全文获取类型
收费全文 | 466篇 |
免费 | 39篇 |
出版年
2021年 | 8篇 |
2020年 | 9篇 |
2019年 | 3篇 |
2018年 | 8篇 |
2017年 | 7篇 |
2016年 | 7篇 |
2015年 | 12篇 |
2014年 | 7篇 |
2013年 | 19篇 |
2012年 | 31篇 |
2011年 | 28篇 |
2010年 | 10篇 |
2009年 | 14篇 |
2008年 | 18篇 |
2007年 | 17篇 |
2006年 | 12篇 |
2005年 | 11篇 |
2004年 | 10篇 |
2003年 | 21篇 |
2002年 | 11篇 |
2001年 | 8篇 |
2000年 | 9篇 |
1999年 | 5篇 |
1998年 | 6篇 |
1992年 | 7篇 |
1991年 | 9篇 |
1990年 | 5篇 |
1989年 | 5篇 |
1988年 | 13篇 |
1987年 | 7篇 |
1986年 | 9篇 |
1985年 | 10篇 |
1984年 | 5篇 |
1982年 | 5篇 |
1981年 | 6篇 |
1980年 | 5篇 |
1979年 | 17篇 |
1978年 | 4篇 |
1977年 | 6篇 |
1976年 | 7篇 |
1975年 | 6篇 |
1974年 | 7篇 |
1973年 | 4篇 |
1971年 | 5篇 |
1968年 | 3篇 |
1936年 | 5篇 |
1934年 | 4篇 |
1928年 | 3篇 |
1918年 | 3篇 |
1915年 | 5篇 |
排序方式: 共有505条查询结果,搜索用时 15 毫秒
81.
82.
83.
Plants of Vicia faba were supplied either with fertilizer inorganic nitrogen or they received only nitrogen fixed by their root nodules. The esterase and transaminase isoenzyme profiles and the total water-soluble protein complement of seed cotyledons and of pollen did not vary irrespective of the N regime employed, whereas those of the leaf did. Possible causes and the implications of these differences are discussed. 相似文献
84.
85.
Parker, Baker &; Smith (1972) have demonstrated mathematically that given the evolution of sexual reproduction, disruptive selection for the production of either many small gametes or a few large gametes may occur, resulting in a stable polymorphism of “sperm” and “egg” producers. Their model for the evolution of anisogamy requires only that zygote fitness (F) increase steeply with increases in zygote volume (V) (for Foc∝ Vx, x must be greater than 1·5) and that a sufficiently broad range of zygote productivity-size variants exist in the population (the higher the value of x, the broader the range needed). They suggest that anisogamy is almost universal in multicellular organisms but relatively rare in unicellular organisms because only for the former is an investment in extra gametic reserves at the expense of the number of gametes produced likely to be worthwhile in terms of increasing the survival probability of the zygote. In this note a graphical analysis and evidence from the anisogamous Protista will be presented concerning this hypothesis. 相似文献
86.
Seven cases of struma lymphomatosa are presented. Two patients had known enlargement of the thyroid for five or more years. In five cases only unilateral involvement was discernible at the time of operation. In one case there was a small nodule in the least involved side. In another there was diffuse involvement. Two of the patients were males. There has been recurrence in three of six cases in which partial thyroidectomy was performed. Only one patient with recurrence was treated with x-ray, apparently with satisfactory results. Six of the seven patients had a postoperative basal metabolic rate below normal. Three of them required desiccated thyroid for symptomatic relief. 相似文献
87.
Frederick L. Gates 《The Journal of general physiology》1929,13(2):231-248
In this first paper of a series on the bactericidal action of ultra violet light the methods of isolating and measuring monochromatic radiations, of preparing and exposing the bacteria, and of estimating the effects of exposure, are given in detail. At all the different wave lengths studied the reactions of S. aureus followed similar curves, but occurred, at each wave length, at a different energy level. The general similarity of these curves to those for monomolecular reactions provokes a discussion of their signifiance, and emphasis is laid upon variations in susceptibility of individual organisms, due especially to age and metabolic activity, so that the typical curve seems to be best interpreted as one of probability. 相似文献
88.
89.
90.
Genetic variations at the human growth hormone receptor (GHR) gene locus are associated with idiopathic short stature
下载免费PDF全文
![点击此处可从《Journal of cellular and molecular medicine》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Christel Dias Mara Giordano Rosalie Frechette Simonetta Bellone Constantin Polychronakos Laurent Legault Cheri L Deal Cynthia Gates Goodyer 《Journal of cellular and molecular medicine》2017,21(11):2985-2999
GH plays an essential role in the growing child by binding to the growth hormone receptor (GHR) on target cells and regulating multiple growth promoting and metabolic effects. Mutations in the GHR gene coding regions result in GH insensitivity (dwarfism) due to a dysfunctional receptor protein. However, children with idiopathic short stature (ISS) show growth impairment without GH or GHR defects. We hypothesized that decreased expression of the GHR gene may be involved. To test this, we investigated whether common genetic variants (microsatellites, SNPs) in regulatory regions of the GHR gene region were associated with the ISS phenotype. Genotyping of a GT‐repeat microsatellite in the GHR 5′UTR in a Montreal ISS cohort (n = 37 ISS, n = 105 controls) revealed that the incidence of the long/short (L/S) genotype was 3.3× higher in ISS children than controls (P = 0.04, OR = 3.85). In an Italian replication cohort (n = 143 ISS, n = 282 controls), the medium/short (M/S) genotype was 1.9× more frequent in the male ISS than controls (P = 0.017, OR = 2.26). In both ISS cohorts, logistic regression analysis of 27 SNPs showed an association of ISS with rs4292454, while haplotype analysis revealed specific risk haplotypes in the 3′ haploblocks. In contrast, there were no differences in GT genotype frequencies in a cohort of short stature (SS) adults versus controls (CARTaGENE: n = 168 SS, n = 207 controls) and the risk haplotype in the SS cohort was located in the most 5′ haploblock. These data suggest that the variants identified are potentially genetic markers specifically associated with the ISS phenotype. 相似文献