全文获取类型
收费全文 | 530065篇 |
免费 | 27643篇 |
国内免费 | 495篇 |
专业分类
耳鼻咽喉 | 6681篇 |
儿科学 | 16930篇 |
妇产科学 | 12538篇 |
基础医学 | 92611篇 |
口腔科学 | 12347篇 |
临床医学 | 48506篇 |
内科学 | 95449篇 |
皮肤病学 | 11868篇 |
神经病学 | 34012篇 |
特种医学 | 19755篇 |
外国民族医学 | 53篇 |
外科学 | 78065篇 |
综合类 | 7610篇 |
现状与发展 | 2篇 |
一般理论 | 107篇 |
预防医学 | 38552篇 |
眼科学 | 11939篇 |
药学 | 41408篇 |
1篇 | |
中国医学 | 1126篇 |
肿瘤学 | 28643篇 |
出版年
2021年 | 3900篇 |
2018年 | 5732篇 |
2017年 | 4130篇 |
2016年 | 4870篇 |
2015年 | 5361篇 |
2014年 | 7118篇 |
2013年 | 10502篇 |
2012年 | 15585篇 |
2011年 | 17395篇 |
2010年 | 9960篇 |
2009年 | 8823篇 |
2008年 | 15715篇 |
2007年 | 17447篇 |
2006年 | 16940篇 |
2005年 | 16266篇 |
2004年 | 15883篇 |
2003年 | 15263篇 |
2002年 | 14784篇 |
2001年 | 22429篇 |
2000年 | 22970篇 |
1999年 | 18919篇 |
1998年 | 5232篇 |
1997年 | 4364篇 |
1996年 | 4397篇 |
1995年 | 4124篇 |
1992年 | 14413篇 |
1991年 | 15817篇 |
1990年 | 15949篇 |
1989年 | 15625篇 |
1988年 | 14308篇 |
1987年 | 14198篇 |
1986年 | 13168篇 |
1985年 | 12686篇 |
1984年 | 9394篇 |
1983年 | 8000篇 |
1982年 | 4177篇 |
1979年 | 8937篇 |
1978年 | 6382篇 |
1977年 | 5149篇 |
1976年 | 5504篇 |
1975年 | 6613篇 |
1974年 | 7419篇 |
1973年 | 7158篇 |
1972年 | 6597篇 |
1971年 | 6309篇 |
1970年 | 5887篇 |
1969年 | 5467篇 |
1968年 | 5161篇 |
1967年 | 4621篇 |
1966年 | 3963篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
OBJECTIVE: To determine the most frequent clinical causes of a prolonged activated partial thromboplastin time (APTT) result, and to determine whether a new heparin-removal device (the Hepchek, Pall Biomedical, Glen Cove, NY 11542) is capable of efficiently detecting the causes of these values. DESIGN: A combination of chart review and laboratory testing comparing the criterion standard--the heparin chromogenic substrate assay--with the Hepchek. Laboratory investigations were blinded and controlled. SETTING: Inpatient, acute-care hospital. PATIENTS: A total of 1,000 hospital patients with a variety of hemostatic disorders. MAIN OUTCOME MEASURE: The extent to which the Hepchek accurately identified the etiology of a prolonged APTT result. RESULTS: The APTT was prolonged in 25.2% of samples. The presence of heparin in the sample was confirmed by chromogenic assay or by using the Hepchek heparin-removal filter. The presence of heparin was confirmed in 12.8% of all samples and in more than 50% of all abnormal samples. The cause of the abnormal APTT was often unappreciated by the clinician. Bayesian analysis of the Hepchek's ability to diagnose heparin correctly as the cause of the abnormal APTT showed a sensitivity of 100% and specificity of 99.9%. CONCLUSION: Use of the Hepchek in the routine clinical laboratory is an efficient and rapid method of detecting heparin as a cause of isolated prolonged APTT results, and should reduce demands for unwarranted coagulation analyses and inappropriate treatment with blood products. 相似文献
52.
