1,855 research outputs found

    HDL and reverse cholesterol transport in humans and animals: Lessons from pre-clinical models and clinical studies

    Get PDF
    The ability to accept cholesterol from cells and to promote reverse cholesterol transport (RCT) represents the best characterized antiatherogenic function of HDL. Studies carried out in animal models have unraveled the multiple mechanisms by which these lipoproteins drive cholesterol efflux from macrophages and cholesterol uptake to the liver. Moreover, the influence of HDL composition and the role of lipid transporters have been clarified by using suitable transgenic models or through experimental design employing pharmacological or nutritional interventions. Cholesterol efflux capacity (CEC), an in vitro assay developed to offer a measure of the first step of RCT, has been shown to associate with cardiovascular risk in several human cohorts, supporting the atheroprotective role of RCT in humans as well. However, negative data in other cohorts have raised concerns on the validity of this biomarker. In this review we will present the most relevant data documenting the role of HDL in RCT, as assessed in classical or innovative methodological approaches

    Risks of hospitalization and drug consumption in children and young adults with diagnosed celiac disease and the role of maternal education: A population-based matched birth cohort study

    Get PDF
    Background: Celiac disease (CD) may affect healthcare use in children and young adults. Socio-economic factors may act as a confounder or effect modifier. We assessed such hypotheses in a population-based birth cohort of young celiac subjects and references matched by maternal education. Methods: The cohort included all newborns recorded in the Medical Birth Register of Friuli-Venezia Giulia Region (Italy) between 1989 and 2011. CD incident cases were identified through pathology reports, hospital discharges and copayment exemptions and matched with up to five references by sex, year of birth and maternal education. Cox regression models were used to estimate Hazard Ratios (HRs) for major causes of inpatient diagnosis and drug prescription occurring after diagnosis in CD patients compared to references, stratifying by time of first event and maternal education. Results: We identified 1294 CD cases and 5681 references. CD cases had a higher risk of hospital admission for any cause (HR: 2.34; 95 % CI 2.08-2.63) and for all major ICD9-CM categories except obstetric complications, skin and musculoskeletal diseases, and injuries and poisoning. Prescription of all major ATC drug categories, except dermatologicals and genito-urinary medications, was significantly increased in CD subjects. For most outcomes, HRs were highest in the first year after CD diagnosis but remained significant after five or more years. HRs were similar across different categories of maternal education. Conclusions: Diagnosed CD subjects had a higher risk of hospitalization and medication use compared to the general population, even five or more years after diagnosis, with no effect modification of maternal education

    Quark propagator in a covariant gauge

    Get PDF
    Using mean--field improved gauge field configurations, we compare the results obtained for the quark propagator from Wilson fermions and Overlap fermions on a \3 lattice at a spacing of a=0.125(2)a=0.125(2) fm.Comment: 5 pages, 8 figures, talk given by F.D.R. Bonnet at LHP 2001 workshop, Cairns, Australi

    Addition of alkynes at bridging vinyliminium ligands in diiron complexes: Unprecedented diene formation by enyne-like metathesis

    Get PDF
    The zwitterionic bridging vinyliminium complex [Fe(2){mu-eta 1: eta 3-C(Tol)]=C(CS2)C] = N(Me)2}(mu-CO)(CO)( Cp)(2)] (5a) undergoes the addition of two equivalents of MeO(2)C-C C-CO(2)Me affording the bridging bis-alkylidene complex [Fe(2){mu-eta 1: eta 3-C(Me)C{C(CO(2)Me)C(CO(2)Me)CSC(CO(2)Me)C(CO(2)Me)S}CNMe(2)}(mu-CO)( CO)(Cp)(2)] (6). One alkyne unit inserts into a C-CS(2) bond of the bridging ligand, with consequent rearrangement that leads to the formation of a diene. The reaction shows analogies with the enyne metathesis. The second alkyne is incorporated into the bridging frame via cycloaddition at the thiocarboxylate function, affording a 1,3-dithiolene. The complexes [Fe(2){mu-eta(1): eta(3)-C(R')]=C(CS(2))C=N(Me)(R)}(mu-CO)(CO)(Cp)(2)] (R = Xyl, R' = Tol, 5b; R = p-C(6)H(4)OMe, R' = Me, 5c; Xyl = 2,6-Me(2)C(6)H(3)), treated with MeO(2)C-C C-CO(2)Me and then with HBF(4), undergo the cycloaddition of the alkyne with the dithiocarboxylate group and protonation of the dithiocarboxylate carbon, affording the complexes [Fe(2){mu-eta 1: eta 3-C(R')]=C{C(H)SC(CO(2)Me)C(CO(2)Me)S}C]=N(Me)(R)}(mu-CO)(CO)(Cp)(2)][BF(4)] (R = Xyl, R' = Tol, 7a; R= p-C(6)H(4)OMe, R' = Me, 7b), respectively. The X-ray molecular structure of 6 has been determined

