INSTITUTO DE PESQUISAS ENERGÉTICAS E NUCLEARES
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Navegação IPEN por Agências de fomento "Instituto de Pesquisas Energéticas e Nucleares (IPEN)"

Navegação IPEN por Agências de fomento "Instituto de Pesquisas Energéticas e Nucleares (IPEN)"

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  • IPEN-DOC 29785

    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

    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

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  • IPEN-DOC 29130

    SILVA, C.A.J. ; BRAGUIN, L.N.M. ; ROSSI, J.L. ; SCAPIN, M.A. ; COSTA, I. ; SAIKI, M. . Analyses of magnesium-based alloys by nuclear techniques. Brazilian Journal of Radiation Sciences, v. 10, n. 3B, p. 1-12, 2022. DOI: 10.15392/2319-0612.2022.1969

    Abstract: Magnesium-based alloys have been proposed for use in temporary biomaterials in the applications that request their biocompatibility and degradability. Analyses of these alloys are of great interest to verify if their element composition is within the product specification and also to evaluate the impurities that may cause toxic effects to the human health or influence in their corrosion processes. In this study, nuclear techniques of neutron activation analysis (NAA) and wavelength dispersive X ray fluorescence spectrometry (WD XRFS) were applied in the analyses of two magnesium-based alloys: commercially pure magnesium (CP-Mg) and AZ31 alloy. The NAA procedure consisted of irradiation aliquots of sample and synthetic element standards followed by measurements using a HGe detector and the WD XFRS was carried out using the Model RIX 3000 X-ray spectrometer. In the CP-Mg sample several element impurities were quantified. In the AZ31 alloy, the alloying element mass fractions were within the product specification and the impurities of As, La, Na and Sb were also quantified. Nickel and sulfur were quantified only by WD XFRS. The Horwitz method was a good parameter to evaluate the repeatability of the results in Al, Mg, Mn and Zn determinations. In conclusion, the results indicated the viability of using NAA and WD XFRS in the analyses of magnesium-based materials mainly due its multielement determinations, precision of the results, quantification of elements in a wide range of mass fractions and the lack of need for sample dissolution.

    Palavras-Chave: magnesium base alloys; biological materials; biodegradation; decomposition; fluorescence spectroscopy; x-ray fluorescence analysis; x radiation; specifications

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  • IPEN-DOC 29978

    CASTRO, LAURA F. ; CRUZ, PEDRO V.D. da ; BONIFACIO, RAFAEL N. ; LAZAR, DOLORES R.R. . Caracterização de materiais à base de grafeno sintetizados a partir de diferentes fontes de grafite. In: PROGRAMA INSTITUCIONAL DE BOLSAS DE INICIAÇÃO CIENTÍFICA; SEMINÁRIO ANUAL PIBIC, 29.; SEMINÁRIO ANUAL PROBIC, 20.; SEMINÁRIO ANUAL PIBITI, 13., 23-24 de novembro, 2023, São Paulo, SP. Resumo expandido... São Paulo, SP: IPEN-CNEN/SP, 2023.

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  • IPEN-DOC 28862

    GONCALVES, JOSEMARY A.C. ; MANGIAROTTI, ALESSIO; BUENO, CARMEN C. . Characterization of a thin photodiode as a routine dosimeter for low-dose radiation processing applications. Radiation Physics and Chemistry, v. 198, p. 1-7, 2022. DOI: 10.1016/j.radphyschem.2022.110200

    Abstract: The characterization of a dosimetry system based on a commercial PIN photodiode as a routine dosimeter in a 60Co industrial facility is reported. The main parameters of the dose rate response (repeatability, reproducibility, and angular dependence) and the dose response (dependence on both dose rate and accumulated dose) are investigated. The results obtained, within a dose rate range of 3.7–52.8 Gy/h and doses up to 200 Gy, fully adhere to the standard protocols established for radiation processing dosimetry. The diode performance as a routine dosimeter is validated by the good overall agreement with radiochromic films and alanine dosimetry.

