461 research outputs found

    Structure of cytochrome a3-Cua3 couple in cytochrome c oxidase as revealed by nitric oxide binding studies

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    The addition of NO to oxidized cytochrome c oxidase (ferrocytochrome c:oxygen oxidoreductase, EC 1.9.3.1) causes the appearance of a high-spin heme electron paramagnetic resonance (EPR) signal due to cytochrome a3. This suggests that NO coordinates to Cu{a3}+2 and breaks the antiferromagnetic couple by forming a cytochrome a3+3-Cu{a3}+2-NO complex. The intensity of the high-spin cytochrome a3 signal depends on the method of preparation of the enzyme and maximally accounts for 58% of one heme. The effect of N3- on the cytochrome a3+3-Cu{a3}+2-NO complex is to reduce cytochrome a3 to the ferrous state, and this is followed by formation of a new complex that exhibits EPR signals characteristic of a triplet species. On the basis of optical and EPR results, a NO bridge between cytochrome a3+2 and Cu{a3}+2 is proposed-i.e., cytochrome a3+2-NO-Cu{a3}+2. The half-field transition observed at g = 4.34 in the EPR spectrum of this triplet species exhibits resolved copper hyperfine splittings with |A{}| = 0.020 cm-1, indicating that the Cu{a3}+2 in the cytochrome a3+2-NO-Cu{a3}+2 complex is similar to a type 2 copper site

    Nutritional and physicochemical meat properties of wild boar (Sus scrofa ferus) x Duroc pig slaughtered to different live weights

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    AbstractDuring the past few years, an increasing interest has been shown for wild and autochthonous pig, that can offer meat of high culinary, technological and health-promoting value. Production of hybrids (wild boar x swine) can be a valid way to give back some properties to pig meat, lost in commercial swine breeding. This study, conducted in a farm in Wronie (Poland), was designed to investigate the effects of slaughter weight and gender on nutritional and physicochemical meat properties derived from crossing the European wild boar (Sus scrofa ferus) with sows of Duroc breed. Twenty-six hybrids (16 barrows and 10 gilts) were reared in pens, housed according to sex, and were fed ad libitum, from a hog feeder, with a feed containing 12,5 MJ of EM/kg and 160g of CP/kg. Animals were slaughtered at two different live weights: 8 barrows and 5 gilts at 92,0 ± 4,2 kg and 8 barrows and 5 gilts at 108,1 ± 4,3 kg. Animals were electrically stunned; following exsanguination, the carcasses were dehaired and evisce..

    Exclusive diffractive photoproduction of dileptons by timelike Compton scattering

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    We derive the forward photoproduction amplitude for the diffractive γp→l+l−p\gamma p \to l^+ l^- p reaction in the momentum space. within the formalism of k⊥k_\perp- factorization. Predictions for the γp→l+l−p\gamma p \to l^+ l^- p reaction are given using unintegrated gluon distribution from the literature. We calculate the total cross section as a function of photon-proton center of mass energy and the invariant mass distribution of the lepton pair. We also discuss whether the production of timelike virtual photons can be approximated by continuing to the spacelike domain q2<0 q^2 < 0. The present calculation provides an input for future predictions for exclusive hadroproduction in the pp→pl+l−pp p \to p l^+ l^- p reaction.Comment: 11 pages, 7 figure

    Susceptibility Provision Enhances Effective De-escalation (SPEED): utilizing rapid phenotypic susceptibility testing in Gram-negative bloodstream infections and its potential clinical impact

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    Abstract Objectives We evaluated the performance and time to result for pathogen identification (ID) and antimicrobial susceptibility testing (AST) of the Accelerate Pheno™ system (AXDX) compared with standard of care (SOC) methods. We also assessed the hypothetical improvement in antibiotic utilization if AXDX had been implemented. Methods Clinical samples from patients with monomicrobial Gram-negative bacteraemia were tested and compared between AXDX and the SOC methods of the VERIGENE® and Bruker MALDI Biotyper® systems for ID and the VITEK® 2 system for AST. Additionally, charts were reviewed to calculate theoretical times to antibiotic de-escalation, escalation and active and optimal therapy Results ID mean time was 21 h for MALDI-TOF MS, 4.4 h for VERIGENE® and 3.7 h for AXDX. AST mean time was 35 h for VITEK® 2 and 9.0 h for AXDX. For ID, positive percentage agreement was 95.9% and negative percentage agreement was 99.9%. For AST, essential agreement was 94.5% and categorical agreement was 93.5%. If AXDX results had been available to inform patient care, 25% of patients could have been put on active therapy sooner, while 78% of patients who had therapy optimized during hospitalization could have had therapy optimized sooner. Additionally, AXDX could have reduced time to de-escalation (16 versus 31 h) and escalation (19 versus 31 h) compared with SOC. Conclusions By providing fast and reliable ID and AST results, AXDX has the potential to improve antimicrobial utilization and enhance antimicrobial stewardship

