432 research outputs found
Asthma treatment in children: A guide to screening for and management of hypothalamic-pituitary-adrenal axis suppression
A recently published approach to paediatric asthma management neither recommended screening for nor suggested any management of hypothalamic-pituitary-adrenal axis suppression in asthmatic children treated with corticosteroids. The existing literature on this topic was therefore reviewed and the quality of the evidence assessed. Recommendations for diagnosis, screening and management are made utilising the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach
Hypertriglyceridaemia in adolescents may have serious complications
Acute pancreatitis is an often-overlooked cause of acute abdominal pain in children and adolescents. Severe hypertriglyceridaemia is an important cause of recurrent acute pancreatitis. Monogenic causes of hypertriglyceridaemia, such as familial chylomicronaemia caused by lipoprotein lipase deficiency, are more frequently encountered in children and adolescents, but remain rare. Polygenic hypertriglyceridaemia is more common, but may require a precipitant before manifesting. With the global increase in obesity and type 2 diabetes, secondary causes of hypertriglyceridaemia in children and adolescents are increasing. We report two cases of severe hypertriglyceridaemia and pancreatitis in adolescent females. Hypertriglyceridaemia improved markedly with restriction of dietary fat. An inhibitor to lipoprotein lipase was found to be the cause in one patient, while in the other limited genetic investigation excluded chylomicronaemia owing to deficiency of lipoprotein lipase, its activators and processing proteins
N-Electron Giant Dipole States in Crossed Electric and Magnetic Fields
Multi-electron giant dipole resonances of atoms in crossed electric and
magnetic fields are investigated. Stationary configurations corresponding to a
highly symmetric arrangement of the electrons on a decentered circle are
derived, and a normal-mode and stability analysis are performed. A
classification of the various modes, which are dominated by the magnetic field
or the Coulomb interactions, is provided. Based on the MCTDH approach, we carry
out a six-dimensional wave-packet dynamical study for the two-electron
resonances, yielding in particular lifetimes of more than 0.1 s for strong
electric fields.Comment: 37 pages, 22 figs. (plus subfigures
The granularity of weakly occupied bosonic fields beyond the local density approximation
We examine ground state correlations for repulsive, quasi one-dimensional
bosons in a harmonic trap. In particular, we focus on the few particle limit
N=2,3,4,..., where exact numerical solutions of the many particle Schroedinger
equation are available employing the Multi-Configuration Time-dependent Hartree
method. Our numerical results for the inhomogeneous system are modeled with the
analytical solution of the homogeneous problem using the Bethe ansatz and the
local density approximation. Tuning the interaction strength from the weakly
correlated Gross-Pitaevskii- to the strongly correlated Tonks-Girardeau regime
reveals finite particle number effects in the second order correlation function
beyond the local density approximation.Comment: 20 pages, 9 figures, submitted to NJ
Bose-Hubbard model with occupation dependent parameters
We study the ground-state properties of ultracold bosons in an optical
lattice in the regime of strong interactions. The system is described by a
non-standard Bose-Hubbard model with both occupation-dependent tunneling and
on-site interaction. We find that for sufficiently strong coupling the system
features a phase-transition from a Mott insulator with one particle per site to
a superfluid of spatially extended particle pairs living on top of the Mott
background -- instead of the usual transition to a superfluid of single
particles/holes. Increasing the interaction further, a superfluid of particle
pairs localized on a single site (rather than being extended) on top of the
Mott background appears. This happens at the same interaction strength where
the Mott-insulator phase with 2 particles per site is destroyed completely by
particle-hole fluctuations for arbitrarily small tunneling. In another regime,
characterized by weak interaction, but high occupation numbers, we observe a
dynamical instability in the superfluid excitation spectrum. The new ground
state is a superfluid, forming a 2D slab, localized along one spatial direction
that is spontaneously chosen.Comment: 16 pages, 4 figure
Asthma treatment in children: A pragmatic approach
Background. Asthma is a heterogeneous condition characterised by chronic inflammation and variable expiratory airflow limitation, with airway reversibility. Management of chronic inflammation with anti-asthma medication improves asthma control and quality of life.Objectives. To provide an evidence-based approach for chronic asthma management in young children and adolescents and provide guidance on the use of new asthma drugs in children.Methods. The South African Childhood Asthma Working Group (SACAWG) convened in January 2017. The asthma treatment task group reviewed the available scientific literature and international asthma treatment guidelines. The evidence was then graded according to the Grades of Recommendation Assessment, Development and Evaluation (GRADE) system and recommendations were made based on scientific evidence and local context. Asthma management recommendations were made for children Ë‚6 years of age and older children and adolescents, as well as for stepping up and stepping down of therapy. This review does not include biologics or novel asthma drugs, which are covered in another CME article in this edition of SAMJ.Conclusions. To ensure good response, treatment and adherence, type of medication, device and checking of technique are all critical. Stepping up of therapy should be done only after ensuring good adherence and technique. Once therapeutic response is achieved, medication administration has to be stepped down to improve ease of use and avoid unnecessary side-effects
