MARIA JOSE ALVES DE OLIVEIRA

MARIA JOSE ALVES DE OLIVEIRA

Página do item completo

Resultados de Busca

Agora exibindo 1 - 10 de 19

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.
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.
Influence of different gamma radiation doses on PVA/gelatin based scaffolds
2017 - OLIVEIRA, JUSTINE P.R. de; OLIVEIRA, MARIA J.A. de; SILVA, ISABELA C. da; VARCA, GUSTAVO H.C.; LUGAO, ADEMAR B.
The present work aimed to study the influence of different radiation doses on a polymer blend at cryogenic and room temperature by means of crosslinking formation, pore size, morphology, topography and mechanical properties. The scaffold was prepared based on two formulations, one composed by gelatin (7%, w/w) and PVA (5%, w/w), and the second by gelatin (10%, w/w) and PVA (5%, w/w). The formulations were separately solubilized in distilled water and heated up to 80 ºC under constant stirring for 1 hour. Posteriorly, both blends were disposed in circular glass moulds. Half of samples was frozen for at least 24 h and then irradiated at 15, 25 and 50 kGy. The other half was cooled at 4 ºC for at least 24 h and then irradiated using the same doses. After irradiation both sample groups were frozen and freeze dried. The scaffold was characterized in terms of structure and morphology by mechanical assays, differential scanning calorimetry, scanning electron microscopy, optical coherence tomography and infrared spectroscopy. In addition, platelet adhesion and release, and cytotoxic assays were also performed. Samples irradiated at 15 kGy presented pore size diameter of around 1.4 μm and porosity of 54%, while samples irradiated at 25 kGy, presented pore size diameter of around 1.1 μm and porosity of 49%. Optical coherence tomography showed that gelatin control samples presented more superficial degradation as irradiation dose increased, while PVA control sample presented higher integrity, indicating that this polymer is less sensitive to gamma radiation. The system presented suitable mechanical properties and the platelet adhesion and release assays showed that the scaffold presented adequate pore size range to host and release the platelets, and non-cytotoxic to platelets, featuring adequate properties to be applied as dressing for wound treatments.
Ionizing radiation for the preservation and conservation of photographic and cinematographic films
2019 - NAGAI, MARIA L.E.; SANTOS, PAULO S.; OTUBO, LARISSA; OLIVEIRA, MARIA J.A. de; VASQUEZ, PABLO A.S.
The Nuclear and Energy research Institute – IPEN-CNEN/SP through the Multipurpose Gamma Irradiation Facility has treated several bibliographical collections of Sao Paulo University-USP for disinfestation and disinfection of contaminated materials with insects and fungi. In this sense, gamma radiation from cobalt-60 is an excellent alternative tool to the traditional preservation process mainly because the biocidal action. Disinfection using gamma radiation for cultural heritage materials has been widely applied around the world in the last decades. Adequate storage of photographic and cinematographic materials is a challenge for conservation 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 effect of ionizing radiation on photographic and cinematographic films. Selected films were characterized by FTIR-ATR spectroscopy and FEGSEM-EDS microscopy. Samples were irradiated by gamma rays 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 gamma rays can be achieved safely applying radiation absorbed doses between 6 kGy and 10 kGy with no change or modification of main properties of the constitutive polymeric materials. Gamma rays due to the effect of crosslinking is presented as an alternative to treat films affected by “vinegar syndrome” applying absorbed dose of 50 kGy in order to increase shelf life of cultural heritage materials.
Effect of gamma irradiation on polymeric gel with glucantime and silver for the alternative treatment of cutaneous leishmania
2018 - OLIVEIRA, M.J.A.; VASQUEZ, P.A.S.; ALCANTARA, M.T.S.; LUGAO, A.B.
The drugs used to treat leishmania are in injectable form and the applications are painful that many patients give up during the treatment. The treatment requires hospitalization to monitor the side effects caused by the drugs, such as cardiac arrhythmia, renal dysfunction, among others. In addition to this situation, if the patient has symptoms such as cardiac arrhythmia, renal dysfunction they can not make use of the treatment. For these reasons finding new forms of treatments with minor side effects as alternative treatments for leishmaniasis has been the object of study of many research laboratories. The objective of this work was to analyze the effects of gamma irradiation on polymeric gel with glucantime and silver as the alternative treatment of cutaneous leishmania. In this case, the polymeric gel prevents the drug from falling directly into the bloodstream, avoiding the side effects, which would make unnecessary the patient's hospitalization. For the development of the gels was used, alginate, polyethylene glycol (PEG), polyvinylpyrrolidone (PVP), laponite clay, silver ions, and glucantime. The cobalt-60 source gamma irradiation was used for gel formation, silver nanoparticles and simultaneous sterilization. The physico-chemical characterizations were elemental analysis for quantification of Sb(V) and Sb(III) antimoniate, infrared spectroscopy (FTIR), dispersive energy spectrometry (EDS), transmission electron microscope (TEM). The results are promising, they show that the irradiation does not interfere with the drug's active principle, as expected in this study.
Hydrogels with silver nanoparticles for wound treatment
