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Made available in DSpace on 2021-06-25T11:00:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-07-31 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Microencapsulation is a potential biotechnological tool, which can overcome antimicrobial peptides (AMP) instabilities and reduce toxic side effects. Thus, this study evaluates the antibacterial activities of the Ctx(Ile21)-Ha AMP against multidrug-resistant (MDR) and non-resistant bacteria and develop and characterize peptide-loaded microparticles coated with the enteric polymers hydroxypropylmethylcellulose acetate succinate (HPMCAS) and hydroxypropylmethylcellulose phthalate (HPMCP). Ctx(Ile21)-Ha was obtained by solid phase peptide synthesis (SPPS) method, purified and characterized by HPLC and Mass Spectrometry. The peptide exhibited potent antibiotic activities against Salmonella enteritidis, Salmonella typhimurium, Pseudomonas aeruginosa (MDR), Acinetobacter baumannii (MDR), and Staphylococcus aureus (MDR). Ctx(Ile21)-Ha microencapsulation was performed by ionic gelation with high efficiency, maintaining the physical-chemical stability. Ctx(Ile21)-Ha coated-microparticles were characterized by DSC, TGA, FTIR-Raman, XRD and SEM. Hemolytic activity assay demonstrated that hemolysis was decreased up to 95% compared to single molecule. In addition, in vitro release control profile simulating different portions of gastrointestinal tract was performed and showed the microcapsules' ability to protect the peptide and release it in the intestine, aiming pathogen's location, mainly by Salmonella sp. Therefore, use of microencapsulated Ctx(Ile21)-Ha can be allowed as an antimicrobial controller in monogastric animal production as an oral feed additive (antimicrobial controller), being a valuable option for molecules with low therapeutic indexes or high hemolytic rates. São Paulo State University (Unesp) School of Agricultural and Veterinarian Sciences, Jaboticabal São Paulo State University (Unesp) Institute of Chemistry, Araraquara São Paulo State University (Unesp) School of Sciences and Engineering, Tupã São Paulo State University (Unesp) School of Pharmaceutical Sciences, Araraquara São Paulo State University (Unesp) School of Technology and Sciences, Presidente Prudente Poultry Health Specialized Laboratory Biological Institute, Bastos Institute of Microbiology and Infection University of Birmingham School of Chemistry University of Birmingham São Paulo State University (Unesp) School of Agricultural and Veterinarian Sciences, Jaboticabal São Paulo State University (Unesp) Institute of Chemistry, Araraquara São Paulo State University (Unesp) School of Sciences and Engineering, Tupã São Paulo State University (Unesp) School of Pharmaceutical Sciences, Araraquara São Paulo State University (Unesp) School of Technology and Sciences, Presidente Prudente FAPESP: 2016/00446-7

Manganese oxides were synthesized during 40 min at 140 ºC via Microwave-Assisted Hydrothermal (MAH) method and treated at different temperatures in order to evaluate the phase evolution using structure refinement (Rietveld method). The samples obtained were heat treated at temperatures defined by means of thermal analysis (160 ºC, 480 ºC, 715 ºC, 870 ºC, 920 ºC and 1150 ºC) and analyzed by X-Ray Diffractometry (XRD), X-Ray Fluorescence (XRF), Fourier Transform Infrared (FTIR) spectroscopy, Raman scattering, UV-Vis absorption and Scanning Electron Microscopy (SEM). Structural characterizations allowed to identify five distinct phases: α-MnO2, Mn3O4, Mn5O8, Na2Mn5O10 and Na4Mn9O18 with weight percentages dependent on the heat treatment. The hausmannite structure (average crystallite size ranging from 28.9 nm to 99.1 nm) is present in all samples and go through various oxidation and reduction processes from 160 ºC to 1150 ºC without any major variation in the lattice parameters. Chemical characterizations identifies the presence of Na+ ions in all samples, either as substitution defects or as components of specific crystalline structures (Na2Mn5O10 and Na4Mn9O18), showing that the synthesized manganese oxides works as Na+ intercalation compounds, important materials for energy storage devices optimization. The results presented enables a better interpretation of the thermal and structural characteristics of manganese oxides synthesized via MAH.

