Probing Interlayer Interactions and Commensurate-Incommensurate Transition in Twisted Bilayer Graphene through Raman Spectroscopy.

Twisted 2D layered materials have garnered much attention recently as a class of 2D materials whose interlayer interactions and electronic properties are dictated by the relative rotation/twist angle between the adjacent layers. In this work, we explore a prototype of such a twisted 2D system, artificially stacked twisted bilayer graphene (TBLG), where we probe, using Raman spectroscopy, the changes in the interlayer interactions and electron-phonon scattering pathways as the twist angle is varied from 0° to 30°. The long-range Moiré potential of the superlattice gives rise to additional intravalley and intervalley scattering of the electrons in TBLG, which has been investigated through their Raman signatures. Density functional theory (DFT) calculations of the electronic band structure of the TBLG superlattices were found to be in agreement with the resonant Raman excitations across the van Hove singularities in the valence and conduction bands predicted for TBLG due to hybridization of bands from the two layers. We also observe that the relative rotation between the graphene layers has a marked influence on the second order overtone and combination Raman modes signaling a commensurate-incommensurate transition in TBLG as the twist angle increases. This serves as a convenient and rapid characterization tool to determine the degree of commensurability in TBLG systems.

Antibiotic Potentiation Through Phytochemical-Based Efflux Pump Inhibitors to Combat Multidrug Resistance Bacteria.

BACKGROUND: Antimicrobial resistance development poses a significant danger to the efficacy of antibiotics, which were once believed to be the most efficient method for treating infections caused by bacteria. Antimicrobial resistance typically involves various mechanisms, such as drug inactivation or modification, drug target modification, drug uptake restriction, and drug efflux, resulting in decreased antibiotic concentrations within the cell. Antimicrobial resistance has been associated with efflux Pumps, known for their capacity to expel different antibiotics from the cell non-specifically. This makes EPs fascinating targets for creating drugs to combat antimicrobial resistance (AMR). The varied structures of secondary metabolites (phytomolecules) found in plants have positioned them as a promising reservoir of efflux pump inhibitors. These inhibitors act as modifiers of bacterial resistance and facilitate the reintroduction of antibiotics that have lost clinical effectiveness. Additionally, they may play a role in preventing the emergence of multidrug resistant strains. OBJECTIVE: The objective of this review article is to discuss the latest studies on plant-based efflux pump inhibitors such as terpenoids, alkaloids, flavonoids, glycosides, and tetralones. It highlighted their potential in enhancing the effectiveness of antibiotics and combating the development of multidrug resistance. strains. RESULTS: Efflux pump inhibitors (EPIs) derived from botanical sources, including compounds like lysergol, chanaoclavine, niazrin, 4-hydroxy-α-tetralone, ursolic acid, phytol, etc., as well as their partially synthesized forms, have shown significant potential as practical therapeutic approaches in addressing antimicrobial resistance caused by efflux pumps. Further, several phyto-molecules and their analogs demonstrated superior potential for reversing drug resistance, surpassing established agents like reserpine, niaziridin, etc. strains. CONCLUSION: This review found that while the phyto-molecules and their derivatives did not possess notable antimicrobial activity, their combination with established antibiotics significantly reduced their minimum inhibitory concentration (MIC). Specific molecules, such as chanaoclavine and niaziridin, exhibited noteworthy potential in reversing the effectiveness of drugs, resulting in a reduction of the MIC of tetracycline by up to 16 times against the tested strain of bacteria. These molecules inhibited the efflux pumps responsible for drug resistance and displayed a stronger affinity for membrane proteins. By employing powerful EPIs, these molecules can selectively target and obstruct drug efflux pumps. This targeted approach can significantly augment the strength and efficacy of older antibiotics against various drug resistant bacteria, given that active drug efflux poses a susceptibility for nearly all antibiotics.

Real-life ankle submovements and computer mouse use reflect patient-reported function in adult ataxias.

