排序方式: 共有60条查询结果,搜索用时 15 毫秒
1.
Amira Mahmoud Mosaab Echabaane Karim Omri Julien Boudon Lucien Saviot Nadine Millot Rafik Ben Chaabane 《Molecules (Basel, Switzerland)》2021,26(4)
Copper-doped zinc oxide nanoparticles (NPs) CuxZn1−xO (x = 0, 0.01, 0.02, 0.03, and 0.04) were synthesized via a sol-gel process and used as an active electrode material to fabricate a non-enzymatic electrochemical sensor for the detection of glucose. Their structure, composition, and chemical properties were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier-transform infrared (FTIR) and Raman spectroscopies, and zeta potential measurements. The electrochemical characterization of the sensors was studied using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV). Cu doping was shown to improve the electrocatalytic activity for the oxidation of glucose, which resulted from the accelerated electron transfer and greatly improved electrochemical conductivity. The experimental conditions for the detection of glucose were optimized: a linear dependence between the glucose concentration and current intensity was established in the range from 1 nM to 100 μM with a limit of detection of 0.7 nM. The proposed sensor exhibited high selectivity for glucose in the presence of various interfering species. The developed sensor was also successfully tested for the detection of glucose in human serum samples. 相似文献
2.
Dr. Itai Carmeli Dr. Karuppannan Senthil Kumar Omri Heifler Prof. Chanoch Carmeli Prof. Ron Naaman 《Angewandte Chemie (International ed. in English)》2014,53(34):8953-8958
Photosystem I (PSI) is one of the most studied electron transfer (ET) systems in nature; it is found in plants, algae, and bacteria. The effect of the system structure and its electronic properties on the electron transfer rate and yield was investigated for years in details. In this work we show that not only those system properties affect the ET efficiency, but also the electrons’ spin. Using a newly developed spintronic device and a technique which enables control over the orientation of the PSI monolayer relative to the device (silver) surface, it was possible to evaluate the degree and direction of the spin polarization in ET in PSI. We find high‐spin selectivity throughout the entire ET path and establish that the spins of the electrons being transferred are aligned parallel to their momenta. The spin selectivity peaks at 300 K and vanishes at temperatures below about 150 K. A mechanism is suggested in which the chiral structure of the protein complex plays an important role in determining the high‐spin selectivity and its temperature dependence. Our observation of high light induced spin dependent ET in PSI introduces the possibility that spin may play an important role in ET in biology. 相似文献
3.
Hamadi Jerbi Thouraya Kharrat Faouzi Omri 《Mediterranean Journal of Mathematics》2016,13(5):2507-2524
In this paper, we consider a class of bilinear systems in dimension three which can be an extension of another one in \({\mathbbm{R}^{2}}\). We prove that there exists some homogeneous feedback of degree zero stabilizing the considered class if and only if these feedbacks are constants. 相似文献
4.
O.M. Lemine K. Omri B. Zhang L. El Mir M. Sajieddine A. Alyamani M. Bououdina 《Superlattices and Microstructures》2012
Magnetite (Fe3O4) nanoparticles were successfully synthesized by a sol–gel method. The obtained nanoparticles were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive analysis by X-ray (EDAX), transmission electron microscopy (TEM), superconducting quantum interference device (SQUID) and Mössbauer spectrometry. XRD and Mössbauer measurements indicate that the obtained nanoparticles are single phase. TEM analysis shows the presence of spherical nanoparticles with homogeneous size distribution of about 8 nm. Room temperature ferromagnetics behavior was confirmed by SQUID measurements. The mechanism of nanoparticles formation and the comparison with recent results are discussed. Finally, the synthesized nanoparticles present a potential candidate for hyperthermia application given their saturation magnetization. 相似文献
5.
