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21.
Jéssica Venância Faria Maurício Silva dos Santos Percilene Fazolin Vegi Julio Cesar Borges Alice M.R. Bernardino 《Tetrahedron letters》2013
In this Letter, we described the synthesis of new 5-(5-amino-1-aryl-1H-pyrazole-4-yl)-1H-tetrazoles 2a–c from 5-amino-1-aryl-1H-pyrazole-4-carbonitriles 1a–c as well as the unexpected 1H-pyrazolo[3,4-d]pyrimidine derivatives 6a–c from 5-amino-1-aryl-3-methyl-1H-pyrazole-4-carbonitriles 4a–c, instead of 5-(5-amino-1-aryl-3-methyl-1H-pyrazole-4-yl)-1H-tetrazoles 5a–c as desired. In an attempt to obtain these tetrazole derivatives containing the methyl group at C3-position in the pyrazole ring, the amino group in 5-amino-1-(4-methoxyphenyl)-3-methyl-1H-pyrazole-4-carbonitrile 4c was protected by the reaction with sodium hydride and di-tert-butyl-dicarbonate (Boc). The tetrazole derivative 5c was synthesized from the protected compound 7c using analogue methodology to obtain 2a–c and 6a–c. 相似文献
22.
We categorify the notion of an infinitesimal braiding in a linear strict symmetric monoidal category, leading to the notion of a (strict) infinitesimal 2-braiding in a linear symmetric strict monoidal 2-category. We describe the associated categorification of the 4-term relations, leading to six categorified relations. We prove that any infinitesimal 2-braiding gives rise to a flat and fake flat 2-connection in the configuration space of n particles in the complex plane, hence to a categorification of the Knizhnik–Zamolodchikov connection. We discuss infinitesimal 2-braidings in a certain monoidal 2-category naturally assigned to every differential crossed module, leading to the notion of a symmetric quasi-invariant tensor in a differential crossed module. Finally, we prove that symmetric quasi-invariant tensors exist in the differential crossed module associated to Wagemann's version of the String Lie-2-algebra. As a corollary, we obtain a more conceptual proof of the flatness of a previously constructed categorified Knizhnik–Zamolodchikov connection with values in the String Lie-2-algebra. 相似文献
23.
Maria Luiza Zeraik Ivani Pauli Luiz A. Dutra Raquel S. Cruz Marilia Valli Luana C. Paracatu Carolina M. Q. G. de Faria Valdecir F. Ximenes Luis O. Regasini Adriano D. Andricopulo Vanderlan S. Bolzani 《Molecules (Basel, Switzerland)》2021,26(8)
Cyclooxygenase (COX) and lipoxygenase (LOX) are key targets for the development of new anti-inflammatory agents. LOX, which is involved in the biosynthesis of mediators in inflammation and allergic reactions, was selected for a biochemical screening campaign to identify LOX inhibitors by employing the main natural product library of Brazilian biodiversity. Two prenyl chalcones were identified as potent inhibitors of LOX-1 in the screening. The most active compound, (E)-2-O-farnesyl chalcone, decreased the rate of oxygen consumption to an extent similar to that of the positive control, nordihydroguaiaretic acid. Additionally, studies on the mechanism of the action indicated that (E)-2-O-farnesyl chalcone is a competitive LOX-1 inhibitor. Molecular modeling studies indicated the importance of the prenyl moieties for the binding of the inhibitors to the LOX binding site, which is related to their pharmacological properties. 相似文献
24.
Lidiane Diniz do Nascimento Sebastio Gomes Silva Mrcia Moraes Cascaes Kauê Santana da Costa Pablo Luis Baia Figueiredo Cristiane Maria Leal Costa Eloisa Helena de Aguiar Andrade Lênio Jos Guerreiro de Faria 《Molecules (Basel, Switzerland)》2021,26(9)
Leaves of Lippia thymoides (Verbenaceae) were dried in an oven at 40, 50 and 60 °C and the kinetic of drying and the influence of the drying process on the chemical composition, yield, and DPPH radical scavenging activity of the obtained essential oils were evaluated. The composition of the essential oils was determined with gas chromatography-mass spectrometry and gas chromatography-flame ionization detection analyses. The influence of drying on the chemical composition of the essential oils of L. thymoides was evaluated by multivariate analysis, and their antioxidant activity was investigated via the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The Midilli model was the most appropriate to describe the behavior of drying kinetic data of L. thymoides leaves. Thymol was the major compound for all analyzed conditions; the maximum content was obtained from fresh leaves (62.78 ± 0.63%). The essential oils showed DPPH radical scavenging activity with an average of 73.10 ± 12.08%, and the fresh leaves showed higher inhibition (89.97 ± 0.31%). This is the first study to evaluate the influence of drying on the chemical composition and antioxidant activity of L. thymoides essential oils rich in thymol. 相似文献
25.
We provide a reviewlike introduction to the quantum mechanical formalism related to non-Hermitian Hamiltonian systems with real eigenvalues. Starting with the time-independent framework, we explain how to determine an appropriate domain of a non-Hermitian Hamiltonian and pay particular attention to the role played by PJ symmetry and pseudo-Hermiticity. We discuss the time evolution of such systems having in particular the question in mind of how to couple consistently an electric field to pseudo-Hermitian Hamiltonians. We illustrate the general formalism with three explicit examples: (i) the generalized Swanson Hamiltonians, which constitute non-Hermitian extensions of anharmonic oscillators, (ii) the spiked harmonic oscillator, which exhibits explicit super-symmetry, and (iii) the ?x 4-potential, which serves as a toy model for the quantum field theoretical ?4-theory. 相似文献
26.
