bluuebunny/crossref_metadata_2025_split huggingface dataset:
Midface Reconstruction: Planning and Outcome
Authors: Biswas Gautam 
Published: January 2021

Abstract
Reconstruction of the complex anatomy and aesthetics of the midface is often a challenge. A careful understanding of this three-dimensional (3D) structure is necessary. Anticipating the extent of excision and its planning following oncological resections is critical.In the past over two decades, with the advances in microsurgical procedures, contributions toward the reconstruction of this area have generated interest. Planning using digital imaging, 3D printed models, osseointegrated implants, and low-profile plates, has favorably impacted the outcome. However, there are still controversies in the management: to use single composite tissues versus multiple tissues; implants versus autografts; vascularized versus nonvascularized bone; prosthesis versus reconstruction.This article explores the present available options in maxillary reconstruction and outlines the approach in the management garnered from past publications and experiences.
Role of Teledentistry in COVID-19 Pandemic: A Nationwide Comparative Analysis among Dental Professionals
Authors: Abbas Beenish , Wajahat Mehreen , Saleem Zakia , Imran Eisha , Sajjad Mehvish , Khurshid Zohaib 
Published: January 2021

AbstractObjectives To assess knowledge, awareness, and practice of health care workers about the role of teledentistry in coronavirus disease 2019 (COVID-19).Materials and Methods A prevalidated structured questionnaire was used to evaluate awareness of general dentists, postgraduate dental students, dental educators, and consultants with postgraduation degrees toward teledentistry. The acceptability, reliability, and language clarity were also pretested. A total of 510 dental professionals contributed to this study.Statistical Analysis A statistical analysis using SPSS (version 20.0) was performed. Responses were noted as yes or no. A p-value of ≤ 0.05 was considered to be significant. Frequencies described data. Chi-square test was performed for intergroup comparison to evaluate if the knowledge and attitude diverge with the increase in the level of seniority in the profession.Results Awareness regarding teledentistry is high among general dentists with bachelor of dental surgery qualification in comparison to final-year students and postgraduate dental students. The majority of participants agreed with improvement in health care (88.20%), access to rural areas (82.90%), and general practicing dentist agreed with statistically significant difference (0.00) on saving time by teledentistry.Conclusion General practicing dentist was observed with high awareness of teledentistry as compared with postgraduate and undergraduate dental students.
Association of Lymphatic Abnormalities with Early Complications after Fontan Operation
Authors: Dittrich Sven , Weise Anja , Cesnjevar Robert , Rompel Oliver , Rüffer André , Schöber Martin , Moosmann Julia , Glöckler Martin 
Published: January 2021

Abstract
Background Increased central venous pressure is inherent in Fontan circulation but not strongly related to Fontan complication. Abnormalities of the lymphatic circulation may play a crucial role in early Fontan complications.
Methods This was a retrospective, single-center study of patients undergoing Fontan operation from 2008 to 2015. The primary outcome was significant early Fontan complication defined as secondary in-hospital treatment due to peripheral edema, ascites, pleural effusions, protein-losing enteropathy, or plastic bronchitis. All patients received T2-weighted magnetic resonance images to assess abdominal and thoracic lymphatic perfusion pattern 6 months after Fontan completion with respect to localization, distribution, and extension of lymphatic perfusion pattern (type 1–4) and with application of an area score (0–12 points).
Results Nine out of 42 patients developed early Fontan complication. Patients with complication had longer chest tube drainage (mean 28 [interquartile range [IQR]: 13–60] vs. 13 [IQR: 2–22] days, p = 0.01) and more often obstructions in the Fontan circuit 6 months after surgery (56 vs. 15%, p = 0.02). Twelve patients showed little or no abnormalities of lymphatic perfusion (lymphatic perfusion pattern type 1). Most frequently magnetic resonance imaging showed lymphatic congestion in the supraclavicular region (24/42 patients). Paramesenteric lymphatic congestion was observed in eight patients. Patients with early Fontan complications presented with higher lymphatic area score (6 [min–max: 2–10] vs. 2 [min–max: 0–8]), p = 0.001) and greater distribution and extension of thoracic lymphatic congestion (type 3–4: n = 5/9 vs. n = 1/33, p = 0.001).
Conclusion Early Fontan complication is related to hemodynamic factors such as circuit obstruction and to the occurrence and extent of lymphatic congestion.
Spontaneous Intracranial Hypotension Complicated by Subdural Effusions Treated by Surgical Relief of Cranial Venous Outflow Obstruction
Authors: Higgins J Nicholas , Axon Patrick R. , Macfarlane Robert 
Published: January 2021

