全文获取类型
收费全文 | 122篇 |
免费 | 13篇 |
专业分类
135篇 |
出版年
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2017年 | 4篇 |
2016年 | 4篇 |
2015年 | 5篇 |
2014年 | 7篇 |
2013年 | 7篇 |
2012年 | 4篇 |
2011年 | 5篇 |
2010年 | 4篇 |
2009年 | 1篇 |
2008年 | 2篇 |
2007年 | 2篇 |
2006年 | 5篇 |
2005年 | 4篇 |
2004年 | 3篇 |
2003年 | 7篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 5篇 |
1998年 | 8篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1988年 | 2篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1979年 | 2篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1973年 | 3篇 |
1971年 | 1篇 |
1969年 | 2篇 |
1967年 | 2篇 |
1966年 | 3篇 |
1953年 | 2篇 |
1952年 | 1篇 |
排序方式: 共有135条查询结果,搜索用时 15 毫秒
41.
42.
The liver is a target for toxic chemicals such as cadmium (Cd). When the liver is damaged, hepatic stellate cells (HSC) are activated and transformed into myofibroblast-like cells, which are responsible for liver fibrosis. Curcuma longa has been reported to exert a hepato-protective effect under various pathological conditions. We investigated the effects of C. longa administration on HSC activation in response to Cd induced hepatotoxicity. Forty adult male albino rats were divided into: group 1 (control), group 2 (Cd treated), group 3 (C. longa treated) and group 4 (Cd and C. longa treated). After 6 weeks, liver specimens were prepared for light and electron microscopy examination of histological changes and immunohistochemical localization of alpha smooth muscle actin (αSMA) as a specific marker for activated HSC. Activated HSC with a positive αSMA immune reaction were not detected in groups 1 and 3. Large numbers of activated HSC with αSMA immune reactions were observed in group 2 in addition to Cd induced hepatotoxic changes including excess collagen deposition in thickened portal triads, interlobular septa with hepatic lobulation, inflammatory cell infiltration, a significant increase in Kupffer cells and degenerated hepatocytes. In group 4, we observed a significant decrease in HSC that expressed αSMA with amelioration of the hepatotoxic changes. C. longa administration decreased HSC activation and ameliorated hepatotoxic changes caused by Cd in adult rats. 相似文献
43.
Several factors related to buoyancy were compared between one marine and two freshwater populations of three‐spined stickleback Gasterosteus aculeatus. Fish from all three populations had buoyancy near to neutral to the ambient water. This showed that neither marine nor freshwater G. aculeatus used swimming and hydrodynamic lift to prevent sinking. Comparing the swimbladder volumes showed that freshwater completely plated G. aculeatus had a significantly larger swimbladder volume than both completely plated marine and low‐plated freshwater G. aculeatus. Furthermore, body tissue density was lower in low‐plated G. aculeatus than in the completely plated marine and freshwater fish. The results show that G. aculeatus either reduce tissue density or increase swimbladder volume to adapt to lower water density. Mass measurements of lateral plates and pelvis showed that loss of body armour in low‐plated G. aculeatus could explain the tissue density difference between low‐plated and completely plated G. aculeatus. This suggests that the common occurrence of plate and armour reduction in freshwater G. aculeatus populations can be an adaptation to a lower water density. 相似文献
44.
Despite the prevalence of developmental myopathies resulting from muscle fiber defects, the earliest stages of myogenesis remain poorly understood. Unc45b is a molecular chaperone that mediates the folding of thick-filament myosin during sarcomere formation; however, Unc45b may also mediate specific functions of non-muscle myosins (NMMs). unc45b Mutants have specific defects in striated muscle development, which include myocyte detachment indicative of dysfunctional adhesion complex formation. Given the necessity for non-muscle myosin function in the formation of adhesion complexes and premyofibril templates, we tested the hypothesis that the unc45b mutant phenotype is not mediated solely by interaction with muscle myosin heavy chain (mMHC). We used the advantages of a transparent zebrafish embryo to determine the temporal and spatial patterns of expression for unc45b, non-muscle myosins and mMHC in developing somites. We also examined the formation of myocyte attachment complexes (costameres) in wild-type and unc45b mutant embryos. Our results demonstrate co-expression and co-regulation of Unc45b and NMM in myogenic tissue several hours before any muscle myosin heavy chain is expressed. We also note deficiencies in the localization of costamere components and NMM in unc45b mutants that is consistent with an NMM-mediated role for Unc45b during early myogenesis. This represents a novel role for Unc45b in the earliest stages of muscle development that is independent of muscle mMHC folding. 相似文献
45.
TDP‐1, the Caenorhabditis elegans ortholog of TDP‐43, limits the accumulation of double‐stranded RNA
46.
