1,921 research outputs found
The Efficacy of Selected Desensitizing OTC Products: A Systematic Review.
Licensed by the Creative Commons Attribution LicenseObjectives. The aim of the present study was to review the published literature in order to identify relevant studies for inclusion and to determine whether there was any evidence on the clinical effectiveness of selected desensitizing toothpastes, calcium sodium phosphosilicate (CSPS), amorphous calcium phosphate (ACP), nanohydroxyapatite, and casein phosphopeptide-amorphous calcium phosphate (tooth mousse) on reducing dentine hypersensitivity (DH). Materials and Methods. Following a review of 593 papers identified from searching both electronic databases (PUBMED) and hand searching of relevant written journals, only 5 papers were accepted for inclusion. Results. Analysis of the included studies (3 CSPS and 2 ACP) would suggest that there may be some benefit for patients using these products for reducing DH. No direct comparative studies were available to assess all these products under the same conditions neither were there any comparative randomised controlled studies that compared at least two of these products in determining their effectiveness in treating DH. Conclusions. Due to the small number of included studies, there are limited clinical data to support any claims of clinical efficacy of these OTC products. Further studies are therefore required to determine the efficacy of these products in well-controlled RCT studies with a larger sample size
Monte-Carlo simulations and image reconstruction for novel imaging scenarios in emission tomography
AbstractEmission imaging incorporates both the development of dedicated devices for data acquisition as well as algorithms for recovering images from that data. Emission tomography is an indirect approach to imaging. The effect of device modification on the final image can be understood through both the way in which data are gathered, using simulation, and the way in which the image is formed from that data, or image reconstruction. When developing novel devices, systems and imaging tasks, accurate simulation and image reconstruction allow performance to be estimated, and in some cases optimized, using computational methods before or during the process of physical construction. However, there are a vast range of approaches, algorithms and pre-existing computational tools that can be exploited and the choices made will affect the accuracy of the in silico results and quality of the reconstructed images. On the one hand, should important physical effects be neglected in either the simulation or reconstruction steps, specific enhancements provided by novel devices may not be represented in the results. On the other hand, over-modeling of device characteristics in either step leads to large computational overheads that can confound timely results. Here, a range of simulation methodologies and toolkits are discussed, as well as reconstruction algorithms that may be employed in emission imaging. The relative advantages and disadvantages of a range of options are highlighted using specific examples from current research scenarios
High Performance 3D PET Reconstruction Using Spherical Basis Functions on a Polar Grid
Statistical iterative methods are a widely used method of image reconstruction in emission tomography. Traditionally, the image space is modelled as a combination of cubic voxels as a matter of simplicity. After reconstruction, images are routinely filtered to reduce statistical noise at the cost of spatial resolution degradation. An alternative to produce lower noise during reconstruction is to model the image space with spherical basis functions. These basis functions overlap in space producing a significantly large number of non-zero elements in the system response matrix (SRM) to store, which additionally leads to long reconstruction times. These two problems are partly overcome by exploiting spherical symmetries, although computation time is still slower compared to non-overlapping basis functions. In this work, we have implemented the reconstruction algorithm using Graphical Processing Unit (GPU) technology for speed and a precomputed Monte-Carlo-calculated SRM for accuracy. The reconstruction time achieved using spherical basis functions on a GPU was 4.3 times faster than the Central Processing Unit (CPU) and 2.5 times faster than a CPU-multi-core parallel implementation using eight cores. Overwriting hazards are minimized by combining a random line of response ordering and constrained atomic writing. Small differences in image quality were observed between implementations
Contrast echocardiography in acute myocardial ischemia. II. The effect of site of injection of contrast agent on the estimation of area at risk for necrosis after coronary occlusion
