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151.
Augusto Colombo Jordi Frigola Juan Parés Blas Andaluz 《Journal of heterocyclic chemistry》1989,26(4):949-955
The synthesis and structure elucidation of new pyrazolo[3,4-b][1,4]diazepines and pyrazolo[3,4-b]pyrazines are reported and the characterisation of isomers and tautomers by proton and carbon-13 nmr are discussed. In some case only NOE experiments allow us to identify the isomeric structure. 相似文献
152.
Selma Giorgio Edlaine Linares Margareth de L. Capurro Antonio G. de Bianchi Ohara Augusto 《Photochemistry and photobiology》1996,63(6):750-754
Peroxynitrite, the potent oxidant formed by the fast reaction between nitric oxide and superoxide anion, has been suggested to be the reactive intermediate responsible for some of the pathologies associated with an overproduction of nitric oxide. In this report, we demonstrate that both nitric oxide and peroxynitrite are formed during infection of the susceptible mouse strain, BALBk, with Leishmania amazonensis. Nitric oxide was detected as the nitrosyl hemoglobin complex by EPR analysis of blood drawn from mice at 35 , 64 and 148 days of infection. The levels of nitrosyl hemoglobin complex increased with disease evolution, which in the murine model used is characterized by skin lesions, ulceration and visceral-ization of the parasites. Peroxynitrite formation was inferred from immunoreaction of homogenates obtained from footpad lesions in the late stages of the infection with anti-nitrotyrosine antibody; homogenates from parasites drawn from the lesions were also immunoreactive, although to a lesser extent. Analysis of protein homogenates by gel electrophoresis and western blots suggests that peroxynitrite may degrade proteins in vivo, in addition to nitrating them. The results demonstrate that peroxynitrite is formed during murine leishmaniasis and may play a role in the aggravation of the disease. 相似文献
153.
In spite of all progressive efforts aiming to optimize SPPS, serious problems mainly affecting the assembly of aggregating sequences have persisted. Following the study intended to unravel the complex solvation phenomenon of peptide-resin beads, the XING and XAAAA model aggregating segments were labeled with a paramagnetic probe and studied via EPR spectroscopy. Low and high substituted resins were also comparatively used, with the X residue being Asx or Glx containing the main protecting groups used in the SPPS. Notably, the cyclo-hexyl group used for Asp and Glu residues in Boc-chemistry induced greater chain immobilization than its tert-butyl partner-protecting group of the Fmoc strategy. Otherwise, the most impressive peptide chain immobilization occurred when the large trytil group was used for Asn and Gln protection in Fmoc-chemistry. These surprising results thus seem to stress the possibility of the relevant influence of the amino-acid side chain protecting groups in the overall peptide synthesis yield. 相似文献
154.
Novel calix[2]imidazolidin[2]arenes were synthesized by solvent-free Mannich-type reaction, in quantitative yields, from 1,3-bis(2′-hydroxy-benzyl)imidazolidines and 1,3,6,8-tetraazatricyclo[4.4.1.13,8]dodecane (TATD). 相似文献
155.
Luís S.H.P. Vale Maria G.P.M.S. Neves Augusto C. Tomé Filipe A.A. Paz 《Tetrahedron letters》2007,48(50):8904-8908
Gallium(III)(pyridine) complex of 5,10,15-tris(pentafluorophenyl)corrole-3-carbaldehyde was used as a precursor of an azomethine ylide, which was trapped in 1,3-dipolar cycloaddition reactions with quinones. Besides the expected dehydrogenated 1,3-dipolar cycloadducts, novel quinone-fused corrole derivatives were also obtained in moderate yields. 相似文献
156.
We analyze the role played by the Brazilian physicist Cesar Lattes (1924–2005) in the historical development of the nuclear emulsion technique and in the co-discovery of the pion. His works influenced and gave impetus to the development of experimental physics in Brazil, the foundation of a national center dedicated to physics research, the beginnings of Brazilian “Big Science,” and the inauguration of a long-lasting collaboration between Brazil and Japan in the field of comic ray physics. 相似文献
157.
German Augusto Gmez‐Ríos Janusz Pawliszyn 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(52):14731-14735
Coated blade spray (CBS) is a technology based on solid‐phase microextraction (SPME) that has been designed for the quick extraction/cleanup of analytes from complex matrices and direct desorption/ionization under ambient mass spectrometry conditions. The entire analytical process can be completed in less than 3 min and enables limits of quantitation in the low picogram‐per‐milliliter region to be reached. 相似文献
158.
Santos Lidya B. Striebeck Maria V. Crespi Marisa S. Ribeiro Clovis A. De Julio Marcelo 《Journal of Thermal Analysis and Calorimetry》2015,122(1):21-32
Journal of Thermal Analysis and Calorimetry - Recently, biochar was introduced as a bioadsorbent material to remove various contaminants in effluents, such as pigments, dyes, heavy metals,... 相似文献
159.
Danilo Augusto Ferreira Fontes Magaly Andreza Marques de Lyra Jeyce Kelle Ferreira de Andrade Giovanna Christinne Rocha de Medeiros Schver Larissa Araújo Rolim Teresinha Gonçalves da Silva José Lamartine Soares-Sobrinho Severino Alves-Júnior Pedro José Rolim-Neto 《Journal of inclusion phenomena and macrocyclic chemistry》2016,85(3-4):281-288
160.
Tatiane Lima Amorim Lucas Mattos Duarte Erick Mendes da Silva Marcone Augusto Leal de Oliveira 《Electrophoresis》2021,42(3):289-304
Fatty acids determination is of paramount importance for quality control and suitable labeling of edible oils, required by regulatory agencies in several countries, and fast methods for this determination are worldly desired. This review article aimed to explore the available analytical methods for vegetable and marine oils analyses employing CE, which can be a straightforward and faster alternative than GC methods for fatty acid determination, considering some purposes. CE usually offers the possibility of a rapid analysis with a simple preparation of the sample, without requiring specific columns, which are inherent advantages of the technique. Instrumental conditions and the key points about fatty acids determination employing the technique are highlighted, and the main challenges and perspectives are also approached. Potential use of CE for edible oil analyses has been demonstrated for research and routine, which can be of interest for industries, regulatory agencies, and edible oil researchers. Therefore, we have explored the analytical approaches described in the last decades, intending to spread the interest of CE methods for fatty acid monitoring, label accuracy assessment, and food authenticity evaluation of edible oils. 相似文献