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21.
Santanu Kumar Padhi Nicoletta Baglieri Valentina Bonino Angelo Agostino Lorenza Operti Nicolae Dan Batalu Mariana Carmen Chifiriuc Marcela Popa Mihail Burdusel Mihai Alexandru Grigoroscuta Gheorghe Virgil Aldica Dana Radu Petre Badica Marco Truccato 《Molecules (Basel, Switzerland)》2021,26(16)
We report for the first time on the antimicrobial activity of MgB2 powders produced via the Reactive Liquid Infiltration (RLI) process. Samples with MgB2 wt.% ranging from 2% to 99% were obtained and characterized, observing different levels of grain aggregation and of impurity phases. Their antimicrobial activity was tested against Staphylococcus aureus ATCC BAA 1026, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, and Candida albicans ATCC 10231. A general correlation is observed between the antibacterial activity and the MgB2 wt.%, but the sample microstructure also appears to be very important. RLI-MgB2 powders show better performances compared to commercial powders against microbial strains in the planktonic form, and their activity against biofilms is also very similar. 相似文献
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59.54 keV gamma ray Compton profiles (CP) of GaP along (100) and (1 1 1) directions are reported. The measured anisotropy has qualitatively similar features as given by the recent pseudopotential calculations for other III–V compound semiconductors. The average valence profile is found to be more peaked compared to that of the pure covalent semiconductors Si and Ge. This suggests that inonicity has the effect of making the valence-electron wave functions of compound semiconductors more diffused. Theoretical calculations on the directional Compton profiles of GaP will be of great use for an exact comparision with the present data, which will help in detailed understanding of the electronic structure of GaP. 相似文献
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Hepcidin is a small cysteine-rich peptide that plays an important role in antimicrobial activity and in maintaining iron homeostasis
in vertebrates. Here we report on the underlying mechanism that maintains high sequence diversities among the hepcidin-like
variants of perciform and pleuronectiform fishes. In contrast to mammals, maximum likelihood-based codon substitution analyses
revealed that positive Darwinian selection (nonsynonymous to synonymous substitution, ω > 1) is the likely cause of accelerated rate of amino acid substitutions in the hepcidin mature peptide region of these
fishes. Comparison of models incorporating positive selection (ω > 1) at certain sites with models not incorporating positive selection (ω < 1) failed to reject (p = 0) the evidence of positive selection among the codon sites of percifom and pleuronectiform hepcidin. The adaptive evolution
of this peptide in perciform and pleuronectiform fishes might be directed by pathogens when the host is exposed to new habitats/environments. 相似文献
26.
E.m.f. measurements on cells of the type Ag(s), AgCNS(s), KCNS(c)//KCl(c), AgCl(s), Ag(s) in four different composition of urea—water mixtures at seven different temperatures from 5 to 35°C have been made to determine the standard potentials of the silver—silver thiocyanate electrode in these media. These values have been used to evaluate the transfer thermodynamic quantities accompanying the transfer of 1 g ion of CNS? ion from the standard state in water to the standard state in urea—water mixtures. 相似文献
27.
This paper is concerned with a class of neutral difference equations of second order with positive and negative coefficients
of the forms
where τ, δ and σ are nonnegative integers and {p
n
}, {q
n
} and {c
n
} are nonnegative real sequences. Sufficient conditions for oscillation of the equations are obtained.
Research of the first author was supported by Department of Science and Technology, New Delhi, Govt. of India, under BOYSCAST
Programme vide Sanc. No. 100/IFD/5071/2004-2005 Dated 04.01.2005. 相似文献
28.
Seshadev Padhi P.D.N. Srinivasu G. Kiran Kumar 《Nonlinear Analysis: Real World Applications》2010,11(4):2610-2618
In this article the minimum number of positive periodic solutions admitted by a non-autonomous scalar differential equation is estimated. This result is employed to find the minimum number of positive periodic solutions admitted by a model representing dynamics of a renewable resource that is subjected to Allee effects in a seasonally varying environment. The Allee effect refers to a decrease in population growth rate at low population densities. Leggett–Williams multiple fixed point theorem is used to establish the existence of positive periodic solutions. 相似文献
29.
This article shows the existence of positive periodic solutions for retarded, advanced, neutral, and ordinary differential equations whose order is a multiple of 4. First, we find a positive Green’s function explicitly. Then assuming that the coefficient of the unknown in the linear part of the equation is bounded above and below by positive constants, we find one and then three solutions by applying the Krasnoselskii and Legget–William fixed point theorems. 相似文献
30.
Seshadev Padhi 《Applied mathematics and computation》2010,216(8):2450-2456
This paper is concerned with the existence of three positive T-periodic solutions of the first order functional differential equations of the form
x′(t)=a(t)x(t)-λb(t)f(t,x(h(t))), 相似文献