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   2524883篇
  免费   189652篇
  国内免费   3815篇
耳鼻咽喉   35422篇
儿科学   82549篇
妇产科学   70546篇
基础医学   359135篇
口腔科学   74780篇
临床医学   223986篇
内科学   484239篇
皮肤病学   55858篇
神经病学   201732篇
特种医学   101060篇
外国民族医学   665篇
外科学   383630篇
综合类   57073篇
现状与发展   4篇
一般理论   806篇
预防医学   187944篇
眼科学   58400篇
药学   194645篇
  10篇
中国医学   5283篇
肿瘤学   140583篇
  2018年   25611篇
  2017年   20332篇
  2016年   23006篇
  2015年   25590篇
  2014年   34672篇
  2013年   52820篇
  2012年   71459篇
  2011年   75867篇
  2010年   44628篇
  2009年   41406篇
  2008年   72361篇
  2007年   76437篇
  2006年   77525篇
  2005年   74835篇
  2004年   72847篇
  2003年   70026篇
  2002年   68291篇
  2001年   122243篇
  2000年   126786篇
  1999年   105952篇
  1998年   28402篇
  1997年   25334篇
  1996年   25137篇
  1995年   24175篇
  1994年   22414篇
  1993年   21214篇
  1992年   83598篇
  1991年   80871篇
  1990年   79397篇
  1989年   76758篇
  1988年   70686篇
  1987年   69526篇
  1986年   65897篇
  1985年   63361篇
  1984年   46897篇
  1983年   40183篇
  1982年   23250篇
  1981年   20559篇
  1979年   43858篇
  1978年   30207篇
  1977年   26069篇
  1976年   23872篇
  1975年   25847篇
  1974年   31025篇
  1973年   29870篇
  1972年   27842篇
  1971年   26251篇
  1970年   24100篇
  1969年   22854篇
  1968年   20760篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
Abstract

Objective: To understand the origin of extremely high gonadotropin levels in a perimenopausal woman.

Methods: A 52-year-old woman with a 2?months of amenorrhea followed spontaneous menstrual cycles recovery was referred to our outpatient clinic with elevated follicle-stimulating hormone (FSH, 483 mUI/ml), luteinizing hormone (LH, 475 mUI/ml) and prolactin (PRL, 173?ng/ml). She was known to take levosulpiride. The gonadotropin levels did not fit with the clinical features.

Results: A gonadotroph tumor was ruled out. Further analysis confirmed constantly high FSH, LH and PRL levels. The measurements were repeated using different analytical platforms with different results. After serial dilutions, nonlinearity was present suggesting an immunoassay interference. After post-polyethylene glycol recovery, hormone levels appeared in the normal range. Anti-goat antibodies were recognized in the serum of the patient.

Conclusions: This case report shows a case of falsely abnormal high gonadotropin and PRL levels in a woman during menopause transition. In the clinical practice the evaluation of gonadotropin profile is not recommended at this age, but the abnormal levels stimulated further evaluation. An interference in the assay due to anti-goat antibodies resulted in abnormally high level of FSH and LH. A strict collaboration between clinicians and the laboratory is needed, when laboratory findings do not correspond to clinical findings.  相似文献   
112.
113.
114.
115.
116.
117.
Esophageal adenocarcinoma is the fastest rising cancer in the United States. It develops from long‐standing gastroesophageal reflux disease which affects >20% of the general population. It carries a very poor prognosis with 5‐year survival <20%. The disease is known to sequentially progress from reflux esophagitis to a metaplastic precursor, Barrett''s esophagus and then onto dysplasia and esophageal adenocarcinoma. However, only few patients with reflux develop Barrett''s esophagus and only a minority of these turn malignant. The reason for this heterogeneity in clinical progression is unknown. To improve patient management, molecular changes which facilitate disease progression must be identified. Animal models can provide a comprehensive functional and anatomic platform for such a study. Rats and mice have been the most widely studied but disease homology with humans has been questioned. No animal model naturally simulates the inflammation to adenocarcinoma progression as in humans, with all models requiring surgical bypass or destruction of existing antireflux mechanisms. Valuable properties of individual models could be utilized to holistically evaluate disease progression. In this review paper, we critically examined the current animal models of Barrett''s esophagus, their differences and homologies with human disease and how they have shaped our current understanding of Barrett''s carcinogenesis.  相似文献   
118.
Background Immune checkpoint blockers (ICBs) activate CD8+ T cells, eliciting both anti-cancer activity and immune-related adverse events (irAEs). The relationship of irAEs with baseline parameters and clinical outcome is unclear.Methods Retrospective evaluation of irAEs on survival was performed across primary (N = 144) and secondary (N = 211) independent cohorts of patients with metastatic melanoma receiving single agent (pembrolizumab/nivolumab—sICB) or combination (nivolumab and ipilimumab—cICB) checkpoint blockade. RNA from pre-treatment and post-treatment CD8+ T cells was sequenced and differential gene expression according to irAE development assessed.Results 58.3% of patients developed early irAEs and this was associated with longer progression-free (PFS) and overall survival (OS) across both cohorts (log-rank test, OS: P < 0.0001). Median survival for patients without irAEs was 16.6 months (95% CI: 10.9–33.4) versus not-reached (P = 2.8 × 10−6). Pre-treatment monocyte and neutrophil counts, but not BMI, were additional predictors of clinical outcome. Differential expression of numerous gene pathway members was observed in CD8+ T cells according to irAE development, and patients not developing irAEs demonstrating upregulated CXCR1 pre- and post-treatment.Conclusions Early irAE development post-ICB is associated with favourable survival in MM. Development of irAEs is coupled to expression of numerous gene pathways, suggesting irAE development in-part reflects baseline immune activation.Subject terms: Immunotherapy, Melanoma  相似文献   
119.
120.
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