bluuebunny/crossref_metadata_2025 huggingface dataset:
On the subject of influence of dissipative and constant of moments on the stability of uniform rotations of non-free two elastically connected gyroscopes of Lagrange
Authors: Kononov Yurii , Sviatenko Yaroslav
Published: June 2021

The conditions for asymptotic stability of uniform rotations in a resisting medium of two heavy Lagrange gyroscopes connected by an elastic spherical hinge are obtained in the form of a system of three inequalities. The bottom gyroscope has a fixed point. The rotation of the gyroscopes is maintained by constant moments in the inertial coordinate system. The influence of the elasticity of the hinge on the stability conditions is estimated. It is shown that for a sufficiently high rigidity of the hinge, the asymptotic stability conditions are determined by only one inequality, which coincides with the inequality obtained for the case of a cylindrical hinge. When the angular velocities of the gyroscopes' own rotations coincide, this inequality coincides with the well--known condition for one gyroscope. Cases of degeneration of an elastic spherical hinge into a spherical inelastic, cylindrical and universal elastic hinge (Hooke's hinge) are considered. For the Hooke hinge, it is shown that there is no asymptotic stability at a sufficiently high angular velocity of gyroscopes rotation.
Strong solution of a hydrodinamics problem with memory
Authors: Krasnoshchok Mykola
Published: June 2021

In the last few years, the concepts of fractional
calculus were frequently applied to other disciplines. Recently, this
subject has been extended in various directions such as signal
processing, applied mathematics, bio-engineering, viscoelasticity,
fluid mechanics, and fluid dynamics. In fluid dynamics, the
fractional derivative models were used widely in the past for the
study of viscoelastic materials such as polymers in the glass
transition and in the glassy state. Recently, it has increasingly
been seen as an efficient tool through which a useful generalization
of physical concepts can be obtained. The fractional derivatives
used most are the Riemann--Liouville fractional derivative and the
Caputo fractional derivative. It is well known that these operators
exhibit difficulties in applications. For example, the
Riemann--Liouville derivative of a constant is not zero. We deal with
so called temporal fractional derivative as a prototype of general
fractional derivative. We prove the global strong solvability of a
linear and quasilinear initial-boundary value problems with a
singular complete monotone kernels. Our main tool is a theory of
evolutionary integral equations. An abstract fractional order
differential equation is studied, which contains as particular case
the Rayleigh–Stokes problem for a generalized second-grade fluid
with a fractional derivative model. This paper concerns with an
initial-boundary value problem for the Navier--Stokes--Voigt
equations describing unsteady flows of an incompressible
viscoelastic fluid. We give the strong formulation of this problem
as a nonlinear evolutionary equation in Sobolev spaces. Using the
Galerkin method with a special basis of eigenfunctions of the Stokes
operator, we construct a global-in-time strong solution in
two-dimensional domain. We also establish an $L_2$ decay estimate
for the velocity field under the assumption that the external forces
field is conservative.
On topological properties of weakly m-convex sets
Authors: Osipchuk Tetiana
Published: June 2021

The topological properties of classes of generally convex sets in multidimensional
real Euclidean space $\mathbb{R}^n$, $n\ge 2$, known as $m$-convex and weakly $m$-convex, $1\le m<n$, are studied in the present work. A set of the space $\mathbb{R}^n$ is called \textbf{\emph{$m$-convex}} if for any point of the complement of the set to the whole space there is an $m$-dimensional plane passing through this point and not intersecting the set. An open set of the space is called \textbf{\emph{weakly $m$-convex}}, if for any point of the boundary of the set there exists an $m$-dimensional plane passing through this point and not intersecting the given set. A closed set of the space is called \textbf{\emph{weakly $m$-convex}} if it is approximated from the outside by a family of open weakly $m$-convex sets. These notions were proposed by Professor Yuri Zelinskii. It is known the topological classification of (weakly) $(n-1)$-convex sets in the space $\mathbb{R}^n$ with smooth boundary. Each such a set is convex, or consists of no more than two unbounded connected components, or is given by the Cartesian product $E^1\times \mathbb{R}^{n-1}$, where $E^1$ is a subset of $\mathbb{R}$. Any open $m$-convex set is obviously weakly $m$-convex. The opposite statement is wrong in general. It is established that there exist open sets in $\mathbb{R}^n$ that are weakly $(n-1)$-convex but not $(n-1)$-convex, and that such sets consist of not less than three connected components. The main results of the work are two theorems. The first of them establishes the fact that for compact weakly $(n-1)$-convex and not $(n-1)$-convex sets in the space $\mathbb{R}^n$, the same lower bound for the number of their connected components is true as in the case of open sets. In particular, the examples of open and closed weakly $(n-1)$-convex and not $(n-1)$-convex sets with three and more connected components are constructed for this purpose. And it is also proved that any compact weakly $m$-convex and not $m$-convex set of the space $\mathbb{R}^n$, $n\ge 2$, $1\le m<n$, can be approximated from the outside by a family of open weakly $m$-convex and not $m$-convex sets with the same number of connected components as the closed set has. The second theorem establishes the existence of weakly $m$-convex and not $m$-convex domains, $1\le m<n-1$, $n\ge 3$, in the spaces $\mathbb{R}^n$. First, examples of weakly $1$-convex and not $1$-convex domains $E^p\subset\mathbb{R}^p$ for any $p\ge3$, are constructed. Then, it is proved that the domain $E^p\times\mathbb{R}^{m-1}\subset\mathbb{R}^n$, $n\ge 3$, $1\le m<n-1$, is weakly $m$-convex and not $m$-convex.
Sumy region wind music festivals from the standpoint of cultural and artistic traditions of the region
Authors: Pakhomov Yuriy
Published: June 2021

