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排序方式: 共有186条查询结果,搜索用时 15 毫秒
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K. Nazari A. Mahmoudi R. Khodafarin A. A. Moosavi-Movahedi A. Mohebi 《Journal of the Iranian Chemical Society》2005,2(3):232-237
The present research discusses the structure stabilizing and protecting effects of Ni2+ against suicide-peroxide inactivation of horseradish peroxidase (HRP). Suicide inactivation of HRP by hydrogen peroxide (3 mM) was monitored by measuring change in the absorbance of the colored product (tetraguaiacol) of the catalytic reaction cycle at 470 nm. Progress curves of the catalytic reaction cycle were obtained at 27 °C, phosphate buffer (5 mM), pH 7.0. The corresponding kinetic parameters (e.g., initial enzyme activity (αo) and the apparent rate constant (ki) of suicide inactivation of HRP by peroxide) were evaluated using a kinetic equation derived in this study. Comparative activatory and inhibitory effects of Ni2+ on the kinetics of suicide-peroxide inactivation of HRP are discussed. 相似文献
3.
Anna Jurowska Janusz Szklarzewicz Maciej Hodorowicz Wiktoria Serafin Ennio Zangrando Ghodrat Mahmoudi 《Molecules (Basel, Switzerland)》2022,27(20)
Four dioxidovanadium(V) complexes with Schiff-base ligands based on 2-hydroxybenzhydrazide with four different substituted salicylaldehydes (5-chlorosalicylaldehyde, 3,5-dichlorosalicylaldehyde, 5-nitrosalicylaldehyde, 3-bromo-5-chlorosalicylaldehyde) were synthesized and described, by using V2O5 and triethylamine. The single crystal X-ray structure measurements as well as elemental analyses and IR spectra confirmed the formulas of the ionic complexes with a protonated triethylamine acting as counterion, HTEA[VO2(L)] (HL = Schiff-base ligand). The kinetic stability of the complexes at pH = 2 and 7 was discussed with respect to the neutral vanadium(V) complexes previously studied as potential insulin-mimetic agents. A correlation between the substituents in an aromatic ring of the Schiff-base ligands with crystal packing, and also with the stability of the compounds, was presented. 相似文献
4.
When exposed to a corona discharge, a dielectric droplet spreads over a grounded substrate. In the present work, the spreading of dielectric liquids subjected to a short-term exposure is investigated. A simple theoretical model was developed to find the spreading law at the very beginning of exposure. The asymptotic approximation for the surface charge density and the interfacial pressure showed that the droplet spreading immediately after the exposure obeys t1/2 law. The high speed imaging of the spreading revealed the same trend as predicted by the theoretical model. 相似文献
5.
Different novel phthalazino[2,3‐b]phthalazine‐5,7,12,14‐tetraones were synthesized in a simple and environmentally benign method from the reaction of phthalic anhydrides with semicarbazide or thiosemicarbazide using montmorillonite K‐10 clay as solid heterogeneous acidic catalyst and microwaves under solvent‐free conditions in good yields and short reaction times. Products were characterized by the elemental analysis, IR, NMR, and mass spectrometry. 相似文献
6.
We propose a scheme to localize a two-level atom inside a classical standing wave field conditioned upon the measurement of the frequency of a weak probe field at resonance excitation of a two-level atomic system. Inside the classical standing wave field, the interaction between the atom and the field is position-dependent due to the Rabi frequency of the driving field; hence, as the absorption frequency of the probe field is measured, the position of an atom inside the classical standing wave field will be determined. The effects of atomic parameters on atom localization are then discussed. 相似文献
7.
We present results on the photoluminescence (PL) properties of porous silicon (PS) as a function of time. Stabilization of PL from PS has been achieved by replacing silicon-hydrogen bonds terminating the surface with more stable silicon-carbon bonds. The composition of the PS surface was monitored by transmission Fourier transform infrared (FTIR) spectroscopy at intervals of 1 month in ageing time up to 1 year. The position of the maximum PL peak wavelength oscillates between a blue-shift and a red-shift in the 615-660 nm range with time. 相似文献
8.
Phase-controlled atom-photon entanglement in a three-level Λ-type closed-loop atomic system 下载免费PDF全文
We study the entanglement of dressed atom and its spontaneous emission in a three-level Λ-type closed-loop atomic system in a multi-photon resonance condition and beyond it.It is shown that the von Neumann entropy in such a system is phase-dependent,and it can be controlled by either the intensity or relative phase of applied fields.It is demonstrated that for the special case of the Rabi frequency of applied fields,the system is disentangled.In addition,we take into account the effect of Doppler broadening on the entanglement and it is found that a suitable choice of laser propagation direction allows us to obtain the steady state degree of entanglement(DEM) even in the presence of the Doppler effect. 相似文献
9.
Ghodrat Mahmoudi Habibar Chowdhury Samuel E. Lofland 《Journal of Coordination Chemistry》2017,70(12):1973-1983
Two coordination polymers, [Mn2(μ-L1)2(μ-N3)2]n (1) and [Mn(μ-HL2)(SCN)2]n (2), were assembled in a single-pot from MnCl2·4H2O, HL1 (2-acetylpyridine isonicotinoylhydrazone) or HL2 (2-acetylpyridine nicotinoylhydrazone) and ancillary ligand sources (NaN3 or NH4NCS). The products were fully characterized, including by single-crystal X-ray diffraction, which revealed a 2-D metal–organic layer in 1 and a 1-D zigzag coordination chain in 2. Both 1 and 2 are constructed from six-coordinate Mn(II) nodes that adopt distorted octahedral (MnN5O) environments; the adjacent nodes are driven by the μ-L1 and μ-N3 linkers in 1 or μ-HL2 linkers in 2 to form different metal–organic networks. Their topological classification was performed, disclosing the hcb and 2C1 topology in 1 and 2, respectively. Different weak non-covalent interactions promote dimensionality extension. Variable-temperature magnetic susceptibility measurements were carried out, revealing weak ferromagnetic and antiferromagnetic interactions in 1 and 2, respectively. 相似文献
10.
Superparamagnetic iron oxide nanoparticles (SPIONs) are promising materials for various biomedical applications including targeted drug delivery and imaging, hyperthermia, magneto-transfections, gene therapy, stem cell tracking, molecular/cellular tracking, magnetic separation technologies (e.g. rapid DNA sequencing), and detection of liver and lymph node metastases. The most recent applications for SPIONs for early detection of inflammatory, cancer, diabetes and atherosclerosis have also increased their popularity in academia. In order to increase the efficacy of SPIONs in the desired applications, especial surface coating/characteristics are required. The aim of this article is to review the surface properties of magnetic nanoparticles upon synthesis and the surface engineering by different coatings. The biological aspects, cytotoxicity, and health risks are addressed. Special emphasis is given to organic and inorganic-based coatings due to their determinant role in biocompatibility or toxicity of the final particles. 相似文献