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Publisher: SciELO   (Total: 715 journals)

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Showing 1 - 200 of 715 Journals sorted alphabetically
ABCD. Arquivos Brasileiros de Cirurgia Digestiva     Open Access   (Followers: 2, SJR: 0.207, h-index: 1)
ACIMED     Open Access   (Followers: 1)
Acta Agronómica     Open Access  
Acta Amazonica     Open Access   (Followers: 5, SJR: 0.36, h-index: 1)
Acta Bioethica     Open Access   (SJR: 0.196, h-index: 0)
Acta Botanica Brasilica     Open Access   (Followers: 3, SJR: 0.325, h-index: 1)
Acta botánica mexicana     Open Access   (Followers: 1, SJR: 0.212, h-index: 0)
Acta Cirurgica Brasileira     Open Access   (SJR: 0.395, h-index: 1)
Acta Limnologica Brasiliensia     Open Access   (Followers: 3, SJR: 0.28, h-index: 1)
Acta Literaria     Open Access   (Followers: 3, SJR: 0.1, h-index: 0)
Acta Medica Colombiana     Open Access   (Followers: 1)
Acta Médica Costarricense     Open Access   (Followers: 2)
Acta Neurológica Colombiana     Open Access   (Followers: 2)
Acta Ortopédica Brasileira     Open Access   (Followers: 1, SJR: 0.343, h-index: 1)
Acta Paulista de Enfermagem     Open Access   (Followers: 2, SJR: 0.275, h-index: 1)
Acta Pediátrica Costarricense     Open Access   (Followers: 1)
Acta Scientiarum. Agronomy     Open Access   (Followers: 7, SJR: 0.431, h-index: 1)
Acta zoológica mexicana     Open Access  
Actualidades Biológicas     Open Access   (Followers: 1)
African Human Rights Law J.     Open Access   (Followers: 18)
African Natural History     Open Access   (Followers: 2, SJR: 0.198, h-index: 1)
Afro-Asia     Open Access  
Ágora - studies in psychoanalytic theory     Open Access   (Followers: 3, SJR: 0.132, h-index: 0)
Agricultura Tecnica     Open Access   (Followers: 5)
Agrociencia     Open Access   (Followers: 1, SJR: 0.2, h-index: 0)
Agrociencia Uruguay     Open Access  
Agronomía Mesoamericana     Open Access  
Aisthesis     Open Access   (Followers: 6, SJR: 0.106, h-index: 0)
Alea : Estudos Neolatinos     Open Access   (Followers: 2, SJR: 0.1, h-index: 0)
Alfa : Revista de Linguística     Open Access  
Alpha (Osorno)     Open Access   (SJR: 0.138, h-index: 0)
Ambiente & sociedade     Open Access   (Followers: 3, SJR: 0.235, h-index: 0)
Ambiente & Agua : An Interdisciplinary J. of Applied Science     Open Access   (Followers: 1, SJR: 0.263, h-index: 1)
Ambiente Construído     Open Access   (Followers: 1)
América Latina en la historia económica     Open Access   (Followers: 2, SJR: 0.134, h-index: 0)
Anais Brasileiros de Dermatologia     Open Access   (Followers: 3, SJR: 0.52, h-index: 1)
Anais da Academia Brasileira de Ciências     Open Access   (Followers: 2, SJR: 0.418, h-index: 1)
Anais do Museu Paulista : História e Cultura Material     Open Access   (Followers: 1)
Anales de Medicina Interna     Open Access   (Followers: 1)
Anales del Instituto de la Patagonia     Open Access  
Anales del Sistema Sanitario de Navarra     Open Access   (Followers: 1, SJR: 0.157, h-index: 0)
Análise Psicológica     Open Access   (Followers: 1, SJR: 0.16, h-index: 0)
Análise Social     Open Access   (Followers: 2, SJR: 0.16, h-index: 0)
Andean geology     Open Access   (Followers: 9, SJR: 0.674, h-index: 1)
Antipoda. Revista de Antropología y Arqueología     Open Access   (Followers: 5, SJR: 0.135, h-index: 0)
Anuario Colombiano de Historia Social y de la Cultura     Open Access   (SJR: 0.1, h-index: 0)