    Palavras-Chave: photodiodes; thin films; gamma radiation; dosimetry; silicon diodes

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  • IPEN-DOC 27864

    GONCALVES, J.A.C. ; BUENO, C.C. ; MANGIAROTTI, A.. Comparative evaluation of the performance of thin diodes used as on-line dosimeters in radiation processing applications. Brazilian Journal of Radiation Sciences, v. 9, n. 1A, p. 1-8, 2021. DOI: 10.15392/bjrs.v9i1A.1327

    Abstract: In this work, we report a comparison between the performance of two samples of commercial PIN photodiodes (SFH206K from Osram® and S2506-04 from Hamamatsu®) mainly addressing the variation of their current sensitivities with accumulated dose ranging from 0-15 kGy. All the results so far obtained have revealed that the radiation induced currents are linearly dependent on dose rates from 3.65 to 55.64 Gy/h. The current sensitivity of both unirradiated diodes (0.178 nA.h/Gy.mm3) slightly decreases with accumulated dose, namely 0.32%/kGy (SFH206K) and 1.4%/kGy (S2506-04). Although the SFH206K device compares favorably with the S2506-04, both diodes can be considered as a low budge alternative, good enough for on-line dosimetry applications in the field of radiation processing.

    Palavras-Chave: cobalt 60; comparative evaluations; dose rates; dosemeters; dosimetry; gamma radiation; performance; photodiodes; sensitivity

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  • IPEN-DOC 29684

    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

    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

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  • IPEN-DOC 28811

    MILAGRE, MARIANA X. ; PEREIRA, MARCO S. ; GOMES, ANTONIO A. ; SCAPIN, MARCOS ; FRANCO, MARGARETH ; YOKAICHIYA, FABIANO; GENEZINI, FREDERICO ; COSTA, ISOLDA . Corrosion characterization of the 6061 Al–Mg–Si alloy in synthetic acid rain using neutron tomography. Applied Radiation and Isotopes, v. 184, p. 1-8, 2022. DOI: 10.1016/j.apradiso.2022.110197

    Abstract: Neutron tomography has gained increasing importance as an imaging technique for materials characterization. In general, neutron beams are able to show microstructure features of hydrogenous materials, even enfolded with thick metal layers. In the present paper, neutron tomography and observation of cross section images were successfully applied to investigate the corrosion features of the 6061 Al–Mg–Si alloy. The results showed good agreement between neutron 3D tomography and the cross section images obtained in the high attenuation areas of the samples, whereas significant differences in depth of corrosion penetration were obtained between the results from Neutron Tomography and 3D optical profilometry.

    Palavras-Chave: aluminium alloys; corrosion resistance; three-dimensional calculations; stresses; neutrons; tomography

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  • IPEN-DOC 29080

    BERBEL, LARISSA O. ; VIVEIROS, BARBARA V.G. de ; MICELLI, ANA L.P. ; NIGRO, FREDERICO ; ROSSI, JESUALDO L. ; COSTA, ISOLDA . Corrosion mechanism of Ti-6Al-4V morse taper dental implants connected to 316 L stainless steel prosthetic abutment. Materials Today Communications, v. 33, p. 1-13, 2022. DOI: 10.1016/j.mtcomm.2022.104583

    Abstract: The aim of this work was to investigate the effect of galvanic coupling between stainless steel AISI 316 L abutment type Morse taper and implant made of ASTM F1108–14 Ti-6Al-4V alloy. The assembly of the two alloys was carried out using mechanical imbrication by means of successive strikes at 0.05 J force onto the abutment inserted in the implant along the centerline. Corrosion attack at the interface of the alloys was evaluated according to the number of strikes used for joining the parts. Corrosion resistance was evaluated for the samples by open circuit potential measurements as function of time and scanning vibrating electrode technique (SVET) and scanning ion selective electrode technique (SIET) in phosphate buffer solution with pH adjusted to 3.0, and into which hydrogen peroxide was added to simulate tissue inflammatory conditions. Samples were evaluated at the cross and longitudinal sections. Results indicated that the number of strikes used in assembling affected corrosion susceptibility. The lowest amount of corrosion products was associated to the highest number of strikes used. The corrosion resistance was related to the characteristics of the crevice between the implant and the abutment.

