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   369篇
  免费   26篇
  2023年   1篇
  2022年   6篇
  2021年   16篇
  2020年   6篇
  2019年   19篇
  2018年   22篇
  2017年   16篇
  2016年   14篇
  2015年   11篇
  2014年   21篇
  2013年   26篇
  2012年   25篇
  2011年   36篇
  2010年   20篇
  2009年   15篇
  2008年   16篇
  2007年   29篇
  2006年   22篇
  2005年   14篇
  2004年   13篇
  2003年   15篇
  2002年   12篇
  2001年   2篇
  2000年   2篇
  1999年   4篇
  1998年   1篇
  1997年   3篇
  1996年   1篇
  1995年   3篇
  1991年   1篇
  1989年   1篇
  1987年   1篇
  1986年   1篇
排序方式: 共有395条查询结果,搜索用时 406 毫秒
141.
BACKGROUND: Fine needle aspiration biopsy is a well-established method for dijfrrentiation of infective from neoplastic lesions. Varions infective agents, such as mycobacteria, leishmaniasis and microfaria can be diagnosed from aspirates, but there are few case reports on fungal infections in aspirates. Cytologic diagnosis of Aspergillus has occasionally occurred on sputum, pulmonary samples, vaginal secretions, endometrial washings and maxillary sinus specimens. One case of hepatic and subcutaneous masses was diagnosed as Aspergillus by fine needle aspiration and confirmed by culture and histology. CASES: Two cases of subcutaneous aspergillosis were diagnosed by fine needle aspiration and confirmed by culture and histology. CONCLUSION: Fine needle aspiration cytology is a rapid, sensitive and important method of diagnosing Aspergillus and provides a rapid diagnosis, which may be life saving in an immunocompromised patient.  相似文献   
142.
A series of novel techniques, adapted from the field of tumor biology, were developed to quantify vascular structure and function and to explore the role of ANG II receptor AT1 in cardiac remodeling after myocardial infarction (MI). We examined the scar neovasculature at 1-4 wk post-MI in Sprague-Dawley rats with a view toward its ability to deliver and exchange oxygen. CD31 and DiOC7(3) staining was used to visualize anatomical vessels vs. those perfused. EF5/Cy3 immunohistochemical staining was used to quantify tissue hypoxia. We compared untreated controls with rats treated with losartan, an AT1 receptor antagonist. Our findings indicated that, at the infarct site, there was not only a 42-75% (1-4 wk post-MI) decrease in the number of anatomical vessels compared with controls but also a decrease in the fraction of perfused vessels from 70% in normal coronary vasculature to 48% at the infarct site. These changes were accompanied by progressive increases in diffusion distance and tissue hypoxia (100% increase in EF5/Cy3 staining at 4 wk post-MI). Losartan-treated rats exhibited a significantly less marked reduction in vascular perfusion and a significantly lesser extent of tissue hypoxia. Over the course of 4 wk post-MI, there is a reduction in coronary vasculature at the infarct site, the extent of which is attenuated by losartan. These findings implicate AT1 receptor upregulation, and perhaps angiotensin-related peptides, as being antiangiogenic.  相似文献   
143.
144.
145.
The predominant proteins (58K) of the intermediate filament complex in the goldfish visual pathway consist of a series of isoelectric variants. Previous biochemical studies have shown that proteins ON1 and ON2 are of neuronal origin, whereas ON3 and ON4 are of nonneuronal origin. Polyclonal antibodies, purified by affinity chromatography, that are specific for ON1 and ON2 or ON3 and ON4 have been used to localize histologically the ON proteins within the normal and crushed optic nerve. Anti-ON1/ON2 antiserum presented a pattern consistent with intraaxonal staining. A nonneuronal staining pattern was observed with anti-ON3/ON4 antiserum. The two patterns were distinct from and complementary to each other. The data suggest that ON3 and ON4 represent a novel glial fibrillary acidic protein. The results are discussed in terms of the function of these proteins in development, plasticity, and regeneration.  相似文献   
146.
147.
148.
Mutated form (G52E) of diphtheria toxin (DT) CRM197 is an inactive and nontoxic enzyme. Here, we provided a molecular insight using comparative molecular dynamics (MD) simulations to clarify the influence of a single point mutation on overall protein and active-site loop. Post-processing MD analysis (i.e. stability, principal component analysis, hydrogen-bond occupancy, etc.) is carried out on both wild and mutated targets to investigate and to better understand the mechanistic differences of structural and dynamical properties on an atomic scale especially at nicotinamide adenine dinucleotide (NAD) binding site when a single mutation (G52E) happens at the DT. In addition, a docking simulation is performed for wild and mutated forms. The docking scoring analysis and docking poses results revealed that mutant form is not able to properly accommodate the NAD molecule.  相似文献   
149.
Genome-wide association studies indicated that hematopoietically-expressed homeobox (HHEX) gene is a remarkable candidate for type 2 diabetes (T2D) mellitus susceptibility in spite of the fact that the results are ambiguous in some cases. So, this study aimed to evaluate the possible correlation between HHEX gene polymorphisms and T2D development in a sample of the Iranian population. The rs1111875G/A, rs7923837A/G, and rs5015480C/T HHEX gene polymorphisms were genotyped in 250 cases and 250 matched (age and sex) healthy controls using tetra-amplification-refractory mutation system-polymerase chain reaction method. The finding revealed the all measured inheritance models of rs1111875G/A and of rs5015480C/T variants dramatically increase the risk of T2D while another polymorphism (rs7923837A/G) was not associated with risk/protective role in T2D. The results indicated that rs1111875G/A and rs5015480C/T may contribute to the enhancement of T2D risk in a sample of the southeast Iranian population.  相似文献   
150.
Cortical development: Cdk5 gets into sticky situations   总被引:4,自引:0,他引:4  
Cyclin-dependent kinase 5 (Cdk5) is much more than its name implies; it plays a role in neuronal migration, neurite outgrowth and degeneration. Recent evidence suggests that Cdk5 regulates neuronal adhesion and cytoskeletal dynamics.  相似文献   
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