Navegação Periódicos - Resumos por ano de publicação "2018"

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  • IPEN-DOC 25567

    MANARAO, D.S.; CORDEIRO, G.L. ; TERTULIANO, A.J.O.; MACHADO, I.F.; LAZAR, D.R.R. ; USSUI, V. ; CESAR, P.F.. Y-TZP reinforced with reduced graphene oxide: evaluation of processing conditions. Dental Materials, v. 34, Suppl. 1, p. e72-e73, 2018. DOI: 10.1016/j.dental.2018.08.149

    Abstract: Purpose/aim: To develop a processing method for yttrium stabilized zirconia pollycrystal (YTZP) reinforced with reduced graphene oxide (rGO) and to verify the effect of rGO concentration on hardness and fracture toughness of the material. Materials and methods: The composite production included several steps: (a) synthesis of Y-TZP powder by coprecipitation route, (b) synthesis of graphene oxide from chemical exfoliation of graphite (modified Hummer’s method) followed by reduction with ascorbic acid, (c) sonication of reduced graphene oxide in Y-TZP suspension followed by drying (d) uniaxial pressing in metal device with diameter of 5mm and (e) sintering in a conventional tubular furnace (Argon/4%hydrogen atmosphere) or spark plasma sintering (SPS). The concentration of rGO in Y-TZP was fixed between 0.01 and 2.0 wt%. Sintered samples were characterized by X-ray diffraction, scanning electron microscopy, density measurements, and Vickers method for hardness and fracture toughness determination (indentation fracture). Data were analyzed by ANOVA and Tukey’s test with global significance level of 5%. Results: Results (Table 1) showed that the procedure stablished for dispersion of rGO in the Y-TZP resulted in good physical homogeneity of rGO and Y-TZP. Regarding the sintering procedure, it was observed that conventional sintering in a controlled atmosphere was not effective for ceramic densification due to microcrack formation at the ceramic surface. For conventional sintering, the hardness obtained for the rGO concentration of 2% was significantly lower than those obtained for all other concentrations, however, for this processing method, fracture toughness was not affected by rGO concentration. For SPS, both fracture toughness and hardness were affected by rGO concentration, with the lowest hardness mean value measured for the concentration of 0.05% and the lowest fracture toughness value measured for specimens with addition of 0.01% of rGO. Conclusions: The production of the composite Y-TZP/rGO was proved possible, and sintering via spark plasma resulted in higher mechanical properties of the composite material compared to conventional sintering. rGO concentration affected the hardness of the composite for both processing methods (conventional and SPS), however fracture toughness was only affected by rGO concentration for specimens processed via SPS.

    Palavras-Chave: graphene; graphite; yttrium oxides; zirconium oxides; sintered materials; mechanical properties; hardness

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  • IPEN-DOC 24740

    HAMADA, MARGARIDA M. . Special section on the 8th World Congress on Industrial Process Tomography (WCIPT8). Measurement Science and Technology, v. 29, n. 060101, 2018. DOI: 10.1088/1361-6501/aabb44

    Abstract: Multiphase flow systems are widely used in the industrial production of polymers, minerals, pharmaceuticals and food processing, among others. Industrial process tomography (IPT) may contribute to increase the production and quality control of the means of production or the industrial product itself. There has been a remarkable development in IPT technology over the past two decades, a fact demonstrated by the quality and innovation of the works presented at the 8th World Congress on Industrial Process Tomography (WCIPT8). This scientific meeting, held in Foz do Iguaçu, Brazil, in September 2016, was crowned by a high scientific and technological level within the natural beauty of the Iguaçu Falls. New sensor technologies and the processing of electronic signals have been continuously under development, and these themes were discussed in the WCIPT8. These new technologies are being implemented in the new IPT versions and, as a corollary, some improvement in the sensitivity of what may be measured with modern IPTs, with the desired accuracy, has been observed. In addition, the miniaturization of sensors and the use of nano-technology push these limits further. Further, thanks to the advancement of modern computers, sophisticated online image reconstruction algorithms are now available and have been incorporated into modern IPT allowing in-situ and on-line data processing. A large number of IPT measurement principles have been and are still under development: electrical methods, such as the measurement of capacitance, inductance and resistance, optical and radiation-based methods, ranging from infrared, microwave, x-rays, gamma rays and even neutrons, magnetic resonance, ultrasound and acoustic methods, to mention a few. The sensor technology for a specific application is primarily selected to achieve sensitivity to a physical property which differs for each of the components of the process, e.g. density or electrical permittivity. For the measurement or imaging of more than two components, multi-modality systems are often employed, either by measuring with one principle at several wavelengths or energies, or by combining several independent sensor principles. IPT is inherently interdisciplinary, so that R&D requires skills in each of the engineering processes (chemical, combustion, pharmaceutical, etc), physics and electronic engineering for the sensor system, plus mathematics and computer science for data processing algorithms. This special issue of Measurement Science and Technology presents innovative papers on IPT technologies, presented at the 8th World Congress on Industrial Process Tomography (WCIPT8), promoted by the International Society on Industrial Process Tomography (ISIPT) and organized by the Nuclear and Energy Research Institute (IPEN) and the Federal University of Technology, Parana. We hope that all readers of this Special Section may find not only interesting information, but also data that is useful for their scientific work.