AbstractSpontaneous intracranial hypotension describes the clinical syndrome brought on by a cerebrospinal fluid (CSF) leak. Orthostatic headache is the key symptom, but others include nausea, vomiting, and dizziness, as well as cognitive and mood disturbance. In severe cases, the brain slumps inside the cranium and subdural collections develop to replace lost CSF volume. Initial treatment is by bed rest, but when conservative measures fail, attention is focused on finding and plugging the leak, although this can be very difficult and some patients remain bedbound for months or years. Recently, we have proposed an alternative approach in which obstruction to cranial venous outflow would be regarded as the driving force behind a chronic elevation of CSF pressure, which eventually causes dural rupture. Instead of focusing on the site of rupture, therefore, investigation and treatment can be directed at locating and relieving the obstructing venous lesion, allowing intracranial pressure to fall, and the dural defect to heal. The case we describe illustrates this idea. Moreover, since there was a graded clinical response to successive interventions relieving venous obstruction, and eventual complete resolution, it also provides an opportunity to consider particular symptoms in relation to cerebral venous insufficiency in its own right.
EUS-guided Gastroenterostomy: Assessing the Competence of the Endoscopist
Authors: Jena Anuraag , Rana Surinder Singh 
Published: January 2021

AbstractAssessing competence is of utmost importance for complex EUS procedures like EUS-guided gastroenterostomy (EUS-GE) that are associated with higher risk of procedural complications. It is a matter of intense debate on what is the training needed to carry out these interventions, how to judge for competence, and who can perform these newer interventions. The procedure has several variations including the methods to identify the jejunal loops on EUS like direct puncture, balloon-assisted, and hybrid rendezvous with ultrathin endoscope. Therefore, there is lack of clarity on the role and ways of assessing the learning curve for EUS-GE. In this news and views, we are discussing two studies that assessed the learning curve for EUS-GE.
Clinical Impact of Universal Screening for COVID-19 before Therapeutic Endoscopy
Authors: Jagtap Nitin , Singh Aniruddha Pratap , Inavolu Pradev , Tandan Manu , Lakhtakia Sundeep , Reddy D Nageshwar 
Published: January 2021

Abstract
Introduction The Coronavirus pandemic (COVID-19) has led to drastic change in gastrointestinal (GI) endoscopy practice. Endoscopy is an aerosol-generating procedure. COVID-19 testing prior to endoscopy can reduce transmission by delaying non-emergency endoscopies in positive patients. There is scarcity of literature to support such protocols. We aimed to study the clinical impact of universal testing for COVID-19 before therapeutic endoscopy.
Methods This is retrospective analysis of prospectively maintained data. All patients requiring therapeutic endoscopy were enrolled between June 15 to July 15, 2020. Clinical profile, indication, endoscopic intervention, and outcome of patients tested positive for COVID-19 real-time polymerase chain reaction (RT PCR) or CT chest suggestive of CO-RADS 3 or more were included for analysis.
Results Out of 772 patients scheduled for endoscopic interventions, 26 (3.34%) patients had COVID-19 infection with mean age (range) of 48.19 (3–75) years. Eight (30.8%) were females. Of them, seven (26.9%) patients underwent emergency endoscopy, and another seven (26.9%) patients underwent endoscopy after minimum of 2 weeks waiting period. Two deaths were seen in patients who underwent emergency interventions which were unrelated to endoscopy. One patient, who was planned for endoscopic ultrasound (EUS) for choledocholithiasis, developed acute biliary pancreatitis in the waiting period.
Conclusion We suggest use of universal testing for COVID-19 by RT-PCR before endoscopic intervention. Endoscopy can be postponed for 2 weeks with marginal risk of adverse events during the waiting period in nonemergency indications. However, this approach needs to be tailored as per local needs, resources availability, and indication of endoscopy.
How Risky are Elective Endoscopic Procedures during the COVID-19 Normalization Process?
Authors: Bayram Mehmet , Yildirim Ozgur 
Published: January 2021