The article considers such kind of musical activity as festivals of wind music. As a result of research, the emergence and development of some orchestral festivals held in Sumy region at different levels of performance have been traced. Their role in aesthetic and patriotic education is determined, as well as the need for such measures to promote orchestral wind music, preservation and further development of orchestral traditions, which are important both in military rituals and in public life of the region. It has been found that nowadays wind music festivals are a major factor in the development of this genre of performance. Despite the rather wide coverage of the festivals, the events in the genre of orchestral wind music taking place at different levels of performance in Sumy region, did not receive due attention. Coverage of this issue is necessary for proper understanding and analysis of the state of performance on wind instruments in the region. The material of the article will be useful for scholars who study the festival movement and develop issues of history and development of wind music in our country.
Personal Selling And Service Relationship With Customer Loyalty In Ud. Successindo Bengkulu
Authors: Hardiyanti Galuh , Anggriani Ida , Indriasari Nia
Published: June 2021

The research aim to know the relationship of personal selling with customer loyalty at UD. Suksesindo Bengkulu and to know the relationship of service with customer loyalty at UD. Suksesindo Bengkulu. Method Analysis the used is correlation spearman rank and hypothesis test. From result of calculation of correlation of rank spearman between personal  selling with customer loyalty at UD Suksesindo Bengkulu known by value of rho count equal to 0,567 its meaning the relationship of personal selling with customer loyalty at UD Suksesindo Bengkulu is enought, because correlation value reside in  coefficient interval 0,400 - 0,599. From result of calculation of correlation of rank spearman between service with customer loyalty at UD Suksesindo Bengkulu known by value of rho count equal to 0,611 its meaning of the relationship service with customer loyalty at UD Suksesindo Bengkulu is strength, because correlation value reside in coefficient interval 0,600 - 0,799. Based on the hypothesis test, it is known that personal selling and service have a significant relationship with customer loyalty at UD. Suksesindo Bengkulu.
Air Conditioning System Performance of a City Hotel Appraised for Energy Use Efficiency
Authors: I Made Rasta  , I Nyoman Suamir
Published: June 2021

This paper presents results of a study on split air conditioning (AC) performance of a city hotel in Bali, Indonesia. The study applied a practical global approach to appraising the performance of existing AC systems and their installation in a city hotel. The results obtained indicate that improper AC system selection and installation potentially reduces their energy performance which include COP (coefficient of performance), EER (energy efficiency ratio), and SEI (system efficiency index). The finding also shows that improper system selection and installation has damaged 54 unit compressors of 90 AC systems installed in a particular building within three years’ period. Overall number of compressors that have been damaged in three years can reach 76 units accounted for about 23.1% of the total AC systems installed in the hotel. It is also found a reduction on AC system cooling capacity.
A Study on Diffuser Augmentation of a Tidal Turbine
Authors: Evi Elisa Ambarita  , Harinaldi  , Nasruddin  , Ridho Irwansyah
Published: June 2021

As tidal energy is progressively earning attention worldwide, there is a lot of existing research about the tidal current potency and the tidal turbine design. Especially on turbine design, existing studies deduced that a diffuser augmentation is a superior choice to increase the turbine performance. However, the research in finding the best diffuser angle whose efficiency is maximum, yet minim cavity risk is still limited. Therefore, this study proposes an innovative, optimized design method on diffuser augmentation of a tidal turbine by comparing four diffuser angles in three inflow velocity circumstances. In particular, three airfoil blades design with a rotor diameter of 0.3 m was developed. The combination of computational fluid dynamic and multi-objective optimization using a general algorithm coupled with the artificial neural network was applied by considering the turbine’s power coefficient and cavitation inception as a trade-off objective. The numerical results display that the different inflow velocity affects the turbine performance insignificantly. The optimization analysis and comparison among four diffuser angles in three variations of inflow velocity show that the tidal turbine's optimal design with diffuser augmentation could be applied to all tidal current speed.
Accurate Estimation of Power Consumption for Binary Comparator System using Back Tracking
Authors: Gupta Mangal Deep , Chauhan ‪Rajeev Kumar
Published: June 2021

This paper presents a design of a binary comparator circuit using minimum fan-in logic gates (NAND-NOR) for achieving low power-delay-product (PDP). A 2-bit binary comparator circuit is re-designed to minimize fan-in of logic gates. Utilizing the concept of 2–bit comparator, a general gate-level architecture of a comparator system is proposed for higher input operands. A back-tracking model has been proposed in this work to estimate the worst-case performance in terms of delay and power or PDP for binary comparator circuits. It combines the advantages of the simulation-based method for power estimation and dynamic timing analysis (DTA) techniques for timing analysis. This work has also been extended for 20, 16, 14, 10, and 7-nm FINFET technology. The comparator circuits are simulated on Pyxis schematic tool by Mentor Graphics.
INVESTIGATION OF RISK FACTORS PERCEPTION LEVELS IN PUBLIC AND PRIVATE SECTOR INSTITUTIONS FOR WORKERS IN THE OFFICE ENVIRONMENT
Authors: YAVUZ Şenol , GÜR Berna , ALTINTAŞ Özlem
Published: June 2021

