全文获取类型
收费全文 | 14093篇 |
免费 | 988篇 |
国内免费 | 32篇 |
专业分类
耳鼻咽喉 | 118篇 |
儿科学 | 430篇 |
妇产科学 | 447篇 |
基础医学 | 2092篇 |
口腔科学 | 242篇 |
临床医学 | 1803篇 |
内科学 | 2475篇 |
皮肤病学 | 408篇 |
神经病学 | 1367篇 |
特种医学 | 272篇 |
外科学 | 1264篇 |
综合类 | 95篇 |
一般理论 | 38篇 |
预防医学 | 1577篇 |
眼科学 | 237篇 |
药学 | 1039篇 |
中国医学 | 24篇 |
肿瘤学 | 1185篇 |
出版年
2024年 | 14篇 |
2023年 | 141篇 |
2022年 | 328篇 |
2021年 | 551篇 |
2020年 | 277篇 |
2019年 | 492篇 |
2018年 | 516篇 |
2017年 | 352篇 |
2016年 | 457篇 |
2015年 | 437篇 |
2014年 | 613篇 |
2013年 | 771篇 |
2012年 | 1105篇 |
2011年 | 1166篇 |
2010年 | 638篇 |
2009年 | 524篇 |
2008年 | 876篇 |
2007年 | 913篇 |
2006年 | 891篇 |
2005年 | 825篇 |
2004年 | 713篇 |
2003年 | 633篇 |
2002年 | 601篇 |
2001年 | 84篇 |
2000年 | 76篇 |
1999年 | 80篇 |
1998年 | 109篇 |
1997年 | 78篇 |
1996年 | 71篇 |
1995年 | 60篇 |
1994年 | 73篇 |
1993年 | 51篇 |
1992年 | 48篇 |
1991年 | 50篇 |
1990年 | 34篇 |
1989年 | 40篇 |
1988年 | 37篇 |
1987年 | 20篇 |
1986年 | 25篇 |
1985年 | 34篇 |
1984年 | 31篇 |
1983年 | 29篇 |
1982年 | 30篇 |
1981年 | 36篇 |
1980年 | 31篇 |
1979年 | 17篇 |
1978年 | 19篇 |
1977年 | 23篇 |
1976年 | 17篇 |
1974年 | 16篇 |
排序方式: 共有10000条查询结果,搜索用时 12 毫秒
11.
12.
Melissa Kang Diana Bernard Michael Booth Susan Quine Garth Alperstein Tim Usherwood David Bennett 《The British journal of general practice》2003,53(497):947-952
BACKGROUND: To adequately address the complex health needs of young people, their access to services, and the quality of services received, must be improved. AIMS: To explore the barriers to service provision for young people and to identify the training needs of primary healthcare service providers in New South Wales (NSW), Australia. DESIGN OF STUDY: A cross-sectional, qualitative study of the perspectives of a range of health service providers. SETTING: A range of primary healthcare organisations across NSW. METHODS: Samples of general practitioners (GPs), youth health workers, youth health coordinators, and community health centre staff were drawn from urban and rural clusters across NSW. Focus groups and interviews were used to identify barriers to service provision and the training needs of service providers. Data were tape recorded, transcribed, and analysed. RESULTS: Barriers to service provision among GPs and community health centre staff included inadequate time, flexibility, skills, and confidence in working with young people, and poor linkages with other relevant services. Training needs included better knowledge of and skills in adolescent health requirements, working with adolescents, and working with other services. Barriers to service provision for youth health workers and coordinators included lack of financial resources and infrastructure. There were few linkages between groups of service providers. CONCLUSION: Models of service provision that allow stronger linkages between service providers, sufficient time for consultation with young people, adequate training and support of health professionals, and flexibility of service provision, including outreach, should be explored and evaluated. 相似文献
13.
14.
Intense synaptophysin immunoreactivity was observed around neuronal cell bodies and in the neuropil of the superior cervical ganglion of adult rats. In newborn rats synaptophysin was comparatively less concentrated and restricted to small interstitial spaces. In contrast, in newborns, consistent traces of positivity were found in the Golgi-like area of larger neurons, in agreement with the higher neonatal rate of synaptophysin synthesis. A few clusters of small neurons, numerically more expanded in adult rats, exhibited a dense reaction product filling the whole cytoplasm. No positivity was found in intraganglionic fibres. 相似文献
15.
16.
Diana A. Lepore Kenneth R. Knight Surajit Bhattacharya Morris Ritz Sonia P. Robbins Peter Sieg Wayne A. Morrison Bernard McC. O'Brien 《Microsurgery》1994,15(10):685-692
The chief aim of this study was to maximize flap survival by counteracting the pathophysiological changes occurring during ischemia-reperfusion. Rabbit epigastric skin flaps given 21 hours of ischemia were infused intra-arterially with selected drugs at the start of reperfusion. Compared with control infused ischemic flaps, which had a 33% survival rate on day 7 post-ischemia, significant improvement was found with vasodilators nitrendipine (61%) and prostacyclin (65%) and the thrombolytic agent urokinase (65%); marginal improvement with the free radical scavenger desferrioxamine (53%); but no change with streptokinase (44%), heparin (21%), and ATP-MgCl2 (35%). A drug mixture comprising all of these agents except streptokinase and urokinase produced 87% survival, suggesting an additive effect. Biochemical assays on skin homogenates and blood implicated oxygen free radicals, neutrophil infiltration, and thromboxane in flap failure. These results imply that multiple factors are responsible for ischemic flap failure and that a mixture of drugs needs to be infused to counteract all of the detrimental changes. © 1994 Wiley-Liss, Inc. 相似文献
17.