    Palavras-Chave: dentistry; implants; titanium alloys; stainless steel-316l; morse potential; corrosion

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  • IPEN-DOC 27204

    GONCALVES, JOSEMARY A.C. ; MANGIAROTTI, ALESSIO; BUENO, CARMEN C. . Current response stability of a commercial PIN photodiode for low dose radiation processing applications. Radiation Physics and Chemistry, v. 167, p. 1-4, 2020. DOI: 10.1016/j.radphyschem.2019.04.026

    Abstract: This work investigates the on-line response of a thin diode, for monitoring low dose radiation processing, with respect to the linearity between current and dose-rate, the most interesting part being the variation of the current sensitivity with the accumulated dose. The results obtained indicate that the current response of this diode is linear and quite stable with repeatability better than 0.2% and a slight decay of 5% of the current sensitivity (0.28 nA h/Gy) for doses up to 15 kGy. In an attempt to give theoretical support to these results, the radiation induced current is calculated as a function of the dose rate assuming the diode to be thin as compared with the standard values of the minority carrier diffusion lengths in intrinsic silicon. Agreement within 2% is found between calculations and experimental data.

    Palavras-Chave: dose rates; radiation doses; low dose irradiation; dosimetry; silicon diodes; thin films; photodiodes; radiation monitoring

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  • IPEN-DOC 27919

    SILVA, C.A.J. ; BRAGUIN, L.N.M. ; ROSSI, J.L. ; COSTA, I. ; SAIKI, M. . Determination of chemical elements in magnesium-based materials by neutron activation analysis. Brazilian Journal of Radiation Sciences, v. 9, n. 1A, p. 1-16, 2021. DOI: 10.15392/bjrs.v9i1A.1584

    Abstract: Over the last decades there was an increasing interest in using magnesium alloys for medical applications due to their biodegradability in the human body, providing a temporary mechanical support and corroding completely after the tissue healing. Although magnesium is a non-toxic element, it is of great importance to evaluate the element concentration, as well as the impurities present in both, pure magnesium and magnesium alloys, as the AZ31. The purpose of this study was to analyze the element composition of these materials using the method of neutron activation analysis (NAA). Standard Reference Materials (SRMs) acquired from National Institute of Standards and Technology (NIST) were analyzed for analytical quality control. Short and long term irradiations were carried out at the IEA-R1 nuclear research reactor and gamma-ray activities induced to the samples and element standard were measured using HPGe detector coupled to a Digital Spectrum Analyzer. The radioisotopes were identified by gamma ray energies and half-life. Concentrations of the elements As, Cr, Cd, Co, Fe, In, La, Mg, Mn, Mo, Na, Sb, V, W and Zn were determined in pure magnesium sample and the Al, As, La, Mg, Mn, Na, Sb and Zn in the AZ31 alloy, calculated by comparative method. The SRMs were analyzed by applying the same experimental conditions used for magnesium-based materials and their results presented good accuracy and precision. Thus, from the measurements obtained in this study it can be concluded that NAA is a suitable method for element determinations in magnesium-based materials providing reliable results.

    Palavras-Chave: biological materials; gamma radiation; high-purity ge detectors; impurities; magnesium alloys; quality control

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  • IPEN-DOC 30158

    ROSERO, WILMMER A.A. ; BARBEZAN, ANGELICA B. ; RIGO, MARIA E.Z. ; RODRIGUES, PRISCILA S. ; TEODORO, LARA E.H. ; TALACIMON, CRISTHIAN F. ; ZEITUNI, CARLOS A. ; ROSTELATO, MARIA E.C.M. . Development of radioactive nanoparticles functionalized with gum arabic to be used in nanobrachytherapy. In: BRAZIL MRS MEETING, 21st, October 1-5, 2023, Maceió, AL. Abstract... São Carlos, SP: Aptor Software, 2023. p. 553-553.