    Palavras-Chave: industrial radiography; tomography; industry; appropriate technology; meetings

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  • IPEN-DOC 25645

    ALIBHAI, A.Y.; PRETTO, LUCAS R. de ; MOULT, ERIC; SCHOTTENHAMML, JULIA; OR, CHRIS; ARYA, MALVIKA; MCGOWAN, MITCHELL; BAUMAL, CAROLINE; WITKIN, ANDRE J.; DUKER, JAY S.; FUJIMOTO, JAMES G.; WAHEED, NADIA K.. Quantitative analysis of capillary non-perfusion in diabetic retinopathy using widefield OCT-angiography. Investigative Ophthalmology & Visual Science, v. 59, n. 9, 2018.

    Abstract: Purpose : Several OCT angiography (OCTA) studies suggest an association between capillary non-perfusion, a surrogate for retinal ischemia, and diabetic retinopathy (DR) severity. However, due to technical limitations, these studies focused on either 3x3mm or 6x6mm fields of view centered on the macula. In contrast, widefield fluorescein angiography (FA) studies suggest that the majority of capillary non-perfusion in early DR occurs outside of the macular region. The recent development of high-speed, widefield OCTA systems, has for the first time allowed non-invasive visualization of retinal vasculature over wider fields of view—a functionality that, in light of previous widefield FA studies, may be promising for early detection and monitoring of DR. This study aims to couple the recent technological advances in high-speed, widefield OCTA with image processing methods to allow for semi-automatic quantitative analysis of capillary non-perfusion of widefield OCTA images of diabetic eyes. Methods : A semi-automatic, texture-based algorithm that detects areas of non-perfusion on 12x12mm SS-OCTA images from the Zeiss PlexElite™ system was developed. We tested the algorithm on a series of patients with diabetes without DR (28 eyes, 21 subjects; 54.8 ± 10.9 y/o), eyes with non-proliferative DR (NPDR) (24 eyes, 16 subjects; 62.1 ± 13.2 y/o) and eyes with proliferative DR (PDR) (21 eyes, 14 subjects; 52.2 ± 12.7 y/o). Results : There was a general trend of increasing capillary non-perfusion with increasing DR severity; however, there was significant overlap between patients having different DR severities (Fig. 1). Conclusions : Quantitative analysis of widefield OCTA images may be useful for early detection and monitoring for diabetic retinopathy progression in diabetics. Additional work is needed to determine the added value of widefield OCTA.

    Palavras-Chave: retina; diabetes mellitus; perfused organs; fluorescein; biomedical radiography

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  • IPEN-DOC 25732

    TAVONI, T.M.; VINAGRE, C.G.; FREITAS, F.R.; MESQUITA, C.H. ; VINAGRE, J.C.; MARIANI, A.C.; KALIL-FILHO, R.; MARANHAO, R.C.. Plasma clearance of chylomicron remnants is delayed in aged subjects: a study with artificial emulsions. Atherosclerosis, v. 275, p. e157-e157, 2018. DOI: 10.1016/j.atherosclerosis.2018.06.468

    Abstract: Aim: Dietary fats absorbed in the intestine are transported in the circulation as chylomicrons and remnants that have atherogenic potential. Although postprandial lipidemia is increased in older subjects, the specific chylomicron metabolism has not been explored in older subjects nor compared to young subjects, which is the focus of this study. Methods: After a 12 h fast, artificially-made emulsions similar to lymph chylomicrons and doubly labeled with radioactive cholesteryl esters and triglycerides were intravenously injected in 23 older (66±4 years) and 20 young (24±3 years) subjects. Sequential blood samples were collected to determine fractional clearance rates (FCR, in min-1) by compartmental analysis. Results: Older subjects had higher LDL-cholesterol (p<0.001) and triglycerides (p<0.0001) than young subjects; HDL-cholesterol presented no difference. The emulsion cholesteryl-ester FCR was lower in older subjects compared to the young (p¼0.0001). The emulsion triglyceride FCR did not differ in the two groups. Tested in vitro, however, the lipolysis of the emulsion triglycerides was less intense in the older than in the young subjects. Conclusions: As delayed removal of remnants, indicated by the pronouncedly smaller cholesteryl ester FCR, is related to the presence of cardiovascular diseases, this can be a risk factor which could accelerate atherogenic complications occurring in aged subjects.

