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   2593篇
  免费   80篇
耳鼻咽喉   7篇
儿科学   53篇
妇产科学   61篇
基础医学   146篇
口腔科学   53篇
临床医学   639篇
内科学   743篇
皮肤病学   81篇
神经病学   56篇
特种医学   1篇
外科学   275篇
综合类   4篇
一般理论   18篇
预防医学   159篇
眼科学   15篇
药学   308篇
肿瘤学   54篇
  2017年   13篇
  2016年   35篇
  2015年   42篇
  2014年   41篇
  2013年   80篇
  2012年   22篇
  2011年   15篇
  2010年   82篇
  2009年   97篇
  2008年   28篇
  2007年   25篇
  2006年   34篇
  2005年   12篇
  2004年   11篇
  2003年   20篇
  2002年   17篇
  2001年   53篇
  2000年   19篇
  1999年   99篇
  1998年   123篇
  1997年   174篇
  1996年   158篇
  1995年   127篇
  1994年   106篇
  1993年   104篇
  1992年   108篇
  1991年   88篇
  1990年   78篇
  1989年   80篇
  1988年   81篇
  1987年   63篇
  1986年   62篇
  1985年   45篇
  1984年   47篇
  1983年   45篇
  1982年   37篇
  1981年   53篇
  1980年   36篇
  1979年   35篇
  1978年   33篇
  1977年   28篇
  1976年   32篇
  1975年   22篇
  1974年   9篇
  1973年   10篇
  1972年   12篇
  1971年   17篇
  1966年   12篇
  1958年   9篇
  1954年   11篇
排序方式: 共有2673条查询结果,搜索用时 15 毫秒
81.
82.
Vascular Plug for ICD Lead.   We describe the case of a young patient with severe hypertrophic cardiomyopathy and marginal defibrillation thresholds (DFTs) at implant of a standard transvenous implantable cardioverter-defibrillator (ICD) system. The patient subsequently experienced multiple failed ICD shocks during a prolonged episode of spontaneous ventricular tachycardia/fibrillation. Placement of a second single-coil shocking lead in the azygous vein resulted in acceptable DFTs, but the new lead migrated superiorly within hours of the procedure. To stabilize the lead position, a vascular plug was placed in the distal azygous vein, and the shocking lead screw was actively fixated to the meshwork of the device. Subsequent testing confirmed both adequate defibrillation and stable lead position. (J Cardiovasc Electrophysiol, Vol. 21, pp. 99–102, January 2010)  相似文献   
83.
84.
ABSTRACT. We assessed the relationship between neonatal hypoglycemia and newborn iron status in 15 hypoglycemic, large-for-date newborn infants, 12 of whom were infants of diabetic mothers. These infants had significantly lower mean serum iron concentrations, ferritin concentrations, percent iron-binding saturation and calculated iron stores, and significantly higher mean transferrin concentrations, total iron-binding capacity concentrations and mid-arm circumference: head circumference ratios when compared with either 15 euglycemic large-for-date or 15 euglycemic appropriate-for-date control infants ( p < 0.001 for all comparisons). All hypoglycemic infants had ferritin concentrations below the 5th percentile as compared to 3 % of controls ( p < 0.001), and 67 % had transferrin concentrations above the 95th percentile (controls: 0 %; p < 0.001). Only the hypoglycemic infants demonstrated a significant negative linear correlation between ferritin and transferrin concentrations ( r =−0.83; p < 0.001). Decreased serum iron concentrations were associated with size at birth ( r =−0.60; p = 0.01) and with increased red cell iron ( r =−0.60; p = 0.01), implying a redistribution of iron dependent on the degree of fetal hyperglycemia and hyperinsulinemia. Infants with increased red cell iron had more profound neonatal hypoglycemia. These results show a significant association between decreased iron stores and neonatal hypoglycemia in macrosomic newborn infants associated with a significant shift of iron into red blood cells.  相似文献   
85.
Summary. Forty-eight pregnancies, five of them multiple, were referred for fetal cardiac assessment following the detection of non-immune hydrops fetalis; there were 52 hydropic fetuses in total. A cardiovascular aetiology was found in 21 of these 52 (40%); structural heart disease was present in 13, tachyarrhythmia in the remaining eight. The accurate delineation of these causes was possible using fetal echo-cardiography, and enabled rational management to be instituted. This included termination of pregnancy, pharmacological control of arrhythmias and appropriate timing of delivery.  相似文献   
86.
