Comparative dosimetry in intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT for brain tumors

Objective Comparative analysis of dosimetry in intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT for treatment of brain tumors. Materials and Methods Simulations of intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT were performed with the MCNP5 code, modeling the treatment of a brain tumor on a voxel computational phantom representing a human head. Absorbed dose rates were converted into biologically weighted dose rates. Results Intracavitary balloon catheter brachytherapy with I-125 produced biologically weighted mean dose rates of 3.2E-11, 1.3E-10, 1.9E-11 and 6.9E-13 RBE.Gy.h-1.p-1.s, respectively, on the healthy tissue, on the balloon periphery and on the I 1 and I 2 tumor infiltration zones. On the other hand, Cf-252 brachytherapy combined with BNCT produced a biologically weighted mean dose rate of 5.2E-09, 2.3E-07, 8.7E-09 and 2.4E-09 RBE.Gy.h-1.p-1.s, respectively on the healthy tissue, on the target tumor and on the I 1 and I 2 infiltration zones. Conclusion Cf-252 brachytherapy combined with BNCT delivered a selective irradiation to the target tumor and to infiltration zones, while intracavitary balloon catheter brachytherapy with I-125 delivered negligible doses on the tumor infiltration zones.

The Gly482Ser genotype at the PPARGC1A gene and elevated blood pressure: a meta-analysis involving 13,949 individuals.

The protein encoded by the PPARGC1A gene is expressed at high levels in metabolically active tissues and is involved in the control of oxidative stress via reactive oxygen species detoxification. Several recent reports suggest that the PPARGC1A Gly482Ser (rs8192678) missense polymorphism may relate inversely with blood pressure. We used conventional meta-analysis methods to assess the association between Gly482Ser and systolic (SBP) or diastolic blood pressures (DBP) or hypertension in 13,949 individuals from 17 studies, of which 6,042 were previously unpublished observations. The studies comprised cohorts of white European, Asian, and American Indian adults, and adolescents from South America. Stratified analyses were conducted to control for population stratification. Pooled genotype frequencies were 0.47 (Gly482Gly), 0.42 (Gly482Ser), and 0.11 (Ser482Ser). We found no evidence of association between Gly482Ser and SBP [Gly482Gly: mean = 131.0 mmHg, 95% confidence interval (CI) = 130.5-131.5 mmHg; Gly482Ser mean = 133.1 mmHg, 95% CI = 132.6-133.6 mmHg; Ser482Ser: mean = 133.5 mmHg, 95% CI = 132.5-134.5 mmHg; P = 0.409] or DBP (Gly482Gly: mean = 80.3 mmHg, 95% CI = 80.0-80.6 mmHg; Gly482Ser mean = 81.5 mmHg, 95% CI = 81.2-81.8 mmHg; Ser482Ser: mean = 82.1 mmHg, 95% CI = 81.5-82.7 mmHg; P = 0.651). Contrary to previous reports, we did not observe significant effect modification by sex (SBP, P = 0.966; DBP, P = 0.715). We were also unable to confirm the previously reported association between the Ser482 allele and hypertension [odds ratio: 0.97, 95% CI = 0.87-1.08, P = 0.585]. These results were materially unchanged when analyses were focused on whites only. However, statistical evidence of gene-age interaction was apparent for DBP [Gly482Gly: 73.5 (72.8, 74.2), Gly482Ser: 77.0 (76.2, 77.8), Ser482Ser: 79.1 (77.4, 80.9), P = 4.20 x 10(-12)] and SBP [Gly482Gly: 121.4 (120.4, 122.5), Gly482Ser: 125.9 (124.6, 127.1), Ser482Ser: 129.2 (126.5, 131.9), P = 7.20 x 10(-12)] in individuals <50 yr (n = 2,511); these genetic effects were absent in those older than 50 yr (n = 5,088) (SBP, P = 0.41; DBP, P = 0.51). Our findings suggest that the PPARGC1A Ser482 allele may be associated with higher blood pressure, but this is only apparent in younger adults.