Abstract
Objective In this study, we aimed to investigate the incidence of COVID-19 after endoscopic procedures were performed with elective indications during the normalization process of the COVID-19 pandemic. We also aimed to investigate safety of these procedures.
Materials and Methods The study included 351 patients who underwent an endoscopic procedure for elective indications in the endoscopy unit of the gastroenterology department of the İstanbul Kanuni Sultan Süleyman Training and Research Hospital and whose risk assessment for COVID-19 was low before the procedure. All patients were followed-up within 14 days after the procedure in terms of getting a COVID-19 PCR test and its results and also assessing development of any symptoms such as fever, cough, and shortness of breath associated with COVID-19.
Results A total of 351 patients were included in the study. A total of 445 procedures were performed: upper gastrointestinal (GI) system endoscopy in 180 patients, colonoscopy in 74 patients, double procedure (upper GI endoscopy + colonoscopy) in 94 patients, and percutaneous endoscopic gastrostomy (PEG) in three patients. It was found that at least one of the symptoms including cough, shortness of breath, and fever developed in 33 (9.4%) of these 351 patients within 14 days. It was observed that 20(5.6‰)of these 33 patients were tested for COVID-19 and the test results were reported as positive in two(5.6‰)patients.
Conclusion In the normalization process of COVID-19, elective endoscopic procedures can be performed in patients, who are shown to be low risk, by paying attention to the consummate use of the personal protective equipment (PPE).
New Modalities of Treatment for Coronary Calcific Lesions
Authors: Padmanabhan TNC , Azam Mohammed Sadiq 
Published: January 2021

Abstract
Since the publication of the previous article on the same topic in the journal, as a result of the better understanding in intravascular imaging (intravascular ultrasound [IVUS] and optical coherence tomography [OCT]) and introduction of intravascular lithotripsy (IVL) into clinical practice, the outcomes in patients with calcified coronary lesions have become more predictable and safe with lesser complication rates.
Expert’s Opinion–Challenging ECG
Authors: Kale Seema 
Published: January 2021

Abstract
Varying kinds of AV blocks can occur in the setting of myocardial ischaemia or due to degeneration of conduction system. Wenckebach AV block can present with typical Wenckebach periodicity or atypical periodicity. A variant of atypical Wenckebach periodicity may present like Mobitz II AV block. This is called Pseudo Mobitz II AV block. As we are aware that Mobitz II AV block is more dangerous and can suddenly convert into complete heart block, it is essential that we should try to differentiate between Mobitz and Pseudo Mobitz II blocks. Infact atypical Wenckebach cycles are quite common at both AV node and his Purkinje system.
Aortic Aneurysm and Dissection in Pregnancy: Report of a Rare Case in a Marfan with Bicuspid Aortic Valve
Authors: Masiello Paolo , Leone Rocco , Benvenga Rossella Maria , Iesu Severino 
Published: January 2021

Abstract

Background Type A aortic dissection is an emergency with high morbidity and mortality when surgery is not performed. Few cases are described in the literature about aortic dissection during pregnancy. A correlation between pregnancy and aortic dissection is mainly reported in patients with family history and connective tissue disorders, such as Marfan’s syndrome (MS), Loeys–Dietz’s syndrome, and Ehlers–Danlos’s syndromes, and patients with bicuspid aortic valve (BAV); exceptional cases are also described in patients without risk factors.

Case presentation A 22-year-old young woman with MS, ascending aorta dilation, and BAV became pregnant. During labor, she experienced a short-term chest pain with spontaneous resolution. The electrocardiogram (ECG) and cardiac biomarkers were negative for acute coronary artery disease, but no transthoracic echocardiogram (TTE) was performed. A caesarean section was performed without complications. After 1 month, a routine TTE showed a chronic ascending aortic dissection involving the aortic arch and supra-aortic vessels. Due to a normally functioning aortic valve, the David operation was performed (sparing aortic valve) with the replacement of the aortic arch and supra-aortic vessels.

