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   936475篇
  免费   67831篇
  国内免费   1360篇
耳鼻咽喉   13073篇
儿科学   24947篇
妇产科学   23325篇
基础医学   133538篇
口腔科学   28375篇
临床医学   80952篇
内科学   184260篇
皮肤病学   19325篇
神经病学   72489篇
特种医学   36963篇
外国民族医学   79篇
外科学   152890篇
综合类   18185篇
现状与发展   1篇
一般理论   236篇
预防医学   62185篇
眼科学   21549篇
药学   73024篇
  3篇
中国医学   2194篇
肿瘤学   58073篇
  2018年   9085篇
  2017年   7125篇
  2016年   7921篇
  2015年   8994篇
  2014年   12216篇
  2013年   17761篇
  2012年   24469篇
  2011年   25414篇
  2010年   15074篇
  2009年   14446篇
  2008年   24887篇
  2007年   25993篇
  2006年   26803篇
  2005年   25711篇
  2004年   24779篇
  2003年   23820篇
  2002年   23309篇
  2001年   54802篇
  2000年   56598篇
  1999年   47017篇
  1998年   10778篇
  1997年   9493篇
  1996年   9630篇
  1995年   8957篇
  1994年   8298篇
  1993年   7616篇
  1992年   35544篇
  1991年   33971篇
  1990年   32774篇
  1989年   31934篇
  1988年   29029篇
  1987年   28293篇
  1986年   26345篇
  1985年   25187篇
  1984年   17868篇
  1983年   15166篇
  1982年   7828篇
  1981年   6802篇
  1979年   15829篇
  1978年   10634篇
  1977年   9086篇
  1976年   7911篇
  1975年   8678篇
  1974年   10522篇
  1973年   9897篇
  1972年   9382篇
  1971年   8895篇
  1970年   8469篇
  1969年   7943篇
  1968年   7231篇
排序方式: 共有10000条查询结果,搜索用时 312 毫秒
41.
42.
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   
43.
44.
45.
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   
46.
47.
48.
49.
The aim of this study is to review the literature to find out the exact etiology of anastomotic cancers of colon post resection and differentiate them between a recurrence, second primary, and metastatic disease (local manifestation of systemic disease). Web-based literature search was done, and datas collected. We searched PubMed for papers using the keywords colon cancer recurrence, anastomotic recurrence, and recurrent colon carcinoma. We also searched for systematic review in the same topic. In addition, we used our personal referrence archive. Anastomotic recurrences of colon are postulated to arise due to inadequate margins, tumor implantation by exfoliated cells, altered biological properties of bowel anastomosis, and missed synchronous lesions. Some tumors are unique with repeated recurrence after repeated resection. Duration after primary surgery plays a major role in differentiating recurrent and second primary lesions. Repeated recurrences after repeated resections have to be considered a manifestation of systemic disease or metastatic disease due to the virulence of the disease. A detailed analysis and study of patients with colonic anastomotic lesion are required to differentiate it between a recurrent, a second primary lesion, and a metastatic disease (local manifestation of a systemic disease). The nomenclature is significant to study the survival of these patients, as a second primary lesion will have different survival compared to that of recurrent lesions.  相似文献   
50.
Neurodegeneration with brain iron accumulation (NBIA) is the term applied to a heterogeneous group of disorders resulting in iron deposition in the basal ganglia. Well-known phenotypic features are progressive regression with extra pyramidal involvement and a variable course. A 10-year-old child born to consanguineous parents presented with progressive generalized opisthotonic dystonia, retrocollis, oromandibular dyskinesias, apraxia for swallowing, optic atrophy and severe self-mutilation of lips. MR imaging showed brain iron accumulation. Other causes of self-mutilation were excluded. Early infantile onset, ophisthotonic dystonia with oromandibular dyskinesias and characteristic MR images are suggestive of NBIA. There is only one case reported in the literature of self-mutilation in this condition.  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