    Palavras-Chave: lipids; chylomicrons; blood plasma; clearance; blood plasma; cardiovascular diseases

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  • IPEN-DOC 23997

    PIRES, NATALIA S.M.; DANTAS, ANDREA T.; DUARTE, ANGELA L.B.P.; AMARAL, MARCELLO M. ; FERNANDES, LUANA O.; DIAS, TEREZA J.C.; MELO, LUCIANA S.A. de; GOMES, ANDERSON S.L.. Optical coherence tomography as a method for quantitative skin evaluation in systemic sclerosis. Annals of the Rheumatic Diseases, v. 77, n. 03, p. 465-466, 2018. DOI: 10.1136/annrheumdis-2016-210875

    Palavras-Chave: rheumatic diseases; diagnostic techniques; optics; tomography; skin; fibrosis

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  • IPEN-DOC 25540

    FUNARI, ANA P. ; ANTEBI, URI; SANTOS, LUIZ A.; VIEIRA, DANIEL P. ; MIRANDA, JURANDIR T. de; ALVES, NELSON M.; FREITAS, ANDERSON Z. de ; MATHOR, MONICA B. . Optical and histological evaluation of human tendon tissue sterilized by ionizing radiation. Regenerative Research, v. 7, n. 1, p. 122-122, 2018.

    Abstract: Sterilization by irradiation is a technique that is used by tissue banks aiming to eliminate contamination of human allografts, being a safe method, free of residue and used as final sterilization. After the tissue procurement, these undergo a series of processing stages and then are packaged and preserved by freezing. Despite aseptic care of the material those may be subjected to sterilization in the final packing by ionizing radiation, raising the security level of sterility of the tissue. The aim of this study was to evaluate the effects of application of ionizing radiation, produced by 60Co source in human tendons preprocessed (A-alcohol + antibiotic; B- H2O2 + ultrasound) obtained through collaboration with tissue banks and preserved by freezing in -80° C, the radiation absorbed doses in processing were 12.5, 15 and 25 kGy, each one with their corresponding non-irradiated control, to examine possible structural or morphological alterations. The irradiated samples and their controls were analyzed by means of optical coherence tomography (OCT) and optical coherence tomography polarization sensitive (PS-OCT), and histological tests had been stained with hematoxylin-eosin (HE). According to the results the tissue processed with alcohol/antibiotic in conjunction with irradiation proved to be the most effective.

    Palavras-Chave: absorbed radiation doses; alcohols; animal tissues; antibiotics; cobalt 60; freezing; histological techniques; ionizing radiations; radiation effects; sterilization; tendons; tomography

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  • IPEN-DOC 25646

    SOUZA, C.D. de ; ROSTELATO, M.C.M. ; ZEITUNI, C. ; GONZALEZ, A. del C.C. ; NOGUEIRA, B.R. . New gold-198 nanoparticle synthesis to be used in cancer treatment. Medical Physics, v. 45, n. 6, p. e243-e243, 2018.

    Palavras-Chave: aqua regia; brachytherapy; citrates; decay; gold 198; high-purity ge detectors; light scattering; nanoparticles; neoplasms; neutron flux; sodium compounds; synthesis; therapy

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  • IPEN-DOC 24736

    GENEZINI, FREDERICO ; CARBONARI, ARTUR W. ; LYNN, JEFFREY W.. International Workshop on Utilization of Research Reactors, São Paulo, Brazil. Neutron News, v. 29, n. 1, p. 2-3, 2018. DOI: 10.1080/10448632.2018.1445922

    Palavras-Chave: research reactors; iear-1 reactor; meetings; neutron activation analysis; security; historical aspects; research programs

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  • IPEN-DOC 25211

    LOPES, P.S.; CORAZZA, F.G.; NAMBU, F.A.N.; ERNESTO, J.V.; VARCA, G.H.C. ; LEITE-SILVA, V.R.; ANDREO-FILHO, N.. In vitro permeability assay using an epithelial model of Caco-2/HT29-MTX/Raji-B cells: enhancer aspects of a papain-cyclodextrin complex. Toxicology Letters, v. 295, Suppl. 1, p. S75-S75, 2018. DOI: 10.1016/j.toxlet.2018.06.534

