全文获取类型
收费全文 | 96827篇 |
免费 | 6596篇 |
国内免费 | 510篇 |
专业分类
耳鼻咽喉 | 1207篇 |
儿科学 | 2286篇 |
妇产科学 | 1384篇 |
基础医学 | 12433篇 |
口腔科学 | 2322篇 |
临床医学 | 9539篇 |
内科学 | 21329篇 |
皮肤病学 | 1517篇 |
神经病学 | 9230篇 |
特种医学 | 3949篇 |
外国民族医学 | 1篇 |
外科学 | 16059篇 |
综合类 | 800篇 |
一般理论 | 194篇 |
预防医学 | 6560篇 |
眼科学 | 1835篇 |
药学 | 5859篇 |
中国医学 | 139篇 |
肿瘤学 | 7290篇 |
出版年
2023年 | 865篇 |
2022年 | 1499篇 |
2021年 | 3286篇 |
2020年 | 1821篇 |
2019年 | 2824篇 |
2018年 | 3323篇 |
2017年 | 2350篇 |
2016年 | 2542篇 |
2015年 | 2855篇 |
2014年 | 3941篇 |
2013年 | 5046篇 |
2012年 | 7639篇 |
2011年 | 7747篇 |
2010年 | 4266篇 |
2009年 | 3705篇 |
2008年 | 6369篇 |
2007年 | 6142篇 |
2006年 | 5948篇 |
2005年 | 5865篇 |
2004年 | 5280篇 |
2003年 | 4847篇 |
2002年 | 4350篇 |
2001年 | 617篇 |
2000年 | 487篇 |
1999年 | 684篇 |
1998年 | 891篇 |
1997年 | 710篇 |
1996年 | 573篇 |
1995年 | 565篇 |
1994年 | 451篇 |
1993年 | 459篇 |
1992年 | 364篇 |
1991年 | 324篇 |
1990年 | 296篇 |
1989年 | 288篇 |
1988年 | 293篇 |
1987年 | 267篇 |
1986年 | 290篇 |
1985年 | 288篇 |
1984年 | 355篇 |
1983年 | 308篇 |
1982年 | 339篇 |
1981年 | 338篇 |
1980年 | 263篇 |
1979年 | 151篇 |
1978年 | 195篇 |
1977年 | 181篇 |
1976年 | 130篇 |
1975年 | 134篇 |
1974年 | 133篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Granulocytic sarcoma is an uncommon extraskeletal tumor most frequently associated with leukemia. We present a case of bone
location with unusual pattern in a patient with no evidence of myeloproliferative disorder at presentation or follow-up. 相似文献
102.
This study investigated a discrete-trial, titration duration discrimination procedure in behavioral pharmacology. Pentobarbital and d-amphetamine, measured with this procedure, selectively affected discrimination more than response tendencies. Pentobarbital also tended to affect selectively discrimination of longer durations, whereas d-amphetamine did not. Further experiments showed that (1) other algorithms for modulating stimulus duration are useful in behavioral pharmacology and toxicology, (2) threshold estimates are similar with the method of constant stimuli and the method of titration, and (3) this titration procedure permits the separate examination of drug effects upon discrimination and upon response tendencies; the fixed-interval procedure does not. Baseline variability was an important correlate of drug effects in that the endpoints with more variable baselines were also more sensitive to drugs. 相似文献
103.
Antidepressant-associated maniform states in acute treatment of patients with bipolar-I depression 总被引:2,自引:0,他引:2
R. Bottlender Daniel Rudolf Anton Strauss Hans-Jürgen Möller 《European archives of psychiatry and clinical neuroscience》1998,248(6):296-300
Medical records of 158 patients with bipolar depression were analysed for the incidence of a switch from depression to maniform
states (mania and hypomania). Relation to psychopharmacological treatment was investigated. Thirty-nine (25%) patients of
the total sample had switched to a maniform state during the treatment period in the hospital. Among that group the phenomenon
occurred in 23 patients (15%) as a hypomania and in 16 patients (10%) as a mania. Patients with a switch were significantly
more often treated with tricyclic antidepressants (TCA) than patients without switch (79.5% vs 51.3%). Mood stabilising medication
might reduce the risk for switching, especially in patients treated with TCA; however, it seems not totally sufficient, since
59% of the switched patients received mood stabilisers. The switch phenomenon was not associated with sociodemographic or
clinical data.
