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1.
Appl Radiat Isot ; 184: 110177, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35272230

RESUMO

Flexible pipes are modular constructions made up of several layers. They are broadly employed in oil & gas industry, playing an important role in the Brazilian Pre-Salt production. Under specific conditions, seawater can ingress and this contact with metallic middle layers can significantly lead to a service life reduction of these layers, especially due to a mechanism known as CO2 Stress Corrosion Cracking (SCC-CO2). Therefore, it becomes mandatory that inspection systems suitable for submarine use in order to detect annulus flooding before the failure of the flexible pipe become available. This paper presents an inspection system based on the gamma rays transmission focused on detecting such flood condition, possibly overcoming limitations of other inspection systems available in the market. The reliability of this solution was statistically evaluated as presented herein, showing great robustness based on the numerous available trials.


Assuntos
Dióxido de Carbono , Brasil , Corrosão , Raios gama , Reprodutibilidade dos Testes
2.
Theriogenology ; 143: 113-122, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31869732

RESUMO

The aim of this study was to evaluate circulating progesterone concentration (P4), LH pulsatility and ovarian follicular dynamics in Nelore (B. indicus) and Holstein (B. taurus) heifers under high (HDMI) and low (LDMI) dry matter/energy intakes. In addition, the effects of dry matter/energy intake and breed on hepatic expression of six genes associated with P4 metabolism (AKR1C4, AKR1D1, CYP3A4, CYP2C19, SRD5A1, and SRD5A3) was evaluated. Heifers received an intravaginal P4 device (1 g), 2 mg of estradiol benzoate (EB) i.m. and 500 µg of PGF2α at the begging of the synchronization protocol (D0). Eight days later, the P4 device was removed and all heifers received 1 mg of EB 24h later. Regardless of dry matter/energy intake, the number of recruited follicles was greater in Nelore than in Holstein heifers. In contrast, the maximum diameter of the dominant follicle was greater in Holstein than in Nelore heifers. Circulating P4 concentrations were greater in Nelore than in Holstein from D2 to D9, and in heifers receiving LDMI than those receiving HDMI from D1 to D8 of hormonal protocol. In addition, Holstein heifers had greater LH pulsatility and area under the curve of LH peaks compared to Nelore heifers. However, no effects were observed for LH values between feed intake levels. Interestingly, Holstein heifers had higher expression of SRD5A1, AKR1C4, AKR1D1 than Nelore heifers; whereas, for Nelore heifers, only the expression of CYP3A4 was higher compared to Holstein heifers. In conclusion, there are important differences in the follicular dynamics, circulating P4 and LH pulsatility concentrations that need to be considered during synchronization protocols for Nelore and Holstein breeds. More importantly, these differences appear to be at least partially modulated by the level of feed intake and the contrasting enzyme system in the liver involved with P4 metabolism between these cattle breeds.


Assuntos
Bovinos/fisiologia , Comportamento Alimentar/fisiologia , Fígado/metabolismo , Folículo Ovariano/fisiologia , Progesterona/sangue , Ração Animal/análise , Animais , Estudos Cross-Over , Dieta/veterinária , Feminino , Regulação Enzimológica da Expressão Gênica , Fígado/enzimologia , Hormônio Luteinizante/metabolismo , Progesterona/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Especificidade da Espécie
3.
Animal ; 10(8): 1303-10, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26927502

