Parathyroid hormone and osteoporosis: solving the puzzle. Physiologic rationale for the therapeutic use of PTH in osteoporosis

Parathyroid hormone (PTH) will be available in a few months for the treatment of osteoporosis. When used as a single daily subcutaneous injection for at least 1 year, it increases bone mass and reduces fracture rate more efficiently than the usual anti-resorptive therapy. Recently published articles show that PTH can act through different intracellular signaling pathways, depending on its concentration, time of exposure and molecular fragments. High concentration and prolonged exposure to amino-terminal PTH fragments stimulate bone resorption. On the other hand, in an intermittent way and in low concentrations, PTH administration increases bone formation. This review aims to present the principal results of clinical and experimental researches on PTH actions, while trying to explain the rationale for its dual effect on bone remodeling.O paratormônio (PTH) estará disponível em breve em nosso mercado como uma possibilidade terapêutica eficiente para a osteoporose. Esta revisão tem por objetivo apresentar os resultados das pesquisas clínicas e experimentais que justificaram tal fato, assim como procurar esclarecer por quais mecanismos o PTH pode ter ações diferenciadas sobre o esqueleto. Os trabalhos bastante recentes demonstram que existem vias diferentes para a atuação do PTH no osteoblasto, e que isto depende da dose, do tempo de exposição e dos fragmentos de PTH utilizados. Seu uso em dose única diária, por via subcutânea, tem demonstrado resultados surpreendentes em termos de ganho de massa óssea e prevenção de fraturas, superando em muito os resultados obtidos com as terapêuticas anti-reabsortivas. Sua disponibilização trará grandes modificações nos conceitos e atuais formas de tratamento da osteoporose.Universidade Federal de São Paulo (UNIFESP) Disciplina de EndocrinologiaUNIFESP, Disciplina de EndocrinologiaSciEL

ESTUDIO DEL PERFORMANCE DE LOS GRUPOS ESTRATÉGICOS EN EL SISTEMA DE FRANQUICIA ESPAÑOL

La preocupación por considerar la heterogeneidad en los comportamientos empresariales dentro de un sector de actividad, ha sido uno de los principales motivos para la búsqueda e identificación de grupos estratégicos, generando un debate inagotable en el ámbito de la estrategia empresarial. Sin embargo, esta preocupación no se ha limitado a identificar arquetipos o configuraciones empresariales, sino que también se ha extendido al estudio de posibles diferencias en el rendimiento entre los grupos identificados. En el presente trabajo, intentamos dar respuesta a esta doble preocupación y todo ello centrándonos en el ámbito de la franquicia. Para ello, se ha elaborado una base de datos con el total de cadenas franquiciadoras (664) que en el año 2005 operaban en España. Los resultados obtenidos revelan la existencia de cinco grupos estratégicos (tipos de franquiciadores) perfectamente diferenciados, los cuales son descritos a partir de las variables estratégicas que los definen. Igualmente, se demuestra la existencia de diferencias en los resultados inter-grupales a partir de determinados indicadores de desempeño (ingresos, resultados ordinarios y rentabilidad)

Quantum Criticality and Superconductivity in Quasi-Two-Dimensional Dirac Electronic Systems

We present a theory describing the superconducting (SC) interaction of Dirac electrons in a quasi-two-dimensional system consisting of a stack of N planes. The occurrence of a SC phase is investigated both at T=0 and T\neq 0, in the case of a local interaction, when the theory must be renormalized and also in the situation where a natural physical cutoff is present in the system. In both cases, at T=0, we find a quantum phase transition connecting the normal and SC phases at a certain critical coupling. The phase structure is shown to be robust against quantum fluctuations. The SC gap is determined for T=0 and T\neq 0, both with and without a physical cutoff and the interplay between the gap and the SC order parameter is discussed. Our theory qualitatively reproduces the SC phase transition occurring in the underdoped regime of the high-Tc cuprates. This fact points to the possible relevance of Dirac electrons in the mechanism of high-Tc superconductivity.Comment: To be published in Nuclear Physics, Section B. 24 pages, 4 figure

Superconductivity in graphene stacks: from the bilayer to graphite

We study the superconducting phase transition, both in a graphene bilayer and in graphite. For that purpose we derive the mean-field effective potential for a stack of graphene layers presenting hopping between adjacent sheets. For describing superconductivity, we assume there is an on-site attractive interaction between electrons and determine the superconducting critical temperature as a function of the chemical potential. This displays a dome-shaped curve, in agreement with previous results for two-dimensional Dirac fermions. We show that the hopping between adjacent layers increases the critical temperature for small values of the chemical potential. Finally, we consider a minimal model for graphite and show that the transition temperature is higher than that for the graphene bilayer for small values of chemical potential. This might explain why intrinsic superconductivity is observed in graphite

Quantum Griffiths effects and smeared phase transitions in metals: theory and experiment