Myocardial contrast echocardiography has been shown to accurately assess the area at risk for necrosis after acute coronary occlusion in the experimental model. The area at risk as determined by this method, however, has been defined in different ways depending on the model used. Some investigators have injected the contrast agent proximal to the site of coronary occlusion (left main coronary artery or aorta) and defined the area at risk as the segment of myocardium not showing a contrast effect (negative risk area). Others have injected the contrast agent directly into the occluded vessel and have defined the area at risk as that showing contrast enhancement (positive risk area).To evaluate whether the areas at risk determined by these two techniques are identical, six open chest dogs were studied using both methods. The area at risk was slightly but significantly larger when the contrast agent was injected into the occluded vessel than when it was injected proximally into the left main coronary artery (4.98 ± 1.69 versus 3.97 ± 1.27 cm2, p < 0.01). It is concluded that the site of injection of the contrast agent significantly influences the determination of area at risk. Therefore, data obtained by the two techniques should not be used interchangeably, and in a given study the area at risk should be measured consistently using one technique
Knowledge of UK Dental Professionals in Treating Dentine Hypersensitivity
Aim: The aim of the present 22 item questionnaire-based study was to evaluate the knowledge and understanding of a representative sample of UK based Dental professionals in treating DH. Materials & Methods: A 22-item questionnaire on DH was sent to a representative sample of 2200 Dentists and Dental Hygienists/Therapists (DH/T). The study was submitted to the local Queen Mary University of London Ethics committee (QMREC 03537) and the research did not present any ethical concerns due to its low risk and therefore did not require the scrutiny of the full Research Ethics Committee. The questionnaire consisted of 22 questions, which included both open and closed questions. The addresses were selected from the General Dental Council (GDC) and Dental Hygienist/Therapists Lists and subsequently randomised using a randomised number generator (RNG)(Graph Pad Software Inc. 2002-2005) and the questionnaires were sent out to the selected Dental practices by Royal Mail. The questionnaires were distributed during a six-month period from June 2011. Data were entered using Microsoft Excel, and the results analysed using SPSS 22.0 for Windows (IBM, Portsmouth UK) in presented in the form of frequency distribution tables and figures. Pearson correlations were undertaken to determine whether there were any association between status, impact on the QoL, confidence of recommending at-home treatment to those suffering with DH. Results: 346 Questionnaires were returned (15.7%), of which 142 Questionnaires were from Dentists (12.9%) and 204 Questionnaires were from DH/Ts (18.5%). Both Dentists and DHTs provided similar responses to the questions with no major differences between the two groups. Conclusions: These results were consistent with previous studies and, would appear to suggest that, in terms of the knowledge and understanding of DH, both Dentists and DHTs had a broad understanding however there were still some confusion concerning aspects of the diagnosis and management of the condition and clinicians therefore need to be updated on the current recommendations and guidelines in the management of DH to both inform their patients in terms of awareness and prevention and to confidently diagnose and manage DH successfully
Conversational Alignment: A Study of Neural Coherence and Speech Entrainment
Conversational alignment refers to the tendency for communication partners to adjust their verbal and non-verbal behaviors to become more like one another during the course of human interaction. This alignment phenomenon has been observed in neural patterns, specifically in the prefrontal areas of the brain (Holper et al., 2013; Cui et al., 2012; Dommer et al., 2012; Holper et al., 2012; Funane et al., 2011; Jiang et al., 2012); verbal behaviors such acoustic speech features (e.g., Borrie & Liss, 2014; Borrie et al., 2015; Lubold & Pon-Barry, 2014), phonological features (e.g., Babel, 2012; Pardo, 2006), lexical selection (e.g., Brennan & Clark, 1996; Garrod & Anderson, 1989), syntactic structure (e.g., Branigan, Pickering, & Cleland, 2000; Reitter, Moore, & Keller, 2006); and motor behaviors including body posture, facial expressions and breathing rate (e.g., Furuyama, Hayashi, & Mishima, 2005; Louwerse, Dale, Bard, & Jeuniaux, 2012; Richardson, March, & Schmit, 2005; Shockley, Santana, & Fowler, 2003; McFarland, 2001).
While conversational alignment in itself, is a largely physical phenomenon, it has been linked to significant functional value, both in the cognitive and social domains. Cognitively, conversational alignment facilitates spoken message comprehension, enabling listeners to share mental models (Garrod & Pickering, 2004) and generate temporal predictions about upcoming aspects of speech. From a social perspective, behavioral alignment has been linked with establishing turn-taking behaviors, and with increased feelings of rapport, empathy, and intimacy between conversational pairs (e.g., Lee et al. 2010; Nind, & Macrae, 2009; Smith, 2008; Bailenson & Yee, 2005; Chartrand & Barg, 1999; Miles, Putman & Street, 1984; Street & Giles, 1982). Benus (2014), for example, observed that individuals who align their speech features are perceived as more socially attractive and likeable, and have interactions that are more successful. These cognitive and social benefits, associated with conversational alignment, have been observed in both linguistic and neural data (e.g., Holper et al., 2012; 2013, Cui et al. 2012; Jiang et al., 2012; Egetemeir et al., 2011; Stephens et al. 2010).
