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   1613篇
  免费   91篇
  国内免费   22篇
耳鼻咽喉   1篇
儿科学   151篇
妇产科学   17篇
基础医学   170篇
口腔科学   47篇
临床医学   155篇
内科学   363篇
皮肤病学   23篇
神经病学   32篇
特种医学   470篇
外科学   100篇
综合类   29篇
预防医学   43篇
眼科学   13篇
药学   51篇
中国医学   3篇
肿瘤学   58篇
  2022年   4篇
  2021年   7篇
  2020年   9篇
  2019年   7篇
  2018年   16篇
  2017年   10篇
  2016年   22篇
  2015年   27篇
  2014年   26篇
  2013年   56篇
  2012年   21篇
  2011年   20篇
  2010年   72篇
  2009年   56篇
  2008年   31篇
  2007年   23篇
  2006年   27篇
  2005年   18篇
  2004年   14篇
  2003年   13篇
  2002年   19篇
  2001年   13篇
  2000年   21篇
  1999年   26篇
  1998年   134篇
  1997年   118篇
  1996年   124篇
  1995年   91篇
  1994年   74篇
  1993年   81篇
  1992年   22篇
  1991年   21篇
  1990年   15篇
  1989年   59篇
  1988年   44篇
  1987年   49篇
  1986年   45篇
  1985年   47篇
  1984年   24篇
  1983年   31篇
  1982年   34篇
  1981年   20篇
  1980年   36篇
  1979年   14篇
  1978年   15篇
  1977年   17篇
  1976年   23篇
  1975年   24篇
  1971年   2篇
  1966年   2篇
排序方式: 共有1726条查询结果,搜索用时 15 毫秒
71.
A new tray has been designed for use during procedures involving needles and other sharp objects. The tray includes a foam adhesive pad, marked into 10 sections, into which the sharp objects can be placed point first. After the procedure, the objects can be safely withdrawn by their handles and then discarded. The tray has been used in more than 250 procedures.  相似文献   
72.
BACKGROUND: The objective of this study was to determine whether the outcome of mid-urethral sling procedures is influenced by the body mass index of Korean women suffering from stress urinary incontinence (SUI). METHODS: A total of 285 women, ranging in age from 28 to 80 years (mean 55.4), all of whom were followed up for at least 6 months, were ultimately included in this study. The patients were classified as follows: normal weight, 18.5-23 kg/m2; overweight, 23-27.5 kg/m2; obesity, 27.5 kg/m2 or higher. RESULTS: We noted bladder perforations in 11 cases (4.9%, 3.8% and 2.2% in the normal weight, overweight, and obesity groups, respectively; P = 0.449). We determined there to be no significant differences among the three groups with regard to cure rate (P = 0.173). The rates of postoperative urinary retention were 9.9% in the normal weight group, 10.1% in the overweight group, and 15.6% in the obesity group (P = 0.396). We determined there to be no significant differences among the three groups with regard to the persistence of urgency (P = 0.312). Seventy-nine patients (27.7%) exhibited symptoms indicative of voiding disorder (hesitancy, poor flow, or sensations of incomplete emptying). The postoperative development of these voiding symptoms was not significantly different among the three groups (P = 0.106). CONCLUSION: Our results demonstrate both the feasibility and the safety of mid-urethral sling procedures for obese Korean women who suffer from SUI. Additional studies, including prospective randomized trials with longer follow-up periods, will be required in order to confirm these findings.  相似文献   
73.

Introduction

Fast track methodology or enhanced recovery schemes have gained increasing popularity in perioperative care. While evidence is strong for colorectal surgery, its importance in gastric and oesophageal surgery has yet to be established. This article reviews the evidence of enhanced recovery schemes on outcome for this type of surgery.

Methods

A systematic literature search was conducted up to March 2014. Studies were retrieved and analysed using predetermined criteria.

