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Ali M. Abdel‐Mageed Alexander Klyushin Azita Rezvani Axel Knop‐Gericke Robert Schlgl R. Jürgen Behm 《Angewandte Chemie (International ed. in English)》2019,58(30):10325-10329
The electronic and structural properties of Au/ZnO under industrial and idealized methanol synthesis conditions have been investigated. This was achieved by kinetic measurements in combination with time‐resolved operando infrared (DRIFTS) as well as in situ near‐ambient pressure X‐ray photoelectron spectroscopy (NAP‐XPS) and X‐ray absorption near‐edge spectroscopy (XANES) measurements at the O K‐edge together with high‐resolution electron microscopy. The adsorption of CO during the reaction revealed the presence of negatively charged Au nanoparticles/Au sites during the initial phase of the reaction. Near‐ambient‐pressure XPS and XANES demonstrate the build‐up of O vacancies during the reaction, which goes along with a substantial increase in the rate of methanol formation. The results are discussed in comparison with previous findings for Cu/ZnO and Au/ZnO catalysts. 相似文献
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Fazeli-Attar Seyede Azita Mirjalili Bi Bi Fatemeh 《Research on Chemical Intermediates》2018,44(10):6419-6430
Research on Chemical Intermediates - Fe3O4@SiO2–TiCl3 NPs, a novel core shell catalyst, was synthesized via preparing Fe3O4@SiO2 as a magnetic support followed by treatment with titanium... 相似文献
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Zahra Bashiri Ali Moghaddaszadeh Reza Falak Farnaz Khadivi Azita Afzali Mehdi Abbasi Ali Mohammad Sharifi Hamid Reza Asgari Farid Ghanbari Morteza Koruji 《Macromolecular bioscience》2023,23(9):2200574
In vitro production of sperm is a desirable idea for fertility preservation in azoospermic men and prepubertal boys suffering from cancer. In this study, a biocompatible porous scaffold based on a triad mixture of silk fibroin (SF), alginate (Alg), and laminin (LM) is developed to facilitate the differentiation of mouse spermatogonia stem cells (SSCs). Following SF extraction, the content is analyzed by SDS-PAGE and stable porous 3D scaffolds are successfully prepared by merely Alg, SF, and a combination of Alg-SF, or Alg-SF-LM through freeze-drying. Then, the biomimetic scaffolds are characterized regarding the structural and biological properties, water absorption capacity, biocompatibility, biodegradability, and mechanical behavior. Neonatal mice testicular cells are seeded on three-dimensional scaffolds and their differentiation efficiency is evaluated using real-time PCR, flow cytometry, immunohistochemistry. Blend matrices showed uniform porous microstructures with interconnected networks, which maintained long-term stability and mechanical properties better than homogenous structures. Molecular analysis of the cells after 21 days of culture showed that the expression of differentiation-related proteins in cells that are developed in composite scaffolds is significantly higher than in other groups. The application of a composite system can lead to the differentiation of SSCs, paving the way for a novel infertility treatment landscape in the future. 相似文献
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Recent preclinical and clinical testing of hypocrellin-based photosensitizer SL052 for use in photodynamic therapy (PDT) of cancer has shown encouraging results. Further optimization of its formulation for delivery could considerably extend the therapeutic efficiency of this drug. A nanoformulation encapsulating SL052 into biodegradable polymer poly(lactic-co-glycolic acid) (PLGA) was developed using a single-emulsion solvent evaporation technique and characterized in terms of particle size and loading of the photosensitizing agent. This nanoformulation, SL052-PLGA-nanoparticles (NPs), was compared with recently created nanoformulation based on polyvinylpyrrolidone (SL052-PVP-NPs) and standard liposomal SL052 preparation in terms of efficacy when used for PDT treatment of squamous cell carcinomas SCCVII growing subcutaneously in syngeneic mice. The therapeutic effect of PDT using these three different SL052 formulations was tested for both 1 and 4 h intervals between drug injection and tumor light exposure. The longer time interval produced higher tumor cure rates with all SL052 preparations. With both drug-light intervals, PDT based on SL052-PLGA-NPs produced superior therapeutic benefit compared with the other two SL052 formulations. 相似文献
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Zoghi Ali T. Shokouhi Mohammad Naderi Fahimeh Abbasghorbani Maryam Fatehi Azita Pouladi Babak Adhami Mohammad Amin 《Journal of solution chemistry》2022,51(1):84-96
Journal of Solution Chemistry - Hydrogen sulfide and carbonyl sulfide represent undesirable impurities in a variety of industrial gas streams such as natural gas, liquefied natural gas and... 相似文献
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Let G be a stratified Lie group and L be the sub-Laplacian on G. Let
We show that Lf(L)δ, the distribution kernel of the operator Lf(L), is an admissible function on G. It is always in the Schwartz
space; one can choose f so that it has all moments vanishing, or has compact support with arbitrarily many moments vanishing.
We also show that, if ξ f(ξ) satisfies Daubechies' criterion, then L f(L)δ generates a frame for any sufficiently fine latticesubgroup
of G. Moreover, we show that the ratio of the frame bounds approaches 1 nearly quadratically as the dilation parameter approaches
1, so that the frame quickly becomes nearly tight (again assuming that the lattice subgroup is sufficiently fine). In particular,
if the dilation parameter is 21/3, and the lattice subgroup is sufficiently fine, then the "Mexican hat" wavelet, Le-L/2δ, generates a wavelet frame, for which the ratio of the optimal frame bounds is 1.0000 to four significant digits. 相似文献
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The aerial oxidation kinetics of hydroquinone in a freshly prepared developer solution at different temperatures and pHs has been studied. The activation parameters, Ea, ΔG# , ΔS# , ΔH# and enthalpy of formation of activated complex, ΔHfo(X# ), are determined. The large negative value of free energy of activation ΔG# proves that hydroquinone extremely tends to be oxidized by air at optimum temperature (20℃) and optimum pH (10.5) and converts to the activated complex semiquinone. It was also found that if the pH of the developer solution is increased from 9.3 to 10.5 the reaction rate will increase by a factor of 2. 相似文献
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A quaternary ammonium hydroxide–type of anion exchange resin (Amberlite IRA-400) was found to be an effective and reusable catalyst for the synthesis of various 4H-benzo[b]pyran derivatives via a one-pot, three-component condensation in aqueous media. Short reaction time, easy and quick isolation of the products, environmentally friendly procedure, excellent chemoselectivity, and excellent yields are the main advantages of this procedure. 相似文献
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Hamid Reza Shaterian Fahimeh Khorami Razieh Doostmohammadi Azita Amirzadeh Majid Ghashang 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):2227-2237
Silica-supported zinc chloride (SiO2-ZnCl2) and novel alumina-supported sodium hydrogensulfate (NaHSO4-Al2O3) as recyclable heterogeneous catalysts have been used for the mild trimethylsilylation of hydroxyl groups under ambient conditions. This procedure also allows for the selective protection of primary and secondary alcohols in the presence of tertiary alcohols. 相似文献