Abstract: Objectives: The primary aim of this ex vivo study was to evaluate thermal damage and cutting efficiency of micro and super pulsed diode lasers. The secondary aim was to suggest a guideline to perform simple surgical excisions adequate for histopathological evaluation. Material and Methods: Ten groups of 10 specimens of pig tongues were excised using a blade (G1), a micro pulsed (G2–G9), and a super pulsed diode (G10) lasers. Different output power, pulse duration, pulse interval, and duty cycle were tested. Quantitative measures of thermal damage and excision times were recorded. Statistical analysis was performed at a significance level of 5%. Results: The control group (G1) presented no thermal damage. Within the laser groups (G2–G10), no statistically significant differences in depth of thermal damage (μm) were noted. G3 showed significantly less area of thermal damage (mm2) when compared with G7 and G9 (p < .05). The median excision time of the control group and super pulsed diode laser group were significantly lower (p < .001) than the micro pulsed diode laser groups. Conclusions: The cutting efficiency of the super pulsed diode laser is comparable to traditional blade, and with appropriate parameters, these lasers can produce predictable surgical outcomes with less collateral damage.

Palavras-Chave: diode-pumped solid state lasers; pulse techniques; animal tissues; oral cavity; damage; diagnostic techniques; biopsy; temperature dependence; depth dose distributions; depth dose distributions; optical depth curve; histological techniques

PRADO, MARILIZA C.O.; NWIZU, NGOZI N.; PATEL, SHALIZEH A.; STRECKFUS, CHARLES F.; ZEZELL, DENISE M.; BARROS, JULIANA. Thermal damage and excision time of micro and super pulsed diode lasers: a comparative ex vivo analysis. Clinical and Experimental Dental Research, v. 8, n. 6, p. 1655-1663, 2022. DOI: 10.1002/cre2.670. Disponível em: http://repositorio.ipen.br/handle/123456789/33579. Acesso em: $DATA.

Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.

Como referenciar este item

Abstract: The activity concentrations of 40K, 210Pb, 210Po, 226Ra, 228Ra, 228Th, 230Th, 232Th, 234U, and 238U were determined in 82 food samples, grouped into 20 food groups according to the Brazilian Total Diet, which reflects the dietary habits of a population, for the rural and urban areas of Poços de Caldas city, a High Background Radiation Area. The highest activity concentration found in the food samples was due to 40K being present in all types of food. Among the other radionuclides, high activity concentrations were found for 210Pb in beans and salt, 210Po in fish, 226Ra and 228Ra in nuts and seeds. The main food groups that contributed most to the effective dose, in urban and rural regions, were beans and beverages. The effective doses, due to the ingestion of the analysed food groups, were of 0.44 and 0.60 mSv y−1 and the lifetime cancer risks were 1.6 × 10−3 and 2.3 × 10−3 for the urban and rural Poços de Caldas population, respectively.

Palavras-Chave: diet; natural radioactivity; food; ingestion; background radiation

ROSA, MYCHELLE M.L.; MAIHARA, VERA A.; TADDEI, MARIA H.T.; CHEBERLE, LUAN T.V.; AVEGLIANO, ROSEANE P.; SILVA, PAULO S.C. The use of total diet study for determination of natural radionuclides in foods of a high background radiation area. Journal of Environmental Radioactivity, v. 242, p. 1-9, 2022. DOI: 10.1016/j.jenvrad.2021.106793. Disponível em: http://repositorio.ipen.br/handle/123456789/33002. Acesso em: $DATA.

Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.

Como referenciar este item

Abstract: Background: Methylene blue (MB)-mediated photodynamic inactivation (PDI) has shown good results in killing Candida spp. Although MB solutions are commonly used, new formulations have been designed to improve PDI. However, chemical substances in the formulation may interfere with the PDI outcome. In this sense, different methodologies should be used to evaluate PDI in vitro. Herein, we report different methodologies to evaluate the effects of PDI with an oral formulation (OF) containing 0.005% MB on Candida albicans biofilm. Methods: Biofilms were treated using the MB-OF, with 5 min pre-irradiation time and exposure to a 640 nm LED device (4.7 J/cm2). PDI was evaluated by the XTT reduction test, counting the colony forming units (CFU), a filamentation assay, crystal violet (CV) staining, and scanning electronic microscopy (SEM). Results: PDI was able to reduce around 1.5 log10 CFU/mL, even though no significant differences were noted in metabolic activity in comparison to the control immediately after PDI. A significant decrease in yeast to hyphae transition was observed after PDI, while the biofilm exhibited flattened cells and a reduced number of yeasts in SEM. The CV assay showed increased biomass. Conclusion: MB-OF-mediated PDI was effective in C. albicans biofilms, as it significantly reduced the CFU/mL and the virulence of surviving cells. The CV data were inconclusive, since the OF components interacted with the CV, making the data useless. Taken together, our data suggest that the association of different methods allows complementary responses to assess how PDI mediated by a formulation impacts biofilms.

