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   1133篇
  免费   44篇
  国内免费   37篇
耳鼻咽喉   2篇
儿科学   36篇
妇产科学   43篇
基础医学   62篇
口腔科学   37篇
临床医学   475篇
内科学   153篇
皮肤病学   6篇
神经病学   47篇
特种医学   116篇
外科学   54篇
综合类   26篇
预防医学   45篇
眼科学   7篇
药学   50篇
肿瘤学   55篇
  2023年   7篇
  2021年   3篇
  2020年   5篇
  2019年   8篇
  2018年   15篇
  2017年   4篇
  2016年   8篇
  2015年   18篇
  2014年   18篇
  2013年   40篇
  2012年   20篇
  2011年   10篇
  2010年   31篇
  2009年   37篇
  2008年   32篇
  2007年   36篇
  2006年   29篇
  2005年   27篇
  2004年   38篇
  2003年   25篇
  2002年   29篇
  2001年   38篇
  2000年   26篇
  1999年   38篇
  1998年   92篇
  1997年   86篇
  1996年   80篇
  1995年   67篇
  1994年   50篇
  1993年   56篇
  1992年   21篇
  1991年   26篇
  1990年   28篇
  1989年   23篇
  1988年   35篇
  1987年   11篇
  1986年   15篇
  1985年   12篇
  1984年   14篇
  1983年   7篇
  1982年   10篇
  1981年   6篇
  1980年   7篇
  1979年   6篇
  1978年   4篇
  1977年   3篇
  1976年   3篇
  1971年   3篇
  1962年   1篇
  1958年   2篇
排序方式: 共有1214条查询结果,搜索用时 31 毫秒
951.
Purpose: To evaluate a variable frequency regimen with intravitreal bevacizumab for treatment of neovascular age‐related macular degeneration (AMD) in eyes that have not received any previous treatment. Methods: Retrospective review of patients with neovascular AMD who were treated with three consecutive monthly intravitreal injections of bevacizumab (1.25 mg) and retreated based on the PrONTO study criteria. Outcome measures included visual acuity (VA) and central retinal thickness. Subgroup analysis was conducted to identify pretreatment characteristics that could determine visual outcome with treatment. Results: A total of 109 eyes of 109 patients were treated. The mean age was 82 years, and the mean follow‐up period was 9.4 months (range 6–12 months). At baseline, the mean VA was 45.6 letters (6/37.5) and mean central retinal thickness 343 µm. This improved to 51 letters (6/30) (P < 0.001)) and 231 µm (P < 0.001) at 6 months. At 6 months, VA was improved by at least five letters in 50%, remained stable in 30% and worsened by at least five letters in 20% of patients. Patients with large intraretinal cysts on optical coherence tomography before treatment had an increased risk of worse vision (odds ratio 10.5, 95% confidence interval 1.69–64.99; P = 0.018). Conclusions: The majority of patients had improvement or stability of VA regardless of the angiographic type of choroidal neovascularization. Intravitreal bevacizumab with this tailored regimen is beneficial in the treatment of neovascular AMD in the short term. The presence of large intraretinal cysts on optical coherence tomography is a poor prognostic factor for visual improvement with this treatment.  相似文献   
952.

Study Objective

Τo investigate whether the use of vasopressin played an important role in the safe expansion of the indications of laparoscopic myomectomy in our practice.

Design

A retrospective comparison of prospectively collected data (Canadian Task Force classification II2).

Setting

A gynecologic endoscopy unit in a tertiary university hospital.

Patients

One hundred fifty patients undergoing laparoscopic myomectomy; 50 were treated without the use of any vasoconstrictive agent (group 1), and 100 were treated with intraoperative intramyometrial injection of dilute vasopressin (20 IU/100 mL normal saline) (group 2).

Interventions

Laparoscopic myomectomy.

