Study of Magnetic Superexchange in diluted Systems Znx Cd1-xCr2Se4 ( 0.35 ≤ x ≤ 0.58 )

The effects of cationic substitutions at different concentrations within the lattice Znx Cd1-xCr2Se4 (0.35≤x≤0.58) on the electronic transfer in chromium ions are investigated. For this propose, after taking into account the exchange integrals, we use the Anderson’s-Kanamori theory of superexchange to determine the transfer integrals bσσ and bπσ . With the use of the conventional molecular orbital model the covalency-mixing parameters, λσ and λπ, the electron spin transfer coefficients, ƒ i (i=σ, π, s ), and the total charge, C, transferred from ligand to the chromium ions, are evaluated. The variation of bσσ and bσπ with x agree with the passage of the system from ferromagnetic to antiferromagnetic order. For the compound presenting re-entrant behaviour (0.45≤x≤0.58), f s exhibits anomalous. The increasing in C with x is consistent with the expected decrease in covalency of the non magnetic cation in tetrahedral site.The effects of cationic substitutions at different concentrations within the lattice Znx Cd1-xCr2Se4 (0.35≤x≤0.58) on the electronic transfer in chromium ions are investigated. For this propose, after taking into account the exchange integrals, we use the Anderson’s-Kanamori theory of superexchange to determine the transfer integrals bσσ and bπσ . With the use of the conventional molecular orbital model the covalency-mixing parameters, λσ and λπ, the electron spin transfer coefficients, ƒ i (i=σ, π, s ), and the total charge, C, transferred from ligand to the chromium ions, are evaluated. The variation of bσσ and bσπ with x agree with the passage of the system from ferromagnetic to antiferromagnetic order. For the compound presenting re-entrant behaviour (0.45≤x≤0.58), f s exhibits anomalous. The increasing in C with x is consistent with the expected decrease in covalency of the non magnetic cation in tetrahedral site

Reconstruction of longitudinal electrons bunch profiles at FACET, SLAC

Work supported by funding from Universite Paris Sud, program "Attractivite" and by the ANR under contract ANR-12-JS05-0003-01 - http://accelconf.web.cern.ch/AccelConf/IPAC2014/papers/thpme093.pdfInternational audienceThe E-203 collaboration is testing a device on FACET at SLAC to measure the longitudinal profile of electron bunches using Smith-Purcell radiation [1]. At FACET the electron bunches have an energy of 20 GeV and a duration of a few hundred femtoseconds [2]. Smith-Purcell radiation is emitted when a charged particle passes close to the sur- face of a metallic grating. We have studied the stability of the measurement from pulse to pulse and the resolution of the measure depending on the number of gratings used

Spectra of Coherent Smith-Purcell Radiation Observed from Short Electron Bunches: Numerical and Experimental Studies

MOPWA056 - ISBN978-3-95450-122-9International audienceThere is a significant interest in the development of compact particle accelerators within research areas including X-ray and THz (T-ray) sources of radiation, particle physics and medical sciences. To support the progress in these areas, non-invasive, electron beam diagnostics that are capable of measuring a single femtosecond electron bunch are required. At the current stage such beam diagnostics for femtosecond-long electron bunches are still not available. The goal of the work presented is to understand the spectral characteristics of coherent Smith-Purcell radiation to enable its quick and reliable interpretation including the longitudinal profile reconstruction of electron bunches. The research presented comprises results from numerical modelling and experimental studies. Using the numerical data, we discuss the radiated spectra dependence on the electron bunch profile and analyse the results. We also discuss the experimental data and compare it with theoretical predictions

Longitudinal Profile Monitor Using Smith-Purcell Radiation: Recent Results from the E-203 Collaboration

TUPC38 - Work supported by seed funding from the John Fell Fund, University of Oxford, Université Paris-Sud, program "Attractivité" and by the ANR under contract ANR-12-JS05-0003-01International audienceWe report on recent measurements made at FACET by the E-203 collaboration to test a longitudinal bunch profile monitor based on Coherent Smith-Purcell radiation. The capacity of this monitor to resolve sub-picosecond bunches will be shown as well as a comparison of profile reconstructed for different beam compression settings. We will also present recent electromagnetic simulations of the interactions between the beam and the grating as well as the expected resolution of such monitor. Comparison between Coherent Smith-Purcell radiation measurement and those made with other techniques will also be discussed. Finally future upgrades of the experiment and steps toward the construction of a single shot longitudinal profile monitor will be presented

Inhibicija rasta plijesni Aspergillus ochraceus ZMPBF 318 i Penicillum expansum ZMPBF 565 djelovanjem četiriju eteričnih ulja

