PAULO DE SOUZA SANTOS

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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.
Moving toward a sustainable conservation
2022 - VIEIRA, ANA C.D.; SALVADOR, PABLO A.V.; SANTOS, PAULO de S.
Most of the ethnographic collections present in traditional museums in Brazil were formed by collectors, purchases, donations and exchanges by large encyclopedic, naturalist museums, typical of the 19th century. It is in this context, the Museum of Archeology and Ethnology (MAE-USP) collection were constituted. The MAE has been made a big effort to guarantee their conservation. Preservation of tangible objects as well thousands of organic objects, composed of plant fibers, wood, skins, feathers, seeds and various materials, has always been challenging as they are prone to deterioration by biological agents such as insects, mold, bacteria and rodents. Chemical treatments are traditionally examples of actions to preserve many museum collections around the world. Since the 19th century, collectors and museum professionals have applied a variety of toxic substances through fumigations and direct applications trying to enhance the conservation. Although a well-intentioned practice, the application of pesticides to protect ethnographic objects could not predict the negative impact on the safety of those who would handle these objects in the future and by restricting the possibilities of using these collections by the descendants of their creators. Today, these contaminated objects cannot be touched without gloves or experienced by for example, indigenous groups. The current insertion of native communities in curatorial actions at museums has made it possible to renew the way in which these institutions work. At this moment, it is no longer plausible that a museum institution continues to carry out toxic treatments on funerary, sacred objects, human remains, among others. The possession and use of these objects transcend the museum’s borders and the possibilities of use must be considered in the perspective of the future. Due to the renewal of the theoretical parameters of the conservation discipline, the Integrated Pest Management policy is more suitable for museological institutions. Efforts to prevent damage have been more effective than just thinking about curative conservation. In addition, the need to develop a more sustainable present and future has led institutions to develop greener prevention policies, without the use of toxic products, respecting the environment and the user. In this scenario, since 2010, MAE-USP has abolished the use of pesticides to treat the collection. Since then, the institution has been dedicated to building a protocol to reduce risks related to infestations. This protocol encompasses, among other actions, the treatment of objects affected by biological agents and the preventive treatment of new objects through ionizing radiation. The use of ionizing radiation for the disinfestation of museum objects is a very safe process and has proved to be a great alternative to traditional methods of disinfestation that involve pesticides of high persistence and toxicity. For this reason, we have also worked to disseminate the technique among conservators. This work intends to share the actions carried out by MAE-USP in partnership with the Nuclear and Energy Research Institute (IPEN) to facilitate the treatment of ethnographic objects, as well as an important collaborator to make the conservation process at MAE more sustainable.
Gamma radiation processing for disinfection of a 19th century photo album
2022 - NAGAI, M.L.E.; SANTOS, P.S.; PARRON, I.; LEE, F.M.; VASQUEZ, P.A.S.
A 19th century photo album was donated to the Hercule Florence Institute collection. After going through the quarantine, it was discovered that the album was contaminated by anobides. The album was sent for disinfestation treatment by ionizing radiation processing at IPEN. The dose applied was 3 kGy for the immediate eradication of the insects. Colorimetry analysis performed before and after irradiation found that treatment with ionizing radiation did not affect human color perception in the album and the photographs present.
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.
Effects of ionizing radiation decontamination on botanical collections in herbaria
2023 - LIMA, LENI M.P.R.; KODAMA, YASKO; BAITELLO, JOAO B.; OTUBO, LARISSA; SANTOS, PAULO de S.; VASQUEZ, PABLO A.S.
