全文获取类型
收费全文 | 2847篇 |
免费 | 177篇 |
国内免费 | 76篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 86篇 |
妇产科学 | 39篇 |
基础医学 | 307篇 |
口腔科学 | 36篇 |
临床医学 | 315篇 |
内科学 | 761篇 |
皮肤病学 | 93篇 |
神经病学 | 127篇 |
特种医学 | 303篇 |
外科学 | 336篇 |
综合类 | 73篇 |
一般理论 | 2篇 |
预防医学 | 200篇 |
眼科学 | 36篇 |
药学 | 179篇 |
中国医学 | 4篇 |
肿瘤学 | 188篇 |
出版年
2021年 | 19篇 |
2020年 | 26篇 |
2019年 | 30篇 |
2018年 | 42篇 |
2017年 | 20篇 |
2016年 | 34篇 |
2015年 | 36篇 |
2014年 | 40篇 |
2013年 | 59篇 |
2012年 | 100篇 |
2011年 | 86篇 |
2010年 | 75篇 |
2009年 | 88篇 |
2008年 | 84篇 |
2007年 | 131篇 |
2006年 | 97篇 |
2005年 | 95篇 |
2004年 | 81篇 |
2003年 | 82篇 |
2002年 | 104篇 |
2001年 | 90篇 |
2000年 | 90篇 |
1999年 | 62篇 |
1998年 | 99篇 |
1997年 | 80篇 |
1996年 | 81篇 |
1995年 | 70篇 |
1994年 | 62篇 |
1993年 | 64篇 |
1992年 | 66篇 |
1991年 | 56篇 |
1990年 | 68篇 |
1989年 | 84篇 |
1988年 | 65篇 |
1987年 | 66篇 |
1986年 | 56篇 |
1985年 | 62篇 |
1984年 | 52篇 |
1983年 | 42篇 |
1982年 | 31篇 |
1981年 | 30篇 |
1980年 | 26篇 |
1979年 | 23篇 |
1978年 | 22篇 |
1977年 | 44篇 |
1976年 | 28篇 |
1975年 | 33篇 |
1974年 | 32篇 |
1973年 | 29篇 |
1972年 | 25篇 |
排序方式: 共有3100条查询结果,搜索用时 31 毫秒
51.
H M Lazarus D J Adelstein R H Herzig M C Smith 《American journal of kidney diseases》1983,2(5):521-525
Eight patients presented with simultaneous multiple myeloma and acute renal failure requiring hemodialysis. Patients had no known pre-existing renal disease nor exposure to nephrotoxic agents or x-ray contrast dye. Renal failure was attributed to light chain nephropathy in all cases. In 4 of these patients the diagnosis of myeloma was initially unsuspected. Renal biopsies in 3 of these patients, and post-mortem material in a fourth revealed the changes of "myeloma kidney." No patient regained renal function and all required chronic hemodialysis. Among these eight patients, three survived for periods greater than 21 months. 相似文献
52.
To compare the accuracy of end-tidal pCO2 measurement derived from the connector (petCO2 proximal) and from the tip of the endotracheal tube (petCO2 distal), we measured paCO2, petCO2-proximal and distal in 42 infants (weight: 2500-9500 g) manually ventilated with an Ayre's t-piece breathing circuit (Kuhn modification). For distal gas sampling we used a commercially available "uncuffed tracheal tube with monitoring lumen" Mallinckrodt, Hennef, with a separate monitoring lumen leading to the distal tip of the endotracheal tube. Compared with paCO2 (26.2 +/- 5.3 mmHg), proximal gas sampling resulted in a significantly lower petCO2 (17.3 +/- 6.0; P less than 0.001) and a large arterial-end-tidal pCO2 difference (pa-etCO2 9.0 +/- 6.8 mmHg). The correlation between paCO2 and petCO2 was poor (r = 0.29; n.s.). In infants weighing less than 5000 g the arterial-end-tidal pCO2 difference was found to be especially high (12.1 +/- 5.1 mmHg); it was slightly smaller in infants with more than 5000 g (5.6 +/- 7.0 mmHg). Distal petCO2 values approximated arterial pCO2 much better (petCO2 26.0 +/- 5.8 mmHg; diff pa-etCO2 0.4 +/- 3.0 mmHg, r = 0.86) even in very small children. In 12 children (weight: 2500-8000 g) ventilated with a circuit (Dr?ger-Kreissystem) accurate petCO2 measurements were obtained from both the proximal and the distal sampling site. Conclusions: When an Ayre's t-piece is used for ventilation of children weighing less than 10 kg, distal gas sampling for petCO2 measurement should be preferred. Proximal gas sampling does not allow correct capnometry except in a circuit with one-way valves. 相似文献
53.
