全文获取类型
收费全文 | 1964篇 |
免费 | 193篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 49篇 |
儿科学 | 60篇 |
妇产科学 | 16篇 |
基础医学 | 248篇 |
口腔科学 | 19篇 |
临床医学 | 202篇 |
内科学 | 268篇 |
皮肤病学 | 37篇 |
神经病学 | 144篇 |
特种医学 | 237篇 |
外科学 | 257篇 |
综合类 | 62篇 |
一般理论 | 2篇 |
预防医学 | 201篇 |
眼科学 | 97篇 |
药学 | 135篇 |
中国医学 | 1篇 |
肿瘤学 | 128篇 |
出版年
2021年 | 39篇 |
2020年 | 21篇 |
2019年 | 30篇 |
2018年 | 46篇 |
2017年 | 19篇 |
2016年 | 29篇 |
2015年 | 26篇 |
2014年 | 49篇 |
2013年 | 56篇 |
2012年 | 76篇 |
2011年 | 101篇 |
2010年 | 63篇 |
2009年 | 56篇 |
2008年 | 81篇 |
2007年 | 84篇 |
2006年 | 86篇 |
2005年 | 80篇 |
2004年 | 92篇 |
2003年 | 68篇 |
2002年 | 58篇 |
2001年 | 50篇 |
2000年 | 45篇 |
1999年 | 37篇 |
1998年 | 30篇 |
1996年 | 26篇 |
1995年 | 21篇 |
1994年 | 22篇 |
1993年 | 19篇 |
1992年 | 40篇 |
1991年 | 38篇 |
1990年 | 50篇 |
1989年 | 42篇 |
1988年 | 39篇 |
1987年 | 34篇 |
1986年 | 47篇 |
1985年 | 24篇 |
1984年 | 22篇 |
1983年 | 22篇 |
1982年 | 17篇 |
1980年 | 17篇 |
1979年 | 23篇 |
1978年 | 23篇 |
1977年 | 21篇 |
1976年 | 17篇 |
1973年 | 21篇 |
1972年 | 23篇 |
1971年 | 19篇 |
1969年 | 18篇 |
1968年 | 24篇 |
1967年 | 24篇 |
排序方式: 共有2163条查询结果,搜索用时 15 毫秒
1.
TG Berger F Kiesewetter C Maczek N Bauer M Lueftl G Schuler M Simon Jr 《Journal of the European Academy of Dermatology and Venereology》2006,20(2):178-183
Vitiligo and psoriasis are both common skin disorders. However, psoriasis strictly confined to pre-existing vitiligo areas is rare and suggests a causal relationship. We report here on two patients with a strict anatomical colocalization of vitiligo and psoriasis. The histopathological examinations showed typical changes for both diseases together with a dense infiltrate of CD4+ and CD8+ T cells. By immunohistochemistry, intracytoplasmatic granzyme B and tumour necrosis factor alpha (TNF-alpha) were detected within the T-cell population, suggesting the functional activity of these cells and the creation of a local T helper 1 (Th1)-cytokine milieu. Additionally, in one patient we could identify anti-melanocytic T cells by tetramer staining and enzyme-linked immunospot (ELISPOT) analysis. These skin-infiltrating lymphocytes might trigger, by the local production of Th-1 cytokines such as TNF-alpha and interferon-gamma (IFN-gamma), the eruption of psoriatic plaques in patients with a genetic predisposition for psoriasis. 相似文献
2.
Early glottic carcinoma, specifically stage I or II, can be treated with endoscopic excision, radiation therapy, or open partial laryngectomy. Over the past two decades, this topic has received intensive interest, and controversies have often focused on techniques and outcomes comparing the use of endoscopic excision versus radiation therapy. This article will discuss philosophy, techniques, and outcomes of resection using the endoscopic approach to early glottic carcinoma. Optimization through appropriate instrumentation, staging, and technical details are critical to postoperative oncologic and vocal outcomes. The reader must remember that over 90% of T1 lesions and approximately 75% of T2 lesions are curable, and therefore adherence to the principles described below is important to achieve these outcomes. 相似文献
3.
