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   93篇
  免费   16篇
  2022年   1篇
  2021年   1篇
  2020年   1篇
  2019年   3篇
  2018年   4篇
  2017年   2篇
  2016年   4篇
  2015年   10篇
  2014年   7篇
  2013年   10篇
  2012年   4篇
  2011年   7篇
  2010年   4篇
  2009年   5篇
  2008年   6篇
  2007年   4篇
  2006年   1篇
  2005年   1篇
  2004年   4篇
  2003年   3篇
  2002年   2篇
  2001年   1篇
  2000年   1篇
  1999年   2篇
  1998年   2篇
  1997年   1篇
  1996年   1篇
  1994年   1篇
  1993年   2篇
  1990年   3篇
  1989年   2篇
  1988年   1篇
  1986年   1篇
  1984年   3篇
  1983年   2篇
  1977年   2篇
排序方式: 共有109条查询结果,搜索用时 359 毫秒
21.
Increasing evidence suggests that conditions in early life have important consequences for body size and fitness in mammals. As regards herbivores, teeth play a central role in the long-term performance of individuals. So far, however, patterns of teeth eruption have been scarcely investigated in relation to environmental and climatic factors experienced by herbivores. We described the eruption timing of mandibular teeth in a population of roe deer (Capreolus capreolus) located in the Apennines (Central Italy), through the analysis of 2161 jaws of fawns (1176 females and 985 males) shot in their first winter of life over three hunting seasons (2013–2015). Results showed that the percentage of juveniles exhibiting permanent teeth depends on the cohort. Among the factors that may affect both incisiviform and molariform teeth replacement timing, our findings include body mass and population density. Additional factors determining the relative speed of teeth replacement are (1) food availability for the mother during the last part of gestation, the birth period and the lactation, (2) winter temperature experienced by the mother, and (3) temperature experienced by fawns during their first summer and autumn. Besides, for the first time in literature, elevation was reported to delay front teeth replacement. A greater number of climatic factors were found to shape the eruption timing of the third molar (M3) in comparison to that of incisiviform teeth. Also, a different pattern was found in males and females. The eruption of M3 is, indeed, a costly and long-lasting process requesting optimal nutritional conditions and the meeting of a threshold jaw size. Our results indicate a strong correlation between environmental conditions and eruption process, i.e., between resource availability during the gestation and rearing periods and eruption timing.  相似文献   
22.
23.

Key message

An algae-based vaccine model against atherosclerosis was developed with positive findings in terms of antigen yield and immunogenicity in mouse.

Abstract

Several immunotherapies against atherosclerosis have been evaluated at the preclinical level thus far, with some of them currently under evaluation in clinical trials. In particular, the p210 epitope from ApoB100 is known to elicit atheroprotective responses. Considering that Chlamydomonas reinhardtii is an attractive host for the production and delivery of subunit vaccines, in this study a chimeric protein consisting of the B subunit of the cholera toxin and the p210 epitope from ApoB100 (CTB:p210) has been expressed in C. reinhardtii chloroplast as an attempt to establish an oral vaccine candidate against atherosclerosis. The Chlamydomonas-made CTB:p210 protein was successfully expressed at levels of up to 60 µg per g of fresh weight biomass. The antigenic activity of the CTB and the p210 moiety was preserved in the CTB:p210 chimera. Moreover the algae-made CTB:p210 showed an immunogenic activity, when orally administered to BALB/c mice, as evidenced the presence of anti-p210 serum antibodies in mice treated with the algae-derived CTB:p210. The antibody response lasts for at least 80 days after the last boost. This experimental model is proposed as a convenient tool in the development of low cost atherosclerosis vaccines of easy compliance and friendly delivery. Further studies will determine the therapeutic potential of this algae-made vaccine in atherosclerosis animal models.
  相似文献   
24.
Myosin light-chain expression during avian muscle development   总被引:11,自引:7,他引:4       下载免费PDF全文
Monoclonal antibodies to adult chicken myosin light chains were generated and used to quantitate the types of myosin light-chain (MLC) isoforms expressed during development of the pectoralis major (PM), anterior latissimus dorsi (ALD), and medial adductor (MA) muscles of the chicken. These are muscles which, in the adult, are composed predominantly of fast, slow, and a mixture of fiber types, respectively. Three distinct phases of MLC expression characterized the development of the PM and MA muscles. The first identifiable pase occurred during the period of 5-7 d of incubation in ovo. Extracts of muscles from the pectoral region (which included the presumptive PM muscle) contained only fast MLC isoforms. This period of exclusive fast light-chain synthesis was followed by a phase (8- 12 d of incubation in ovo) in which coexpression of both fast and slow MLC isoforms was apparent in both PM and MA muscles. During the period, the composition of both fast and slow MLC isoforms in the PM and MA muscles was identical. Beginning at day 12 in ovo, the ALD was also subjected to immunochemical analyses. The proportion of fast and slow MLCs in this muscle at day 12 was similar to that present in the other muscles studied. The third development phase of MLC expression began at approximately 12 d of incubation in ovo and encompassed the transition in MLC composition to the isoform patterns incubation in ovo and encompassed the transition in MLC composition to the isoform patterns typical of adult muscle. During this period, the relative proportion of slow MLC rose in both the MA and ALD and fell in the PM. By day 16, the third fast light chain, LC(3f), was apparent in extracts of both the PM and MA. These results show that there is a developmental progression in the expression of MLC in the two avian muscles studied from day 5 in ovo; first, only fast MLCs are accumulated, then both fast and slow MLC isoforms are expressed. Only during the latter third of development in ovo is the final MLC isoform pattern characteristic of a particular muscle type expressed.  相似文献   
25.
26.

Background  

Development of efficient analytic methodologies for combining microarray results is a major challenge in gene expression analysis. The widely used effect size models are thought to provide an efficient modeling framework for this purpose, where the measures of association for each study and each gene are combined, weighted by the standard errors. A significant disadvantage of this strategy is that the quality of different data sets may be highly variable, but this information is usually neglected during the integration. Moreover, it is widely known that the estimated standard deviations are probably unstable in the commonly used effect size measures (such as standardized mean difference) when sample sizes in each group are small.  相似文献   
27.
28.
The localisation of the vacuolar proton pump (V-H+ -ATPase) and the enzyme carbonic anhydrase II (CAII) was investigated in the human eccrine sweat gland employing standard immunohistochemical techniques after antigen retrieval using microwave heat treatment and high pressure. The high-pressure antigen retrieval unmasked the presence of V-H+ -ATPase in the clear cells of the secretory coil, with a distribution similar to that previously observed for CAII. However, the dark cells were unreactive to both antibodies. In addition, heat and high-pressure antigen retrieval demonstrated the presence of CAII in the apical zone of luminal cells of the reabsorptive duct, a location not previously reported. The localisation of V-H+ -ATPase and CAII in the secretory coil clear cells suggests that the formation of HCO3- and H+ by carbonic anhydrase II and the transport of H+ by V-H+ -ATPase may play an role in sweat fluid secretion. Their presence at the apex of the duct cells indicates involvement in ductal ion reabsorption.  相似文献   
29.
30.
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