23 research outputs found
Special session in honor of Antonio Carlos Massabni
The present issue of International Journal of Advances in Medical Biotechnology (IJAMB) introduces a set of five papers elaborated by Prof. Antonio Carlos Massabni and students that have attended a graduate course nominated Seminars of Integration from the Postgraduate Program in Biotechnology of the University of Araraquara (UNIARA), Araraquara, Brazil. The authors have focused on the impact of Industry 4.0 technologies on Biotechnology as well as the chance for future professionals and the work relations in this context. In other papers, the importance of biotechnology in the development of vaccines, antibiotics, hormones and scaffolds for regenerative medicine are discussed. This issue is dedicated in honor of Prof. Massabni for his commitment with teaching, research and administrative duties
Spectroscopic characterization of schiff base-copper complexes immobilized in smectite clays
Herein, the immobilization of some Schiff base-copper(II) complexes in smectite clays is described as a strategy for the heterogenization of homogeneous catalysts. The obtained materials were characterized by spectroscopic techniques, mostly UV/Vis, EPR, XANES and luminescence spectroscopy. SWy-2 and synthetic Laponite clays were used for the immobilization of two different complexes that have previously shown catalytic activity in the dismutation of superoxide radicals, and disproportionation of hydrogen peroxide. The obtained results indicated the occurrence of an intriguing intramolecular redox process involving copper and the imine ligand at the surface of the clays. These studies are supported by computational calculations
Gestão de Componentes em Dinâmico
A crescente evolução das tecnologias de informação e comunicação, aliadas ao desenvolvimento industrial, proporcionou um aumento de competitividade entre as indústrias, originando uma subida do nível da relação qualidade preço. Esta premissa causou uma maior preocupação com a procura contínua pela melhoria dos processos, de forma a aumentar as actividades de valor acrescentado, eliminando todo o tipo de desperdícios.
Nesta conjuntura, a Grohe Portugal Componentes Sanitários, Lda propôs uma melhoria no âmbito da gestão de stocks de componentes existentes em dinâmico. Esta acção de melhoria passa pela definição e implementação de um método de gestão destes componentes, acompanhado por um conjunto de regras de identificação de actividades e respectivos intervenientes, por forma a optimizar os meios existentes e evitar a ocorrência de falhas de componentes nas linhas.
Trata-se de um método baseado no cálculo das necessidades das linhas, que através da procura média semanal e constituição dos produtos finais define um nível de prioridade entre os componentes, identificando quais os mais requisitados pelas linhas e possibilitando a gestão do dinâmico. Na contínua tentativa de combater possíveis falhas, desenvolveu-se um sistema de gestão do tipo Kanban com a capacidade de gerir o produto semi-acabado para consumo interno. Foram, ainda, criadas melhorias que permitem um acréscimo de eficiência na gestão dos componentes em estante dinâmica, diminuindo o capital imobilizado investido em stocks, levando a um rearranjo de layouts, proporcionando melhores condições de trabalho e optimizando percursos e recursos.
Descreve-se detalhadamente o processo de (i) actualização, definição e implementação do método de gestão de componentes em dinâmico, acompanhado pelo respectivo conjunto de regras, (ii) a implementação de um sistema do tipo Kanban orientado às reais preocupações da empresa, (iii) a redefinição de layouts em conformidade com a actualização dos dinâmicos e (iv) a identificação e execução de um conjunto de melhorias. Todas estas actividades acompanhadas pelo impacto financeiro na organização. Por fim, efectua-se o balanço deste projecto e sugerem-se oportunidades de melhoria.The growing evolution of information and communication technologies, allied to the industrial development, provided an increase of competitive edge between the industries, originating a rise in the level of quality price relationship. This premise caused a bigger concern with the continuous search for processes improvement, in order to increase the activities of added value, eliminating all kind of waste.
In this conjuncture, Grohe Portugal Componentes Sanitários, Lda proposed na improvement in the scope of stocks management of existing components in dynamic shelfs. This action of improvement goes by the definition and implementation of a management method of these components, accompanied by a set of rules of activity identification and respective stakeholders, in such a way to optimize the existing means and avoid the shortage of the components in the production lines.
It is a method based in the calculation of the lines needs, that through the weekly average search and final products constitution defines a priority level between components, identifying which is the most required by the lines and allowing the dynamics management. In the continuous attempt to counter possible failures, it was developed a management system of Kanban type with the capacity of managing the semi-finished product for internal consumption. There were, still, created improvements that allow an increase of efficiency in the management of components in a dynamic shelf, decreasing the immobilized capital invested in stocks, leading to a rearrangement of layouts, providing better working conditions and optimizing pathways and resources.