Palavras-Chave: antimicrobial agents; methylene blue; chemotherapy; photodynamic therapy

COLLINA, GABRIELA A. da; CABRAL, FERNANDA V.; MONTEIRO, CAROLINA M.; MACHADO, GABRIELA B.; GONCALVES, JOSE M.L.A.; FREIRE, FERNANDA; PRATES, RENATO A.; RIBEIRO, MARTHA S.; PAVANI, CHRISTIANE. The importance of combining methods to assess Candida albicans biofilms following photodynamic inactivation. Photodiagnosis and Photodynamic Therapy, v. 38, p. 1-6, 2022. DOI: 10.1016/j.pdpdt.2022.102769. Disponível em: http://repositorio.ipen.br/handle/123456789/33201. Acesso em: $DATA.

Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.

Como referenciar este item

Abstract: The effect of hot stamping on the corrosion properties of boron-manganese 22MnB5 steel coated with hot-dip aluminum-silicon was evaluated under severe conditions by a continuous salt spray test (SST). The corrosion mechanism changed from localized to generalized, as cathodic precipitates were not present after hot stamping. Intrinsic defects in press-hardened steel samples were the reason for severe damage in both metallic coating and steel substrate under SST conditions. The red rust formed at the top surface, characterized as different iron-based compounds, is due to both the iron diffusion from the steel substrate toward the surface and the corrosion of the steel substrate.

COUTO, CAMILA P.; BAERT, KITTY; COSTA, ISOLDA; PANOSSIAN, ZEHBOUR; DE GRAEVE, IRIS; TERRYN, HERMAN; ROSSI, JESUALDO L.; REVILLA, REYNIER I. The hot-stamping effect on the corrosion properties of the 22MnB5 steel coated with hot-dip aluminum-silicon assessed by a salt spray test and Raman spectroscopy. Corrosion, v. 78, n. 4, p. 339-349, 2022. DOI: 10.5006/4016. Disponível em: http://repositorio.ipen.br/handle/123456789/33886. Acesso em: $DATA.

Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.

Como referenciar este item

Abstract: Zinc oxide (ZnO) and ZnO-silver (ZnO-Ag) nanoparticles (NPs) are widely used in different fields, such as biomedicine and food packaging, due to their recognized antibacterial activity and safety for human health. In this paper, ZnO and ZnO-Ag NPs were incorporated into poly(butylene adipate-co-terephthalate) (PBAT), in two contents (0.5 and 1 wt%), to prepare antibacterial films. The NPs were characterized by TEM and FT-Raman, and the films were analyzed by FT-Raman and FTIR, mechanical properties, SEM–EDS, TGA, DSC, XRD, and antibacterial properties against Escherichia coli. The results indicate that both NPs were physically retained in the polymer structure, with a strong electrostatic interaction between the mixture components, reflecting excellent mechanical behavior. The films showed good thermal stability, without significant changes, and the nanocomposites enhanced PBAT crystallinity from 18 to 23% and 27% for PBAT-ZnO and PBAT-ZnO-Ag films, respectively. The mechanical, thermal, and crystallinity results indicated the excellent potential of NPs in biodegradable films to improve properties and expand applicability. The antimicrobial activity is higher for PBAT-ZnO-Ag films than the pristine PBAT due to the synergic effect between the NPs and the oxidation–reduction potential of each nanoparticle, where the ZnO protect and stabilized the Ag-NPs, acting as an Ag-carrier, enhancing its antimicrobial effects after the film’s preparation and allowing its applicability in biomedical products or food packaging.

Palavras-Chave: antimicrobial agents; zinc oxides; nanoparticles; silver; polymers; bacteria; escherichia coli

SOUZA, ALANA G. de; KOMATSU, LUIZ G.H.; BARBOSA, RENNAN F.S.; PARRA, DUCLERC F.; ROSA, DERVAL S. The effect of ZnO nanoparticles as Ag‑carrier in PBAT for antimicrobial films. Polymer Bulletin, v. 79, n. 6, p. 4031-4048, 2022. DOI: 10.1007/s00289-021-03681-2. Disponível em: http://repositorio.ipen.br/handle/123456789/33109. Acesso em: $DATA.

Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.

