全文获取类型
收费全文 | 65110篇 |
免费 | 7494篇 |
国内免费 | 1156篇 |
专业分类
耳鼻咽喉 | 390篇 |
儿科学 | 1959篇 |
妇产科学 | 1303篇 |
基础医学 | 3658篇 |
口腔科学 | 1777篇 |
临床医学 | 9872篇 |
内科学 | 12239篇 |
皮肤病学 | 627篇 |
神经病学 | 4892篇 |
特种医学 | 1251篇 |
外国民族医学 | 1篇 |
外科学 | 6375篇 |
综合类 | 5578篇 |
现状与发展 | 8篇 |
一般理论 | 15篇 |
预防医学 | 12830篇 |
眼科学 | 785篇 |
药学 | 5006篇 |
92篇 | |
中国医学 | 728篇 |
肿瘤学 | 4374篇 |
出版年
2024年 | 236篇 |
2023年 | 1720篇 |
2022年 | 2804篇 |
2021年 | 3882篇 |
2020年 | 3713篇 |
2019年 | 3569篇 |
2018年 | 3475篇 |
2017年 | 3233篇 |
2016年 | 3153篇 |
2015年 | 2817篇 |
2014年 | 4977篇 |
2013年 | 6272篇 |
2012年 | 3541篇 |
2011年 | 3862篇 |
2010年 | 2913篇 |
2009年 | 2880篇 |
2008年 | 2907篇 |
2007年 | 2658篇 |
2006年 | 2277篇 |
2005年 | 2028篇 |
2004年 | 1635篇 |
2003年 | 1366篇 |
2002年 | 1175篇 |
2001年 | 1071篇 |
2000年 | 816篇 |
1999年 | 669篇 |
1998年 | 603篇 |
1997年 | 509篇 |
1996年 | 432篇 |
1995年 | 382篇 |
1994年 | 345篇 |
1993年 | 308篇 |
1992年 | 253篇 |
1991年 | 208篇 |
1990年 | 161篇 |
1989年 | 144篇 |
1988年 | 120篇 |
1987年 | 103篇 |
1986年 | 87篇 |
1985年 | 117篇 |
1984年 | 89篇 |
1983年 | 40篇 |
1982年 | 59篇 |
1981年 | 43篇 |
1980年 | 34篇 |
1979年 | 24篇 |
1978年 | 10篇 |
1977年 | 11篇 |
1975年 | 8篇 |
1974年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
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
32.
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
33.
Pierre Pradat 《Genetic epidemiology》1994,11(2):131-140
During the period 1981–1986, 1605 infants presenting a major congenital heart defect (CHD) were identified in Sweden. Using the personal identification numbers of the mothers, 1507 of them could be linked to the Medical Birth Registry and two controls were selected for each infant. For this total of 4521 infants, 2686 postoccurrence sibs born during the period 1981–1989 were identified from the Medical Birth Registry. The tendency to have one or more sibs was higher among cases than among controls and was correlated to the life status of the proband. This tendency did not vary according to the type of CHD when controlling for life status. The prevalence at birth of CHD was almost four times higher among sibs of CHD infants than among sibs of normal infants. The tendency to have a sib with an extracardiac malformation did not differ between CHD probands and normal probands. The importance of only including births occurring after the proband when evaluating recurrence risks is stressed. © 1994 Wiley-Liss, Inc. 相似文献
34.
In a sample of 55 consecutive methadone maintenance admissions to our clinic, 42% were diagnosed with antisocial personality disorder (ASPD) using the National Institute of Mental Health Diagnostic Interview Schedule NIMH DIS. Individuals with ASPD exhibited greater risk for HIV infection as defined by more sexual contacts, needle use and equipment sharing. Data at 1 year follow-up were obtained on this group of patients. The objective was to compare the ASPD and non-ASPD groups with regards to demographics, drug abuse history, outcome and retention in treatment. There were no significant differences between the groups on any demographic or treatment outcome variables. Survival analysis indicated that there were no group differences in treatment retention. In conclusion, although there were no differences in treatment outcome between ASPD and non-ASPD groups it is possible that ASPD patients who drop out of treatment will be at higher risk for contracting and spreading HIV within the IV drug using population. These data also suggest that in this population the diagnosis of ASPD using primarily behavioral traits as measured in the NIMH-DIS-III, has little utility in predicting treatment outcome. 相似文献
35.