Results

From 34 articles reviewed, 18 eligible studies were identified: 7 on gastric and 11 on oesophageal resection. Three randomised controlled trials, five case-controlled studies and ten case series were identified. The reported protocols included changes to each stage of the patient journey from pre to postoperative care. The specific focus following oesophageal resections was on early mobilisation, a reduction in intensive care unit stay, early drain removal and early (or no) contrast swallow studies. Following gastric resections, the emphasis was on reducing epidural anaesthesia along with re-establishing oral intake in the first three postoperative days and early removal of nasogastric tubes.In the papers reviewed, mortality rates following fast track surgery were 0.8% (9/1,075) for oesophageal resection and 0% (0/329) for gastric resection. The reported morbidity rate was 16.5% (54/329) following gastric resection and 38.6% (396/1,075) following oesophageal resection. Length of stay was reduced in both groups compared with conventional recovery groups in comparative studies.

Conclusions

The evidence for enhanced recovery schemes following gastric and oesophageal resection is weak, with only three (low volume) published randomised controlled trials. However, the enhanced recovery approach appears safe and may be associated with a reduction in length of stay.  相似文献   
74.

Background:

Hip resurfacing arthroplasty (HRA) is primarily indicated for young, active patients with disabling coxarthrosis who wish to remain active and return to sports after surgery. Relatively few prospective studies have assessed return to sporting activity and impact of gender and age on this.

Materials and Methods:

Seventy-nine consecutive patients treated with HRA were included. Patients were reviewed clinically and radiologically. Function was assessed using the modified University of California Los Angeles (UCLA) activity score. The Oxford, Harris and WOMAC hip scores were calculated.

Results:

Average age at the time of surgery was 54.9 years (range 34.5–73.6 years). Average preoperative and postoperative UCLA scores were 4 and 7.6 respectively. Patients were involved in 2 (0–4) sporting activities preoperatively and 2 (0–5) postoperatively. Preoperative and postoperative Oxford Hip Scores, Harris Hip Score and WOMAC scores were 40, 46 and 51 and 16, 94 and 3 respectively (P < 0.0001). Patients returned to sports at an average of 3 months postoperatively.

Conclusion:

Patients were able to return to sports by 3 months and perform the same number of activities at preoperative intensity. Activity levels are maintained up to the medium term with few complications.  相似文献   
75.
Three-dimensional (3D) printing is a rapidly evolving and promising field to improve outcomes of orthopaedic surgery. The use of patient-specific 3D-printed models is specifically interesting in paediatric orthopaedic surgery, as limb deformity corrections often require an individual 3D treatment. In this editorial, various operative applications of 3D printing in paediatric orthopaedic surgery are discussed. The technical aspects and the imaging acquisition with computed tomography and magnetic resonance imaging are outlined. Next, there is a focus on the intraoperative applications of 3D printing during paediatric orthopaedic surgical procedures. An overview of various upper and lower limb deformities in paediatrics is given, in which 3D printing is already implemented, including post-traumatic forearm corrections and proximal femoral osteotomies. The use of patient-specific instrumentation (PSI) or guiding templates during the surgical procedure shows to be promising in reducing operation time, intraoperative haemorrhage and radiation exposure. Moreover, 3D-printed models for the use of PSI or patient-specific navigation templates are promising in improving the accuracy of complex limb deformity surgery in children. Lastly, the future of 3D printing in paediatric orthopaedics extends beyond the intraoperative applications; various other medical applications include 3D casting and prosthetic limb replacement. In conclusion, 3D printing opportunities are numerous, and the fast developments are exciting, but more evidence is required to prove its superiority over conventional paediatric orthopaedic surgery.  相似文献   
76.
77.
78.
Chronic rejection accounts for most renal allograft losses after the first year posttransplantation. On March 24 and 25, 1997, a roundtable of five transplant surgeons, two nephrologists, and one pathologist assembled in Dallas, Texas, to review critical issues surrounding chronic renal allograft rejection. This article summarizes the presentations and relevant discussions of this meeting regarding the cause of chronic rejection, clinical diagnoses, risk factors, future prospects for intervention strategies, and general recommendations for the transplant community. Growing evidence indicates that chronic rejection is the aggregate sum of irreversible immunologic and nonimmunologic injuries to the renal graft over time. A history of acute rejection episodes and inadequate immunosuppression, likely attributable to inconsistent cyclosporine exposure or poor patient compliance, are among the most recognizable immunologic risk factors for chronic rejection. Donor organ quality, delayed graft function, and other donor and recipient variables leading to reduced nephron mass are nonimmunologic factors that contribute to the progressive deterioration of renal graft function. Clinical management of renal transplant recipients should incorporate both immunologic- and nonimmunologic-based intervention strategies aimed at minimizing risk factors to thwart the progression of chronic rejection and improve long-term allograft and patient survival.  相似文献   
79.
Serum albumin concentration has been strongly associated with risk of death in hemodialysis patients, with mortality increasing as albumin decreases. Metabolic acidosis stimulates protein catabolism and decreases protein synthesis. A study was undertaken to investigate the effect of increasing predialysis serum bicarbonate (HCO3) concentrations on the nutrition of hemodialysis patients as measured by albumin and total lymphocyte count (TLC). Metabolic acidosis was defined as a predialysis serum bicarbonate concentration of < or = 18 mEq/L. Thirty-six hemodialysis patients were enrolled in the study. Each had been stable on hemodialysis for > or = 3 months and each had a mean serum bicarbonate concentration of < or = 18 mEq/L on predialysis monthly laboratory values during the preceding 3 months. The subjects were randomized into 2 groups. The first group consisted of 18 control subjects who were dialyzed on a standard bicarbonate bath of 35 mEq/L. The second group consisted of 18 experimental patients who were dialyzed on a bicarbonate bath of 40 mEq/L. Subjects in the experimental group who had predialysis serum bicarbonate concentrations less than 22 mEq/L after 2 weeks on the higher bicarbonate bath were additionally supplemented with oral sodium bicarbonate at a dosage of 1 mEq/kg dry weight/d. Monthly predialysis laboratory values were checked for all subjects and included serum electrolytes, blood urea nitrogen, calcium, and albumin. TLCs were obtained at the initiation and at the conclusion of the study. Intact parathyroid hormone, blood pressures, and interdialytic weight gains were also followed. The study lasted 16 weeks; 32 subjects completed the study (16 in each group). There were no statistically significant differences between the two groups at the initiation of the study. The serum bicarbonate concentrations were significantly different between the two groups at the end of the study (control HCO3 17.3 +/- 3.2 mEq/L v experimental HCO3 20.2 +/- 2.9 mEq/L; P = 0.01). Serum albumin concentrations and TLCs were not statistically different (P > 0.05) between the two groups at the end of the study (control albumin 3.88 +/- 0.28 g/dL v experimental albumin 3.76 +/- 0.26 g/dL and control TLC 1,780.0 +/- 779.4/mm3 v experimental TLC 2,020.1 +/- 888.0/mm3). Potassium, intact parathyroid hormone, interdialytic weight gain, blood pressures, Kt/Vs, and protein catabolic rates did not differ. We found that the change in serum bicarbonate concentration was well-tolerated and was without any demonstrable side effects. We conclude that increasing the serum bicarbonate concentration by 3 mEq/L for 16 weeks has no effect on the indicators of nutrition that we measured (serum albumin and TLC).  相似文献   
80.
The vasa vasorum and angioplasty   总被引:2,自引:0,他引:2  
Interruption of flow in the vasa vasorum may lead to medial necrosis and aneurysm formation. The purpose of this study was to determine whether angioplasty produces significant alterations in the morphology or blood flow of the vasa vasorum of the dilated artery. The morphology of the canine vasa vasorum was studied before and after angioplasty; in a separate experiment vessel wall blood flow (VWBF) in canine carotid arteries was measured after angioplasty to determine whether physiologic regulation of the blood flow was disrupted by arterial dilation. No morphologic changes could be demonstrated in the vasa vasorum of the dilated artery; however, VWBF was increased by 1194 +/- 215% (mean +/- standard error, p less than 0.01) between 90 and 120 minutes after angioplasty. VWBF in the adjacent nondilated arterial segment was also increased (720 +/- 177% between 10-30 minutes, p less than 0.01) but returned toward normal after 60 minutes. Adenosine caused a "paradoxical" decrease in VWBF (p less than 0.05) of the dilated arterial segment while causing increased VWBF (p less than 0.05) in the thoracic aorta. Angioplasty appears to produce persistent hyperemia in the dilated arterial wall. A paradoxical response to adenosine suggests that vasa vasorum in the dilated arterial segment are maximally vasodilated. This may be due to mechanical disruption of vasomotor tone or to release of vasoactive substances.  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