全文获取类型
收费全文 | 139133篇 |
免费 | 9754篇 |
国内免费 | 238篇 |
专业分类
耳鼻咽喉 | 1296篇 |
儿科学 | 3898篇 |
妇产科学 | 2912篇 |
基础医学 | 21635篇 |
口腔科学 | 3781篇 |
临床医学 | 11758篇 |
内科学 | 27897篇 |
皮肤病学 | 2386篇 |
神经病学 | 13707篇 |
特种医学 | 5646篇 |
外国民族医学 | 20篇 |
外科学 | 17722篇 |
综合类 | 586篇 |
现状与发展 | 1篇 |
一般理论 | 123篇 |
预防医学 | 15326篇 |
眼科学 | 2241篇 |
药学 | 8301篇 |
中国医学 | 250篇 |
肿瘤学 | 9639篇 |
出版年
2023年 | 590篇 |
2022年 | 983篇 |
2021年 | 2089篇 |
2020年 | 1537篇 |
2019年 | 2222篇 |
2018年 | 2788篇 |
2017年 | 2363篇 |
2016年 | 2612篇 |
2015年 | 2895篇 |
2014年 | 3954篇 |
2013年 | 5194篇 |
2012年 | 7960篇 |
2011年 | 8021篇 |
2010年 | 4211篇 |
2009年 | 4381篇 |
2008年 | 7181篇 |
2007年 | 7381篇 |
2006年 | 7116篇 |
2005年 | 6768篇 |
2004年 | 5851篇 |
2003年 | 5565篇 |
2002年 | 5014篇 |
2001年 | 4868篇 |
2000年 | 4800篇 |
1999年 | 4337篇 |
1998年 | 1758篇 |
1997年 | 1474篇 |
1996年 | 1543篇 |
1995年 | 1246篇 |
1994年 | 1164篇 |
1993年 | 1081篇 |
1992年 | 2972篇 |
1991年 | 2717篇 |
1990年 | 2603篇 |
1989年 | 2432篇 |
1988年 | 2243篇 |
1987年 | 1958篇 |
1986年 | 1863篇 |
1985年 | 1780篇 |
1984年 | 1252篇 |
1983年 | 1090篇 |
1982年 | 583篇 |
1981年 | 513篇 |
1979年 | 950篇 |
1978年 | 578篇 |
1977年 | 504篇 |
1974年 | 496篇 |
1973年 | 489篇 |
1972年 | 481篇 |
1971年 | 452篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
E S C Korf E C W van Straaten F-E de Leeuw W M van der Flier F Barkhof L Pantoni A M Basile D Inzitari T Erkinjuntti L-O Wahlund E Rostrup R Schmidt F Fazekas P Scheltens 《Diabetic medicine》2007,24(2):166-171
HYPOTHESIS: Based on recent findings on the association between vascular risk factors and hippocampal atrophy, we hypothesized that hypertension and diabetes mellitus (DM) are associated with medial temporal lobe atrophy (MTA) in subjects without disability, independent of the severity of white matter hyperintensities. METHODS: In the Leukoaraiosis And DISability in the elderly (LADIS) study, we investigated the relationships between DM, hypertension, blood pressure and MTA in 582 subjects, stratified by white matter hyperintensity severity, using multinomial logistic regression. MTA was visually scored for the left and right medial temporal lobe (score 0-4), and meaned. RESULTS: Mean age was 73.5 years (sd 5.1), 54% was female. Of the subjects, 15% had DM, and 70% had a history of hypertension. The likelihood of having MTA score 3 was significantly higher in subjects with DM (OR 2.9; 95% CI: 1.1-7.8) compared with an MTA score of 0 (no atrophy). The odds ratio for MTA score 2 was not significantly increased (OR 1.8; CI: 0.9-4). Systolic and diastolic blood pressure and a history of hypertension were not associated with MTA. There was no interaction between DM and hypertension. Stratification on white matter hyperintensities (WMH) did not alter the associations. CONCLUSION: Our study strengthens the observation that MTA is associated with DM, independently of the amount of small vessel disease as reflected by WMH. 相似文献
52.
53.
Anneloes Dirks Lucianne Groenink Koen G C Westphal Jocelien D A Olivier P Monika Verdouw Jan van der Gugten Mark A Geyer Berend Olivier 《Neuropsychopharmacology》2003,28(10):1790-1798
Chronically elevated levels of corticotropin-releasing factor (CRF) in transgenic mice overexpressing CRF in the brain (CRF-OE) appear to be associated with alterations commonly associated with major depressive disorder, as well as with sensorimotor gating deficits commonly associated with schizophrenia. In the present study, we tested the hypothesis that antipsychotics may be effective in normalizing prepulse inhibition (PPI) of acoustic startle in CRF-OE mice, which display impaired sensorimotor gating compared to wild-type (WT) mice. The typical antipsychotic haloperidol and atypical antipsychotic risperidone improved PPI in the CRF-OE mice, but were ineffective in WT mice. The atypical antipsychotic clozapine did not influence PPI in CRF-OE mice, but reduced gating in WT mice. This effect of clozapine in the CRF-OE mice may thus be regarded as a relative improvement, consistent with the observed effect of haloperidol and risperidone. As expected, the anxiolytic, nonantipsychotic chlordiazepoxide was devoid of any effect. All four compounds dose-dependently reduced the acoustic startle response irrespective of genotype. These results indicate that antipsychotic drugs are effective in improving startle gating deficits in the CRF-OE mice. Hence, the CRF-OE mouse model may represent an animal model for certain aspects of psychotic depression, and could be a valuable tool for research addressing the impact of chronically elevated levels of CRF on information processing. 相似文献
54.
