Abstract: O objetivo deste artigo é analisar a divulgação do índice do PIB brasileiro, divulgado em 2022, como exemplo do que pode se chamar “fake news oficial”, onde a confiabilidade do emissor se sobrepõe ao caráter factível e plausível da informação, necessárias ao fato real. Para isso se baseia nas teorias de Castell, das relações de poder nos processos de comunicação socializada e da desordem da informação.

Palavras-Chave: communications; information dissemination; public information; knowledge management; gross domestic product

SANTOS, RAPHAEL A.V. dos; SARKIS, JORGE E. de S.; ANDRADE, DELVONEI A. de. Fake news oficial: um exemplo do uso da notícia emfalso contexto na sociedade em rede. Cuadernos de Educación y Desarrollo, v. 15, n. 6, p. 5782-5803, 2023. DOI: 10.55905/cuadv15n6-049. Disponível em: http://repositorio.ipen.br/handle/123456789/34227. Acesso em: $DATA.

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Abstract: The AA 2198-T851 is a third-generation Al-Li alloy developed for use in the aircraft industry. Al-Li alloys are susceptible to localized corrosion due to their complex microstructure resulting from the used thermomechanical treatment. In order to prevent localized corrosion, these alloys are usually protected by anodizing in order to avoid a corrosive environment. Subsequently, for anodizing, a sealing treatment is usually performed for parts. Some sealing treatments use hexavalent-chromiumion-containing solutions. In this investigation, a chromium-free sealing treatment in a solution with cerium ions has been carried out, and the effect on the corrosion resistance of the AA2198-T851 alloy was investigated. Hydrothermally sealed or unsealed samples were also tested for corrosion resistance for comparison reasons. The corrosion resistance of the anodized aluminum alloy, either hydrothermally sealed or in a cerium-ion-containing solution, was evaluated in a sodium chloride solution by electrochemical impedance spectroscopy as a function of immersion time. The samples sealed in a cerium-containing solution increased their corrosion resistance when compared to the hydrothermally sealed. The effectiveness of the sealing process with cerium that was observed in the electrochemical tests indicated that after the corrosive attack of the barrier layer, there was a “sealing” process of the sample surface.

Palavras-Chave: corrosion resistance; tartaric acid; sulfuric acid; anodization; cerium ions

QUEIROZ, FERNANDA M.; BUGARIN, ALINE de F.S.; AYUSSO, VICTOR H.; TERADA, MAYSA; COSTA, ISOLDA. Investigation on the Effect of a Chromium-Free Sealing Treatment for the Corrosion Resistance of AA2198-T851 after Tartaric Sulphuric Anodizing (TSA). Corrosion and Materials Degradation, v. 4, n. 2, p. 331-344, 2023. DOI: 10.3390/cmd4020017. Disponível em: http://repositorio.ipen.br/handle/123456789/34225. Acesso em: $DATA.

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Abstract: This paper presents a comparison of traditional thermal and chemical reduction methods with more recent ionizing radiation reduction via gamma rays and electron beams (e-beams). For GO, all synthesis protocols were adapted to increase production scale and are a contribution of this work. The typical Raman D-band of the GO was prominent (ID/IG ratio increased sixfold). When comparing the GO reduction techniques, dramatic differences in efficiency and GO particle characteristics were observed. Although thermal and chemical reduction are effective reduction methods, as shown through the use of FTIR spectroscopy and the C/O ratio from EDS chemical analysis, the thermal process renders great weight losses, whereas chemical processing may involve the use of hazardous chemical compounds. On the other hand, comparing the gamma rays and e-beam for 80 kGy, the Raman spectra and chemical analysis suggested that the e-beam caused a greater GO reduction: C/O ratio from EDS of 5.4 and 4.1, respectively. In addition to being fast and effective, ionizing radiation reduction processes allow easier control of the reduction degree by adjusting the radiation dose. When the dose increased from 40 to 80 kGy, the Raman spectra and EDS showed that the ID/IG and C/O ratios increased by 15 and 116%, respectively.

Palavras-Chave: graphene; oxides; chemical preparation; chemical reactions; electron beams; radiations; reduction

BARROS, NATALIA G. de; GONZAGA NETO, ABEL C.; VACCIOLI, KLEBER B.; ANGULO, HUGO R.V.; SILVA, LEONARDO G de A. e; TOFFOLI, SAMUEL M.; VALERA, TICIANE S. Graphene oxide: a comparison of reduction methods. C-Journal of Carbon Research, v. 9, n. 3, p. 1-17, 2023. DOI: 10.3390/c9030073. Disponível em: http://repositorio.ipen.br/handle/123456789/34223. Acesso em: $DATA.

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Abstract: Paint is a prevalent type of surface of coating well known to most people. It is an easy-to-apply product, with excellent physical and chemical resistance and a wide range of applications. The function of a paint is to protect and beautify amongst other properties. Paints are formed using five components: resin, pigments, fillers, solvents and additives. This work deals with a specific type of paint, composed of a water-based acrylic emulsion, whose film formation is by coalescence and used to coat walls and other surfaces. The aim of this innovative research was to evaluate the effect of the addition of cellulosic dispersion of waste paper tissues treated by electron beam irradiation to an acrylic emulsion-based paint. The methodology used was a case study carried out at the Nuclear and Energy Research Institute that consisted of adding aqueous dispersions of cellulosic wipes with mass concentrations varying from 0.1% to 10% in deionized water, and treated by electron beam processing with absorbed doses from 5 kGy to 50 kGy. The results obtained followed the parameters of the Abrafati Sectorial Quality Program. The main sample parameters analyzed were specific density, which reached an average of 1.35 g/cm3 ; and covering power, whose value of 93.55% was above the specified limit (minimum of 90%). Among other results obtained, improvements in appearance, applicability and functionality were significant. It was concluded that this research constitutes an incremental improvement to the acrylic emulsion paints segment, and environmental sustainability, through the reuse of cellulosic tissue residues.

NASCIMENTO, F.C.; MUNHOZ, P.M.; NASCIMENTO, L.F.N.; CALVO, W.A.P. Development of an acrylic emulsion paint added with cellulosic dispersion treated with an electron beam accelerator. Brazilian Journal of Radiation Sciences, v. 11, n. 3, p. 1-18, 2023. DOI: 10.15392/2319-0612.2023.2291. Disponível em: http://repositorio.ipen.br/handle/123456789/34221. Acesso em: $DATA.

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Abstract: Flue gas desulfurization (FGD) waste is an industrial by-product generated during the flue gas desulfurization process in coal-fired power plants. This by-product contain trace quantities of naturally occurring radionuclides and elements such as As, Ba, Co, Cr, Zn. The characteristics of FGD waste are important for its reuse and are mainly depend on the desulfurization process. In this work, two types of FGD materials collected from three coal-fired power plants using semi-dry and wet processes were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), X-ray fluorescence (XFR) and particle size analysis. The radioactive content of 238U, 232Th, 228Th, 226Ra, 228Ra, 210Pb and 40K and trace elements were also determined using Neutron activation analysis and Gamma-ray spectrometry. The major constituents for all samples were Ca, Si, S, Al and Fe. Wet FGD by-product presented also high magnesium content. The wastes contain mainly semi-hydrate calcium sulfite and calcium sulfate. The particle size of FGD from semi-dry process was lower than that from the wet process. The average activity concentration of 238U, 232Th, 226Ra, 210Pb, 228Ra, 228Th and 40K varied between were 50-71, 33-42, 28-52, 113-150, 26-33, 33-39, 161-390 Bq kg-1 , respectively. According to the results of leaching and solubilization tests, FGD samples were classified as non-hazardous and non-inert. The obtained data are useful for evaluation of possible applications of FGD by-products

Palavras-Chave: by-products; calcium sulfates; calcium sulfides; coal; combustion; desulfurization; elements; flue gas; industrial wastes; particle size; trace amounts

FUNGARO, D.A.; GROSCHE, L.C.; SILVA, P.S.C. Physicochemical and radiological characterization of flue gas desulfuration waste samples from Brazilian coal-fired power plants. Brazilian Journal of Radiation Sciences, v. 11, n. 2, p. 1-18, 2023. DOI: 10.15392/2319-0612.2023.2275. Disponível em: http://repositorio.ipen.br/handle/123456789/34219. Acesso em: $DATA.

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Abstract: This work aimed to analyze the fungal contamination of air-conditioning filter waste (n=15) as an indicator of Quality Air Indoor from different car models in São Paulo city in São Paulo State, Brazil, during the period from October 2018 to July 2019. Three different treatments were used for the decontamination of car air conditioning filters, such as mechanical vacuum cleaning (I), vacuum cleaning and use of sanitizing product (II), and sanitizing product associated with radiation treatment at a dose of 17 kGy (III). After the treatments, microbiological analyses were performed and samples were plated in Petri dishes containing Sabouraud agar transferred by Swabs, and incubated for 7 days at 25 °C. The Petri dishes were stored in a standard Biochemical Oxygen Demand incubator, for the growth of fungal cultures. After incubation, the fungal cultures were evaluated, and the fungal counting was expressed in unit-forming colonies (UFC) and frequency in samples (%). The fungi were examined by lactophenol blue solution staining for microscopy. All samples of treatment I and II were contaminated with various fungal genera and high bioburden, namely (treatment I) Alternaria alternata, Aspergillus flavus, A. niger, Cladosporium spp., Fusarium spp., Mucor spp., Nigrospora spp., Not Sporulated Fungi (NSF), Penicillium spp., Rhizopus spp., Rhodotorula spp., Trichoderma spp. and yeasts. Treatment II showed Alternaria alternata, Aspergillus flavus, A. fumigatus, A. niger, A. ochraceus, Cladosporium spp., Mucor spp., NSF, Penicillium spp., Phoma spp., Rhizopus spp., Rhodotorula spp., Trichoderma spp., and yeasts. Treatment III presented NSF and yeasts, with 80% of material decontamination.

Palavras-Chave: absorbed radiation doses; air conditioners; air conditioning; cryogenics; environmental quality; fungi; heating; indoor air pollution; irradiation; pollutants; radiation doses; vehicles

AQUINO, S.; LIMA, J.E.A.; BORRELY, S.I. Combined application of gamma radiation, cleaning and chemical sanitizers in decontamination of vehicle air conditioning filters. Brazilian Journal of Radiation Sciences, v. 11, n. 2, p. 1-11, 2023. DOI: 10.15392/2319-0612.2023.2244. Disponível em: http://repositorio.ipen.br/handle/123456789/34217. Acesso em: $DATA.

