全文获取类型
收费全文 | 1719000篇 |
免费 | 136460篇 |
国内免费 | 4090篇 |
专业分类
耳鼻咽喉 | 24314篇 |
儿科学 | 55066篇 |
妇产科学 | 49727篇 |
基础医学 | 249882篇 |
口腔科学 | 49806篇 |
临床医学 | 154093篇 |
内科学 | 327842篇 |
皮肤病学 | 37240篇 |
神经病学 | 138295篇 |
特种医学 | 67751篇 |
外国民族医学 | 462篇 |
外科学 | 262882篇 |
综合类 | 44904篇 |
现状与发展 | 2篇 |
一般理论 | 636篇 |
预防医学 | 135557篇 |
眼科学 | 40847篇 |
药学 | 126788篇 |
3篇 | |
中国医学 | 3370篇 |
肿瘤学 | 90083篇 |
出版年
2018年 | 16708篇 |
2016年 | 14917篇 |
2015年 | 17096篇 |
2014年 | 23798篇 |
2013年 | 36487篇 |
2012年 | 48430篇 |
2011年 | 51249篇 |
2010年 | 30386篇 |
2009年 | 28630篇 |
2008年 | 48092篇 |
2007年 | 51626篇 |
2006年 | 51899篇 |
2005年 | 50354篇 |
2004年 | 49173篇 |
2003年 | 47234篇 |
2002年 | 45727篇 |
2001年 | 75137篇 |
2000年 | 76792篇 |
1999年 | 64760篇 |
1998年 | 18973篇 |
1997年 | 17325篇 |
1996年 | 17170篇 |
1995年 | 16345篇 |
1994年 | 15511篇 |
1993年 | 14530篇 |
1992年 | 53571篇 |
1991年 | 52570篇 |
1990年 | 51653篇 |
1989年 | 49922篇 |
1988年 | 46016篇 |
1987年 | 45953篇 |
1986年 | 43179篇 |
1985年 | 41979篇 |
1984年 | 31933篇 |
1983年 | 27282篇 |
1982年 | 16731篇 |
1981年 | 15256篇 |
1979年 | 31034篇 |
1978年 | 22421篇 |
1977年 | 18894篇 |
1976年 | 17698篇 |
1975年 | 18850篇 |
1974年 | 23195篇 |
1973年 | 22358篇 |
1972年 | 20890篇 |
1971年 | 19400篇 |
1970年 | 18323篇 |
1969年 | 17454篇 |
1968年 | 15938篇 |
1967年 | 14473篇 |
排序方式: 共有10000条查询结果,搜索用时 375 毫秒
991.
In the period 1979-1980 the following anthropometric measurements were recorded in 2351 healthy Dutch children from 0-17 years of age: height, weight, sitting height, arm span, lengths of upper-arm, lower-arm and hand, tibial length, foot length, biacromial diameter, biiliacal diameter, and head circumference. Corresponding percentile values were constructed on the basis of normality assumptions, the mean and standard deviation at age t being determined by a cubic spline approximation. The results are compared with other studies and given in the form of growth charts. 相似文献
992.
G Benton R C Thomas B G Nickerson J C McQuitty J Okikawa 《American journal of diseases of children (1960)》1989,143(6):678-681
Studies of adults suggest that metered-dose inhalers with spacers are as effective as hand-held nebulizers for bronchodilator delivery. We studied 13 children with acute asthma. They received two puffs every 2 minutes from metered-dose inhalers with spacers (range, 4 to 14 puffs) titrated until improvement stopped. Peak expiratory flow increased 34% for metered-dose inhalers with spacers after the first 2 puffs and increased 87% for metered-dose inhalers with spacers after dose titration. After titration, respiratory rate decreased by 12%, heart rate increased by 2%, and breath sounds improved in 92% of the patients. We concluded that the metered-dose inhalers with spacers are an effective device for the treatment of asthma in the pediatric emergency department and that the use of metered-dose inhalers with spacers with titration can achieve significant bronchodilation in the treatment of patients with acute asthma. 相似文献
993.
Experimental results in female rats with marginal magnesium deficiency a and clinical results in over 100 female tetanic patients suggest the deleterious influence of magnesium on oro-facial tissues. 相似文献
994.
Extensive clinical experience and anecdotal evidence indicate that application of laser technology has improved the management of many congenital and acquired diseases of the head and neck in pediatric patients. The general principles of laser surgery, with respect to laser-tissue interaction, must be adhered to at all times to achieve the best surgical effect. Improperly used, the laser can damage normal tissue in the infant's or child's larynx, with devastating consequences. 相似文献
995.
996.