    Abstract: The oral route is one of the main routes for administration of drugs, however, the gastrointestinal tract is a hostile environment due to pH variation, presence of several digestive enzymes and the intestinal barrier that undermines the permeation of drugs. The aim of this study was to evaluate the ability of papain complexed with β-cyclodextrin to enhancer the permeation of furosemide, as a model drug, in a triple co-culture of Caco-2, HT29-MTX and Raji cells. Papain and the papain-β-cyclodextrin complex were evaluated at 0.3, 0.7 and 1.0 μM and the biophysical integrity of the cell layer was evaluated by RET (Transepitelial Electrical Resistance) at 0, 4, 24, 48 and 72 hours. The epithelium was also stained using DAPI and Alexa Fluor™ 488 Phalloidin. HPLC was employed to quantification of furosemide. The RET results at initial time for all the samples and control were in a range of 267.63 to 318.28 Ω*cm2 and after 72 h this values were raised to a range of 365.14 to 492.64 Ω*cm2. There was a decrease of RET after samples’ application, nevertheless, the results showed that the epithelium presents a recovery, proportional to the time of cell replication, and that this recovery occurs in all samples tested with no significant statistical difference. The RET recovery implies that papain, complexed or not, was not able to kill the cells, corroborating the hypothesis that the action mechanism is the disruption of the tight junction. In addition, the triple co-culture presents a higher resistance to papain action, in comparison with the Caco-2 monolayer assays, emphasizing the importance of testing new drugs, potential candidates for oral formulations, in epitheliums that faithfully mimics what actually happens in in vivo systems. The fluorescent microscopy observation of the cells stained with DAPI and the junctions stained with Alexa Fluor™ 488 Phalloidin, showed that co-culture exhibits microvilli inherent to the intestinal tissue. The results obtained in the triple co-culture model bi-directional transport experiments confirmed the significant increase in furosemide transport indicating the importance of the paracellular route. In conclusion, the triple co-culture model was successfully standardized and papain complexed with β-cyclodextrin acts probably over the tight junctions enhancing the permeation of furosemide.

    Palavras-Chave: drugs; papain; digestive system; animal cells; epithelium

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  • IPEN-DOC 24946

    FURUKAWA, C.Y. ; MENDONCA, V. ; FUKUMORI, N.T.O. ; MATSUDA, M.M.N. . Improvement of iodide and iodate identification method in the radiochemical analysis of Iodine-131 radiopharmaceutical. EJNMMI Radiopharmacy and Chemistry, v. 3, n. 7, 1, p. 25-25, 2018. DOI: 10.1186/s41181-018-0041-4

    Abstract: Aim: Sodium Iodide (131 I) is a radiopharmaceutical available as oral capsule or solution, and is largely used in nuclear medicine for tyroid scintigraphy imaging and in radioiodine therapy. Radiochemical purity (% RqP) is defined as the percent of total radioactivity in the desired chemical form. The main methods to determine % RqP is paper chromatography (PC), thin-layer chromatography (TLC) and high perfomance liquid chromatography (HPLC). Some compendial methods also establish procedures for retardation factor (Rf) determination1-2. The objective of this work was to evaluate the mobile phase effect on the Rf of iodide (I-) and iodate (IO3 -) in the % RqP analysis of Sodium Iodide (131 I). Methods: Whatman 3MM PC (1.5 × 12.5 cm), methanol and glacial acetic acid were from Merck Millipore. Methanol and purified water in the proportion of 50%, 70%, 75% and 85% (v/v) were the mobile phases. Diluent solution containing 0.1 mg/mL KIO3, 0.2 mg/mL KI and 1.0 g/mL Na2CO3, and standard solutions of 0.2 g/mL KI and 0.4 g/mL KIO3 were prepared. In the origin position of a 10 cm paper strip, 5 μL of the diluent solution were applied. After chromatographic separation in each mobile phase, the suitable standard solution was dripped on the iodate and iodide expected positions followed by drops of glacial acetic acid to reveal the Rf of the species with formation of a brown spot3. Results: The American and Argentine pharmacopoeial methods present iodate-131 as the main radiochemical impurity but differ in the mobile phase composition and in the color development method for iodide and/or iodate1-2. The systems advocate the use of 30 and 20 cm long stationary phases which require several hours for separation of the species, and methanol 70% and 75% (v/v), respectively. In a 10 cm strip and 70% (v/v) methanol, the Rf for iodate was 0.5-0.7 and for iodide was 0.7-0.9; with 85% (v/v) methanol, the Rf were 0.3- 0.5 for iodate and 0.7-1.0 for iodide, respectively, taking an hour and a half for the chromatografic run. The resolution obtained with 85% (v/v) methanol was better when compared to methanol 70% (v/v). Conclusion: By the use of the staining test for iodate and iodide proposed by the Argentine pharmacopoeia, it was possible to improve the % RqP analysis of Sodium Iodide (131 I), decreasing the analysis time of more than 4 hours to an hour and a half.

