42 results match your criteria: "2242 - Cidade Universitaria[Affiliation]"
Beilstein J Nanotechnol
May 2024
Instituto de Pesquisas Energéticas e Nucleares, IPEN/CNEN-SP, Av. Prof. Lineu Prestes, 2242 Cidade Universitária, São Paulo, SP, CEP 05508-000, Brazil.
In this study, we present a novel approach for the exfoliation of titanium nitride (TiN) powders utilizing a rapid, facile, and environmentally friendly non-thermal plasma method. This method involves the use of an electric arc and nitrogen as the ambient gas at room temperature to generate ionized particles. These ionized species interact with the ceramic crystal of TiN, resulting in a pronounced structural expansion.
View Article and Find Full Text PDFSci Total Environ
April 2024
International Atomic Energy Agency, Department of Nuclear Sciences and Applications, Division of Physical and Chemical Sciences, Isotope Hydrology Section, Vienna International Centre, PO Box 100, 1400, Vienna, Austria.
Fundamental approaches to the study of groundwater rely on investigating the spatial and temporal distribution of stable and radioactive isotopes and other anthropogenic compounds in natural waterbodies. The most often used tracers for estimating groundwater flow paths and residence times, groundwater/surface water interaction as well as tracing chemical (contamination) sources include stable isotopes of water (δ O and δ H), radiocarbon (C; t = 5730 a), tritium (H; t = 12.43 a) as well as unreactive fluorine-containing gases (e.
View Article and Find Full Text PDFNanomaterials (Basel)
August 2022
Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China.
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.
View Article and Find Full Text PDFACS Omega
July 2022
Instituto de Pesquisas Energéticas e Nucleares, IPEN/CNEN-SP, Av. Prof. Lineu Prestes, 2242 Cidade Universitária, CEP 05508-000 São Paulo, SP, Brazil.
Methane is an abundant resource and the main constituent of natural gas. It can be converted into higher value-added products and as a subproduct of electricity co-generation. The application of polymer electrolyte reactors for the partial oxidation of methane to methanol to co-generate power and chemical products is a topic of great interest for gas and petroleum industries, especially with the use of materials with a lower amount of metals, such as palladium complex.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
June 2022
IPEN/CNEN, Av. Prof. Lineu Prestes, Instituto de Pesquisas Energéticas e Nucleares, 2242 - Cidade Universitária, Sao Paulo, SP, 05508-000, Brazil.
The main goal of this study was to assess alternatives to the current challenges on environmental quality and circular economy. The former is here addressed by the treatment of radioactively contaminated solutions, and the latter by using abundant and low-cost biomass. In this paper, we examine the biosorption of hexavalent uranium (U(VI)) in a batch system using the macrophytes Limnobium laevigatum and Azolla sp.
View Article and Find Full Text PDFAppl Radiat Isot
February 2022
Instituto de Pesquisas Energéticas e Nucleares, IPEN/CNEN, Av Prof. Lineu Prestes, 2242 - Cidade Universitária, São Paulo, CEP 05508-000, Brazil.
The PSMA-targeted radionuclide therapy has been explored since 2015 with radioisotope lutetium-177, whose β emission range is adequate for micrometastases treatment. This radioisotope is obtained by two different production routes that directly affect the specific activity of lutetium-177 (non-carrier added and carrier added) and, consequently, the specific activity of radiopharmaceuticals, like Lu-PSMA-617. The influence of the specific activity of lutetium-177 on the properties of the radiopharmaceutical PSMA-617 was evaluated through pre-clinical studies.
View Article and Find Full Text PDFBull Environ Contam Toxicol
July 2021
Instituto de Ciências Biomédicas, Av. Prof. Lineu Prestes, 1524, São Paulo, 05508-900, Brazil.
In the present study, sea urchin Sterechinus neumayeri tissues were used for the passive biomonitoring of toxic and trace elements at the Comandante Ferraz Station, Antarctica and compared to a pristine region (Botany). As, Ba, Br, Ca, Co, Cr, Fe, K, Na, Rb, Sc, Se and Zn concentrations were determined by instrumental neutron activation analysis (INAA), while toxic metals (Cd, Hg, Ni and Pb), and Cu were determined by atomic absorption spectrometry (GF-AAS). The findings were compared to other organisms commonly applied for biomonitoring purposes and to the sediment concentrations of each sampling region.
View Article and Find Full Text PDFRSC Adv
July 2020
Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP Av. Prof. Lineu Prestes, 2242 Cidade Universitária São Paulo SP CEP 05508-000 Brazil
Even with all the biological problems associated with bisphenol-A (BPA), this chemical is still being widely used, especially in thermal paper receipts. In this study, renewable mesoporous silica nanoparticles (MSN), obtained from sugarcane ash, functionalized with hexadecyltrimethylammonium (CTAB) were applied as an adsorbent in the removal of BPA from the aqueous solution. The versatility of this material and its BPA adsorption capacity were tested at different pH values, being practically constant at pH between 4 and 9, with a slight increase in pH 10 and a greater increase in pH 11.