    Reactions of diiron MU-aminocarbyne complexes containing nitrile ligands

    Get PDF
    The acetonitrile ligand in the mu-aminocarbyne complexes [Fe-2{mu-CN(Me) R}(mu-CO)( CO)(NCMe)(Cp)(2)][SO3CF3] (R = Me, 2a, CH2Ph, 2b, Xyl, 2c) (Xyl = 2,6-Me2C6H3) is readily displaced by halides and cyanide anions affording the corresponding neutral species [Fe-2{mu-CN( Me) R}(mu-CO)(CO)(X)(Cp)(2)] (X = Br, I, CN). Complexes 2 undergo deprotonation and rearrangement of the coordinated MeCN upon treatment with organolithium reagents. Trimethylacetonitrile, that does not contain acidic a hydrogens has been used in place of MeCN to form the complexes [Fe-2{mu-CN(Me)R}(mu-CO)(CO)(NCCMe3)(Cp)(2)][SO3CF3] (7a-c). Attempts to replace the nitrile ligand in 3 with carbon nucleophiles ( by reaction with RLi) failed, resulting in decomposition products. However the reaction of 7c with LiC= CTol (Tol = C6H4Me), followed by treatment with HSO3CF3, yielded the imino complex [Fe-2{mu-CN(Me) Xyl}(mu-CO)(CO) {N(H) C(C= CC6H4Me-4) CMe3}(Cp)(2)][SO3CF3] (8), obtained via acetilyde addition at the coordinated NCCMe3

    Métodos multivariados aplicados ao melhoramento genético do feijoeiro visando ao aumento da tolerância ao estresse osmótico e biofortificação de grãos

    Get PDF
    O feijoeiro (Phaseolus vulgaris L.) é uma cultura agrícola muito importante economicamente e nutricionalmente para a população brasileira e necessita de metodologias simples e eficazes que auxiliem o processo de melhoramento genético. As técnicas empregadas devem minimizar os efeitos indesejáveis da multicolinearidade entre as características estudadas durante o processo de seleção. A produção de sementes de feijão, normalmente, é limitada pela escassez hídrica e solos salinos. No entanto, devido a grande variabilidade genética, característica da espécie, é possível encontrar materiais genéticos mais tolerantes a esses estresses osmóticos. A germinação e o desenvolvimento inicial da plântula são fases críticas e desta maneira é importante selecionar os matérias genéticos mais tolerantes nestas fases. Além de selecionar genótipos tolerantes é necessário selecionar materiais genéticos que sejam ricos nutricionalmente, principalmente, em relação à composição mineralógica. Os principais objetivos almejados com este trabalho foram reduzir a multicolinearidade e selecionar genótipos para a tolerância ao estresse osmótico e a biofortificação dos grãos do feijoeiro, com base nos valores genéticos. Desta maneira, foram utilizadas duas técnicas para reduzir a influência da multicolinearidade: o descarte de variáveis redundantes pelas variáveis canônicas, e o uso das análises de fatores para reduzir o número de variáveis. As variáveis analisadas foram: porcentagem de germinação e de plântulas normais, tempo médio de germinação, índice de velocidade de germinação, comprimentos de raiz e de hipocótilo, massas seca de raiz e da parte aérea, razão raiz/parte aérea e o produto da porcentagem de plântulas normais pelo comprimento das plântulas. Avaliou-se também a composição mineralógica dos grãos em relação à concentração de cálcio, ferro, zinco, potássio, magnésio, manganês e fósforo. Adicionalmente, para estimar os parâmetros e os valores genéticos realizou-se análise via modelos mistos, utilizando-se a técnica de REML/BLUP. Os genótipos foram selecionados com base da média genética, estabilidade e adaptabilidade, utilizando-se a técnica da média harmônica da performance relativa dos valores genéticos. Os genótipos que apresentaram as maiores tolerâncias, adaptabilidade e estabilidade quanto aos estresses osmóticos foram: CNFC 15466, CNFC 15462, CNFC 15630, BRS Valente, Capixaba Precoce, CNFP 15290, CNFP 15292 e CNFP 15302. Enquanto os genótipos mais ricos e divergentes geneticamente do grupo comercial carioca foram: CNFC 15475 e CNFC 15625, e do grupo comercial preto foram: CNFP 15310 e CNFP 15304. Conclui-se que a utilização de técnicas multivariadas facilita a seleção de genótipos promissores como parentais na formação de linhagens tolerantes ao estresse osmótico e biofortificados. Palavras-chave: feijoeiro comum; seleção de genótipos; estresse hídrico e salino; multicolinearidade; composição mineral