Anuario de Historia Regional y de las Fronteras     Open Access  
Apuntes : Revista de Estudios sobre Patrimonio Cultural - J. of Cultural Heritage Studies     Open Access   (Followers: 6)
Archivos de Medicina Veterinaria     Open Access   (Followers: 1, SJR: 0.194, h-index: 0)
Archivos de Neurociencias     Open Access   (Followers: 3, SJR: 0.111, h-index: 0)
Archivos de Pediatria del Uruguay     Open Access   (Followers: 3)
Archivos de Zootecnia     Open Access   (Followers: 1, SJR: 0.202, h-index: 0)
Archivos Españoles de Urología     Open Access   (SJR: 0.178, h-index: 0)
Argos     Open Access   (Followers: 1)
ARQ     Open Access   (Followers: 4, SJR: 0.113, h-index: 0)
Arquitectura y Urbanismo     Open Access   (Followers: 3)
Arquivo Brasileiro de Medicina Veterinária e Zootecnia     Open Access   (SJR: 0.248, h-index: 0)
Arquivos Brasileiros de Cardiologia     Open Access   (Followers: 1, SJR: 0.381, h-index: 1)
Arquivos Brasileiros de Endocrinologia e Metabologia     Open Access  
Arquivos Brasileiros de Oftalmologia     Open Access   (SJR: 0.518, h-index: 1)
Arquivos de Gastroenterologia     Open Access   (Followers: 1, SJR: 0.396, h-index: 1)
Arquivos de Medicina     Open Access  
Arquivos de Neuro-Psiquiatria     Open Access   (SJR: 0.448, h-index: 1)
Arquivos do Instituto Biológico     Open Access   (Followers: 1)
Arquivos Internacionais de Otorrinolaringologia     Open Access  
ARS     Open Access   (Followers: 3)
Atenea (Concepción)     Open Access   (SJR: 0.112, h-index: 0)
Atmósfera     Open Access   (Followers: 2, SJR: 0.449, h-index: 1)
Audiology - Communication Research     Open Access   (Followers: 8)
Avaliação : Revista da Avaliação da Educação Superior (Campinas)     Open Access  
Avances en Odontoestomatologia     Open Access   (Followers: 1, SJR: 0.105, h-index: 0)
Avances en Periodoncia e Implantología Oral     Open Access   (Followers: 1)
Bakhtiniana : Revista de Estudos do Discurso     Open Access   (SJR: 0.103, h-index: 0)
BAR. Brazilian Administration Review     Open Access   (Followers: 1, SJR: 0.137, h-index: 0)
Biota Neotropica     Open Access   (SJR: 0.381, h-index: 1)
Biotecnología Aplicada     Open Access   (SJR: 0.146, h-index: 0)
Biotecnología en el Sector Agropecuario y Agroindustrial     Open Access  
Boletim de Ciências Geodésicas     Open Access   (SJR: 0.188, h-index: 0)
Boletim do Museu Paraense Emílio Goeldi. Ciências Humanas     Open Access   (Followers: 1, SJR: 0.238, h-index: 0)
Boletin Chileno de Parasitologia     Open Access  
Boletín de Filología     Open Access  
Boletín de la Sociedad Botánica de México     Open Access  
Boletin de la Sociedad Chilena de Quimica     Open Access  
Boletín de la Sociedad Geológica Mexicana     Open Access   (SJR: 0.291, h-index: 1)
Boletín del Museo Chileno de Arte Precolombino     Open Access   (Followers: 1, SJR: 0.233, h-index: 0)
Bosque     Open Access   (Followers: 2, SJR: 0.29, h-index: 1)
Bragantia     Open Access   (Followers: 2, SJR: 0.555, h-index: 1)
Brazilian Archives of Biology and Technology     Open Access   (Followers: 3, SJR: 0.281, h-index: 1)
Brazilian Dental J.     Open Access   (Followers: 2, SJR: 0.476, h-index: 1)
Brazilian J. of Biology     Open Access   (Followers: 3, SJR: 0.523, h-index: 1)
Brazilian J. of Chemical Engineering     Open Access   (Followers: 4, SJR: 0.395, h-index: 1)
Brazilian J. of Food Technology     Open Access   (Followers: 3, SJR: 0.206, h-index: 0)
Brazilian J. of Medical and Biological Research     Open Access   (SJR: 0.611, h-index: 2)
