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   46477篇
  免费   3820篇
  国内免费   860篇
耳鼻咽喉   148篇
儿科学   836篇
妇产科学   654篇
基础医学   1782篇
口腔科学   1249篇
临床医学   4767篇
内科学   7663篇
皮肤病学   600篇
神经病学   1986篇
特种医学   657篇
外科学   1866篇
综合类   5253篇
现状与发展   8篇
一般理论   4篇
预防医学   8269篇
眼科学   649篇
药学   11630篇
  31篇
中国医学   1273篇
肿瘤学   1832篇
  2024年   131篇
  2023年   845篇
  2022年   1361篇
  2021年   1933篇
  2020年   2178篇
  2019年   2070篇
  2018年   2032篇
  2017年   1997篇
  2016年   1792篇
  2015年   1625篇
  2014年   3179篇
  2013年   5594篇
  2012年   2669篇
  2011年   2871篇
  2010年   2441篇
  2009年   2083篇
  2008年   1999篇
  2007年   1990篇
  2006年   1840篇
  2005年   1579篇
  2004年   1273篇
  2003年   1107篇
  2002年   974篇
  2001年   855篇
  2000年   652篇
  1999年   610篇
  1998年   510篇
  1997年   410篇
  1996年   382篇
  1995年   295篇
  1994年   233篇
  1993年   256篇
  1992年   249篇
  1991年   225篇
  1990年   170篇
  1989年   128篇
  1988年   117篇
  1987年   82篇
  1986年   77篇
  1985年   82篇
  1984年   54篇
  1983年   41篇
  1982年   30篇
  1981年   40篇
  1980年   29篇
  1979年   13篇
  1978年   12篇
  1977年   11篇
  1976年   13篇
  1974年   7篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
92.
93.
An important operational aspect of Syringe Exchange Programmes (SEPs) is the venue of service delivery. This report describes the programmatic features of the Sacramento Area Needle Exchange (SANE), an illegal SEP operating in California, USA. SANE utilises “satellite exchangers” to distribute the bulk of its syringes and HIV risk reduction supplies. Advantages of relying primarily on Designated Exchangers (DE) for delivery of SEP services are that it: (1) allows for coverage of a large geographical area; (2) keeps operational cost low; (3) provides syringes to clients who may not want to or cannot use fixed site programmes; (4) limits the possibility of detection of programme personnel and clients by law enforcement. Limitations are that: (1) it is not as conducive as fixed sites to providing a wide range of ancillary services; (2) it may not be optimal for drug users who do not want to be reliant on other people for access to syringes; (3) those who receive services from a satellite exchanger may not derive as much counselling and referral services as direct exchangers. The lack of legal status, political support and adequate funding threatens the programme’s existence.  相似文献   
94.
 Resource implications of hospitalization for osteoporosis-related vertebral fracture are sparsely documented. This study utilized data abstracted from a national sample of hospitalized patients to identify characteristics of patients who are hospitalized with vertebral fracture and their patterns of resource utilization. These were compared with patterns observed for hip fracture hospitalizations. Data from the Nationwide Inpatient Sample (NIS) for 1997 were used to identify men and women age 45 years and above who had a primary diagnosis of vertebral fracture. After patients whose fractures might have been due to metastatic cancer or severe trauma were excluded, 68 901 individuals hospitalized for vertebral fracture were identified. Seventy-seven percent of these were women, most were white, 75 years and older, and had multiple comorbid diagnoses. Total charges averaged US$8000–10 000 per hospitalization and were higher in men. Mean length of stay was just under 6 days and more than 50% of discharged patients required some form of continuing care. Hospitalizations for vertebral fracture occurred at only one-fourth the rate of those for hip fracture, and created only half the hospital charges per admission. Vertebral fracture accounted for over 400 000 total hospital days and generated charges in excess of US$500 million. This resource impact is considerably higher than has been described in prior studies. Received: 25 June 2002 / Accepted: 13 August 2002 Acknowledgement This research was supported by Procter & Gamble Pharmaceuticals and Aventis.  相似文献   
95.