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Abstract: The activimeter calibration has the purpose of ensure greater reliability in measurement results, hence the activimeters used are commonly installed in controlled areas and, in some cases, with difficult access. The activimeter “in situ” calibration methodology presented in this work allows its execution only with the displacement of the radioactive samples and not of the activimeter itself, which simplifies the procedure of nuclear medicine services and at radiopharmaceuticals production centers, without affecting the quality and accuracy of measurements. After the application of the methodology by qualified technicians, the obtained results of the tested activimeters showed its importance since the calibration factors can present correction of up to 5% for 111In and greater than 5% for 123I.

Palavras-Chave: calibration; activity meters; measuring methods; in-situ processing

MARTINS, E.W.; POTIENS, M.P.A. Activimeter “in situ” calibration methodology to 111In and 123I. Brazilian Journal of Radiation Sciences, v. 11, n. 1A, p. 1-9, 2023. DOI: 10.15392/2319-0612.2023.2212. Disponível em: http://repositorio.ipen.br/handle/123456789/34215. Acesso em: $DATA.

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Abstract: The unbridled use of antimicrobial drugs over the last decades contributed to the global dissemination of drug-resistant pathogens and increasing rates of life-threatening infections for which limited therapeutic options are available. Currently, the search for safe, fast, and efective therapeutic strategies to combat infectious diseases is a worldwide demand. Antimicrobial photodynamic therapy (APDT) rises as a promising therapeutic approach against a wide range of pathogenic microorganisms. APDT combines light, a photosensitizing drug (PS), and oxygen to kill microorganisms by oxidative stress. Since the APDT feld involves branches of biology and physics, the strengthening of interdisciplinary collaborations under the aegis of biophysics is welcome. Given this scenario, Brazil is one of the global leaders in the production of APDT science. In this review, we provide detailed reports of APDT studies published by the Laboratory of Optical Therapy (IPEN-CNEN), Group of Biomedical Nanotechnology (UFPE), and collaborators over the last 10 years. We present an integrated perspective of APDT from basic research to clinical practice and highlight its promising use, encouraging its adoption as an efective and safe technology to tackle important pathogens. We cover the use of methylene blue (MB) or Zn(II) porphyrins as PSs to kill bacteria, fungi, parasites, and pathogenic algae in laboratory assays. We describe the impact of MB-APDT in Dentistry and Veterinary Medicine to treat diferent infectious diseases. We also point out future directions combining APDT and nanotechnology. We hope this review motivates further APDT studies providing intuitive, vivid, and insightful information for the readers.

Palavras-Chave: antimicrobial agents; methylene blue; inactivation; photodynamic therapy; photosensitivity; porphyrins; zinc

CABRAL, FERNANDA V.; SOUZA, TIAGO H. dos S.; SALLERA, FABIO P.; FONTES, ADRIANA; RIBEIRO, MARTHA S. Strengthening collaborations at the Biology‑Physics interface: trends in antimicrobial photodynamic therapy. Biophysical Reviews, v. 15, n. 4, p. 685-697, 2023. DOI: 10.1007/s12551-023-01066-5. Disponível em: http://repositorio.ipen.br/handle/123456789/34213. Acesso em: $DATA.

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Abstract: : Air pollution in the Metropolitan Area of São Paulo (MASP), Brazil, is a serious problem and is strongly affected by local sources. However, atmosphere column composition in MASP is also affected by biomass burning aerosol (BB). Understanding the impacts of aerosol particles, from both vehicles and BB, on the air quality and climate depends on in-depth research with knowledge of some parameters such as the optical properties of particles and their chemical composition. This study characterized fine particulate matter (PM2.5) from July 2019 to August 2020 in the eastern part of the MASP, relating the chemical composition data obtained at the surface and columnar optical parameters, such as aerosol optical depth (AOD), Ångström Exponent (AE), and single-scattering albedo (SSA). According to the analyzed data, the mean PM2.5 concentration was 18.0 ± 12.5 µg/m3 ; however, daily events exceeded 75 times the air quality standard of the World Health Organization (15 µg/m3 ). The mean black carbon concentration was 1.8 ± 1.5 µg/m3 in the sampling period. Positive matrix factorization (PMF) identified four main sources of aerosol: heavy vehicles (42%), followed by soil dust plus local sources (38.7%), light vehicles (9.9%), and local sources (8.6%). AOD and AE presented the highest values in the dry period, during which biomass burning events are more frequent, suggesting smaller particles in the atmosphere. SSA values at 440 nm were between 0.86 and 0.94, with lower values in the winter months, indicating the presence of more absorbing aerosol.

Palavras-Chave: particulates; air pollution; air quality; urban areas; aerosols; optical properties

VIEIRA, ERICK V.R.; ROSARIO, NILTON E. do; YAMASOE, MARCIA A.; MORAIS, FERNANDO G.; MARTINEZ, PEDRO J.P.; LANDULFO, EDUARDO; MIRANDA, REGINA M. de. Chemical characterization and optical properties of the aerosol in São Paulo, Brazil. Atmosphere, v. 14, n. 9, p. 1-21, 2023. DOI: 10.3390/atmos14091460. Disponível em: http://repositorio.ipen.br/handle/123456789/34211. Acesso em: $DATA.

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Abstract: The procedure followed by the Nuclear Metrology Laboratory (LMN) at the IPEN for the primary standardization of a ( 243Am + 239Np) solution, in secular equilibrium, is described. The measurement was carried out in a 4π(PC) (α,β)− γ coincidence system. The total activity per unit mass of the solution was determined by the extrapolation technique, using a software coincidence counting systsem. The extrapolation curves were compared with Monte Carlo calculations by means of Code ESQUEMA, used in previous works, which, was improved and applied in order to calculate the alpha, beta, gamma, X-rays and coincidence spectra.

Palavras-Chave: americium 243; neptunium 239; coincidence methods; monte carlo method

KOSKINAS, MARINA F.; MOREIRA, DENISE S.; YAMAZAKI, IONE M.; COLONNO, MARCELO; SEMMLER, RENATO; MORAIS, THALES S.L.; DIAS, MAURO S. Primary standardization and Monte Carlo modeling of ( 243Am + 239Np) by means of a 4π(PC)-γ coincidence counting system. Applied Radiation and Isotopes, v. 202, p. 1-7, 2023. DOI: 10.1016/j.apradiso.2023.111070. Disponível em: http://repositorio.ipen.br/handle/123456789/34209. Acesso em: $DATA.

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Abstract: The objective of this work was to investigate the luminescent properties of CaSO4:Mn synthesized by slow evaporation route. The crystalline structure, morphology, thermal and optical properties of the phosphors were characterized by X-ray diffraction analysis (XRD), Scanning electron microscopy (SEM), photoluminescence (PL) and thermogravimetric analysis (TGA). Moreover, using thermoluminescence (TL) and optically stimulated luminescence (OSL) techniques, the dosimetric properties of the phosphors, such as emission spectra, glow curve reproducibility, dose-response linearity, fading of the luminescent signal, variation of the TL intensity with the heating rate, OSL decay curves, correlation between TL and OSL emissions and minimum detectable dose (MDD) were comprehensively investigated. For dosimetric analyses, the samples were irradiated with doses from 169 mGy to 10 Gy. The emission band fits with the characteristic line of the Mn2+ emission features, ascribed to 6 A1→4 T1 transition. CaSO4:Mn pellets present a TL glow curve with a single typical peak centered around 494 nm, an OSL decay curve with predominance of a fast decay component, and a MDD on the order of mGy. The luminescent signals showed to be linear and reproducible in the studied dose range. The trapping centers located between 0.83 eV and 1.07 eV were revealed for different heating rates in the TL study. The high TL sensitivity of CaSO4:Mn was proven when comparing with commercially available dosimeters. The luminescent signals exhibit a smaller fading than described in the literature for CaSO4:Mn produced by other methods.

Palavras-Chave: calcium sulfates; comparative evaluations; decay; diagrams; dosemeters; emission spectra; evaporation; glow curve; heating rate; irradiation; manganese ions; optical properties; phosphors; photoluminescence; radiation doses; thermal gravimetric analysis

SILVA, ANDERSON M.B.; RODRIGUES, DANIEL S.; ANTONIO, PATRICIA L.; JUNOT, DANILO O.; CALDAS, LINDA V.E.; SOUZA, DIVANIZIA N. Investigation of dosimetric properties of CaSO4:Mn phosphor prepared using slow evaporation route. Applied Radiation and Isotopes, v. 199, p. 1-9, 2023. DOI: 10.1016/j.apradiso.2023.110874. Disponível em: http://repositorio.ipen.br/handle/123456789/34207. Acesso em: $DATA.

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Abstract: Currently, there are six Generation IV nuclear reactor designs in development. Four are fast neutron reactors, and all designs operate at higher temperatures that permit hydrogen production. Thus, the interest in fluoride salts has grown due to their hightemperature application in fission and fusion reactor designs. The aircraft propulsion project was the initial plan, which used molten salt as a coolant and was started by Bettis and Briant in the 1940s. The molten salt reactor has been designed to operate at temperatures of 700 to 800°C with fissile material dissolved in a molten fluoride salt composition. Molten fluoride salts are stable at high temperatures, show good thermodynamic properties, and can also dissolve actinides and fission products easily. It creates a candidate for a thorium reactor with more than 45% efficiency. The purpose of this work was to investigate the physical characteristics of two systems of fluoride salt combinations, namely LiF-BeF2 (FliBe) and LiF-NaF-KF (FliNaK), including melting temperature, density, and heat capacity. The aim is to characterize the advantages of the various designs proposed for Generation IV by reviewing properties evidenced by safety improvements and limitations.

Palavras-Chave: molten salt reactors; flibe; sodium fluorides; potassium fluorides; thorium reactors

GOMES, DANIEL de S. Overview of the physical properties of molten salt reactor using FLiBe. Journal of Engineering Research, v. 3, n. 36, p. 1-12, 2023. DOI: 10.22533/at.ed.3173362325107. Disponível em: http://repositorio.ipen.br/handle/123456789/34205. Acesso em: $DATA.

