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   14079篇
  免费   524篇
  国内免费   127篇
耳鼻咽喉   111篇
儿科学   269篇
妇产科学   472篇
基础医学   1494篇
口腔科学   363篇
临床医学   1148篇
内科学   3563篇
皮肤病学   234篇
神经病学   1503篇
特种医学   577篇
外科学   2082篇
综合类   42篇
一般理论   1篇
预防医学   470篇
眼科学   259篇
药学   835篇
  1篇
中国医学   19篇
肿瘤学   1287篇
  2024年   68篇
  2023年   153篇
  2022年   275篇
  2021年   475篇
  2020年   334篇
  2019年   412篇
  2018年   477篇
  2017年   321篇
  2016年   392篇
  2015年   425篇
  2014年   612篇
  2013年   741篇
  2012年   1111篇
  2011年   1097篇
  2010年   611篇
  2009年   549篇
  2008年   886篇
  2007年   879篇
  2006年   827篇
  2005年   778篇
  2004年   727篇
  2003年   623篇
  2002年   534篇
  2001年   116篇
  2000年   126篇
  1999年   144篇
  1998年   118篇
  1997年   92篇
  1996年   94篇
  1995年   79篇
  1994年   59篇
  1993年   54篇
  1992年   73篇
  1991年   77篇
  1990年   38篇
  1989年   41篇
  1988年   34篇
  1987年   37篇
  1986年   35篇
  1985年   23篇
  1984年   32篇
  1983年   23篇
  1982年   22篇
  1981年   16篇
  1980年   8篇
  1978年   7篇
  1976年   7篇
  1971年   6篇
  1970年   8篇
  1969年   7篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Midface fractures, especially if related to traffic accidents, represent a remarkable problem from a surgical, psychological, and social standpoint. In trauma dynamics, the pattern of the fractures can extend to all bony fragments and is often associated with soft tissue injuries and loss of bony structures. This can lead to posttraumatic deformities that greatly influence the patient psychologically and limit his social rehabilitation, sometimes permanently. Panfacial trauma includes midface fractures associated with fractures of other areas (i.e., mandible, frontal bone). Orbits and the nasoethmoidal area are often involved with loss of soft tissue and, in severe cases, loss of orbital contents. We report an unusual complex clinical case representative of this kind of pathological profile in which the guidelines described in the literature were followed in the reconstructive procedure.  相似文献   
12.
Alendronate is a bisphosphonate frequently used to reduce bone resorption. It has been used for osteoporosis, Paget's disease, and also as adjunctive therapy for periodontal disease. The aim of this study was to evaluate the effect of systemic alendronate with or without endoalveolar collagen sponge on vertical bone resorption after lower wisdom tooth extraction. Forty patients referred for wisdom tooth impaction were selected. Before surgery, patients were randomly assigned to receive one of the following pharmacologic treatments: no medication (group 1), postextractive endoalveolar collagen sponge (group 2), systemic alendronate for 4 months starting the day of surgery (group 3), and group 2 + group 3 (group 4). Standardized orthopantomographic evaluation was obtained during recruitment (T1), immediately after surgery (T2), and 4 months (T3) to evaluate crestal and alveolar socket changes. Results indicate that at T2, crest and socket level did not show significant differences between the four groups. At T3, test sites treated showed less bone resorption compared with controls. In particular, higher vertical bone height levels and a faster intraalveolar healing were achieved in groups 3 and 4. Systemically given alendronate may be used successfully to reduce vertical bone resorption after wisdom tooth extraction.  相似文献   
13.
14.
In this multicenter study, submerged implants were prospectively followed to evaluate their long-term prognosis in irradiated patients. In a total of 77 patients treated for oral or neck cancer, 188 implants were consecutively placed. After a healing period, the successfully integrated implants were restored with 69 removable and 38 fixed restorations. The implants cumulative survival and success rates were evaluated over a period of at least 36 months. In addition, cumulative success rates were calculated for implant subgroups divided per implant site (mandible or maxilla), radiation dosage, and the time interval between the last irradiation and implant placement. During the healing period, 20 implants did not successfully integrate, whereas 168 implants were classified as success (including both survival and success rates). The analysis of implant subgroups showed slightly more favorable cumulative success rate for mandibular implants (98.4%) compared with maxillary implants (57.1%) and clearly better success rate for a radiation dosage minor of 50-Gy doses. A time greater than 12 months as interval between last irradiation and implant placement seems not to promote better clinical results.  相似文献   
15.
16.
Patent foramen ovale (PFO) is a common congenital anatomical defect in the general population with a mean prevalence of 20 %. Transcranial Doppler sonography and echocardiography, both with infusion of agitated saline as an echo contrast, have been introduced for the diagnosis of PFO. Transesophageal echocardiography is considered the gold standard. Several studies have suggested an association between cryptogenetic stroke and PFO, but the role of this condition as a risk factor for stroke is still debated. The aims of this prospective multicentre study are the evaluation of PFO prevalence in the whole ischemic stroke population and the identification of a stroke recurrence profile risk in patients with PFO. All consecutive patients admitted for acute ischemic stroke and with a confirmed diagnosis at discharge are eligible cases for the study. Demographic and vascular risk factors are registered. Clinical severity is summarized by the National Institute of Health stroke scale. Echocardiographic and transcranial studies are performed in each patient to detect the presence of PFO. Prevalence of PFO will be calculated with 95 % CIs. Univariate analysis will be performed to detect the correlation of PFO with different registered factors and multivariable analysis with PFO as independent variable. The present study should contribute to better identify the role of PFO in ischemic stroke risk and recurrence-related events. Qualifying findings of the study are represented by the high number of enrolled patients, the prospective methodology of the study and the presence of secondary instrumental endpoints.  相似文献   
17.
18.

