全文获取类型
收费全文 | 3777076篇 |
免费 | 302218篇 |
国内免费 | 14693篇 |
专业分类
耳鼻咽喉 | 50709篇 |
儿科学 | 119378篇 |
妇产科学 | 97631篇 |
基础医学 | 590574篇 |
口腔科学 | 102281篇 |
临床医学 | 339980篇 |
内科学 | 673520篇 |
皮肤病学 | 98459篇 |
神经病学 | 316817篇 |
特种医学 | 146916篇 |
外国民族医学 | 262篇 |
外科学 | 581158篇 |
综合类 | 113871篇 |
现状与发展 | 23篇 |
一般理论 | 2355篇 |
预防医学 | 310758篇 |
眼科学 | 88941篇 |
药学 | 261017篇 |
26篇 | |
中国医学 | 11413篇 |
肿瘤学 | 187898篇 |
出版年
2021年 | 55659篇 |
2020年 | 35413篇 |
2019年 | 58518篇 |
2018年 | 72763篇 |
2017年 | 55544篇 |
2016年 | 61406篇 |
2015年 | 75151篇 |
2014年 | 109392篇 |
2013年 | 174845篇 |
2012年 | 104435篇 |
2011年 | 106330篇 |
2010年 | 120787篇 |
2009年 | 123687篇 |
2008年 | 92858篇 |
2007年 | 97449篇 |
2006年 | 106922篇 |
2005年 | 101720篇 |
2004年 | 103420篇 |
2003年 | 93345篇 |
2002年 | 82716篇 |
2001年 | 136158篇 |
2000年 | 129678篇 |
1999年 | 122059篇 |
1998年 | 68617篇 |
1997年 | 65293篇 |
1996年 | 63020篇 |
1995年 | 58563篇 |
1994年 | 52557篇 |
1993年 | 48919篇 |
1992年 | 85102篇 |
1991年 | 81021篇 |
1990年 | 76698篇 |
1989年 | 75140篇 |
1988年 | 69055篇 |
1987年 | 67232篇 |
1986年 | 63562篇 |
1985年 | 62800篇 |
1984年 | 54891篇 |
1983年 | 49596篇 |
1982年 | 43627篇 |
1981年 | 41001篇 |
1980年 | 38463篇 |
1979年 | 44858篇 |
1978年 | 38244篇 |
1977年 | 34921篇 |
1976年 | 31967篇 |
1975年 | 30796篇 |
1974年 | 32486篇 |
1973年 | 31179篇 |
1972年 | 29034篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
LUCAS D.; MENEZ J. F.; BODENEZ P.; BACCINO E.; BARDOU L. G.; FLOCH H. H. 《Alcohol and alcoholism (Oxford, Oxfordshire)》1988,23(1):23-31
Acetaldehyde, the first metabolite of ethanol, reacts with haemoglobinin vitro to produce acetaldehydehaemoglobin adducts.Some clinical studies on the minor haemoglobins have suggestedthat these adducts may be formed in people abusing alcohol.Under hydrolysis of haemoglobin, with oxalic acid at 100°Cin sealed vials, some acetaldehyde was released and then specificallydetermined by HPLC. The kinetics of hydrolysis were studiedusing haemoglobin previously labelled with 14[C] acetaldehyde.The maximum liberation of 14[C] acetaldehyde was obtained after3 hr 30 min hydrolysis and this time factor was then utilizedin the analysis of alcoholic and control haemoglobin. Thus,we have confirmed the formation of acetaldehyde haemoglobinadducts in vivo. It must be noted that the released acetaldehydecorresponds only to an index of the stable adducts. The levelswere higher in alcoholics than in controls (1.417±0.171and 1.295±0.139 nmol/mg Hb, respectively, P<0.001).In conclusion, this marker is not a convenient tool for themonitoring of alcohol exposure levels because of the low differencesbetween alcoholic and control haemoglobins. 相似文献
992.
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
993.
Ticks of the Ornithodoros moubata complex were collected from domestic pig sties and dwelling houses, and from a warthog habitat, and tested for the presence of African swine fever (ASF) virus. Collections were made in 9 of the 24 districts of Malawi, these being primarily the districts in which O. moubata is most numerous. ASF virus was isolated from ticks collected in both domestic pig sties and houses in certain villages in Mchinji district where ASF outbreaks had recently occurred. Mchinji district is in the centre of a large ASF enzootic area which stretches into other districts of Malawi and also into Zambia and Mozambique. The high titre of virus in some of the ticks demonstrates that O. moubata can act as a virus reservoir and potential vector of disease in the field situation in Malawi. 相似文献
994.
995.
996.
Judith B. Erickson 《Child & youth care forum》1988,17(2):86-103
Several million American children are currently unsupervised during the hours between school and parents' leaving for and/or return from the workplace. Many families would prefer other arrangements, but cost or availability factors present insurmountable barriers. Although growing, the public response continues to fall far short of the need; in the meantime, private entrepreneurs are moving to fill the gaps in available services. But if these programs for school-aged children are to serve functions other than the aggrandizement of their sponsors, they must be focused on the real needs that exist among real American children. Among the real children in need of care are those who are impoverished, unsupervised, unfit physically, unprepared for the demands of school and workplace, hurried into premature adulthood, and/or disconnected from the social worlds around them. Professional child and youth care workers with experience in day care and residential settings have the preparation needed to take leadership roles in creating developmentally appropriate, effective programs to meet the emerging demands for school-age child care and to weave them into a fabric of youth-centered community services. 相似文献
997.
998.
999.
1000.
J. E. BLUNDELL 《Nutrition Bulletin》1988,13(1):29-38
Do brain systems exist which control not only increases or decreases in food intake, but also bring about specific changes in the size and distribution of meals consumed, alter the selection of particular macronutrients and adjust feeding responses to the perceived pleasantness (hedonic value) of the food? A cautious yes can be given to each of these questions. Moreover, since most experimental work has been carried out on the brains of animals, we can also ask how well these animal data relate to the human condition; given the methodological issues involved in making such inferences, the answer is remarkably well. 相似文献