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Abstract: The sediments were collected from paleodunes, river terraces, islands, and sand bars at Mariuá Archipelago, Rio Negro, Brazil. XRD analysis revealed that quartz is the predominant mineral along with a trace quantity of kaolinite. Neutron activation analysis of the sediments revealed the assembly of rare-earth elements, metals and semi-metals. The values of U and Th were found to be 3–5 ppm in paleodunes and 9–16 ppm in terraces, and K-40 concentration is below detectable limit. The OSL of quartz (dune) is composed of three components with decay times of 0.2, 11.0 and 350 s, respectively. This OSL emission is related to the TL peaks below 380 °C. Also, photo-transferred TL is observed in the temperature range of 190–250 °C for a blue stimulation of 500 s. TL peaks kinetic parameters were calculated and discussed. The lifetimes of TL peaks at 272 and 355 °C are approximately 4.0×104 and 1.5×109 years, respectively. Using the conventional SAR protocol, 11 samples were dated, including two old paleodunes with ages of 124.4 and 169.7 ka, increasing the age interval of the site, the other samples were younger sediments, with ages between 0.39 and 53.9 ka.

Palavras-Chave: sediments; radioisotopes; alluvial deposits; radioactivity; neutron activation analysis; optical fibers; luminescence

TATUMI, SONIA H.; YEE, MARCIO; SOARES, EMILIO A.A.; SOUZA, JEFFERSON J. de; GRUDZIN, EMANUELE D.O.; MUNITA, CASIMIRO S.; RIBEIRO, ROGÉRIO B.; SOARES, ALVARO de F.; SILVA, NOEMI A.; FERNANDES, CAROLINE P.; MATHIAS, MATHEUS T.; ROCCA, RENE R.; NAGABHUSHANA, K.R.; LOKESHA, H.S.; ROCHA, MARCELO S.; LOPEZ, LUIS A.C.; VENANCIO, DIEGO W.P.; COSTA, SOLANGE dos S. Radiometric and stimulated luminescent characterization of Amazonian sediments from the Middle Rio Negro, Western Amazon. Radiation Physics and Chemistry, v. 212, p. 1-12, 2023. DOI: 10.1016/j.radphyschem.2023.111117. Disponível em: http://repositorio.ipen.br/handle/123456789/34203. Acesso em: $DATA.

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Abstract: The goal of this study was to analyze the management and reverse logistics of sharp wastes, such as needle syringes and lancets, from domestic use by insulin-dependent diabetics, which were attended by the Brazilian Unified Health System. This is an exploratory case study, carried out by from data collected from 233 insulin-dependent diabetics and interviews with a health professional from October 2014 to September 2015. It was estimated that, in one year, 68% of insulin users received standard biosafety boxes below the necessary quantity for the disposal of needles, syringes, and lancets. Around 1,300 kg of sharp wastes were generated and only 1,831 boxes were distributed, showing a deficit in the reverse logistic system and indicating that sharp residues were incorrectly disposed of in residential garbage. A new Brazilian model to distribute the standard biosafety boxes to diabetics to guarantee the correct environmental disposal of sharp wastes is necessary.

AQUINO, SIMONE; CAVALCANTE, CRISTIANE das G.D.; ZAJAC, MARIA A.L.; LOPES, EVANDRO L. Environmental challenges of a Brazilian basic health unit in managing sharp waste produced by diabetics in domestic use. International Journal of Social Ecology and Sustainable Development, v. 13, n. 1, p. 1-14, 2022. DOI: 10.4018/IJSESD.305124. Disponível em: http://repositorio.ipen.br/handle/123456789/34201. Acesso em: $DATA.

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Abstract: The design of efficient luminescent lanthanide materials with a wide range of different excitation wavelengths in the UVA, UVB, and UVC regions, as well as under sunlight exposure, is highly desirable for application as molecular light-converting devices. In this work, [Ln(fluf)3(L)] complexes (Ln3+: Eu, Gd, and Tb) and doped PMMA:(1%)Tb(fluf)3(L) films, where fluf stands for the flufenamate ligand and L is H2O, phen, tppo, topo, and dpso, were successfully prepared by a facile one-pot method, and their photophysical properties were also investigated. The Ln3+ compounds were characterized by elemental analysis, Fourier transform infrared absorption spectroscopy, thermogravimetric analysis, X-ray powder diffraction, and diffuse reflectance spectroscopy techniques. The Eu3+ complexes present very weak emission intensities at 300 K temperature, showing very low intrinsic quantum yield (QEuEu) values due to a highly operative luminescence quenching by a low-lying ligand to metal charge transfer state. However, these values are significantly increased when obtained at low temperature (77 K). For Tb3+ complexes and the doped PMMA, polymeric films revealed an unprecedented bright emission under excitation at UVA, UVB, and UVC radiation. In addition, the doped polymers under sunlight exposure show the characteristic 5D4 → 7F6–0 transitions of the Tb3+ ion, exhibiting green emission color. These luminescent doped polymeric materials act as efficient energy harvesters and converters. Hence, the optical results show that the PMMA:(1%)Tb(fluf)3(L) photonic materials are highly versatile and desirable, presenting suitable application as efficient light-converting molecular devices and as luminescent solar concentrators.

Palavras-Chave: charge transport; ligands; photoluminescence; rare earth complexes; energy transfer; solar radiation; sun

ASSUNCAO, ISRAEL P.; COSTA, ISRAEL F.; SANTOS, PAULO R.S.; TEOTONIO, ERCULES E.S.; FELINTO, MARIA C.F.C.; KYNAST, ULRICH; FAUSTINO, WAGNER M.; MALTA, OSCAR; BRITO, HERMI F. Luminescent analysis of Eu3+ and Tb3+ flufenamate complexes doped in PMMA polymer: unexpected terbium green emission under sunlight exposure. ACS Applied Optical Materials, v. 1, n. 1, p. 354-366, 2023. DOI: 10.1021/acsaom.2c00070. Disponível em: http://repositorio.ipen.br/handle/123456789/34191. Acesso em: $DATA.

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Abstract: A software package for INAA (Instrumental Neutron Activation Analysis), developed at the Nuclear Metrology Laboratory of the IPEN-CNEN/SP, called k0-IPEN, is described. The package consists of a main program linked to nine subprograms designed to perform automatically most of the tasks necessary in order to obtain the mass fractions of the irradiated samples. External efficiency curves calculated by the Monte Carlo code MCNP6 can be read to extend the calibration curve to source to detector distances where only a few experimental points are available. Covariance analysis was used in all steps of the calculation. The validation of the code was tested in an intercomparison sponsored by the IAEA.

Palavras-Chave: ge semiconductor detectors; interlaboratory comparisons; monte carlo method; neutron activation analysis; neutron activation analyzers; neutron flux

DIAS, MAURO da S.; SEMMLER, RENATO; KOSKINAS, MARINA F.; MOREIRA, DENISE S.; YAMAZAKI, IONE M.; BRANCACCIO, FRANCO; BARROS, LIVIA F.; RIBEIRO, RAFAEL V.; MORAIS, THALES S.L. de. k0‑IPEN: a new software for INAA. Journal of Radioanalytical and Nuclear Chemistry, v. 332, n. 8, p. 3401-3409, 2023. DOI: 10.1007/s10967-022-08743-x. Disponível em: http://repositorio.ipen.br/handle/123456789/34186. Acesso em: $DATA.

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Abstract: Magnesium tetraborate (MgB4O7) is an example of a material that has attracted the attention of researchers in the field of ionising radiation dosimetry. Several challenges are present in order to achieve considerable advances in luminescence dosimetry. The incorporation of efficient dopants in the host matrix has been an experimentally useful but limited strategy. The lack of specific information about the introduced defects as well as their connection with the trapping and recombination processes associated with light emission may be quoted as challenging examples. Here, we demonstrate the influence of lithium incorporation on Optically Stimulated Luminescence (OSL)/Thermoluminescence (TL) signal modification/suppression of MgB4O7 by combining experimental and computational procedures. Li substitution into the Mg site leads to a signal suppression due to the probable quenching of the Fs and Fs + centres in MgO and the formation of O’’i , drastically reducing the possibility of MgO anti-Schottky defect formation in MgB4O7. When using Li-co-doped MgB4O7:Ce3+, the Li ions act as a charge balancer, facilitating the entry of Ce ions into the interstitial pores and making possible a positive synergistic effect on the luminescence and dosimetric properties. These findings provide new insights into designing more efficient dosimeters by tuning dopants.

Palavras-Chave: lithium; cerium; magnesium; luminescence; thermoluminescent dosemeters

BATISTA, JOAO V.B.; TROMBINI, HENRIQUE; OTSUKA, ANDRE; SILVEIRA, IURY S.; CALDAS, LINDA V.E.; SOUZA, ANTONIO O. de; SOUZA, ADELMO S.; SANTOS, JORGE L.O.; COELHO, VINICIUS; LIMA, HEVESON. Unlocking the effect of Li and Ce ions on the thermoluminescence and optically stimulated luminescence signals of the MgB4O7 compound. Dalton Transactions, v. 52, n. 19, p. 6407–6419, 2023. DOI: 10.1039/d3dt00485f. Disponível em: http://repositorio.ipen.br/handle/123456789/34166. Acesso em: $DATA.

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Abstract: Electrochemical CO2 reduction to fuels or commodity chemicals using renewable energy has drawn attention as a strategy for closing the anthropogenic chemical carbon cycle. More than that, enhancing the C–C coupling between the intermediates could lead to producing a range of high-value multi-carbon molecules. Although the research mainly focuses on the aqueous media for the electrochemical CO2 reduction reaction (eRRCO2), using nonaqueous electrolytes has the advantage of suppressing the hydrogen evolution reaction, controlling the protonassisted reduction reactions, and favoring the C–C coupling. Herein, the use of nonaqueous electrolytes for eRRCO2 and the components of the electrochemical reactor that affect the selectivity of the reaction are revisited. This review provides a perspective view of recent findings compared to well-established papers while presenting what is known about eRRCO2 in nonaqueous media.

Palavras-Chave: nonaqueous solvents; electrocatalysts; chemical reactions; reduction; electrolytes; carbon dioxide

REIS, EDUARDO A. dos; SILVA, GELSON T.S.T. da; SANTIAGO, ELISABETE I.; RIBEIRO, CAUE. Revisiting electrocatalytic CO2 reduction in nonaqueous media: promoting CO2 recycling in organic molecules by controlling H2 evolution. Energy Technology, v. 11, n. 6, p. 1-18, 2023. DOI: 10.1002/ente.202201367. Disponível em: http://repositorio.ipen.br/handle/123456789/34164. Acesso em: $DATA.

