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Spatial distribution, ecological indices and interactions of arthropods on Sapindus saponaria (Sapindaceae) plants
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Souza, R. F. A.

; Leite, G. L. D.

; Soares, M. A.

; Teixeira, D. L.

; Silva, J. L.

; Sampaio, R. A.

; Guanabens, R. E. M.

; Santos, M. M.

; Faustino Júnior, W.

; Silva, R. S. da

; Zanuncio, J. C.

Brazilian Journal of Biology

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2023, Volumen 83 elocation e265435

Resumen: En Pt | Texto: En Pt | PDF: En | PDF: Pt

Abstract Sapindus saponaria L. (Sapindaceae) is a pioneer species used in programs to recover degraded areas. The trees also assist in the pest control of some insects due to the composition of saponins on their leaves. In addition, these chemical components are important to pharmaceutical product production. The objective was to evaluate the impact of spatial distribution, indices and ecological relationship of arthropods on S. saponaria leaves to preserve the balance of biodiversity. Aggregated distribution of arthropods was observed; the numbers of phytophagous arthropods were higher on the adaxial leaf face than on the abaxial part. Only Aleyrodidae (Hemiptera) had a higher presence on the abaxial leaf face of S. saponaria saplings. Abundance, diversity, and species richness of natural enemies correlated positively with phytophagous and pollinators insects. On the other hand, the number of Lyriomyza sp. mines correlated negatively with Pseudomyrmex termitarius (Smith) (Hymenoptera: Formicidae). All this information can assist and guide integrated pest management programs.

Resumo Sapindus saponaria L. (Sapindaceae) é uma espécie pioneira utilizada em programas de recuperação de áreas degradadas. As árvores também auxiliam no controle de alguns insetos pragas devido à composição de saponinas em suas folhas. Além disso, esses componentes químicos são importantes para a produção de produtos farmacêuticos. O objetivo foi avaliar o impacto da distribuição espacial, índices e relações ecológicas de artrópodes nas folhas de S. saponaria, a fim de preservar o equilíbrio da biodiversidade. Observou-se distribuição agregada; os números de artrópodes fitófagos foram maiores na face adaxial da folha do que na parte abaxial. Apenas indivíduos de Aleyrodidae (Hemiptera), tiveram maior presença na face abaxial das folhas, em mudas de S. saponaria. Abundância, diversidade e riqueza de espécies de inimigos naturais correlacionaram-se positivamente com insetos fitófagos e polinizadores. Por outro lado, o número de minas de Lyriomyza sp. correlacionou-se negativamente com o de Pseudomyrmex termitarius (Smith) (Hymenoptera: Formicidae). Todas essas informações podem ser usadas para auxiliar e orientar programas de manejo integrado de pragas.

https://doi.org/10.1590/1519-6984.265435

Consenso de leucemia mieloide aguda en México
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Arana-Luna, Luara L.

; Alvarado-Ibarra, Martha

; Silva-Michel, Luis G.

; Morales-Maravilla, Adrián

; González-Rubio, María del C.

; Chávez-Aguilar, Lénica A.

; Tena-Iturralde, María Fernanda

; Mojica-Balceras, Liliana

; Zapata-Canto, Nidia

; Galindo-Delgado, Patricia

; Miranda-Madrazo, María Raquel

; Morales-Hernández, Alba E.

; Silva-Vera, Karina

; Grimaldo-Gómez, Flavio A.

; Hernández-Caballero, Álvaro

; Bates-Martin, Ramón A.

; Álvarez-Vera, José L.

; Tepepa-Flores, Fredy

; Teomitzi-Sánchez, Óscar

; Fermín-Caminero, Denisse J.

; Peña-Celaya, José A. de la

; Salazar-Ramírez, Óscar

; Flores-Villegas, Luz V.

; Guerra-Alarcón, Lidia V.

; Leyto-Cruz, Faustino

; Inclán-Alarcón, Sergio I.

; Milán-Salvatierra, Andrea I.

; Ventura-Enríquez, Yanet

; Pérez-Lozano, Uendy

; Báez-Islas, Pamela E.

; Tapia-Enríquez, Ana L.

; Palma-Moreno, Orlando G.

; Aguilar-Luévano, Jocelyn

; Espinosa-Partida, Arturo

; Pérez-Jacobo, Luis F.

; Rojas-Castillejos, Flavio

; Ruiz-Contreras, Josué I.

