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1.
Guizellini Filipe Corrêa Franzin Bruno Trevizan da Silva Matheus Antonio Abra Luciana Mazotti Hojo Ossamu Pastre Iêda Aparecida Ribeiro Clóvis Augusto Paiva-Santos Carlos de Oliveira Fertonani Fernando Luis 《Journal of Thermal Analysis and Calorimetry》2021,143(1):47-60
Journal of Thermal Analysis and Calorimetry - The aim of this work is to synthesize and characterize a new structured silver–clay dried, calcined or sintered at different temperatures... 相似文献
2.
Gustavo Guadagnucci Fontanari José Manuel Martins Marcelo Kobelnik Iêda Aparecida Pastre José Alfredo Gomes Arêas José Paschoal Batistuti Fernando Luis Fertonani 《Journal of Thermal Analysis and Calorimetry》2012,108(1):141-148
This study used TG, DSC, and SDS-PAGE techniques to study protein isolates (PIs) in the powder form obtained from lupin seeds
flour Lupinus albus. Different methods of preparing PIs were tested, resulting in final products that were different only in relation to the
yield and protein content. The results of the protein analysis by SDS-PAGE showed that the same protein fractions were present
in the lupin seeds and in the obtained PIs. This result shows that the process of extraction was not damaging to the composition
of the original protein. On the other hand, the results of the thermal analysis (DSC and TG–DTG curves) obtained for the different
PIs, led to the detection of changes in the protein conformation through the ΔH values, which in general decreased with increasing values of pH and ionic strength in the experimental conditions of extraction. 相似文献
3.
G. G. Fontanari G. R. Souza J. P. Batistuti V. A. Neves I. A. Pastre F. L. Fertonani 《Journal of Thermal Analysis and Calorimetry》2008,93(2):397-402
Glutelin, the major protein fraction from guava seed, was obtained by fractioning as described by Osborne. The total proteins
were extracted and the isolates obtained by isoelectric precipitation presented similar DSC curves, concordant with the results
obtained by gel filtration chromatography and electrophoresis in polyacrylamide gel (PAGE-SDS). However, the DSC curves showed
a higher enthalpy with regard to the denaturing protein isolate (PI) extracted at pH 10.0 when compared to a PI at pH 11.5.
Such results are in accordance with those obtained for PI extracted at pH 10.0 using chromatography, this one being present
in the form of molecular aggregates of greater molecular mass. The glutelin fraction, however, did not present a denaturation
peak in the DSC curve, showing that the process for obtaining the same significantly altered its conformation. 相似文献
4.
5.
M. G. Neumann I. A. Pastre A. M. Chinelatto O. A. El Seoud 《Colloid and polymer science》1996,274(5):475-481
The surface potential, ψ in mV, was determined for the following polyelectrolytes and co-polyelectrolytes in aqueous solution: sodium poly(styrene sulfonate); sodium poly(vinyl sulfonate); poly(vinyl alcohol-co-55% sodium vinyl sulfate); poly(methylmethacrylate-co-40% sodium styrene sulfonate); poly (methylmethacrylate-co-60% sodium styrene sulfonate); poly(styrene-co-56% styrene sulfonate); and poly(styrene-co-80% styrene sulfonate). For comparison, the surface potentials of aqueous sodium dodecyl sulfate and sodium dodecylbenzene sulfonate micelles were also determined. The dyes neutral red and safranine-T were used as indicators. ThepKa of the former was calculated from the Henderson-Hasselbach equation, using UV-VIS spectroscopy to determine the concentration of protonated ground state as a function of pH. The surface potential of the aggregates was culculated from the equation: $$pKa_{\text{i}} = pKa_0 - {{F\Psi } \mathord{\left/ {\vphantom {{F\Psi } {2.3RT}}} \right. \kern-\nulldelimiterspace} {2.3RT}}$$ wherepKa i andpKa o refer to the indicatorpKa in the presence of charged and nonionic interfaces, respectively, and the other terms have their usual meaning. The protonation kinetics of the triplet state of safranine-T (measured from the decay of its transient absorption at 830 nm) was used to determine hydronium ion concentrations at aggregate interfaces, and the corresponding surface potentials were calculated from: $$a_{{\text{Hi}}} = a_{{\text{Haq}}} \times \exp \left( {{{ - F\Psi } \mathord{\left/ {\vphantom {{ - F\Psi } {RT}}} \right. \kern-\nulldelimiterspace} {RT}}} \right)$$ wherea Hi anda Haq refer to the hydronium ion activity at the aggregate interface, and in bulk water, respectively. Surface potentials determined by both techniques were in excellent agreement. Values of ψ were found to depend on the structure of the polyelectrolyte, sodium poly(styrene sulfonate) versus sodium poly(vinyl sulfonate) and, for the same type of co-polyelectrolyte, on the percentage of charged monomer. 相似文献
6.
