An Interesting Fitting of Quark Masses

In this note we show an empirical formula of quark masses, which is found by implementing a least squares fit. In this formula the measured QCD coupling is almost a "best fitting coupling".Comment: 5 pages, 2 figure

La chloritisation supergène zincifère des phlogopites de Canoas (PR, Brésil)

Dans l'altération superficielle de la mine de Pb-Zn-Ba de Canoas, les chlorites apparaissent en pseudomorphose des phlogopites avec un faciès et une composition tout à fait particuliers et sont très fortement zincifères (de 15 à 20% ZnO). Cette chlorite se substitue aux phlogopites du gisement. La chloritisation supergène est transitoire, avec une altération de la chlorite en smithsonite. La chlorite zincifère, (Zn3,48Mg5,11Fe3,71Al0,48Ti0,08)(Si5,67Al2,33)O26(OH)16, est de genèse et de compostion différentes de celles de la baileychlore. (Résumé d'auteur

Sustained gene expression in the retina by improved episomal vectors

Gene and cellular therapies are nowadays part of therapeutic strategies for the treatment of diverse pathologies. The drawbacks associated with gene therapy-low levels of transgene expression, vector loss during mitosis, and gene silencing-need to be addressed. The pEPI-1 and pEPito family of vectors was developed to overcome these limitations. It contains a scaffold/matrix attachment region, which anchors its replication to cell division in eukaryotic cells while in an extrachromosomal state and is less prone to silencing, due to a lower number of CpG motifs. Recent success showed that ocular gene therapy is an important tool for the treatment of several diseases, pending the overcome of the aforementioned limitations. To achieve sustained gene delivery in the retina, we evaluated several vectors based on pEPito and pEPI-1 for their ability to sustain transgene expression in retinal cells. These vectors stably transfected and replicated in retinal pigment epithelial (RPE) cells. Expression levels were promoter dependent with constitutive promoters cytomegalovirus immediate early promoter (CMV) and human CMV enhancer/human elongation factor 1 alpha promoter yielding the highest levels of transgene expression compared with the retina-specific RPE65 promoter. When injected in C57Bl6 mice, transgene expression was sustained for at least 32 days. Furthermore, the retina-specific RPE65 promoter showed higher efficiency in vivo compared to in vitro. In this study, we demonstrate that by combining tissue-specific promoters with a mitotic stable system, less susceptible to epigenetic silencing such as pEPito-based plasmids, we can achieve prolonged gene expression and a sustained therapeutic effect.Fundacao para a Ciencia e Tecnologia, Portugal [PEst/OE/EQB-LA 0023/2013, SFRH/BD/76873/2011, SFRH/BD/70318/2010, PTDC/SAU/BEB/098475/2008]; European Union [PIRG-GA-2009-249314

Jarosita e plumbojarosita nos gossans do distrito mineiro de Canoas (PR)

Jarosites and plumbojarosites in gossans related to Pb-Zn mineralization in the Canoas District are described. They are always associated with goethite and in minor extent with hematite. Some crystals show zoning with a core of jarosite and a rim of plumjarosite. Others are rather homogeneous with intermediate composition. In the general formula AB3(SO4)2(OH)6, A sites are occupied by K and Pb and B sites by Fe, Al and Zn. A and B sites are often incompletely filled. A sites generally show excess of charge. B sites show deficiency. Jarosites and plumbojarosites are secondary minerals formed by sulfur, iron and lead derived from the weathering of sulphides, and potassium from the gangue mineral orthoclase. The jarosite-goethite association in gossans percolated by meteoric waters is thermodynamically unstable. It persists due to the sluggishness of the transformation of the jarosite into goethite. Thus, the Canoas jarosites are transitory Pb bearing phases. In the mature gossans Pb is associated only with the oxyhydroxides. (Résumé d'auteur

Mutations of Bruton's tyrosine kinase gene in Brazilian patients with X-linked agammaglobulinemia