    Palavras-Chave: radiochemical analysis; radiopharmaceuticals; iodine 131; iodides; iodates; chromatography

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  • IPEN-DOC 24853

    MOSCA, RODRIGO C. ; SANTOS, SOFIA N. ; NOGUEIRA, GESSE E.C.; PEREIRA, DAISA L. ; COSTA, FRANCIELLI C.; ARANY, PRAVEEN; ZEITUNI, CARLOS A. . Efficacy of photobiomodulation therapy in mitigating skin radiation damage. Lasers in Surgery and Medicine, v. 50, 29, p. S15-S16, 2018. DOI: 10.1002/lsm.22799

    Abstract: Background: The use of sophisticated radiation dose delivery and fractionation has significantly improved cancer care. One of these involves localized, sustained ionizing dose delivery termed brachytherapy. Despite it therapeutic efficacy, specific side effects of brachytherapy include localized skin damage and breakdown for which only palliative treatments are currently available. The use of low dose biophotonics treatments to promote tissue healing is termed photobiomodulation (PBM) therapy. The aim of this study was to evaluate efficacy and molecular pathways of PBM therapy using two common wavelengths, red and near-infrared (NIR) to treat radiation wounds in athymic mice subjected to brachytherapy (sustained ionizing radiation from 125I seeds). Study Design/Materials and Method: A pilot study was performed with thirty-six athymic mice were accomplished for 60 days and divided into six groups: Surgical Control Group (No radiation and no PBM treatments); Radiation Control Group (125I seed 0.4252 mCi, no PBM); NIR-PBM Control Group (NIR PBM alone, LED at l¼880 nm); Red-PBM Control Group (Red PBM alone LED at l¼660 nm); Radiation- NIR PBM Group; Radiation-Red PBM Group. Following 21 days, radiation-induced wounds are evident. PBM treatments (both wavelengths with output power 40mW for 20 s, fluence 20 J/cm2 on top of implantation site) were performed every week up to 60 days. Wounds were evaluated every 7 days digital imaging, Laser Doppler Flowmetry (LDF) and tissue temperature with a thermographic camera. We also performed mPET-CT imaging using radioactive fluorodeoxyglucose (18F-FDG) at 51 and 81 days post-implantation. Animals were sacrifices progressively at each time point to correlate clinical observations with imaging and molecular tissue analyses. Tissues were collected to analyze molecular pathways correlating with inflammation, immune response, wound healing and angiogenesis using mRNA (qRT-PCR) and protein expression (immunostaining). Results: Both PBM treated groups demonstrated significant (p<0.05) improvements in skin radiation wound healing as compared to radiation group. Distinct improvements in clinical wound size and closure, improved tissue perfusion and reduced inflammation as evidenced by decreased wound thermal images. These wounds were also noted to have significant differences in the cytokine profiles (TGF-b, VEGF and PDGF) correlating with better healing responses. Radiation damage reduces brown fat composition that can potentially contribute to additional radiation-associated morbidities. The mPET-CT imaging noted significant preservation of brown fat composition in PBM-treated radiation alone groups. Further validation of these pathways is ongoing. Conclusion: Within the parameters of this study, PBM treatments demonstrated improved healing in radiation wounds due to ionizing radiation from 125I seeds. Ongoing work is examining the precise molecular pathways contributing to these therapeutic benefits. It is hoped this study will enable further development of this innovative therapy for managing side- effects from radiation treatments.

    Palavras-Chave: neoplasms; brachytherapy; radiation doses; radiation injuries; wounds; biological recovery

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  • IPEN-DOC 25541

    VARCA, JUSTINE P.R.O. ; FERRARI, ANDRE ; PIGNATA, DANILO R. ; GUAZZELLI, STEFANE K. ; KLINGBEIL, MARIA F.G. ; VARCA, GUSTAVO H.C. ; LUGAO, ADEMAR B. ; MATHOR, MONICA B. . Development of gelatin based scaffold by gamma radiation for application as platelet rich plasma support for wound treatment. Regenerative Research, v. 7, n. 2, p. 44-44, 2018.

