bluuebunny/crossref_metadata_2025 huggingface dataset:
Method for calculating the groundwater inflow into pit when mining the placer deposits by dredger
Authors: Sobko Borys , Haidin Anatolii , Lozhnikov Oleksii , Jarosz Jacek
Published: October 2019

The research aims to increase the performance efficiency of hydromechanization equipment under the conditions of pit operation of the Motronivskyi Mining and Concentrating Plant by determining the dynamics of change in the water level in the mine workings when developing the overburden rocks and mineral. It has been generalized the world experience of determining the groundwater inflows into mine workings, which are mined by means of hydromechanization equipment. The methods have been developed for calculating the underground water inflow into the pit reservoir, when mining the placer ores by hydromechanization equipment. It has been proved that the dredger work in the conditions of the Motronivskyi MCP pit is possible without external source of water supply. The research results in determining the influence of underwater mining of overburden rocks and ore by dredger for decreasing the water level and its subsequent recovery in the reservoir of the Motronivskyi MCP pit, allow to develop a mode of mining operations without an external source of water supply. The dynamics of water level fluctuations in mine working during the working week have been established. The research results have shown that the dredger, taking into account the technical characteristics, can continuously operate for 9.5 days under the conditions of underground water inflow into the Motronivskyi MPP pit. It has also been established that after the dredging of the overburden rocks is stopped, the level of water in the pit for 2.5 days will recover.
Studying the efficiency of a complex individual protective device
Authors: Cheberiachko Serhii , Yavorska Olena , Hridiaiev Volodymyr , Yavorskyi Andrii
Published: October 2019

Objective is to study efficiency of a complex protective device including coefficients of penetration and suction of aerosols for dust half-masks of various designs. The half-masks were tested experimentally on specially designed laboratory stands with the help of volunteer-testees; the tests included specifications according to EN 149, EN 352-1, ISO 6942. The studies have demonstrated that a complex protective device for workers is rather efficient providing average coefficient of suction being 1.5% that is almost by 30% less than the values of standard filtering respirators of similar protection class. Noise attenuation within the range of 4000 – 8000 Hz is from 19 to 26.7 dB; within the range of speech frequency (0.5÷2.0 kHz), acoustic efficiency is up to 8÷16 dB helping preserve the possibility of communication and timely reaction to warning signals. Use of thermal protecting elements makes it possible to reduce temperature of head heating by 80% comparing to the results obtained without the protective device application. The developed balaclava with the built-in dust respirator and hearing protection devices may be used in the context of the corresponding filter class up to 12 MAC in terms of the most hazardous aerosols, when noise level is up to 14 dB within 2000 – 8000 Hz frequency range; moreover, it provides slow temperature rise up to 2 ºС per minute.
Geochemical properties of water under the waste heaps in Chervonohrad mining region
Authors: Popovych Vasyl , Voloshchyshyn Andrii , Rudenko Dmytro , Popovych Nataliia
Published: October 2019

The geochemical properties of water under the waste heaps within the Chervonohrad mining region have been studied. The environmental remediation around the technogenic reservoirs of rock heaps using the bioplateau systems is proposed. In 2017, samples were taken from reservoirs of technogenic origin located at the foot of rock heaps of such coal mines as “Mezhyrichanska”, “Velykomostivska”, “Stepova”, “Zarichna”, “Lisova” and “Chervonohradska”. According to the analysis of the studied parameters, it has been determined that water under the Mezhyrichanska Mine waste heaps is the most polluted. The most dangerous landscape-transforming factor of water under the waste heaps is the transfer of polluting substances into the soil, surface and subterranean waters. Through the use of the Pearson coefficients of correlation, the ratios between pollution patameters have been obtained. The determined correlation coefficients are high, positive (r = 0.78 – 0.99) and evidence of the toxic components spread in water under the waste heaps throughout the entire coal mining region. The obtained geochemical data on water under the waste heaps of mines in the Chervonohrad mining region are important in terms of the environmental impact assessment of mining activity on the human body and the biosphere components – the hydrosphere, the phytogenic field. It is necessary to establish environmental monitoring systems and to develop measures for the environmentally safe decommissioning the waste heaps of coal mines.
Development of natural bitumen (bituminous sands) deposits based on the technology of hydraulic mining by boreholes
Authors: Pedchenko Larysa , Pedchenko Nazar , Manhura Andrii , Pedchenko Mykhailo
Published: October 2019

The modern state and trends in the development of technologies for mining the heavy oil and native bitumen deposits have been analyzed. It has been set that presently known technologies for heavy oil and natural bitumen extraction do not cover the entire depths range of their occurrence. The main possibility of the development of heavy oil and natural bitumen deposits on the basis of technology by hydraulic mining by boreholes has been substantiated. The peculiarities of this technology are analyzed. The ways of its main elements adaptation for mining the natural bitumen from bituminous sands deposits are offered. The principal scheme has been substantiated for a method of mining the natural bitumen on the basis of hydraulic mining by boreholes. The thermodynamic processes occurring in the productive formation during its drilling with the simultaneous circulation of the heat-transfer medium have been analyzed. A mathematical model has been developed of the thermal penetration process into the productive formation for the time interval from the beginning the borehole drilling to the beginning the rock disintegration. Also, it has been solved the task of stationary mode in the borehole at the stage of its drilling.
Formation of the adaptive fuzzy model of the rock geological structure for exploratory drilling
Authors: Tron Vitalii , Tsokurenko Oleksandr , Paraniuk Dmytro , Haponenko Iryna
Published: October 2019

