Mechanical stress distribution over the palate by different pacifiers assessed by finite element analysis and clinical data.

The mechanical behavior of each type of pacifier on rigid structures and their various impacts on orofacial growth have yet to be discovered. The study aimed to evaluate the stress distribution over a child's palate by three types of pacifiers using finite element analysis and clinical and laboratory data. Modulus of elasticity was obtained from 30 specimens comprising 10 of each conventional (A), orthodontic (B), and breast-shaped (C) pacifiers. Tongue strength was assessed in eight 3-year-old children (kPa). A hemi-maxilla model was obtained from 2- to 3-year-old skull tomography, and the images of pacifiers A, B, and C were captured using 3D scanning. The Hypermesh® program generated a mesh of 6-node tetrahedral elements for applying forces in the X, Y, and Z directions to enable a nonlinear analysis. Pacifier B exhibited the highest values for distributed stress on the palate, followed by pacifier A. Pacifier B stimulated the maxilla forward and sideways. In contrast, pacifier A promoted a forward and upward load, favoring a more atresic palate. Pacifiers A and B tended to rotate in the sagittal plane, generating tensions in the anterior incisors and favoring the open bite. Pacifier C exhibited lateral expansion by stress induction over the mid-palatal suture with less influence on incisor inclination. Pacifiers showed different detrimental stress distributions on the palate. This information can be helpful for improving recommendations given to parents.

Pulp changes from rapid maxillary expansion: A systematic review.

INTRODUCTION: This study aimed to systematically review the current evidence on the occurrence of pulp changes as side effects from orthopaedic rapid maxillary expansion (ORME) or surgically assisted rapid maxillary expansion (SARME). METHODS: An electronic search was performed in eleven databases. The eligibility criteria included clinical studies assessing vitality, sensibility or dimensions of the pulp chamber of permanent teeth before and after ORME or SARME, without restrictions on publication year or language. The risk of bias was analysed with the NIH 'Quality Assessment Tool for Before-After (Pre-Post) Studies with No Control Group' and the 'JBI for quasi-experimental studies' tool. The GRADE tool was used to assess the certainty of evidence. RESULTS: The initial search resulted in 1,197 records, from which only seven before-after studies were included. There was a change in the pulpal blood flow (PBF) of maxillary incisors and canines up to 5 days after SARME, which gradually returned after 7 days to 3 months. After ORME, one study observed an increased PBF and one study observed a reduced PBF, which gradually returned after the end of expansion. Two studies observed that both ORME and SARME caused temporary changes in pulp sensibility. Three studies observed a significant reduction in the pulp chamber after ORME or SARME. The outcomes presented a very low certainty of evidence. CONCLUSIONS: Although limited, the evidence shows that ORME and SARME caused temporary changes in pulp vitality and sensibility, with the possibility of inducing a reduction in pulp chamber dimensions.

Torqued and conventional cantilever for uprighting mesially impacted molars: A 3-dimensional finite element analysis.

INTRODUCTION: The objective of this study was to evaluate the effects of the torqued cantilever (TC) and conventional tip-back cantilever (CC) made of stainless steel (SS) and titanium-molybdenum alloy (TMA) on the uprighting of mesially impacted mandibular molars using three-dimensional finite element analysis. METHODS: The 3-dimensional mandibular model included part of the mandible with mesially tipped and impacted mandibular second molar, periodontal ligament (PDL), molar tube, mini-implant, and cantilevers. Four finite element method models (TC-SS, TC-TMA, CC-SS, and CC-TMA) were created to simulate different skeletally anchored uprighting mechanics. CC mechanics involved a known 0.019 × 0.025-in helical cantilever acting on a buccal molar tube. TC mechanics included a 0.019 × 0.025-in cantilever capable of producing mesial root torque by acting on a tube positioned on the molar disto-occlusal surface with the slot in a buccolingual direction. Three-dimensional molar displacement and stress distribution on the molar PDL were recorded. RESULTS: The SS cantilever produced almost twice as much molar displacement as the TMA. TC mechanics showed more evident mesial displacement of the molar root apexes. CC mechanics had greater molar rotation. TC uprighting moment produced greater molar mesial extrusion and greater intrusion of the distal root apex. The dual deflection system of the TC mechanics induced the lowest stress on the PDL, regardless of the metallic alloy. CONCLUSIONS: TC delivered a more efficient uprighting moment to the molar with less unwanted tooth movement and stress on the PDL and a more accessible site for bonding the molar tube.

