5,816 research outputs found
Isolated development of inner (wall) caries like lesions in a bacterial-based in vitro model
The study conducted in a bacterial-based in vitro caries model aimed to determine whether typical inner secondary caries lesions can be detected at cavity walls of restorations with selected gap widths when the development of outer lesions is inhibited. Sixty bovine tooth specimens were randomly assigned to the following groups: test group 50 (TG50; gap, 50μm), test group 100 (TG100; gap, 100μm), test group 250 (TG250; gap, 250μm) and a control group (CG; gap, 250μm). The outer tooth surface of the test group specimens was covered with an acid-resistant varnish to inhibit the development of an outer caries lesion. After incubation in the caries model, the area of demineralization at the cavity wall was determined by confocal laser scanning microscopy. All test group specimens demonstrated only wall lesions. The CG specimens developed outer and wall lesions. The TG250 specimens showed significantly less wall lesion area compared to the CG (p < 0.05). In the test groups, a statistically significant increase (p < 0.05) in lesion area could be detected in enamel between TG50 and TG250 and in dentine between TG50 and TG100. In conclusion, the inner wall lesions of secondary caries can develop without the presence of outer lesions and therefore can be regarded as an entity on their own. The extent of independently developed wall lesions increased with gap width in the present settin
In children 18 years and under, what promotes recurrent shoulder instability after traumatic anterior shoulder dislocation? A systematic review and meta-analysis of risk factors
Background Skeletal maturity and age-related changes in the composition of the glenoid labrum and joint capsule may influence rates of recurrent instability in children. We systematically review risk factors which predispose children to recurrent shoulder instability. Methods The systematic review-concerned studies published before May 2015. Statistical analysis was undertaken to compare rates of recurrence for each extracted risk factor. Pooled ORs were analysed using random effects meta-analysis. Results 6 retrospective cohort studies met the inclusion criteria. 8 risk factors were identified across the studies including age, sex, shoulder dominance and injury side, mechanism of injury, state of physis closure, and Hill-Sachs and Bankart lesions. The rate of recurrent instability was 73%. Children aged 14–18 years were 24 times more likely to experience recurrent instability than children aged 13 years and less (93% vs 40%; OR=24.14, 95% CI (3.71 to 156.99), Z=3.33, p=0.001, I2=6.83%). There was a non-significant trend indicating males were 3.4 times more likely to experience recurrent instability (OR=3.44, 95% CI (0.98 to 12.06), Z=1.93, p=0.053, I2=0%). Analysis of one study found that children with a closed physis are 14 times more likely to experience recurrent instability compared with those with an open physis (OR=14.0, 95% CI (1.46 to 134.25), Z=2.29, p=0.02, I2=0%) . Conclusions Male children aged 14 years and over had the greatest risk of recurrent shoulder instability following a first-time traumatic anterior shoulder dislocation. This meta-analysis summarises a mix of 6 acceptable and poor quality level III retrospective cohort studies. Further examination of this population with blinded prospective cohort studies will assist clinicians in the appropriate management of first-time traumatic anterior shoulder dislocation
The Use Of Oral Ranolazine To Convert New Or Paroxysmal Atrial Fibrillation: A Review Of Experience With Implications For Possible "Pill In The Pocket" Approach To Atrial Fibrillation
Background: Atrial fibrillation (AF) is the most common arrhythmia requiring treatment. High dose oral anti-arrhythmics may cardiovert some paroxysmal AF. This "pill in pocket" approach has allowed patients to treat themselves on an as needed basis. Pro-arrhythmic concerns have limited the usefulness of this approach to patients without structural heart disease. Ranolazine is an anti-anginal agent, which inhibits abnormal late Na+ channel currents in cardiomyocytes and decreases sodium-calcium overload. Ranolazine is a potent inhibitor of after-depolarizations, which have been implicated in the initiation and propagation of AF. Because ranolazine has no known pro-arrhythmic effects, it could be useful as a safe "pill in the pocket" agent if it were effective in converting AF. We describe our experience using oral ranolazine to convert new or paroxysmal AF. Method: 2000 mg of ranolazine were administered to 18 patients with new (11 patients) or paroxysmal (7 patients) AF of at least 3, but not greater than 48 hours duration. Most patients (14) were in the hospital at the time ranolazine was administered. Age, sex, echocardiographic data, associated health conditions and structural heart disease were recorded. Successful conversion was defined as restoring sinus rhythm within 6 hours of ranolazine administration. Results: All but 1 patient had some form of structural heart disease and all but 2 patients had left atrial enlargement. Thirteen of 18 patients converted to sinus rhythm. No pro-arrhythmic effects, hemodynamic instability, adverse rate effects, or perceived intolerance (other than constipation) were noted. The 72% conversion rate was comparable to other reported "pill in the pocket" protocols. Conclusion: High dose oral ranolazine shows utility as a possible safe agent to convert new or paroxysmal AF. Lack of blinded controls and small numbers limits the power of this observation
