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   1385篇
  免费   55篇
  国内免费   10篇
耳鼻咽喉   72篇
儿科学   24篇
妇产科学   15篇
基础医学   187篇
口腔科学   18篇
临床医学   103篇
内科学   316篇
皮肤病学   9篇
神经病学   63篇
特种医学   65篇
外科学   239篇
综合类   6篇
预防医学   29篇
眼科学   26篇
药学   95篇
中国医学   6篇
肿瘤学   177篇
  2023年   7篇
  2022年   8篇
  2021年   21篇
  2020年   16篇
  2019年   25篇
  2018年   25篇
  2017年   18篇
  2016年   20篇
  2015年   32篇
  2014年   47篇
  2013年   48篇
  2012年   98篇
  2011年   114篇
  2010年   60篇
  2009年   43篇
  2008年   85篇
  2007年   88篇
  2006年   89篇
  2005年   68篇
  2004年   96篇
  2003年   101篇
  2002年   86篇
  2001年   16篇
  2000年   10篇
  1999年   14篇
  1998年   32篇
  1997年   17篇
  1996年   24篇
  1995年   15篇
  1994年   10篇
  1993年   11篇
  1992年   14篇
  1991年   9篇
  1990年   12篇
  1989年   8篇
  1988年   7篇
  1987年   8篇
  1986年   4篇
  1985年   2篇
  1984年   7篇
  1983年   2篇
  1982年   5篇
  1981年   9篇
  1980年   6篇
  1979年   5篇
  1978年   1篇
  1976年   2篇
  1975年   2篇
  1973年   1篇
  1966年   1篇
排序方式: 共有1450条查询结果,搜索用时 125 毫秒
21.
22.
Two autopsy cases of leiomyosarcoma of the liver in a 49-year old female and 63-year-old male are reported. Both of the liver tumors showed electron microscopically dense patches in the cytoplasm and intermediate junctions between the tumor cells, suggesting a smooth muscle cell origin, irrespective of their different histological features. The nature of both tumors was confirmed by positive immunoreactivity for muscle-specific actin in the tumor cells, whereas desmin immunoreactivity was labile in both cases, showing a higher diagnostic value of the former compared with the latter in these leiomyosarcomas. Both cases, showed extensive distant metastases in spite of an evident difference in their mitotic indices, indicating that this index is not reliable for judging the metastatic potential of these tumors. Acta Pathol Jpn 41: 461–465, 1991.  相似文献   
23.
An 18-year-old woman with abdominal pain was diagnosed as having splenic cysts by computed tomography scan. She had high serum levels of CA19-9 (2886.8 U/mL; normal value, <35 U/mL), CA125 (131.1 U/mL; normal value, <35 U/mL) and soluble IL-2 receptor (1490 U/mL; normal range, 220-530 U/mL). The resected spleen weighed 1050 g, was 14 x 28 cm, and had more than 10 macroscopic cysts up to 10.3 x 9.5 cm. There were numerous microscopic cysts in the spleen and several on the splenic capsule. The levels of CA19-9 and CA125 in the cyst fluid were 2165550 U/mL and 160400 U/mL, respectively. After the surgery, the serum levels of the tumor markers decreased gradually. The inside of the largest cyst was mainly covered by granulation tissue with a focal lining of epithelial cells, and the other macroscopic cysts had stratified squamous epithelium. The microscopic splenic cysts and cysts on the splenic capsule were lined by either attenuated single-layered or multilayered epithelial cells. The lining epithelial cells of these cysts were positive for epithelial membrane antigen and cytokeratins. CA19-9 and CA125 were detected in the lining cells of the splenic cysts. In the present case, it is suspected that the splenic cysts were derived from the capsular lining cells that showed migration from the capsule or formed microcysts on the splenic capsule, as in the case of ovarian inclusion cysts.  相似文献   
24.