H Matej M Ka?amarz B Nowakowska J Pacyńska A Myc 《Archivum immunologiae et therapiae experimentalis》1989,37(1-2):115-120
In our work we investigated factors which can influence the alloimmunization and especially the ranges of cytotoxic antibodies that develop in patients on dialysis awaiting their first graft. Up to 15 liters of administered blood the proportion of immunized patients is rather stabile, not exceeding 50%. After further transfusions the percentage of immunized patients is growing rapidly reaching about 85%. Hyperimmunization, marked by cytotoxic antibodies with more than 80% panel reactivity is significantly more frequent in patients who obtained 15 and more liters of blood. In females the hyperimmunization is about 4 times more frequent than in males. 相似文献
997.
Diflunisal, a lipophilic salicylate, is absorbed more slowly in healthy volunteers than aspirin. In this paper we report on attempts to influence diflunisal absorption by buffering the gastric milieu. Sodium bicarbonate given together and 30 min after diflunisal tablets significantly (p less than 0.05) shortened the time to reach peak plasma concentration (tmax greater than 15 per cent), raised maximum plasma concentration slightly (Cmax 6 per cent) and increased the area under the plasma concentration-time curve (AUC greater than 8 per cent). Other pharmacokinetic parameters, including terminal half-life and renal elimination of the compound, were not considerably influenced. These findings indicate that the absorption of diflunisal was enhanced by increased gastric pH, presumably a result of an increased solubility of diflunisal in the stomach together with faster transport into the small intestine. In one volunteer, after intravenous administration diflunisal plasma concentrations declined in a triphasic manner with a terminal half-life of 12.8 h. The volume of distribution was approximately 10 per cent of body weight. Based on the ratio of AUC after equivalent i.v. and oral diflunisal doses, the absolute bioavailability was 89.5 per cent. 相似文献
998.
L M van Wijk P den Heijer H J Crijns W H van Gilst K I Lie 《Journal of cardiovascular pharmacology》1989,13(1):32-36
We compared the efficacy of flecainide versus quinidine in preventing paroxysms of atrial fibrillation in a randomized open crossover study. Twenty-six patients with weekly attacks of atrial fibrillation during the last 3 months, objectified by 24-h holter monitoring or 12-lead electrocardiogram (ECG) were treated for a period of 3 months with flecainide 100 mg b.i.d. or quinidine 500 mg b.i.d. Efficacy was assessed by 24-h holter monitoring and a questionnaire at the end of each month. Dosage was adjusted to flecainide 100 mg t.i.d. or quinidine 500 mg t.i.d. if patients still had symptomatic paroxysms of atrial fibrillation according to a questionnaire or on holter monitoring. In 46% of the patients, flecainide 100 mg b.i.d. caused total abolition of supraventricular tachycardia; after dose adjustment it caused 50% total abolition. For quinidine, the figures are 16% (p less than 0.05) and 32% (NS), respectively. Side effects occurred with flecainide only after dose adjustment (23%), but on quinidine they occurred before (8%) and after dose adjustment (20%). We conclude that flecainide suppresses paroxysms of atrial fibrillation significantly more often as compared with quinidine in the lower dosage regimen. Optimal treatment dosage of flecainide is 100 mg b.i.d. After quinidine dose adjustment, the difference in efficacy is no longer significant. However, side effects necessitating discontinuation of quinidine developed in 20% of the patients as compared to none in patients treated with flecainide 100 mg b.i.d. 相似文献
999.
J. Saßmannshausen N. Bornfeld A. Kluge W. Sauerwein F. Härting A. Wessing 《International ophthalmology》1989,13(4):243-251
Advanced malignant melanomas of the uvea unsuited for an eye salvaging approach require enucleation of the tumor containing eye. A series of 68 patients is reported who underwent enucleation combined with insertion of a spherical dura-encased implant after 30 Gray pre-irridiation therapy of the orbit. Postoperative results with special attention to cosmetic outcome and motility of the prosthesis suggest that the insertion of an orbital implant should be preferred to the enucleation with no implant. 相似文献
1000.
M K Song W Y Shin N F Adham N V Costea 《The American journal of clinical nutrition》1989,49(4):701-707
The effects of different amounts of dietary zinc on the Zn absorption rate and on Zn, calcium and magnesium concentrations in tissues of MOPC 104E tumor-bearing Balb/c mice were determined. The Zn absorption rate was inversely related to the amounts of Zn in their diets and was lower than that of nontumor-bearing control mice fed a laboratory mice chow. Zn concentrations of tumor-bearing mice were also low compared with control mice but tumor Zn concentrations, regardless of the concentrations of Zn in the diets, were higher than those of normal tissues of the host other than the pancreas. Ca concentrations in tumor and tissues of tumor-bearing mice were higher than in control animals but Mg concentrations in tissues of tumor-bearing mice appeared to be similar to those of control mice. Results suggest that tumor-bearing mice have a lower intestinal Zn absorption capacity and a higher Zn uptake rate causing other tissues to become hypozincemic and hypercalcemic. 相似文献