New Material For Low-dose Brachytherapy Seeds: Xe-doped Amorphous Carbon Films With Post-growth Neutron Activated 125i

We report a novel material for use in 125I brachytherapy that consists of amorphous carbon films grown by ion-beam-assisted deposition and doped with Xe (5at%) by implantation. Samples of these films grown on Si substrates were irradiated with neutrons in a TRIGA-I nuclear reactor for the production 125Xe, and latter characterized by gamma spectroscopy. The results indicate that the 124Xe was efficiently converted into 125Xe, the precursor of 125I, and support the activity calculations for a model brachytherapy seed. © 2010 Elsevier Ltd.691118121Abdukayumov, M.N., Abdulakhatov, P., Abdusalyamov, N.N., Tillaev, T.S., Rikhsiev, A.Z., Yakushev, V.P., Optimization of the process for preparing high-purity carrier-free Na125I (2004) Radiochemistry, 46, pp. 287-289Belonoshko, A.B., Ahuja, R., Johansson, B., Molecular dynamics study of melting and fcc-bcc transitions in Xe (2001) Phys. Rev. Lett., 87, p. 165505(2000), CDTN, Manual de Operação do Reator TRIGA IPR-R1 (MO/TRIGA IPR-R1)Crook, J., Fleshner, N., Roberts, C., Pond, G., Long-term urinary sequelae following (125) iodine prostate brachytherapy (2007) J. Urol., 179, pp. 141-145Cynn, H., Yoo, C.S., Baer, B., Iota-Herbei, V., McMahan, A., Nicol, M., Carlson, S., Martensitic fcc-to-hcp transformation observed in xenon at high pressure (2001) Phys. Rev. Lett., 86, p. 4552Federmann, F., Bjorneholm, O., Beutler, A., Moller, T., Resonant X-ray absorption of neon clusters: the influence of cluster size on the character of core excited states (1994) Phys. Rev. Lett., 73, p. 1549Kakar, S., Bjorneholm, O., Weigelt, J., deCastro, A., Troger, L., Frahm, R., Moller, T., Size-dependent K-edge EXAFS study of the structure of free Ar clusters (1997) Phys. Rev. Lett., 78, p. 1675Knop, A., Wassermann, B., Ruhl, E., Site-specific excitation in free krypton clusters (1998) Phys. Rev. Lett., 80, p. 2302Krainyukova, N.V., Belan, V.G., Noble gas and metal clusters in carbon nanopores: from models to applications (2007) Eur. Phys. J. D, 43, pp. 169-172Lacerda, R.G., dos Santos, M.C., Tessler, L.R., Hammer, P., Alvarez, F., Marques, F.C., Pressure-induced physical changes of noble gases implanted in highly stressed amorphous carbon films (2003) Phys. Rev. B, 68, p. 054104Mélinon, P., Masenelli, B., Tournus, F., Perez, A., Playing with carbon and silicon at the nanoscale (2007) Nat. Mater., 6, pp. 479-490Neuville, S., Matthews, A., A perspective on the optimisation of hard carbon and related coatings for engineering applications (2007) Thin Solid Films, 515, pp. 6619-6653Parry, S.J., (2003) Handbook of neutron activation analysis, , Viridian PublishingPopov, C., Kulisch, W., Jelinek, M., Bock, A., Strnad, J., Nanocrystalline diamond/amorphous carbon composite films for applications in tribology, optics and biomedicine (2006) Thin Solid Films, 494, pp. 92-97Pritychenco, B., Herman, M.W., Mughabghab, S.F., Oblozinsky, P., Sonzogni, A.A., (2006), Nuclear reaction and structure databases of the national nuclear data centerRobertson, R., (1999), Method for making iodine-125 loaded substrates for use in radioactive sources. Patent CA2261444-A1Romanov, E.G., (2003), Research Center for Atomic Reactor. Chainsolver: A tool to calculate nuclear transmutations in a neutron fluxShultis, J., Faw, R., (2002) Fundamentals of Nuclear Science and Engineering, , Marcel DekkerSolberg, T., DeMarco, J., Hugo, G., Wallace, R., Dosimetric parameters of three new solid core I-125 brachytherapy sources (2002) J. Appl. Clin. Med. Phys., 3, p. 2Woolsey, J., Miller, N., Theodorescu, D., Permanent interstitial brachytherapy for prostate cancer: a current review (2003) World J. Urol., 21, pp. 209-219Zhu, H., Venkataraman, R., Mueller, W., Lamontagne, J., Bronson, F., Morris, K., Berlizov, A., X-ray true coincidence summing correction in Genie 2000 (2009) Appl. Radiat. Isot., 67, pp. 696-70

Evaluation of cardiovascular toxicity of carbon nanotubes functionalized with sodium hyaluronate in oral regenerative medicine

It has been demonstrated that carbon nanotubes (CNTs) associated with sodium hyaluronate (HY-CNTs) accelerate bone repair in the tooth sockets of rats. Before clinical application of HY-CNTs, it is important to assess their biocompatibility. Moreover, cardiac toxicity may be caused by the translocation of these particles to the blood stream. The aim of this study was to evaluate possible changes in cardiovascular function in male Wistar rats whose tooth sockets were treated with either CNTs or HY-CNTs (100 μg/mL, 0.1 mL). Blood pressure and heart rate were monitored in conscious rats 7 days after treatment. Cardiac function was evaluated using the Langendorff perfusion technique. The data showed no changes in blood pressure or heart rate in rats treated with either CNTs or HY-CNTs, and no significant changes in cardiac function were found in any of the groups. To confirm these findings, experiments were conducted in rats injected intraperitoneally with a high concentration of either CNTs or HY-CNTs (0.75 mg/kg). The same parameters were analyzed and similar results were observed. The results obtained 7 days following injection indicate that the administration of low concentrations of CNTs or HY-CNTs directly into tooth sockets did not cause any significant change in cardiovascular function in the rats. The present findings support the possibility of using these biocomposites in humans