Brazilian J. of Microbiology     Open Access   (Followers: 3, SJR: 0.63, h-index: 2)
Brazilian J. of Oceanography     Open Access   (Followers: 1, SJR: 0.425, h-index: 1)
Brazilian J. of Oral Sciences     Open Access   (Followers: 1, SJR: 0.131, h-index: 0)
Brazilian J. of Physical Therapy     Open Access   (SJR: 0.802, h-index: 2)
Brazilian J. of Plant Physiology     Open Access   (Followers: 3, SJR: 1.178, h-index: 3)
Brazilian J. of Veterinary Research and Animal Science     Open Access   (Followers: 8, SJR: 0.225, h-index: 0)
Brazilian Oral Research     Open Access  
Brazilian Political Science Review     Open Access   (Followers: 1)
Caderno CRH     Open Access   (Followers: 3, SJR: 0.233, h-index: 0)
Caderno de Estudos     Open Access  
Cadernos CEDES     Open Access   (Followers: 1, SJR: 0.119, h-index: 0)
Cadernos de Pesquisa     Open Access   (Followers: 2, SJR: 0.183, h-index: 0)
Cadernos de Saúde Pública     Open Access   (Followers: 1, SJR: 0.568, h-index: 1)
Cadernos de Tradução     Open Access  
Cadernos Metrópole     Open Access   (Followers: 1)
Cadernos Nietzsche     Open Access  
Cadernos Pagu     Open Access   (SJR: 0.356, h-index: 0)
Cadernos Saúde Coletiva     Open Access   (Followers: 1)
Caldasia     Open Access   (SJR: 0.195, h-index: 0)
Calidad en la educación     Open Access   (Followers: 1)
Cerâmica     Open Access   (Followers: 5, SJR: 0.186, h-index: 0)
CES Medicina     Open Access  
Chilean J. of Agricultural Research     Open Access   (Followers: 1, SJR: 0.377, h-index: 1)
Chungara (Arica) - Revista de Antropologia Chilena     Open Access   (Followers: 1, SJR: 0.565, h-index: 1)
Ciência & Educação (Bauru)     Open Access  
Ciência & Saúde Coletiva     Open Access   (Followers: 2, SJR: 0.566, h-index: 1)
Ciência Animal Brasileira     Open Access   (Followers: 1, SJR: 0.216, h-index: 0)
Ciência da Informação     Open Access   (Followers: 1, SJR: 0.121, h-index: 0)
Ciencia del suelo     Open Access   (Followers: 2)
Ciência e Agrotecnologia     Open Access   (SJR: 0.383, h-index: 1)
Ciencia e Cultura     Open Access   (Followers: 1)
Ciencia e investigación agraria     Open Access   (Followers: 1, SJR: 0.211, h-index: 0)
Ciencia forestal en México     Open Access  
Ciência Rural     Open Access   (Followers: 2, SJR: 0.337, h-index: 1)
Ciencia y Enfermeria - Revista Iberoamericana de Investigacion     Open Access   (Followers: 3, SJR: 0.158, h-index: 0)
Ciencias Marinas     Open Access   (Followers: 2, SJR: 0.414, h-index: 1)
Ciencias Psicológicas     Open Access  
Cirugia Plastica Ibero-Latinoamericana     Open Access   (SJR: 0.166, h-index: 0)
CLEI Electronic J.     Open Access  
Clínica y Salud     Open Access   (SJR: 0.173, h-index: 0)
Clinics     Open Access   (SJR: 0.536, h-index: 1)
CoDAS     Open Access   (SJR: 0.267, h-index: 0)
Computación y Sistemas     Open Access   (SJR: 0.226, h-index: 1)
Comuni@cción     Open Access  
Comunicación y sociedad     Open Access   (Followers: 2, SJR: 0.327, h-index: 0)
Contaduría y Administración     Open Access   (SJR: 0.219, h-index: 0)
Contexto Internacional     Open Access  
Convergencia     Open Access   (Followers: 3, SJR: 0.196, h-index: 0)
Correo Científico Médico     Open Access  
Corrosão e Protecção de Materiais     Open Access  
Crop Breeding and Applied Biotechnology     Open Access   (Followers: 3, SJR: 0.609, h-index: 1)
Cuadernos de Economía     Open Access   (Followers: 2)
Cuadernos de Economia - Latin American J. of Economics     Open Access   (Followers: 2)
