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   2688篇
  免费   124篇
  国内免费   22篇
耳鼻咽喉   80篇
儿科学   180篇
妇产科学   169篇
基础医学   187篇
口腔科学   162篇
临床医学   168篇
内科学   461篇
皮肤病学   58篇
神经病学   252篇
特种医学   88篇
外科学   727篇
综合类   21篇
一般理论   1篇
预防医学   45篇
眼科学   64篇
药学   81篇
肿瘤学   90篇
  2024年   3篇
  2023年   32篇
  2022年   63篇
  2021年   108篇
  2020年   78篇
  2019年   86篇
  2018年   104篇
  2017年   93篇
  2016年   125篇
  2015年   143篇
  2014年   135篇
  2013年   163篇
  2012年   219篇
  2011年   217篇
  2010年   120篇
  2009年   106篇
  2008年   168篇
  2007年   183篇
  2006年   159篇
  2005年   126篇
  2004年   98篇
  2003年   66篇
  2002年   81篇
  2001年   27篇
  2000年   29篇
  1999年   20篇
  1998年   11篇
  1997年   11篇
  1996年   6篇
  1995年   15篇
  1994年   3篇
  1993年   5篇
  1992年   8篇
  1991年   4篇
  1990年   4篇
  1989年   2篇
  1988年   2篇
  1987年   3篇
  1986年   3篇
  1985年   1篇
  1984年   2篇
  1979年   1篇
  1977年   1篇
排序方式: 共有2834条查询结果,搜索用时 15 毫秒
71.
72.
73.
74.
Therapeutic delays in cases of external incarcerated hernias typically result in increasing morbidity, mortality, and health expenditures. We investigated the diagnostic role of blood fibrinogen level, white blood count (WBC), mean platelet volume (MPV), and platelet distribution width (PDW) in patients with incarcerated hernia. Two groups, each containing 100 patients, were studied. Group A underwent elective, and group B underwent incarcerated and urgent external hernia repair. We observed high fibrinogen and WBC levels but low MPV and PDW values for patients in group B. Contrary to our expectations, we found lower MPV and PDW values in the complicated group than in the elective group. The morbidity rate and cost burden were higher in group B, and the results were statistically significant. Early operation should be recommended for patients with incarcerated external hernias if their fibrinogen and WBC levels are high.Key words: Incarcerated external hernia, Fibrinogen, Complete blood countExternal strangulated hernia is one of the most common causes of intestinal obstruction especially in the elderly. Delay in treatment may be dangerous.1 Andrews found that the need of bowel resection rate was 27% and the mortality rate was 21% when diagnosis was delayed more than 48 hours; whereas these rates were 7% and 1.4% when diagnosis was obtained in the first 24 hours.2 In addition to increased morbidity and mortality rates, a delay in the treatment of strangulated external hernias is associated with extended hospital stays and an increased need for intensive care, thereby resulting in increased health costs. Of course, clinical signs and symptoms are the most important evidences in diagnosis of incarcerated hernias. In order to make correct diagnosis, we also have powerful weapons such as radiologic imaging methods. However, these clinical and radiologic evidences show complications, especially intestinal perforation due to incarceration. Awareness of probable complications is essential. In this regard, we sometimes need simple methods to alert us. The white blood count (WBC), mean platelet volume (MPV), platelet distribution width (PDW), and blood fibrinogen level have been shown to be valuable predictive parameters for ischemic events in different parts of the body.39 There are probable ischemic tissues and organs in incarcerated hernia sac. So, in this study, we aimed to investigate the effectiveness of these simple blood tests in diagnosis. Generally, there is no problem in diagnosis, but sometimes the delay in treatment results in additional morbidity such as a need for bowel resection.  相似文献   
75.
Many techniques are described for the ligation of a difficult cystic duct (CD). The aim of this study is to assess the effectiveness and safety of stapling of a difficult CD in acute cholecystitis using Endo-GIA. From January 2008 to June 2012, 1441 patients with cholelithiasis underwent laparoscopic cholecystectomy (LC) at the Department of General Surgery, Haydarpasa Numune Education and Research Hospital. Of these, 19 (0.62%) were identified as having a difficult CD and were ligated using an Endo-GIA stapler. All patients were successfully treated with a laparoscopic approach. The length of hospital stay was 3.4 days. There were umbilical wound infections in 4 patients (21%). The length of follow-up ranged from 1.0 to 50.4 months. In conclusion, Endo-GIA is a safe and easy treatment method for patients with a dilated and difficult CD. The cystic artery should be isolated and ligated if possible before firing the Endo-GIA stapler. If isolation and stapling are not possible, fibrin sealant can be applied to avoid bleeding. The vascular Endo-GIA can be applied in a large