Bone response to a Ca- and P-enriched titanium surface obtained by anodization

This study evaluated bone response to a Ca- and P- enriched titanium (Ti) surface treated by a multiphase anodic spark deposition coating (BSP-AK). Two mongrel dogs received bilateral implantation of 3 Ti cylinders (4.1 x 12 mm) in the humerus, being either BSP-AK treated or untreated (machined - control). At 8 weeks postimplantation, bone fragments containing the implants were harvested and processed for histologic and histomorphometric analyses. Bone formation was observed in cortical area and towards the medullary canal associated to approximately 1/3 of implant extension. In most cases, in the medullary area, collagen fiber bundles were detected adjacent and oriented parallel to Ti surfaces. Such connective tissue formation exhibited focal areas of mineralized matrix lined by active osteoblasts. The mean percentages of bone-to-implant contact were 2.3 (0.0-7.2 range) for BSP-AK and 0.4 (0.0-1.3 range) for control. Although the Mann-Whitney test did not detect statistically significant differences between groups, these results indicate a trend of BSP-AK treated surfaces to support contact osteogenesis in an experimental model that produces low bone-to-implant contact values.

Fitossociologia de um Cerrado denso em ��rea de influ��ncia de torre de fluxo de carbono, P��-de-Gigante, Parque Estadual de Vassununga, SP

O dom��nio do Cerrado compreende uma ��rea cont��nua nos estados centrais do Brasil e ��reas disjuntas em outros estados, incluindo S��o Paulo. Essa vegeta����o ocupava originalmente 21% do territ��rio brasileiro, restando atualmente apenas 21,6% de sua extens��o original. A ��rea recoberta por essa vegeta����o em S��o Paulo cobria 14% de sua ��rea total e seus remanescentes recobrem menos de 1% da ocorr��ncia original dessa vegeta����o. Estudos recentes indicam que o valor da produtividade l��quida no Cerrado P��-de-Gigante (SP) constitui um pequeno dreno de carbono e indicou que a sazonalidade foi o fator determinante do valor observado. Os estudos dos fluxos de carbono em ecossistemas terrestres s��o raramente acompanhados de abordagens ecofisiol��gicas de modo a explorar a rela����o funcional das esp��cies que comp��em o ecossistema e os valores l��quidos obtidos para o mesmo. Assim, o objetivo deste trabalho foi caracterizar estruturalmente a vegeta����o presente na ��rea de maior influ��ncia da torre de fluxo instalada no Cerrado P��-de-Gigante, visando possibilitar estudos relacionados �� quantifica����o em longo prazo da din��mica dos fluxos de ��gua, energia e CO2 na vegeta����o de Cerrado. Para isso foram levantadas 20 parcelas (10 x 10 m) em 0,2 ha de Cerrado, e amostraram-se todas as plantas com per��metro ao n��vel do solo >6 cm (exceto lianas e ��rvores mortas). A distribui����o das classes de di��metro e estrutura vertical, assim como os par��metros fitossociol��gicos foram analisados. Encontramos 1451 indiv��duos, distribu��dos em 85 esp��cies, 52 g��neros e 31 fam��lias. A densidade absoluta e ��rea basal foram de 7255 ind. ha-1 e de 7,9 m��.ha-1, respectivamente. A fam��lia Leguminosae apresentou o maior n��mero de esp��cies (13). O ��ndice de diversidade de Shannon (H') foi 3,27 nats.ind-1. A distribui����o em classes de di��metro mostrou uma curva de "J" invertido, estando a maioria dos indiv��duos na primeira classe. Conclu��mos que a ��rea deve ser classificada como Cerrado denso, devido principalmente �� domin��ncia pela esp��cie arb��rea Anadenanthera falcata, cuja ocorr��ncia no estado foi relatada apenas em locais com solos ricos em satura����o de bases na regi��o das Cuestas Bas��lticas, devido tamb��m �� maior ��rea basal dos indiv��duos, comparando com outros fragmentos de Cerrado. Al��m da esp��cie citada, Myrcia lingua e Xylopia aromatica, apresentaram os maiores IVI (Valor de import��ncia).

A novel missense mutation p.L76P in the GJB2 gene causing nonsyndromic recessive deafness in a Brazilian family

Mutations in the GJB2 gene, encoding connexin 26 (Cx26), are a major cause of nonsyndromic recessive hearing loss in many countries. We report here on a novel point mutation in GJB2, p.L76P (c.227C>T), in compound heterozygosity with a c.35delG mutation, in two Brazilian sibs, one presenting mild and the other profound nonsyndromic neurosensorial hearing impairment. Their father, who carried a wild-type allele and a p.L76P mutation, had normal hearing. The mutation leads to the substitution of leucine (L) by proline (P) at residue 76, an evolutionarily conserved position in Cx26 as well as in other connexins. This mutation is predicted to affect the first extracellular domain (EC1) or the second transmembrane domain (TM2). EC1 is important for connexon-connexon interaction and for the control of channel voltage gating. The segregation of the c.227C>T (p.L76P) mutation together with c.35delG in this family indicates a recessive mode of inheritance. The association between the p.L76P mutation and hearing impairment is further supported by its absence in a normal hearing control group of 100 individuals, 50 European-Brazilians and 50 African-Brazilians.