    Abstract: Gelatin is a natural polymer originated from the collagen, and presents poor mechanical properties, however it is a natural and biocompatible polymer, and collagen is the main component of the extracellular matrix1. Poly-vynil (alcohol) is an artificial polymer with interesting mechanical properties and biocompatibility. Such polymers have been largely scientific studied for biomedical application2. Platelet Rich Plasma (PRP) has been widely scientific explored in many medical fields in the last decades, especially in orthopedic area and in athletic treatments3. Based on the PRP desired properties regarded to the tissue regeneration, the present work aimed to develop a scaffold to support PRP release for wound treatment and study the influence of different radiation doses on a scaffold formation to apply as support for PRP release for wound treatment. In specific terms, the impact of radiation will be evaluated through physicochemical and morphologic characteristics. In the study, two polymers of different characteristics were applied, and scaffolds were prepared based on two formulations, one composed by gelatin (7%, w/w) and PVA (5%, w/w), and the second by gelatin (10%, w/w) and PVA (5%, w/w). The formulations were solubilized together in distilled water and heated up to 80 ºC under constant stirring for 1 hour. Posteriorly, the blends were disposed in circular glass molds. The samples were cooled at 4 ºC for at least 24 h and then irradiated at 15, 25 and 50 kGy. After irradiation, the samples were frozen and freeze dried. The scaffolds were characterized in terms of structure and morphology by mechanical assays, differential scanning calorimetry, scanning electron microscopy, optical coherence tomography and infrared spectroscopy. In addition, platelet adhesion and release, and cytotoxic assays were also performed. Samples irradiated at 15 kGy presented pore size diameter of around 1.4 μm and porosity of 54%, while samples irradiated at 25 kGy, presented pore size diameter of around 1.1 μm and porosity of 49%. Optical coherence tomography showed that gelatin control samples presented more superficial degradation as irradiation dose increased, while PVA control sample presented higher integrity, indicating that this polymer is less sensitive to gamma radiation. The system presented suitable mechanical properties and the platelet adhesion and release assays showed that the scaffold presented adequate pore size range to host and release the platelets, and non-cytotoxic to platelets, featuring adequate properties to be applied as dressing for wound treatments.

    Palavras-Chave: polymers; gelatin; gamma radiation; mechanical properties; wounds; therapy; animal tissues; biological regeneration

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  • IPEN-DOC 22303

    RIELLA, HUMBERTO . Da pesquisa básica à produção. Brasil Nuclear, v. 25, n. 49, p. 33-33, 2018.

    Observação: Depoimento

    Palavras-Chave: nuclear fuells; fuel cycle centers; fuel fabrication plants; uranium dioxide; fuel plates; scientific personnel

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  • IPEN-DOC 24799

    RIBEIRO, MARTHA S. ; GARGANO, RONALDO G.; SABINO, CAETANO P.; ANJOS, CAROLINA dos; POGLIANI, FABIO C.; SELLERA, FABIO P.. Clinical challenges of antimicrobial photodynamic therapy for bovine mastitis. Photodiagnosis and Photodynamic Therapy, v. 21, p. 327-327, 2018. DOI: 10.1016/j.pdpdt.2018.01.007

    Abstract: Sir, Antimicrobial photodynamic therapy (aPDT) is emerging as a new promising tool to treat local infections in Veterinary Medicine [1]. In 2016, our group was the pioneer to investigate its use to inactivate pathogens related to bovine mastitis [2]. In this regard, in a recent report published in this journal, Moreira et al. [3] explored the use of toluidine blue (TBO)-mediated aPDT to treat subclinical bovine mastitis. Remarkably, bovine mastitis still remains as the most economically relevant disease for dairy industry worldwide, resulting in substantial economic losses for milk producers due to extensive antibiotic use and product losses. In this sense, antibiotic misuse or overuse to treat bovine mastitis is worrisome because it can simultaneously lead to antibiotic residues in dairy products and increase multidrug-resistant foodborne pathogens. Unfavorably, there is still no consensus on the ideal approach for bovine mastitis treatment; therefore, aPDT represents a viable option to reduce the use of antibiotics in dairy farms. The preliminary results of Moreira et al. [3] are exciting and deserve discussion on some points. In this letter, we intend to highlight other relevant aspects to be addressed in order to consolidate the use of aPDT for management of bovine mastitis. The concentration of the photosensitizer (PS) diluted in the milk plays a pivotal role. In the study by Moreira et al. [3], the authors designed a clinical assay using a 2.5% TBO solution, which promoted a significant reduction of bacterial load. It is noteworthy that clinical mastitis represents a more complex challenge for aPDT than subclinical mastitis since the alterations in the milk composition could influence the PS absorption properties. Additionally, we believe that intermolecular interactions between PS and milk components should be considered to optimize clinical protocols because it could induce aggregation of phenothiazine dyes and leads to lower photodynamic inactivation efficiency [[4], [5]]. Another important point is in respect to the light diffusion within mammary parenchyma. Appropriated light delivery systems need to reach deeper mammary tissue since pathogens normally colonize the entire mammary gland [6]. Therefore, the use of diffuser fibers should be considered to deliver homogeneous light intensities inside the gland parenchyma. Hence, investigations regarding different light delivery systems could optimize clinical protocols and facilitate the establishment of aPDT into the dairy industry. Finally, we encourage the development of innovative strategies to improve selective PS delivery to pathogens using targeted molecular and nanoparticle systems. In summary, we hope that this letter motivates further studies to develop safe and effective protocols for bovine mastitis and promote aPDT applications in Veterinary Medicine.