A New Proposal for Calibrated Gauges for Removable Partial Dentures: A Finite Element Analysis.

AIM: The aim of this study was to evaluate the stress distribution of a planned removable partial denture (RPD) using new proposals for calibrated gauges of 0.3 mm and 0.35 mm undercuts through the three-dimensional (3D) finite element methodology, and compare them with 0.25 mm and 0.5 mm gauges that are already existing in clinical practice. MATERIALS AND METHODS: Kennedy class-I edentulous 3D models and their respective RPDs (InVesalius software; Rhinoceros and SolidWorks CAD) were created and exported to the finite element program HyperMesh 2019 for mesh configuration. In the following steps, axial loading (0º) of 40 N per point was performed, with 3 points on the molars and 2 points on the premolars, totaling 280 N unilaterally. The model was processed by the OptiStruct 2019 software and imported into the HyperView 2019 software to obtain the stress maps (MPa). RESULTS: The use of 0.30 and 0.35 mm calibrated gauges presented tensions similar to those with the 0.25 mm gauge (gold standard) and caused no significant damage to biological structures. The use of a 0.5 mm undercut caused greater traction force in the periodontal ligament of the abutments. CONCLUSIONS: The 0.35 mm undercut seems promising as it presented more favorable results in this simulation, on the other hand, a 0.5 mm undercut is greater than that necessary for retainers made of CoCr. CLINICAL SIGNIFICANCE: This study aims to measure a new undercut gauge (0.35 mm) to increase the retention area in abutment teeth of removable partial dentures.

Controlling Movement at Nanoscale: Curvature Driven Mechanotaxis.

Locating and manipulating nano-sized objects to drive motion is a time and effort consuming task. Recent advances show that it is possible to generate motion without direct intervention, by embedding the source of motion in the system configuration. In this work, an alternative manner to controllably displace nano-objects without external manipulation is demonstrated, by employing spiral-shaped carbon nanotube (CNT) and graphene nanoribbon structures (GNR). The spiral shape contains smooth gradients of curvature, which lead to smooth gradients of bending energy. It is shown that these gradients as well as surface energy gradients can drive nano-oscillators. An energy analysis is also carried out by approximating the carbon nanotube to a thin rod and how torsional gradients can be used to drive motion is discussed. For the nanoribbons, the role of layer orientation is also analyzed. The results show that motion is not sustainable for commensurate orientations, in which AB stacking occurs. For incommensurate orientations, friction almost vanishes, and in this instance, the motion can continue even if the driving forces are not very high. This suggests that mild curvature gradients, which can already be found in existing nanostructures, could provide mechanical stimuli to direct motion.

Ninety Years of Multiple Psychotic-Like and Spiritual Experiences in a Doctor Honoris Causa: A Case Report and Literature Review.

ABSTRACT: Psychotic experiences are common experiences shared by a considerable part of the world's population. Moreover, most of the individuals who report these experiences also report those called spiritual and dissociative phenomena. In specific culture and religious backgrounds, these experiences are frequently seen as a part of normal human experiences, usually called mediumship. We report a case of a famous Brazilian medium with 90 years of experiencing psychotic-like, dissociative and/or spiritual experiences, but coped well with the experiences and never sought psychiatric or psychological assistance. The medium received several honorific prizes, such as doctor honoris causa from different institutions, published more than 200 books, and ran a nonprofit organization that takes care of 5000 people daily. Finally, we review the literature on this topic and stress the urge for more research aiming to distinguish pathological and nonpathological psychotic experiences to avoid overmedicalization and iatrogenic treatments.

Few-Wall Carbon Nanotube Coils.