The purpose of the current study was to examine conversational alignment as a multi-level communication phenomenon, by examining the relationship between neural and speech behaviors. To assess neural alignment, we used Near-Infrared Spectroscopy (NIRS), a non-invasive neuroimaging technology that detects cortical increases and decreases in the concentration of oxygenated and deoxygenated hemoglobin at multiple measurement sites to determine the rate that oxygen is being released and absorbed (Ferrari & Quaresima, 2012). While still considered a relatively new neural imaging technique, NIRS has been well established as an efficacious and effective data collection approach, particularly appropriate for social interaction research (e.g., Holper et al., 2013; Jiang et al., 2012; Holper et al., 2012; Suda et al., 2010). We utilized hyperscanning, a technique that allows for the quantitation of two simultaneous signals, allowing us to document neural alignment between two individuals (Babiloni & Astolfi, 2012). Recent studies have revealed neural alignment between two persons in cooperative states, including alignment in the right superior frontal cortices and medial prefrontal regions (Cui et al., 2012; Dommer et al., 2012; Funane et al., 2011). This increased prefrontal interbrain alignment has also been observed in other social interactions, including joint attention tasks (Dommer et al., 2012), imitation tasks (Holper et al., 2012), competitive games (Cheng et al., 2015, Duan et al., 2013), teaching-learning interactions (Holper et al., 2013), face- to-face communication (Jiang et al., 2012), mother-child interactions (Hirata et al., 2014), and during cooperative singing tasks (Osaka et al., 2015). Interestingly, Jiang et al. (2012) showed that increased neural alignment only occurred between conversational participants when they were speaking face-to-face, but not when participants had their backs facing one another. The authors speculated that the multi-sensory information, for example motor behaviors such as gestures, was required for neural alignment to occur
Heart failure after conventional metal-on-metal hip replacements: a retrospective cohort study
Background and purpose - It is unclear whether metal particles and ions produced by mechanical wear and corrosion of hip prostheses with metal-on-metal (MoM) bearings have systemic adverse effects on health. We compared the risk of heart failure in patients with conventional MoM total hip arthroplasty (THA) and in those with metal-on-polyethylene (MoP) THA. Patients and methods - We conducted a retrospective cohort study using data from the Australian Government Department of Veterans' Affairs health claims database on patients who received conventional THA for osteoarthritis between 2004 and 2012. The MoM THAs were classified into groups: Articular Surface Replacement (ASR) XL Acetabular System, other large-head (LH) (> 32 mm) MoM, and small-head (SH) (≤ 32 mm) MoM. The primary outcome was hospitalization for heart failure after THA. Results - 4,019 patients with no history of heart failure were included (56% women). Men with an ASR XL THA had a higher rate of hospitalization for heart failure than men with MoP THA (hazard ratio (HR) = 3.2, 95% CI: 1.6-6.5). No statistically significant difference in the rate of heart failure was found with the other LH MoM or SH MoM compared to MoP in men. There was no statistically significant difference in heart failure rate between exposure groups in women. Interpretation - An association between ASR XL and hospitalization for heart failure was found in men. While causality between ASR XL and heart failure could not be established in this study, it highlights an urgent need for further studies to investigate the possibility of systemic effects associated with MoM THA.Marianne H Gillam, Nicole L Pratt, Maria C S Inacio, Elizabeth E Roughead, Sepehr Shakib, Stephen J Nicholls & Stephen E Grave
Recommended from our members
Intensive archaeological survey of the F/H Surface Enhancement Project Area, Savannah River Site, Aiken and Barnwell Counties, South Carolina
Twelve archaeological sites and four artifact occurrences were located by intensive survey of two tracts of land for the F and H Surface Enhancement Project on the Savannah River Site, Aiken and Barnwell Counties, South Carolina. Fieldwork in the 480-acre project area included surface reconnaissance of 3.6 linear kilometers of transects, 140 shovel tests along 4.2 linear kilometers of transects, an additional 162 shovel tests at sites and occurrences, and the excavation of six l {times} 2 m test units. All but one of the sites contained artifacts of the prehistoric era; the twelfth site consists of the remains of a twentieth-century home place. The historic site and six of the prehistoric sites consist of limited and/or disturbed contexts of archaeological deposits that have little research potential and are therefore considered ineligible for nomination to the National Register of Historic Places (NRHP). The remaining five sites have sufficient content and integrity to yield information important to ongoing investigations into upland site use. These sites (38AK146, 38AK535, 38AK539, 38AK541, and 38AK543) are thus deemed eligible for nomination to the NRHP and the Savannah River Archaeological Research Program (SRARP) recommends that they be preserved through avoidance or data recovery
Availability and quality of publicly available health workforce data sources in Australia: a scoping review protocol.
