bluuebunny/crossref_metadata_2025 huggingface dataset:
Insights into the Cnx1E catalyzed MPT-AMP hydrolysis
Authors: Hercher Thomas W. , Krausze Joern , Hoffmeister Sven , Zwerschke Dagmar , Lindel Thomas , Blankenfeldt Wulf , Mendel Ralf R. , Kruse Tobias
Published: January 2020

Molybdenum insertases (Mo-insertases) catalyze the final step of molybdenum cofactor (Moco) biosynthesis, an evolutionary old and highly conserved multi-step pathway. In the first step of the pathway, GTP serves as substrate for the formation of cyclic pyranopterin monophosphate, which is subsequently converted into molybdopterin (MPT) in the second pathway step. In the following synthesis steps, MPT is adenylated yielding MPT-AMP that is subsequently used as substrate for enzyme catalyzed molybdate insertion. Molybdate insertion and MPT-AMP hydrolysis are catalyzed by the Mo-insertase E-domain. Earlier work reported a highly conserved aspartate residue to be essential for Mo-insertase functionality. In this work, we confirmed the mechanistic relevance of this residue for the Arabidopsis thaliana Mo-insertase Cnx1E. We found that the conservative substitution of Cnx1E residue Asp274 by Glu (D274E) leads to an arrest of MPT-AMP hydrolysis and hence to the accumulation of MPT-AMP. We further showed that the MPT-AMP accumulation goes in hand with the accumulation of molybdate. By crystallization and structure determination of the Cnx1E variant D274E, we identified the potential reason for the missing hydrolysis activity in the disorder of the region spanning amino acids 269 to 274. We reasoned that this is caused by the inability of a glutamate in position 274 to coordinate the octahedral Mg2+-water complex in the Cnx1E active site.
Optimal synthesis of reconfigurable sparse arrays via multi‐convex programming
Authors: Qi Zhengdong , Bai Yechao , Wang Qiong , Zhang Xinggan , Chen Hao
Published: January 2020

A new approach for the synthesis of one‐dimensional (1D) and 2D reconfigurable sparse arrays generating sum and difference power patterns is presented in this study. In the case of 1D arrays, the design procedure provides solutions in which only one set of amplitude coefficients is required and the reconfigurability is obtained by modifying only the excitation phases. In the case of 2D arrays, the simplification of the antenna system is investigated by sharing some excitations for the sum and difference channels. An iterative scheme is used where the array response in the main lobe direction is cast as a multi‐convex problem at each step that the non‐convex lower bound constraint is relaxed while concurrently minimising a reweighted objective function based on the magnitudes of the element excitations. To ensure the robustness of the array, worst‐case performance optimisation technique and white noise gain constraint are introduced in the array. Numerical tests and electromagnetic simulations, referred to known optimal solutions, show that the proposed design is able to obtain good radiation performance with a smaller number of elements.
Gaussian process‐based Bayesian non‐linear filtering for online target tracking
Authors: Lu Kelin , Sun Changyin , Zhu Qian
Published: January 2020

This study deals with the problem of online target tracking based on Gaussian process regression and deterministic sampling. A general mathematical formulation of the non‐linear system identification problem is constructed based on the Gaussian process model, in which the computational efficiency is improved with a sparsification method, and the regular Gaussian process regression algorithm is extended to the online case where the learned surrogate model is able to be updated recursively. After that, the problem of non‐linear transformation with stochastic uncertainty is considered, in which the mean and covariance of a random variable is transformed based on a Gaussian process model. Then the proposed non‐linear transformation method is applied to solve the Bayesian non‐linear filtering problem with unknown dynamics and measurement models. In the end, extensive Monte‐Carlo simulations are conducted to verify the performance of the Gaussian process‐based non‐linear filtering method in a reentry target tracking scenario.
Identifying Earth-impacting asteroids using an artificial neural network
Authors: Hefele John D. , Bortolussi Francesco , Zwart Simon Portegies
Published: January 2020

By means of a fully connected artificial neural network, we identified asteroids with the potential to impact Earth. The resulting instrument, named the Hazardous Object Identifier (HOI), was trained on the basis of an artificial set of known impactors which were generated by launching objects from Earth’s surface and integrating them backward in time. HOI was able to identify 95.25% of the known impactors simulated that were present in the test set as potential impactors. In addition, HOI was able to identify 90.99% of the potentially hazardous objects identified by NASA, without being trained on them directly.
Nutritional Quantification and Shelf Life Analysis of Non-thermal Processed Coconut Juice
Authors: Kongruang Sasithorn , Kleesuwan Srawut
Published: January 2020