The authors suggest an approach aimed at improving the technology, increasing energy efficiency and quality of controlling borehole drilling in mining various mineralogical-technological types of iron ore through applying a geological structure model based on data of measuring drilling parameters of a drilling rig (drilling rate, torque, energy characteristics) and rock properties on the basis of studying regularities of changing parameters of the specifically formed ultrasonic field. In rapidly changing conditions of borehole drilling, it is offered to apply a two-level adaptive optimization strategy implying a simultaneous investigation into drilling and improvement of control over this process by means of the adaptive fuzzy system.
Application of the emulsion explosives in the tunnels construction
Authors: Khomenko Oleh , Kononenko Maksym , Myronova Inna , Savchenko Mykola
Published: October 2019

The analysis has been made of the technical parameters of the existing passport for drilling and blasting operations (DBO) in terms of compliance with labour safety requirements and scientific-technical standards. The methodology for constructing the DBO passport has been developed, which takes into account the areas of blast-hole groups and the properties of emulsion explosives. The type of the cut has been analysed, modelled and accepted for use, which corresponds to the conditions of tunnelling as much as possible. The zones of deformation and fracturing in the massif around blast-hole charges have been simulated. The level of decrease in the hazard index for atmospheric air has been set when using the emulsion explosive Ukrainit-PP instead of TNT-containing charge – Ammonite No.6 ZhV.
The globalization of the world coal market – contradictions and trends
Authors: Sribna Yevheniia , Trokhymets Olena , Nosatov Ihor , Kriukova Iryna
Published: October 2019

The article describes the global coal market as the ratio of demand and supply depending on the development of energy technologies in the historical section. The continental specificity of coal mining is given. The basic world exporters and importers of coal and their role in the sale of energy fuels are analyzed. The key coal producing countries are China, India, the USA, and Australia. The largest consumers of coal products are China, India, Japan and Korea. There are unconditional leaders in the export coal market: Indonesia and Australia. In addition, a comparison of large coal companies and their share in the world market is presented. The features of coal supplies are analyzed in accordance with international rules (Incoterms), which regulate the rights and obligations of the buyer when conducting international trade, as well as determine the moment of transfer of risks from the seller to the buyer. The following supply bases were characterized: FOB (Free On Board), FAS (Free Alongside Ship), CIF (Cost Insurance and Freight), DAP (Delivered At Place), FCA (Free Carrier) etc. Trends in the logistics component of the global coal industry are revealed. Logistic of coal supply chains in comparison with other energy fuels and their features are disclosed. The problem of profitability of mines and their effectiveness is presented. Assessment of the environmental components of coal use in industry and energy is analyzed. It was noted that on the background of the trend to protect the environment and promote renewable energy, coal is becoming less popular in developed countries. This trend is further exacerbated by state subsidies for green energy.
Factors Affecting Crash Frequencies: A Negative Binomial Regression Based Analysis of Indus Highway, Pakistan
Authors: Ullah Khan Rafi , Yin Jingbo , Shair Mustafa Faluk
Published: October 2019

The increase in vehicular traffic have also increased the highway crash frequency with the passage of time. Improvements in highway safety is of vital importance as it could save vast life and monetary losses. The highway crash frequency analysis of major Pakistani highways is a subject less discovered and many important strategic and trade routes are not studied in this regard. This study is aimed to analyze the crash frequency and the prominent factors that cause these crashes on a 302 km section of Indus highway; one of the most important trade routes of the country. Eight years’ data from 2011 till 2018 was arranged into 19 variables where the crash frequency is set as dependent variable, while the eighteen prominent causation factors as independent variables. The tool used for analysis was negative binomial regression being run in the SPSS software. The results indicate that the driver’s behavior, understanding & risk recognition, negligence and law adherence have a significant effect on the crash frequency. Furthermore, highway crash frequency significantly increases with increase in highway segment lengths, number of lanes and lane widths. Similarly, the highway crash frequency significantly enhances when the light, pavement surface and climate condition gets deteriorated. The results of this study are of vital importance to government, transportation companies and general public in order to recognize the most important accident causing factors and devise the transport policies, rules and behaviors accordingly.
Setting the Configuration Parameters of the Algorithm for the Periodic Vehicle Routing Problem by HPC Power
Authors: Grakova Ekaterina , Martinovič Jan , Slaninová Kateřina , Janurová Kateřina , Cima Vojtěch , Golasowski Martin , Montemanni Roberto , Salani Matteo
Published: October 2019

The quality of an opt imal solut ion of the Vehicle Rout ing Problem is st rongly depended on the sett ing of the configurat ion parameters of the algorithm. The paper is focused on the int roduct ion of hyperparameter search for solving the Vehicle Rout ing Problem using a HyperLoom plat form for defining and execut ing scient ific pipelines in a dist ributed environment . To give a concrete example, we focused on Periodic Vehicle Rout ing Problem for the waste collect ion. HyperLoom plat form was used to define and execute the hyperparameters sweep pipeline. The heurist ic algorithm was tested on a real benchmark of the waste collect ion in Ostrava, Czech Republic. The aim of our ca se was to effect ively combine the minimizat ion of the total t ravelled distance and the opt imizat ion of the fairness of the routes in terms of the standard deviat ion of a tour length. The waste collect ion problem was very extensive and computat ionally demanding, so it was necessary to use high performance comput ing architecture for test ing a large number of different sett ings of configurat ion parameters. The experiments were run on the supercomputer Salomon operated by IT4Innovations Nat ional Supercomput ing Center in the Czech Republic.
Manufacture of silicon carbide reinforced aluminium 6061 metal matrix composites for enhanced sliding wear properties
Authors: Bhat Avinash , Kakandikar Ganesh
Published: October 2019

