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91.
Background
General iron-sulfur cluster biosynthesis proceeds through assembly of a transient cluster on IscU followed by its transfer to a recipient apo-protein. The efficiency of the second step is increased by the presence of HscA and HscB, but the reason behind this is poorly understood. To shed light on the function of HscB, we began a study on the nature of its interaction with IscU. Our work suggested that the binding site of IscU is in the C-terminal domain of HscB, and two different triple alanine substitutions ([L92A, M93A, F153A] and [E97A, E100A, E104A]) involving predicted binding site residues had detrimental effects on this interaction. However, the individual contribution of each substitution to the observed effect remains to be determined as well as the possible involvement of other residues in the proposed binding site. 相似文献92.
93.
We describe the first phase of a project concerned with the foundations of algebra. Data consists of the responses of 11 year-olds to selected questions from national tests. We focus on one question, which concerns a sequence of shapes and classify successful methods and incorrect solutions. The most common method of successful solution involves some form of table of numbers. Other methods include drawing and use of a relationship. Examination of incorrect answers suggests four common errors. The idea of a'best method' proves problematic, as both the apparently sophisticated and reliable methods sometimes produced incorrect solutions. 相似文献
94.
95.
G. J. Spühler K. J. Weingarten R. Grange L. Krainer M. Haiml V. Liverini M. Golling S. Schön U. Keller 《Applied physics. B, Lasers and optics》2005,81(1):27-32
We present two novel semiconductor saturable absorber mirror (SESAM) designs which can exhibit more than ten times lower saturation
fluence than classical SESAM devices. Design considerations and characterization data are presented. These devices are particularly
suited for passively mode-locked lasers with ultra-high repetition rates. 相似文献
96.
The intralaminar fracture toughness of a unidirectionally reinforced glass/epoxy composite is determined experimentally at
several mode I and mode II loading ratios. The crack propagation criterion, expressed as a quadratic form in terms of single-mode
stress intensity factors (alternatively, linear in terms of energy release rates), approximates the test results reasonably
well. The mixed-mode cracking criterion obtained is used to predict the intralaminar crack on set in a cross-ply glass/epoxy
composite under off-axis tensile loading.
Translated from Mekhanika Kompozitnykh Materialov, Vol. 44, No. 6, pp. 785–794, November–December, 2008. 相似文献
97.
Jenny WettergrenAlexander B.E. Minidis 《Tetrahedron letters》2003,44(41):7611-7612
Using microwave technology, rapid ω-methoxylation of aryl alkynes is possible. 相似文献
98.
Calculation of the stability of nonperiodic solids using classical force fields and the method of increments: N2o as an example 下载免费PDF全文
Combining classical force fields for the Hartree–Fock (HF) part and the method of increments for post‐HF contributions, we calculate the cohesive energy of the ordered and randomly disordered nitrous oxide (N2O) solid. At 0 K, ordered N2O is most favorable with a cohesive energy of ?27.7 kJ/mol. At temperatures above 60 K, more disordered structures become compatible and a phase transition to completely disordered N2O is predicted. Comparison with experiment in literature suggests that experimentally prepared N2O crystals are mainly disordered due to a prohibitively high activation energy of ordering processes. © 2015 Wiley Periodicals, Inc. 相似文献
99.
E. Makrlík P. Vaňura P. Selucky Z. Spíchal 《Journal of Radioanalytical and Nuclear Chemistry》2011,289(1):13-18
Extraction of microamounts of europium and americium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H+B−) in the presence of 1,2-(diphenylphosphino)ethane dioxide (DPPEtDO, L) has been investigated. The equilibrium data have been
explained assuming that the species HL+, HL2
+, ML2
3+ and ML4
3+ (M3+ = Eu3+, Am3+) are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated
with water have been determined. It was found that the stability constants of the corresponding complexes EuL
n
3+ and AmL
n
3+, where n = 2, 4 and L is DPPEtDO, in water-saturated nitrobenzene are comparable. 相似文献
100.
N,N'-Carbonyldiimidazole-mediated functionalization of superparamagnetic nanoparticles as vaccine carrier 总被引:1,自引:0,他引:1
Ho J Al-Deen FM Al-Abboodi A Selomulya C Xiang SD Plebanski M Forde GM 《Colloids and surfaces. B, Biointerfaces》2011,83(1):83-90
Particulates with specific sizes and characteristics can induce potent immune responses by promoting antigen uptake of appropriate immuno-stimulatory cell types. Magnetite (Fe(3)O(4)) nanoparticles have shown many potential bioapplications due to their biocompatibility and special characteristics. Here, superparamagnetic Fe(3)O(4) nanoparticles (SPIONs) with high magnetization value (70emug(-1)) were stabilized with trisodium citrate and successfully conjugated with a model antigen (ovalbumin, OVA) via N,N'-carbonyldiimidazole (CDI) mediated reaction, to achieve a maximum conjugation capacity at approximately 13 microgmicrom(-2). It was shown that different mechanisms governed the interactions between the OVA molecules and magnetite nanoparticles at different pH conditions. We evaluated as-synthesized SPION against commercially available magnetite nanoparticles. The cytotoxicity of these nanoparticles was investigated using mammalian cells. The reported CDI-mediated reaction can be considered as a potential approach in conjugating biomolecules onto magnetite or other biodegradable nanoparticles for vaccine delivery. 相似文献