全文获取类型
收费全文 | 10334篇 |
免费 | 495篇 |
国内免费 | 56篇 |
专业分类
耳鼻咽喉 | 115篇 |
儿科学 | 176篇 |
妇产科学 | 221篇 |
基础医学 | 1183篇 |
口腔科学 | 258篇 |
临床医学 | 780篇 |
内科学 | 2827篇 |
皮肤病学 | 149篇 |
神经病学 | 1113篇 |
特种医学 | 298篇 |
外科学 | 1334篇 |
综合类 | 24篇 |
一般理论 | 3篇 |
预防医学 | 459篇 |
眼科学 | 204篇 |
药学 | 722篇 |
中国医学 | 14篇 |
肿瘤学 | 1005篇 |
出版年
2024年 | 9篇 |
2023年 | 64篇 |
2022年 | 144篇 |
2021年 | 264篇 |
2020年 | 164篇 |
2019年 | 211篇 |
2018年 | 241篇 |
2017年 | 214篇 |
2016年 | 241篇 |
2015年 | 260篇 |
2014年 | 351篇 |
2013年 | 525篇 |
2012年 | 760篇 |
2011年 | 782篇 |
2010年 | 420篇 |
2009年 | 408篇 |
2008年 | 716篇 |
2007年 | 760篇 |
2006年 | 747篇 |
2005年 | 701篇 |
2004年 | 693篇 |
2003年 | 615篇 |
2002年 | 554篇 |
2001年 | 70篇 |
2000年 | 70篇 |
1999年 | 56篇 |
1998年 | 110篇 |
1997年 | 76篇 |
1996年 | 78篇 |
1995年 | 76篇 |
1994年 | 73篇 |
1993年 | 64篇 |
1992年 | 45篇 |
1991年 | 33篇 |
1990年 | 36篇 |
1989年 | 29篇 |
1988年 | 19篇 |
1987年 | 21篇 |
1986年 | 21篇 |
1985年 | 18篇 |
1984年 | 19篇 |
1983年 | 18篇 |
1982年 | 17篇 |
1981年 | 24篇 |
1980年 | 11篇 |
1979年 | 8篇 |
1978年 | 8篇 |
1977年 | 6篇 |
1972年 | 5篇 |
1966年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
Lack of association between angiotensin converting enzyme polymorphism and sporadic Alzheimer's disease 总被引:3,自引:0,他引:3
Monastero R Caldarella R Mannino M Cefalù AB Lopez G Noto D Camarda C Camarda LK Notarbartolo A Averna MR Camarda R 《Neuroscience letters》2002,335(2):147-149
Epidemiological and pathogenetic evidences suggest a strong association between vascular risk factors and sporadic Alzheimer's disease (sAD). In agreement with the vascular hypothesis of AD, the role of various candidate genes for atherosclerosis has been investigated, leading to conflicting results. In order to clarify the significance of angiotensin-converting enzyme (ACE) gene insertion (I)/deletion (D) polymorphism in a group of patients with sAD, we conducted a case-control study including 149 cases and 149 age and sex matched controls. All subjects were genotyped for ACE and Apolipoprotein E (APOE). There were no significant differences in ACE genotype or allele frequencies between cases and controls, even after stratification for APOE4 carrier status. Our data suggest that the ACE I/D polymorphism is not associated to genetic susceptibility in sAD patients. 相似文献
62.
Riccardo Asero Alberto Tedeschi Maurizio Lorini Maria Gerosa Pierluigi Meroni Piersandro Riboldi 《Annals of allergy, asthma & immunology》2003,91(1):79-81
BACKGROUND: The nature of histamine-releasing factors involved in the pathogenesis of chronic idiopathic urticaria (CIU) is still controversial, since functional IgG autoantibodies specific for the high-affinity IgE receptor, Fc(epsilon)RI, can be detected in only 20% of patients showing a strong skin reactivity on the autologous serum skin test. The absence of systemic eosinophilia in CIU patients, along with the increase in mast cells in skin biopsy specimens, suggests a possible role for stem cell factor (SCF), the only cytokine/growth factor known to induce mediator release from human mast cells. OBJECTIVE: To investigate the possible role of SCF as a histamine-releasing factor in patients with CIU. METHODS: The SCF levels were measured in serum samples from 65 patients with CIU who scored strongly positive on the autologous serum skin test; of these patients, 32 had negative results and 33 had positive results on in vitro histamine release assay by a quantitative commercial sandwich immunoassay technique. Serum samples from 40 healthy subjects were used as controls. RESULTS: Serum SCF levels in all 65 CIU patients did not differ from those found in healthy controls. No difference in SCF levels was found between patients with positive and negative results on histamine release assay. CONCLUSIONS: An increase in serum SCF levels does not play a pathogenic role in CIU. 相似文献
63.
64.
65.