Herbaria collections are very sensitive to attacks from microorganisms and insects. Therefore, preservation strategies and appropriate treatments are essential to manage these artifacts. Decontamination by ionizing radiation has become an effective strategy to preserve cultural heritage objects and archived materials, achieving excellent results. Therefore, this work aimed to study the effects of Co-60 gamma radiation on botanical collections. To accomplish this, samples of exsiccates, including botanical pressed and dehydrated specimens from Asteraceae and Solanaceae families, collected on diferentes dates were selected from the Dom Bento José Pickel Herbarium (SPSF), located in São Paulo (Brazil). Irradiation was performed at the Multipurpose Gamma Irradiation Facility at IPEN, applying absorbed doses of 1 kGy, 6 kGy and 10 kGy. Gamma radiation effect was analyzed using colorimetry with CIELAB color space scale, scanning electron microscopy (SEM) and attenuated total reflectance with Fourier transform infrared (ATR-FTIR) spectroscopy. Results showed no significant colorimetric changes, or changes in the morphological properties of samples, indicating that this decontamination method can be used as an alternative treatment to eliminate insects and micro-fungi of botanical collections without the use of toxic substances.
A radiação ionizante como tecnologia para a inativação de vírus
2022 - ARAUJO, MARCIO M. de; BARREIRA, DAILI A.S.; BRITO, SUSYLEIDE G. de; SANTOS, PAULO de S.; BORRELY, SUELI I.; VASQUEZ, PABLO
Encontrar meios acessíveis e eficientes para inativação de patógenos, e, assim diminuir as consequências maléficas destes para a população, é uma questão que desafia os gestores públicos e a comunidade científica. Diante disso, nosso objetivo foi realizar uma revisão narrativa sobre o histórico do uso da radiação ionizante como tecnologia para inativação viral. Para isso, foram utilizados artigos disponíveis no Google Acadêmico, Scielo, PubMed e Periódicos da CAPES totalizando 35 artigos entre os anos de 1971 e 2022. A radiação ionizante é um método físico que destrói os ácidos nucleicos e inibi a replicação viral, mantendo sua imunogenicidade, sem requerer todas as etapas necessárias para desintoxicar as culturas provenientes de processos químicos, o que facilita o manuseio de antígenos em laboratório de segurança nível 2. Observamos que doses distintas para cada vírus dependente de condições relacionadas ao preparo da amostra, temperatura, umidade, falta de oxigênio, taxa da dose e penetração (estado físico do material); e também ao próprio vírus, como por exemplo o tamanho genômico. A radiorresistência presente nos vírus e esporos bacterianos também foi um fator relevante observado na literatura quanto a esterilização de materiais hospitalares por afetar algumas estruturas poliméricas do polipropileno em máscaras descartáveis, cuja a solução adotada foi a utilização da radiação não ionizante dependente do tempo, a ultra-violeta (UV – C). Portanto, apesar de ser um método mais custoso, a praticidade do processo que é continuo, sem residual e a segurança promovida pela não lisura da embalagem, permite a competitividade da radiação ionizante frente aos métodos existes tanto na esterilização de insumos quanto para produção de vacinas através da inativação viral.
Uso de pele de rã na cicatrização de feridas em equinos
2021 - OLIVEIRA, ANDRESSA B.; FAGUNDES, JESSYCA L.A.; VEADO, HENRIQUE C.; FORTES, BEATRIZ N.A.; BITTENCOURT, ALEXANDRA A.; ADORNO, JOSE; CASTRO, MARCIO B.; VASQUEZ, PABLO A.S.; SANTOS, PAULO S.; DALLAGO, BRUNO S.L.; CAMPEBELL, RITA C.