; Loera-Fragoso, Sergio J.

; Medina-Coral, Jesús E.

; Acosta-Maldonado, Brenda L.

; Soriano-Mercedes, Emely J.

; Saucedo-Montes, Erick E.

; Valero-Saldana, Luis M.

; González-Prieto, Susana G.

; Nava-Villegas, Lorena

; Hernández-Colin, Ana K.

; Hernández-Alcántara, Areli E.

; Zárate-Rodríguez, Pedro A.

; Ignacio-Ibarra, Gregorio

; Meillón-García, Luis A.

; Espinosa-Bautista, Karla A.

; Ledesma de la Cruz, Cindy

; Barbosa-Loría, Diego M.

; García-Castillo, Carolina

; Balderas-Delgado, Carolina

; Cabrera-García, Álvaro

; Pérez-Zúñiga, Juan M.

; Hernández-Ruiz, Eleazar

; Villela-Peña, Atenas

; Gómez Cortés, Sue Cynthia

; Romero-Rodelo, Hilda

; Garzón-Velásquez, Katheryn B.

; Serrano-Hernández, Cristina

; Martínez-Ríos, Annel

; Pedraza-Solís, María Luisa

; Martínez-Coronel, Jorge A.

; Narváez-Davalos, Iris M.

; García-Camacho, Alinka S.

; Merino-Pasaye, Laura E.

; Aguilar-Andrade, Carolina

; Aguirre-Domínguez, Juan A.

; Guzmán-Mera, Pedro G.

; Delgado-de la Rosa, Elizabeth

; Flores López, Perla E.

; González-Aguirre, Lilia L.

; Ramírez-Alfaro, Edgar M.

; Vera-Calderón, Heidi

; Meza-Dávalos, María Lizeth

; Murillo-Cruz, Juan

; Pichardo-Cepín, Yayra M.

; Ramírez-Romero, Eva F.

Gaceta médica de México

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2022, Volumen 158 Nº spe3 Paginas M1 - M51

Resumen: En Es | Texto: En Es | PDF: En | PDF: Es

Abstract Acute myeloid leukemia (AML) comprises a heterogeneous group of hematopoietic cell neoplasms of myeloid lineage that arise from the clonal expansion of their precursors in the bone marrow, interfering with cell differentiation, leading to a syndrome of bone marrow failure. AML is a consequence of genetic and epigenetic changes (point mutations, gene rearrangements, deletions, amplifications, and arrangements in epigenetic changes that influence gene expression) in hematopoietic precursor cells, which create a clone of abnormal cells that are capable of proliferating but cannot differentiate into mature hematopoietic cells or undergo programmed cell death. The diagnosis requires more than 20% myeloid blasts in the bone marrow and certain cytogenic abnormalities. Treatment will depend on age, comorbidities, and cytogenetic risk among the most frequent.

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https://doi.org/10.24875/gmm.m21000597 895 descargas

REDUçãO DE CO2 EM HIDROCARBONETOS E OXIGENADOS: FUNDAMENTOS, ESTRATéGIAS E DESAFIOS
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Silva, Gelson T. S. T. da

; Lopes, Osmando F.

; Dias, Eduardo H.

; Torres, Juliana A.

; Nogueira, André E.

; Faustino, Leandro A.

; Prado, Fernando S.

; Patrocínio, Antônio O. T.

; Ribeiro, Caue

Química Nova

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Ago 2021, Volumen 44 Nº 8 Paginas 963 - 981

Resumen: Pt | Texto: Pt | PDF: Pt

CO2 REDUCTION TO HYDROCARBONS AND OXYGENATES: FUNDAMENTALS, STRATEGIES AND CHALLENGES. The development of renewable energy sources (e.g., solar and wind) moves foward, the tendance for replacing fossil fuels increases. However, these technologies have as primary barriers to industrial processes’ efficiency and especially storage. Thus, CO2 reduction routes using these energy sources could chemically store part of the energy as fuels or chemicals, offering alternatives to current oil and gas industry. This process is inspired by photosynthesis, e.g., photochemical or electrochemical processes, using homogeneous or heterogeneous catalysts. Nevertheless, this reaction is thermodynamically unfavorable and has very slow kinetics, given the high stability of the CO2 molecule and the complexity of the redox reactions involved. Therefore, this review addresses this process’s kinetic and thermodynamic challenges, and the fundamental concepts of the photo(electro)chemical processes for CO2 reduction, besides presenting and discussing the materials with the potential to act as catalysts. The main reaction mechanisms and advances in the understanding of such processes are discussed, as well as future perspectives

https://doi.org/10.21577/0100-4042.20170745 107 descargas

Differential defense responses of tropical grasses to Mahanarva spectabilis (Hemiptera: Cercopidae) infestation
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BARROS, RAFAEL DE A.