A. Omri M. Bejar M. Sajieddine E. Dhahri E.K. Hlil M. Es-Souni 《Physica B: Condensed Matter》2012,407(13):2566-2572
Structural, magnetic and magnetocaloric properties of manganites series with the AMn1−xGaxO3 (A=La0.75Ca0.08Sr0.17 and x=0, 0.05, 0.1 and 0.2) composition have been investigated to shed light on Ga-doping influence. Solid-state reaction method was used for preparation. From XRD study, all samples are found single phase and crystallize in the orthorhombic structure with the Pnma space group. The variation of the magnetization M vs. temperature T, under an applied magnetic field of 0.05 T, reveals a ferromagnetic–paramagnetic transition for all samples. The experimental results indicate that TC decreases from 336 to 135 K with increasing Ga substitution. Magnetocaloric effect (MCE) was estimated, in terms of isothermal magnetic entropy change (−ΔSM), using the M(T, μ0H) data and employing the thermodynamic Maxwell equation. The maximum entropy change and Relative Cooling Power (RCP) show non-monotonic behaviors with increasing the concentration of Gallium. In fact, the maximum value of ΔSMmaxof AMn1−xGaxO3 for x=0.00 and 0.2 samples is found to be, respectively, 2.87 and 1.17 J/kg/K under an applied magnetic field change of 2 T. For the same applied magnetic field (μ0H=2 T), the RCP values are found to vary between 97.58 and 89 J/kg. 相似文献
6.
We classify deformations of the standard embedding of the Lie superalgebra $
\mathcal{K}
$
\mathcal{K}
(2) of contact vector fields on the (1, 2)-dimensional supercircle into the Lie superalgebra SΨD(S
1|2
) of pseudodifferential operators on the supercircle S
1|2
. The proposed approach leads to the deformations of the central charge induced on $
\mathcal{K}
$
\mathcal{K}
(2) by the canonical central extension of SΨD(S
1|2
). 相似文献
7.
We classify the ergodic invariant Radon measures for the horocycle flow on geometrically infinite regular covers of compact
hyperbolic surfaces. The method is to establish a bijection between these measures and the positive minimal eigenfunctions
of the Laplacian of the surface. Two consequences arise: if the group of deck transformations G is of polynomial growth, then these measures are classified by the homomorphisms from G
0 to ℝ where G
0 ≤ G is a nilpotent subgroup of finite index; if the group is of exponential growth, then there may be more than one Radon measure
which is invariant under the geodesic flow and the horocycle flow. We also treat regular covers of finite volume surfaces.
The first author was supported by NSF grant 0500630.
The second author was supported by NSF grant 0400687. 相似文献
8.
Amirhossein Nazhand Alessandra Durazzo Massimo Lucarini Maria Alessandra Mobilia Besma Omri 《Natural product research》2020,34(1):110-121
AbstractTaxol is one of the anticancer drugs synthesized naturally in the evergreen Taxus brevifolia forest tree belonging to the yew family (Taxaceae) growing on the Pacific. There are reportedly evidence for treating ovarian, breast and lung cancers through this drug given its unique structural and functional features. Extraction of this drug from yew trees bark is one of the most common ways of producing this drug, but 3000 trees are needed to obtain a kilogram of Taxol. Hence, further attention has recently been attracted to the metabolic engineering strategies, including, engineering cellular metabolism of microorganisms and their optimization. Accordingly, the present paper article was aimed to review recent advances in elevating the production and commercialization of Taxol through metabolic engineering techniques. 相似文献
9.
We present an experimental study of the stability of passively mode-locked pulses against noise in multipulse operation of an erbium-doped fiber laser. The laser properties are determined by two dimensionless combinations of the laser parameters. Measurements of the pulses' destabilization threshold as a function of those laser parameters show the optimal regions that maximize the mode-locked pulse stability. We find good agreement between the experimental observations and the theoretical predictions. 相似文献
10.
Jörg Votteler Elena Iavnilovitch Orit Fingrut Vivian Shemesh Daniel Taglicht Omri Erez Stefan Sörgel Torsten Walther Norbert Bannert Ulrich Schubert Yuval Reiss 《BMC biochemistry》2009,10(1):1-14