Leon M van den Toorn 《Annals of allergy, asthma & immunology》2004,92(6):589-94; quiz 595-7, 658
OBJECTIVE: To determine whether inhaled corticosteroids should be prescribed to patients with milder forms of asthma and whether markers of airway inflammation should be considered when making therapy decisions. DATA SOURCES: A PubMed search was performed of the English-language literature published in the preceding 10 years (January 1, 1993, through December 31, 2003) concerning epidemiology, pathophysiology, therapy, and prognosis of mild intermittent asthma, with asthma, mild, and intermittent as indexing terms. STUDY SELECTION: All relevant studies including author's expert opinions were selected. RESULTS: Several studies have addressed the question of a possible benefit of maintenance therapy (ie, inhaled steroids) in patients with mild intermittent asthma. Although a diminishing effect on airway inflammation has been widely demonstrated, even in patients with mild disease, the impact of inhaled steroids on the long-term prognosis is much less clear. For patients with mild disease who are long-term inhaled steroid users, alternative therapy strategies, including low-dose inhaled steroids and leukotriene receptor antagonists, have been advocated. CONCLUSIONS: Mild intermittent asthma is a disease characterized not only by infrequent symptoms and normal lung function but also by chronic airway inflammation, possibly resulting in irreversible airflow limitation if left unattended. Therefore, maintenance therapy, such as (low-dose) inhaled steroids or leukotriene receptor antagonists, should be considered in patients with mild disease. Future studies should give more insight into the impact of prolonged anti-inflammatory therapy on the long-term prognosis of mild intermittent asthma patients. Whether results from these studies will justify a more aggressive treatment for these patients remains to be answered. 相似文献
55.
R. J. Bosma A. J. Kwakernaak J. J. Homan van der Heide P. E. de Jong G. J. Navis 《American journal of transplantation》2007,7(3):645-652
Obesity is a risk factor for renal graft loss. Higher body mass index (BMI) in native kidneys is associated with glomerular hyperfiltration. Whether higher BMI in renal transplants is associated with hyperfiltration is unknown. We investigated the impact of BMI on renal hemodynamics 1 year post-transplant. We analyzed glomerular filtration rate (GFR, (125)I-iothalamate) and effective renal plasma flow (ERPF, (131)I-hippurate) in 838 kidney transplants. Data were analyzed for all patients and for the subpopulation without diabetes. Long-term impact of BMI and renal hemodynamics were explored by Cox-regression. With higher BMI GFR and filtration fraction (FF) increased significantly. Multivariate analysis supported impact of BMI on GFR (adjusted r(2) of the model 0.275) and FF (adjusted r(2) of the model 0.158). This association was not explained by diabetes mellitus. On Cox-regression analysis, lower GFR and higher FF were independent determinants of overall graft loss and graft loss by patient mortality. Lower GFR and higher BMI were determinants of death-censored graft loss, with borderline contribution of higher FF. In renal transplants higher BMI is independently associated with higher GFR and FF one year posttransplant, suggesting glomerular hyperfiltration with altered afferent-efferent balance. Mechanisms underlying the long-term prognostic impact of hyperfiltration deserve further exploration. 相似文献
56.
Nienhaus A. Kromark K. Raulf-Heimsoth M. van Kampen V. Merget R. 《Trauma und Berufskrankheit》2007,10(1):75-77
Trauma und Berufskrankheit - Die Vermeidung gepuderter Latexhandschuhe gilt als wichtige Maßnahme zur Prävention von latexbedingten Haut- und Atemwegsallergien bei Beschäftigten im... 相似文献
57.
58.
59.
60.
Contributions of ovarian failure and aging to blood pressure in normotensive perimenopausal women: a mixed longitudinal study 总被引:1,自引:0,他引:1
Epidemiologic studies have shown that blood pressure increases more rapidly in middle-aged women than in middle-aged men. Whether or not ovarian failure contributes to this rapid rise is still not clear. In a follow-up study begun in 1979 and to continue for 10 years, the blood pressure of 193 healthy normotensive perimenopausal women, who lived in the mixed rural/industrial community of Ede, the Netherlands and who were initially aged between 49 and 56 years, was measured annually. During the course of the study, the onset of menopause of each participant could be established. Because of the mixed longitudinal design of the study, it was possible to evaluate the effects of both chronologic aging and time pre- or postmenopause on blood pressure. After the first seven years of follow-up, it was demonstrated that blood pressure did not increase in 168 women whose body weight was relatively stable. After multivariate analyses, systolic as well as diastolic pressure showed a significant negative relation (slope, 1.34 mmHg per year and 0.63 mmHg per year, respectively) with the years since menopause. On the other hand, the observed positive relation (slope, 0.81 mmHg per year) of systolic pressure with chronologic aging was not significant. No consistent association was found between diastolic pressure and chronologic aging. It is concluded that menopause cannot be regarded as a cause of hypertension; on the contrary, ovarian failure appears to have a protective effect on the increase in blood pressure as a result of chronologic aging. on the increase in blood pressure as a result of chronologic aging. 相似文献