Cuadernos de Historia     Open Access   (Followers: 1)
Cuadernos de Historia de la Salud Publica     Open Access  
Cuadernos de Medicina Forense     Open Access   (Followers: 2, SJR: 0.1, h-index: 0)
Cuadernos.info     Open Access   (SJR: 0.38, h-index: 0)
Cubo. A Mathematical J.     Open Access  
Cuicuilco     Open Access   (Followers: 1)
Cultivos Tropicales     Open Access   (Followers: 1)
Culturales     Open Access   (Followers: 3)
Dados - Revista de Ciências Sociais     Open Access   (SJR: 0.37, h-index: 0)
De Jure     Open Access   (Followers: 1)
DELTA : Documentação de Estudos em Lingüística Teórica e Aplicada     Open Access   (SJR: 0.133, h-index: 0)
Dementia & Neuropsychologia     Open Access   (Followers: 8, SJR: 0.205, h-index: 0)
Dental Press J. of Orthodontics     Open Access   (Followers: 2, SJR: 0.489, h-index: 1)
Desacatos     Open Access   (Followers: 1)
Desarrollo y Sociedad     Open Access   (Followers: 3, SJR: 0.109, h-index: 0)
Diálogo Andino - Revista de Historia, Geografía y Cultura Andina     Open Access   (SJR: 0.116, h-index: 0)
Diánoia     Open Access   (Followers: 1)
Dimensión Empresarial     Open Access  
Dynamis : Acta Hispanica ad Medicinae Scientiarumque Historiam Illustrandam     Open Access   (Followers: 2, SJR: 0.131, h-index: 0)
e-J. of Portuguese History     Open Access   (Followers: 2, SJR: 0.101, h-index: 0)
Eclética Química     Open Access   (Followers: 1)
Ecología en Bolivia     Open Access  
Economia Aplicada     Open Access   (SJR: 0.208, h-index: 0)
Economia e Sociedade     Open Access  
EconoQuantum     Open Access  
Educação & Sociedade     Open Access   (Followers: 3)
Educação e Pesquisa     Open Access   (Followers: 1, SJR: 0.163, h-index: 0)
Educação em Revista     Open Access  
Educación Matemática     Open Access  
Educación Médica     Open Access   (Followers: 1, SJR: 0.236, h-index: 0)
Educación Médica Superior     Open Access   (Followers: 1, SJR: 0.237, h-index: 0)
Educación y Educadores     Open Access  
Educar em Revista     Open Access  
EDUMECENTRO     Open Access  
En-Claves del pensamiento     Open Access   (Followers: 1, SJR: 0.194, h-index: 0)
Encuentros     Open Access  
Ene : Revista de Enfermería     Open Access  
Enfermería Global     Open Access   (Followers: 3, SJR: 0.165, h-index: 0)
Enfermería Nefrológica     Open Access   (Followers: 1, SJR: 0.198, h-index: 0)
Enfoques     Open Access  
Engenharia Agrícola     Open Access   (SJR: 0.305, h-index: 1)
Engenharia Sanitaria e Ambiental     Open Access   (SJR: 0.218, h-index: 0)
Ensaio Avaliação e Políticas Públicas em Educação     Open Access   (Followers: 1, SJR: 0.254, h-index: 0)
Entomologia y Vectores     Open Access   (Followers: 2)
Escritos de Psicología : Psychological Writings     Open Access   (Followers: 2)
Estudios Atacameños     Open Access   (Followers: 2, SJR: 0.446, h-index: 1)
Estudios Constitucionales     Open Access   (Followers: 5, SJR: 0.319, h-index: 0)
Estudios de Cultura Maya     Open Access   (Followers: 2, SJR: 0.272, h-index: 0)
Estudios de Economía     Open Access   (SJR: 0.121, h-index: 0)
Estudios de historia moderna y contemporánea de México     Open Access   (SJR: 0.101, h-index: 0)
Estudios Filologicos     Open Access   (SJR: 0.107, h-index: 0)
Estudios Fronterizos     Open Access   (Followers: 1)
Estudios internacionales     Open Access   (Followers: 5)
Estudios Pedagogicos (Valdivia)     Open Access   (Followers: 1, SJR: 0.338, h-index: 0)

