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   595篇
  免费   61篇
  国内免费   3篇
耳鼻咽喉   2篇
儿科学   27篇
妇产科学   10篇
基础医学   67篇
口腔科学   14篇
临床医学   26篇
内科学   138篇
皮肤病学   8篇
神经病学   20篇
特种医学   3篇
外科学   229篇
综合类   8篇
预防医学   34篇
眼科学   24篇
药学   29篇
中国医学   1篇
肿瘤学   19篇
  2023年   2篇
  2022年   10篇
  2021年   16篇
  2020年   17篇
  2019年   32篇
  2018年   29篇
  2017年   24篇
  2016年   17篇
  2015年   16篇
  2014年   20篇
  2013年   44篇
  2012年   48篇
  2011年   54篇
  2010年   30篇
  2009年   21篇
  2008年   34篇
  2007年   37篇
  2006年   38篇
  2005年   31篇
  2004年   21篇
  2003年   16篇
  2002年   13篇
  2001年   7篇
  2000年   6篇
  1999年   6篇
  1998年   3篇
  1997年   2篇
  1996年   2篇
  1993年   3篇
  1992年   3篇
  1988年   6篇
  1986年   3篇
  1980年   1篇
  1979年   3篇
  1978年   1篇
  1977年   1篇
  1974年   2篇
  1973年   4篇
  1972年   5篇
  1971年   5篇
  1970年   3篇
  1969年   1篇
  1968年   1篇
  1967年   1篇
  1966年   3篇
  1965年   2篇
  1964年   1篇
  1962年   2篇
  1960年   2篇
  1947年   1篇
排序方式: 共有659条查询结果,搜索用时 15 毫秒
31.
32.

Background

Patients with inflammatory bowel disease (IBD) – ulcerative colitis (UC) and Crohn’s disease (CD) have an elevated risk of developing colorectal carcinoma (CRC). Major risk factor in IBD patients is the continuous chronic inflammation leading to development of dysplasia and carcinoma. Nevertheless, other types of non-conventional but suspicious mucosal changes serrated change/dysplasia, NOS and villous hypermucinous change, have also been reported in IBD patients. Preneoplastic potential of these lesions is still not well elucidated.

Aims

The aim of this study was identification of IBD-associated CRCs focusing on finding related precursor lesions in the surgical specimen or in archival biopsy samples followed by a detailed morphological, immunohistochemical and molecular evaluation. For the purpose of the study the mucosal lesions were divided into conventional IBD-associated dysplasia and non-conventional lesions that were merged under a provisory term of putative preneoplastic lesions (PPL).

Methods

A total of 309 consecutive IBD colectomy specimens diagnosed during a 10-year period were reviewed. Detailed morphological evaluation, immunohistochemical analysis of mismatch repair (MMR) proteins, p53 and O6-methylguanine DNA methyltransferase (MGMT) expression and molecular analysis for KRAS, NRAS and BRAF gene mutation were performed in the retrieved CRC cases as well as in the detected dysplasia and PPLs of these patients.

Results

We identified 11 cases of morphologically heterogenous IBD-associated CRCs, occurring in 5 males and 6 females, aged 26–79 years (mean 44 years). A total of 22 mucosal lesions were revealed in 8 CRC patients comprising conventional IBD-associated dysplasia (4 lesions), PPLs as serrated change/dysplasia NOS (11 lesions), villous hypermucinous change (5 lesions), and two true serrated lesions (one sessile serrated adenoma and one traditional serrated adenoma). More than one type of lesion was found in 6 patients. Seven CRC cases harbored mutation of KRAS/NRAS and one case of BRAF. Two patients with KRAS-mutated CRC showed the same mutation in PPL in the same specimen (one serrated change NOS and one TSA with high-grade dysplasia). Similarly, one BRAF-mutated carcinoma case presented the same mutation in serrated change/dysplasia, NOS in the same specimen. Of the CRCs, two showed deficient MMR system profile, six presented with loss of MGMT expression, and six showed aberrant p53 expression. PPLs showed deficient MGMT expression (14 cases) and aberrant p53 (10 cases) as well.

