489 resultados para Yunnan.


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Dendritic cells (DCs) play a pivotal role in linking the innate immunity and acquired immunity in responses to pathogen. Non-human primates such as Chinese Rhesus Macaque (CRM) are the favorable models for preclinical study of potential therapeutic drugs,

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Chemical investigation of the vines and leaves of Momordica charantia resulted in isolation of fourteen cucurbitane triterpenoids, kuguacins F-S (1-14), including two pentanorcucurbitacins (6 and 7), one octanorcucurbitacin (8), and two trinorcucurbitacin

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The 70% EtOH extract of Polygonum cuspidatum showed inhibitory action against HIV-1-induced syncytium formation at non-cytotoxic concentrations in vitro with a 50% effective concentration (EC50) of 13.94 +/- 3.41 mu g/mL. Through bioactivity-guided fractionation, 20 phenolic compounds, including eight stilbenoids, were isolated from the roots of Polygonum cuspidatum, and their anti-HIV-1 activities were evaluated. Results showed that compounds 1, 13, 14, and 16 demonstrated fairly strong antiviral activity against HIV-1-induced cytopathic effects in C8166 lymphocytes at non-cytotoxic concentrations, with EC50 values of 4.37 +/- 1.96 mu g/mL, 19.97 +/- 5.09, 14.4 +/- 1.34 mu g/mL, and 11.29 +/- 6.26 mu g/mL and therapeutic index (TI) values of 8.12, > 10.02, > 13.89, and > 17.71, respectively. Other compounds showed either weak or no effects. Compound 6 also showed weak inhibition (153.42 +/- 19.25 mu g/mL); however, it possesses very good water solubility and showed almost no cytotoxicity (> 2000 mu g/mL), therefore achieving a fairly good TI (13.04). The activities of the two compounds (3 and 18) from Polygonum multiflorum were also assayed. The relationship between molecular structures and their bioactivities was also discussed.

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A total of 36 compounds (1-36) were obtained from the stem bark of Poncirus trifoliata including three new prenylated flavonoids, (-)-5,4'-dihydroxy-7,8-[(3 '',4 ''-cis-dihydroxy-3 '',4 ''-dihydro)-2 '',2 ''-dimethylpyrano]-flavone (1), (-)-5,4'-dihydroxy-7,8-[(3 ''-hydroxy-4 ''-one)-2 '',2 ''-dimethylpyrano]-flavone (2), and (-)-5,4'-dihydroxy-7,8-[(cis-3 ''-hydroxy-4 ''-ethoxy-3 '',4 ''-dihydro)-2 '',2 ''-dimethylpyrano]-flavone (3). The new structures were elucidated by means of spectroscopic methods. Compounds 1-20 were evaluated for their anti-human immunodeficiency virus-1 (HIV-1) activity, in which 2 showed significant anti-HIV-1 activity with high therapeutic index (T1) of 143.65.

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To search for compounds with superior anti-human immunodeficiency virus type 1 (HIV-1) activity, ten 5,5'-(p-phenylenebisazo)-8-hydroxyquinoline sulfonates (4a-j) were synthesized and preliminarily evaluated as HIV-1 inhibitors in vitro for the first time. Some compounds demonstrated anti-HIV-1 activity, especially 5,5'-(p-phenylenebisazo)-8-hydroxyquinoline p-ethylbenzenesulfonate (4g) and 5,5'-(p-phenylenebisazo)-8-hydroxyquinoline p-chlorobenzenesulfonate (41) showed the more potent anti-HIV-1 activity with 50% effective concentration (EC50) values of 2.59 and 4.01 mu g/ml, and therapeutic index (TI) values of 31.77 and 24.51, respectively.

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By impairing both function and survival, the severe reduction in oxygen availability associated with high-altitude environments is likely to act as an agent of natural selection. We used genomic and candidate gene approaches to search for evidence of such genetic selection. First, a genome-wide allelic differentiation scan (GWADS) comparing indigenous highlanders of the Tibetan Plateau (3,200 3,500 m) with closely related lowland Han revealed a genome-wide significant divergence across eight SNPs located near EPAS1. This gene encodes the transcription factor HIF2 alpha, which stimulates production of red blood cells and thus increases the concentration of hemoglobin in blood. Second, in a separate cohort of Tibetans residing at 4,200 m, we identified 31 EPAS1 SNPs in high linkage disequilibrium that correlated significantly with hemoglobin concentration. The sex-adjusted hemoglobin concentration was, on average, 0.8 g/dL lower in the major allele homozygotes compared with the heterozygotes. These findings were replicated in a third cohort of Tibetans residing at 4,300 m. The alleles associating with lower hemoglobin concentrations were correlated with the signal from the GWADS study and were observed at greatly elevated frequencies in the Tibetan cohorts compared with the Han. High hemoglobin concentrations are a cardinal feature of chronic mountain sickness offering one plausible mechanism for selection. Alternatively, as EPAS1 is pleiotropic in its effects, selection may have operated on some other aspect of the phenotype. Whichever of these explanations is correct, the evidence for genetic selection at the EPAS1 locus from the GWADS study is supported by the replicated studies associating function with the allelic variants.