Nonthermal processing methods are attracted by many food and beverage industry because it can kill the microbial contamination under mild temperatures used in thermal processing; They can sustain flavours, essential nutrients, and vitamins undergo minimal changes. The objective of this research was to evaluate nonthermal processing as the high current impulse generator (HCIG) and investigate the reduction the contaminated microorganism in coconut juice under the batch and continuous treatment of HCIG. The physical, biochemical and nutritional changes of treated coconut juice were also investigated. The application of the direct electricity through cathode of high current impulse generator (HCIG) in 1,170 chambers contained the contaminated coconut juice. Significantly reduction bothSaccharomyces cerevisiaeandEscherichia colias 5-log were found when treatments were applied with impulses at 5.17 kA. Comparison of nutritional value of non-thermal processes before and after high current impulse was showed no significant differences between main nutritional values and free amino acid. For the continuous HCIG treatment under the treatment of 5.17 kA current with 9, 15 and 30 pulses with 5 L coconut juice at the flow rate of 1 L/min, results from initial concentration at 1.41 × 105CFU/mL showed thatS. cerevisiaereductions were found 78%, 66% and 96% as increasing number of pulses as 9, 15 and 30 pulses, respectively. The increment of microbial reduction with the increasing number of pulses was also detected as 78 %, 82 % and 96 % from 1.11 × 105CFU/mlE. coli.Results revealed that the microbial reduction with HCIG under batch treatment were successful preserved the nutritional components of the coconut juice without significant physicochemical changes.
Management of creative class. The case of IT professionals in Latvia
Authors: Gribanova Svetlana , Abeltina Anna
Published: January 2020

This paper has purpose to the study of factors for motivation of the creative class to work more efficiently. The paper examines the case of IT professionals in Latvia, a significant participant in knowledge economy. IT professionals are more flexible in terms of looking for a job on the labor market all over the world, opportunities of remote job allows they benefit on proposals from abroad, as there is a huge need for qualified IT employees in contemporary international environment. The article uses the results of an online survey of IT professionals in a sample of 1,200 individuals. Methodology of the study uses factor analysis and multiple regression models in order to reveal the connection between motivation for labour, stimulus for increasing productivity and demographic characteristics of IT professionals. The results of research show that IT professionals in Latvia are a special professional group and cannot be administrated using traditional management methods. The incentive for efficiency to work, which is associated with solving interesting and prestigious tasks, is universal for IT professionals with any motivation to work, regardless of any demographic characteristics. At the same time, material incentive motivates only ambitious people, and the fear of dismissal and calls for responsibility generally does not motivate anyone.
Buying organic food as sustainable consumer decision-making behavior: Cognitive and affective attitudes as drivers of purchase intentions toward environmentally friendly products
Authors: Nica Elvira
Published: January 2020

We inspect the relevant literature on trust management in organic agriculture, providing both quantitative evidence on trends and numerous in-depth empirical examples. Our study adds to current research by analyzing environmentally sustainable consumer behavior, consumers’ perceptions, motivations, attitudes, trust, values, and purchasing intentions and decisions regarding organically produced foods, the credence characteristics of organic food and perception of and motives for buying it, and the link between consumer perceptions of certified organic products and pro-environmental food purchasing behavior. We define buying organic food as sustainable consumer decision-making behavior and identify cognitive and affective attitudes that act as drivers of purchase intentions toward environmentally friendly products. Using and replicating data from The Conference Board, Eurostat, FiBL-AMI, The Hartman Group, The Independent, indy100, Nielsen, Organic Trade Association, Pew Research Center, Statista, USDA, and USA Today, we performed analyses and made estimates regarding countries with the largest markets for organic food and with the highest per capita consumption, distinctions consumers make between organic and natural products, the percentages of people willing to pay 20% more or higher for organic groceries, and willingness to pay a premium (more than average price) for products that provide certain organic attributes or benefits. Data were analyzed using structural equation modeling.
Globalization and export flows between Eurasian Economic Union countries: a gravity model approach
Authors: Abakumova Juliet , Primierova Olena
Published: January 2020

