全文获取类型
收费全文 | 11344篇 |
免费 | 565篇 |
国内免费 | 59篇 |
专业分类
耳鼻咽喉 | 120篇 |
儿科学 | 202篇 |
妇产科学 | 238篇 |
基础医学 | 1306篇 |
口腔科学 | 268篇 |
临床医学 | 832篇 |
内科学 | 3064篇 |
皮肤病学 | 159篇 |
神经病学 | 1240篇 |
特种医学 | 349篇 |
外科学 | 1479篇 |
综合类 | 30篇 |
一般理论 | 3篇 |
预防医学 | 492篇 |
眼科学 | 216篇 |
药学 | 833篇 |
中国医学 | 16篇 |
肿瘤学 | 1121篇 |
出版年
2024年 | 10篇 |
2023年 | 66篇 |
2022年 | 159篇 |
2021年 | 284篇 |
2020年 | 172篇 |
2019年 | 227篇 |
2018年 | 276篇 |
2017年 | 232篇 |
2016年 | 261篇 |
2015年 | 288篇 |
2014年 | 384篇 |
2013年 | 567篇 |
2012年 | 818篇 |
2011年 | 851篇 |
2010年 | 446篇 |
2009年 | 436篇 |
2008年 | 763篇 |
2007年 | 808篇 |
2006年 | 792篇 |
2005年 | 738篇 |
2004年 | 749篇 |
2003年 | 657篇 |
2002年 | 593篇 |
2001年 | 100篇 |
2000年 | 97篇 |
1999年 | 80篇 |
1998年 | 126篇 |
1997年 | 90篇 |
1996年 | 87篇 |
1995年 | 84篇 |
1994年 | 81篇 |
1993年 | 69篇 |
1992年 | 67篇 |
1991年 | 51篇 |
1990年 | 52篇 |
1989年 | 50篇 |
1988年 | 39篇 |
1987年 | 30篇 |
1986年 | 38篇 |
1985年 | 27篇 |
1984年 | 27篇 |
1983年 | 23篇 |
1982年 | 24篇 |
1981年 | 30篇 |
1980年 | 15篇 |
1979年 | 10篇 |
1978年 | 11篇 |
1975年 | 10篇 |
1974年 | 10篇 |
1971年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
Marchini Maurizio; Manfredi Barbara; Tozzi Luca; Sacerdote Paola; Panerai Alberto; Fedele Luigi 《Human reproduction (Oxford, England)》1995,10(4):815-817
Dysmenorrhoea is a recurrent painful disease which causes physicaland psychological stress. The purpose of the present study wasto investigate whether there was a measurable derangement ofimmune cells and immune responses in women with severe primarydysmenorrhoea. On day 26 of one cycle and on days 1 and 3 ofthe following cycle we measured polyclonal, mitogen-inducedlymphocyte proliferation and -endorphin concentration in peripheralblood mononuclear cells obtained from 16 infertile women withnormal pelvis, of whom eight had and eight did not have thedisorder. In women with dysmenorrhoea, polyclonal mitogen-inducedlymphocyte proliferation was lower than in controls on all 3days considered, but the difference was statistically significantonly on day 26 (43 605 ± 9876 µg/ml versus 67 305± 15 249 µg/ml; P < 0.01). Monocyte -endorphinconcentrations in the patients with dysmenorrhoea were significantlyelevated on day 3 compared to controls (67.8 ± 24.3 pg/106cells versus 29.7 ± 6.9 pg/106 cells; P < 0.05). Ourresults demonstrate that immune responses are modified in patientswith primary dysmenorrhoea. These effects are independent ofcirculating hormone concentrations and are consistent with therole of dysmenorrhoea as a stressful event. 相似文献
93.
Maurizio Severino Anja F. Pedersen Viktorija Trajkovska Ellen Christensen Rasmus Lohals Lone M. Veng Gitte M. Knudsen Susana Aznar 《Neuroscience letters》2007
Although loss of cholinergic neurons in the basal forebrain is considered a key initial feature in Alzheimer's disease (AD), changes in other transmitter systems, including serotonin and 5-HT2A receptors, are also associated with early AD. The aim of this study was to investigate whether elimination of the cholinergic neurons in the basal forebrain directly affects 5-HT2A receptor levels. For this purpose intraventricular injection of the selective immunotoxin 192 IgG-Saporin was given to rats in doses of either 2.5 or 5 μg. The rats were sacrificed after 1, 2, 4 and 20 weeks. 5-HT2A protein levels were determined by western techniques in frontal cortex and hippocampus. A significant 70% downregulation in frontal cortex and a 100% upregulation in hippocampus of 5-HT2A receptor levels were observed 20 weeks after the cholinergic lesion when using the highest dose of 192 IgG-Saporin. Our results show that cholinergic deafferentation leads to decreased frontal cortex and increased hippocampal 5-HT2A receptor levels. This is probably a consequence of the interaction between the serotonergic and the cholinergic system that may vary depending on the brain region. 相似文献
94.
Fava M Alpert JE Carmin CN Wisniewski SR Trivedi MH Biggs MM Shores-Wilson K Morgan D Schwartz T Balasubramani GK Rush AJ 《Psychological medicine》2004,34(7):1299-1308
BACKGROUND: Anxious depression, defined as Major Depressive Disorder (MDD) with high levels of anxiety symptoms, may represent a relatively common depressive subtype, with distinctive features. OBJECTIVE: The objective of this study was to determine the prevalence of anxious depression and to define its clinical correlates and symptom patterns. METHOD: Baseline clinical and sociodemographic data were collected on 1450 subjects participating in the STAR*D study. A baseline Hamilton Rating Scale for Depression (HAM-D) Anxiety/ Somatization factor score of > or =7 was considered indicative of anxious depression. The types and degree of concurrent psychiatric symptoms were measured using the Psychiatric Diagnostic Screening Questionnaire (PDSQ), by recording the number of items endorsed by study participants for each diagnostic category. MDD symptoms were assessed by clinical telephone interview with the 30-item Inventory of Depressive Symptomatology (IDS-C30). RESULTS: The prevalence of anxious depression in this population was 46 %. Patients with anxious MDD were significantly more likely to be older, unemployed, less educated, more severely depressed, and to have suicidal ideation before and after adjustment for severity of depression. As far as concurrent psychiatric symptoms are concerned, patients with anxious depression were significantly more likely to endorse symptoms related to generalized anxiety, obsessive compulsive, panic, post-traumatic stress, agoraphobia, hypochondriasis, and somatoform disorders before and after adjustment for severity of depression. Anxious-depression individuals were also significantly less likely to endorse IDS-C30 items concerning atypical features, and were significantly more likely to endorse items concerning melancholic/endogenous depression features. CONCLUSION: This study supports specific clinical and sociodemographic correlates of MDD associated with high levels of anxiety (anxious depression). 相似文献
95.
96.
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
97.
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
98.
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
99.
100.
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