    Palavras-Chave: veterinary medicine; cattle; mammary glands; infectious diseases; bacterial diseases; therapy; photosensitivity

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  • IPEN-DOC 26530

    SCAGLIUSI, SANDRA R. ; CARDOSO, ELIZABETH C.L. ; LUGAO, ADEMAR B. . Butyl rubber recycling by means of gamma radiation followed by mechanical shear. International Journal of Waste Resources, v. 8, p. 53-54, 2018. DOI: 10.4172/2252-5211-C1-011

    Abstract: Polymeric materials (plastics and rubbers) cover a continuously raising proportion of urban and industrial solid wastes discarded in landfills and consequently their impact on environment are more and more concern. Rubbers exhibit a very slow natural decomposition due to their chemical structure weather resistant as well to enzymatic degradation and to microorganisms. Rubber recovering is hampered by its insolubility caused by crosslinked structures. Besides, this tridimensional structure causes various problems for material recovering and reprocessing. Just 8% to 12% of polymeric residues are thermoplastic polymers; remaining are elastomers especially post consumption tires. It is relevant to emphasize that the crosslinking is essential for practical use of rubber and this process is worldwide known as vulcanizing process, discovered by North American Charles Goodyear. The implementation of new technologies in order to reduce polymeric residues, acceptable from the environmental viewpoint and at an effective cost proved to be a great problem due to inherent complexities for polymers reuse. Ionizing radiation has capacity to change structure and properties of polymeric materials. Butyl rubbers have been used in wide scale within a variety of applications such as tires spare-parts and diverse artifacts. Major effect of high energy photon, such as gamma rays in butyl and halo-butyl rubbers is the creation of free radicals accompanied by changes in mechanical properties. This work aims to the development of processes of controlled degradation (de-vulcanizing) of butyl rubber in order to characterize their availability for modification and changes of their properties. Experimental results obtained showed that butyl rubbers irradiated at 25 kGy and further sheared can be used as the starting point for mixtures with pristine rubber.

    Palavras-Chave: rubbers; recycling; gamma radiation; ionizing radiations; environmental protection; shear; mechanical properties; tensile properties

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✔ A pesquisa apresentará melhor resultado selecionando um dos filtros disponíveis em Navegar

✔ Os filtros disponíveis em Navegar tais como: Coleções, Ano de publicação, Títulos, Assuntos, Autores, Revista, Tipo de publicação são autoexplicativos. O filtro, Autores IPEN apresenta uma relação com os autores vinculados ao IPEN; o ID Autor IPEN diz respeito ao número único de identificação de cada autor constante no RD e sob o qual estão agrupados todos os seus trabalhos independente das variáveis do seu nome; Tipo de acesso diz respeito à acessibilidade do documento, isto é , sujeito as leis de direitos autorais, ID RT apresenta a relação dos relatórios técnicos, restritos para consulta das comunidades indicadas.

A opção Busca avançada utiliza os conectores da lógica boleana, é o melhor recurso para combinar chaves de busca e obter documentos relevantes à sua pesquisa, utilize os filtros apresentados na caixa de seleção para refinar o resultado de busca. Pode-se adicionar vários filtros a uma mesma busca.

Exemplo:

Buscar os artigos apresentados em um evento internacional de 2015, sobre loss of coolant, do autor Maprelian.

Autor: Maprelian

Título: loss of coolant

Tipo de publicação: Texto completo de evento

Ano de publicação: 2015

✔ Para indexação dos documentos é utilizado o Thesaurus do INIS, especializado na área nuclear e utilizado em todos os países membros da International Atomic Energy Agency – IAEA , por esse motivo, utilize os termos de busca de assunto em inglês; isto não exclui a busca livre por palavras, apenas o resultado pode não ser tão relevante ou pertinente.

✔ 95% do RD apresenta o texto completo do documento com livre acesso, para aqueles que apresentam o significa que e o documento está sujeito as leis de direitos autorais, solicita-se nesses casos contatar a Biblioteca do IPEN, bibl@ipen.br .

✔ Ao efetuar a busca por um autor o RD apresentará uma relação de todos os trabalhos depositados no RD. No lado direito da tela são apresentados os coautores com o número de trabalhos produzidos em conjunto bem como os assuntos abordados e os respectivos anos de publicação agrupados.

✔ O RD disponibiliza um quadro estatístico de produtividade, onde é possível visualizar o número dos trabalhos agrupados por tipo de coleção, a medida que estão sendo depositados no RD.

✔ Na página inicial nas referências são sinalizados todos os autores IPEN, ao clicar nesse símbolo será aberta uma nova página correspondente à aquele autor – trata-se da página do pesquisador.

✔ Na página do pesquisador, é possível verificar, as variações do nome, a relação de todos os trabalhos com texto completo bem como um quadro resumo numérico; há links para o Currículo Lattes e o Google Acadêmico ( quando esse for informado).

ATENÇÃO!

