336 research outputs found
Antimicrobial resistance gene shuffling and a three-element mobilisation system in the monophasic Salmonella typhimurium strain ST1030
In this study we describe the genetic elements and the antimicrobial resistance units (RUs) harboured by the Salmonella Typhimurium monophasic variant 1,4,[5],12:i:- strain ST1030. Of the three identified RUs two were chromosomal, RU1 (IS26-blaTEM-1-IS26-strAB-sul2- IS26) and RU2 (IS26-tetR(B)-tetA(B)-ΔIS26), and one, RU3 (a sul3-associated class 1 integron with cassette array dfrA12-orfF-aadA2-cmlA1-aadA1), was embedded in a Tn21-derived element harboured by the conjugative I1 plasmid pST1030-1A. IS26 elements mediated the antimicrobial resistance gene (ARG) shuffling and this gave rise to pST1030-1A derivatives with different sets of ARGs. ST1030 also harboured two ColE1-like plasmids of which one, pST1030-2A, was mobilisable and the target of an intracellular translocation of the Tn21-derived element; the second (pST1030-3) was an orphan mob-associated oriT plasmid co-transferred with pST1030-1A and pST1030-2A. pST1030-2A and pST1030-3 also carried a parA gene and a type III restriction modification system, respectively. Overall analysis of our data reinforces the role played by IS26, Tn21-derived elements and non-conjugative plasmids in the spread of ARGs and supplies the first evidence, at least in Salmonella, for the identification of a natural isolate harbouring a three-element mobilisation system in the same cell
Diabetes insipidus secondary to nivolumab-induced neurohypophysitis and pituitary metastasis
A 62-year-old patient with metastatic hypopharyngeal carcinoma underwent treatment with nivolumab, following which he developed symptoms suggestive of diabetes insipidus. Nivolumab was stopped and therapy with methylprednisolone was started. During corticosteroid therapy, the patient presented himself in poor health condition with fungal infection and glycemic decompensation. Methylprednisolone dose was tapered off, leading to the resolution of mycosis and the restoration of glycemic compensation, nevertheless polyuria and polydipsia persisted. Increase in urine osmolarity after desmopressin administration was made diagnosing central diabetes insipidus as a possibility. The neuroradiological data by pituitary MRI scan with gadolinium was compatible with coexistence of metastatic localization and infundibuloneurohypophysitis secondary to therapy with nivolumab. To define the exact etiology of the pituitary pathology, histological confirmation would have been necessary; however, unfortunately, it was not possible. In the absence of histological confirmation, we believe it is likely that both pathologies coexisted
Optimization of cw sodium laser guide star efficiency
Context: Sodium laser guide stars (LGS) are about to enter a new range of
laser powers. Previous theoretical and numerical methods are inadequate for
accurate computations of the return flux and hence for the design of the
next-generation LGS systems.
Aims: We numerically optimize the cw (continuous wave) laser format, in
particular the light polarization and spectrum.
Methods: Using Bloch equations, we simulate the mesospheric sodium atoms,
including Doppler broadening, saturation, collisional relaxation, Larmor
precession, and recoil, taking into account all 24 sodium hyperfine states and
on the order of 100 velocity groups.
Results: LGS return flux is limited by "three evils": Larmor precession due
to the geomagnetic field, atomic recoil due to radiation pressure, and
transition saturation. We study their impacts and show that the return flux can
be boosted by repumping (simultaneous excitation of the sodium D2a and D2b
lines with 10-20% of the laser power in the latter).
Conclusions: We strongly recommend the use of circularly polarized lasers and
repumping. As a rule of thumb, the bandwidth of laser radiation in MHz (at each
line) should approximately equal the launched laser power in Watts divided by
six, assuming a diffraction-limited spot size.Comment: 15 pages, 12 figures, to be published in Astronomy & Astrophysics,
AA/2009/1310
Prevalence and risk factors for chronic obstructive lung disease in HIV-infected patients in the HAART era
Our results suggest a role for HIV infection itself and for
current cigarette smoking in the development of respiratory
symptoms and COPD in HIV-infected patients.
HAART did not seem to reduce the risk of respiratory
symptoms and COPD, in our cases. Thus, our results
suggest that HIV-infected patients should be screened for
chronic respiratory disease in order to early identify those
at risk or those who need specific treatment
Geomonumental routes: the granitic bridges over the Guadarrama river (Madrid, Spain) and the calcarenitic coastal towers from the Salento (Italy)
8 pages, 7 figures.-- Published in: Proceedings of the 11th International Congress on Deterioration and Conservation of Stone (Torun Poland, 15-20 September 2008), eds. Jadwiga W. Lukaszewicz and Piotr Niemcewicz.-- Presentation in PDF format available at: https://digital.csic.es/handle/10261/7648.This paper focuses on the new concept of GeoMonumental Routes, which mainly consists of the dissemination of architectural heritage with the added value of geology.
Geology, so far, has not been considered in all its aspects in architectural heritage: i.e. geography, geomorphology, quarries provenance, building stones, and their relationship with historical and architectural aspects, constructive techniques and technological developments, as well as the connection of heritage structures to the settlement of historical routes. For this purpose, two scientific teams have gathered to develop two of this kind of routes following a common methodology, based on different geographical
context, geological settlement, history, structure tipology and building stones.Thanks are given to both Ministries of Education from Spain and Italy for granting
the CSIC-CNR bilateral cooperation project (2006IT0021).Peer reviewe
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