全文获取类型
收费全文 | 542篇 |
免费 | 34篇 |
出版年
2023年 | 3篇 |
2021年 | 6篇 |
2020年 | 9篇 |
2019年 | 4篇 |
2018年 | 15篇 |
2017年 | 6篇 |
2016年 | 12篇 |
2015年 | 22篇 |
2014年 | 28篇 |
2013年 | 38篇 |
2012年 | 39篇 |
2011年 | 46篇 |
2010年 | 26篇 |
2009年 | 22篇 |
2008年 | 37篇 |
2007年 | 27篇 |
2006年 | 32篇 |
2005年 | 26篇 |
2004年 | 22篇 |
2003年 | 22篇 |
2002年 | 20篇 |
2001年 | 4篇 |
2000年 | 6篇 |
1999年 | 7篇 |
1998年 | 8篇 |
1997年 | 4篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 6篇 |
1992年 | 9篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 7篇 |
1982年 | 7篇 |
1981年 | 7篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1966年 | 2篇 |
1965年 | 1篇 |
排序方式: 共有576条查询结果,搜索用时 46 毫秒
11.
12.
Karoline Schousboe Gonneke Willemsen Kirsten O Kyvik Jakob Mortensen Dorret I Boomsma Belinda K Cornes Chayna J Davis Corrado Fagnani Jacob Hjelmborg Jaakko Kaprio Marlies De Lange Michelle Luciano Nicholas G Martin Nancy Pedersen Kirsi H Pietil?inen Aila Rissanen Suoma Saarni Thorkild I A S?rensen G Caroline M Van Baal Jennifer R Harris 《Twin research》2003,6(5):409-421
Body mass index (BMI), a simple anthropometric measure, is the most frequently used measure of adiposity and has been instrumental in documenting the worldwide increase in the prevalence of obesity witnessed during the last decades. Although this increase in overweight and obesity is thought to be mainly due to environmental changes, i.e., sedentary lifestyles and high caloric diets, consistent evidence from twin studies demonstrates high heritability and the importance of genetic differences for normal variation in BMI. We analysed self-reported data on BMI from approximately 37,000 complete twin pairs (including opposite sex pairs) aged 20-29 and 30-39 from eight different twin registries participating in the GenomEUtwin project. Quantitative genetic analyses were conducted and sex differences were explored. Variation in BMI was greater for women than for men, and in both sexes was primarily explained by additive genetic variance in all countries. Sex differences in the variance components were consistently significant. Results from analyses of opposite sex pairs also showed evidence of sex-specific genetic effects suggesting there may be some differences between men and women in the genetic factors that influence variation in BMI. These results encourage the continued search for genes of importance to the body composition and the development of obesity. Furthermore, they suggest that strategies to identify predisposing genes may benefit from taking into account potential sex specific effects. 相似文献
13.
Giuseppe Comi Corrado Pipan Giuseppe Botta Luca Cocolin Carlo Cantoni Marisa Manzano 《FEMS immunology and medical microbiology》1996,16(1):45-49
Abstract A combined polymerase chain reaction and restriction endonuclease (RE) enzyme assay was developed to discriminate between Campylobacter coli and Campylobacter jejuni . Amplimers of the FlaA gene obtained by PCR were digested with Alu I and Hin fI to distinguish C. coli from C. jejuni . With Alu I digestion C. jejuni -specific bands were observed at 110, 140 and 160 bp and C. coli -specific bands at 293 and 147 bp. C. jejuni -specific bands of 349 and 109 bp were found by Hin fI digestion but Hin fI did not digest the Fla A amplimer of C. coli . This combined technique is fast and easy to perform, and distinguishes the two campylobacters unequivocally. 相似文献
14.
15.
Histone mRNA, labeled with 32P or 3H-methionine during the S phase of partially synchronized HeLa cells, was isolated from the polyribosomes and purified as a “9S” component by sucrose gradient sedimentation. We identified two types of 5′ terminals, m7G(5′)pppNmpN and m7G(5′)pppNm-pNmpN, in which the first methylated nucleoside is 7-methylguanosine, the second is either N6,2′-O-dimethyladenosine, 2′-O-methyladenosine, or 2′-O-methylguanosine, and the third is 2′-O-methyluridine, 2′-O-methylcytidine, or 2′-O-methyladenosine. Approximately 1.7% of the 32P label was present in the 5′ terminal structures. Assuming a similar specific radioactivity for all phosphates, this percentage corresponds to an average of one terminal per 335 nucleotides. Histone mRNA differed from bulk polyadenylylated mRNA of HeLa cells in lacking significant amounts of 2′-O-methyluridine or 2′-O-methylcytidine in the second position of the 5′ terminal oligonucleotide and in lacking N6-methyladenosine residues at internal positions. 相似文献
16.
The elucidation of the structure and stereochemistry of cynanchoside, a new highly oxygenated iridoid glucoside isolated from Macfadyena cynanchoides (Bignoniaceae), has been accomplished using mainly 1H and 13C NMR spectral data and further confirmed by simple chemical transformations. 相似文献
17.
Corrado Barghigiani Giuliano Colombetti Francesco Lenci Rosalba Banchetti Maria Pia Bizzaro 《Archives of microbiology》1979,120(3):239-245
We have investigated the effect of some metabolic drugs, 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), 2,4-dinitrophenol (DNP), sodium azide (NaN3), on the photobehavior of single cells of Euglena gracilis, in order to clarify the relevance of different metabolic pathways in the process of photoperception and sensory transduction in this alga. The results obtained show that the photophobic response of Euglena is not affected by the action of these drugs. This suggests that neither the photosynthetic process nor oxidative phosphorylation play a significant role in the phenomenon of photosensory transduction in Euglena.List of Abbreviations DNP
2,4-dinitrophenol
- DCMU
3-(3,4-dichlorophenyl)-1,1-dimethylurea
- PSI
Photosystem I
- PSII
Photosystem II 相似文献
18.
Vincenzo Amico Rosario Currenti Giovanna Oriente Mario Piattelli Corrado Tringali 《Phytochemistry》1981,20(6):1451-1453
The major lipid component of the brown seaweed Zonaria tournefortii was identified as the acylphlorogluconol (all Z)-2′-icosa-5,8,11,14,17-pentae 相似文献
19.
20.