Mutations in Bruton's tyrosine kinase (BTK) gene are responsible for X-linked agammaglobulinemia (XLA), which is characterized by recurrent bacterial infections, profound hypogammaglobulinemia, and decreased numbers of mature B cells in peripheral blood. We evaluated 5 male Brazilian patients, ranging from 3 to 10 years of age, from unrelated families, whose diagnosis was based on recurrent infections, markedly reduced levels of IgM, IgG and IgA, and circulating B cell numbers <2%. BTK gene analysis was carried out using PCR-SSCP followed by sequencing. We detected three novel (Ala347fsX55, I355T, and Thr324fsX24) and two previously reported mutations (Q196X and E441X). Flow cytometry revealed a reduced expression of BTK protein in patients and a mosaic pattern of BTK expression was obtained from mothers, indicating that they were XLA carriers

Mutations of bruton's tyrosine kinase gene in Brazilian patients with X-linked agammaglobulinemia

Mutations in Bruton's tyrosine kinase (BTK) gene are responsible for X-linked agammaglobulinemia (XLA), which is characterized by recurrent bacterial infections, profound hypogammaglobulinemia, and decreased numbers of mature B cells in peripheral blood. We evaluated 5 male Brazilian patients, ranging from 3 to 10 years of age, from unrelated families, whose diagnosis was based on recurrent infections, markedly reduced levels of IgM, IgG and IgA, and circulating B cell numbers <2%. BTK gene analysis was carried out using PCR-SSCP followed by sequencing. We detected three novel (Ala347fsX55, I355T, and Thr324fsX24) and two previously reported mutations (Q196X and E441X). Flow cytometry revealed a reduced expression of BTK protein in patients and a mosaic pattern of BTK expression was obtained from mothers, indicating that they were XLA carriers439COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPNão tem2008/54220-

Compared to mycophenolate mofetil, rapamycin induces significant changes on growth factors and growth factor receptors in the early days post‐kidney transplantation

We found 1 article: Transplantation. 2002 Mar 27;73(6):915-20. Compared to mycophenolate mofetil, rapamycin induces significant changes on growth factors and growth factor receptors in the early days post-kidney transplantation. Oliveira JG, Xavier P, Sampaio SM, Henriques C, Tavares I, Mendes AA, Pestana M. Renal Department, Hospital S. João, Porto, Portugal. Abstract BACKGROUND: The new immunosuppressive drug Rapamycin (Rapa) is endowed with a mechanism of action that is distinct from that of calcineurin inhibitors. It has been claimed that Rapa does not significantly modulate either the cytokine expression or the transcription of several growth factors in mitogen-activated T cells. Previously, we reported that fine-needle aspiration biopsy (FNAB) sample cultures synthesize a large array of cytokines, and some of them may be powerful predictors of acute rejection in renal transplants. We hypothesized that Rapa may induce significant changes on cytokine production by FNAB sample cultures and on serum cytokine receptors when compared to other immunosuppressive drugs. METHODS: Kidney transplants treated with CsA-Rapa-Pred (Rapa group) were compared with transplants treated with CsA-mycophenolate mofetil-Pred (MMF group). They were studied on day 7 posttransplantation, and they remained rejection free for at least the first 6 months. FNAB samples were cultured and the supernatants were collected at 48 hr of incubation and analyzed by ELISA for interleukin 1 receptor antagonist (IL-1ra), IL-2, IL-6, IL-10, IL-18, monocyte chemotactic protein 1 (MCP-1), soluble tumor necrosis factor I, and transforming growth factor (TGF)-beta(1). The soluble receptors for IL-1, IL-2, IL-6, and tumor necrosis factor alpha, together with IL-2 and IL-18 were also measured in serum. RESULTS: Significant differences were observed when comparing Rapa with the MMF group. IL-18 and TGF-beta(1) synthesis were up-regulated, whereas IL-6 and MCP-1 were down-regulated in FNAB sample cultures. The Rapa group showed a significant down-regulation of each cytokine receptor and of IL-2 in serum. CONCLUSIONS: Rapa was associated with a decreased synthesis of primarily monocyte-derived cytokines and enhanced production of TGF-beta(1), which in an appropriate cytokine milieu may promote allograft tolerance. The down-regulation of cytokine receptors and IL-2 may be associated with a depressed immune response towards the kidney allograft. PMID: 11923692 [PubMed - indexed for MEDLINE