Time resolved emission spectroscopy of poly(2,5-dicyano-p-phenylene-vinylene) films

Films of poly (2,5-dicyano-p-phenylene vinylene), DCNPPV, were obtained by electrochemical synthesis over gold thin layer (20 nm) transparent electrode deposited on a glass plate. The DCNPPV films of 4 ��m thickness were produced by electropolymerization process of α,α,α',α'-tetrabromo-2-5-dicyano-p-xilene at different applied potentials (-0.15, -0.25, -0.40, -0.60, -0.80, and -1.0 V) using 0.1 mol L-1 of tetraethylammonium bromide in acetonitrile as the supporting electrolyte. The emission decays have three exponential components: a fast component in the picosecond range (200-400 ps), and two other of about one and five nanoseconds at 293 K. The fluorescence quenching process seems to occur by exciton trapping in a low-energy site and quenching by residual bromine monomer attached at the end of the polymer chain. However, the electrochemical synthesis generates entrapped bromide or ion pairs during the growth step of the film which also contributes to the deactivation. The change of the electrolyte from bromide to perchlorate reduces significantly this additional quenching effect by allowing ion exchange of formed bromide with the nonquenching perchloride anion.

Estudo da eletrocristaliza����o de Ni e Ni-P sobre ultramicroeletrodo de platina

This work describes a comparative study of the electrocrystallization of Ni and Ni-P on Pt ultramicroelectrodes using chronoamperometric measurements. It was possible to confirm that in all cases a progressive nucleation was the predominant mechanism. Moreover, the application of the Atomistic Theory to the experimental rate of nuclei formation showed that the number of atoms in the critical nucleus was zero, except for Ni-P on Pt at low overpotentials were a value of one was observed. Furthermore, the physical characterisation of the different deposits on Pt by atomic force microscopy allowed observing the coalescence of the hemispherical nuclei of Ni and Ni-P at t max thus confirming the results obtained from the current-time analysis.

Recovery of p-TBC from a butadiene washing stream in a pilot plant

Results obtained in a pilot-scale unit designed for COD removal and p-TBC (p-tert-butylcatechol) recovery from a butadiene washing stream (pH 14, 200,000 mg COD L-1, highly toxic) at a petrochemical industry are presented. By adding H3PO4, phase separation is achieved and p-TBC is successfully recovered (88 g L-1 of washing stream). Information (time for phase separation and organic phase characterization) was gathered for designing a future industrial unit. The estimated heat generation rate was 990 kJ min-1 and 15 min were enough to promote phase separation for a liquid column of approximately 1.15 m.

Estudo cl��nico da aplica����o de matriz inorg��nica de osso associado a pept��deo sint��tico de ades��o celular (MIO/P-15), PepGen P-15��, em les��es periodontais avan��adas de c��es

Os mecanismos biol��gicos desenvolvidos para aumentar a qualidade da regenera����o ��ssea e da repara����o tecidual de s��tios periodontais espec��ficos continuam a ser um desafio e t��m sido complementado pela capacidade de ades��o celular do col��geno do tipo I, promovida por um pept��deo sint��tico de ades��o celular (P-15), associado a uma matriz inorg��nica de osso (MIO) para formar MIO/P-15. O objetivo deste estudo foi avaliar a perda do n��vel cl��nico de inser����o e a resposta da bolsa periodontal em dentes ap��s 3 e 6 meses da aplica����o de enxerto com MIO/P-15. Vinte e um c��es do Hospital Veterin��rio da Universidade de S��o Paulo foram anestesiados para realiza����o de tratamento periodontal e 132 faces dentais com perda de n��vel cl��nico de inser����o foram tratadas, sendo que 36,4% (48 faces) receberam o pept��deo de ades��o celular e 63,6% (84 faces) compuseram o grupo controle que recebeu tratamento convencional (retalho muco-gengival e aplainamento radicular). O procedimento foi documentado atrav��s de radiografia intra-oral e todas as sondagens de bolsas periodontais foram fotografadas. Depois de 3 e de 6 meses, os animais foram re-anestesiados a fim de se obter novas avalia����es, radiografias, fotografias e sondagens periodontais. As 48 faces com perda de n��vel cl��nico de inser����o que receberam material de enxertia apresentaram taxa de 40% de recupera����o do n��vel cl��nico de inser����o ap��s 6 meses. O grupo controle de faces dentais n��o apresentou altera����o do n��vel cl��nico de inser����o. A face palatina foi a que apresentou melhor taxa de regenera����o (40%) e os dentes caninos e molares mostraram as melhores respostas (57,14% e 65%, respectivamente). N��o houve sinais de infec����o p��s-cir��rgica relacionadas �� falta de higieniza����o oral dos animais. Pode-se concluir que o MIO/P-15 auxilia na regenera����o e re-ader��ncia das estruturas periodontais, incluindo osso alveolar. Sua aplica����o mostrou-se f��cil e pr��tica e a incid��ncia de complica����es p��s-cir��rgicas foi baixa. Ainda assim, mais estudos e pesquisas s��o necess��rios para que se avalie a quantidade e a qualidade do osso e do ligamento periodontal formados.