    Derived equivalence classification of the cluster-tilted algebras of Dynkin type E

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    We obtain a complete derived equivalence classification of the cluster-tilted algebras of Dynkin type E. There are 67, 416, 1574 algebras in types E6, E7 and E8 which turn out to fall into 6, 14, 15 derived equivalence classes, respectively. This classification can be achieved computationally and we outline an algorithm which has been implemented to carry out this task. We also make the classification explicit by giving standard forms for each derived equivalence class as well as complete lists of the algebras contained in each class; as these lists are quite long they are provided as supplementary material to this paper. From a structural point of view the remarkable outcome of our classification is that two cluster-tilted algebras of Dynkin type E are derived equivalent if and only if their Cartan matrices represent equivalent bilinear forms over the integers which in turn happens if and only if the two algebras are connected by a sequence of "good" mutations. This is reminiscent of the derived equivalence classification of cluster-tilted algebras of Dynkin type A, but quite different from the situation in Dynkin type D where a far-reaching classification has been obtained using similar methods as in the present paper but some very subtle questions are still open.Comment: 19 pages. v4: completely rewritten version, to appear in Algebr. Represent. Theory. v3: Main theorem strengthened by including "good" mutations (cf. also arXiv:1001.4765). Minor editorial changes. v2: Third author added. Major revision. All questions left open in the earlier version by the first two authors are now settled in v2 and the derived equivalence classification is completed. arXiv admin note: some text overlap with arXiv:1012.466

    Direct antimicrobial susceptibility testing of positive blood cultures: A comparison of the accelerate Pheno™ and VITEK® 2 systems

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    Objectives To compare the performance and time-to-result (TTR) for antimicrobial susceptibility testing (AST) of positive blood cultures (PBC) using the Accelerate Pheno™ system (AXDX) and both a direct VITEK® 2 card inoculation workflow (DV2) and traditional FDA-approved VITEK® 2 workflow using subcultured isolates (V2). Methods Patient samples with monomicrobial Gram-negative rod bacteremia were tested on AXDX and DV2 in tandem, and compared to V2 AST results. Categorical agreement (CA) errors were adjudicated using broth microdilution. Instrumentation times and AST TTR were compared. Results AXDX and DV2 had a CA of 91.5% and 97.4%, respectively, compared to V2. Post-adjudication, AXDX, DV2, and V2 had CA of 94.7%, 95.7% and 96.5%, respectively. Instrument run times were 6.6 h, 9.4 h, and 9.2 h, and AST TTR were 8.9 h, 12.9 h and 35.5 h, respectively. Conclusions AXDX and DV2 AST is fast and reliable, which may have significant antimicrobial stewardship implications

    New approach to the conceptual design of STUMM: A module dedicated to the monitoring of neutron and gamma radiation fields generated in IFMIF-DONES

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    International Fusion Materials Irradiation Facility — DEMOsingle bondOriented Neutron Source (IFMIF-DONES) is a planned powerful neutron source, which will generate an intense flux of neutrons (up to ∼1015n/s/cm2) with a fusion-relevant energy spectrum. It will be an accelerator source based on deuteron beam - lithium target reactions. The engineering design of IFMIF-DONES is elaborated in the frame of the Early Neutron Source work package of the EUROfusion consortium. The facility will be dedicated to the irradiation of suitable structural materials planned for the construction of future fusion reactors such as DEMO (Demonstration Fusion Power Plant). Start-up Monitoring Module (STUMM) is designed to monitor radiation and thermal conditions during the commissioning phase of IFMIF-DONES, characterize the produced neutron flux and validate neutronic modeling of the facility. The conceptual design of STUMM is prepared by a team of physicists and engineers from the Institute of Nuclear Physics Polish Academy of Sciences (IFJ PAN) and the National Centre for Nuclear Research (NCBJ), Poland. This paper presents the concept of STUMM, the proposed design of the module, and selected measuring systems
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