全文获取类型
收费全文 | 1213篇 |
免费 | 242篇 |
国内免费 | 1篇 |
出版年
2021年 | 17篇 |
2020年 | 24篇 |
2019年 | 49篇 |
2018年 | 36篇 |
2017年 | 13篇 |
2016年 | 29篇 |
2015年 | 48篇 |
2014年 | 36篇 |
2013年 | 61篇 |
2012年 | 51篇 |
2011年 | 39篇 |
2010年 | 43篇 |
2009年 | 39篇 |
2008年 | 47篇 |
2007年 | 57篇 |
2006年 | 43篇 |
2005年 | 39篇 |
2004年 | 32篇 |
2003年 | 32篇 |
2002年 | 37篇 |
2001年 | 46篇 |
2000年 | 43篇 |
1999年 | 36篇 |
1998年 | 34篇 |
1997年 | 32篇 |
1996年 | 37篇 |
1995年 | 39篇 |
1994年 | 16篇 |
1993年 | 23篇 |
1992年 | 23篇 |
1991年 | 23篇 |
1990年 | 20篇 |
1989年 | 29篇 |
1988年 | 17篇 |
1987年 | 16篇 |
1986年 | 17篇 |
1985年 | 19篇 |
1984年 | 21篇 |
1983年 | 9篇 |
1982年 | 11篇 |
1981年 | 9篇 |
1980年 | 14篇 |
1979年 | 13篇 |
1978年 | 12篇 |
1977年 | 11篇 |
1976年 | 11篇 |
1975年 | 8篇 |
1974年 | 10篇 |
1973年 | 7篇 |
1972年 | 14篇 |
排序方式: 共有1456条查询结果,搜索用时 203 毫秒
41.
42.
R. Kemp P. Hayward G. Applewhaite B. Everitt A. David 《BMJ (Clinical research ed.)》1996,312(7027):345-349
OBJECTIVE--To determine whether compliance therapy, a cognitive-behavioural intervention, could improve compliance with treatment and hence social adjustment in acutely psychotic inpatients, and if so, whether the effect persisted six months later. DESIGN--Randomised controlled trial of compliance therapy and non-specific counselling, each comprising 4-6 sessions lasting 10-60 minutes. SETTING--Acute psychiatric admissions ward serving an inner London catchment area. SUBJECTS--47 patients with psychosis. MAIN OUTCOME MEASURES--Informant and observer reported measure of compliance; observer assessed global functioning after intervention and three and six months later; self-rated attitudes to drug treatment after the intervention and one month later; symptom scores after intervention and six months later. RESULTS--25 patients received compliance therapy and showed significantly greater improvements in their attitudes to drug treatment and in their insight into illness and compliance with treatment compared with the control group. These gains persisted for six months. The intervention group was 5.2 times more likely than the control group to reach a criterion level of compliance (95% confidence interval 1.5 to 18.3). Global functioning showed a tendency to improve more in the intervention group after a delay (odds ratio 3.0 (0.8 to 11.5) to reach the criterion level at six months). Four subjects given compliance therapy and six in the control group were readmitted during follow up (odds ratio 2.0 (0.48 to 8.2)). CONCLUSIONS--Compliance therapy is a pragmatic method for improving compliance with drug treatment in psychotic inpatients and its gains persist for at least six months. Overall functioning may also be enhanced. 相似文献
43.
4-Thiaproline reduces heart lipid peroxidation and collagen accumulation in the diabetic db/db mouse
Summary Collagen accumulation is a main pathological feature of diabetic cardiomyopathy. The underlying mechanisms seem to be increased cross linking by reactive carbonyles. The purpose of the study was to decrease the collagen content of total ventricular tissue by the oral administration of thiaproline, which could reduce collagen due to its functions as a proline analogue, blocking collagen production and as a free oxygen radical scavenger, blocking reactive carbonyles and oxygen species and subsequently collagen cross linking.Thiaproline was administered to genetically diabetic db/db mice and compared to untreated animals. Total ventricular collagen as expressed by hydroxyproline was significantly lower in the treated group (means 0.23 micromoles/10 tissue in the treated vs 0.35 micromoles/100 mg tissue in the untreated group, p < 0.001). Significantly more collagen could be eluted in the treated group (p < 0.001) and carboxymethyllysine was significantly reduced in the treated group (p < 0.001). Di-tyrosine and glycemic control did not differ between the groups. Glutathione was significantly increased in the TP treated experimental group (p < 0.001) and lipid peroxidation products were significantly decreased (means 0.221 absorbance in the treated group versus 0.321 absorbance in the untreated diabetic group) correlating with total ventricular collagen content (r = 0.87, p < 0.01).We conclude that thiaproline reduced total ventricular collagen content by inhibiting collagen cross linking as reflected by increased solubility of collagen and expressed by higher elution quantity of collagen. Thiaproline, and/or its metabolites induced increase of heart glutathione which may well have been scavenging reactive carbonyles derived from lipid peroxidation and advanced stage nonenzymatic glycosylation as shown by decreased total ventricular carboxy-methyllysine and lipid peroxidation products paralleling reduced heart collagen content.It remains to be shown that the successful reduction of heart collagen by thiaproline is paralleled by improved functional properties. 相似文献
44.