Workplaces are divided into three as very dangerous, dangerous and less dangerous according to the principle of the work done. When occupational accidents and diseases are mentioned, construction sites and mines are considered. However, although the probability of occupational accidents and diseases is low, most working areas throughout the country are offices. In the offices, there are obligations that the employer must fulfill according to the law numbered 6331. Employees in offices that accommodate employees from all levels of the public and private sector are likely to be exposed to risk factors. Office workers are most exposed to physical, psychosocial and ergonomic risk factors. The employer is likely to prevent work accidents and occupational diseases by providing a healthy and safe working environment for its employees. In this study, a questionnaire consisting of 28 questions was applied to examine the perception levels of physical, psychosocial and ergonomic risk factors for 246 office workers in public and private sector institutions in Samsun. The answers to the questionnaire questions were analyzed with the program "IBM SPSS Statistics 22.0" and the value of "Cronbach Alpha (α)" was found to be 0.667. The fact that α value is in the range of 0.6 <α <0.8 indicates that the study is reliable. As a result of the study, the majority of the participants are women, the 26-33 age group, undergraduate graduates and work in public institutions. We found that the level of perception of psychosocial risk factors depends on monthly income, the level of perception of ergonomic risk factors changes depending on the sector and weekly working period, and the level of perception of physical risk factors does not change depending on demographic data.
Multisystem Inflammatory Syndrome due to COVID-19 in a Newborn Patient: A Case Report from Lebanon
Authors: Houmani Haidar , Hazimeh Narjes , Skafi Oussama , Medlej Fawziya , Ahmad Fatima , Mahfouz Rayan , Jazzar Alaa , Cheet Mohamad
Published: June 2021

Background: Multisystem inflammatory syndrome in children (MIS-C) is a hyperinflammatory condition associated with COVID-19 in children, with features that are similar to Kawasaki disease and toxic shock syndrome. Several reports are emerging from all over the world on this condition that is associated with increased fatality rate.
Case Report: In this article, we present one of the first reports of a newborn diagnosed with MIS-C attributed to COVID-19. In addition, we discuss the diagnostic criteria and the possible pathophysiology.
Conclusion: Although COVID-19 does not frequently affect newborns, when it does, it may lead to devastating complications, such as MIS-C. As a result, providers should be on the lookout for any symptoms that can indicate a complicated infection. Further studies are still needed to develop a better understanding of the pathophysiology of this disease and establish appropriate therapeutic guidelines.
Labiodentals /r/ here to stay: Deep learning shows us why
Authors: King Hannah , Ferragne Emmanuel
Published: June 2021

L’articulation labiale secondaire qui accompagne l’approximante post-alvéolaire /r/ en anglais a beaucoup moins suscité l’intérêt des linguistes que son articulation primaire, linguale. Or les lèvres peuvent présenter un intérêt tout particulier dans la variété d’anglais parlée en Angleterre car les réalisations labiodentales sans geste lingual ([ʋ]) sont en voie d’expansion. La labiodentalisation résulte probablement de la préservation d’un geste labial aux dépens du geste lingual, ce qui impliquerait que /r/ soit toujours labiodental, y compris dans les productions linguales. Nous vérifions cette hypothèse en comparant la configuration des lèvres du /r/ et du /w/ chez des locuteurs d’anglais d’Angleterre qui ont conservé la composante linguale dans leur production. Si le /r/ post-alvéolaire est labiodental, le geste labial du /w/, qui est unanimement considéré comme arrondi, devrait être très différent. Nous avons utilisé des techniques de l’apprentissage profond afin de classer automatiquement et de mesurer la configuration labiale de /r/ et /w/ à partir d’images des lèvres de 23 locuteurs. Nos résultats suggèrent qu’il existe bel et bien une différence nette de configuration labiale entre /r/ et /w/, qu’un réseau de neurones artificiels à convolution est capable de détecter avec une très grande précision. Des mesures effectuées automatiquement au niveau des lèvres au moyen d’un réseau de neurones artificiels montrent que /r/ a effectivement une configuration des lèvres de type labiodental, ce qui nous permet de décrire précisément la réalisation phonétique de cette labiodentalisation. Nous finirons avec une discussion des implications méthodologiques de l’utilisation de l’apprentissage profond dans les analyses phonétiques.
The suffix -ee: history, productivity, frequency and violation of stress rules
Authors: Trevian Ives
Published: June 2021

