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   15008篇
  免费   845篇
  国内免费   103篇
耳鼻咽喉   80篇
儿科学   264篇
妇产科学   117篇
基础医学   1827篇
口腔科学   227篇
临床医学   1061篇
内科学   4318篇
皮肤病学   260篇
神经病学   1045篇
特种医学   576篇
外科学   2506篇
综合类   44篇
预防医学   425篇
眼科学   376篇
药学   935篇
中国医学   30篇
肿瘤学   1865篇
  2023年   67篇
  2022年   67篇
  2021年   356篇
  2020年   172篇
  2019年   255篇
  2018年   320篇
  2017年   269篇
  2016年   333篇
  2015年   413篇
  2014年   450篇
  2013年   524篇
  2012年   879篇
  2011年   1026篇
  2010年   545篇
  2009年   457篇
  2008年   844篇
  2007年   939篇
  2006年   888篇
  2005年   927篇
  2004年   942篇
  2003年   940篇
  2002年   890篇
  2001年   308篇
  2000年   342篇
  1999年   297篇
  1998年   181篇
  1997年   143篇
  1996年   146篇
  1995年   117篇
  1994年   118篇
  1993年   126篇
  1992年   202篇
  1991年   183篇
  1990年   146篇
  1989年   179篇
  1988年   123篇
  1987年   110篇
  1986年   91篇
  1985年   92篇
  1984年   65篇
  1983年   70篇
  1982年   31篇
  1981年   29篇
  1980年   29篇
  1979年   47篇
  1978年   26篇
  1977年   24篇
  1976年   24篇
  1975年   25篇
  1972年   23篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Background and Aims: Video capsule endoscopy (VCE) has become increasingly important as a simple method for observing the entire small intestine. The indications for VCE are obscure gastrointestinal bleeding and investigation of Crohn’s disease (CD). However, the correlation between endoscopic findings obtained by VCE and clinical findings in known cases of CD is not clear, and we therefore investigated this in the present study. Patients and methods: In 30 patients with known CD (Crohn’s disease activity index [CDAI] 0–420; median = 158.3), double contrast enteroclysis (ENT) was performed 1–3 weeks prior to VCE. The relationship between the VCE findings and hematological analysis/CDAI was examined. Results: In 17 of 30 patients, the entire small intestine could be investigated by VCE, whereas in the remaining 13 patients the terminal ileum could not be investigated. The following exhibited positive correlations: total lesions and CDAI (correlation coefficient values: rs = 0.661, adjusted P < 0.0061), ulcers and C‐reactive protein (CRP) (rs = 0.607, adjusted P < 0.0061), total lesions and CRP (rs = 0.604, adjusted P < 0.0061). Conclusions: Analysis with VCE suggests that CDAI and CRP indicate the activity of intestinal lesions in patients with known CD, and that CRP, in particular, is associated with the activity of ulcerative lesions of the intestine. This may contribute to revised guidelines for VCE in the future.  相似文献   
5.
6.
7.
In lung cancer patients, hypercalcemia is a fairly common metabolic problem associated with malignancy. However, the occurrence of hypercalcemia in lung cancer patients means an ominous prognostic sign. As hypercalcemia often causes early death, quick diagnosis and treatment for hypercalcemia are required. A 69-year-old woman was admitted to our hospital with anorexia caused by hypercalcemia. On admission, serum level of PTH was elevated and PTHrP was normal. From the results of CT findings and transbronchial lung biopsy, the cause of the hypercalcemia was determined as lung cancer incidentally complicated with primary hyperparathyroidism. First, serum calcium level was returned to normal through hydration with saline and bisphosphonates. Next, left hemithyroidectomy for primary hyperparathyroidism was performed. Histologically, the tumor was diagnosed as parathyroid adenoma. Fifteen days later, left lower lobectomy for primary lung cancer was performed under a video-assisted thoracoscopic approach. Histologically, the tumor was diagnosed as a moderately differentiated adenocarcinoma. Four years and three months after the operation, the patient is alive and well with no sign of recurrence. When a lung cancer patient is complicated with hypercalcemia, we need to consider that primary hyperparathyroidism is a possible cause of the hypercalcemia.  相似文献   
8.
9.
Mediastinal cystic tumors are well-marginated round lesions that comprise 12% to 18% of all mediastinal masses. These lesions include a variety of diseases with overlapping radiologic appearances and variable prognoses. Pathological examinations are almost always required for differential diagnosis. We encountered a case of anterior mediastinal tumor discovered in the process of investigation of Raynaud's phenomenon. Taking into account the tumor location, a pericardial cyst was initially suspected. However, the tumor was surgically resected and histopathological examinations demonstrated thymus-like tissue in the cyst walls. Raynaud's phenomenon greatly improved after surgery. These findings suggested that cystic thymoma originated from ectopic thymic tissue and is accompanied by paraneoplastic syndrome.  相似文献   
10.
In this study, we used a novel 4-fluid nozzle spray drier to prepare composite microparticles of a water-insoluble drug, flurbiprofen (FP), and a water-soluble drug, sodium salicylate (SS), for the purpose of improving the water solubility of FP. An ethanol solution of FP and an aqueous SS solution were simultaneously introduced through different liquid passages in the 4-fluid nozzle spray drier and then spray-dried. Quantitative elemental analysis suggested that the FP/SS ratio in each composite microparticle was nearly the same as the formulation ratio. We also found that SS and FP exist in a low crystallinity state in the composite particles. Release of FP from dissolved composite microparticles was markedly improved because of an increase in the effective surface area following rapid dissolution of SS. This study shows that it is possible to prepare FP-SS composite microparticles using a 4-fluid nozzle spray drier in single process and that this can improve the ability of FP to dissolve in water.  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