Composite materials have the capability of being customised to provide specific mechanical and tribological properties. This paper presents the manufacture of a novel composite of Al6061 with 5% SiC (50 μm size) by the stir casting method. Experimental investigations of mechanical and tribological properties of SiC reinforced Al6061 are discussed. Investigations with a Rockwell hardness tester revealed that this composite had enhanced hardness. Wear characteristics were investigated for Al6061 and the novel composite Al6061 + SiC with a Pin on disc tribometer for a load range of 5N-200N and RPM varying from 200 to 1500. The effect of crucial parameters such as load and RPM on the wear of the novel composite were presented with sensitivity analysis. The results obtained are encouraging, showing the novel composite having a lower wear rate.
Leberʼsche hereditäre Optikusneuropathie
Authors: Priglinger Claudia , Klopstock Thomas , Rudolph Günter , Priglinger Siegfried Georg
Published: October 2019

Die Leberʼsche hereditäre Optikusneuropathie (LHON) betrifft typischerweise junge Erwachsene mit einer Prädilektion für das männliche Geschlecht, kann letztlich aber in jedem Alter auftreten. Die Erkrankung beruht auf Punktmutationen der mitochondrialen DNA, die zu einem Defekt des Komplexes I der mitochondrialen Atmungskette führen. Dieser verursacht wiederum eine Dysfunktion und später Degeneration retinaler Ganglienzellen, gefolgt von einer aufsteigenden Optikusatrophie. Klinische Merkmale der LHON sind ein zunächst meist unilateraler subakuter Visusverlust, Farbsinnstörungen im Rot-Grün-Bereich und Gesichtsfeldausfälle in Form eines Zentral- oder Zentrozökalskotoms. Das Partnerauge ereilt innerhalb von 3 – 6 Monaten nach Erkrankungsbeginn meist eine ähnliche Symptomatik. In 25% der Fälle beginnt die Erkrankung jedoch bilateral. Im natürlichen Verlauf bleibt ein Großteil der Patienten bei einem Visus < 0,1, auch wenn ein kleiner Anteil eine spontane Visusverbesserung erfährt. Im Jahr 2015 wurde das Ubiquinonanalogon Idebenon von der Europäischen Arzneimittel-Agentur (EMA) für die Behandlung der LHON zugelassen. Ausschlaggebend für den Therapieerfolg sind ein früher Therapiebeginn und eine ausreichende Therapiedauer. Dabei ist zu beachten, dass es bei einem Anteil der Patienten zu einem verzögerten Therapieansprechen kommen kann. Eine vollständige Visuserholung ist allerdings auch unter Therapie selten. Da es sich meist um junge Erwachsene im erwerbsfähigen Alter handelt, die weitgehend akut erblinden, ist weiterhin eine umgehende Unterstützung mit vergrößernden Sehhilfen und Beratung zur sozialen und beruflichen Rehabilitation essenziell. Alternative Therapieansätze wie Gentherapie, Neuroprotektion oder stammzellbasierte Aspekte sind derzeit bereits Gegenstand von klinischen Studien und lassen auf weitere Perspektiven für die Betroffenen hoffen. Obwohl für die LHON mit Idebenon bereits eine kausale Therapie zugelassen wurde, sind gerade die Pathogenese der Erkrankung betreffend noch viele Fragen nicht restlos geklärt. Dies betrifft insbesondere die Geschlechterprävalenz und mögliche zusätzliche Trigger oder protektive Faktoren. In dieser Übersicht werden die klinischen Verlaufsformen der LHON, Diagnostik und aktuelle Therapieempfehlungen sowie die Besonderheiten und gegenwärtigen Erklärungsansätze zur inkompletten Penetranz und Symptomatik der LHON erläutert.
Simple mathematical equation to predict distance to gastroesophageal junction through the submucosal tunnel during peroral endoscopic myotomy
Authors: Bapaye Jay , Bharadwaj Tarun , Bapaye Amol , Mahadik Mahesh , Pujari Rajendra , Date Suhas , Korrapati Sravan Kumar , Jain Rishabh , Dubale Nachiket
Published: October 2019

Background and aim Accurate estimation of the distance to the gastroesophageal junction (GEJ) through a tunnel during per oral endoscopic myotomy (POEM) is technically challenging. The methods currently employed are often insufficient, and resultant errors may lead to incomplete myotomy and/or prolonged procedure times. Our hypothesis states that the additional distance while traversing the tunnel is directly proportional to the widest esophageal diameter; and is calculated by the formula X = Y + CZ (X = distance to the GEJ through the tunnel, Y = distance to the GEJ through the lumen, Z = widest esophageal diameter, C = arithmetic constant). This study evaluates the validity and accuracy of this hypothesis.

Patients and methods This was a prospective single-center study with 80 patients, 12 in the pilot group and 68 in the study group. In the pilot group, Y was recorded during esophagogastroduodenoscopy (EGD) before POEM, Z on barium swallow/contrast enhanced computed tomography (CECT), and X was measured during POEM. Using the formula, mean C (SD) was calculated. In the study group, ‘C’ was substituted in the equation to predict the GEJ distance through the tunnel (Xp) before POEM. The operator was blinded to Xp and recorded the true Xt during POEM. The correlation between Xp and Xt was calculated.

