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   159篇
  免费   6篇
  2019年   3篇
  2017年   5篇
  2016年   2篇
  2015年   6篇
  2014年   3篇
  2013年   2篇
  2012年   3篇
  2011年   6篇
  2010年   2篇
  2009年   4篇
  2008年   7篇
  2007年   5篇
  2006年   3篇
  2005年   8篇
  2004年   10篇
  2003年   3篇
  2002年   7篇
  2001年   2篇
  2000年   5篇
  1999年   2篇
  1998年   3篇
  1996年   2篇
  1987年   3篇
  1983年   2篇
  1982年   2篇
  1981年   3篇
  1968年   3篇
  1960年   3篇
  1958年   3篇
  1946年   1篇
  1943年   2篇
  1942年   1篇
  1941年   1篇
  1940年   1篇
  1939年   1篇
  1938年   1篇
  1936年   1篇
  1934年   1篇
  1933年   2篇
  1932年   3篇
  1931年   1篇
  1930年   1篇
  1929年   2篇
  1928年   1篇
  1927年   4篇
  1926年   6篇
  1925年   3篇
  1924年   2篇
  1922年   1篇
  1890年   1篇
排序方式: 共有165条查询结果,搜索用时 15 毫秒
121.
122.
123.
R. R. Struthers 《CMAJ》1929,21(6):685-690
  相似文献   
124.
125.
126.
OBJECTIVE: To assess the comparative contribution of clinical assessment, electrocardiography, and chest radiography to the diagnosis of left ventricular systolic dysfunction in patients admitted to a general medical ward with acute dyspnoea. DESIGN: Prospective cross sectional study. SETTING: Acute medical admissions ward of a teaching hospital. SUBJECTS: 71 randomly selected patients admitted with acute dyspnoea. MAIN OUTCOME MEASURES: Sensitivity and specificity of each investigation and logistic regression analysis of each variable in identifying left ventricular systolic dysfunction. RESULTS: Clinical assessment in this cohort of patients with severe dyspnoea was generally sensitive (sensitivity 81%). Patients were divided into three groups on the basis of clinical assessment. In the first group (37 patients) the diagnosis of systolic dysfunction was clear, in the second (22) it was in doubt, and in the third (12) it was unlikely. The sensitivity of clinical assessment in identifying left ventricular systolic dysfunction was 81% and the specificity was 47%. The specificity of diagnosis was improved by electrocardiography (69%) and chest radiography (92%). Logistic regression analysis showed that isolated pulmonary crepitations were a comparatively poor predictor of left ventricular systolic dysfunction chi 2 = 10.215, P = 0.0014) but that a full clinical examination had reasonable predictive value (chi 2 = 24.82, P < 0.00001). The combination of clinical assessment and chest radiography improved the accuracy of diagnosis (chi 2 = 28.08, P < 0.00001), as did the combination of clinical assessment and electrocardiography (chi 2 = 32.41, P < 0.00001). CONCLUSION: Clinical assessment in patients admitted with acute dyspnoea is comparatively accurate. Patients with abnormal results on chest radiography, electrocardiography, and clinical examination have a high likelihood of having left ventricular systolic dysfunction. Echocardiography contributes little more to the diagnosis in these patients and may be more efficiently directed towards patients in whom the diagnosis is still in doubt after clinical assessment, chest radiography, and electrocardiography.  相似文献   
127.
A novel class of human β3-adrenergic receptor agonists was designed in effort to improve selectivity and metabolic stability versus previous disclosed β3-AR agonists. As observed, many of the β3-AR agonists seem to need the acyclic ethanolamine core for agonist activity. We have synthesized derivatives that constrained this moiety by introduction of a pyrrolidine. This unique modification maintains human β3 functional potency with improved selectivity versus ancillary targets and also eliminates the possibility of the same oxidative metabolites formed from cleavage of the N-C bond of the ethanolamine. Compound 39 exhibited excellent functional β3 agonist potency across species with good pharmacokinetic properties in rat, dog, and rhesus monkeys. Early de-risking of this novel pyrrolidine core (44) via full AMES study supports further research into various new β3-AR agonists containing the pyrrolidine moiety.  相似文献   
128.
A new class of small molecule GnRH antagonists, the 7-aryl-8-fluoro-pyrrolo[1,2-a]pyrimid-4-ones, was designed and a novel synthesis for these compounds was developed. The synthesis utilizes a base-catalyzed intramolecular cyclization of fluoromethyl pyrimidone 5 to generate the bicyclic core. Amongst the compounds synthesized, we discovered some highly potent GnRH receptor antagonists (e.g., 12, K(i)=9 nM), which showed enhanced stability towards acidic physiological conditions compared to the des-fluoro analogues.  相似文献   
129.
130.

Background

In rectal cancer, total mesorectal excision surgery combined with preoperative (chemo)radiotherapy reduces local recurrence rates but does not improve overall patient survival, a result that may be due to the harmful side effects and/or co-morbidity of preoperative treatment. New biomarkers are needed to facilitate identification of rectal cancer patients at high risk for local recurrent disease. This would allow for preoperative (chemo)radiotherapy to be restricted to high-risk patients, thereby reducing overtreatment and allowing personalized treatment protocols. We analyzed genome-wide DNA copy number (CN) and allelic alterations in 112 tumors from preoperatively untreated rectal cancer patients. Sixty-six patients with local and/or distant recurrent disease were compared to matched controls without recurrence. Results were validated in a second cohort of tumors from 95 matched rectal cancer patients. Additionally, we performed a meta-analysis that included 42 studies reporting on CN alterations in colorectal cancer and compared results to our own data.

Results

The genomic profiles in our study were comparable to other rectal cancer studies. Results of the meta-analysis supported the hypothesis that colon cancer and rectal cancer may be distinct disease entities. In our discovery patient study cohort, allelic retention of chromosome 7 was significantly associated with local recurrent disease. Data from the validation cohort were supportive, albeit not statistically significant, of this finding.

Conclusions

We showed that retention of heterozygosity on chromosome 7 may be associated with local recurrence in rectal cancer. Further research is warranted to elucidate the mechanisms and effect of retention of chromosome 7 on the development of local recurrent disease in rectal cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1550-0) contains supplementary material, which is available to authorized users.  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