The structural basis of the high affinity interleukin-2 receptorwhich was previously reconstituted in a cultured murine T cellline, EL4 by expressing either wild-type Tac antigen complementaryDNA (cDNA) or a chimeric cDNA was characterized. The chimericcDNA encodes a membrane portion whose extracellular portionconsists of that of Tac antigen whereas transmembrane and cytoplasmicportions consists of those the human insulin beta chain. TheTac antigen/anti-Tac antibody complex was treated by chemicalcrosslinking reagents, purified by goat anti-mouse immunoglobulin(lg), and was analysed by SDS–PAGE. We here demonstrated the presence in mouse EL4 transfectantsof a novel membrane protein which is closely associated withthe products of transfected cDNAs in the absence of interleukln-2.The protein is 75 kDa in size and is detected in cells whichexpress high affinity interieukln-2 receptor but not in cellswhich only express low affinity interleukin-2 receptor. Thetransmembrane region and the cytoplasmic region of Tac antigenis not necessary for the formation of the complex consistingof Tac antigen and 75 kDa molecule, indicating that a murine75 kDa molecule associates with Tac antigen extra-cellularly.  相似文献   
25.
Five cases of primary sclerosing scrotal lipogranuloma were examined histologically and immunohistochemically. Every case lacked a history of injection or trauma, and revealed Common histologicat features; a typical granuloma composed of epithelioid cells and multinucleated giant cells, and inflammatory infiltrates of eosinophils, lymphocytes and macrophageimonocytes in the interstitium. lmmunahistochemistry disclosed the epithelioid cells and multinuclaated giant cells of the granuloma to be monocytetr in nature, as bath types of cells were positive for lyso-yme, α-1-antltrypin, α-1-antichymotrypsin, and KP-1. In the interstitium, KP-1 positive monocytes, L-26 positive B lymphocytes, UCHL-1 positive T lymphocytes and 5–100 protein positive Langerhans-like cells were frequently found. 5100 protein positive cells could not be detected in the granuloma. Primary sclerosing lipogranuloma of the scrotum, therefore, is a peculiar inflammation characterized by granulomas consisting of monocytes and marked tissue eosinophilia of unknown etiology.  相似文献   
26.
27.
28.
We report herein an unusual case of primary malignant fibrous histiocytoma (MFH) of the ascending colon. A 47-year-old man was admitted to our hospital for further investigations following the discovery of a mass in the right lower quadrant of the abdomen during a medical checkup. Abdominal ultrasonography (US) and computed tomography (CT) demonstrated a mass extending to the right lateral side from the ascending colon. At laparotomy, a tumor was found originating in the ascending colon and infiltrating the right lateral peritoneum. A right hemicolectomy and partial peritoneal dissection were performed followed by an ileotransverse colostomy reconstruction. The resected specimen contained a tumor measuring 7×5×4 cm, the cut surface of which was yellowish white, and the mucosa of the colon was intact. Based on histological and immunohistochemical inspection, the tumor was diagnosed as MFH of the ascending colon. We reviewed the total 18 known cases of colorectal MFH documented in the literature including our case. After surgery, 4 of 17 patients died of local recurrence, all within 42 months, indicating that early and complete excision of tumor is essential to achieve cure.  相似文献   
29.
We report herein the case of a 32-year-old woman who underwent distal gastrectomy with D2 lymph node dissection for gastric cancer. Microscopic examination of the resected specimen revealed signet-ring cell carcinoma of the stomach with lymph node metastases, and endosalpingiosis in the normal lymph nodes. There was no evidence of malignancy in the peritoneal cavity. To our knowledge, no other case of endosalpingiosis in the lymph nodes along the stomach has ever been reported. The possible significance of endosalpingiosis is discussed following this case report.  相似文献   
30.
We evaluated the usefulness of fluorine-18-fluoro-2-deoxy-d-glucose positron emission tomography (FDG PET) in the detection of mediastinal lymph node metastases in patients with non-small cell lung cancer and then compared the findings with the results of X-ray CT by region based on the histological diagnoses. We examined 29 patients with non-small cell lung cancer. One hundred and thirty-two mediastinal lymph nodes were surgically removed and the histological diagnoses were confirmed. FDG PET images, including 146 mediastinal regions, were visually analysed and the mediastinal lymph nodes were scored as positive when the FDG uptake was higher than that in the other mediastinal structures. On the X-ray CT scans, any mediastinal lymph nodes with a diameter of 10 mm or larger were scored as positive. All three examinations were successfully performed on 71 regions. For FDG PET, we found a sensitivity of 76%, a specificity of 98% and an accuracy of 93%. On the other hand, for X-ray CT a sensitivity of 65%, a specificity of 87% and an accuracy of 82% were observed. A significant difference was observed in respect of both specificity and accuracy (P<0.05). Based on the above findings, FDG PET is suggested to be superior to X-ray CT when used for the detection of mediastinal lymph node metastases in patients with non-small cell lung cancer.  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