RESUMO

Oilseeds offer some protection to the access of ruminal microorganisms and may be an alternative to calcium salts of fatty acids (FA), which are not fully inert in the ruminal environment. This study aimed to evaluate the effects of different sources of FA supplementation on apparent total tract nutrient digestibility, milk yield and composition, and energy balance (EB) of cows during the transition period and early lactation. We compared diets rich in C18:2 and C18:3 FA. Multiparous Holstein cows were randomly assigned to receive one of the four diets: control (n=11); whole flaxseed (WF, n=10), 60 and 80 g/kg (diet dry matter (DM) basis) of WF during the prepartum and postpartum periods, respectively; whole raw soybeans (WS, n=10), 120 and 160 g/kg (diet DM basis) of WS during the prepartum and postpartum periods, respectively; and calcium salts of unsaturated fatty acids (CSFA, n=11), 24 and 32 g/kg (diet DM basis) of CSFA during the prepartum and postpartum periods, respectively. Dry cows fed WF had higher DM and net energy of lactation (NEL) intake than those fed WS or CSFA. The FA supplementation did not alter DM and NDF apparent total tract digestibility, dry cows fed WF exhibited greater NDF total tract digestion than cows fed WS or CSFA. Feeding WS instead of CSFA did not alter NEL intake and total tract digestion of nutrients, but increased milk fat yield and concentration. Calculated efficiency of milk yield was not altered by diets. FA supplementation increased EB during the postpartum period. Experimental diets increased long-chain FA (saturated and unsaturated FA) in milk. In addition, cows fed WS and CSFA had higher C18:1 trans-11 FA and C18:2 cis, and lower C18:3 FA in milk than those fed WF. Furthermore, cows fed CSFA had higher C18:1 trans-11 and cis-9, trans-11 FA than cows fed WS. Although supplemental C18:2 and C18:3 FA did not influence the milk yield of cows, they positively affected EB and increased unsaturated long-chain FA in milk fat.


Assuntos
Bovinos/fisiologia , Digestão , Metabolismo Energético/efeitos dos fármacos , Ácidos Graxos/metabolismo , Linho/química , Glycine max/química , Leite/efeitos dos fármacos , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal/efeitos dos fármacos , Animais , Cálcio/metabolismo , Dieta/veterinária , Suplementos Nutricionais/análise , Digestão/efeitos dos fármacos , Feminino , Lactação , Leite/química , Leite/metabolismo , Distribuição Aleatória , Sais/metabolismo
4.
Reprod Domest Anim ; 49(3): 448-52, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24689827

RESUMO

In Bos taurus cattle, antimullerian hormone (AMH) has been demonstrated to have a high degree of correlation with ovarian antral follicle count and the number of healthy follicles and oocytes. To document the correlation between the plasma concentration of AMH and follicular number in Bos indicus and Bos taurus heifers, Nelore (Bos indicus, n = 16) and Holstein heifers (Bos taurus, n = 16) had their ovarian follicular waves synchronized. After synchronization, ovarian antral follicular population (AFP) was evaluated three times at 60-day (d) intervals (T-120 d, 120 days before plasma AMH determination; T-60 d, 60 days before; and T0, at the time of plasma AMH determination). The plasma AMH concentration was positively correlated with the number of ovarian follicles on the day of the follicular wave emergence in Bos indicus (Nelore) and Bos taurus (Holstein) heifers at each evaluation time (p < 0.05). The AFP was higher in Bos indicus (Nelore) than in Bos taurus (Holstein) heifers (p < 0.05). Similarly, the AMH concentration was higher in Bos indicus (Nelore) than in Bos taurus (Holstein) heifers (p < 0.0001). When heifers were classified as to present high or low AFP according to the mean of the AFP within each genetic group, high-AFP heifers presented a greater (p < 0.0001) AMH concentration than low-AFP heifers, regardless of the genetic group. In conclusion, the AFP is positively correlated with plasma AMH concentration in both Bos indicus (Nelore) and Bos taurus (Holstein) heifers. Furthermore, Bos indicus (Nelore) heifers presented both greater plasma AMH concentrations and AFP than Bos taurus (Holstein) heifers.


Assuntos
Hormônio Antimülleriano/sangue , Bovinos/sangue , Folículo Ovariano/anatomia & histologia , Animais , Feminino , Folículo Ovariano/diagnóstico por imagem , Especificidade da Espécie , Ultrassonografia
5.
J Environ Radioact ; 128: 91-6, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24334195

RESUMO

Polonium-210 ((210)Po) concentration was quantified in the muscle tissue and organs of two predatory marine fishes (Genypterus brasiliensis and Cynoscion microlepidotus) from Cabo Frio, Rio de Janeiro, Brazil. The species C. microlepidotus, a benthic carnivore, registered higher (210)Po in its tissue. The organs associated with digestion displayed the maximum radionuclide compared with other organs. The average activity was 2 mBq kg(-1) for G. brasiliensis and it was 6 mBq kg(-1) for C. microlepidotus. The activity concentrations varied significantly between the species and among organs.