It is described in detail the process of (i) update, definition and implementation of the management method of dynamic shelfs components, accompanied by the respective set of rules, (ii) the implementation of a Kanban type system guided to the real concerns of the company, (iii) the redefinition of layouts in conformity with the dynamics update and (iv) the identification and execution of a set of improvements. All of these activities are accompanied by the financial impact on the organization. Lastly, the balance of this project is done and are suggested some opportunities to improve it
Theoretical studies of Mefenamic Acid Polymorphs: Solid-state 13C carbon-NMR and vibrational (IR and Raman) Spectroscopies.
The two polymorphs of mefenamic acid (MEF) or 2-[(2,3-(dimethyphenyl)amino] benzoic acid polymorphs (known as I and II forms) were studies in the framkework of density functional theory (DFT). The DFT calculations were performed using the Gaussian03 package and these results were compared with experimental data of solid-state 13C Nuclear Magnetic Resonance (NMR), vibrational Raman and infrared spectroscopies.CAPESCNPqFAPES
Industrial scale isolation, structural and spectroscopic characterization of epiisopiloturine from Pilocarpus microphyllus stapf leaves: a promising alkaloid against schistosomiasis
This paper presents an industrial scale process for extraction, purification, and isolation of epiisopiloturine (EPI) (2(3H)- Furanone,dihydro-3-(hydroxyphenylmethyl)-4-[(1-methyl-1H-imidazol-4-yl)methyl]-, [3S-[3a(R*),4b]]), which is an alkaloid from jaborandi leaves (Pilocarpus microphyllus Stapf). Additionally for the first time a set of structural and spectroscopic techniques were used to characterize this alkaloid. EPI has shown schistomicidal activity against adults and young forms, as well as the reduction of the egg laying adult worms and low toxicity to mammalian cells (in vitro). At first, the extraction of EPI was done with toluene and methylene chloride to obtain a solution that was alkalinized with ammonium carbonate. The remaining solution was treated in sequence by acidification, filtration and alkalinization. These industrial procedures are necessary in order to remove impurities and subsequent application of the high performance liquid chromatography (HPLC). The HPLC was employed also to remove other alkaloids, to obtain EPI purity higher than 98%. The viability of the method was confirmed through HPLC and electrospray mass spectrometry, that yielded a pseudo molecular ion of m/z equal to 287.1 Da. EPI structure was characterized by single crystal X-ray diffraction (XRD), 1H and 13C nuclear magnetic resonance (NMR) in deuterated methanol/chloroform solution, vibrational spectroscopy and mass coupled thermal analyses. EPI molecule presents a parallel alignment of the benzene and the methyl imidazol ring separated by an interplanar spacing of 3.758 Å indicating a π-π bond interaction. The imidazole alkaloid melts at 225°C and decomposes above 230°C under air. EPI structure was used in theoretical Density Functional Theory calculations, considering the single crystal XRD data in order to simulate the NMR, infrared and Raman spectra of the molecule, and performs the signals attribution
Produção de compósitos à base de Celulose bacteriana/Laponita organofuncionalizados com 3-aminopropiltrimetóxisilano visando aplicações médico farmacêuticas.
Compared to traditional dressings, bacterial cellulose (BC) membranes have interesting characteristics in the treatment of skin lesions, such as: immediate pain relief, maintenance of local humidity, action as a protective physical barrier, and adsorption of exudates during the inflammatory phase; however, they do not have intrinsic antibacterial properties. As far as drug release systems are concerned, BC presents a model of rapid release of the active ingredient ("burst release") which has negative effects and can be pharmacologically dangerous. The aim of this work is to obtain composites based on BC and Laponite clay organofunctionalized with amino groups in order to develop a new material that can serve as a precursor to multifunctional dressings with antibacterial action and a controlled drug release system. Infrared vibrational spectroscopy showed bands referring to the -NH2 and Si-O groups of the silane and clay structure, respectively, thus indicating the presence of these components in the sample. In addition, the modification of cellulose led to structural changes in the crystalline regions of BC. The presence of surface granules on the fibers, a reduction in thermal stability and a change in water vapor permeation were observed, compared to pristine BC, indicating success in modifying the polymer.Em comparação com os curativos tradicionais, as membranas de celulose bacteriana (CB) apresentam características interessantes no tratamento de lesões cutâneas como: o alívio imediato da dor, a manutenção da umidade local, a ação como barreira física de proteção, e a adsorção de exsudatos durante a fase inflamatória; contudo, não possuem propriedade antibacteriana intrínseca. Já em sistema de liberação de fármacos, a CB apresenta