Injuries in national karate competitions in Finland   总被引:3,自引:0,他引:3  
The injuries sustained in 6 national karate competitions in Finland were studied by analyzing data from 450 bouts during the season 1991–1992. The analyzed data included a personal interview with each competitor and detailed information on the bouts and any injuries sustained. The overall probability of injury was 0.28 per bout. These injuries occurred to 16% of the 647 competitors. Occurrence of injury was greatest among adult men, which was pronounced in final bouts. Of all injuries diagnosed by the physicians for the competitions, more than 95% were localized to the head. The majority of these were minor injuries. Experienced competitors were more injury-prone than beginners. On the other hand, none of the background factors studied significantly affected the probability of injuring one's opponent. Most injuries and penalties, as well as full scores, were caused by direct punches to the head. From these findings it was concluded that a protective guard for the head together with modification of competition rules could significantly reduce injuries.  相似文献   
96.
A cohort study was undertaken to compare the effect at the timeof oocyte retrieval of the i.v. administration of either 1000ml of lactated Ringer' solution or 1000 ml of a 5% solutionof human albumin on in-vitro fertilization patients at riskfor severe ovarian hyperstimulation syndrome (OHSS). A totalof 207 patients with an oestradiol concentration > 10 000pmol/l and/or > 15 follicles (>10 mm diameter) on theday of human chorionic gonadotrophin (HCG) injection were reviewed.Of these, 158 women received 500 ml of lactated Ringer’ssolution both before and after egg retrieval, and 49 women receivedtwo infusions of 500 ml of 5% human albumin in normal salineat the time of egg retrieval. Severe OHSS developed in two patientswho received human albumin and in 10 women who did not receivethe albumin. This difference was not statistically significant.There were no differences between the two groups in terms ofage, number of follicles punctured at transvaginal oocyte retrievalor oestradiol concentration at the time of HCG injection. Theadministration of a 5% human albumin solution does not preventthe development of severe OHSS in at risk patients. It doesappear to blunt the severity of the condition.  相似文献   
97.
本文采用超凝胶柱层析法分离纯化日本血吸虫成虫31/32KD抗原。分离的抗原经银染色及免疫印迹法分析证明已达免疫纯及生化纯级。该抗原PAS染色呈阴性,经过碘酸钠处理后不失去活性,在琼脂糖凝胶电泳中趋向阳极。鉴于血吸虫成虫31/32KD组分是一种主要血清学抗原,它的分离纯化为改进和标化血吸虫病的诊断提供了条件。  相似文献   
98.
应用0.5%环孢霉素A(cyclosporin A,CsA)滴眼治疗穿透性角膜移植术后发生免疫排斥患者16例(16只眼),治愈9只眼,好转6只眼,无效1只眼。随访5~24个月,其中2只眼因停药复发,1只眼于拆线后复发,继续用药或增加给药次数后治愈。研究表明0.5%CsA滴眼剂治疗术前移植床条件较好,角膜移植术后发生免疫排斥的病例可得到良好疗效;而对术前移植床条件较差,角膜移植术后发生免疫排斥的病例有一定的疗效。作者对眼局部应用CsA治疗角膜移植排斥的疗效和作用机理进行了讨论。  相似文献   
99.
检测256例肝病患者HA,结果表明各肝病组均增高,幅度从慢迁肝到慢活肝至肝硬化呈递增,其数值的高低可反映肝脏病变的程度。根据HA与中医血瘀证关系的分析,HA的增高与血瘀证存在明显的正相关关系。  相似文献   
100.
A型肉毒杆菌毒素治疗麻痹性斜视   总被引:2,自引:0,他引:2  
采用眼外肌注射A型肉毒杆菌毒素的方法,治疗17例(18只眼)麻痹性内斜视患者。最大的肌肉麻痹作用发生于注射后7~14天,最大斜视矫正度为50-,随访时间为4~20周,5例最终获得双眼视。未见全身副作用。认为,这种疗法可在部分患卉中替代斜视矫正术。  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