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   1470篇
  免费   121篇
  国内免费   28篇
耳鼻咽喉   5篇
儿科学   47篇
妇产科学   18篇
基础医学   155篇
口腔科学   25篇
临床医学   139篇
内科学   198篇
皮肤病学   35篇
神经病学   48篇
特种医学   202篇
外科学   292篇
综合类   130篇
一般理论   2篇
预防医学   156篇
眼科学   3篇
药学   68篇
  1篇
中国医学   2篇
肿瘤学   93篇
  2023年   7篇
  2022年   8篇
  2021年   26篇
  2020年   16篇
  2019年   21篇
  2018年   40篇
  2017年   31篇
  2016年   15篇
  2015年   24篇
  2014年   33篇
  2013年   56篇
  2012年   59篇
  2011年   56篇
  2010年   49篇
  2009年   47篇
  2008年   81篇
  2007年   74篇
  2006年   57篇
  2005年   45篇
  2004年   55篇
  2003年   41篇
  2002年   36篇
  2001年   33篇
  2000年   43篇
  1999年   33篇
  1998年   52篇
  1997年   45篇
  1996年   45篇
  1995年   27篇
  1994年   26篇
  1993年   28篇
  1992年   46篇
  1991年   26篇
  1990年   24篇
  1989年   44篇
  1988年   30篇
  1987年   30篇
  1986年   33篇
  1985年   24篇
  1984年   15篇
  1983年   8篇
  1982年   19篇
  1981年   14篇
  1980年   14篇
  1979年   7篇
  1978年   11篇
  1977年   15篇
  1976年   9篇
  1975年   7篇
  1970年   9篇
排序方式: 共有1619条查询结果,搜索用时 23 毫秒
91.
Colonoscopy and bacteraemia.   总被引:3,自引:0,他引:3       下载免费PDF全文
G P Coughlin  R N Butler  M H Alp    A K Grant 《Gut》1977,18(8):678-679
A prospective study was performed on 35 patients undergoing colonoscopy. Aerobic and anaerobic blood cultures before, during and after the investigation failed to demonstrate bacteraemia in any instance.  相似文献   
92.

Background

The sudden increase in incidence and magnitude of mine blast injuries prompted us to highlight the problem and its management.

Methods

The cases of mine blast injuries occurring during mining and demining in a particular geographical area were analysed. Total 27 cases of mine blast injuries occurred during mining or demining operations in a period of 13 months.

Results

Various body regions were involved in the mine blast injuries but the main brunt was borne by feet and legs followed by multiple body regions due to splinters. 14 patients underwent below knee (BK) amputation while 4 patients required through knee (TK) amputations. The effect of blast was so severe that most of the cases required 2 to 5 times wound debridements. The initial aggressive debridement / open stump amputation saved the limb and life of all patients.

