859 research outputs found
Validação de método analítico por espectrofotometria no ultravioleta para doseamento de tenoxicam nas formas farmacêuticas comprimido e cápsula
O presente trabalho tem por objetivo demonstrar a adequação de um procedimento analítico em relação ao doseamento do antiinflamatório não-esteróide tenoxicam nas formas farmacêuticas comprimido e cápsula. A validação do método, realizada por espectrofotometria na região do ultravioleta, demonstrou linearidade (r = 0,99995), precisão ( DPR = 0,693 % para comprimidos e 0,722 % para cápsulas) e exatidão com 99,11 % e 99,94 % para comprimidos e cápsulas, respectivamente. Os limites de detecção e quantificação foram 0,12 μg/mL e 0,38 μg/mL, respectivamente
Skeletal imaging of child abuse (non-accidental injury)
In recent years there has been a worldwide increased awareness that children are physically abused by their carers. Radiologists play a vital role in the detection of inflicted injuries. This article reviews the skeletal imaging findings seen in child abus
Lattice perturbation theory for gluonic and fermionic actions
We calculate the two loop Landau mean links and the one loop renormalisation
of the anisotropy for Wilson and improved SU(3) gauge actions, using twisted
boundary conditions as a gauge invariant infrared regulator. We show these
accurately describe simulated results, and outline a method for generating
Feynman rules for general lattice field theories, in a form suitable for
efficient numerical calculation of perturbative loop diagrams.Comment: 6 pages of LaTeX. Two posters at Lattice2002(improve) combine
Mitigating voltage losses in photoelectrochemical cell scale up
In solar water splitting, efforts in scaling up the photoelectrochemical cell beyond laboratory scale have started to attract significant attention. Several large area devices have been demonstrated, but typically the efficiencies are much lower than their small area equivalent. Here, two dimensional finite element modeling is used to evaluate the different sources of voltage loss specifically related to scale up in solar water splitting devices operated in neutral pH solutions. We quantitatively investigate the influence of the electrode area to these scale up associated losses substrate ohmic loss, electrolyte ohmic loss, and local pH gradient related losses . About 600 mV additional overpotential is needed due to these losses for a cell with electrodes of height of 8 cm at a current density of 10 mA cm amp; 8722;2. We show, however, that by applying engineering and cell design strategies, the voltage losses can be mitigated, resulting in an acceptable amp; 8764;50 mV overpotential. Overall, this study highlights the additional challenges to be considered in photoelectrochemical cell scale up and provides strategies to manage and mitigate scaling related losse
Adsorption of mono- and multivalent cat- and anions on DNA molecules
Adsorption of monovalent and multivalent cat- and anions on a deoxyribose
nucleic acid (DNA) molecule from a salt solution is investigated by computer
simulation. The ions are modelled as charged hard spheres, the DNA molecule as
a point charge pattern following the double-helical phosphate strands. The
geometrical shape of the DNA molecules is modelled on different levels ranging
from a simple cylindrical shape to structured models which include the major
and minor grooves between the phosphate strands. The densities of the ions
adsorbed on the phosphate strands, in the major and in the minor grooves are
calculated. First, we find that the adsorption pattern on the DNA surface
depends strongly on its geometrical shape: counterions adsorb preferentially
along the phosphate strands for a cylindrical model shape, but in the minor
groove for a geometrically structured model. Second, we find that an addition
of monovalent salt ions results in an increase of the charge density in the
minor groove while the total charge density of ions adsorbed in the major
groove stays unchanged. The adsorbed ion densities are highly structured along
the minor groove while they are almost smeared along the major groove.
