全文获取类型
收费全文 | 60854篇 |
免费 | 3925篇 |
国内免费 | 1105篇 |
专业分类
耳鼻咽喉 | 863篇 |
儿科学 | 1513篇 |
妇产科学 | 796篇 |
基础医学 | 2367篇 |
口腔科学 | 1299篇 |
临床医学 | 8021篇 |
内科学 | 7535篇 |
皮肤病学 | 837篇 |
神经病学 | 4074篇 |
特种医学 | 1373篇 |
外科学 | 7880篇 |
综合类 | 8326篇 |
一般理论 | 6篇 |
预防医学 | 7475篇 |
眼科学 | 687篇 |
药学 | 6670篇 |
117篇 | |
中国医学 | 2713篇 |
肿瘤学 | 3332篇 |
出版年
2024年 | 133篇 |
2023年 | 1075篇 |
2022年 | 2214篇 |
2021年 | 2666篇 |
2020年 | 2612篇 |
2019年 | 2581篇 |
2018年 | 2544篇 |
2017年 | 2175篇 |
2016年 | 2374篇 |
2015年 | 2209篇 |
2014年 | 4925篇 |
2013年 | 5418篇 |
2012年 | 3933篇 |
2011年 | 4341篇 |
2010年 | 3567篇 |
2009年 | 3101篇 |
2008年 | 2977篇 |
2007年 | 2777篇 |
2006年 | 2258篇 |
2005年 | 1981篇 |
2004年 | 1648篇 |
2003年 | 1467篇 |
2002年 | 1202篇 |
2001年 | 1116篇 |
2000年 | 807篇 |
1999年 | 636篇 |
1998年 | 528篇 |
1997年 | 382篇 |
1996年 | 346篇 |
1995年 | 266篇 |
1994年 | 257篇 |
1993年 | 185篇 |
1992年 | 162篇 |
1991年 | 128篇 |
1990年 | 104篇 |
1989年 | 88篇 |
1988年 | 76篇 |
1987年 | 76篇 |
1986年 | 62篇 |
1985年 | 110篇 |
1984年 | 76篇 |
1983年 | 46篇 |
1982年 | 45篇 |
1981年 | 33篇 |
1980年 | 49篇 |
1979年 | 38篇 |
1978年 | 14篇 |
1975年 | 13篇 |
1974年 | 11篇 |
1972年 | 13篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
P. Kiviskk W. Tian S. Fredrikson H. Link M. Sderstrm 《European journal of neurology》1997,4(5):460-467
Beta-interferon (IFN-β) is a promising treatment in multiple sclerosis (MS), reducing the exacerbation rate and MRI lesion burden, as well as the disease progression in relapsing-remitting MS. IFN-β was originally defined by its antiviral effects, but the interest has recently been focused on its immunomodulatory properties. Myelin basic protein (MBP) is one of several autoantigens considered to be the target for autoaggressive immune responses, which eventually might lead to the development of MS. To study in-vitro effects of IFN-β1b on MBP induced cytokine expression, mRNA for the Th1 cytokines IFN-γ and TNF-α, the Th2 related IL-4 and IL-6, the cytolytic perforin and the immune response downregulating TGF-β was measured with in situ hybridization after culture of blood mononuclear cells (MNC) in the presence and absence of MBP. Numbers of cells expressing IFN-γ, TNF-α, perforin and IL-4 mRNA were significantly suppressed after culture with 10 U/ml IFN-β1b. No such effect was seen on MBP induced IL-6 or TGF-β mRNA expression. These observations suggest that one of the major effects of IFN-β1b is the induction of a shift in the cytokine mRNA profile towards a more immunosuppressive pattern. In parallel in vitro tests, the control substance dexametasone (40 μg/ml) reduced the numbers of cells expressing mRNA for all cytokines under study with the exception of TGF-β, to an extent equal to or even more pronounced than IFN-β1b. 相似文献
32.
Abstract: Most individuals concerned about hereditary breast cancer risk will neither order nor benefit from genetic testing at the present time. Many will, however, seek information about their risk and testing. Risk assessment services, in addition to providing information about hereditary risk and genetic testing, need also to include assessment of non-hereditary risks, information about how to evaluate risks, early detection modalities, the etiology of cancer, and assistance in devising follow-up health care plans. Psychosocial factors, particularly those pertaining to the individual's past history with illness and beliefs about causes and prognosis, must be taken into account to provide relevant information that is understood. A case history with examples of some of the types of information that lead to informed consent in a cancer risk assessment setting is provided. 相似文献
33.
34.
