全文获取类型
收费全文 | 905篇 |
免费 | 75篇 |
国内免费 | 45篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 85篇 |
妇产科学 | 9篇 |
基础医学 | 83篇 |
口腔科学 | 19篇 |
临床医学 | 134篇 |
内科学 | 200篇 |
皮肤病学 | 20篇 |
神经病学 | 77篇 |
特种医学 | 134篇 |
外科学 | 74篇 |
综合类 | 20篇 |
预防医学 | 40篇 |
眼科学 | 11篇 |
药学 | 71篇 |
中国医学 | 3篇 |
肿瘤学 | 26篇 |
出版年
2021年 | 13篇 |
2020年 | 9篇 |
2019年 | 13篇 |
2018年 | 19篇 |
2017年 | 15篇 |
2016年 | 11篇 |
2015年 | 21篇 |
2014年 | 23篇 |
2013年 | 35篇 |
2012年 | 16篇 |
2011年 | 28篇 |
2010年 | 32篇 |
2009年 | 36篇 |
2008年 | 27篇 |
2007年 | 48篇 |
2006年 | 23篇 |
2005年 | 24篇 |
2004年 | 17篇 |
2003年 | 20篇 |
2002年 | 19篇 |
2001年 | 13篇 |
2000年 | 19篇 |
1999年 | 20篇 |
1998年 | 49篇 |
1997年 | 39篇 |
1996年 | 38篇 |
1995年 | 26篇 |
1994年 | 18篇 |
1993年 | 23篇 |
1992年 | 16篇 |
1991年 | 20篇 |
1990年 | 26篇 |
1989年 | 36篇 |
1988年 | 46篇 |
1987年 | 36篇 |
1986年 | 29篇 |
1985年 | 21篇 |
1984年 | 9篇 |
1983年 | 14篇 |
1982年 | 10篇 |
1981年 | 6篇 |
1980年 | 7篇 |
1979年 | 3篇 |
1978年 | 8篇 |
1977年 | 11篇 |
1976年 | 8篇 |
1975年 | 6篇 |
1973年 | 5篇 |
1972年 | 4篇 |
1969年 | 4篇 |
排序方式: 共有1025条查询结果,搜索用时 62 毫秒
101.
102.
BACKGROUND: The management of splenic injuries has evolved with a greater emphasis on nonoperative management. Although several institutions have demonstrated that nonoperative management of splenic injuries can be performed with an increasing degree of success, the impact of this treatment shift on outcome for all patients with splenic injuries remains unknown. We hypothesized that outcomes for patients with splenic injuries have improved as the paradigm for splenic injury treatment has shifted. METHODS: Consecutive patients from 1987 to 2001 with splenic injuries who were entered into a state trauma registry were reviewed. Demographic variables, injury characteristics, and outcome data were collected. RESULTS: The number of patients who were diagnosed with splenic injuries increased from 1987 through 2001, despite a stable number of institutions submitting data to the registry. The number of minor injuries and severe splenic injuries remained stable, and the number of moderately severe injuries significantly increased over time. Overall mortality rate improved but primarily reflected the decreased mortality rates of moderately severe injuries; the mortality rate for severe splenic injuries was unchanged. CONCLUSION: Trauma centers are seeing increasing numbers of splenic injuries that are less severe in magnitude, although the number of the most severe splenic injuries is stable. The increased proportion of patients with less severe splenic injuries who are being admitted to trauma centers is a significant factor in the increased use and success rate of nonoperative management. 相似文献
103.
Citation
Borgman MA, Spinella PC, Perkins JG, Grathwohl KW, Repine T, Beekley AC, Sebesta J, Jenkins D, Wade CE, Holcomb JB: The ratio of blood products transfused affects mortality in patients receiving massive transfusions at a combat support hospital. J Trauma 2007, 63: 805–813 [1].Background
Patients with severe traumatic injuries often present with coagulopathy and require massive transfusion. The risk of death from hemorrhagic shock increases in this population. To treat the coagulopathy of trauma, some have suggested early, aggressive correction using a 1:1 ratio of plasma to red blood cell (RBC) units.Methods
Objective
To determine whether the ratio of plasma to RBCs transfused would affect survival by decreasing death from hemorrhage.Design
Retrospective chart review.Setting
United States Army combat support hospital in Iraq.Subjects
246 patients who received a massive transfusion (≥10 units of RBCs in 24 hours) from November 2003 to September 2005. Three groups of patients were constructed according to the plasma to RBC ratio transfused during massive transfusion.Intervention
None.Outcome
Hospital mortality rates and the cause of death were compared among groups. Multivariable logistic regression was used to determine the independent association between plasma to RBC ratio and hospital mortality.Results
For the low ratio group the plasma to RBC median ratio was 1:8 (interquartile range (IQR), 0:12–1:5), for the medium ratio group, 1:2.5 (IQR, 1:3.0–1:2.3), and for the high ratio group, 1:1.4 (IQR, 1:1.7–1:1.2) (p < 0.001). Median Injury Severity Score (ISS) was 18 for all groups (IQR, 14–25). For low, medium, and high plasma to RBC ratios, overall mortality rates were 65%, 34%, and 19%, (p < 0.001); and hemorrhage mortality rates were 92.5%, 78%, and 37%, respectively (p < 0.001). Upon logistic regression, plasma to RBC ratio was independently associated with survival (odds ratio 8.6, 95% confidence interval 2.1–35.2).Conclusion
In patients with combat-related trauma requiring massive transfusion, a high 1:1.4 plasma to RBC ratio is independently associated with improved survival to hospital discharge, primarily by decreasing death from hemorrhage. For practical purposes, massive transfusion protocols should utilize a 1:1 ratio of plasma to RBCs for all patients who are hypocoagulable with traumatic injuries. 相似文献104.
