Ecletica Quimica最新文献_第9页

Magnetic nanoparticles: the cobalt 磁性纳米颗粒:钴

Ecletica Quimica Pub Date : 2018-01-22 DOI: 10.26850/1678-4618eqj.v35.4.2010.p153-163

V. Sargentelli, Antonio Aparecido Pupim Ferreira

{"title":"Magnetic nanoparticles: the cobalt","authors":"V. Sargentelli, Antonio Aparecido Pupim Ferreira","doi":"10.26850/1678-4618eqj.v35.4.2010.p153-163","DOIUrl":"https://doi.org/10.26850/1678-4618eqj.v35.4.2010.p153-163","url":null,"abstract":"The development of nanoparticles has been intensively pursued because of their technological importance. The magnetic nanoparticulate materials exhibit a series of interesting properties between which are mentioned the electrical, optical, magnetic and chemical properties. Magnetic nanostructures can be used in microelectronic and in medicine as in: magnetic memory storage, magnetic transport of biochemical complexes, magnetic resonance imaging, among others. The magnetic properties of nanoparticles there are very sensitive to its size and form. In this direction, many efforts they have been carried through with the intention of to control the form and distribution of the size of the nanoparticles. In the last few decades nanoparticles constituted by iron oxides had been studied. However, more recently, the focus of the researches has come back to others transitions metals. Amongst these, the cobalt comes being investigated due to its high magnetic susceptibility. In this context, the present article has the aim of to presents and to effect a comparative analysis of the more significant synthetic ways utilized in the present moment to obtain cobalt nanoparticles.","PeriodicalId":35894,"journal":{"name":"Ecletica Quimica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46742998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Potentiometric and conductimetric studies of chemical equilibria for pyridoxine hydrochloride in aqueous solutions: simple experimental determination of pKa values and analytical applications to pharmaceutical analysis 盐酸吡哆醇水溶液化学平衡的电位法和电导法研究:pKa值的简单实验测定及其在药物分析中的应用

Ecletica Quimica Pub Date : 2018-01-22 DOI: 10.1590/S0100-46702010000400010

T. A. Santos, D. Costa, Samuel Pita, F. Semaan

{"title":"Potentiometric and conductimetric studies of chemical equilibria for pyridoxine hydrochloride in aqueous solutions: simple experimental determination of pKa values and analytical applications to pharmaceutical analysis","authors":"T. A. Santos, D. Costa, Samuel Pita, F. Semaan","doi":"10.1590/S0100-46702010000400010","DOIUrl":"https://doi.org/10.1590/S0100-46702010000400010","url":null,"abstract":"The combination of two low-cost classical procedures based on titrimetric techniques is presented for the determination of pyridoxine hydrochloride in pharmaceuticals samples. Initially some experiments were carried out aiming to determine both pKa1 and pKa2 values, being those compared to values of literature and theoretical procedures. Commercial samples containing pyridoxine hydrochloride were electrochemically analysed by exploiting their acid-base and precipitation reactions. Potentiometric titrations accomplished the reaction between the ionizable hydrogens present in pyridoxine hydrochloride, being NaOH used as titrant; while the conductimetric method was based on the chemical precipitation between the chloride of pyridoxine hydrochloride molecule and Ag+ ions from de silver nitrate, changing the conductivity of the solution. Both methods were applied to the same commercial samples leading to concordant results when compared by statistical tests (95 and 98% confidence levels). Recoveries ranging from 99.0 to 108.1% were observed, showing no significant interference on the results.","PeriodicalId":35894,"journal":{"name":"Ecletica Quimica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67637907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 29

ESTUDO DE ESTABILIDADE DO FOSFATO DISSÓDICO DE PREDNISOLONA EM CONDIÇÕES DE ESTRESSE OXIDATIVO E TÉRMICO, EM FORMULAÇÃO ORAL 强的松龙磷酸二钠在氧化和热应激条件下口服配方的稳定性研究

Ecletica Quimica Pub Date : 2018-01-22 DOI: 10.1590/S0100-46702010000400001

Cleber Antônio Lindino, Marcia Lina Mitsui, Rodolfo Ortiguara, Daiane Felin, M. Rosa, R. A. Bariccatti

引用次数: 1

Synthesis, characterization and thermal behaviour of heavy trivalent lanthanide malonates 重三价丙二酸镧系化合物的合成、表征及热性能

Ecletica Quimica Pub Date : 2018-01-22 DOI: 10.1590/S0100-46702010000400012

J. R. Locatelli, C. T. Carvalho, F. Caires, M. Ionashiro

引用次数: 5

Análise conformacional de compostos de Biginelli com atividade antineoplásica 具有抗肿瘤活性的比格烯属化合物的构象分析

