首页 | 官方网站   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   6864篇
  免费   636篇
  国内免费   378篇
医药卫生   7878篇
  2024年   13篇
  2023年   87篇
  2022年   147篇
  2021年   262篇
  2020年   223篇
  2019年   174篇
  2018年   234篇
  2017年   190篇
  2016年   193篇
  2015年   250篇
  2014年   339篇
  2013年   348篇
  2012年   559篇
  2011年   620篇
  2010年   394篇
  2009年   359篇
  2008年   469篇
  2007年   416篇
  2006年   396篇
  2005年   375篇
  2004年   268篇
  2003年   223篇
  2002年   171篇
  2001年   147篇
  2000年   158篇
  1999年   151篇
  1998年   91篇
  1997年   73篇
  1996年   72篇
  1995年   69篇
  1994年   51篇
  1993年   38篇
  1992年   47篇
  1991年   39篇
  1990年   39篇
  1989年   28篇
  1988年   23篇
  1987年   24篇
  1986年   24篇
  1985年   14篇
  1984年   14篇
  1983年   11篇
  1982年   6篇
  1981年   6篇
  1979年   10篇
  1973年   2篇
  1972年   4篇
  1971年   3篇
  1970年   6篇
  1969年   6篇
排序方式: 共有7878条查询结果,搜索用时 109 毫秒
21.
Serum interleukin-2 receptor (sIL-2R) level, activities of natural killer cell (NK) and lymphokine activated killer (LAK) cells were determined in 60 patients with advanced carcinoma (AC) before and after treatment with Shenmai Injection (SMI), forty healthy persons were taken as non-carcinoma control (NC). The results showed that: Serum sIL-2R level in AC were much higher than those in NC (P<0.05) and activities of NK and LAK cells in AC were much lower than those in NC (P<0.05) before treatment. There was no significant difference among gastric, colonic and lung cancer (P>0.05). After treatment with SMI, it was found that the level of sIL-2R in all patients were obviously lowered (P<0.05) while the activities of NK and LAK cells were signifficantly higher than that prior the treatment (P<0.05). Relevancy was not found between sIL-2R and NK, LAK cells. These data suggested that the immune function was compromised in AC, and SMI has a wide effect of immuno-regulation.  相似文献   
22.
本文探讨食管胃腔内弹力环扎吻合术的力学机理。这是一种不用任何缝合材料或吻合器进行胃食管吻合的新技术,我们已成功应用于临床。取临床所用的乳胶管按该材料多向异性特征、实验条件以及弹力环数目分为8组,每组3个样品进行各种体外力学试验。通过应力—应变(拉力—伸长)关系曲线和定伸长松驰试验确定它的力学特性是一种粘弹性材料。根据实验所得的应力换算为弹力环对食管和胃组织所施加的最佳压力(压强)是4.23±0.23Kg/cm~2,这样才能保证这一种新颖的吻合术可达到简便、安全、可靠的目的。  相似文献   
23.
考察了褐煤离子交换处理前后的加氢液化性能,探讨了不同形态铁催化剂和不同溶剂对褐煤加氢液化的影响。发现在液化反应条件下,离子交换煤中的(RCOO)_3Fe分解为Fe_3O_4,后者在有较高供氢性能的溶剂中和有硫存在的条件下进一步转化为Fe_(1-x)S,其催化活性高于Fe_3O_4。此外,在液化残渣的Mossbauer谱中发现有γ-Fe,它可能是由Fe_(1-x)S还原而成,其催化活性比Fe_(1-x)S更高。  相似文献   
24.
目的 观察白术桃花汤治疗习惯性便秘的疗效。方法 自拟白术桃花汤 (白术 30g ,桃花 12g ,生地黄 30g ,枳实 10g) ,每日服 1剂 ,7d为 1个疗程。对照组服用果导片作对比观察。结果 白术桃花汤治疗习惯性便秘 117例 ,治愈 10 6例 ,好转 4例 ,总有效率 94 .0 2 %;果导片治疗 6 6例 ,治愈18例 ,好转 30例 ,总有效率 72 .73%。两组总有效率比较 ,经统计学处理P <0 0 1,差异有非常显著性意义。结论 白术桃花汤功能为补气除湿 ,增液行气 ,通调大便 ,治疗习惯性便秘疗效满意。  相似文献   
25.
