Direct laser printing of thin-film polyaniline devices

We report the fabrication of electrically functional polyaniline thin-film microdevices. Polyaniline films were printed in the solid phase by Laser Induced Forward Transfer directly between Au electrodes on a Si/SiO2 substrate. To apply solid-phase deposition, aniline was in situ polymerized on quartz substrates. Laser deposition preserves the morphology of the films and delivers sharp features with controllable dimensions. The electrical characteristics of printed polyaniline present ohmic behavior, allowing for electroactive applications. Results on gas sensing of ammonia are presented.Comment: In Pres

The effectiveness of laceback ligatures during initial orthodontic alignment: a systematic review and meta-analysis

Lacebacks may be used to limit unwanted incisor proclination during initial orthodontic alignment; however, their use has not met with universal approval. This systematic review aims to appraise the evidence in relation to the effectiveness of lacebacks in controlling incisor position during initial alignment. Electronic database searches of published literature (MEDLINE via Ovid, Cochrane Central Register of Controlled Trials, LILACS, and IBECS) and unpublished literature were performed. Search terms used included randomized controlled trial, controlled clinical trial, random allocation, double blind method, orthodontics, and laceback. Data were extracted using custom forms. Risk of bias assessment was made using the Cochrane Collaboration risk of bias tool. The quality of the evidence was also assessed using GRADE. Mean differences in incisor inclination and antero-posterior changes in incisor and molar position during alignment were calculated. Two studies involving 97 participants were found to be at low risk of bias and were included in the quantitative synthesis. The random effects meta-analysis demonstrated that the use of lacebacks was associated with 0.5 mm greater posterior movement of the incisors during alignment; this finding was of limited clinical importance and statistically non-significant [95 per cent confidence interval (CI): −1.25, 0.25, P = 0.19]. Little difference (0.46 mm) was also found between laceback and non-laceback groups with regards to mesial molar movement (95 per cent CI: −0.33, 1.24, P = 0.26). According to the GRADE assessment, the overall quality of evidence relating to the use of lacebacks was high. There is no evidence to support the use of lacebacks for the control of the sagittal position of the incisors during initial orthodontic alignmen

Sample size in orthodontic randomized controlled trials: are numbers justified?

Sample size calculations are advocated by the Consolidated Standards of Reporting Trials (CONSORT) group to justify sample sizes in randomized controlled trials (RCTs). This study aimed to analyse the reporting of sample size calculations in trials published as RCTs in orthodontic speciality journals. The performance of sample size calculations was assessed and calculations verified where possible. Related aspects, including number of authors; parallel, split-mouth, or other design; single- or multi-centre study; region of publication; type of data analysis (intention-to-treat or per-protocol basis); and number of participants recruited and lost to follow-up, were considered. Of 139 RCTs identified, complete sample size calculations were reported in 41 studies (29.5 per cent). Parallel designs were typically adopted (n = 113; 81 per cent), with 80 per cent (n = 111) involving two arms and 16 per cent having three arms. Data analysis was conducted on an intention-to-treat (ITT) basis in a small minority of studies (n = 18; 13 per cent). According to the calculations presented, overall, a median of 46 participants were required to demonstrate sufficient power to highlight meaningful differences (typically at a power of 80 per cent). The median number of participants recruited was 60, with a median of 4 participants being lost to follow-up. Our finding indicates good agreement between projected numbers required and those verified (median discrepancy: 5.3 per cent), although only a minority of trials (29.5 per cent) could be examined. Although sample size calculations are often reported in trials published as RCTs in orthodontic speciality journals, presentation is suboptimal and in need of significant improvemen

A simple model to estimate atmospheric concentrations of aerosol chemical species based on snow core chemistry at Summit, Greenland

