全文获取类型
收费全文 | 172篇 |
免费 | 13篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 9篇 |
2015年 | 4篇 |
2014年 | 7篇 |
2013年 | 13篇 |
2012年 | 11篇 |
2011年 | 12篇 |
2010年 | 13篇 |
2009年 | 8篇 |
2008年 | 9篇 |
2007年 | 7篇 |
2006年 | 11篇 |
2005年 | 9篇 |
2004年 | 10篇 |
2003年 | 19篇 |
2002年 | 6篇 |
2001年 | 4篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1975年 | 2篇 |
1972年 | 3篇 |
1971年 | 3篇 |
1970年 | 1篇 |
1969年 | 2篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1928年 | 1篇 |
1926年 | 1篇 |
排序方式: 共有185条查询结果,搜索用时 812 毫秒
61.
Sorin Comorosan 《Bulletin of mathematical biology》1975,37(4):419-425
A new type of physical transition, denotedS→S *, has been detected in irradiated organic molecules (λ=546 nm) through their interaction with specific biological macromolecules. In a specific enzyme-substrate interaction, a clear enhancement of the reaction rate is observed, when the substrate is irradiated with sharply well defined times. These “efficient irradiation times” are always of the 5k sec type (k=1, 2, 3, …). They have been consistently revealed in a great number of specific biological interactions. The present note demonstrates an important property, i.e. that forevery irradiation time aS→S * transition is induced in organic molecules. It is shown that for any irradiation times different from the 5k sec type (k=1, 2, 3, …) states of theS * type may occur, but the biological macromolecules may “detect” only theS * states induced by irradiations of the 5k sec type. 相似文献
62.
C Turleau F Chavin-Colin J Seger M Sorin D Salet J de Grouchy 《Annales de génétique》1978,21(4):239-242
A satellited Y chromosome (Yqs) occurred de novo in a boy born to first cousins. The child had severe mental retardation, facial dysmorphism, congenital heart disease, and amaurosis, and died at 6 months and of age. The chromosome rearrangement was confirmed by R-, G-, C-, Q-, and Ag-NOR banding. Its significance and the difficulty of genetic counseling are discussed. 相似文献
63.
A semantic analysis of the annotations of the human genome 总被引:2,自引:0,他引:2
The correct interpretation of any biological experiment depends in an essential way on the accuracy and consistency of the existing annotation databases. Such databases are ubiquitous and used by all life scientists in most experiments. However, it is well known that such databases are incomplete and many annotations may also be incorrect. In this paper we describe a technique that can be used to analyze the semantic content of such annotation databases. Our approach is able to extract implicit semantic relationships between genes and functions. This ability allows us to discover novel functions for known genes. This approach is able to identify missing and inaccurate annotations in existing annotation databases, and thus help improve their accuracy. We used our technique to analyze the current annotations of the human genome. From this body of annotations, we were able to predict 212 additional gene-function assignments. A subsequent literature search found that 138 of these gene-functions assignments are supported by existing peer-reviewed papers. An additional 23 assignments have been confirmed in the meantime by the addition of the respective annotations in later releases of the Gene Ontology database. Overall, the 161 confirmed assignments represent 75.95% of the proposed gene-function assignments. Only one of our predictions (0.4%) was contradicted by the existing literature. We could not find any relevant articles for 50 of our predictions (23.58%). The method is independent of the organism and can be used to analyze and improve the quality of the data of any public or private annotation database. 相似文献
64.
Optimal selection of SNP markers for disease association studies 总被引:5,自引:0,他引:5
Genetic association studies with population samples hold the promise of uncovering the susceptibility genes underlying the heritability of complex or common disease. Most association studies rely on the use of surrogate markers, single-nucleotide polymorphism (SNP) being the most suitable due to their abundance and ease of scoring. SNP marker selection is aimed to increase the chances that at least one typed SNP would be in linkage disequilibrium (LD) with the disease causative variant, while at the same time controlling the cost of the study in terms of the number of markers genotyped and samples. Empirical studies reporting block-like segments in the genome with high LD and low haplotype diversity have motivated a marker selection strategy whereby subsets of SNPs that 'tag' the common haplotypes of a region are picked for genotyping, avoiding typing redundant SNPs. Based on these initial observations, a plethora of 'tagging' algorithms for selecting minimum informative subsets of SNPs has recently appeared in the literature. These differ mostly in two major aspects: the quality or correlation measure used to define tagging and the algorithm used for the minimization of the final number of tagging SNPs. In this review we describe the available tagging algorithms utilizing a 3-step unifying framework, point out their methodological and conceptual differences, and make an assessment of their assumptions, performance, and scalability. 相似文献
65.