Mona Dverdal Jansen Gun Peggy Knudsen Ronny Myhre Gudrun Høiseth Jørg Mørland Øyvind Næss Kristian Tambs Per Magnus 《Molecular biology reports》2014,41(5):2733-2743
Single nucleotide polymorphisms (SNPs) in loci 1p13 and 9p21 have previously been found to be associated with incident coronary heart disease (CHD). This study aimed to investigate whether these SNPs show associations with fatal CHD in a population-based cohort study after adjustment for socioeconomic- and lifestyle-related CHD risk factors not commonly included in genetic association studies. Using the population-based Cohort of Norway (CONOR), a nested case-cohort study was set up and DNA from 2,953 subjects (829 cases and 2,124 non-cases) were genotyped. The association with fatal CHD was estimated for four SNPs, three from locus 1p13 and one from locus 9p21. Multivariable Cox regression was used to estimate unstratified and gender-stratified hazard ratios while adjusting for major CHD risk factors. The associations between three SNPs from locus 1p13 and non-HDL cholesterol levels were also estimated. Men homozygous for the risk alleles on rs1333049 (9p21) and rs14000 (1p13) were found to have significantly increased hazard ratios in crude and adjusted models, and the hazard ratios remained statistically significant when both genders were analyzed together. Adjustment for additional socioeconomic- and lifestyle-related CHD risk factors influenced the association estimates only slightly. No significant associations were observed between the other two SNPs in loci 1p13 (rs599839 and rs646776) and CHD mortality in either gender. Both rs599839 and rs646776 showed significant, gradual increases in non-HDL cholesterol levels with increasing number of risk alleles. This study confirms the association between 9p21 (rs1333049) and fatal CHD in a Norwegian population-based cohort. The effect was not influenced by several socioeconomic- and lifestyle-related risk factors. Our results show that 1p13 (rs14000) may also be associated with fatal CHD. SNPs at 1p13 (rs599839 and rs646776) were associated with non-HDL cholesterol levels. 相似文献
47.
Animals maintain complex microbial communities within their guts that fill important roles in the health and development of the host. To what degree a host's genetic background influences the establishment and maintenance of its gut microbial communities is still an open question. We know from studies in mice and humans that external factors, such as diet and environmental sources of microbes, and host immune factors play an important role in shaping the microbial communities (Costello et al. 2012 ). In this issue of Molecular Ecology, Bolnick et al. ( 2014a ) sample the gut microbial community from 150 genetically diverse stickleback isolated from a single lake to provide evidence that another part of the adaptive immune response, the major histocompatibility complex class II (MHCII) receptors of antigen‐presenting cells, may play a role in shaping the gut microbiota of the threespine stickleback, Gasterosteus aculeatus (Bolnick et al. 2014a ). Bolnick et al. ( 2014a ) provide insight into natural, interindividual variation in the diversity of both stickleback MHCII alleles and their gut microbial communities and correlate changes in the diversity of MHCII receptor alleles with changes in the microbiota. 相似文献
48.
Helle Tessand Baalsrud Bernt‐Erik Sæther Ingerid Julie Hagen Ane Marlene Myhre Thor Harald Ringsby Henrik Pärn Henrik Jensen 《Molecular ecology》2014,23(11):2653-2668
Effective population size (Ne) is a key parameter to understand evolutionary processes and the viability of endangered populations as it determines the rate of genetic drift and inbreeding. Low Ne can lead to inbreeding depression and reduced population adaptability. In this study, we estimated contemporary Ne using genetic estimators (LDNE, ONeSAMP, MLNE and CoNe) as well as a demographic estimator in a natural insular house sparrow metapopulation. We investigated whether population characteristics (population size, sex ratio, immigration rate, variance in population size and population growth rate) explained variation within and among populations in the ratio of effective to census population size (Ne/Nc). In general, Ne/Nc ratios increased with immigration rates. Genetic Ne was much larger than demographic Ne, probably due to a greater effect of immigration on genetic than demographic processes in local populations. Moreover, although estimates of genetic Ne seemed to track Nc quite well, the genetic Ne‐estimates were often larger than Nc within populations. Estimates of genetic Ne for the metapopulation were however within the expected range (<Nc). Our results suggest that in fragmented populations, even low levels of gene flow may have important consequences for the interpretation of genetic estimates of Ne. Consequently, further studies are needed to understand how Ne estimated in local populations or the total metapopulation relates to actual rates of genetic drift and inbreeding. 相似文献
49.
Zettel MF Garza LR Cass AM Myhre RA Haizlip LA Osadebe SN Sudimack DW Pathak R Stone TL Polymenis M 《FEMS microbiology letters》2003,223(2):253-258
Budding marks initiation of cell division in Saccharomyces cerevisiae. Consequently, cell cycle progression can be monitored by the fraction of budded cells (budding index) in a proliferating cell population. We determined the budding index of a large collection of deletion strains, to systematically identify genes involved in cell cycle progression. 相似文献
50.
Ronny Myhre Stina Steinkjer Alice Stormyr Gina L Nilsen Hiba Abu Zayyad Khalid Horany Mohamad K Nusier Helge Klungland 《BMC neurology》2008,8(1):47