全文获取类型
收费全文 | 2812篇 |
免费 | 207篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 127篇 |
妇产科学 | 65篇 |
基础医学 | 279篇 |
口腔科学 | 50篇 |
临床医学 | 606篇 |
内科学 | 405篇 |
皮肤病学 | 25篇 |
神经病学 | 205篇 |
特种医学 | 240篇 |
外科学 | 234篇 |
综合类 | 51篇 |
预防医学 | 197篇 |
眼科学 | 159篇 |
药学 | 302篇 |
中国医学 | 2篇 |
肿瘤学 | 104篇 |
出版年
2021年 | 24篇 |
2019年 | 38篇 |
2018年 | 40篇 |
2017年 | 20篇 |
2016年 | 32篇 |
2015年 | 46篇 |
2014年 | 46篇 |
2013年 | 89篇 |
2012年 | 91篇 |
2011年 | 92篇 |
2010年 | 61篇 |
2009年 | 79篇 |
2008年 | 93篇 |
2007年 | 93篇 |
2006年 | 94篇 |
2005年 | 86篇 |
2004年 | 103篇 |
2003年 | 97篇 |
2002年 | 73篇 |
2001年 | 85篇 |
2000年 | 82篇 |
1999年 | 101篇 |
1998年 | 114篇 |
1997年 | 109篇 |
1996年 | 106篇 |
1995年 | 84篇 |
1994年 | 67篇 |
1993年 | 73篇 |
1992年 | 52篇 |
1991年 | 73篇 |
1990年 | 67篇 |
1989年 | 62篇 |
1988年 | 68篇 |
1987年 | 44篇 |
1986年 | 45篇 |
1985年 | 41篇 |
1984年 | 31篇 |
1983年 | 34篇 |
1982年 | 25篇 |
1981年 | 28篇 |
1980年 | 21篇 |
1979年 | 21篇 |
1978年 | 25篇 |
1977年 | 15篇 |
1976年 | 18篇 |
1973年 | 19篇 |
1972年 | 15篇 |
1969年 | 19篇 |
1967年 | 15篇 |
1966年 | 16篇 |
排序方式: 共有3059条查询结果,搜索用时 46 毫秒
91.
Simone CS Wolfkamp Caroline Verseyden Esther WM Vogels Sander Meisner Kirsten Boonstra Charlotte P Peters Pieter CF Stokkers Anje A te Velde 《World journal of gastroenterology : WJG》2014,20(10):2664-2672
AIM:To investigate if the presence of relevant genetic polymorphisms has effect on the effectual clearance of bacteria by monocytes and granulocytes in patients with Crohn’s disease(CD).METHODS:In this study,we assessed the differential responses in phagocytosis by measuring the phagocytic activity and the percentage of active phagocytic monocytes and granulocytes in inflammatory bowel disease patients as well as healthy controls.As both autophagy related like 1(ATG16L1)and immunityrelated guanosine triphosphatase gene are autophagy genes associated with CD and more recently nucleo-tide-binding ligomerization domain-containing protein2(NOD2)has been identified as a potent inducer of autophagy we genotyped the patients for these variants and correlated this to the phagocytic reaction.The genotyping was done with restriction fragment length polymorphisms analysis and the phagocytosis was determined with the pHrodo?Escherichia coli Bioparticles Phagocytosis kit for flowcytometry.RESULTS:In this study,we demonstrate that analysis of the monocyte and granulocyte populations of patients with CD and ulcerative colitis showed a comparable phagocytic activity(ratio of mean fluorescence intensity)between the patient groups and the healthy controls.CD patients show a significantly higher phagocytic capacity(ratio mean percentage of phagocytic cells)compared to healthy controls(51.91%±2.85%vs 37.67%±7.06%,P=0.05).The extend of disease was not of influence.However,variants of ATG16L1(WT:2.03±0.19 vs homozygoot variant:4.38±0.37,P<0.009)as well as NOD2(C-ins)(heterozygous variant:42.08±2.94 vs homozygous variant:75.58±4.34(P=0.05)are associated with the phagocytic activity in patients with CD.CONCLUSION:Monocytes of CD patients show enhanced phagocytosis associated with the presence of ATG16L1 and NOD2 variants.This could be part of the pathophysiological mechanism resulting in the disease. 相似文献
92.