J. de Pedro-Cuesta V. Abraira G.-X. Jiang G. Solders S. Fredrikson 《Acta neurologica Scandinavica》1996,93(2-3):175-183
Using hierarchical cluster analysis, applied to 47 cases of Guillain-Barre Syndrome (GBS) incident in South-West Stockholm (SWS) during the period from January 1973 to June 1992, we identified three major clinicoepidemiological subgroups. The first subgroup, 25.5% of the cases (26.7 ± 6.7 years), recorded a peak incidence at ages 20–29 years and presented significant differences from other subgroups, a high proportion of cases with onset at low age preceded by respiratory infection (83.3%) and with normal motor conduction velocity (50.0%). Also found, were less affected biological parameters, a rapidly progressive course and independence in gait at one month after onset. A second subgroup, 27.7% of cases, was severely affected, clinically and functionally. It consisted predominantly of young individuals (22.7 ± 11.1 years), with a high incidence (69.2% of cases) in autumn. A third subgroup, comprising 40.47; of cases, was older (61.1 ± 11.0 years) and, in general, also severely affected. The incidence of this form appeared to be invariant with time. 相似文献
53.
54.
In experiments on albino rats it was established that three administrations of indomethacin in a dose of 0.01 g/kg body weight induced a severe damage of the liver characterized by disturbances of hepatocytic membranes, bile-producing and protein-producing functions of the liver, an enhancement of lipid peroxidation, a decrease of reduced glutathione pool. Antioxidants (tocopherol acetate, essentiale, legalon, flacumin) limit manifestations of indomethacin, hepatotoxicity, as a result of which tha functional-biochemical disorders in the liver show up to a lesser degree. During the combined use of antioxidants in indomethacin-induced lesions of the liver their hepatoprotective activity increases. 相似文献
55.
L R?stam R V Luepker M B Mittelmark D M Murray J S Slater H Blackburn 《American journal of preventive medicine》1988,4(5):249-254
To determine the potential effect of screening on referral patterns, an adult population sample (4,404 men, 5,164 women, 20-69 years of age) was systematically recruited and screened for hypercholesterolemia and then analyzed by different cholesterol referral recommendations. Using levels suggested by the Lipid Research Clinics Coronary Primary Prevention Trial (greater than or equal to 265 mg/dL), 7.3% of men and 5.8% of women would be referred for follow-up. With the suggested recommendations of the National Cholesterol Education Program (NCEP), (greater than or equal to 200 mg/dL), 49.2% of men and 40.2% of women would be referred. The use of age-related definitions of the NIH Consensus Conference on Lipid Lowering results in 28.0% referrals in men and 21.8% in women. From this population, hypercholesterolemia subjects (greater than or equal to 265 mg/dL at screening; n = 624) were invited for a second cholesterol determination (58% returned), which found 36% below the 265 mg/dL level. Population screening for cholesterol is likely to produce large numbers of patients for follow-up, with the actual numbers strongly dependent on cutoff levels and age-sex distributions. Referral and follow-up of these patients may place a significant load on an unprepared health care community. 相似文献
56.
57.
58.
59.
A. Giacometti O. Cirioni G. Greganti A. Fineo R. Ghiselli M. Del Prete F. Mocchegiani B. Fileni F. Caselli E. Petrelli V. Saba G. Scalise 《European journal of clinical microbiology & infectious diseases》2002,21(7):553-556
The in vitro activities of povidone iodine, potassium peroxymonosulfate, and dimethyldidecylammonium chloride were investigated
against 379 nosocomial isolates of Staphylococcus aureus and Pseudomonas aeruginosa responsible for surgical wound infections in patients operated on between July 1995 and June 2001. Overall, the isolates
were inhibited by the antiseptics at concentrations below those used routinely. In spite of increasing resistance to the various
antibiotics used to treat surgical wound infections, no significant variation in the susceptibility to antiseptics was demonstrated
during this 6-year study.
Electronic Publication 相似文献
60.