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   964篇
  免费   57篇
  国内免费   9篇
耳鼻咽喉   6篇
儿科学   70篇
妇产科学   5篇
基础医学   126篇
口腔科学   45篇
临床医学   85篇
内科学   192篇
皮肤病学   43篇
神经病学   34篇
特种医学   151篇
外国民族医学   1篇
外科学   77篇
综合类   40篇
预防医学   57篇
眼科学   5篇
药学   49篇
中国医学   1篇
肿瘤学   43篇
  2022年   3篇
  2020年   5篇
  2019年   7篇
  2018年   11篇
  2017年   13篇
  2016年   13篇
  2015年   26篇
  2014年   16篇
  2013年   33篇
  2012年   27篇
  2011年   29篇
  2010年   31篇
  2009年   46篇
  2008年   31篇
  2007年   25篇
  2006年   17篇
  2005年   14篇
  2004年   38篇
  2003年   21篇
  2002年   15篇
  2001年   14篇
  2000年   11篇
  1999年   29篇
  1998年   57篇
  1997年   63篇
  1996年   56篇
  1995年   45篇
  1994年   40篇
  1993年   39篇
  1992年   9篇
  1991年   13篇
  1990年   19篇
  1989年   17篇
  1988年   29篇
  1987年   27篇
  1986年   24篇
  1985年   11篇
  1984年   8篇
  1983年   12篇
  1982年   19篇
  1981年   4篇
  1980年   11篇
  1979年   7篇
  1978年   5篇
  1977年   8篇
  1976年   7篇
  1975年   3篇
  1968年   3篇
  1964年   2篇
  1959年   2篇
排序方式: 共有1030条查询结果,搜索用时 15 毫秒
21.
22.

INTRODUCTION

The Triathlon® (Stryker, Kalamazoo, MI, US) total knee replacement was designed to improve patient function and survivorship. The aim of this study was to determine whether the Triathlon® prosthesis produces better patient reported outcomes than a previous design by the same manufacturer, the Kinemax Plus.

METHODS

The outcome of 233 knees of patients with a mean age of 68 years (range: 40–80 years) who received the Kinemax Plus prosthesis were compared with the outcomes of 220 knees of patients with a mean age of 70 years (range: 42–90 years) who received the Triathlon® prosthesis. Data were collected via postal questionnaire prior to surgery as well as at 8–12 weeks and at 1 year following surgery. Validated questionnaires were used including the WOMAC® (Western Ontario and McMaster Universities) pain and function scales, the Knee injury and Osteoarthritis Outcome Score quality of life scale and the self-administered patient satisfaction scale.

RESULTS

This study found that patients who had the Triathlon® prosthesis had significantly better pain relief (p<0.0001), function (p=0.028), knee related quality of life (p<0.0001) and satisfaction (p=0.0003) at three months after surgery than those who received the Kinemax Plus prosthesis. In addition, knee related quality of life (p=0.002) and satisfaction (p=0.021) were significantly higher at one year after surgery in Triathlon® patients.

CONCLUSIONS

The findings suggest that return to function and reduction in pain may occur more quickly in patients with a Triathlon® prosthesis than in those with the Kinemax Plus.  相似文献   
23.
24.
小儿淋巴管瘤的MRI诊断   总被引:7,自引:0,他引:7  
目的分析小儿淋巴管瘤的磁共振表现及其病理基础。方法对6例经手术病理证实的、年龄7天至7岁的小儿淋巴管瘤患者的磁共振表现进行回顾性分析。结果淋巴管瘤磁共振表现为T1WI上呈与肌肉相似或稍高的信号,T2WI上高于脂肪信号。5例瘤内可见低信号分隔,1例瘤内见血管流空影,3例见明显包膜,3例边界不清。2例病理诊断为海绵状淋巴管瘤,4例诊断为囊状淋巴管瘤。结论磁共振成像可较好地显示肿瘤的大小、形态及范围,从而指导手术治疗。  相似文献   
25.

Background

Direct stenting without balloon dilatation may reduce procedural costs and duration, and hypothetically, the restenosis rate. This study was designed to compare the in-hospital and long-term outcomes of direct stenting (DS) versus stenting after pre-dilatation (PS) in our routine clinical practice.

Methods

The 1 603 patients treated with stenting for single coronary lesions were enrolled into a prospective registry. Patients with acute myocardial infarction (MI) within the preceding 48 hours, and those with highly calcified lesions, total occlusions, or a lesion in a saphenous graft were excluded. The baseline, angiographic and procedural data, inhospital outcomes and follow-up data were recorded in our database and analysed with appropriate statistical methods.

Results

Eight hundred and fifty-seven patients (53.5%) were treated with DS and 746 (46.5%) underwent PS. In the DS group, lesions were shorter in length, larger in diameter and had lower pre-procedural diameter stenosis. Type C and diffuse lesions and drug-eluting stents were found less often (p < 0.001). With univariate analysis, dissection and non-Q-wave MI occurred less frequently in this group (0.2 and 0.6% vs 3.9 and 2.1%, p < 0.001 and p = 0.01, respectively). However, the cumulative major adverse cardiac events (MACE) did not differ significantly (4.9 vs 4.6%, p = 0.79). With multivariate analysis, direct stenting reduced the risk of dissection (OR = 0.07, 95% CI: 0.01–0.33, but neither the cumulative endpoint of MACE (OR = 1.1, 95% CI = 0.58–2.11, p = 0.7) nor its constructing components were different between the groups.