While various electronic components based on carbon nanotubes (CNTs) have already been demonstrated, the realization of miniature electromagnetic coils based on CNTs remains a challenge. Coils made of single-wall CNTs with accessible ends for contacting have been recently demonstrated but were found unsuitable to act as electromagnetic coils because of electrical shorting between their turns. Coils made of a few-wall CNT could in principle allow an insulated flow of current and thus be potential candidates for realizing CNT-based electromagnetic coils. However, no such CNT structure has been produced so far. Here, we demonstrate the formation of few-wall CNT coils and characterize their structural, optical, vibrational, and electrical properties using experimental and computational tools. The coils are made of CNTs with 2, 3, or 4 walls. They have accessible ends for electrical contacts and low defect densities. The coil diameters are on the order of one micron, like those of single-wall CNT coils, despite the higher rigidity of few-wall CNTs. Coils with as many as 163 turns were found, with their turns organized in a rippled raft configuration. These coils are promising candidates for a variety of miniature devices based on electromagnetic coils, such as electromagnets, inductors, transformers, and motors. Being chirally and enantiomerically pure few-wall CNT bundles, they are also ideal for fundamental studies of interwall coupling and superconductivity in CNTs.

Stabilization of a Highly Concentrated Colloidal Suspension of Pristine Metallic Nanoparticles.

A colloidal suspension containing a high concentration of metallic nanoparticles (NPs) finds potential applications in flexible electronic printing, nanofluids, healthcare, antifouling coating, and so on. Here, we demonstrate a generic, easily scalable, simple, and contamination-free cryogenic temperature grinding method, which can effectively be used to prepare pristine NPs that can be stabilized in polar liquids in high concentrations. These surfactant-free pristine NPs have been found to remain dispersed in different polar liquids (CH3OH, C2H5OH, glycol, etc.) for weeks. The long-term stability of the NPs in these liquids has been investigated using zeta potential, in situ Fourier transform infrared spectroscopy, indicating electrostatic stabilization for ultrapure, surfactant-free NPs. Furthermore, stabilization of the NPs has been probed with detailed calculations using the Derjaguin Landau Verwey Overbeek theory as well as atomistic molecular dynamics simulation (MD). Experimental measurements along with theoretical calculations categorically indicate that the electrostatic energy is helping these NPs to be stabilized in a polar liquid.

Accuracy and Psychometric Properties of the Brazilian Version of the Montreal Cognitive Assessment as a Brief Screening Tool for Mild Cognitive Impairment and Alzheimer's Disease in the Initial Stages in the Elderly.

OBJECTIVE: To evaluate the applicability and the psychometric properties of Montreal Cognitive Assessment Brazilian Version (MoCA-BR) in the elderly, as well as comparing its accuracy as a tracking test for mild cognitive impairment (MCI) and mild Alzheimer's disease (AD) with the accuracy of Mini-Mental State Examination (MMSE). METHOD: A transversal study was performed in 4 reference medical centers that care for the elderly. In all, 229 elderly participated in the study. To select the sample, the clinical history of the elderly, Pfeffer Functional Activities Questionnaire, and neuropsychological battery, apart from MMSE and MoCA-BR cognitive tests, were selected. The elderly were classified into control, MCI, and mild AD groups. RESULTS: There was a significant statistical difference between the MoCA-BR scores of the elderly and the control group, MCI, and mild AD (p < 0.001). The Cronbach alpha for MoCA-BR was 0.77, indicating a good internal consistency. The test-retest reliability was elevated, with intraclass correlation coefficient (ICC) 0.91. The inter-examiner reliability was excellent (ICC 0.96). The area under curve of the receiver operating characteristics curve was 0.95, when evaluating the ability of MoCA-BR to discriminate between the elderly with cognitive impairment and cognitively healthy elderly. CONCLUSIONS: The results of the study show that the Brazilian version of MoCA is a reliable cognitive tracking tool and is accurate for the detection of MCI and early stage AD, with good applicability on the elderly with education equal to or more than 4 years and adequate to discriminate between cognitively healthy elderly, and those with MCI and mild, proving to be superior to MMSE in tracking MCI and similar to this test when tracking mild AD.

Is the Montreal Cognitive Assessment (MoCA) screening superior to the Mini-Mental State Examination (MMSE) in the detection of mild cognitive impairment (MCI) and Alzheimer's Disease (AD) in the elderly?

