全文获取类型
收费全文 | 1472651篇 |
免费 | 104982篇 |
国内免费 | 8865篇 |
专业分类
耳鼻咽喉 | 20191篇 |
儿科学 | 42295篇 |
妇产科学 | 39214篇 |
基础医学 | 223187篇 |
口腔科学 | 39410篇 |
临床医学 | 135893篇 |
内科学 | 269367篇 |
皮肤病学 | 29593篇 |
神经病学 | 106499篇 |
特种医学 | 57059篇 |
外国民族医学 | 261篇 |
外科学 | 220199篇 |
综合类 | 50482篇 |
现状与发展 | 24篇 |
一般理论 | 381篇 |
预防医学 | 111973篇 |
眼科学 | 34920篇 |
药学 | 115874篇 |
116篇 | |
中国医学 | 9145篇 |
肿瘤学 | 80415篇 |
出版年
2021年 | 13947篇 |
2019年 | 12425篇 |
2018年 | 16427篇 |
2017年 | 13123篇 |
2016年 | 14153篇 |
2015年 | 17645篇 |
2014年 | 24088篇 |
2013年 | 33184篇 |
2012年 | 46817篇 |
2011年 | 50410篇 |
2010年 | 30362篇 |
2009年 | 27127篇 |
2008年 | 44629篇 |
2007年 | 48188篇 |
2006年 | 47142篇 |
2005年 | 45669篇 |
2004年 | 42998篇 |
2003年 | 41152篇 |
2002年 | 39134篇 |
2001年 | 58349篇 |
2000年 | 59289篇 |
1999年 | 50089篇 |
1998年 | 15242篇 |
1997年 | 13641篇 |
1996年 | 13378篇 |
1995年 | 12605篇 |
1992年 | 40296篇 |
1991年 | 41197篇 |
1990年 | 40725篇 |
1989年 | 39493篇 |
1988年 | 36687篇 |
1987年 | 36299篇 |
1986年 | 34163篇 |
1985年 | 32996篇 |
1984年 | 25142篇 |
1983年 | 21456篇 |
1982年 | 12779篇 |
1979年 | 25074篇 |
1978年 | 18074篇 |
1977年 | 14953篇 |
1976年 | 14495篇 |
1975年 | 16366篇 |
1974年 | 19643篇 |
1973年 | 18873篇 |
1972年 | 17814篇 |
1971年 | 16646篇 |
1970年 | 15800篇 |
1969年 | 15064篇 |
1968年 | 13790篇 |
1967年 | 12591篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
102.
Patient history and clinical examination are important for the diagnosis of degenerative joint disease. Here the typical statements of a patient suffering from early osteoarthritis are described and, as far as possible, explained. The joint in question must be systematically examined. Furthermore, the neighboring joints and soft-tissue structures, i.e., muscles, tendons etc., should be examined and evaluated with respect to their importance in hindering the functional chain. The neuroreflectory mechanisms involved herein are described. 相似文献
103.
104.
Effects of the MAO-A-inhibitor brofaromine (BRO), 10 mg/kg po after repeated (twice daily for 14 days) administration on the spontaneous behavior (exploratory and basal locomotor activities) and the exploratory activity modified by methoxamine, clonidine and d-amphetamine in male Wistar rats were studied in both light and dark phases of a diurnal cycle (L: 0700-1900 h). After single administration BRO in the light phase had no effects. In the dark phase BRO decreased the exploration (62% of control, p less than 0.01), increased the clonidine-evoked hypoactivity and amphetamine-evoked hyperactivity. The L-D differences occurred also after repeated administration. BRO in the light phase did not influence the exploration, decreased basal locomotor activity, did not change methoxamine and clonidine action and potentiated the action of amphetamine. In the dark phase, however, it did not influence the exploration and basal locomotor activity, intensified the methoxamine effect, and did not change the clonidine and amphetamine actions. The results demonstrate that the effects of BRO on behavior in rats: 1) differ from the effects caused by other antidepressants which are not MAO inhibitors; 2) are phase-dependent after both single and repeated administration. 相似文献
105.
A new range of stand magnifiers has been released by the COIL company in the United Kingdom. Examination of these magnifiers reveals that they fail to deliver the rated magnifications labelled prominently on the appliances, as a result of the manufacturer's conformance with the requirements of the German DIN standard and the use of back vertex power (F'v) rather than equivalent dioptric power (Fm) of the magnifier. In this study we provide information on the optometric parameters of these new stand magnifiers that will assist the more accurate specification of improvements in vision expected from their use. 相似文献
106.
W. F. S. Sellers 《Anaesthesia》1996,51(5):513-513
107.
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
108.
W Lees 《Ultrasound in obstetrics & gynecology》1993,3(3):162-163
An ultrasound contrast agent which survives transit through the pulmonary circulation after injection into a peripheral vein can also be used for the demonstration of flow characteristics in the peripheral organs. Such a substance (SH U 508 A, Schering AG, Berlin) was tested in the Gynecological Department of the University of Marburg for its suitability for enhancing color-coded Doppler signals in mammary diagnosis in a group of ten women with breast tumors. The observations made are compared with the histologically confirmed diagnoses. The very distinct enhancement of the color-coded Doppler signals allows reliable demonstration of the vascularization characteristics, not only of the malignant, but also of all benign solid tumors examined. Color signals were even recorded from normal mammary tissue, which means that the demonstration of perfusion can no longer be used on its own as a diagnostic criterion. Observation of the characteristics of the blood supply to a tumor might, on the other hand, be an advantage, not only in respect of tumor typing, but also as regards the prognosis of a tumor. In this connection, the registration of the arrival, retention and wash-out phases specific to a contrast agent appears to furnish particularly interesting information about the growth dynamics of a tumor. 相似文献
109.
110.
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