Summary Aims This study investigated the early and mid–term results following valve replacement with the new Shelhigh? stentless bioprosthesis made entirely of biological material in patients with active infective endocarditis (AIE). Material and methods Between 02/2000 and 12/2004, 164 patients (n = 122 men, mean age 59, 18–85 years) received implantation of an AIE Shelhigh? stentless bioprosthesis in the aortic, mitral, tricuspid or pulmonary position. A total of 119 patients (72.6%) had native AIE and 45 (27.4%) prosthetic AIE. A large proportion of the patients reached the operating room in a condition of cardiac decompensation: 37 (22.6%) patients were intubated, 40 (24.4%) had protracted septic shock and 41 (25.0%) required intensive catecholamine treatment. Surgery was regarded as urgent in 94 patients (57.4%) and was performed as an emergency procedure in 70 (42.6%). The mean follow–up time is 1.5 ± 0.11 years (range, 5 months to 5.2 years). Echocardiographic follow–up examinations were performed early postoperatively and after 12 months. Results In terms of the operative indication, we found a highly significant difference in the survival rate between patients who were operated on urgently vs in an emergency. In patients who died within 30 days, the main cause of death was septic multiorgan failure (67.6%). Only three patients required reoperation due to reinfection of the Shelhigh? bioprostheses; this represents a reinfection rate of 1.8% in relation to the whole cohort. The postoperative echocardiographic examinations showed the Shelhigh? valves to have very good hemodynamics without relevant pressure gradients. Conclusion Our experience in the use of Shelhigh? bioprostheses in patients with native and prosthetic endocarditis show the early and mid–term results, in particular the low reinfection rate and the good hemodynamics, to be comparable with the results achieved using homografts. Since these prostheses are readily available and their implantation straightforward, they are increasingly being used in patients with endocarditis. These promising results need to verified in the long term. This paper was presented at a lecture held at the 71st annual meeting of the German Society for Cardiology, Mannheim, 31. March—2. April 2005. Disclosure Form: The following study discloses my relationship with any corporate sponsor that might relate in some way to the subject presented.  相似文献   
26.
脂质沉积性肌病42例临床治疗和预后随访   总被引:3,自引:1,他引:2  
目的探讨脂质沉积性肌病(LSM)的临床特点、药物治疗效果和预后情况。方法回顾性分析42例LSM患者临床资料并对其治疗效果和预后情况进行随访。结果全部患者均有治疗期间的短期随访资料,其中小剂量泼尼松治疗33例,单用核黄素(维生素B2)治疗9例,全部患者1个月内肌无力症状均获明显改善。随访1年以上者共32例,其中26例肌力完全恢复正常,另6例仍不能耐受重体力劳动,运动耐力较健康人差。13例患者症状有不同程度复发,其中7例有家族史,复发的13例中有12例是在冬季复发,均以劳累、感冒为诱因,5例患者复发2次以上。结论LSM是可治疗的肌肉疾病,对小剂量泼尼松治疗有效,部分患者有复发倾向,有家族史患者更容易复发。单用核黄素治疗反应良好的LSM可能为戊二酸尿症Ⅱ型所致,提示应根据LSM的不同病因采取不同的治疗方案。  相似文献   
27.
OBJECTIVE: We investigated outcomes after surgical therapy in patients with active infective endocarditis (AIE) with regard to survival in relation to surgical urgency, valve position, number of valves implanted and abscess formation. We aimed to identify independent risk factors for early mortality. METHODS AND RESULTS: Two hundred and fifty-five patients received Shelhigh bioprostheses between February 2000 and March 2007. A total of 74.1% had native and 25.9% prosthetic AIE. Surgery was regarded as urgent in 57.3% and as an emergency procedure in 38.4%. There was a highly significant difference in survival rate between patients who were operated on urgently versus in an emergency (p<0.0001), between single and double valve replacement (p=0.0206) and between patients with and without abscess formation (p=0.0245). There were two cases of early reinfection (0.78%) and six of late reinfection (2.35%) leading to re-operation. CONCLUSIONS: The survival of patients differs significantly in dependence on their surgical urgency. Better outcome could have been achieved if patients had been referred earlier for surgery and operated upon before heart failure or septic shock developed. Long-term survival was better in patients without abscess formation. The low reinfection rate of Shelhigh bioprostheses in AIE is promising and the early and mid-term results achieved need to be verified in the long-term course.  相似文献   
28.