; VITAL, CAMILO E.

; JÚNIOR, NEILIER R.S.

; VARGAS, MANUEL A.S.

; MONTEIRO, LUANA P.

; FAUSTINO, VERÔNICA A.

; AUAD, ALEXANDER M.

; PEREIRA, JORGE F.

; OLIVEIRA, EUGÊNIO E. DE

; RAMOS, HUMBERTO J.O.

; OLIVEIRA, MARIA GORETI DE A.

Anais da Academia Brasileira de Ciências

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2021, Volumen 93 Nº 3 elocation e20191456

Resumen: En | Texto: En | PDF: En

Abstract The spittlebugs Mahanarva spectabilis economically challenges cattle production of neotropical regions, due to its voracious feeding on tropical grasses. Here, we evaluated biochemical responses of the interaction between M. spectabilis and the widely cultivated tropical grasses Brachiaria spp. (i.e., brizantha and decumbens) and elephant grasses (cvs. Roxo de Botucatu and Pioneiro), regarding lipoxygenases, protease inhibitors, phytohormones, and proteolytic activities in the midgut of M. spectabilis. The M. spectabilis-infested grasses increased lipoxygenases activity, except for cv. Pioneiro. The levels of the phytohormones jasmonic and abscisic acids were similarly low in all genotypes and increased under herbivory. Furthermore, salicylic acid concentration was constitutively higher in Brachiaria sp., increasing only in spittlebug-infested B. decumbens. M. spectabilis infestations did not induce increases of protease inhibitors in any forage grass type. The trypsin activity remained unaltered, and the total proteolytic activity increased only in B. decumbens-fed insects. Our findings revealed that most forage grasses exposed to spittlebugs activate the lipoxygenases pathway, resulting in increased abscisic and jasmonic acids. However, greater amounts of these hormones do not induce protease inhibitory activity in response to spittlebug attack. This knowledge certainly helps to guide future projects aiming at reducing the impact of spittlebugs on forage production.

https://doi.org/10.1590/0001-3765202120191456 123 descargas

The Research on Porphyrins and Analogues in Brazil: A Small Review Covering Catalytic and other Applications since the Beginning at Universidade de São Paulo in Ribeirão Preto until the Joint Venture between Brazilian Researchers and Colleagues from Universidade de Aveiro, Portugal
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Nakagaki, Shirley

; Castro, Kelly A. D. F.

; Neves, Maria da Graça P. M. S.

; Faustino, Maria do Amparo

; Iamamoto, Yassuko

Journal of the Brazilian Chemical Society

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Dic 2019, Volumen 30 Nº 12 Paginas 2501 - 2535

Resumen: En | Texto: En | PDF: En

The synthetic versatility and the potential applications of porphyrins and analogues in different fields have aroused special interest in their study, especially to mimic biological systems, such as cytochrome P-450. The ability of the porphyrin tetrapyrrolic core to accommodate metal ions of varying charges can modulate the type of application of these compounds. As a contribution, in this special number in honor to the Brazilian women who have devoted their lives to the growth and dissemination of chemistry knowledge, we report the advances in porphyrin research in Brazil for catalytic purposes and other applications, beginning at the Universidade de São Paulo (USP) at Ribeirão Preto. We also discuss some works that have resulted from joint research effort between Brazilian researchers and Portuguese colleagues from the Universidade de Aveiro, Portugal, working in the porphyrin field.

https://doi.org/10.21577/0103-5053.20190153 865 descargas

Tuning Emitting Color of Electroluminescent Devices Containing Tris(2-acyl-1,3-indandionate)aluminum(III) Complexes as Emitting Layers
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Costa, Israel F.

; Moura, Jandeilson L.

; Aderne, Rian E.

; Avila, Harold C.

; Cremona, Marco

; Brito, Hermi F.

; Felinto, Maria Cláudia F. C.

; Faustino, Wagner M.

; Teotonio, Ercules E. S.