A simple model is presented to estimate atmospheric concentrations of chemical species that exist primarily as aerosols based on snow core/ice core chemistry at Summit, Greenland. The model considers the processes of snow, fog, and dry deposition. The deposition parameters for each of the processes are estimated for SO42− and Ca2+ and are based on experiments conducted during the 1993 and 1994 summer field seasons. The seasonal mean atmospheric concentrations are estimated based on the deposition parameters and snow cores obtained during the field seasons. The ratios of the estimated seasonal mean airborne concentration divided by the measured mean concentration ( ) for SO42− over the 1993 and 1994 field seasons are 0.85 and 0.95, respectively. The ratios for Ca2+ are 0.45 and 0.90 for the 1993 and 1994 field seasons. The uncertainties in the estimated atmospheric concentrations range from 30% to 40% and are due to variability in the input parameters. The model estimates the seasonal mean atmospheric SO42− and Ca2+ concentrations to within 15% and 55%, respectively. Although the model is not directly applied to ice cores, the application of the model to ice core chemical signals is briefly discussed

A comparison of apical root resorption after orthodontic treatment with surgical exposure and traction of maxillary impacted canines versus that without impactions

SUMMARYBACKGROUND/OBJECTIVES: Orthodontic management of maxillary canine impaction (MCI), including forced eruption, may result in significant root resorption; however, the association between MCI and orthodontically induced root resorption (OIRR) is not yet sufficiently established. The purpose of this retrospective cohort study was to comparatively evaluate the severity of OIRR of maxillary incisors in orthodontically treated patients with MCI. Additionally, impaction characteristics were associated with OIRR severity. SUBJECTS AND METHODS: The sample comprised 48 patients undergoing fixed-appliance treatment—24 with unilateral/bilateral MCI and 24 matched controls without impaction. OIRR was calculated using pre- and post-operative panoramic tomograms. The orientation of eruption path, height, sector location, and follicle/tooth ratio of the impacted canine were also recorded. Mann-Whitney U-test and univariate and multivariate linear mixed models were used to test for the associations of interest. RESULTS: Maxillary central left incisor underwent more OIRR in the impaction group (mean difference = 0.58mm, P = 0.04). Overall, the impaction group had 0.38mm more OIRR compared to the control (95% confidence interval, CI: 0.03, 0.74; P = 0.04). However, multivariate analysis demonstrated no difference in the amount of OIRR between impaction and non-impaction groups overall. A positive association between OIRR and initial root length was observed (95% CI: 0.08, 0.27; P < 0.001). The severity of canine impaction was not found to be a significant predictor of OIRR. LIMITATIONS: This study was a retrospective study and used panoramic tomograms for OIRR measurements. CONCLUSIONS: This study indicates that MCI is a weak OIRR predictor. Interpretation of the results needs caution due to the observational nature of the present stud

Modeling of the processing and removal of trace gas and aerosol species by Arctic radiation fogs and comparison with measurements

A Lagrangian radiation fog model is applied to a fog event at Summit, Greenland. The model simulates the formation and dissipation of fog. Included in the model are detailed gas and aqueous phase chemistry, and deposition of chemical species with fog droplets. Model predictions of the gas phase concentrations of H2O2, HCOOH, SO2, and HNO3 as well as the fog fluxes of S(VI), N(V), H2O2, and water are compared with measurements. The predicted fluxes of S(VI), N(V), H2O2, and fog water generally agree with measured values. Model results show that heterogeneous SO2 oxidation contributes to approximately 40% of the flux of S(VI) for the modeled fog event, with the other 60% coming from preexisting sulfate aerosol. The deposition of N(V) with fog includes contributions from HNO3 and NO2 initially present in the air mass. HNO3 directly partitions into the aqueous phase to create N(V), and NO2 forms N(V) through reaction with OH and the nighttime chemistry set of reactions which involves N2O5 and water vapor. PAN contributes to N(V) by gas phase decomposition to NO2, and also by direct aqueous phase decomposition. The quantitative contributions from each path are uncertain since direct measurements of PAN and NO2 are not available for the fog event. The relative contributions are discussed based on realistic ranges of atmospheric concentrations. Model results suggest that in addition to the aqueous phase partitioning of the initial HNO3 present in the air mass, the gas phase decomposition of PAN and subsequent reactions of NO2 with OH as well as nighttime nitrate chemistry may play significant roles in depositing N(V) with fog. If a quasi-liquid layer exists on snow crystals, it is possible that the reactions taking place in fog droplets also occur to some extent in clouds as well as at the snow surface

The evidence from systematic reviews and meta-analyses published in orthodontic literature. Where do we stand?

