全文获取类型
收费全文 | 55080篇 |
免费 | 7739篇 |
国内免费 | 129篇 |
专业分类
耳鼻咽喉 | 954篇 |
儿科学 | 1928篇 |
妇产科学 | 1608篇 |
基础医学 | 4847篇 |
口腔科学 | 1547篇 |
临床医学 | 9894篇 |
内科学 | 12701篇 |
皮肤病学 | 733篇 |
神经病学 | 4419篇 |
特种医学 | 1043篇 |
外国民族医学 | 1篇 |
外科学 | 5320篇 |
综合类 | 382篇 |
现状与发展 | 2篇 |
一般理论 | 49篇 |
预防医学 | 8823篇 |
眼科学 | 665篇 |
药学 | 2561篇 |
中国医学 | 44篇 |
肿瘤学 | 5427篇 |
出版年
2024年 | 183篇 |
2023年 | 1339篇 |
2022年 | 799篇 |
2021年 | 1491篇 |
2020年 | 1762篇 |
2019年 | 1329篇 |
2018年 | 2162篇 |
2017年 | 1959篇 |
2016年 | 2229篇 |
2015年 | 2268篇 |
2014年 | 3225篇 |
2013年 | 4164篇 |
2012年 | 3663篇 |
2011年 | 3757篇 |
2010年 | 2763篇 |
2009年 | 3015篇 |
2008年 | 3338篇 |
2007年 | 3150篇 |
2006年 | 3391篇 |
2005年 | 2979篇 |
2004年 | 2705篇 |
2003年 | 2359篇 |
2002年 | 2249篇 |
2001年 | 505篇 |
2000年 | 435篇 |
1999年 | 516篇 |
1998年 | 747篇 |
1997年 | 578篇 |
1996年 | 487篇 |
1995年 | 395篇 |
1994年 | 365篇 |
1993年 | 316篇 |
1992年 | 238篇 |
1991年 | 202篇 |
1990年 | 198篇 |
1989年 | 184篇 |
1988年 | 154篇 |
1987年 | 131篇 |
1986年 | 141篇 |
1985年 | 136篇 |
1984年 | 142篇 |
1983年 | 116篇 |
1982年 | 107篇 |
1981年 | 110篇 |
1980年 | 86篇 |
1979年 | 53篇 |
1978年 | 45篇 |
1977年 | 55篇 |
1976年 | 34篇 |
1975年 | 40篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
GILBERTE A. VANSINTEJAN RN MPH EDD PETER J. PURDY MPH 《Journal of obstetric, gynecologic, and neonatal nursing : JOGNN / NAACOG》1986,15(6):492-495
Since the mid-1970s, the Margaret Sanger Center of Planned Parenthood of New York City has prepared nurses and nurse midwives from less developed countries to be family-planning nurse practitioners. These nurse practitioners then provide services to patients, train other staff, and manage integrated family-planning clinics. More than 120 nurses and nurse midwives have arrived in groups of 10 at the Sanger Center, with 72 attending since 1981. Each course lasts 10 weeks. The core curriculum provides trainees with skills in women's health care including contraception, in training and advocacy, and in management of clinics. Whether, in the current period of scarce resources, cross-cultural training programs of this type remain a worthwhile investment, and if so, which of their components are most important to this success, is assessed. 相似文献
73.
An ecologically based examination of barriers to physical activity in students from grade seven through first-year university 总被引:1,自引:0,他引:1
Nancy C. Gyurcsik Ph.D. Kevin S. Spink Ph.D. Steven R. Bray Ph.D. Karen Chad Ph.D. Matt Kwan B.Sc. 《The Journal of adolescent health》2006,38(6):704-711
PurposeThe first purpose was to identify barriers to physical activity that students in grade seven through first-year university experienced. A second purpose was to classify barriers using an ecological framework and to examine the pattern of barrier categories (i.e., intrapersonal, interpersonal, institutional, community, public policy, and physical environmental) and specific barrier types as grade increased. The use of an ecological model addressed limitations in prior research revolving around the identification of salient barriers in a manner that makes the design of effective interventions difficult.MethodsParticipants in grades 7–8 (n = 35), 9–10 (n = 67), 11–12 (n = 80), and the freshmen year of university (n = 109) listed barriers to physical activity on an open-ended measure.ResultsFindings revealed a trend for the average number of barriers reported per student to increase as grade in school increased. First-year university students reported significantly more barriers than all other grade groupings. The frequency of barriers reported within the ecological categories was dependent on the specific grade groupings. Further, within each ecological category, distinct barriers were reported across the different grade groupings.ConclusionsFindings highlight the utility of using an ecological model to categorize barriers, rather than simply classifying barriers as internal or external to an individual, as done in prior research. Understanding the pattern of ecologically based barrier categories and specific types of barriers will help to inform the content of future research and interventions designed to alleviate salient barriers to physical activity. 相似文献
74.
