全文获取类型
收费全文 | 8756篇 |
免费 | 870篇 |
国内免费 | 62篇 |
专业分类
耳鼻咽喉 | 55篇 |
儿科学 | 176篇 |
妇产科学 | 162篇 |
基础医学 | 1235篇 |
口腔科学 | 211篇 |
临床医学 | 1035篇 |
内科学 | 1891篇 |
皮肤病学 | 80篇 |
神经病学 | 966篇 |
特种医学 | 596篇 |
外科学 | 997篇 |
综合类 | 200篇 |
一般理论 | 2篇 |
预防医学 | 844篇 |
眼科学 | 272篇 |
药学 | 526篇 |
中国医学 | 9篇 |
肿瘤学 | 431篇 |
出版年
2021年 | 136篇 |
2020年 | 81篇 |
2019年 | 135篇 |
2018年 | 143篇 |
2017年 | 111篇 |
2016年 | 105篇 |
2015年 | 133篇 |
2014年 | 189篇 |
2013年 | 295篇 |
2012年 | 444篇 |
2011年 | 396篇 |
2010年 | 234篇 |
2009年 | 217篇 |
2008年 | 361篇 |
2007年 | 389篇 |
2006年 | 361篇 |
2005年 | 328篇 |
2004年 | 336篇 |
2003年 | 267篇 |
2002年 | 317篇 |
2001年 | 260篇 |
2000年 | 209篇 |
1999年 | 208篇 |
1998年 | 143篇 |
1997年 | 116篇 |
1996年 | 156篇 |
1995年 | 125篇 |
1994年 | 113篇 |
1993年 | 112篇 |
1992年 | 221篇 |
1991年 | 192篇 |
1990年 | 196篇 |
1989年 | 219篇 |
1988年 | 208篇 |
1987年 | 193篇 |
1986年 | 170篇 |
1985年 | 190篇 |
1984年 | 148篇 |
1983年 | 128篇 |
1982年 | 84篇 |
1981年 | 83篇 |
1980年 | 84篇 |
1979年 | 110篇 |
1978年 | 94篇 |
1977年 | 95篇 |
1975年 | 79篇 |
1974年 | 85篇 |
1973年 | 78篇 |
1972年 | 70篇 |
1970年 | 70篇 |
排序方式: 共有9688条查询结果,搜索用时 15 毫秒
21.
22.
23.
Adult physical activity behavior: a trend analysis 总被引:1,自引:0,他引:1
C Brooks 《Journal of clinical epidemiology》1988,41(4):385-392
One of the health objectives for the nation is to have 60% of adults 18-64 years regularly active in vigorous physical activity by 1990. In this paper an effort is made to determine whether American society is making satisfactory progress toward this goal. Two independent databases are analyzed: time diaries collected from a national sample of American adults in 1981; and the Simmons Market Research Bureau, Inc., survey undertaken in 1984. Participation of adults 25-64 in moderate to vigorous activities that included racquet sports, swimming, hiking, bicycling, skiing, jogging, outdoor gardening, skating, etc. is compared between the two time periods. After adjusting for social desirability bias the results indicated there were a similar number of non-participants of the activities analyzed in 1981 and 1984. There was, however, an increase in the number of adults participating occasionally in vigorous activity, although, there did not appear to be any increase in the number who were regularly active, i.e. at least 3 days/week. Thus, while there are indications that adults 25-64 years are adopting more vigorous activity, less than 20% were regular enough in 1984 for improvements in cardiovascular functioning to occur. Unless there were dramatic increases in the activity status of adults 18-24 years of age which was not assessed in this study, the 1990 goal is unlikely to be met. 相似文献
24.
We report a case of Fusarium solani keratitis which highlights the difficulties often associated with management of fungal corneal infections. This case demonstrates several unusual and interesting features: the occurrence of deep fungal pathology after superficial injury, the difficulties encountered in attempting to isolate and identify the causative organism, and the protracted course taken by an organism often noted to be rapidly destructive. These features necessitated an individual approach to therapy, employing unconventional medical and surgical techniques to achieve a satisfactory outcome 相似文献
25.
26.
27.
The effect of solvent conditions on the aggregation of IgM in serum specimens from patients with macroglobulinemia was studied by a turbidimetric procedure. Aggregation of IgM varied considerably among the samples and was affected by a number of experimental parameters. In general, IgM aggregation was more pronounced under acidic conditions and in solvents with low ionic strength. The presence of water-miscible organic solvents also promoted aggregation. Based on these studies, it was concluded that the major force involved in the formation of immunoglobulin aggregates in the serum of patients with macroglobulinemia was electrostatic, rather than hydrophobic, interactions. A number of additives known to prevent protein aggregation were evaluated for their effectiveness in inhibiting IgM aggregation. The only additives that were shown to inhibit or reduce IgM aggregation were charged molecules, such as arginine, sodium chloride, ethylenediamintetraacetic acid and quaternary ammonium beta-cyclodextrin. Some of these charged additives were also effective in dissociating the IgM aggregates once they were formed, even in the presence of detergent. 相似文献
28.
Excellent interobserver and intraobserver reliability (reproducibility) was seen for the grip strength, walking time and button test measures in 40 patients with rheumatoid arthritis (RA), when measurement was performed according to a standard protocol. Evidence of reliability, coupled with the observation that baseline measures predict longterm morbidity and mortality in individual patients, suggests that these measures might be more widely used in general rheumatologic care. 相似文献
29.
30.
M L Brooks D P Mayer R T Sataloff D L Myers J R Spiegel S Ruiz 《Computerized medical imaging and graphics》1992,16(4):283-285
A patient with a surgically proven intracanalicular arachnoid cyst was studied using computed tomography, magnetic resonance imaging, and air CT cisternography. The lesion had a similar radiographic appearance to acoustic neuroma and therefore, although rare, must be considered in the differential diagnosis of intracanalicular mass lesions. We report a case in which examination was performed, in evaluating the lesion, utilizing high-resolution air CT cisternography and magnetic resonance imaging (MRI). 相似文献