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   1753篇
  免费   97篇
  国内免费   20篇
耳鼻咽喉   19篇
儿科学   18篇
妇产科学   4篇
基础医学   170篇
口腔科学   24篇
临床医学   114篇
内科学   546篇
皮肤病学   17篇
神经病学   147篇
特种医学   48篇
外科学   431篇
综合类   4篇
预防医学   35篇
眼科学   9篇
药学   80篇
中国医学   2篇
肿瘤学   202篇
  2024年   3篇
  2023年   17篇
  2022年   32篇
  2021年   63篇
  2020年   44篇
  2019年   51篇
  2018年   60篇
  2017年   58篇
  2016年   61篇
  2015年   61篇
  2014年   70篇
  2013年   62篇
  2012年   113篇
  2011年   136篇
  2010年   78篇
  2009年   41篇
  2008年   105篇
  2007年   112篇
  2006年   133篇
  2005年   121篇
  2004年   108篇
  2003年   80篇
  2002年   77篇
  2001年   14篇
  2000年   6篇
  1999年   19篇
  1998年   23篇
  1997年   15篇
  1996年   17篇
  1995年   17篇
  1994年   10篇
  1993年   4篇
  1992年   4篇
  1991年   4篇
  1990年   4篇
  1989年   4篇
  1988年   6篇
  1987年   2篇
  1985年   2篇
  1984年   4篇
  1983年   4篇
  1982年   2篇
  1981年   6篇
  1980年   4篇
  1979年   2篇
  1977年   3篇
  1974年   2篇
  1973年   1篇
  1967年   1篇
  1965年   1篇
排序方式: 共有1870条查询结果,搜索用时 15 毫秒
21.
A 33-year-old man referred to our hospital with a painful swelling of the left scrotal content which had gradually enlarged during the past 4 years. Physical examination revealed a hard, irregular, nontender mass of 5x4 cm in the left scrotum. The mass was fixed to the left epididymis and spermatic cord. Local excision was performed and histologcal examination revealed leiomyosarcoma originating from the spermatic cord. Distant metastases were not observed. Because of the reportedly high propensity for local recurrence, we performed radical orchiectomy and adjuvant radiation. The patient has been alive for 13 months with no evidence of disease.  相似文献   
22.
Inflammatory myofibroblastic tumor of the renal pelvis   总被引:3,自引:0,他引:3  
Inflammatory myofibroblastic tumor (IMT) of the genitourinary tract is rare and has been classified into separate groups based on their anatomical site and postulated aetiology. Herein, we present a case of IMT of the renal pelvis. A 44-year-old man presented with gross hematuria. Abdominal computed tomography (CT) and magnetic resonance imaging (MRI) revealed a tumor of the left renal pelvis. Under the diagnosis of left renal pelvic tumor, he underwent left nephrectomy and ureterectomy. Microscopic examination revealed fascicular spindle cell proliferation in an oedematous myxoid background with an infiltrate of plasma cells. The spindle cells were strongly positive for smooth muscle actin (SMA) and vimentin, and negative for desmin and anaplastic lymphoma kinase (ALK). Diagnosis of the lesion was IMT of the renal pelvis.  相似文献   
23.
BACKGROUND/AIMS: Platelet-derived endothelial cell growth factor (PD-ECGF) is one of the angiogenic factors. The aim of this study was to examine the PD-ECGF concentrations in hepatocellular carcinoma, background liver, and normal liver tissues, and to elucidate their significance on clinicopathological outcomes. METHODOLOGY: The concentration of PD-ECGF in the tissue extract was determined by enzyme-linked immunosorbent assay. RESULTS: PD-ECGF concentrations were significantly higher in hepatocellular carcinoma and background liver tissues compared with normal control liver (p = 0.003, p = 0.001, respectively). PD-ECGF concentrations in hepatocellular carcinoma tissues were positively correlated with intratumoral arteriole densities (r = 0.667, p = 0.009), and were higher in less differentiated carcinomas (p = 0.039). However, tumor PD-ECGF concentration did not affect the patients' disease-free survival rates. Those in the background liver tissues were positively correlated with histological activity index scores (r = 0.650, p = 0.001) and serum alanine aminotransferase levels (r = 0.0452, p = 0.035). CONCLUSIONS: PD-ECGF is up-regulated in hepatocellular carcinoma and the corresponding hepatitis liver. The PD-ECGF concentrations in hepatocellular carcinoma correlated positively with microvessel density, lower differentiation, yet not with patients' prognosis. The concentrations of PD-ECGF in the corresponding hepatitis liver correlated positively with the degree of active hepatitis.  相似文献   
24.