In the empirical tools for the research of trade integration a special place is occupied by gravity models, insofar as these models have rather high accuracy in explaining mutual trade flows. Recently, however, the gravity model approach has been subjected to critical rethinking: globalization brought considerable changes not only in economic growth, but also in international trade, what allowed speaking about a “Death of Distance”. At the same time, estimates based on gravity models almost always demonstrated an increase in the coefficient of distance as a proxy for transport costs, which contradicts the general perception of the phenomenon of globalization. The paper is devoted to testing the validity of inclusion of the globalization index in the model, which would allow consider the role of globalization in bilateral cross-country trade, as well as testing the hypothesis of reducing the coefficient of distance. Based on the annual panel data over the period 2000-2016 the trade integration model for the EEU countries was estimated. To test the hypothesis of a decrease in the estimated coefficient of distance over time, the gravity model was also evaluated at different time intervals. And the positive impact of the globalization factor on the volume of exports is revealed.
Zeitmanagement der operativen Therapie – was wird wann operiert?
Authors: Bernstorff Maria Alexandra , Hamsen Uwe , Waydhas Christian
Published: January 2020

Die adäquate Versorgung eines polytraumatisierten Patienten ist nach wie vor eine individualisierte und anspruchsvolle Aufgabe. Die ersten Entscheidungen sollten nach dem Leitsatz: „Treat first, what kills first“ getroffen worden. An dieser Stelle gibt es wenig Raum für freie Entscheidungen. Schwierig wird es dann im Nachgang zu beurteilen, ab wann ein Patient für definitive Operationen von Frakturen operationsfähig ist. Hier wird immer mehr eine möglichst frühzeitige endgültige Versorgung angestrebt, um den Patienten schnellstmöglich mobilisieren zu können, das Risiko für Folgekomplikationen zu minimieren und generell die Intensivzeit zu verkürzen. Grundsätzlich gilt, stammnahe Frakturen werden zuerst versorgt (Wirbelsäule und Beckenring), danach die großen Röhrenknochen der Extremitäten (Oberarm/Oberschenkel) und anschließend dann die weiteren Frakturen. Die Behandlung der gleichzeitig bestehenden Weichteilverletzungen (offen > Kompartment > geschlossen) nehmen hier einen besonderen Stellenwert ein. Eine Sonderstellung nehmen Wirbelsäulenverletzungen mit und ohne Rückmarkläsionen ein. Neuere Studien belegen, dass das neurologische Outcome eines Patienten bei frühzeitiger (unter 24 Stunden, nach Möglichkeit sogar unter 8 Stunden) Versorgung signifikant besser ist, sofern eine Operabilität besteht.
Intraoperative Vorbereitungen und Tischaufbau
Authors: Zander Sabine
Published: January 2020

Wieso die Sterilzone unbedingt eingehalten werden sollte, warum die Händedesinfektion Leben retten kann, wie sich der Instrumentierende steril ankleidet und welche Aufgaben der Springer erfüllt, erfahren Sie im 3. Teil unserer Serie.
Wann sollten wir Patienten postoperativ verlegen?
Authors: Ries Gisler Tobias , Barandun Schäfer Ursi , Morgenthaler Beuttenmüller Nadine , Borer Katharina , Pretto Manuela
Published: January 2020

Pflegende in einem Aufwachraum bewegen sich im Spannungsfeld zwischen den Bedürfnissen der Patienten und den Anforderungen des operativen Bereichs sowie der weiterbehandelnden Bettenstationen. Patienten rechtzeitig zu verlegen, ist aus organisatorischen und ökonomischen Gründen zwingend, birgt aber auch gewisse Risiken. Um die Patientensicherheit zu erhöhen und die Verlegungsreife systematisch einzuschätzen, stellen die Autoren postoperative Kriterien vor.
„Ach, was Sie nicht sagen“
Authors: Hertlein Margit
Published: January 2020

Menschen sind verschieden – zum Glück. Was dem einen Spaß macht, empfindet der andere als gähnend langweilig – und trotzdem arbeiten sie mitunter im selben Beruf. Mehr über menschliche Unterschiede und wie Sie diese gezielt im Team einsetzen können.
Differenzialtherapie nicht-invasive Beatmung – nasale High-Flow-Therapie
Authors: Bräunlich J. , Wirtz H.
Published: January 2020

Der nasale High-Flow führt zu einer stabilen Sauerstoffzufuhr bei der akuten hypoxämischen respiratorischen Insuffizienz, reduziert die Atmungsarbeit und vermindert die Hyperkapnie. Damit geht der NHF über ein reines Oxygenierungssystem hinaus und zeigt Charakteristika einer Atmungsunterstützung. Verschiedene Untersuchungen unterstützen diese These. Dieser Artikel soll daher diskutieren, ob der NHF in ähnlichen Situationen oder Erkrankungen wie die NIV eingesetzt werden kann.
Lungenkarzinom mit ausgeprägter mediastinaler Lymphadenopathie – wer denkt an ein NUT-Karzinom?
Authors: Keymel S. , Krüger S.
Published: January 2020

