全文获取类型
收费全文 | 1859篇 |
免费 | 79篇 |
国内免费 | 6篇 |
学科分类
医药卫生 | 1944篇 |
出版年
2024年 | 6篇 |
2023年 | 17篇 |
2022年 | 59篇 |
2021年 | 83篇 |
2020年 | 48篇 |
2019年 | 66篇 |
2018年 | 67篇 |
2017年 | 60篇 |
2016年 | 60篇 |
2015年 | 64篇 |
2014年 | 93篇 |
2013年 | 111篇 |
2012年 | 145篇 |
2011年 | 149篇 |
2010年 | 96篇 |
2009年 | 88篇 |
2008年 | 109篇 |
2007年 | 98篇 |
2006年 | 74篇 |
2005年 | 71篇 |
2004年 | 65篇 |
2003年 | 57篇 |
2002年 | 31篇 |
2001年 | 21篇 |
2000年 | 27篇 |
1999年 | 26篇 |
1998年 | 11篇 |
1997年 | 4篇 |
1996年 | 5篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1992年 | 5篇 |
1991年 | 7篇 |
1990年 | 10篇 |
1989年 | 8篇 |
1988年 | 11篇 |
1987年 | 5篇 |
1986年 | 13篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1981年 | 2篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 5篇 |
1975年 | 8篇 |
1974年 | 6篇 |
1973年 | 7篇 |
1972年 | 3篇 |
1966年 | 3篇 |
排序方式: 共有1944条查询结果,搜索用时 15 毫秒
1.
2.
3.
Maternal and fetal plasma vitamin E to total lipid ratio and fetal RBC antioxidant function during gestational development 总被引:1,自引:0,他引:1
S Abbasi A Ludomirski V K Bhutani S Weiner L Johnson 《Journal of the American College of Nutrition》1990,9(4):314-319
Placental transfer of vitamin E was investigated from 19 to 35 weeks of gestation by analysis of fetal and maternal blood samples for total tocopherol, total lipids, and fetal red blood cell antioxidant reserves. Fifty-two fetal blood samples were obtained under ultrasonographic guide by percutaneous umbilical blood sampling. Thirteen were from fetuses with gestational age less than or equal to 22 weeks (x serum vitamin E = 0.4 +/- 0.14 mg/dl), 12 were from fetuses at 23-27 weeks gestation (x serum vitamin E = 0.4 +/- 0.21 mg/dl), and 27 were from fetuses with gestational age 28-38 weeks (x serum level = 0.37 +/- 0.18). Total lipid levels ranged from 140 to 216 mg/dl. Maternal plasma vitamin E concentrations correlated significantly with concurrent values in the fetus. There were no significant differences in serum vitamin E levels or vitamin E to total lipid ratio in samples from early, mid, or late gestation in either the mother or fetus. Red blood cell antioxidant reserve on samples from 18 fetuses were grossly abnormal by three different functional assays. On the basis of these data, placental transfer of vitamin E appears to be relatively constant through advancing gestation. Red blood cell antioxidant reserve is uniformly low. 相似文献
4.
5.
Hadis Sabour Arash Hossein-Nezhad Zhila Maghbooli Farzaneh Madani Elham Mir Bagher Larijani 《Gynecological endocrinology》2006,22(10):585-589
Poor maternal vitamin D status affects fetal and infant skeletal growth. The aim of the present study was to determine the association between newborn outcomes and maternal calcium and vitamin D intakes. Four hundred and forty-nine pregnant women, healthy at the point of delivery, and their newborns were enrolled in the study, which was performed in three university hospitals in Tehran in March 2004. Maternal anthropometric data and energy, protein, calcium and vitamin D intakes were collected, and newborn outcomes (weight, length, head circumference and 1-min Apgar score) were determined. Almost two-thirds of the mothers (64.3%) took no supplements during pregnancy. Only one-third of the mothers (33.8%) had adequate intakes of calcium and vitamin D (from supplements and foods) compared with the Recommended Dietary Allowances. Mean length at birth and 1-min Apgar score were higher in newborns whose mothers had adequate calcium and vitamin D intake than in newborns whose mothers had inadequate intake (p = 0.03 and p = 0.04, respectively). Significant correlations were found between adequate maternal calcium and vitamin D intake and both appropriate birth weight and 1-min Apgar score of newborns and weight gain of mothers during pregnancy. Informing mothers of the critical importance of consuming adequate amounts of calcium and vitamin D seems necessary. 相似文献
6.
Approximately 5% of Americans over age 65, or 1.5 million individuals, currently reside in the nations's 20,000 nursing homes. The authors present material that lead to three conclusions about this population. First, nutritional deficiencies are common underlying causes of adverse clinical outcomes. Second, nutritional deficiencies are frequently not recognized. Third, opportunities for preventing or correcting undernutrition exist, provided that the significant and reversible nature of the nutrient deficiencies are identified. 相似文献
7.
Wajid M Abbasi AA Ansar M Pham TL Yan K Haque S Ahmad W Leal SM 《European journal of human genetics : EJHG》2003,11(10):812-815
This article describes the identification of a novel locus (DFNB39) responsible for an autosomal recessive form of hearing loss segregating in a Pakistani consanguineous family. The hearing impaired members of this family present with profound prelingual sensorineural hearing impairment and use sign language for communications. Linkage was established to microsatellite markers located on chromosome 7q with a maximum multipoint lod score of 3.8. The region of homozygosity spans a 19 cM region that is bounded by markers D7S3046 and D7S644. 相似文献
8.
Amini-Bavil-Olyaee S Sarrami-Forooshani R Mahboudi F Sabahi F Adeli A Noorinayer B Azizi M Reza Zali M 《Journal of medical virology》2005,75(2):227-234
Hepatitis B virus (HBV) is one of the major causative agents of acute and chronic liver disease worldwide and is believed to be responsible for a million deaths annually. Eight genotypes of HBV, A to H, have been described on the basis of similarity of the complete genomes sequence. Although, it is reported that the predominant HBV genotype in the Mediterranean area and the middle east is genotype D, there are no reports on HBV genotypes prevalent in Iran. In this study, the C and S regions of HBV from 26 chronic hepatitis B Iranian patients were amplified and sequenced. Phylogenetic analysis revealed that all Iranian HBV isolates sequences were classified into genotype D with bootstrap values of 100%, 73%, and 100% (1,000 replicates each) for S, C, and preS2 regions, respectively. The mean percent intra-distance of S and C regions were 0.8% and 2.3%, respectively. The mean percent inter-distance of S and C regions between Iranians and genotype D isolates were 1.7% and 3.0%, respectively, and the range of mean percent nucleotide distance of S and C regions between Iranians and the other reference isolates were 7.9%-17.5% and 4.8%-14.7%, respectively. Thirteen out of 23 HBV C region sequences showed nucleotide "A" at position 1896 (precore mutant) in C region. Nucleotide 1858 showed presence of "T" in all isolates. No insertion or deletion was found in both regions. SimPlot and BootScanning analyses did not show any recombination between Iranian isolates and other genotypes in both regions. 相似文献
9.
10.
Kiani Zahra Simbar Masoumeh Nazarpour Soheila Rashidi Fakari Farzaneh 《Archives of sexual behavior》2022,51(7):3223-3224
Archives of Sexual Behavior - 相似文献