OBJECTIVE: Due to the shortage of donor hearts, the criteria for organ acceptability have been considerably extended and donor grafts with coronary atherosclerosis are among those offered. This study evaluated whether and to what degree pre-existing coronary atherosclerosis may be acceptable. METHODS: A total of 1253 consecutive HTx recipients were investigated retrospectively for donor-transmitted coronary atherosclerosis (DCAS). Donor-transmitted coronary atherosclerosis was defined as focal atherosclerosis with stenosis of at least 50%. Inclusion criteria were absence of pre-HTx angiogram but performance of angiogram or autopsy within 6 months after heart transplantation. Kaplan-Meier analysis and log-rank test were used. RESULTS: Eighty-five out of 1253 (6.8%) cases were excluded, since coronary evaluation was not performed within 6 months (n=45) or hearts had undergone pre-transplant angiography (n=40). In 1086 patients no donor-transmitted coronary atherosclerosis was found (NDCAS group) and in 82 patients (7%) donor-transmitted coronary atherosclerosis was diagnosed by angiography (n=49) or autopsy (n=33). Single-vessel donor-transmitted coronary atherosclerosis was found in 53/82 patients (DCAS1 group) and double- or triple-vessel donor-transmitted coronary atherosclerosis in 26/82 patients (DCAS2/3 group). Three of the 82 patients with donor-transmitted coronary atherosclerosis were excluded since the autopsy report was unclear regarding degree of atherosclerosis. Early after heart transplantation the 30-day mortality in the NDCAS and DCAS1 groups was 12.2% versus 13.2% whereas in the DCAS2/3 group it was 61.5%. Beyond the first year the annual decrease with and without donor-transmitted coronary atherosclerosis (single-vessel disease) is comparable. CONCLUSIONS: Donor screening without coronary angiogram overlooks significant atherosclerotic lesions in a considerable number of cases (7.0%). Therefore, angiographic donor screening should be performed. Donor grafts with single-vessel coronary atherosclerosis may be accepted as marginal hearts; however, in our opinion, revascularisation (CABG, PTCA) should be considered. Grafts with two- or even three-vessel coronary atherosclerosis seem to have a serious risk for early graft failure. Beyond the first year the outcome of healthy grafts and grafts with donor-transmitted coronary atherosclerosis seems to be comparable.  相似文献   
29.
目的 建立实时荧光定量逆转录聚合酶链反应(FQ-RT-PCR)检测AMACR mRNA的方法学并检测其在前列腺癌(PCa)组织中的表达.方法 在AMACR基因的2、3外显子之间设计一对引物及MGB探针,将PCR扩增产物与pMD18-T载体连接,构建重组质粒作为定量检测的标准品,建立实时荧光定量RT-PCR方法,然后对32例PCa、60例良性前列腺增生(BPH)及34例其它肿瘤组织进行AMACR mRNA的定量检测.结果 重组质粒经PCR扩增及序列测定,表明克隆成功,该方法灵敏度高,线性范围为5~5×108copies/reaction.AMACR mRNA在PCa组织中表达量显著高于BPH组织(P<0.01)及其他类型肿瘤组(P<0.01).ROC曲线分析结果显示,曲线下面积(AUC-ROC)为0.890,AMACR mRNA诊断前列腺癌的敏感度和特异度分别为81.3%和86.7%.PCa组织中AMACR mRNA表达量及检测阳性率与不同临床分期和病理分级之间的差异尚不具有统计学意义(P值均>0.05).结论 实时荧光定量RT-PCR检测AMACR mRNA的方法具有敏感、特异、准确、重复性好等特点.AMACR mRNA在前列腺组织中的表达对PCa的诊断具有一定的临床应用价值.  相似文献   
30.
Three rare cases of upper eyelid trauma are presented. In high-speed traffic accidents, the upper eyelids were penetrated by glass, avulsed, and then, together with pieces of glass, pushed over the globe and buried deeply in the retrobulbar area. The invaginated eyelids were pulled out gently, the conjunctiva still attached to the globes. They were repaired primarily. In these patients eyelid function and cosmesis were preserved.  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-23

京公网安备 11010802026262号