全文获取类型
收费全文 | 3890篇 |
免费 | 306篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 182篇 |
妇产科学 | 125篇 |
基础医学 | 421篇 |
口腔科学 | 95篇 |
临床医学 | 387篇 |
内科学 | 938篇 |
皮肤病学 | 59篇 |
神经病学 | 281篇 |
特种医学 | 190篇 |
外国民族医学 | 1篇 |
外科学 | 470篇 |
综合类 | 97篇 |
一般理论 | 1篇 |
预防医学 | 414篇 |
眼科学 | 14篇 |
药学 | 214篇 |
中国医学 | 3篇 |
肿瘤学 | 302篇 |
出版年
2021年 | 50篇 |
2020年 | 36篇 |
2019年 | 59篇 |
2018年 | 57篇 |
2017年 | 48篇 |
2016年 | 50篇 |
2015年 | 50篇 |
2014年 | 99篇 |
2013年 | 132篇 |
2012年 | 182篇 |
2011年 | 169篇 |
2010年 | 136篇 |
2009年 | 110篇 |
2008年 | 142篇 |
2007年 | 198篇 |
2006年 | 188篇 |
2005年 | 175篇 |
2004年 | 147篇 |
2003年 | 145篇 |
2002年 | 116篇 |
2001年 | 103篇 |
2000年 | 129篇 |
1999年 | 107篇 |
1998年 | 77篇 |
1997年 | 64篇 |
1996年 | 63篇 |
1995年 | 47篇 |
1994年 | 50篇 |
1993年 | 40篇 |
1992年 | 78篇 |
1991年 | 77篇 |
1990年 | 59篇 |
1989年 | 65篇 |
1988年 | 75篇 |
1987年 | 56篇 |
1986年 | 52篇 |
1985年 | 39篇 |
1984年 | 53篇 |
1983年 | 36篇 |
1981年 | 31篇 |
1980年 | 44篇 |
1978年 | 42篇 |
1977年 | 34篇 |
1974年 | 44篇 |
1972年 | 32篇 |
1970年 | 49篇 |
1969年 | 33篇 |
1968年 | 34篇 |
1967年 | 31篇 |
1966年 | 35篇 |
排序方式: 共有4215条查询结果,搜索用时 15 毫秒
991.
Berg David D. Yeh Robert W. Mauri Laura Morrow David A. Kereiakes Dean J. Cutlip Donald E. Gao Qi Jarolim Petr Michelson Alan D. Frelinger Andrew L. Cange Abby L. Sabatine Marc S. O’Donoghue Michelle L. 《Journal of thrombosis and thrombolysis》2021,51(3):675-681
Journal of Thrombosis and Thrombolysis - Prolonged use of dual antiplatelet therapy (DAPT) post-percutaneous coronary intervention (PCI) has been shown to reduce the risk of major adverse... 相似文献
992.
993.
Qualitative Research in Emergency Care Part I: Research Principles and Common Applications 下载免费PDF全文
Esther K. Choo MD MPH Aris C. Garro MD MPH Megan L. Ranney MD MPH Zachary F. Meisel MD MPH Kate Morrow Guthrie PhD 《Academic emergency medicine》2015,22(9):1096-1102
Qualitative methods are increasingly being used in emergency care research. Rigorous qualitative methods can play a critical role in advancing the emergency care research agenda by allowing investigators to generate hypotheses, gain an in‐depth understanding of health problems or specific populations, create expert consensus, and develop new intervention and dissemination strategies. This article, Part I of a two‐article series, provides an introduction to general principles of applied qualitative health research and examples of its common use in emergency care research, describing study designs and data collection methods most relevant to our field, including observation, individual interviews, and focus groups. In Part II of this series, we will outline the specific steps necessary to conduct a valid and reliable qualitative research project, with a focus on interview‐based studies. These elements include building the research team, preparing data collection guides, defining and obtaining an adequate sample, collecting and organizing qualitative data, and coding and analyzing the data. We also discuss potential ethical considerations unique to qualitative research as it relates to emergency care research. 相似文献
994.