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Journal Cover
Anais da Academia Brasileira de Ciências
Journal Prestige (SJR): 0.418
Citation Impact (citeScore): 1
Number of Followers: 2  

  This is an Open Access Journal Open Access journal
ISSN (Print) 0001-3765 - ISSN (Online) 1678-2690
Published by SciELO Homepage  [715 journals]
  • Commemorative Volume on the Centenary of the Brazilian Academy of
           Sciences: “Brazil: Frontiers of Chemical Sciences”

    •  
  • Carbon dioxide/methanol conversion cycle based on cascade enzymatic
           reactions supported on superparamagnetic nanoparticles

    • Abstract: ABSTRACT The conversion of carbon dioxide into important industrial feedstock is a subject of growing interest in modern society. A possible way to achieve this goal is by carrying out the CO2/methanol cascade reaction, allowing the recycle of CO2 using either chemical catalysts or enzymes. Efficient and selective reactions can be performed by enzymes; however, due to their low stability, immobilization protocols are required to improve their performance. The cascade reaction to reduce carbon dioxide into methanol has been explored by the authors, using, sequentially, alcohol dehydrogenase (ADH), formaldehyde dehydrogenase (FalDH), and formate dehydrogenase (FDH), powered by NAD+/NADH and glutamate dehydrogenase (GDH) as the co-enzyme regenerating system. All the enzymes have been immobilized on functionalized magnetite nanoparticles, and their reactions investigated separately in order to establish the best performance conditions. Although the stepwise scheme led to only 2.3% yield of methanol per NADH; in a batch system under CO2 pressure, the combination of the four immobilized enzymes increased the methanol yield by 64 fold. The studies indicated a successful regeneration of NADH in situ, envisaging a real possibility of using immobilized enzymes to perform the cascade CO2-methanol reaction.
       
  • The long and successful journey of electrochemically active amino acids.
           From fundamental adsorption studies to potential surface engineering
           tools.

    • Abstract: ABSTRACT Proteins have been the subject of electrochemical studies. It is possible to apply electrochemical techniques to obtain information about their structure due to the presence of five electroactive amino acids that can be oriented to the outside of the peptidic chain. These amino acids are L-Tryptophan (L-Trp), L-Tyrosine (L-Tyr), L-Histidine (L-His), L-Methionine (L-Met) and L-Cysteine (L-Cys); their electrochemical behavior being subject of extensive research, but it is still controversial. No spectroscopic investigations have been reported on L-Trp, and due to the short life time of the intermediates, ex situ techniques cannot be employed, leading to a never-ending discussion about possible intermediates. In the L-Tyr and L-His cases, spectroelectrochemical studies were performed and different intermediates were observed, suggesting that some intermediates may be observed under specific conditions, as proposed for L-Cys. This amino acid is the most interesting among the electroactive ones because of the presence of a thiol moiety at its side chain, leading to a wide range of oxidation states. It can adsorb onto surfaces of different crystallographic orientation in stereoselective conformation, modifying the surface for different applications.as a surface engineering tool since it plays the role of as an anchor for the growing of nanocrystals inside proteic templates.
       
  • Enzymes immobilized in Langmuir-Blodgett films: Why determining the
           surface properties in Langmuir monolayer is important'

    • Abstract: ABSTRACT In this review we discuss about the immobilization of enzymes in Langmuir-Blodgett films in order to determine the catalytic properties of these biomacromolecules when adsorbed on solid supports. Usually, the conformation of enzymes depends on the environmental conditions imposed to them, including the chemical composition of the matrix, and the morphology and thickness of the film. In this review, we show an outline of manuscripts that report the immobilization of enzymes as LB films since the 1980’s, and also some examples of how the surface properties of the floating monolayer prepared previously to the transfer to the solid support are important to determine the efficiency of the resulting device.
       