Conclusions Aortic dissection is a rare cardiovascular complication that can occur during pregnancy and is associated with very high-risk mortality. We have reported a rare case of undiagnosed type A aortic dissection involving the aortic arch during unplanned pregnancy in patients with BAV and MS, subsequently treated with the David surgery and replacement of ascending aortic arch and supra-aortic vessels. A closer clinical and instrumental follow-up is necessary in this particular group of patients at risk. Awareness of all physicians involved is mandatory.
Spinning tops and magnetic orbits
Authors: Novikov S. P. 
Published: January 2021

Abstract
A number of directions were initiated by the author and his students in their papers of 1981–1982. However, one of them, concerning the properties of closed orbits on the sphere

and in the groups

and

, has not been sufficiently developed. This paper revives the discussion of these questions, states unsolved problems, and explains what was regarded as fallacies in old papers. In general, magnetic orbits have been poorly discussed in the literature on dynamical systems and theoretical mechanics, but Grinevich has pointed out that in theoretical physics one encounters similar situations in the theory related to particle accelerators such as proton cyclotrons. It is interesting to look at Chap. III of Landau and Lifshitz’s Theoretical physics, vol. 2, Field theory (Translated into English as The classical theory of fields [12]. where mathematical relatives of our situations occur, but the physics is completely different and there are actual strong magnetic fields.
Bibliography: 12 titles.
Investigation on nanosecond surface sliding discharge in a supersonic airflow with oblique shock wave
Authors: Mursenkova I , Ivanov I , Ulanov P , Liao Yu , Sazonov A 
Published: January 2021

Abstract
We report investigations of the nanosecond surface sliding discharge in supersonic airflows with the oblique shock wave at Mach numbers of the flow 1.30-1.60 in shock tube. We show that the surface sliding discharge developed in flows as a single channel located near a zone of interaction of the oblique shock with the boundary layer on the wall of the channel. A pulse voltage of 25 kV powered the discharge; the electric current was of 1 kA. The electron concentration in the localized discharge channel was (0.7-1.4).1015 cm-3 and the electron energy was of 1.8-2.2 eV from the analysis the emission spectra. High-speed flow field shadowgraphy after the surface sliding discharge showed that the localized discharge channel generates a strong shock wave, leading to restructuring the shock-wave structure of the flow within ∼100 μs and subsequent relaxation to a stationary configuration.
Nanosecond discharges in a non-stationary flow around an obstacle
Authors: Znamenskaya I. , Tatarenkova D. , Kuli-zade T. , Ivanov I. 
Published: January 2021

Abstract
The purpose of the work is to study the effect of a pulsed surface discharge (plasma sheet) on the transverse flow upon its initiation in an unsteady gas-dynamic flow in a channel with an obstacle on the wall. Also a comparison with the effect of a pulsed volume discharge under similar conditions was studied. The dynamics of the blast waves propagating from the separation zone behind the obstacle after self-localization of the discharge plasma there is investigated.
Space potential and charged particles density variation in a glow discharge plasma during shock wave propagation
Authors: Basargin I V , Bezverhniy N O , Bobashev S V , Monakhov N A , Sakharov V A 
Published: January 2021

Abstract
The plasma parameters in a glow discharge plasma near the front of shock wave moving perpendicularly to the discharge axis has been investigated using a double electrical probe. It has been discovered that the shock wave propagation is accompanied by an increase in the potential of discharge plasma. A relatively small change in the potential is observed before the shock wave arrival and a significant one behind shock wave front. The varying potential in the glow discharge plasma distorts the current of the double probe. A method of its correction is proposed, which consists in the joint processing of two signals obtained in separate experiments with different surface areas of the negative probe electrode. The method allows us determine the ionic current and the change in the potential of space. The magnitude of ion current corresponding to the charged particles concentration remains unperturbed before the shock wave arrival to the measurement point. A gradual increase in the ionic current is observed behind the shock wave front in contrast with the abrupt change in gas-dynamic parameters on the shock wave front.
Redistribution of energy in a viscous heat-conductive medium during the interaction of a shock wave with a temperature layered plasma region
Authors: Azarova O A , Krasnobaev K V , Kravchenko O V , Lapushkina T A , Erofeev A V 
Published: January 2021

