28,341 research outputs found
Antimicrobial susceptibility assessment of Campylobacter on outdoor iberian pig sows
Both Campylobacter and Salmonella are considered the most frequent bacterial causes of human enteritis in
industrialized countries. The consumption of raw or undercooked poultry and pork contaminated meat products
are the main sources of human infection. The prevalence of Campylobacter and Salmonella was determined in
the present work for extensive production Iberian pig sows, Sus mediterraneus. Samples were collected at the
maternity area of a creator from, water drinkers, feed and feed containers as well as from sows faecal matter. Of
42 samples, 31 and 23 carried Campylobacter spp. and Salmonella spp. respectively. Only Salmonella spp. was
found in all 3 tested water and feed containers. Of the 58 isolated Campylobacter strains only one was identified,
by multiplex-PCR, as Campylobacter jejuni, all other were C. coli. Antibiotic susceptibility was performed by
disc diffusion method with Nalidixic acid, Ciprofloxacin, Erythromycin, Tetracycline, Chloramphenicol and
Ampicilin. While 95% of the tested strains were susceptible to chloramphenicol, 66% and 53% were resistant to
the tested fluoroquinolones, Ciprofloxacin and Nalidixic acid respectively. Erythromycin resistance was fairly
low in comparison to previous publications with 14% of resistant strains. 38% were resistant to Tetracycline and
57% to Ampicilin. Seven of the 58 Campylobacter strains were entirely susceptible and none were resistant to all
the antimicrobials tested. Multiple drug resistance was found in 88% of strains. Cross contamination may occur
between sows inside maternity facilities and piglets may become infected in an early age by their mothers. New
and better control measures are therefore necessary to minimize transmission between animals reducing the
number of contaminated individuals and the potential transmission to human handlers and consumers
Enhancement of by disorder in underdoped iron pnictides
We analyze how disorder affects the transition temperature of the
superconducting state in the iron pnictides. The conventional wisdom is
that should rapidly decrease with increasing inter-band non-magnetic
impurity scattering, but we show that this behavior holds only in the overdoped
region of the phase diagram. In the underdoped regime, where superconductivity
emerges from a pre-existing magnetic state, disorder gives rise to two
competing effects: breaking of the Cooper pairs, which tends to reduce ,
and suppression of the itinerant magnetic order, which tends to bring
up. We show that for a wide range of parameters the second effect wins, leading
to an increase of with disorder in the coexistence state. Our results
explain several recent experimental findings and provide another evidence for
-pairing in the iron pnictides.Comment: 5 pages, 3 figures; revised version accepted in PRB-R
Transfer of optical spectral weight in magnetically ordered superconductors
We show that, in antiferromagnetic superconductors, the optical spectral
weight transferred to low frequencies below the superconducting transition
temperature originates from energies that can be much larger than twice the
superconducting gap . This contrasts to non-magnetic superconductors,
where the optical spectrum is suppressed only for frequencies below .
In particular, we demonstrate that the superfluid condensate of the
magnetically ordered superconductor is not only due to states of the
magnetically reconstructed Fermi surface, but is enhanced by transfer of
spectral weight from the mid infrared peak generated by the spin density wave
gap. We apply our results to the iron arsenide superconductors, addressing the
decrease of the zero-temperature superfluid density in the doping regime where
magnetism coexists with unconventional superconductivity.Comment: 5 figures, 10 pages; revised versio
Büchwald-Hartwig reaction applied to synthesis of new luminescent liquid crystal triarylamines derived from isoxazoles
© 2015 Taylor & Francis Group, LLC. The present work describes the synthesis and characterization of novel series of triarylamines isoxazoles (TAA) addressed to the organic photovoltaic materials. Diarylisoxazoles were synthesized by sequential [3+2] 1,3-dipolar cycloaddition reaction between arylnitrile oxides and selected arylalkenes followed by MnO2-oxidation. Isoxazoles were coupled to diarylamines by Büchwald-Hartwig reaction to afford desired compounds 6a-k. Some TAA display liquid-crystalline behaviour and UV-Vis absorption and fluorescence emission were analysed for all samples of TAA 6a-k
Gap nodes induced by coexistence with antiferromagnetism in iron-based superconductors
We investigate the pairing in iron pnictides in the coexistence phase, which
displays both superconducting and antiferromagnetic orders. By solving the
pairing problem on the Fermi surface reconstructed by long-range magnetic
order, we find that the pairing interaction necessarily becomes
angle-dependent, even if it was isotropic in the paramagnetic phase, which
results in an angular variation of the superconducting gap along the Fermi
surfaces. We find that the gap has no nodes for a small antiferromagnetic order
parameter M, but may develop accidental nodes for intermediate values of M,
when one pair of the reconstructed Fermi surface pockets disappear. For even
larger M, when the other pair of reconstructed Fermi pockets is gapped by
long-range magnetic order, superconductivity still exists, but the
quasiparticle spectrum becomes nodeless again. We also show that the
application of an external magnetic field facilitates the formation of nodes.
We argue that this mechanism for a nodeless-nodal-nodeless transition explains
recent thermal conductivity measurements of hole-doped Ba_{1-x}K_xFe_2As_2.
[J-Ph. Read et.al. arXiv:1105.2232].Comment: 13 pages, 10 figures, submitted to PR
Clinical, histological and prognostic features of a novel nail-bed lesion of cats: 41 cases
There is a distinct subset of lesions arising on the digits of cats, located at or close to the nail-bed epithelium, which are typically composed of proliferative fibroblast-like cells, multinucleate giant cells and areas of osseous metaplasia, but currently there is no published literature detailing the clinical or histological features of these lesions. This study identified 41 such cases from two large commercial diagnostic laboratories and assessed various histological and clinical features; 22 cases had additional follow-up data available
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Spectroscopy of Stardust from 200nm to 16µM (with a gap in the middle)
UV/Vis and IR spectroscopy are complementary, non-destructive techniques that can be used to identify the presence of a range of organic and inorganic, hydrated and anhydrous minerals within micron-sized grains. We look forward to applying these techniques to the Stardust materials
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