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41.
Braga Renata M. Melo Dulce M. A. Melo Marcus A. F. Freitas Julio C. O. Boateng Akwasi A. 《Journal of Thermal Analysis and Calorimetry》2022,147(12):6655-6663
Journal of Thermal Analysis and Calorimetry - Elephant grass (Pennisetum purpureum Schum.) is one such resource with a great amount of carbohydrate and lignin polymers that together represent high... 相似文献
42.
43.
Glaydston C. Bento Jefferson G. Melo 《Journal of Optimization Theory and Applications》2012,152(3):773-785
In this paper, a subgradient type algorithm for solving convex feasibility problem on Riemannian manifold is proposed and
analysed. The sequence generated by the algorithm converges to a solution of the problem, provided the sectional curvature
of the manifold is non-negative. Moreover, assuming a Slater type qualification condition, we analyse a variant of the first
algorithm, which generates a sequence with finite convergence property, i.e., a feasible point is obtained after a finite
number of iterations. Some examples motivating the application of the algorithm for feasibility problems, nonconvex in the
usual sense, are considered. 相似文献
44.
Janaína Versiani dos Anjos Rajendra M. Srivastava Silene Carneiro do Nascimento Sebastião J. de Melo 《Journal of carbohydrate chemistry》2013,32(4):258-277
A copper‐catalyzed reaction of propargyl 4,6‐di‐O‐acetyl‐2,3‐dideoxy‐α‐D‐erythro‐hex‐2‐enopyranoside with 3‐(4‐azidophenyl)‐1,2,4‐oxadiazoles gave the corresponding hexenopyranosides bearing an 1,2,4‐oxadiazole subunit in the aglyconic part of the molecule. The same reaction between ethyl 4‐azido‐2,3,4‐trideoxy‐α‐D‐erythro‐hex‐2‐enopyranoside and acetylenic 1,2,4‐oxadiazoles afforded the corresponding hexenopyranosides carrying a triazole and a 1,2,4‐oxadiazole ring at C‐4 of the carbohydrate. Combination of the two sequences gave hexenopyranosides displaying two 1,2,4‐oxadiazole subunits, each one being embedded in the C‐1 and C‐4 frameworks, of the carbohydrate moiety. A simple dihydroxylation reaction of these unsaturated carbohydrates yielded a series of mannopyranosides bearing one or two 1,2,4‐oxadiazole subunits at C‐1 or C‐4. These new compounds were evaluated for their cytotoxic activities against two cell strains: NCI‐H292 (lung carcinoma) and Hep‐2 (larynx carcinoma), some of them presenting impressive cell growth inhibitions. 相似文献
45.
João Miller de Melo Henrique Pablo Cañizares Cristina Saez Elisama Vieira dos Santos Manuel Andrés Rodrigo 《Current Opinion in Electrochemistry》2021
Treatment of polluted soil is one of the priorities in the search of a more sustainable planet. Electrochemically assisted soil remediation has been considered a good option for removing organic contaminants contained in soil, including the removal of volatile organic compounds, associated with gaseous streams produced during the treatment. Also, recently, electrochemical gas treatment technologies have been appointed as promising for the treatment of volatile organic compounds. In this work, we review the current opinion about the most recent studies in both areas. The first section focuses on the production of gaseous compounds during soil remediation by conventional and electrochemical systems. The second section describes the recent progress in the integration of adsorption and absorption with electrochemical processes. Finally, we discuss the holistic application of assisted electrochemical technologies in soil remediation, considering also emerging processes recently published in the literature. 相似文献
46.
J. Zavadlav R. Podgornik M.N. Melo S.J. Marrink M. Praprotnik 《The European physical journal. Special topics》2016,225(8-9):1595-1607
We present a dual-resolution model of a deoxyribonucleic acid (DNA) molecule in a bathing solution, where we concurrently couple atomistic bundled water and ions with the coarse-grained MARTINI model of the solvent. We use our fine-grained salt solution model as a solvent in the inner shell surrounding the DNA molecule, whereas the solvent in the outer shell is modeled by the coarse-grained model. The solvent entities can exchange between the two domains and adapt their resolution accordingly. We critically asses the performance of our multiscale model in adaptive resolution simulations of an infinitely long DNA molecule, focusing on the structural characteristics of the solvent around DNA. Our analysis shows that the adaptive resolution scheme does not produce any noticeable artifacts in comparison to a reference system simulated in full detail. The effect of using a bundled-SPC model, required for multiscaling, compared to the standard free SPC model is also evaluated. Our multiscale approach opens the way for large scale applications of DNA and other biomolecules which require a large solvent reservoir to avoid boundary effects. 相似文献
47.
