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101.
Dr. Alireza Mashaghi Samaneh Mashaghi Prof. Dr. Ir. Sander J. Tans 《Angewandte Chemie (International ed. in English)》2014,53(39):10390-10393
The folding of complex proteins can be dramatically affected by misfolding transitions. Directly observing misfolding and distinguishing it from aggregation is challenging. Experiments with optical tweezers revealed transitions between the folded states of a single protein in the absence of mechanical tension. Nonfolded chains of the multidomain protein luciferase folded within seconds to different partially folded states, one of which was stable over several minutes and was more resistant to forced unfolding than other partially folded states. Luciferase monomers can thus adopt a stable misfolded state and can do so without interacting with aggregation partners. This result supports the notion that luciferase misfolding is the cause of the low refolding yields and aggregation observed with this protein. This approach could be used to study misfolding transitions in other large proteins, as well as the factors that affect misfolding. 相似文献
102.
Samaneh Mahmoudi-Gom Yek Davood Azarifar Masoud Khaleghi-Abbasabadi Hassan Keypour Masoumeh Mahmoudabadi 《应用有机金属化学》2020,34(12):e5989
In this article, the synthesis of a novel and highly efficient recyclable and reusable heterogeneous nanocatalyst has been reported via the functionalizing of the Fe3O4-magnetized graphene oxide nanosheets with the N6-Schiff base Cu (II) complex (GO/Fe3O4@SPNC). The structure of this novel nanocatalyst was determined by different analytical techniques such as FTIR, FE-SEM, TEM, TGA-DTG, and VSM. The catalytic activity of the synthesized GO/Fe3O4@SPNC nanocatalyst was explored for the synthesis of several new 2H-pyrido[3′,2′:6,7]pyrano[2,3-d]pyrimidine-7-carbonitrile derivatives with excellent yields. All new derivatives were fully identified by various spectral (1H NMR, 13C NMR, FT-IR, ESI-MS) analyses. In addition, this nanocatalyst carried out satisfactory catalytic maintenance of activity and high chemical stability in the titled reactions after seven-time of recycling without substantial loss of leaching. 相似文献
103.
Journal of Solid State Electrochemistry - The surface of a glassy carbon electrode modified with multi-walled carbon nanotubes (GCE/MWCNTs) was coated with a layer of phosphomolybdic acid (PMo12)... 相似文献
104.
Mohsen Behpour Mazaheri Samaneh Motaghedifard Mohammad Hassan 《Russian Journal of Electrochemistry》2022,58(1):21-31
Russian Journal of Electrochemistry - In this paper we report direct electrochemical synthesis of sponge-like MnO2 nanostructures using ultrasonic vibration on the surface of MWCNT modified pencil... 相似文献
105.
Thermodynamics of single-phase complex systems of glucose + alcohol + water is significantly important in food and pharmaceutical industries. The water activity is a practical parameter in thermodynamic characterization in food and pharmaceutical and other biological industries, which its value has an important role in growing microorganisms and rate of reactions. In this work, the NRTL-NRF excess Gibbs function has extended for ternary system of water, different alcohols (as second molecular solvent) and a special molecular solute like a sugar. The extended NRTL-NRF model with three parameters was used for correlation of the osmotic coefficient of the aqueous systems of glucose and alcohol at different concentrations. The data of the osmotic coefficient of water for these systems are obtained by an isopiestic method. The adjustable parameters are calculated by optimization of the experimental data of the osmotic coefficient using the Nedler–Mead algorithm. It is shown that the results of the modified NRTL-NRF model demonstrate low deviation from the experimental data. 相似文献
106.
Samaneh Sharbati 《Optical and Quantum Electronics》2018,50(9):337
In this paper an improved design for thin film solar cells is proposed to enhance conversion efficiency. This proposed structure includes two pairs of additional contact to the reversed bias of absorber and buffer layers, directly. The purpose of additional electrodes is to control the carrier distribution in the active region of device. This idea has been implemented on the fabricated Copper indium gallium selenide solar cell with the record efficiency of 22%. The simulations show an improvement of 2% in the conversion efficiency is obtained by direct application of reverse biasing on the absorber and buffer layer. The increase of short circuit current more than 3 mA/cm2 is responsible for the improved performance. The open circuit voltage and fill factor of cell can also be increased by the controlling reverse bias. 相似文献
107.
Samaneh Kharian Nader Teymoori Mohammad A. Khalilzadeh 《Journal of Solid State Electrochemistry》2012,16(2):563-568
In this work, we describe an electrochemical method using p-chloranil as a mediator and multi-wall carbon nanotube and TiO2 as sensors for sensitive determination of epinephrine (EP) in aqueous solution at pH = 10.0. It has been found that under
optimum condition (pH 10.0) in cyclic voltammetry, the oxidation of EP occurred at a potential about 171 mV less positive
than that unmodified carbon nanotube paste electrode. The diffusion coefficient (D) and the kinetic parameters, such as electron transfer coefficient, (α) and heterogeneous rate constant (k
h) for EP were also determined using electrochemical approaches. The electrocatalytic currents increase linearly with the EP
concentration over the range 0.6–135 μM. The detection limits for EP will be equal to 0.25 μM. The relative standard deviation
percentage values for 10.0 and 15.0 μM EP were 1.7% and 1.9%, respectively. Finally, this modified electrode was also examined
as a selective, simple, and precise new electrochemical sensor for the determination of EP in real sample such as urine and
epinephrine injection solution. 相似文献
108.