Rimvydas Jasiulionis Gediminas Adlys Diana Adliene Linas Vycinas 《Applied radiation and isotopes》2007,65(7):836-842
The presence of noble gas and other short-lived radionuclides in air borne effluents from RBMK-1500-type reactor has been investigated using experimental and theoretical instrumentation for detection purposes. Activity concentrations of (85m)Kr, (87)Kr, (88)Kr, (135m)Xe, (135)Xe, (133)Xe and (41)Ar were measured in air emissions from Ignalina NPP using a special method and special equipment. Theoretical detection of reactor-borne radionuclides and investigation of their behaviour in a nuclear fuel during operation of nuclear reactor was performed using an analytical model based on reactor physics. An innovative method for the estimation of noble gas flow time from the defective nuclear fuel element through the ventilation stack of NPP to the atmosphere based on comparison of the experimentally and theoretically evaluated activity ratios of (88)Kr/(85m)Kr; (135)Xe/(133)Xe has been proposed. The estimated flow time of noble gas provides an excellent possibility to obtain modelling-based information about the qualitative and quantitative content of atmospheric releases from NPP. 相似文献
18.
Diana Bell Yi-Jue Zhao Pulivarthi H. Rao Randal S. Weber Adel K. El-Naggar 《Head and neck pathology》2007,1(2):165-168
We present an adenoid cystic carcinoma of the base of tongue in a 48-year-old male with a restricted chromosomal alteration
by cytogenetic and spectral karyotypic analysis (SKY). SKY and G-banding analyses identified the t(6;14)(q25;q13) as the sole
structural aberration in all metaphases analyzed. This finding supports a critical role for this event in the development
of this tumor. The implications of chromosome 6q translocation in this case and in previously reported adenoid cystic carcinomas
are highlighted and discussed. 相似文献
19.
OBJECTIVE: The purpose of this study was to compare the preparation costs of two common methods used for neonatal red blood cell transfusion aliquots. METHODS: Three months of data from a Level 2 and Level 3 neonatal intensive care unit (NICU) were used to determine the comparative cost for red cell aliquot transfusions using an eight bag aliquot/transfer system or the syringe set system. Using leuko-poor red blood cell blood collected in Adsol and containing approximately 320 ml of red blood cells and supernatant solution, the average cost of neonatal transfusion aliquots was determined using the Charter Medical syringe set and the Charter Medical eight bag aliquot/transfer system. RESULTS: A total of 126 red blood cell transfusion aliquots were used over the three month period. The amount transfused with each aliquot ranged from 5.0 ml - 55.0 ml with an average of 24.0 ml per aliquot. The cost per aliquot using the eight aliquot/transfer set was calculated as $36.25 and the cost per aliquot using the syringe set cost was calculated as $30.71. Additional benefits observed with the syringe set included decreased blood waste. CONCLUSION: When comparing Charter Medical multiple aliquot bag sets and the Charter Medical syringe aliquot system to provide neonatal transfusions, the use of the syringe system decreased blood waste and proved more cost effective. 相似文献
20.
Bruce G. Haffty M.D. Peter L. Perrotta M.D. † Barbara Ward M.D. ‡ Meena Moran M.D. Malcolm Beinfield M.D. ‡ Charles McKhann M.D. ‡ Diana Fischer Ph.D. Darryl Carter M.D. † 《The breast journal》1997,3(1):7-14
Abstract: Between 1970 and 1990, 1,008 patients with early-stage breast cancer were treated by conservative surgery without axillary dissection followed by radiation therapy to the intact breast in the Department of Therapeutic Radiology at Yale-New Haven Hospital. The patient population, broken down by histologic subtype, was as follows: 761 patients presented with infiltrating ductal carcinoma, 70 patients with pure intraductal, 38 intraductal with focal invasion, 54 infiltrating lobular, 21 tubular, 17 medullary, 16 mucinous, and 29 with other various histologic subtypes. Patients were followed on a regular basis by the referring physicians and radiation oncologists. Diagnostic studies for distant metastases were performed as clinically indicated. Annual mammography was a routine component of the follow-up program. As of 3/96, with a median follow-up of 10.5 years, 83 patients developed an ipsilateral breast tumor recurrence, and 109 patients developed distant metastases resulting in an overall 10-year breast recurrence-free rate of 84%, and a 10-year distant metastasis-free rate of 78%. There were significant differences in clinical stage, pathological nodal involvement, and administration of systemic therapy between various histologic subtypes. As expected, those patients with histologies of low metastatic potential (such as intraductal, tubular, and mucinous) had significantly superior distant recurrence-free survival rates. With respect to breast relapse rates, there were no statistically significant differences in the 5- and 10-year breast recurrence-free rates between any of the histologic subtypes. Patients with intraductal carcinoma with or without focal invasion had similar breast relapse rates as those with other histologic subtypes. Patients with lobular carcinoma in situ as a histologic component also had a similar overall breast relapse-free recurrence rate. In conclusion, long-term follow-up of conservatively treated breast cancer patients demonstrates no significant differences in ipsilateral breast tumor recurrence rates between various histologic subtypes. There are no histologies which had a statistically significantly higher breast-relapse rate than infiltrating ductal carcinomas and therefore no primary histologic subtype represents a relative contraindication to breast conservation therapy. 相似文献