45.
46.
T. Mainprize A. Shuaib MD FRCPC S. Ijaz R. Kanthan H. Miyashita J. Kalra 《Neurochemical research》1995,20(8):957-961
GABAergic neurons in the striatum are very sensitive to the effects of ischemia. The progressive decline in striatal GABA following transient forebrain ischemia in gerbils may be secondary to either a decreased production or an increase in reuptake mechanisms or both. The current experiment was designed to evaluate release of GABA by stimulation with K+ or inhibition of its uptake with nipecotic acid or their combination (K+ nipecotic) after repetitive forebrain ischemia in gerbils by in-vivo microdialysis on Days 1, 3, 5, and 14 following the insult. Infusion of nipecotic acid or potassium chloride, resulted in a significant increase in extracellular GABA. This response was significantly decreased in the post-ischemic animals. The synergistic effect of increased GABA concentrations by the infusion of nipecotic acid+potassium chloride seen in the controls was not evident in the post-ischemic animals. In conclusion, though there is a reduction in the extracellular GABA concentrations in the first week following an ischemic insult, restorative mechanisms are operative in the second week as seen by the increasing GABA concentrations. 相似文献
47.
48.
Prenatal diagnosis of cystic fibrosis by assay of amniotic fluid microvillar enzymes 总被引:2,自引:0,他引:2
Summary Activities of the microvillar enzymes -glutamyl-transpeptidase (GGTP), aminopeptidase M (APM), phosphodiesterase and maltase have been examined in second-trimester amniotic fluid as possible aids to the early prenatal diagnosis of cystic fibrosis (CF). The two peptidases, GGTP and APM, gave best results. If the fifth percentile of the normal range is used as an action line, the sensitivity of a positive test (low GGTP value) is 78% and the predictability 84%. At the tenth percentile the sensitivity is 100% and the predictability 77%. These approximate figures apply only to pregnancies where there has been a previous affected child. Until the primary protein defect in CF is discovered, this may prove an acceptable form of prenatal diagnosis to the high-risk mother. 相似文献
49.
Urine albumin excretion rates were measured in overnight timed samples from diabetic and non-diabetic schoolchildren. The excretion rates in the diabetics were significantly higher than those in the controls and were positively correlated with age, duration of diabetes, and glycaemic control. Diabetic children aged 12 years and older had significantly higher albumin excretion rates than younger diabetic children matched for duration of disease. Among the non-diabetic controls there was no correlation between albumin excretion rate and age and the girls excreted significantly more albumin than the boys. Measurement of the overnight albumin excretion rate may provide a useful early indicator of the progression to clinical proteinuria in diabetes and is free from random variations such as that due to exercise. 相似文献
50.
Summary Cilia of the 9+2 pattern are found electron microscopically in nonependymal cells of the habenulae and the interpeduncular nucleus of the tadpole of Rana esculenta at an early stage of development (8 mm length, head to tip of tail). A comparison is made between these and the ependymal and sensory cilia in the same specimens. The cilia project into the neuropil emerging from a perikaryon rich in free ribosomes and displaying a prominent Golgi apparatus. These perikarya contain dense core vesicles. Synapses with vesicles of the clear spherical type have been observed along the ciliary shaft. On a purely morphologic basis the authors hypothesize that these cilia, at least in this early ontogenetic stage, may extend considerably the conducting surface of the cell and represent a sensory structure which could be stimulated by terminal processes belonging to distantly located cells. In addition, they could also be involved in the trophic exchange of material with the adjacent structures. 相似文献