排序方式: 共有49条查询结果,搜索用时 4 毫秒
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Michael Okafor Paulina Gonzalez Pascale Ronot Islah El Masoudi Anne Boos Stphane Ory Sylvette Chasserot-Golaz Stphane Gasman Laurent Raibaut Christelle Hureau Nicolas Vitale Peter Faller 《Chemical science》2022,13(40):11829
Copper (Cu) in its ionic forms is an essential element for mammals and its homeostasis is tightly controlled. Accordingly, Cu-dyshomeostasis can be lethal as is the case in the well-established genetic Wilson''s and Menkes diseases. In Alzheimer''s disease (AD), Cu-accumulation occurs in amyloid plaques, where it is bound to the amyloid-beta peptide (Aβ). In vitro, Cu–Aβ is competent to catalyze the production of reactive oxygen species (ROS) in the presence of ascorbate under aerobic conditions, and hence Cu–Aβ is believed to contribute to the oxidative stress in AD. Several molecules that can recover extracellular Cu from Aβ and transport it back into cells with beneficial effects in cell culture and transgenic AD models were identified. However, all the Cu-shuttles currently available are not satisfactory due to various potential limitations including ion selectivity and toxicity. Hence, we designed a novel peptide-based Cu shuttle with the following properties: (i) it contains a Cu(ii)-binding motif that is very selective to Cu(ii) over all other essential metal ions; (ii) it is tagged with a fluorophore sensitive to Cu(ii)-binding and release; (iii) it is made of a peptide platform, which is very versatile to add new functions. The work presented here reports on the characterization of AKH-αR5W4NBD, which is able to transport Cu ions selectively into PC12 cells and the imported Cu appeared bioavailable, likely via reductive release induced by glutathione. Moreover, AKH-αR5W4NBD was able to withdraw Cu from the Aβ1–16 peptide and consequently inhibited the Cu-Aβ based reactive oxygen species production and related cell toxicity. Hence, AKH-αR5W4NBD could be a valuable new tool for Cu-transport into cells and suitable for mechanistic studies in cell culture, with potential applications in restoring Cu-homeostasis in Cu-related diseases such as AD.The synthetic peptide AKH-αR5W4NBD was designed as a shuttle to counteract copper imbalance in Alzheimer’s disease. In vitro, this shuttle is able to abstract Cu(ii) selectively from amyloid-β and transport it into cells in a bioavailable form. 相似文献
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S. F. Masoudi Zh. Ebrahiminejad 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2010,59(3):421-425
The Bohm sheath criterion is modified for collisional plasma containing
Boltzmann electrons and cold fluid ions at the presence of external magnetic
field. Based on fluid model, the effects of the strength and the orientation
of an external magnetic field on the upper and lower limits of Bohm sheath
criterion have been studied by considering the collision frequency between
ions and neutrals. The results show that the sheath criterion depends on the
orientation and magnitude of magnetic field and the ion flow velocity at the
sheath boundary. 相似文献
33.
Saeed S. Jahromi Seyed Farhad Masoudi 《Applied Physics A: Materials Science & Processing》2010,99(1):255-263
By knowing the phase and modules of the reflection coefficient in neutron reflectometry problems, a unique result for the scattering length density (SLD) of a thin film can be determined which will lead to the exact determination of type and thickness of the film. In the past decade, several methods have been worked out to resolve the phase problem such as dwell time method, reference layer method and variation of surroundings, among which the reference method and variation of surroundings by using a magnetic substrate and polarized neutrons is of the most applicability. All of these methods are based on the solution of Schrödinger equation for a discontinuous and step-like potential at each interface. As in a real sample there is some smearing and roughness at the boundaries, and consideration of smoothness and roughness of interfaces would affect the final output result. In this paper, we have investigated the effects of the smoothness of interfaces on the determination of the phase of reflection as well as the retrieval process of the SLD, by using a smooth varying function (Eckart potential). The effects of the roughness of interfaces on the same parameters have also been investigated by random variation of the interface around its mean position. 相似文献
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Tomáš Křenek Nataliya Murafa Petr Bezdička Jan Šubrt Husain M. Masoudi Josef Pola 《应用有机金属化学》2012,26(3):135-139
Pulsed IR laser irradiation of metal (Au or Ag) target in gaseous tetramethyltin (TMT) results in metal ablation and adjacent dielectric breakdown (DB) in TMT and allows gas phase deposition of films containing metal (Au or Ag), Sn and C elements. Volatile products of DB of TMT were examined by FT‐IR spectroscopy and revealed as intermediates of gas phase carbonization reactions. The solid films were analyzed by FT‐IR and Raman spectroscopy, X‐ray diffraction and electron microscopy and shown as amorphous nanostructured Au–Sn/C and Ag–Sn/C phases containing β‐Sn nanograins. These Sn nanograins exhibit irreversible amorphization upon heating and melt below the melting point of bulk β‐Sn phase. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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Mozhgan Masoudi Mohammad Anary-Abbasinejad Alireza Maleki 《Journal of the Iranian Chemical Society》2017,14(11):2299-2304
An efficient one-pot synthesis of 2H-pyrroline derivatives by a four-component reaction between carbon disulfide, aniline, arylglyoxals and β-enaminocarbonyls in acetonitrile at room temperature under mild reaction conditions is reported. The addition reaction has been done to access broad range of 5-hydroxy-4-phenylcarbamodithioate 2-H pyrroline derivatives after about 6 h stirring. All reactions were performed in acetonitrile at room temperature. Reactions are clean, and products were isolated by simple filtration. 相似文献
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R. Iqbal M. Zareef S. Ahmed J. H. Zaidi M. Arfan M. Shafique N. A. Al‐Masoudi 《中国化学会会志》2006,53(3):689-696
Twelve novel primary ( 4a‐c , 5a‐c ) and secondary ( 4d‐f, 5d‐f ) benzenesulfonamides bearing 2,5‐disubstituted‐1,3,4‐oxadiazole moiety have successfully been prepared by direct chlorosulfonation of phenyl substitutent present on the 2‐position of 5‐mercapto‐1,3,4‐oxadiazoles 2a‐c and their methylhio derivatives 3a‐c using chlorosulfonic acid under anhydrous conditions. Structures of the synthesized compounds were established by their physical and spectral data. Some of the synthesized compounds have been screened in vitro for their antimicrobial and anti‐HIV activity; the results were in accordance with SAR. 相似文献