54.
Lehmann O Jeltsch H Lehnardt O Pain L Lazarus C Cassel JC 《The European journal of neuroscience》2000,12(1):67-79
This study assessed behavioural and neurochemical effects of i.c.v. injections of both the cholinergic toxin 192 IgG-saporin (2 microgram) and the serotonergic toxin 5,7-dihydroxytryptamine (5,7-DHT; 150 microgram) in Long-Evans female rats. Dependent behavioural variables were locomotor activity, forced T-maze alternation, beam walking, Morris water-maze (working and reference memory) and radial-maze performances. After killing by microwave irradiation, the concentrations of acetylcholine, monoamines and 5-hydroxyindoleacetic acid (5-HIAA) were measured in the hippocampus, frontoparietal cortex and striatum. 192 IgG-saporin reduced the concentration of acetylcholine by approximately 40% in the frontoparietal cortex and hippocampus, but had no effect in the striatum. 5,7-DHT lesions reduced the concentration of serotonin by 60% in the frontoparietal cortex and 80% in the hippocampus and striatum. Noradrenaline was unchanged in all structures except the ventral hippocampus where it was slightly increased in rats given 192 IgG-saporin. Cholinergic lesions induced severe motor deficits but had no other effect. Serotonergic lesions produced diurnal and nocturnal hyperactivity but had no other effect. Rats with combined lesions were more active than those with only serotonergic lesions, showed motor dysfunctions similar to those found in rats with cholinergic lesions alone, and exhibited impaired performances in the T-maze alternation test, the water-maze working memory test and the radial-maze. Taken together and although cholinergic lesions were not maximal, these data show that 192 IgG-saporin and 5,7-DHT lesions can be combined to selectively damage cholinergic and serotonergic neurons, and confirm that cholinergic-serotonergic interactions play an important role in some aspects of memory, particularly in spatial working memory. 相似文献
55.
56.
Prealbumin is as important as albumin in the nutritional assessment of hemodialysis patients 总被引:6,自引:0,他引:6
BACKGROUND: Although serum prealbumin is considered a valid indicator of nutritional status in hemodialysis patients, there is relatively little evidence that its determination is of major prognostic significance. In this study, we aimed to determine the independent association of serum prealbumin with survival in hemodialysis patients, after adjusting for serum albumin and other indicators of protein energy nutritional status. METHODS: Serum prealbumin was measured in more than 1600 maintenance hemodialysis patients. We determined the correlations among prealbumin and other indicators of nutritional status, including serum albumin, and bioimpedance-derived indicators of body composition. The relationship between serum prealbumin and survival was determined using proportional hazards regression. RESULTS: The serum albumin was directly correlated with the serum prealbumin (r = 0.47, P < 0.0001), but still explained <25% of the variability in prealbumin. Prealbumin was inversely related to mortality, with a relative risk reduction of 6% per 1 mg/dL increase in prealbumin, even after adjusting for case mix, serum albumin, and other nutritional indicators. The increase in risk with lower serum prealbumin concentrations was observed whether the serum albumin was high or low. CONCLUSION: In hemodialysis patients, the serum prealbumin provides prognostic value independent of the serum albumin and other established predictors of mortality in this population. 相似文献
57.
J VALENTINE E ROSSI P O'LEARY TS PARRY JJ KURINCZUK P SLY 《Journal of paediatrics and child health》1997,33(2):117-120
To determine the prevalence of thyroid hormone abnormalities and generalized resistance to thyroid hormone in a population of children with attention deficit hyperactivity disorder (ADHD) as compared to reference ranges determined from a control population and hence to determine if routine thyroid hormone screening in children with non-familial ADHD is indicated.
Children attending the State Child Development Centre in Perth, Western Australia with ADHD, as defined by the Diagnostic and Statistical Manual of Mental Disorders (fourth edition) provided the study population. The control population consisted of 353 normal children with a history of allergy in whom radioallergosorbent (RAST) testing was being performed.
The prevalence of thyroid hormone abnormalities in the study population was 2.3% (95% CI 0.6%, 5.7%). There were no cases of generalized resistance to thyroid hormone. The prevalence of thyroid hormone abnormalities in the general population of children and adolescents has been reported to vary between 1 and 3.7%.
