35 research outputs found
The magnetic anisotropy of spin S=1 BaMoP2O8 system
In this work the magnetic anisotropy of low dimensional magnetic compound BaMoP2O8 was studied by using density functional theory and inelastic neutron scattering techniques. Obtained results show that anisotropy of the system has the easy-axis character, where the on-site term plays the leading role in stabilisation of the magnetic ordering.The reported study was funded by RFBR according to the research project № 18-32-00018
The development of a 16S rRNA gene based PCR for the identification of Streptococcus pneumoniae and comparison with four other species specific PCR assays
<p>Abstract</p> <p>Background</p> <p><it>Streptococcus pneumoniae </it>is one of the most frequently encountered pathogens in humans but its differentiation from closely related but less pathogenic streptococci remains a challenge.</p> <p>Methods</p> <p>This report describes a newly-developed PCR assay (Spne-PCR), amplifying a 217 bp product of the 16S rRNA gene of <it>S. pneumoniae</it>, and its performance compared to other genotypic and phenotypic tests.</p> <p>Results</p> <p>The new PCR assay designed in this study, proved to be specific at 57°C for <it>S. pneumoniae</it>, not amplifying <it>S. pseudopneumoniae </it>or any other streptococcal strain or any strains from other upper airway pathogenic species. PCR assays (psaA, LytA, ply, spn9802-PCR) were previously described for the specific amplification of <it>S. pneumoniae</it>, but <it>psaA</it>-PCR was the only one found not to cross-react with <it>S. pseudopneumoniae</it>.</p> <p>Conclusion</p> <p>Spne-PCR, developed for this study, and psaA-PCR were the only two assays which did not mis-identify <it>S. pseudopneumoniae </it>as <it>S. pneumoniae</it>. Four other PCR assays and the AccuProbe assay were unable to distinguish between these species.</p
The Alvarado score for predicting acute appendicitis: a systematic review
Background: The Alvarado score can be used to stratify patients with symptoms of suspected appendicitis; the validity of the score in certain patient groups and at different cut points is still unclear. The aim of this study was to assess the discrimination (diagnostic accuracy) and calibration performance of the Alvarado score. Methods: A systematic search of validation studies in Medline, Embase, DARE and The Cochrane library was performed up to April 2011. We assessed the diagnostic accuracy of the score at the two cut-off points: score of 5 (1 to 4 vs. 5 to 10) and score of 7 (1 to 6 vs. 7 to 10). Calibration was analysed across low (1 to 4), intermediate (5 to 6) and high (7 to 10) risk strata. The analysis focused on three sub-groups: men, women and children. Results: Forty-two studies were included in the review. In terms of diagnostic accuracy, the cut-point of 5 was good at 'ruling out' admission for appendicitis (sensitivity 99% overall, 96% men, 99% woman, 99% children). At the cut-point of 7, recommended for 'ruling in' appendicitis and progression to surgery, the score performed poorly in each subgroup (specificity overall 81%, men 57%, woman 73%, children 76%). The Alvarado score is well calibrated in men across all risk strata (low RR 1.06, 95% CI 0.87 to 1.28; intermediate 1.09, 0.86 to 1.37 and high 1.02, 0.97 to 1.08). The score over-predicts the probability of appendicitis in children in the intermediate and high risk groups and in women across all risk strata. Conclusions: The Alvarado score is a useful diagnostic 'rule out' score at a cut point of 5 for all patient groups. The score is well calibrated in men, inconsistent in children and over-predicts the probability of appendicitis in women across all strata of risk
Evaluation of Several Biochemical and Molecular Techniques for Identification of Streptococcus pneumoniae and Streptococcus pseudopneumoniae and Their Detection in Respiratory Samples
The identification and detection of mitis group streptococci, which contain Streptococcus pneumoniae, have been hampered by the lack of sensitive and specific assays. In this study, we evaluated several biochemical and molecular assays for the identification of S. pneumoniae and Streptococcus pseudopneumoniae and their distinction from other mitis group streptococci using a collection of 54 isolates obtained by the routine culturing of 53 respiratory specimens from patients with community-acquired pneumonia. The combined results of the biochemical and molecular assays indicated the presence of 23 S. pneumoniae, 2 S. pseudopneumoniae, and 29 other mitis group streptococcal isolates. The tube bile solubility test that is considered gold standard for the identification of S. pneumoniae showed concordant results with optochin susceptibility testing (CO(2) atmosphere) and a real-time multiplex PCR assay targeting the Spn9802 fragment and the autolysin gene. Optochin susceptibility testing upon incubation in an O(2) atmosphere, bile solubility testing by oxgall disk, matrix-assisted laser desorption ionization–time of flight mass spectrometry, and sequence analysis of the tuf and rpoB genes resulted in several false-positive, false-negative, or inconclusive results. The S. pseudopneumoniae isolates could be identified only by molecular assays, and the multiplex real-time PCR assay was concluded to be most convenient for the identification of S. pneumoniae and S. pseudopneumoniae isolates. Using this method, S. pneumoniae and S. pseudopneumoniae DNA could be detected in the respiratory samples from which they were isolated and in an additional 11 samples from which only other streptococci were isolated