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   177篇
  免费   19篇
  国内免费   9篇
耳鼻咽喉   1篇
儿科学   3篇
基础医学   31篇
口腔科学   4篇
临床医学   24篇
内科学   68篇
皮肤病学   1篇
神经病学   5篇
特种医学   7篇
外科学   12篇
综合类   8篇
预防医学   5篇
眼科学   1篇
药学   3篇
中国医学   4篇
肿瘤学   28篇
  2023年   1篇
  2022年   6篇
  2021年   6篇
  2020年   4篇
  2019年   6篇
  2018年   13篇
  2017年   9篇
  2016年   4篇
  2015年   8篇
  2014年   11篇
  2013年   8篇
  2012年   10篇
  2011年   14篇
  2010年   15篇
  2009年   6篇
  2008年   11篇
  2007年   3篇
  2006年   8篇
  2005年   6篇
  2004年   7篇
  2003年   2篇
  2002年   5篇
  2001年   2篇
  1996年   1篇
  1995年   2篇
  1994年   2篇
  1993年   1篇
  1992年   3篇
  1990年   1篇
  1987年   1篇
  1984年   1篇
  1982年   1篇
  1980年   1篇
  1979年   1篇
  1978年   2篇
  1977年   3篇
  1976年   4篇
  1975年   2篇
  1974年   1篇
  1973年   4篇
  1972年   3篇
  1971年   2篇
  1970年   2篇
  1968年   1篇
  1967年   1篇
排序方式: 共有205条查询结果,搜索用时 31 毫秒
61.
62.
Cardona  Carol J.  Nazerian  Keyvan  Reed  Willie M.  Silva  Robert F. 《Virus genes》2001,22(3):353-361
The structure of the icosahedral adenovirus capsid is highly conserved among Adenoviridae. In its native form, the hexon is the major capsid protein. The nascent hexon requires the 100 kDa folding protein to fold into its native, trimeric form. The hexon and 100 kDa folding protein were co-expressed in a fowlpox virus (FPV) vector and in the recombinant FPVs (rFPVs) in which the hexon and 100 kDa folding protein genes are cloned head to tail, the native hexon could be detected with indirect immunofluorescence and immunoprecipitation using a native hexon monoclonal antibody. The FPV-@X100 construct, in which the 100 kDa folding protein gene follows the hexon gene in a head to tail fashion, elicited the best humoral response in chickens. An attenuated HEV commercial vaccine elicited higher and longer lasting anti-HEV titers than FPV-@X100. Humoral immunity was also compared in turkeys inoculated with rFPVs expressing the hexon alone, the 100 kDa folding protein alone, or expressing both genes in different configurations. No anti-HEV humoral immune response was detected in turkeys inoculated with the rFPVs expressing the hexon alone or the 100 kDa folding protein alone.  相似文献   
63.
64.
65.
AIM/OBJECTIVES: Previous work has shown that the electromechanical activation time (EMAT) is prolonged in patients with abnormally low left ventricular (LV) dP/dt. In the present study, we investigated whether EMAT was responsive to rapid changes in LV systolic function induced by abrupt increases in LV preload. METHODS AND RESULTS: A total of 116 patients were assessed before and after LV angiography with a bolus injection of 40 mL of non-ionic contrast dye. Left ventricular end-diastolic pressure (LVEDP) increased from 18 ± 7 mmHg to 20 ± 8 mmHg (P < 0.01). In patients with a baseline dP/dt < 1500 mmHg/sec, dP/dt increased from 1098 ± 213 mmHg/sec to 1146 ±306 mmHg/sec (P=0.02) and EMAT decreased from 106 ± 29 ms to 103 ±18 ms (P=0.02). In patients with a baseline dP/dt > 1500 mmHg/sec, dP/dt decreased from 1894 ± 368 mmHg/sec to 1762 ± 403 mmHg/sec (P=0.01) and EMAT increased from 88 ± 13 ms to 93 ± 16 ms (P=0.02). Changes in negative dP/dt were similar to changes in dP/dt. CONCLUSION: Electromechanical activation time is a non-invasively measured parameter that allows accurate and rapid detection of changes in LV contractility.  相似文献   
66.
