全文获取类型
收费全文 | 1569篇 |
免费 | 149篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 28篇 |
儿科学 | 43篇 |
妇产科学 | 45篇 |
基础医学 | 267篇 |
口腔科学 | 81篇 |
临床医学 | 155篇 |
内科学 | 379篇 |
皮肤病学 | 50篇 |
神经病学 | 96篇 |
特种医学 | 27篇 |
外科学 | 144篇 |
综合类 | 30篇 |
一般理论 | 1篇 |
预防医学 | 144篇 |
眼科学 | 1篇 |
药学 | 170篇 |
中国医学 | 2篇 |
肿瘤学 | 59篇 |
出版年
2023年 | 9篇 |
2021年 | 22篇 |
2020年 | 20篇 |
2019年 | 32篇 |
2018年 | 32篇 |
2017年 | 18篇 |
2016年 | 23篇 |
2015年 | 32篇 |
2014年 | 34篇 |
2013年 | 58篇 |
2012年 | 71篇 |
2011年 | 84篇 |
2010年 | 42篇 |
2009年 | 49篇 |
2008年 | 83篇 |
2007年 | 92篇 |
2006年 | 89篇 |
2005年 | 74篇 |
2004年 | 74篇 |
2003年 | 71篇 |
2002年 | 59篇 |
2001年 | 48篇 |
2000年 | 39篇 |
1999年 | 34篇 |
1998年 | 17篇 |
1994年 | 18篇 |
1993年 | 12篇 |
1992年 | 37篇 |
1991年 | 38篇 |
1990年 | 28篇 |
1989年 | 21篇 |
1988年 | 20篇 |
1987年 | 34篇 |
1986年 | 22篇 |
1985年 | 34篇 |
1984年 | 19篇 |
1983年 | 20篇 |
1982年 | 9篇 |
1981年 | 11篇 |
1979年 | 17篇 |
1978年 | 8篇 |
1977年 | 9篇 |
1976年 | 10篇 |
1975年 | 12篇 |
1974年 | 10篇 |
1973年 | 10篇 |
1972年 | 15篇 |
1971年 | 16篇 |
1970年 | 14篇 |
1969年 | 9篇 |
排序方式: 共有1722条查询结果,搜索用时 328 毫秒
61.
62.
Mazda Adli Katja Wiethoff Christopher Baethge Andrea Pfennig Thomas Stamm Michael Bauer 《International journal of psychiatry in clinical practice》2013,17(3):202-209
Objective. Depression with psychotic features is a severe subtype of major depression associated with the presence of delusions, hallucinations and specific neurobiological features. Despite clinical consensus and guideline recommendations, data comparing the efficacy of combining antipsychotics with antidepressants compared to antidepressants alone remain inconclusive. The aim of the study was to investigate effectiveness and tolerability of the atypical antipsychotic olanzapine in acute depression with psychotic features. Methods. Seventeen inpatients with major depressive disorder with psychosis (MDDp) were treated with a combination of an antidepressant and olanzapine for 6 weeks in a prospective open-label study. Depressive and psychotic symptoms, extrapyramidal and general side effects were assessed every 2 weeks. Sixteen patients were eligible for final analysis. Results. The Brief Psychiatric Rating Scale (BPRS) showed a 30% symptom reduction after week 2, a 45% symptom reduction after week 4 and no considerable improvement thereafter. Depressive symptoms (Bech–Rafaelsen Melancholia Scale, BRMS) receded by 37% after week 2 and 50% after week 4. No extrapyramidal side effects occurred. Conclusion. Olanzapine is effective and tolerable in combination with an antidepressant in an MDDp inpatient sample. The results concur with data supporting good efficacy in negative and depressive symptoms of patients with schizophrenic and schizoaffective diseases. 相似文献
63.
64.
65.
Rozaini Abdullah Sebastiaan Wesseling Bert Spenkelink Jochem Louisse Ans Punt Ivonne M.C.M. Rietjens 《Journal of applied toxicology : JAT》2020,40(12):1647-1660
Aristolochic acid I (AAI) is a well-known genotoxic kidney carcinogen. Metabolic conversion of AAI into the DNA-reactive aristolactam-nitrenium ion is involved in the mode of action of tumor formation. This study aims to predict in vivo AAI-DNA adduct formation in the kidney of rat, mouse and human by translating the in vitro concentration-response curves for AAI-DNA adduct formation to the in vivo situation using physiologically based kinetic (PBK) modeling-based reverse dosimetry. DNA adduct formation in kidney proximal tubular LLC-PK1 cells exposed to AAI was quantified by liquid chromatography-electrospray ionization-tandem mass spectrometry. Subsequently, the in vitro concentration-response curves were converted to predicted in vivo dose-response curves in rat, mouse and human kidney using PBK models. Results obtained revealed a dose-dependent increase in AAI-DNA adduct formation in the rat, mouse and human kidney and the predicted DNA adduct levels were generally within an order of magnitude compared with values reported in the literature. It is concluded that the combined in vitro PBK modeling approach provides a novel way to define in vivo dose-response curves for kidney DNA adduct formation in rat, mouse and human and contributes to the reduction, refinement and replacement of animal testing. 相似文献
66.