Furthermore, for a fixed amount of added salt, the major groove cationic charge
is independent on the counterion valency. For increasing salt concentration the
major groove is neutralized while the total charge adsorbed in the minor groove
is constant. DNA overcharging is detected for multivalent salt. Simulations for
a larger ion radii, which mimic the effect of the ion hydration, indicate an
increased adsorbtion of cations in the major groove.Comment: 34 pages with 14 figure
Colistin Versus Ceftazidime-Avibactam in the Treatment of Infections Due to Carbapenem-Resistant Enterobacteriaceae
Background The efficacy of ceftazidime-Avibactam-a cephalosporin-β-lactamase inhibitor combination with in vitro activity against Klebsiella pneumoniae carbapenemase-producing carbapenem-resistant Enterobacteriaceae (CRE)-compared with colistin remains unknown. Methods Patients initially treated with either ceftazidime-Avibactam or colistin for CRE infections were selected from the Consortium on Resistance Against Carbapenems in Klebsiella and other Enterobacteriaceae (CRACKLE), a prospective, multicenter, observational study. Efficacy, safety, and benefit-risk analyses were performed using intent-To-Treat analyses with partial credit and the desirability of outcome ranking approaches. The ordinal efficacy outcome was based on disposition at day 30 after starting treatment (home vs not home but not observed to die in the hospital vs hospital death). All analyses were adjusted for confounding using inverse probability of treatment weighting (IPTW). Results Thirty-eight patients were treated first with ceftazidime-Avibactam and 99 with colistin. Most patients received additional anti-CRE agents as part of their treatment. Bloodstream (n = 63; 46%) and respiratory (n = 30; 22%) infections were most common. In patients treated with ceftazidime-Avibactam versus colistin, IPTW-Adjusted all-cause hospital mortality 30 days after starting treatment was 9% versus 32%, respectively (difference, 23%; 95% bootstrap confidence interval, 9%-35%; P =.001). In an analysis of disposition at 30 days, patients treated with ceftazidime-Avibactam, compared with those treated within colistin, had an IPTW-Adjusted probability of a better outcome of 64% (95% confidence interval, 57%-71%). Partial credit analyses indicated uniform superiority of ceftazidime-Avibactam to colistin. Conclusions Ceftazidime-Avibactam may be a reasonable alternative to colistin in the treatment of K. pneumoniae carbapenemase-producing CRE infections. These findings require confirmation in a randomized controlled trial
Characteristics of the nuclear (18S, 5.8S, 28S and 5S) and mitochondrial (12S and 16S) rRNA genes of Apis mellifera (Insecta: Hymenoptera): structure, organization, and retrotransposable elements
As an accompanying manuscript to the release of the honey bee genome, we report the entire sequence of the nuclear (18S, 5.8S, 28S and 5S) and mitochondrial (12S and 16S) ribosomal RNA (rRNA)-encoding gene sequences (rDNA) and related internally and externally transcribed spacer regions of Apis mellifera (Insecta: Hymenoptera: Apocrita). Additionally, we predict secondary structures for the mature rRNA molecules based on comparative sequence analyses with other arthropod taxa and reference to recently published crystal structures of the ribosome. In general, the structures of honey bee rRNAs are in agreement with previously predicted rRNA models from other arthropods in core regions of the rRNA, with little additional expansion in non-conserved regions. Our multiple sequence alignments are made available on several public databases and provide a preliminary establishment of a global structural model of all rRNAs from the insects. Additionally, we provide conserved stretches of sequences flanking the rDNA cistrons that comprise the externally transcribed spacer regions (ETS) and part of the intergenic spacer region (IGS), including several repetitive motifs. Finally, we report the occurrence of retrotransposition in the nuclear large subunit rDNA, as R2 elements are present in the usual insertion points found in other arthropods. Interestingly, functional R1 elements usually present in the genomes of insects were not detected in the honey bee rRNA genes. The reverse transcriptase products of the R2 elements are deduced from their putative open reading frames and structurally aligned with those from another hymenopteran insect, the jewel wasp Nasonia (Pteromalidae). Stretches of conserved amino acids shared between Apis and Nasonia are illustrated and serve as potential sites for primer design, as target amplicons within these R2 elements may serve as novel phylogenetic markers for Hymenoptera. Given the impending completion of the sequencing of the Nasonia genome, we expect our report eventually to shed light on the evolution of the hymenopteran genome within higher insects, particularly regarding the relative maintenance of conserved rDNA genes, related variable spacer regions and retrotransposable elements
Origins of the Ambient Solar Wind: Implications for Space Weather
The Sun's outer atmosphere is heated to temperatures of millions of degrees,
and solar plasma flows out into interplanetary space at supersonic speeds. This
paper reviews our current understanding of these interrelated problems: coronal
heating and the acceleration of the ambient solar wind. We also discuss where
the community stands in its ability to forecast how variations in the solar
wind (i.e., fast and slow wind streams) impact the Earth. Although the last few
decades have seen significant progress in observations and modeling, we still
do not have a complete understanding of the relevant physical processes, nor do
we have a quantitatively precise census of which coronal structures contribute
to specific types of solar wind. Fast streams are known to be connected to the
central regions of large coronal holes. Slow streams, however, appear to come
from a wide range of sources, including streamers, pseudostreamers, coronal
loops, active regions, and coronal hole boundaries. Complicating our
understanding even more is the fact that processes such as turbulence,
stream-stream interactions, and Coulomb collisions can make it difficult to
unambiguously map a parcel measured at 1 AU back down to its coronal source. We
also review recent progress -- in theoretical modeling, observational data
analysis, and forecasting techniques that sit at the interface between data and
theory -- that gives us hope that the above problems are indeed solvable.Comment: Accepted for publication in Space Science Reviews. Special issue
connected with a 2016 ISSI workshop on "The Scientific Foundations of Space
Weather." 44 pages, 9 figure
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