View Article and Find Full Text PDFJ Colloid Interface Sci
October 2020
Instituto de Pesquisas Energéticas e Nucleares, IPEN/CNEN-SP, Av. Prof. Lineu Prestes, 2242 Cidade Universitária, CEP 05508-900, São Paulo, SP, Brazil.
PdNi electrocatalysts supported on carbon were used as anode materials for methane oxidation in alkaline direct methane fuel cells (ADMEFCs). The electrocatalysts were successfully synthesized by the NaBH reduction method. X-ray diffraction measurements showed the formation of non-alloyed Pd in the face- centered cubic (FCC) structure for all materials and formation of NiO and Ni(OH) species.
View Article and Find Full Text PDFAppl Radiat Isot
June 2020
Instituto de Pesquisas Energéticas e Nucleares, Avenida Lineu Prestes, 2242 - Cidade Universitária, São Paulo, SP, 05508-000, Brazil.
In this paper we present the impact of variability, a surface source parameter, on the efficiency evaluation of surface contamination monitors. This study was based on two source uniformity correction methodologies and data from real surface source distributions. Surface source intensity distribution has been changed by rearranging the cells (portions of the active area of each LARS) while keeping the same source uniformity value.
View Article and Find Full Text PDFBull Environ Contam Toxicol
April 2020
UNESP - Univ Estadual Paulista, Campus do Litoral Paulista, Núcleo de Estudos em Poluição e Ecotoxicologia Aquática (NEPEA), USP - Universidade de São Paulo, Praça Infante Dom Henrique s/n-Parque Bitaru, São Vicente, SP, CEP11330-900, Brazil.
This short note aims to report in detail a preliminary assessment of the concentrations of Cd, Hg and Pb in tissues of blue crabs Callinectes danae collected from the Cananéia-Iguape-Peruíbe estuarine complex (CIP), in the South of São Paulo State coast, Brazil. In October 2014, blue crabs were collected from CIP. Tissues were removed by dissection and metal determination was performed by GF-AAS and CV-AAS.
View Article and Find Full Text PDFJ Environ Radioact
July 2019
Instituto de Pesquisas Energéticas e Nucleares, Av. Prof. Lineu Prestes, 2242 - Cidade Universitária, São Paulo, SP, 05508-000, Brazil.
Biosorption-based technologies have been proposed for the removal of radionuclides from radioactive liquid waste containing organic compounds. Nevertheless, pytoremediation potential of uranium (U) by nonliving aquatic macrophytes Lemna sp. and Pistia stratiotes has not been previously addressed.
View Article and Find Full Text PDFBMC Cancer
November 2018
Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP, Av. Prof. Lineu Prestes, 2242- Cidade Universitária, São Paulo, 05508-000, Brazil.
Background: Experimental models of prostate cancer have demonstrated increased levels of protoporphyrin IX (PpIX) in the blood and faeces of mice. Hence, the quantification of these autofluorescent molecules could be hypothesized to be a potential marker for this type of tumour. In this case-control study, the autofluorescence of porphyrins in human faeces from patients with prostate cancer and control subjects was analysed using fluorescence spectroscopy.
View Article and Find Full Text PDFEcotoxicol Environ Saf
December 2018
UNESP - Univ Estadual Paulista, Campus do Litoral Paulista, Núcleo de Estudos em Poluição e Ecotoxicologia Aquática (NEPEA), Praça Infante Dom Henrique s/n°, Parque Bitaru, CEP11330-900 São Vicente SP, Brazil.
Ecotoxicol Environ Saf
October 2018
UNESP - Univ Estadual Paulista, Campus do Litoral Paulista, Núcleo de Estudos em Poluição e Ecotoxicologia Aquática (NEPEA), Praça Infante Dom Henrique s/n°, Parque Bitaru, CEP 11330-900, São Vicente, SP, Brazil.
This study aimed to assess the bioaccumulation of Pb and induction of metallothionein-like proteins (MT) in Callinectes danae through single and combined dietary and waterborne exposures. Male C. danae individuals were collected in the south area of the Cananéia-Iguape-Peruíbe Protected Area (APA-CIP), in São Paulo State, Brazil.
View Article and Find Full Text PDFSmall
July 2018
Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST,, Campus UAB, Bellaterra, E-08193, Barcelona, Spain.
Understanding the microstructure in heterostructured nanoparticles is crucial to harnessing their properties. Although microscopy is ideal for this purpose, it allows for the analysis of only a few nanoparticles. Thus, there is a need for structural methods that take the whole sample into account.
View Article and Find Full Text PDFAppl Radiat Isot
October 2018
Instituto de Pesquisas Energéticas e Nucleares/ Comissão Nacional de Energia Nuclear, IPEN/CNEN, Av. Prof. Lineu Prestes, 2242 - Cidade Universitária, 05508-000 São Paulo, SP, Brazil. Electronic address:
The absorbed dose rate is the main characterization quantity for beta radiation. The extrapolation chamber is considered the primary standard instrument. To determine absorbed dose rates in beta radiation beams, it is necessary to establish several correction factors.