Ian J. Stewart Kristen R. Glass Jeffrey T. Howard Benjamin D. Morrow Jonathan A. Sosnov Edward D. Siew Nancy Wickersham Wayne Latack Hana K. Kwan Kelly D. Heegard Christina Diaz Aaron T. Henderson Kristin K. Saenz T. Alp Ikizler Kevin K. Chung 《Critical care (London, England)》2015,19(1)
IntroductionTraditional risk scoring prediction models for trauma use either anatomically based estimations of injury or presenting vital signs. Markers of organ dysfunction may provide additional prognostic capability to these models. The objective of this study was to evaluate if urinary biomarkers are associated with poor outcomes, including death and the need for renal replacement therapy.MethodsWe conducted a prospective, observational study in United States Military personnel with traumatic injury admitted to the intensive care unit at a combat support hospital in Afghanistan.ResultsEighty nine patients with urine samples drawn at admission to the intensive care unit were studied. Twelve patients subsequently died or needed renal replacement therapy. Median admission levels of urinary cystatin C (CyC), interleukin 18 (IL-18), L-type fatty acid binding protein (LFABP) and neutrophil gelatinase-associated lipocalin (NGAL) were significantly higher in patients that developed the combined outcome of death or need for renal replacement therapy. Median admission levels of kidney injury molecule-1 were not associated with the combined outcome. The area under the receiver operating characteristic curves for the combined outcome were 0.815, 0.682, 0.842 and 0.820 for CyC, IL-18, LFABP and NGAL, respectively. Multivariable regression adjusted for injury severity score, revealed CyC (OR 1.97, 95 % confidence interval 1.26-3.10, p = 0.003), LFABP (OR 1.92, 95 % confidence interval 1.24-2.99, p = 0.004) and NGAL (OR 1.80, 95 % confidence interval 1.21-2.66, p = 0.004) to be significantly associated with the composite outcome.ConclusionsUrinary biomarker levels at the time of admission are associated with death or need for renal replacement therapy. Larger multicenter studies will be required to determine how urinary biomarkers can best be used in future prediction models.
Electronic supplementary material
The online version of this article (doi:10.1186/s13054-015-0965-y) contains supplementary material, which is available to authorized users. 相似文献995.
Effect of phagocytosis on the reduced soluble sulfhydryl content of human granulocytes 总被引:3,自引:0,他引:3
The role of reduced glutathione in relation to hexose monophosphate shunt activity and peroxide detoxification has been well established in human erythrocytes. Less is known about the content of reduced glutathione in phagocytic leukocytes and the changes that occur during functional activity. We have measured the reduced sulfhydryl content of normal resting human granulocytes and of cells isolated from a patient with chronic granulomatous disease. Normal cells and those from the patient with chronic granulomatous disease contained similar concentrations of reduced sulfhydryls. Stimulation of a phagocytic response by incubation with opsonized zymosan particles resulted in prompt and nearly complete depletion of intracellular glutathione from normal granulocytes. This fall in reduced glutathione concentration was dependent on the phagocytic load. Exposure of chronic granulomatous disease granulocytes to a similar phagocytic load resulted in a slower and less complete fall in reduced glutathione. In normal cells, those from the chronic granulomatous disease patient, and those from an obligate carrier of the disease, the decrement in reduced glutathione during phagocytosis was correlated with oxidation of 14C-1-glucose and 14C-formate, nitroblue tetrazolium reduction, and the chemiluminescence phenomenon. 相似文献
996.
Effect of low dietary lipid on the development of Sj?gren's syndrome and haematological abnormalities in (NZB x NZW)F1 mice. 下载免费PDF全文
A diet low in fat was found to retard the development of autoimmune disease in (NZB x NZW)F1 mice, whereas diets high in fat content were associated with more severe disease. The ability of a reduced lipid intake to ameliorate the progression of autoimmune disease was indicated by preserved lacrimal gland secretion (measured by a modified Schirmer test), decreased infiltration of inflammatory cells into the exocrine tissue, and decreased severity of immunohaemolytic anaemia as indicated by near-normal packed cell volume and reticulocyte values. These results suggest that nutritional intervention may be of some help in reducing the severity of pathological abnormalities associated with human systemic lupus erythematosus and Sjögren''s syndrome. 相似文献
997.
998.
CD4 and CD8 T lymphocyte subsets, the late T cell activation marker,
HLA-DR, and serum interleukin-6 (IL-6) levels of 57 polymyalgia rheumatica
(PMR) patients were followed over 2 yr to investigate whether they could be
used to predict the safe withdrawal of steroid therapy. Cell phenotypes
were studied by flow cytometry and IL-6 levels by ELISA. %CD8 cells were
reduced below the normal range in PMR patients prior to steroid therapy. In
56% of patients, the %CD8 T lymphocytes failed to return to normal levels
when quiescent disease allowed cessation of steroid therapy. Activated CD8
T cells, as detected by HLA-DR positivity, were above the normal range at
the initiation of therapy and showed a negative correlation with %CD8 T
cells. The serum concentration of IL-6 fluctuated over 24 months, and the
correlation between IL-6 and erythrocyte sedimentation rate (ESR) seen
prior to treatment was not seen at later intervals. The %CD8 T cell and
serum IL-6 levels are not a good indicator of disease activity in PMR and
are, therefore, unable to predict the safe withdrawal of steroids.
相似文献
999.
1000.