AIM: To analyse meta-analyses included in systematic reviews (SRs) published in leading orthodontic journals and the Cochrane Database of Systematic Reviews (CDSR) focusing on orthodontic literature and to assess the quality of the existing evidence. MATERIALS AND METHODS: Electronic searching was undertaken to identify SRs published in five major orthodontic journals and the CDSR between January 2000 and June 2014. Quality assessment of the overall body of evidence from meta-analyses was conducted using the Grading of Recommendations Assessment, Development and Evaluation working group (GRADE) tool. RESULTS: One hundred and fifty-seven SRs were identified; meta-analysis was present in 43 of these (27.4 per cent). The highest proportion of SRs that included a meta-analysis was found in Orthodontics and Craniofacial Research (6/13; 46.1 per cent), followed by the CDSR (12/33; 36.4 per cent) and the American Journal of Orthodontics and Dentofacial Orthopaedics (15/44; 34.1 per cent). Class II treatment was the most commonly addressed topic within SRs in orthodontics (n = 18/157; 11.5 per cent). The number of trials combined to produce a summary estimate was small for most meta-analyses with a median of 4 (range: 2-52). Only 21 per cent (n = 9) of included meta-analyses were considered to have a high/moderate quality of evidence according to GRADE, while the majority were of low or very low quality (n = 34; 79.0 per cent). CONCLUSIONS: Overall, approximately one quarter of orthodontic SRs included quantitative synthesis, with a median of four trials per meta-analysis. The overall quality of evidence from the selected orthodontic SRs was predominantly low to very low indicating the relative lack of high quality of evidence from SRs to inform clinical practice guideline

Asynchronous Graph Pattern Matching on Multiprocessor Systems

Pattern matching on large graphs is the foundation for a variety of application domains. Strict latency requirements and continuously increasing graph sizes demand the usage of highly parallel in-memory graph processing engines that need to consider non-uniform memory access (NUMA) and concurrency issues to scale up on modern multiprocessor systems. To tackle these aspects, graph partitioning becomes increasingly important. Hence, we present a technique to process graph pattern matching on NUMA systems in this paper. As a scalable pattern matching processing infrastructure, we leverage a data-oriented architecture that preserves data locality and minimizes concurrency-related bottlenecks on NUMA systems. We show in detail, how graph pattern matching can be asynchronously processed on a multiprocessor system.Comment: 14 Pages, Extended version for ADBIS 201

Particle wall-loss correction methods in smog chamber experiments

The interaction of particles with the chamber walls has been a significant source of uncertainty when analyzing results of secondary organic aerosol (SOA) formation experiments performed in Teflon chambers. A number of particle wall-loss correction methods have been proposed including the use of a size-independent loss rate constant, the ratio of suspended organic mass to that of a conserved tracer (e.g., sulfate seeds), and a size-dependent loss rate constant, etc. For complex experiments such as the chemical aging of SOA, the results of the SOA quantification analysis can be quite sensitive to the adopted correction method due to the evolution of the particle size distribution and the duration of these experiments. We evaluated the performance of several particle wall-loss correction methods for aging experiments of α-pinene ozonolysis products. Determining the loss rates from seed loss periods is necessary for this system because it is not clear when chemical reactions have been completed. Results from the OA&thinsp;∕&thinsp;sulfate ratio and the size-independent correction methods can be influenced significantly by the size dependence of the particle wall-loss process. Coagulation can also affect the particle size distribution, especially for particles with diameter less than 100&thinsp;nm, thus introducing errors in the results of the wall-loss correction. The corresponding loss rate constants may vary from experiment to experiment, and even during a specific experiment. Friction between the Teflon chamber walls and non-conductive surfaces can significantly increase particle wall-loss rates and the chamber may require weeks to recover to its original condition. Experimental procedures are proposed for the characterization of particle losses during different stages of these experiments and the evaluation of corresponding particle wall-loss correction.</p