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Abstract: Random lasers have been studied using many materials, but only a couple have used glass matrices. Here, we present a study of zinc tellurite and aluminum oxide doped with different percentages of neodymium oxide (4 wt.%, 8 wt.%, and 16 wt.%) and demonstrate for the first time random laser action at 1337 nm. Laser emission was verified and the laser pulse’s rise time and input–output power slope were obtained. A cavity composed of the sample’s pump surface and an effective mirror formed by a second, parallel layer at the gain-loss boundary was probably the main lasing mechanism of this random laser system. The reason for the absence of emission at 1064 nm is thought to be a measured temperature rise in the samples’ active volume.

Palavras-Chave: doped materials; laser materials; neodymium lasers; scattering; glass; tellurium oxides

DIPOLD, JESSICA; BORDON, CAMILA D.S.; MAGALHAES, EVELLYN S.; KASSAB, LUCIANA R.P.; JIMENEZ-VILLAR, ERNESTO; WETTER, NIKLAUS U. 1337 nm emission of a Nd3+-doped TZA glass random laser. Nanomaterials, v. 13, n. 13, p. 1-11, 2023. DOI: 10.3390/nano13131972. Disponível em: http://repositorio.ipen.br/handle/123456789/34162. Acesso em: $DATA.

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Abstract: When considering dynamically stable resonators, ring lasers are good choices because they have a stability interval that is twice as large as that of linear resonators and sensitivity to misalignment decreasing with pump power; however, the literature does not provide easy design guidelines. A ring resonator utilizing Nd:YAG side pumped by diodes allowed single-frequency operation. The output single-frequency laser had good output characteristics; however, the overall length of the resonator did not allow for building a compact device with low misalignment sensitivity and larger spacing between longitudinal modes which could improve single-frequency performance. Based on previously developed equations, which allow for ease of design of a ring dynamically stable resonator, we discuss how to build an equivalent ring resonator, aiming to building a shorter resonator with the same stability zone parameters. The study of the symmetric resonator containing a pair of lenses allowed us to find the conditions to build the shortest possible resonator.

Palavras-Chave: resonators; lasers; neodymium lasers; yttrium compounds; length; semiconductor diodes

BERECZKI, ALLAN; WETTER, NIKLAUS U. Dynamic stable ring resonator for high-power continuous single-frequency lasers: conditions for a compact resonator. Applied Optics, v. 62, n. 8, p. C38 - C42, 2023. DOI: 10.1364/AO.477415. Disponível em: http://repositorio.ipen.br/handle/123456789/34159. Acesso em: $DATA.

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Abstract: Cutaneous leishmaniasis is a neglected parasitic disease that leads to destructive lesions. The emergence of drug resistance has been a global concern over the past years. Photodynamic therapy (PDT) mediated by a red LED and methylene blue (MB) involves the overproduction of oxidative stress, which oxidizes several cellular biomolecules and prevents the selection of resistant strains. Herein, we investigated the potential of PDT mediated by MB against wild-type and miltefosine-resistant strains of Leishmania amazonensis. As a result, both strains were susceptible to PDT, thus encouraging us to seek the best conditions to overcome the drug resistance problem in cutaneous leishmaniasis.

Palavras-Chave: protozoa; parasitic diseases; skin diseases; photodynamic therapy; methylene blue; light emitting diodes

CABRAL, FERNANDA V.; YOSHIMURA, TANIA M.; SILVA, DANIELA de F.T. da; CORTEZ, MAURO; RIBEIRO, MARTHA S. Photodynamic therapy mediated by a red LED and methylene blue inactivates resistant leishmania amazonensis. Journal of the Optical Society of America A, v. 40, n. 5, p. 996-1005, 2023. DOI: 10.1364/JOSAA.482314. Disponível em: http://repositorio.ipen.br/handle/123456789/34107. Acesso em: $DATA.

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Abstract: Surface modification corresponds to a set of viable technological approaches to introduce antimicrobial properties in materials that do not have such characteristics. Antimicrobial materials are important to prevent the proliferation of microorganisms and minimize the transmission of diseases caused by pathogens. Herein, poly (lactic acid) (PLA) was decorated with nanocones through copper sputtering followed by a plasma etching. Antiviral assays by Quantitative Reverse Transcription-Polymerase Chain Reaction (RT-qPCR) show that nanostructured Cu-coated PLA has high antiviral activity against Omicron SARS-CoV-2, showing a relative reduction in the amplified RNA (78.8 ± 3.9 %). Atomic Force Microscopy (AFM), X-ray Photoelectron Spectroscopy (XPS), and wear-resistance tests show that 20 wear cycles disrupt the surface nanocone patterns and significantly reduce the Cu content at the surface of the nanostructured Cu-coated PLA, leading to total loss of the antiviral properties of nanostructured PLA against Omicron SARS-CoV-2.

Palavras-Chave: coronaviruses; polymers; lactic acid; copper; plasma; nanotechnology; wear

SILVA, DANIEL J. da; DURAN, ADRIANA; FONSECA, FERNANDO L.A.; PARRA, DUCLERC F.; BUENO, RODRIGO F.; ROSA, DERVAL S. Omicron SARS-CoV-2 antiviral on poly(lactic acid) with nanostructured copper coating: wear effects. Applied Surface Science, v. 623, p. 1-9, 2023. DOI: 10.1016/j.apsusc.2023.157015. Disponível em: http://repositorio.ipen.br/handle/123456789/34105. Acesso em: $DATA.

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Abstract: Local treatment of bladder cancer faces several limitations such as short residence time or low permeation through urothelium tissue. The aim of this work was to develop patient-friendly mucoadhesive gel formulations combining gemcitabine and the enzyme papain for improved intravesical chemotherapy delivery. Hydrogels based on two different polysaccharides, gellan gum and sodium carboxymethylcellulose (CMC), were prepared with either native papain or papain nanoparticles (nanopapain) to explore for the first time their use as permeability enhancers through bladder tissue. Gel formulations were characterized regarding enzyme stability, rheological behavior, retention on bladder tissue and bioadhesion, drug release properties, permeation capacity, and biocompatibility. After 90 days of storage, the enzyme loaded in the CMC gels retained up to 83.5 ± 4.9 % of its activity in the absence of the drug, and up to 78.1 ± 5.3 with gemcitabine. The gels were mucoadhesive and the enzyme papain showed mucolytic action, which resulted in resistance against washing off from the urothelium and enhanced permeability of gemcitabine in the ex vivo tissue diffusion tests. Native papain shortened lag-time tissue penetration to 0.6 h and enhanced 2-fold drug permeability All formulations demonstrated pseudoplastic behavior and no irritability. Overall, the developed formulations have potential as an upgraded alternative to intravesical therapy for bladder cancer treatment.

Palavras-Chave: hydrogels; papain; polysaccharides; drug delivery; bladder; neoplasms

LIMA, CAROLINE S.A. de; RIAL-HERMIDA, MARIA I.; FREITAS, LUCAS F. de; PEREIRA-DA-MOTA, ANA F.; VIVERO-LOPEZ, MARIA; FERREIRA, ARYEL H.; KADŁUBOWSKI, SŁAWOMIR; VARCA, GUSTAVO H.C.; LUGAO, ADEMAR B.; ALVAREZ-LORENZO, CARMEN. Mucoadhesive gellan gum-based and carboxymethyl cellulose -based hydrogels containing gemcitabine and papain for bladder cancer treatment. International Journal of Biological Macromolecules, v. 242, n. 3, p. 1-16, 2023. DOI: 10.1016/j.ijbiomac.2023.124957. Disponível em: http://repositorio.ipen.br/handle/123456789/34103. Acesso em: $DATA.

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Abstract: The broad network of nuclear reactions populated in the 18O + 12C collision was studied to test the capability of state-of-art nuclear structure and reaction theories to describe both the direct and sequential components of the (18O, 18F) single charge exchange nuclear reaction. The experiment was performed using the 18O beam at 275 MeV incident energy produced by the K800 superconducting cyclotron and the MAGNEX magnetic spectrometer at the Laboratori Nazionali del Sud of the Istituto Nazionale di Fisica Nucleare. A unique comprehensive and coherent theoretical calculation, able to describe the whole network of direct reactions, is the approach proposed for the first time to analyse this large set of experimental data. This holistic approach, applied both to the experimental and theoretical analysis, is the main feature and novelty of the work here presented.

Palavras-Chave: nuclear matrix; matrix elements; transfer reactions; nuclear reactions

SPATAFORA, A.; CARBONE, D.; CAPPUZZELLO, F.; CAVALLARO, M.; ACOSTA, L.; AGODI, C.; AMADOR-VALENZUELA, P.; BORELLO-LEWIN, T.; BRISCHETTO, G.A.; CALABRESE, S.; CALVO, D.; CAPIROSSI, V.; CHAVEZ-LOMELI, E.R.; CIRALDO, I.; DE GREGORIO, G.; DELAUNAY, F.; DJAPO, H.; EKE, C.; FINOCCHIARO, P.; FIRAT, S.; FISICHELLA, M.; FOTI, A.; GARGANO, A.; HACISALIHOGLU, A.; IAZZI. F.; LA FAUCI, L.; LAY, J.A.; LINARES, R.; LUBIAN, J.; MEDINA, N.; MORALLES, M.; OLIVEIRA, J.R.B.; PAKOU, A.; PANDOLA, L.; PETRASCU, H.; PINNA, F.; RUSSO, G.; SGOUROS, O.; SILVEIRA, M.A.G. da; SOLAKCI, S.O.; SOUKERAS, V.; SOULIOTIS, G.; TORRESI, D.; TUDISCO, S.; YILDIRIM, A.; ZAGATTO, V.A.B. Multi-channel experimental and theoretical approach to study the 12C(18O,18F)12B single charge exchange reaction. Journal of Physics: Conference Series, v. 2453, n. 1, p. 1-7, 2023. DOI: 10.1088/1742-6596/2453/1/012019. Disponível em: http://repositorio.ipen.br/handle/123456789/34101. Acesso em: $DATA.

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Abstract: Introduction: Prostate cancer is the second most common cancer in men worldwide. In Brazil, regional disparities in incidences of intermediate and high-risk in late-diagnosed PC cases are expected. Objective: To investigate the clinical and demographic profiles of patients treated with metastatic castration-resistant prostate cancer (mCRPC) in Brazil, using real-world data from public databases. Method: Prostate cancer data from the Brazilian cancer registries were filtered from Brazilian public databases from 2008 to 2018. The number of health institutions and registries at a cancer public database were used to separate the Brazilian Federative Units into two comparison groups. mCRPC patients were estimated by using a combination of filters of staging and treatment (Tx, Nx and M1 + chemotherapy). The patients’ median age and the number and type of treatments were evaluated. Results: A total of 325,987 patients with prostate cancer and 5,367 patients with mCRPC were identified. The median age of the mCRPC patients was 63 years. The percentage of patients who underwent one, two or three treatments was 21.0%, 43.2% and 28.1%, respectively. In addition, management differences were noticed depending on the group analyzed. Conclusion: The results revealed regional discrepancies in the distribution of registered mCRPC patients in the Brazilian territory and in their treatment. This information can be used to strengthen the recently updated treatment and improve the palliative care offered. This work presents suggestions to improve specific prostate cancer databases.

Palavras-Chave: prostate; neoplasms; metastases; radiotherapy; public health; data processing

POZZO, LORENA; OLIVEIRA, MÉRCIA L. de; MONTEIRO, LUCILENA R.; MENEZES, MARIO O. de; GIAMMARILE, FRANCESCO; SADI, MARCUS V. Metastatic castration-resistant prostate cancer in Brazil: a real-world investigation using INCA database. Revista Brasileira de Cancerologia, v. 69, n. 2, p. 1-10, 2023. DOI: 10.32635/2176-9745.RBC.2023v69n2.3763. Disponível em: http://repositorio.ipen.br/handle/123456789/34098. Acesso em: $DATA.

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Abstract: Recently, in Brazil, corn ethanol industries are being installed and the integration with sugar/energy-cane has been proposed, using bagasse for cogeneration and the juice to dilute the corn. However, this integration may have some limitations, such as the quality of the cane juice and potential contamination by microorganisms brought with the cane from the field. In this article, we first tested the effects of mixing energy cane juice with corn on fermentative parameters. We also assessed the effects of Lactobacilli. contamination on organic acids produced during the fermentation and fermentation parameters and proposed the use of ionizing radiation to replace antibiotics as a disinfection control method. Our results showed that mixing energy cane juice with corn does not have any negative effect on fermentation parameters, including ethanol production. The contamination with Lactobacilli. considerably increased the production of acetic, lactic, and succinic acid, reducing the pH and ethanol content from 89.2 g L-1 in the sterilized treatment to 72.9 g L-1 in the contaminated treatment. Therefore, for the integration between corn and cane to be applied on an industrial scale, it is essential to have effective disinfection before fermentation. Ionizing radiation (20 kGy) virtually disinfected the wort, showing itself to be a promising technology; however, an economic viability study for adopting it in the industry should be carried out.

Palavras-Chave: biofuels; refining; sustainability; biomass; antibiotics

SILVA, ANA P.M. da; PIETRO, SICA; PIRES, LUCAS de A.N.; SPIRONELLO, LIANDRA; MOTA, LAYNA A.; PEIXOTO, GUSTAVO T.; CALEGARI, RUBENS P.; BASSO, THIAGO O.; TONSO, ALDO; GOMES, MARCELO P.; SOMESSARI, SAMIR L.; DUARTE, HEITOR G.; SOMESSARI, ELIZABETH S.R.; CARVALHO, RENAN DE S.; BAPTISTA, ANTONIO S. Integration of corn and cane for ethanol production: effects of lactobacilli contamination on fermentative parameters and use of ionizing radiation treatment for disinfection. Fermentation, v. 9, n. 2, p. 1-13, 2023. DOI: 10.3390/fermentation9020089. Disponível em: http://repositorio.ipen.br/handle/123456789/34090. Acesso em: $DATA.

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Abstract: In this work, the effects of friction stir welding (FSW) on the microstructure and electrochemical activities of dissimilar AA2050 and AA7050 aluminum alloys have been investigated. Local electrochemical tests supported by surface analytical characterization were used to study the local electrochemical activities developed along the weld zones of the dissimilar alloys. The investigation was carried out on the cross-section of the welded Al alloys. The results showed that the friction stir welding (FSW) of the dissimilar alloys affected the microstructure and the electrochemical behavior of the different regions (HAZ, TMAZ, SZ) formed by the welding process. Scanning vibrating electrode technique (SVET) and micropotentiometry by using an ion-selective microelectrode showed that TMAZ was the zone with the highest electrochemical activity. This zone corresponded to the transition region between the two welded alloys. The high electrochemical activity observed in this region was associated with the effect of welding on the microstructure and, also, with the galvanic coupling between the two alloys, where the alloy AA7050 acted as an anode and the AA2050 as a cathode. Preferential corrosion attack on the AA7050 alloy was also evident.

Palavras-Chave: aluminium alloys; friction; welding; coupling; electrochemical corrosion; potentiometry

VIVEIROS, BARBARA V.G. de; SILVA, REJANE MARIA P. da; DONATUS, UYIME; COSTA, ISOLDA. Welding and galvanic coupling effects on the electrochemical activity of dissimilar AA2050 and AA7050 aluminum alloys welded by Friction Stir Welding (FSW). Electrochimica Acta, v. 449, p. 1-15, 2023. DOI: 10.1016/j.electacta.2023.142196. Disponível em: http://repositorio.ipen.br/handle/123456789/34088. Acesso em: $DATA.

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Abstract: Background: Cutaneous leishmaniasis (CL) is an important tropical neglected disease with broad geographical dispersion. The lack of effective drugs has raised an urgent need to improve CL treatment, and antimicrobial photodynamic therapy (APDT) has been investigated as a new strategy to face it with positive outcomes. Natural compounds have emerged as promising photosensitizers (PSs), but their use in vivo remains unexplored. Purpose: In this work, we investigated the potential of three natural anthraquinones (AQs) on CL induced by Leishmania amazonensis in BALB/c mice. Study Design/Methods: : Animals were infected and randomly divided into four groups: CG (control, non-treated group), G5ClSor-gL (treated with 5-chlorosoranjidiol and green LED, 520±10 nm), GSor-bL and GBisor-bL (treated with soranjidiol and bisoranjidiol, respectively, exposed to violet-blue LED, 410±10 nm). All AQs were assayed at 10 μM and LEDs delivered a radiant exposure of 45 J/cm2 with an irradiance of 50 mW/cm2 . We assessed the parasite burden in real time for three consecutive days. Lesion evolution and pain score were assessed over 3 weeks after a single APDT session. Results: G5ClSor-gL was able to sustain low levels of parasite burden over time. Besides, GSor-bL showed a smaller lesion area than the control group, inhibiting the disease progression. Conclusion: Taken together, our data demonstrate that monoAQs are promising compounds for pursuing the best protocol for treating CL and helping to face this serious health problem. Studies involving host-pathogen interaction as well as monoAQ-mediated PDT immune response are also encouraged.

Palavras-Chave: skin diseases; parasites; protozoa; light emitting diodes; luminescence; pain

DIMMER, JESICA A.; CABRAL, FERNANDA V.; MONTOYA, SUSANA C.N.; RIBEIRO, MARTHA S. Towards effective natural anthraquinones to mediate antimicrobial photodynamic therapy of cutaneous leishmaniasis. Photodiagnosis and Photodynamic Therapy, v. 42, p. 1-6, 2023. DOI: 10.1016/j.pdpdt.2023.103525. Disponível em: http://repositorio.ipen.br/handle/123456789/34086. Acesso em: $DATA.

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Abstract: Growth hormone (GH) deficiency is characterized by impaired growth and development, and is currently treated by repeated administration of recombinant human GH (hGH). Encapsulated cell therapy (ECT) may offer a less demanding treatment-strategy for long-term production and release of GH into circulation. We used PiggyBac-based (PB) transposon delivery for engineering retinal pigment epithelial cells (ARPE-19), and tested a series of viral and non-viral promoters as well as codon-optimization to enhance transgene expression. Engineered cells were loaded into TheraCyte macrocapsules and secretion was followed in vitro and in vivo. The cytomegalovirus (CMV) promoter supports strong and persistent transgene expression, and we achieved clonal cell lines secreting over 6 µg hGH/106 cells/day. Codon-optimization of the hGH gene did not improve secretion. ARPE-19 cells endured encapsulation in TheraCyte devices, and resulted in steady hormone release for at least 60 days in vitro. A short-term pilot experiment in immunodeficient SCID mice demonstrated low systemic levels of hGH from a single 40 µL capsule implanted subcutaneously. No significant increase in weight increase or systemic hGH was detected after 23 days in the GH-deficient lit/SCID mouse model using 4.5 µL capsules loaded with the highest secreting clone of ARPE-19 cells. Our results demonstrate that PB-mediated engineering of ARPE-19 is an efficient way to generate hormone secreting cell lines compatible with macroencapsulation, and our CMV-driven expression cassette allows for identification of clones with high level and long-term secretory activity without addition of insulator elements. Our results pave the way for further in vivo studies of encapsulated cell therapy.

Palavras-Chave: hormones; sth; epithelium; pigments; therapy

CECCHI, CLAUDIA R.; ALSING, SIDSEL; JESUS, GUSTAVO P.P.; ZACARIAS, ENIO A.; KJAER, LISBETH; CLEMENT, MICHELLE S.; KUMAGAI-BRAESCH, MAKIKO; CORYDON, THOMAS J.; BARTOLINI, PAOLO; PERONI, CIBELE N.; AAGAARD, LARS. Sustained secretion of human growth hormone from TheraCyte devices encapsulated with PiggyBac-engineered retinal pigment epithelium cells. Tissue and Cell, v. 82, p. 1-13, 2023. DOI: 10.1016/j.tice.2023.102095. Disponível em: http://repositorio.ipen.br/handle/123456789/34084. Acesso em: $DATA.

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Abstract: In this work, the use of gold and silver nanoshells was evaluated as a starting point for the establishment of colorimetric sensor platforms. The sensitivity and linearity of the nanoplatforms (SiO2 core–metallic shell nanoparticles) were assessed under the influence of the nanoshell configuration, color space, and light source illuminant. A computational procedure for selecting high-performance plasmonic colorimetric sensor platforms is described. The evaluation methodology involves considering five different color spaces and 15 different color components. By exploring crucial figures of merit for sensing, the performance of the plasmonic nanoplatforms was evaluated, exploring Mie theory. We determined that gold nanoshells are highly efficient on colorimetric sensing, while silver nanoshells are a better choice for spectroscopic sensors. Plasmonic nanoplatforms based on nanoshells with 10 nm SiO2 core radii and 5 nm thick Au shells presented sensitivity values up to 4.70 RIU−1 , considering the hue angle of the HSV color space. Color variation of up to 40% was observed, due to the adsorption of a 10 nm thick molecular layer on the gold nanoshell surface. In the search for advances in colorimetric biosensors, the optimization approach used in this work can be extended to different nanostructures.