Received: 23 September 1998 / Accepted: 28 September 1998 相似文献
104.
105.
James D. Bader DDS MPH Mark S. Scurria DDS Daniel A. Shugars DDS PhD 《The Journal of rural health》1994,10(1):26-30
There have been few reports of relative rates of provision of dental health services in rural and urban settings, a comparative measure of access to care in these populations. One part of a statewide survey of active North Carolina general dentists (n=959, response rate=47%) was designed to quantify provision of prosthetic services. To determine contrasting rural and urban rates, responses were analyzed according to dentists'self-report of practice city size using analysis of covariance with percent of insured patients in the practice as the covariate. Mean per-patient-visit rates for crowns, fixed partial dentures, removable partial dentures, and extractions, as well as the distributions of treatment following tooth extraction, differed by city size, with practitioners in the smallest cities reporting treatment distributions reflecting more frequent loss of teeth and less frequent replacement. These differences in patterns of prosthetic care echo the limited existing information describing oral health status, provider supply, and receipt of care, all of which suggest that differential levels of access to care exist and lead to differences in oral health outcomes. 相似文献
106.
Background: The gastric bypass operation has evolved since 1966 when it was first introduced. The purpose of this study was
to determine the present state of gastric bypass by consensus among the members of the American Society for Bariatric Surgery
(ASBS). Method: A questionnaire was sent to all members of the ASBS. Forty-three percent responded reporting over 41,200 cases.
Results: Results were analyzed by using χ2 tests with a null hypothesis. Surgeons agreed on several technical aspects, preferring a vertical to a horizontal stapleline;
estimating, rather than measuring, the pouch volume at an average of 22 cc. Few surgeons divide the short gastric vessels,
and only 25% of surgeons polled use a restrictive ring or band proximal to the gastroenterostomy. Most surgeons calibrate
the gastroenterostomy, reporting a preferred average diameter of 12.3 cm. There was no consensus regarding forming the gastroenterostomy,
58% preferring hand-sewn and 42% stapled anastomoses. There was no consensus regarding dividing the gastric pouch from the
bypassed stomach: Conclusion: The preferred gastric bypass is vertical, with the pouch estimated at 20-25 cc, and the gastroenterostomy
calibrated at 12 mm diameter. The short gastric vessels need not be divided, and restrictive bands or rings are not preferred.
This technique of gastric bypass should be used as the control procedure when modifications are tested in future trials. Randomized
prospective studies are suggested to probe the benefits of division of the stomach pouch from the bypassed stomach. 相似文献
107.
108.
Pantin Hilda Coatsworth J. Douglas Feaster Daniel J. Newman Frederick L. Briones Ervin Prado Guillermo Schwartz Seth J. Szapocznik José 《Prevention science》2003,4(3):189-201
This paper reports a test of the efficacy of Familias Unidas, a Hispanic-specific, ecologically focused, parent-centered preventive intervention, in promoting protection against and reducing risk for adolescent behavior problems. Specifically, the intervention was designed to foster parental investment, reduce adolescent behavior problems, and promote adolescent school bonding/academic achievement, all protective factors against drug abuse and delinquency. One-hundred sixty seven Hispanic families of 6th and 7th grade students from three South Florida public schools were stratified by grade within school and randomly assigned to intervention and no-intervention control conditions. Results indicated that Familias Unidas was efficacious in increasing parental investment and decreasing adolescent behavior problems, but that it did not significantly impact adolescent school bonding/academic achievement. Summer-vacation rates of adolescent behavior problems were six times higher in the control condition than in the intervention condition. Furthermore, change in parental investment during the intervention was predictive of subsequent levels of adolescent behavior problems. The findings suggest that Familias Unidas is efficacious in promoting protection and reducing risk for adolescent problem behaviors in poor immigrant Hispanic families. 相似文献
109.
Daniel W. Walsh Vincent B. Ho Michael F. Haggerty 《Journal of magnetic resonance imaging : JMRI》1997,7(2):312-315
Mycotic aneurysms of the abdominal aorta are potentially fatal but uncommon. We report the MRI and MRA features of an abdominal aortic mycotic aneurysm in a patient who presented with nonspecific low back pain. By delineating the saccular nature of the aneurysm and identifying the coexistence of vertebral enhancement, MRI was crucial for the final diagnosis. A potential pitfall of contrast-enhanced MRA is also demonstrated. 相似文献