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   2233篇
  免费   153篇
  国内免费   7篇
  2023年   27篇
  2022年   40篇
  2021年   104篇
  2020年   75篇
  2019年   126篇
  2018年   145篇
  2017年   79篇
  2016年   103篇
  2015年   103篇
  2014年   119篇
  2013年   200篇
  2012年   169篇
  2011年   170篇
  2010年   91篇
  2009年   72篇
  2008年   85篇
  2007年   78篇
  2006年   59篇
  2005年   61篇
  2004年   62篇
  2003年   58篇
  2002年   40篇
  2001年   23篇
  2000年   21篇
  1999年   14篇
  1998年   10篇
  1996年   13篇
  1994年   7篇
  1993年   5篇
  1992年   12篇
  1991年   10篇
  1990年   14篇
  1989年   6篇
  1988年   14篇
  1987年   11篇
  1986年   10篇
  1985年   15篇
  1984年   13篇
  1983年   9篇
  1982年   5篇
  1981年   8篇
  1980年   11篇
  1979年   10篇
  1978年   11篇
  1977年   10篇
  1976年   7篇
  1975年   7篇
  1974年   8篇
  1973年   8篇
  1969年   5篇
排序方式: 共有2393条查询结果,搜索用时 46 毫秒
1.
2.
Phenotypic diversity of five Jordanian populations of cyst nematodes, Heterodera spp. collected from five regions from Jordan (Ar-Ramtha, Madaba, Dana, Al-Karak, and Jerash) was investigated. Soil samples were collected from one representative field in each region. Morphological and morphometrical characteristics revealed that Heterodera latipons is dominated in cereal fields at Ar-Ramtha, Madaba, Dana and Al-Karak regions and Heterodera schachtii in Jerash. Cysts populations from all cereal fields had bifenestrate vulval cone and a strong underbridge. Wherever, cysts of the cabbage population had ambifenestrate vulval cone with long vulval slit. The bullae were absent in Ar-Ramtha, Madaba and Dana populations, but present in Al-Karak and Jerash. Based on 12 morphometrical characters, the first three functions in canonical discriminant analysis accounted 99.3% of the total variation. Distance from dorsal gland duct opening to stylet base, underbridge length, a = L/W (body length/midbody width) and length of hyaline tail tip had strong and significant contributions in the first function. While the second function was strongly influenced by length of hyaline tail, fenestral length, fenestral width and tail length. However, the third canonical discriminate function was found to be influenced by stylet length, fenestral length, a = L/W (body length/midbody width) and underbridge width. The graphical representation of the distribution of the samples showed that the first canonical discriminant function clearly separated H. schachtii from Jerash from other populations. Whereas, H. latipons collected from Madaba and Dana were clearly separated in the second function. The results indicated that differences at morphological and morphometrical levels revealed diverse populations of Heterodera spp. in Jordan.  相似文献   
3.
4.
Glycoprotein O (gO) is conserved among betaherpesviruses, but little is known about the maturation process of gO in human herpesvirus 6 (HHV-6). We found that HHV-6 gO maturation was accompanied by cleavage of its carboxyl terminus and required coexpression of gH and gL, which promoted the export of gO out of the endoplasmic reticulum (ER). Finally, we also found that gO was not required for HHV-6A growth in T cells.  相似文献   
5.
6.
7.
8.

Background  

We have previously shown that supernatant from Candida albicans (CA) culture contains a Secretory Interleukin (IL)-12 Inhibitory Factor (CA-SIIF), which inhibits IL-12 production by human monocytes. However, the effect of CA-SIIF on secretion of other cytokines by monocytes is unknown, and detailed characterization of this factor has not been performed.  相似文献   
9.
The World Society for Virology (WSV) was founded and incorporated as a nonprofit organization in the United States in 2017. WSV seeks to strengthen and support both virological research and virologists who conduct research of viruses that affect humans, other animals, plants, and other organisms. One of the objectives of WSV is to connect virologists worldwide and support collaboration. Fulfilling this objective, virologists from fourteen countries in North America, Europe, Africa, Asia, and the Middle East met on 25–27th August 2019 in Stockholm, Sweden at the Karolinska University Hospital for the first Committee Meeting of WSV. This meeting included compelling keynote and honorary speeches and a series of 18 scientific talks were given encompassing a diverse array of subjects within virology. Followed by the scientific session, a business session was held where multiple aspects and next steps of the society were discussed and charted out.  相似文献   
10.
Rapid diagnosis of the etiology of infection is highly important for an effective treatment of the infected patients. Bacterial and viral infections are serious diseases that can cause death in many cases. The human immune system deals with many viral and bacterial infections that cause no symptoms and pass quietly without treatment. However, oncology patients undergoing chemotherapy have a very weak immune system caused by leukopenia, and even minor pathogen infection threatens their lives. For this reason, physicians tend to prescribe immediately several types of antibiotics for febrile pediatric oncology patients (FPOPs). Uncontrolled use of antibiotics is one of the major contributors to the development of resistant bacteria. Therefore, for oncology patients, a rapid and objective diagnosis of the etiology of the infection is extremely critical. Current identification methods are time‐consuming (>24 h). In this study, the potential of midinfrared spectroscopy in tandem with machine learning algorithms is evaluated for rapid and objective diagnosis of the etiology of infections in FPOPs using simple peripheral blood samples. Our results show that infrared spectroscopy enables the diagnosis of the etiology of infection as bacterial or viral within 70 minutes after the collection of the blood sample with 93% sensitivity and 88% specificity.  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