全文获取类型
收费全文 | 5266篇 |
免费 | 608篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 74篇 |
儿科学 | 228篇 |
妇产科学 | 148篇 |
基础医学 | 804篇 |
口腔科学 | 83篇 |
临床医学 | 574篇 |
内科学 | 1162篇 |
皮肤病学 | 35篇 |
神经病学 | 543篇 |
特种医学 | 327篇 |
外科学 | 613篇 |
综合类 | 107篇 |
一般理论 | 4篇 |
预防医学 | 572篇 |
眼科学 | 37篇 |
药学 | 274篇 |
中国医学 | 7篇 |
肿瘤学 | 299篇 |
出版年
2022年 | 36篇 |
2021年 | 68篇 |
2020年 | 45篇 |
2019年 | 54篇 |
2018年 | 96篇 |
2017年 | 85篇 |
2016年 | 93篇 |
2015年 | 96篇 |
2014年 | 129篇 |
2013年 | 179篇 |
2012年 | 214篇 |
2011年 | 230篇 |
2010年 | 180篇 |
2009年 | 155篇 |
2008年 | 192篇 |
2007年 | 225篇 |
2006年 | 207篇 |
2005年 | 184篇 |
2004年 | 203篇 |
2003年 | 205篇 |
2002年 | 196篇 |
2001年 | 161篇 |
2000年 | 153篇 |
1999年 | 164篇 |
1998年 | 121篇 |
1997年 | 102篇 |
1996年 | 115篇 |
1995年 | 94篇 |
1994年 | 77篇 |
1993年 | 74篇 |
1992年 | 141篇 |
1991年 | 130篇 |
1990年 | 139篇 |
1989年 | 127篇 |
1988年 | 124篇 |
1987年 | 100篇 |
1986年 | 92篇 |
1985年 | 82篇 |
1984年 | 81篇 |
1983年 | 70篇 |
1982年 | 53篇 |
1981年 | 42篇 |
1980年 | 42篇 |
1979年 | 42篇 |
1978年 | 36篇 |
1977年 | 46篇 |
1976年 | 49篇 |
1974年 | 34篇 |
1973年 | 35篇 |
1971年 | 34篇 |
排序方式: 共有5891条查询结果,搜索用时 31 毫秒
11.
12.
13.
K R Clark J L Forsythe K M Rigg J Sharp L Rangecroft J Wagget N R Parrott T W Lennard M G Coulthard 《Journal of pediatric surgery》1992,27(6):780-783
Since 1982 eight patients under 1 year of age with end-stage renal failure have been treated by chronic peritoneal dialysis (CPD) following insertion of an abdominal Tenckhoff catheter. We routinely perform a partial omentectomy now, and in males undertake bilateral exploration of the groins at the time of catheter insertion, with herniotomy or ligation of the patent processus vaginalis as required. Up to January 1990, 19 straight double-cuff catheters had been inserted with a total follow-up of 244.5 patient months. The median age at the initial catheter insertion was 14.6 weeks (range, 2 days to 11 months) and the median weight was 3.89 kg (range, 2.2 to 5.5). Peritonitis was the most common complication, with 46 episodes, representing one episode of peritonitis per 5.3 patient months on dialysis. The frequency of peritonitis has decreased in the last 6 months since all patients have been dialysed by two caregivers. The present rate of peritonitis is 1 episode per 10 patient months on dialysis. One patient has died of septicemia secondary to associated congenital abnormalities, one patient has regained renal function, and two patients have been transplanted, one successfully. Five patients are currently dialysing via their abdominal Tenckhoff catheters and awaiting transplantation. We conclude that neonates and infants under 1 year of age can be treated satisfactorily by CPD to enable successful preparation for transplantation later in childhood. 相似文献
14.
Shirley Kobar Coni C Francis Samantha MaWhinney Teresa Sharp 《Nutrition in clinical practice》2003,18(5):417-421
BACKGROUND: Development of an acclimation protocol for use when measuring resting energy expenditure (REE) would simplify and standardize data collection. The purpose of this study was to determine if our 2 metabolic carts could be used interchangeably and to determine if excluding the first 3 or 5 minutes of data collected as an acclimation period would significantly improve the coefficients of variation (CVs) for oxygen consumed (VO(2)) and carbon dioxide produced (VCO(2)) when performing REE assessments with our metabolic cart systems. METHODS: Thirteen healthy, nonsmoking adults ranging in age from 32 to 45 years, with activity levels ranging from sedentary to highly active, participated. Indirect calorimetry was performed twice in the morning after 30 minutes of supine resting. Subjects had fasted for 12 hours, and did not exercise within the last 24 hours. The system order for testing was randomized for the first measurement. When the first measurement was completed, subjects were crossed over for measurement using a second metabolic cart. RESULTS: The CVs for VO(2) and VCO(2) were significantly lower when excluding the first 3 (VO(2), p = .0005), (VCO(2), p = .0024) or 5 minutes (VO(2), p = .0001, VCO(2), p = .0021) of data compared with no exclusions. No significant differences in CVs between the 3- and 5-minute exclusions were found for VO(2) (p = .3224) or VCO(2) (p = .2255). CONCLUSIONS: Clearly, our machines cannot be used interchangeably within a study. An acclimation period improves CVs of VO(2) and VCO(2.) The similarities in CVs led us to adopt a 3-minute acclimation period for measuring REE. 相似文献
15.
