RAMS)多态性,对北半球的高卢蜜环菌的遗传多样性进行了分析,结果发现了高卢蜜环菌的6种IGS-RFLP图谱类型,其中gal(B)和gal(D)是国内外无报道的新的IGS-RFLP型,RFLP系统树发现该种有明显的大陆之间的遗传分化,存在中国,欧洲,北美和亚洲4个亚群体,RAMS分析表明北半球高卢蜜环菌存在亚洲,欧洲,北美-中国和北美-欧洲和北美-欧洲等4个高卢蜜环菌发育系,而且不同大陆的高卢蜜环菌具有较近的亲缘关系,而相同大陆的却具有不同的起源,特别是北美的高卢蜜环菌两个发育系异源性很高,北美东部的发育系同欧洲的关系比较近,而北西部的同亚洲关系比较近,同时表明RAMS技术是分析菌物种内遗传多样性的优越方法。  相似文献   

17.
《Forest Pathology》1986,16(3):190-192
Books reviwed in this article: Forest diseases of China . Edited by the Chinese Academy of Forest Sciences. Wood , R. K. S.; Jellis , G. J. (eds.): Plant Diseases. Infection, Damage and Loss. Armitage , F. B.: Irrigated Forestry in Arid and Semi-Arid Lands Andersson , F.; Olsson , B. (Eds.), 1985: Lake Gardsjön. An Acid Forest Lake and its Catchment. Ellis , M. B.; Ellis , J. P., 1985: Microfungi on Land Plants. An Identification Handbook. Hill , Stephan A., 1984: Methods in Plant Virology. Schrader , S.; schönwald , H. R.; dujesiefken , D.: Immissionen und Waldschäden Bibliographie III , 1984.  相似文献   

18.
南亚热带杉木人工林材种结构长期立地与密度效应   总被引:3,自引:0,他引:3       下载免费PDF全文
[目的]揭示南亚热带杉木人工林材种发育的长期立地和密度动态效应规律。[方法]以广西大青山A(1667株·hm^-2)、B(3333株·hm^-2)、C(5000株·hm^-2)、D(6667株·hm^-2)、E(10000株·hm^-2株)5种初植密度、36 a生杉木(Ctmninghamia lanceolata)密度试验林为研究对象,分析密度和立地影响下材种株数与材种材积分布的动态变化规律。[结果]杉木林分小径材株数和材积比率在初期随林龄增长而递增,达峰值后随林龄增长而减少,初植密度越小、立地指数级越高,减少速度越快;中、大径材株数和材积比率随林龄增长而增加,初植密度越小、立地指数级越高,增速越快。18立地指数级D及以下密度林分28 a生前中径材材积比例约50%;36 a生时A密度林分大径材材积比例约50%。16立地指数级中低初植密度林分中径材材积比例均超过45%,且以C密度林分最高、约48%;36 a生时A密度林分大径材材积比例超过26%。14立地指数级,A密度林分中径材材积比例24 a生时达44%,A、B、D密度林分小径材材积分别于12、18、24 a生时达83%、76%、69%o 10立地指数级C、E密度林分36 a生时小径材材积比例分别达71%、61%。[结论]杉木林材种形成与立地、密度和林龄关系密切,立地质量具决定性作用,而培育高规格材种时初植密度亦可成为关键限制因素。初植密度越低、立地指数越高,越利于中、大径材形成。在杉木南带产区,10指数级立地短周期经营时只适宜培育小径材及小条木。14指数级立地适宜培育中、小径材,若以中径材为第一培育材种时初植密度宜低。16指数级立地适宜培育中径材,长周期经营时也可培育大径材,但初植密度不宜超1667株·hm^-2。18指数级立地中径材生产潜力很大,但更宜培育大径材,且初植密度宜控制在A密度,轮伐期不宜低于36 a。  相似文献   

19.
The optimal formula of Beta-Cypermethrin aqueous capsule suspension was screened out through the experiment,preparation and manufacture of basic formulas, which has no sedimentation, suspended drops of oil, peels and agglomerating and the diameter of capsule is in range of 10-30μm, conformed to the technical requirement. The aftereffect of the 3.3% Beta-Cypermethrin aqueous capsule suspension which was manufactured according to the optimal formula was up more than 25 days. The experiments on controlling the larvae of Dendrolinmus superans Butler and the adults of Xylotrechus rusticus L were carried out with different concentrations of this chemical. The death rate reached 80% when 250 times solution of the chemical was sprayed on stem to control the larvae of D. superans. For control of the adults of X. rusticus, 200, 400 and 600 times solution of the chemical were applied and their control effects (death rate) reached 85.23%, 74.21% and 66.59% respectively. Two kinds of solution (200 times and 300 times) of the chemical were used to control the larvae of D. superans in large area, and the control effect for both concentrations was over 90%.  相似文献   

20.
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