Assuntos
Exposição Ambiental , Peixes/metabolismo , Polônio/metabolismo , Poluentes Radioativos da Água/metabolismo , Animais , Brasil , Monitoramento de Radiação , Especificidade da Espécie
6.
Environ Geochem Health ; 35(3): 333-40, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23124728

RESUMO

The aim of this study was to evaluate the public and occupational exposure to radon and metal-bearing particles in museums and public buildings located in the city of Rio de Janeiro, Brazil. For this study, four buildings were selected: two historic buildings, which currently house an art gallery and an art museum; and two modern buildings, a chapel and a club. Integrated radon concentration measurements were performed using passive radon detectors with solid state nuclear track detector-type Lexan used as nuclear track detector. Air samplers with a cyclone were used to collect the airborne particle samples that were analyzed by the particle-induced X-ray emission technique. The average unattached-radon concentrations in indoor air in the buildings were above 40 Bq/m(3), with the exception of Building D as measured in 2009. The average radon concentrations in indoor air in the four buildings in 2009 were below the recommended reference level by World Health Organization (100 Bq/m(3)); however, in 2011, the average concentrations of radon in Buildings A and C were above this level, though lower than 300 Bq/m(3). The average concentrations of unattached radon were lower than 148 Bq/m(3) (4pCi/L), the USEPA level recommended to take action to reduce the concentrations of radon in indoor air. The unattached-radon average concentrations were also lower than the value recommended by the European Union for new houses. As the unattached-radon concentrations were below the international level recommended to take action to reduce the radon concentration in air, it was concluded that during the period of sampling, there was low risk to human health due to the inhalation of unattached radon in these four buildings.


Assuntos
Poluentes Radioativos do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Metais/análise , Radônio/análise , Brasil , Poeira/análise , Exposição Ambiental/análise , Monitoramento Ambiental/métodos , Humanos , Metais/química , Museus , Exposição Ocupacional/análise , Monitoramento de Radiação/métodos
7.
Anal Sci ; 24(7): 839-42, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18614822

RESUMO

Knowledge about the spatial distribution and the local concentration of trace elements in tissues is of great importance, since trace elements are involved in many biological functions of living organisms. However, there are few methods available to measure the spatial (two (three)-dimensional) elemental distribution in animal brain. X-ray microfluorescence with synchrotron radiation is a multielemental mapping technique, which was used in this work to determine the topographic of iron, zinc and copper in coronal sections of female Wistar rats of different ages. Young (14 days old) and middle-aged (20 months old) rats (n = 8) were analyzed. The measurements were carried out at the XRF beam line at the Synchrotron Light National Laboratory (Campinas, Brazil). Two-dimensional scanning was performed in order to study the tendency of elemental concentration variation. The acquisition time for each pixel was 10 s/step and the step size was 300 microm/step in both directions. It was observed that the iron distribution was more conspicuous in the cortical area, thalamus and bellow the thalamus. On the other hand, the zinc distribution was more pronounced in the hippocampus. The iron, copper and zinc levels increased with advancing age. Therefore, this study reinforces the idea that these elements are involved in the chemical mechanisms of the brain that induce some neurological diseases, since they are also present in high levels in specific areas of the brain, such as the hippocampus and the substantia nigra of patients with these disorders.