Journal of the Brazilian Chemical Society

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Ago 2019, Volumen 30 Nº 8 Paginas 1647 - 1656

Resumen: En | Texto: En | PDF: En

In this study, a novel type of tris(2-acyl-1,3-indandione)-aluminum(III) coordination compounds of the general formula [Al(acind)3]H2O, where 2-acyl-1,3-indandione (acind), 2-acetyl-1,3-indandione (aind), 2-benzoyl-1,3-indandione (bind), and 4-methyl-2-benzoyl-1,3-indandione (mbind), were synthesized and characterized by elemental analysis (CHN), Fourier transform infrared (FTIR) and nuclear magnetic resonance (1H NMR) spectroscopies, thermal analysis (TG/DTG and DTA), and optical absorption spectroscopy in the UV-Vis region. These compounds present remarkably high green luminescence in powder and in thin-film forms. However, when these compounds are applied in glass/ITO/β-NPB/spiro-2CBP/[Al(acind)3]/Al and glass/ITO/β-NPB/[Al(acind)3]/LiF/Al electroluminescent devices, where spiro-2CBP is 2,7-bis(carbazol-9-yl)-9,9-spirobifluorene and β-NPB is N,N’-bis(naphthalen-2-yl)-N,N’-bis(phenyl)-benzidine, the emission color tuned from green to red, reflecting a change from the direct charge recombination in the emitting layer of the [Al(acind)3] complexes to an exciplex-based emission in which [Al(acind)3] complexes and spiro 2-CBP acted as acceptor and donor, respectively. These results suggest that [Al(acind)3] complexes have potential applications as molecular light converter materials for fabricating new electroluminescent devices.

https://doi.org/10.21577/0103-5053.20190064 455 descargas

FATTY ACID ETHYL ESTERS FROM MICROALGAE OF Scenedesmus ecornis BY ENZYMATIC AND ACID CATALYSIS
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Almeida, Gabryelle F. de

; Araújo, Pedro H. F. de

; Florentino, Alexandro C.

; Bezerra, Roberto M.

; Carvalho, José C. T.

; Faustino, Silvia M. M.

; Ferreira, Irlon M.

Química Nova

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Ene 2018, Volumen 41 Nº 1 Paginas 1 - 4

Resumen: En | Texto: En | PDF: En

Microalgae are an indispensable food source for the various growth stages of mollusks, crustaceans, and several fish species. Using a microalgae biomass present in the Amazonian ecosystem (Macapá-AP), we study extraction methods for fatty acid such as solvent extraction (magnetic stirring and/or Soxhlet) and/or hydrolysis (acid and/or enzymatic catalysis) followed by esterification and/or direct transesterification. Extraction of crude triacylglycerides by mechanical stirring at room temperature was more efficient than continuous reflux (Soxhlet). Subsequently, the lipid extract was subject to transesterification with ethanol and CAL-B as a biocatalyst, leading to production of fatty acid ethyl esters (FAEE). Additionally, FAEEs were prepared by hydrolysis of crude triacylglycerides followed by acid-mediated esterification or enzymatic catalysis (lipase). In this case, the type of catalyst did not significantly influence FAEE yields. In the lipid extract, we identified palmitic, linoleic, oleic, and stearic acids with palmitic acid being the most abundant. Our results suggest that enzymatic catalysis is a viable method for the extraction of lipids in the microalga, Scenedesmus ecornis.

https://doi.org/10.21577/0100-4042.20170147 1186 descargas

Evaluation of meso-substituted cationic corroles as potential antibacterial agents
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CARDOTE, TERESA A.F.

; BARATA, JOANA F.B.

; AMADOR, CAROLINA

; ALVES, ELIANA

; NEVES, MARIA GRAÇA P.M.S.

; CAVALEIRO, JOSÉ A.S.

; CUNHA, ÂNGELA

; ALMEIDA, ADELAIDE

; FAUSTINO, MARIA AMPARO F.

Anais da Academia Brasileira de Ciências

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2018, Volumen 90 Nº 1 Paginas 1175 - 1185

Resumen: En | Texto: En | PDF: En

ABSTRACT Cationic derivatives of 5,10,15-tris[4-(pyridin-4-ylsulphanyl)-2,3,5,6-tetrafluorophenyl]-corrolategallium(III)pyridine and 5,10,15-tris[4-(pyridin-2-ylsulfanyl)-2,3,5,6-tetrafluorophenyl]-correlategallium(III)pyridine were synthesized and their photosensitizing properties against the naturally bioluminescent Gram-negative bacterium Allivibrio fischeri were evaluated. The cationic corrole derivatives exhibited antibacterial activity at micromolar concentrations against this Gram-negative bacterium strain.

https://doi.org/10.1590/0001-3765201820170824 1219 descargas

An insight on the role of photosensitizer nanocarriers for Photodynamic Therapy
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MESQUITA, MARIANA Q.