The ability of the BANA test to detect different levels of P. gingivalis, T. denticola and T. forsythia

The aim of this study was to evaluate the ability of the BANA Test to detect different levels of Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia or their combinations in subgingival samples at the initial diagnosis and after periodontal therapy. Periodontal sites with probing depths between 5-7 mm and clinical attachment level between 5-10 mm, from 53 subjects with chronic periodontitis, were sampled in four periods: initial diagnosis (T0), immediately (T1), 45 (T2) and 60 days (T3) after scaling and root planing. BANA Test and Checkerboard DNA-DNA hybridization identified red complex species in the subgingival biofilm. In all experimental periods, the highest frequencies of score 2 (Checkerboard DNA-DNA hybridization) for P. gingivalis, T. denticola and T. forsythia were observed when strong enzymatic activity (BANA) was present (p < 0.01). The best agreement was observed at initial diagnosis. The BANA Test sensitivity was 95.54% (T0), 65.18% (T1), 65.22% (T2) and 50.26% (T3). The specificity values were 12.24% (T0), 57.38% (T1), 46.27% (T2) and 53.48% (T3). The BANA Test is more effective for the detection of red complex pathogens when the bacterial levels are high, i.e. in the initial diagnosis of chronic periodontitis.

Forward Neutral-Pion Transverse Single-Spin Asymmetries in p plus p Collisions at s=200 GeV

We report precision measurements of the Feynman x (x(F)) dependence, and first measurements of the transverse momentum (p(T)) dependence, of transverse single-spin asymmetries for the production of pi(0) mesons from polarized proton collisions at s=200 GeV. The x(F) dependence of the results is in fair agreement with perturbative QCD model calculations that identify orbital motion of quarks and gluons within the proton as the origin of the spin effects. Results for the p(T) dependence at fixed x(F) are not consistent with these same perturbative QCD-based calculations.

Longitudinal double-spin asymmetry for inclusive jet production in (p)over-right-arrow + (p)over-right-arrow collisions at root s=200 GeV

We report a new STAR measurement of the longitudinal double-spin asymmetry A(LL) for inclusive jet production at midrapidity in polarized p+p collisions at a center-of-mass energy of root s = 200 GeV. The data, which cover jet transverse momenta 5 < p(T) < 30 GeV/c, are substantially more precise than previous measurements. They provide significant new constraints on the gluon spin contribution to the nucleon spin through the comparison to predictions derived from one global fit to polarized deep-inelastic scattering measurements. They provide significant new constraints on the gluon spin contribution to the nucleon spin through the comparison to predictions derived from one global fit to polarized deep-inelastic scattering measurements.

Enhanced strange baryon production in Au+Au collisions compared to p+p at root s(NN)=200 GeV

We report on the observed differences in production rates of strange and multistrange baryons in Au+Au collisions at s(NN)=200 GeV compared to p+p interactions at the same energy. The strange baryon yields in Au+Au collisions, when scaled down by the number of participating nucleons, are enhanced relative to those measured in p+p reactions. The enhancement observed increases with the strangeness content of the baryon, and it increases for all strange baryons with collision centrality. The enhancement is qualitatively similar to that observed at the lower collision energy s(NN)=17.3 GeV. The previous observations are for the bulk production, while at intermediate p(T),1 < p(T)< 4 GeV/c, the strange baryons even exceed binary scaling from p+p yields.

Azimuthal correlations of electrons from heavy-flavor decay with hadrons in p plus p and Au plus Au collisions at root s(NN)=200 GeV

Measurements of electrons from the decay of open-heavy-flavor mesons have shown that the yields are suppressed in Au+Au collisions compared to expectations from binary-scaled p+p collisions. These measurements indicate that charm and bottom quarks interact with the hot dense matter produced in heavy-ion collisions much more than expected. Here we extend these studies to two-particle correlations where one particle is an electron from the decay of a heavy-flavor meson and the other is a charged hadron from either the decay of the heavy meson or from jet fragmentation. These measurements provide more detailed information about the interactions between heavy quarks and the matter, such as whether the modification of the away-side-jet shape seen in hadron-hadron correlations is present when the trigger particle is from heavy-meson decay and whether the overall level of away-side-jet suppression is consistent. We statistically subtract correlations of electrons arising from background sources from the inclusive electron-hadron correlations and obtain two-particle azimuthal correlations at root s(NN) = 200 GeV between electrons from heavy-flavor decay with charged hadrons in p+p and also first results in Au+Au collisions. We find the away-side-jet shape and yield to be modified in Au+Au collisions compared to p+p collisions.