View Article and Find Full Text PDFWaste Manag
October 2017
Nuclear and Energy Research Institute, IPEN-CNEN/SP, Av. Prof. Lineu Prestes, 2242 Cidade Universitária, CEP 05508-000 São Paulo, SP, Brazil.
Management of waste of electric and electronic equipment (WEEE) is a key issue for modern societies; furthermore, it contains valuable materials that can be recycled, especially in printed circuit boards (PCB), which have approximately one-third of their weight in copper. In this study we demonstrated the use of laser to strip the covering soldering mask on PCB's, thus exposing the copper underneath so that extraction techniques may take place. Using a Q-Switched Nd:YAG laser operating at 1064nm and 532nm we tested the procedure under different energy conditions.
View Article and Find Full Text PDFAppl Radiat Isot
October 2017
Instituto de Pesquisas Energéticas e Nucleares/ Comissão Nacional de Energia Nuclear, IPEN/CNEN, Av. Prof. Lineu Prestes, 2242 - Cidade Universitária, 05508-000 São Paulo, SP, Brazil. Electronic address:
This paper aims to show how the variance reduction technique "Geometry splitting/Russian roulette" improves the statistical error and reduces uncertainties in the determination of the absorbed dose rate in tissue using an extrapolation chamber for beta radiation. The results show that the use of this technique can increase the number of events in the chamber cavity leading to a closer approximation of simulation result with the physical problem. There was a good agreement among the experimental measurements, the certificate of manufacture and the simulation results of the absorbed dose rate values and uncertainties.
View Article and Find Full Text PDFACS Omega
June 2017
Departamento de Química Fundamental, Universidade Federal de Pernambuco, Cidade Universitária, 50670-901 Recife, PE, Brazil.
Anderson localization of light and random lasing in this critical regime is an open research frontier, which besides being a basic research topic could also lead to important applications. This article investigates the random laser action at the localization transition in a strongly disordered scattering medium composed of a colloidal suspension of core-shell nanoparticles (TiO@Silica) in ethanol solution of Rhodamine 6G. The classical superfluorescence band of the random laser was measured separately by collecting the emission at the back of the samples, showing a linear dependence with pumping fluence without gain depletion.
View Article and Find Full Text PDFMater Sci Eng C Mater Biol Appl
June 2017
Nuclear and Energy Research Institute, IPEN-CNEN/SP, Av. Prof. Lineu Prestes, 2242 - Cidade Universitária - CEP, 05508-000 São Paulo, Brazil.
This paper presents a study on biocidal effect of polymer nanocomposite films of gamma irradiated polypropylene (PP) and silver nanoparticles. The modified polypropylene was obtained from isotactic polypropylene (iPP) in pellets form by irradiation with gamma rays in the presence of acetylene. A new morphology with long chain branching of PP and distinct rheology is obtained by this process.
View Article and Find Full Text PDFInt J Mol Sci
February 2017
Biotechnology Center, Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP-Avenida Prof. Lineu Prestes, 2242-Cidade Universitária, 05508-000 São Paulo, Brazil.
Human thyrotropin (hTSH) is a glycoprotein with three potential glycosylation sites: two in the α-subunit and one in the β-subunit. These sites are not always occupied and occupancy is frequently neglected in glycoprotein characterization, even though it is related to folding, trafficking, initiation of inflammation and host defense, as well as congenital disorders of glycosylation (CDG). For the first time -glycoprofiling analysis was applied to the site-occupancy determination of two native pituitary hTSH, in comparison with three recombinant preparations of hTSH, a widely used biopharmaceutical.
View Article and Find Full Text PDFLasers Med Sci
January 2017
Special Laboratory of Lasers in Dentistry (LELO), Department of Restorative Dentistry, School of Dentistry, University of São Paulo, Av. Professor Lineu Prestes 2227-Cidade Universitária, CEP 05508-000, São Paulo, SP, Brazil.
This study aimed to use optical coherence tomography (OCT) to assess the progression of erosive lesions after irradiation with Nd:YAG laser and application of topical fluoride. One-hundred and twenty dentin samples (4 × 4 × 2 mm) obtained from bovine incisors were used. Samples were protected with acid-resistant nail varnish, with exception of a central circular area 2 mm in diameter.
View Article and Find Full Text PDFPhotodiagnosis Photodyn Ther
March 2016
Department of Internal Medicine, School of Veterinary Medicine and Animal Science, University of São Paulo, Av. Prof. Dr. Orlando Marques de Paiva, 87-Cidade Universitária, 05508-270 São Paulo, SP, Brazil.
J Mech Behav Biomed Mater
January 2016
School of Material Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China.
The sandblasted, large-grit and acid-etched (SLA) surface is easy to be contaminated during storage and its surface chemical state is usually changed by different sterilization methods. This causes an undesirable increase in surface hydrophobicity and results in osseointegration degradation. To overcome this problem, a low temperature hydrothermal (HT) sterilization method was proposed in this study.
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