; DIAS, CRISTINA J.

; GAMELAS, SARA

; FARDILHA, MARGARIDA

; NEVES, MARIA G.P.M.S.

; FAUSTINO, MARIA AMPARO F.

Anais da Academia Brasileira de Ciências

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2018, Volumen 90 Nº 1 Paginas 1101 - 1130

Resumen: En | Texto: En | PDF: En

ABSTRACT Photodynamic therapy (PDT) is a modality of cancer treatment in which tumor cells are destroyed by reactive oxygen species (ROS) produced by photosensitizers following its activation with visible or near infrared light. The PDT success is dependent on different factors namely on the efficiency of the photosensitizer deliver and targeting ability. In this review a special attention will be given to the role of some drug delivery systems to improve the efficiency of tetrapyrrolic photosensitizers to this type of treatment.

https://doi.org/10.1590/0001-3765201720170800 4632 descargas

10.

Rare Earth-Indomethacinate Complexes with Heterocyclic Ligands: Synthesis and Photoluminescence Properties
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Resende Filho, João Batista M.

; Santos, Paulo R.

; Vale, Juliana A.

; Faustino, Wagner M.

; Farias, Danyelle S.

; Brito, Hermi F.

; Felinto, Maria C. F. C.

; Teotonio, Ercules E. S.

Journal of the Brazilian Chemical Society

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Dic 2017, Volumen 28 Nº 12 Paginas 2281 - 2290

Resumen: En | Texto: En | PDF: En

In this work, synthesis, characterization and photophysical properties of trivalent rare earth complexes with a nonsteroidal anti-inflammatory drug [the indomethacinate (indo), presenting formulas RE(indo)3(H2O)x (x = 3, for Eu3+ and Gd+3, and x = 4 for Tb+3), RE(indo)3(bipy) and RE(indo)3(phen) (bipy: 2,2'-bipyridine, and phen: 1,10-phenanthroline)] were investigated. Based on photoluminescent results, the intramolecular energy transfer process from T1 triplet states of indo, phen and bipy ligands to the 5D0 emitting level of the Eu3+ ion in the coordination compounds is discussed. Accordingly, it is proposed two possible intramolecular energy transfer mechanisms between indomethacinate ligand and rare earth ions, which involve the participation of excited electronic states of the heterocyclic ligands as intermediate ones.

https://doi.org/10.21577/0103-5053.20170079 671 descargas

11.

Low Temperature Synthesis of Luminescent RE2O3:Eu3+ Nanomaterials Using Trimellitic Acid Precursors
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Silva, Ivan G. N.

; Mustafa, Danilo

; Felinto, Maria C. F. C.

; Faustino, Wagner M.

; Teotonio, Ercules E. S.

; Malta, Oscar L.

; Brito, Hermi F.

Journal of the Brazilian Chemical Society

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Dic 2015, Volumen 26 Nº 12 Paginas 2629 - 2639

Resumen: En | Texto: En | PDF: En

[RE(TLA)·(H2O)n:Eu3+] (RE3+: Y, Gd and Lu; TLA: trimellitic acid) precursor complexes were synthesized by an one step aqueous co-precipitation method. After annealing for 1 h, RE2O3:Eu3+ nanophosphors were formed through the benzenetricarboxylate low temperature thermolysis method (500-1000 ºC). The compounds were characterized by using different techniques [elemental analysis (CHN), Fourier transform infrared spectroscopy (FTIR), thermogravimetry (TG/DTG), X-ray powder diffraction (XPD) and scanning electron microscope (SEM)]. The XPD data indicated that the Y2O3:Eu3+ materials have crystallite size range from 11 to 62 nm. The SEM and transmission electron microscopy (TEM) images show that the annealed materials keep morphological similarities with the precursor complexes. The photoluminescence properties were studied based on the excitation and emission spectra, and luminescence decay lifetimes of the 5D0 emitting level of the Eu3+ ion. The experimental intensity parameters (Ωλ), lifetimes (τ), as well as radiative (Arad) and non-radiative (Anrad) decay rates were calculated and discussed. The RE2O3:Eu3+ phosphors (RE: Y3+ and Lu3+) annealed at 500 to 1000 ºC have emission quantum efficiency (intrinsic quantum yield) values from 60 to 82%, indicating that this material can be potentially used for optical markers applications.

https://doi.org/10.5935/0103-5053.20150314 1179 descargas

12.