Selon Bauer (1983), Barker (1998), Plag (2003) et Mühleisen (2010), -ee est aujourd’hui un suffixe très productif qui ne se réduit plus à son rôle classique, dans la langue juridique, de suffixe de passivation mis en contraste avec le suffixe de nom d’agent -or (ex : bailor / bailee). De nombreux nouveaux mots sont censés avoir fait leur apparition au 20e siècle, au point que 163 entrées en -ee sont désormais consignées dans les dictionnaires en ligne du moteur de recherche OneLook (ex : American Heritage Dictionary, Cambridge Advanced Learner's Dictionary, Collins English Dictionary, Merriam Webster's Dictionary, Oxford Dictionaries, etc.). Certains noms formés avec ce suffixe ne sont désormais plus noms de patient mais noms d'agent (ex : escapee, returnee), parfois rivaux d’autres suffixes de nom d’agent (ex : signee = signer). De plus, outre les formations déverbales traditionnelles (ex : abductee), les formations dénominales et même déadjectivales (ex : asylee, presentee) sont désormais licites. Le but de cet article est (1) d’établir comment ce processus historique a vu le jour, autrement dit quand s’est produit le changement d’usage, de la langue juridique à d’autres domaines ; (2) d’examiner ce suffixe selon sa productivité morphologique, notamment de distinguer les noms entrés dans les dictionnaires des mots de circonstance, principalement usités comme contrastifs (ex : cutter / cuttee, jester / jestee) ; (3) de vérifier la fréquence d’usage des suffixés en -ee; pour ce faire nous avons confronté notre corpus au moteur de recherche de fréquence d’usage Google Books Ngram Viewer ainsi qu’aux Recorded Usage Charts du Collins Dictionary, le premier notant la fréquence de mots depuis le début du XVIe siècle, le dernier contenant des exemples de phrases datées) ; (4) de déterminer combien de suffixés en -ee violent la règle qui proscrit deux accents consécutifs au sein d’un même mot, cette violation étant, par principe, seulement licite dans les mots composés (ex : ˈbootˌlegger, ˈteenˌager) et les préfixés transparents (ˌreˈmake, ˌunˈthaw, verbes); une tentative de rendre compte de ces violations est proposée dans cet article, qui nous a inévitablement amené à nous interroger sur les effets de ce suffixe sur les règles de métricalité.
Voice assimilation of morphemic -s in the L2 English of L1 French, L1 Italian and L1 Spanish learners
Authors: Contreras Roa Leonardo , Mairano Paolo , Capliez Marc , Bouzon Caroline
Published: June 2021

Cette étude examine la règle d'assimilation progressive de voisement du -s morphémique final en anglais L2. Nous avons analysé les données du corpus IPCE-IPAC de productions orales d'apprenants en mesurant la périodicité de toutes les réalisations du -s morphémique et nous avons comparé trois groupes de locuteurs : 15 francophones natifs, 15 italophones natifs et 10 hispanophones natifs. En nous appuyant sur les distributions et sur le statut phonologique de [s] et [z] dans les L1 des apprenants, ainsi que sur le SLM (Speech Learning Model) et la MDH (Markedness Differential Hypothesis), nous avons émis l'hypothèse que les locuteurs francophones et italophones natifs seraient capables de reproduire la règle d'assimilation de voisement de l'anglais plus facilement que les apprenants hispanophones natifs. Nos prédictions ne sont que partiellement confirmées par les résultats obtenus : les apprenants francophones natifs (dont la L1 présente /s/ et /z/ en qualité de phonèmes en position finale) réussissent effectivement mieux à reproduire les schémas de périodicité. Cependant, les hispanophones natifs reproduisent la règle de voisement de manière plus fidèle que les italophones natifs. Nous comparons ces résultats avec notre étude précédente sur /s/ et /z/ non-morphémiques par les mêmes locuteurs et nous les discutons en relation avec la marque de ces deux sons. Nous proposons que l’opposition de voix entre /s/ ~ /z/ pourrait constituer une exception à la hiérarchie de la marque pour les contrastes de voix des consonnes obstruantes (début de mot < milieu de mot < fin de mot), où la position finale de mot ne se révèle pas plus marquée que les autres. De plus, les résultats de nos deux études révèlent des différences de voisement concernant les sibilantes morphémiques et non-morphémiques dans les productions d’anglais L2 (comme pour l’anglais L1). Cela pourrait avoir des répercussions sur les modèles d’acquisition de la phonologie des langues secondes, car ces modèles ne prennent actuellement pas en compte une interaction entre les sons d’une L2 et leur statut morphologique.
Grammaire interactionnelle, paradigme et gradient de la subjectivité
Authors: Hancil Sylvie
Published: June 2021

Cet article offre une analyse diachronique de la particule finale but dans un corpus de l’anglais du nord, un dialecte où les particules finales représentent un trait caractéristique de la grammaire. Récemment, ce but final a été étudié essentiellement d’un point de vue synchronique en anglais américain et en anglais australien. Cette étude se propose de compléter cette approche en s’intéressant à l’anglais du nord dans le corpus DECTE, qui couvre une période de 50 ans (1960-2010). Les différentes valeurs sémantico-pragmatiques font l’objet d’une analyse historique. On montre que la particule finale but est soumise à un processus de paradigmatisation en entrant dans le paradigme des particules finales par un enrichissement de la persistance lexicale et de la persistance structurelle. De surcroît, les valeurs subjectives sont évaluées selon le gradient de la subjectivité de Traugott & Dasher (2002).
Stratégies argumentatives dans les discours politiques américains sur la législation des substances psychoactives : quel emploi du pathos à l’ère de la post-vérité ?
Authors: Bourse Sarah
Published: June 2021

Le terme « post-truth » a été déclaré mot de l’année 2016 par le dictionnaire The Oxford Dictionary, étant donné sa résonance dans le monde anglo-saxon contemporain. Terme faisant initialement référence aux mensonges au cœur de scandales politiques (le scandale Iran-Contra, la Guerre du Golfe, https://en.oxforddictionaries.com/word-of-the-year/word-of-the-year-2016), il renvoie désormais à une situation dans laquelle les faits objectifs ont beaucoup moins d’importance et d’impact que l’utilisation des émotions et des croyances personnelles pour influencer l’opinion publique (https://en.oxforddictionaries.com/word-of-the-year/word-of-the-year-2016).Dans le contexte de cette ère de la post-vérité, où les émotions occupent une place plus importante que les faits, la question du pathos dans le discours politique se pose plus que jamais. Dans quelle mesure observe-t-on le recours aux émotions dans les discours politiques récents ?La présente étude porte sur un corpus de discours politiques au sujet de la réforme des substances psychoactives. « The War on drugs », abordée tantôt sous son aspect médical, tantôt sous son aspect criminel, représente une affaire de santé publique et fait l’objet de nombreux débats qu’il convient d’examiner.
AI OPTIMIZATION OF THE EXOTHERMIC REACTION OF ETHYLENE OXIDE WITH WATER
Authors: Al-Utaibi Khaled A. , Sohail Ayesha , Zafar Andleeb , Talha Rana , Sait Sadiq M.
Published: June 2021