Novel disease-modifying therapies are being evaluated in spinocerebellar ataxias and multiple system atrophy. Clinician-performed disease rating scales are relatively insensitive for measuring disease change over time, resulting in large and long clinical trials. We tested the hypothesis that sensors worn continuously at home during natural behaviour and a web-based computer mouse task performed at home could produce interpretable, meaningful and reliable motor measures for potential use in clinical trials. Thirty-four individuals with degenerative ataxias (spinocerebellar ataxia types 1, 2, 3 and 6 and multiple system atrophy of the cerebellar type) and eight age-matched controls completed the cross-sectional study. Participants wore an ankle and wrist sensor continuously at home for 1 week and completed the Hevelius computer mouse task eight times over 4 weeks. We examined properties of motor primitives called 'submovements' derived from the continuous wearable sensors and properties of computer mouse clicks and trajectories in relationship to patient-reported measures of function (Patient-Reported Outcome Measure of Ataxia) and ataxia rating scales (Scale for the Assessment and Rating of Ataxia and the Brief Ataxia Rating Scale). The test-retest reliability of digital measures and differences between ataxia and control participants were evaluated. Individuals with ataxia had smaller, slower and less powerful ankle submovements during natural behaviour at home. A composite measure based on ankle submovements strongly correlated with ataxia rating scale scores (Pearson's r = 0.82-0.88), strongly correlated with self-reported function (r = 0.81), had high test-retest reliability (intraclass correlation coefficient = 0.95) and distinguished ataxia and control participants, including preataxic individuals (n = 4) from controls. A composite measure based on computer mouse movements and clicks strongly correlated with ataxia rating scale total (r = 0.86-0.88) and arm scores (r = 0.65-0.75), correlated well with self-reported function (r = 0.72-0.73) and had high test-retest reliability (intraclass correlation coefficient = 0.99). These data indicate that interpretable, meaningful and highly reliable motor measures can be obtained from continuous measurement of natural movement, particularly at the ankle location, and from computer mouse movements during a simple point-and-click task performed at home. This study supports the use of these two inexpensive and easy-to-use technologies in longitudinal natural history studies in spinocerebellar ataxias and multiple system atrophy of the cerebellar type and shows promise as potential motor outcome measures in interventional trials.

Free-Living Motor Activity Monitoring in Ataxia-Telangiectasia.

With disease-modifying approaches under evaluation in ataxia-telangiectasia and other ataxias, there is a need for objective and reliable biomarkers of free-living motor function. In this study, we test the hypothesis that metrics derived from a single wrist sensor worn at home provide accurate, reliable, and interpretable information about neurological disease severity in children with A-T.A total of 15 children with A-T and 15 age- and sex-matched controls wore a sensor with a triaxial accelerometer on their dominant wrist for 1 week at home. Activity intensity measures, derived from the sensor data, were compared with in-person neurological evaluation on the Brief Ataxia Rating Scale (BARS) and performance on a validated computer mouse task.Children with A-T were inactive the same proportion of each day as controls but produced more low intensity movements (p < 0.01; Cohen's d = 1.48) and fewer high intensity movements (p < 0.001; Cohen's d = 1.71). The range of activity intensities was markedly reduced in A-T compared to controls (p < 0.0001; Cohen's d = 2.72). The activity metrics correlated strongly with arm, gait, and total clinical severity (r: 0.71-0.87; p < 0.0001), correlated with specific computer task motor features (r: 0.67-0.92; p < 0.01), demonstrated high reliability (r: 0.86-0.93; p < 0.00001), and were not significantly influenced by age in the healthy control group.Motor activity metrics from a single, inexpensive wrist sensor during free-living behavior provide accurate and reliable information about diagnosis, neurological disease severity, and motor performance. These low-burden measurements are applicable independent of ambulatory status and are potential digital behavioral biomarkers in A-T.

Effect of electron-phonon coupling on the transport properties of monolayers of ZrS2, BiI3 and PbI2: a thermoelectric perspective.

Thermoelectric materials are used for the conversion of waste heat to electrical energy. The transport coefficients that determine their thermoelectric properties depend on the band structure and the relaxation time of the charge carriers. Both of these are significantly affected by electron-phonon coupling. In this work, using a combination of density functional theory and semiclassical Boltzmann transport theory, we have studied the effect of electron-phonon coupling in monolayers of ZrS2, BiI3 and PbI2. Our results show that in these ionic materials charge carriers are primarily scattered by the optical modes that strongly couple with them. From our study it is conclusively shown that neglecting the contributions of optical modes to electron-phonon coupling in these low-dimensional ionic solids, as is usually done in the computation of relaxation time from deformation theory, results in severe overestimation of the relaxation time. In particular, neglecting the scattering of the optical phonons results in about two orders of magnitude overestimation of relaxation times in these materials. Moreover, we also find that the renormalization of the band structure not only results in the reduction of band gaps but also changes the band dispersion, which strongly affect different transport properties like the electrical conductivity and Seebeck coefficient. Amongst these three materials, we observe that carrier relaxation time due to electron-phonon scattering is reduced as the ionicity of the material decreases.