Made available in DSpace on 2022-04-29T08:32:04Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Glass-ceramic materials were obtained by heat treatment (960°C for 2, 4, and 6 hs) of glasses with CaCO3 47.50 wt%-TiO2 23.75 wt%-SiO2 23.75-Al2O3 5.00 wt% formulation produced by the melt-quenching technique (melting at 1650°C and subsequent annealing at 650°C). The materials' structural characterization and crystallization kinetics (Kissinger method) indicate the presence of CaTiO3, CaSiO3, and CaTiSiO5 crystalline phases with activation energies 217, 281, and 446 kJ/mol, respectively. The structure refinement (Rietveld method) suggests metastability for the CaSiO3 and CaTiSiO5 phases as a function of the heat treatment time. The increase in time favors CaTiO3 crystallization, from 62.97 wt%, in the 2 hs treated sample, to 79.21 wt%, in the 6 hs treated sample. EDS and microstructure analyses confirm the glass-ceramic production and indicate segregation of the CaTiO3 phase for longer heat treatment times. Universidade Estadual Paulista (UNESP) Faculdade de Ciências e Tecnologia Departamento de Física Universidade Estadual Paulista (UNESP) Faculdade de Ciências Departamento de Química Universidade Estadual Paulista (UNESP) Faculdade de Ciências e Tecnologia Departamento de Física Universidade Estadual Paulista (UNESP) Faculdade de Ciências Departamento de Química

Made available in DSpace on 2021-06-25T11:14:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Since the optical and electrical properties of organic thin films devices depend on their supramolecular arrangement and the molecular chemical structure, the understanding of such characteristics is essential for the optimization of these devices. In this study, we determine the supramolecular arrangement of thin films produced using the Langmuir-Schaefer (LS) technique and explain how its supramolecular arrangement is affected by the molecular chemical structure using two perylene derivatives: bis-butylimide (BuPTCD) and bis-phenethylimide (PhPTCD). The optical absorption measurements reveal that both films grow homogeneously and indicate that the presence of H aggregates (forbidden emission) is higher for BuPTCD LS film than for PhPTCD LS film. Atomic force microscopic analysis shows that the PhPTCD LS film is rougher than the BuPTCD film. In addition, FTIR analyses indicate that both films have head-on molecular organization. XRD patterns reveal that both the BuPTCD LS film and the PhPTCD LS film are crystalline, but that crystallinity is more prevalent in the BuPTCD LS film. Thus, the results show that the difference presented in the chemical structures leads the films to have different supramolecular arrangements, with consequences for their optical properties. School of Technology and Applied Sciences São Paulo State University (UNESP) School of Technology and Applied Sciences São Paulo State University (UNESP)

Manganese oxides were synthesized during 40 min at 140 ºC via Microwave-Assisted Hydrothermal (MAH) method and treated at different temperatures in order to evaluate the phase evolution using structure refinement (Rietveld method). The samples obtained were heat treated at temperatures defined by means of thermal analysis (160 ºC, 480 ºC, 715 ºC, 870 ºC, 920 ºC and 1150 ºC) and analyzed by XRD, XRF, FTIR spectroscopy, Raman scattering and SEM. Structural characterizations allowed to identify five distinct phases: α-MnO2, Mn3O4, Mn5O8, Na2Mn5O10 and Na4Mn9O18 with weight percentages dependent on the heat treatment. The hausmannite structure (average crystallite size ranging from 28.9 nm to 99.1 nm) is present in all samples and go through various oxidation and reduction processes from 160 ºC to 1150 ºC without any major variation in the lattice parameters. The results presented enables a better interpretation of the thermal and structural characteristics of manganese oxides synthesized via MAH.

Made available in DSpace on 2021-07-14T10:26:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-10-30. Added 1 bitstream(s) on 2021-07-14T11:30:02Z : No. of bitstreams: 1 S0366-69132020000400413.pdf: 1427762 bytes, checksum: 101c416ef2eff63ec6e1bcc4c1cc8722 (MD5) A reciclagem tem sido apontada como alternativa ao descarte de resíduos em aterros industriais. No presente trabalho é mostrada a transformação de resíduos (areia descartada de fundição - ADF, grits e lama de cal) em materiais vitrocerâmicos. Os vidros foram obtidos pelo método de fusão/resfriamento. Os materiais precursores, compostos vítreos e vitrocerâmicos foram caracterizados pelas técnicas de difração de raios X (DRX), fluorescência de raios X (FRX) e calorimetria exploratória diferencial/análise termogravimétrica (CED/ATG). Os materiais vítreos foram moídos, pastilhados e tratados termicamente nas temperaturas de cristalização obtidas por CED para preparar os materiais vitrocerâmicos (885, 961 e 1090 ºC). As fases obtidas foram cristobalita, α-wolastonita (parawolastonita) e β-wolastonita (pseudowolastonita). As vitrocerâmicas apresentaram baixa absorção de água e porosidade aparente (0,26 até 0,88 wt% e 0,66 até 1,77 vol%, respectivamente). Os resultados confirmaram que os resíduos estudados podem ser utilizados como matéria-prima na fabricação de materiais vítreos e vitrocerâmicos. Recycling has been pointed out as an alternative to the disposal of waste materials in industrial landfills. In the present study, the transformation of residues (discarded foundry sand - DFS, grits, and lime mud) in glass-ceramic materials is shown. The glasses were obtained by the melting/cooling method. The precursor materials, glasses, and glass-ceramics were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), and differential scanning calorimetry/thermal gravimetric analysis (DSC/TGA). The glassy materials were milled, pelleted, and thermally treated at the crystallization temperatures given by DSC data to obtain the glass-ceramics (885, 961, and 1090 ºC). The main formed phases were cristobalite, α-wollastonite (parawollastonite), and β-wollastonite (pseudowollastonite). The glass-ceramics showed very low water absorption and apparent porosity (0.26 to 0.88 wt% and 0.66 to 1.77 vol%, respectively). The results confirmed that the studied residues can be used as raw materials for the manufacture of vitreous and glass-ceramic materials. Universidade Estadual Paulista, Faculdade de Ciências e Tecnologia Universidade do Oeste Paulista, Faculdade de Engenharia e Arquitetura Universidade Estadual Paulista, Faculdade de Ciências e Tecnologia

