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1.
BARI NUHOLU ALI AYYILDIZ VECIHI FIDAN ÖZDEN CEBECI UUR KOAR CANKON GERMIYANOLU 《International journal of urology》2006,13(2):109-110
OBJECTIVE: Nocturnal enuresis is a common pediatric problem, the etiology of which is unclear. In recent years, various studies have been published stating that children with nocturnal enuresis exhibit growth and skeletal maturation retardation. METHODS: In this cross-sectional study, we included 27 patients (16 boys, 11 girls) between the ages of 6 and 14 years who had presented with primary nocturnal enuresis (PNE) complaints. We included in the evaluation 19 healthy subjects (12 boys, 7 girls), who were the siblings of the children with PNE, as the control group. RESULTS: The patients in both groups were similar in chronological age, bone age, height and weight, with no significant difference between groups (P>0.05). CONCLUSION: The two groups in our study consisted of the same genetic background. Thus, our results were found to be different from the previous studies. We have concluded that there is no direct relationship between enuresis nocturnal and skeletal maturation. 相似文献
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The cardiac effects of terfenadine after inhibition of its metabolism by grapefruit juice 总被引:2,自引:0,他引:2
C. P. Clifford D. A. Adams S. Murray G. W. Taylor M. R. Wilkins A. R. Boobis D. S. Davies 《European journal of clinical pharmacology》1997,52(4):311-315
Objective: To determine whether the pharmacokinetics and electrocardiographic pharmacodynamics of terfenadine are affected by the concomitant
administration of grapefruit juice.
Methods: Six healthy volunteers were recruited for a balanced cross-over study. Each volunteer received 120 mg terfenadine 30 min
after drinking 300 ml of either water or freshly squeezed grapefruit juice. The alternative treatment was administered on
the second study day 2 weeks later. Measurements of the area under the terfenadine plasma concentration-time curve (AUC),
maximum terfenadine concentration (Cmax) and the time to maximum concentration (tmax) were made, and the corrected QT (QTc) interval was measured from the surface electrocardiogram.
Results: Terfenadine was quantifiable in plasma in all 6 subjects on both study days for up to 24 h post-dosing. The AUC of terfenadine
was significantly increased by concomitant grapefruit administration (median values 40.6 vs 16.3 ng · ml−1 · h), as was the Cmax (median values 7.2 vs 2.1 ng · ml−1). The tmax was not significantly increased and there was no significant change in the median QTc interval despite the increased terfenadine
levels. The 95% confidence interval for the difference in the change in QTc interval at Cmax was −13 to +38 ms.
Conclusion: Administration of grapefruit juice concomitantly with terfenadine may lead to an increase in terfenadine bioavailability,
but the increase observed in this study did not lead to significant cardiotoxicity in normal subjects. However, this does
not exclude the risk of cardiotoxicity in high-risk subjects given greater doses of grapefruit juice over longer periods of
time.
Received: 14 October 1996 / Accepted in revised form: 10 December 1996 相似文献
5.
Septic or inflammatory stimuli suppress drug metabolism by cytochrome P-450 in the liver, presumably at the pretranslational level. We have shown previously that nitric oxide is responsible at least in part for the inhibition by bacterial lipopolysaccharide of phenobarbital-induced CYP2B1/2 activity in vivo. This was attributed to the interaction of nitric oxide with heme in the active-center of cytochrome P450, leading to enzyme inactivation. Here, we report of nitric oxide with heme in the active-center of cytochrome P450, leading to enzyme inactivation. Here, we report that endogeneous nitric oxide also contributes to LPS-induced suppression of CYP2B1/2 in vivo by down-regulating the expression of CYP2B1/2 protein and mRNA. 相似文献
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Cytoprotection by iloprost against paracetamol-induced toxicity in hamster isolated hepatocytes. 总被引:1,自引:0,他引:1
P. Nasseri-Sina D. J. Fawthrop J. Wilson A. R. Boobis D. S. Davies 《British journal of pharmacology》1992,105(2):417-423
1 The ability of iloprost (ZK36374) to protect hamster isolated hepatocytes from the toxic effects of paracetamol and its reactive metabolite N-acetyl-p-benzoquinoneimine (NABQI) was investigated. The cytoprotection provided by iloprost was compared with that of N-acetyl-L-cysteine. 2 Treatment of hepatocytes with either NABQI (0.4 mM) or paracetamol (2 mM) alone resulted in a considerable loss of cell viability, as assessed by trypan blue exclusion or leakage of lactate dehydrogenase, accompanied by an increase in the percentage of viable cells that were blebbed. N-acetyl-L-cysteine (1.25 mM) pretreatment diminished the loss of cell viability and the percentage of blebbed cells resulting from exposure to NABQI or paracetamol, whereas iloprost (10(-16) M to 10(-10) M) pretreatment reduced only the loss of cell viability, not the percentage of viable cells exhibiting blebbing. Pretreatment with N-acetyl-L-cysteine significantly attenuated the depletion by paracetamol of glutathione and decreased the covalent binding of [14C]-paracetamol to cellular proteins, whereas iloprost was without any such effects. 3 The effects of iloprost and N-acetyl-L-cysteine were also investigated by use of a model of paracetamol toxicity in which it is possible to study the biochemical events leading to cell injury separate from the generation of toxic metabolites. Hamster hepatocytes were incubated with paracetamol (4 mM) for 90 min at 37 degrees C during which metabolism of paracetamol occurs with minimal loss of cell viability.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
8.
