MARIA JOSE ALVES DE OLIVEIRA

MARIA JOSE ALVES DE OLIVEIRA

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Preservation of photographic and cinematographic films by electron-beam irradiation
2022 - VASQUEZ, P.A.S.; NAGAI, M.L.E.; OLIVEIRA, M.J.A.; OTUBO, L.; SOMESSARI, E.S.R.
The Nuclear and Energy Research Institute – IPEN through the Multipurpose Gamma Irradiation Facility and the Electron Beam Irradiation Facilities has disinfected several tangible cultural collections from the University of São Paulo – USP. Brazilian weather conditions added to the actions of insects and fungi promote biodegradation especially in cellulose-based materials. In this sense, ionizing radiation is an excellent alternative to the traditional preservation process mainly because the biocidal action. Electron beam irradiation also presents new possibilities for processing materials with greater speed, despite having limited penetration. Adequate storage of photographic and cinematographic materials is a challenge for experts from preservation institutions. Contamination by fungi is one of leading causes of problem in this kind of collections. In addition, another common physicochemical degradation affecting cellulose triacetate films causing deacetylation of polymer chain is called “vinegar syndrome”. In this work are presented results of the effect of the electron beam irradiation on photographic and cinematographic films using an electron beam accelerator with energy of 1.5 MeV and beam power of 37.5 kW. Selected film samples were characterized by FTIR-ATR spectroscopy and FEGSEM-EDS microscopy. Samples were irradiated with absorbed dose between 2 kGy and 200 kGy. Irradiated samples were analyzed by UV-Vis spectrophotometry, FEGSEM, thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). Results showed that disinfection by electron beam radiation can be achieved safely applying radiation absorbed doses between 6 kGy to 10 kGy with no significant change or modification of main properties of the constitutive polymeric materials. Electron beam irradiation, due to the effect of crosslinking is presented as an alternative to treat films affected by “vinegar syndrome” applying absorbed dose of 80 kGy in order to increase shelf life of cultural heritage materials.
New trends and applications of ionizing radiation for preservation of cultural heritage tangible materials
2022 - VASQUEZ, PABLO A.S.; VIEIRA, ANA C.; LIMA, LENI; NAGAI, MARIA L.; KODAMA, YASKO; OLIVEIRA, MARIA J.; SANTOS, PAULO
Disinfection of cultural heritage artefacts and archived materials using ionizing radiation has been successfully applied and accepted by the Brazilian conservation and preservation institutions and community in recent years. Several works of art, museum collections artefacts, books, manuscripts, drawings, archive documents, musical instruments, ethnographic objects, archaeological findings and natural history collections have been decontaminated. Several research studies have been developed addressing the behaviour of cellulosic based materials treated with the ionizing radiation. However, many Brazilian collections have objects made from the most diverse constitutive materials and these are affected by biodeterioration. In order to the effective decontamination of the most diverse types of objects there was a need to establish protocols for care of institutions and individuals carrying cultural and historical collections and for the effective processing by ionizing radiation in the facilities respecting the ethical principles of conservation and restoration covering activities from the problem detection to the final cleaning. Additionally, ionizing radiation has allowed the development of innovative nanostructured cross-linked materials, with applicability in cleaning delicate surfaces. This work presents the most recent results of the effect of ionizing radiation on morphology and physicochemical properties of photographic and cinematographic films, featherwork and botanical collections – exsiccate; as well as the protocols developed as a practical guide for conservatives and professionals of the irradiation for treatment of tangible objects. Preliminary results of nanostructured cross-linked polymeric hydrogels for cleaning surface of artworks obtained by ionizing radiation are also presented. The IAEA sponsored projects have helped to increase the acceptance of nuclear technology by the Brazilian society, especially by the community of restorers, curators and conservators of material cultural goods. The research developed and disseminated with the support of IAEA contributes to the understanding that the cultural heritage is the legacy of physical artefacts and intangible attributes of a group or society that are inherited from past generations, maintained in the present and restored for the benefit of future generations.
Silver nanoparticles-based hydrogels synthetized by ionizing radiation for cleaning of tangible cultural heritage surfaces
2022 - OLIVEIRA, MARIA J.A.; OTUBO, LARISSA; PIRES, ADRIANA; BRAMBILLA , RODRIGO F.; CARVALHO, ANA C.; SANTOS, PAULO S.; OLIVEIRA NETO, ALMIR; VASQUEZ, PABLO
The surfaces of the works of art are one of their most important parts since they interact directly with the observer's perception. On the other hand, they are also in direct contact with physical, chemical and biological agents that can induce degradation and signs of aging. Dust deposits, stains and aged layers of protection can degrade, causing irreversible damage to works of art. In this way, the removal of undesirable materials from artistic surfaces is essential to preserve cultural heritage articles. The aim of this work was to develop silver nanoparticles-based hydrogels and to study the behavior regarding solvent concentration, stability and ability to clean dirt samples based on paper and canvas. The hydrogels were synthesized (reticulated) by gamma rays having the simultaneous formation of silver nanoparticles (AgNP) in the same process. The samples were characterized by swelling tests, attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR), Raman spectroscopy, differential scanning calorimetry (DSC), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and optical microscopy (OM). The results showed the removal of dirt from the paper samples, as well as the softening of the dirt from the canvas, without leaving residues and without affecting the integrity of the art works submitted to treatment.
