Conventional Scale Research Articles

Multipartite entanglement and quantum criticality of Rydberg atoms trapped in a two-dimensional optical lattice.

We investigate the multipartite entanglement and quantum criticality of neutral atoms on a two-dimensional square lattice, interacting via laser excitation to atom Rydberg states. It is found that the first derivative of residual entanglement with respect to detuning has peaks near the critical point, and corresponding critical behaviors are shown to obey conventional finite-sized scaling, from which we numerically determine the quantum critical point and the critical exponent of the associated correlation length. We also show that there is a sharp peak in the fidelity susceptibility near the critical point, and the critical exponent of the associated correlation length is obtained based on the finite size analysis.

Toward Unified pH of Saline Solutions

Fluctuations of pH in coastal systems are generally surveyed through potentiometric pH measurements. A new concept of a unified pH scale was introduced with the great advantage of enabling comparability of absolute values, pHabs, pertaining to any medium. Using water as an anchor solvent, yielding pHabsH2O, enables referencing the pHabs values to the conventional aqueous pH scale. The current work aims at contributing to implement pHabsH2O to saline solutions. To this purpose, differential potentiometric measurements, with a salt bridge of ionic liquid [N2225][NTf2], were carried out aiming at overcoming problems related to residual liquid junction potentials that affect the quality of such measurements. The ability to measure pHabsH2O with acceptable uncertainty was evaluated using Tris-Tris·HCl standard buffer solutions prepared in a background matrix close to the characteristics of estuarine systems (salinity of 20) as well as with NaCl solutions with ionic strength between 0.005 and 0.8 mol kg−1. The present study shows that for high ionic strength solutions, such as seawater, challenges remain when addressing the assessment and quantification of ocean acidification in relation to climate change. Improvements are envisaged from the eventual selection of a more adequate ionic liquid.

Erbium-doped: yttrium-aluminum-garnet (Er:YAG) versus scaling and root planing for the treatment of periodontal disease: A single-blinded split-mouth randomized clinical trial.

This randomized, controlled clinical trial aimed to compare the differences in periodontal clinical outcomes, duration of the procedure, and patient's experience between conventional scaling and root planing and erbium-doped: yttrium-aluminum-garnet (Er:YAG) in the treatment of generalized moderate to severe chronic periodontitis or generalized Stages II or III, and Grade B periodontitis based on the Centers for Disease Control (CDC), American Academy of Periodontology (AAP), and European Federation of Periodontology (EFP) definitions. Thirty subjects were initially recruited. In a split-mouth fashion, right and left sides were randomly allocated into two treatment arms: conventional scaling and root planing (C-SRP) versus laser-assisted scaling and root planing (L-SRP). A blinded examiner recorded clinical measurements at baseline and 3 months. Duration of the procedure was also recorded for each visit, and the patient's experience was assessed with a questionnaire at baseline, 1, and 3 months. The final sample consisted of 26 subjects. Both treatments resulted in overall improvement, but no significant differences were found between modalities for clinical attachment gain or probing depth reduction. The duration of the procedure was approximately half for L-SRP, and postoperative sensitivity was greater in C-SRP. The low-energy protocol with Er:YAG (50 mJ) used for the non-surgical treatment of moderate-severe chronic or Stage II-III, Grade B periodontitis performed in this study population was a treatment modality that yielded similar clinical improvements when compared to conventional scaling and root planing.

An analytical solution for nonlinear vibration of floating plate on the fluid by modified multiple scales method

The aim of the present paper is to analytically study the nonlinear forced vibration of a rectangular plate floating on the fluid by Modified Multiple Time Scales method for the first time. It is assumed that the fluid is stationary, incompressible, non-viscous, and non-rotational, and the plate is subjected to transversal excitation. The boundary condition is considered to be simply supported. Using von Karman nonlinear strain displacement relationships, the extended Hamilton principle, and FSTD plate theory, the partial differential equations of motion are derived. The fluid is mathematically modeled by Bernoulli equation and the velocity potential function. Galerkin method is then applied for converting the nonlinear partial differential equations into time-dependent nonlinear ordinary differential equations. The resulted equations are solved analytically by the Modified Multiple Scales Method, thereafter. Despite the large number of derivatives and calculations of the conventional multiple scale method, this approach is very simple and straightforward. The results reveal an excellent agreement with the traditional Multiple Scales method results and existing studies, and are more accurate than other available results. The effect of the presence of fluid near the plate on natural frequency and amplitude of vibration of plate are studied. The effects of some key parameters of the system are also examined.