Stable isotope dilution assay for the accurate determination of mycotoxins in maize by UHPLC-MS/MS
A fast, easy-to-handle and cost-effective analytical method for 11 mycotoxins currently regulated in maize and other cereal-based food products in Europe was developed and validated for maize. The method is based on two extraction steps using different acidified acetonitrile–water mixtures. Separation is achieved using ultrahigh-performance liquid chromatography (UHPLC) by a linear water–methanol gradient. After electrospray ionisation, tandem mass spectrometric detection is performed in dynamic multiple reaction monitoring mode. Since accurate mass spectrometric quantification is hampered by matrix effects, uniformly [13C]-labelled mycotoxins for each of the 11 compounds were added to the sample extracts prior to UHPLC-MS/MS analysis. Method performance parameters were obtained by spiking blank maize samples with mycotoxins before as well as after extraction on six levels in triplicates. The twofold extraction led to total recoveries of the extraction steps between 97% and 111% for all target analytes, including fumonisins. The [13C]-labelled internal standards efficiently compensated all matrix effects in electrospray ionisation, leading to apparent recoveries between 88% and 105% with reasonable additional costs. The relative standard deviations of the whole method were between 4% and 11% for all analytes. The trueness of the method was verified by the measurement of several maize test materials with well-characterized concentrations. In conclusion, the developed method is capable of determining all regulated mycotoxins in maize and presuming similar matrix effects and extraction recovery also in other cereal-based foods
T-2 toksin - pojavnost i toksiÄŤnost u peradi
T-2 toxin is the most toxic type A trichothecene mycotoxin. It is the secondary metabolite of the Fusarium fungi, and is common in grain and animal feed. Toxic effects have been shown both in experimental animals and in livestock. It has been implicated in several outbreaks of human mycotoxicoses. Toxic effects in poultry include inhibition of protein, DNA, and RNA synthesis, cytotoxicity, immunomodulation, cell lesions in the digestive tract, organs and skin, neural disturbances and low performance in poultry production (decreased weight gain, egg production, and hatchability). Concentrations of T-2 toxin in feed are usually low, and its immunosuppressive effects and secondary infections often make diagnosis difficult. If at the onset of the disease, a change in diet leads to health and performance improvements in animals, this may point to mycotoxin poisoning. Regular control of grain and feed samples is a valuable preventive measure, and it is accurate only if representative samples are tested. This article reviews the incidence and toxic effects of T-2 toxin in poultry.T-2 toksin je najtoksičniji predstavnik trikotecenskih mikotoksina tipa A. On je sekundarni produkt metabolizma plijesni roda Fusarium i često je prisutan u žitaricama i hrani za životinje. Štetni učinci uočeni su u eksperimentalnih životinja i životinja u uzgoju. On se povezuje s pojavom bolesti ljudi od mikotoksikoza. Učinci toksina u peradi su višestruki: inhibicija sinteze proteina, DNA i RNA, citotoksični učinak, imunomodulatorni učinak, oštećenje stanica probavnog sustava, organa i kože, živčani poremećaji te pad proizvodnih karakteristika u uzgoju peradi (slabiji prirast, pad nesivosti i valivosti). Koncentracije T-2 toksina u hrani redovito su vrlo malene, a zbog imunosupresivnog djelovanja toksina te istodobne sekundarne infekcije bolest se često teško dijagnosticira. Pri pojavi bolesti promjenom hrane može doći do poboljšanja zdravstvenog stanja, što tako|er upućuje na moguće trovanje mikotoksinima. Redovita kontrola uzoraka žitarica i hrane za životinje jedna je od preventivnih mjera, a detekcija mikotoksina u žitaricama i hrani pouzdana je samo ako se ispituje reprezentativan uzorak. U radu su opisani učestalost i toksični učinci T-2 toksina u peradi
Genetic diversity fuels gene discovery for tobacco and alcohol use
Tobacco and alcohol use are heritable behaviours associated with 15% and 5.3% of worldwide deaths, respectively, due largely to broad increased risk for disease and injury(1-4). These substances are used across the globe, yet genome-wide association studies have focused largely on individuals of European ancestries(5). Here we leveraged global genetic diversity across 3.4 million individuals from four major clines of global ancestry (approximately 21% non-European) to power the discovery and fine-mapping of genomic loci associated with tobacco and alcohol use, to inform function of these loci via ancestry-aware transcriptome-wide association studies, and to evaluate the genetic architecture and predictive power of polygenic risk within and across populations. We found that increases in sample size and genetic diversity improved locus identification and fine-mapping resolution, and that a large majority of the 3,823 associated variants (from 2,143 loci) showed consistent effect sizes across ancestry dimensions. However, polygenic risk scores developed in one ancestry performed poorly in others, highlighting the continued need to increase sample sizes of diverse ancestries to realize any potential benefit of polygenic prediction.Peer reviewe
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