Ecletica Quimica Pub Date : 2018-01-22 DOI: 10.1590/S0100-46702010000400004

M. Marques, D. Russowsky, L. M. A. Fontoura

{"title":"Análise conformacional de compostos de Biginelli com atividade antineoplásica","authors":"M. Marques, D. Russowsky, L. M. A. Fontoura","doi":"10.1590/S0100-46702010000400004","DOIUrl":"https://doi.org/10.1590/S0100-46702010000400004","url":null,"abstract":"Abstract : .Dihydropyrimidinones, such as monastrol and analogues, are heterocycles with known antineoplastic activity. Conformational analysis represents an important preliminary step in structure-activity correlation studies. Herein we describe the conformational analysis of monastrol and analogues by AM1 semi-empirical and ab initio HF/6-31G* calculations. Four equilibrium geometries were found ( s-cis/ap, s-cis/sp, s-trans/ap and s-trans/sp) , and the important internal rotations were those of the ab-unsaturated carbonyl system and of the aryl group connected to the heterocycle Keywords: conformational analysis, dihydropyrimidinones, Biginelli compound, AM1, HF/6-31G* Referencias [1] C. O. Kappe, Eur. J. Med. Chem. 35(12) (2000) 1043. [2] B. Desai, D. Dallinger, C. O. Kappe, Tetrahedron 62 (2006) 4651. [3] C. O. Kappe, O. V. Shishkin, G. Uray, P. Verdino Tetrahedron 56 (2000) 1859. [4] D. Russowsky, R. F. S. Canto, S. A. A. Sanches, M. G. M. D´Oca, A.Fatima, R. A. Pilli, L. K. Kohn, M. A. Antonio, J. E. Carvalho, Bioorg. Chem. 34 (2006) 173. [5] E. L. Eliel, S.H. Wilen, Stereochemistry of Organic Compounds, Wiley, New York, 1994.[6] C.R. Rodrigues, Cadernos Tematicos Quim. Nova Esc. 3 (2001) 43.[7] C. O. Kappe, W . M. F Fabian, A. Semones, Tetrahedron 53 (1997) 2803. [8] M.J.S. Dewar , E.G. Zoebisch, E.F . Healy J.J.P Stewart, J. Am. Chem. Soc. 107(13) (1985) 3902. [9] Spartan´02 (1.0.1), Wavefunction: Irvine, 2002.[10] G. D. Smith, R. L. Jaffe, J. Phys. Chem. 100 (48) (1996) 18718.M. J. Hafezi, F. Sharif, Mol. Struct.: THEOCHEM 814(1-3) (2007) 43.","PeriodicalId":35894,"journal":{"name":"Ecletica Quimica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48508838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Quimiometria como ferramenta analitica para definição das condiçoes de ensaio da enzima peroxidase de soja 化学计量学作为确定大豆过氧化物酶试验条件的分析工具

Ecletica Quimica Pub Date : 2018-01-22 DOI: 10.1590/S0100-46702010000400016

M. C. Santos, J. O. Tognolli, O. Oliveira

{"title":"Quimiometria como ferramenta analitica para definição das condiçoes de ensaio da enzima peroxidase de soja","authors":"M. C. Santos, J. O. Tognolli, O. Oliveira","doi":"10.1590/S0100-46702010000400016","DOIUrl":"https://doi.org/10.1590/S0100-46702010000400016","url":null,"abstract":"Peroxidases enzymes are heme-proteins found in the different organisms livings creature, especially vegetal, present in important physiological paper/biochemist as protection against microorganisms. The soy, one of the most important products for the Brazilian agribusiness, presents in the rind of its seeds (by-product) where has high activity of peroxidase, called soybean peroxidase, with potential of use in clinical analytical methods. The proposal of the work was to apply the factorial planning for optimization of the conditions extraction of this enzyme, definition of the conditions of kinetic-enzyme assay conditions (pH and temperature), using methodology of reply surface. The data obtained: i) extraction in cetonico power, ii) reactional medium: pH 3,3, volume of the sample contend enzyme 330 µL - 340 µL, hydrogen peroxide 4,2 mmol.L-1 150 µL, time of reaction 20 seconds, temperature 50o C, substrate guaiacol 30mmol.L-1 300 µL, and 0.1 mol.L-1 of NaCl. This chemometric methodology used to definition of the extraction conditions and parameters kinetic assay of soybean peroxidase was very efficient, compared the classical methodology of variations/repetitions (attempt and error).","PeriodicalId":35894,"journal":{"name":"Ecletica Quimica","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48379135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Determinação de coeficiente de expansão térmica do biodiesel e seus impactos no sistema de medição volumétrico 生物柴油热膨胀系数的测定及其对体积测量系统的影响

Ecletica Quimica Pub Date : 2018-01-22 DOI: 10.1590/S0100-46702010000400014

D. Santos, D. Vieira

引用次数: 9

Comparação de técnicas analíticas para a extração de potássio de amostras de tecido vegetal com água e soluções ácidas concentrada e diluída 比较水、浓酸和稀酸溶液从植物组织样品中提取钾的分析技术

Ecletica Quimica Pub Date : 2018-01-16 DOI: 10.1590/S0100-46702010000200005

A. C. C. Bernardi, S. Oka, G. Souza

引用次数: 5

Determination of patulin in apple juice by HPLC using a simple and fast sample preparation method 高效液相色谱法测定苹果汁中棒曲霉素的含量

Ecletica Quimica Pub Date : 2018-01-16 DOI: 10.1590/S0100-46702010000200002

S. Sargenti, C. A. Almeida