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   643篇
  免费   27篇
  国内免费   7篇
耳鼻咽喉   4篇
儿科学   6篇
妇产科学   18篇
基础医学   104篇
口腔科学   5篇
临床医学   61篇
内科学   118篇
皮肤病学   4篇
神经病学   51篇
特种医学   62篇
外科学   119篇
综合类   3篇
预防医学   51篇
眼科学   1篇
药学   40篇
中国医学   1篇
肿瘤学   29篇
  2024年   1篇
  2023年   5篇
  2022年   15篇
  2021年   29篇
  2020年   9篇
  2019年   9篇
  2018年   15篇
  2017年   11篇
  2016年   7篇
  2015年   14篇
  2014年   27篇
  2013年   40篇
  2012年   46篇
  2011年   65篇
  2010年   36篇
  2009年   23篇
  2008年   40篇
  2007年   43篇
  2006年   35篇
  2005年   40篇
  2004年   33篇
  2003年   38篇
  2002年   29篇
  2001年   3篇
  2000年   3篇
  1999年   6篇
  1998年   7篇
  1997年   9篇
  1996年   5篇
  1995年   1篇
  1994年   3篇
  1993年   2篇
  1992年   3篇
  1991年   2篇
  1989年   3篇
  1988年   2篇
  1985年   3篇
  1983年   1篇
  1982年   2篇
  1981年   1篇
  1979年   3篇
  1977年   2篇
  1976年   1篇
  1973年   1篇
  1972年   1篇
  1970年   1篇
  1964年   1篇
  1957年   1篇
排序方式: 共有677条查询结果,搜索用时 15 毫秒
91.
Angioleiomyoma represents a benign stromal tumor, which usually occurs in the subcutaneous tissue of the extremities, although its occurrence in the gastrointestinal tract is very rare. A case of rectal angioleiomyoma in a 40 year-old female patient is described here. Six months earlier, the patient suffered from periodical prolapse of an oval tumor from the anus, along with difficulties in bowel movement. A transanal extirpation of the tumor was performed. This is the first reported case in the English literature of a patient presenting with prolapsed angioleiomyoma of the rectum. During the immediate postoperative period, as well as 6 mo later, the patient had an unremarkable postoperative recovery.  相似文献   
92.
93.
GustiloⅢB和ⅢC高能量胫骨骨折--截肢与保肢的比较   总被引:2,自引:0,他引:2  
截肢和保肢患者长期的功能和心理结果相似。如果早期不截肢而采取保肢,就必须考虑到:二期截肢的风险(5%~14%)、潜在的并发症(保肢术通常更高)以及住院时间延长。由于胫骨骨折严重程度不同采取的治疗可能不同(G ustiloⅢC型比ⅢB型更可能截肢),这使得对比很困难,而且相关的队列研究文献很少。  相似文献   
94.
Anemia is common in patients who have both heart failure and chronic kidney disease, and there is an association between anemia and progression of both diseases. The main causes of anemia are deficient production of erythropoietin (EPO), iron deficiency, and chronic disease with endogenous EPO resistance. EPO has been successfully used for over a decade to treat anemia in patients with chronic kidney disease. Less obvious are the safety and efficacy of EPO treatment in patients with both heart failure and renal disease. Up to 10% of patients receiving EPO are hyporesponsive to therapy and require large doses of the agent. Several mechanisms could explain resistance to endogenous and exogenous EPO. Proinflammatory cytokines antagonize the action of EPO by exerting an inhibitory effect on erythroid progenitor cells and by disrupting iron metabolism (a process in which hepcidin has a central role). EPO resistance might also be caused by inflammation, which has a negative effect on EPO receptors. Furthermore, neocytolysis could have a role. As resistance to exogenous EPO is associated with an increased risk of death, it is important to understand how cardiorenal failure affects EPO production and function.  相似文献   
95.

Purpose  

The purpose of this study was to simplify and enhance the ultrasound (US) analysis of the infant’s hip by introducing a novel parameter named “L value” into the widely used Graf method.  相似文献   
96.
Objective: We report the mid-term follow-up of patients, who underwent arterial switch operation (ASO) for transposition of the great arteries (TGA) with intact ventricular septum and left-ventricular outflow tract obstruction (LVOTO) over a 10-year period from 2000 to 2009. Methods: Thirteen TGA patients (3.9% of our ASO cohort) with intact ventricular septum and LVOTO underwent ASO. LVOTO was defined as pulmonary valve z-score ≤ −2.0 (n = 3) or peak LVOT gradient ≥40 mmHg with (n = 7) or without (n = 3) anatomic subvalvar stenosis on echocardiography. Median age and weight were 14 days (range, 7–130 days) and 3.2 kg (range, 2.1–4.6 kg). The LVOT abnormalities included fibromuscular narrowing (n = 5) and atrioventricular valve-related findings (n = 5). LVOT clearance was achieved by resection of accessory mitral tissue (n = 2) only. Results: Follow-up was 100% complete. There were no early or late deaths. Freedom from re-operation for neo-aortic valve regurgitation and/or LVOTO was 100% at a median follow-up of 38 months (range, 6–115 months). All patients had functional status appropriate for their age. Three patients had mild aortic regurgitation. The median Doppler estimated LVOT systolic gradient was 12 mmHg (range, 0–18 mmHg) for the entire cohort at the latest follow-up. Conclusions: Mid-term outcomes of ASO for a highly selected group of patients with pulmonary valve annulus z-score ≤ −2.0 ≥ −0.4, resectable organic LVOTO, and dynamic peak LVOT gradient ≥40 mmHg remain satisfactory, with a need for long-term follow-up.  相似文献   
97.

