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   259篇
  免费   13篇
  国内免费   3篇
妇产科学   1篇
基础医学   20篇
口腔科学   35篇
临床医学   18篇
内科学   94篇
皮肤病学   2篇
神经病学   19篇
特种医学   9篇
外科学   43篇
综合类   2篇
预防医学   13篇
眼科学   5篇
药学   4篇
肿瘤学   10篇
  2023年   1篇
  2022年   3篇
  2021年   4篇
  2020年   1篇
  2019年   7篇
  2018年   11篇
  2017年   8篇
  2016年   8篇
  2015年   6篇
  2014年   21篇
  2013年   14篇
  2012年   16篇
  2011年   21篇
  2010年   12篇
  2009年   2篇
  2008年   20篇
  2007年   13篇
  2006年   14篇
  2005年   13篇
  2004年   9篇
  2003年   10篇
  2002年   8篇
  2001年   5篇
  2000年   6篇
  1999年   11篇
  1998年   10篇
  1997年   2篇
  1994年   1篇
  1992年   1篇
  1991年   4篇
  1988年   2篇
  1987年   2篇
  1986年   3篇
  1985年   1篇
  1984年   1篇
  1979年   2篇
  1978年   1篇
  1977年   1篇
排序方式: 共有275条查询结果,搜索用时 0 毫秒
51.
52.

Background

We examined tumor genotype characteristics of human epidermal growth factor receptor 2 (HER2)-positive relapsed (R-) and de novo (dn-) metastatic breast cancer (MBC) in trastuzumab-treated patients who were previously not exposed to this agent.

Materials and Methods

We analyzed genotypes obtained upon deep sequencing from 113 HER2-positive primary tumors from 69 patients with R-MBC and 44 patients with dn-MBC.

Results

Mutations were observed in 90 (79.6%) tumors, 56 R-MBC and 34 dn-MBC (median number per tumor: 2; mean: 11.2; range: 0-150). The top mutated gene was TP53 (63.7%) followed by PIK3CA (24.8%) and others that were mostly co-mutated with TP53 (eg, 22 of 28 PIK3CA mutated tumors were co-mutated in TP53, 17 of these were R-MBC [P = .041]). dn-MBC had higher CEN17 average copies (P = .048). Tumor mutational burden inversely correlated with average HER2 copies (rho ?0.32; P < .001). In all patients, PIK3CA mutations and higher proliferation rate were independent unfavorable prognosticators. In R-MBC, longer disease-free interval between initial diagnosis and relapse conferred lower risk for time-to-progression (P < .001) and death (P = .009); PIK3CA mutations conferred higher risk for death (P = .035). In dn-MBC, surgical removal of the primary tumor before any other therapy was favorable for time-to-progression (P = .002); higher tumor mutational burden was unfavorable for survival (P = .026).

