全文获取类型
收费全文 | 2532795篇 |
免费 | 223426篇 |
国内免费 | 13635篇 |
专业分类
耳鼻咽喉 | 34502篇 |
儿科学 | 79010篇 |
妇产科学 | 62685篇 |
基础医学 | 427996篇 |
口腔科学 | 66854篇 |
临床医学 | 225686篇 |
内科学 | 424922篇 |
皮肤病学 | 75188篇 |
神经病学 | 224923篇 |
特种医学 | 99622篇 |
外国民族医学 | 28篇 |
外科学 | 400415篇 |
综合类 | 84000篇 |
现状与发展 | 23篇 |
一般理论 | 2010篇 |
预防医学 | 217301篇 |
眼科学 | 56600篇 |
药学 | 169290篇 |
22篇 | |
中国医学 | 8127篇 |
肿瘤学 | 110652篇 |
出版年
2022年 | 22579篇 |
2021年 | 54168篇 |
2020年 | 34554篇 |
2019年 | 57417篇 |
2018年 | 68701篇 |
2017年 | 52192篇 |
2016年 | 57469篇 |
2015年 | 72387篇 |
2014年 | 106366篇 |
2013年 | 171239篇 |
2012年 | 66733篇 |
2011年 | 62457篇 |
2010年 | 109071篇 |
2009年 | 115812篇 |
2008年 | 50152篇 |
2007年 | 49598篇 |
2006年 | 61869篇 |
2005年 | 57594篇 |
2004年 | 60076篇 |
2003年 | 51610篇 |
2002年 | 41677篇 |
2001年 | 54328篇 |
2000年 | 45264篇 |
1999年 | 55351篇 |
1998年 | 60142篇 |
1997年 | 59307篇 |
1996年 | 56746篇 |
1995年 | 52388篇 |
1994年 | 46532篇 |
1993年 | 43654篇 |
1992年 | 35431篇 |
1991年 | 32954篇 |
1990年 | 30278篇 |
1989年 | 30917篇 |
1988年 | 28902篇 |
1987年 | 28130篇 |
1986年 | 26801篇 |
1985年 | 28222篇 |
1984年 | 31067篇 |
1983年 | 29981篇 |
1982年 | 35734篇 |
1981年 | 34205篇 |
1980年 | 32335篇 |
1979年 | 23171篇 |
1978年 | 24502篇 |
1977年 | 23597篇 |
1976年 | 21338篇 |
1975年 | 18858篇 |
1974年 | 17375篇 |
1973年 | 16634篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.
Olgierd Pucilowski W. Danysz D.H. Overstreet A.H. Rezvani B. Eichelman D.S. Janowsky 《Brain research bulletin》1991,26(4):621-625
The Flinders Sensitive Line (FSL) of rats has been selectively bred to have increased sensitivity to cholinergic agonists. However, these rats exhibit altered responsiveness to a number of noncholinergic agents, such as apomorphine, buspirone and ethanol. This study compared the FSL and control Flinders Resistant Line (FRL) rats in terms of their hyperthermic response to the phencyclidine (PCP) receptor agonist, MK-801 (0.2 mg/kg SC) and their MK-801 binding characteristics. We have found that FSL rats react with a delayed hyperthermia, having a significantly lower hyperthermia for the first 120 min of observation. Thereafter the response does not differ in FSL and FRL rats. Both groups had similar affinities and numbers of [3H]MK-801 binding sites in the hippocampus/cerebral cortex. Pretreatment with scopolamine (1 mg/kg SC) failed to affect MK-801-induced hyperthermia in either line of rats. These findings suggest that selective breeding of FSL rats attenuated the secondary mechanisms involved in the PCP receptor-mediated hyperthermic response. However, by itself cholinergic supersensitivity does not appear to be a major factor in the blunted responsiveness of FSL rats to MK-801. 相似文献
993.
Abstract— Biomedical determinants of dental caries have been more extensively investigated than psychosocial factors and their impact on caries prevalence and incidence seems to be greater. However, a majority of these investigations relate to children and adolescents. An implementation of social and psychologic variables may be more relevant regarding dental caries in adults. In addition, a multidisciplinary approach might improve our understanding of dental caries as a multifactorial disease and bridge the gap between a biomedical concept and a more holistic approach to dental health. 相似文献
994.
C. I. V. FRANKLIN 《Journal of Medical Imaging and Radiation Oncology》1991,35(1):68-71
The records of 108 adult patients with supratentorial low grade astrocytoma presenting between 1/1/80 and 31/12/87 were examined for the following factors which might affect survival: patient age, extent of surgical resection, site of tumour, tumour grade, radiation field size and radiation dose. Univariate analysis showed that patient age, field size and radiation dose were significant prognostic factors, but with multivariate analysis only patient age and radiation field size were significant independent variables. It is possible that field size is a proxy variable for tumour size. 相似文献
995.