Implementation of Game-based Oral Health Education vs Conventional Oral Health Education on Children's Oral Health-related Knowledge and Oral Hygiene Status.

INTRODUCTION: For the prevention of oral health problems, health education of schoolchildren has a vital role. The oral health status of the children can be improved if health promotion in schools is conducted in a comprehensive and interesting manner. OBJECTIVE: Effectivity of game-based oral health education over conventional on the oral health-related knowledge and oral hygiene status among 8- to 12-year-old schoolchildren. MATERIALS AND METHODS: A total of 150 children aged 8 to 12 years were divided into two groups. A pretest evaluation of their knowledge regarding oral health and the estimation of plaque index was carried out. Children in group I were given oral health education through PowerPoint presentation once daily for 7 days. Children in group II were educated through the play method (i.e., crosswords and quiz with PowerPoint presentation). The evaluations regarding oral health-related knowledge and plaque scores were recorded on postintervention 1 and 3 months. RESULTS: In group II, high knowledge scores of 10.32 and 9.98 were obtained by the on postintervention 1 and 3 months respectively. In both the groups, there was a significant increase in good oral hygiene scores and a significant decrease in plaque scores on postintervention 1 and 3 months follow-up, but much better scores were seen in group II compared to group I at both the follow-ups. CONCLUSION: Implementation of crossword game-based oral health education program is an easy and effective aid for teaching oral health instructions and preventing oral diseases in children as the knowledge scores of children increased considerably when the game-based teaching intervention was used. HOW TO CITE THIS ARTICLE: Malik A, Sabharwal S, Kumar A, Samant PS, Singh A, Pandey VK. Implementation of Game-based Oral Health Education vs Conventional Oral Health Education on Children's Oral Health-related Knowledge and Oral Hygiene Status. Int J Clin Pediatr Dent 2017;10(3):257-260.

Attitude among dental practioners towards use of rotary instruments and hand instruments for root canal treatment: a comparative study

Aim: The purpose of present study is to assess the attitude of general dental practioners towards use rotary instruments and hand instruments for root canal treatment. Material and Methods: It was a cross-sectional questionnaire study conducted in the private clinics in Lucknow city, Uttar Pradesh. A total of 400 clinics were visited and face to face interview schedule was conducted. Questionnaire consists of demographic details of dental professionals. Information regarding the years of experience, OPD details and number of root canal treatment done per week by dental professionals was obtained. Use of rotary and hand instruments by dental professionals was inquired. Years of experience with Rotary instruments, procedural problems with rotary instruments faced by dental professionals and reasons for not using the rotary instruments if any was also recorded. Results: 102 (33%) of the total study samples were using rotary instruments for root canal treatment and 100 (32%) using both rotary and hand instruments for root canal treatment. Dentists who are using rotary instruments are facing the procedural problem of file breakage {70 (36%)}. And those dental professionals using hand instruments are facing the problem of ledge formation {82(40%)}. Conclusions: The main procedural failure of the rotary instruments in root canal treatment, faced by dental professionals was file breakage and with hand instrument is ledge formation. Lack of expertise is the main reason which restricts dental professionals from using rotary instruments.

Study of root canal morphology of mandibular premolars in an indian population

AIM: The purpose of this study was to describe the external and internal anatomy of the mandibular premolars. MATERIAL AND METHODS: 100 extracted human permanent mandibular first and second premolars teeth were collected. The length of the tooth from the cusp tip to root apex was measured with the help of Vernier calliper. In case of curved roots, ligature wire was adapted to the root and then straightened and measured. Each tooth was examined for the number of roots, curvature of root, presence of root canal invagination. India ink was injected into the pulp chamber through the access opening with a no.27 gauge needle mounted on a disposable syringe. The ink was then drawn through the root canal system by applying negative pressure to the apical end of tooth with the use of central suction system. RESULTS: The average (mean) length of mandibular first premolar was 22.25 mm. Average (mean) length of mandibular second premolar was 21.90 mm. Mandibular first premolar had a ribbon shaped root canal orifice in 35% of teeth. Mandibular second premolar had a ribbon shaped of root canal orifice in 44% teeth. Mesial invagination of the root was found in 18% of first and 8% second mandibular premolar teeth. 78% had a Type I canal pattern with Type II, Type IV, Type V, Type VI and Type VII canals being identified in 1%, 2%, 13%, 2% and 1% of the teeth respectively. CONCLUSIONS: Complex root canal anatomy frequently found with mandibular premolars among which more common with mandibular first premolars in Indian population.