Poly(vinyl alcohol) (PVAl) and poly(N-2-vinyl-pyrrolidone) hydrogels nanostructured by laponite clay for drug delivery
2022 - OLIVEIRA, MARIA J.A.; SANTOS, VINICIUS J.; FREITAS, LUCAS F. de; LUGAO, ADEMAR B.; PARRA, DUCLERC F.
Hydrogels for wound dressings are usually developed for contact surfaces where mechanical properties are conveniently required. In this sense nanocomposite hydrogels based on PVAl (poly(vinyl alcohol) and PVP (poly(N-2-vinil-pirrolidone)) containing 0.5-1.5 wt% of the synthetic laponite RD clay were prepared by a gamma radiation process and compared with similar membranes composed separately of PVP or PVAl. This study aimed to evaluate the effect of clay on the properties and the differences of the polymer blend instead of a unique polymer. The morphology of the hydrogels was evaluated by spectrometric techniques using XRD (X-ray diffraction), SEM (scanning electron microscopy), swelling assay, and FTIR (infrared spectroscopy). The swelling kinetics at 22 °C and the mechanical properties by a tensile test comprised the structural properties that were assessed. The results showed PVA/PVP network depends directly on the clay concentration in the nanocomposite hydrogels. The blend PVP/PVAl proved to have potentially efficient mechanical properties for drug delivery in the treatment of wounds.
Development of methodologies for decontamination, reuse and improvement of the properties of respiratory protective equipment using ionizing radiation
2020 - VASQUEZ, P.A.S.; MORAIS, F.; LIMA, F.S.; SANTOS, P.S.; MORAES, O.; ARTAXO, P.; JOHN, V.M.; NAGAI, M.L.E.; OLIVEIRA, M.J.A.; CATALANI, L.H.; KODAMA, Y.; OTUBO, L.
Gamma and electron beam irradiation effects for conservation treatment of cellulose triacetate photographic and cinematographic films
2021 - NAGAI, MARIA L.E.; SANTOS, PAULO de S.; OTUBO, LARISSA; OLIVEIRA, MARIA J.A.; VASQUEZ, PABLO A.S.
Photographic and cinematographic films of cellulose triacetate safeguarded in historical and cultural institutions are often contaminated by fungi when stored in inadequate conditions of humidity and temperature. The presence of fungi affects the image contained in the films, accelerates the process of biodeterioration and represents a risk to the health of people working with contaminated materials. In addition, another common physicochemical degradation affecting cellulose triacetate films causing deacetylation of polymer chain is called “vinegar syndrome”. Considering the dose interval established for the disinfection of cultural heritage materials, in this work the effects of irradiation with gamma rays and electron beam on photographic and cinematographic films of cellulose triacetate were evaluated. Additionally, the thermal stability behavior of the films and the feasibility of crosslinking of CTA films were investigated. Film samples were selected and characterized by FTIR-ATR spectroscopy. Irradiated samples by gamma rays and electron beam with radiation absorbed doses between 6 kGy and 200 kGy were examined by FEGSEM microscopy, UV–Vis spectrophotometry and differential scanning calorimetry (DSC). The results showed that disinfection by gamma and electron beam irradiation, in the dose range of 6 kGy–10 kGy, does not change or modification of main properties of the constitutive materials of photographic and cinematographic films. The applied dose of 50 kGy, both gamma rays and electron beam, indicated a crosslinking effect on the films and can be considered a possibility for the treatment of films affected by the “vinegar syndrome”.
Influence of gamma radiation on Amphotericin B incorporated in PVP hydrogel as an alternative treatment for cutaneous leishmaniosis
2021 - OLIVEIRA, MARIA J.A. de; VILLEGAS, GETHZEMANI M.E.; MOTTA, FLAVIA D.; FABELA-SANCHEZ, OMAR; ESPINOSA-ROA, ARIAN; FOTORAN, WESLEY L.; PEIXOTO, JANAINA C.; TANO, FABIA T.; LUGAO, ADEMAR B.; VASQUEZ, PABLO A.S.