The Weanling's dilemma: Are we making progress?   总被引:1,自引:0,他引:1  
ABSTRACT. In many developing countries the weanling child (the breastfed child who is regularly receiving additional food) still suffers a high level of morbidity and mortality from diarrhoeal disease. The initiation of weaning is a critical event. No clear strategy exists for substantially enhancing the breast milk output of demand feeding mothers in underprivileged communities. Remarkably little progress has been made in our ability to advise mothers, either on a collective or an individual basis, as to when they should supplement the diet of their breastfed offspring, one continuing problem being the failure to adopt appropriate growth standards for infants. Furthermore there has been little attempt to improve traditional weaning foods in terms of consistency, shelf life and bioavailability of nutrients. Increasing insights into the normal growth pattern of breastfed infants and knowledge of localised appropriate traditional food technology remain grossly underexploited.  相似文献   
87.
PURPOSE: We report a 5-year experience with 52 patients who underwent radical cystoprostatectomy for bladder cancer and orthotopic bladder substitution using a novel personal modification of the S pouch. MATERIALS AND METHODS: From September 1995 to December 1999, 52 men 36 to 72 years old (mean age 63) underwent bladder substitution with an S pouch. They were followed until September 2000. The pouch was constructed with a 36 cm. segment of ileum with the whole length used for the reservoir. The ureters were directly anastomosed with one above the other in the mid segment of the pouch without any antireflux procedure. Complications were documented and classified as early or up to 3 months postoperatively and late, and further subdivided by the relationship to neobladder construction. Continence and voiding pattern were evaluated by personal interview and neobladder function was urodynamically assessed. Mean followup in our patients was 30 months. RESULTS: The most common of the 5 early and 9 late neobladder related complications were persistent urine leakage and reflux, respectively. There was no reflux greater than grade III in the 4 patients with reflux (5 refluxing ureters) and no functional disorders. We observed 12 early and 5 late complications unrelated to the neobladder. Open reoperation was required in 5 cases. Good or satisfactory daytime and nighttime continence was reported by 95% and 88% of our patients, respectively. By year 1 postoperatively 91% of our patients voided at an interval of 3 to 5 hours during the day. Mean maximum neobladder capacity was 672 ml. and mean post-void residual was 30 ml. by year 3 postoperatively. Two patients required self-catheterization once daily and mild hyperchloremia without acidosis developed in 2. CONCLUSIONS: The advantages of our modified S pouch are technical simplicity, substantially shorter operative time and decreased bowel length required. It is associated with an acceptable complication rate and functional parameters with subsequent patient satisfaction and good quality of life.  相似文献   
88.
OBJECTIVE: To identify the characteristics of neonates exposed to drugs in utero but admitted to the normal newborn nursery because of apparent good health. DESIGN: Retrospective evaluation with chart review of toxicology screening tests sent from a normal newborn nursery. SETTING: Newborn service in an urban hospital. PARTICIPANTS: Fifty newborns with positive drug screening results. MAIN OUTCOMES: Frequency of positive results and assessment of demographic features and neonates' clinical features. RESULTS: 43 (86%) of the apparently healthy newborns tested positive for cocaine. The results of simultaneous or proximate drug testing of mothers and their newborns were discordant in 11 (22%) cases. CONCLUSIONS: Neonates with in utero drug exposure often are born with few or no signs of abnormality and are admitted to the normal newborn nursery.  相似文献   
89.
90.
Summary. Knee haemarthroses are very common in the haemophiliac and often, despite infusion of the missing coagulation factor, synovitis develops. The warm swollen joint is maintained in the most comfortable position for the haemophiliac: flexion. Ambulation is achieved by planterflexion of the ankle joint and toewalking. As the chronic synovitis persists, the range of movement of the knee is affected, with loss of full extension. Development of radiological degenerative signs develop. The quadriceps muscle usually weaken due to disuse, but the hamstrings are active in maintaining the flexion of the joint. As the process continues, the tibia subluxes posteriorly on the condyles of the femur. The posterior capsule of the knee joint soon contracts, permanently limiting knee extension. A case is described on whom an Ilizarov device was used to gradually return the limb to a function position. This will allow the patient to complete his growth prior to a definitive orthopaedic procedure.  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