The natural history of untreated phenylketonuria over 20 years 总被引:1,自引:0,他引:1
Fifty-one adults with untreated phenylketonuria (PKU), have been reviewed after a 20 year interval, at ages ranging from 28.8 to 71.8 years. Five died of causes unrelated to PKU. Three severely affected individuals had shown a progressive loss of motor function and three had developed epilepsy, bringing the total with this problem to 12. No loss of abilities was apparent in 41 patients. Other health problems, including cataracts, were not frequent. Serum phenylalanine levels had decreased over the 20 year period. Untreated PKU does not generally cause progressive loss of abilities during adult life. 相似文献
35.
Tibor P. Palfai 《Cognitive therapy and research》2002,26(3):317-333
This study examined the association between smoking outcome expectancy accessibility and smoking behavior. Daily smokers completed a smoking expectancy accessibility task in which they made timed judgments to a series of positive consequences of smoking either after 6 hr deprivation or within 10 min of smoking. Participants then completed a questionnaire battery that contained assessments of smoking behavior and smoking outcome expectancies. Results of hierarchical regression analyses showed that expectancy accessibility was associated with the number of cigarettes smoked per day even when controlling for corresponding questionnaire measures of smoking expectancies. Moreover, smoking expectancy accessibility predicted urge to smoke ratings following exposure to a smoking cue after controlling for the effects of deprivation. Findings suggest that smoking expectancy accessibility may play a central role in smoking behavior and that individual differences in this attribute may be assessed directly through reaction time assessment. 相似文献
36.
HCVRNA阳性的丙型肝炎46例,均经临床和/或组织学确诊。治疗组24例用IFNa-nl或a-2b3×106IU,隔日一次;对照组22例用一般护肝药物。HCVRNA12周转阴率治疗组为83.3%,对照组为9.0%(P<0.001)。ALT和AST复常率治疗组也优于对照组(P<0.05)。随访观察满48周者治疗组15例中HCVRNA持续转阴11例(73.3%).对照组5例均持续阳性。治疗组中5例做了Ⅰ~Ⅲ型HCV基因分型,结果均为Ⅱ型。同时对急、慢性丙型肝炎的发病过程和病理诊断作了讨论。 相似文献
37.
右室梗死临床诊疗新进展 总被引:3,自引:0,他引:3
右室梗死过去只能在尸检时确诊。20世纪70年代以来,随着医师诊断水平和检测设备的不断进步,临床上已能在患者生病确诊右室梗死[1],现对国内有关资料综述如下,仅供同道参考。1右心室栓塞发病及研究进展右心室心肌梗死是指累及右心室壁的心肌梗死。临床上相对少见。尸检病例中,单独右心室梗死不到3%,左心室心肌梗死同时延伸至右心室者占43%[1]。按其梗死发生部位分为:右心室游离下壁;右心室游离前壁;右心室游离下壁、前壁及右心室乳头肌。受累部位取决于受损血管的来源,右心室前壁和前乳头肌由左前支和圆锥支供血,前者分支较多,一般不会全部阻… 相似文献
38.
超声对宫角妊娠的诊断及治疗意义 总被引:5,自引:0,他引:5
目的 探讨对误诊率高,危害大的罕见特殊部位宫角妊娠的诊断和治疗。方法 对我院1991-2001年收治的宫角妊娠临床资料进行回顾性分析。结果 宫角妊娠17例中误诊宫内妊娠行人流失败4例。13例行腹部手术,3例行B超监视下人流术,1例行子宫动脉栓塞术。结论 宫角妊娠临床诊断困难,误诊率高,破裂后造成迅猛的腹腔内出血,应提高对少见部位宫角妊娠的认识,减少孕妇死亡。 相似文献
39.
D. Caroline Blanchard Jon K. Shepherd R. J. Rodgers Robert J. Blanchard 《Psychopharmacology》1992,106(4):531-539
The Proxemics/Activity test and the Eat/Drink test, two components of the Anxiety/Defense Test Battery, were developed to measure defensive reactions to situations associated with a natural predator (cat). In the present studies the behavioral effects of 8-OH-DPAT treatment (0.01–1.0 mg/kg, SC) were entirely consistent with anxiety/fear reduction. These effects included an increase in time spent near the cat compartment, and a complimentary decrease in time spent farthest from this compartment, together with an increase in transits and locomote behavior. 8-OH-DPAT (1.0 mg/kg) also increased eat frequencies and durations (highly preferred food) both during and following cat presentation, without influencing drinking. This finding is discussed with reference to previous findings with 8-OH-DPAT in studies assessing both food intake and anxiolysis. Interestingly, 8-OH-DPAT was more potent in a majority of its effects in female subjects, a finding consistent with recent neurochemical data. These findings provide important behavioral evidence for a sexual differentiation in 5-HT function, and support the case for greater emphasis on female subjects in animal models of anxiety.Supported by NIH MH42803 and RCMI Grants RR03061 and RR01825 相似文献
40.