529 research outputs found

    Nuevos conocimientos sobre la actividad antifúngica de las bacterias del ácido láctico aisladas de diferentes matrices alimentarias

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    The anti-mold activity of 397 strains of lactic acid bacteria was evaluated using both the spot method in Petri plates and coculture in liquid medium. The study led to the selection of 34 strains isolated from table olives or olive brines, 15 strains from dairy products, and 10 strains from sourdoughs, all able to inhibit a strain of Penicillium crustosum and/or a strain of Aspergillus section Nidulantes, prevailing in two Calabrian olive brines. Seven representative strains were identified as Lactobacillus pentosus (four strains) and Lactobacillus sanfranciscensis (three strains) and are currently under testing for their antifungal activity during table olive fermentation. This research constitutes an initial contribution to the control of fungal growth and mycotoxin accumulation during table olive fermentation. The selected strains could be used as adjunct cultures in table olive fermentation, allowing for the biological control of table olive safety.La actividad antimoho de 397 bacterias del ácido láctico se evaluó utilizando tanto el método puntual en placas de Petri como el co-cultivo en medio líquido. El estudio condujo a la selección de 34 cepas aisladas de aceitunas de mesa o salmueras de oliva, 15 cepas de productos lácteos y 10 cepas de masa madre, todas capaces de inhibir una cepa de Penicillium crustosum y/o una cepa de Aspergillus sección Nidulantes, que prevalecen en dos salmueras de aceituna de Calabria. Se identificaron siete cepas representativas como Lactobacillus pentosus (cuatro cepas) y Lactobacillus sanfranciscensis (tres cepas) y actualmente se están probando su actividad antifúngica durante la fermentación de aceituna de mesa. Esta investigación constituye una primera contribución para controlar el crecimiento de hongos y la acumulación de micotoxinas durante la fermentación de aceitunas de mesa. Las cepas seleccionadas podrían usarse como cultivos adjuntos en la fermentación de aceitunas de mesa

    Critical Excitation Spectrum of Quantum Chain With A Local 3-Spin Coupling

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    This article reports a measurement of the low-energy excitation spectrum along the critical line for a quantum spin chain having a local interaction between three Ising spins and longitudinal and transverse magnetic fields. The measured excitation spectrum agrees with that predicted by the (D4_4, A4_4) conformal minimal model under a nontrivial correspondence between translations at the critical line and discrete lattice translations. Under this correspondence, the measurements confirm a prediction that the critical line of this quantum spin chain and the critical point of the 2D 3-state Potts model are in the same universality class.Comment: 7 pages, 2 figure

    Tof ion spectra de convolution for lasergenerated plasmas

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    EnA study of different targets (Fe, Ti, Ni, Al2O3) ablation, in vacuum, by using a ns Nd:YAG laser radiation, 1064 nm and 532 nm (second harmonic) wavelengths, is reported. Laser pulse with high intensity generates a plasma at the target surface, with high non-isotropic emission of neutral and ion species, mainly emitted along the normal to the target surface. Time of flight (TOF) measurements are performed by using an ion collector consisting of a collimated Faraday cup placed along the normal to the target surface and an Ion Energy Analyzer (IEA) detector. The TOF spectra are converted as a function of the ions velocity and they are deconvolved for the various ion charge states by using the “Coulomb-Boltzmann shifted” function approach through the “Peakfit” mathematical code. The fit of the experimental distribution data permits to estimate the equivalent plasma temperature and the average energy shift of the distributions as a function of the ion charge state. This energy shift leads to the evaluation of the electric field producing the ion acceleration inside the plasma

    Electrodos hidrodinámicos : aplicación a la determinación contínua de pequeñas concentraciones de uranio en solución

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    Fil: Caridi, Aurora F.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

    Form factors of descendant operators in the massive Lee-Yang model

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    The form factors of the descendant operators in the massive Lee-Yang model are determined up to level 7. This is first done by exploiting the conserved quantities of the integrable theory to generate the solutions for the descendants starting from the lowest non-trivial solutions in each operator family. We then show that the operator space generated in this way, which is isomorphic to the conformal one, coincides, level by level, with that implied by the SS-matrix through the form factor bootstrap. The solutions we determine satisfy asymptotic conditions carrying the information about the level that we conjecture to hold for all the operators of the model.Comment: 23 page

    Single-Center Experience with Simultaneous Mural Aortic Thrombosis and Peripheral Obstructive Disease in Pre-COVID-19 and COVID-19 Era

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    Background: Mural aortic thrombosis associated with chronic peripheral obstruction of the lower limbs is an unusual event. Repeated embolism of instability aortic mural thrombosis caused acute limb ischemia (Rutherford 2 classification) in patients with peripheral arterial disease (PAD). We report a single-center experience for patients with transmural aortic thrombosis and peripheral artery disease. Methods: We retrospectively analyzed data of 54 patients with aortic mural thrombus disease with PAD presentation, treated at our center between 2013 and 2022. Results: Thirty patients (six with proven SARS-CoV-2 infection) underwent hybrid or staged treatment for an aortic lesion and for lower limb ischemia, by the placement of an endovascular aortic stent graft and a femoro-distal or a popliteal-distal bypass graft. The remaining 24 cases were only subjected to an intravascular treatment of the thoracic or abdominal aorta. Transient renal failure occurred in three patients. No embolic events were detected during the procedures. Aortic-related mortality was reported in just one patient who died from multiple organ failure. There was an embolic stroke in one patient with proven SARS-CoV-2 infection, three major amputations in patients with proven SARS-CoV-2 infection and no aortic-related mortality. Conclusions: Stent coverage of complex aortic lesions, alone or in association with a distal bypass graft, supports this approach in a variety of settings. The COVID-19 pandemic caused an increased mortality and amputation rate

    Water disinfection by orifice-induced hydrodynamic cavitation

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    Abstract Hydrodynamic Cavitation (HC) is considered as a promising water-disinfection technique. Due to the enormous complexity of the physical and chemical processes at play, research on HC reactors is usually carried out following an empirical approach. Surprisingly, past experimental studies have never been designed on dimensional-analysis principles, which makes it difficult to identify the key processes controlling the problem, isolate their effects and scale up the results from laboratory to full-scale scenarios. The present paper overcomes this issue and applies the principles of dimensional analysis to identify the major non-dimensional parameters controlling disinfection efficacy in classical HC reactors, namely orifice plates. On the basis of this analysis, it presents results from a new set of experiments, which were designed to isolate mainly the effects of the so-called cavitation number ( σ v ). Experimental data confirm that the disinfection efficacy of orifice plates increases with decreasing σ v . Finally, in order to discuss the significance of the results presented herein and frame the scope of future research, the present paper provides an overview of the drawbacks associated with dimensional analysis within the context of HC

    Chemical and physical modifications of polyethylene containing nanostructures

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    The polyethylene is an interesting polymer with a good mechanical strength, ductility, biocompatibility and chemical inertia. It founds several applications in many fields, such as chemistry, engineering, bio-medicine and micro-electronics. The polyethylene chemical and physical properties can be modified embedding different nanostructures in its bulk. Carbon nanotubes, metallic oxides, coloured pigments and other species can be inserted at different concentrations in the polymer material during the preparation phase of thin films and sheets. Mechanical, optical, thermal and chemical properties can be modified significantly depending on the filler concentration. The absorption coefficient at different radiations can be controlled by the amount of doping structure. In the visible region, for example, the high transparency of pure polyethylene can be strongly reduced by low concentrations of carbon nanotubes. The colour, the mechanical resistance, the wet ability of the polyethylene and other parameters can be changed by the doping species in order to prepare special devices useful for many applications
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