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   1330556篇
  免费   102032篇
  国内免费   4235篇
耳鼻咽喉   16817篇
儿科学   43593篇
妇产科学   36385篇
基础医学   197447篇
口腔科学   35891篇
临床医学   129087篇
内科学   256918篇
皮肤病学   26368篇
神经病学   111811篇
特种医学   48197篇
外国民族医学   366篇
外科学   184107篇
综合类   28751篇
现状与发展   1篇
一般理论   460篇
预防医学   113727篇
眼科学   28931篇
药学   98766篇
  6篇
中国医学   3176篇
肿瘤学   76018篇
  2021年   10776篇
  2019年   11642篇
  2018年   16340篇
  2017年   12302篇
  2016年   13274篇
  2015年   15207篇
  2014年   20833篇
  2013年   32083篇
  2012年   44328篇
  2011年   46971篇
  2010年   27126篇
  2009年   24959篇
  2008年   42788篇
  2007年   45132篇
  2006年   45247篇
  2005年   43668篇
  2004年   41627篇
  2003年   39563篇
  2002年   38363篇
  2001年   60883篇
  2000年   62538篇
  1999年   52308篇
  1998年   14586篇
  1997年   13278篇
  1996年   13117篇
  1995年   12357篇
  1994年   11575篇
  1993年   10834篇
  1992年   41495篇
  1991年   40753篇
  1990年   39436篇
  1989年   37324篇
  1988年   34554篇
  1987年   33677篇
  1986年   32128篇
  1985年   30633篇
  1984年   22996篇
  1983年   19528篇
  1982年   11693篇
  1979年   20768篇
  1978年   14773篇
  1977年   12018篇
  1976年   11833篇
  1975年   12082篇
  1974年   14777篇
  1973年   14456篇
  1972年   13351篇
  1971年   12409篇
  1970年   11473篇
  1969年   10404篇
排序方式: 共有10000条查询结果,搜索用时 328 毫秒
101.
102.
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   
103.
104.
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   
105.
106.
107.
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   
108.
109.
110.
Medical education fellowship programs (MEFPs) are a form of faculty development contributing to an organization’s educational mission and participants’ career development. Building an MEFP requires a systematic design, implementation, and evaluation approach which aligns institutional and individual faculty goals. Implementing an MEFP requires a team of committed individuals who provide expertise, guidance, and mentoring. Qualified MEFP directors should utilize instructional methods that promote individual and institutional short and long term growth. Directors must balance the use of traditional design, implementation, and evaluation methodologies with advancing trends that may support or threaten the acceptability and sustainability of the program. Drawing on the expertise of 28 MEFP directors, we provide twelve tips as a guide to those implementing, sustaining, and/or growing a successful MEFP whose value is demonstrated by its impacts on participants, learners, patients, teaching faculty, institutions, the greater medical education community, and the population’s health.  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