首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   283篇
  免费   17篇
  300篇
  2024年   1篇
  2023年   4篇
  2022年   18篇
  2021年   12篇
  2020年   22篇
  2019年   30篇
  2018年   17篇
  2017年   13篇
  2016年   19篇
  2015年   11篇
  2014年   24篇
  2013年   22篇
  2012年   22篇
  2011年   17篇
  2010年   12篇
  2009年   11篇
  2008年   6篇
  2007年   10篇
  2006年   9篇
  2005年   7篇
  2004年   5篇
  2003年   3篇
  2002年   3篇
  2001年   1篇
  1990年   1篇
排序方式: 共有300条查询结果,搜索用时 15 毫秒
131.
Here, we investigated the biological effects of arachidonic acid (AA) in human cumulus granulosa cells (CGCs) after exposure to ASA. Cells were isolated from the follicular fluid and incubated with 0.5 mM acetylsalicylic acid (ASA) and 50 µM AA. Cell viability was analyzed by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay. E2 and P4 levels were measured by chemiluminescence assay. Expression of genes including CYP19A1, FACN, and SCD1 was measured by real‐time polymerase chain reaction assay. Oxidative status was analyzed by monitoring glutathione peroxidase activity. The fatty acid profile was analyzed by the gas chromatography technique. Enzyme‐linked immunosorbent assay was used to measure prostaglandin E2 (PGE2) in CGCs after exposure to ASA and AA. Protein levels of the estrogen receptor were studied by immunofluorescence staining. Ultrastructural changes were evaluated by transmission electron microscopy imaging. ASA treatment reduced E2 production, Cyp19a1 expression, glutathione peroxidase (GPx) activity, and estradiol receptor expression in CGCs. The addition of AA prevented the ASA‐induced E2 reduction (p < .05) and expression of Cyp19a1. Moreover, AA increased the antioxidant capacity of CGCs exposed to ASA by promoting GPx activity (p < .05). AA increased monounsaturated fatty acid/saturated fatty acid ratio compared with the ASA group (p < .05). AA supplementation triggered the synthesis and secretion of PGE2 in ASA‐treated CGCS (p < .05). Cytoplasmic vacuolation observed in the ASA group and treatment with AA intensified vacuolation rate. The expression of the estrogen receptor was increased after AA supplementation. Data demonstrated that AA decreased the detrimental effects of ASA on human CGCs after 72 hr.  相似文献   
132.
133.
International Journal of Peptide Research and Therapeutics - Heat shock proteins (HSPs) have over-expression in the human malignancies. However, many studies reported inconsistent results. The...  相似文献   
134.
Landscape and Ecological Engineering - Local amphibian populations at the edge of a species range are possibly of greater conservation concern than any other amphibians group. They experience...  相似文献   
135.
We have analyzed the effect of external electric field on the zigzag (6,0) single-wall BC2N nanotube using density functional theory calculations. Analysis of the structural parameters indicates that the nanotube is resistant against the external electric field strengths. Analysis of the electronic structure of the nanotube indicates that the applied parallel electric field strengths have a much stronger interaction with the nanotube with respect to the transverse electric field strengths and the nanotube is easier to modulate by the applied parallel electric field. Our results show that the properties of the nanotube can be controlled by the proper external electric field for use in nano-electronic circuits.
Figure
Three-dimensional (3D) views of the (6,0) zigzag BC2N nanotube under electric field effect  相似文献   
136.
This article reviews recent advances achieved during recent years on various aspects of antibody humanization theories and techniques. Common methods for producing humanized antibodies including framework-homology-based humanization, germline humanization, complementary determining regions (CDR)-homology-based humanization and specificity determining residues (SDR) grafting, as well as advantages and disadvantages of each of these methods and their applications are discussed.  相似文献   
137.