Risk factors which predispose first-time traumatic anterior shoulder dislocations to recurrent instability in adults: a systematic review and meta-analysis
Recurrent instability following a first-time anterior traumatic shoulder dislocation may exceed 26%. We systematically reviewed risk factors which predispose this population to events of recurrence
System Tests of the ATLAS Pixel Detector
The innermost part of the ATLAS (A Toroidal LHC ApparatuS) experiment at the
LHC (Large Hadron Collider) will be a pixel detector, which is presently under
construction. Once installed into the experimental area, access will be
extremely limited. To ensure that the integrated detector assembly operates as
expected, a fraction of the detector which includes the power supplies and
monitoring system, the optical readout, and the pixel modules themselves, has
been assembled and operated in a laboratory setting for what we refer to as
system tests. Results from these tests are presented.Comment: 5 Pages, 9 Figures, to appear in Proceedings of the Eleventh Workshop
on Electronics for LHC and Future Experiment
The effect of ranolazine on maintaining sinus rhythm in patients with resistant atrial fibrillation
Background: Atrial fibrillation (AF) may arise out of anomalous impulse activity at atrial venous junctions. Triggered activity may be a source of abnormal impulse activity. Ranolazine is an anti-anginal agent, which inhibits normal and abnormal late Na+ channel current in the ventricle and peak Na+ channel current in the atrium. This produces an energy sparing effect and stabilizes cardiac membranes. Ranolazine is a potent inhibitor of triggered activity. The purpose of this report is to describe our initial experience with ranolazine used in patients with resistant AF.Methods: Seven patients (4 males, 3 females, 67 ± 9 years) who developed recurrent AF within hours to a few days of restoring sinus rhythm despite AF ablation and /or failing one or more anti-arrhythmic agents were started on ranolazine (500-1000 mg/twice/day) after stopping all other anti-arrhythmic therapy. All but one patient had some form of associated structural heart disease. Results: Two patients received no apparent benefit from ranolazine developing recurrent AF within 2 days. All other patients derived significant benefit. Four patients have experienced no recurrent AF. The other patient relapsed at 3 months and again at 6 months. The mean time in sinus rhythm to date, or to the first relapse, for the five responders was 27 ± 11 weeks. No clinically evident pro-arrhythmic episodes occurred. Conclusion: Ranolazine was helpful in maintaining sinus rhythm in the majority of patients in which more established measures had failed. A controlled prospective trial is warranted to further investigate the efficacy of ranolazine in AF
Human visual cortical responses to specular and matte motion flows
Determining the compositional properties of surfaces in the environment is an important visual capacity. One such property is specular reflectance, which encompasses the range from matte to shiny surfaces. Visual estimation of specular reflectance can be informed by characteristic motion profiles; a surface with a specular reflectance that is difficult to determine while static can be confidently disambiguated when set in motion. Here, we used fMRI to trace the sensitivity of human visual cortex to such motion cues, both with and without photometric cues to specular reflectance. Participants viewed rotating blob-like objects that were rendered as images (photometric) or dots (kinematic) with either matte-consistent or shiny-consistent specular reflectance profiles. We were unable to identify any areas in low and mid-level human visual cortex that responded preferentially to surface specular reflectance from motion. However, univariate and multivariate analyses identified several visual areas; V1, V2, V3, V3A/B, and hMT+, capable of differentiating shiny from matte surface flows. These results indicate that the machinery for extracting kinematic cues is present in human visual cortex, but the areas involved in integrating such information with the photometric cues necessary for surface specular reflectance remain unclear. © 2015 Kam, Mannion, Lee, Doerschner and Kersten
Algebraic properties of Gardner's deformations for integrable systems
An algebraic definition of Gardner's deformations for completely integrable
bi-Hamiltonian evolutionary systems is formulated. The proposed approach
extends the class of deformable equations and yields new integrable
evolutionary and hyperbolic Liouville-type systems. An exactly solvable
two-component extension of the Liouville equation is found.Comment: Proc. conf. "Nonlinear Physics: Theory and Experiment IV" (Gallipoli,
2006); Theor. Math. Phys. (2007) 151:3/152:1-2, 16p. (to appear
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