G. Gozzi L. D. Cagnani R. M. Faria L. F. Santos 《Journal of Solid State Electrochemistry》2014,18(11):3181-3190
A phenomenological model has been developed to account for the results of impedance/admittance spectroscopy measurements from light-emitting electrochemical cells (LECs) comprising a polymer electrolyte and two different conjugated polymers used as organic semiconductor. The application of a d.c. offset bias superimposed to the a.c. modulation voltage was used to observe the transition from the behavior prior to device operation and after the formation of the electrochemical p-i-n junction. The analysis of the whole device “conductivity” as a function of the applied bias and of the frequency was used to support the assumptions considered to develop the model. The results show that the device, after the p-i-n junction formation, can be considered as composed by two highly conductive electrochemically doped (n and p) regions and a thin (few tens nanometers), insulating layer, where the electrical current is dominated by electronic charge carrier injection via tunneling through a rectangular energy barrier. Before the p-i-n junction formation, there is no doping of semiconductor material, and the device electrical properties are dominated by the intrinsic electronic charge carriers in the organic semiconductor. Results from devices made of organic semiconductors with different band gap energy and different layer thicknesses are used to corroborate the proposed model. 相似文献
27.
Carlos Eduardo Barão Leandro Daniel de Paris João Henrique Dantas Matheus Mendonça Pereira Lucio Cardozo Filho Heizir Ferreira de Castro Gisella Maria Zanin Flavio Faria de Moraes Cleide Mara Faria Soares 《Applied biochemistry and biotechnology》2014,172(1):263-274
The use of lipases in industrial processes can result in products with high levels of purity and at the same time reduce pollutant generation and improve both selectivity and yields. In this work, lipase from Thermomyces lanuginosus was immobilized using two different techniques. The first involves the hydrolysis/polycondensation of a silica precursor (tetramethoxysilane (TMOS)) at neutral pH and ambient temperature, and the second one uses tetraethoxysilane (TEOS) as the silica precursor, involving the hydrolysis and polycondensation of the alkoxide in appropriate solvents. After immobilization, the enzymatic preparations were dried using the aerogel and xerogel techniques and then characterized in terms of their hydrolytic activities using a titrimetric method with olive oil and by the formation of 2-phenylethyl acetate in a transesterification reaction. The morphological properties of the materials were characterized using scanning electron microscopy, measurements of the surface area and pore size and volume, thermogravimetric analysis, and exploratory differential calorimetry. The results of the work indicate that the use of different silica precursors (TEOS or TMOS) and different drying techniques (aerogel or xerogel) can significantly affect the properties of the resulting biocatalyst. Drying with supercritical CO2 provided higher enzymatic activities and pore sizes and was therefore preferable to drying, using the xerogel technique. Thermogravimetric analysis and differential scanning calorimetry analyses revealed differences in behavior between the two biocatalyst preparations due to the compounds present. 相似文献
28.
de Farias Davi Marques de Faria Lucas Vinícius Lisboa Thalles Pedrosa Matos Maria Auxiliadora Costa Muñoz Rodrigo Alejandro Abarza Matos Renato Camargo 《Journal of Solid State Electrochemistry》2020,24(5):1165-1173
Journal of Solid State Electrochemistry - In this paper, we compare reduced graphene oxide (RGO) electrode with multi-walled carbon nanotubes (MWCNT) as modifiers for the sensitive detection of... 相似文献
29.
Alexandre Marletta M.L. Vega Y. Galvão Gobato R.M. Faria 《Applied Surface Science》2010,256(10):3018-213
In this work, we have studied the surface morphology of photo-irradiated poly(p-phenylene vinylene) (PPV) thin films by using atomic force microscopy (AFM). We have analyzed the first-order statistical parameters, the height distribution and the distance between selected peaks. The second-order statistical analysis was introduced calculating the auto-covariance function to determine the correlation length between heights. We have observed that the photo-irradiation process produces a surface topology more homogeneous and isotropic such as a normal surface. In addition, the polymer surface irradiation can be used as a new methodology to obtain materials optically modified. 相似文献
30.
Paulo A.?Faria da VeigaEmail author M.?O’Carroll Ricardo?Schor 《Communications in Mathematical Physics》2004,245(2):383-405
We consider a functional integral formulation for one-flavor lattice Quantum Chromodynamics in d=2,3 space dimensions and imaginary time, and work in the regime of the small hopping parameter , and zero plaquette coupling. Following the standard construction, this model exhibits positivity which is used to obtain the underlying physical Hilbert space . Then, using a Feynman-Kac formalism, we write the correlation functions for the model as functional integrals over the space of Grassmannian (fermionic) fields for one quark specie and the SU(3) gauge fields. We determine the energy-momentum spectrum associated with gauge invariant local baryon (anti-baryon) fields which are composites of three quark (anti-quark) fields. With the associated correlation functions, we establish a Feynman-Kac formula, and a spectral representation for the Fourier transform of the two-point functions. This representation allows us to show that baryons and anti-baryons arise as tightly bound, bound states of three (anti-)quarks. Labelling the components of the baryon fields by s=3/2,1/2,-1/2,-3/2, we show that the baryon and anti-baryon mass spectrum only depends on |s|, and the associated masses are given by Ms= –3ln+rs(), where rs() is real analytic in , for each d=2,3. The mass splitting is M3/2–M1/2=186, for d=2 and, if any, is at least of (7), for d=3. In the subspace o generated by an odd number of fermions, the baryon and anti-baryon energy-momentum dispersion curves are isolated up to near the baryon-meson threshold –5ln (upper gap property), identical and are determined up to (5). The symmetries of coordinate reflections, spatial lattice rotations, parity and charge conjugation are established for the correlation functions, and are shown to be implemented on by unitary (anti-unitary, for time reversal) operators. 相似文献