A meta-analysis of observational studies on anticholinergic burden and fracture risk: evaluation of conventional burden scales

BackgroundAnticholinergic burden potentially increases the risk of fracture. Although there are various anticholinergic burden scales, little is known about the inter-scale compatibility regarding the relationship of anticholinergic burden with fracture risk. We performed meta-analysis to examine the association of fracture risk with anticholinergic burden measured using various scales.MethodsPrimary literature was retrieved from PubMed (1966 to March, 2021), the Cochrane Library (1974 to March, 2021), Scopus (1970 to March, 2021), and Ichushi-web (1983 to March, 2021). Cohort and case-control studies that evaluated the association between any fracture and anticholinergic drugs were included. Additionally, we included studies in which patients were administered anticholinergic drugs included on the anticholinergic risk scale (ARS), anticholinergic cognitive burden (ACB), anticholinergic drug scale, or drug burden index-anticholinergic component. Random effects models were used to calculate pooled relative risk (RR) and 95% confidence interval (CI) due to heterogeneity among the studies. Publication bias was examined by funnel plots and the Begg’s test.ResultsA total of 49 datasets from 10 studies were included in the meta-analysis. Six of the 10 studies included only patients aged over 65 years, who accounted for 93% of the total study population (453,186/487,247). Meta-analysis indicated a positive relationship between use of anticholinergic drugs and fracture risk, regardless of the anticholinergic burden scale used. However, the relationship between anticholinergic burden and fracture risk varied depending on the scale used. Fracture risk increased linearly with increasing anticholinergic burden measured using ARS. ARS 1 point was associated with 28% increase in fracture risk, ARS 1–2 point(s) with 39%, ARS 2 points with 54%, ARS 3 points with 66%, and ARS ≥ 4 points with 77%. On the other hand, ACB 1 point and ACB 2 points were associated with similar fracture risk (pooled RR [95% CI]: overall; 1.28 [1.18–1.39], 1 point; 1.12 [1.06–1.18], 2 points; 1.15 [1.08–1.23]).ConclusionsThis result suggests that the relationship between anticholinergic drug burden and fracture risk may differ depending on the anticholinergic burden scale used.

Economic Assessment of the Performance of Metal Trading Enterprises

Aim. The presented study aims to improve the theoretical and methodological approach to assessment and to develop practical recommendations for improving the performance of metal trading enterprises.Tasks. Based on a study of the essence of the concept of “performance” and assessment models, the authors develop methodological provisions for assessing the performance of enterprises; investigate industry-specific features and factors affecting the performance level of metal trading enterprises; develop a comprehensive methodology for assessing the performance level of enterprises in the metal trading industry; test the developed methodology on metal trading enterprises in the Republic of Crimea; identify potential directions for improving the performance of the analyzed group of enterprises.Methods. This study uses a wide range of general scientific methods: induction and deduction, abstraction, analysis and synthesis, modeling, systematization of theoretical and practical material. Analytical, graphical, and statistical methods and the method of comparative economic analysis are applied. The research methodology is based on the key provisions of the theory and practice of financial and economic analysis of enterprise activity.Results. The problem of ensuring the performance of an enterprise essentially comes down to increasing economic results per cost unit. At the same time, among the existing assessment models, the management model provides the most comprehensive accounting of various aspects of operation. The main aspects for assessing the performance of enterprises include the application of a dialectical approach, compliance with certain principles, and the sequence of implemented actions. The conducted analysis of factors affecting the performance level of metal trading enterprises reveals the most negative factors: decreasing purchasing power, increasing tax burden, non-market competition, and underdeveloped industrial infrastructure. This study presents a comprehensive methodology for assessing the performance level of metal trading enterprises, the idea of which goes back to the “performance pyramid” model for analyzing and evaluating operating results developed by K. McNair and is supplemented with a system of key indicators. The proposed methodology is tested on actual enterprises in the Republic of Crimea, and recommendations for increasing the achieved level of performance are formulated.Conclusions. The developed assessment methodology is based on the idea of performance as a pyramid, the volume of which reflects the level of performance; the sides of the base are key indicators showing the state of various aspects of the enterprise’s operation; the base area is the current potential of the enterprise formed by its activities; the pyramid’s height is the position of the enterprise in the market. The integrated index calculated based on the methodology makes it possible to assess the current performance level of the enterprise in accordance with the conventional assessment scale and to develop a list of the most significant measures for improving it.