  • From Medicinal Chemistry to Human Health: Current Approaches to Drug
           Discovery for Cancer and Neglected Tropical Diseases

    • Abstract: ABSTRACT Scientific and technological breakthroughs have compelled the current players in drug discovery to increasingly incorporate knowledge-based approaches. This evolving paradigm, which has its roots attached to the recent advances in medicinal chemistry, molecular and structural biology, has unprecedentedly demanded the development of up-to-date computational approaches, such as bio- and chemo-informatics. These tools have been pivotal to catalyzing the ever-increasing amount of data generated by the molecular sciences, and to converting the data into insightful guidelines for use in the research pipeline. As a result, ligand- and structure-based drug design have emerged as key pathways to address the pharmaceutical industry’s striking demands for innovation. These approaches depend on a keen integration of experimental and molecular modeling methods to surmount the main challenges faced by drug candidates - in vivo efficacy, pharmacodynamics, metabolism, pharmacokinetics and safety. To that end, the Laboratório de Química Medicinal e Computacional (LQMC) of the Universidade de São Paulo has developed forefront research on highly prevalent and life-threatening neglected tropical diseases and cancer. By taking part in global initiatives for pharmaceutical innovation, the laboratory has contributed to the advance of these critical therapeutic areas through the use of cutting-edge strategies in medicinal chemistry.
       
  • Brazilian Bioluminescent Beetles: Reflections on Catching Glimpses of
           Light in the Atlantic Forest and Cerrado

    • Abstract: ABSTRACT Bioluminescence - visible and cold light emission by living organisms - is a worldwide phenomenon, reported in terrestrial and marine environments since ancient times. Light emission from microorganisms, fungi, plants and animals may have arisen as an evolutionary response against oxygen toxicity and was appropriated for sexual attraction, predation, aposematism, and camouflage. Light emission results from the oxidation of a substrate, luciferin, by molecular oxygen, catalyzed by a luciferase, producing oxyluciferin in the excited singlet state, which decays to the ground state by fluorescence emission. Brazilian Atlantic forests and Cerrados are rich in luminescent beetles, which produce the same luciferin but slightly mutated luciferases, which result in distinct color emissions from green to red depending on the species. This review focuses on chemical and biological aspects of Brazilian luminescent beetles (Coleoptera) belonging to the Lampyridae (fireflies), Elateridae (click-beetles), and Phengodidae (railroad-worms) families. The ATP-dependent mechanism of bioluminescence, the role of luciferase tuning the color of light emission, the “luminous termite mounds” in Central Brazil, the cooperative roles of luciferase and superoxide dismutase against oxygen toxicity, and the hypothesis on the evolutionary origin of luciferases are highlighted. Finally, we point out analytical uses of beetle bioluminescence for biological, clinical, environmental, and industrial samples.
       
  • Chemistry Inspired by the Colors of Fruits, Flowers and Wine

    • Abstract: ABSTRACT An overview is provided of the status of research at the frontiers of investigation of the chemistry and photochemistry of two classes of natural plant pigments, the anthocyanins and the betalains, as well as of the pyranoanthocyanin pigments formed from anthocyanins during the maturation of red wine. Together, anthocyanins and betalains are responsible for almost all of the red, purple and blue colors of fruits and flowers and anthocyanins and pyranoanthocyanins are major contributors to the color of red wines. All three types of pigments are cationic below about pH 3, highly colored, non-toxic, reasonably soluble in water or alcohol and fairly stable to light. They exhibit good antioxidant or antiradical activity and, as part of our diet, confer a number of important health benefits. Systematic studies of model compounds containing the basic chromophoric groups of these three types of pigments are providing a deeper understanding of the often complex chemistry and photochemistry of these pigments and their relationship to the roles in vivo of these pigments in plants. These natural pigments are currently being exploited as starting materials for the preparation of novel semi-synthetic dyes, pigments and fluorescence probes.
       
  • Activity and Stability of Dispersed Multi Metallic Pt-based Catalysts for
           CO Tolerance in Proton Exchange Membrane Fuel Cell Anodes

    • Abstract: ABSTRACT Studies aiming at improving the activity and stability of dispersed W and Mo containing Pt catalysts for the CO tolerance in proton exchange membrane fuel cell (PEMFC) anodes are revised for the following catalyst systems: (1) a carbon supported PtMo electrocatalyst submitted to heat treatments; (2) Pt and PtMo nanoparticles deposited on carbon-supported molybdenum carbides (Mo2C/C); (3) ternary and quaternary materials formed by PtMoFe/C, PtMoRu/C and PtMoRuFe/C and; (4) Pt nanoparticles supported on tungsten carbide/carbon catalysts and its parallel evaluation with carbon supported PtW catalyst. The heat-treated (600 oC) Pt-Mo/C catalyst showed higher hydrogen oxidation activity in the absence and in the presence of CO and better stability, compared to all other Mo-containing catalysts. PtMoRuFe, PtMoFe, PtMoRu supported on carbon and Pt supported on Mo2C/C exhibited similar CO tolerances but better stability, as compared to as-prepared PtMo supported on carbon. Among the tungsten-based catalysts, tungsten carbide supported Pt catalyst showed reasonable performance and reliable stability in comparison to simple carbon supported PtW catalyst, though an uneven level of catalytic activity towards H2 oxidation in presence of CO is observed for the former as compared to Mo containing catalyst. However, a small dissolution of Mo, Ru, Fe and W from the anodes and their migration toward cathodes during the cell operation is observed. These results indicate that the fuel cell performance and stability has been improved but not yet totally resolved.
       
