全文获取类型
收费全文 | 530篇 |
免费 | 13篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 2篇 |
妇产科学 | 7篇 |
基础医学 | 71篇 |
口腔科学 | 11篇 |
临床医学 | 78篇 |
内科学 | 173篇 |
皮肤病学 | 1篇 |
神经病学 | 17篇 |
特种医学 | 18篇 |
外科学 | 54篇 |
一般理论 | 1篇 |
预防医学 | 52篇 |
眼科学 | 3篇 |
药学 | 13篇 |
中国医学 | 1篇 |
肿瘤学 | 32篇 |
出版年
2021年 | 5篇 |
2020年 | 5篇 |
2019年 | 5篇 |
2018年 | 6篇 |
2017年 | 6篇 |
2016年 | 7篇 |
2015年 | 8篇 |
2014年 | 12篇 |
2013年 | 18篇 |
2012年 | 25篇 |
2011年 | 13篇 |
2010年 | 9篇 |
2009年 | 13篇 |
2008年 | 16篇 |
2007年 | 24篇 |
2006年 | 18篇 |
2005年 | 22篇 |
2004年 | 31篇 |
2003年 | 19篇 |
2002年 | 18篇 |
2001年 | 14篇 |
2000年 | 11篇 |
1999年 | 13篇 |
1998年 | 5篇 |
1997年 | 10篇 |
1996年 | 6篇 |
1995年 | 4篇 |
1994年 | 4篇 |
1993年 | 10篇 |
1992年 | 10篇 |
1991年 | 19篇 |
1990年 | 13篇 |
1989年 | 8篇 |
1988年 | 9篇 |
1987年 | 15篇 |
1986年 | 12篇 |
1985年 | 16篇 |
1984年 | 7篇 |
1983年 | 6篇 |
1982年 | 3篇 |
1981年 | 7篇 |
1980年 | 5篇 |
1979年 | 13篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1975年 | 6篇 |
1974年 | 5篇 |
1972年 | 6篇 |
1966年 | 4篇 |
1963年 | 2篇 |
排序方式: 共有543条查询结果,搜索用时 15 毫秒
51.
52.
53.
It is now hard to think of blood transfusion activities without data processing. Blood transfusion centers are unable to work without it since a long time. Its necessity in hospital blood banks is following the same pattern. Electronic data interchange between them is growing because of their high interdependence. A lot has already been done and works routinely. But a lot remains to be done, due to continuous evolution of computer science and blood transfusion itself. 相似文献
54.
J.-Y. Py I. Sandid S. Jbilou M. Dupuis R. Adda D. Narbey R. Djoudi 《Transfusion Clinique et Biologique》2014,21(4-5):216-222
Postdonation information is the knowledge of information about the donor or his donation, occurring after it, which challenges quality or safety of the blood products stemming from this or other donations. Classical hemovigilance sub-processes concerning donors or recipients adverse events do not cover this topic. France is just about to make it official as a fourth sub-process. Less formal management of postdonation information is already set up for more than ten years. French data of the year 2013 are presented, including the regional notification level and the national reporting one. A significant level of heterogeneity is observed as for other hemovigilance sub-processes. It is mainly due to subjective rather than objective differences in risk appreciation. A real consensual work is expected about it in the future. 相似文献
55.
56.
The effects of transdermal estrogen therapy on bone mass and turnover in early postmenopausal smokers: a prospective, controlled study 总被引:2,自引:0,他引:2
Välimäki MJ Laitinen KA Tähtelä RK Hirvonen EJ Risteli JP 《American journal of obstetrics and gynecology》2003,189(5):1213-1220
OBJECTIVE: The purpose of this study was to investigate whether smoking reduces the effects of transdermal estrogen replacement therapy on bone. STUDY DESIGN: One hundred forty-eight women (0.5-5 years after menopause, aged 46-58 years) completed the study. Smokers were assigned randomly to receive either 1.0 mg (n=32 women) or 1.5 mg (n=31 women) of transdermal estradiol in gel daily, and nonsmokers (n=46 women) were assigned to receive 1.0 mg of transdermal estradiol for 2 years. The control group consisted of 17 smokers and 22 nonsmokers. Bone mineral density was measured by dual-energy x-ray absorptiometry. Bone turnover was assessed by measurements of urinary aminoterminal telopeptide of type I collagen and serum aminoterminal propeptide of type I procollagen. RESULTS: Lumbar spine bone mineral density increased similarly in smoking (+3.6%) and nonsmoking (+2.6%) estrogen users (P<.0001 to a decrease of 2.5% in the control group). Femoral neck bone mineral density increased 2.2% to 2.4% in smoking and nonsmoking estrogen users but decreased 0.2% in control subjects (P<.05). Urinary aminoterminal telopeptide of type I collagen decreased similarly in all estrogen-using groups (P<.05 to control group), but serum aminoterminal propeptide of type I procollagen decreased more in smoking than in nonsmoking estrogen users (P=.006). Serum 25-hydroxyvitamin D was 20% lower (P=.004) in smokers than in nonsmokers. CONCLUSION: Transdermal estrogen treatment protects smoking women as effectively as nonsmokers from osteoporosis. Smoking worsens the vitamin D state of postmenopausal women. 相似文献
57.