The toxicity of paracetamol has been investigated in freshly isolated hamster hepatocytes. Two phases of toxicity have been identified. In phase 1, metabolic activation of paracetamol occurs with depletion of glutathione. In phase 2, there is progressive morphological damage, leading ultimately to cell death. This occurs even in the absence of further exposure to paracetamol. The thiol reductant, dithiothreitol, added at the start of phase 2, prevents and reverses the toxicological damage that would otherwise occur. Thus, it is most likely that paracetamol causes hepatotoxicity through oxidation of SH groups in key enzymes. N-Acetylcysteine, but not methionine, has an effect similar to that of dithiothreitol. This difference is probably due to oxidation of the enzymes involved in the conversion of methionine to cysteine, whereas N-acetylcysteine can still serve as a precursor of glutathione. The glutathione can act both by adduct formation with the metabolite of paracetamol and as a thiol reductant. Species differences in sensitivity to paracetamol toxicity were shown to be due to differences in the rate of oxidation of the drug to its toxic metabolite. Most people are relatively poor activators of paracetamol, but in few subjects the reaction proceeds quite rapidly, rendering such individuals more sensitive to the hepatotoxic effects of the drug. 相似文献
9.
Bufuralol 1'-hydroxylase activity of the rat. Strain differences and the effects of inhibitors 总被引:1,自引:0,他引:1
The kinetics of bufuralol 1'-hydroxylase activity of hepatic microsomal fractions have been determined in female DA and Fischer 344 rats, strains between which there is a large difference in debrisoquine 4-hydroxylase activity. Two components of bufuralol 1'-hydroxylase activity could be observed in both strains. Although there were differences between the strains in Vmax and Km of both components of activity, these were much less marked than the differences previously reported for debrisoquine 4-hydroxylase (Kahn et al., Drug Metab. Dispos. 13, 510 (1985)). The kinetics of bufuralol 1'-hydroxylase activity were such that the difference in activity between the strains varied with the concentration of bufuralol, 4-5-fold at 2.5 microM, no difference at 100 microM Competitive inhibitors of debrisoquine 4-hydroxylase activity in man were competitive inhibitors of bufuralol 1'-hydroxylase activity in the Fischer 344 rat, but not in the DA rat. The Ki for inhibition of bufuralol 1'-hydroxylase activity by debrisoquine in the Fischer 344 rat was 184 microM, compared with a Km for the 4-hydroxylation of this compound of 10.5 microM. It is concluded that the major isozyme of cytochrome P-450 catalysing the 1'-hydroxylation of bufuralol in the rat is different from that catalysing debrisoquine 4-hydroxylation (P-450UT-H). 相似文献
10.
Serum ionic fluoride levels in haemodialysis and continuous ambulatory peritoneal dialysis patients 总被引:1,自引:1,他引:0
al-Wakeel JS; Mitwalli AH; Huraib S; al-Mohaya S; Abu-Aisha H; Chaudhary AR; al-Majed SA; Memon N 《Nephrology, dialysis, transplantation》1997,12(7):1420-1424
High serum fluoride (F-) in patients with chronic renal failure (CRF) and
end-stage renal disease (ESRD) is associated with risk of renal
osteodystrophy and other bone changes. This study was done to determine F-
in normal healthy controls and patients with ESRD on haemodialysis (HD) or
peritoneal dialysis (PD). Seventeen healthy controls (12 males, 5 females)
and 39 ESRD patients on dialysis (17 males, 22 females) were recruited in
the study in a community with 47.4 +/- 3.28 microM/l (range 44-51 microM/l)
of F- content in drinking water. Control subjects showed a mean serum F-
concentration of 1.08 +/- 0.350 microM/l. Males in control group showed
slightly higher F- levels (1.15 +/- 0.334, range 0.55-1.9 microM/l) than
females (0.92 +/- 0.370, range 0.6-1.5 microM/l). Mean serum F-
concentration did not correlate significantly with age and sex among
control subjects, whereas such correlation was observed in patients with
ESRD on dialysis. Mean serum F- concentration was significantly higher in
patients on dialysis (2.67 +/- 1.09, range 0.8-5.2 microM/l) than normal
controls. When grouped according to sex, the mean serum F- concentration in
males (3.05 +/- 1.04, range 1.8-5.2 microM/l) was significantly higher than
females (2.38 +/- 1.08, range 0.8-5.2 microM/l). When patients were grouped
according to age, it was observed that F- concentration was significantly
higher in patients with age groups 21-70 (2.86 +/- 1.05) than those with
age group 13-20 years (1.42 +/- 0.531). Thus F- concentration correlated
with age and sex, being higher in males and above 20 years. Despite
appreciable clearance of F- (39-90%) across the peritoneum, patients on
CAPD showed higher serum F- concentration than those on HD (3.1 +/- 1.97 vs
2.5 +/- 1.137 microM/l). Of the total 39 patients on dialysis 39% had their
serum F- concentration above 3.0 microM/l, posing the risk of renal
osteodystrophy.
相似文献