全文获取类型
收费全文 | 489篇 |
免费 | 19篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 67篇 |
妇产科学 | 16篇 |
基础医学 | 61篇 |
口腔科学 | 64篇 |
临床医学 | 53篇 |
内科学 | 66篇 |
皮肤病学 | 11篇 |
神经病学 | 36篇 |
特种医学 | 21篇 |
外科学 | 38篇 |
综合类 | 3篇 |
预防医学 | 27篇 |
眼科学 | 2篇 |
药学 | 21篇 |
肿瘤学 | 19篇 |
出版年
2020年 | 5篇 |
2019年 | 9篇 |
2018年 | 7篇 |
2017年 | 8篇 |
2016年 | 5篇 |
2015年 | 7篇 |
2014年 | 7篇 |
2013年 | 26篇 |
2012年 | 18篇 |
2011年 | 25篇 |
2010年 | 13篇 |
2009年 | 10篇 |
2008年 | 31篇 |
2007年 | 32篇 |
2006年 | 27篇 |
2005年 | 23篇 |
2004年 | 26篇 |
2003年 | 22篇 |
2002年 | 17篇 |
2001年 | 6篇 |
1999年 | 6篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 6篇 |
1995年 | 9篇 |
1994年 | 9篇 |
1993年 | 7篇 |
1992年 | 8篇 |
1991年 | 6篇 |
1990年 | 5篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1986年 | 6篇 |
1985年 | 11篇 |
1984年 | 8篇 |
1983年 | 7篇 |
1982年 | 12篇 |
1981年 | 4篇 |
1980年 | 6篇 |
1978年 | 3篇 |
1977年 | 8篇 |
1976年 | 5篇 |
1975年 | 7篇 |
1968年 | 2篇 |
1967年 | 3篇 |
1965年 | 2篇 |
1935年 | 10篇 |
1933年 | 3篇 |
1929年 | 3篇 |
1928年 | 2篇 |
排序方式: 共有511条查询结果,搜索用时 0 毫秒
21.
Attenuated lipid peroxidation in preterm infants during subsequent doses of intravenous lipids 总被引:2,自引:0,他引:2
The aim of this study was to determine whether the administration of a lipid emulsion containing less polyunsaturated fatty acids but rich in monounsaturated fatty acids causes less in vivo lipid peroxidation in preterm infants. The prospective intervention study included 13 infants with birth weights and gestational ages ranging between 1,100 and 2,660 g and from 28.4 to 32.9 weeks. All were in a stable condition and randomly allocated for a 3-hour infusion (0.16 g/kg/h) of an olive oil-based and a soybean oil + medium chain fatty acid (MCT) emulsion on 2 consecutive days. Expired pentane and plasma triglycerides (TGs) were measured before, during, and after the 3-hour infusion. Basal exhaled pentane averaged 9.4 +/- 7.0 pmol/kg/min (mean +/- SD). During the olive oil-based emulsion, exhaled pentane increased to 95.2 +/- 56.7, and during soybean oil + MCT it increased to 110 +/- 93.9 pmol/kg/min (p < 0.05 both from basal, n.s. between preparations). One hour after discontinuation of the infusion, exhaled pentane returned to 21.1 +/- 12.6 pmol/kg/min (p < 0.05 vs. basal). Combined data on expired pentane measurements demonstrated that on day 1 pentane peaked at 124 +/- 87.0 pmol/kg/min which was significantly attenuated to 57.5 +/- 24.4 pmol/kg/min after an identical dose of lipid on day 2 (p < 0.05). No difference in peak TGs was detected between the two preparations or the study days. Infusion of a constant dose of intravenous lipids on 2 subsequent days to the newborn infants is associated with a reduction in lipid peroxidation. This finding may be dependent on normal postnatal maturation or may represent an appropriate adaptive response aiming at a reduction in oxidative stress. Peroxidation of soybean oil + MCT and olive oil-based lipid emulsions was similar in the newborn infants. 相似文献
22.
23.