Results In the pilot group, the mean distances (cm, SD) for X, Y, and Z were 42.58 (3.33), 39.83 (3.08), and 4.39 (1.16), respectively. The calculated mean C was 0.63 (0.11). In the study group, the mean distances (cm, SD) for Y, Z, Xp, and Xt were 40.45 (2.58), 4.99 (1.43), 43.57 (2.68), and 43.54 (2.78), respectively. The Xp and Xt values demonstrated a high correlation (r = 0.97, P = 0.000).

Conclusions Formula X = Y + CZ reliably predicts the GEJ distance through a tunnel during POEM. It is user friendly and requires no additional resources.
Impact of Nuclear Oestrogen Receptor Beta Expression in Breast Cancer Patients Undergoing Neoadjuvant Chemotherapy
Authors: Heitz Florian , Kümmel Sherko , Lederer Bianca , Solbach Christine , Engels Knut , Ataseven Beyhan , Sinn Bruno , Blohmer Jens Uwe , Denkert Carsten , Barinoff Jana , Fisseler-Eckhoff Annette , Loibl Sibylle
Published: October 2019

Introduction Oestrogen receptor beta (ER-β) is abundantly expressed in breast cancer (BC), but its impact on neoadjuvant chemotherapy outcome is unknown.

Patients and Methods Patients treated in the neoadjuvant GeparTrio trial with available tissue for immunohistochemical analyses were included. Nuclear ER-β expression was correlated with clinico-pathologic characteristics. The impact of its expression on pathological complete response (pCR [ypT0/ypN0]) and survival was determined.

Results Samples of 570 patients were available. Low nuclear ER-β expression (IRS < 9) was observed in 48.4% of hormone receptor positive and 58.6% of hormone receptor negative tumours. Low nuclear ER-β expression was associated with higher pCR rates compared to high nuclear ER-β expression (16.1% vs. 4.7%, p = 0.026). Low ER-β expression was no independent predictor of pCR in multivariate analyses. Disease-free and overall survival were not statistically different between patients with high and low nuclear ER-β expression. Triple-negative BCs showed low nuclear ER-β expression in 57.7%, and pCR rates were 27.1% and 0% (p = 0.23) in low and high ER-β expressing tumours, respectively.

Conclusion Low ER-β expression is associated with improved pCR rates in univariate analyses. However multivariate analyses and survival analyses do not indicate an impact of ER-β on survival in patients undergoing neoadjuvant chemotherapy. Further examination of ER-β as predictor for endocrine therapy might be of value.
Videoassistierte thorakoskopische Chirurgie in Lokalanästhesie und Analgosedierung – eine Umfrage unter den Mitgliedern der Deutschen Gesellschaft für Thoraxchirurgie
Authors: Galetin Thomas , Lopez-Pastorini Alberto , Kosse Nils , Koryllos Aris , Stoelben Erich
Published: October 2019

Einleitung Videothorakoskopische Eingriffe (VATS) bei erhaltener Spontanatmung erfahren vor dem Hintergrund älterer und multimorbider Patienten international eine zunehmende Verbreitung. Daten zur Anwendung und Akzeptanz in Deutschland liegen bisher nicht vor.

Methode Deutschlandweite, onlinebasierte Umfrage an den bei der Deutschen Gesellschaft für Thoraxchirurgie (DGT) registrierten thoraxchirurgischen Abteilungen zur Anwendung der VATS in Lokalanästhesie (LA).

Ergebnisse 101 von 157 angeschriebenen Kliniken haben geantwortet (64%). 42% der Befragten führen Non-intubated VATS (NIVATS) durch, 31% VATS in LA. Gründe, VATS in LA nicht durchzuführen, sind mangelnde Erfahrung (51%), Zweifel an der Durchführbarkeit (29%) und fehlende Indikationen (24%). Unter den durchführenden Kliniken sind die häufigsten Prozeduren Anlage von Pleuraverweilkathetern (94%), Pleuraprobeexzisionen (87%) und Pleurodesen (87%). 42% der Kliniken führen Keilresektionen und 10% auch anatomische Resektionen in LA durch. Hauptzielgruppen sind multimorbide Patienten (77%), ältere Patienten (65%), Patienten mit Angst vor einer Allgemeinanästhesie (55%) und mit vorbestehenden Lungenerkrankungen (52%). In 97% der Kliniken führt die Anästhesie die Sedierung durch. Als technische Schwierigkeiten werden vor allem mangelnde Übersicht (39%), Hyperkapnie (29%) und Panikattacken (23%) genannt. Schmerzen spielen eine untergeordnete Rolle (3%).

Diskussion Rund ⅓ der befragen Kliniken führt bereits VATS in LA durch, weitere haben Pläne zur Einführung der Methode. Die Mehrheit der Befragten sieht als Hauptzielgruppen multimorbide, ältere und lungenerkrankte Patienten, weil sie weniger inflammatorische, respiratorische und neurologische Komplikationen erwartet.
Soziale Determinanten von Gesundheit als Lehr- und Prüfungsinhalte im Medizinstudium
Authors: Hommes Franziska , Drees Simon , Geffert Karin , von Philipsborn Peter , Stratil Jan
Published: October 2019

Ziele Die Weltgesundheitsorganisation (WHO) hat dazu aufgerufen, ÄrztInnen und andere Gesundheitsprofessionen stärker darin auszubilden, soziale Determinanten von Gesundheit (SDH) zu erkennen, zu verstehen und auf diese zu reagieren. Bisher ist jedoch wenig darüber bekannt, inwieweit die derzeitige medizinische Ausbildung AbsolventInnen auf diese Herausforderung vorbereitet. Ziel der vorliegenden Untersuchung ist eine Bestandsaufnahme, wie und in welchem Umfang SDH in der medizinischen Ausbildung berücksichtigt werden.