Como referenciar este item

Abstract: Background: Besides controlling the expression of peripheral tissue antigens, the autoimmune regulator (AIRE) gene also regulates the expression of adhesion genes in medullary thymic epithelial cells (mTECs), an essential process for mTEC-thymocyte interaction for triggering the negative selection in the thymus. For these processes to occur, it is necessary that the medulla compartment forms an adequate three-dimensional (3D) architecture, preserving the thymic medulla. Previous studies have shown that AIRE knockout (KO) mice have a small and disorganized thymic medulla; however, whether AIRE influences the mTEC-mTEC interaction in the maintenance of the 3D structure has been little explored. Considering that AIRE controls cell adhesion genes, we hypothesized that this gene affects 3D mTEC-mTEC interaction. To test this, we constructed an in vitro model system for mTEC spheroid formation, in which cells adhere to each other, establishing a 3D structure. Results: The comparisons between AIRE wild type (AIREWT) and AIRE KO (AIRE−/−) 3D mTEC spheroid formation showed that the absence of AIRE: i) disorganizes the 3D structure of mTEC spheroids, ii) increases the proportion of cells at the G0/G1 phase of the cell cycle, iii) increases the rate of mTEC apoptosis, iv) decreases the strength of mTECmTEC adhesion, v) promotes a differential regulation of mTEC classical surface markers, and vi) modulates genes encoding adhesion and other molecules. Conclusions: Overall, the results show that AIRE influences the 3D structuring of mTECs when these cells begin the spheroid formation through controlling cell adhesion genes.

Palavras-Chave: spheroids; genes; immune system diseases; adhesion; epithelium; cell cultures

MONTELEONE-CASSIANO, ANA C.; DERNOWSEK, JANAINA A.; MASCARENHAS, ROMARIO S.; ASSIS, AMANDA F.; PITOL, DIMITRIUS; MOREIRA, NATALIA C.S.; SAKAMOTO-HOJO, ELZA T.; ISSA, JOAO P.M.; DONADI, EDUARDO A.; PASSOS, GERALDO A. The absence of the autoimmune regulator gene (AIRE) impairs the three‑dimensional structure of medullary thymic epithelial cell spheroids. BMC Molecular and Cell Biology, v. 23, n. 1, p. 1-17, 2022. DOI: 10.1186/s12860-022-00414-9. Disponível em: http://repositorio.ipen.br/handle/123456789/33159. Acesso em: $DATA.

Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.

Como referenciar este item

Abstract: Porous ceria: 20 mol% gadolinia (20GDC) ceramic membranes were prepared by tape casting (TC) and freeze-drying (FD) techniques, obtaining ceramic matrices with randomly dispersed round pores and with an aligned pore structure, respectively. Samples were sintered at 1450 °C, followed by infiltration of molten eutectic sodium-lithium carbonates (NLC). The pore morphology of 20GDC-TC and 20GDC-FD composite membranes was evaluated by analysis of scanning electron microscopy images. The electrical resistivity was determined by electrochemical impedance spectroscopy in the 1 Hz - 10 MHz frequency range from 300 °C to 700 °C, covering the solid-to-molten NLC temperature range, showing that the aligned pore structure improved the conductivity of the ceramic matrix in addition to facilitating molten carbonate infiltration, improving the total (bulk + interfaces) electrical conductivity of the composite membrane. Permeation experiments showed high CO2 permeation rates reached 5.35 × 10−7 mol m−2 s−1 Pa−1 at 800 °C. The infiltration of molten sodium-lithium carbonate in gadolinium-doped ceria prepared by the freeze-drying technique is proposed as an optimized procedure for producing membranes for carbon dioxide separation.

Palavras-Chave: cerium; doped materials; gadolinium oxides; molten salts; carbon dioxide; composite materials

CARVALHO, SABRINA G.M.; MUCCILLO, ELIANA N.S.; FONSECA, FABIO C.; MULLER, MICHAEL; SCHULZE-KUPPERS, FALK; BAUMANN, STEFAN; MEULENBERG, WILHELM A.; GUILLON, OLIVIER; MUCCILLO, REGINALDO. Tape-casting and freeze-drying gadolinia-doped ceria composite membranes for carbon dioxide permeation. Journal of Membrane Science, v. 648, p. 1-10, 2022. DOI: 10.1016/j.memsci.2022.120355. Disponível em: http://repositorio.ipen.br/handle/123456789/33006. Acesso em: $DATA.

Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.

Como referenciar este item

Abstract: Owing to the localized plasmon resonance of an ensemble of interacting plasmonic nanoparticles (NPs), there has been a tremendous drive to conceptualize complex optical nanocircuits with versatile functionalities. In comparison to modern research, there is still not a sufficient level of sophistication to treat the nanostructures as lumped circuits that can be adjusted into complex systems on the basis of a metatronic touchstone. Here, we present the design, assembly, and characterization of single relatively complex photonic nanocircuits by accurately positioning several metallic and dielectric nanoparticles acting as modular lumped elements. In this research, Au NPs along with silica NPs were used to compare the proficiency and precision of our lumped circuit model analytically. On increasing the size of an individual Au NP, the spectral peak resonance not only modifies but also causes more scattering efficiency which increases the fringe capacitance linearly and decreases the nanoinductance of lumped circuit element. The NPs-based assembly induced the required spectral resonance ascribed by simple circuit methods and are depicted to be actively reconfigurable by tuning the direction or polarization of input signals. Our work demonstrates a vital step toward developing the modern modular designing tools of complex electronic circuits into nanophotonic-related applications.