Long-term outcome in fetuses with cardiac arrhythmias 总被引:3,自引:0,他引:3
OBJECTIVE: The objectives of this follow-up study of 292 fetuses with various cardiac arrhythmias were to estimate the incidence of structural heart defects and fetal compromise, to investigate the effects of antiarrhythmic medication, and to evaluate perinatal mortality and morbidity and long-term outcome. METHODS: The arrhythmias were classified into atrial extrasystoles (n = 200), atrial tachycardias (n = 35), atrioventricular block (n = 36), sinus bradycardia (n = 14), and ventricular extrasystoles (n = 7), and outcome of the infants was analyzed. RESULTS: The incidence of cardiac anomalies was 12% in the study population. In utero cardiac failure was noted in 11%. Among fetuses with atrial extrasystoles, 1% developed supraventricular tachycardia after birth. During antiarrhythmic therapy, sinus rhythm was achieved in 92% of nonhydropic and in 63% of hydropic fetuses. The latter had higher mortality and risk for neurologic morbidity than did nonhydropic fetuses; 38% versus 3.7% and 40% versus 12%, respectively. Among fetuses with atrioventricular block only, the survival rate was 82%, with a heart defect, prognosis was poor: 50% survived. Sinus bradycardia and ventricular extrasystoles were associated with survival rates of 75% and 67%. In the follow-up of the whole study population lasting a median 5 years, 93% are alive and 3% have a neurologic disorder. CONCLUSION: All fetal arrhythmias except atrial extrasystoles were associated with a moderately high risk for fetal distress. In cases of compromise, fetal and neonatal prognosis was poor and was an indication for perinatal medication. After the newborn period, the prognosis has been good. However, the risk for neurologic morbidity must be taken into consideration. 相似文献
24.
25.
26.
27.
Early urinary changes in Tamm-Horsfall protein and epidermal growth factor in diabetic children 总被引:1,自引:0,他引:1
Peter Holmquist O. Torffvit Per E. Jørgensen Niels Tørring Ebba Nexø Sture Sjöblad 《Pediatric nephrology (Berlin, Germany)》2001,16(6):488-492
Both glomerular and tubular markers have been used to follow diabetic nephropathy. However, neither albumin nor proximal tubular
markers have proven useful in prepubertal diabetes. Hence we studied two markers derived from the distal tubular cells, Tamm-Horsfall
protein (THP) and epidermal growth factor (EGF). The urinary excretion of THP and EGF was examined in samples obtained during
the first 20 days and 1 year after diagnosis of diabetes in children aged 4–15 years. Fourteen children without and 18 with
ketonuria were examined, and 17 age-matched healthy children participated as controls. The excretion rate of EGF was increased
at diagnosis, while that of THP was not. After 20 days of treatment the excretion of EGF had normalized, while the excretion
of THP was decreased. Similar results were obtained after 1 year. In conclusion, in spite of good metabolic control a reduced
excretion of THP persisted for at least 1 year after the diagnosis of diabetes. Whether the finding of reduced excretion of
THP has any biological significance awaits further study.
Received: 21 July 2000 / Revised: 16 January 2001 / Accepted: 17 January 2001 相似文献
28.
The significance of coronal growth of periodontal ligament tissue for new attachment formation 总被引:4,自引:0,他引:4
Flemming Isidor Thorkild Karring Sture Nyman Jan Lindhe 《Journal of clinical periodontology》1986,13(2):145-150
The present study was designed to examine whether coronal growth of granulation tissue originating from the periodontal ligament is a prerequisite for new attachment formation. In each of 4 monkeys, 1 central incisor and 2 first molars in the maxilla and the mandible were selected for experimentation. Angular bony defects were surgically produced to the mid-root level around each single root after crown resection and root separation of the multirooted teeth. The periodontal ligament tissue and the root cementum were removed to the bottom of the bony defects. In half the number of the teeth, an elastic ligature was placed tightly around each root at the bottom of the defects (test roots). In the remaining teeth, an elastic ligature was placed loosely around each root at the same level (control roots). All roots were subsequently covered by laterally displaced flaps. After 3 months of healing, the animals were sacrificed and the jaws removed and placed in fixative. Following decalcification, histological sections of the experimental roots and their surrounding periodontal tissues were produced. The histological analysis disclosed that new attachment had former to a level coronal to the elastic ligature in 10 of 14 control roots but in only 1 of 18 test roots. The results indicate that the repopulation of a detached root surface by cells from the periodontal ligament is a prerequisite for new attachment formation. 相似文献
29.
30.