Novel luminescent Eu3+-indandionate complexes containing heterobiaryl ligands
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Resende Filho, João B. M.

; Silva, Jannine C.

; Vale, Juliana A.

; Brito, Hermi F.

; Faustino, Wagner M.

; Espínola, José G. P.

; Felinto, Maria C. F. C.

; Teotonio, Ercules E. S.

Journal of the Brazilian Chemical Society

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Nov 2014, Volumen 25 Nº 11 Paginas 2080 - 2087

Resumen: Pt En | Texto: Pt En | PDF: Pt | PDF: En

Novos complexos indandionatos de fórmulas [Ln(aind)3L(H2O)] e [Ln(bind)3L]∙H2O, (L: 1,10-fenantrolina (phen) ou 4,7-dimetil-1,10-fenantrolina (dmphen), Ln3+: Eu3+ ou Gd3+, aind: 2-acetil-1,3-indandionato e bind: 2-benzoil-1,3-indandionato) foram sintetizados e caracterizados por análise elementar, espectroscopia de absorção na região do infravermelho e análise termogravimétrica. Os dados de caracterização são consistentes com a presença de uma molécula de água de cristalização nas estruturas dos compostos [Ln(bind)3L]∙H2O, enquanto que nos complexos [Ln(aind)3L(H2O)] a molécula de água atua como ligante. As geometrias dos complexos do íon Eu3+, otimizadas pelo modelo SPARKLE/AM1, foram consistentes com os resultados experimentais de luminescência. As propriedades luminescentes dos compostos de Eu3+ são discutidas em termos de parâmetros de intensidade experimentais (Ω2 e Ω4), taxas radiativas (Arad) e não-radiativas (Anrad) e eficiência quântica de emissão (η). Os maiores valores de η foram obtidos para os compostos [Eu(bind)3L]∙H2O, refletindo a ausência de moléculas de água na primeira esfera de coordenação do íon Eu3+.

Novel Ln3+-indandionate complexes of formulas [Ln(aind)3L(H2O)] and [Ln(bind)3L]∙H2O (L: 1,10-phenanthroline (phen) or 4,7-dimethyl-1,10-phenanthroline (dmphen), Ln3+: Eu3+ or Gd3+, aind: 2-acetyl-1,3-indandionate and bind: 2-benzoyl-1,3-indandionate) were synthesized and characterized by elemental analysis, infrared spectroscopy, and thermogravimetric analyses. The characterization data are consistent with the presence of a water lattice molecule in the [Ln(bind)3L]∙H2O compounds. However, the data also suggest that the water acts as a coordinated molecule in the [Ln(aind)3L(H2O)] ones. Theoretical geometries of the Eu3+-complexes have been optimized via the SPARKLE/AM1 Model for lanthanide complexes that are consistent with their luminescence experimental data. The photoluminescence properties of the Eu3+-compounds have been discussed in terms of experimental intensity parameters (Ω2 and Ω4), radiative (Arad), and non-radiative (Anrad) spontaneous emission coefficients. The higher values of emission quantum efficiency (η) of the [Eu(bind)3L]∙H2O compounds reflect the absence of luminescence-quenching water molecule in their first coordination spheres.

https://doi.org/10.5935/0103-5053.20140197 1113 descargas

13.

Estatus actual de conservación de seis especies de peces dulceacuícolas de la península de Baja California, México
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Ruiz-Campos, Gorgonio

; Camarena-Rosales, Faustino

; González-Acosta, Adrián F.

; Maeda-Martínez, Alejandro M.

; García de León, Francisco J.