    Abstract: The development of new materials emerges as an alternative to the treatment of cancer, from the combination of nanotechnology and brachytherapy a new area of research was born, Nanobrachytherapy, which through the properties of nanometric materials can achieve better results in the fight against cancer. The objective of this work is classified as radiotherapy, which consists of the use of ionizing radiation to destroy or inhibit the growth of abnormal cells that form a tumor. [1] The ability to integrate NPsAu into biological systems is due to the nanometric dimensions of NPsAu probes which facilitate their incorporation into biological systems, as well as their bioconjugation and non-cytotoxic potential. [2] Taking into account the previous objective, gold was selected as the base element for obtaining nanometric systems, which due to its chemical richness and especially due to the intrinsic properties of one of its radioisotopes, which would allow us in theory to meet the stated objective. . Initially, it was based on the knowledge of the literature, and non-radioactive nanometric systems were obtained, and after a series of stability, characterization and application tests, the radioactive nanometric systems were obtained. Working with radioactive systems posed a great challenge, and up to now it presents us with situations to solve, but we have managed to create a methodology for obtaining, characterizing and applying radioactive gold nanoparticles, and also obtaining positive results from their application.

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  • IPEN-DOC 30047

    BERECZKI, ALLAN ; DIPOLD, JESSICA ; FREITAS, ANDERSON Z. ; WETTER, NIKLAUS . Direct nanoplastics detection below the diffraction limit using micro Raman. In: CONFERENCE ON LASERS AND ELECTRO-OPTICS: APPLICATIONS AND TECHNOLOGY, May 7-12, 2023, San Jose, CA, USA. Proceedings... Washington, DC, USA: Optica Publishing Group, 2023. DOI: 10.1364/CLEO_AT.2023.ATh3I.2

    Abstract: Raman spectra of polystyrene nanoparticles of 50 nm diameter were directly measured using micro-Raman spectroscopy. Data analysis demonstrated that particles as small as 20 nm could be directly measured with this simple and robust technique.

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  • IPEN-DOC 29098

    GONCALVES, JOSEMARY A.C. ; MANGIAROTTI, ALESSIO; BUENO, CARMEN C. . Dose rate mapping of an industrial 60Co irradiator using an online photodiode-based dosimetry system. Radiation Physics and Chemistry, v. 200, p. 1-6, 2022. DOI: 10.1016/j.radphyschem.2022.110387

    Abstract: In this work, a housemade dosimetry system based on a thin photodiode is applied for online mapping of dose rates, between 2.6 and 37.7 Gy/h, delivered by a Panoramic 60Co industrial facility. The operational principle of the dosimeter relies on the real-time acquisition of the induced currents from the irradiated diode operating in the short-circuit mode without externally applied voltage. The radial mapping of the radiation field is performed by rotating the diode around the central axis of the panoramic irradiator, covering 360° at intervals of 18°. The results are benchmarked with alanine dosimeters, Monte Carlo simulations, and reference dose rates retrieved from the facility calibration. The overall consistency of the whole data complies with the maximum response variation (8%, k = 2) recommended by the International Standard Protocols for routine dosimeters in radiation processing dosimetry. It reveals that the photodiode-dosimetry system is a reliable alternative to map dose rate fields and the effectiveness of Monte Carlo simulations as a predictive tool for dose rate measurements in an irradiator.

    Palavras-Chave: dose rates; dosemeters; photodiodes; irradiation; cobalt 60; dosimetry

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  • IPEN-DOC 30086

    FERREIRA, LUANA da S. . Efeito da hipóxia na expressão de transportadores de zinco em linhagem de adenocarcinoma renal / Effect of hypoxia on the expression of zinc transporters in renal adenocarcinoma cell line . 2023. Dissertação (Mestrado em Tecnologia Nuclear) - Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP, São Paulo. 47 p. Orientador: Maria Helena Bellini Marumo. DOI: 10.11606/D.85.2023.tde-06102023-144033