Lenny Kamelia Laura de Haan Bert Spenkelink Ben Bruyneel Hans B. Ketelslegers Peter J. Boogaard Ivonne M.C.M. Rietjens 《Journal of applied toxicology : JAT》2020,40(3):330-341
In vitro assays presently used for prenatal developmental toxicity (PDT) testing only assess the embryotoxic potential of parent substances and not that of potentially embryotoxic metabolites. Here we combined a biotransformation system, using hamster liver microsomes, with the ES-D3 cell differentiation assay of the embryonic stem cell test (EST) to compare the in vitro PDT potency of two 5-ring polycyclic aromatic hydrocarbons (PAHs), benzo[a]pyrene (BaP) and dibenz[a,h]anthracene (DBA), and dimethyl sulfoxide extracts from five PAH-containing petroleum substances (PS) and a gas-to-liquid base oil (GTLb), with and without bioactivation. In the absence of bioactivation, DBA, but not BaP, inhibited the differentiation of ES-D3 cells into beating cardiomyocytes in a concentration-dependent manner. Upon bioactivation, BaP induced in vitro PDT, while its major metabolite 3-hydroxybenzo[a]pyrene was shown to be active in the EST as well. This means BaP needs biotransformation to exert its embryotoxic effects. GTLb extracts tested negative in the EST, with and without bioactivation. The PS-induced PDT in the EST was not substantially changed following bioactivation, implying that metabolism may not play a crucial role for the PS extracts under study to exert the in vitro PDT effects. Altogether, these results indicate that although some PAH require bioactivation to induce PDT, some do not and this latter appears to hold for the (majority of) the PS constituents responsible for the in vitro PDT of these complex substances. 相似文献
67.
Rafael?Campos-Rodríguez Marycarmen?Godínez-Victoria Humberto?Reyna-Garfias Ivonne?Maciel?Arciniega-Martínez Aldo?Arturo?Reséndiz-Albor Edgar?Abarca-Rojano Teresita?Rocío?Cruz-Hernández Maria?Elisa?Drago-SerranoEmail author 《Age (Dordrecht, Netherlands)》2016,38(1):13
Intermittent fasting (IF) reportedly increases resistance and intestinal IgA response to Salmonella typhimurium infection in mature mice. The aim of this study was to explore the effect of aging on the aforementioned improved immune response found with IF. Middle-aged male BALB/c mice were submitted to IF or ad libitum (AL) feeding for 40 weeks and then orally infected with S. typhimurium. Thereafter, infected animals were all fed AL (to maximize their viability) until sacrifice on day 7 or 14 post-infection. We evaluated body weight, bacterial load (in feces, Peyer’s patches, spleen and liver), total and specific intestinal IgA, lamina propria IgA+ plasma cells, plasma corticosterone, and messenger RNA (mRNA) expression of α-chain, J-chain, and the polymeric immunoglobulin receptor (pIgR) in liver and intestinal mucosa. In comparison with the infected AL counterpart, the infected IF group (long-term IF followed by post-infection AL feeding) generally had lower intestinal and systemic bacterial loads as well as higher total IgA on both post-infection days. Both infected groups showed no differences in corticosterone levels, body weight, or food and caloric intake. The increase in intestinal IgA was associated with enhanced pIgR mRNA expression in the intestine (day 7) and liver. Thus, to maintain body weight and caloric intake, IF elicited metabolic signals that possibly induced the increased hepatic and intestinal pIgR mRNA expression found. The increase in IgA probably resulted from intestinal IgA transcytosis via pIgR. This IgA response along with phagocyte-induced killing of bacteria in systemic organs (not measured) may explain the resolution of the S. typhimurium infection. 相似文献
68.
The gene encoding the Treponema denticola factor H-like protein 1 (FHL-1) binding protein, FhbB, was recovered and characterized. Sequence conservation, expression, and properties of FhbB were analyzed. The identification of FhbB represents an important step in understanding the contribution of FHL-1 binding in T. denticola pathogenesis and in development of periodontal disease. 相似文献
69.