    Diiron-aminocarbyne complexes with amine or imine ligands: C-N coupling between imine and aminocarbyne ligands promoted by tolylacetilyde addition to [Fe2{m-CN(Me)R}(m-CO)(CO)(NH=CPh2)(Cp)2][SO3CF3]

    Get PDF
    A terminally coordinated CO ligand in the complexes [Fe2{m-CN(Me)R}(m-CO)(CO)2(Cp)2][SO3CF3] (R = Me, 1a; R = Xyl, 1b; Xyl = 2,6-Me2C6H3), is readily displaced by primary and secondary amines (L), in the presence of Me3NO, affording the complexes [Fe2{m-CN(Me)R}(m-CO)(CO)(L)(Cp)2][SO3CF3] (R = Me, L = NH2Et, 4a; R = Xyl, L = NH2Et, 4b; R = Me, L = NH2Pri, 5a; R = Xyl, L = NH2Pri, 5b; R = Xyl, L = NH2C6H11, 6; R = Xyl, L = NH2Ph, 7; R = Xyl, L = NH3, 8; R = Me, L = NHMe2, 9a; R = Xyl, L = NHMe2, 9b; R = Xyl, L= NH(CH2)5, 10). In the absence of Me3NO, NH2Et gives addition at the CO ligand of 1b, yielding [Fe2{CN(Me)(Xyl)}(m-CO)(CO)C(O)NHEt(Cp)2] (11). Carbonyl replacement is also observed in the reaction of 1a-b with pyridine and benzophenone imine, affording [Fe2{m-CN(Me)R}(m-CO)(CO)(L)(Cp)2][SO3CF3] (R= Me, L= Py, 12a; R = Xyl, L= Py, 12b; R= Me, L= HN=CPh2, 13a; R = Xyl, L= HN=CPh2, 13b). The imino complex 13b reacts with p-tolylacetylide leading to the formation of the m-vinylidene-diaminocarbene compound [Fe2-C=C(Tol)C(Ph)2N(H)CN(Me)(Xyl)(m-CO)(CO)(Cp2)] (15) which has been studied by X-ray diffraction

    About the Use of mineral and vegetable Oils to improve the Sustainability of Steel Quenching

    Get PDF
    Abstract The Die Assisted Oil Quenching process is a highly customisable heat treatment that permits a relevant reduction of distortions thus limiting or avoiding following grinding operations. Distortion reductions can be obtained not only by an action on process parameters and equipment but also by choosing suitable quenching media. Nowadays, the most widely used quenching fluids are mineral oils. Nevertheless, a number of innovative quenchants that are derived from oily plants are available on the market as possible alternatives to such media. Such multiplicity leads to a decision-making problem that may deeply affect the global sustainability of the process. In this paper, a comparative study between a mineral and a vegetable oil is performed. A preliminary analysis of the environmental impacts of the two quenching media is presented. Then, an experimental activity has been performed to investigate the technical performances of the two media in terms of dimensional and metallurgical properties of the quenched parts. Furthermore, a measurement of oily fogs has been performed during quenching to verify possible emission reductions. The experimental activity pointed out a better control of part distortions and a comparable metallurgical microstructure when vegetable oil is used for quenching. In addition, no oily fogs have been observed for this quenching medium
    corecore