79 research outputs found

    Reactivity of bulky tris(Phenylpyrazolyl) methanesulfonate copper(I) complexes towards small unsaturated molecules

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    Reaction of the tris(3-phenylpyrazolyl)methane sulfonate species (Tpms(Ph))Li with the copper(I) complex [Cu(MeCN)(4)][PF6] affords [Cu(Tpms(Ph))(MeCN)] 1. The latter, upon reaction with equimolar amounts of cyclohexyl-(CyNC) or 2,6-dimethylphenyl (XylNC) isocyanides, or excess CO, furnishes the corresponding Cu(I)complexes [Cu(Tpms(Ph))(CNR)] (R = Cy 2, Xyl 3) or [Cu(Tpms(Ph))(CO)] 4. The ligated isocyanide in 2 or 3 (or the acetonitrile ligand in 1)is displaced by 3-iminoisoindolin-1-one to afford 5, the first copper(I) complex containing an 3-iminoisoindolin-1-one ligand. The ligated acetonitrile in 1 undergoes nucleophilic attack by methylamine to give the amidine complex [Cu(Tpms(Ph)){MeC(NH)NHMe}] 6, whereas only the starting materials were recovered from the attempted corresponding reactions of 2 and 3 with methylamine. Complexes 1 or 6 form the trinuclear hydroxo-copper(II)species [(mu-Cu){Cu(mu-OH) (2)(Tpms(Ph))}(2)] 7 upon air oxidation in moist methanol. In all the complexes the scorpionate ligand facially caps the metal in the N,N,O-coordination mode

    New high statistics measurement of Ke4K_{e4} decay form factors and ππ\pi\pi scattering phase shifts

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    We report results from a new measurement of the Ke4K_{e4} decay K±π+πe±νK^{\pm} \rightarrow \pi^{+}\pi^{-}e^{\pm}\nu by the NA48/2 collaboration at the CERN SPS, based on a partial sample of more than 670000 Ke4K_{e4} decays in both charged modes collected in 2003. The form factors of the hadronic current (F, G, H) and ππ\pi\pi phase difference (δ=δsδp\delta=\delta_{s}-\delta_{p}) have been measured in ten independent bins of the ππ\pi\pi mass spectrum to investigate the variation. A sizeable acceptance at large ππ\pi\pi mass, a low background and a very good resolution contribute to an improved experimental accuracy, a factor two better than in the previous measurement, when extracting the ππ\pi\pi scattering lengths a00a^{0}_{0} and a02a^{2}_{0}. Under the assumption of isospin symmetry and using numerical solutions of the Roy equations, the following values are obtained in the plane (a00,a02):a00=0.233±0.016stat±0.007syst,a02=0.0471±0.011stat±0.004systa^{0}_{0}, a^{2}_{0}): a^{0}_{0}=0.233 \pm 0.016_{stat} \pm 0.007_{syst}, a^{2}_{0}=-0.0471 \pm 0.011_{stat} \pm 0.004_{syst}. The presence of potentially large isospin effects is also considered and will allow comparison with precise predictions from Chiral Perturbation Theory

    The first case of Brucella canis in Sweden: background, case report and recommendations from a northern European perspective

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    Infection with Brucella canis has been diagnosed in Sweden for the first time. It was diagnosed in a three-year-old breeding bitch with reproductive disturbances. Fifteen in-contact dogs were tested repeatedly and all of them were negative for B. canis. The source of infection could not be defined. The present article describes the case and the measures undertaken and gives a short review over B. canis. Recommendations on how to avoid the infection in non-endemic countries are given

    Search for direct CP violating charge asymmetries in K±π±π+πK^\pm\to\pi^\pm\pi^+\pi^- and K±π±π0π0K^\pm\to\pi^\pm\pi^0\pi^0 decays

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    A measurement of the direct CP violating charge asymmetries of the Dalitz plot linear slopes Ag=(g+g)/(g++g)A_g=(g^+-g^-)/(g^++g^-) in K±π±π+πK^\pm\to\pi^\pm\pi^+\pi^- and K±π±π0π0K^\pm\to\pi^\pm\pi^0\pi^0 decays by the NA48/2 experiment at CERN SPS is presented. A new technique of asymmetry measurement involving simultaneous K+K^+ and KK^- beams and a large data sample collected allowed a result of an unprecedented precision. The charge asymmetries were measured to be Agc=(1.5±2.2)×104A^c_g=(-1.5\pm2.2)\times10^{-4} with 3.11×1093.11\times 10^9 K±π±π+πK^{\pm}\to\pi^\pm\pi^+\pi^- decays, and Agn=(1.8±1.8)×104A^n_g=(1.8\pm1.8)\times10^{-4} with 9.13×1079.13\times 10^7 K±π±π0π0K^{\pm}\to\pi^\pm\pi^0\pi^0 decays. The precision of the results is limited mainly by the size of the data sample.Comment: 29 pages, 9 figures. An updated version accepted by the EPJ