Fungi produce a large variety of extracellular proteins, organic acids, and other metabolites and can adapt to several environmental conditions. Mycotoxin-producing moulds of the genera Aspergillus and Penicillium are common food contaminants. One of the natural ways to protect food from mould contamination is to use essential oils. In this study, we evaluated the effect of essential oils of cinnamon, lavender, rosemary, and sage at 1 % (v/v) concentration in yeast media inoculated with spores (fi nal concentration 106 mL-1 media) of Aspergillus ochraceus ZMPBF 318 and Penicillium expansum ZMPBF 565, alone or in combination, on fungal biomass. Cinnamon showed the best inhibitory effect (100 %). Lavender oil best inhibited the growth of Aspergillus ochraceus (nearly 100 %), and was less successful with Penicillium expansum (having dropped to 57 % on day 28). With cultivation time the inhibitory effect of sage and rosemary oil grew for Aspergillus ochraceus and dropped for Penicillium expansum. These results suggest that fungi can be controlled with essential oils, especially with cinnamon oil.Plijesni su poznate po svojoj visokoj sposobnosti proizvodnje različitih izvanstaničnih proteina, organskih kiselina i drugih metabolita i po svojoj mogućnosti prilagodbe na nepovoljne okolišne uvjete, a primjenjuju se i u obradi otpadnih voda. Plijesni iz rodova Aspergillus i Penicillium česti su kontaminanti u hrani i posebno opasne jer tvore toksične metabolite mikotoksine. Eterična ulja mogu se primijeniti kao prirodna sredstva za zaštitu hrane od kontaminacije plijesnima. U radu su prikazani rezultati istraživanja utjecaja eteričnih ulja cimeta, lavande, ružmarina i kadulje na kontrolu rasta biomase plijesni Aspergillus ochraceus ZMPBF 318 i Penicillium expansum ZMPBF 565, u obliku čistih i miješanih kultura. Ulja su dodavana u koncentraciji od 1 % (v/v), a podloga (kvaščev ekstrakt) bila je nacijepljena suspenzijama spora plijesni (106 mL-1 podloge). Eterično ulje cimeta pokazalo je najveći inhibitorni učinak (100 %). Inhibitorni učinak eteričnog ulja lavande bio je veći na rast Aspergillusa ochraceusa (skoro 100 %) nego Penicilliuma expansuma (57 %). Eterična ulja kadulje i ružmarina pokazala su suprotne učinke. Inhibitorni učinak na Aspergillus ochraceus tijekom perioda uzgoja je rastao, a na Penicillium expansum opadao. Rezultati pokazuju da se rast plijesni može kontrolirati primjenom eteričnih ulja, a posebno uljem cimeta. Također upućuju na ekonomsku vrijednost takvih tretmana

In vitro activities of natural products against oral Candida isolates from denture wearers

Background: Candida-associated denture stomatitis is a frequent infectious disease. Treatment of this oral condition is difficult because failures and recurrences are common. The aim of this study was to test the in vitro antifungal activity of pure constituents of essentials oils. -- Methods: Eight terpenic derivatives (carvacrol, farnesol, geraniol, linalool, menthol, menthone, terpinen-4-ol, and aterpineol), a phenylpropanoid (eugenol), a phenethyl alcohol (tyrosol) and fluconazole were evaluated against 38 Candida isolated from denture-wearers and 10 collection Candida strains by the CLSI M27-A3 broth microdilution method. -- Results: Almost all the tested compounds showed antifungal activity with MIC ranges of 0.03-0.25% for eugenol and linalool, 0.03-0.12% for geraniol, 0.06-0.5% for menthol, a-terpineol and terpinen-4-ol, 0.03-0.5% for carvacrol, and 0.06-4% for menthone. These compounds, with the exception of farnesol, menthone and tyrosol, showed important in vitro activities against the fluconazole-resistant and susceptible-dose dependent Candida isolates. -- Conclusions: Carvacrol, eugenol, geraniol, linalool and terpinen-4-ol were very active in vitro against oral Candida isolates. Their fungistatic and fungicidal activities might convert them into promising alternatives for the topic treatment of oral candidiasis and denture stomatitis.Funding: this work has been funded in part by projects GIC07 123-IT-222-07 (Departamento de Educacion, Universidades e Investigacion, Gobierno Vasco), S-PR09UN01 and S-PR10UN03 (Saiotek 2009 and 2010, Departamento de Industria, Comercio y Turismo, Gobierno Vasco)

Beneficial effect of Mentha suaveolens essential oil in the treatment of vaginal candidiasis assessed by real-time monitoring of infection

<p>Abstract</p> <p>Background</p> <p>Vaginal candidiasis is a frequent and common distressing disease affecting up to 75% of the women of fertile age; most of these women have recurrent episodes. Essential oils from aromatic plants have been shown to have antimicrobial and antifungal activities. This study was aimed at assessing the anti-fungal activity of essential oil from <it>Mentha suaveolens </it>(EOMS) in an experimental infection of vaginal candidiasis.</p> <p>Methods</p> <p>The <it>in vitro </it>and <it>in vivo </it>activity of EOMS was assessed. The <it>in vitro </it>activity was evaluated under standard CLSI methods, and the <it>in vivo </it>analysis was carried out by exploiting a novel, non-invasive model of vaginal candidiasis in mice based on an <it>in vivo </it>imaging technique.</p> <p>Differences between essential oil treated and saline treated mice were evaluated by the non-parametric Mann-Whitney U-test. Viable count data from a time kill assay and yeast and hyphae survival test were compared using the Student's t-test (two-tailed).</p> <p>Results</p> <p>Our main findings were: i) EOMS shows potent candidastatic and candidacidal activity in an <it>in vitro </it>experimental system; ii) EOMS gives a degree of protection against vaginal candidiasis in an <it>in vivo </it>experimental system.</p> <p>Conclusions</p> <p>This study shows for the first time that the essential oil of a Moroccan plant <it>Mentha suaveolens </it>is candidastatic and candidacidal <it>in vitro</it>, and has a degree of anticandidal activity in a model of vaginal infection, as demonstrated in an <it>in vivo </it>monitoring imaging system. We conclude that our findings lay the ground for further, more extensive investigations to identify the active EOMS component(s), promising in the therapeutically problematic setting of chronic vaginal candidiasis in humans.</p