Background

Endoscopic treatment of gastric leaks (GL) following sleeve gastrectomy (SG) involves different techniques; however, standard management is not yet established. We report our experience about endoscopic internal drainage of leaks using pigtail stents coupled with enteral nutrition (EDEN) for 4 to 6 weeks until healing is achieved.

Methods

In 21 pts (18 F, 41 years), one or two plastic pigtail stents were delivered across the leak 25.6 days (4–98) post-surgery. In all patients, nasojejunal tube was inserted. Check endoscopy was done at 4 to 6 weeks with either restenting if persistent leak, or removal if no extravasation of contrast in peritoneal cavity, or closure with an Over-the-Scope Clip® (OTSC®) if contrast opacifying the crossing stent without concomitant peritoneal extravasation.

Results

Twenty-one out of 21 (100 %) patients underwent check endoscopy at average of 30.15 days (26–45) from stenting. In 7/21 (33.3 %) patients leak sealed, 2/7 needed OTSC®. Second check endoscopy, 26.7 days (25–42) later, showed sealed leak in 10 out 14; 6/10 had OTSC®. Four required restenting. One patient, 28 days later, needed OTSC®. One healed at 135 days and another 180 days after four and seven changes, respectively. One patient is currently under treatment. In 20/21 (95.2 %), GL have healed with EID treatment of 55.5 days (26–?180); all are asymptomatic on a normal diet at average follow-up of 150.3 days (20–276).

Conclusions

EDEN is a promising therapeutic approach for treating leaks following SG. Multiple endoscopic sessions may be required.  相似文献   
19.
20.

Introduction

Blood transfusion is often required in total knee replacement (TKR); several methods of blood preservation are commonly used but the ideal solution is to reduce the blood loss during and after surgery. Aim of the study was to evaluate the hemostatic efficacy and safety of intravenous use of tranexamic acid in patients receiving TKR (cemented).

Materials and methods

Forty-five patients after TKR receive treatment with tranexamic acid (TXA, treatment group), and 45 were managed with fibrin tissue adhesive (control group). Hemoglobin values decrease and transfusions in both groups were recorded. Statistical analysis was performed with Student t test and χ 2 test. A statistical model was elaborated to evaluate together all variables and to underline what data can increase transfusions need.

Results

A significant reduction was detected in hemoglobin values in the first 3 days after surgery in the treatment group. The difference in all cases was significant. When tranexamic acid was administered, the need for transfusions was lower (difference statistically significant). No major adverse events were recorded in our series. The use of autologous blood preparation before surgery led to a higher transfusion rate.

Conclusion

Tranexamic acid reduced blood loss in TKR and significantly reduced the blood transfusion need also when compared to fibrin tissue adhesive. The use of tranexamic acid is safe and in future may avoid preparation of autologous blood unit before surgery with a decrease of cost and medical figures involved.  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