Measurements and Main Results

We compared the 2 groups in terms of size, number, and type of myomas; estimated blood loss (EBL); procedure length; transfusion rates; laparoconversion rates; and rates of complications. Two cases in group 1 (4%) were laparoconverted versus none (0%) in group 2. Overall, the mean EBL was 321.8 ± 246.0 mL in group 1 compared with 147.8 ± 171.8 mL in group 2, respectively (p <.001). Additionally, EBL was significantly lower in the vasopressin group in all of the study's subgroups of patients stratified according to the size and number of myomas. Procedure length did not differ significantly between the 2 groups (130.8 ± 49.5 vs 115.6 ± 49.4 minutes, p?=?.078). The risk factors for prolongation of the procedure included size and number of myomas independently of vasopressin. The rates of hypercapnea and subcutaneous emphysema were higher in group 1. The risk factors for hypercapnea and subcutaneous emphysema included the size and intramural position of the largest myoma. Vasopressin was not associated with serious cardiovascular adverse events.

Conclusions

Vasopressin is effective in reducing blood loss during laparoscopic myomectomy. Although experienced surgeons may achieve comparable operation times without vasopressin, even in the most challenging cases, blood loss may still be considerable. The occurrence of hypercapnea is higher in untreated cases and may contribute to laparoconversion.  相似文献   
953.
Primary hyperparathyroidism in childhood and adolescence   总被引:2,自引:0,他引:2  
Objective : The aim of this study was to determine the nature of the presentation and pathology of primary hyperparathyroidism in children and adolescents and to compare these findings with adults.
Methodology : Data were obtained from the Thyroid Surgery Database at Royal North Shore Hospital on all children and adolescents undergoing parathyroid surgery. These results were then compared to data obtained from the last 100 consecutive adult parathyroidectomies.
Results : A total of eight younger patients underwent parathyroidectomy including three children (0–12 years) and five adolescents (13–18 years). A common presentation in the younger age group was hypercalcaemic crisis (50%) with a serum calcium >3.5 mmol/L and clinical signs of calcium intoxication. This compared to the adult age group where only 8% presented with crisis ( P <0.05). Eighty-eight per cent of the younger patients complained of abdominal symptoms compared to only 1% of adults. Seven of eight young patients had sporadic hyperparathyroidism.
Conclusions : Primary hyperparathyroidism, although uncommon in the younger age group, is still most commonly associated with sporadic tumours. Familial syndromes do not constitute a large percentage of patients. Younger patients are more prone to present late with abdominal symptoms, toxicity and hypercalcaemic crisis, presumably due to delayed diagnosis of an uncommon condition in this age group.  相似文献   
954.

Background

The orbital floor (OrF) and infraorbital rim (IOR) repair in cases of complete destruction is challenging mainly due to the fact that the defect length cannot be measured. The aim of the current study is to develop a method of calculating the Orf length by using the gender and the lengths of the medial, superior and lateral orbital walls (OrW) of the same orbit.

Material and methods

Ninety-seven (59 male and 38 female) European adult dry skulls were classified according to age: 20–39, 40–59 and 60 years and above. The length of each OrW was measured by using the direct distance between the optic foramen and a landmark in each orbital rim.

Results

A side asymmetry was detected for the lengths of the inferior, superior and medial OrW. Although a gender dimorphism was detected, no correlation with the age was found. Using the Stepwise multiple regression analysis two formulas were developed, one for the right and one for the left OrF with coefficient of determination R2 0.43 and 0.57, respectively.

Conclusions

The proposed formulas represent a simple, applicable and individualized method to calculate the OrF linear length in cases of complete destruction of the IOR and OrF, with accuracy and without the use of expertise material. Such data may improve the surgery planning of orbital floor fractures and complex orbital reconstructions.  相似文献   
955.
Arylamine N-acetyltransferase (NAT) research has been influenced in recent years by the rapid progress in genomics, proteomics, structural genomics and other cutting-edge disciplines. To keep up with these advancements, the NAT scientific community has fostered collaboration and exchange of know-how between its members. As a specialized event bringing together experts from many different laboratories, the triennial International NAT Workshop has been instrumental in maintaining this culture over the past ten years. The 2007 Workshop took place in Alexandroupolis, Greece, and covered ongoing research on the structure and enzymatic function of human NATs, the prokaryotic and eukaryotic models for NAT, the mechanisms of NAT gene regulation and expression, the frequencies and effects of polymorphisms in the human NAT genes, and the involvement of NATs in multifactorial diseases, including cancer, allergic conditions, endometriosis and endemic nephropathies. Gene nomenclature issues were also addressed and the participants discussed current trends in the field.  相似文献   
956.
957.
958.
959.
960.
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