Amphotericin B (Amph-B) is an antifungal drug used intravenously for the treatment of leishmaniasis. Side-effects from Amph-B treatment can arise such as cardiac arrhythmia and renal dysfunctions, which will lead to discontinuation of treatment. Unfortunately, patients in endemic countries do not have access to alternative therapies. The objective of this study was to analyze the effects of Cobalt-60 gamma irradiation on crosslinking polymeric hydrogels (Hydg) and the incorporation of Amph-B into the gel as a controlled-release drug delivery alternative. Polyvinylpyrrolidone (PVP)/Amph-B solutions were irradiated with 15 kGy at 0 °C and 25 °C. The drug's stability was ascertained by UV–visible spectrometry, liquid chromatography/mass spectrometry and proton nuclear magnetic resonance. Irradiated Hydg/Amph-B achieved similar stability to the standard Amph-B solution and was enough to promote hydrogel crosslinking. In vitro trials were carried out to ensure Amph-B was still biologically active after irradiation. The results from flow cytometry and MTT assay show that Amph-B had an IC50 = 16.7 nM. A combination of Hydg at 1.324 gmL−1 and Amph-B at 25.1 nM for 24 h lead to the greatest inhibition of L. amazonensis promastigotes, and could be used as an alternative treatment method for cutaneous leishmaniosis.
Effect of gamma radiation cobalt-60 on caffeine
2019 - MAIA, TIAGO C. dos S.; LUGAO, ADEMAR B.; AZOUBEL, ROBERTA; RAPOSO, MARCOS T.; OLIVEIRA, MARIA J.A. de
Objective: The objective of the study was to evaluate the effects of the incidence of gamma radiation of Cobalt-60 on caffeine. Material and Methods: The samples were studied in aqueous solution and powdered form after irradiation at doses: 2, 4, 8, 16 and 32 kGy by ionizing radiation source of 60Co. After wards, they were analyzed by differential scanning calorimetry (DSC), thermogravimetry (TG), and high performance liquid chromatography (HPLC). Results and Discussion: For the DSC technique no changes were observed in the curves after irradiation, which could witness changes in physicochemical properties after irradiation. The TG corroborated with the expected mass loss of caffeine, independent of the action of ionizing radiation. Furthermore, the results obtained by the chromatographic analysis did not show a percentage of caffeine degradation in the dose of the applied radiation when compared to the nonirradiated caffeine. Conclusion: In view of the results obtained, it was possible to observe the stability of caffeine on the influence of gamma radiation on the Cobalt-60 source.
Efeito do CMC no intumescimento de curativos de hidrogel à base de PVP com nanoprata
2019 - ALCANTARA, M.T.S.; OLIVEIRA, M.J.A.; LIERMANN, G.M.; LUGAO, A.B.
Hidrogéis de PVP são redes poliméricas tridimensionais, hidrofílicas, que apresentam propriedades de intumescimento e biocompatibilidade o que favorece seu uso como curativos. Por propiciar umidade no leito da ferida mantém o ambiente ideal para cicatrização, além de não aderir a ela. Por outro lado as nanopartículas de prata apresentam propriedades antimicrobianas e antiinflamatórias e o uso de radiação ionizante permite a reticulação e esterilização simultânea do curativo. O objetivo deste estudo foi avaliar o efeito do CMC no intumescimento de curativos de hidrogel com 22 e 80 ppm de nanopartículas de prata, reticulado por radiação ionizante, assim como avaliar a resistência mecânica dos curativos estudados. Os curativos foram avaliadas a partir de ensaios de fração gel, intumescimento e resistência mecânica. Os resultados indicaram um aumento importante no intumescimento do curativo com a adição de CMC, principalmente para o curativo com maior concentração de nanoprata, porém um menor grau de reticulação e consequentemente redução da sua resistência mecânica.
PVGA/Alginate-AgNPs hydrogel as absorbent biomaterial and its soil biodegradation behavior
2020 - ESTRADA-VILLEGAS, G.M.; MORSELLI, G.; OLIVEIRA, M.J.A.; GONZALEZ-PEREZ, G.; LUGAO, A.B.
PVGA, silver nitrate ( AgNO3) and alginate (Alg) were cross-linked by using γ-ray radiation to obtain Alg/PVGA/AgNPs as a potential biomaterial. The hydrogel composition was characterized by several analytics methods, and the morphology was evaluated by scanning electron microscopy. The swelling behavior was tested in different mediums. The stability of AgNPs was followed by UV–Vis at 400 nm for 1 month. The hydrogel soil biodegradation was analyzed by visual observation, weight loss, Fourier transform infrared spectroscopy and thermogravimetric analysis for 120 days. A simple biodegradation mechanism has been proposed based on results. Additionally, cytotoxicity assays were carried out using NCTC 929 cells to observe cell viability.