Lucas J. M. F. Prezas P. R. Soreto Teixeira S. Ferreira N. M. Sales A. J. M. Melo B. M. G. Graça M. P. F. 《Journal of Sol-Gel Science and Technology》2021,98(3):580-592
Journal of Sol-Gel Science and Technology - Lithium ferrite (LiFe5O8) in the cubic crystal system is a very important and versatile material for several technological applications as it possesses... 相似文献
48.
Surface Changes at Platinized Platinum Based Hydrogen Gas Electrodes Following Use in Highly Saline Aqueous Solutions 下载免费PDF全文
Platinized platinum based hydrogen gas electrodes, Pt(Pt)|H2(g)|H+(aq), and silver‐silver chloride electrodes, Ag|AgCl|Cl? (aq), make up the Harned cell, without transfer, working in the potentiometric mode at Cl? concentrations and ionic strengths, I, below 0.1 mol kg?1, for assigning primary pH values to reference pH buffer solutions. This work reports on experiments performed at higher I and Cl? solutions up to 0.7 mol kg?1, aiming at addressing seawater conditions with results of equally high quality. In the course of measurements, the occasional occurrence of highly unstable potentials denoted electrode malfunction; Pt metal surfaces observed by SEM/EDS and XRD exhibit strong Ag and Cl peaks corresponding to the presence of AgCl crystals deposited at both surfaces. 相似文献
49.
Sayonara Maria Calado Gonçalves Glória Najara Silva Ivan da Rocha Pitta Moacyr Jesus Barreto de Melo Rêgo Simone Cristina Baggio Gnoato 《Natural product research》2020,34(12):1702-1711
AbstractBetulin (BE) is a pentacyclic triterpenes, obtained from natural sources and with several biological activities described, such as anti-tumoral and anti-inflammatory activities. The BE esterification at hydroxyl group (C-3 and C-28) resulted in five new ester derivatives with different numbers of carbons or halogens (chlorine and fluorine). Among these BE derivatives, two (2a e 2c) were able to significantly decrease IFN-g (*p?=?0.0391; **p?=?0.0156) and 2c modulated the expression of COX-2 better than Dexamethasone (DEXA). Regarding to cytotoxic assay, the best results were obtained for BE without modifications, with emphasis on tumoral cell lines Raji and MCF-7. The derivatives 2a and 2c showed immunomodulation activity (for the cytokines IFN-g). The presence of chorine in BE seems to be important for the ability of modulate COX-2 expression, since the ester chloride derivative 2c at 100?μM is more powerful inhibitor of COX-2 than DEXA. 相似文献
50.
Carolina Resmini Melo Elidio Angioletto Humberto Gracher Riella Michael Peterson Márcio Roberto Rocha Aline Resmini Melo Luciano Silva Susane Strugale 《Journal of Thermal Analysis and Calorimetry》2012,109(3):1341-1345
Research focused on the transformation and utilization of industrial wastes into products of commercial interest plays an increasingly important role. Residual pulp can become useful in the manufacture of different materials, providing high value to this waste and reducing its environmental impact when disposed of improperly in the environment. The main constituents of this waste are kaolin and calcium carbonate (CaCO3). Starting from kaolin, metakaolin can be produced by calcination of the residue at 630?°C for 2?h in a rotary reactor with air flow, followed by solubilization with hydrochloric acid to remove the CaCO3. The development of technological alternatives aimed at the reuse of certain wastes can result in applications of real economic interest to the chemical industry and ceramics and glass, which is the case in this study. The raw material and metakaolin obtained were analyzed by thermogravimetric analysis and derivative thermogravimetric analysis, X-ray diffraction, and X-ray fluorescence spectroscopy with promising results. This is because metakaolin was obtained free of contamination by other materials. 相似文献