Single-walled carbon nanotubes functionalized with sodium hyaluronate enhance bone mineralization

The aim of this study was to evaluate the effects of sodium hyaluronate (HY), single-walled carbon nanotubes (SWCNTs) and HY-functionalized SWCNTs (HY-SWCNTs) on the behavior of primary osteoblasts, as well as to investigate the deposition of inorganic crystals on titanium surfaces coated with these biocomposites. Primary osteoblasts were obtained from the calvarial bones of male newborn Wistar rats (5 rats for each cell extraction). We assessed cell viability using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay and by double-staining with propidium iodide and Hoechst. We also assessed the formation of mineralized bone nodules by von Kossa staining, the mRNA expression of bone repair proteins, and the deposition of inorganic crystals on titanium surfaces coated with HY, SWCNTs, or HY-SWCNTs. The results showed that treatment with these biocomposites did not alter the viability of primary osteoblasts. Furthermore, deposition of mineralized bone nodules was significantly increased by cells treated with HY and HY-SWCNTs. This can be partly explained by an increase in the mRNA expression of type I and III collagen, osteocalcin, and bone morphogenetic proteins 2 and 4. Additionally, the titanium surface treated with HY-SWCNTs showed a significant increase in the deposition of inorganic crystals. Thus, our data indicate that HY, SWCNTs, and HY-SWCNTs are potentially useful for the development of new strategies for bone tissue engineering

Performance and carcass traits of Nellore and Red Norte steers finished in feedlot Desempenho e características de carcaça de novilhos das raças Nelore e Red Norte terminados em confinamento

The objective of this work was to evaluate average daily gain (ADG) and carcass traits in Nellore and Red Norte steers, finished in feedlots and to evaluate performance predictions by using the systems BR-CORTE, CNCPS 5.0 and NRC (2000). It was used 41 steers: 19 Nelore animals with initial body weight of 361 ± 31 kg and 22 Red Norte animals with initial body weight of 367 ± 30 kg. Adaptation period lasted 28 days. Animal performance evaluation was composed of three 28 day period, totaling 84 days. At the end of each period, animals were weighed after a 16-hour feeding fast. Average gain weight of Red Norte steers was greater than Nellore breed animals (1.43 vs. 1.81 kg/day, respectively). Red Norte animals also presented greater loin eye area (75.41 cm² vs. 68.67 cm²). It was not observed any differences on subcutaneous fat thickness and on rump fat among the genetic groups. None of the nutritional requirement system evaluated were efficient in predicting animal performance. For Nellore breed, daily average gain observed was 1.53kg/day, with values of 1.53, 1.70 and 1.82 kg/day predicted by NRC, CNCPS and BR-CORTE systems. Although average values and predicted by NRC were similar, according to the regression equation, intercept and inclination were different from zero and one. For Red Norte breed, performance observed was 1.88 kg/day with values of 1.50, 1.66 and 1.72 predicted by the systems NRC, CNCPS and BR-CORTE, probably because database of those systems is based mainly on results obtained from Angus bovines.<br>Objetivou-se avaliar o ganho médio diário (GMD) e as características de carcaça em novilhos das raças Nelore e Red Norte, não-castrados, terminados em confinamento e avaliar as predições do desempenho pelos sistemas CNCPS 5.0, NRC (2000) e BR-CORTE. Utilizaram-se 41 novilhos: 19 do grupo Nelore com peso vivo inicial de 361 ± 31 kg e 22 do grupo Red Norte com peso vivo inicial de 367 ± 30 kg. O período de adaptação teve duração de 28 dias. A avaliação do desempenho animal foi composta de três períodos de 28 dias, totalizando 84 dias. Ao final de cada período, realizou-se a pesagem dos animais após jejum alimentar de 16 horas. Na raça Red Norte, o ganho médio diário foi superior ao da raça Nelore (1,81 vs. 1,43 kg/dia). Os animais da raça Red Norte apresentaram também maior área de olho-de-lombo (75,41 cm² vs. 68,67 cm²). Não foi observada diferença nas espessuras de gordura subcutânea e de gordura na garupa entre os grupos genéticos. Nenhum dos sistemas de exigências nutricionais avaliados foram eficientes para a predição do desempenho animal. Na raça Nelore, o ganho médio diário observado foi de 1,53 kg/dia, com valores preditos de 1,53; 1,70 e 1,82 kg/dia pelos sistemas NRC, CNCPS e BR-CORTE. Apesar de os valores médio e preditos pelo sistema NRC terem sido semelhantes, de acordo com a equação de regressão, o intercepto e a inclinação foram diferentes de zero e um. Na raça Red Norte, o desempenho observado foi de 1,88 kg/dia com valores preditos de 1,50; 1,66 e 1,72 kg/dia pelos sistemas NRC, CNCPS e BR-CORTE, provavelmente porque o banco de dados desses sistemas é baseado principalmente em resultados obtidos em bovinos Angus