全文获取类型
收费全文 | 30609篇 |
免费 | 2242篇 |
国内免费 | 2427篇 |
专业分类
耳鼻咽喉 | 90篇 |
儿科学 | 325篇 |
妇产科学 | 1240篇 |
基础医学 | 1770篇 |
口腔科学 | 619篇 |
临床医学 | 2683篇 |
内科学 | 7870篇 |
皮肤病学 | 1438篇 |
神经病学 | 4064篇 |
特种医学 | 878篇 |
外科学 | 7040篇 |
综合类 | 293篇 |
预防医学 | 4823篇 |
眼科学 | 161篇 |
药学 | 841篇 |
中国医学 | 9篇 |
肿瘤学 | 1134篇 |
出版年
2018年 | 279篇 |
2017年 | 424篇 |
2016年 | 1058篇 |
2015年 | 1037篇 |
2014年 | 1288篇 |
2013年 | 2178篇 |
2012年 | 487篇 |
2011年 | 630篇 |
2010年 | 1034篇 |
2009年 | 1487篇 |
2008年 | 598篇 |
2007年 | 573篇 |
2006年 | 1099篇 |
2005年 | 922篇 |
2004年 | 737篇 |
2003年 | 845篇 |
2002年 | 830篇 |
2001年 | 956篇 |
2000年 | 721篇 |
1999年 | 828篇 |
1998年 | 827篇 |
1997年 | 816篇 |
1996年 | 1002篇 |
1995年 | 1147篇 |
1994年 | 963篇 |
1993年 | 843篇 |
1992年 | 882篇 |
1991年 | 777篇 |
1990年 | 642篇 |
1989年 | 619篇 |
1988年 | 588篇 |
1987年 | 629篇 |
1986年 | 507篇 |
1985年 | 614篇 |
1984年 | 538篇 |
1983年 | 453篇 |
1982年 | 463篇 |
1981年 | 431篇 |
1980年 | 406篇 |
1979年 | 387篇 |
1978年 | 355篇 |
1977年 | 348篇 |
1976年 | 276篇 |
1975年 | 229篇 |
1974年 | 217篇 |
1973年 | 182篇 |
1972年 | 147篇 |
1968年 | 151篇 |
1967年 | 164篇 |
1966年 | 131篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
3.
4.
5.
Iron Fortification of Flours in Venezuela 总被引:1,自引:0,他引:1
This paper reviews a conference about the impact of the iron fortification program in Venezuela; it was presented at the Pan American Health Organization regional technical meeting: "Iron Fortification: Where Are We in Terms of Iron Compounds," held in Washington January 10–12, 2001. Some of the data presented were published in the American Journal of Clinical Nutrition , including stimulating results about the impact of fortification of precooked corn and white wheat flours, as well as the prevalence of anemia and iron deficiency in the Venezuelan population. This article reports results from three surveys carried out in 1997, 1998, and 1999 on the same age and socioeconomic group that had been evaluated in 1990, 1992, and 1994. This article also shows the impact of iron fortification programs and the influence of other factors on the prevalence of iron deficiency and anemia during the last 7 years. 相似文献
6.
Elizabeth Campbell Ph.D. Danna Peterkin R.N. Richard Abbott M.B. B.S. John Rogers M.B. B.S. 《Preventive medicine》1997,26(6):801-807
Background.Computers that collect data from patients and provide both patients and practitioners with printed feedback on a range of health risks are a tool for assisting general practitioners with preventive care. This study assessed the impact of computer-generated printed feedback on cervical screening among women who were underscreened for cervical cancer.Method.Female attenders at two Australian general practices were randomly allocated to Experimental or Control groups. Women in both groups completed a health risk survey on a touch screen computer prior to their consultation. Those in the Experimental group received printed pages summarizing their results, including their eligibility for cervical screening and last Pap test, for themselves and their doctor. The number and proportion of underscreened women who had a Pap test in the 6 months after completing the computer survey, as determined by pathology records, were examined.Results.Of the 679 participants, 139 were classified as underscreened on the basis of self-report (74 Experimental, 65 Control) and 272 on the basis of their pathology records (148 Experimental, 124 Control). Overall about one-third of women had a test in the 6-month period, and the differences between the groups were not significant for women overall (18–70 years) or for women 18–49 years. Among women 50–70 who were underscreened based on self-report, those receiving the printout were more likely to have a Pap test in the next 6 months (P< 0.05). This pattern was also evident, but did not reach statistical significance, for older women who were underscreened based on pathology records.Conclusions.We are unable to draw conclusions regarding the effectiveness of the computer system due to the modest proportions of women screened, the small numbers, and the fact that the computer survey may have created an intervention effect in the Control group. As the study suggests the computer system is acceptable to women and may be effective for encouraging screening among older women, further exploration of the system is desirable. 相似文献
7.
8.
J.P. Flatt Ph.D. 《Nutrition reviews》1992,50(9):267-270
Ethanol account for a significant fraction of the energy intake of persons consuming even moderate amounts of alcohol. A recent study has shown that although alcohol does not reveal itself as a layer floating at the top of a drink, metabolically it behaves more like oil than sugar. 相似文献
9.
10.
Aaron H. Burstein Pharm.D. William G. Reiss Pharm.D. Eric Kantor B.A. Gail D. Anderson Ph.D. 《Pharmacotherapy》1998,18(6):1271-1276
Study Objective . To characterize cytochrome P450 (CYP) 3A4 activity in premenopausal and postmenopausal women by evaluating the urinary 6-β-hydroxycortisokcortisol ratio. Design . Prospective study. Subjects . Thirteen premenopausal and 13 postmenopausal women who were healthy and not receiving drugs known to affect CYP3A4 activity. Interventions . Beginning on day 2 of menses, premenopausal women collected first morning urine samples every other day for a complete menstrual cycle. Postmenopausal women collected first morning urine every other day for 28 days. Measurements and Main Results . Mean weekly 6-β-hydroxycortisol:cortisol ratios did not differ during the phase (week) of the menstrual cycle. Daily ratios did not differ in postmenopausal women. No difference between premenopausal and postmenopausal women was found on comparing overall median ratios. Conclusion . Cytochrome P450 3A4 activity as measured by 6-β-hydroxy cortisol:cortisol ratio did not differ by week of menstrual cycle, suggesting no menstrual cycle-related changes. Menopause does not appear to be associated with differences in CYP3A4 activity, compared with premenopause. 相似文献