Dental erosion: In vitro model of wine assessor's erosion

The document attached has been archived with permission from the Australian Dental Association. An external link to the publisher’s copy is included.Background: Wine makers and assessors frequently experience severe dental erosion. The objectives of this study were to develop an in vitro model of dental erosion caused by frequent wine contact with teeth, and to use this model to assess the effectiveness of a variety of methods which might protect against this form of erosion. Methods: An initial pilot study found that riesling style wine was more erosive than champagne style, and both more than claret. Wine tasting was simulated by subjecting exposed windows of enamel and root surfaces on 50 intact, extracted human teeth to 1400 one minute exposures to white wine (pH 3.2). A variety of dental materials were applied to the exposed windows on groups of teeth prior to erosive challenge, to assess their protective ability. Results: Protective resin coatings and fluoride varnishes protected both enamel and roots against wine induced erosion. A high degree of protection was provided by APF gel, with less by NaF gel. Conclusions: It was concluded that dentists may be able to help minimise erosion resulting from frequent wine-tasting in their patients by the clinical application of one or a combination of these agents at times prior to prolonged assessment periods.Tong Bee Mok, J McIntyre and D Hun

Making co-enrolment feasible for randomised controlled trials in paediatric intensive care.

Enrolling children into several trials could increase recruitment and lead to quicker delivery of optimal care in paediatric intensive care units (PICU). We evaluated decisions taken by clinicians and parents in PICU on co-enrolment for two large pragmatic trials: the CATCH trial (CATheters in CHildren) comparing impregnated with standard central venous catheters (CVCs) for reducing bloodstream infection in PICU and the CHIP trial comparing tight versus standard control of hyperglycaemia

Premature recruitment of oocyte pool and increased mTOR activity in Fmr1 knockout mice and reversal of phenotype with rapamycin.

While mutations in the fragile X mental retardation-1 (FMR1) gene are associated with varying reproductive outcomes in females, the effects of a complete lack of FMR1 expression are not known. Here, we studied the ovarian and reproductive phenotypes in an Fmr1 knockout (KO) mouse model and the role of mammalian target of rapamycin (mTOR) signaling. Breeding, histologic and mTOR signaling data were obtained at multiple time points in KO and wild type (WT) mice fed a control or rapamycin (mTOR inhibitor) diet. KO mice showed an earlier decline in ovarian reserve than WT mice with an increased proportion of activated follicles. mTOR and phosphorylated S6 kinase (p-S6K) levels, a measure of downstream mTOR signaling, were elevated in the KO ovaries. Rapamycin blocked these effects in KO mice, and increased the primordial follicle pool and age of last litter in WT mice. Our data demonstrates an early decline in reproductive capacity in Fmr1 KO mice and proposes that premature recruitment of the primordial pool via altered mTOR signaling may be the mechanism. Reversal of phenotypes and protein levels in rapamycin-treated KO mice, as well as increased reproductive lifespan of rapamycin-fed WT mice, suggest the mTOR pathway as a potential therapeutic target

Anomalous Light Scattering by Topological PT{\mathcal{PT}}-symmetric Particle Arrays

Robust topological edge modes may evolve into complex-frequency modes when a physical system becomes non-Hermitian. We show that, while having negligible forward optical extinction cross section, a conjugate pair of such complex topological edge modes in a non-Hermitian $\mathcal{PT}$-symmetric system can give rise to an anomalous sideway scattering when they are simultaneously excited by a plane wave. We propose a realization of such scattering state in a linear array of subwavelength resonators coated with gain media. The prediction is based on an analytical two-band model and verified by rigorous numerical simulation using multiple-multipole scattering theory. The result suggests an extreme situation where leakage of classical information is unnoticeable to the transmitter and the receiver when such a $\mathcal{PT}$-symmetric unit is inserted into the communication channel.Comment: 16 pages, 8 figure

A computer-enhanced pH study of the formaldehyde–sulphite clock reaction

The formaldehyde-sulphite clock reaction was studied using an Orion SA 720 pH/ISE meter interfaced to an IBM PC. The laboratory software ‘ASYST’ was employed to facilitate data acquisition and data treatment. Experimental pH profiles thus obtained for the first time were simulated by invoking a theoretical model based on the reaction mechanism suggested by Burnett [1]. The variation of rate constants with compositions of reaction mixtures was also discuseed in light of the empirical expression proposed by Bell and Evans [2] for instantaneous rate constant of the clock reaction

VALIDATION OF MODEL-BASED IMAGE-MATCHING TECHNIQUE WITH BONE-PIN MARKER BASED MOTION ANALYSIS ON ANKLE KINEMATICS: A CADAVER STUDY

Krosshaug (2005) introduced a model-based image-matching (MBIM) technique for 3D reconstruction of human motion from uncalibrated video sequences. The aim of this study is to validate the MBIM technique on ankle joint movement with the reference to bone-pin marker based motion analysis on a cadaver. One cadaveric below-hip specimen was prepared for performing full-range plantarflexion/dorsiflexion, inversion/eversion and relative circular motion between two segments. The videos were recorded and analyzed by the MBIM technique and bone-pin marker based motion analysis. The results are presented as the qualitative visual evaluation and the root mean square (RMS) error. In general, the validation results showed good agreement between the MBIM estimation and bone-pin marker based motion analysis results. This technique will contribute to the motion measurement of ankle joint kinematics in the future, for instance, the motion analysis in real game situations and understanding the injury mechanisms of real injury cases

INTRA-RATER AND INTER-RATER RELIABILITY OF A MODEL-BASED IMAGE-MATCHING MOTION ANALYSIS TECHNIQUE IN MEASURING ANKLE JOINT KINEMATICS

The aim of this study was to assess the intra-rater and inter-rater reliability of the MBIM technique in measuring ankle joint kinematics. Three cadaveric below-hip specimens were prepared for performing full-range plantar/dorsiflexion, in/eversion and relative circular motion between the shank and foot segments. A detailed skeleton matching protocol was given to two researchers and each researcher performed the matching five times on each specimen. Intra-rater and inter-rater reliability were assessed with interclass correlation (ICC). The results showed excellent intra-rater reliability (ICC coefficient > 0.978) and excellent inter-rater reliability (ICC coefficient > 0.981). Therefore, the MBIM technique for analyzing ankle joint kinematics is repeatable and is a good motion analysis tool for sports science and sports medicine related research