Efeito de elementos intersticiais nas propriedades físicas e biocompatibilidade da liga 'TI'-13'NB'-13'ZR'

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Na 50 Nachlass Arthur Schopenhauer - 'Schopenhauer-Archiv', 125 - Ankündigung des Besuchs in Frankfurt am Main

veröffentlicht in: Schopenhauer, Arthur : Arthur Schopenhauers sämtliche Werke - München : Piper - Bd. 14 : Der Briefwechsel Arthur Schopenhauers ; 1 (1799 - 1849), Nr. 331;

Major and trace element composition of sepentine muds and metabasic rocks of ODP Leg 195 and Leg 125 sites

New geochemical data on serpentinite muds and metamorphic clasts recovered during Ocean Drilling Program Legs 195 (Holes 1200A-1200E) and 125 (Holes 778A and 779A) provide insights into the proportions of rock types of various sources that compose the serpentinite mudflows and the fluid-rock interactions that predominate in these muds. We interpret the metamorphic rock fragments as derivatives of mostly metamorphosed mafic rocks from the descending Pacific oceanic crust. Based on their mid-ocean-ridge basalt (MORB)-like Al2O3, TiO2, CaO, Si/Mg, and rare earth element (REE) systematics, these metamorphic rocks are classified as metabasalts/metagabbros and, therefore, ~30-km depths represent an active subduction zone setting. The serpentinite muds from Holes 1200A and 1200E have slightly lower REE when compared to Hole 1200D, but overall the REE abundance levels range between 0.1-1 x chondrite (CI) levels. The chondrite-normalized patterns have [La/Sm]N ~ 2.3 and [Sm/Yb]N ~ 2. With the exception of one sample, the analyzed metamorphic clasts show flat to slightly depleted light REE patterns with 1.0-15 x CI levels, resembling MORBs. Visually, ~6 vol% of the serpentinized muds are composed of 'exotic' materials (metamorphic clasts [schists]). Our mixing calculations confirm this result and show that the serpentinite muds are produced by additions of ~5% metamafic materials (with flat and up to 10 x CI REE levels) to serpentinized peridotite clast material (with very low REE abundances and U-shaped chondrite-normalized patterns). The preferential incorporation of B, Cs, Rb, Li, As, Sb, and Ba into the structure of H2O-bearing sheet silicates (different than serpentine) in the Leg 125 and Leg 195 metamorphic clasts (chlorite, amphibole, and micas) have little effect on the overall fluid-mobile element (FME) enrichments in the serpentinite muds (average B = ~13 ppm; average Cs = ~0.05 ppm; average As = ~1.25 ppm). The extent of FME enrichment in the serpentinized muds is similar to that described for the serpentinized peridotites, both recording interaction with fluids very rich in B, Cs, and As originating from the subducting Pacific slab.

Iodine and boron concentrations in pore fluids, ultramafic clasts and interstitial serpentinite mud of ODP Hole 125-779A and Site 195-1200

Iodine and boron were analyzed in pore fluids, serpentinized ultramafic clasts, and the serpentinized mud matrix of the South Chamorro Seamount mud volcano (Ocean Drilling Program Leg 195 Site 1200) to determine the distribution of these elements in deep forearc settings. Similar analyses of clasts and muds from the Conical Seamount mud volcano (Leg 125 Site 779) were also carried out. Interstitial pore fluids are enriched in boron and iodine without appreciable change in chloride concentration relative to seawater. Both the ultramafic clasts and the associated serpentinized mud present the highest documented iodine concentrations for all types of nonsedimentary rocks (6.3-101.7 µmol/kg). Such high iodine concentrations, if commonplace in marine forearc settings, may constitute a significant, previously unknown reservoir of iodine. This serpentinized forearc mantle reservoir may potentially contribute to the total crustal iodine budget and provide a mechanism for its recycling at convergent plate margins. Both clasts and mud show concurrent enrichments in boron and iodine, and the similarity in pore fluid profiles also suggests that these two incompatible, fluid-mobile elements behave similarly at convergent plate margins.