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排序方式: 共有123条查询结果,搜索用时 31 毫秒
1.
Su Lai Yee Mon Moe Lwin Aye Aye Maw Lat Lat Htun Saw Bawm Kotaro Kawabe Yasuhiko Wada Shin Okamoto Takeshi Shimogiri 《Animal Science Journal》2021,92(1):e13647
Myanmar indigenous chickens play important roles in food, entertainment, and farm business for the people of Myanmar. In this study, complete mitochondrial D-loop sequences (1232 bp) were analyzed using 176 chickens, including three indigenous breeds, two fighting cock populations, and three indigenous populations to elucidate genetic diversity and accomplish a phylogenetic analysis of Myanmar indigenous chickens. The average haplotype and nucleotide diversities were 0.948 ± 0.009 and 0.00814 ± 0.00024, respectively, exhibiting high genetic diversity of Myanmar indigenous chickens. Sixty-four haplotypes were classified as seven haplogroups, with the majority being haplogroup F. The breeds and populations except Inbinwa had multiple maternal haplogroups, suggesting that they experienced no recent purifying selection and bottleneck events. All breeds and populations examined shared haplogroup F. When 232 sequences belonging to haplogroup F (79 from Myanmar and 153 deposited sequences from other Asian countries/region) were analyzed together, the highest genetic diversity was observed in Myanmar indigenous chickens. Furthermore, Myanmar indigenous chickens and red junglefowls were observed in the center of the star-like median-joining network of 37 F-haplotypes, suggesting that Myanmar is one of the origins of haplogroup F. These findings revealed the unique genetic characteristic of Myanmar indigenous chickens as important genetic resources. 相似文献
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The effects of schisandrin B (Sch B) and its analogs on solar irradiation-induced oxidative injury were examined in BJ human fibroblasts. Sch B and schisandrin C (Sch C) increased cellular reduced glutathione (GSH) level and protected against solar irradiation-induced oxidative injury. The photoprotection was paralleled by decreases in the elastases-type protease activity and matrix-metalloproteinases-1 expression in solar-irradiated fibroblasts. The cytochrome P-450-mediated metabolism of Sch B or Sch C caused ROS production. The results suggest that by virtue of its pro-oxidant action and the subsequent glutathione antioxidant response, Sch B or Sch C may offer the prospect of preventing skin photo-aging. 相似文献
6.
J K Yee 《Science (New York, N.Y.)》1989,246(4930):658-661
An 88-base pair fragment in the core promoter of the human hepatitis B virus (HBV) contains a functional promoter and a strong liver-specific enhancer. This enhancer functions in human hepatoma cells, where it is much more active than the previously described HBV enhancer in stimulating expression of the linked bacterial chloramphenicol acetyltransferase gene expressed from heterologous promoters. Studies of the role of this enhancer-promoter in HBV may help to clarify mechanisms of gene expression in cells infected with HBV and the role of the virus in the pathogenesis of hepatitis and hepatocellular carcinoma. 相似文献
7.
Crystal structure of defensin HNP-3, an amphiphilic dimer: mechanisms of membrane permeabilization 总被引:34,自引:0,他引:34
Defensins (molecular weight 3500 to 4000) act in the mammalian immune response by permeabilizing the plasma membranes of a broad spectrum of target organisms, including bacteria, fungi, and enveloped viruses. The high-resolution crystal structure of defensin HNP-3 (1.9 angstrom resolution, R factor 0.19) reveals a dimeric beta sheet that has an architecture very different from other lytic peptides. The dimeric assembly suggests mechanisms by which defensins might bind to and permeabilize the lipid bilayer. 相似文献
8.
Suppression of the neoplastic phenotype by replacement of the RB gene in human cancer cells 总被引:80,自引:0,他引:80
H J Huang J K Yee J Y Shew P L Chen R Bookstein T Friedmann E Y Lee W H Lee 《Science (New York, N.Y.)》1988,242(4885):1563-1566
Mutational inactivation of the retinoblastoma susceptibility (RB) gene has been proposed as a crucial step in the formation of retinoblastoma and other types of human cancer. This hypothesis was tested by introducing, via retroviral-mediated gene transfer, a cloned RB gene into retinoblastoma or osteosarcoma cells that had inactivated endogenous RB genes. Expression of the exogenous RB gene affected cell morphology, growth rate, soft agar colony formation, and tumorigenicity in nude mice. This demonstration of suppression of the neoplastic phenotype by a single gene provides direct evidence for an essential role of the RB gene in tumorigenesis. 相似文献
9.
Wang Z Carter JA Lagutchev A Koh YK Seong NH Cahill DG Dlott DD 《Science (New York, N.Y.)》2007,317(5839):787-790
At the level of individual molecules, familiar concepts of heat transport no longer apply. When large amounts of heat are transported through a molecule, a crucial process in molecular electronic devices, energy is carried by discrete molecular vibrational excitations. We studied heat transport through self-assembled monolayers of long-chain hydrocarbon molecules anchored to a gold substrate by ultrafast heating of the gold with a femtosecond laser pulse. When the heat reached the methyl groups at the chain ends, a nonlinear coherent vibrational spectroscopy technique detected the resulting thermally induced disorder. The flow of heat into the chains was limited by the interface conductance. The leading edge of the heat burst traveled ballistically along the chains at a velocity of 1 kilometer per second. The molecular conductance per chain was 50 picowatts per kelvin. 相似文献
10.
Yan Wang Paul S. F. Yip 《Journal of Agricultural, Biological & Environmental Statistics》2002,7(4):574-585
A unified approach is suggested to estimate the population size for continuous time capture studies with possible removals during the capture process. It extends and improves the Lin-Yip estimator. The usual recaptureand removal models can be shown to be particular cases of the general formulation. A Horvitz-Thompson procedure is used to estimate the population size based on the estimated capture probabilities. The resultant estimators for the regression parameters and population size are consistent and asymptotically normal underappropriateregularity conditions. We assess the properties of the proposed estimators through Monte Carlo simulation. Two examples are given. 相似文献