Methodik Dieser Diskussionsbeitrag basiert auf einer qualitativen und quantitativen Inhaltsanalyse von zentralen Dokumenten für Lehr- und Prüfungsinhalte des Medizinstudiums in Deutschland.

Ergebnisse Die Analyse zeigt Lücken in der Rolle von SDH in wichtigen Rahmenwerken der deutschen medizinischen Ausbildung auf. Zwischen 4 und 27% der analysierten Dokumentenelemente enthielten Bezüge zu SDH, jedoch waren diese nur in 0–3% der Fälle explizit. Während einige Themenbereiche umfassend behandelt wurden (z. B. Aspekte der betrieblichen Gesundheit), wurden andere Themen nicht oder kaum behandelt, wie bspw. gesundheitliche Ungleichheit oder Determinanten außerhalb des Gesundheitssystems.

Schlussfolgerung Eine stärkere und explizitere Behandlung von SDH während der medizinischen Ausbildung in Deutschland könnte dazu beitragen, AbsolventInnen besser auf gegenwärtige und zukünftige Herausforderungen in unserer globalisierten Welt vorzubereiten. Der derzeitige Reformprozess des Nationalen Kompetenzbasierten Lernzielkatalog Medizin (NKLM) sollte genutzt werden, um bestehende Lücken zu füllen, bspw. durch stärkere Betonung von Aspekten wie Armut und Gesundheit, gesundheitliche Ungleichheiten und Fragen des Zugangs zur Gesundheitsversorgung.
Thyroid Hormone Effects on Mesenchymal Stem Cell Biology in the
Tumour Microenvironment
Authors: Schmohl Kathrin Alexandra , Müller Andrea Maria , Nelson Peter Jon , Spitzweg Christine
Published: October 2019

Non-classical thyroid hormone signalling via cell surface receptor integrin
αvβ3, expressed on most cancer cells and proliferating
endothelial cells, has been shown to drive tumour cell proliferation and
survival, as well as angiogenesis. Tumours develop within a complex
microenvironment that is composed of many different cell types, including
mesenchymal stem cells. These multipotent progenitor cells actively home to
growing tumours where they differentiate into cancer-associated fibroblast-like
cells and blood vessel-stabilising pericytes and thus support the
tumour’s fibrovascular network. Integrin αvβ3 expression
on mesenchymal stem cells makes them susceptible to thyroid hormone stimulation.
Indeed, our studies demonstrated – for the first time – that
thyroid hormones stimulate the differentiation of mesenchymal stem cells towards
a carcinoma-associated fibroblast-/pericyte-like and hypoxia-responsive,
pro-angiogenic phenotype, characterised by the secretion of numerous paracrine
pro-angiogenic factors, in addition to driving their migration, invasion, and
recruitment to the tumour microenvironment in an experimental hepatocellular
carcinoma model. The deaminated thyroid hormone metabolite tetrac, a specific
inhibitor of thyroid hormone action at the integrin site, reverses these
effects. The modulation of mesenchymal stem cell signalling and recruitment by
thyroid hormones via integrin αvβ3 adds a further layer to the
multifaceted effects of thyroid hormones on tumour progression, with important
implications for the management of cancer patients and suggests a novel
mechanism for the anti-tumour activity of tetrac.
Neuromuscular Ultrasound for Peripheral Neuropathies
Authors: Baute Penry Vanessa , Cartwright Michael S.
Published: October 2019

Neuromuscular ultrasound (NMUS) is a diagnostic technique that is now commonly used to complement electrodiagnostic studies when evaluating for suspected peripheral nerve pathology. The use of NMUS has been described in focal mononeuropathies, polyneuropathies, and motor neuron disease. This article provides a general overview of NMUS for the evaluation of peripheral neuropathies based on clinical practice guidelines, primary literature, and expert opinion. The characteristic changes detected by NMUS are described in focal mononeuropathies (including entrapment and other causes), polyneuropathies (including demyelinating and axonal processes), and motor neuron disease.
Acetic Acid Catalysed One-Pot Synthesis of Pyrrolo[1,2-a]quinoxaline Derivatives
Authors: Allan Pia N. M. , Ostrowska Martyna I. , Patel Bhaven
Published: October 2019

An efficient acetic acid catalysed reaction has been developed for the synthesis of 4-aryl substituted pyrrolo[1,2-a]quinoxalines from readily available starting materials. A range of structures have been synthesised in very good to excellent yields. The one-pot reaction proceeds through imine formation, cyclisation followed by air oxidation.
Nasal Profile Hump Reduction Using the Let-Down Technique
Authors: Montes-Bracchini Jose Juan
Published: October 2019

In rhinoplasty, the nasal dorsum represents an important aspect for form and function. Surgical management should be performed accurately to avoid complications. The goal for dorsal preservation is to preserve the keystone area intact above the nasal bones and its relationship with the upper lateral cartilages. Unlike other rhinoplasty techniques, the lowering of the nasal dorsum requires dorsal modification prior to the surgery of the tip since it modifies the tip position by rotating it. Unlike the push-down technique, that places the nasal bones inside the nasal cavity, producing obstruction of the airway, the let-down technique improves the airway and releases the valve area, making it a functional-friendly technique.
Anatomy of the Facial Profile
Authors: Floyd Elizabeth Mia , Perkins Stephen W.
Published: October 2019

