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   1388篇
  免费   139篇
  国内免费   5篇
耳鼻咽喉   11篇
儿科学   43篇
妇产科学   36篇
基础医学   245篇
口腔科学   25篇
临床医学   143篇
内科学   257篇
皮肤病学   5篇
神经病学   132篇
特种医学   47篇
外科学   203篇
综合类   22篇
预防医学   138篇
眼科学   62篇
药学   54篇
肿瘤学   109篇
  2021年   11篇
  2020年   11篇
  2019年   19篇
  2018年   17篇
  2017年   17篇
  2016年   13篇
  2015年   15篇
  2014年   17篇
  2013年   39篇
  2012年   54篇
  2011年   63篇
  2010年   29篇
  2009年   25篇
  2008年   59篇
  2007年   57篇
  2006年   64篇
  2005年   57篇
  2004年   59篇
  2003年   48篇
  2002年   43篇
  2001年   50篇
  2000年   58篇
  1999年   50篇
  1998年   22篇
  1997年   13篇
  1996年   18篇
  1995年   13篇
  1994年   27篇
  1993年   16篇
  1992年   51篇
  1991年   45篇
  1990年   36篇
  1989年   27篇
  1988年   34篇
  1987年   31篇
  1986年   29篇
  1985年   20篇
  1984年   18篇
  1983年   17篇
  1982年   17篇
  1981年   23篇
  1980年   18篇
  1979年   38篇
  1978年   18篇
  1977年   11篇
  1974年   11篇
  1973年   10篇
  1972年   11篇
  1969年   10篇
  1966年   11篇
排序方式: 共有1532条查询结果,搜索用时 15 毫秒
21.
22.
OBJECTIVES: To report the utilization of a modified Endo GIA vascular stapler to obtain the full length of the renal vein during transperitoneal laparoscopic live donor right nephrectomy. METHODS: We used a modified Endo GIA stapler, in which the triple staggered rows of staples were removed from the kidney donor side to obtain the full length of the right renal vein. This technique has currently been used in nine consecutive transperitoneal laparoscopic right donor nephrectomies. RESULTS: With this technique, the entire right renal vein length was harvested in all cases, without vascular complications. Mean renal warm ischemia time from clamping of the renal vessels to cold perfusion was 135s, and mean receptor postoperative glomerular filtration rate after 30 d was 67.3 ml/min. There were no graft losses. CONCLUSIONS: A novel technique for laparoscopic live donor right nephrectomy is described. It allows harvesting the full length of the right renal vein in a safe and feasible way without compromising warm ischemia time.  相似文献   
23.
Seroma has long been listed as a complication of MammoSite brachytherapy. Palpable abnormalities are clinically apparent months after treatment and a vast majority of patients demonstrate seroma formation in radiologic studies. We embarked on this study to evaluate the actual sonographic incidence and eventual sonographic resolution, possible contributing factors, cosmesis, pain, and local control associated with seroma formation after MammoSite partial breast irradiation (PBI). We investigated 160 patients who underwent MammoSite PBI from 2002 to 2006 of whom 100 patients had serial sonographic information. Clinical and tumor variables, infection, pain, and cosmesis were investigated. Dosimetric data including volume of balloon, dose at balloon surface, and at skin were analyzed. After a median follow-up of 36 months, the incidence of sonographically confirmed post-radiation seroma was 78% within the first 1 year following radiation and steadily decreased with time. The average size of a seroma cavity was 2.3 cm (range 0.6-6 cm) with a decline to an average of 1.4 cm after 1 year, with complete resolution in 65% of patients at 2 years. No statistically significant correlation was found between patient characteristics, tumor variables, and volumetric or dosimetric data for seroma formation. Excellent/good cosmetic scores were achieved in 94% of women with and 92% without seroma. Local control was equivalent between patients with and without seroma. Consecutive sonographic imaging reveals a high rate of seroma formation after MammoSite PBI, with resolution in 65% of patients by 2 years without intervention. Seroma formation does not prevent an excellent cosmetic result or alter local control.  相似文献   
24.
Human parathyroid hormone 1-34 reverses bone loss in ovariectomized mice.   总被引:3,自引:0,他引:3  
The experimental work characterizing the anabolic effect of parathyroid hormone (PTH) in bone has been performed in nonmurine ovariectomized (OVX) animals, mainly rats. A major drawback of these animal models is their inaccessibility to genetic manipulations such as gene knockout and overexpression. Therefore, this study on PTH anabolic activity was carried out in OVX mice that can be manipulated genetically in future studies. Adult Swiss-Webster mice were OVX, and after the fifth postoperative week were treated intermittently with human PTH(1-34) [hPTH(1-34)] or vehicle for 4 weeks. Femoral bones were evaluated by microcomputed tomography (microCT) followed by histomorphometry. A tight correlation was observed between trabecular density (BV/TV) determinations made by both methods. The BV/TV showed >60% loss in the distal metaphysis in 5-week and 9-week post-OVX, non-PTH-treated animals. PTH induced a approximately 35% recovery of this loss and a approximately 40% reversal of the associated decreases in trabecular number (Tb.N) and connectivity. PTH also caused a shift from single to double calcein-labeled trabecular surfaces, a significant enhancement in the mineralizing perimeter and a respective 2- and 3-fold stimulation of the mineral appositional rate (MAR) and bone formation rate (BFR). Diaphyseal endosteal cortical MAR and thickness also were increased with a high correlation between these parameters. These data show that OVX osteoporotic mice respond to PTH by increased osteoblast activity and the consequent restoration of trabecular network. The Swiss-Webster mouse model will be useful in future studies investigating molecular mechanisms involved in the pathogenesis and treatment of osteoporosis, including the mechanisms of action of known and future bone antiresorptive and anabolic agents.  相似文献   
25.