The Combination of Chinese Traditional Pentatonic Rhythm and New Media Art

By combining new media art to express art, the aesthetics of art can be presented more intuitively. Such a combination allows art forms to become more diverse than Chinese traditional art and deepens understanding and perception of art. This study aims to make audiences experience the unique charm of ancient Chinese art and music through the new form of media art and create real-time interaction between the audience, music, and screen using traditional Chinese rhythm. This study explores the various ways to combine traditional art and new media art and enhance the latter’s aesthetic effect. With rapid economic development, science and technology have progressed to a great extent. The proposed work includes not only the conventional five-tone scales in the traditional Chinese rhythm but also the traditional musical art itself. In addition, by increasing the spectrum of application of traditional art forms, recognition and understanding of Chinese musical rhythm can be widened worldwide.

Comparison of Clinical Attachment Level Gain Using Scaling Root Planing Versus Adjunctive Azithromycin on Chronic Periodontitis

Objective: The objective of the study was to compare the mean clinical attachment gain in patients of chronic periodontitis after scaling and root alone versus Azithromycin as an adjunct to scaling and root. Study Design Comparative study Place and Duration: Conducted at Operative Dentistry Department, Azra Naheed Dental College, Lahore for a duration of 4 months from December 2019 to March 2020. Methodology: Total Sixty patients fulfilling the selection criteria were randomly allocated to SRP and SRP+Az groups. In both groups, conventional scaling and root planing was done. In the SRP group placebo capsules were prescribed, while in the SRP+Az group, Azithromycin (500mg) once daily was prescribed for 3 days. Clinical attachment level (CAL) was measured initially and after 5 weeks. Data was analyzed in SPSS version 19.0 using independent sample t-test. Results: Both groups showed gain in CAL compared to baseline. However, SRP+Az group showed significantly more gain in CAL in comparison to SRP group (P value < 0.05). Conclusion: Use of Azithromycin adjunctive to SRP is an effective treatment modality in chronic periodontitis patients. Keywords: Anti‐Bacterial Agents, Azithromycin, Chronic periodontitis, Clinical attachment level, Periodontal Debridement, Scaling and root planing,

Targeted Nanoscale 3D Thermal Imaging of Tumor Cell Surface with Functionalized Quantum Dots.

Measuring the changes in tumor cell surface temperature can provide insights into cellular metabolism and pathological features, which is significant for targeted chemotherapy and hyperthermic therapy. However, conventional micro-nano scale methods are invasive and can only measure the temperature of cells across a single plane, which excludes specific organelles. In this study, fluorescence quantum dots (QDs) are functionalized with the membrane transport protein transferrin (Tf) as a thermo-sensor specific for tumor cell membrane. The covalent conjugation is optimized to maintain the relative fluorescence intensity of the Tf-QDs to >90%.In addition, the Tf-QDs undergo changes in the fluorescence spectra as a function of temperature, underscoring its thermo-sensor function. Double helix point spread function imaging optical path is designed to locate the probe at nanoscale, and 3D thermal imaging technology is proposed to measure the local temperature distribution and direction of heat flux on the tumor cell surface. This novel targeted nanoscale 3D thermometry method can be a highly promising tool for measuring the local and global temperature distribution across intracellular organelles.

