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   3246篇
  免费   112篇
  国内免费   24篇
耳鼻咽喉   54篇
儿科学   81篇
妇产科学   53篇
基础医学   345篇
口腔科学   79篇
临床医学   168篇
内科学   742篇
皮肤病学   55篇
神经病学   151篇
特种医学   177篇
外国民族医学   1篇
外科学   604篇
综合类   9篇
预防医学   84篇
眼科学   62篇
药学   229篇
中国医学   4篇
肿瘤学   484篇
  2024年   3篇
  2023年   28篇
  2022年   38篇
  2021年   84篇
  2020年   36篇
  2019年   47篇
  2018年   69篇
  2017年   55篇
  2016年   66篇
  2015年   70篇
  2014年   110篇
  2013年   147篇
  2012年   201篇
  2011年   227篇
  2010年   142篇
  2009年   111篇
  2008年   231篇
  2007年   220篇
  2006年   203篇
  2005年   207篇
  2004年   239篇
  2003年   199篇
  2002年   208篇
  2001年   30篇
  2000年   34篇
  1999年   40篇
  1998年   47篇
  1997年   40篇
  1996年   41篇
  1995年   28篇
  1994年   26篇
  1993年   11篇
  1992年   11篇
  1991年   11篇
  1990年   11篇
  1989年   12篇
  1988年   10篇
  1987年   11篇
  1986年   5篇
  1985年   7篇
  1984年   7篇
  1983年   5篇
  1982年   6篇
  1981年   7篇
  1980年   11篇
  1979年   5篇
  1978年   8篇
  1977年   5篇
  1973年   3篇
  1968年   3篇
排序方式: 共有3382条查询结果,搜索用时 15 毫秒
51.
Cyclosporin A is an immunosuppressive agent which is well known as a specific inhibitor of calcineurin (protein phosphatase 2B). In this study, we investigated the effects of cyclosporin A on water-immersion stress-induced gastric ulcer formation and gastric acid secretion in rats. We also examined the localization of calcineurin immunohistochemically. Calcineurin was specifically expressed in gastric parietal cells and chief cells of the gastric mucosa. The intraperitoneal administration of cyclosporin A dose-dependently suppressed the development of gastric mucosal lesions induced by water-immersion stress and inhibited gastric acid secretion, as assessed by pylorus ligation. These results indicated that calcineurin may play an important role in gastric acid secretion. Received: October 14, 1999 / Accepted: January 28, 2000  相似文献   
52.
Amyloidosis associated with chronic lymphocytic leukemia.   总被引:2,自引:0,他引:2  
Chronic lymphocytic leukemia (CLL), the most common form of leukemia in Western countries, rarely induces glomerular disease, but membranoproliferative glomerulonephritis or immunotactoid glomerulopathy has been reported. The proliferating cells in CLL are of mature B-cell origin and produce monoclonal immunoglobulin (Ig), thus leading to various kinds of autoimmune disorders or immunotactoid glomerulopathy. Although there have been a few reported cases of amyloidosis accompanying CLL, the type of amyloid fibrils has not been demonstrated nor described in detail, particularly regarding monoclonal Ig productivity. We report a rare case of amyloidosis associated with CLL, in which we detected ?-light chain type monoclonal Ig in the sera, urine, and on the surface membrane of lymphocytes, and discuss an association between monoclonal Ig-related disease and non-Hodgkin's lymphoma.  相似文献   
53.
The patient was a 39-year-old woman admitted with complaints of fever, clubbed fingers and arthralgia. A chest roentgenogram and chest computed tomographic scan revealed a mass in the left lower lobe. Transbronchial lung biopsy was performed, and a diagnosis of moderately differentiated adenocarcinoma was made. Physical examination confirmed finger clubbing in both hands. Bone scintigram showed marked accumulation of 99mTc-MDP in the long bones, bones of the elbows, and patellae. These findings yielded a diagnosis of pulmonary hypertrophic osteoarthropathy associated with primary lung cancer in young adult. The patient had fever and disturbance of gait of arthralgia on admission, and was treated with an oral non-steroidal anti-inflammation drug (NSAID). Advanced non small cell lung cancer (clinical stage T2 N3 M1, Stage IV) was then diagnosed. Gefitinib was administered after EGFR mutation was found in the tumor specimen. NSAID therapy alleviated the fever and arthralgia. After starting gefitinib and discontinuing the NSAID, She had kept a remission of rational symptom with cytoreductive effect. The abnormal findings of bone scintigrams subsequently disappeared and the patient's serum ICTP dropped.  相似文献   
54.