Assuntos
Encéfalo , Espectrometria por Raios X/métodos , Síncrotrons , Oligoelementos/análise , Animais , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Encéfalo/patologia , Córtex Cerebral/química , Córtex Cerebral/patologia , Cobre/análise , Feminino , Hipocampo/química , Hipocampo/patologia , Ferro/análise , Radiografia , Ratos , Ratos Wistar , Reprodutibilidade dos Testes , Espectrometria por Raios X/instrumentação , Substância Negra/química , Substância Negra/patologia , Tálamo/química , Tálamo/patologia , Zinco/análise
8.
Radiat Prot Dosimetry ; 119(1-4): 201-5, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16644938

RESUMO

In this work we present the synthesis, characterisation and the thermoluminescence (TL) response of nanoporous carbon doped aluminium oxide Al2O3:C produced by anodic oxidation of aluminium in organic and inorganic solvents. The X-ray and scanning electron microscopy (SEM) measurements reveal that the synthesised samples are amorphous and present highly ordered structures with uniform pore distribution with diameter of the order 50 nm. The photoluminescence and spectroscopic analysis in the visible and infrared regions show that the luminescence properties presented by the samples prepared in organic acid are due to carboxylate species, incorporated in anodic alumina films during the synthesis process. After an annealing treatment, part of the incorporated species decomposes and is incorporated into the structure of the aluminium oxide yielding a highly thermoluminescent detector (TL) . The results for X-ray irradiation in the range from 21 to 80 keV indicate a linear TL response with the dose in the range from 5 mGy to 1 Gy, suggesting that nanoporous aluminium oxide produced in the present route of synthesis is a suitable detector for radiation measurements.


Assuntos
Óxido de Alumínio/química , Óxido de Alumínio/efeitos da radiação , Carbono/química , Nanoestruturas/química , Nanoestruturas/efeitos da radiação , Nanotecnologia/instrumentação , Dosimetria Termoluminescente/instrumentação , Carbono/efeitos da radiação , Relação Dose-Resposta à Radiação , Desenho de Equipamento , Análise de Falha de Equipamento , Teste de Materiais , Nanoestruturas/ultraestrutura , Nanotecnologia/métodos , Tamanho da Partícula , Porosidade , Doses de Radiação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Dosimetria Termoluminescente/métodos
9.
Radiat Prot Dosimetry ; 101(1-4): 553-6, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12382810

RESUMO

Polycrystalline CaSO4 powder, doped with different elements but mainly rare earths, is one of the most interesting thermoluminescent (TL) materials. Although many electron spin resonance (ESR) analyses have been reported for these materials few studies have been published about the potential of CaSO4 for ESR dosimetry; almost all studies used CaSO4:Dy with a very low Dy concentration as the material for TL measurements. Pure CaSO4 from Merck was used to prepare CaSO4:Dy and CaSO4:P:Dy with different Dy concentrations. Samples were annealed at 600 degrees C for 1 h before irradiation in a Gammacell 220 irradiator with a 60Co gamma source at a dose rate of 100 Gy x min(-1). The ESR spectra of the pure CaSO4 and CaSO4 doped with P and Dy show the lines usually observed with these types of material, with the factor g around 2.036 and an intense line at g = 2.0011 found only in the pure material. This line, probably an axial SO4-, grows linearly with absorbed dose until 1.0 kGy and shows good stability with time. The line should be stabilized by matrix impurities because it can be removed by a simple treatment with hot sulphuric acid.


Assuntos
Sulfato de Cálcio/química , Radioisótopos de Cobalto , Disprósio/efeitos da radiação , Espectroscopia de Ressonância de Spin Eletrônica/métodos , Fósforo , Reprodutibilidade dos Testes , Dosimetria Termoluminescente/métodos
10.
Appl Radiat Isot ; 53(4-5): 717-24, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11003511

RESUMO

At low angles the scattering of X-rays in the diagnostic energy range (low-momentum transfer), it is probable that the scattering interaction will be coherent. This coherence gives rise to interference effects resulting in X-ray diffraction patterns that are characteristic of the scattering material. The usefulness of coherent scattering is not limited to crystallography. It can provide information about biological material as well. The interatomic and intermolecular co-operative effects which modify the free-atom coherent scattering process are well known for highly ordered structures such as crystalline materials but are important for amorphous solids and liquids where short-range ordering occurs. X-ray diffraction using synchrotron radiation has became a well established technique. This work introduces a non-destructive synchrotron radiation X-ray diffraction imaging technique. The feasibility of the X-ray diffraction computed microtomography using synchrotron radiation has been investigated. This research was carried out at the X-ray diffraction beam line of the National Synchrotron Light Laboratory supported by the National Council for Scientific and Technological Development (LNLS/CNPq) in Brazil. These experimental patterns were carried out with a 500 microm slit in front of the detector and an 11.101 keV beam (lambda = 1.117 A) monochromatic beam from the double crystal monochromator. The diffracted beam was detected by a fast scintillation detector (10(6) counts s(-1)) designed specifically to meet the needs of high quality X-ray diffraction and synchrotron radiation experiments. The data were recorded at rates of one second per degree of 2theta (angular steps equal to 0.05 +/- 0.01 degrees) and registered by a multichannel analyzer. These experimental data could be used to evaluate the scattering properties of different tissue-substitute (water, lucite, nylon, plastic and polystyrene) and bone-substitute (hydroxyapatite and aluminum) materials. The data are in good agreement with those obtained by other authors, indicating the feasibility of the imaging technique.