Winkler J Kroiss S Rand ML Azzouzi I Annie Bang KW Speer O Schmugge M 《British journal of haematology》2012,156(4):508-515
To evaluate the role of intravenous immunoglobulin (IVIg) in platelet apoptosis in paediatric immune thrombocytopenia, we investigated the platelets of 20 paediatric patients with acute immune thrombocytopenia (ITP), before and after IVIg treatment. Healthy children with platelet counts in the normal range and children with thrombocytopenia due to chemotherapy were enrolled as controls. All ITP patients presented with platelet counts <20 × 109/l and bleeding symptoms. Markers of apoptosis, including activated caspase‐3, ‐8 and ‐9, phosphatidylserine (PS) exposure, mitochondrial inner membrane potential (ΔΨm), as well as platelet‐derived microparticle formation, were analysed by flow cytometry. After IVIg treatment, platelet counts increased to >20 × 109/l in all patients. ITP patients had significantly increased proportions of platelets with activated caspase‐3, ‐8 and ‐9, with PS exposure, and with decreased ΔΨm, and demonstrated increased microparticle formation. Except for ΔΨm, these markers for apoptosis were reduced by IVIg treatment. Platelets of children with thrombocytopenia after chemotherapy also demonstrated increased microparticle formation and decreased ΔΨm, but no activation of caspases 3, 8 and 9 or PS exposure. In conclusion, in acute paediatric ITP, enhanced platelet apoptosis is seen at diagnosis that normalizes after IVIg treatment. 相似文献
93.
94.
Jay R Shapiro Caressa Lietman Monica Grover James T Lu Sandesh CS Nagamani Brian C Dawson Dustin M Baldridge Matthew N Bainbridge Dan H Cohn Maria Blazo Timothy T Roberts Feng‐Shu Brennen Yimei Wu Richard A Gibbs Pamela Melvin Philippe M Campeau Brendan H Lee 《Journal of bone and mineral research》2013,28(7):1523-1530
95.
96.
Amelia N. Deitchman Ravi Shankar Prasad Singh Kenneth H. Rand Hartmut Derendorf 《International journal of antimicrobial agents》2018,51(5):799-802
The lack of availability of novel antibiotic agents and the rise of resistance to existing therapies has led clinicians to utilise combination therapy to adequately treat bacterial infections. Here we examined how chelators may impact the in vitro activity of tigecycline (TIG) against Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumoniae. Minimum inhibitory concentrations (MICs) were determined by broth dilution with and without various combinations of chelators (EDTA and other tetracyclines) and metal ions (i.e. calcium, magnesium). Trimethoprim (TMP) was used as a non-chelating control. Addition of metal ions led to increases in MICs, whilst addition of EDTA led to decreases in MICs. The chelating effects of EDTA were reversed by addition of magnesium and most profoundly calcium. Similar effects of EDTA and calcium were observed for tetracycline (TET) and TMP. When other tetracyclines (TET, oxytetracycline (OXY) and chlortetracycline (CHL)) were used as chelators at concentrations below their MICs, TIG MICs decreased for P. aeruginosa but not for E. coli. Some decreases in TIG MICs were observed for K. pneumoniae when TET and CHL were added. A dose-dependent decrease in TIG MIC was observed for TET and was reversed by the addition of calcium. The presence of effects of EDTA and calcium on TMP MICs indicates that mechanisms outside of TIG chelation likely play a role in enhanced activity. Full characterisation of an unexpected interaction such as TIG–TET with different microorganisms could provide valuable insights into the underlying mechanisms and design of physiologically viable chelators as candidates for future combinations regimens. 相似文献
97.
Long‐term care services are provided to help people manage the consequences of impairment, but their impact goes beyond the meeting of basic needs. Accordingly, the main aim was to explore the marginal effectiveness of care when measured in terms of people's overall care‐related quality of life (CRQoL) and assess changes in marginal effect for increasing intensity. The associated aim was to refine and apply an observational method to estimate marginal effectiveness. A “production function” approach was used with survey data, including Adult Social Care Outcomes Toolkit‐measured CRQoL, whereby we statistically modelled the expected relationship between service utilisation rates and CRQoL. This method seeks to limit endogeneity issues by controlling on observables and using instrumental variable. Using a survey of publicly funded long‐term care service users in England, we found that community‐based long‐term care significantly improved people's CRQoL but with diminishing marginal effects and effects differentiated by baseline impairment levels. There are implications for how the care system should respond to changes in global public budgets. For example, where there is unmet need, a system aimed to maximise (unadjusted) CRQoL would put more emphasis on access (more recipients) than intensity of support compared to a system operating on a needs basis. 相似文献
98.
99.
100.
Provision of childhood primary care services and differences between types of providers (family practice physicians, pediatricians, nurse practitioners, and physicians' assistants) were explored in this study. A mail survey was conducted in Wyoming using a questionnaire based on the recommendations from the U. S. Preventive Service Task Force. Sixty-one percent of the providers returned questionnaires. While some areas of assessment, screening, and treatment/counseling services were provided at high levels, many were not. Gaps exist particularly in the areas of behavioral and lifestyle assessment and treatment/counseling. Only small differences existed between types of providers. However, nurse practitioners and pediatricians were more likely to report that they followed recommendations, while physicians' assistants were least likely to report that they followed recommendations. 相似文献