; Varela-Romero, Alejandro

; Andreu-Soler, Asunción

Revista mexicana de biodiversidad

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2014, Volumen 85 Nº 4 Paginas 1235 - 1248

Resumen: En Es | Texto: En Es | PDF: En | PDF: Es

The current distribution and conservation status of six native freshwater fishes of the Baja California peninsula (Entosphenus tridentatus, Oncorhynchus mykiss nelsoni, Fundulus lima, Cyprinodon macularius, Gasterosteus aculeatus and Gobiesox juniperoserrai), included in the Norma Oficial Mexicana-059-2010, were assessed on the basis of information generated during the study period of 2000-2014. Except for E. tridentatus in the Santo Domingo river drainage and G. juniperoserrai in the Las Pocitas-San Hilario drainage, most of the species were recorded in the hydrological basins sampled. Oncorhynchus mykiss nelsoni showed a significant population fluctuation in the San Rafael river in relation to the dynamics of the base flow and the forest fire events. Fundulus lima presented the probable extirpation from four drainages (San Javier, Bebelamas, San Luis, and Las Pocitas-San Hilario) that is contrasting with the finding of a new population in the Santa Cruz stream. Cyprinodon macularius in the most important remnant population in Baja California (cerro Prieto geothermal ponds) showed interannual fluctuations related with the level of flooding and availability of marginal habitats. Gasterosteus aculeatus showed a progressive population reduction in the southernmost distributional locality (mouth of El Rosario river), as well as the extirpation in the lower Santo Domingo river basin and its recent presence in the mouth of the Cantamar river. Gobiesox juniperoserrai, known only from the type locality is determined as extirpated.

Se determinó el estatus actual de conservación de 6 peces dulceacuícolas nativos de la península de Baja California (Entosphenus tridentatus, Oncorhynchus mykiss nelsoni, Fundulus lima, Cyprinodon macularius, Gasterosteus aculeatus y Gobiesox juniperoserrai), incluidos en la Norma Oficial Mexicana 059-2010, a partir de la información obtenida durante el periodo 2000-2014. Con excepción de E. tridentatus en la cuenca del río Santo Domingo y de G. juniperoserrai en la cuenca de Las Pocitas-San Hilario, la mayoría de las especies fueron registradas en las cuencas hidrológicas muestreadas. Oncorhynchus mykiss nelsoni registró una marcada fluctuación poblacional en el río San Rafael, en estrecha relación con la dinámica del flujo hidrológico y los eventos de incendio forestal. Fundulus lima presentó su probable extirpación en 4 cuencas: San Javier, Bebelamas, San Luis y Las Pocitas-San Hilario, lo cual contrasta con el hallazgo de una nueva población en el arroyo Santa Cruz. Cyprinodon macularius en su población remanente más importante en Baja California -lagunas de la planta geotérmica cerro Prieto- denotó fluctuaciones interanuales relacionadas directamente con el nivel de inundación de las lagunas y la disponibilidad de hábitat. Gasterosteus aculeatus exhibió un descenso poblacional progresivo en la localidad más austral de su distribución (río El Rosario), además de la extirpación de la población de la bocana del río Santo Domingo y el redescubrimiento de una nueva población en la bocana del río Cantamar. Gobiesox juniperoserrai, especie conocida sólo de la localidad tipo, es determinada como extirpada.

https://doi.org/10.7550/rmb.43747 2849 descargas

14.

Estudo de caracterização de argilas não plásticas da região de Poços de Caldas, MG
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Maestrelli, S. C.

; Roveri, C. D.

; Nunes, A. G. P.

; Faustino, L. M.

; Aielo, G. F.

; Pinto, L. P. A.

; Manochio, C.

; Cal, T. M. L.

; Ribeiro, F. F.

; Mariano, N. A.

Cerâmica

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Jun 2013, Volumen 59 Nº 350 Paginas 242 - 248

Resumen: Pt En | Texto: Pt En | PDF: Pt | PDF: En

Poços de Caldas é um importante centro hidrotermomineral do Brasil, o qual apresenta depósitos de argilas não plásticas para as quais não há registros significativos a respeito da caracterização direcionada destes materiais, o que prejudica estudos de aplicação industrial. Estas argilas não plásticas, não aproveitadas, vêm sendo armazenadas em galpões ou a céu aberto, o que gera um elevado custo para a indústria, além de transformar-se em um passivo ambiental. No presente trabalho realizou-se o estudo químico-mineralógico de seis amostras de argilas de baixa plasticidade, além da caracterização preliminar destas amostras quanto à granulometria, plasticidade e propriedades cerâmicas básicas, visando ampliar os horizontes das investigações destes materiais. Este estudo preliminar mostrou que, de maneira geral, as amostras são compostas por minerais refratários como caulinita e gibbsita, apresentando teores menos significativos de outras fases, como quartzo, vermiculita e illita. Juntamente às análises químicas, estes dados permitiram o agrupamento das matérias-primas em dois grupos em função de sua refratariedade, norteando assim, a caracterização posterior. Dentre as amostras, há material com potencial uso na formulação de massas de porcelanato, além de uma amostra turfosa, cuja aplicação está relacionada à correção de solos.