Silvano Adami Maurizio Rossini Nicoletta Zamberlan Francesco Bertoldo Romolo Dorizzi Vincenzo Lo Cascio 《Maturitas》1993,17(3):191-196
The transdermal and oral administration of estrogens for one year were compared with respect to the effects on lipid metabolism. Eighty-one postmenopausal women (1.5-3 years after menopause) were randomly divided into three groups. The first two groups received sequential estrogen treatment with either transdermal estradiol (Estraderm TTS, Ciba Geigy; 50 μg/day; 24 women) or 0.625 mg/day conjugated estrogens (Premarin, Wyeth; 20 subjects), respectively. In both groups medroxyprogesterone (10 mg/day per os) was added for 12 days of each cycle. Thirty-five subjects served as control group without therapy. No significant changes in the lipid profile was observed in control subjects after 1 year of follow-up. Serum triglycerides decreased significantly (-10.9 ± 26% S.D.; P < 0.05) in transdermal treated women, whereas it slightly rose in oral estrogen group. Comparable significant decreases in total and low density lipoprotein (LDL) cholesterol (mean range -6.5/-18.0%) were observed in women on estrogen replacement therapy. High density lipoprotein (HDL) cholesterol significantly diminished in transdermal estradiol group, but it rose slightly in the oral estrogen group. Thus the fraction of HDL cholesterol over LDL cholesterol did not change in the transdermal group whereas it significantly rose in subjects treated with oral estrogens. It remains to be established to what extent these differences on lipid metabolism are relevant for the prevention of cardiovascular diseases. 相似文献
66.
Postnatal development of dopamine receptor expression in rat peripheral blood lymphocytes. 总被引:1,自引:0,他引:1
Daniele Tomassoni Elena Bronzetti Franco Cantalamessa Fiorenzo Mignini Alberto Ricci Maurizio Sabbatini Seyed K Tayebati Damiano Zaccheo 《Mechanisms of ageing and development》2002,123(5):491-498
Postnatal development in the expression of dopamine D1-like and D2-like receptors was investigated in peripheral blood lymphocytes of male Wistar rats aged 1, 3, 4, 8, 12 and 16 weeks of age by radioligand binding assay techniques. Sample of frontal cortex, striatum and hippocampus were also investigated as reference tissues. The dopamine D1-like receptor antagonist [3H]SCH 23390 and the dopamine D2-like receptor agonist [3H]7-OH-DPAT were used as radioligands. The affinity (K(d)) of [3H]SCH 23390 or of [3H]7-OH-DPAT binding was unchanged in lymphocytes of rats of different age groups. The density (B(max)) of [3H]SCH 23390 binding sites increased from the 1st to the 3rd week of age, remained constant from the 3rd to the 8th week of age, and then increased slightly at 12 and 16 weeks of age. The B(max) value of [3H]7-OH-DPAT binding to lymphocytes increased from the 1st to the 3rd week of age, remained constant from the 3rd to the 4th week, increased again until the 12th week and then plateaued. Dopamine D1-like and D2-like receptor maturation in frontal cortex, hippocampus and striatum revealed an increased receptor density until the 4th week of age and a relative stabilization of receptor density values between the 4th to the 12th week depending on the area considered. Comparatively postnatal maturation of lymphocyte dopamine D1-like receptors displayed a pattern different from that of brain areas investigated, whereas maturation of D2-like receptors displayed a pattern similar to that of striatum. The quantitative and/or qualitative dissimilarities between development of lymphocyte and brain dopamine receptors suggest that from a developmental point of view lymphocyte dopamine receptors probably cannot be considered as a marker of homologous brain receptors. 相似文献
67.
Claudia Tonini Marco Segatto Francesca Martino Luisa Cigliano Martina Nazzaro Laura Barberio Maurizio Mandal Valentina Pallottini 《Nutrients》2021,13(1)
Background: A major problem of aging is the disruption of metabolic homeostasis. This is particularly relevant in the brain where it provokes neurodegeneration. Caloric restriction is a physiologic intervention known to delay the deleterious consequences of aging in several species ranging from yeast to mammals. To date, most studies on experimental models have started this dietary intervention from weaning, which is very difficult to be translated to human beings. Here, we study the effects of a more realistic dietary regimen in rats, starting at an advanced age and lasting for six months. Methods: we analyzed in the cortex and hippocampus, the proteins involved in the energetic balance of the cells, cholesterol metabolism, oxidative stress response, inflammation, synaptic impairment, and brain trophism. Results: our results suggest that caloric restriction in late life can revert only some age-related changes studied here. 相似文献
68.
69.
Claudia Tonini Marco Segatto Simona Bertoli Alessandro Leone Arianna Mazzoli Luisa Cigliano Laura Barberio Maurizio Mandal Valentina Pallottini 《Nutrients》2021,13(6)
Bisphenol A (BPA) is an organic chemical compound widely used for manufacturing plastics. BPA exposure originates principally from the diet, but it can also originate from dermal contact. In over 90% of individuals, including pregnant women, BPA is detectable in several body fluids. The effects of this exposure on the fetus are under active investigation in several research laboratories. The aim of our work was to study the impact of prenatal exposure to BPA in the liver of rat fetuses from a sex-dependent point of view. We particularly investigated the effects of prenatal BPA exposure on hepatic lipids because of their crucial role, not only for the liver, but also for the whole-body functions. Our results demonstrate that the liver of rat fetuses, in utero exposed to a very low dose of BPA (2.5 µg/kg/day), displays significant modulations with regard to proteins involved in cholesterol and fatty acid biosynthesis and trafficking. Moreover, an impact on inflammatory process has been observed. All these effects are dependent on sex, being observable only in female rat fetuses. In conclusion, this work demonstrates that maternal exposure to BPA compromises hepatic lipid metabolism in female offspring, and it also reveals the perspective impact of BPA on human health at doses currently considered safe. 相似文献
70.
Luvero Daniela Filippini Maurizio Salvatore Stefano Pieralli Annalisa Farinelli Miriam Angioli Roberto 《Lasers in medical science》2021,36(9):1837-1843
Lasers in Medical Science - Childbirth is a great change in woman life because of hormonal, physical and psychological alterations that are associated with this process. Dyspareunia and perineal... 相似文献