Marc G Weisskopf Honglei Chen Michael A Schwarzschild Ichiro Kawachi Alberto Ascherio 《Movement disorders》2003,18(6):646-651
Anxiety disorders are common in Parkinson's disease (PD). However, the risk of PD among people with anxiety has not been examined in a prospective cohort study. We examined this relation prospectively within the Health Professionals Follow-Up Study, a cohort of US male health professionals. In 1988, anxiety was assessed using the Crown-Crisp phobic anxiety index in 35,815 men without PD, stroke, or cancer at baseline. There were 189 incident cases of PD during 12 years of follow-up. After adjusting for age, smoking, and caffeine intake, the relative risk of PD among men with the highest level of anxiety (Crown-Crisp index scores of 4 and above) was 1.5 (95% CI = 1.0-2.1; P-trend = 0.01) compared to men with the lowest level of anxiety. This positive association persisted after excluding cases of PD with onset in the first 2 years of follow-up. Use of anxiolytic medication was also associated with an elevated risk of PD (RR= 1.6; 95% CI = 0.9-3.1), but adjusting for this potential confounder did not materially affect the association between anxiety and risk of PD. Our results suggest that anxiety is a risk factor for PD. Whether this association is causal or the result of shared underlying biology remains a question. 相似文献
36.
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
37.
目的 :探讨夜间电子生物阻抗测量装置 (NEVA)在阴茎勃起功能障碍的诊断中的应用价值。方法 :对 4 1例主诉阴茎勃起功能障碍者 (障碍组 ) 19例主诉无勃起功能障碍但有射精障碍者 (无障碍组 )进行NEVA检测。结果 :障碍组夜间试验中的夜间勃起的次数、阴茎勃起的最大体积改变、最长持续时间等客观指标均要差于无障碍组 ,差异有统计学意义 (P <0 .0 1)。结论 :NEVA为非侵入性检测、可鉴别心理性阴茎勃起功能障碍和严重的器质性勃起功能障碍 ,且对勃起功能障碍的定性和定量具有一定的客观性。 相似文献
38.
39.
Risk factors for predicting recurrences of febrile seizures were studied in an unselected series of 169 children after their first febrile seizure. Follow-up data covering 2.1–6.8 (mean 3.8) years from the first febrile seizure were available from 167 of them (98.8%) including 72 girls. Altogether 35/167 (21.0%, 95% confidence intervals (CI) 14.6% to 29.1%) had further febrile seizures, and multivariate logistic regression analysis showed the number of febrile episodes (p = 0.011) and the occurrence of such seizures among first degree relatives (p = 0.015, relative risk 3.75, CI 1.22 to 11.5) to be significant risk factors for recurrences. Our findings indicate that more emphasis should be placed on preventing febrile episodes rather than concentrating only on preventing seizures with antiepileptic therapy. 相似文献
40.
D. A. Basketter E. W. Scholes M. Cumberbatch C. D. Evans I. Kimber 《Contact dermatitis》1992,27(4):209-213
The guinea pig maximization test (GPMT) has proven to be a valuable tool for the identification of the skin sensitization potential of chemicals. The method identifies a hazard which can lead in the EC to compulsory labelling of that chemical. In the present study, data on sulphanilic acid derived from the GPMT has been compared with results from a second guinea pig assay (the cumulative contact enhancement test) and the murine local lymph node assay, both of which require only topical application of chemical. Except for the GPMT, no test identified any sensitizing activity associated with exposure to sulphanilic acid. These latter results are consistent with the experience gained from substantial human exposure in an occupational setting and from which no cases of allergic contact dermatitis to sulphanilic acid have arisen over a 20-year period. In consequence, it is questioned which test protocol in practice has given the more accurate identification of sensitization hazard relevant to man. 相似文献