um modelo de liberação rápida do princípio ativo (“burst release”) que possui efeitos negativos, podendo ser farmacologicamente perigosos. Desta forma, o objetivo do presente trabalho é a obtenção de compósitos à base de CB e a argila Laponita organofuncionalizados com grupos amino para o desenvolvimento de um novo material que sirva como precursor de curativos multifuncionais com ação antibacteriana e sistema de liberação controlada de fármacos. A espectroscopia vibracional no infravermelho mostrou as bandas referentes aos grupos -NH2 e Si-O, da estrutura do silano e da argila, respectivamente, indicando assim a presença desses componentes na amostra. Além disso, a modificação da celulose ocasionou mudanças estruturais das regiões cristalinas da CB. Observou-se a presença de grânulos superficiais nas fibras, a redução da estabilidade térmica e uma mudança na permeação ao vapor de água, comparados com a CB prístina, indicando sucesso na modificação do polímero
New insights into two ciprofloxacin-intercalated arrangements for layered double hydroxide carrier materials
International audienceThis paper describes the intercalation of ciprofloxacin (CIP), a bactericidal antibiotic, into the interlayer space of layered double hydroxides (LDHs). To counter the problem of bacterial resistance and also to improve the properties of the CIP drug, the drug carrier approach promises significant benefits. Through the tight control over the synthesis parameters, particularly the amounts of CIP with respect to aluminum ions, two different LDH-CIP-intercalated structures were obtained with significantly different interlayer distances, namely, 21 and 32 Å. The samples were fully characterized in terms of composition, structure, and morphology. Interestingly, the structure with the largest interlayer distance incorporated both CIP anions and Al(CIP)3 complex, exhibiting the possibility to increase the CIP drug loading beyond the anionic-exchange capacity of the LDH carrier. In vitro release in a simulated intestinal fluid (phosphate-buffered solution at pH 7.5) confirmed that LDH was a potentially efficient carrier to deliver CIP in a sustained manner via the anion- exchange mechanism. Different release rates were observed depending on the intercalated structure, which were also influenced by the morphological characteristics
Spectroscopic Study on the Structural Differences of Thermally Induced Cross-Linking Segments in Emeraldine Salt and Base Forms of Polyaniline
This paper reports the spectroscopic study on the structural differences of thermally induced cross-linking segments in polyaniline in its emeraldine salt (PANI-ES) and base (PANI-EB) forms. Casting films of PANI-ES (ES-film) and PANI-EB (EB-film) were prepared and heated at 150 degrees C under atmospheric air for 30 min. Raman spectra excited at 632.8 nm of heated ES-film presented the characteristic bands of phenazine-like structures at 1638, 1392, and 575 cm(-1), whereas EB-film showed lower relative intensities for these bands. The lower content of phenazine-like segments in heated EB-film is related to residual polaronic segments from preparation procedures, as revealed by Raman. This statement was confirmed by a sequence of thermal and doping experiments in both films. Quantum-chemical calculations by density functional theory (DFT) and time-dependent density functional theory (TD-DFT) showed that the phenazine-like structure presents the intense Raman band at 1350 cm(-1) due to heterocycle breathing mode, and the non-phenazine-like structure (substituted hydrophenazine-type) presents higher energy for HOMO-LUMO transition, indicating the lack of conjugation in the heterocycle compared with the phenazine-like structure. According to experimental and theoretical data reported here, it is proposed that only thermally treated PANI-ES presents phenazine-like rings, whereas PANI-EB presents heterocyclic non-aromatic structures.CNPqCNPqFAPESPFAPES
Thermal decomposition of a layered double hydroxide as a bottom up approach for the synthesis of metallic nanoparticles embedded in carbon structures
International audienceIn the present study, the thermal behaviour of a layered double hydroxide (LDH) intercalated with a carboxymethylcellulose (CMC) polymer was evaluated to inspect the effect of the temperature on the chemical processes that occur during its decomposition under a nitrogen atmosphere, ranging from 500 to 1000 1C, as well as the product properties. The intercalation compound (LDH-CMC) proved to be a suitable precursor to develop inorganic nanocomposites based on Ni metallic nanoparticles (Ni-MNPs) embedded in a carbonaceous matrix by a bottom-up strategy involving a carbothermal reaction. Considering the temperature effect on the LDH-CMC decomposition processes, as well as the dispersion of metallic and carbon sources at the nanoscale level favoured by the intercalated structure, the simple synthetic approach reported in this work permits fine tuning of the production of valuable phases. The nanocomposites with ordered carbonaceous structures and transition metallic nanoparticles are interesting functional materials for electrocatalysis