Palavras-Chave: plasmons; nanostructures; colorimetric dosemeters; gold

BALTAR, RAPHAEL M.S.M.; FAROOQ, SAJID; ARAUJO, RENATO E. de. Selecting plasmonic nanoshells for colorimetric sensors. Journal of the Optical Society of America B, v. 40, n. 4, p. C40-C47, 2023. DOI: 10.1364/JOSAB.479446. Disponível em: http://repositorio.ipen.br/handle/123456789/34082. Acesso em: $DATA.

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Abstract: 8 mol% Y2O3 -stabilized ZrO2 (8YSZ) ceramics were prepared with KCl and LiF additions to obtain porous specimens with high skeletal density. Thermogravimetric and differential thermal analyses (TG/DTA) were carried out on 8YSZ and on 8YSZ mixed to 5 wt.% KCl or 5 wt.% LiF as sacrificial pore formers that were thermally removed during sintering. The melting and evaporation of the alkali halides were evaluated by differential thermal analysis. Dilatometric analysis was also carried out following the same TG/DTA temperature profile with results suggesting rearrangement of the 8YSZ particles during LiF and KCl melting. The dilatometric data of 8YSZ green pellets mixed to KCl or LiF exhibited an initial expansion up to the melting of the alkali halide, followed by shrinkage due to sintering evolution with grain growth and pore elimination. The time that the alkali halide molten phase was kept during sintering was found to be an important parameter for obtaining 8YSZ-sintered specimens with specific pore content; bulk density and open porosity could then be tuned by controlling the time the alkali halide remained liquid during sintering. Scanning electron microscopy images of the pellet fracture surfaces showed pores that contributed to increasing the electrical resistivity as evaluated by impedance spectroscopy analysis.

Palavras-Chave: yttrium oxides; zirconium oxides; impedance; thermal analysis; alkali metals; halides

DIAZ, JULIO C.C.A.; MUCCILLO, ELIANA N. dos S.; MUCCILLO, REGINALDO. Porous 8YSZ ceramics prepared with alkali halide sacrificial additives. Materials, v. 16, n. 9, p. 1-11, 2023. DOI: 10.3390/ma16093509. Disponível em: http://repositorio.ipen.br/handle/123456789/34080. Acesso em: $DATA.

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Abstract: Ionizing radiation has attracted attention due to its ability to inhibit pathogens and microorganisms, with low doses reported as being able to degrade cyanotoxins and inhibit toxic cyanobacteria growth. In this context, the aim of the present study was to investigate how electron beam irradiation (EBI) applied at doses between 1 and 10 kGy affect intracellular and extracellular microcystin variants. Effects on M. aeruginosa culture recovery, as well as changes in physico-chemical cyanobacterial suspension parameters and water quality alterations were assessed through ecotoxicity assays. The findings indicate that doses over 2 kGy may are lethal to M. aeruginosa even at 48 h post-irradiation. Concerning physico-chemical parameters, exposure to 2–5 kGy doses decrease pH values and later stabilizing. At least 50 % of intracellular MC led to significant degradation of all variants at 3 kGy. No acute toxicity effects were observed in Daphnia similis exposed to sample supernatants. Statistically significant differences were observed when cladocerans were exposed to M. aeruginosa cells treated with EBI doses ranging from 3 to 10 kGy compared to non-treated cyanobacterial suspensions. These findings suggest that low EBI radiation doses are suitable for the control of toxic cyanobacteria in water treatment processes, providing a less toxic environment compared to non-treated solutions.

Palavras-Chave: daphnia; toxicity; cyanobacteria; electron beams; irradiation; ionizing radiations; oxidation

SILVA, THALITA T.; JACINAVICIUS, FERNANDA R.; PINTO, ERNANI; BORRELY, SUELI I. Intracellular microcystins degradation and acute toxicity decrease towards Daphnia similis by low electron-beam irradiation doses. Algal Research, v. 72, p. 1-7, 2023. DOI: 10.1016/j.algal.2023.103086. Disponível em: http://repositorio.ipen.br/handle/123456789/34078. Acesso em: $DATA.

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Abstract: The photoelastic dispersion coefficient represents the relationship between stress and the differences in refractive indices in a birefringent material. However, determining the coefficient using photoelasticity is challenging, as it is difficult to determine the refractive indices within photoelastic samples that are under tension. Here we present, for the first time, to our knowledge, the use of polarized digital holography to investigate the wavelength dependence of the dispersion coefficient in a photoelastic material. A digital method is proposed to analyze and correlate the differences in mean external stress with differences in mean phase. The results confirm the wavelength dependence of the dispersion coefficient, with an accuracy improvement of 25% compared to other photoelasticity methods.

Palavras-Chave: photoelasticity; wavelengths; coefficient of performance; refraction; holography; lasers

SILVA, SIDNEY L. da; PRADO, FELIPE M.; TOFFOLI, DANIEL J.; WETTER, NIKLAUS U. Characterization of the photoelastic dispersion coefficient using polarized digital holography. Journal of the Optical Society of America A, v. 40, n. 4, p. C108-C114, 2023. DOI: 10.1364/JOSAA.482543. Disponível em: http://repositorio.ipen.br/handle/123456789/34076. Acesso em: $DATA.

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Abstract: At the beginning of 2020, the COVID-19 pandemic surprised the world, affecting activities that promote attendance, including abruptly impacting the education area. Educational institutions, from preschool to university, were required to adopt alternative teaching methods to continue their activities. Distance learning has been adopted by educators to address this unprecedented challenge. Our University, more specifically the Department of Physics, reacted to the problem in an ambitious and creative way, taking advantage of it as an opportunity to put into practice methodologies related to the teaching of disciplines that were only practiced in person, such as the discipline of Experimental Physics. This study aims to describe the implementation of the discipline of Experimental Physics I at our University, promoted remotely by professors of the Department of Physics. We verified: (i) that the choice of the best technologies as a tool for teaching is fundamental for the better dissemination of knowledge, (ii) that inclusive programs for each course are very important, (iii) the importance of prior presentation of a schedule, (iv) the importance of defining clear assessment rules for students on remote teaching. We also evaluated the number of accesses as a measure of student participation and analysed the statistics of the discipline in several engineering courses.

Palavras-Chave: education; educational tools; learning; e-learning; coronaviruses; epidemiology; physics

FRANCO, MARGARETH K.K.D.; SERBENA, JOSE PEDRO M.; MATTOSO FILHO, NEY P.; WIENER, DENIS de O.; YOKAICHIYA, FABIANO; FUJIMOTO, MILTON M. Feasibility of teaching experimental physics during Covid-19 pandemic. Physics Education, v. 58, n. 3, p. 1-8, 2023. DOI: 10.1088/1361-6552/acbf1d. Disponível em: http://repositorio.ipen.br/handle/123456789/34073. Acesso em: $DATA.

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Abstract: This study investigates the use of biocarbon electrodes, produced from coffee grounds through plasma pyrolysis, in the electrochemically mediated precipitation process for phosphorus removal in a flow reactor. The structural and electrochemical properties of biocarbon were analyzed using X-ray powder diffraction (XRD), Raman spectroscopy, and cyclic voltammetry. The results show that biocarbon consists of both graphene oxide and lignocellulose with surface OH groups that facilitate the breakdown of water, a key step in the electrochemically mediated precipitation process for phosphorus removal. The addition of graphite to the biocarbon paste was found to be necessary to obtain a response from the biocarbon in cyclic voltammetry. The Gr75BC25 electrode achieved higher phosphorus removal rates than other tested electrodes, particularly at low flows, due to the functional groups present in biocarbon enhancing the breakdown of water. However, electrodes with a greater amount of biocarbon exhibit lower rates of phosphorus removal and higher consumption of electrical power, which can be attributed to their higher electrical resistivity. Thus, to optimize its use, it is important to balance the benefits of increased phosphorus removal rates with the trade-off of increased energy consumption and decreased phosphorus removal at higher levels of biocarbon. The results suggest that biocarbon produced from coffee grounds by plasma pyrolysis has the potential to be used as an effective electrode material for electrochemically mediated precipitation processes.

Palavras-Chave: electrochemistry; synthesis; phosphates; removal; carbon; water treatment

SILVESTRIN, G.A.; GONCALVES, M.H.; GODOI, C.M.; MAIA, V.A.; FERREIRA, J.C.; GUILHEN, S.N.; NETO, A.O.; SOUZA, R.F.B. de. Effective phosphate removal from water by electrochemically mediated precipitation with coffee grounds biocarbon obtained by non-thermal plasma method. The Academic Society Journal, v. 7, n. 1, p. 3-12, 2023. DOI: 10.32640/tasj.2023.1.3. Disponível em: http://repositorio.ipen.br/handle/123456789/34071. Acesso em: $DATA.

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Abstract: This work aimed to study the effects of coating a thin film of Silicon Carbide and chromium interlayer on the fatigue behavior of Ti-6Al-4V alloy and the correspondent failure evaluation. In the characterization of the layer, the roughness, thickness, and adhesion were determined. Uniaxial fatigue tests were performed under R = 0.1 and the fracture surfaces and corresponding failure mechanisms were observed and identified by SEM, respectively. In the specimens coated using the DC source the number of cycles to failure of the fatigue was increased. The fracture surfaces showed that the crack initiation occurred in the internal regions of the specimens and not superficially. In this case, the layer remained adhered to the specimens even after the tests, showing the effectiveness of the film. In specimens coated using the HiPIMS source, the number of cycles to failure decreased, the cracks were mostly superficial, and the deposited film showed low adhesion after the tests. It proved to be ineffective, worsening the material fatigue behavior.

Palavras-Chave: fatigue; titanium alloys; aluminium alloys; vanadium alloys; thin films; magnetrons; sputtering

ARBEX, ALEXANDRA A.; REIS, LUIS; ALMEIDA, GISELE F.C.; MERIJ, ABRAO C.; MASSI, MARCOS; COUTO, ANTONIO A. Cracking failure analysis due to fatigue of the Ti-6Al-4V alloy coated with SiC layer and Cr interlayer deposited by magnetron sputtering. Engineering Failure Analysis, v. 150, p. 1-14, 2023. DOI: 10.1016/j.engfailanal.2023.107325. Disponível em: http://repositorio.ipen.br/handle/123456789/34068. Acesso em: $DATA.