In this paper, we review theoretical and experimental research on rare region effects at quantum phase transitions in disordered itinerant electron systems. After summarizing a few basic concepts about phase transitions in the presence of quenched randomness, we introduce the idea of rare regions and discuss their importance. We then analyze in detail the different phenomena that can arise at magnetic quantum phase transitions in disordered metals, including quantum Griffiths singularities, smeared phase transitions, and cluster-glass formation. For each scenario, we discuss the resulting phase diagram and summarize the behavior of various observables. We then review several recent experiments that provide examples of these rare region phenomena. We conclude by discussing limitations of current approaches and open questions.Comment: 31 pages, 7 eps figures included, v2: discussion of the dissipative Ising chain fixed, references added, v3: final version as publishe

Efeitos da aplicação de retardador (CCC) e acelerador (GA) de crescimento na morfologia e produtividade do feijoeiro (Phaseolus vulgaris L. cv. Carioca)

Verificou-se os efeitos de CCC e GA quando aplicados sob a forma de pulverização das plântulas, na morfologia, florescimento e produtividade do feijoeiro cultivar Carioca, em condições de casa de vegetação. Estudou-se as concentrações de 500, 2000 e 4000 ppm de CCC juntamente com 50 pprn de GA; sendo que CCC 500 + GA 50 ppm promoveu aceleração no crescimento da haste principal e CCC 4000 + GA 50 ppm retardou esse crescimento em relação ao controle. Aplicação de CCC 500 + GA 50 ppm aumentou o número de folhas do feijoeiro. Num período de 2 semanas após o tratamento com CCC 500 + GA 50 ppm ocorreu aumento no comprimento dos meritalos, sendo que 30 dias após a aplicação de CCC 4000 + GA 50 ppm verificou-se diminuição no comprimento dos mesmos. Observou-se aumento no comprimento do limbo foliar 5 dias após os tratamentos com CCC 500 + GA 50 ppm ou CCC 2000 + GA 50 ppm. Ocorreu aumento no número médio de flores com aplicação de CCC 500 + GA 50 ppm. Não ocorreram diferenças significativas entre a produtividade das plantas tratadas com relação ao controle.In this paper the autors tested the effects of (2 - chloroethyl) trimethylammonium chloride (CCC) and gibberellic acid (GA) on the cultivar Carioca of bean, in three different concentrations (500, 2000, and 4000 ppm) of CCC and one concentration of GA (50 ppm). Treatment with CCC 500 ppm + GA 50 ppm increased the height of bean plant and CCC 4000 ppm + GA 50 ppm reduced the height of Phaseolus vulgaris. Application of CCC 500 ppm + GA 50 ppm or CCC 2000 ppm + GA 50 ppm increased the leaf number of bean plant. CCC 500 ppm + GA 50 ppm promoted a increase in the internode length and CCC 4000 ppm + GA 50 ppm reduced the length of internodcs. Application of CCC 500 ppm + GA 50 ppm or CCC 2000 ppm + GA 50 ppm increased the leaf length 5 days after the treatment. CCC 500 ppm + GA 50 ppm promoted higher flowering in relation to the check.

Effect of varying dietary levels of LC-PUFA and vegetable oil sources on performance and fatty acids of Senegalese sole post larvae: Puzzling results suggest complete biosynthesis pathway from C18 PUFA to DHA

Lipid nutrition of marine fish larvae has focused on supplying essential fatty acids (EFA) at high levels to meet requirements for survival, growth and development. However, some deleterious effects have been reported suggesting that excessive supply of EFA might result in insufficient supply of energy substrates, particularly in species with lower EFA requirements such as Senegalese sole (Solea senegalensis). This study addressed how the balance between EFA and non-EFA (better energy sources) affects larval performance, body composition and metabolism and retention of DHA, by formulating enrichment emulsions containing two different vegetable oil sources (olive oil or soybean oil) and three DHA levels. DHA positively affected growth and survival, independent of oil source, confirming that for sole post-larvae it is advantageous to base enrichments on vegetable oils supplying higher levels of energy, and supplement these with a DHA-rich oil. In addition, body DHA levels were generally comparable considering the large differences in their dietary supply, suggesting that the previously reported ∆4 fatty acyl desaturase (fad) operates in vivo and that DHA was synthesized at physiologically significant rates through a mechanism involving transcriptional up-regulation of ∆4fad, which was significantly up-regulated in the low DHA treatments. Furthermore, data suggested that DHA biosynthesis may be regulated by an interaction between dietary n - 3 and n - 6 PUFA, as well as by levels of LC-PUFA, and this may, under certain nutritional conditions, lead to DHA production from C18 precursors. The molecular basis of putative fatty acyl ∆5 and ∆6 desaturation activities remains to be fully determined as thorough searches have found only a single (∆4) Fads2-type transcript. Therefore, further studies are required but this might represent a unique activity described within vertebrate fads

An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics

For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types

Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe