全文获取类型
收费全文 | 20042篇 |
免费 | 2224篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 214篇 |
儿科学 | 818篇 |
妇产科学 | 449篇 |
基础医学 | 3037篇 |
口腔科学 | 255篇 |
临床医学 | 2453篇 |
内科学 | 3568篇 |
皮肤病学 | 358篇 |
神经病学 | 2030篇 |
特种医学 | 520篇 |
外科学 | 2338篇 |
综合类 | 676篇 |
一般理论 | 30篇 |
预防医学 | 2347篇 |
眼科学 | 313篇 |
药学 | 1391篇 |
中国医学 | 14篇 |
肿瘤学 | 1484篇 |
出版年
2023年 | 200篇 |
2022年 | 290篇 |
2021年 | 531篇 |
2020年 | 372篇 |
2019年 | 518篇 |
2018年 | 578篇 |
2017年 | 416篇 |
2016年 | 452篇 |
2015年 | 503篇 |
2014年 | 624篇 |
2013年 | 857篇 |
2012年 | 1256篇 |
2011年 | 1268篇 |
2010年 | 672篇 |
2009年 | 602篇 |
2008年 | 964篇 |
2007年 | 1140篇 |
2006年 | 985篇 |
2005年 | 994篇 |
2004年 | 894篇 |
2003年 | 773篇 |
2002年 | 836篇 |
2001年 | 458篇 |
2000年 | 438篇 |
1999年 | 416篇 |
1998年 | 238篇 |
1997年 | 175篇 |
1996年 | 169篇 |
1995年 | 148篇 |
1994年 | 161篇 |
1993年 | 172篇 |
1992年 | 326篇 |
1991年 | 269篇 |
1990年 | 263篇 |
1989年 | 267篇 |
1988年 | 206篇 |
1987年 | 221篇 |
1986年 | 197篇 |
1985年 | 221篇 |
1984年 | 176篇 |
1983年 | 165篇 |
1982年 | 119篇 |
1979年 | 129篇 |
1978年 | 104篇 |
1977年 | 97篇 |
1976年 | 99篇 |
1974年 | 109篇 |
1973年 | 100篇 |
1972年 | 99篇 |
1971年 | 88篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Inhibitory motor control in children with attention-deficit/hyperactivity disorder: event-related potentials in the stop-signal paradigm. 总被引:4,自引:0,他引:4
Aneta Dimoska Stuart J Johnstone Robert J Barry Adam R Clarke 《Neuropsychopharmacology》2003,54(12):1345-1354
BACKGROUND: The aim of the study was to investigate the inhibitory control of an ongoing motor response and to identify underlying neural deficiencies, manifested in event-related potentials, that cause poorer inhibitory performance in children with attention-deficit/hyperactivity disorder. METHODS: A stop-signal paradigm with a primary visual task and auditory stop signal was used to compare performance in 13 children with attention-deficit/hyperactivity disorder and 13 control children, while event-related potentials were recorded simultaneously. RESULTS: Children with attention-deficit/hyperactivity disorder showed poorer inhibitory performance through a slower inhibitory process. Inhibitory processing of auditory stop signals was marked by a frontal N2 component that was reduced in the attention-deficit/hyperactivity disorder group relative to controls. A central positive component (P3) was associated with the success of inhibiting a response, but there were no group differences in its amplitude or latency. CONCLUSIONS: Findings support the hypothesis of deficient inhibitory control in children with attention-deficit/hyperactivity disorder. Slower inhibitory processing appears to be due to a specific neural deficiency that manifests in the processing of the stop signal as attenuated negativity in the N2 latency range. 相似文献
32.
Charlotte Gray 《Canadian Medical Association journal》1995,153(6):819-821
Few bureaucratic appointments have raised as many eyebrows as the announcement that controversial health economist Jane Fulton would become Alberta's deputy minister of health. A staunch supporter of private health care, Fulton joins the Alberta ministry just as Premier Ralph Klein's Progressive Conservatives gear up for a battle with Ottawa over two-tier medicine. 相似文献
33.
34.
Intensive versus standard blood glucose awareness training (BGAT) with insulin-dependent diabetes: mechanisms and ancillary effects 总被引:1,自引:0,他引:1
D J Cox L Gonder-Frederick D Julian P Cryer J H Lee F E Richards W Clarke 《Psychosomatic medicine》1991,53(4):453-462
Insulin-dependent diabetes mellitus (IDDM) patients make critical daily self-care decisions on the basis of what they estimate their blood glucose (BG) levels to be. This study: a) replicated efficacy of Standard Blood Glucose Awareness Training (BGAT), b) evaluated the relative efficacy of an Intensive Blood Glucose Awareness Training (BGAT) to enhance patient accuracy of BG estimation, and c) evaluated the mechanisms and ancillary effects of BGAT. Thirty-nine subjects were randomly assigned to one of three groups. Compared with Control, both Standard and Intensive BGAT improved accuracy (p less than 0.001). Intensive BGAT post-treatment accuracy relative to Standard BGAT did not reach statistical significance (p = 0.177). Greater improvement in accuracy was associated with poorer pretreatment accuracy. Only Intensive BGAT improved metabolic control (glycosylated hemoglobin), and this improvement was associated with poorer pretreatment control. The effects of BGAT were highly specific, affecting only accuracy and metabolic control, and not affecting fear of hypoglycemia, diabetes knowledge, of frequency of blood glucose monitoring. 相似文献
35.
36.
L P Clarke S J Cullom R Shaw C Reece B C Penney M A King M Silbiger 《Journal of nuclear medicine》1992,33(1):161-166
Quantitative imaging of bremsstrahlung from pure beta emitters is proposed as a means for in vivo management of antibody therapy. The method involves the use of high-energy collimation, an empirically selected broad photon energy window to enhance detector sensitivity, and a Wiener restoration filter to compensate for system blur. The measured and filtered data were obtained for an idealized scattering medium and isolated spherical sources. An effective linear attenuation coefficient of about 0.13 cm-1 was determined from the raw image data of 32P. A coefficient of 0.14 cm-1 was determined after the images were restored using the Wiener filter. The measured attenuation was not significantly dependent on the size of the region of interest or the size of the source. Its variation was within the experimental error of measurement (+/- 5%). The measured sensitivity (6 x 10(-6) cps/Bq) was sufficient for imaging therapy doses of 32P or 90Y. 相似文献
37.
James F. Jekel David F. Allen Nelson Clarke Henry Podlewski Hannah Gray Carolyn Roberts 《The American journal on addictions / American Academy of Psychiatrists in Alcoholism and Addictions》1994,3(1):14-24
Nine years after the beginning of the epidemic of freebase (crack) cocaine abuse in the Bahamas, this historical study was done to characterize the natural course of the epidemic and to estimate the effectiveness of control measures. The authors' data include the incidence of new cases at the only psychiatric hospital in the Bahamas and at the primary community psychiatric clinic in the nation. The Bahamian response included 1) demand reduction, 2) supply reduction, and 3) reduction of money laundering. The annual number of new cases of crack abuse presenting for treatment declined from 1987 to mid-1991 in both facilities, but in 1992 it began rising again in the inpatient setting only. The changes in recent years have been accompanied by an increase in violent crimes against persons, especially robberies. (American Journal on Addictions 1994; 3:14–24) 相似文献
38.
39.
Suzanne C. Tough David W. Johnston Jodi E. Siever Gayleen Jorgenson Linda Slocombe Carolyn Lane Margaret Clarke 《分娩》2006,33(3):183-194
ABSTRACT: Background: The addition of supplementary prenatal support may improve the health and well‐being of high‐risk women and families. The objective of this randomized controlled trial was to examine the impact of supplementary prenatal care on resource use among a community‐based population of pregnant women. Methods: Pregnant women from three urban maternity clinics were randomized (a) to current standard of physician care, (b) to current standard of care plus consultation with a nurse, or (c) to (b) plus consultation with a home visitor. Participants were 1,352 women who received 3 telephone interviews. The primary outcome was resource use (e.g., attended prenatal classes, used nutritional counseling). Results: Overall, those in the nurse intervention group were more likely to attend an “Early Bird” prenatal class and parenting classes, and to use nutrition counseling and agencies that assist with child care. Women provided with extra nursing and home visitation supports were more likely to use a written resource guide, nutrition counseling, and agencies that assist with child care. Among women at higher risk (e.g., language barriers, young maternal age, low income), the nurse intervention significantly increased use of early prenatal classes, whereas the nurse and home visitor intervention significantly increased use of the written resource guide and nutrition counseling. The intervention substantially increased the amount of information received on numerous pregnancy‐related topics but had little impact on resource use for mental health and poverty‐related needs. Among those with added support, resource use among low‐risk women was generally greater than among high‐risk women. Conclusions: Additional support provided by nurses, or nurses and home visitors, can successfully address informational needs and increase the likelihood that women will use existing community‐based resources. This finding was true even for high‐risk women, although this intervention did not reduce the difference in resource use between high‐ and low‐risk women. (BIRTH 33:3 September 2006) 相似文献
40.
Nir Giladi Babak Boroojerdi Amos D Korczyn David J Burn Carl E Clarke Anthony H V Schapira 《Movement disorders》2007,22(16):2398-2404
Rotigotine is a new, non-ergot dopamine agonist formulated in a transdermal delivery system. The present study was to investigate the efficacy and safety of the rotigotine transdermal patch in the treatment of early Parkinson's disease. Patients (n = 561) were randomized to rotigotine, ropinirole, or placebo. The titration period was up to 13 weeks, and there was a minimum dose-maintenance period of 24 weeks for ropinirole and 33 weeks for rotigotine. The primary endpoint was the proportion of patients with a minimum of 20% decrease in the combined Unified Parkinson's Disease Rating Scale Part II and Part III scores. The responder rate in the rotigotine group was significantly higher than in the placebo group (52% vs. 30%, P < 0.0001). Transdermal rotigotine at doses < or =8 mg/24 h did not show noninferiority to ropinirole at doses < or =24 mg/day. In a post-hoc subgroup analysis, rotigotine < or =8 mg/24 hours had a similar efficacy to ropinirole at doses < or =12 mg/day. The rotigotine transdermal patch was well tolerated. The most common adverse events were application-site reactions, nausea, and somnolence. Application-site reactions were predominantly mild or moderate in intensity. In conclusion, the rotigotine transdermal patch represents an effective and safe option for the treatment of patients with early Parkinson's disease. 相似文献