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61.
Partovi-Nia R Beheshti S Qin Z Mandal HS Long YT Girault HH Kraatz HB 《Langmuir : the ACS journal of surfaces and colloids》2012,28(15):6377-6385
A surface-based approach is presented to study the interactions of Aβ12-28-Cys assembled on gold surfaces with Congo red (CR) and a β-sheet breaker (BSB) peptide. The various aspects of the peptide film have been examined using different electrochemical and surface analytical techniques. Cyclic voltammetry and electrochemical impedance spectroscopy (EIS) results using redox probes [Fe(CN)(6)](3-/4-) show that Aβ12-28-Cys on gold forms a stable and reproducible blocking film. EIS analysis shows that CR and BSB have different effects on the electrochemical properties of Aβ12-28-Cys films, presumably due to changes in the interactions between the film and CR and BSB. EIS results indicate that in the case of CR film resistance decreases significantly presumably due to better penetration of the solution-based redox probe into the film, whereas in the case of BSB, the film resistance increases. We interpret this difference to BSB being able to interact with the Aβ12-28-Cys on the surface and presumably forming a film that presents a higher resistance for electron transfer from the redox probe to the solution. 相似文献
62.
Aliakbar Dehno Khalaji Gholamhossein Grivani Samaneh Jalali Akerdi Helen Stoeckli-Evans Debasis Das 《Journal of chemical crystallography》2012,42(1):83-88
Abstract
Two zinc(II) complexes [ZnI2((2,3-MeO-ba)2en)] (1) and [ZnCl2((2,3-MeO-ba)2en)] (2), with the symmetrical bidentate Schiff-base ligand (2,3-MeO-ba)2en [N,N′-bis(2,3-dimethoxybenzylidene)-1,2-diaminoethane] have been synthesized and characterized by elemental analyses (CHN), FT-IR and 1H-NMR spectroscopy. The thermal behaviors of these complexes were studied using thermogravimetry in order to evaluate their thermal stability and thermal decomposition pathways. The crystal structure of [ZnI2((2,3-MeO-ba)2en)] (1) was determined from single-crystal X-ray diffraction. The coordination polyhedron about the zinc(II) center in the complex 1 is best described as a distorted tetrahedron. 相似文献63.
Synchrotron radiation (SR), as a result of its high-intensity, brilliant, monochromatic, and collimated beams, is becoming one of the most crucial components of research in various fields of materials science such as nanomaterials, biomaterials, and energy materials. SR-based characterization methods can be employed to analyze different systems such as powders, thin films, and bulk forms having complex crystalline or amorphous structures. In this review, peculiarities of SR are briefly explained. Moreover, various techniques carried out utilizing this instrument for material characterization such as X-ray powder diffraction, grazing-incidence X-ray diffraction, small/wide-angle X-ray scattering, X-ray absorption spectroscopy, different techniques of X-ray imaging, X-ray photoelectron spectroscopy, and X-ray microprobes/nanoprobes are presented. As a result, by shedding light on the advantages of SR and its superiority to the equivalent laboratory experiments, researchers are recommended to exploit the capabilities of this invaluable tool in their materials characterization. 相似文献
64.
Let G be a finite group andA be a normal subgroup ofG. We denote by ncc(A) the number ofG-conjugacy classes ofA andA is calledn-decomposable, if ncc(A)= n. SetK
G = {ncc(A)|A ⊲ G}. LetX be a non-empty subset of positive integers. A groupG is calledX-decomposable, ifK
G =X.
Ashrafi and his co-authors [1-5] have characterized theX-decomposable non-perfect finite groups forX = {1, n} andn ≤ 10. In this paper, we continue this problem and investigate the structure ofX-decomposable non-perfect finite groups, forX = {1, 2, 3}. We prove that such a group is isomorphic to Z6, D8, Q8, S4, SmallGroup(20, 3), SmallGroup(24, 3), where SmallGroup(m, n) denotes the mth group of ordern in the small group library of GAP [11]. 相似文献
65.