  • Controlled synthesis of noble metal nanomaterials: motivation, principles,
           and opportunities in nanocatalysis

    • Abstract: ABSTRACT This review describes some principles of the controlled synthesis of metal nanoparticles, focusing on how the fundamental understanding of their synthesis in the solution-phase can be put to tailor size, shape, composition, and architecture. The maneuvering over these parameters not only enable the tuning of properties, but also the maximization and optimization of performances for various applications. Herein, we start with a brief description of metallic nanoparticles, highlighting the motivation for achieving physicochemical control in their synthesis. After that, we turn our attention to some important definitions and classifications as well as their unique properties such as surface and quantum effects. Moreover, we discuss the strategies for the controlled synthesis of metal nanomaterials based on the top-down and bottom-up approaches, focusing our discussion on their formation mechanisms in liquid-phase in terms of both thermodynamic and kinetic control. Finally, we point out the promising applications of controlled nanomaterials in the field of nanocatalysis and plasmon-enhanced catalysis, describing some of the current challenges in these fields.
       
  • Sunlight-driven water splitting using hematite nanorod photoelectrodes

    • Abstract: ABSTRACT The efficiency of nanostructures for photoelectrochemical water-splitting is fundamentally governed by the capability of the surface to sustain the reaction without electron trapping or recombination by photogenerated holes. This brief review will summarize the latest progress on hematite, designed with columnar morphology via chemical synthesis, for photoelectrochemical cell application. The columnar morphology efficiently minimizes the number of defects, grain boundaries, and surface traps normally present on the planar morphology. The major drawback related to hole diffusion through the solid/liquid interface was addressed by using high annealing temperature combined with dopant addition. A critical view and depth of understanding of these two parameters were discussed focusing on the molecular oxygen evolution mechanism from the sunlight-driven water oxidation reaction.
       
  • The potential contribution of the natural products from Brazilian
           biodiversity to bioeconomy

    • Abstract: ABSTRACT The development of our society has been based on the use of biodiversity, especially for medicines and nutrition. Brazil is the nation with the largest biodiversity in the world accounting for more than 15% of all living species. The devastation of biodiversity in Brazil is critical and may not only cause the loss of species and genes that encode enzymes involved in the complex metabolism of organisms, but also the loss of a rich chemical diversity, which is a potential source for bioeconomy based on natural products and new synthetic derivatives. Bioeconomy focus on the use of bio-based products, instead of fossil-based ones and could address some of the important challenges faced by society. Considering the chemical and biological diversity of Brazil, this review highlights the Brazilian natural products that were successfully used to develop new products and the value of secondary metabolites from Brazilian biodiversity with potential application for new products and technologies. Additionally, we would like to address the importance of new technologies and scientific programs to support preservation policies, bioeconomy and strategies for the sustainable use of biodiversity.
       
  • New trends in plasmonic (bio)sensing

    • Abstract: The strong enhancement and localization of electromagnetic field in plasmonic systems have found applications in many areas, which include sensing and biosensing. In this paper, an overview will be provided of the use of plasmonic phenomena in sensors and biosensors with emphasis on two main topics. The first is related to possible ways to enhance the performance of sensors and biosensors based on surface plasmon resonance (SPR), where examples are given of functionalized magnetic nanoparticles, magnetoplasmonic effects and use of metamaterials for SPR sensing. The other topic is focused on surface-enhanced Raman scattering (SERS) for sensing, for which uniform, flexible, and reproducible SERS substrates have been produced. With such recent developments, there is the prospect of improving sensitivity and lowering the limit of detection in order to overcome the limitations inherent in ultrasensitive detection of chemical and biological analytes, especially at single molecule levels.
       