Conclusion

IBD-associated CRCs are very heterogeneous entities. Besides conventional IBD-related dysplasia, other types of mucosal lesions may be associated with long lasting IBD and CRC e.g. villous hypermucinous change and serrated change/dysplasia, NOS. Since these lesions share certain genetic or immunohistochemical changes with the related CRC, a suspicion is raised that these lesions may also have preneoplastic potential. Awareness of these changes is necessary to prevent their missing and under-reporting, and further studies of these lesions should be carried out.  相似文献   
33.
34.
35.
In the submitted review the authors present electrocardiographic record of patients with atrial, ventricular and dual-chamber pacemakers. They also describe specially ECG findings in complications of cardiostimulation. Recommended procedures in these situation: changing pacemaker programme or electric cardioversion or surgical solution--reimplantation of pacemaker generator and/or lead or implantation of second lead.  相似文献   
36.
37.
Calcium and/or phosphate tolerance tests were performed on patients with familial hypophosphataemia, normal control subjects, and patients with vitamin D deficient osteomalacia.Intestinal calcium absorption was similar in patients with familial hypophosphataemia and control subjects. The phosphate tolerance test, which is known to be `flat'' in patients with familial hypophosphataemia, was normal in patients with vitamin D deficient osteomalacia.These findings suggest that rickets and osteomalacia in familial and some cases of non-familial hypophosphataemia are unrelated to abnormal metabolism of vitamin D. This hypothesis is supported by the fact that intestinal calcium absorption as measured by calcium tolerance test is normal in familial hypophosphataemia.It is suggested that the primary abnormality in familial hypophosphataemia is a partial metabolic block in the intestinal absorption and renal tubular reabsorption of phosphate.  相似文献   
38.
Predictive factors of anemia within the first year post renal transplant   总被引:2,自引:0,他引:2  
BACKGROUND: The aim of our study was to identify the independent factors that might predict anemia at 6 (M6) and 12 (M12) months posttransplantation. METHODS: Postrenal transplant anemia (PTA) was defined as having a hemoglobin (Hb) level below 13 g/dl for men and below 12 g/dL for women. In this study, we included all the recipients who received a renal transplant in 2001 at our department, and for whom the graft was still functioning 1 year later (n=92). RESULTS: Anemia was observed in 78%, 35.5% and 25% of patients at day (D)0 and at M6 and M12, respectively. Iron deficiency was found in 14% of patients at D0 and in 13% of patients at M12. A total of 59.8% of patients had received at least one blood transfusion in the postoperative period, whereas 41.3% of patients had received recombinant erythropoietin (rEpo) therapy within the first months posttransplantation. In multivariate analysis, the independent predictive factors of anemia at M6 were Epo level at D0, initial nephropathy (polycystic kidney disease vs. others), posttransplantation rEpo therapy, hematocrit at M3, platelets at D7, and sirolimus therapy. The independent predictive factors of anemia at M12 were Epo level at D0, platelets at D7, delayed graft function (DGF), creatinine clearance at M12, serum creatinine at M12, and Hb level at M6. CONCLUSIONS: The prevalence of PTA was 25% at M12. DGF, renal function at M12, and anemia at M6 were independent risk factors for still having anemia at M12.  相似文献   
39.
The aim of our study was to assess hepatitis C virus (HCV) evolution and long term liver histology outcome in anti-HCV(+)/RNA(+) renal-transplant (RT) patients. Fifty-five anti-HCV(+)/RNA(+) RT patients underwent every 3-4 years after transplantation liver biopsies (LB) (2 LBs, N = 55; 3 LBs, N = 44; 4 LBs, N = 10). The hypervariable region (HVR)-1 of the HCV genome from all patients was characterized over time. Overall, the rate of liver fibrosis progression was 0.07 +/- 0.03 Metavir units/year. We identified three groups of patients: those in whom liver fibrosis remained stable (group I, N = 21), those with progressing liver fibrosis (group II, N = 21), and those with a regression in liver fibrosis (group III, N = 13). Initial fibrosis stage and high diversification of the HVR-1 of HCV genome between the transplantation and the first liver biopsy were independent factors associated with liver fibrosis regression. In conclusion, in this study, after renal transplantation, HCV infection is not harmful upon liver histology in more than fifty percent of the patients. The diversification of the HVR-1 of the HCV genome might be used to predict liver fibrosis outcome.  相似文献   
40.
Tuberculosis of the central nervous system is uncommon. The intramedullary localization is exceptional. We report five cases of intramedullary tuberculosis observed in four women and one man with a mean age of 43 years. Two patients had a prior history of tuberculosis. Spinal cord compression was found clinically in all cases. The spinal MRI visualized the tuberculoma in all patients; two had a double tumor. Complete removal of the tuberculoma was possible in only one patient. Outcome was stationary for four patients.  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