全文获取类型
收费全文 | 2716篇 |
免费 | 178篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 23篇 |
儿科学 | 103篇 |
妇产科学 | 42篇 |
基础医学 | 285篇 |
口腔科学 | 254篇 |
临床医学 | 244篇 |
内科学 | 695篇 |
皮肤病学 | 95篇 |
神经病学 | 121篇 |
特种医学 | 184篇 |
外科学 | 305篇 |
综合类 | 43篇 |
预防医学 | 207篇 |
眼科学 | 74篇 |
药学 | 153篇 |
中国医学 | 18篇 |
肿瘤学 | 74篇 |
出版年
2023年 | 19篇 |
2022年 | 50篇 |
2021年 | 77篇 |
2020年 | 57篇 |
2019年 | 108篇 |
2018年 | 111篇 |
2017年 | 84篇 |
2016年 | 86篇 |
2015年 | 97篇 |
2014年 | 122篇 |
2013年 | 146篇 |
2012年 | 171篇 |
2011年 | 161篇 |
2010年 | 118篇 |
2009年 | 100篇 |
2008年 | 129篇 |
2007年 | 113篇 |
2006年 | 117篇 |
2005年 | 95篇 |
2004年 | 103篇 |
2003年 | 72篇 |
2002年 | 59篇 |
2001年 | 45篇 |
2000年 | 36篇 |
1999年 | 43篇 |
1998年 | 51篇 |
1997年 | 45篇 |
1996年 | 45篇 |
1995年 | 30篇 |
1994年 | 38篇 |
1993年 | 36篇 |
1992年 | 32篇 |
1991年 | 21篇 |
1990年 | 21篇 |
1989年 | 29篇 |
1988年 | 31篇 |
1987年 | 21篇 |
1986年 | 19篇 |
1985年 | 17篇 |
1984年 | 10篇 |
1983年 | 18篇 |
1982年 | 20篇 |
1981年 | 11篇 |
1980年 | 15篇 |
1978年 | 6篇 |
1977年 | 16篇 |
1976年 | 8篇 |
1975年 | 9篇 |
1970年 | 6篇 |
1966年 | 6篇 |
排序方式: 共有2920条查询结果,搜索用时 15 毫秒
81.
Camila C. Abreu Priscilla A. Nakayama Clayton I. Nogueira Leonardo P. Mesquita Priscila F. R. Lopes Flademir Wouters Mary S. Varaschin Pedro S. Bezerra Jr 《Journal of neurovirology》2014,20(4):388-397
We performed a histopathological and immunohistochemical study of tissues outside the central nervous system in 48 cases of bovine rabies confirmed by direct immunofluorescence and/or immunohistochemistry (IHC) of the central nervous system. In the bovines of this study, mononuclear inflammation in all ganglia (trigeminal, spinal, stellate, and celiac) and adrenal medulla was observed. This injury also occurred in 85 % of neuro-pituitaries in 55 % of pars intermediate and 15 % of the pars distalis of pituitary evaluated. IHC was positive in 92.31 % of lumbar spinal ganglia, 90.9 % of trigeminal ganglia, stellate ganglia of 41.67 and 16.67 % of the celiac ganglia. One of the evaluated adrenal (1/17) showed strong immunohistochemical labeling in the cytoplasm of pheochromocytes. The pituitary IHC was positive in one case in the neurohypophysis (1/20) and in one case in the pars intermedia of the adenohypophysis (1/20). Data from this study indicate that in suspected cases of rabies, besides the complex pituitary rete mirabile and trigeminal ganglion, the evaluation of other ganglia, particularly the lumbar spinal, and adrenal may also contribute to the diagnosis and understanding of the clinical presentation and pathogenesis of the disease in bovines. 相似文献
82.
