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   1504626篇
  免费   105893篇
  国内免费   4668篇
耳鼻咽喉   19179篇
儿科学   50269篇
妇产科学   41653篇
基础医学   219920篇
口腔科学   41043篇
临床医学   143369篇
内科学   288220篇
皮肤病学   30444篇
神经病学   122517篇
特种医学   57665篇
外国民族医学   461篇
外科学   209419篇
综合类   29809篇
现状与发展   1篇
一般理论   465篇
预防医学   128521篇
眼科学   32899篇
药学   110672篇
  8篇
中国医学   3294篇
肿瘤学   85359篇
  2021年   11188篇
  2019年   11946篇
  2018年   19775篇
  2017年   16070篇
  2016年   16353篇
  2015年   19819篇
  2014年   24965篇
  2013年   35550篇
  2012年   53782篇
  2011年   51819篇
  2010年   29471篇
  2009年   28682篇
  2008年   45151篇
  2007年   48142篇
  2006年   48433篇
  2005年   54213篇
  2004年   53725篇
  2003年   47422篇
  2002年   41844篇
  2001年   64231篇
  2000年   63851篇
  1999年   56800篇
  1998年   15114篇
  1997年   13584篇
  1996年   13459篇
  1995年   12833篇
  1994年   11933篇
  1992年   46782篇
  1991年   46222篇
  1990年   45018篇
  1989年   42688篇
  1988年   39548篇
  1987年   38563篇
  1986年   36735篇
  1985年   34752篇
  1984年   25845篇
  1983年   21904篇
  1982年   12570篇
  1979年   23858篇
  1978年   16739篇
  1977年   13515篇
  1976年   13148篇
  1975年   14137篇
  1974年   17362篇
  1973年   16729篇
  1972年   15661篇
  1971年   14703篇
  1970年   13659篇
  1969年   12480篇
  1968年   11842篇
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
91.
A 17‐year‐old boy presented with recurring severe dermatitis of the face of 5‐months duration that resembled impetigo. He had been treated with several courses of antibiotics without improvement. Biopsy showed changes consistent with allergic contact dermatitis and patch testing later revealed sensitization to benzoyl peroxide, which the patient had been using for the treatment of acne vulgaris.  相似文献   
92.
93.
In 1963, Goffman argued that forming a group based on shared stigma may provide benefits. However, there is no empirical research on whether perception that a separate, unique, coherent group exists (i.e., group entitativity) influences coping, such as educating others or secrecy, for the stigmatized individual or his or her spouse. Further, little is known about how spouses influence each other in terms of promoting the education of others about a stigmatizing condition, especially when it comes to the role of believing that stigma-based groups, to which they may both belong, exist. This study provides a step toward bridging this gap in the research by applying the label management model in efforts to understand coping for couples in which one spouse is diagnosed with genetic mutations leading to alpha-1 antitrypsin deficiency (AATD). This study included 50 married couples in which one spouse is diagnosed with genetic mutations leading to alpha-1 antitrypsin deficiency (AATD). We found that group entitativity related to those with AATD counterbalanced the influence of genetic stigma on spouses’ intentions to keep the diagnosis secret or to educate others about it. Intrapersonal and interpersonal influences appeared among spouses. Attention is needed on the power of creating groups for stigmatized persons and their relatives. Indeed, people live within a dynamic world of group entities, and multiple social identities including spousal and familial. While attention has been paid to the diffusion of stigmas to loved ones, less has been paid to the uplift of group entities for them.  相似文献   
94.
95.
Pancreatic ductal adenocarcinoma (PDAC) is predicted to become the second leading cause of cancer-related mortality within the next decade, with limited effective treatment options and a dismal long-term prognosis for patients. Genomic profiling has not yet manifested clinical benefits for diagnosis, treatment or prognosis in PDAC, due to the lack of available tissues for sequencing and the confounding effects of low tumour cellularity in many biopsy specimens. Increasing focus is now turning to the use of minimally invasive liquid biopsies to enhance the characterisation of actionable PDAC tumour genomes. Circulating tumour DNA (ctDNA) is the most comprehensively studied liquid biopsy analyte in blood and can provide insight into the molecular profile and biological characteristics of individual PDAC tumours, in real-time and in advance of traditional imaging modalities. This can pave the way for identification of new therapeutic targets, novel risk variants and markers of tumour response, to supplement diagnostic screening and provide enhanced scrutiny in treatment stratification. In the roadmap towards the application of precision medicine for clinical management in PDAC, ctDNA analyses may serve a leading role in streamlining candidate biomarkers for clinical integration. In this review, we highlight recent developments in the use of ctDNA-based liquid biopsies for PDAC and provide new insights into the technical, analytical and biological challenges that must be overcome for this potential to be realised.  相似文献   
96.
ABSTRACT

Domestic chickens (Gallus gallus domesticus) were exposed to imidacloprid by gavage once daily for 7 consecutive days at 0, 0.03, 0.34, 3.42, 10.25, and 15.5 mg/kg/day (n = 20 per group; 5 6-week-old males, 5 6-week-old females, 5 9-week-old males, and 5 9-week-old females). The severity and duration of neurobehavioral abnormalities were recorded. Components of the innate and adaptive immune system were assessed with 7 standard functional assays. Temporary neurobehavioral abnormalities were observed in a dose-dependent manner, including muscle tremors, ataxia, and depressed mentation. Based upon mean clinical severity scores, the no observed adverse effect level (NOAEL) was 3.42 mg/kg/day, and the lowest observed adverse effect level (LOAEL) was 10.25 mg/kg/day. The effective dose value for the presence of any neurobehavioral abnormalities in 50% of the test group (ED50) was 4.62 ± 0.98 mg/kg/day. The ED50 for an adjusted score that included both severity and duration of neurobehavioral abnormalities was 11.24 ± 9.33 mg/kg/day. These ED50 values are equivalent to a 1 kg bird ingesting 29 or 70 imidacloprid treated soybean seeds respectively. Immunotoxicity was not documented, possible causes include the assays were insensitive, relevant immune functions were not examined, or imidacloprid is not immunotoxic at this dosing schedule in this species. Neurobehavioral abnormalities were a more sensitive indicator of the sublethal effects of imidacloprid than immunotoxicity.  相似文献   
97.
98.
99.
100.
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