The facial profile is an essential part of facial analysis and significantly impacts surgical decision making. Knowledge of the underlying anatomy, which creates the facial profile, and the anatomic sources of the common abnormalities in the profile can help to ensure adequate surgical correction of the abnormality.
Complications in Reductive Profileplasty
Authors: Perkins Stephen W. , Shadfar Scott
Published: October 2019

The ability of a surgeon to create an aesthetically pleasing and functionally competent nasal dorsum weighs heavily on following the foundations of rhinoplasty, beginning with the examination and analysis. These same fundamental principles should be used and applied in secondary rhinoplasty. The most common chief complaints of those patients seeking primary rhinoplasty relates to the presence of a hump or dorsal convexity, and similarly complications surrounding the dorsum are the most common indications for secondary rhinoplasty. The surgeon must be able to appropriately evaluate and correct deformities in patients who have already undergone rhinoplasty with dorsal profileplasty. Patients can present with a wide range of postoperative deformities within the bony pyramid or middle vault, including, but not limited to, contour irregularities and internal nasal valve compromise, respectively. The authors will outline the evolving methods by which these techniques can be executed to correct deformities and give a balanced functional and aesthetically pleasing profile.
Blood Transfusion and Risk of Venous Thromboembolism: A Population-Based Cohort Study
Authors: Lin Shih-Yi , Chang Yun-Lung , Yeh Hung-Chieh , Lin Cheng-Li , Kao Chia-Hung
Published: October 2019

Background The risk of venous thromboembolism (VTE) in generally ill patients, both under outpatient and inpatient care, following blood transfusion has not been determined.

Methods This retrospective population-based cohort study was conducted using the National Health Insurance Research Database. We studied patients who received blood transfusion, defined as red blood cell transfusion of any type, from January 1, 2000 to December 31, 2011. The index date was defined as the date of blood transfusion. The primary outcome was VTE. Propensity score matching and Cox proportional hazard models were used.

Results A total of 41,866 patients who underwent blood transfusion and 41,866 matched controls were studied. Generally, the blood transfusion cohort has 2.98 times higher risk of VTE than the control cohort (95% confidence interval [CI] = 1.23–7.22). The blood transfusion cohort had respectively 1.99 and 1.64 times higher risk of deep vein thrombosis (DVT) and pulmonary embolism (PE) compared with the control cohort (DVT, 95% CI = 1.65–2.41; PE, 95% CI = 1.19–2.26). Patients in the blood transfusion cohort who did not use warfarin were 1.95 times more likely to develop VTE than those in the control cohort (adjusted hazard ratio [HR]: 1.95, 95% CI = 1.65–2.31). Patients in the blood transfusion cohort were 1.74 times more likely to die than those in the control cohort (adjusted HR: 1.74, 95% CI = 1.48–2.05).

Conclusion Blood transfusion is associated with an increased risk of VTE. The risk of VTE decreased in those who took warfarin.
Three-Dimensional Joint Kinematics in a Canine Elbow Joint with Medial Coronoid Disease before and after Bi-Oblique Dynamic Proximal Ulnar Osteotomy
Authors: Rohwedder Thomas , Rebentrost Pia , Böttcher Peter
Published: October 2019

Objective The aim of this study was to report the humeroulnar joint kinematics in a dog with medial coronoid process disease (MCPD) before and after dynamic proximal ulnar osteotomy (DPUO).

Study Design A 15-month-old female Labrador Retriever with advanced MCPD was treated by DPUO and fragment removal. Bi-planar fluoroscopic kinematography of the affected joint was performed before and 12 weeks after DPUO along with computed tomography. Static axial radioulnar incongruence (sRUI), dynamic relative proximodistal radioulnar motion (dynamic RUI), axial humeroulnar rotation, as well as humeroulnar joint contact at the medial coronoid process (MCP) were calculated.

Results Static axial radioulnar incongruence was reduced from 2.3 to 1.5 mm after DPUO but dynamic RUI remained unchanged (0.2 vs. 0.3 mm). Mean humeroulnar rotational amplitude increased from 2.6° (standard deviation 0.4) to 4.5° (standard deviation 2.0). Joint contact area at the MCP became substantially increased as well as broadly distributed among the MCP following DPUO (52.5 vs. 63.0%; p = 0.0012).

Conclusion Dynamic proximal ulnar osteotomy failed to restore the radioulnar congruence and increased the humeroulnar rotational instability. No effect was observed on dynamic RUI. Nevertheless, joint contact area at the MCP was increased and became more homogeneously distributed, which might explain the beneficial effect of clinical outcome in this case.
Preoperative Expectations of Patients Undergoing Knee Surgery
Authors: Stevens Kali N. , Nadarajah Vidushan , Jauregui Julio J. , Song Xuyang , Medina Shaun H. , Smuda Michael P. , Packer Jonathan D. , Henn R. Frank
Published: October 2019

