In vitro and In vivo Evaluationof Different Gingival Retraction Cords

Modern impression techniques used in restorative dentistry require displacementof gingival tissue to expose the subgingival finish lines on the tooth preparation. Many different medications are used on gingival retraction cords in order to minimize hemorrhage from the gingival sulcus during impression making. A common method of accomplishing gingival displacement is by packing cord into the gingival crevice. This is especially critical when using hydrophobic impression materials such as polyvinyl siloxanes. The purpose of this study was to determine whether any of the commonly used gingival retraction medications could inhibit the polymerization of polyvinyl siloxane impression materials when they are in direct contact with the setting material and to evaluate the clinical performance of retraction cords. Many gingival retraction cords in various shapes, sizes and medications are available on the market. The literature is replete with reports on the effects of medicated and non-medicated cords on impression and gingival tissue. In this study, the number of the criteria of evaluation was increased and both in vitro and in vivo studies were conducted together by three prosthodontists

Intraoral Repair of Metal Ceramic Restorations Following Preparation of the Endodontic Access Cavity (Case Reports)

The Manufacture of dental crowns and bridgework of porcelain fused to metal, a technique that results in highly functional and esthetic restorations, has been widely used for about 45 years. Bonded porcelain is exceptionally strong. However, the reasons for porcelain fracture may be multifactorial, and include where the bridge or crown substructure has been weakened by excessive occlusal adjustment or by the introduction of an endodontic access cavitiy. An esthetic and functional repair, wherever possible, has many advantages over time-consuming and expensive remakes of crowns and/or bridges. This report is a presentation of a simple method for both the dentist and the patient to repair a tooth with root canal treatment. In cases where the fracture is due to an endodontic access cavity, intraoral repair was performed using various porcelain repairing kits. The patients were recalled for follow up on a 3-month basis after treatment. This technique can be considered as a treatment of choice regarding the successful results

What is limiting near-infrared astrometry in the Galactic Center?

We systematically investigate the error sources for high-precision astrometry from adaptive optics based near-infrared imaging data. We focus on the application in the crowded stellar field in the Galactic Center. We show that at the level of <=100 micro-arcseconds a number of effects are limiting the accuracy. Most important are the imperfectly subtracted seeing halos of neighboring stars, residual image distortions and unrecognized confusion of the target source with fainter sources in the background. Further contributors to the error budget are the uncertainty in estimating the point spread function, the signal-to-noise ratio induced statistical uncertainty, coordinate transformation errors, the chromaticity of refraction in Earth's atmosphere, the post adaptive optics differential tilt jitter and anisoplanatism. For stars as bright as mK=14, residual image distortions limit the astrometry, for fainter stars the limitation is set by the seeing halos of the surrounding stars. In order to improve the astrometry substantially at the current generation of telescopes, an adaptive optics system with high performance and weak seeing halos over a relatively small field (r<=3") is suited best. Furthermore, techniques to estimate or reconstruct the seeing halo could be promising.Comment: accepted by MNRAS, 13 pages, 14 figure

What utility scores do mental health service users, healthcare professionals and members of the general public attribute to different health states? A co-produced mixed methods online survey

Utility scores are integral to health economics decision-making. Typically, utility scores have not been scored or developed with mental health service users. The aims of this study were to i) collaborate with service users to develop descriptions of five mental health states (psychosis, depression, eating disorder, medication side effects and self-harm); ii) explore feasibility and acceptability of using scenario-based health states in an e-survey; iii) evaluate which utility measures (standard gamble (SG), time trade off (TTO) and rating scale (RS)) are preferred; and iv) determine how different participant groups discriminate between the health scenarios and rank them

Decolonising the curriculum is an ongoing and collective effort: Responding to Townsend (2020) and Gibson and Farias (2020)

This paper responds to Townsend (2020), and Gibson and Farias (2020), who were invited to write commentaries regarding Simaan’s (2020) ‘Decolonising occupational science education through learning activities based on a study from the Global South’. My reply acknowledges work done by scholars in the Global North and South, both in and outside occupational science, that critiques Western-centric hegemony in academia. It recognises the multiple aspects of decolonial work in occupational science education, and its collective and continuous nature. I argue that my objective of stimulating reflections and discussion about decolonising occupational science education and knowledge has been achieved by this collective effort to extend this discourse. Future reflections, research, and activism in this area are of paramount importance if we are to truly decolonise occupational science

Precision Astrometry of a Sample of Speckle Binaries and Multiples with the Adaptive Optics Facilities at the Hale and Keck II Telescopes

Using the adaptive optics facilities at the 200-in Hale and 10-m Keck II, we observed in the near infrared a sample of 12 binary and multiple stars and one open cluster. We used the near diffraction limited images of these systems to measure the relative separations and position angles between their components. In this paper, we investigate and correct for the influence of the differential chromatic refraction and chip distortions on our relative astrometric measurements. Over one night, we achieve an astrometric precision typically well below 1 miliarcsecond and occasionally as small as 40 microarcseconds. Such a precision is in principle sufficient to astrometrically detect planetary mass objects around the components of nearby binary and multiple stars. Since we have not had sufficiently large data sets for the observed sample of stars to detect planets, we provide the limits to planetary mass objects based on the obtained astrometric precision.Comment: 18 pages, 8 figures, 9 tables, to appear in MNRA