A computational framework, for the numerical approximation of the exothermic reaction of ethylene oxide (EO) with water, to form ethylene glycol is presented in this paper. Ethylene Glycol also known as Mono-ethylene Glycol (MEG), is a diol with a boiling of 198[Formula: see text]C and conventionally produced through hydrolysis of ethylene oxide which is obtained through the oxidation of ethylene. It is used as an excellent automobile coolant as the 1:1 ratio mixture of MEG with Water boils at 129[Formula: see text]C and freezes at [Formula: see text]C. Other than its use as an antifreeze, it is also used as a reagent during the production of polyester fibers, pharmaceutics, cosmetics, hydraulic fluids, printing inks, explosives, polyesters and paint solvents. The mathematical model presented here, consists of an energy balance and a material balance system, described in an axisymmetric coordinate system. The optimized resulting values using the artificial intelligence approach are summarized in this paper. We derive an analytical solution. The analytical solution for the mathematical model equations is in general not possible for this model but it may be possible to derive an analytical solution to this mathematical model if we consider the equation for the conservation of material (chemical species) as a formulation for plug flow and isothermal conditions. Noteworthy findings are reported in this paper for future research.
Vasoplegic Syndrome in Patients Undergoing Cardiac Surgery: A Literature Review
Authors: Nash Colleen M.
Published: June 2021

Vasoplegic syndrome is a rising problem affecting morbidity and mortality in patients undergoing cardiac surgery. Vasoplegia is a vasodilatory, shocklike syndrome characterized by decreased systemic vascular resistance, normal to high cardiac index, and hypotension refractory to fluid resuscitation and vasopressors. This review describes the presentation, physiology, risk factors, treatments, and implications of vasoplegia after cardiac surgery. No standardized methods for diagnosing and treating vasoplegia are available. Vasoplegia is caused by surgical trauma, systemic inflammation, and vascular dysregulation. Patients with comorbidities and those undergoing complex surgical procedures are at increased risk for vasoplegia. The use of β-blockers is protective. Vasoplegia is potentially reversible. Vasopressin is likely the most effective first-line vasopressor, and the use of methylene blue and/or hydroxocobalamin may restore vascular tone. Alternative therapies such as methylene blue and hydroxocobalamin show promise, but additional research and education are needed.
Impact of a Nurse-Driven Heparin Monitoring Protocol for Ventricular Assist Devices
Authors: Gannon Michelle , Simone Pamela B.
Published: June 2021

Background:

Ventricular assist devices require anticoagulation to reduce thrombosis risk. Nurse-driven unfractionated heparin monitoring protocols have been validated for various indications, although data in patients with ventricular assist devices are lacking.

Objective:

To evaluate a nurse-driven protocol for managing unfractionated heparin therapy in stable patients with ventricular assist devices.

Methods:

This was a retrospective analysis of adult patients with ventricular assist devices requiring unfractionated heparin therapy, divided into 2 groups: before and after protocol implementation. The primary outcome was time to first therapeutic activated partial thromboplastin time.

Results:

Each group included 29 patients. There was no difference between the preintervention and postintervention groups in time to therapeutic activated partial thromboplastin time (25 vs 23 hours, P = .95) or proportion of patients with therapeutic activated partial thromboplastin time within the first 24 hours (45% vs 34%, P = .42). Suspected pump thrombosis and bleeding events were similar in the 2 groups.

Conclusion:

A nurse-driven heparin monitoring protocol was similar in time to therapeutic activated partial thromboplastin time compared with provider-driven monitoring and adjustments in patients with ventricular assist devices.
Synthesis and Characterization of a Ring-Opening Oxaspiro Comonomer by a Novel Catalytic Method for Denture Base Resins
Authors: Ajay Ranganathan , Rakshagan Vikraman , Ganeshkumar Rajamani , Ambedkar Elumalai , RahmathShameem Shafiullah , Praveena Kanagesan
Published: June 2021

Background:

3,9-Dimethylene-1,5,7,11-tetraoxaspiro[5,5]undecane (DMTOSU) is a double ring-opening monomer that exhibits expansion upon polymerization and may be used as a denture base resin's comonomer to offset or minimize polymerization shrinkage. It's synthesis by transesterification reaction (TE) catalyzed by distannoxane is not reported in the literature. The synthesis became the prime concern because this monomer is hardly available commercially.

Purpose:

The purpose is to confirm the DMTOSU synthesis and compare the synthesized monomers obtained by two different catalytic processes through Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopies.

Materials and Methods:

Scheme I synthesis was by TE catalyzed by dichlorotetrabutyl distannoxane (DCBS) yielding M1 monomer. Scheme II synthesis was catalyzed by dibutyltin oxide-carbon disulfide (DBTO-CS2) yielding M2 monomer.