    Comparative Genomic Analysis of Human Fungal Pathogens Causing Paracoccidioidomycosis

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    Paracoccidioides is a fungal pathogen and the cause of paracoccidioidomycosis, a health-threatening human systemic mycosis endemic to Latin America. Infection by Paracoccidioides, a dimorphic fungus in the order Onygenales, is coupled with a thermally regulated transition from a soil-dwelling filamentous form to a yeast-like pathogenic form. To better understand the genetic basis of growth and pathogenicity in Paracoccidioides, we sequenced the genomes of two strains of Paracoccidioides brasiliensis (Pb03 and Pb18) and one strain of Paracoccidioides lutzii (Pb01). These genomes range in size from 29.1 Mb to 32.9 Mb and encode 7,610 to 8,130 genes. To enable genetic studies, we mapped 94% of the P. brasiliensis Pb18 assembly onto five chromosomes. We characterized gene family content across Onygenales and related fungi, and within Paracoccidioides we found expansions of the fungal-specific kinase family FunK1. Additionally, the Onygenales have lost many genes involved in carbohydrate metabolism and fewer genes involved in protein metabolism, resulting in a higher ratio of proteases to carbohydrate active enzymes in the Onygenales than their relatives. To determine if gene content correlated with growth on different substrates, we screened the non-pathogenic onygenale Uncinocarpus reesii, which has orthologs for 91% of Paracoccidioides metabolic genes, for growth on 190 carbon sources. U. reesii showed growth on a limited range of carbohydrates, primarily basic plant sugars and cell wall components; this suggests that Onygenales, including dimorphic fungi, can degrade cellulosic plant material in the soil. In addition, U. reesii grew on gelatin and a wide range of dipeptides and amino acids, indicating a preference for proteinaceous growth substrates over carbohydrates, which may enable these fungi to also degrade animal biomass. These capabilities for degrading plant and animal substrates suggest a duality in lifestyle that could enable pathogenic species of Onygenales to transfer from soil to animal hosts.National Institute of Allergy and Infectious Diseases (U.S.)National Institutes of Health. Department of Health and Human Services (contract HHSN266200400001C)National Institutes of Health. Department of Health and Human Services(contract HHSN2722009000018C)Brazil. National Council for Scientific and Technological Developmen

    Contribution of Genetic Background, Traditional Risk Factors, and HIV-Related Factors to Coronary Artery Disease Events in HIV-Positive Persons

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    We show in human immunodeficiency virus-positive persons that the coronary artery disease effect of an unfavorable genetic background is comparable to previous studies in the general population, and comparable in size to traditional risk factors and antiretroviral regimens known to increase cardiovascular ris

    First measurement of the quark-to-photon fragmentation function

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    Production of excited beauty states in Z decays

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    A data sample of about 3.0 million hadronic Z decays collected by the ALEPH experiment at LEP in the years 1991 through 1994, is used to make an inclusive selection of B~hadron events. In this event sample 4227 \pm 140 \pm 252 B^* mesons in the decay B^* \to B \gamma and 1944 \pm 108 \pm 161 B^{**} mesons decaying into a B~meson and a charged pion are reconstructed. For the well established B^* meson the following quantities areobtained: \Delta M = M_{B^*} - M_{B} = (45.30\pm 0.35\pm 0.87)~\mathrm{MeV}/c^2 and N_{B^*}/(N_B+N_{B^*}) = (77.1 \pm 2.6 \pm 7.0)\%. The angular distribution of the photons in the B^* rest frame is used to measure the relative contribution of longitudinal B^* polarization states to be \sigma_L/(\sigma_L + \sigma_T)= (33 \pm 6 \pm 5)\%. \\ Resonance structure in the M(B\pi)-M(B) mass difference is observed at (424 \pm 4 \pm 10)~\mathrm{MeV}/c^2. Its shape and position is in agreement with the expectation for B^{**}_{u,d} states decaying into B_{u,d}^{(*)} \pi^\pm. The signal is therefore interpreted as arising from them. The relative production rate is determined to be \frac{BR(Z \to b \to B_{u,d}^{**})}{BR(Z \to b \to B_{u,d})} = [27.9 \pm 1.6(stat) \pm 5.9(syst) \phantom{a}^{+3.9}_{-5.6}(model)]\%. where the third error reflects the uncertainty due to different production and decay models for the broad B_{u,d}^{**} states

    Inclusive production of neutral vector mesons in hadronic Z decays

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