63 research outputs found

    Chemical Composition and Anticandidal Effect of Three Thymus Species Essential Oils from Southwest of Morocco against the Emerging Nosocomial Fluconazole-Resistant Strains

    Get PDF
    The purpose of this present work is to study the essential oils composition of three endemic Thymus species from southwest of Morocco: Thymus satureioides Coss., Thymus pallidus Batt. and Thymus leptobotrys Murb., as well as their antifungal activity towards nineteen strains of emerging nosocomial Fluconazole-resistant Candida species. The chemical composition of the essential oils was determined by capillary gas chromatographic-mass spectrometry analysis. The results reveal qualitative and quantitative variation in composition of Thymus species. Seventy-three different compounds, 56 for T. satureioides accounting for 99.97% of the total essential oil, 52 for T. pallidus, accounting for 98.94% of the total essential oil, and 40 for T. leptobotrys accounting for 99.20%, were determined. The results obtained for the anticandidal disc-diffusion assay shows that the 19 strains of Candida species tested were inhibited by the Moroccan Thymus essential oils to a varying degree, with the diameters of the inhibition zone ranging from 49±1.00 to 85±1.15 mm. There were significant differences (p ? 0.05) in the antifungal activities of the essential oils on all species tested who showed larger inhibition zones than the positive control fluconazole and amphotericine B. Candida albicans showed a high sensitivity to essential oils of Thymus pallidus and Thymus leptobotrys compared with essential oil of Thymus satureioides and controls. While non- albicans Candida species showed less sensitivity to essential oils of Thymus pallidus and Thymus leptobotrys and are more sensitive to essential oils of Thymus satureioides than Candida albicans. Interestingly C. krusei, C. dubliniensis and C. glabrata were found to be resistant to conventional antifungal (fluconazole and amphotericine B), while our essential oils tested were able to inhibit the growth of Candida strains resistant to antifungal agents. The value of Minimal inhibitory concentration (MIC) and Minimal Fungicidal Concentration (MFC) of the Thymus essential oils studied ranges from 0.33 mg/mL to 0.91 mg/mL. All the essential oils possessed higher antifungal potential than classical fungicide. Keywords: Thymus species, essential oils, anticandidal activity, Nosocomial fluconazole-resistant strains

    Determination of masses of the central black holes in NGC524 and NGC2549 using Laser Guide Star Adaptive Optics

    Full text link
    [abridged] We present observations of NGC524 and NGC2549 with LGS AO obtained at GEMINI North telescope using the NIFS IFU in the K band. The purpose of these observations, together with previously obtained observations with the SAURON IFU, is to determine the masses (Mbh) of the supermassive black holes (SMBH). The targeted galaxies were chosen to have central light profiles showing a core (NGC524) and a cusp (NGC2549), to probe the feasibility of using the galaxy centre as the NGS required for LGS AO. We employ an innovative `open loop' technique. The data have spatial resolution of 0.23" and 0.17" FWHM, showing that high quality LGS AO observations of these objects are possible. We construct axisymmetric three-integral dynamical models which are constrained with both the NIFS and SAURON data. The best fitting models yield Mbh=(8.3 +2.7 -1.3) x 10^8 Msun for NGC524 and Mbh=(1.4 +0.2 -1.3) x 10^7 Msun for NGC2549 (all errors are at the 3 sigma CL). We demonstrate that the wide-field SAURON data play a crucial role in the M/L determination increasing the accuracy of M/L by a factor of at least 5, and constraining the upper limits on Mbh. The NIFS data are crucial in constraining the lower limits of Mbh and in combination with the large scale data reducing the uncertainty by a factor of 2 or more. We find that the orbital structure of NGC524 shows significant tangential anisotropy, while at larger radii both galaxies are consistent with having almost perfectly oblate velocity ellipsoids. Tangential anisotropy in NGC524 coincides with the size of SMBH sphere of influence and the core region in the light profile. We test the accuracy to which Mbh can be measured using seeings obtained from typical LGS AO observations, and conclude that for a typical conditions and Mbh the expected uncertainty is of the order of 50%.Comment: 19 pages, 14 figure

    Anti-tumour necrosis factor discontinuation in inflammatory bowel disease patients in remission: study protocol of a prospective, multicentre, randomized clinical trial

    Get PDF
    Background: Patients with inflammatory bowel disease who achieve remission with anti-tumour necrosis factor (anti-TNF) drugs may have treatment withdrawn due to safety concerns and cost considerations, but there is a lack of prospective, controlled data investigating this strategy. The primary study aim is to compare the rates of clinical remission at 1?year in patients who discontinue anti-TNF treatment versus those who continue treatment. Methods: This is an ongoing, prospective, double-blind, multicentre, randomized, placebo-controlled study in patients with Crohn?s disease or ulcerative colitis who have achieved clinical remission for ?6?months with an anti-TNF treatment and an immunosuppressant. Patients are being randomized 1:1 to discontinue anti-TNF therapy or continue therapy. Randomization stratifies patients by the type of inflammatory bowel disease and drug (infliximab versus adalimumab) at study inclusion. The primary endpoint of the study is sustained clinical remission at 1?year. Other endpoints include endoscopic and radiological activity, patient-reported outcomes (quality of life, work productivity), safety and predictive factors for relapse. The required sample size is 194 patients. In addition to the main analysis (discontinuation versus continuation), subanalyses will include stratification by type of inflammatory bowel disease, phenotype and previous treatment. Biological samples will be obtained to identify factors predictive of relapse after treatment withdrawal. Results: Enrolment began in 2016, and the study is expected to end in 2020. Conclusions: This study will contribute prospective, controlled data on outcomes and predictors of relapse in patients with inflammatory bowel disease after withdrawal of anti-TNF agents following achievement of clinical remission. Clinical trial reference number: EudraCT 2015-001410-1

    A Search for Photons with Energies Above 2X10(17) eV Using Hybrid Data from the Low-Energy Extensions of the Pierre Auger Observatory

    Get PDF
    Ultra-high-energy photons with energies exceeding 10(17) eV offer a wealth of connections to different aspects of cosmic-ray astrophysics as well as to gamma-ray and neutrino astronomy. The recent observations of photons with energies in the 10(15) eV range further motivate searches for even higher-energy photons. In this paper, we present a search for photons with energies exceeding 2 x 10(17) eV using about 5.5 yr of hybrid data from the low-energy extensions of the Pierre Auger Observatory. The upper limits on the integral photon flux derived here are the most stringent ones to date in the energy region between 10(17) and 10(18) eV
    corecore