2017 - OLIVEIRA, MARIA J.A.; SANTOS, JONNATAN J.; TOMA, SERGIO H.; ALCANTARA, MARA T.S.; VASQUEZ, PABLO A.V.; ARAKI, KOITI; LUGAO, ADEMAR B.
In recent years, the study and preparation of nanoparticles have attracted considerable interest for both fundamental and applied research. In biomedical area, silver nanoparticles have been a vast field of study, although antimicrobial properties have originated from their medical application since 19th century. Since silver has had several uses and its enormous potential for the treatment of injuries. Silver-containing topcoats are an excellent option for topical microbial combat on wounds that present infection, as well as being an essential tool for controlling bacterial load. Among these coatings are the hydrogel dressings with silver nanoparticles that have broad spectrum of antimicrobial action. In vitro studies have demonstrated bactericidal activity in strains of antibiotic resistant microorganisms. The objective of this work is characterize hydrogels with silver nanoparticles, prepared using polyvinylpyrrolidone (PVP), carboxymethylcellulose (CMC), used to treat wounds. A gamma radiation source cobalt-60 was used to crosslink the hydrogels, sterilize and form the silver nanoparticles simultaneously. Irradiation is recognized as a very viable tool because there is no need to add possibly harmful primers or crosslink that are difficult to remove. The results showed uniform distribution of the nanoparticles on the surface of the hydrogels, making it feasible for topical application.
Obtaining of a hydrogel gel dressing of PVP with nanosilver for deep and complex wounds
2017 - ALCANTARA, MARA T.S.; COUTINHO, CAMILA M.; OLIVEIRA, MARIA J.A.; MUNHOZ, MARA M.L.; LUGAO, ADEMAR B.
Introduction Chronic and some acute wounds of difficult treatment that challenge medical and nursing teams are classificadas como Complex wound (Ferreira et al., 2006). Due to the long cicatrization time and successive relapses, cause a problem social on patients' lives and economic a major impact on the health system (Azoubel et al., 2017). Throughout the world there has been a growing interest in the use of hydrogels for application as dressings in view that they are able to maintain the humidity of the wound, favoring the epithelialization of lesions and favoring the relief of pain. On the other hand, silver is an agent that has been used since ancient times, but it has been replaced after the discovery of antibiotics. However, with the advent of bacterial resistance to antibiotics and the development of nanotechnology, it has regained notoriety, since the clinical incidence of silver resistance remains low (Chopra, 2007).In addition to its bactericidal properties, silver nanoparticles (AgNPs) also have anti-inflammatory properties, which, allied to hydrogels’ advantages of maintaining moisture in the wound, represent a great advantage for use as a dressing. However, conventional dressings do not address the need for direct contact with the wound when this is a deep wound. The objective of this work was to obtain a hydrogel gel with silver nanoparticles for wound dressing, synthesized in situ by using ionizing radiation for gelation (crosslinking of PVP-Ag+ aqueous solution), synthesis of the AgNPs and simultaneous sterilization of the final product, able to fill the cavity of deep wounds, thus allowing the direct contact of the dressing with the lesioned walls. Methodology The gel was prepared from the mixture of PVP with plasticizers, water, and silver ions; next, the mixture was irradiated / sterilized by gamma-irradiation from a 60-Co source at a dose of 20 kGy. . Results The result of this work is a viscous and transparent gel (Fig. 1), easy to be applied, able to control pain since it reduces the local temperature due to evaporation of water. Fig. 1 - Hydrogel gel of PVP with silver nanoparticles for wound dressing. The studies are being continued with the aim of evaluating its stability and bactericidal activity.
Influence of gamma radiation on anphotericin b to possible incorporation into wound dressing
2016 - OLIVEIRA, M.J.A.; ESTRADA-VILLEGAS, G.M.; VASQUEZ, P.A.S.; ALCANTARA, M.T.S.; LUGAO, A.B.
In recent decades, many investigations have been addressed to develop alternative non–conventional treatments for several human body burns and wounds as well as new drug delivery systems in the treatment of diseases such as cutaneous leishmaniasis, always aiming to improve the quality of life of patients. Amphotericin B (Amph-B) is an antifungal drug often used intravenously for serious leishmaniasis treatment, but is well known for its severe and potentially lethal side effects. Hydrogels wound-dressing containing (Amph-B) will be able to offer an alternative to some patients that cannot be treated by conventional treatment due to (Amph-B) side effects. Many is these hydrogels are produced by gamma radiation in a simultaneous sterilization and cross-linking process. The hydrogels are useful as a wound-dressings, because they hold the wound moisture, are good as a drug delivery system and low cost production. The aim of this work is show the effects of gamma radiation (60 Cobalt) into (Amph-B) at different irradiation dose (10 kGy, 15kGy and 20kGy) and different temperatures (25ºC, 0ºC and -70ºC) to find the optimum conditions for future incorporation into hydrogels as an alternative treatment of cutaneous leishmaniasis. The study is very important to evaluate the molecule behavior when irradiated. The drug stability will be characterized by High Performance Liquid Cromatography (HPLC), UV-vis and Nuclear Magnetic Ressonance (NMR).
Desenvolvimento de membranas de hidrogel com nanoparticulas de argilas
2014 - SILVA, J.S.; OLIVEIRA, M.J.A.; LUGAO, A.B.; PARRA, D.F.