T R?nnemaa M Laakso V Kallio K Py?r?l? J Marniemi P Puukka 《American journal of epidemiology》1989,130(4):632-645
Serum lipids, lipoproteins, and major apolipoproteins and their association with previous myocardial infarction were studied in patients with non-insulin-dependent diabetes mellitus (NIDDM) and nondiabetic subjects in East and West Finland in 1982-1984. NIDDM patients had higher age-adjusted serum triglyceride and apolipoprotein B levels and a higher apolipoprotein B/apolipoprotein A-I ratio, lower serum high density lipoprotein (HDL) cholesterol and apolipoprotein A-1 levels, and a lower HDL cholesterol/apolipoprotein A-1 ratio than nondiabetic subjects. With a few exceptions, these differences persisted after adjustment for body mass index, alcohol intake, physical activity, smoking, and hypertension, which suggests that the atherogenic serum lipoprotein pattern in NIDDM is an inherent feature of the disease. In general, the association of serum lipids, lipoproteins, and apolipoproteins with myocardial infarction was similar in nondiabetic subjects and NIDDM patients, although it was somewhat stronger in the diabetic subjects. A low serum HDL cholesterol/apolipoprotein A-1 ratio, which was closely linked to high serum triglyceride level, seemed to be more consistently related to myocardial infarction in NIDDM patients than in nondiabetic subjects. Serum lipids, lipoproteins, and apolipoproteins, either separately or in various combinations, could only to a small extent explain the higher prevalence of myocardial infarction in diabetic subjects compared with nondiabetic subjects when tested in multivariate analysis with other cardiovascular risk factors as background variables. The association between serum lipoproteins and myocardial infarction was largely similar in East and West Finland, two areas that differ markedly with respect to the occurrence of coronary heart disease. 相似文献
58.
ErpA, an iron sulfur (Fe S) protein of the A-type essential for respiratory metabolism in Escherichia coli 下载免费PDF全文
Loiseau L Gerez C Bekker M Ollagnier-de Choudens S Py B Sanakis Y Teixeira de Mattos J Fontecave M Barras F 《Proceedings of the National Academy of Sciences of the United States of America》2007,104(34):13626-13631
Understanding the biogenesis of iron-sulfur (Fe-S) proteins is relevant to many fields, including bioenergetics, gene regulation, and cancer research. Several multiprotein complexes assisting Fe-S assembly have been identified in both prokaryotes and eukaryotes. Here, we identify in Escherichia coli an A-type Fe-S protein that we named ErpA. Remarkably, erpA was found essential for growth of E. coli in the presence of oxygen or alternative electron acceptors. It was concluded that isoprenoid biosynthesis was impaired by the erpA mutation. First, the eukaryotic mevalonate-dependent pathway for biosynthesis of isopentenyl diphosphate restored the respiratory defects of an erpA mutant. Second, the erpA mutant contained a greatly reduced amount of ubiquinone and menaquinone. Third, ErpA bound Fe-S clusters and transferred them to apo-IspG, a protein catalyzing isopentenyl diphosphate biosynthesis in E. coli. Surprisingly, the erpA gene maps at a distance from any other Fe-S biogenesis-related gene. ErpA is an A-type Fe-S protein that is characterized by an essential role in cellular metabolism. 相似文献
59.
Pajunen P Koukkunen H Ketonen M Jerkkola T Immonen-Räihä P Kärjä-Koskenkari P Kuulasmaa K Palomäki P Mustonen J Lehtonen A Arstila M Vuorenmaa T Lehto S Miettinen H Torppa J Tuomilehto J Kesäniemi YA Pyörälä K Salomaa V 《Diabetologia》2005,48(12):2519-2524
Aims/hypothesis We compared the risk of acute coronary events in diabetic and non-diabetic persons with and without prior myocardial infarction
(MI), stratified by age and sex.
Methods A Finnish MI-register study known as FINAMI recorded incident MIs and coronary deaths (n=6988) among people aged 45 to 74 years in four areas of Finland between 1993 and 2002. The population-based FINRISK surveys
were used to estimate the numbers of persons with prior diabetes and prior MI in the population.
Results Persons with diabetes but no prior MI and persons with prior MI but no diabetes had a markedly greater risk of a coronary
event than persons without diabetes and without prior MI. The rate of recurrent MI among non-diabetic men with prior MI was
higher than the incidence of first MI among diabetic men aged 45 to 54 years. The rate ratio was 2.14 (95% CI 1.40–3.27) among
men aged 50. Among elderly men, diabetes conferred a higher risk than prior MI. Diabetic women had a similar risk of suffering
a first MI as non-diabetic women with a prior MI had for suffering a recurrent MI.
Conclusions/interpretation Both persons with diabetes but no prior MI, and persons with a prior MI but no diabetes are high-risk individuals. Among men,
a prior MI conferred a higher risk of a coronary event than diabetes in the 45–54 year age group, but the situation was reversed
in the elderly. Among diabetic women, the risk of suffering a first MI was similar to the risk that non-diabetic women with
prior MI had of suffering a recurrent MI. 相似文献