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   2434762篇
  免费   185273篇
  国内免费   3758篇
耳鼻咽喉   33983篇
儿科学   79414篇
妇产科学   68491篇
基础医学   345827篇
口腔科学   71576篇
临床医学   216102篇
内科学   468186篇
皮肤病学   53257篇
神经病学   192545篇
特种医学   97464篇
外国民族医学   665篇
外科学   370512篇
综合类   56701篇
现状与发展   4篇
一般理论   772篇
预防医学   182516篇
眼科学   56278篇
药学   188196篇
  10篇
中国医学   5179篇
肿瘤学   136115篇
  2018年   23528篇
  2016年   20789篇
  2015年   23706篇
  2014年   32605篇
  2013年   49021篇
  2012年   66545篇
  2011年   70254篇
  2010年   41538篇
  2009年   39407篇
  2008年   66700篇
  2007年   70537篇
  2006年   71860篇
  2005年   69223篇
  2004年   67666篇
  2003年   64806篇
  2002年   63181篇
  2001年   119752篇
  2000年   123538篇
  1999年   104091篇
  1998年   27610篇
  1997年   24717篇
  1996年   24602篇
  1995年   23718篇
  1994年   22004篇
  1993年   20778篇
  1992年   83185篇
  1991年   80509篇
  1990年   79058篇
  1989年   76413篇
  1988年   70408篇
  1987年   69194篇
  1986年   65646篇
  1985年   62943篇
  1984年   46493篇
  1983年   39853篇
  1982年   22870篇
  1981年   20232篇
  1980年   19057篇
  1979年   43572篇
  1978年   29946篇
  1977年   25799篇
  1976年   23634篇
  1975年   25600篇
  1974年   30794篇
  1973年   29679篇
  1972年   27701篇
  1971年   26098篇
  1970年   23949篇
  1969年   22714篇
  1968年   20619篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
Background A high Mandard score implies a non-response to chemotherapy in oesophageal adenocarcinoma. However, some patients exhibit tumour volume reduction and a nodal response despite a high score. This study examines survival and recurrence patterns in these patients.Methods Clinicopathological factors were analysed using multivariable Cox regression assessing time to death and recurrence. Computed tomography-estimated tumour volume change was examined in a subgroup of consecutive patients.Results Five hundred and fifty-five patients were included. Median survival was 55 months (Mandard 1–3) and 21 months (Mandard 4 and 5). In the Mandard 4 and 5 group (332 patients), comparison between complete nodal responders and persistent nodal disease showed improved survival (90 vs 18 months), recurrence rates (locoregional 14.75 vs 28.74%, systemic 24.59 vs 48.42%) and circumferential resection margin positivity (22.95 vs 68.11%). Complete nodal response independently predicted improved survival (hazard ratio 0.34 (0.16–0.74). Post-chemotherapy tumour volume reduction was greater in patients with a complete nodal response (−16.3 vs −7.7 cm3, p = 0.033) with no significant difference between Mandard groups.Conclusion Patients with a complete nodal response to chemotherapy have significantly improved outcomes despite a poor Mandard score. High Mandard score does not correspond with a non-response to chemotherapy in all cases and patients with nodal downstaging may still benefit from adjuvant chemotherapy.Subject terms: Oesophageal cancer, Surgical oncology  相似文献   
103.
104.
105.
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   
106.
107.
108.
109.
110.
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   
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