Assuntos
Materiais Biomédicos e Odontológicos , Substitutos Ósseos , Tomografia Computadorizada por Raios X/métodos , Difração de Raios X/métodos , Alumínio , Durapatita , Nylons , Plásticos , Polimetil Metacrilato , Poliestirenos , Síncrotrons , Água
11.
Appl Radiat Isot ; 52(5): 1297-303, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10836446

RESUMO

Electron spin resonance (ESR) spectroscopy is used to assess absorbed doses of six teeth belonging to victims of the highly irradiated group of Goiânia accident. The influence of the broad background signal at g = 2.0040 as well as of the unstable fraction of CO2- radicals was taken into account in dose estimates. Three victims teeth showed absorbed doses comparable to those estimated by chromosomal analysis. For the other three teeth, the doses were higher by a factor of 1.3, 1.8 and 2.2.


Assuntos
Espectroscopia de Ressonância de Spin Eletrônica/métodos , Liberação Nociva de Radioativos , Radiometria/métodos , Dente/efeitos da radiação , Brasil , Aberrações Cromossômicas , Estudos de Avaliação como Assunto , Radicais Livres , Humanos
12.
Appl Radiat Isot ; 48(10-12): 1437-42, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9463870

RESUMO

The microfocus radiography system has been realized by means of a microfocus X-ray tube (maximum 160 kV), an image intensifier data collector and a five degree of freedom manipulation table. An 8-bit image acquisition PC-card and software were included to compose the microtomography system. To assemble the system, an image quantitative analysis was carried out by evaluation of the focal spot size, modulation transfer function of the system, and the 'defect discernibility curves'. The 2D microtomographies were carried out using the mean of 10 image central lines in each projection. Image processing techniques were also used to obtain better results. The image reconstruction program is based on a filtered backprojection algorithm using a special window. Images of various types of samples were carried out in order to verify the performance of the system.


Assuntos
Tomografia Computadorizada por Raios X/métodos , Processamento de Imagem Assistida por Computador/métodos , Tomografia Computadorizada por Raios X/instrumentação
13.
Appl Radiat Isot ; 47(11-12): 1647-53, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-9022204

RESUMO

ESR spectra of the hard seed cover and kernel coating of irradiated orange and tangerine fruits were obtained under different sample drying conditions to analyze the effect of treatment on ESR line at g = 2.0033 (line A). The spectra shows almost the same lines that appear in stalks, achenes, seeds and skins of fresh fruit. The peak-to-peak intensity of the line A of the spectra shows a linear variation with dose in the range studied (up to 5 kGy) under controlled sample preparation. Q-band ESR spectra shows that this line is composed for three different lines from different species. A1, A2 and A3. The A2 and A3 lines are associated with dose but grow also during drying of the sample and are probably due to 'cellulosic' components of the seed cover. The A1 line appears only when sample is dried and is probably associated with the quinones of the internal kernel coat.


Assuntos
Citrus/efeitos da radiação , Espectroscopia de Ressonância de Spin Eletrônica/métodos , Irradiação de Alimentos , Radiometria/métodos , Citrus/química , Dessecação , Radicais Livres/análise , Radicais Livres/efeitos da radiação , Doses de Radiação , Sementes/química , Sementes/efeitos da radiação
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