Abstract
Experimental data on the creation of ionization unstable gas discharge plasma with large-scaled and small-scaled ionisation strata are presented. The redistribution of kinetic and internal energy between a stratified energy source and the area behind a shock wave is numerically studied on the base of the system of Navier-Stokes equations. Generation of the Richtmyer-Meshkov instabilities at many points is obtained which bend the shock wave front and, in some cases, completely destroy it (in density fields). The influence of heat conductivity on the obtained flow structures has been studied. For viscous heat conducting medium it was established the possibility to obtain local high energy zones behind the shock wave with values of energies several times higher than those for a non-stratified energy source with the same total energy. The values of energies in these zones were shown to be possibly controlled via the rarefaction parameter/temperature of a gas in the layers of a stratified energy source or by its geometry.
Investigation of Pulsed Electric Discharge in Hypersonic Air Flow and in Magnetic Field
Authors: Fomichev V P , Yadrenkin M A 
Published: January 2021

Abstract
The problem of local braking of a high-speed air flow (M = 6) using an electric discharge plasma in a magnetic field has been considered. The studies were carried out on an experimental MHD test rig based on a shock tube, at the end of the low pressure channel of which a Laval nozzle was placed with gas flowing into the Eiffel chamber. The discharge was initiated across the flow, between narrow electrodes, and across the magnetic field. It was shown that with increasing of the magnetic field the discharge is localized between the electrodes and then moved toward the flow as a result of strong MHD-interaction. At the same time the bow shock in front of MHD-interaction zone is observed. A comparison of the shock wave structures during the flow around the discharge on free electrodes, near the plate and in front of the blunt body has been shown.
Spectroscopic determination of the composition and spatial distribution of active particles in a plasma jet of helium and argon being blown out into atmospheric air
Authors: Akishev Yu S , Karalnik V B , Petryakov A V , Trushkin N I 
Published: January 2021

Abstract
Optical emission spectroscopy was used to determine the composition and spatial distribution of reactive species along a non-thermal plasma jet in a stream of argon and helium, expanding in the ambient air. It was shown that the composition and spatial distribution of reactive species in argon and helium plasma jets differ significantly. The geometric dimensions of the Ar and He plasma jets are also noticeably different. The features of the observed patterns of the composition and spatial distribution of active particles are discussed.
2D simulation of interaction between separation region and gasdynamic perturbation caused by rapid heat release in supersonic airflow
Authors: Saveliev A.S. 
Published: January 2021

Abstract2D modeling of rapid local release of thermal energy (0.1 – 7 J/m) into the supersonic airflow (Mach numberM=2) was carried out in order to change the flow pattern around the wing model. It was shown that the results of numerical simulation of the process of a single instantaneous local heat release on the surface of the model are in good agreement with the experimentally obtained patterns of the flow around the wing model when energy was released using long spark discharge. The simulation of the process of local rapid energy deposition in a pulse-periodic mode was carried out and it was shown that, on the average over time, it is possible to significantly reduce the separation region size. In this case the calculated aerodynamic coefficients of the model change by several percent. It was found that the right choice value of frequency is important, since at an inappropriate value, the effect may be the opposite. It was shown that the stability of the repetition rate of local energy inputs is also important for the shift of the separation point downstream. The mechanisms of the effect of rapid local energy input on the separation region at relatively low and high values of thermal energy are discussed.
Estimation of gas-dynamic characteristics of supersonic plasma jets based on spectroscopy results
Authors: Pashchina A S , Chinnov V F , Efimov A V 
Published: January 2021

Abstract
A method for estimating the gas-dynamic characteristics of supersonic plasma jets based on the minimum number of plasma parameters (electron number density and temperature) that are easily measured by spectral diagnostic methods is considered. The course of the most important parameters characterizing the gas dynamics of the nonequilibrium plasma flow in the shock-wave region of a supersonic plasma jet created by a pulsed capillary discharge is revealed, and their values are estimated. A significant difference between the electron and gas temperatures was found in the vicinity of the central shock wave.