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   10741篇
  免费   487篇
  国内免费   62篇
耳鼻咽喉   75篇
儿科学   200篇
妇产科学   118篇
基础医学   1470篇
口腔科学   184篇
临床医学   755篇
内科学   2524篇
皮肤病学   162篇
神经病学   759篇
特种医学   412篇
外科学   2198篇
综合类   22篇
一般理论   1篇
预防医学   278篇
眼科学   247篇
药学   942篇
中国医学   41篇
肿瘤学   902篇
  2023年   52篇
  2022年   103篇
  2021年   178篇
  2020年   103篇
  2019年   130篇
  2018年   191篇
  2017年   133篇
  2016年   146篇
  2015年   174篇
  2014年   238篇
  2013年   264篇
  2012年   417篇
  2011年   460篇
  2010年   241篇
  2009年   194篇
  2008年   404篇
  2007年   423篇
  2006年   421篇
  2005年   459篇
  2004年   426篇
  2003年   412篇
  2002年   463篇
  2001年   324篇
  2000年   386篇
  1999年   376篇
  1998年   134篇
  1997年   92篇
  1996年   117篇
  1995年   96篇
  1994年   101篇
  1993年   98篇
  1992年   342篇
  1991年   322篇
  1990年   278篇
  1989年   320篇
  1988年   281篇
  1987年   257篇
  1986年   251篇
  1985年   239篇
  1984年   150篇
  1983年   124篇
  1982年   61篇
  1979年   124篇
  1978年   90篇
  1977年   56篇
  1975年   64篇
  1974年   56篇
  1973年   53篇
  1972年   50篇
  1969年   54篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
Endoscopic ultrasonography (EUS) was performed preoperatively in 82 patients with gastric carcinoma (40 with early and 42 advanced malignancy). Measurements of wall thickness were performed in each case and showed good correlation with histological findings. Wall thickening was found to consist of both tumorous and accompanying ulcerous tissue. Thus, increasing wall thickness, as demonstrated by EUS, may not necessarily mean progressive tumor growth. The EUS features of gastric carcinoma were analyzed and four distinct growth patterns found: predominantly intramural (IM) or intraluminal (IL) growth with preservation (Type 1) or destruction (Type 2) of the submucosal echo-rich layer. All early carcinomas displayed the IL-type growth pattern on EUS (98% IL1-type) and 81% of advanced tumors showed IM-type features. EUS was able to differentiate between early and advanced carcinoma in 98% of cases. The EUS pattern of submucosal destruction (type IM2 or IL2) corresponded to the expanding type tumor according to Ming's histopathological classification. On the other hand, 24 of 26 infiltrative tumors according to Ming were found on EUS to have an intramural growth pattern with preservation of the submucosa (type IM1). It is concluded that EUS is highly sensitive in predicting the tumor growth pattern in gastric carcinoma, providing important additional information to the currently used TNM staging system. Measurements of wall thickness are reliable but differentiation between tumorous growth and peritumorous changes is not possible.  相似文献   
32.
Annexin V, a calcium-binding protein, is widely present in various organs and tissues. In the present study, plasma annexin V concentration was measured in 158 patients who were brought to the emergency room, including 25 patients suffering from acute myocardial infarction (AMI), 14 with cerebrovascular disease, 11 with trauma of the extremities, 11 with severe trauma associated with visceral damage, and 35 with witnessed cardiac arrest. Annexin V concentration in normal healthy individuals (n=110) was 1.9+/-0.7 ng/ml. Annexin V concentration in AMI and cardiac arrest patients was 11.0+/-4.9 and 15.3+/-7.9 ng/ml, respectively, being significantly higher than that in patients with cerebrovascular disease (5.4+/-2.7 ng/ml). The value in severe trauma patients was 15.9+/-9.4 ng/ml, being significantly higher than that in patients with trauma of the extremities (5.6+/-1.2 ng/ml). Annexin V concentrations in the cardiac arrest and AMI patients who survived more than 24 h after admission were lower than those in patients who died within 24 h after the onset of symptoms. Annexin V content in the lungs and myocardium in normal rats was extremely high in comparison to that in brain and skeletal muscle. These results suggest that the high levels of plasma annexin V in patients with AMI, cardiac arrest and severe trauma reflect the severity of damage of the myocardium and/or other visceral organs, and measurement of plasma annexin V concentration may help to assess the prognosis of patients brought to the emergency room.  相似文献   
33.
Overnight polysomnography (PSG) is indispensable for diagnosis of obstructive sleep apnea hypopnea syndrome. However, studies on interscorer agreement on PSG scoring between laboratories are few. The purpose of this study was to examine the reliability of interscorer agreement on PSG scoring among 16 sleep laboratories in Japan. We found a relatively moderate interscorer reliability of the index of oxygen desaturation and arousal during sleep, but a relatively low reliability of the index of transient reduction in and complete cessation of breathing (apnea hypopnea index). The median rate of interscorer coincidence of sleep staging was the lowest for slow wave (deep) sleep (23.5%), followed by those for Stage 1 (59.8%), Wake (73.2%) and Stage 2 (74.2%) in this order, and rapid eye movement was the most reliably identified stage (91.3%). The median rate of interscorer coincidence for all stages was 71.8%. The present study demonstrates that scorers tend to analyze PSG data according to a relatively empirical decision as opposed to a rule-dependent decision. Further detailed scoring manuals are required to decrease the interscorer discrepancy in PSG scoring.  相似文献   
34.