Conclusion

A mine blast causes extensive injuries and psychological trauma. Management is needed urgently, surgery is difficult, and amputation is often inevitable. Maximum lives and limbs can be saved with aggressive debridement, repeated inspections and dressings under anaesthesia and definitive closure at optimum time.Key Words: Amputation, Antipersonnel mine, Crush syndrome, Debridements, Mine blast injury, Secondary missiles, Shrapenels  相似文献   
93.
BACKGROUND: Excessive first ray mobility has been implicated as the cause of many forefoot abnormalities. The association between hypermobility and forefoot pathology is controversial, and this is largely related to the difficulty in quantifying first ray motion. Manual examinations have been shown to be unreliable. Klaue etal. developed a device consisting of a modified ankle-foot orthosis with an attached micrometer to objectively measure first ray mobility. The purpose of this study was to evaluate the validity and reliability of this device. METHODS: Sixteen fresh-frozen, below-knee amputation specimens with hallux valgus were used for the study. The study was divided into two parts. Part I was an analysis of the validity of the Klaue device; first ray dorsal displacement was measured on lateral radiographs following manual manipulation, and values were statistically compared to the Klaue device measurements. Part II of the study was an evaluation of intraobserver and interobserver agreement. Two clinicians used the Klaue device on each of the cadaver limbs, and values of first ray sagittal mobility were recorded and compared. RESULTS: The mean value of first ray mobility measured with the Klaue device was 7.5 mm and the average displacement measured from the lateral radiographs was 7.4 mm. Paired t-testing showed no significant difference between the Klaue and radiographic measurements (p = 0.83). The mean first ray mobility by examiners 1 and 2 with the Klaue device were identical (10.5 mm), and statistical analysis showed no significant interobserver or intraobserver differences. CONCLUSIONS: The results confirm the validity of the Klaue device and limited variability of measurements between experienced users.  相似文献   
94.
BACKGROUND: The proximal crescentic osteotomy is an effective technique for correcting a widened 1-2 intermetatarsal angle associated with moderate to severe hallux valgus deformities. However, postoperative dorsal malunion at the osteotomy site from loss of fixation has been reported. The purpose of this study was to evaluate the biomechanical characteristics of a new custom-designed plate and compare it to the traditional screw and Kirschner wire construct. METHODS: Twenty identical Sawbone (Pacific Research Laboratories, Vashon, WA) models were used for the study. A proximal crescentic osteotomy was done on each specimen, and 10 were secured with a dorsomedial plate (group I). The remaining 10 models were fixed with a screw and Kirschner wire combination (group II). Physiologic cyclical testing was done using a mechanical testing machine to evaluate dorsal displacement of the metatarsal. Load-to-failure testing was then done on each specimen to evaluate ultimate failure and stiffness of the constructs. Groups I and II were statistically compared using paired t-testing. RESULTS: The mean dorsal displacement of the first metatarsal head after 1000 cycles was 0.19 mm (SD = 0.09 mm) for group I and 0.28 mm (SD = 0.15) for group II, and the difference was not statistically significant (p = 0.08). Group I demonstrated statistically superior ultimate failure strength (95.2 N) and stiffness (26.8 N/mm) compared to group II (73.7 N, 19.4 N/mm). CONCLUSIONS: Based on Sawbone models, dorsal plate fixation of proximal crescentic osteotomy provides a stronger construct than the traditional screw and Kirschner wire construct. The clinical use of the specially-designed plate described in this study may lower the incidence of dorsal malunions that occur postoperatively and may decrease the occurrence of transfer metatarsalgia. Its application may be particularly helpful in patients with poor bone quality.  相似文献   
95.
96.
The authors describe a simple technique for diagnosis of tricuspid regurgitation. Red blood cells were labeled in vivo with 99mTc and 22 patients were studied with ECG-gated blood-pool imaging of the liver. A single region of interest was manually drawn around the liver and a time-activity curve obtained. The per cent change in liver counts during the cardiac cycle was found to be significantly higher in the 12 patients with tricuspid regurgitation (Group I) (mean, 4.04 +/- 1.6%; range, 1.3-21.4%) compared with the 10 controls (Group II) (mean, 0.35 +/- 0.16%; range, 0.013-1.3%) (p less than 0.05). Using a 1% change in liver counts as the criterion of a positive study, all 12 cases in Group I were diagnosed correctly, but there was one false positive in Group II; thus the sensitivity was 100% and the specificity 90%.  相似文献   
97.
98.
Thoracic computed tomographic (CT) scans of 250 patients with newly diagnosed or recurrent lymphoma revealed thoracic wall involvement in 24 patients (11 with Hodgkin disease, 13 with non-Hodgkin lymphoma). Thoracic wall involvement occurred without contiguous mediastinal or parenchymal involvement in 17 patients. Of these, 13 patients had masses beneath the pectoralis muscles or within the breast, and four had masses arising from the ribs. Five additional patients had mediastinal masses with thymic involvement and parasternal extension through the thoracic wall. Pulmonary parenchymal lymphoma with thoracic wall invasion was noted in the remaining two patients. In five of nine patients receiving radiation therapy, treatment plans were modified by CT demonstration of thoracic wall lymphoma.  相似文献   
99.
Since the introduction of mediastinoscopy, there has been a great deal of discussion regarding indications for this technique and the significance of positive findings. We undertook this study to determine the role of clinical staging and the value of routine mediastinoscopy in the treatment selection of patients with primary lung cancer.From 1975 to 1983, 1,259 consecutive patients with proven and operable lung cancer underwent preresection mediastinoscopy. Nodes were sampled at three levels, and findings were recorded by location, invasiveness, and histology. There were no operative deaths, but 3 patients had a major complication.Mediastinoscopy was positive in 339 (27%) patients and negative in 920 (73%). In the group with positive findings, 303 patients had no operation because a curative resection was not possible (extranodal metastases, 180; location, 76; histology, 47). No patient survived 5 years, and only 4% survived 2 years. Of the 36 patients considered to have operable disease, 28 underwent resection with a projected 5-year survival of 18%. In the group with negative findings, 89% had a curative resection with a hospital mortality of 3.2% and 5-year survival of 53%. When results of mediastinoscopy were correlated with findings at thoracotomy, the sensitivity of the test was 93% on nodes in the superior mediastinum and the specificity, 100%.This study shows that mediastinoscopy is safe and is an accurate indicator of the presence or absence of tumor in superior mediastinal nodes. If positive nodes are found, a curative resection is generally not possible, thoracotomy is avoided, and the overall survival is low.  相似文献   
100.
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