CD, but for acute cholecystitis with an edematous CD, the Endo-GIA roticulator 4.8 or 3.5 stapler is preferred.Key words: Cholecystectomy, Endo-GIA, Acute cholecystitis, StaplerAfter the introduction of laparoscopic cholecystectomy (LC) in 1987,1 LC replaced open cholecystectomy as the gold standard for the treatment of cholelithiasis in international guidelines.2 LC was initially considered to be contraindicated for acute gallbladder inflammation, but it is currently a common procedure for acute cholecystitis.Some of the difficult situations a surgeon is likely to face during the performance of a laparoscopic cholecystectomy include anatomic anomalies such as a sessile gallbladder or short cystic duct and pathologic entities such as an empyema, Mirizzi syndrome, or a frozen Calot''s triangle secondary to infection and fibrosis.3It is suggested that laparoscopic surgery should be carried out within 72 hours from the onset of the symptoms because after that time there are higher rates of conversion to open procedures, increased risks of complications, and longer operative times.46 The generally accepted procedure in patients whose symptoms started 72 hours before admission is to “cool down” the patient with appropriate medical therapy and to perform LC after a period of 6 to 12 weeks.7,8 This approach aims to avoid a potentially more difficult cholecystectomy during an emergency admission and to avoid the difficulties of access to an emergency room.9,10 However, more than 20% of patients may fail to respond to conservative treatment and require an urgent and rather more difficult cholecystectomy, and a further 25% of patients will require readmission with a severe acute complication of cholelithiasis while awaiting a cholecystectomy.11,12 The scar formation, distortion, and organized adhesions around the gallbladder occurring secondary to the chronic inflammation in Calot''s triangle make the dissection difficult. The cystic duct (CD) is sometimes edematous, fibrous, or enlarged owing to inflammation and adhesions in acute cholecystitis and may be difficult to manage. Several methods were proposed for ligating the CD, including titanium or absorbable endoclip, endoloop, tie, ultrasonic or bipolar sealer, and the Endo-GIA stapler (Covidien, Mansfield, Massachusetts).1319This study proposes an effective, safe, and easy procedure for the stapling of dilated or difficult CD using the Endo-GIA.  相似文献   
76.
Despite mechanical reperfusion, the outcome is still unsatisfactory in elderly patients with ST-segment elevation myocardial infarction (STEMI). The vast majority of studies have been conducted without extensive use of glycoprotein (Gp) IIb–IIIa inhibitors, which have been associated with improved perfusion and survival. Thus the aim of the current study was to evaluate the impact of age on the angiographic and clinical outcome patients with STEMI undergoing primary angioplasty with Gp IIb–IIIa inhibitors. Our population is represented by a total of 1,662 patients undergoing primary angioplasty for STEMI included in 11 randomized trials comparing early versus late administration of Gp IIb–IIIa inhibitors. Myocardial perfusion was evaluated by myocardial blush grade and ST-segment resolution. Follow-up data were collected between 30 days and 1 year after primary angioplasty. A total of 231 (13.9 %) patients were older than 75 years. Elderly patients showed a larger prevalence of female gender, hypertension, and diabetes, more advanced Killip class at presentation and longer time to treatment, but a smaller prevalence of smoking. All patients were treated with GP IIb–IIIa inhibitors. Elderly patients showed a significantly impaired postprocedural thrombolysis in myocardial infarction (TIMI) flow (TIMI 0–2: 17.7 vs 10.3 %, P = 0.002) and myocardial perfusion (myocardial blush grade 0–1: 38.3 vs 26.5 %, P = 0.001), and higher prevalence of distal embolization (19.2 vs 9.8 %, P < 0.001), whereas no difference was observed in terms of ST-segment resolution. At follow-up, elderly patients showed a significantly higher mortality (3.2 vs 11.0 %, hazard ratio (HR) (95 % confidence interval (CI)) = 3.78 (2.31–6.16), P < 0.001), which was confirmed after adjustment for baseline confounding factors (HR (95 % CI) = 5.01 (2.63–9.55), P < 0.0001). This study showed that among patients with STEMI undergoing primary angioplasty, advanced age is an independent predictor of mortality after primary angioplasty. Higher rates of distal embolization and poor myocardial perfusion, in addition to the worse risk profile, contribute toward explaining the impact of aging on mortality.  相似文献   
77.