A new analysis of the pQCD contributions to the electroweak parameter ρ using the single-scale approach of principle of maximum conformality

It has been observed that conventional renormalization scheme and scale ambiguities for the pQCD predictions can be eliminated by using the principle of maximum conformality (PMC). However, being the intrinsic nature of any perturbative theory, there are still two types of residual scale dependences due to uncalculated higher-order terms. In the paper, as a step forward of our previous work Wang et al. (2014) [16], we reanalyze the electroweak ρ parameter by using the PMC single-scale approach. Using the PMC conformal series and the Padé approximation approach, we observe that the residual scale dependence can be greatly suppressed and then a more precise pQCD prediction up to N4LO-level can be achieved, e.g. Δρ|PMC≃(8.204±0.012)×10−3, where the errors are squared averages of those from unknown higher-order terms and Δαs(MZ)=±0.0010. We then predict the magnitudes of the uncertainties of the W-boson mass and the effective leptonic weak-mixing angle: δMW|N4LO=−0.26 MeV and δsin2⁡θeff|N4LO=0.14×10−5, which are well below the precision anticipated for the future electron-position colliders such as FCC, CEPC and ILC. Thus by measuring those parameters, it is possible to test SM with high precision.

Scaling analysis of the thermal hydraulic behavior in the secondary side of steam generator

Steam generator is one of the key facilities in nuclear power plant. Due to its complex structure and huge volume, the experimental and numerical research of steam generator needs a large amount of costs and computational resources. One feasible method is to replace the prototype steam generator with a model by the scaling analysis. In this work, a systematical scaling analysis for the thermal hydraulic phenomenon in the secondary side of steam generator in ocean motions is carried out. The scaling analysis is decomposed into three processes, natural circulation, forced convection and lateral flow. A series of scaling criteria are obtained. It is found that the similarity of heat transfer could be achieved by adjusting the parameters of the primary side. It is also revealed that the conventional scaling method could not guarantee the similarity of transverse flow due to the improper similarity of lateral resistance. Besides that, the scaling criteria for the amplitude and period are also obtained, which could be used in the subsequent experiments and numerical simulation.

Assessing health gradient with different equivalence scales for household income – A sensitivity analysis

:Research on health inequalities shows considerable variation in health by socioeconomic position regardless of measurement. Income level is among the most commonly used indicators to measure the social gradient in health. The income gradient in health may, however, vary according to what aspect of health is studied but equally it may depend on how income is measured. The traditional approach of measuring income is to use household income and to modify it with consumption needs and size of the household. Our hypothesis was that the traditional picture of the income-health gradient becomes more nuanced when we use different equalization scales for household incomes than the most often used modified OECD equalization scale. More technically, we expected the steepness of the income-health gradient to change when the equivalence scale for adjusting household size and composition is altered. The data were Finnish cross-sectional 2017 data from EU-SILC (N = 9406). The primary measures were perceived health status and total household disposable annual income by household type. Ordered probit estimation using Stata package was applied to solving the function between health and income controlling for age, age-squared and gender. Respondents’ health status associated with their household type similarly to the association between personal income and household type. Those living in a single household tend to report poorer health but also tend to have lower personal income. Our main finding was that the health-income gradient becomes steeper with the larger equivalence scales, i.e., larger scale relativities, which assume bigger consumption needs for additional household members. One should be more aware of the fact that when household consumption is adjusted with conventional equivalence scales, other income-related aspects beyond consumption potential – such as social status, economic security – are also adjusted for.

SHORT TERM EFFECTS OF PHOTODYNAMIC THERAPY ON CLINICAL, MICROBIAL AND BIOCHEMICAL PARAMETERS IN PATIENTS WITH CHRONIC PERIODONTITIS