Conclusions

Except for the overall unfavorable prognostic effect of PIK3CA mutations in trastuzumab-treated MBC, our exploratory findings indicate that the outcome of patients with R-MBC is related to patient benefit from the preceding adjuvant chemotherapy and provide initial evidence that tumor mutational burden may be related to prognosis in dn-MBC, which is of potential clinical relevance and merits further investigation.  相似文献   
53.
Sclerosing cholangitis represents a spectrum of chronic biliary diseases that either has an unknown etiology (i.e., primary) or is caused by identifiable insults to the biliary tree (i.e., secondary). To date, the epidemiology of primary sclerosing cholangitis has been appraised; however, its etiology continues to be unclear. In contrast, the etiology of secondary sclerosing cholangitis is always known, but the epidemiology of this clinical entity is difficult to study. This paper was originally presented as part of the SSAT/AHPBA Joint Symposium on Sclerosing Cholangitis at the SSAT 48th Annual Meeting, May 2007, in Washington, DC. The other articles presented in the symposium were Schulick RD, Primary Sclerosing Cholangitis: Detection of Cancer in Strictures; Ahrendt SA, Surgical Approaches to Strictures in Primary Sclerosing Cholangitis; and Chapman WC, Primary Sclerosing Cholangitis: Role of Liver Transplantation.  相似文献   
54.
55.
ObjectiveTo evaluate the proximal and distal (iliac) fixation of seven self-expanding endografts, used in the endovascular treatment (EVAR) of abdominal-aortic aneurysm (AAA), by measuring the displacement force (DF) necessary to dislocate the devices from their fixation sites.MethodsA total of 20 human cadaveric aortas were exposed, left in situ and transected to serve as fixation zones. The Anaconda, EndoFit aorto-uni-iliac, Endurant, Powerlink, Excluder, Talent and Zenith stent grafts were deployed and caudal force was applied at the flow divider, through a force gauge. The DF needed to dislocate each device ≥ 20 mm from the infrarenal neck was recorded before and after moulding-balloon dilatation. Cephalad force was similarly applied to each iliac limb to assess distal fixation before and after moulding-balloon dilatation.ResultsEndografts with fixation hooks or barbs displayed a significantly higher DF necessary to dislocate the proximal portion compared with devices with no such fixation modalities (p < 0.001). Balloon dilatation produced a significant increase in DF in both devices with (p < 0.001) or without (p = 0.003) hooks or barbs. Suprarenal support did not enhance proximal fixation (p = 0.90). Balloon dilatation significantly increased the DF necessary to dislodge the iliac limbs (p = 0.007).ConclusionsDevices with fixation hooks displayed higher proximal fixation. Moulding-balloon dilatation increased proximal and distal fixation. Suprarenal support did not affect proximal fixation.  相似文献   
56.
Screening and treatment of diabetic nephropathy by primary care physicians   总被引:2,自引:0,他引:2  
OBJECTIVE: To describe the practices of Indiana primary care physicians related to diabetic nephropathy screening and management. DESIGN: Cross-sectional, observational. SETTING: The state of Indiana. PARTICIPANTS: Active primary care physicians (defined as general internists, family practitioners, and general practitioners) in Indiana who provided care for diabetic patients at the time of the survey (n = 1,018) MEASUREMENTS AND MAIN RESULTS: Practice patterns relevant to microalbuminuria and overt albuminuria screening and management were assessed along two dimensions: the percentage of patients to whom the practices were applied and the frequency with which the practices were performed. Of 1,141 physicians who responded to the survey, 1,018 were eligible for analysis. Eighty-six percent of physicians reported screening more than half of their patients with type 1 diabetes for overt albuminuria, as did 82% of physicians for their patients with type 2 diabetes. Only 17% of physicians indicated performing microalbuminuria testing on more than half of their type 1 patients. Angiotensin-converting enzyme inhibitor agents were used frequently to treat abnormal urinary albumin excretion when hypertension was present, but less often when hypertension was absent. Physician specialty, year of graduation from medical school, practice location, and familiarity with the results of the Diabetes Control and Complications Trial were significant predictors of screening and treatment practice patterns. CONCLUSIONS: Primary care physicians report practices that allow them to detect overt albuminuria but not microalbuminuria. Angiotensin-converting enzyme inhibitors are frequently used by physicians who test for microalbuminuria, but efforts to increase the detection of early renal damage are needed so that these agents and other therapeutic strategies may be employed at the earliest opportunity.  相似文献   
57.
Bile secretion involves the structural and functional interplay of hepatocytes and cholangiocytes, the cells lining the intrahepatic bile ducts. Hepatocytes actively secrete bile acids into the canalicular space and cholangiocytes then transport bile acids in a vectorial manner across their apical and basolateral plasma membranes. The initial step in the transepithelial transport of bile acids across rat cholangiocytes is apical uptake by a Na(+)-dependent bile acid transporter (ASBT). To date, the molecular basis of the obligate efflux mechanism for extrusion of bile acids across the cholangiocyte basolateral membrane remains unknown. We have identified an exon-2 skipped, alternatively spliced form of ASBT, designated t-ASBT, expressed in rat cholangiocytes, ileum, and kidney. Alternative splicing causes a frameshift that produces a 154-aa protein. Antipeptide antibodies detected the approximately 19 kDa t-ASBT polypeptide in rat cholangiocytes, ileum, and kidney. The t-ASBT was specifically localized to the basolateral domain of cholangiocytes. Transport studies in Xenopus oocytes revealed that t-ASBT can function as a bile acid efflux protein. Thus, alternative splicing changes the cellular targeting of ASBT, alters its functional properties, and provides a mechanism for rat cholangiocytes and other bile acid-transporting epithelia to extrude bile acids. Our work represents an example in which a single gene appears to encode via alternative splicing both uptake and obligate efflux carriers in a bile acid-transporting epithelial cell.  相似文献   
58.
Opinion statement  
–  Primary biliary cirrhosis (PBC) is one of the most common chronic cholestatic liver diseases affecting the adult population.
–  The clinical presentation of PBC can be diverse, ranging from the presymptomatic individual to the patient with advanced liver disease. The initial evaluation to establish the diagnosis, and the appropriate followup, are very important in the lifelong management of these patients.
–  The primary medical treatment in PBC should focus on reducing the rate of disease progression. To this extent, ursodeoxycholic acid has been extensively evaluated and proven to improve liver biochemistries and survival in patients with PBC.
–  The secondary medical management in PBC should address the treatment of complications of chronic cholestasis, hepatic cirrhosis, and failure.
–  Liver transplantation remains the only established therapeutic approach in treating patients with end-stage PBC and its associated complications.
  相似文献   
59.
Primary biliary cirrhosis (PBC) is an idiopathic chronic autoimmune liver disease that primarily affects women. It is believed that the aetiology for PBC is a combination between environmental triggers in genetically vulnerable persons. The diagnosis for PBC is made when two of the three criteria are fulfilled and they are: (1) biochemical evidence of cholestatic liver disease for at least 6 month's duration; (2) anti-mitochondrial antibody (AMA) positivity; and (3) histologic features of PBC on liver biopsy. Ursodeoxycholic acid (UDCA) is the only FDA-approved medical treatment for PBC and should be administered at a recommended dose of 13-15 mg/kg/day. Unfortunately despite adequate dosing of UDCA, approximately one-third of patients does not respond adequately and may require liver transplantation. Future studies are necessary to elucidate the role of environmental exposures and overall genetic impact not only in the development of PBC, but on disease progression and variable clinical response to therapy.  相似文献   
60.

Abstracts

1st Biennial Meeting of the Eurasian Colorectal Technologies Association (ECTA), 13-15 November 2009, Guangzhou/Canton, China President: F. Seow-Choen  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