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   175634篇
  免费   980篇
  国内免费   15篇
耳鼻咽喉   1142篇
儿科学   6631篇
妇产科学   3012篇
基础医学   16558篇
口腔科学   1548篇
临床医学   12404篇
内科学   30848篇
皮肤病学   656篇
神经病学   16425篇
特种医学   8956篇
外国民族医学   12篇
外科学   28907篇
综合类   2312篇
一般理论   3篇
预防医学   18071篇
眼科学   2725篇
药学   9452篇
中国医学   623篇
肿瘤学   16344篇
  2021年   27篇
  2019年   28篇
  2018年   21942篇
  2017年   17371篇
  2016年   19511篇
  2015年   900篇
  2014年   812篇
  2013年   770篇
  2012年   6959篇
  2011年   21003篇
  2010年   18804篇
  2009年   11512篇
  2008年   19504篇
  2007年   21721篇
  2006年   544篇
  2005年   2177篇
  2004年   3356篇
  2003年   4334篇
  2002年   2485篇
  2001年   279篇
  2000年   415篇
  1999年   184篇
  1998年   219篇
  1997年   208篇
  1996年   93篇
  1995年   112篇
  1994年   108篇
  1993年   73篇
  1992年   48篇
  1991年   95篇
  1990年   126篇
  1989年   85篇
  1988年   68篇
  1987年   48篇
  1986年   28篇
  1985年   39篇
  1984年   26篇
  1983年   30篇
  1982年   31篇
  1980年   42篇
  1974年   25篇
  1970年   22篇
  1969年   23篇
  1939年   20篇
  1938年   60篇
  1937年   25篇
  1935年   22篇
  1934年   30篇
  1932年   56篇
  1930年   46篇
排序方式: 共有10000条查询结果,搜索用时 12 毫秒
141.

Background  

Nasal NK/T cell lymphoma is an aggressive disease and has a poor prognosis. Nasal NK/T cell lymphoma is refractory to conventional chemotherapy and has strong tendency of widespread relapse or dissemination into distant sites.  相似文献   
142.

Background  

Colorectal cancer, if detected early, has greater than 90% 5-year survival. However, survival has been shown to vary across racial/ethnic groups in the United States, despite the availability of early detection methods.  相似文献   
143.
Pituitary metastases of solid tumours are infrequent, specially as a first manifestation. When they happen, they are usually due to breast or lung cancer and are asymptomatic or produce diabetes insipidus. It is very strange that they produce hormonal deficiency. We present a case report of a bronchogenic adenocarcinoma in a 65-year-old man which began with panhypopituitarism, diabetes insipidus and visual alterations. Magnetic resonance imaging revealed a large sellar mass, with clivus infiltration and invading the right cavernous sinus. The biopsy result was adenocarcinoma metastases from lung cancer.  相似文献   
144.
Background. Accepted practices of informed consent often result in suboptimal patient understanding of research studies.Methods. This pilot study aimed to assess trial-specific tailored materials, compared to a widely used generic booklet about clinical trials, randomly assigned to 118 candidates for cancer clinical trials. Study outcomes were: satisfaction with decision-making; satisfaction with materials; and subjective understanding of the clinical trial.Results. There were no major differences between groups. Participants rated tailored materials higher as a useful reference.Conclusions. Trial-specific materials hold utility for reference during clinical trials. Studies of informed consent are feasible, although important factors limit research.  相似文献   
145.
The leaf essential oil of Eugenia zuchowskiae from Monteverde, Costa Rica, has been obtained by hydrodistillation and analyzed by GC–MS. The principal constituents of E. zuchowskiae leaf oil were α-pinene (28.3%), β-caryophyllene (13.2%), α-humulene (13.1%), and α-copaene (8.1%). The leaf essential oil of E. zuchowskiae showed pronounced in-vitro cytotoxic activity against MCF-7, MDA-MB-468, and UACC-257 human tumor cell lines. The major components showed cytotoxic activities comparable to doxorubicin (LC50 14–70 μg/ml).  相似文献   
146.
Objective: To evaluate the effect and safety of clinical use of zoledronic acid in the treatment of malignant hypercalcemia. Methods: A multi-center, open phase II clinical trial was conducted in 15 cases with malignant hypercalcemia who received zoledronic acid intravenously for 15 min. The level of blood calcium and side effects were recorded regularly within 28 days after injection. Results: One case was dropped out due to bad compliance. The complete response rate (the corrected serum calcium was reduced to normal level) was 100.00% (14/14). The medium time of complete response rate was 5.07 days. The medium maintain time was 22.30 days. Slight, or moderate fever was observed. Conclusion: Zoledronic acid can effectively reduce the malignant hypercalcemia. The use of zoledronic acid appears to be safety and convenient.  相似文献   
147.
148.
149.
We report a case of groove pancreatitis (GP) associated with a true pancreatic cyst. An 81-year-old man who had suffered epigastric pain for 4 months was referred to Saisekai Kure Hospital. Computed tomography and endoscopic retrograde pancreatography showed a cystic lesion in the groove area of the pancreas. Serum amylase elevation and imaging findings suggested GP due to the cyst. Six weeks of medical treatment did not improve the clinical symptoms. Therefore, pancreatoduodenectomy was performed. Histologic examination revealed a true cyst with intraluminal necrosis, which produced a protein plug that obstructed the Santorini duct. The parenchyma surrounding the groove area showed marked fibrosis and inflammatory cell infiltration. GP due to true pancreatic cyst was diagnosed. Although GP is usually caused by overconsumption of alcohol, which leads to changes in the pancreatic juice and the ultimate blockage of pancreatic outflow, the histologic features in our patient suggest that true pancreatic cyst stands as a secondary cause of GP.  相似文献   
150.
There is no universally accepted method to determine effective therapy for central sleep apnea (CSA). Continuous positive airway pressure (CPAP) applied acutely most often does not eliminate apneas and hypopneas. We hypothesized that the application of two or more therapeutic modalities after the diagnostic phase of polysomnography, a multi-modality titration study (MMTS), would identify a successful CSA treatment more often than a standard split-night study (SNS) and obviate the need for additional polysomnograms to determine a successful therapy. We retrospectively analyzed polysomnograms of patients diagnosed with CSA at our Sleep Disorders Center. We defined a therapy trial that resulted in an apnea–hypopnea index < 10 with at least one treatment modality as a therapeutic success. One hundred fifteen patients with CSA were studied. Sixty-six patients (57.4%) underwent a SNS, and 49 patients (42.6%) underwent a MMTS. SNS yielded only 8/66 (12.1%) successes on the first night, whereas a MMTS yielded 19/49 (38.8%) successes (p = 0.001, two-tailed Fishers exact). Patients who underwent a SNS eventually had similar rate of success as patients studied with MMTS (60.6 vs 63.3%, NS), but required more testing. Adaptive servo-ventilation was the most successful modality tested, yielding 36/46 (78.3%) successes. Trials of additional modalities following a failed trial of CPAP often produce a successful option that may guide therapy in patients with CSA. This approach may lead to establishing the diagnosis and treatment plans faster, while reducing unnecessary testing.  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