Influence of ink rheology and post processing in the structural performance of silicon nitride-based ceramics fabricated by robocasting

The fabrication of complex shaped Si3N4 parts by conventional methods is challenging due to its high hardness and mechanical strength. Additive manufacturing (AM) appeared as a competitive way to attain three-dimensional complexity at lower costs. However, most of AM technologies still present limitations in producing high dense ceramics, mainly due to several difficulties in developing proper feedstock. This work presents the fabrication of dense silicon nitride-based ceramics by using an extrusion based additive manufacturing technique (direct ink writing, also known as robocasting) and cold isostatic pressing (CIP) as a post processing step. Silicon-nitride aqueous based inks containing different amounts of solids loading (36, 38 and 39 vol%) and proper rheological characteristics for the printing process were studied. The use of CIP (200 MPa) is suggested to reduce or even eliminate defects and porosity and consequently, to improve mechanical performance of the final parts. Relative density, microhardness and flexural strength increased as solids loading in the inks increased and were further improved when CIP pressing was used. Parts produced by robocasting with an ink containing 39 vol% and cold isostatic pressed at 200 MPa exhibited an average relative density around 99%, 1475 HV2 microhardness value and 650 MPa flexural strength, values similar to those of silicon nitride ceramics fabricated by conventional processing.publishe

Influence of cone-beam computed tomography image artifacts on the determination of dental arch measurements

Objective: To compare dental plaster model (DPM) and cone-beam computed tomography (CBCT) in the measurement of the dental arches, and investigate whether CBCT image artifacts compromise the reliability of such measurements. Materials and Methods: Twenty patients were divided into two groups based on the presence or absence of metallic restorations in the posterior teeth. Both dental arches of the patients were scanned with the CBCT unit i-CAT, and DPMs were obtained. Two examiners obtained eight arch measurements on the CBCT images and DPMs and repeated this procedure 15 days later. The arch measurements of each patient group were compared separately by the Wilcoxon rank sum (Mann-Whitney U) test, with a significance level of 5% (alpha = .05). Intraclass correlation measured the level of intraobserver agreement. Results: Patients with healthy teeth showed no significant difference between all DPM and CBCT arch measurements (P > .05). Patients with metallic restoration showed significant difference between DPM and CBCT for the majority of the arch measurements (P > .05). The two examiners showed excellent intraobserver agreement for both measuring methods with intraclass correlation coefficient higher than 0.95. Conclusion: CBCT provided the same accuracy as DPM in the measurement of the dental arches, and was negatively influenced by the presence of image artifacts.To compare dental plaster model (DPM) and cone-beam computed tomography (CBCT) in the measurement of the dental arches, and investigate whether CBCT image artifacts compromise the reliability of such measurements. Twenty patients were divided into two gro842274278sem informaçãosem informaçã

The lateritic ore deposits of Brazil

Au Brésil, les mécanismes d'altération supergène ont conduit à la formation d'un épais recouvrement latéritique sur environ 65 % de la surface totale; dans des conditions particulières, l'accumulation de certains métaux dans ce manteau peut atteindre le stade économique. La latéritisation des diverses roches mères, tout à fait spécifiques de chaque type de gisement, est intervenue pour l'essentiel au Tertiaire, pendant des épisodes de stabilité tectonique auxquels correspondent des surfaces d'aplanissement généralisées. Le rôle des facteurs lithologiques, climatiques et morpho-tectoniques dans le mécanisme de genèse des gisements latéritiques est discut