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   1761002篇
  免费   134372篇
  国内免费   2575篇
耳鼻咽喉   22700篇
儿科学   59091篇
妇产科学   49054篇
基础医学   242886篇
口腔科学   48627篇
临床医学   152080篇
内科学   342765篇
皮肤病学   34706篇
神经病学   145158篇
特种医学   73049篇
外国民族医学   474篇
外科学   270516篇
综合类   41958篇
现状与发展   3篇
一般理论   544篇
预防医学   139378篇
眼科学   39057篇
药学   129967篇
  2篇
中国医学   3597篇
肿瘤学   102337篇
  2018年   35167篇
  2017年   27796篇
  2016年   31023篇
  2015年   15850篇
  2014年   21351篇
  2013年   32010篇
  2012年   48960篇
  2011年   64293篇
  2010年   43803篇
  2009年   36032篇
  2008年   61116篇
  2007年   65359篇
  2006年   46457篇
  2005年   46606篇
  2004年   47183篇
  2003年   46164篇
  2002年   43536篇
  2001年   75910篇
  2000年   78703篇
  1999年   66525篇
  1998年   17911篇
  1997年   16512篇
  1996年   16379篇
  1995年   16101篇
  1994年   15157篇
  1993年   14269篇
  1992年   55451篇
  1991年   53851篇
  1990年   52673篇
  1989年   50889篇
  1988年   47264篇
  1987年   46591篇
  1986年   44303篇
  1985年   42865篇
  1984年   32049篇
  1983年   27584篇
  1982年   16166篇
  1981年   14436篇
  1979年   30462篇
  1978年   21071篇
  1977年   17766篇
  1976年   16701篇
  1975年   17579篇
  1974年   21505篇
  1973年   20673篇
  1972年   18853篇
  1971年   17770篇
  1970年   16307篇
  1969年   15287篇
  1968年   13964篇
排序方式: 共有10000条查询结果,搜索用时 437 毫秒
71.
72.
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   
73.
74.
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   
75.
76.
77.
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   
78.
79.
80.
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