75.
76.
Ricardo J. Wray Jo Ellen Stryker Eric Winer George Demetri Karen M. Emmons 《Journal of cancer education》2007,22(1):21-24
Background. Accepted practices of informed consent often result in suboptimal patient understanding of research studies.Methods. This pilot study aimed to assess trial-specific tailored materials, compared to a widely used generic booklet about clinical
trials, randomly assigned to 118 candidates for cancer clinical trials. Study outcomes were: satisfaction with decision-making;
satisfaction with materials; and subjective understanding of the clinical trial.Results. There were no major differences between groups. Participants rated tailored materials higher as a useful reference.Conclusions. Trial-specific materials hold utility for reference during clinical trials. Studies of informed consent are feasible, although
important factors limit research. 相似文献
77.
Fix Joseph A. Alexander Jose Cortese Margot Engle Karen Leppert Paula Repta A. J. 《Pharmaceutical research》1990,7(4):384-387
Short-chain alkyl esters of L-dopa were administered to rats and mice via oral and rectal routes. Plasma L-dopa esters and L-dopa were determined in the systemic and portal circulation by HPLC. A comparison of isopropyl, butyl, and 4-hydroxybutyl esters of L-dopa demonstrated significantly higher levels of the esters in both systemic and portal blood samples following rectal administration than following oral administration. In most cases, oral administration resulted in nondetectable (<0.01 µg/ml) levels of the esters in plasma. Correspondingly, the plasma levels of L-dopa itself were consistently higher following rectal administration. At very high oral doses (500 mg L-dopa equivalents/kg body weight), systemic plasma levels of the butyl ester could be detected (1.25 µg/ml at 10 min), which might indicate saturation of the esterase activity of the small intestine. These studies indicate that the systemic availability of L-dopa from short-chain alkyl esters of L-dopa may be best optimized by rectal administration, which avoids the relatively high esterase activity characteristic of the small intestine. 相似文献
78.
Walter F. McKeever Karen S. Seitz Annette J. Krutsch Patti L. Van Eys 《Neuropsychologia》1995,33(12):1627-1635
Rasmussen and Milner [N.Y. Acad. Sci. Vol. 299, pp. 355–379, 1977] published data on late-lesioned (after age 6) epileptic patients who had suffered left hemisphere lesions. They estimated that left hemisphere dominance occurred in 96% of dextrals and 70% of sinistrals. These figures have been regarded as valid estimates for normal dextrals and sinistrals. We administered the Bilateral Object Naming Latency Task, a verbal tachistoscopic task with very good psychometric properties, to 188 dextral and 72 sinistral normals. Results showed that 93.6% of the dextrals and 80.3% of the sinistrals were left hemisphere dominant. A consideration of results from a number of carefully conducted dichotic listening studies suggests, as do present results, that the 70% left-dominance estimate of Rasmussen and Milner for normal sinistrals may be too low by about 10%. It is suggested that ‘bilateral dominance’, present in 15% of the epileptic sinistrals of Rasmussen and Milner, may be much less common in normal sinistrals. 相似文献
79.
MARIE A. BERNARD MD VICKI LAMPLEY-DALLAS MD MPH LULA SMITH RN MPH 《Journal of the American Dietetic Association》1997,97(7):771-776
This article reviews the primary health problems of African-American, Hispanic-American, Asian/Pacific Islander-American, and Native-American elders. The goal is to familiarize practicing dietitians with the differences in longevity, disease spectrum, and functional status (where data are available) for each of these ethnic groups. These data should be of assistance in making decisions regarding dietary counseling for ethnic elders. It is acknowledged that most data accumulated according to race do not accurately measure ethnicity. The degree of acculturation may vary widely among individuals. Therefore, it is recommended that dietitians solicit clients’ perceptions of the factors that may contribute to illness and the barriers to implementing recommended remedies. 相似文献
80.