全文获取类型
收费全文 | 295篇 |
免费 | 13篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 14篇 |
妇产科学 | 1篇 |
基础医学 | 38篇 |
口腔科学 | 8篇 |
临床医学 | 26篇 |
内科学 | 51篇 |
皮肤病学 | 1篇 |
神经病学 | 47篇 |
特种医学 | 49篇 |
外科学 | 10篇 |
综合类 | 2篇 |
预防医学 | 41篇 |
眼科学 | 1篇 |
药学 | 7篇 |
中国医学 | 1篇 |
肿瘤学 | 8篇 |
出版年
2021年 | 2篇 |
2020年 | 1篇 |
2018年 | 2篇 |
2016年 | 6篇 |
2015年 | 2篇 |
2014年 | 3篇 |
2013年 | 8篇 |
2012年 | 9篇 |
2011年 | 4篇 |
2010年 | 12篇 |
2009年 | 15篇 |
2008年 | 7篇 |
2007年 | 10篇 |
2006年 | 11篇 |
2005年 | 11篇 |
2004年 | 14篇 |
2003年 | 10篇 |
2002年 | 14篇 |
2001年 | 10篇 |
2000年 | 10篇 |
1999年 | 7篇 |
1998年 | 13篇 |
1997年 | 15篇 |
1996年 | 7篇 |
1995年 | 5篇 |
1994年 | 8篇 |
1993年 | 4篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 11篇 |
1988年 | 8篇 |
1987年 | 11篇 |
1986年 | 6篇 |
1985年 | 11篇 |
1984年 | 2篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 4篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1975年 | 6篇 |
1973年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有308条查询结果,搜索用时 250 毫秒
101.
102.
Ross EG Upshur Rahim Moineddin Eric Crighton Lori Kiefer Muhammad Mamdani 《BMC health services research》2005,5(1):13
Background
Seasonality is a common feature of communicable diseases. Less well understood is whether seasonal patterns occur for non-communicable diseases. The overall effect of seasonal fluctuations on hospital admissions has not been systematically evaluated. 相似文献103.
Age as a prognostic indicator in carcinoma of the lung 总被引:1,自引:0,他引:1
104.
105.
Fidani L Goulas A Mirtsou V Petersen RC Tangalos E Crook R Hardy J 《Neuroscience letters》2002,323(1):81-83
Over the past few years, association studies have proposed a number of potential genetic risk factors for Alzheimer's disease (AD). With the exception of the varepsilon4 allele of the apolipoprotein E gene, whose association with the late onset type of AD (LOAD) has been confirmed, the relative significance of most of these associations is still in question. A polymorphism in the interleukin-1A gene (IL-1A2) has been suggested as a risk factor for the early onset as well as for LOAD. In this study, the distribution of IL-1A alleles was examined in a cohort of predominantly LOAD patients and in control individuals. No significant difference was detected in genotype or allele frequencies (odds ratios of 0.929 and 0.743, respectively; P>0.5). We conclude that IL-1A genotype is not a major risk factor for LOAD. 相似文献
106.
107.
Vitamin K deficiency or administration of vitamin K antagonists results in the biosynthesis of abnormal des-gamma-carboxy forms of the vitamin K-dependent proteins. Monoclonal antibody H-11 binds several vitamin K- dependent proteins at a determinant that includes the first two residues of gamma-carboxyglutamic acid. Antibody H-11 binds fully carboxylated prothrombin and protein C in the presence of EDTA but binding is inhibited by the divalent metal ions, calcium, magnesium, and manganese. By contrast, des-gamma-carboxy prothrombin and protein C bind antibody H-11 the same in the presence of EDTA or calcium ion. Antibody H-11 thus appears to bind a conserved antigenic site containing gamma-carboxyglutamic acid that in the presence of divalent metal ion undergoes a conformational transition. This ability of antibody H-11 to bind des-gamma-carboxy prothrombin and protein C in the presence of calcium ion allowed the development of an immunoassay for these proteins in plasma. Prothrombin and protein C from stably anticoagulated individuals receiving warfarin were characterized by their ability to bind antibody H-11 in the presence of calcium ion. Binding of prothrombin and protein C to antibody H-11 in the presence of calcium correlated temporally with warfarin administration. The inability of calcium ion to inhibit binding of antibody H-11 to abnormal prothrombin and protein C in plasma suggests that the circulating forms of both proteins following warfarin administration cannot undergo the metal ion-dependent conformational transition that includes sequence residues 1 through 12. 相似文献
108.