Results:

The appearance of a characteristic peak at 1212 cm−1 in FTIR spectrum, a doublet at δ 4.95 in 1H-NMR spectrum and a peak at δ 117.12 in 13C-NMR spectrum confirmed the synthesis of DMTOSU-M1catalyzed by DCBS, which is not significantly different from DMTOSU-M2 catalyzed by DBTO-CS2.

Conclusion:

The catalytic action of DCBS is a successful alternative to the DBTO-CS2 catalysis in DMTOSU synthesis.
The Effects of Double Antibiotic Paste and Amoxicillin-clavulanate Paste Used in Endodontic Regeneration on Microhardness of Radicular Dentine: An In vitro Study
Authors: Madhukumar Meenu , Geetha Praveena , Nair K. Radhakrishnan , Unnikrishnan Manu
Published: June 2021

Objective:

Double antibiotic paste is a root canal medicament used in regenerative endodontics and its long-term exposure to dental hard tissues was shown to reduce its mechanical properties. The amoxicillin-clavulanate paste is a medicament effective against endodontic pathogens and is effective in endodontic regeneration. Its effect on radicular dentine is yet to be investigated. The purpose of this study is to investigate and compare the effects of double antibiotic paste and amoxicillin-clavulanate paste on the microhardness of radicular dentine.

Materials and Methods:

The root canal of 45 premolars was mechanically prepared and divided into three groups for the placement of intracanal medicament: Group 1 (n = 15) double antibiotic paste, Group 2 (n = 15) amoxicillin-clavulanate paste, and Group 3 control group (n = 15). All the specimens were subject to microhardness testing at 500 and 1000 microns depth for 1 week, 1 month, and 3 months and analyzed.

Results:

There is no significant reduction in microhardness of radicular dentin at 1 week on all the three groups. At 1 month and 3 month period, the amoxicillin-clavulanate paste is found to have no significant effect on dentin microhardness when compared to double antibiotic paste.

Conclusion:

The use of amoxicillin-clavulanate paste as an intracanal medicament does not cause significant weakening of dentin even after its long-term use.
A Comparative Evaluation of Abrasion Resistance of Three Commercially Available Type IV Dental Stone, Dried using Three Different Drying Techniques - An In vitro Study
Authors: Killedar Sayed M. , Shetty Rajesh , J Rahul , James Jittin , Karaththodiyil Ranjith , Edwin Annie
Published: June 2021

Background:

The microwave technique of drying dental stone to achieve improved hardness and strength has been suggested in recent years. However, its effect on the wear properties of dental stone has not been thoroughly examined.

Aim:

The present study was conducted in vitro to determine the abrasion resistance of three commercially available Type IV dental stones using three different drying techniques.

Materials and Methods:

A total of 180 samples were prepared from 3 Type IV dental stones; namely Eliterock, Zhermack (Italy), Kalrock, Kalabhai industries (India), and Gyprock (Rajkot, India). Samples were subjected to drying in open air for 2 h, hot air oven at a temp of 230°C for 1 h and microwave oven for 5 min at 900Watts. Abrasion resistance was determined using a customized metallic abrasion resistance tester.

Results:

Microwave oven drying produced samples with increased abrasion resistance values when compared to samples dried in hot air oven and air-dried specimens. Eliterock showed significantly higher mean abrasion resistance values followed by Kalrock and Gyprock.

Conclusion:

Drying type IV dental stone in a microwave oven at 900W for 5 min increased the abrasion resistance within short time.
Analysis of Clinical, Radiographic, and Treatment Profile of 10 Cases of Neurogenic Tumors and Tumor-Like Lesions of the Oral and Maxillofacial Region: An Observational Study
Authors: Mohindra Mohit , Verma Sumit , Kang Manraj Singh , Goel Bhavneesh , Kumar Anjali Pawan , Manchanda Gunjan Virendra
Published: June 2021

Background:

Soft tissues of the head and neck areas are a very frequent site of occurrence of certain benign tumors of the peripheral nerve sheath, especially the neurofibromas. Hence, the present study was conducted for assessing clinical, radiographic, and treatment profile of 10 cases of neurogenic tumors and tumor-like lesions of the oral and maxillofacial region.

Materials and Methods:

Data records of a total of 10 patients who were diagnosed with tumors of neurogenic origin were enrolled in the present study. Data files were analyzed over a time period of 2 years, and complete clinical and radiographic details were evaluated. All the patients in which incomplete information was present in the record files were excluded from the present study. The assessment of the histopathologic reports was done, and final diagnosis was recorded separately in the master chart.

Results:

Neurofibroma was the diagnosis in two cases. In another set of two cases, final diagnosis of traumatic neuroma was achieved. A single case Schwannoma of mandible depicting multilocular radiolucency was present. Granular cell tumor was present in three cases. It was present clinically in the form of swelling, ulcerative nodule, and nodular growth in the three respective cases. Surgical excision was carried out in all the cases, and follow-up records did not depict any case of recurrence of complication posttreatment.

Conclusion:

Neurogenic tumors of oral and maxillafacial region are a rare phenomenon and mainly present in the form of benign neoplasm. However, careful recognition and diagnosis of these lesions are necessary to rule any possible malignant changes.
Comparative Evaluation of Salivary Visfatin Levels in Healthy and Periodontally Diseased Patients before and after Scaling and Root Planing
Authors: Saseendran Greeshma , Abraham Seba , Nair Aparna M. , Reejamol M. K.
Published: June 2021

Aim:

The aim of this study was to compare the levels of salivary visfatin in healthy controls, patients with gingivitis and patients with chronic periodontitis and also to assess the outcome of scaling and root planing (SRP) on the levels of salivary visfatin in patients with gingivitis and chronic periodontitis.