Made available in DSpace on 2020-12-12T02:13:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-10-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Instituto Nacional de Ciência e Tecnologia em Eletrônica Orgânica Universidade Estadual Paulista Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Transitions from the singlet electronic excited states higher than S1 level (S2) to the fundamental state (S0) are unlikely, although such transitions are observed for perylene derivative compounds. This rareness led us to investigate the role of the molecular structure of two perylene derivatives (bis(butylimido) – BuPTCD and bis(phenetylimido) – PhPTCD), as well as their supramolecular arrangements, such as molecular organization, crystallinity, and molecular aggregates (before and after thermal treatment) on the radiative transition S2→S0. The emission spectra of BuPTCD and PhPTCD solutions (monomers) indicated that differences in their molecular structures (lateral groups) do not influence such transitions. Besides, it was verified that the relative intensity (RI) S1→S0 over S2→S0 (RI = IS1→S0/IS2→S0) obtained for BuPTCD and PhPTCD PVD films increases around 15 and 1.5, respectively (in comparison to their respective solutions). However, it was surprising to observe a decrease of RI = IS1→S0/IS2→S0 by a factor of 88 for both BuPTCD and PhPTCD PVD films after their thermal treatment at 200 °C for 2 h. The latter led to an increase of the emission intensity from S2→S0 transition in relation to S1→S0. The decrease of H aggregates, presence of J aggregates and formation of other types of molecular aggregates, induced by thermal treatment, seem to be the cause of the S2→S0 emission increase, which is supported by theoretical calculations. São Paulo State University (UNESP) School of Technology and Applied Sciences São Paulo State University (UNESP) Campus of Itapeva São Paulo State University (UNESP) School of Technology and Applied Sciences São Paulo State University (UNESP) Campus of Itapeva FAPESP: 2013/14262–7 FAPESP: 2016/09633–4 CNPq: 420449/2018–3 CNPq: 448310/2014–7

Made available in DSpace on 2021-06-25T10:10:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-16 Pt/Al2O3La2O3 catalysts were prepared by a “one-pot” sol–gel method, with different final synthesis temperatures. The catalysts were characterized by in situ X-ray absorption spectroscopy (XAS). The partial oxidation of methane (POM) reaction was used to evaluate catalyst stability. DRIFTS-CO analysis indicated the interaction of Pt with the support by Pt-O-(Al-O, La-O) bonds, which suppressed bridge CO adsorption. In situ POM-DXAS-MS analysis showed that after use in the POM reaction at about 1000 K and cooling to room temperature, the Pt/Al2O3La2O3 catalysts presented partial oxidation of Pt0, indicating the formation of a core–shell structure. The nanoparticles generated using the “one-pot” method showed higher Pt-O-Al type interaction with the support, relative to free Pt-O at the surface, resulting in high resistance to sintering in the POM reaction. The temperature used in the “one-pot” synthesis significantly influenced the Pt-O-Al interaction, which modified the resistance to sintering at 1073 K in air. São Paulo State University (UNESP) Department of Chemistry Science Faculty Av. Eng. Luiz Edmundo Carrijo Coube, 14-01 São Paulo State University (UNESP) Department of Physics Federal University of São Carlos (UFSCar) Department of Chemistry, C.P. 676 Federal University of São Carlos (UFSCar) Department of Chemical Engineering, C.P. 676 São Paulo State University (UNESP) Department of Chemistry Science Faculty Av. Eng. Luiz Edmundo Carrijo Coube, 14-01 São Paulo State University (UNESP) Department of Physics