全文获取类型
收费全文 | 340篇 |
免费 | 27篇 |
出版年
2024年 | 2篇 |
2023年 | 3篇 |
2022年 | 5篇 |
2021年 | 22篇 |
2020年 | 4篇 |
2019年 | 6篇 |
2018年 | 15篇 |
2017年 | 13篇 |
2016年 | 15篇 |
2015年 | 14篇 |
2014年 | 17篇 |
2013年 | 25篇 |
2012年 | 50篇 |
2011年 | 40篇 |
2010年 | 16篇 |
2009年 | 17篇 |
2008年 | 20篇 |
2007年 | 23篇 |
2006年 | 16篇 |
2005年 | 12篇 |
2004年 | 9篇 |
2003年 | 6篇 |
2002年 | 8篇 |
2001年 | 2篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
排序方式: 共有367条查询结果,搜索用时 15 毫秒
311.
Triops cancriformis was reported first from India in 1871 and has been subsequently shown to occur in different regions of the country. In this paper, we have morphologically re-examined the Triops cancriformis population from Kashmir from where this species was first reported. We have compared some morphological traits of our T. cancriformis population with a few closely related species. The result shows that the Kashmir population is more similar to the typical non gonochoric Triops cancriformis in morphology. From literature records, we show that T. cancriformis has a peculiar distribution in India with no record of occurrences below 23°N. We also highlight the 125 years of history of T. cancriformis records from India. 相似文献
312.
Shainaba A Saadhali Sameer Hassan Luke Elizabeth Hanna Uma Devi Ranganathan Vanaja Kumar 《Journal of molecular modeling》2016,22(8):180
Mycobacteriophages produce lysins that break down the host cell wall at the end of lytic cycle to release their progenies. The ability to lyse mycobacterial cells makes the lysins significant. Mycobacteriophage Che12 is the first reported temperate phage capable of infecting and lysogenising Mycobacterium tuberculosis. Gp11 of Che12 was found to have Chitinase domain that serves as endolysin (lysin A) for Che12. Structure of gp11 was modeled and evaluated using Ramachandran plot in which 98 % of the residues are in the favored and allowed regions. Che12 lysin A was predicted to act on NAG-NAM-NAG molecules in the peptidoglycan of cell wall. The tautomers of NAG-NAM-NAG molecule were generated and docked with lysin A. The stability and binding affinity of lysin A – NAG-NAM-NAG tautomers were studied using molecular dynamics simulations. 相似文献
313.
Shear modulation of intercellular contact area between two deformable cells colliding under flow 总被引:2,自引:0,他引:2
Shear rate has been shown to critically affect the kinetics and receptor specificity of cell-cell interactions. In this study, the collision process between two modeled cells interacting in a linear shear flow is numerically investigated. The two identical biological or artificial cells are modeled as deformable capsules composed of an elastic membrane. The cell deformation and trajectories are computed using the immersed boundary method (IBM) for shear rates of 100-400s(-1). As the two cells collide under hydrodynamic shear, large local cell deformations develop. The effective contact area between the two cells is modulated by the shear rate, and reaches a maximum value at intermediate levels of shear. At relatively low shear rate, the contact area is an enclosed region. As the shear rate increases, dimples form on the membrane surface, and the contact region becomes annular. The nonmonotonic increase of the contact area with the increase of shear rate from computational results implies that there is a maximum effective receptor-ligand binding area for cell adhesion. This finding suggests the existence of possible hydrodynamic mechanism that could be used to interpret the observed maximum leukocyte aggregation in shear flow. The critical shear rate for maximum intercellular contact area is shown to vary with cell properties such as radius and membrane elastic modulus. 相似文献
314.
Noor M. Shaik Manish Arha A. Nookaraju Sushim K. Gupta Sameer Srivastava Arun K. Yadav Pallavi S. Kulkarni O. U. Abhilash Rishi K. Vishwakarma Somesh Singh Rajeshri Tatkare Kannan Chinnathambi Shuban K. Rawal Bashir M. Khan 《Physiology and Molecular Biology of Plants》2009,15(4):311-318
Leucaena leucocephala is a fast growing multipurpose legume tree used for forage, leaf manure, paper and pulp. Lignin in Leucaena pulp adversely influences the quality of paper produced. Developing transgenic Leucaena with altered lignin by genetic engineering demands an optimized regeneration system. The present study deals with optimization of regeneration system for L. leucocephala cv. K636. Multiple shoot induction from the cotyledonary nodes of L. leucocephala was studied in response to cytokinins, thidiazuron (TDZ) and N6-benzyladenine (BA) supplemented in half strength MS (½-MS) medium and also their effect on in vitro rooting of the regenerated shoots. Multiple shoots were induced from cotyledonary nodes at varied frequencies depending on the type and concentration of cytokinin used in the medium. TDZ was found to induce more number of shoots per explant than BA, with a maximum of 7 shoots at an optimum concentration of 0.23 µM. Further increase in TDZ concentration resulted in reduced shoot length and fasciation of the shoots. Liquid pulse treatment of the explants with TDZ did not improve the shoot production further but improved the subsequent rooting of the shoots that regenerated. Regenerated shoots successfully rooted on ½-MS medium supplemented with 0.54 µM α-naphthaleneacetic acid (NAA). Rooted shoots of Leucaena were transferred to coco-peat and hardened plantlets showed ≥ 90 % establishment in the green house.Key words: Cotyledonary nodes, Multiple shoot induction, Pulse treatment, TDZ 相似文献
315.