Palavras-Chave: plasmons; nanomaterials; elements; nanoparticles; electronic circuits

FAROOQ, SAJID; SHAFIQUE, SHAREEN; AHSAN, ZISHAN; CARDOZO, OLAVO; WALI, FAIZ. Tailoring the scattering response of optical nanocircuits using modular assembly. Nanomaterials, v. 12, n. 17, p. 1-12, 2022. DOI: 10.3390/nano12172962. Disponível em: http://repositorio.ipen.br/handle/123456789/33452. Acesso em: $DATA.

Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.

Como referenciar este item

Abstract: The present work aimed at the development of Pt-TiO2/SiO2 materials applied to the degradation of a pharmaceutical pollutant in a fixed-bed microreactor in continuous mode. First, a wide investigation of the optimal platinum content in TiO2/SiO2 was carried out based on extensive characterization through XRD, DRS, SEM, TEM, and XPS techniques. For the content range studied, no significant changes were observed in the crystallinity of the material, with peaks related to the anatase phase and PtO2 in the diffractograms. SEM images combined with EDS spectra indicated the presence of platinum and a large heterogeneity in the particles. MET analyses showed PtO2 nanoparticles in close contact with TiO2, allowing the formation of a type II heterojunction. XPS showed platinum in the 0 and +4 oxidation states, suggesting that platinum metal and PtO2 are both present. Regarding the degradation experiments, the optimal catalyst achieved 81% degradation of acetaminophen for a residence time of 1 h, while the catalyst without platinum reached only 27% degradation. The catalyst activity dropped from 81 to 57% in 2 h and remained stable for six reuse cycles. Increasing the inlet flow rate and concentration reduced the pollutant degradation although there was an increase in the reaction rate. Finally, a photocatalytic mechanism was proposed in which a type II heterojunction was developed, with generation of hydroxyl radicals by the positive holes in the VB of TiO2 as well as superoxide radicals by the electrons in the CB of PtO2.

GUSMAO, CAROLINA de A.; BORGES, LAURA T.; PALHARIM, PRISCILA H.; OTUBO, LARISSA; RODRIGUES, ORLANDO; GOUVEA, DOUGLAS; RAMOS, BRUNO; TEIXEIRA, ANTONIO C.S.C. Synthesis, characterization, and application of Pt/PtO2-TiO2/SiO2 materials on a continuous flow packed bed microreactor for enhanced photocatalytic activity under sunlight. Water, v. 14, n. 23, p. 1-18, 2022. DOI: 10.3390/w14233864. Disponível em: http://repositorio.ipen.br/handle/123456789/33885. Acesso em: $DATA.

Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.

Como referenciar este item

Abstract: A tailored nanostructured CuO–ZnO/Al2O3 catalyst was obtained from nanocomposites via sonochemical route through core/shell assisted by reverse micelle synthesis. The as-synthesized nanocomposites consisted of Cu, Zn and Al domains coated by a lauric acid shell structure with controlled physicochemical properties. Combining these features, a porous CuO–ZnO/Al2O3 supported catalyst was obtained from CuZnAl@C nanocomposite, in which Cu and Zn oxide nanoparticles interacted quite strongly with alumina. In this study, a nanostructured CuO–ZnO/Al2O3 was applied to oxidize ethylbenzene in the presence of H2O2. Catalytic results further demonstrated that the nanostructured solid had ethylbenzene conversion superior to 20% and good selectivities to acetophenone, benzaldehyde and benzoic acid compared to a benchmark CuZnAl catalyst obtained by the sol-gel method.

Palavras-Chave: porous materials; aluminium oxides; nanocomposites; oxidation; nanomaterials; copper alloys

CARMO, JOSE V.C. do; BEZERRA, RITA de C.F.; TEHAUACANERO-CUAPA, SAMUEL; RODRIGUEZ-AGUADO, E.; LANG, ROSSANO; CAMPOS, ADRIANA F.; DUARTE, GIAN; SARAIVA, GILBERTO D.; OTUBO, LARISSA; OLIVEIRA, ALCINEIA C.; RODRIGUEZ-CASTELLON, E. Synthesis of tailored alumina supported Cu-based solids obtained from nanocomposites: catalytic application for valuable aldehyde and ketones production. Materials Chemistry and Physics, v. 292, p. 1-18, 2022. DOI: 10.1016/j.matchemphys.2022.126800. Disponível em: http://repositorio.ipen.br/handle/123456789/33443. Acesso em: $DATA.

Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.

Como referenciar este item