Digestive Diseases and Sciences - Enoxaparin, a low molecular weight heparin, has been used to prevent thrombotic events during major surgery without increasing the rate of hemorrhage. On the other...  相似文献   
25.
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   
26.
27.
28.
It is well known that host immunity plays an important role in the defense against colorectal cancer (CRC) progression. The effects of autoimmune diseases, such as rheumatic disease (RD) in which the immune system is deregulated, on this immunity have not been fully investigated. The medical records of 1299 consecutive patients diagnosed with primary colorectal cancer who underwent surgical resection were retrospectively reviewed. The clinicopathologic factors of 28 subjects with RD (RD group) were compared with those of 1271 patients without RD (non-RD group). Compared to the non-RD group, the RD group was typified by a predominance of females (P < 0.01), older age (P < 0.01), and a lower incidence of rectal cancer (P = 0.02). Although no difference was observed between the groups in terms of TNM classification, disease-free and overall survival were significantly poorer in the RD group in both univariate and multivariate analyses. Subjects who had RD for more than 10 years tended to have a higher frequency of lymph node metastasis (P = 0.06) and a significantly higher incidence of synchronous distant metastasis (P = 0.035) at the time of cancer diagnosis. RD was associated with a significantly poorer prognosis of colorectal cancer, suggesting that deregulation of the immune system by autoimmune diseases may adversely affect the host immune defense against colorectal cancer progression.Key words: Colorectal cancer, Rheumatic disease, Host immunity, PrognosisIt is well known that host immunity plays an important role in defenses against the development and progression of cancer. The degree of lymphocyte infiltration into tumors has been reported to correlate with improvements of patient survival.1 In carcinogen-induced mouse models of cancer, primary tumor susceptibility has been found to be enhanced in immunocompromised mice; conversely, the capacity for such tumors to grow after transplantation into wild-type mice is reduced.2,3 Although cancer cells originate from autologous normal tissue, the immune system can recognize even minimal cellular alterations, distinguish cancerous from normal cells, and elicit an immune response.In autoimmune diseases represented by rheumatic disease (RD), the immune system loses the ability to distinguish nonself from self, eliciting an immune response against self-antigens; in this process, there is a possibility that immune defenses against non-normal cells are lost or impaired, facilitating the development and progression of cancer. In addition, the development of RD associated with cancer has been reported, and as its development is dependent on the production of substances such as hormones, peptides, autocrine and paracrine mediators, and antibodies or the stimulation of cytotoxic lymphocytes, the condition is known as paraneoplastic rheumatic syndrome. In such cases, RD tends to be less responsive to therapy than its nonparaneoplastic equivalents, and instead, treatment of the underlying cancer usually results in regression of RD.4,5 Thus, it is postulated that RD and cancer are closely associated. However, only a few reports on the incidence and risk of cancer among patients with RD exist,6,7 and the characteristics and prognosis of colorectal cancer (CRC) in these patients remain to be elucidated.In the present study, we investigated the development of CRC in the background of an immunologic disorder caused by RD, with the hypothesis that patients with CRC and autoimmune diseases such as RD will have a poorer prognosis than those without RD, as a result of depressed antitumor immunity caused by immune system incompetence. Thus, we aimed to clarify the features and prognosis of CRC-associated RD, and for this purpose, we compared the clinicopathologic features of patients with CRC with or without underlying RD.  相似文献   
29.
30.
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