Bruno Cópio Fábregas Mery Natali Silva Abreu Aieska Kellen Dantas dos Santos Alexandre Sampaio Moura Ricardo Andrade Carmo Antônio Lúcio Teixeira 《General hospital psychiatry》2014
Objective
The objective was to investigate impulsiveness among chronic hepatitis C (CHC) patients and its association with sociodemographic, clinical and psychopathological factors.Method
Ninety-one CHC individuals were enrolled in a cross-sectional study at a Brazilian public university-based outpatient’s service for infectious diseases. They were assessed using the Barrat Impulsiveness Scale, Brief Fatigue Inventory, Beck Depression Inventory and Hamilton Anxiety Scale. Structured psychiatric interview was performed according to the Mini International Neuropsychiatric Interview. Multivariate analysis was performed according to linear stepwise forward regression.Results
The total score of impulsiveness according to BIS in studied population was 64.6±9.8. The scores for the nonplanning, cognitive–attentional and motor domains were 23.8±5, 19.4±2.9 and 21.4±5, respectively. Impulsiveness was associated with lower educational level, current interferon-α (IFN) use, attention-deficit/hyperactivity disorder, alcohol use disorder, mixed anxiety and depressive disorder, specific phobia, bipolar spectrum disorders and anxiety symptoms. During IFN treatment, impulsiveness was also associated with suicide risk.Conclusion
Impulsiveness was frequent in CHC patients and was associated with several psychopathological alterations. Impulsiveness management should be considered when attending CHC patients. 相似文献83.
Iman Amy Betawi Sinaria Kamil Abdel Jabbar Mohammad. A. AL Jabery Haidar Ibrahim Zaza Muhannad Al-Shboul 《Early child development and care》2014,184(12):1992-2003
This study examined fathers' perceptions regarding their home-based activities (HBA) and the influence of fathers' demographic characteristics on their perceptions and practices at home. A total of 396 fathers completed a survey questionnaire describing their demographic information, perceptions and their practices regarding their involvement in HBA. Results indicated that fathers have moderate level of practice concerning their HBA, yet they have low perception of their actual practice at HBA. In addition, there was a statistical significance in HBA due to fathers' age, educational level and specialisation which had an influence on their perceptions as well. Recommendations and implications of future research were discussed. 相似文献
84.
Adriana C. S. Pais Carlos A. Pinto Patrícia A. B. Ramos Ricardo J. B. Pinto Daniela Rosa Maria F. Duarte M. Helena Abreu Silvia M. Rocha Jorge A. Saraiva Armando J. D. Silvestre Snia A. O. Santos 《RSC advances》2019,9(68):39893
The brown macroalgae Bifurcaria bifurcata have gained special attention due to their ability to biosynthesize linear diterpenes (rarely found in other species). However, the conventional extraction methods normally used to extract these compounds involve organic solvents and often high temperatures, leading to the degradation of thermo-labile compounds. In this context, the main objective of this work was to study and optimize for the first time the extraction of diterpenes from B. bifurcata through an environmentally friendly methodology, namely, high pressure extraction (HPE) using ethanol : water. This was compared with conventional Soxhlet extraction, using dichloromethane. Box–Behnken design was employed to evaluate the linear, quadratic, and interaction effects of 3 independent variables (pressure (X1), ethanol percentage (X2), and time of extraction (X3)) on response variables (extraction yield and diterpenes content (mg g−1 of extract and mg kg−1 of dry weight)) and the optimal extraction conditions (X1: 600 MPa; X2: 80%; X3: 5 min) were estimated by response surface methodology (RSM). B. bifurcata extract obtained under HPE optimal conditions showed a diterpenes content (612.2 mg g−1 of extract) 12.2 fold higher than that obtained by conventional extraction (50.1 mg g−1 of extract). The HPE extract, obtained under optimal conditions, showed antioxidant and antibacterial (against Staphylococcus aureus) activities considerably higher than the Soxhlet extract, and also presented a promising synergic effect with antibiotics, improving the antibiotic efficacy against S. aureus. In conclusion, these results indicate that HPE is a promising methodology, compared to conventional methodologies to obtain linear diterpene rich extracts from B. bifurcata with great potential to be exploited in pharmaceutical or biomedical applications.Bioactive linear diterpenes were selectively extracted from the macroalga Bifurcaria bifurcata through optimized high-pressure extraction. 相似文献
85.