William R Henderson Paolo B Dominelli Donald EG Griesdale Daniel Talmor A William Sheel 《Canadian respiratory journal》2014,21(2):107-111
High-frequency oscillation is a novel form of ventilation increasingly being used to treat refractory hypoxic respiratory failure resulting from acute lung injury or acute respiratory distress syndrome. Although there is no known relationship between airway pressure and transpulmonary pressure during conventional mechanical ventilation, no study has attempted to determine transpulmonary pressure during high-frequency oscillation.
BACKGROUND:
High-frequency oscillation (HFO) is used for the treatment of refractory hypoxic respiratory failure.OBJECTIVE:
To demonstrate that the mean transpulmonary pressure (PL) cannot be inferred from mean airway pressure (mPaw).METHODS:
In seven patients already undergoing HFO for refractory acute respiratory distress syndrome, esophageal pressure (Pes) was measured using an esophageal balloon catheter. Pleural pressure (Ppl) and PL were calculated from Pes.MAIN RESULTS:
In the seven patients (mean [± SD] age 59±9 years) treated with HFO at 5±1 Hz and amplitude 75±10 cmH2O, the mPaw was 27±6 cmH2O, Ppl was 9±6 cmH2O and PL was 18±11 cmH2O. Successful catheter placement and measurement of Pes occurred in 100% of subjects. There was no correlation between PL and mPaw. The majority of subjects required hemodynamic support during the use of HFO; the frequency and degree of support during the study period was no different than that before the study.CONCLUSION:
The present report is the first to describe measuring Pes and calculating Ppl during HFO for acute respiratory distress syndrome. While both current guidelines and recent trials have titrated treatment based on mPaw and oxygenation, there is wide variability in PL during HFO and PL cannot be predicted from mPaw. 相似文献109.
Instrument monitoring of vital signs in neonates undergoing magnetic resonance (MR) imaging can be difficult because of the unique environmental restrictions imposed by the imager. The authors present their experience with monitoring more than 50 newborn infants and discuss the interaction of monitoring devices with the MR imager. Several MR-compatible monitors allow continuous evaluation of body temperature, heart rate, blood pressure, and auscultation of heart sounds and respiration in mechanically ventilated infants. Signal-to-noise (S/N) ratio measurements taken during imaging of the head of an infant with these monitors in place did not differ appreciably from the ratio obtained during imaging without monitors. Tip angles should be optimized to account for widely varying head size among neonates, since adverse monitoring effects are significantly compounded by improper tip angle adjustment. 相似文献
110.
Confrontation naming does not add incremental diagnostic utility in MCI and Alzheimer's disease. 总被引:4,自引:0,他引:4
Julie A Testa Robert J Ivnik Bradley Boeve Ronald C Petersen V Shane Pankratz David Knopman Eric Tangalos Glenn E Smith 《Journal of the International Neuropsychological Society》2004,10(4):504-512
As the incidence of dementia increases, there is a growing need to determine the diagnostic utility of specific neuropsychological tests in the early diagnosis of Alzheimer's disease (AD). In this study, the relative utility of Boston Naming Test (BNT) in the diagnosis of AD was examined and compared to the diagnostic utility of other neuropsychological measures commonly used in the evaluation of AD. Individuals with AD (n = 306), Mild Cognitive Impairment (MCI; n = 67), and cognitively normal subjects (n = 409) with at least 2 annual evaluations were included. Logistic regression analysis suggested that initial BNT impairment is associated with increased risk of subsequent AD diagnosis. However, this risk is significantly less than that imparted by measures of delayed recall impairments. A multivariate Cox proportional hazards regression analysis suggested that BNT impairment imparted no additional risk for subsequent AD diagnosis after delayed recall impairments were included in the model. Although BNT impairment occurred in all severity groups, it was ubiquitous only in moderate to severe dementia. Collectively these results suggest that although BNT impairments become more common as AD progresses, they are neither necessary for the diagnosis of AD nor particularly useful in identifying early AD. 相似文献