ABSTRACTObjective:To compare the accuracy of Mini-Mental State Examination (MMSE) and of the Montreal Cognitive Assessment (MoCA) in tracking mild cognitive impairment (MCI) and Alzheimer's Disease (AD). METHOD: A Systematic review of the PubMed, Bireme, Science Direct, Cochrane Library, and PsycInfo databases was conducted. Using inclusion and exclusion criteria and staring with 1,629 articles, 34 articles were selected. The quality of the selected research was evaluated through the Quality Assessment of Diagnostic Accuracy Studies 2 tool (QUADAS-2). RESULT: More than 80% of the articles showed MoCA to be superior to MMSE in discriminating between individuals with mild cognitive impairment and no cognitive impairment. The area under the curve varied from 0.71 to 0.99 for MoCA, and 0.43 to 0.94 for MMSE, when evaluating the ability to discriminate MCI in the cognitively healthy elderly individuals, and 0.87 to 0.99 and 0.67 to 0.99, respectively, when evaluating the detection of AD. The AUC mean value for MoCA was significantly larger compared to the MMSE in discriminating MCI from control [0.883 (CI 95% 0.855-0.912) vs MMSE 0.780 (CI 95% 0.740-0.820) p < 0.001]. CONCLUSION: The screening tool MoCA is superior to MMSE in the identification of MCI, and both tests were found to be accurate in the detection of AD.

Genetics and telemetry indicate unexpected movements among structured populations for Brachyplatystoma platynemum in the Amazon.

The genetic analysis of Brachyplatystoma platynemum individuals sampled from the lower Madeira River reinforces the existence of two structured populations in the Amazon Basin (Madeira and Amazon populations). However, the recapture of an individual from the Amazon population in the Solimões River, which was telemetry-tagged in the Madeira River after the damming, indicates that fish from the Amazon population move between the two river systems. This has not yet been observed, however, in the Madeira River population, which is currently divided and isolated in the lower and upper Madeira River by the construction of two dams.

Influence of Age and Education on the Performance of Elderly in the Brazilian Version of the Montreal Cognitive Assessment Battery.

AIMS: To provide normative data for the Brazilian version of the Montreal Cognitive Assessment (MoCA-BR) and to measure the effect of sociodemographic variables on the cognitive performance of cognitively healthy elderly people. METHODS: A sample of 110 cognitively healthy individuals, aged over 65 years, with at least 4 years of schooling were recruited from 3 health care centers for the elderly in Recife, Brazil. The cognitive performance was assessed using MoCA-BR. RESULTS: The average score of these elderly people in the MoCA-BR was 23.2 ± 2.7. Their schooling correlated positively with the cognitive performance, with a Spearman's coefficient of 0.33 (p < 0.001). There was a statistically significant negative correlation between age and the cognitive performance (Spearman's rho = -0.19). The multiple linear regression model with the highest adjusted coefficient of determination was the one that included schooling and age (adjusted R2 = 0.127). CONCLUSIONS: The cognitive performance of healthy elderly was evaluated and was strongly influenced by schooling and, to a lower degree, by age.

Metabolic risk management, physical exercise and lifestyle counselling in low-active adults: controlled randomized trial (BELLUGAT).