Pit J. S. M. Kerstens Jan N. Stolk Ronney A. De Abreu Lambert H. J. Lambooy Leo B. A. De Van Putte Agnes A. M. T. Boerbooms 《Arthritis \u0026amp; Rheumatology》1995,38(1):142-145
Objective. Azathioprine (AZA) metabolism largely parallels the endogenous purine pathways. To date, thiopurine methyltransferase (TPMT) deficiency has been reported as a cause of AZA-related bone marrow toxicity in 1 patient with rheumatoid arthritis (RA). We therefore studied purine enzyme activities in 3 patients with RA who experienced AZA-related bone marrow toxicity. Methods. Lymphocyte activity of purine nucleoside phosphorylase and 5′-nucleotidase (5NT) and erythrocyte activity of TPMT, key enzymes in thiopurine catabolism, were measured in 3 RA patients who had experienced AZA-related bone marrow toxicity and in 16 RA patients without signs of toxicity despite at least 6 months of treatment with AZA. Results. Two patients with AZA-related bone marrow toxicity were found to have a TPMT deficiency, 1 partial and 1 total. In the third patient, 5NT activity was found to be well below the lowest level observed in the control subjects. Conclusion. All 3 patients with severe AZA-related bone marrow toxicity had abnormal purine enzyme activities. Deficiency of purine enzymes, including TPMT and 5NT, may be a cause of AZA-related bone marrow toxicity in patients with RA. 相似文献
86.
Tnia Silva-Santos Pedro Moreira Olívia Pinho Patrícia Padro Sandra Abreu Sílvia Esteves Luís Oliveira Pedro Norton Micaela Rodrigues Altin Ndrio Carla Gonalves 《Nutrients》2022,14(1)
(1) Background: Excessive salt consumption is associated with an increased risk of hypertension and cardiovascular disease, and it is essential to reduce it to the level recommended by the World Health Organization (<5 g/day). The main objective of this study is to verify the impact of an intervention, which used the Salt Control H equipment to reducing salt consumption; (2) Methods: The study was an 8-week randomized control trial with 114 workers from a public university. The intervention group (n = 57) used the equipment to monitor and control the use of salt during cooking (Salt Control H) at home for 8 weeks. The primary outcome was 24 h urinary sodium excretion as a proxy of salt intake. Secondary outcomes included changes in 24 h urinary potassium excretion, sodium to potassium ratio (Na:K), and blood pressure. (3) Results: There was a decrease in sodium intake after the intervention but with no statistical significance. When analyzing the results by sex and hypertension status, there was a reduction in sodium (−1009 (−1876 to −142), p = 0.025) and in Na:K ratio (−0.9 (−1.5 to −0.3), p = 0.007) in hypertensive men in the intervention group. (4) Conclusions: Interventions with dosage equipment can be valid approaches in individual salt reduction strategies, especially in hypertensive men. 相似文献
87.
AL Naik A Savlania A Gupta P Rastogi A Singh 《Annals of the Royal College of Surgeons of England》2021,103(3):e94
Behçet’s disease is a rare disease characterised by recurrent oral ulcers, with systemic manifestations including genital ulcers, ocular disease, skin lesions, gastrointestinal disease, neurologic disease, vascular disease and arthritis. Most clinical manifestations of Behçet’s disease are believed to be due to vasculitis. The heterogeneous clinical spectrum is influenced by sex, ethnicity and country of residence. Vascular manifestation in the form of isolated large brachial artery aneurysm is rare in children. Treatment involves aneurysmorrhaphy to avoid rupture or ischaemic sequelae in addition to lifelong medical management to control vasculitis. 相似文献
88.
89.
Rafael Genario Murilo S. de Abreu Ana C.V.V. Giacomini Konstantin A. Demin Allan V. Kalueff 《The European journal of neuroscience》2020,52(1):2586-2603
Sex is an important variable in biomedical research. The zebrafish (Danio rerio) is increasingly utilized as a powerful new model organism in translational neuroscience and pharmacology. Mounting evidence indicates important sex differences in zebrafish behavioral and neuropharmacological responses. Here, we discuss the role of sex in zebrafish central nervous system (CNS) models, their molecular mechanisms, recent findings and the existing challenges in this field. We also emphasize the growing utility of zebrafish models in translational neuropharmacological research of sex differences, fostering future CNS drug discovery and the search for novel sex‐specific therapies. Finally, we highlight the interplay between sex and environment in zebrafish models of sex‐environment correlations as an important strategy of CNS disease modeling using this aquatic organism. 相似文献