The fiberoptic training jig   总被引:1,自引:0,他引:1  
Rosenblatt W 《Anaesthesia》2007,62(2):201-202
  相似文献   
26.
The WizAir-DVT is a miniature, lightweight (690 g), battery-operated and mobile intermittent pneumatic compression device (ICD), which enables continuous intraoperative use and immediate patient mobilization postoperatively. We compared its efficacy with a commonly used ICD, the Kendall SCD. Peak femoral vein flow velocity was measured in 20 apparently healthy volunteers at rest and with each device: we found no significant differences between them. A second prospective, randomized, clinical trial was used to compare the efficiency of the device in preventing deep venous thrombosis (DVT) after joint replacement in 50 patients (n=25/group). None developed DVT. Doppler ultrasonography revealed no significant differences. The WizAir-DVT antithrombotic compression device is as safe and effective as the Kendall SCD.  相似文献   
27.
OBJECTIVE: To test the hypothesis that a supply of frozen red blood cells and a system for processing pyrogen-free crystalloid solution would meet the needs of an echelon 3 medical treatment facility in the U.S. military, caring for casualties during the initial phase of a military medical operation. DATA SOURCES: Blood requirements for potential combat casualties were estimated from transfusion data on: (1) patients admitted to Boston City Hospital following trauma, utilizing a computerized data base, (2) patients admitted to the Naval Support Hospital-Da Nang during the Vietnam War, from 1966 to 1970, from published and unpublished material, and (3) casualties estimated by Department of Defense expert panels for specific conflicts. The procedure for processing frozen red blood cells was evaluated at the Naval Blood Research Laboratory. Estimates of wounded in action were provided by the Department of Defense. DATA SYNTHESIS: Computer modeling using standard spreadsheet software on a personal computer. CONCLUSIONS: Under military conditions, a frozen red blood cell bank and a system for processing pyrogen-free resuscitative fluid could be used to prepare 96 units of red cells and 960 1 of crystalloid solution per day. This would be adequate to treat approximately 180 casualties, the number projected for a 5-day battle with heavy casualties (6 wounded in action/1,000 soldiers/day). It was concluded that a frozen blood bank system and system for processing pyrogen-free resuscitative fluid could successfully meet the needs of an echelon 3 medical facility in the initial phase of a military medical operation.  相似文献   
28.
29.
We studied the putative role of endorphins in modulating hypoxic ventilatory responsiveness. In 12 healthy men, minute ventilation (VE)and mouth occlusion pressure (P0.1) responses to progressive isocapnic hypoxia were determined before and after the intravenous administration of the opioid antagonist naloxone (10 mg) or placebo. Plasma levels of beta-endorphin were measured before and after hypoxia. Naloxone did not affect the slopes or x-intercepts of the relationships between either VE or P0.1 and arterial O2 saturation. There was no correlation between the baseline plasma level of beta-endorphin and any measure of responsiveness to hypoxia. Plasma beta-endorphin levels were not affected by either short-term hypoxia or naloxone alone; however, when hypoxia followed naloxone administration, mean +/- SD beta-endorphin increased from 8.0 +/- 8.9 pg/ml to 20.2 +/- 16.6 pg/ml (p less than 0.005). We concluded that endogenous opioids do not have an important modulating influence on hypoxic ventilatory responsiveness in adult human volunteers.  相似文献   
30.
Diet plays an important role in the pathogenesis of a variety of diseases. Recently, there has been an increasing interest in the role of diet in the development of common skin conditions such as acne and rosacea. The association of diet and acne has been controversial and unclear. Historically, it was thought that diet did not cause acne; however, recent studies reveal a potential role of diet in the pathogenesis of acne. Individuals that have a diet with a high glycemic load or increased milk consumption are reported to have a greater likelihood of having acne. This effect may be mediated by insulin-like growth factor-1 (IGF-1) since IGF-1 levels increase with milk consumption and with a high glycemic load and are known to contribute to the formation of acne. In contrast to acne, the association of diet and rosacea is much more accepted and established. There are a variety of foods that aggravate rosacea, including spicy foods, alcoholic beverages, and hot, caffeinated drinks. Patients are advised to avoid these triggers. Interestingly, omega-3 and omega-6 fatty acids may be beneficial in the treatment of rosacea, although further investigation is necessary. Understanding the etiologic role of diet in acne and rosacea may help in the prevention and treatment of these conditions.  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