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   8577篇
  免费   408篇
  国内免费   73篇
耳鼻咽喉   172篇
儿科学   164篇
妇产科学   62篇
基础医学   1070篇
口腔科学   202篇
临床医学   530篇
内科学   2205篇
皮肤病学   86篇
神经病学   628篇
特种医学   388篇
外科学   1599篇
综合类   39篇
一般理论   1篇
预防医学   304篇
眼科学   57篇
药学   413篇
中国医学   8篇
肿瘤学   1130篇
  2023年   51篇
  2022年   100篇
  2021年   166篇
  2020年   106篇
  2019年   135篇
  2018年   190篇
  2017年   153篇
  2016年   229篇
  2015年   218篇
  2014年   299篇
  2013年   334篇
  2012年   535篇
  2011年   573篇
  2010年   364篇
  2009年   296篇
  2008年   489篇
  2007年   536篇
  2006年   534篇
  2005年   552篇
  2004年   510篇
  2003年   483篇
  2002年   435篇
  2001年   146篇
  2000年   140篇
  1999年   161篇
  1998年   135篇
  1997年   79篇
  1996年   88篇
  1995年   74篇
  1994年   61篇
  1993年   62篇
  1992年   90篇
  1991年   68篇
  1990年   93篇
  1989年   83篇
  1988年   70篇
  1987年   55篇
  1986年   51篇
  1985年   39篇
  1984年   38篇
  1983年   30篇
  1982年   17篇
  1980年   25篇
  1979年   17篇
  1978年   18篇
  1977年   16篇
  1976年   12篇
  1974年   14篇
  1973年   13篇
  1966年   11篇
排序方式: 共有9058条查询结果,搜索用时 93 毫秒
11.
We report a rare case of advanced renal cell carcinoma in apatient who showed complete resolution of metastases to thelung and bones after nephrectomy, partial jejunectomy and subsequentalpha-interferon therapy. The patient was a 54-year-old manwhose right lung and left femur metastases were detected beforenephrectomy. In the seventh week after nephrectomy, a partialjejunectomy was carried out because of the obstructive ileuscaused by intraluminal multiple metastases of the jejunum. Apathological fracture of the metastasized right humerus occurredsubsequently. After four months of intramuscular alpha-interferonadministration (3x106 units/day), however, x-rays revealed thecomplete disappearance of the metastatic lung shadow and a solidunion of the humerus, and there were no tumor cells in the femurspecimen resected at the subsequent reconstruction surgery ofthe left leg. Seven years have passed from onset, and the patientis still alive and disease free.  相似文献   
12.
 We describe a rare case of papillary carcinoma with extensive proliferation of stromal cells. The stromal cells were immunocytochemically positive for vimentin, α-smooth muscle actin and desmin, but negative for cytokeratin, epithelial membrane antigen, S-100, thyroglobulin and CD34. These results and the ultrastructure of the stromal cells, which exhibited the characteristics of both fibroblasts and smooth muscle cells, indicated an origin from myofibroblasts. We conclude that myofibroblastic proliferation may contribute to the stromal response in the slow growth of the papillary carcinoma. Received: 29 August 1996 / 26 May 1997  相似文献   
13.
Hepatocyte regeneration has been widely investigated, with the mitotic index and the incorporation of [3H]thymidine being used as regeneration markers. We focused on the induction of DNA replication enzymes, particularly DNA polymerases (pol) α, δ, and ε. Using rat models, we have shown that the activity of pol α in crude liver extract well represents the regenerating capacity of hepatocytes. Using pol α as an indicator, we analyzed liver regeneration in rat models under various conditions: obstructive jaundice, external or internal biliary drainage, and the obstruction of portal vein branches. It has been revealed that the ligation of the common bile duct alone induces a certain amount of hepatocyte proliferation. It was striking that external biliary drainage suppressed regeneration capacity in cholestatic rat liver after partial hepatectomy. The strong regeneration in nonligated lobes induced by portal branch ligation was similar to the liver regeneration seen after partial hepatectomy with respect to the induction of DNA polymerases. Taken together, the aspects of DNA replication, particularly the induction of DNA polymerases, may contribute to shedding new light on the regeneration of human liver. This work was supported in part by a Grant-in-Aid for General Scientific Research and for Cancer Research from the Ministry of Education, Science and Culture, Japan, and by grants from the Uehara Memorial Foundation  相似文献   
14.