There is limited validated data regarding the relationship between preoperative expectations and patient-reported outcomes (PROs) in patients undergoing knee surgery. The purpose of this study was to (1) assess the preoperative expectations of patients undergoing knee surgery and (2) determine the relationship between preoperative patient demographics, PROs, and preoperative patient expectations. We hypothesized that younger patients with worse function and worse general health status would have greater expectations of knee surgery. We analyzed data from 399 patients undergoing knee surgery at an urban academic medical center. We utilized the Musculoskeletal Outcomes Data Evaluation and Management System to measure preoperative expectations. Multiple legacy PRO measures were recorded, as well as the new Patient-Reported Outcomes Measurement Information Systems (PROMIS) Computer Adaptive Testing. Nonparametric statistical analyses were performed to determine significance. Overall, patients undergoing knee surgery had high expectations, with a mean of 88.0 (95% confidence interval [CI], 86.7–89.3) and median of 91.7 (95% CI, 89.2–94.3). Greater preoperative expectations of knee surgery were associated with higher income, surgically naïve knee, lower Charlson Comorbidity Index, better PROMIS Depression and Anxiety scores, greater Marx knee activity scores, and lower total body pain (p < 0.05). Preoperative expectations of patients undergoing knee surgery are associated with a history of prior knee surgery, income, general and mental health, activity, and pain. Expectations were also found to be associated with PRO measures of function and psychological well-being. These findings may have implications for patient education and shared decision-making preoperatively. The level of evidence for the study is IV.
Modeling and coupling of acoustical layered systems that consist of elements having different transfer matrix dimensions
Authors: Xue Y. , Bolton J. S. , Liu Y.
Published: October 2019

The transfer matrix method that is often used to model layered or lumped acoustical systems was inspired by a classical methodology commonly used in electrical engineering. To take advantage of that procedure’s accuracy and modeling efficiency, the transfer matrix method has been further adapted here to allow coupling of layered acoustic media having different matrix dimensions. For example, in the case of fluid, or effective fluid, media, the acoustic transfer matrix elements are conventionally modeled using two-by-two matrices. In contrast, a four-by-four matrix is required to model an elastic solid layer, and a six-by-six matrix is required to model a poroelastic layer, since multiple wave types propagate within the latter elements. Here, we introduce a modified transfer matrix calculation process that draws on various matrix operations to couple four-by-four and/or six-by-six matrices with the two-by-two matrices of other acoustical elements. The matrix operations include singular value decomposition and QR decomposition. These tools are used to reduce the order of elastic solid or poroelastic layer matrices from four-by-four or six-by-six to two-by-two, respectively, so that a layered system can be modeled simply by multiplying together a sequence of two-by-two matrices representing all the layered acoustic elements regardless of their complexity, thus finally creating an overall two-by-two matrix. In this article, the proposed method is applied to several different layered or multipanel structures, and the predicted acoustical properties are compared to results obtained by using previously-existing methods in order to validate the modified transfer matrix method.
Spin-wave excitation and critical angles in a hybrid photon-magnon-coupled system
Authors: Kim Bosung , Bhoi Biswanath , Kim Sang-Koog
Published: October 2019

We studied “strongly enhanced” excitations of magnetostatic spin-waves in a hybrid magnon-photon-coupled system consisting of an inverted split-ring resonator and an yttrium iron garnet film. The backward-volume magnetostatic wave, magnetostatic surface wave, forward-volume magnetostatic wave modes, as well as multiple mixed modes were observed according to the direction of externally applied magnetic fields with respect to the spin-wave propagation direction. From experimental measurements, we found that there exist certain characteristic angles, which is to say, critical angles (θc, ϕc), whereby the group velocity of the excited spin-wave modes reaches zero, along with a single ferromagnetic resonance peak. Furthermore, we analytically derived the critical angles as sinθc=(Heff/H){2−(1+μ0Ms/Heff)sin2ϕc}−1/2, where Heff is the effective magnetic-field strength, H the externally applied field strength, and μ0Ms is the saturation magnetization. This analytical form is in quantitative agreement with estimations from experimentally observed spin-wave modes. This work not only provides a better understanding of multiple-mode spin-wave excitations in given field directions with the help of photon-magnon coupling, but also offers better coupling controllability based on the change of the external magnetic field direction.
On a direct description of pseudorelativistic Nelson Hamiltonians
Authors: Schmidt Julian
Published: October 2019

Abstract interior-boundary conditions allow for the direct description of the domain and the action of Hamiltonians for a certain class of ultraviolet-divergent models in quantum field theory. This method, which comes without the need for renormalization, was recently applied to the nonrelativistic Nelson model. Here, we demonstrate the flexibility of the novel approach by applying it to two relativistic variants of Nelson’s model. The existence of Hamiltonians for these models was shown using renormalization techniques by Eckmann [Commun. Math. Phys. 18, 247 (1970); J. Math. Phys. 15, 190 (1974)]. However, many important properties, such as the domain and the action of the Hamiltonian, were not known. We construct the Hamiltonians for such models via abstract boundary conditions, describing their action explicitly for the first time. In addition, we obtain a detailed characterization of their domain.
Space-slice ion imaging: High slice resolution imaging in the polarization plane of arbitrarily polarized ionizing light
Authors: Mizuse Kenta , Fujimoto Romu , Ohshima Yasuhiro
Published: October 2019