Chris P. Verschoor Sameer D. Pant Flavio S. Schenkel Bhawani S. Sharma Niel A. Karrow 《Mammalian genome》2009,20(7):447-454
Altering the balance between pro- and anti-inflammatory responses can influence an animal’s susceptibility to acute or chronic
inflammatory disease; bovine mastitis is no exception. Genetic variation in the form of single nucleotide polymorphisms (SNPs)
may alter the function and expression of genes that regulate inflammation, making them important candidates for defining an
animal’s risk of developing acute or chronic mastitis. The objective of the present study was to identify SNPs in genes that
regulate anti-inflammatory responses and test their association with estimated breeding values (EBVs) for somatic cell score
(SCS), a trait highly correlated with the incidence of mastitis. These genes included bovine interleukin-10 (IL-10) and its
receptor (IL-10R), and transforming growth factor β1 (TGF-β1) and its receptor (TGF-βR). Sequencing-pooled DNA allowed for
the identification of SNPs in IL-10 (n = 2), IL-10Rα (n = 6) and β (n = 2), and TGF-β1 (n = 1). These SNPs were subsequently genotyped in a cohort of Holstein (n = 500), Jersey (n = 83), and Guernsey (n = 50) bulls. Linear regression analysis identified significant SNP effects for IL-10Rα 1185C>T with SCS. Haplotype IL-10Rα
AAT showed a significant effect on increasing SCS compared to the most common haplotype. The results presented here indicate
that SNPs in IL-10Rα may contribute to variation in the SCS of dairy cattle. Although functional studies are necessary to
ascertain whether these SNPs are causal polymorphisms or merely in linkage with the true causal SNP(s), a selection program
incorporating these markers could have a beneficial influence on the average SCS and productivity of a dairy herd. 相似文献
316.
Background
Colorants derived from natural sources look set to overtake synthetic colorants in market value as manufacturers continue to meet the rising demand for clean label ingredients – particularly in food applications. Many ascomycetous fungi naturally synthesize and secrete pigments and thus provide readily available additional and/or alternative sources of natural colorants that are independent of agro-climatic conditions. With an appropriately selected fungus; using in particular chemotaxonomy as a guide, the fungal natural colorants could be produced in high yields by using the optimized cultivation technology. This approach could secure efficient production of pigments avoiding use of genetic manipulation. 相似文献317.
318.
Selective binding of ions to biomolecules plays a vital role in numerous biological processes. To understand the specific role of induced effects in selective ion binding, we use quantum chemical and pairwise-additive force-field simulations to study Na+ and K+ binding to various small molecules representative of ion binding functional groups in biomolecules. These studies indicate that electronic polarization significantly contributes to both absolute and relative ion-binding affinities. Furthermore, this contribution depends on both the number and the specific chemistries of the coordinating molecules, thus highlighting the complexity of ion-ligand interactions. Specifically, multibody interactions reduce as well as enhance the dipole moments of the ion-coordinating molecules, thereby affecting observables like coordination number distributions of ions. The differential polarization induced in molecules coordinating these two equivalently charged, but different-sized, ions also depends upon the number of coordinating molecules, showing the importance of multibody effects in distinguishing these ions thermodynamically. Because even small differences in ionic radii (0.4 Å for Na+ and K+) produce differential polarization trends critical to distinguishing ions thermodynamically, it is likely that polarization plays an important role in thermodynamically distinguishing other ions and charged chemical and biological functional groups. 相似文献
319.
320.
Whitaker HC Kote-Jarai Z Ross-Adams H Warren AY Burge J George A Bancroft E Jhavar S Leongamornlert D Tymrakiewicz M Saunders E Page E Mitra A Mitchell G Lindeman GJ Evans DG Blanco I Mercer C Rubinstein WS Clowes V Douglas F Hodgson S Walker L Donaldson A Izatt L Dorkins H Male A Tucker K Stapleton A Lam J Kirk J Lilja H Easton D;IMPACT Study Steering Committee;IMPACT Study Collaborators;UK GPCS Collaborators Cooper C Eeles R Neal DE 《PloS one》2010,5(10):e13363