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Abstract: Este trabalho avaliou retrospectivamente correções de imagens planares de pacientes já submetidos a tratamentos de neuroeixo, a fim de quantificar a magnitude dos erros de posicionamento e aplicá-los em diferentes técnicas de radioterapia em arco modulada volumetricamente (VMAT) para definir a que possui o menor impacto dosimétrico considerando estes erros, para implementação na prática clínica, que é objetivo deste estudo. Ao todo 219 imagens planares de 15 pacientes foram selecionadas para avaliação estatística de erros de posicionamento. Para os planejamentos, quatro pacientes pediátricos já tratados com técnica 3D conformacional foram selecionados. Para cada um, cinco planos de tratamento VMAT foram otimizados em duas técnicas: sobreposição com 3 cm, 6 cm e 9 cm de junção e gradiente com 6 cm e 9 cm e foram avaliados pelos índices: V100%, V95%, D98%, D2%, número de conformidade (CN) e índice de heterogeneidade (HI). Em cada plano, foram inseridos erros de posicionamento com a magnitude encontrada na análise retrospectiva das imagens, bem como avaliar a diferença na distribuição de dose quando considerado a mesa de tratamento. As imagens demonstraram deslocamentos médios entre 1 e 5 mm e em alguns casos chegando à 15 mm. Em relação à qualidade dos planejamentos, todos obtiveram resultados coerentes baseados nas métricas avaliadas sem diferenças significativas. Porém, a técnica de gradiente (9 cm de junção) reduziu o impacto dosimétrico em comparação às outras técnicas quando submetida aos erros de posicionamento. Por fim, ao considerar a mesa de tratamento nos planejamentos, foi encontrada uma redução de 10% no V100%. Os resultados mostraram que para implementação da técnica VMAT para neuroeixo recomenda-se realizar imagem de posicionamento diária para minimizar erros de posicionamento com magnitudes maiores que a média encontrada de 3 mm no sentido longitudinal, pois estes têm impacto significativo na distribuição de dose nos planejamentos modulados.

Palavras-Chave: neoplasms; tumor cells; radiotherapy; nuclear medicine; physics

BULL, HENRIQUE C.; RIBEIRO NETO, MARIO; MAISTRO, CARLOS EDUARDO B.; YORIYAZ, HELIO; SAMPAIO, CAROLINE C. Avaliação dosimétrica de erros de posicionamento para implementação da técnica de neuroeixo com arcoterapia volumétrica modulada (VMAT). Revista Brasileira de Física Médica, v. 17, n. 649, p. 1-8, 2023. DOI: org/10.29384/rbfm.2023.v17.19849001649. Disponível em: http://repositorio.ipen.br/handle/123456789/34066. Acesso em: $DATA.

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Abstract: In this article, we present a chitosan–zeolite composite, which was synthesized and used as an adsorbent material for caesium (Cs) removal from aqueous media and real liquid radioactive organic waste (LROW). The compound was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy techniques. The physicochemical characterization indicates the production of a composite. Adsorption experiments were first performed using the prepared solutions contaminated with Cs using full factorial design with two variables of interest: initial Cs concentration (Cs0) and adsorbent dosage (mg L−1 ). The results indicated a high caesium removal rate with removal values above 93% and adsorption capacity of up to 10 mg g−1 . With the best experimental conditions according to our experimental domain, time was evaluated and equilibrium was reached in 180 min. Finally, the adsorbent material was tested as an adsorbent for Cs, Am, and U from LROW. When in contact with LORW, the removal rates (%) were 21.51 (137Cs), 26.39 (241Am), and 20.26 (U (total)). Although lower, this material indicated that it has the potential to be used for multi-elemental adsorption.

Palavras-Chave: adsorption; chitin; zeolites; polysaccharides; radioactive wastes; liquid wastes; radioactive effluents

ARAUJO, LEANDRO G. de; MEDEIROS, VINICIUS L.; GUARNIERI, GUILHERME de P.; SILVA, DANILO A. da; WATANABE, TAMIRES; MARUMO, JULIO T.; NERY, JOSE G. An adsorption agent based on chitosan–zeolite composite: environmental and radioactive liquid waste remediation. Environmental Science: Advances, v. 2, n. 3, p. 484–494, 2023. DOI: 10.1039/d2va00148a. Disponível em: http://repositorio.ipen.br/handle/123456789/34064. Acesso em: $DATA.

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Abstract: Introduction: Laboratories are inextricably dangerous work environments, as fatal incidents are reported in both academic and non-academic environments worldwide, where poor safety culture has been recognized as the major accident contributor. Workers can be exposed to chemical, biological, physical, or radioactive hazards, in addition to musculoskeletal stresses. In Brazil, hundreds of thousands of workers are employed in laboratories, either in private or public institutions. Although laboratory safety can be governed by local, state, or federal regulations, learning how to identify common laboratory hazards is the first step to preventing accidents in the lab environment. Methods: The study aimed to assess the degree level of safety culture in an academic population of research laboratories, located in the largest city in Brazil, and their compliance with occupational safety regulations during the COVID-19 outbreak. This study was carried out between October and November 2020. The results were obtained from the standardized questionnaire used to assess 98 researchers working in laboratories during the COVID-19 pandemic. Results: The majority of respondents (95%) reported being exposed to more than two risks, simultaneously. About two-thirds (66%) of them were not fully aware of the laboratory's risk map. About half of the researchers (50%) were lacking in safety culture, and 57%and 43% were preoccupied with chemical and non-chemical hazards, respectively. Personal protective equipment (PPE) during laboratory work was used by most researchers, but 75% of researchers claim that security awareness learning should be a high priority for admission to laboratories. About 39% of researchers agreed that awareness of security must be improved in their laboratories Conclusion: The survey proves the lack of information and attitudes about chemical safety, especially among less experienced researchers, even if they use personal protective equipment when necessary.

Palavras-Chave: hazards; laboratories; safety analysis; risk assessment; health hazards; chemical composition; occupational exposure; viruses

PEDREIRA FILHO, W.R.; PASSOS, J.S.; RUSCINC, N.; SILVA, M.L. da; MONTEIRO, L.R.; COSTA, S.K.P. Chemical safety knowledge assessment of academic researchers from Brazil during Covid-19 pandemic. International Journal of Occupational Safety and Health, v. 13, n. 2, p. 146-154, 2023. DOI: 10.3126/ijosh.v13i2.48904. Disponível em: http://repositorio.ipen.br/handle/123456789/34062. Acesso em: $DATA.

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Abstract: A channel box installation in the IEA-R1 research reactor core was numerically investigated to increase fluid flow in fuel assemblies (FAs) and side water channels (SWCs) between FAs by minimizing bypasses in specific regions of the reactor core, which is expected to reduce temperatures and oxidation effects in lateral fuel plates (LFPs). To achieve this objective, an isothermal three-dimensional computational fluid dynamics model was created using Ansys CFX to analyze fluid flow distribution in the Brazilian IEA-R1 research reactor core. All regions of the core and realistic boundary conditions were considered, and a detailed mesh convergence study is presented. Results comparing both scenarios are presented in the percentage of use of the primary circuit pump. It is indicated that 21.4% of fluid bypass to unnecessary regions can be avoided with the channel box installation, which leads to the total mass flow from the primary circuit for all FAs increasing from 68.9% (without a channel box) to 77.6% (with a channel box). For the SWCs, responsible for cooling LFPs, an increment from 9.7% to 22.4%, avoiding all nondesired cross three-dimensional effects, was observed, resulting in a more homogeneous fluid flow and vertical velocities. It was concluded that the installation of a channel box numerically indicates an expressive mass flow increase and homogeneous fluid flow distribution for flow dynamics in relevant regions. This gives greater confidence to believe that lower temperatures, and consequently oxidation effects in LFPs, can be expected with a channel box installation.

Palavras-Chave: computer codes; fluid mechanics; reactor cores; distribution; fluid flow

SCURO, N.L.; ANGELO, G.; ANGELO, E.; PIRO, M.H.A.; UMBEHAUN, P.E.; TORRES, W.M.; ANDRADE, D.A. Computational fluid dynamics analysis of an open-pool nuclear research reactor core for fluid flow optimization using a channel box. Nuclear Science and Engineering, v. 197, n. 6, p. 1100-1116, 2023. DOI: 10.1080/00295639.2022.2142437. Disponível em: http://repositorio.ipen.br/handle/123456789/34060. Acesso em: $DATA.

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Abstract: In this work, the local electrochemical activity of the zones coupled by Friction Stir Welding (FSW) of an Al-Cu-Li alloy was studied and the results were correlated to the microstructural characteristics of each zone. Electrochemical studies were carried out in the zones affected by welding using cyclic voltammetry (CV) and scanning electrochemical techniques (namely, SECM - Scanning Electrochemical Microscopy and LEIS – Local electrochemical impedance spectroscopy). The results showed that the welding joint (WJ) is predominantly cathodic relatively to the heat affected zones (HAZ). The HAZ was always anodic and showed the highest electrochemical activities among the tested ones. The high electrochemical activity of the HAZ was associated with the effect of galvanic coupling between the cathodic region (WJ) and the anodic region (HAZ). In addition, the advancing side (AS) presented increased electrochemical activity compared to the retreating one (RS).

Palavras-Chave: friction welding; aluminium alloys; copper alloys; lithium alloys; electrochemistry

SILVA, REJANE M.P. da; MILAGRE, MARIANA X.; ARAUJO, JOAO V. de S.; RAMIREZ, OSCAR M.P.; MACHADO, CARULINE de S.C.; ANTUNES, RENATO A.; COSTA, ISOLDA. Investigação da atividade eletroquímica de liga Al-Cu-Li após processo de soldagem por fricção e mistura. Quimica Nova, v. 46, n. 4, p. 307-318, 2023. DOI: 10.21577/0100-4042.20230014. Disponível em: http://repositorio.ipen.br/handle/123456789/34058. Acesso em: $DATA.