Conclusions

Direct stenting in the real world has at least similar long-term outcomes in patients treated with stenting after pre-dilatation, and is associated with lower dissection rates.  相似文献   
26.
A prospective study was carried out to compare the fertilizing capability and pregnancy outcome following intracytoplasmic sperm injection (ICSI) using spermatozoa obtained from ejaculates, or surgically from epididymis or seminiferous tubules. A total of 77 ICSI cycles (one per patient) was included. In all, 28 patients had severe oligoasthenoteratozoospermia, 19 patients had obstructive azoospermia and 30 patients had non-obstructive azoospermia. The main outcome measures were fertilization rate per injected metaphase II oocyte and the clinical pregnancy rate per embryo transferred back to the female recipients. In patients with severe oligoasthenoteratozoospermia, the fertilization and pregnancy rates were 79 and 25 %. In patients with obstructive azoospermia, for whom epididymal spermatozoa were used, these were 75 and 28%, and in the non-obstructive group for which testicular spermatozoa were used for injection, they were 69 and 21% respectively. These rates were not significantly different in the three groups (P = 0.85 and P = 0.14 respectively), suggesting that spermatozoa from the ejaculates and epididymal or testicular biopsies are able to fertilize equally by using ICSI. Live birth per embryo transfer was significantly reduced in patients with non-obstructive azoospermia compared to the other two groups. The high abortion rate (50%) in the group in which testicular spermatozoa were used raises doubts about the developmental competence of such embryos.   相似文献   
27.
Entamoeba histolytica invades the intestine and other organs during the pathogenesis of amoebiasis. In the early stages, the host organism responds with an inflammatory infiltrate composed mostly of neutrophils. It has been reported that these immune cells, activated by E. histolytica, exert a protective role by releasing proteolytic enzymes and generating reactive oxygen/nitrogen species (ROS/RNS) and antimicrobial peptides. It is now known that neutrophils also produce neutrophil extracellular traps (NETs), which are able to damage and kill pathogens. Studies have shown that intracellular protozoan pathogens, including Toxoplasma gondi, Plasmodium falciparum and Leishmania spp, induce neutrophils to release NETs and are damaged by them. However, the action of this mechanism has not been explored in relation to E. histolytica trophozoites. Through scanning electron, epifluorescence microscopy and viability assays, we show for first time that during in vitro interaction with E. histolytica trophozoites, human neutrophils released NETs that covered amoebas and reduced amoebic viability. These NETs presented histones, myeloperoxidase and decondensed chromatin. The results suggest that NETs participate in the elimination of the parasite.  相似文献   
28.
目的 探讨成人胆管囊肿及其合并症的超声、核磁及胰胆管水成像 (MR/ MRCP)的影像表现。方法 选取胆管扩张病例进行超声及核磁检查 ,观察胆胰管内径、胆管扩张形态、管壁厚度、回声 ,并进行彩色多普勒血流检测及核磁胰胆管水成像 (MR/ MRCP)检查 ,两者结果与术后病理对照。结果 经手术证实胆管囊肿 2 0例 ,包括 :Caroli's病 2例 , 型胆总管囊肿 14例 ,呈囊性、梭形、圆柱形扩张 ;肝门部胆管囊肿 (囊肿型 ) 3例 ,胆总管上段憩室 1例 ( 型 )。合并胆囊结石 10例 ,肝内胆管、胆总管结石 8例 ;合并肝局灶性炎 3例 ,肝脓肿 1例 ;合并癌变 5例 (高、低分化腺癌 3例 ,黏液腺癌 1例 ,类癌 1例 ) ;共同管过长 (>1.5 cm) 6例。超声与 MRCP对胆管囊肿全部诊断。合并症中超声对炎变、结石、癌变诊断分别为 95 % ,10 0 % ,95 % ,而 MRCP/MR为 10 0 % ,90 % ,95 %。超声对结石、癌变及管壁的微细结构观察优于 MRCP,MRCP对胆管全程显示优于超声 ,结合平扫及增强扫描诊断炎变符合率 10 0 %。结论 超声与 MR成像在成人胆管囊肿及其合并症中的诊断意义重大 ,联合应用有利于对该病的全面认识 ,便于指导临床。  相似文献   
29.
Lung carcinoids occur sporadically and rarely in association with multiple endocrine neoplasia type 1 (MEN1). There are no well defined genetic abnormalities known to occur in these tumors. We studied 11 sporadic lung carcinoids for loss of heterozygosity (LOH) at the locus of the MEN1 gene on chromosome 11q13, and for mutations of the MEN1 gene using dideoxy fingerprinting. Additionally, a lung carcinoid from a MEN1 patient was studied. In four of 11 (36%) sporadic tumors, both copies of the MEN1 gene were inactivated. All four tumors showed the presence of a MEN1 gene mutation and loss of the other allele. Observed mutations included a 1 bp insertion, a 1 bp deletion, a 13 bp deletion and a single nucleotide substitution affecting a donor splice site. Each mutation predicts truncation or potentially complete loss of menin. The remaining seven tumors showed neither the presence of a MEN1 gene mutation nor 11q13 LOH. The tumor from the MEN1 patient showed LOH at chromosome 11q13 and a complex germline MEN1 gene mutation. The data implicate the MEN1 gene in the pathogenesis of sporadic lung carcinoids, representing the first defined genetic alteration in these tumors.   相似文献   
30.
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