    Abstract: O carcinoma de células renais (CCR) é um tumor sólido, maligno e heterogêneo, de origem no epitélio tubular renal. Existem diversas classificações histopatológicas, sendo de maior ocorrência a de células claras (CCRcc). Seu surgimento está associado à síndrome de von Hippel-Lindau, um regulador de resposta ao estresse, divisão, morte e diferenciação celular, e a perda de sua funcionalidade faz com que a degradação do fator induzido por hipóxia (HIF) seja afetado. Por sua vez, a subunidade HIFα se torna altamente expressa devido ao microambiente tumoral hipóxico ocasionado pelo tumor sólido, uma característica importante deste tipo de tumor. HIFα superexpresso se torna um dímero junto a subunidade HIF-β no núcleo celular, ativando diversas vias favoráveis para a progressão do tumor. Zinco (Zn) é o segundo oligoelemento mais abundante do corpo humano, sendo assim, pequenas variações da sua concentração poderão afetar o ambiente celular. Os transportadores de zinco possuem papel fundamental na homeostase deste oligoelemento, os ZnTs e ZIPs possuem papéis opostos nessa regulação, mas orquestram a homeostase em conjunto. O perfil de expressão destes transportadores no adenocarcinoma renal ainda não está esclarecido, bem como o efeito da hipóxia sobre eles. Na linhagem celular imortalizada 786-0, a técnica de RT-qPCR foi capaz de verificar um aumento na expressão do RNA mensageiro (RNAm) de HIF1-α, comprovando a eficiência da técnica de indução da hipóxia. Os canais ZnT1, ZnT2 e ZIP14 apresentaram um aumento de sua expressão, enquanto os canais ZnT9, ZIP1, ZIP4 ZIP10 e ZIP11 apresentaram diminuição da expressão. Através da técnica de western blot, foi verificado um aumento do nível proteico de ZnT1 e ZIP14, e uma diminuição de ZnT9 e ZIP1. Tais resultados indicam que a hipóxia é capaz de modular os transportadores de zinco, trazendo novas perspectivas para modelos de estudos.

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  • IPEN-DOC 29619

    BORDON, CAMILA D. da S.; DIPOLD, JESSICA ; WETTER, NIKLAUS U. ; ROSSI, WAGNER de ; FREITAS, ANDERSON Z. ; KASSAB, LUCIANA R.P.. Effect of silver nanoparticles on the optical properties of double line waveguides written by fs laser in Nd3+-doped GeO2-PbO glasses. Nanomaterials, v. 13, n. 4, p. 1-13, 2023. DOI: 10.3390/nano13040743

    Abstract: Nd3+-doped GeO2-PbO glass with silver (Ag) nanoparticles (NPs) are produced with double line waveguides through fs laser processing for photonic applications. A Ti:sapphire fs laser at 800 nm was used to write the waveguides directly into the glass 0.7 mm beneath the surface. This platform is based on pairs of parallel lines with spacing of 10 µm, each pair being formed by two identical written lines but in two different configurations of 4 or 8 separately processed lines, which are coincident. The results of optical microscopy, absorbance measurements, refractive index change, beam quality factor (at 632 and 1064 nm), photoluminescence, propagation losses, and relative gain at 1064 nm are presented. The structural changes in the glass due to the presence of Ag NPs were investigated by Raman spectroscopy. At 632 and 1064 nm, x,y-symmetrical guiding was observed, and for both kinds of overlapping pulses, a refractive index alteration of 10−3 was found in both directions. Photoluminescence growth of ~47% at 1064 nm was observed due to the plasmonic effect of Ag NPs. In dual waveguides containing Ag NPs, the relative gain obtained increased by 40% and 30% for four and eight overlapping lines, respectively, at 600 mW of 808 nm pump power, when compared to waveguides without those metallic NPs. We highlight the resultant positive internal gains of 5.11 and 7.12 dB/cm that showed a growth of ~40% and ~30%, respectively, with respect to the samples without Ag NPs. The increase in photoluminescence and relative gain were related to the local field growth produced by Ag NPs. The present results show that the addition of Ag NPs impacts positively on the optical performance at 1064 nm of double line waveguides processed by fs laser writing in Nd3+-doped GeO2-PbO glass, opening news perspectives for photonics.

    Palavras-Chave: lasers; pulses; germanates; waveguides; optical equipment; silver; nanoparticles

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  • IPEN-DOC 29540

    FERREIRA, LUANA da S. ; OLIVEIRA, SORAIA B. de ; BELLINI, MARIA H. . Effect of the hypoxia on the expression of zinc transporters in renal adenocarcinoma cell line. In: ANNUAL MEETING OF THE BRAZILIAN SOCIETY FOR BIOCHEMISTRY AND MOLECULAR BIOLOGY (SBBq), 51st; CONGRESS OF BRAZILIAN BIOPHYSICAL SOCIETY (SBBf)/LATIN AMERICAN FEDERATION OF BIOPHYSICAL SOCIETIES (Lafebs), 46th, September 5-8, 2022, Águas de Lindóia, SP. Abstract... São Paulo, SP: Sociedade Brasileira de Bioquímica e Biologia Molecular - SBBq, 2022. p. 366-366.