Objectives: Photodynamic therapy applies to the elimination of target cells by reactive oxygen species using a photosensitizing agent and a sufcient wavelength of light. It is a new, non-invasive approach to preventing infection. It is now an upcoming alternative treatment modality for periodontitis patients as a supplement to traditional scaling and root planing. The objective of the present study was to assess and compare the effect of photodynamic therapy with conventional Scaling and Root planing in patients with chronic periodontitis. Methods: The study included a minimum of 5 non-smoking males with mild to moderate periodontitis. Clinical parameters such as plaque index, gingival index, gingival bleeding index, pocket probing depth, clinical attachment level; microbiological parameter – anaerobic bacterial CFU count in subgingival plaque samples and biochemical parameter – GCF SOD levels were evaluated at baseline and 28 days postoperatively. The obtained data were analyzed using SPSS (SYSTAT 12) statistical software. The Wilcoxon signed Rank test was used to compare the mean values of various parameters before and after treatment. Results: The results of the study show that all clinical parameters improved from baseline to day 28. Following therapy, the mean levels of the anaerobic bacterial CFU and GCF SOD have decreased dramatically. Conclusion: The results of this study suggest a signicant improvement in clinical, microbiological and Biochemical parameters with the use of PDT as an adjunct to conventional SRP in chronic periodontitis patients

How people perceive influence of fake news and why it matters

ABSTRACT Employing theoretical frameworks regarding people’s perception of media effects (e.g. third-person effect), this study examines how people perceive the effects of fake news, what may lead to these perceptions, and how people act on them. Findings from an online survey provide evidence that people perceive fake news to have negative influence on themselves and others, with greater influence on others than themselves. This study revealed that the extended internal political efficacy scale – the conventional internal political efficacy scale with a measure specific to fake news – serves as an antecedent of the perceived influence of fake news on oneself, others, and the self-other perceptual disparity. Further, the perceptions of fake news effects on oneself and others, separately and jointly, were significantly associated with several likely behaviors including support for fake news regulation, social media withdrawal, and information sharing on social media.

The role of mental health symptomology and quality of life in predicting referrals to special child and adolescent mental health services

BackgroundChildren and adolescents’ mental health problems have been largely assessed with conventional symptom scales, for example, Strengths and Difficulties Questionnaire (SDQ) given that it is one of the mostly widely used measures in specialist Child and Adolescent Mental Health Services (CAMHS). However, this emphasis on symptom scales might have missed some important features of the mental health challenges that children and young people experience including day to day functioning and life satisfaction aspect (i.e. qualify of life).MethodThe study examined longitudinal association between a young person’s self-perceptions of quality of life and mental health difficulties and referral to specialist CAMHS service using a population cohort study (Targeted Mental Health in Schools service data) nested within a large-scale linkage between school (National Pupil Data base) and child mental health service administrative data (South London and Maudsley NHS Foundation Trust children and adolescent mental health services health records). Cox proportional hazard regression to estimate crude and adjusted hazard ratios (HRs) for the association between participant psychopathology, and incidence of CAMHS referral.ResultsPupils experiencing more behavioural difficulties, had an increased incidence of CAMHS referral (adjusted hazard ratio 1.1, 95% confidence interval 1.0–1.2). However, pupils who reported higher health related quality of life had a lower incidence of CAMHS referral over the follow-up period (adjusted hazard hario 0.94, 95% confidence interval 0.9–0.98).ConclusionChildren and young people’s perception of their quality of life should be considered at the stages of a clinical needs assessment.

Residual periodontal pocket treatment with Er:YAG laser-assisted comprehensive periodontal pocket therapy: a retrospective study

Recently, the application of erbium-doped yttrium aluminum garnet (Er:YAG) laser has been increasing in periodontal therapy. In this retrospective study, we evaluated the safety and effectiveness of a novel pocket therapy using Er:YAG laser in combination with conventional mechanical scaling and root planing treatment (Er:YAG laser-assisted comprehensive periodontal pocket therapy). Forty sites in 29 elderly patients having residual periodontal pockets of ≥ 5mm depth were treated by curette and Er:YAG laser from 2006 to 2009. After root debridement by curette, laser irradiation was performed on the root surfaces. Then, inflamed connective tissue on the inner gingival surface and on the bone surface/within extant bone defects was thoroughly debrided by curette and laser. Furthermore, in most cases, removal of the outer epithelium and coagulation of the blood clot in the pocket entrance were additionally performed with laser. Clinical parameters were evaluated before and 3, 6, and 12months after treatment. With Er:YAG laser-assisted pocket therapy, debridement of pockets was thoroughly and safely performed, and favorable clinical improvements were observed in most cases, without any adverse side effects and complications. After 1year, probing pocket depth significantly decreased from 6.4 ± 1.4 to 3.5 ± 1.3mm (p < 0.001, 3.0mm reduction), and clinical attachment level significantly decreased from 7.5 ± 1.6 to 5.2 ± 1.9mm (p < 0.001, 2.3mm gain). The results of this study indicate that Er:YAG laser-assisted therapy is useful for the treatment of residual pockets as a minimally invasive flapless surgery. Er:YAG laser-assisted comprehensive pocket therapy reduces the necessity of more conventional surgical therapies.