66.
Reactive separations using green catalysts offer great opportunities for manufacturing fatty esters, involved in specialty chemicals and biodiesel production. Integrating reaction and separation into one unit provides key benefits such as: simplified operation, no waste, reduced capital investment and low operating costs.This work presents a novel heat-integrated reactive absorption process that eliminates all conventional catalyst related operations, efficiently uses the raw materials and equipment, and considerably reduces the energy requirements for biodiesel production - 85% lower as compared to the base case. Rigorous simulations based on experimental results were carried out using Aspen Plus and Dynamics. Despite the high degree of integration, the process is well controllable using an efficient control structure proposed in this work. The main results are provided for a plant producing 10 ktpy fatty acid methyl esters from methanol and waste vegetable oil with high free fatty acids content, using sulfated zirconia as solid acid catalyst. 相似文献
67.
68.
Cyril Ronco Geoffroy Sorin Florian Nachon Richard Foucault Ludovic Jean Anthony Romieu Pierre-Yves Renard 《Bioorganic & medicinal chemistry》2009,17(13):4523-4536
New series of Huprine (12-amino-6,7,10,11-tetrahydro-7,11-methanocycloocta[b]quinolines) derivatives have been synthesized and their inhibiting activities toward recombinant human acetylcholinesterase (rh-AChE) are reported. We have synthesized two series of Huprine analogues; in the first one, the benzene ring of the quinoline moiety has been replaced by different heterocycles or electron-withdrawing or electron-donating substituted phenyl group. The second one has been designed in order to evaluate the influence of modification at position 12 where different short linkers have been introduced on the Huprine X, Y skeletons. All these molecules have been prepared from ethyl- or methyl-bicyclo[3.3.1]non-6-en-3-one via Friedländer reaction involving selected o-aminocyano aromatic compounds. The synthesis of two heterodimers based on these Huprines has been also reported. Activities from moderate to same range than the most active Huprines X and Y taken as references have been obtained, the most potent analogue being about three times less active than parent Huprines X and Y. Topologic data have been inferred from molecular dockings and variations of activity between the different linkers suggest future structural modifications for activity improvement. 相似文献
69.
An abstract representation of biological systems from the standpoint of the theory of supercategories is presented. The relevance
of such representations forG-relational biologies is suggested. In section A the basic concepts of our representation, that is class, system, supercategory
and measure are introduced. Section B is concerned with the mathematical representation starting with some axioms and principles
which are natural extensions of the current abstract representations in biology. Likewise, some extensions of the principle
of adequate design are introduced in section C. Two theorems which present the connection between categories and supercategories
are proved. Two other theorems concerning the dynamical behavior of biological and biophysical systems are derived on the
basis of the previous considerations. Section D is devoted to a general study of oscillatory behavior in enzymic systems,
some general quantitative relations being derived from our representation. Finally, the relevance of these results for a quantum
theoretic approach to biology is discussed. 相似文献
70.
The effects of pulsed, high frequency radio waves on rat liver (ultrastructural and biomedical observations) 总被引:1,自引:0,他引:1
L Pop M Muresan S Comorosan L Paslaru 《Physiological chemistry and physics and medical NMR》1989,21(1):45-55
The effects of a high frequency electro-magnetic field, generated by a Diapulse instrument (Diapulse Corporation of America) on rat liver has been investigated. Ultrastructural aspects are described and quantitative determinations of mitochondrial enzymes MAO, CyT-Ox, MDH, SDH and ATP-ase recorded. The standard therapeutic parameters generally used with the Diapulse instrument in medicine were found to induce a stimulation effect at the investigated level, without apparent degenerative modifications. A concordance between the qualitative ultrastructural data and quantitative subcellular enzymic determinations has been observed. 相似文献