A pele de rã (Rana catesbeiana) possui peptídeos com ação antimicrobiana, resistência mínima a perda de água e otimiza o processo cicatricial de feridas. Objetivou-se avaliar a cicatrização de feridas experimentais tratadas com pele de rã (GPR), desidratada e esterilizada com raios gama, comparando os achados clínicos e histopatológicos com feridas tratadas com ringer com lactato (GC). Utilizando-se cinco equinos saudáveis, foram realizadas feridas (3 x 3 cm), duas de cada lado da região lombar, distantes 7 cm, incluindo pele e subcutâneo, sendo que um lado foi realizado avaliação clínica e outro histopatológica, aleatoriamente. Durante o período experimental, realizaram-se avaliações e coletas para exame histopatológico nos dias 0, 3, 7, 14 e 21, e curativos diários no GC e troca de pele, a cada 3 dias no GPR. Observou-se o preenchimento total do leito da ferida por tecido de granulação no 14º dia, nos dois grupos e epitelização evidente em ambos grupos no 21º dia. As menores médias das áreas das feridas e as maiores taxas de contração foram observadas no GPR até o 7º dia. No entanto, nas aferições seguintes, o GC apresentou menores médias de área e maiores taxas de contração. Na avaliação histopatológica o GPR apresentou maior fibroplasia e neovascularização precoce até o 7º dia, mas posteriormente, notou-se essas características mais acentuadas no GC. Não foram observadas diferenças estatísticas entre os grupos estudados. De acordo com os resultados obtidos, a pele de rã possui precoce neovascularização e fibroplasia, podendo ser um potencial curativo biológico temporário em equinos.
Gamma radiation processing for disinfection of a 19th century photo album
2021 - NAGAI, M.L.E.; SANTOS, P.S.; PARRON, I.; LEE, F.M.; VASQUEZ, P.
Application of gamma irradiation to conservation
2021 - VIEIRA, ANA C.D.; KODAMA, YASKO; OTUBO, LARISSA; SANTOS, PAULO S.; VASQUEZ, PABLO A.S.; GARCIA, RAFAEL H.L.
Featherwork is one of the most remarkable categories of material culture produced by Brazilian indigenous peoples due to its technical qualities and aesthetic beauty. Weapons, baskets, and musical instruments are frequently decorated with feathers, which are also used in body adornments that, in addition to their aesthetic purpose, are intended to convey information about the wearer, their position within a group, and the cultural values that they wish to transmit. The preservation of this type of artifacts is demanding given the biological cycle of the organic materials that compose them, which are inevitably subject to various stages of deterioration. In addition to the damage resulting from their use and perishable materials, these ethnographic objects are exposed to a new environment when they are incorporated into museum collections, where their existence must be prolonged. Since Brazil’s tropical climate often leads to pest proliferation, their degradation can be exacerbated by the action of insects such as moths and microorganisms such as fungi with irreversible consequences, making their conservation a daily challenge. Although the art of featherwork is still practiced by indigenous communities, the scarce supply of raw materials and contact with the tribes involved has reduced the scale of production. The preservation of this material heritage is thus very important, particularly in ethnographic museums. The use of gamma radiation for the disinfestation of cultural heritage artifacts and archived materials has been shown to be a safe process and an excellent alternative to traditional methods, which usually involve toxic chemical pesticides. Ionizing radiation has been used for more than 40 years and, since 2004, the Multipurpose Irradiator at the Institute of Energy and Nuclear Research (IPEN), a pioneering technology developed in Brazil, has made its application to cultural heritage a reality. With more than 20,000 cultural artifacts irradiated, IPEN is currently the national and international reference center for the use of radiation technology applied to the preservation of cultural heritage collections. Several studies have been conducted to determine the optimal dose required to eliminate contamination by biological agents in organic materials such as wood, leather, and feathers.A maximum dose of 10 kGy is recommended for featherwork in order to avoid affecting the physical and chemical properties of this type of material. This poster reports on the results of the effects of ionizing radiation on the color and morphological properties of a featherwork from the Museum of Archaeology and Ethnology at the University of São Paulo (MAE/USP). Samples of feathers were selected and irradiated with gamma rays at the Multipurpose Gamma Irradiation Facility, applying absorbed doses of between 0.5 and 200 kGy. The samples were chosen according to the color of the feathers and then photographed and analyzed using colorimetry based on the CIELAB 1976 color space scale before and 48 hours after irradiation and scanning electron microscopy. There were no significant changes in morphological and color properties within the disinfestation range applied.
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.