Routine thyroid hormone screening is not indicated in children with non-familial ADHD. 相似文献
Method:
Children attending the State Child Development Centre in Perth, Western Australia with ADHD, as defined by the Diagnostic and Statistical Manual of Mental Disorders (fourth edition) provided the study population. The control population consisted of 353 normal children with a history of allergy in whom radioallergosorbent (RAST) testing was being performed.
Results:
The prevalence of thyroid hormone abnormalities in the study population was 2.3% (95% CI 0.6%, 5.7%). There were no cases of generalized resistance to thyroid hormone. The prevalence of thyroid hormone abnormalities in the general population of children and adolescents has been reported to vary between 1 and 3.7%.
Conclusion:
Routine thyroid hormone screening is not indicated in children with non-familial ADHD. 相似文献
58.
JJ Rangasami DC Greenwood B McSporran PJ Smail CC Patterson NR Waugh 《Archives of disease in childhood》1997,77(3):210-213
OBJECTIVES: To calculate the incidence of type 1 diabetes in Scottish children aged less than 15 years between 1984 and 1993; to examine changes in incidence; and to calculate the prevalence of diabetes at the end of this period. DESIGN: Three data sources were used to construct the Scottish Study Group for the Care of Young Diabetics register: active reporting of all new cases; reports from the Scottish Morbidity Register 1; and local registers. SUBJECTS: All children resident in Scotland diagnosed with primary insulin dependent diabetes mellitus when less than 15 years of age between 1984 and 1993. MAIN OUTCOME MEASURES: Annual incidence and prevalence rate for Scotland; time trend in incidence over the 10 years; differences in incidence between the three different age groups; and completeness of the register. RESULTS: The average annual incidence for Scotland was 23.9/100,000 children. The prevalence rate was 1.5/1000 in 1993. A total of 2326 cases was identified from the three sources. Capture-recapture analysis suggests a case ascertainment of 98.6%. The annual incidence rates increased at a rate of 2% each year (rate ratio = 1.02, 95% confidence interval (CI) 1.01 to 1.03). The incidence was higher in boys than girls (rate ratio = 1.08, 95% CI 1.00 to 1.18), and the incidence rates increased with age: 15.3/100,000/year for age 0-4 years, 24.4/ 100,000/year for age 5-9 years, and 31.9/ 100,000/year for age 10-14 years. CONCLUSIONS: The incidence of type 1 diabetes in Scotland is increasing and the prevalence is relatively high. These findings have important implications for health service resource allocation. The Scottish Study Group for the Care of Young Diabetics' register provides a base for monitoring and research. 相似文献
59.
Auricular infections caused by high ear piercing in adolescents 总被引:1,自引:0,他引:1
60.
High-density lipoprotein subclasses and esterification rate of cholesterol in children: effect of gender and age 总被引:1,自引:0,他引:1
M. Dobi ov Z. Urbanov H. Rauchov M. am nek JJ Frohlich 《Acta paediatrica (Oslo, Norway : 1992)》1998,87(9):918-923
Since the development of coronary heart disease (CAD) is affected by a specific pattern of plasma high density lipoprotein (HDL) effects it may be useful to know whether this occurs already in childhood. In this study we evaluated particle size distribution of HDL by gradient gel electrophoresis and the determination of cholesterol esterification rate (FERHDL) in plasma depleted of apo B lipoproteins in 221 children (108 boys and 113 girls) aged 4 months to 20 years. Total plasma- (TC), low-density lipoprotein- (LDL-C) and HDL- (HDL-C) cholesterol, HDL unesterified cholesterol (HDL-UC) and plasma triglycerides (TG) were also measured. There were no significant gender and age differences with respect to the plasma TC, LDL-TC and TG but concentration of HDL-TC increased with age. Post-pubertal girls had significantly higher relative concentrations of HDL2b compared to boys (30.4% vs 17.2%), while HDL3b,c was lower in post-pubertal girls (8.7% vs. 16.5 %). FERHDL correlated inversely with HDL2b and positively with HDL3b,c particles and was significantly higher in boys of the post-pubertal group compared to girls (16.9%/h vs 12.5%/h). While in girls there was a positive correlation between age and HDL-C, HDL-UC and the relative concentration of HDL2b no significant correlation were observed in boys. In girls the increase in TC showed a significant correlation with a simultaneous increase in HDL-C, HDL-UC and HDL2b. In boys TC correlated significantly with changes in TG only. When HDL2b and HDL3b,c cholesterol levels are calculated from HDL-C concentration and per cent distribution the differences between males and females are further emphasized. These data indicate that HDL particle size distribution is age- and gender-dependent. 相似文献