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   7796篇
  免费   423篇
  国内免费   21篇
  2024年   9篇
  2023年   100篇
  2022年   139篇
  2021年   400篇
  2020年   352篇
  2019年   511篇
  2018年   403篇
  2017年   287篇
  2016年   398篇
  2015年   424篇
  2014年   517篇
  2013年   678篇
  2012年   646篇
  2011年   635篇
  2010年   354篇
  2009年   297篇
  2008年   327篇
  2007年   324篇
  2006年   287篇
  2005年   245篇
  2004年   195篇
  2003年   152篇
  2002年   130篇
  2001年   29篇
  2000年   28篇
  1999年   31篇
  1998年   29篇
  1997年   25篇
  1996年   17篇
  1995年   8篇
  1994年   10篇
  1993年   15篇
  1992年   14篇
  1991年   21篇
  1990年   12篇
  1989年   14篇
  1988年   7篇
  1987年   17篇
  1986年   14篇
  1985年   17篇
  1984年   16篇
  1983年   13篇
  1982年   9篇
  1981年   7篇
  1980年   8篇
  1979年   5篇
  1974年   12篇
  1973年   6篇
  1972年   6篇
  1969年   6篇
排序方式: 共有8240条查询结果,搜索用时 31 毫秒
91.
Molecular Biology Reports - Monoclonal antibodies (mAbs) are widely employed as invaluable therapeutics for a vast number of human disorders. Several approaches have been introduced for the...  相似文献   
92.
Molecular Biology Reports - Combination therapy has been considered as a potential method to overcome the BC chemoresistance. MicroRNAs (miRs) have been suggested as a therapeutic factor in the...  相似文献   
93.
Molecular Biology Reports - Autophagy process is an important defense mechanism against intracellular infection. This process plays a critical role in limiting the development of Toxoplasma gondii....  相似文献   
94.
Background

Strawberry crinkle virus (SCV) is a member of the genus Cytorhabdovirus, family Rhabdovirida, and order Mononegavirales. SCV affects the production of various strawberry cultivars. In this study we investigated the genetic diversity of SCV in strawberry fields based on P3 (movement protein) gene.

Methods and results

The samples were collected from strawberry fields in the Kurdistan Province, Iran. P3 gene from 20 SCV isolates, representing 18 nucleic acid haplotypes, is composed of 729 nucleotides, encoding a protein with 243 amino acids. SCV-P3 sequences shared 98.77%–99.86% nucleotide and 97.5%–100% amino acid sequence identity. Phylogenetic analyses of the new P3 sequences with two previously published SCV-P3 sequences from the Czech Republic showed that there are two major phylogroups (I and II) and three minor phylogroups in the body of the phylogeny, I-1, I-2, II-1. Comparisons of P3 gene sequences revealed a mutational bias, with more differences being transitions than transversions. The ratio of non-synonymous/synonymous nucleotide changes was?<?1, indicating that SCV-P3 gene is under predominantly negative selection.

Conclusions

Phylogenetic and sequence identity analyses showed that SCV isolates from Iran are closely related and have not diverged more than 2% based on P3 gene despite geographical separation and strawberry cultivar. This is the first report of the genetic diversity of SCV worldwide.

  相似文献   
95.
Molecular Biology Reports - Hepatocellular carcinoma (HCC) is the most common primary liver cancer characterized by dysregulation of several crucial cellular signaling pathways such as...  相似文献   
96.
Molecular Biology Reports - Peri-implantitis (PI) is a multifactorial condition caused by the interactions of pathogens and the host immune response. Previous studies have demonstrated a...  相似文献   
97.

Non-albicans Candida species and other rare yeasts have emerged as major opportunistic pathogens in fungal infections. Identification of opportunistic yeasts in developing countries is mainly performed by phenotypic assay, which are time-consuming and prone to errors. The aim of the present study was to evaluate PCR-RFLP as a routinely used identification technique for the most clinically important Candida species in Iran and make a comparison with a novel multiplex PCR, called 21-plex PCR. One hundred and seventy-three yeast isolates from clinical sources were selected and identified with sequence analysis of the D1/D2 domains of rDNA (LSU rDNA) sequencing as the gold standard method. The results were compared with those obtained by PCR-RFLP using MspI restriction enzyme and the 21-plex PCR. PCR-RFLP correctly identified 93.4% of common pathogenic Candida species (C. albicans, C. glabrata, C. parapsilosis, C. tropicalis, and P. kudriavsevii (=?C. krusei)) and was able to identify 45.5% of isolates of the uncommon yeast species compared to the D1/D2 rDNA sequencing. Compared with PCR-RFLP, all common Candida species and 72.7% of uncommon yeast species were correctly identified by the 21-plex PCR. The application of the 21-plex PCR assay as a non-sequence-based molecular method for the identification of common and rare yeasts can reduce turnaround time and costs for the identification of clinically important yeasts and can be applied in resource-limited settings.

  相似文献   
98.
Mycopathologia - Candida albicans has been reported globally as the most widespread pathogenic species contributing candidiasis from superficial to systemic infections in immunocompromised...  相似文献   
99.
Coral Reefs - Shallow water tropical reefs are widely threatened by anthropogenic ocean warming which sometimes exceeds their thermal tolerance limit. The majority of reefs have been currently...  相似文献   
100.
Journal of Plant Growth Regulation - Plants require optimum amounts of nutrients for suitable growth and yield production. Accordingly, the most efficient methods of fertilization, including the...  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