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A new nortriterpenoid, 20-hydroxymicrandilactone D (1) and a novel lignan glycoside, lancilignanside A (2) were isolated from leaves and stems of Schisandra lancifolia, together with three known nortriterpenoids (3-5) and nine known phenolics (6-14). The structures of new compounds 1 and 2 were determined by detailed analysis of their 1D and 2D NMR spectra, and chemical evidences. In addition, compounds 1-2, 6-7, and 9-11 showed anti-human immunodeficiency virus (HIV)-1 activities with 50% effective concentration (EC50) in the range of 3.0-99.0 mu g/ml. Compound 12 was not bioactive in this assay with EC50 more than 200 mu g/ml.

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This study investigated the 70% aqueous acetone extract of the fruits of Schisandra rubriflora which led to the isolation of eight lignans, including a new isolate, rubrisandrin C (1), and seven known lignans (2-8). The structure of 1 was established by extensive 1D and 2D NMR spectroscopy and its absolute stereochemistry was determined by CD spectrum. Compounds 1-5 and 7-8 were evaluated for their anti-HIV-1 activity that showed inhibitory activity on HIV-1(IIIB) induced syncytium formation with EC50 values in the range of 2.26 similar to 20.4 mu g/mL. Compounds 1 and 7 exerted their obvious protection of HIV-1(IIIB) inducted MT-4 host cells lytic effects with a selectivity index of 15.4 and 24.6, respectively.

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Trigonothyrins A-C (1-3), which are highly functionalized daphnane diterpenoids, were isolated from the stems of Trigonostemon thyrsoideum. Compounds 1-3 represent the first examples of daphnanes with an oxygen-bridged four-membered-ring system, and a linkage mode of 12,13,14-orthoester. Compound 3 was observed to inhibit HIV-1 induced cytopathic effects. The EC50 value was 2.19 mu g/mL, and the therapeutic index (TI) was more than 90.

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Three new dibenzocyclooctadiene lignans, wilsonilignans A-C (1-3), together with nine known ones, were isolated from the fruits of Schisandra wilsoniana. The structures of 1-3 were elucidated by spectroscopic methods including extensive 1D and 2D NMR techniques. Compounds 1-3 were also evaluated for their anti-HIV-1 activities and showed bioactivity with EC50 values of 3.26, 6.18, and 2.87g/ml, respectively.

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描述了云南省大白蚁亚科新记录3个种,分别为近三型大白蚁、海南大白蚁,梯头大白蚁.

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报道云南贡山黄胡蜂属Vespula 1 新种, 即贡山黄胡蜂Vespula gongshanensis, sp. nov.。模式标本保存在中国科学院昆明动物研究所。

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报道云南怒江峡谷的蝴蝶共11 科115 属225 种。同时提出改造怒江峡谷为蝴蝶峡谷、开办蝴蝶牧场、发展蝴蝶 贸易、建立科普园地、加强生态环境的恢复和蝶类资源保护等5 点建议。

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云南高原位于北纬21°9′~29°15′和东经97°39′~106°12′之间,总面积394000 km2 ,地质和气候、植被非常复杂。大 陆漂移和冰期的进退是影响昆虫起源和演替的一个重要原因。昆虫的祖先是起源于一个统一大陆,在这个大陆上共 同起源,共同进化,随着原始大陆的分离和漂移,把这些类群运载到各地,形成现今昆虫分布格局。昆虫的扩散是以中 心分布方式成环状向周围扩散的。云南胡蜂的祖先是来自冈瓦那古陆。有两支昆虫进入云南,其中一支来自喜马拉 雅山,另一支来自缅甸。冰期是导致南北生物互相混合和渗入的重要因素。胡蜂的特有类群是在冈瓦那古陆分裂之 后才发展起来的。其祖先最早是分布在原始古陆较狭窄的区域内。

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1997 年5~ 8 月至1998 年4~ 8 月, 对昆明地区的花卉害虫及天敌进行了考 察和标本采集, 共采到花卉害虫及天敌标本4500 多号, 经鉴定分14 目, 65 科, 158 属, 205 种。标本保存在中国科学院昆明动物研究所。