Background context

Posterior cervical foraminotomy (PCF) with or without microdiscectomy (posterior cervical discectomy [PCD]) is a frequently used surgical technique for cervical radiculopathy secondary to foraminal stenosis or a laterally located herniated disc. Currently, these procedures are being performed with increasing frequency using advanced minimally invasive techniques. Although the safety and efficacy of minimally invasive PCF/PCD (MI-PCF/PCD) have been established, reports on long-term outcome and need for secondary surgical intervention at the index or adjacent level are lacking.

Purpose

To determine the rates of complications, long-term outcomes, and need for secondary surgical intervention at the index or adjacent level after MI-PCF and microdiscectomy.

Study design

Retrospective analysis of a prospective cohort.

Patient sample

Seventy patients treated with MI-PCF and/or MI-PCD for cervical radiculopathy.

Outcome measures

Visual Analog Scale for neck/arm (VASN/A) pain and Neck Disability Index (NDI).

Methods

Ninety-seven patients underwent MI-PCF with or without MI-PCD between 2002 and 2011. Adequate prospective follow-up was available for 70 patients (95 cervical levels). The primary outcome assessed was need for secondary surgical intervention at the index or adjacent level. The secondary outcomes assessed included complications and improvements in NDI and VASN/A scores. All complications were reviewed. Mixed-model analyses of variance with random subject effects and autoregressive first-order correlation structures were used to test for differences among NDI, VASA, and VASN measurements made over time while accounting for the correlation among repeated observations within a patient. All statistical hypothesis tests were conducted at the 5% level of significance.

Results

Patients were followed for a mean of 32.1 months. Of 70 patients operated, there were 3 (4.3%) complications (1 cerebrospinal fluid leak, 1 postoperative wound hematoma, and 1 radiculitis), none of which required a secondary operative intervention. Five patients required an anterior cervical discectomy and fusion (eight total levels fused) on average 44.4 months after the index surgery. Of those, five (5.3%) were at the index level and three (2.1%) were at adjacent levels. Neck Disability Index scores improved significantly (p<.0001) immediately postoperatively and continued to decrease gradually with time. Visual Analog Scale for neck/arm scores improved significantly (p<.0001) from baseline immediately postoperatively but tended to plateau with time.

Conclusions

Minimally invasive PCF with or without MI-PCD is an excellent alternative for cervical radiculopathy secondary to foraminal stenosis or a laterally located herniated disc. There is a low rate (1.1% per index level per year) of future index site fusion and a very low rate (0.9% per adjacent level per year) of adjacent-level disease requiring surgery.  相似文献   
98.
99.
BACKGROUND/AIM: Surgical strategy for the treatment of resectable synchronous hepatic metastases of colorectal cancer (CRC) remains controversial. The aim of this study was to assess safety of simultaneous colon and liver rese cions and the direct effects of this type of treatment upon morbidity and mortality of the patients with synchronus hepatic metastases of CRC. METHODS: Intraoperative and postoperative data of 31 patients with simultaneous liver and colorectal resection were compared with the data of 51 patients who had undergone colon and hepatic resection in the staging setting. Analized were demographic data, number of metastases, type of the liver resection, operation time, intraoperative blood loss, percentage of postoperative complications, morbidity and mortality and lenght of hospitalisation. RESULTS: In the group of the patients operated simultaneously 5 hepatectomies, 3 sectionectomies, 2 trisegmentectomies, 3 bisegmentectomy, 6 segmentectomies, and 12 metastasectomies were combined with colon resection. In this group operation time (280 vs. 330 minutes) and in traoperative blood loss (450 vs. 820 ml) were lower than those in the two staged operation group. Postoperative complication rate was lower in the simultaneous group (19.35%o) than in the two-staged operation group (19.60%), without statistical significance. There was no hospital mortality in both groups. The patients having simultaneous resection required fewer days in the hospital (median 10.2 days) than the patients undergone operation in the two stage (18.34 days). CONCLUSION: By avoiding a second laparotomy, overall operation time, blood loss, hospital stay and complication rate are reduced with no change in hospital mortality, so simultaneous colon and hepatic resection performed by the competent surgeons are safe and efficient for the treatment of synchronous colorectal liver metastases.  相似文献   
100.
In gamma-ray spectrometry, true coincidence summing correction factors for an extended sample can be calculated from full-energy-peak and total efficiencies as if the sample were a point source, if the so-called linear-to-square- (LS) curve, introduced by Blaauw and Gelsema, is known and properly applied. A method is described for obtaining the efficiencies and the corresponding LS-curve for an arbitrary cylindrical sample from calibration measurements in a reference geometry. The approach is aimed at the analysis of samples measured on p-type HPGe detectors in environmental gamma-ray spectrometry and was successfully verified against experimental data.  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