Vajiheh Neshati Samaneh Mollazadeh Bibi Sedigheh Fazly Bazzaz Antoine A. F. de Vries Majid Mojarrad Hojjat Naderi-Meshkin Zeinab Neshati Mahdi Mirahmadi Mohammad Amin Kerachian 《Applied biochemistry and biotechnology》2018,186(1):245-255
Since the adult mammalian heart has limited regenerative capacity, cardiac trauma, disease, and aging cause permanent loss of contractile tissue. This has fueled the development of stem cell-based strategies to provide the damaged heart with new cardiomyocytes. Bone marrow-derived mesenchymal stem cells (BM-MSCs) are capable of self-renewal and differentiation into cardiomyocytes, albeit inefficiently. MicroRNAs (miRNAs, miRs) are non-coding RNAs that have the potential to control stem cell fate decisions and are employed in cardiac regeneration and repair. In this study, we tested the hypothesis that overexpression of miR-499a induces cardiomyogenic differentiation in BM-MSCs. Human BM-MSCs (hBM-MSCs) were transduced with lentiviral vectors encoding miR-499a-3p or miR-499a-5p and analyzed by immunostaining and western blotting methods 14 days post-transduction. MiR-499a-5p-transduced cells adopted a polygonal/rod-shaped (myocyte-like) phenotype and showed an increase in the expression of the cardiomyocyte markers α-actinin and cTnI, as cardiogenic differentiation markers. These results indicate that miR-499a-5p overexpression promotes the cardiomyogenic differentiation of hBM-MSCs and may thereby increase their therapeutic efficiency in cardiac regeneration. 相似文献
66.
Shahram Mehdipour-Ataei Samal Babanzadeh Ebrahim Abouzari-Lotf Samaneh Khodami 《Soft Materials》2018,16(4):265-274
A new diamine was prepared via reaction between 8-hydroxy-5-nitroquinoline and 4-nitrobenzoyl chloride, followed by reduction of the nitro groups of the resulted compound. Novel quinoline-based poly(ester-amide)s were produced through polycondensation reactions of the prepared diamine with different diacid chlorides. The monomer and poly(ester-amide)s were characterized and properties of the polymers including solution viscosity, thermal behavior and stability, solubility, and crystallinity were studied.High thermal stability and improved solubility was observed for the polymers, indicating successful designing of monomer and related polymers for overcoming the main issue of thermally stable polymers, i.e. the problem of increasing solubility versus high thermal stability.Also, by changing the diacid chlorides for the preparation of poly(ester-amide)s, the structure-property relations were investigated. 相似文献
67.
Transport in Porous Media - The wettability of the reservoir rock has an important effect on the displacement of fluids on a microscopic scale in all EOR processes, especially in the microbial... 相似文献
68.
The hierarchical product of graphs was introduced very recently by L. Barriére et al. in [L. Barriére, F. Comellas, C. Dafló and M. A. Fiol, On the spectra of hypertrees, Linear Algebra Appl. 428 (2008) 1499–1510]. In this paper, some properties of the hierarchical product, as well as its extension under Szeged, revised Szeged and edge Szeged indices of graphs are studied. 相似文献
69.
Hamid Saeidian Mehran Babri Davood Ashrafi Mansour Sarabadani Mohammad Taghi Naseri 《Analytical and bioanalytical chemistry》2013,405(21):6749-6759
The electron-impact (EI) mass spectra of a series of O-alkyl methylphosphonothionocyanidates were studied for Chemical Weapons Convention (CWC) purposes. General EI fragmentation pathways were constructed and discussed, and collision-induced dissociation studies of the major EI ions were performed to confirm proposed fragment structures by analyzing fragment ions of deuterated analogs and by use of density functional theory (DFT) calculations. Thiono–thiolo rearrangement, McLafferty-type rearrangement, and a previously unknown intramolecular electrophilic aromatic substitution reaction were observed and confirmed. The study also focused on differentiation of isomeric compounds. Retention indices for all compounds, and an electrophilicity index for several compounds, are reported and interpreted. 相似文献
70.