IntroductionThe health workforce is an integral component of the healthcare system. Comprehensive, high-quality data on the health workforce are essential to identifying gaps in health service provision, as well as informing future health workforce and health services planning, and health policy. While many data sources are used in Australia for these purposes, the quality of the data sources with respect to relevance, accessibility and accuracy is not clear.Methods and analysisThis scoping review aims to identify and appraise publicly available data sources describing the Australian health workforce. The review will include any data source (eg, registry, administrative database and survey) or document reporting a data source (eg, journal article, report) on the Australian health workforce, which is publicly available and describes the characteristics of the workforce. The search will be conducted in 10 bibliographic databases and the grey literature using an iterative process. Screening of titles and abstracts will be undertaken by two investigators, independently, using Covidence software. Any disagreement between investigators will be resolved by a third investigator. Documents/data sources identified as potentially eligible will be retrieved in full text and reviewed following the same process. Data will be extracted using a customised data extraction tool. A customised appraisal tool will be used to assess the relevance, accessibility and accuracy of included data sources.Ethics and disseminationThe scoping review is a secondary analysis of existing, publicly available data sources and does not require ethics approval. The findings of this scoping review will further our understanding of the quality and availability of data sources used for health workforce and health services planning in Australia. The results will be submitted for publication in peer-reviewed journals and presented at conferences targeted at health workforce and public health topics
The natural history of regional wall motion in the acutely infarcted canine ventricle
Two-dimensional echocardiography was employed to define the natural history of regional wall motion abnormalities in a canine model of acute experimental myocardial infarction. Serial short-axis two-dimensional echocardiograms were recorded in 11 closed chest dogs before coronary occlusion and 10, 30, 60, 180 and 360 minutes after permanent coronary ligation. Radiolabeled microsphere-derived blood flows were obtained in each study period and the histochemical (triphenyltetrazolium chloride) extent of infarction was determined at 6 hours. Previously published methods were used to quantitate field by field (every 16.7 ms) excursion of 36 evenly spaced endocardial targets. The circumferential extent of abnormal wall motion was followed sequentially using previously published definitions of abnormality: 1) systolic fractional radial change of less than 20%; 2) dyskinesia (systolic bulging) at the point in time (echocardiographic field) in which there is maximal dyskinesia; and 3) correlation with composite normal ray motion falling outside the 95 % confidence limits defined in the control period. On the basis of the triphenyltet razolium chloride staining pattern, the ventricle was divided into five zones: central infarct zone, zone with greater than 25% transmural infarction, total infarct zone, border zones and normal zone. Mean systolic fractional radial change was calculated for each zone and used as an index of the magnitude of abnormal wall motion.Regardless of the definition of abnormality employed, the circumferential extent of abnormal wall motion manifested at 10 minutes after occlusion did not significantly change, even up to 6 hours later. Similarly, 10 minutes after coronary occlusion the three infarct zones and border zones demonstrated significantly reduced systolic fractional radial change. This remained stable over the remainder of the 6 hour study period.It is concluded that once established at 10 minutes after coronary occlusion, the circumferential extent and magnitude of abnormal wall motion do not significantly change in the immediate postinfarct (6 hour) period
- …