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   21019篇
  免费   5941篇
  国内免费   127篇
耳鼻咽喉   628篇
儿科学   625篇
妇产科学   724篇
基础医学   322篇
口腔科学   2647篇
临床医学   4149篇
内科学   5052篇
皮肤病学   455篇
神经病学   1815篇
特种医学   984篇
外科学   3759篇
综合类   56篇
现状与发展   12篇
预防医学   2704篇
眼科学   336篇
药学   226篇
中国医学   6篇
肿瘤学   2587篇
  2024年   135篇
  2023年   1089篇
  2022年   358篇
  2021年   644篇
  2020年   1217篇
  2019年   484篇
  2018年   1325篇
  2017年   1288篇
  2016年   1505篇
  2015年   1566篇
  2014年   1962篇
  2013年   2364篇
  2012年   768篇
  2011年   736篇
  2010年   1359篇
  2009年   1944篇
  2008年   735篇
  2007年   493篇
  2006年   644篇
  2005年   450篇
  2004年   326篇
  2003年   289篇
  2002年   251篇
  2001年   379篇
  2000年   274篇
  1999年   376篇
  1998年   501篇
  1997年   481篇
  1996年   532篇
  1995年   387篇
  1994年   300篇
  1993年   259篇
  1992年   173篇
  1991年   154篇
  1990年   136篇
  1989年   140篇
  1988年   122篇
  1987年   121篇
  1986年   98篇
  1985年   92篇
  1984年   75篇
  1983年   90篇
  1982年   83篇
  1981年   67篇
  1980年   47篇
  1979年   32篇
  1978年   32篇
  1977年   43篇
  1976年   32篇
  1975年   27篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
Abstract

Background/Objective: Children with spinal cord injury (SCI) are at risk for musculoskeletal and cardiovascular complications. Stationary cycling using functional electrical stimulation (FES) or passive motion has been suggested to address these complications. The purpose of this case series is to report the outcomes of a 6-month at-home cycling program for 4 children with SCI.

Methods: Two children cycled with FES and 2 cycled passively at home for 1 hour, 3 times per week.

Outcome Measures: Data collected included bone mineral density of the left femoral neck, distal femur, and proximaltibia; quadriceps and hamstring muscle volume; stimulated quadriceps and hamstring muscle strength; a fasting lipid profile; and heart rate and oxygen consumption during incremental upper extremity ergometry testing.

Results: The 2 children cycling with FES and 1 child cycling passively exhibited improved bone mineral density, muscle volume, stimulated quadriceps strength, and lower resting heart rate. For the second child cycling passively, few changes were realized. Overall, the lipid results were inconsistent, with some positive and some negative changes seen.

Conclusions: This case series suggests that cycling with or without FES may have positive health benefits and was a practical home exercise option for these children with SCI.  相似文献   
972.
Abstract

Background/Objective: We conducted a randomized, double-blind comparison of twice daily bladder irrigation using 1 of 3 different solutions in community-residing persons with neurogenic bladder who used indwelling catheters to evaluate efficacy in treatment of bacteriuria.

Methods: Eighty-nine persons with bacteriuria were randomized to irrigate their bladders twice daily for 8 weeks with 30 mL of (a) sterile saline, (b) acetic acid, or (c) neomycin-polymyxin solution. Urinalysis, cultures, and antimicrobial susceptibility tests were performed at baseline and weeks 2, 4, and 8 to determine the extent to which each of the solutions affected numbers and types of bacteria, urinary pH, urinary leukocytes, and generation of antimicrobial-resistant organisms.

Results: Bladder irrigation was well tolerated with the exception of 3 participants who had bladder spasms. None of the 3 irrigants had a detectable effect on the degree of bacteriuria or pyuria in 52 persons who completed the study protocol. A significant increase in urinary pH occurred in all 3 groups. No significant development of resistance to oral antimicrobials beyond what was observed at baseline was detected.

Conclusions: Bladder irrigation was generally well tolerated for 8 weeks. No advantages were detected for neomycin-polymyxin or acetic acid over saline in terms of reducing the urinary bacterial load and inflammation. We cannot recommend bladder irrigation as a means of treatment for bacteriuria in persons with neurogenic bladder.  相似文献   
973.
974.
Objectives: This paper reports the prevalence and severity of caries in a group of 16‐month‐old American Indian children. Methods: The study is an ongoing longitudinal study of risk factors for caries in children from a Northern Plains Tribal community. Children were examined for caries and risk factor data collected at approximately 1, 4, 8, 12, and 16 months of age. Surface‐specific caries data were collected and the presence of precavitated “white spot” lesions was recorded at the subject level. Results: The mean age was 15.4 months for the sample of 232 children. Caries prevalence was 31.9 percent, while an additional 29.3 percent had white spot lesions only. Mean dmfs was 1.57, and ranged from 0 to 44 surfaces. Nearly 3 percent of all erupted tooth surfaces were affected and maxillary central incisors had the highest prevalence of caries (22 percent). Conclusions: Among the very youngest children, dental caries prevalence was very high among these American Indian children.  相似文献   
975.
Introduction: Nerve cross-sectional area reference values have been reported for many nerves, but there have been few studies in pediatric and geriatric populations. This study was conducted to determine the influence of age on nerve cross-sectional area. Methods: Thirty-two children (3 months to 16 years) and 20 geriatric adults (67–92 years) without known neurologic conditions underwent bilateral ultrasound to measure the area of the following nerves: median at the wrist and forearm; ulnar at the wrist and elbow; radial in the spiral groove; sciatic in the distal thigh; fibular at the knee; tibial at the knee and ankle; and sural at the ankle. Results: In general, nerve cross-sectional area increased with age. Nerve size correlated most closely with age, but a correlation was also seen with body mass index. Conclusions: Nerve cross-sectional area increases with age, which is important to note when using ultrasound to evaluate children and geriatric patients. Muscle Nerve 47: 890–893, 2013  相似文献   
976.
Introduction: In 2004, a Cochrane Review and AAN practice parameter concluded that prednisone 0.75 mg/kg/day is of short‐term efficacy in Duchenne muscular dystrophy (DMD). Subsequent efforts to standardize care for DMD indicated wide variation in corticosteroid use. Methods: We surveyed physicians who follow patients with DMD, including: (1) clinics in the TREAT‐NMD (Translational Research in Europe—Assessment and Treatment of Neuromuscular Diseases) network (predominantly Europe) and (2) U.S. MDA clinic directors. We also documented the co‐administered corticosteroids in a trial of a putative treatment (ataluren) for DMD. Results: Of 105 Treat‐NMD clinicians, corticosteroids were not used in 10 clinics, and 29 different regimens were used—the most frequent 0.75 mg/kg/day prednisone (61 centers); 10 days on/10 days off (36 centers); 0.9 mg/kg/day deflazacort (32 centers); and 5 mg/kg/day on weekends (10 centers). Similar diversity was identified in MDA clinics and in the ataluren trial. Conclusions: Variability in corticosteroid use suggests uncertainty about risks/benefits of corticosteroid regimens for DMD. Muscle Nerve, 2013  相似文献   
977.
978.
979.
980.
Introduction: Nerve and muscle ultrasound has been studied in several conditions, but validity and reliability have not been assessed systematically. Methods: Nerve cross‐sectional area and muscle thickness were measured ultrasonographically at several sites in 4 cadavers, which were then dissected, and actual measurements were obtained. To assess intrarater and interrater reliability, between 3 and 5 ultrasonographers, with varying experience levels, made repeated measurements on healthy volunteers. Results: Correlation coefficients for nerve and muscle validity were >0.968 (P < 0.001), and for intrarater reliability were >0.901 (P < 0.001) for still and real‐time images. Correlation coefficients for interrater reliability were more varied, but for still images they were all significant at the P < 0.001 (0.542–0.998) level, and for real‐time images they were significant at the P < 0.05 level for half the sites (0.243–0.981). Conclusion: Overall, nerve and muscle ultrasound is a valid and reliable diagnostic imaging technique. Muscle Nerve, 2013  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