Samaneh Beheshti Dr. Sanela Martić Prof. Heinz‐Bernhard Kraatz 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(29):9099-9105
Hierarchical self‐assembly of disubstituted ferrocene (Fc)–peptide conjugates that possess Gly‐Val‐Phe and Gly‐Val‐Phe‐Phe peptide substituents leads to the formation of nano‐ and micro‐sized assemblies. Hydrogen‐bonding and hydrophobic interactions provide directionality to the assembly patterns. The self‐assembling behavior of these compounds was studied in solution by using 1H NMR and circular dichroism (CD) spectroscopies. In the solid state, attenuated total reflectance (ATR) FTIR spectroscopy, single‐crystal X‐ray diffraction (XRD), powder X‐ray diffraction (PXRD), and scanning electron microscopy (SEM) methods were used. Spontaneous self‐assembly of Fc–peptides through intra‐ and intermolecular hydrogen‐bonding interactions induces supramolecular assemblies, which further associate and give rise to fibers, large fibrous crystals, and twisted ropes. In the case of Fc[CO‐Gly‐Val‐Phe‐OMe]2 ( 1 ), molecules initially interact to form pleated sheets that undergo association into long fibers that form bundles and rectangular crystalline cuboids. Molecular offsets and defects, such as screw dislocations and solvent effects that occur during crystal growth, induce the formation of helical arrangements, ultimately leading to large twisted ropes. By contrast, the Fc–tetrapeptide conjugate Fc[CO‐Gly‐Val‐Phe‐Phe‐OMe]2 ( 2 ) forms a network of nanofibers at the supramolecular level, presumably due to the additional hydrogen‐bonding and hydrophobic interactions that stem from the additional Phe residues. 相似文献
109.
Mahmoud Nasrollahzadeh Samaneh Mahmoudi‐Gom Yek Narjes Motahharifar Mostafa Ghafori Gorab 《Chemical record (New York, N.Y.)》2019,19(12):2436-2479
Among different metallic nanoparticles, sliver nanoparticles (Ag NPs) are one of the most essential and fascinating nanomaterials. Importantly, among the metal based nanoparticles, Ag NPs play a key role in various fields such as biomedicine, biosensors, catalysis, pharmaceuticals, nanoscience and nanotechnology, particularly in nanomedicine. A main concern about the chemical synthesis of Ag NPs is the production of hazardous chemicals and toxic wastes. To overcome this problem, many research studies have been carried out on the green synthesis of Ag NPs using green sources such as plant extracts, microorganisms and some biopolymers without formation of hazardous wastes. Among green sources, plants could be remarkably valuable to exploring the biosynthesis of Ag NPs. In this review, the green synthesis of Ag‐based nanocatalysts such as Ag NPs, AgPd NPs, Au?Ag NPs, Ag/AgPd NPs, Ag/Cu NPs, Ag@AgCl NPs, Au?Ag@AgCl nanocomposite, Ag?Cr‐AC nanocomposite and Ag NPs immobilized on various supports such as Natrolite zeolite, bone, ZnO, seashell, hazelnut shell, almond shell, SnO2, perlite, ZrO2, TiO2, α‐Al2O3, CeO2, reduced graphene oxide (rGO), h‐Fe2O3@SiO2, and Fe3O4 using numerous plant extracts as reducing and stabilizing agents in the absence of hazardous surfactant and capping agents has been focused. This work describes the state of the art and future challenges in the biosynthesis of Ag‐based nanocatalysts. The fact about the application of living plants in metal nanoparticle (MNPs) industry is that it is a more economical and efficient biosynthesis biosynthetic procedure. In addition, the catalytic activities of the synthesized, Ag‐based recyclable nanocatalysts using various plant extracts in several chemical reactions such as oxidation, reduction, coupling, cycloaddition, cyanation, epoxidation, hydration, degradation and hydrogenation reactions have bben extensively discussed. 相似文献
110.
Samaneh Mozaffari Mohsen Dehghan Mahmood Borhanizarandi Mohamad Reza Nateghi 《Journal of Solid State Electrochemistry》2014,18(3):655-663
A hybrid of polymer/dispersed single-wall carbon nanotubes was utilized in networking a novel composition of gel electrolyte in dye-sensitized solar cells. The gel is composed of polyethylene glycol, polyvinyl pyrrolidone, single-wall carbon nanotubes, and I?/I3 ? as electrolyte. Formation of the less conductive polyiodide species in electrolyte was prohibited by the addition of single-wall carbon nanotubes leading to the excellent photovoltaic behavior of the cell under simulated standard illumination of the fabricated device owing to the increased open circuit voltage (0.47 V). Electrochemical impedance spectroscopy was employed to quantify the charge transport resistance and the electron lifetime at the TiO2 conduction band. Charge transport resistances at the TiO2/dye/electrolyte interface were determined for the cells consisting of the non-gel reference and our new gel electrolytes, and it was indicated that the charge recombination between injected electrons and electron acceptors (I3 ?) in the redox electrolyte was remarkably retarded. Electrochemical parameters obtained by the fitting showed all of the resistances increased as compared to liquid electrolyte dye-sensitized solar cells that can be related to the increase in viscosity of the gel, which hinders the ionic transportation through the electrolyte. These results were also confirmed by the electron lifetime analyses. The characteristic peak shifted to a lower frequency in the Bode phase plot for the cell containing gel electrolyte which is an indication of a longer electron lifetime in comparison with that of the cell containing very conventional liquid electrolyte. 相似文献