Materials and Methods:

A total of 48 patients, both males and females, in the age group of 25–50 years were enrolled into three groups, based on their clinical parameters: Group I (Healthy controls - 16), Group II (Patients with gingivitis - 16), and Group III (Patients with chronic periodontitis - 16). Groups II and III were examined 2 months after SRP. The clinical parameters that were recorded include plaque index, modified gingival index, gingival bleeding index, pocket depth, and clinical attachment level. The samples of saliva were collected from each patient and the levels of visfatin were evaluated using enzyme-linked immunosorbent assay kit.

Results:

The mean concentration of salivary visfatin at baseline was found to be highest in Group III and lowest in Group I. A statistically significant reduction (P < 0.01) in the mean concentration of salivary visfatin and the clinical parameters were observed after 2 months of SRP.

Conclusion:

The levels of salivary visfatin can thus be considered as an inflammatory biomarker for periodontal diseases. However, future longitudinal prospective studies are needed to support these findings.
Knowledge and Apprehension of Dental Health Professionals Pertaining to COVID in Southern India: A Questionnaire Study
Authors: Izna  , Sasank Kuntamukkula Venkata Krishna , Khanna Shilpa Sunil , Salokhe Onkar , Chandra Tiwari Rahul Vinay , Tiwari Heena
Published: June 2021

Aim:

This study was intended to evaluate the knowledge and apprehension of dental health professionals pertaining to COVID-19.

Materials and Methods:

In this cross-sectional survey, a self-administered questionnaire survey was used to validate the dental health professional's knowledge and apprehension pertaining to COVID-19. In this regard, a preliminary study with a convenience sample of 124 dentists working in various clinics in southern India was conducted so as to evaluate the knowledge and apprehension of dentists related to COVID-19 in India. This study, while limited in sample size, benefits the general practitioners as target readers to assess the awareness pertaining to COVID-19.

Results:

The results of this study reveal that there exists a good knowledge among dental health professionals pertaining to the COVID-19 virus and its oral manifestations in addition to the precautions to be taken for the prevention of COVID-19 in a clinical setup. However, there exists an apprehension as well as lack of awareness pertaining to the laboratory test to be carried out in a patient suspected with COVID-19 infections as well as the role of a mouthwash and the management of contaminated air in the dental clinic.

Conclusion:

The results elicited that there is a dearth of knowledge and relatively a fair apprehension among dental health professionals pertaining to COVID-19.
The Knowledge and Awareness of Medical Emergencies and Management among Dental Students
Authors: Mohideen Khadijah , Thayumanavan Balakrishnan , Krithika C. , Nazia Rafique , Murali Balasubramaniam , Pravda C. , Arshadha Maimoon
Published: June 2021

Background:

Every dentist should anticipate being confronted with a medical emergency (ME), and one should always be ready to treat the most catastrophic ones.

Aim:

This study aimed to assess the knowledge of dental clinical students of Tamil Nadu in the ME understanding and management to create awareness toward patient care.

Methodology:

A total of 768 dental students, including final-year students and residents from different colleges, took part in the questionnaire-based cross-sectional study. The selection of study participants was by the convenience sampling method. The questionnaire contained thirty closed multiple-choice questions to assess their knowledge of MEs. Microsoft Office Excel software was used for compiling the answers. The descriptive analysis of the data is exhibited in graphs.

Results:

The majority of participants were mindful of the vital signs; only 55% of the participants know the importance of checking their respiration rate. The knowledge of identifying MEs such as anaphylaxis was 91%, and only 27%–37% of the respondents knew to identify angina, transient ischemia, and lidocaine toxicity. Approximately 15%–40% of the respondents only knew the management of angina, cardiac arrest, hyperventilation, respiratory obstruction, and seizure. Only 10% agreed that the best office emergency kit should be prepared by themselves. Roughly 78% of the respondents were conscious of the patient's referral whenever necessary and aware of state dental acts.

Conclusion:

This study reflects a significant need for training in executing ME among dental students who are to transmute into future dental professionals.
Copolymerization of Ring-Opening Oxaspiro Comonomer with Denture Base Acrylic Resin by Free-Radical/Cationic Hybrid Polymerization
Authors: Ajay Ranganathan , Rakshagan Vikraman , Sreevarun Murugesan , Bhuvaneshkumar Dharanividhya , SajidaBegum Sekaran , Vignesh Veerakumar
Published: June 2021

Background:

Polymerization shrinkage is an innate characteristic of thermo-polymerized denture base acrylic resin. Volumetric shrinkage is still a problem, although myriad material modifications. Ring-opening oxaspiro monomers have promising volumetric expansions of about 7%. These monomers have diminished the shrinkage in dental filling resins through copolymerization (CP). However, their CP with denture base resins is not reported yet.

Purpose:

The aim is to confirm the CP of an oxaspiro monomer with methyl methacrylate (MMA) by radical-cationic hybrid polymerization and to assess the degree of conversion (DC) of the formed copolymer.