    Abstract: INTRODUCTION: Renal cell carcinoma (RCC) is a tumor responsible for about 1 to 3 % of all malignancies. The most common histological variant is the clear cell carcinoma (ccRCC), representing about 45% of all cases of RCC in adults. ccRCC is associated with the VHL gene mutation. The loss of the VHL protein prevents the degradation of HIF subunits, which are involved in critical oncogenic pathways. Zinc is an essential trace element and its cellular homeostasis is regulated by zinc transporters such as ZIPs and ZNTs. The profile of their expression in renal tumor is still unknown. OBJECTIVES: Evaluate the expression profile of zinc transporters in ccRCC in normoxia and hypoxia culturing conditions. MATERIALS AND METHODS: 786-0 tumor cells were cultured in hypoxic conditions inside a hypoxia chamber with an oxygen absorber to the atmosphere of 1% O2, 5% CO2, and 94% N2, and placed in an incubator at 37°C for 24 hours. The Altair PRO Single-Gas Detector was used to measure the percentage of O2. For gene expression analysis, RTq-PCR was used and the results were analyzed by the Delta-Delta ct method. DISCUSSION AND RESULTS: VEGF and HIF2a expression in 786-0 cells were evaluated to confirm the efficacy of hypoxia chamber. There was a significant increase in the VEGF expression of 312.8±2.14% (P< 0.0001) and HIF2a of 593.4±57.21% (P< 0.0092). Besides that, the gene expression analysis revealed a downregulation in the hypoxic environment of the channels ZNT9 of 71.41±0.84% (P< 0.0001), ZIP1 of 17.45±3.68% (P< 0.0418), ZIP4 of 76.3±9.75% (P< 0.0054) and ZIP10 of 44.96±4.31% (P< 0.0001). CONCLUSION: The hypoxia modulates the expression of Zn channels in 786-0 cells indicating that such channels play a role in the pathophysiology of ccRCC.

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  • IPEN-DOC 28382

    CANTEIRO, LEONARDO T. ; GENOVA, LUIS A. . Estudo do processo de síntese de microesferas de titanato de sódio. In: PROGRAMA INSTITUCIONAL DE BOLSAS DE INICIAÇÃO CIENTÍFICA; SEMINÁRIO ANUAL PIBIC, 27.; SEMINÁRIO ANUAL PROBIC, 18.; SEMINÁRIO ANUAL PIBITI, 11, 6-7 de dezembro, 2021, Online. Resumo expandido... São Paulo, SP: IPEN-CNEN/SP, 2021. p. 84-85.

    Palavras-Chave: titanates; microspheres; sodium compounds; titanium oxides; crystallization; waste water

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  • IPEN-DOC 29865

    GOMES, PAULO V.R. ; BONIFACIO, RAFAEL N. ; SILVA, BARBARA P.G. ; FERREIRA, JOAO C. ; SOUZA, RODRIGO F.B. de ; OTUBO, LARISSA ; LAZAR, DOLORES R.R. ; NETO, ALMIR O. . Graphene deposited on glass fiber using a non-thermal plasma system. Eng, v. 4, n. 3, p. 2100–2109, 2023. DOI: 10.3390/eng4030119

    Abstract: This study reports a bottom-up approach for the conversion of cyclohexane into graphene nanoflakes, which were then deposited onto fiberglass using a non-thermal generator. The composite was characterized using transmission electron microscopy, which revealed the formation of stacked few-layer graphene with a partially disordered structure and a d-spacing of 0.358 nm between the layers. X-ray diffraction confirmed the observations from the TEM images. SEM images showed the agglomeration of carbonaceous material onto the fiberglass, which experienced some delamination due to the synthesis method. Raman spectroscopy indicated that the obtained graphene exhibited a predominance of defects in its structure. Additionally, atomic force microscopy (AFM) analyses revealed the formation of graphene layers with varying levels of porosity.