Differences in effectiveness between haloperidol injection and oral atypical antipsychotics in the acute-phase treatment of schizophrenia are not well examined. We retrospectively investigated whether these treatment options affected the length of mechanical restraint. We used the Japanese Diagnosis Procedure Combination Database to identify schizophrenia patients who were involuntarily hospitalized and receiving mechanical restraint between July and December, 2006–2009. Data included patient demographics, use of antipsychotics, and number of days on which patients underwent mechanical restraint. Propensity score matching was performed to compare the number of days of mechanical restraint between the haloperidol injection group and the oral atypical antipsychotics group. We used survival analysis to examine whether the initial difference in treatment affected the number of days of mechanical restraint. Cox regression was performed to compare the concurrent effects of various factors. Among 1731 eligible patients, 574 were treated with haloperidol injections and 420 with atypical antipsychotics. Matching produced 274 patients in each group. Cox regression analysis showed that the initial therapeutic agents did not significantly affect the number of days of mechanical restraint. The results indicate that atypical antipsychotics were as effective as haloperidol injections in the acute-phase treatment of schizophrenia.  相似文献   
35.
Immunoaffinity purification of human erythrocyte prolidase   总被引:3,自引:0,他引:3  
A procedure including immunoaffinity gel chromatography of an immobilized monoclonal antibody was used to isolate human erythrocyte prolidase (EC 3.4.13.9). The monoclonal antibody was developed against liver prolidase and the antibody recognized the erythrocyte enzyme. The purification procedure included three steps of DEAE cellulose (batcher), immunoaffinity gel chromatography and gel filtration column chromatography. The overall recovery was approximately 20% and the specific activity of the purified preparation was approximately 260 U/mg of protein, a value exceeding that obtained using conventional procedures.  相似文献   
36.
Iron metabolism in rats with acute turpentine-induced inflammation was evaluated. In acute inflammation, reduced plasma iron and total iron-binding capacity values, shortened plasma iron disappearance time and lower plasma iron turnover were observed. The administration of 59Fe chondroitin ferrous sulfate in order to evaluate the reticuloendothelial (RE) function revealed a significantly increased 59Fe retention in the liver and lower incorporation into red blood cells. Radioactivity in hepatic RE cells was higher in acute inflammation than in control. These results suggest the possibility of a block in the transfer of iron from RE cells to the plasma iron pool during acute inflammation.  相似文献   
37.
38.
39.
Objective Owing to advances in direct-acting antiviral (DAA) therapy, a considerable number of patients with hepatitis C virus (HCV)-positive hepatocellular carcinoma (HCC) are now able to achieve a sustained viral response (SVR) after curative treatment of HCC. However, the beneficial effect of a DAA-SVR on the survival remains unclear. Methods A total of 205 patients with HCC who were HCV-positive with Child-Pugh A at the onset from 2008 to 2018 were categorized into 2 groups: 140 patients untreated for HCV throughout the entire course after HCC development (untreated group) and 65 patients treated for HCV with DAAs following HCC treatment who achieved an SVR (SVR group). After propensity score matching, 63 patients from each group were selected. Using these patients, the survival and maintenance of Child-Pugh A after HCC treatment were compared between the untreated group and SVR group. Results There was a significant difference in the overall survival (p<0.001) and the rate of maintaining Child-Pugh A (p<0.001) between the groups. The 5-year survival rates were 96% (SVR group) and 60% (untreated group), and the proportions of patients with Child-Pugh A at 5 years after HCC treatment were 96% (SVR group) and 38% (untreated group). Conclusion In patients with HCV-positive HCC, achieving a DAA-SVR after HCC treatment significantly improved the overall survival rate compared with HCV-untreated patients. The contribution of DAA-SVR during the course of HCC treatment to a longer survival is mainly due to the prevention of the progression of Child-Pugh A to B/C. Further research is needed to determine whether aggressive antiviral therapy is also effective for HCC patients with Child-Pugh B/C.  相似文献   
40.
Immune checkpoint inhibitors (ICIs) are widely used for the treatment of various cancers. However, paradoxical exacerbation of neoplasms, referred to as “hyperprogressive disease,” has been reported in a proportion of patients treated with anti-programmed cell death-1 (PD-1)/PD-1 ligand (PD-L1) blockade. We herein report a case of acute adult T-cell leukemia (ATL) that developed shortly after the administration of nivolumab, a PD-1 inhibitor, to treat non-small-cell lung cancer. There were no signs of ATL before the administration of nivolumab, and seropositivity for human T-cell leukemia virus type-1 (HTLV-1) was confirmed after the development of acute ATL. We speculate that nivolumab likely contributed to the development of acute ATL.  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