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Abstract: The application of solid electrolyte reactors for methane oxidation and energy co-generation is attractive, especially with the use of catalysts synthesized from noble metals such as palladium. In this work, we prepared three different compositions of palladium on carbon support to evaluate the composition that had the greatest potential for energy generation. Catalysts in the proportions of 5, 10 and 20% of Pd/C were tested for the conversion of greenhouse gases into organic molecules of higher added value using electrochemical fuel cell solid electrolyte reactors. The focus of this work was the conversion of methane into methanol, using the fuel cell as a reactor and the commercial Pd/C as electrocatalyst. The electrocatalysts were tested at the anode, analyzed by infrared (IR) spectroscopy and their activities verified by experiments with rotating ring disk electrode (RRDE). Higher levels of palladium (Pd/C 20%) favored obtaining electrical power, and the intermediate composition (Pd/C 10%) showed a greater production of less oxidized compounds, such as methanol, in addition to generating electricity.

Palavras-Chave: methane; oxidation; palladium; catalysts; fuel cells

SILVA, ARACELI J.; ZAMBIAZI, PRISCILLA J.; GOMES, PAULO V.R.; NANDENHA, JULIO; GODOI, CAMILA M.; SOUZA, RODRIGO F.B. de; NETO, ALMIR O.; AZEREDO, NATHALIA F.B. Conversão de metano em metanol com co-geração de energia elétrica a partir de catalisadores de paládio suportados em carbono. Revista Virtual de Química, v. 15, n. 2, p. 221-226, 2023. DOI: 10.21577/1984-6835.20220101. Disponível em: http://repositorio.ipen.br/handle/123456789/34056. Acesso em: $DATA.

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Abstract: The aim of the study described in this article was to evaluate a product containing titania (titanium dioxide, TiO2) applied on stones — particularly two types used at Brazilian stone-built heritage sites — that have been exposed to weathering and anthropogenic activities. This product was prepared by producing a suspension of TiO2 at two concentrations (1% and 4% w/v) with tetraethyl orthosilicate (TEOS) in the presence of n-octylamine as surfactant. The characteristics of the TiO2 were then observed by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface-area measurements, particle-size distribution analysis (CILAS) and X-ray diffraction. After applying the TiO2-TEOS composite, the stones were examined for contact angle, spectrophotometry, sorptivity, thermal shock resistance, and UV-radiation resistance. The product proved ineffective on Itararé sandstone, mainly due to its mineralogical components, as the product does not adhere to quartz. When applied on Itaquera granite, the 1% TiO2 (w/v) concentration proved to be an appropriate treatment, as it demonstrated better thermal shock resistance, photocatalytic activity, porosity maintenance, and global colour when compared to the 4% concentration.

Palavras-Chave: architecture; cultural resources; photocatalysis; sandstones; composite materials; titanium oxides

GROSSI, DANIELLE; LAZAR, DOLORES R.R.; DEL LAMA, ELIANE A.; USSUI, VALTER. Titania-silica composite with photocatalytic properties and its application on Brazilian granite and sandstone. International Journal of Architectural Heritage, v. 17, n. 5, p. 770-787, 2023. DOI: 10.1080/15583058.2021.1969483. Disponível em: http://repositorio.ipen.br/handle/123456789/34054. Acesso em: $DATA.

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Abstract: Bioinspired bactericidal surfaces are artificial surfaces that mimic the nanotopography of insect wings and are capable of inhibiting microbial growth by a physicomechanical mechanism. The scientific community has considered them an alternative method to design polymers with surfaces that inhibit bacterial biofilm formation, suitable for self-disinfectant medical devices. In this contribution, poly(lactic acid) (PLA) with nanocone patterns was successfully produced by a novel two-step procedure involving copper plasma deposition followed by argon plasma etching. According to reverse transcription-quantitative polymerase chain reaction tests, the bioinspired PLA nanostructures display antiviral performance to inactivate infectious Omicron severe acute respiratory syndrome coronavirus 2 particles, reducing the amount of the viral genome to less than 4% in just 15 min due to a possible combined effect of mechanical and oxidative stress. The bioinspired antiviral PLA can be suitable for designing personal protection equipment to prevent the transmission of contagious viral diseases, such as Coronavirus Disease 2019.

Palavras-Chave: coronaviruses; topography; surfaces; copper; lactic acid; polymers; antimicrobial agents

SILVA, DANIEL J. da; DURAN, ADRIANA; CABRAL, ALINE D.; FONSECA, FERNANDO L.A.; WANG, SHU H.; PARRA, DUCLERC F.; BUENO, RODRIGO F.; PEREYRA, INES; ROSA, DERVAL S. Bioinspired antimicrobial PLA with nanocones on the surface for rapid deactivation of Omicron SARS-CoV‑2. ACS Biomaterials Science and Engineering, v. 9, n. 4, p. 1891-1899, 2023. DOI: 10.1021/acsbiomaterials.2c01529. Disponível em: http://repositorio.ipen.br/handle/123456789/34016. Acesso em: $DATA.

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Abstract: The addition of titania to zirconia dental implants has been considered a promising choice to improve its bioactivity. This study aimed to evaluate the effect of different sintering conditions on the microstructure, density, optical properties and flexural strength of a 3Y-TZP/TiO2 dental ceramic based on zirconia with two different titania contents (7.5 mol% and 12.5 mol%). 3Y-TZP/TiO2 ceramic powders were synthesized by coprecipitation, uniaxially pressed and sintered at six different sintering conditions. Microstructural analysis of the sintered samples was performed by scanning electron microscopy and X-ray diffraction. Optical properties were measured using a spectrophotometer. The density was determined by Archimedes principle. Flexural strength was estimated by the biaxial flexure device. The microstructure and flexural strength of the 3Y-TZP/TiO2 dental ceramic with 7.5% and 12.5 mol% were affected by the sintering conditions. Sintering the specimens at 1460 °C for 2 h increased the grain size and significantly decreased the flexural strength of 3Y-TZP/TiO2 dental ceramic. The interaction (titania content x sintering conditions) affected the relative density and optical properties. A relative density greater than 98% was achieved for the T7.5 groups (sintered at 1260 °C/1 h, 1300 °C/1 h and 1300 °C/2 h) and for the T12.5 groups (sintered at 1260 °C/1 h, 1260 °C/4 h, 1300 °C/1 h and 1300 °C/2 h). The highest values of L*, a* and b* were respectively 87.2 (T7.5 group sintered at 1460 °C/2hs), 4.3 (T12.5 group sintered at 1300 °C/2hs) and 15.8 (T12.5 group sintered at 1300 °C/1 h). The material developed with 12.5 mol% of titania and sintered at 1300 °C/2 h showed high densification, flexural strength of 670 MPa and has good potential to be used in dentistry.

Palavras-Chave: yttrium oxides; zirconium oxides; titanium oxides; dentistry; ceramics; implants; optical properties; flexural strength; sintering

MIRANDA, RANULFO B. de P.; USSUI, VALTER; LAZAR, DOLORES R.R.; LIMA, NELSON B. de; MARCHI, JULIANA; CESAR, PAULO F. Characterization of 3Y-TZP/TiO2 hybrid experimental dental ceramics. Ceramics International, v. 49, n. 10, p. 15734-15740, 2023. DOI: 10.1016/j.ceramint.2023.01.167. Disponível em: http://repositorio.ipen.br/handle/123456789/34014. Acesso em: $DATA.

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Abstract: The unbridled dissemination of multidrug-resistant pathogens is a major threat to global health and urgently demands novel therapeutic alternatives. Antimicrobial photodynamic therapy (aPDT) has been developed as a promising approach to treat localized infections regardless of drug resistance profile or taxonomy. Even though this technique has been known for more than a century, discussions and speculations regarding the biochemical mechanisms of microbial inactivation have never reached a consensus on what is the primary cause of cell death. Since photochemically generated oxidants promote ubiquitous reactions with various biomolecules, researchers simply assumed that all cellular structures are equally damaged. In this study, biochemical, molecular, biological and advanced microscopy techniques were employed to investigate whether protein, membrane or DNA damage correlates better with dose-dependent microbial inactivation kinetics. We showed that although mild membrane permeabilization and late DNA damage occur, no correlation with inactivation kinetics was found. On the other hand, protein degradation was analyzed by three different methods and showed a dose-dependent trend that matches microbial inactivation kinetics. Our results provide a deeper mechanistic understanding of aPDT that can guide the scientific community toward the development of optimized photosensitizing drugs and also rationally propose synergistic combinations with antimicrobial chemotherapy.

Palavras-Chave: antimicrobial agents; photodynamic therapy; biochemical reaction kinetics; microbial drug resistance

SABINO, CAETANO P.; RIBEIRO, MARTHA S.; WAINWRIGHT, MARK; ANJOS, CAROLINA dos; SELLERA, FABIO P.; DROPA, MILENA; NUNES, NATHALIA B.; BRANCINI, GUILHERME T.P.; BRAGA, GILBERTO U.L.; ARANA-CHAVEZ, VICTOR E.; FREITAS, RAUL O.; LINCOPAN, NILTON; BAPTISTA, MAURICIO S. The biochemical mechanisms of antimicrobial photodynamic therapy. Photochemistry and Photobiology, v. 99, n. 2, p. 742-750, 2023. DOI: 10.1111/php.13685. Disponível em: http://repositorio.ipen.br/handle/123456789/34012. Acesso em: $DATA.

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Abstract: Nitrate stable isotopes provide information about nitrate contamination and cycling by microbial processes. The Fischa-Dagnitz (Austria) spring and river system in the agricultural catchment of the Vienna basin shows minor annual variance in nitrate concentrations. We measured nitrate isotopes (δ15N, δ18O) in the source spring and river up to the confluence with the Danube River (2019–2020) with chemical and water isotopes to assess mixing and nitrate transformation processes. The Fischa-Dagnitz spring showed almost stable nitrate concentration (3.3 ± 1.0 mg/l as NO3–-N) year-round but surprisingly variable δ15N, δ18O-NO3– values ranging from +5.5 to +11.1‰ and from +0.5 to +8.1‰, respectively. The higher nitrate isotope values in summer were attributed to release of older denitrified water from the spring whose isotope signal was dampened downstream by mixing. A mixing model suggested denitrified groundwater contributed > 50 % of spring discharge at baseflow conditions. The isotopic composition of NO3– in the gaining streams was partly controlled by nitrification during autumn and winter months and assimilation during the growing season resulting in low and high δ15N-NO3– values, respectively. NO3– isotope variation helped disentangle denitrified groundwater inputs and biochemical cycling processes despite minor variation of NO3– concentration.