The OARSI standardised definition of osteoarthritis: A lay version

Purpose: A standard definition has been produced by OARSI to achieve consensus for defining and classifying for osteoarthritis (OA). The aim is to “facilitate communication about the disease among industry and non-industry researchers, regulatory agencies, funding agencies, third party payers, and patients”.A Research Users Group (RUG) of lay members was asked for views on the OARSI definition and to propose a lay version of the definition if it was needed.Methods: A meeting of the Research User Group (RUG) was convened. All 13 RUG members (8 female, 5 male) were aged 45 years and over and had a musculoskeletal condition with nine having a diagnosis of OA. RUG members reviewed the definition, either individually or in pairs, and were asked write down the meaning of the definition in their own words. RUG members then shared their own lay definitions. Following the meeting, researchers and RUG members worked in partnership to co-produce a single lay definition of OA.Results: Initial reactions to OARSI definition were mostly negative. While there was agreement that the definition seemed to be aimed at “medics and biomedical researchers”, it was not understandable to the general public (“it’s too detailed for a lay audience”; “to a lay person you need a dictionary to read it”). The group felt that the definition was aimed at “top biology scientists and medics” and questioned the usefulness of it to a lay audience. The RUG agreed that a simple lay version of the definition would be useful that included additional concepts important to patients, such as symptoms and impact.The RUG’s suggestions for an alternative version fell into two themes: 1) a literal translation into lay language, and 2) a simplified lay version. There was general consensus that a literal translation would offer greater consistency with the OARSI version and allow inclusion of all concepts agreed as important by OARSI. Extracts of the proposed lay definition of OA are shown in Table 1.Conclusions: The current OARSI definition for defining and classifying OA should help conversations between researchers, health care professionals and patients. However the current definition requires translation into lay language, therefore a Research User Group has developed a lay definition of OA which is consistent with the OARSI definition. Whether this lay version could be used for public communication and to improve awareness of OA for all stakeholders needs to be tested

Cluster Transformation Coefficients for Structure and Dynamics Calculations in n-Particle Systems: Atoms, Nuclei, and Quarks

The structure and dynamics of an n-particle system are described with coupled nonlinear Heisenberg's commutator equations where the nonlinear terms are generated by the two-body interaction that excites the reference vacuum via particle-particle and particle-hole excitations. Nonperturbative solutions of the system are obtained with the use of dynamic linearization approximation and cluster transformation coefficients. The dynamic linearization approximation converts the commutator chain into an eigenvalue problem. The cluster coefficients factorize the matrix elements of the (n)-particles or particle-hole systems in terms of the matrix elements of the (n-1)-systems coupled to a particle-particle, particle-hole, and hole-hole boson. Group properties of the particle-particle, particle-hole, and hole-hole permutation groups simplify the calculation of these coefficients. The particle-particle vacuum-excitations generate superconductive diagrams in the dynamics of 3-quarks systems. Applications of the model to fermionic and bosonic systems are discussed.Comment: 13 pages, 5 figures, Wigner Proceedings for Conference Wigner Centenial Pecs, July 8-12, 200

Connected Green function approach to ground state symmetry breaking in Φ1+14\Phi^4_{1+1}-theory

Using the cluster expansions for n-point Green functions we derive a closed set of dynamical equations of motion for connected equal-time Green functions by neglecting all connected functions higher than $4^{th}$ order for the $\lambda \Phi^4$-theory in $1+1$ dimensions. We apply the equations to the investigation of spontaneous ground state symmetry breaking, i.e. to the evaluation of the effective potential at temperature $T=0$. Within our momentum space discretization we obtain a second order phase transition (in agreement with the Simon-Griffith theorem) and a critical coupling of $\lambda_{crit}/4m^2=2.446$ as compared to a first order phase transition and $\lambda_{crit}/4m^2=2.568$ from the Gaussian effective potential approach.Comment: 25 Revtex pages, 5 figures available via fpt from the directory ugi-94-11 of [email protected] as one postscript file (there was a bug in our calculations, all numerical results and figures have changed significantly), ugi-94-1

Centrality and sNNDependenceofthe\sqrt{s_{NN}} Dependence of the dE_{T}/d\etaand and dN_{ch}/d\eta$ in Heavy Ion Collisions at Mid-Rapidity

The PHENIX experiment at RHIC has measured transverse energy and charged particle multiplicity at mid-rapidity in Au + Au collisions at $\sqrt{s_{NN}}$ = 19.6, 130, 62.4 and 200 GeV as a function of centrality. The presented results are compared to measurements from other RHIC experiments, and experiments at lower energies. The $\sqrt{s_{NN}}$ dependence of $dE_{T}/d\eta$ and $dN_{ch}/d\eta$ per pair of participants is consistent with logarithmic scaling for the most central events. The centrality dependence of $dE_{T}/d\eta$ and $dN_{ch}/d\eta$ is similar at all measured incident energies. At RHIC energies the ratio of transverse energy per charged particle was found independent of centrality and growing slowly with $\sqrt{s_{NN}}$. A survey of comparisons between the data and available theoretical models is also presented.Comment: Proccedings of the Workshop: Focus on Multiplcity at Bari, Italy, June 17-19,2004. To be submitted to the Jornal of Physics, "Conference series". Includes: 20 Pages, 15 figures, 3 Tables, 80 Referencie