Objective assessment of impulse control disorder in patients with Parkinson\u2019s disease using a low-cost LEGO-like EEG headset: a feasibility study

BackgroundPatients with Parkinson’s disease (PD) can develop impulse control disorders (ICDs) while undergoing a pharmacological treatment for motor control dysfunctions with a dopamine agonist (DA). Conventional clinical interviews or questionnaires can be biased and may not accurately diagnose at the early stage. A wearable electroencephalogram (EEG)-sensing headset paired with an examination procedure can be a potential user-friendly method to explore ICD-related signatures that can detect its early signs and progression by reflecting brain activity.MethodsA stereotypical Go/NoGo test that targets impulse inhibition was performed on 59 individuals, including healthy controls, patients with PD, and patients with PD diagnosed by ICDs. We conducted two Go/NoGo sessions before and after the DA-pharmacological treatment for the PD and ICD groups. A low-cost LEGO-like EEG headset was used to record concurrent EEG signals. Then, we used the event-related potential (ERP) analytical framework to explore ICD-related EEG abnormalities after DA treatment.ResultsAfter the DA treatment, only the ICD-diagnosed PD patients made more behavioral errors and tended to exhibit the deterioration for the NoGo N2 and P3 peak amplitudes at fronto-central electrodes in contrast to the HC and PD groups. Particularly, the extent of the diminished NoGo-N2 amplitude was prone to be modulated by the ICD scores at Fz with marginal statistical significance (r = − 0.34, p = 0.07).ConclusionsThe low-cost LEGO-like EEG headset successfully captured ERP waveforms and objectively assessed ICD in patients with PD undergoing DA treatment. This objective neuro-evidence could provide complementary information to conventional clinical scales used to diagnose ICD adverse effects.

Comparison of maximum likelihood and conventional PET scatter scaling methods for 18 F-FDG and 68 Ga-DOTATATE PET/CT.

We aim to quantify differences between a new maximum likelihood (ML) background scaling (MLBS) algorithm and two conventional scatter scaling methods for clinical PET/CT. A common source of reduced image quantification with conventional scatter corrections is attributed to erroneous scaling of the initial scatter estimate to match acquired scattered events in the sinogram. MLBS may have performance advantages over conventional methods by using all available data intersecting the subject. A retrospective analysis was performed on subjects injected with 18 F-FDG (N=71) and 68 Ga-DOTATATE (N=11) and imaged using time-of-flight (TOF) PET/CT. The scatter distribution was estimated with single scatter simulation approaches. Conventional scaling algorithms included (a) tail fitted background scaling (TFBS), which scales the scatter to "tails" outside the emission support, and (b) absolute scatter correction (ABS), which utilizes the simulated scatter distribution with no scaling applied. MLBS consisted of an alternating iterative reconstruction with a TOF-based ML activity image update allowing negative values (NEG-ML) and nested loop ML scatter scaling estimation. Scatter corrections were compared using reconstructed images as follows: (a) normalized relative difference images were generated and used for voxel-wise analysis, (b) liver and suspected lesion ROIs were drawn to compute mean SUVs, and (c) a qualitative analysis of overall diagnostic image quality, impact of artifacts, and lesion conspicuity was performed. Absolute quantification and normalized relative differences were also assessed with an 18 F-FDG phantom study. For human subjects 18 F-FDG data, Bland-Altman plots demonstrated that the largest normalized voxel-wise differences were observed close to the lower limit (SUV=1.0). MLBS reconstructions trended towards higher scatter fractions compared to TFBS and ABS images, with median voxel differences across all subjects for TFBS-MLBS measured at 1.7% and 7.6% for 18 F-FDG and 68 Ga-DOTATATE, respectively. For mean SUV analysis, there was a high degree of correlation between the scatter corrections. For 18 F-FDG, ABS scatter correction reconstructions trended towards higher liver mean SUVs relative to MLBS. The qualitative image analysis revealed no significant differences between TFBS and MLBS image reconstructions. For a uniformly filled relatively large 37cm diameter phantom, MLBS produced the lowest bias in absolute quantification, while normalized voxel-wise differences showed a trend in scatter correction performance consistent with the human subjects study. For 18 F-FDG, MLBS is at least a valid substitute to TFBS, providing reconstructed image performance comparable to TFBS in most subjects but exhibiting quantitative differences in cases where TFBS is typically prone to inaccuracies (e.g., due to patient motion and CT-based attenuation map truncation). Particularly for low contrast regions, quantification differs for ABS compared to MLBS and TFBS, and caution should be taken when utilizing ABS for decision-making based on quantitative metrics.