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  • IPEN-DOC 28769

    TEIXEIRA, LUIZ F.S. ; GIGLIOTTI, RODRIGO; FERREIRA, LUANA da S. ; BELLINI, MARIA H. . Identification of appropriate housekeeping genes for gene expression studies in human renal cell carcinoma under hypoxic conditions. Molecular Biology Reports, v. 49, p. 3885-3891, 2022. DOI: 10.1007/s11033-022-07236-0

    Abstract: Background: Hypoxia pathways are deregulated in clear renal cell carcinoma (ccRCC) because of the loss of the von Hippel-Lindau tumor suppressor function. Quantitative PCR is a powerful tool for quantifying differential expression between normal and cancer cells. Reliable gene expression analysis requires the use of genes encoding housekeeping genes. Therefore, in this study, eight reference candidate genes were evaluated to determine their stability in 786-0 cells under normoxic and hypoxic conditions. Methods and Results: Four different tools were used to rank the most stable genes—geNorm, NormFinder, BestKeeper, and Comparative Ct (ΔCt), and a general ranking was performed using RankAggreg. According to the four algorithms, the TFRC reference gene was identified as the most stable. There was no agreement among the results from the algorithms for the 2nd and 3rd positions. A general classification was then established using the RankAggreg tool. Finally, the three most suitable reference genes for use in 786-0 cells under normoxic and hypoxic conditions were TFRC, RPLP0, and SDHA. Conclusions: To the best of our knowledge, this is the first study to identify reliable genes that can be used for gene expression analysis in ccRCC in a hypoxic environment.

    Palavras-Chave: kidneys; neoplasms; carcinomas; anoxia; genes; standardization

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  • IPEN-DOC 29317

    BORDON, CAMILA D.S.; DIPOLD, JESSICA ; ROSSI, WAGNER de ; FREITAS, ANDERSON Z. ; KASSAB, LUCIANA R.P.; WETTER, NIKLAUS U. . Influence of Ag nanoparticles in waveguides on doped germanate glasses. In: ENCONTRO BRASILEIRO DE ESPECTROSCOPIA RAMAN, 7., 5-8 de dezembro, 2022, São Pedro, SP. Resumo... 2022.

    Abstract: Writing by using femtossecond (fs) laser enables fast prototyping and has low complexity compared to other fabrication methods. For materials that do not allow light confinement and propagation, waveguiding by double-line technology is necessary. Previously, we demonstrated waveguiding in double-lines for undoped germanate and tellurite glasses, as well as GeO2-PbO doped with Er3+/Yb3+ and Nd3+. The results for the Nd3+ glass were promising for the fabrication of integrated amplifiers, lossless components and lasers. This motivated the present investigation, where silver (Ag) nanoparticles (NPs) were added to the Nd3+ doped GeO2-PbO bulk in order to enhance its guiding capabilities. Raman measurements were made with a LabRam HR Evolution - HORIBA, using a 532 nm laser with 100 mW power and a 10 x objective lens with 0.25 NA. An integration time of 1 second and 15 accumulations was used to reduce noise and make the observed peaks clearer. First, the Raman spectrum was measured for the bulk (b) glass (Fig. 1a) and between the written lines (Fig. 1a). There are no substantial changes between these, indicating, as expected, that there are no relevant structural changes in the guiding region between the two lines. However, comparing the bulk region (Fig. 1a) with the inside of the written line with 4 superimposed lines (Fig. 1b), there are major changes in some of the peaks. The peak at 411.2 cm-1 (b) shifted to 433.9 cm-1, indicating modification in the symmetric stretching vibrations of the Ge-O-Ge bonds. The peak at 517.5 cm-1 (b) to 508.1 cm-1 shows changes in the symmetric stretching vibrations along the Ge- O-Ge chain, demonstrating lower density of these bonds in the irradiated region. A slight change of the 782.3 cm-1 and 867.4 cm-1 (b) are also verified, and are related to the Ge-O- and Ge-O-Ge symmetric stretching vibrations in the GeO4 tetrahedral units and asymmetric stretching vibrations of the Ge-O-Ge bonds, respectively. These changes are larger than the ones previously shown for the same material without the Ag NPs, which shows the influence of the nanoparticles during the writing process.

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