Thermal behaviour of intercalated 8-hydroxyquinoline (oxine) in montmorillonite clay 总被引:1,自引:0,他引:1
I. A Pastre I. do Nascimento Oliveira A. B. S Moitinho G. R. de Souza E. Y. Ionashiro F. L. Fertonani 《Journal of Thermal Analysis and Calorimetry》2004,75(2):661-669
The composite montmorillonite-8-hydroxyquinoline (Swy-1-8-HQ) was prepared by two different processes and studied by using
thermogravimetric analysis (TG/DTG and DSC), as well as helpful techniques as fluorescence in the UV-visible region and X-ray
diffraction. The composites developed fluorescent appearance, however with quantum poor efficiency and they exhibited distinct
TG and DSC thermal behavior. The fluorescence data of spectra associated to the TG/DT curves allowed to suggest that the 8-HQ
was present in the composites in two different circumstances: 1 - intercalated in the interlayer spaces (Swy-1-8-HQ2), rigidly
associated to the substrate feasible as a monolayer with the aromatic rings parallel to the silica layer; and/or, 2 - adsorbed
on the surface (Swy-1-8-HQ1), either as a bilayer formation or tilting of the molecules to the silicate layer sheet. All results
confirmed above are in agreement with X-ray diffraction patterns, once the interlayer space increases when 8-HQ is incorporated.
The experimental results confirm the formation of the composites in agreement with the method used in the preparation.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
7.
[reaction: see text] The Heck arylation of acyclic- and cyclic-substituted acrylates using several arenediazonium tetrafluoroborates was investigated. Arylations were carried out under aerobic, ligand-free conditions to provide the corresponding substituted acrylates in moderate to high isolated yields. Heck arylations were usually completed in less than 2 h in refluxing methanol. The aza-endocyclic acrylate derivative 11a was converted into the antidepressant drug (+/-)-paroxetine in a concise new route in good overall yield. 相似文献
8.
An improved LC‐MS/MS method for quantitation of indapamide in whole blood: application for a bioequivalence study 下载免费PDF全文
Guilherme Araújo Pinto Kátia Isabel Fercondini Pastre Karini Bruno Bellorio Leonardo de Souza Teixeira Weidson Carlo de Souza Fernanda Crunivel de Abreu Fabiana Fernandes de Santana e Silva Cardoso Gerson Antônio Pianetti Isabela Costa César 《Biomedical chromatography : BMC》2014,28(9):1212-1218
An improved LC‐MS/MS method for the quantitation of indapamide in human whole blood was developed and validated. Indapamide‐d3 was used as internal standard (IS) and liquid–liquid extraction was employed for sample preparation. LC separation was performed on Synergi Polar RP‐column (50 × 4.6 mm i.d.; 4 µm) and mobile phase composed of methanol and 5 mm aqueous ammonium acetate containing 1 mm formic acid (60:40), at flow rate of 1 mL/min. The run time was 3.0 min and the injection volume was 20 μL. Mass spectrometric detection was performed using electrospray ion source in negative ionization mode, using the transitions m/z 364.0 → m/z 188.9 and m/z 367.0 → m/z 188.9 for indapamide and IS, respectively. Calibration curve was constructed over the range 0.25–50 ng/mL. The method was precise and accurate, and provided recovery rates >80% for indapamide and IS. The method was applied to determine blood concentrations of indapamide in a bioequivalence study with two sustained release tablet formulations. The 90% confidence interval for the geometric mean ratios for maximum concentration was 95.78% and for the area under the concentration–time curve it was 97.91%. The tested indapamide tablets (Eurofarma Laboratórios S.A.) were bioequivalent to Natrilix®, according to the rate and extent of absorption. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
9.
Guillou N Pastre S Livage C Férey G 《Chemical communications (Cambridge, England)》2002,(20):2358-2359
A three-dimensional nickel fumarate has been isolated by hydrothermal reaction and its structure solved from powder X-ray diffraction; its organisation reveals an unusual topology not previously seen in nickel chemistry and provided a scarce ferrimagnetic behaviour below 20 K. 相似文献
10.
Isabella G. Alonso Lais T. Yamane Verônica S. de Freitas-Blanco Luiz F.T. Novaes Michelle Franz-Montan Eneida de Paula Marili V.N. Rodrigues Rodney A.F. Rodrigues Julio C. Pastre 《Tetrahedron》2018,74(38):5192-5199
A 5-step synthesis of spilanthol (affinin) is reported, where the route features complete control of alkene geometry during the assembling of the double bonds, with the use of a Sonogashira cross-coupling reaction, a Z-selective alkyne semi-reduction and a HWE olefination reaction as the key steps. A simplified analogue was also prepared in 4 steps. Both compounds were found to permeate dermatomed pig ear skin through an in vitro Franz-type diffusion cell. The simplified analogue presented a superior anesthetic effect in vivo, using the tail flick model, when compared to spilanthol and to the commercial standard EMLA®. These results suggest that both spilanthol and its analogue could be useful as a topical anesthetic in clinical practice. 相似文献