Nurses need to take advantage of multiple internships and fellowships to learn about and experience the daily work of making health policy in Washington, DC. This article lists several of the current programs available for nurses and other health professionals. These internships and fellowships are career-changing experiences. Additionally, new relationships will be built with other health professionals that nurses will be able to use for years to come. Finally, if one of the structured experiences doesn't fit the nurse's timeframe, there is always the possibility to create a special internship to meet the nurse's needs. 相似文献
16.
Research has demonstrated environmentally induced plasticity of hippocampal dentate gyrus-evoked potentials. Other research has shown a role of the NMDA receptor in dentate gyrus long-term potentiation (LTP). The authors tested the role of the NMDA receptor in one form of environmentally induced plasticity, in which transferring animals from their home cages to another environment results in significant excitatory postsynaptic potential (EPSP) enhancement and concomitant depression of the population spike. Rats were chronically implanted with stimulating electrodes in the perforant path and recording electrodes in the dentate gyrus bilaterally. Evoked potentials were recorded from freely behaving rats for four 20-minute sessions (1/wk), which took place immediately following an environmental transfer. Rats received 0.00, 0.05, 0.08, or 0.10 mg/kg MK-801 s.c. 30 minutes prior to recording sessions in either an ascending- or descending-dose series. Results showed that MK-801 produced a reduction of the EPSP enhancement, which takes place over the 20-minute session. The effects of MK-801 on spike depression varied as a function of dose series and time within a session, suggesting a long-term effect of MK-801 on spike depression. There was no detected effect of MK-801 on behavior. Results suggest a role of the NMDA receptor in this form of environmentally induced plasticity with different effects of NMDA receptor antagonism on EPSP enhancement and spike depression. 相似文献
17.
Previously, all carcinoid tumors were considered to occur sporadically. We present an extremely rare series of three first-degree relatives in two generations with proximal duodenal carcinoid tumors and other family-associated neoplasms. This unusual circumstance, which has never been described previously, represents the sixth case of familial clustering of carcinoid tumors reported in the world's literature. 相似文献
18.
Judith A. Maloni RN PhD Ching-Yu Cheng RN MSN Cary P. Liebl RNC BSN Jeanmarie Sharp Maier RN BSN 《Journal of obstetric, gynecologic, and neonatal nursing : JOGNN / NAACOG》1996,25(1):17-23
The current model for delivery of prenatal care was developed more than 100 years ago. Evidence suggests that this model is no longer appropriate for meeting national health objectives or for meeting the needs of a diverse population of pregnant women. This article provides a historical overview of prenatal care; describes the current system for care delivery and problems associated with it; and suggests strategies for transforming care into an effective, comprehensive model. JOGNN, 25, 17–23; 1996. 相似文献
19.
R Mokni A Chakar F Bleiberg-Daniel JL Mahu PA Walravens P Chappuis J Navarro D Lemonnier 《Acta paediatrica (Oslo, Norway : 1992)》1993,82(6-7):539-543
Biochemical markers of nutritional status (albumin, transthyretin, insulin-like growth factor-I and zinc) were measured in slowly growing two- to five-year-old, low-income Parisian children whose weight-for-height or height-for-age z scores (WHZ or HAZ) were between — 1 and — 2 SD of the NCHS median. The results were compared to controls who were matched for age, sex, and ethnic origin with WHZ and HAZ between — 1 and + 2 SD. Mean serum levels of transthyretin, albumin and insulin-like growth factor-I and mean plasma zinc concentrations were significantly lower in the growth-impaired children than in the controls ( p = 0.002, p = 0.006, p = 0.015, and p = 0.035, respectively). While the height-retarded children had low mean serum insulin-like growth factor-I values, the weight-retarded subjects had decreased levels of albumin, transthyretin and zinc when compared to controls. Lower mean levels of nutritional markers in healthy, slowly growing children suggest that inadequate dietary intakes of zinc, protein and/or energy may result in marginal delays in weight and height gains. 相似文献
20.
M. D. Holzman K. Sharp G. W. Holcomb M. Frexes-Steed W. O. Richards 《Surgical endoscopy》1994,8(8):927-930
The current methods utilized for laparoscopic cholangiography involve cystic duct cannulation and present practical difficulties and potential hazards. An alternative method for intraoperative cholangiography is described which is easy, quick, and safe. The Kumar clamp (a gift from Sabi Kumar, M.D.) is placed across the infundibulum. A 23-gauge sclerotherapy needle is introduced through a side port in the clamp and directed into the infundibulum. The cholangiogram is obtained prior to any dissection in the triangle of Calot, thereby avoiding iatrogenic common bile duct injuries due to misidentification of the cystic duct or anomalous anatomy. To date no pathology has been missed and no complications have resulted from this technique. 相似文献