  • Solid-phase extractions in flow analysis

    • Abstract: ABSTRACT Coupling solid-phase extraction (SPE) to flow systems has promoted a synergistic development. Whereas SPE mechanization leads to improved precision and higher sample throughput, as well as diminishes systematic errors and contamination risks, analyte concentration and separation from the sample matrix provides a remarkable impact on detectability and selectivity in flow analysis. Historical aspects, main cornerstones, tips for system design, and recent applications are critically reviewed, in the context of analyte(s) separation/concentration, sample clean-up, and release of sorbed chemical species involving both packed (e.g. mini-columns, cartridges, and disks) or fluidized (e.g. beads and magnetic materials) particles. Novel (bio)sorbents, selective synthetic materials, and stationary phases for low-pressure chromatography are also discussed. Moreover, the feasibility of SPE for sample treatment before chromatographic separation, as well as the exploitation of direct measurements on the solid phase (optosensing) are emphasized.
       
  • Advances in enzyme bioelectrochemistry

    • Abstract: ABSTRACT Bioelectrochemistry can be defined as a branch of Chemical Science concerned with electron-proton transfer and transport involving biomolecules, as well as electrode reactions of redox enzymes. The bioelectrochemical reactions and system have direct impact in biotechnological development, in medical devices designing, in the behavior of DNA-protein complexes, in green-energy and bioenergy concepts, and make it possible an understanding of metabolism of all living organisms (e.g. humans) where biomolecules are integral to health and proper functioning. In the last years, many researchers have dedicated itself to study different redox enzymes by using electrochemistry, aiming to understand their mechanisms and to develop promising bioanodes and biocathodes for biofuel cells as well as to develop biosensors and implantable bioelectronics devices. Inside this scope, this review try to introduce and contemplate some relevant topics for enzyme bioelectrochemistry, such as the immobilization of the enzymes at electrode surfaces, the electron transfer, the bioelectrocatalysis, and new techniques conjugated with electrochemistry vising understand the kinetics and thermodynamics of redox proteins. Furthermore, examples of recent approaches in designing biosensors and biofuel developed are presented.
       
  • Traditional and New methods for the Preparation of Diazocarbonyl Compounds

    • Abstract: ABSTRACT For many years diazocarbonyl compounds have been studied due to their versatility and usability in many chemical transformations. In this review, we summarize the traditional methods to prepare these compounds as well as the new methods and recent improvements in experimental procedures. Moreover, emergence of continuous flow techniques has allowed safer and environmentally friendly procedures for the handling of diazomethane and diazo compounds and will also be a topic in this review.
       
  • Organic Synthesis: New Vistas in the Brazilian Landscape

    • Abstract: ABSTRACT In this overview, we present our analysis of the future of organic synthesis in Brazil, a highly innovative and strategic area of research which underpins our social and economical progress. Several different topics (automation, catalysis, green chemistry, scalability, methodological studies and total syntheses) were considered to hold promise for the future advance of chemical sciences in Brazil. In order to put it in perspective, contributions from Brazilian laboratories were selected by the citations received and importance for the field and were benchmarked against some of the most important results disclosed by authors worldwide. The picture that emerged reveals a thriving area of research, with new generations of well-trained and productive chemists engaged particularly in the areas of green chemistry and catalysis. In order to fulfill the promise of delivering more efficient and sustainable processes, an integration of the academic and industrial research agendas is to be expected. On the other hand, academic research in automation of chemical processes, a well established topic of investigation in industrial settings, has just recently began in Brazil and more academic laboratories are lining up to contribute. All these areas of research are expected to enable the future development of the almost unchartered field of scalability.
       
  • Enzymatic reactions involving the heteroatoms from organic substrates

    • Abstract: ABSTRACT Several enzymatic reactions of heteroatom-containing compounds have been explored as unnatural substrates. Considerable advances related to the search for efficient enzymatic systems able to support a broader substrate scope with high catalytic performance are described in the literature. These reports include mainly native and mutated enzymes and whole cells biocatalysis. Herein, we describe the historical background along with the progress of biocatalyzed reactions involving the heteroatom(S, Se, B, P and Si) from hetero-organic substrates.
       
 
 
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