INTRODUCTION

Atypical presentations of appendix have been reported including backache, left lower quadrant pain and groin pain from a strangulated femoral hernia containing the appendix. We report a case presenting an epigastric pain that was diagnosed after computed tomography as a perforated appendicitis on intestinal malrotation.

PRESENTATION OF CASE

A 27-year-old man was admitted with a three-day history of epigastric pain. Physical examination revealed tenderness and defense on palpation of epigastric region. There was a left subcostal incision with the history of diaphragmatic hernia repair when the patient was 3 days old. He had an intestinal malrotation with the cecum fixed at the epigastric region and the inflamed appendix extending beside the left lobe of liver.

DISCUSSION

While appendicitis is the most common abdominal disease requiring surgical intervention seen in the emergency room setting, intestinal malrotation is relatively uncommon. When patients with asymptomatic undiagnosed gastrointestinal malrotation clinically present with abdominal pain, accurate diagnosis and definitive therapy may be delayed, possibly increasing the risk of morbidity and mortality.

CONCLUSION

Atypical presentations of acute appendicitis should be kept in mind in patients with abdominal pain in emergency room especially in patients with previous childhood operation for diaphragmatic hernia.  相似文献   
78.

Background

Although many methods have been proposed to restore the internal nasal valve (INV) such as suture techniques, various grafts, upper lateral cartilage folding techniques, and combined techniques, the most popular and effective one remains spreader grafts. The aim of the present study is to propose a new graft design for INV reconstruction and to test the reliability and feasibility of the technique.

Methods

Thirty-two primary septorhinoplasty patients divided in three groups underwent surgery with railway, spreader, and no graft techniques. The functional results were evaluated with the Nasal Obstruction Evaluation Scale (NOSE) scores subjectively.

Results

Significant improvements were observed comparing preoperative and postoperative NOSE scores in railway and spreader grafts groups. However, there was no significant difference in NOSE scores between those groups of patients.

Conclusions

Railway graft is an effective method that can be recommended if septal cartilage is limited for reconstruction of INV. Level of Evidence: Level IV, therapeutic study.  相似文献   
79.

Introduction

The most common variant muscle of the ankle, peroneus quartus muscle, is located in the lateral leg compartment. In literature there is ambiguous nomenclature of this muscle because of its different origin and insertion sides. It is related to many pathologic conditions in the lateral ankle compartment but also it can be used as a tendon graft for reconstructive procedures.

Material and method

We dissected 115 cadaver legs and investigated prevalence of peroneus quartus. We also present 2 year result of a patient who had torn superior peroneal retinaculum reconstructed with peroneus quartus tendon.

Results

The peroneus quartus muscle, with a number of different attachments, was present in 5.2 % (6/115) of the legs. It most commonly arose from the peroneus brevis muscle and inserted into the retrotrochlear eminence of the calcaneus. Associated pathologies are longitudinal degeneration and tear in the tendon of peroneus brevis. There is no any association between the prevalence of peroneus quartus and the height of retrotrochlear eminence or presence of peroneal tubercule (p > 0.05). But there is strong relationship between peroneus brevis degeneration and peroneus quartus existence (p: 0.03). We also defined a new type of peroneus quartus with a bifurcated insertion around the peroneus brevis. In literature our case report is unique because we present a patient who has torn superior peroneal retinaculum which is reconstructed with peroneus quartus tendon with 2 year follow up.

Conclusion

Peroneus quartus may lead to some pathologic conditions (pain, snapping, tear, synovitis, etc.) in the lateral ankle compartment but it may be used to reconstruct some pathologic conditions. Orthopaedics, anatomists and radiologists should be aware of this accessory tendon structure because of its clinical importance.  相似文献   
80.
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