Poços de Caldas is an important "hydro-thermo-mineral" center in Brazil, where non-plastic clays deposits can be found with no significant records about their characterization, impeding the studies of industrial application. These non-plastic clays, not used, have been stored in sheds or open, which creates a high cost to the industry, and become an environmental liability. In the present work, the chemical-mineralogical study of six samples of non-plastic clays was realized, and also the preliminary characterization of these samples about the grain size, plasticity and basic ceramic properties, to expand the horizons of researches about such materials. This preliminary study showed that, overall, the samples are composed of refractory minerals such as kaolinite and gibbsite, with less significant amounts of other phases such as quartz, illite and vermiculite. The chemical analysis permitted the grouping of raw materials into two groups according to their refractory properties, guiding to the subsequent characterization. Among the samples, there is material with potential use in porcelain formulation, and also a peat sample, which implementation is related to soil correction.

3081 descargas Citado 3 veces en SciELO

15.

Energy transfer processes in Tb(III)-dibenzoylmethanate complexes with phosphine oxide ligands
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Silva Jr., Francisco A.

; Nascimento, Helenise A.

; Pereira, Dariston K. S.

; Teotonio, Ercules E. S.

; Brito, Hermi F.

; Felinto, Maria Cláudia F. C.

; Espínola, José Geraldo P.

; Sá, Gilberto F.

; Faustino, Wagner M.

Journal of the Brazilian Chemical Society

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Abr 2013, Volumen 24 Nº 4 Paginas 601 - 608

Resumen: Pt En | Texto: Pt En | PDF: Pt | PDF: En

Este trabalho relata a síntese, a caracterização e as propriedades luminescentes dos complexos de fórmulas [Tb(DBM)3L], [Tb(DBM)2(NO3)L2)] e [Tb(DBM)(NO3)2(HMPA)2)] (DBM = dibenzoilmetanato; L: TPPO = óxido de trifenilfosfina ou HMPA = óxido de hexametilfosforamida). Os compostos foram caracterizados por análise elementar (CHN), titulação complexométrica com EDTA e espectroscopia no infravermelho com transformada de Fourier (FTIR), e as propriedades de fotoluminescência foram avaliadas. As energias dos estados tripletos do ligante DBM foram determinadas experimentalmente a partir dos espectros de fosforescência resolvidos no tempo dos compostos análogos do íon Gd3+. As energias aumentam em função do número de ânions nitratos que substituem o ligante DBM nos complexos. Ademais, os espectros de luminescência e os tempos de vida dos níveis emissores revelaram que a eficiência de transferência de energia ligante-metal segue a mesma tendência. Ao contrário dos complexos tris-DBM, o bis- e o mono-DBM apresentaram elevada intensidade de luminescência, sendo candidatos promissores para camadas emissoras de luz em dispositivos moleculares conversores de luz (LCMD).

The Tb3+-β-diketonate complexes [Tb(DBM)3L], [Tb(DBM)2(NO3)L2] and [Tb(DBM)(NO3)2(HMPA)2] (DBM = dibenzoylmethanate; L: TPPO = triphenylphosphine oxide or HMPA = hexamethylphosphine oxide) were prepared and characterized by elemental analysis (CHN), complexometric titration with EDTA and Fourier transform infrared (FTIR) spectroscopy, and the photoluminescence properties evaluated. The triplet state energies of the coordinated DBM ligands were determined using time-resolved phosphorescence spectra of analogous Gd3+ complexes. The results show that the energies increase along with the number of coordinated nitrate anions replacing the DBM ligand in the complexes. The luminescence spectra and emission lifetime measurements revealed that the ligand-to-metal energy transfer efficiency follows the same tendency. Unlike the tris-DBM complexes, bis- and mono-DBM presented high luminescence, and may act as promising candidates for preparation of the emitting layer of light converting molecular devices (LCMDs).

https://doi.org/10.5935/0103-5053.20130073 2158 descargas

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