De Almeida Claro J Kaufmann OG Alarcon G Aguiar W Nadozza A Ortiz V Srougi M 《BJU international》2007,99(1):127-129
OBJECTIVE: To determine the prevalence of erectile dysfunction (ED) in a specific population and explore potential correlates with lifestyle. SUBJECTS AND METHODS: This prospective observational study, covering a population of a very small rural town, included 2000 men aged > or = 20 years from a total population of 121 831 (51% female and 49% male). The International Index of Erectile Function was completed by each of the 2000 men at their homes over a 1-year period. Another questionnaire assessing socio-economic status and health-related determinants of ED were also completed. RESULTS: All 2000 men completed the questionnaires; overall, only 34 reported ED (1.7%). The frequency of mild, mild to moderate, moderate and severe ED was 12%, 29%, 20% and 38%, respectively. Significantly more men aged > 51 years had ED than those aged <41 years (0.05% and 0.45%, respectively; P < 0.001). There was no difference in ED with salary levels. CONCLUSION: The prevalence of ED in this particular rural population of Brazil was very low, at only 1.7%. Although ED increases with age, this association was not apparent for all age groups. It seems that several others factors, e.g. lifestyle, culture and diet, could be important for the onset of ED. 相似文献
105.
G Williams E Alarcon S Jittimanee M Walusimbi M Sebek E Berga T S Villa 《The international journal of tuberculosis and lung disease》2008,12(3):236-240
The first two chapters of Best practice for the care of patients with tuberculosis: a guide for low-income countries include an introduction and guidance regarding implementation of best practice. The background to how the guide was developed is significant, as it was developed in collaboration with nurses and other health workers working in the most challenging settings. It therefore provides realistic and practical guidance for best practice where patient loads are large and resources are stretched. Guidance regarding standard setting and clinical audit is an important part of enabling people to recognise the strengths that already exist in their practice and approach those areas that require change in a systematic and practical way. The guide itself consists of a series of standards covering different aspects of patient care, from the moment they seek health care with symptoms to their diagnosis to early stages of treatment, directly observed treatment, the continuation phase and transfer of treatment. There are also standards relating specifically to HIV testing and the care of patients co-infected with tuberculosis and HIV. The standards themselves will appear in full in the subsequent chapters of this series. 相似文献
106.
Sickle cell anemia patients have low erythropoietin levels for their degree of anemia 总被引:3,自引:1,他引:2
We have studied serum immunoreactive erythropoietin (SIE) levels in 28 patients with sickle cell anemia (SCA) without renal insufficiency and in 17 patients with nonhemoglobinopathy anemias of comparable severity using a sensitive radioimmunoassay procedure. An exponential relationship between SIE level and degree of anemia was noted in all patients. However, in nonhemoglobinopathy anemia, a sharp rise in the SIE level occurred as hemoglobin (Hb) levels fell below about 12 g/dL, whereas in sickle cell patients the increase was not marked until hemoglobin fell to about 9 g/dL. The response was more blunted in older SCA patients than in younger ones. A linear regression model relating SIE level to Hb level, presence/absence of SCA, and age explained 63% of the variation in SIE. We conclude that the serum erythropoietin levels in SCA increased at a lower hemoglobin concentration and are of a lower magnitude than that of the other anemias. 相似文献
107.
J R Smythies R D Alarcon D Morere J A Monti M Steele L C Tolbert W G Walter-Ryan 《Neuropsychopharmacology》1986,21(14):1391-1398
Two independent lines of inquiry have implicated some disturbance of one-carbon cycle metabolism in affective disorders. Folic acid deficiency commonly leads to depression, and S-adenosylmethionine has been reported to have antidepressant properties. Methionine adenosyltransferase has been reported to be underactive in depression and schizophrenia and overactive in mania. This study reports the effects on erythrocyte methionine adenosyltransferase (MAT) kinetics (Vmax) of a 2-week treatment in a population of patients housed on a psychiatric research ward. The drug-free schizophrenic patients and depressives had, upon admission, low Vmax values, and the drug-free manic patients had high Vmax values on admission. After 2 weeks of appropriate treatment, the values for all three patient samples showed significant normalization (i.e., the levels rose in schizophrenics and depressives and fell in manics). We have further shown that pretreatment low levels of erythrocyte membrane phosphatidylcholine in depressives and high levels in manics show statistically significant normalization following 2 weeks of pharmacotherapy. The significance of these results is discussed. 相似文献
108.
109.
110.