ESTE TEXTO "AJUDA" ESTÁ SUJEITO A ATUALIZAÇÕES CONSTANTES, A MEDIDA QUE NOVAS FUNCIONALIDADES E RECURSOS DE BUSCA FOREM SENDO DESENVOLVIDOS PELAS EQUIPES DA BIBLIOTECA E DA INFORMÁTICA.

O gerenciamento do Repositório está a cargo da Biblioteca do IPEN. Constam neste RI, até o presente momento 20.950 itens que tanto podem ser artigos de periódicos ou de eventos nacionais e internacionais, dissertações e teses, livros, capítulo de livros e relatórios técnicos. Para participar do RI-IPEN é necessário que pelo menos um dos autores tenha vínculo acadêmico ou funcional com o Instituto. Nesta primeira etapa de funcionamento do RI, a coleta das publicações é realizada periodicamente pela equipe da Biblioteca do IPEN, extraindo os dados das bases internacionais tais como a Web of Science, Scopus, INIS, SciElo além de verificar o Currículo Lattes. O RI-IPEN apresenta também um aspecto inovador no seu funcionamento. Por meio de metadados específicos ele está vinculado ao sistema de gerenciamento das atividades do Plano Diretor anual do IPEN (SIGEPI). Com o objetivo de fornecer dados numéricos para a elaboração dos indicadores da Produção Cientifica Institucional, disponibiliza uma tabela estatística registrando em tempo real a inserção de novos itens. Foi criado um metadado que contém um número único para cada integrante da comunidade científica do IPEN. Esse metadado se transformou em um filtro que ao ser acionado apresenta todos os trabalhos de um determinado autor independente das variáveis na forma de citação do seu nome.

A elaboração do projeto do RI do IPEN foi iniciado em novembro de 2013, colocado em operação interna em julho de 2014 e disponibilizado na Internet em junho de 2015. Utiliza o software livre Dspace, desenvolvido pelo Massachusetts Institute of Technology (MIT). Para descrição dos metadados adota o padrão Dublin Core. É compatível com o Protocolo de Arquivos Abertos (OAI) permitindo interoperabilidade com repositórios de âmbito nacional e internacional.

1. Portaria IPEN-CNEN/SP nº 387, que estabeleceu os princípios que nortearam a criação do RDI, clique aqui.


2. A experiência do Instituto de Pesquisas Energéticas e Nucleares (IPEN-CNEN/SP) na criação de um Repositório Digital Institucional – RDI, clique aqui.

O Repositório Digital do IPEN é um equipamento institucional de acesso aberto, criado com o objetivo de reunir, preservar, disponibilizar e conferir maior visibilidade à Produção Científica publicada pelo Instituto, desde sua criação em 1956.

Operando, inicialmente como uma base de dados referencial o Repositório foi disponibilizado na atual plataforma, em junho de 2015. No Repositório está disponível o acesso ao conteúdo digital de artigos de periódicos, eventos, nacionais e internacionais, livros, capítulos, dissertações, teses e relatórios técnicos.

A elaboração do projeto do RI do IPEN foi iniciado em novembro de 2013, colocado em operação interna em julho de 2014 e disponibilizado na Internet em junho de 2015. Utiliza o software livre Dspace, desenvolvido pelo Massachusetts Institute of Technology (MIT). Para descrição dos metadados adota o padrão Dublin Core. É compatível com o Protocolo de Arquivos Abertos (OAI) permitindo interoperabilidade com repositórios de âmbito nacional e internacional.

O gerenciamento do Repositório está a cargo da Biblioteca do IPEN. Constam neste RI, até o presente momento 20.950 itens que tanto podem ser artigos de periódicos ou de eventos nacionais e internacionais, dissertações e teses, livros, capítulo de livros e relatórios técnicos. Para participar do RI-IPEN é necessário que pelo menos um dos autores tenha vínculo acadêmico ou funcional com o Instituto. Nesta primeira etapa de funcionamento do RI, a coleta das publicações é realizada periodicamente pela equipe da Biblioteca do IPEN, extraindo os dados das bases internacionais tais como a Web of Science, Scopus, INIS, SciElo além de verificar o Currículo Lattes. O RI-IPEN apresenta também um aspecto inovador no seu funcionamento. Por meio de metadados específicos ele está vinculado ao sistema de gerenciamento das atividades do Plano Diretor anual do IPEN (SIGEPI). Com o objetivo de fornecer dados numéricos para a elaboração dos indicadores da Produção Cientifica Institucional, disponibiliza uma tabela estatística registrando em tempo real a inserção de novos itens. Foi criado um metadado que contém um número único para cada integrante da comunidade científica do IPEN. Esse metadado se transformou em um filtro que ao ser acionado apresenta todos os trabalhos de um determinado autor independente das variáveis na forma de citação do seu nome.