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131.
Metallothioneins (MTs) are ubiquitous, low molecular mass and cysteine-rich proteins that play important roles in maintaining intracellular metal homeostasis, eliminating metal toxification and protecting the cells against oxidative damages. MTs are able to bind metal ions through the thiol groups of their cysteine residues. Plants have several MT isoforms which are classified into four types based on the arrangement of cysteine residues. In the present study, a rice (Oryza sativa) gene encoding type 1 MT isoform, OsMTI-1b, was inserted in vector pET41a and overexpressed in Escherichia coli as carboxy-terminal extensions of glutathione-S-transferase (GST). The recombinant protein GST-OsMTI-1b was purified using affinity chromatography and its ability to bind with Ni2+, Cd2+, Zn2+ and Cu2+ ions was analyzed. The results demonstrated that this isoform has ability to bind Ni2+, Cd2+ and Zn2+ ions in vitro, whereas it has no substantial ability to bind Cu2+ ions. From competitive reaction with 5,5′-dithiobis(2-nitrobenzoic acid), DTNB, the affinity of metal ions for recombinant form of GST-OsMTI-1b was as follows: Ni2+/Cd2+ > Zn2+ > Cu2+ 相似文献
132.
Jamshid L. Manzoori Abolghasem Jouyban Mohammad Amjadi Vahid Panahi‐Azar Elnaz Tamizi Jalil Vaez‐Gharamaleki 《Luminescence》2011,26(4):244-250
A novel, rapid and sensitive spectroflurimetric method was developed and validated for the determination of deferasirox in urine, serum and tablet samples based on sensitization of terbium fluorescence. The excitation and emission wavelengths were 328 and 545 nm, respectively. The optimum conditions for the determination of deferasirox were investigated considering the effects of various parameters. The method was quantitatively evaluated in terms of linearity, recovery, reproducibility and limit of detection. Under the optimal conditions, the fluorescence intensities were linear with the concentration of deferasirox in the range of 5 × 10?9 to 5×10?6 mol L?1, with a detection limit of 1.5 × 10?9 mol L?1 and a relative standard deviation of 1.1–2.3%. Linearity, reproducibility, recovery and limit of detection made the method suitable for determination of deferasirox in urine, serum and tablets samples. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
133.
The earliest fossil schizopterid bug (Insecta: Heteroptera) in the Lower Cretaceous amber of Lebanon
Dany Azar 《法国昆虫学会纪事》2013,49(1-2):193-197
The schizopterid bug Libanohypselosoma popovi n. gen., n. sp. belonging to the subfamily Hypselosomatinae is described from the Lower Cretaceous amber of Lebanon. This fossil is the earliest record of the Schizopteridae. The species is distinguished from its related taxa, a discussion is given. 相似文献
134.
Dany Azar 《法国昆虫学会纪事》2013,49(1-2):198-203
Abstract Two chironomid flies, Ziadeus kamili n. gen., n. sp. and Paicheleria magnifica n. gen., n. sp., respectively attributed to the recent subfamilies Tanypodinae and Prodiamesinae, are described from the Early Cretaceous Lebanese amber. Although very old, this non-biting midge fauna was very diverse with no less than 11 genera and species. However, it was also strongly different from the recent faunas for the complete absence of the Chironominae, that is today the dominant subfamily. The development of the modern chironomid fauna occurred during the Late Cretaceous and/or the Early Paleogene, but when and how? 相似文献
135.
Two novel gene orders and the role of light-strand replication in rearrangement of the vertebrate mitochondrial genome 总被引:22,自引:8,他引:14
Macey JR; Larson A; Ananjeva NB; Fang Z; Papenfuss TJ 《Molecular biology and evolution》1997,14(1):91-104
Two novel mitochondrial gene arrangements are identified in an agamid
lizard and a ranid frog. Statistical tests incorporating phylogeny indicate
a link between novel vertebrate mitochondrial gene orders and movement of
the origin of light-strand replication. A mechanism involving errors in
light-strand replication and tandem duplication of genes is proposed for
rearrangement of vertebrate mitochondrial genes. A second mechanism
involving small direct repeats also is identified. These mechanisms
implicate gene order as a reliable phylogenetic character. Shifts in gene
order define major lineages without evidence of parallelism or reversal.
The loss of the origin of light-strand replication from its typical
vertebrate position evolves in parallel and, therefore, is a less reliable
phylogenetic character. Gene junctions also evolve in parallel. Sequencing
across multigenic regions, in particular transfer RNA genes, should be a
major focus of future systematic studies to locate novel gene orders and to
provide a better understanding of the evolution of the vertebrate
mitochondrial genome.
相似文献
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138.
Spectroscopic and molecular docking studies on the interaction between N‐acetyl cysteine and bovine serum albumin
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The interaction between N‐acetyl cysteine (NAC) and bovine serum albumin (BSA) was investigated by UV–vis, fluorescence spectroscopy, and molecular docking methods. Fluorescence study at three different temperatures indicated that the fluorescence intensity of BSA was reduced upon the addition of NAC by the static quenching mechanism. Binding constant (Kb) and the number of binding sites (n) were determined. The binding constant for the interaction of NAC and BSA was in the order of 103 M?1, and the number of binding sites was obtained to be equal to 1. Enthalpy (ΔH), entropy (ΔS), and Gibb's free energy (ΔG) as thermodynamic values were also achieved by van't Hoff equation. Hydrogen bonding and van der Waals force were the major intermolecular forces in the interaction process and it was spontaneous. Finally, the binding mode and the binding sites were clarified using molecular docking which were in good agreement with the results of spectroscopy experiments. © 2015 Wiley Periodicals, Inc. Biopolymers 103: 638–645, 2015. 相似文献
139.
Azar Gat 《Evolutionary anthropology》2015,24(3):111-126
Was human fighting always there, as old as our species? Or is it a late cultural invention, emerging after the transition to agriculture and the rise of the state, which began, respectively, only around ten thousand and five thousand years ago? Viewed against the life span of our species, Homo sapiens, stretching back 150,000–200,000 years, let alone the roughly two million years of our genus Homo, this is the tip of the iceberg. We now have a temporal frame and plenty of empirical evidence for the “state of nature” that Thomas Hobbes and Jean‐Jacque Rousseau discussed in the abstract and described in diametrically opposed terms. All human populations during the Pleistocene, until about 12,000 years ago, were hunter‐gatherers, or foragers, of the simple, mobile sort that lacked accumulated resources. Studying such human populations that survived until recently or still survive in remote corners of the world, anthropology should have been uniquely positioned to answer the question of aboriginal human fighting or lack thereof. Yet access to, and the interpretation of, that information has been intrinsically problematic. The main problem has been the “contact paradox.” Prestate societies have no written records of their own. Therefore, documenting them requires contact with literate state societies that necessarily affects the former and potentially changes their behavior, including fighting. 相似文献
140.