4.
C A Wilson E Stefánsson L Klombers L D Hubbard S C Kaufman F L Ferris 《American journal of ophthalmology》1988,106(2):131-134
We measured retinal vessel diameter before and after panretinal photocoagulation in 59 eyes with diabetic retinopathy and moderate to severe optic disk neovascularization. Treatment significantly reduced mean arteriolar and venular diameter. The diameter of the retinal arterioles after treatment correlated significantly with the amount of regression in disk neovascularization. Eyes with large diameter vessels after treatment usually had little or no regression of proliferative retinopathy, whereas regression was more frequently seen in eyes with smaller diameter vessels after treatment. 相似文献
5.
McKernan RM Rosahl TW Reynolds DS Sur C Wafford KA Atack JR Farrar S Myers J Cook G Ferris P Garrett L Bristow L Marshall G Macaulay A Brown N Howell O Moore KW Carling RW Street LJ Castro JL Ragan CI Dawson GR Whiting PJ 《Nature neuroscience》2000,3(6):587-592
Inhibitory neurotransmission in the brain is largely mediated by GABA(A) receptors. Potentiation of GABA receptor activation through an allosteric benzodiazepine (BZ) site produces the sedative, anxiolytic, muscle relaxant, anticonvulsant and cognition-impairing effects of clinically used BZs such as diazepam. We created genetically modified mice (alpha1 H101R) with a diazepam-insensitive alpha1 subtype and a selective BZ site ligand, L-838,417, to explore GABA(A) receptor subtypes mediating specific physiological effects. These two complimentary approaches revealed that the alpha1 subtype mediated the sedative, but not the anxiolytic effects of benzodiazepines. This finding suggests ways to improve anxiolytics and to develop drugs for other neurological disorders based on their specificity for GABA(A) receptor subtypes in distinct neuronal circuits. 相似文献
6.
Rabbit uterus as a source of renin 总被引:6,自引:0,他引:6
7.
A solid-phase competition ELISA for measuring antibody to foot-and-mouth disease virus 总被引:6,自引:0,他引:6
A solid-phase competition ELISA has been developed to measure antibodies to foot-and-mouth disease (FMD) virus and has been validated using an extensive range of sera from cattle. The assay uses polyclonal antisera and inactivated purified 146S antigens of FMD virus and was compared with the liquid-phase blocking ELISA and the virus neutralisation test on a range of serum sets. When examining test sera at a 1:5 dilution with a cut-off point of 30% inhibition of reaction, the solid-phase competition ELISA was as sensitive as the liquid-phase blocking ELISA for sera from infected or vaccinated animals. The limit of detection of the solid-phase ELISA was similar to that of the liquid-phase assay and both tests had lower limit of detection (i.e. were able to detect lower amounts of antibody) than the virus neutralisation test. The specificity of the solid-phase ELISA was considerably higher than that of the liquid-phase blocking ELISA and almost equivalent to that of the virus neutralisation test. The assay thus retains the sensitivity of the liquid-phase blocking ELISA whilst being easier to use, more robust and specific, and therefore offers an improvement for FMD virus antibody detection. 相似文献
8.
Kluger A Ferris SH Golomb J Mittelman MS Reisberg B 《Journal of geriatric psychiatry and neurology》1999,12(4):168-179
This study examined whether baseline neuropsychological performance in elderly assessed at a research clinic could accurately predict subsequent decline to dementia. Logistic regression analyses were applied to (1) 213 nondemented elderly with a Global Deterioration Scale (GDS) score of 1, 2, or 3, of whom 74 (35%) subsequently declined to any diagnosis of dementia, and (2) a diagnostically more restricted subset of this sample (N = 179), of whom 56 (31%) declined to a diagnosis of probable Alzheimer's disease (AD). The mean follow-up intervals were 3.8 and 3.7 years, respectively. A small set of baseline neuropsychological measures (especially a Paragraph Delayed Recall Test) significantly differentiated decliners from nondecliners to dementia or AD, after accounting for the contribution of age, sex, education, follow-up interval, and the rating of global clinical status. When examined in combination with the other factors or alone, the cognitive tests produced reasonably high specificities (91%-97%) and sensitivities (73%-89%). Using the obtained regression model, a similar level of classification accuracy was replicated on an independent sample of 119 nondemented elderly. A subanalysis of the high-risk GDS 3 subgroup indicated that cut scores from the paragraph test distinguished nondecliners from decliners (overall accuracies 87%-91%), implying that this assessment may accurately predict future cognitive status in elderly with mild cognitive impairment. 相似文献
9.