BACKGROUND: The primary aim of this study is to evaluate the effectiveness of different doses (intensity) of supervised exercise training - concomitant with lifestyle counselling - as a primary care intervention tool for the management of metabolic syndrome risk factors in low-active adults with one or more such factors (programme name in Catalan: Bellugat de CAP a peus). METHODS/DESIGN: Three-arm, randomized controlled clinical trial implemented in the primary care setting, with a duration of 40 weeks (16 weeks intervention and 24-week follow-up). Adults aged 30 to 55 years with metabolic risk factors will be randomized into three intervention groups: 1) aerobic interval training (16 supervised training lessons) plus a healthy lifestyle counselling programme (6 group and 3 individual meetings); 2) low-to-moderate intensity continuous training (16 supervised training lessons) plus the same counselling programme; or 3) the counselling- programme without any supervised physical exercise. The main output variables assessed will be risk factors for metabolic syndrome (waist circumference, blood pressure, and levels of plasma triglycerides, high-density lipoproteins and glucose), systemic inflammation, cardiorespiratory fitness, physical activity and sedentary behaviour, dietary habits, health-related quality of life, self-efficacy and empowerment. Economic factors will also be analysed in order to determine the cost-effectiveness of the programme. These variables will be assessed three times during the study: at baseline, at the end of the intervention, and at follow-up. We estimate to recruit 35 participants per group. DISCUSSION: The results of this study will provide insight into the immediate and medium-term effects on metabolic risk and lifestyle of a combined approach involving aerobic interval training and a multidisciplinary behavioural intervention. If effective, the proposed intervention would provide both researchers and practitioners in this field with a platform on which to develop similar intervention programmes for tackling the repercussions of an unhealthy lifestyle. TRIAL REGISTRATION: Clinical trials.gov. NTC02832453 . Registered 6 July 2016 (retrospectively registered).

Strain Rate Dependent Shear Plasticity in Graphite Oxide.

Graphene oxide film is made of stacked graphene layers with chemical functionalities, and we report that plasticity in the film can be engineered by strain rate tuning. The deformation behavior and plasticity of such functionalized layered systems is dominated by shear slip between individual layers and interaction between functional groups. Stress-strain behavior and theoretical models suggest that the deformation is strongly strain rate dependent and undergoes brittle to ductile transition with decreasing strain rate.

Defect-Free Carbon Nanotube Coils.

Carbon nanotubes are promising building blocks for various nanoelectronic components. A highly desirable geometry for such applications is a coil. However, coiled nanotube structures reported so far were inherently defective or had no free ends accessible for contacting. Here we demonstrate the spontaneous self-coiling of single-wall carbon nanotubes into defect-free coils of up to more than 70 turns with identical diameter and chirality, and free ends. We characterize the structure, formation mechanism, and electrical properties of these coils by different microscopies, molecular dynamics simulations, Raman spectroscopy, and electrical and magnetic measurements. The coils are highly conductive, as expected for defect-free carbon nanotubes, but adjacent nanotube segments in the coil are more highly coupled than in regular bundles of single-wall carbon nanotubes, owing to their perfect crystal momentum matching, which enables tunneling between the turns. Although this behavior does not yet enable the performance of these nanotube coils as inductive devices, it does point a clear path for their realization. Hence, this study represents a major step toward the production of many different nanotube coil devices, including inductors, electromagnets, transformers, and dynamos.

The structural and dynamical aspects of boron nitride nanotubes under high velocity impacts.

This communication report is a study on the structural and dynamical aspects of boron nitride nanotubes (BNNTs) shot at high velocities (∼5 km s(-1)) against solid targets. The experimental results show unzipping of BNNTs and the formation of hBN nanoribbons. Fully atomistic reactive molecular dynamics simulations were also carried out to gain insights into the BNNT fracture patterns and deformation mechanisms. Our results show that longitudinal and axial tube fractures occur, but the formation of BN nanoribbons from fractured tubes was only observed for some impact angles. Although some structural and dynamical features of the impacts are similar to the ones reported for CNTs, because BNNTs are more brittle than CNTs this results in a larger number of fractured tubes but with fewer formed nanoribbons.

Happiness and Defense Styles in Psychiatrists.

The aim of this study was to measure happiness in a sample of Brazilian psychiatrists and correlate it with the defense styles used by them and sociodemographic data. This study was observational, cross-sectional, and analytical. Data were collected through self-administered questionnaires by Brazilian psychiatrists who participated in the XXXII Brazilian Congress of Psychiatry, 2014. In this sample of psychiatrists, happiness levels were high (scoring 5.69 of a total of 7), and mature defense styles prevailed, especially humor and anticipation. In a multivariate analysis, having children, good sleep quality, increased sexual interest, and use of defense styles such as humor, anticipation, and idealization all showed a positive relationship with happiness; on the other hand, using defense style such as acting out or annulment demonstrated a negative relationship with happiness. Despite the well-known professional burden that they bear, Brazilian psychiatrists surveyed presented, in general, high levels of subjective well-being and happiness.