Transplant-associated thrombotic microangiopathy (TA-TMA) is a complication of allogeneic transplantation (allo-HCT). The incidence and risk factors associated with TA-TMA are not well known. A retrospective analysis from the Center for International Blood and Marrow Transplant Research (CIBMTR) was conducted including patients receiving allo-HCT between 2008 and 2016, with the primary objective of evaluating the incidence of TA-TMA. Secondary objectives included identification of risk factors associated with TA-TMA, and the impact of TA-TMA on overall survival and the need for renal replacement therapy (RRT). Among 23,665 allo-HCT recipients, the 3-year cumulative incidence of TA-TMA was 3%. Variables independently-associated with increased incidence of TA-TMA included female sex, prior autologous transplant, primary disease (acute lymphoblastic leukaemia and severe aplastic anaemia), donor type (mismatched or unrelated donor), conditioning intensity (myeloablative), GVHD prophylaxis (sirolimus + calcineurin inhibitor), pre-transplant kidney dysfunction and acute GVHD (time-varying effect). TA-TMA was associated with higher mortality (HR = 3·1, 95% Confidence Interval [CI] = 2·8–16·3) and RRT requirement (HR = 7·1, 95% CI = 5·7–311·6). This study provides epidemiologic data on TA-TMA and its impact on transplant outcomes. Increased awareness of the risk factors will enable providers to be vigilant of this uncommon but serious transplant complication. The results will also provide benchmarking for future study designs and comparisons.  相似文献   
67.
Type A aortic dissection (AD) is a deadly disease. Rapid identification of patients requiring immediate advanced aortic imaging or transfer to specialized centers is needed to improve outcomes. We evaluated the diagnostic performance of transthoracic focus cardiac ultrasound (FOCUS) performed by emergency physicians, alone and in combination with the aortic dissection detection (ADD) risk score in suspected type A AD. This was a prospective study performed on patients with suspected type A AD. FOCUS evaluated the presence of intimal flap/intramural hematoma (direct signs of AD), ascending aorta dilatation, aortic valve insufficiency or pericardial effusion/tamponade (indirect signs of AD). The ADD risk score of each patient was calculated according to guidelines. The final diagnosis was established after review of complete clinical data. 50 (18 %) patients of 281 had a final diagnosis of type A AD. Detection of any FOCUS sign (direct or indirect) of AD had a sensitivity of 88 % (95 % CI 76–95 %) for the diagnosis of type A AD. Presence of ADD risk score > 0 or detection of any FOCUS sign increased diagnostic sensitivity to 96 % (95 % CI 86–99 %). Detection of direct FOCUS signs had a specificity of 94 % (95 % CI 90–97 %), while combination of ADD risk score > 1 with detection of direct FOCUS signs had a specificity of 98 % (95 % CI 96–99 %). FOCUS demonstrated acceptable accuracy as a triage tool to rapidly identify patients with suspected type A AD needing advanced aortic imaging or transfer, but it cannot be used as a stand-alone test even if combined with ADD risk score classification.  相似文献   
68.
Shao S  Sun W  Zhang J  An Q  Xiao T  Yang P  Cheng S  Gao Y 《中华医学杂志》2002,82(11):740-742
目的 在染色体 8p2 1 8p2 2界定发生于中国人肺腺癌的杂合性缺失 (LOH)的最小区域 ,为定位克隆肺腺癌相关抑癌基因提供线索。方法 利用 32例肺腺癌患者肿瘤组织检测位于 8p2 1~p2 2的 17个微卫星多态性标记的LOH频率 ,并且探讨各位点LOH与病理分级和临床分期的关系。结果 在 32例肺腺癌患者组织中有 31例 (96 6 7% )存在至少 1个位点的LOH ;主要集中于 3个区域 :位于 8p2 2的D8S2 5 4~ 2 6 1、D8S182 7~ 1731以及D8S1135。所检测位点中仅D8S2 6 1位点的LOH发生频率与肺腺癌分期呈正相关 (P <0 0 5 )。结论  8p2 2区域可能存在位于D8S2 5 4~ 2 6 1,D8S1135和D8S182 7~ 1731的、与中国人肺腺癌相关的抑癌基因  相似文献   
69.
为筛选新型杀菌抑霉药物,本文报道了标题化合物对7种细菌和4种真菌的杀菌抑霉活性。18~64%的受试菌株对配体Ⅰ_2~Ⅰ_(11)和配合物Ⅱ_2~Ⅱ_(11)表现敏感;多数化合物对大肠杆菌有抑制作用;串珠镰刀菌、毛霉菌、黄曲霉菌、青霉菌对化合物Ⅰ_2高度敏感,抑菌圈直径为15~25mm;化合物Ⅰ_(11)和Ⅱ_(11)分别对73%和64%的菌株有抑菌作用。  相似文献   
70.
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