We present a conceptually new, slit-based slice imaging technique for ion-imaging experiments, offering a way for high slice resolution imaging in the polarization plane of an ionizing laser pulse. In the present method, a mechanically adjustable slit is installed in the drift region of the flight of the ions so that only a thin central slice of a three-dimensionally expanding ion cloud (Newton sphere) passes through the slit. The sliced cloud is then projected onto a two-dimensional position-sensitive ion detector installed parallel to the slice plane. Compared to the conventional two-dimensional imaging, the present “space-slice imaging” scheme has two principle novelties: (1) The slit acts as an ideal gate for the slicing, and a slice resolution of 1% or higher can be achieved, in principle, using submillimeter slit width for a typical a few-centimeter ion cloud. (2) The imaging plane can be automatically parallel to the polarization plane of a laser pulse regardless of the state of polarization, resulting in a hitherto unrealized “camera angle.” We developed a space-slice ion imaging apparatus to realize and validate the present scheme. To evaluate its performance, we carried out the Coulomb explosion imaging of the N2 molecule. By adjusting slit width, slicing up to approximately 0.33% was achieved without remarkable image distortion. The polarization-dependent imaging shows that the ejection angles of ions can be directly read from the observed images obtained with any polarization states. The present imaging measurements in the laser polarization plane opens new avenues for the study of laser-induced dynamics; these dynamics cannot be fully characterized with the existing two-dimensional setups. As an example, we applied the present approach to the time-resolved imaging of a laser-driven rotational wave packet of N2, using a circularly polarized exploding pulse as an isotropic probe in the imaging plane. We successfully observed clear time-dependent images containing full spatiotemporal information of the wave packet dynamics. Details of the concept, design, and operation of our apparatus are presented in the present paper.
Modeling study of the onset density for divertor detachment on EAST
Authors: Liu X. J. , Wang L. , Deng G. Z. , Xu J. C. , Liu J. B. , Gao S. L. , Wu C. R. , Huang J. , Zhang L. , Li G. Q. , Gao X. ,   EAST Team
Published: October 2019

The onset density of detachment for L-mode discharges on Experimental Advanced Superconductiong Tokamamak has been studied using the SOLPS code. The effect of divertor closure on the onset density has been assessed by modifying the location of the strike point on a divertor plate. The modeling shows qualitative agreement with experiments in the density threshold. It is found that increasing divertor closure by moving the strike point close to the “V” corner can effectively trap neutrals in a localized region near the plasma strike point and then lower the density threshold of detachment. The influence of plasma current (Ip) on the onset density has also been investigated. The simulation shows that with Ip increased, divertor detachment was achieved at a relatively low normalized density due to the increase in Greenwald density (nG). In addition, the effect of the power across the scrape-off-layer (PSOL) and the radiation fraction on the detachment density threshold has also been studied. The detachment density increases significantly with PSOL as expected, and it can be approximately scaled by PSOL5/7, which is in accordance with the basic two-point model. It is also found that the detachment density can be reduced remarkably through increasing impurity radiative loss.
Influence of clamp-widening on the quality factor of nanomechanical silicon nitride resonators
Authors: Sadeghi Pedram , Tanzer Manuel , Christensen Simon L. , Schmid Silvan
Published: October 2019

Nanomechanical resonators based on strained silicon nitride (Si3N4) have received a lot of attention in fields such as sensing and quantum optomechanics due to their exceptionally high quality factors (Qs). Room-temperature Qs approaching 1×109 are now in reach by means of phononic crystals (soft-clamping) and strain engineering. Despite great progress in enhancing Qs, difficulties in the fabrication of soft-clamped samples limit their implementation into actual devices. An alternative means of achieving ultrahigh Qs was shown using trampoline resonators with engineered clamps, which serves to localize the stress to the center of the resonator while minimizing stress at the clamping. The effectiveness of this approach has since come into question from recent studies employing string resonators with clamp-tapering. Here, we investigate this idea using nanomechanical string resonators with engineered clampings similar to those presented for trampolines. Importantly, the effect of orienting the strings diagonally or perpendicularly with respect to the silicon frame is investigated. It is found that increasing the clamp width for diagonal strings slightly increases Qs of the fundamental out-of-plane mode at small radii, while perpendicular strings only deteriorate with increasing clamp width. Measured Qs agree well with finite element method simulations even for higher-order resonances. The small increase cannot account for previously reported Qs of trampoline resonators. Instead, we propose the effect to be intrinsic and related to surface and radiation losses.
Characterization of radiative and kinetic properties of laser produced plasmas for efficient extreme ultraviolet nanolithography sources
Authors: Sizyuk Tatyana
Published: October 2019

Increasing extreme ultraviolet (EUV) photon power in laser-produced plasma (LPP) sources is critically important for efficient future nanolithography devices. Enhancing the lifetime of the optical collector system in these devices is another important challenge for reliable and economically feasible devices. In this work, various mechanisms affecting ion acceleration in LPP were investigated to predict the maximum ion energies and flux arriving at the collecting mirror surfaces. Plasma evolution produced by an Nd:YAG laser from Sn targets was studied in detail to predict the dynamics of EUV producing ions and their contribution to the EUV power. The multiphysics fully 3D integrated HEIGHTS computer package was used in this analysis. HEIGHTS simulations of detail plasma evolution and ion kinetic energies were compared with various worldwide experimental data. Excellent agreement was shown regarding the range of ion kinetic energies and their angular distribution as well as recombination processes and their effect on the temporal output of EUV photons. Spatial and charge distributions were predicted for EUV producing ions and ionic debris. The analysis showed that mainly two Sn ions, i.e., Sn XII and Sn XIII, determine the EUV source intensity and spatial location. It was also shown that reducing the laser spot size and increasing the pulse duration allow a significant reduction in ion kinetic energies that is important for a longer lifetime of the optical collection system.