In Vitro Comparison of Root Surface Treatment Effect between Root Scaling with Ultrasonic Inserts and Gracey Curette and Polishing with Different Cleaning Pastes

The aim of this study was the morphological evaluation of root surfaces subjected to manual (curette) and ultrasonic (conventional and diamond tips) scaling. The surface was then polished with a rubber cup and three medium-sized pastes. Ninety teeth were randomly divided into three groups of 30 and subjected to three different root instrumentation: (1) manual instrumentation with a Gracey® curette; (2) ultrasonic instrumentation with a standard steel tip (Universal Perio S-SERIES: USU, Hu-Friedy, Chicago, IL, USA) at a power equal to 50%; and (3) with a diamond tip (Punta Piezo Serie E Scaling, Hu-Friedy, Chicago, IL, USA) at a power of 20%. Each group of the instrumented teeth was then divided in three subgroups of 10 and subjected to 30 s of rubber polishing with three different polishing pastes with medium grain sizes in single-dose cups: (1) Ultrapro Tx cool mint medium®; (2) Stomyprox media®; and (3) Nupro medium orange®. Polyether root surface replicas were then taken from all 90 samples and analyzed by SEM to evaluate surface morphology after scaling and polishing procedures. All scaling techniques caused an alteration of the root surface without statistically significant difference, whereas polishing resulted in maintenance or improvement of the surface texture.

A Novel Combined Level Set Model for Carpus Segmentation from Magnetic Resonance Images with Prior Knowledge aligned in Polar Coordinate System

Background and ObjectiveSegmentation on carpus provides essential information for clinical applications including pathological evaluations, therapy planning, wrist biomechanical analysis, etc. Along with the acquisition procedure of magnetic resonance (MR) technique, poor quality of wrist images (e.g., occlusion, low signal-to-noise ratio, and contrast) often causes segmentation failure. MethodsIn this work, to address such problems, a shape prior enhanced level set model was proposed. By transferring a shape contour in Cartesian Coordinate System (COS) into a curve in Polar Coordinate System (POS), parameters describing conventional shape invariance, i.e., translations, rotation, and scale were simplified into a single parameter for phase shift, which strongly improved algorithm efficiency. Given a training set in COS, a confidence interval representing the corresponding curves in POS was utilized as the shape prior set term in the model. Integrated with an edge detector, a local intensity descriptor, and a regularization term, the proposed method further possessed abilities against noise, intensity inhomogeneity as well as re-initialization problem. Images from 15 in-vivo acquired MR-datasets of the human wrist were used for validation. The performance of the proposed method has been compared with three state-of-the-art methods. ResultsWe reported a Dice Similarity Coefficient of 96.88±1.20%, a Relative Volume Difference of -1.53±3.01%, a Volume Overlap Error of 6.03±2.23%, a 95% Hausdorff Distance of 1.43±0.66 mm, an Average Symmetric Surface Distance of 0.50±0.17 mm, and a Root Mean Square Distance of 0.71±0.25 mm for the proposed method. The time consumption was 36.03±19.98 s. ConclusionsExperimental results indicated that, compared with three other methods, the proposed method achieved significant improvement in terms of accuracy and efficiency.