55.
56.
BackgroundThe data on acute kidney injury (AKI) in patients without chronic kidney disease (CKD) after transcatheter aortic valve replacement (TAVR) are limited. The study sought to compare the incidence of AKI and its impact on 5-year mortality after TAVR and surgical aortic valve replacement (SAVR) in patients without CKD.MethodsThis registry included data from 6463 consecutive patients who underwent TAVR or SAVR. CKD was defined as estimated glomerular filtration rate <60 mL/min/1.73 m2. AKI was defined according to the Kidney Disease Improving Global Outcomes criteria. For sensitivity analysis, propensity-score matching between TAVR and SAVR was performed.ResultsThe study included 4555 consecutive patients (TAVR, n = 1215 and SAVR, n = 3340) without CKD. Propensity-score matching identified 542 pairs. Patients who underwent TAVR had a significantly lower incidence of AKI in comparison to those who underwent SAVR (unmatched 4.7% vs 16.4%, P < 0.001, multivariable analysis: odds ratio, 0.29, 95% confidence interval [CI], 0.20-0.41; matched 5.9% vs 19.0%, P < 0.001). Patients with AKI had significantly increased 5-year mortality compared with those without AKI (unmatched 36.0% vs 19.1%, log-rank P < 0.001; matched 36.3% vs 24.0%, log-rank P < 0.001). The adjusted hazard ratios for 5-year mortality were 1.58 (95% CI, 1.20-2.08) for AKI grade 1, 3.27 (95% CI, 2.09-5.06) for grade 2, and 4.82 (95% CI, 2.93-8.04) for grade 3.ConclusionsTAVR in patients without CKD was associated with a significantly less frequent incidence of AKI compared with SAVR. AKI significantly increased the risk of 5-year mortality after either TAVR or SAVR, and increasing severity of AKI was incrementally associated with 5-year mortality.  相似文献   
57.
Bronchoesophageal fistulae associated with lymphomas are generally associated with chemo-radiotherapy. We report here an unusual case of lymphoma with a therapy-unrelated bronchoesophageal fistula. Previously, only 10 similar cases have been reported. A 70-year-old male was diagnosed as having gastric diffuse large B-cell lymphoma in May 1998. In January 1999, he noted a cough after eating and drinking. Because of the presence of a febrile temperature, productive cough and dyspnea, he was referred to our hospital and diagnosed as having aspiration pneumonia. Antibiotics did not improve his symptoms. When tracheal intubation was performed with bronchoscopy, a bronchoesophageal fistula was revealed. Malignant lymphoma cells were found around the fistula in the biopsy specimen. The patient died of pneumonia after treatment with airway stenting and chemotherapy. Induction of necrosis by chemotherapy or low blood flow with stenting and dopamine probably caused enlargement of the fistula.  相似文献   
58.
We devised an experimental design in primary cultures of fetal rat hepatocytes for studying hepatocyte differentiation over a short period. In the present study, hepatocytes were first cultured for 3 days in dexamethasone-supplemented medium and then for an additional 3 days in dexamethasone- or epidermal growth factor-supplemented medium. In hepatocytes cultured continuously in dexamethasone-supplemented medium, the expression of connexin 32 increased and bile canaliculus-like structures and localization of alkaline phosphatase in the plasma membrane around bile canaliculus-like structures were maintained. Few cells incorporated bromodeoxyuridine. On the other hand, in most of the hepatocytes cultured in epidermal growth factor-supplemented medium, the expression of connexin 32 was minimally recognized, bile canaliculus-like structures were shortened or eliminated, and alkaline phosphatase was localized as numerous fine spots throughout the cytoplasm. More than 20% of all hepatocytes incorporated bromodeoxyuridine.The present study suggests that in hepatocytes, there is a close relationship among connexin 32 expression, the maintenance of bile canaliculus-like structures, and the localization of alkaline phosphatase to the plasma membrane around the bile canaliculus-like structures, and this indicates that the present experimental model is useful for studying hepatocyte differentiation over a short period.  相似文献   
59.
60.
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