Materials and Methods:

The oxaspiro monomer was synthesized by a transesterification reaction. The study groups were based on the composition and thermo-polymerization method. The control and E1 groups were thermo-polymerized in water-bath, whereas the E2 group in a laboratory autoclave. Both E1 and E2 groups contained the oxaspiro monomer and cationic initiator. E2 group had an additional radical initiator. The CP and DC were confirmed and assessed by infrared spectroscopy.

Results:

Accentuation of carbonyl peak, the disappearance of the spiro-carbon peak, and the appearance of ether linkages in experimental groups confirmed the ring-opening. E2 group had the highest DC.

Conclusion:

The oxaspiro monomer successfully copolymerized with MMA and had good DC.
Evaluation of Tensile Bonding Strength of Permanent Soft Relining Material to Denture Base Acrylic Resin after Erbium:Yttrium– Aluminum–Garnet Laser Treatment – An in vitro Study
Authors: Kumari Vinutha Varadharaju , Nadiger Ramesh K. , Aldhuwayhi Sami , Shaikh Saquib Ahmed , Joseph Angel Mary , Mustafa Mohammed Ziauddeen
Published: June 2021

Purpose:

The purpose of the study was to assess the effectiveness of erbium:yttrium–aluminum–garnet (Er:YAG) laser surface pretreatment at various pulse durations of exposure on increasing the tensile bonding strength of permanent soft relining material and acrylic resin.

Materials and Methods:

Polymethyl methacrylate resin samples were fabricated and grouped as comparison group (no laser surface pretreatment) and three test groups (received Er:YAG laser surface pretreatment at various pulse durations of 10 s, 20 s, and 30 s) for bonding with the permanent soft relining material, Molloplast B. Following the surface pretreatment, the samples were tested for tensile stress using a universal testing machine. Loads at the point of failure were noted and the tensile bond strength values were obtained. Parametric tests of one-way-ANOVA and Tukey's post hoc tests were done.

Results:

The highest tensile bonding strength was recorded in Group C, and the control group recorded the lowest bonding strength.

Conclusion:

Er:YAG laser surface pretreatment at 10 Hz, 3 W, and 300 mJ for 30 s improved the bonding strength of the permanent soft relining material to heat-processed acrylic resin material.
A Comparative Assessment of Three Different Irrigating Systems in Root Canal Treatment: An In vitro Study
Authors: Mandhotra Prabhat , Rai Kulwant , Grewal Gurkirat Singh , Singh Kanwarpreet , Galhotra Vineet , Gagan Neel
Published: June 2021

Background:

Exact diagnosis, efficient cleaning, shaping as well as disinfection of the root canals lead to successful root canal treatment. The present study compared three different irrigating systems in root canal treatment.

Methodology:

Sixty recently extracted permanent mandibular molars were classified into four groups: Group I, II, III, and IV with 15 teeth each. Group I comprised Endo-Irrigator Plus system. Group II comprised EndoActivator, Group III utilized passive ultrasonic irrigation (PUI), and Group IV was control, in which no activation of the irrigant was done. Stereomicroscope (X20) magnification was used for checking isthmus cleanliness. The scoring criteria were divided into score 1–5 depending on the amount of debris in root canal walls.

Results:

The mean ± standard deviation debris removal score in Group I was 2.6 ± 0.80, in Group II was 3.8 ± 0.72, in Group III was 3.9 ± 1.06, and in Group IV was 4.2 ± 0.82. The difference was significant (P < 0.05).

Conclusion:

Authors found that Endo-Irrigator Plus exhibited better cleaning efficacy followed by EndoActivator and PUI.
Assessment of Knowledge about Ergonomics and Determining Musculoskeletal Disorders in Dentists: An Original Research
Authors: Kumar Mukesh , Mishra Gaurav , Vaibhav Ramasubramoniam , Priyadarshini Sunayana , Simran  , Turagam Neeraja
Published: June 2021

Background:

Musculoskeletal disorders (MSDs) are commonly occurring disorders nowadays. The present study was conducted with the aim of determining MSDs in dentists and to assess knowledge about ergonomics.

Materials and Methods:

This questionnaire study was conducted among 460 dental professionals of different age groups. Parameters such as posture of dentists, working alone or with an assistant, and number of breaks were recorded. Type of MSDs and the type and effectiveness were recorded.

Results:

BDS students were seventy, interns were 112, general dentists were 186, and specialists were 92. Year of practice was <5 years in 215, 5–10 years in 70, 10–20 years in 35, and >20 years in 140 students. Fourteen percent of students, 18% interns, 45% general practitioners, and 32% of specialists had a prevalence of MSD. Most common MSDs in students were upper back pain seen in 6%, in interns were upper back pain seen in 8%, in general practitioners were shoulder pain seen in 21%, and in specialists were hand/wrist pain seen in 10%. Forty-five percent of students, 67% interns, 72% general dentists, and 80% of specialists had idea about ergonomics. Seventy-four percent of students, 80% of interns, 83% of general dentists, and 87% of specialists think that ergonomics may improve performance. Sitting position was preferred seen in 53% of students, 58% of interns, 65% general dentists, and 60% of specialists. Forty-five percent of students, 47% of interns, 56% of general dentists, and 52% of specialists perform physical activity during work. The difference was found to be statistically significant (P < 0.05). Seventy-nine percent of students, 83% of interns, 86% of general dentists, and 88% of specialists show prolong sitting or standing.

Conclusion:

Authors found that all prefer to apply ergonomic in clinical practice. There is a lack of knowledge among BDS students and interns about ergonomics.