Manganese-oxo porphyrins have been well studied as biomimetic models of cytochromes P450 and are known to be able to catalyze substrate hydroxylation reactions. Recent experimental studies [J.Y. Lee, Y.-M. Lee, H. Kotani, W. Nam, S. Fukuzumi, Chem. Commun. (2009) 704] showed that Mn(V)-oxo porphyrins react rapidly with 10-methyl-9,10-dihydroacridine (AcrH2) via a proton-coupled-electron-transfer followed by an electron transfer. In this work, we present a computational study on the reactivity patterns of Mn(V)-oxo and Mn(IV)-oxo with respect to AcrH2. This study shows that although both oxidants are capable of hydroxylating AcrH2, the MnV-oxo species is the more active oxidant. We have generalized these observations with thermodynamic cycles that explain the reaction mechanisms and electron transfer processes. For the MnV-oxo mechanism the reactions proceed with a fast spin state crossing from the ground state singlet to the triplet spin state prior to a hydrogen atom transfer followed by another electron transfer. The present results are fully consistent with previous studies on iron-oxo porphyrins and manganese-oxo porphyrins and shows that the interplay of low lying singlet and triplet spin state surfaces influences the reaction mechanisms and kinetics.  相似文献   
138.
Molecular and morphological data were used to assess the taxonomic placement of an undescribed lichenicolous basidiomycete teleomorph collected in Luxembourg, Belgium and Germany. The new species is ecologically and morphologically similar to Marchandiobasidium aurantiacum, teleomorph of the common bulbilliferous lichen pathogen Marchandiomyces aurantiacus. However phylogenetic analysis of nuclear and mitochondrial rDNA sequences indicated a close relationship of the new species-not to M. aurantiacum but to turf grass pathogens in genera Laetisaria and Limonomyces, including the generic type of Laetisaria. We are including the new species in Laetisaria based on strong statistical support for the clade containing these teleomorphs and several Marchandiomyces anamorphs. The morphological and ecological diversity of this clade indicates a potentially significant evolutionary role played by lichen-associated species in the Corticiales.  相似文献   
139.
Mental retardation (MR) has a worldwide prevalence of around 2% and is a frequent cause of severe disability. Significant excess of MR in the progeny of consanguineous matings as well as functional considerations suggest that autosomal recessive forms of MR (ARMR) must be relatively common. To shed more light on the causes of autosomal recessive MR (ARMR), we have set out in 2003 to perform systematic clinical studies and autozygosity mapping in large consanguineous Iranian families with non-syndromic ARMR (NS-ARMR). As previously reported (Najmabadi et al. in Hum Genet 121:43-48, 2007), this led us to the identification of 12 novel ARMR loci, 8 of which had a significant LOD score (OMIM: MRT5-12). In the meantime, we and others have found causative gene defects in two of these intervals. Moreover, as reported here, tripling the size of our cohort has enabled us to identify 27 additional unrelated families with NS-ARMR and single-linkage intervals; 14 of these define novel loci for non-syndromic ARMR. Altogether, 13 out of 39 single linkage intervals observed in our cohort were found to cluster at 6 different loci on chromosomes, i.e., 1p34, 4q27, 5p15, 9q34, 11p11-q13 and 19q13, respectively. Five of these clusters consist of two significantly overlapping linkage intervals, and on chr 1p34, three single linkage intervals coincide, including the previously described MRT12 locus. The probability for this distribution to be due to chance is only 1.14 × 10(-5), as shown by Monte Carlo simulation. Thus, in contrast to our previous conclusions, these novel data indicate that common molecular causes of NS-ARMR do exist, and in the Iranian population, the most frequent ones may well account for several percent of the patients. These findings will be instrumental in the identification of the underlying genes.  相似文献   
140.
Probiotics and Antimicrobial Proteins - Hepatic stellate cell (HSC) activation is a key phenomenon in development of liver fibrosis. Recently, Akkermansia muciniphila has been introduced as a...  相似文献   
[首页] « 上一页 [9] [10] [11] [12] [13] 14 [15] [16] [17] [18] [19] 下一页 » 末  页»
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号