Granular cell tumors (GCT) are rare neoplasms, and only 173 cases of benign GCT of the breast have been documented. We report herein the cases of two patients with this tumor and discuss the methods of diagnosis and treatment. The first patient was a 60-year-old woman who presented with a firm ill-defined mass in her left breast. Mammography showed a dense shadow with spicula and skin thickness, and ultrasonography revealed a hypoechoic mass with an irregular border. Radical mastectomy was performed under the wrong preoperative diagnosis of breast cancer. The second patient was a 31-year-old woman who presented with an elastic-hard mass in her left breast. Mammography showed a well-demarcated dense mass, and ultrasonography revealed a well-defined hypoechoic mass with a large depth-width ratio. Fine-needle aspiration cytology (FNAC) showed a large number of histiocytic cells with abundant granular cytoplasm. An excisional biopsy was performed, and histological examination confirmed a diagnosis of GCT. GCT is benign, but often misdiagnosed as breast cancer both clinically and radiologically. Therefore, histological examination is essential for making a correct diagnosis, while FNAC is also useful. Local resection is still the treatment of choice, and surgeons should do their utmost to avoid performing needless radical mastectomy.  相似文献   
15.
16.
A 64-year-old man was admitted for further examinations of a liver tumor. The patient was diagnosed as chronic hepatitis C complicated with advanced hepatocelluar carcinoma (HCC) with left portal vein tumor thrombosis. As he refused surgical treatment, hepatic arterial infusion chemotherapy (HAIC) using cisplatin and 5-fluorouracil was performed initially. Administration of ursodesoxycholic acid (UDCA) was also started. Following HAIC, microwave coagulation therapy for residual tumor was added. Consequently, viable lesions of HCC disappeared completely. At present, after more than 8 years, neither signs of tumor recurrence, nor elevation of hepatic enzymes has been observed. Although the precise reason for long survival of this patient is not known, we speculate that suppression of levels of hepatic enzymes, as well as HAIC for subclinical intrahepatic metastasis, contributed to the good outcome. Therapeutic strategy for hepatic inflammation seems to be important for long-term prevention of hepatocarcinogenesis.  相似文献   
17.
18.
The aim of this study was to investigate whether the metabolic syndrome (MS) was associated with an elevated level of C-reactive protein (CRP) and increased arterial stiffness, and to clarify whether combined MS and CRP data had a stronger relation to arterial stiffness than did MS data alone. Brachial-ankle pulse wave velocity (baPWV), CRP, and conventional risk factors were evaluated in 3,412 men and 854 women. Adjusted mean values of baPWV in men with 0, 1, 2, and > or = 3 components were 1,309, 1,372, 1,422, and 1,462 cm/s, respectively (p for trend <0.001). Adjusted mean values of baPWV in women with 0, 1, 2, and > or =3 components were 1,212, 1,292, 1,357, and 1,391 cm/s, respectively (p for trend <0.001). Adjusted geometric mean concentrations of CRP in men with 0, 1, 2, and > or = 3 components were 0.036, 0.049, 0.059, and 0.076 mg/dI, respectively (p for trend <0.001). Adjusted geometric mean concentrations of CRP in women with 0, 1, 2, and > or = 3 components were 0.023, 0.030, 0.057, and 0.077 mg/dI, respectively (p for trend <0.001). In analyses of adjusted mean values of baPWV according to the number of MS components and according to CRP levels within or without top quartile levels, the p value for the trend was significant (<0.001) in both men and women but, in post hoc analyses, comparing high and low CRP levels in each MS component-number group, no significant difference was found. These results suggest that, for prediction of increased arterial stiffness, combining MS and CRP data has little additive effect compared to the use of MS data alone.  相似文献   
19.
A case of early gastric carcinoma accompanied by Dieulafoy ulcer is presented. The patient, a 26‐year‐old female, visited our emergency room with chief complaints of massive hematemesis and tarry stool. The initial endoscopic examination revealed a superficial depressed lesion with a faded color accompanied by a tiny ulcer with converging folds at the anterior wall of the middle gastric body. Although no active bleeding vessel was found at that time, the patient was admitted to our hospital for further check‐ups and treatment. On the 6th hospital day, she developed massive hematemesis resulting in shock. Urgent endoscopy, this time, disclosed an exposed bleeding vessel at the small ulcer floor previously mentioned, and endoscopic hemostasis was achieved. Since, however, a biopsy at initial examination from the surrounding depressed area proved carcinoma, a partial distal gastrectomy was subsequently carried out. Histological examination of the resected specimen confirmed the diagnosis of carcinoma limited to the mucosa and submucosa along with findings consistent with Dieulafoy ulcer. This is a rare case of combination of early cancer and Dieulafoy ulcer particularly in such a young patient. A review of the literature is also presented.  相似文献   
20.
A rare case of jejunal carcinoma coexisting with adenoma, situated 120 cm distal to the ligament of Treitz in a 53 year old male, is reported herein. We also review cases of adenoma and carcinoma in the jejunum and ileum from the Japanese literature, and discuss the histogenesis of carcinoma of the jejunum and ileum.  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