32nd Annual Meeting of the Scandinavian Society for Psychopharmacology Copenhagen, Denmark April 10–12, 1991 Abstracts 相似文献
996.
Studies in patients with autoimmune disorders strongly support a role for interferon (IFN) in the disease process. In the present study we investigated the in vivo production of alpha-IFN in lupus erythematosus patients after stimulation with dipyridamole, recently characterized as an alpha-IFN inducer in mice and humans. Levels of IFN were measured in serum samples from 22 patients with systemic lupus erythematosus (SLE) and 12 patients with discoid lupus erythematosus (DLE) before and 24 h after dipyridamole administration. IFN activity was assayed on human and bovine cells in parallel. Initial serum concentrations of alpha-IFN in SLE patients were markedly elevated. The percentage of DLE positive responders to dipyridamole induction was about twice as high as that found for SLE. Studies of factors responsible for IFN production in lupus erythematosus might result in better understanding of the relationship between DLE and SLE. 相似文献
997.
998.
Geoffrey G. Hallock M.D. 《Aesthetic plastic surgery》1989,13(4):285-289
Reconstitution of the nasal scaffolding with maintainence of soft tissue proportions either following severe facial trauma or as a sequela to aesthetic rhinoplasty misadventures frequently is best achieved using the stability afforded by bone grafts. Split cranial bone grafts offer many advantages and may be the donor site of choice, and may even allow such surgery to be performed on an outpatient basis in some cases. The use of miniplate or screw osteosynthesis, now commonly accepted as a superior technique in craniomaxillofacial procedures, may simplify fixation of these calvarial nasal bone grafts with an apparent decrease in the risk of resorption. 相似文献
999.
WARHEIT DAVID B.; KELLY DAVID P.; CARAKOSTAS MICHAEL C.; SINGER ALLEN W. 《Toxicological sciences》1989,12(2):333-345
A 90-Day Inhalation Toxiaty Study with Benomyl in Rats. WARHEIT,D. B., KELLY, D. P., CARAKOSTAS, M. C., AND SINGER, A. W. (1989).Fundam Appl Toxicol./ 12, 333-345. Benomyl [methyl 1-(butylcarbamoyl)-2-benzimidazolecarbamate,CAS Registry No. 17804-35-2] is a fungicide and the possibilityfor inhalation exposure exists for field workers. To assessthe toxicity of benomyl, groups of 20 male and 20 female CDrats were exposed nose-only 6 hr a day, 5 days a week, to concentrationsof 0, 10, 50 or 200 mg/m3 of a benomyl atmosphere. At the midpoint(approximately 45 days on test) and at the end of the exposureperiod, blood and urine samples for clinical evaluation werecollected from 10 rats/group/sex, and these animals were sacrificedfor pathological examination. Similar evaluations were performadon all remaining rats at the end of the 90-day test period.After approximately 45 days on test, compoundrelated degenerationof the olfactory epithelium was observed in all males and in8 of 10 female rats exposed to 200 mg/m3 benomyl. Two male ratsexposed to 50 mg/m3 had similar, although less severe, areasof olfactory epithelial degeneration. After approximately 90days of exposure, the remaining 10 rats/group/sex were sacrificedand examined. Of these rats, all of the males and females exposedto 200 mg/m3 had olfactory degeneration, along with 3 malesexposed to 50 mg/m3 of benomyl. No other observed lesions wereinterpreted to have been caused by the benomyl exposure. Inaddition, male rats exposed to 200 mg/m3 benomyl had depressedmean body weights compared to controls and this finding correlatedwith a reduction in food consumption. Based on pathologicalobservations, 10 mg/m3 represents the no-observable-effect level(NOEL) for the male rats, and 50 mg/m3 is the NOEL for the femalerats. 相似文献
1000.
Edward T. Crosby Stephen H. Halpern Stephen H. Rolbin 《Journal canadien d'anesthésie》1989,36(6):701-704
The safety of epidural anaesthesia in patients with active, recurrent genital herpes simplex (HSV) infections is controversial. We reviewed the six-year experience of the use of epidural anaesthesia in this patient population in two institutions. Eighty-nine parturients with active genital HSV were administered epidural anaesthesia for Caesarean section. No patient suffered an adverse outcome related to either the anaesthetic or the virus. The theoretical risks of regional anaesthesia in the parturient with active herpes genitalis are reviewed. We conclude from available data that the risk of an adverse outcome is small and does not contraindicate the use of epidural anaesthesia in patients with recurrent infection. 相似文献