J A Ortega García D Carrizo Gallardo J Ferris i Tortajada M M P García J O Grimalt 《Archives of disease in childhood》2006,91(8):642-646
BACKGROUND: Exposure to organochlorine compounds (OCs) has been a subject of interest in recent years, given their potential neurotoxicity. Meconium is easily available and accumulates neurotoxicants and/or metabolites from the 12th week of gestation. AIMS: To determine whether neurotoxicants, specifically OCs, could be detected in serially collected meconium, and to compare the results with those obtained in cord blood samples. METHODS: A sample of cord blood and three serial stool samples were analysed in 10 newborns. Pentachlorobenzene (PeCB), hexachlorobenzene (HCB), polychlorinated biphenyls (PCBs), dichlorodiphenyl trichloroethane (p,p'-DDT) and its metabolite dichlorodiphenyl dichloroethylene (p,p'-DDE), and hexachlorocyclohexane isomers (alpha-, beta-, gamma-, and delta-HCH) were analysed by gas chromatography. RESULTS: From serial stool collection and analysis in newborns, there was an increase in the concentrations of HCB, p,p'-DDE, PCBs, and beta-HCH between the first and last stools of the newborn. Levels of DDT diminished as pregnancy progressed. Concentrations in cord blood were positively associated with concentrations in meconium for p,p'-DDE and beta-HCH. CONCLUSIONS: Meconium is a very useful instrument for the investigation of fetal exposure to neurotoxicants; serial collection and analysis of meconium should estimate the timing and degree of in utero exposure of the fetus to neurotoxicants. Analysis and interpretation of neurotoxicants in meconium results is a complex process. Measurement in meconium of a wide range of neurotoxic substances should facilitate early identification of harmful exposures, and enable rehabilitation and instigation of preventive measures. 相似文献
10.
Whitney P Witt Lisa Fortuna Eijean Wu Robert S Kahn Jonathan P Winickoff Paul A Pirraglia Timothy G Ferris Karen Kuhlthau 《Ambulatory Pediatrics》2006,6(3):145-151
OBJECTIVE: To determine the relative contribution of maternal psychological distress, maternal restraint use, and sociodemographic characteristics to the likelihood that a child would not be restrained in a motor vehicle. METHODS: We examined data on 6251 children aged 0-17 years from the 1998 National Health Interview Survey. The level of children's motor vehicle restraint use (low vs high) was examined by maternal psychological distress and motor vehicle restraint use. Multivariate regression analyses were used to model the odds of children's low use of motor vehicle restraints, controlling for potential confounders. RESULTS: According to maternal reports, more than 10% of children and nearly 13% of mothers reported low use of motor vehicle restraints. Multivariate analyses revealed that maternal use of restraints and psychological distress were both independently related to children's use of restraints, with maternal low use as the stronger correlate. Older children were more likely than younger children to be low users of motor vehicle restraints if the mother reported that she was a low user of restraints. Families with male children, black and Hispanic mothers, and 4 or more members reported lower use of restraints for their children. CONCLUSIONS: Children's low use of motor vehicle restraints was associated with low levels of maternal motor vehicle restraint use and maternal psychological distress. Moreover, maternal motor vehicle restraint practices become increasingly important as children age. Health care providers should consider maternal motor vehicle restraint use, maternal psychological distress, and child age in addition to sociodemographics when assessing children's motor vehicle safety. 相似文献