Unzipping carbon nanotubes at high impact.

The way nanostructures behave and mechanically respond to high impact collision is a topic of intrigue. For anisotropic nanostructures, such as carbon nanotubes, this response will be complicated based on the impact geometry. Here we report the result of hypervelocity impact of nanotubes against solid targets and show that impact produces a large number of defects in the nanotubes, as well as rapid atom evaporation, leading to their unzipping along the nanotube axis. Fully atomistic reactive molecular dynamics simulations are used to gain further insights of the pathways and deformation and fracture mechanisms of nanotubes under high energy mechanical impact. Carbon nanotubes have been unzipped into graphene nanoribbons before using chemical treatments but here the instability of nanotubes against defect formation, fracture, and unzipping is revealed purely through mechanical impact.

Factors associated with improved outcomes in the first psychotic episode at a specialized outpatient clinic in northeastern Brazil.

OBJECTIVES: The present study aimed to evaluate data from patients admitted to the first-episode psychotic (FEP) outpatient clinic at the Hospital of Clinics of the Federal University of Pernambuco from July 2018 to July 2021, seeking to identify factors related to better clinical outcomes. METHODS: This study was conducted using a convenience sample, including all patients between 15 and 65 years of age who were admitted to the FEP outpatient clinic from July 2018 to July 2021. Descriptive statistical analysis was performed using mean and standard deviation or median and interquartile range for continuous quantitative variables, and absolute number/percentage for qualitative variables. Paired T-test, a parametric test, was used to compare PANSS scores upon admission and after 6 months. Spearman's correlation test was employed to assess the correlation between duration of untreated psychosis (DUP) and treatment response with other variables. RESULTS: The sample consisted of 85.3% male individuals, with 50% of patients aged between 19 and 30 years, and 82% residing in the metropolitan area of Recife. Seventy percent of patients responded to the treatment implemented by the outpatient clinic, and only 30% required psychiatric hospitalization within 6 months of follow-up. The majority of patients had a history of psychoactive substance use (82.4%); however, the use of these substances did not impact the prognosis within the analysed sample. The median DUP was 4 weeks, and a shorter DUP was associated with a lower probability of psychiatric hospitalization and a greater treatment response (reduction >50% in PANSS). CONCLUSION: A shorter DUP was associated with a lower likelihood of psychiatric hospitalization and a greater treatment response. Furthermore, the specialized early psychosis outpatient clinic itself appears to yield positive outcomes, as 70% of the treated patients exhibited a positive treatment response.

Deep learning for automatic mandible segmentation on dental panoramic x-ray images.

Many studies in the last decades have correlated mandible bone structure with systemic diseases like osteoporosis. Mandible segmentation, as well as segmentation of other oral structures, is an essential step in studies that correlate oral structures' conditions with systemic diseases in general. However, manual mandible segmentation is a time-consuming and training-required task that suffers from inter and intra-user variability. Further, the dental panoramic x-ray image (PAN), the most used image in oral studies, contains overlapping of many structures and lacks contrast on structures' interface. Those facts make both manual and automatic mandible segmentation a challenge. In the present study, we propose a precise and robust set of deep learning-based algorithms for automatic mandible segmentation (AMS) on PAN images. Two datasets were considered. An in-house image dataset with 393 image/segmentation pairs was prepared using image data of 321 image patient data and the corresponding manual segmentation performed by an experienced specialist. Additionally, a publicly available third-party image dataset (TPD) composed of 116 image/segmentation pairs was used to train the models. Four deep learning models were trained using U-Net and HRNet architectures with and without data augmentation. An additional morphological refinement routine was proposed to enhance the models' prediction. An ensemble model was proposed combining the four best-trained segmentation models. The ensemble model with morphological refinement achieved the highest scores on the test set (98.27%, 97.60%, 97.18%, ACC, DICE, and IoU respectively), with the other models scoring above 95% in all performance metrics on the test set. The present study achieved the highest ranked performance considering all the previously published results on AMS for PAN images. Additionally, those are the most robust results achieved since it was performed over an image set with considerable gender representativeness, a wide age range, a large variety of oral conditions, and images from different imaging scans.