全文获取类型
收费全文 | 507篇 |
免费 | 38篇 |
国内免费 | 39篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 16篇 |
妇产科学 | 6篇 |
基础医学 | 61篇 |
口腔科学 | 14篇 |
临床医学 | 80篇 |
内科学 | 135篇 |
皮肤病学 | 5篇 |
神经病学 | 12篇 |
特种医学 | 97篇 |
外科学 | 30篇 |
综合类 | 15篇 |
预防医学 | 30篇 |
眼科学 | 2篇 |
药学 | 42篇 |
中国医学 | 9篇 |
肿瘤学 | 28篇 |
出版年
2020年 | 5篇 |
2018年 | 7篇 |
2016年 | 5篇 |
2015年 | 11篇 |
2014年 | 14篇 |
2013年 | 25篇 |
2012年 | 10篇 |
2011年 | 10篇 |
2010年 | 25篇 |
2009年 | 24篇 |
2008年 | 8篇 |
2007年 | 32篇 |
2006年 | 10篇 |
2005年 | 12篇 |
2004年 | 8篇 |
2003年 | 7篇 |
2002年 | 6篇 |
2001年 | 7篇 |
2000年 | 4篇 |
1999年 | 7篇 |
1998年 | 24篇 |
1997年 | 19篇 |
1996年 | 17篇 |
1995年 | 13篇 |
1994年 | 15篇 |
1993年 | 15篇 |
1992年 | 10篇 |
1991年 | 16篇 |
1990年 | 6篇 |
1989年 | 17篇 |
1988年 | 16篇 |
1987年 | 8篇 |
1986年 | 14篇 |
1985年 | 8篇 |
1984年 | 8篇 |
1983年 | 13篇 |
1982年 | 5篇 |
1980年 | 9篇 |
1979年 | 5篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1976年 | 8篇 |
1975年 | 4篇 |
1945年 | 4篇 |
1944年 | 4篇 |
1841年 | 7篇 |
1840年 | 13篇 |
1838年 | 8篇 |
1833年 | 3篇 |
1830年 | 5篇 |
排序方式: 共有584条查询结果,搜索用时 15 毫秒
101.
Arianne C Lim Kitty WM Bloemenkamp Kees Boer Johannes J Duvekot Jan Jaap HM Erwich Tom HM Hasaart Pieter Hummel Ben WJ Mol Jos PM Offermans Charlotte M van Oirschot Job G Santema Hubertina CJ Scheepers Willem A Schöls Frank PHA Vandenbussche Maurice GAJ Wouters Hein W Bruinse 《BMC pregnancy and childbirth》2007,7(1):1-6
Background
Adequate vitamin D concentrations during pregnancy are necessary to neonatal calcium homeostasis, bone maturation and mineralization. The aim of study is to evaluate serum vitamin D concentrations in mothers and their newborns and effect of vitamin D deficiency on pregnancy outcomes.Methods
552 pregnant women were recruited from Tehran University educating hospitals in the winter of 2002. Maternal and cord blood samples were taken at delivery. The serum was assayed for 25-hydroxyvitamin D3, calcium, phosphorus and parathyroid hormone.Results
The prevalence of vitamin D deficiency in maternal and cord blood samples were 66.8% and 93.3%, respectively (<35 nmol/l). There was significant correlation between maternal and cord blood serum concentrations of vitamin D. In mothers with vitamin D deficiency, cord blood vitamin D concentrations was lower than those from normal mothers (P = .001). Also, a significant direct correlation was seen between maternal vitamin D intake and weight gain during pregnancy.Conclusion
Consideration to adequate calcium and vitamin D intake during pregnancy is essential. Furthermore, we think it is necessary to reconsider the recommendation for vitamin D supplementation for women during pregnancy. 相似文献102.
Wever G. K. Althausen T. L. Biskind G. R. Kerr WM. J. 《The American journal of digestive diseases》1935,2(2):93-99
The American Journal of Digestive Diseases - In our patients with acute hepatitis, as a group, the Rose Bengal test was positive in 94 per cent, and the modified glucose tolerance test in 93 per... 相似文献
103.
104.
Yuanyuan Wu Kathryn CB Tan Sammy WM Shiu Yishan Luo Lin Shi Timothy CY Kwok 《Journal of diabetes investigation.》2022,13(11):1873
Aims/IntroductionTo examine the association between cholesterol efflux capacity (CEC) of serum high‐density lipoprotein (HDL) and cognitive function and brain structures in older people with diabetes mellitus.Materials and MethodsParticipants of a randomized placebo‐controlled trial of 27‐month vitamin B12 supplementation in older people with diabetes mellitus, which showed no effect on cognition, were further followed up at month 72. Cognitive tests included the Clinical Dementia Rating scale, Neuropsychological Test Battery in memory, executive function and psychomotor speed. Brain magnetic resonance imaging scans were carried out in a subset at baseline, month 27 and month 45. Fasting serum at baseline, month 9, month 27 and month 72 were analyzed for adenosine triphosphate‐binding cassette transporter A1‐mediated CEC of HDL and apolipoprotein A1 (ApoA1).ResultsSerum HDL cholesterol at baseline was associated with better executive and memory function at follow up. Serum ApoA1 was associated with a better memory Z‐score at month 18. Serum CEC and ApoA1 were not associated with Clinical Dementia Rating scale, Neuropsychological Test Battery, hippocampal volume and white matter disease on magnetic resonance imaging at baseline and whole brain atrophy rates. They were also not associated with cognitive function at month 27 and 72 on multilevel modeling. CEC and ApoA1 decreased significantly from baseline to month 27. Faster decliners in CEC had a greater increase in brain peak width of skeletonized mean diffusivity.ConclusionsHigher serum HDL cholesterol was associated with more favorable changes in memory and executive function in older people with diabetes mellitus. However, this was not due to CEC or ApoA1. A decline in CEC was associated with small vessel disease in the brain. 相似文献
105.
106.
107.
108.
109.
110.
M. H. F. Friedman D. J. Abolofia B. R. Adolph Helen Battle WM. D. Beamer Ivan Bennett J. Edward Berk J. B. Bernstine G. P. Blundell R. L. Burdick R. E. Capps F. X. Chockley C. G. Clements John J. Cox H. W. Davenport E. R. Feaver Carmela Forderaro S. A. Friedman J. Logan Irvin G. Klenner Edgar G. Knerr S. A. Komarov Harry Metzger M. J. Oppenheimer K. E. Paschkis I. J. Pincus B. C. Riggs F. E. St. Georce Frederick H. Scharles N. M. Small G. N. N. Smith WM. J. Snape G. W. Starvraky Horace Stilyung I. M. Theone C. A. H. Tice Adolph A. Walkling D. A. Wocker 《The American journal of digestive diseases》1945,12(8):276-280