Eine 39-jährige Patientin hat sich initial wegen Rückenschmerzen orthopädisch vorgestellt. Nachdem sich in der Magnetresonanztomografie der Lendenwirbelsäule der Verdacht auf eine tumoröse Erkrankung gestellt hatte, war in den weiterführenden Untersuchungen eine pulmonale Raumforderung, eine ausgedehnte mediastinale Lymphadenopathie und ein großer einseitiger Pleuraerguss nachweisbar. Histologisch zeigte sich sowohl in den Proben des Tumors im Wirbelkörper als auch in den Proben der transbronchialen Nadelaspiration eines mediastinalen Lymphknotens ein NUT-Karzinom. Das NUT-Karzinom, das früher als NUT-Mittellinienkarzinom bezeichnet wurde, ist eine sehr seltene, aggressive Tumorentität mit ungünstiger Prognose. Der Tumor wurde zunächst gehäuft in der Mittellinie der oberen Atemwege und des Mediastinums beschrieben, ist aber nicht darauf beschränkt. Das NUT-Karzinom trifft häufig junge Patienten. Aufgrund der Seltenheit existiert bisher keine etablierte Therapie.
Tratamento cirúrgico da rigidez pós-traumática do cotovelo por via posterior ampla
Authors: Gracitelli Mauro E.C. , Guglielmetti César L.B. , Botelho Caio A.S. , Malavolta Eduardo A. , Assunção Jorge H. , Ferreira Neto Arnaldo A.
Published: January 2020

Objetivo Demonstrar os resultados clínicos e a taxa de complicações da liberação cirúrgica por via única posterior no tratamento da rigidez pós-traumática de cotovelo.

Métodos Estudo prospectivo, com pacientes submetidos a cirurgia entre maio de 2013 e junho de 2018 em um único centro. Foi realizado acesso ao cotovelo por via posterior. O seguimento dos pacientes foi feito por uma equipe de terapia ocupacional, e eles foram submetidos a um protocolo de reabilitação padronizado, com órteses estáticas progressivas e dinâmicas. O desfecho primário foi a amplitude de flexoextensão do cotovelo após 6 meses.

Resultados Um total de 26 pacientes completaram o seguimento mínimo de 6 meses. A média de flexoextensão do cotovelo, ao final de 6 meses, foi de 98,3° ± 22,0°, com um ganho de amplitude de 40,0° ± 14,0° em relação ao pré-operatório (p < 0,001). A média de ganho relativo de flexoextensão, ao final de 6 meses, foi de 51,7% ± 17,1% (p < 0,001). A média de pronossupinação, ao final de 6 meses, foi de 129,0° ± 42,7° (p < 0,001). Metade dos casos apresentava rigidez moderada e grave no pré-operatório, contra 7,7% aos 6 meses de pós-operatório (p < 0,001). A pontuação nos instrumentos Mayo Elbow Performance Score (MEPS) e Disabilities of the Arm, Shoulder and Hand (DASH) apresentou melhora estatisticamente significativa em relação ao pré-operatório, atingindo 74,4 ± 16,8 pontos e 31,7 ± 21,9 pontos, respectivamente. A escala visual analógica (EVA) não apresentou diferença estatisticamente significativa em relação ao pré-operatório (p = 0,096). Complicações foram observadas em 6 (23%) pacientes, não sendo necessária nova abordagem cirúrgica em nenhum paciente.

Conclusões A liberação cirúrgica do cotovelo associada a protocolo de reabilitação é técnica segura, com resultados satisfatórios e baixa taxa de complicações.
Prognosis of Patients Victim of Spontaneous Subarachnoid Hemorrhage: A Comparison between Radiologic Scales
Authors: Hanna Luiza Maria Dias Abboud , Biguelini Sarah Eloisa , de Araujo Junior Francisco Alves , Matsubara Anderson , dos Santos Neto Pedro Helo
Published: January 2020

Objective To analyze the population and the early mortality rate (up to thirty days) of patients victim of spontaneous subarachnoid hemorrhage (SAH) according to the Hunt-Hess clinical scale and the Fisher and modified Fisher radiological scales.

Materials and Methods We analyzed 46 medical records and skull computed tomography (CT) scans of patients with spontaneous SAH admitted between February 2014 and December 2017 at Hospital Universitário Evangélico Mackenzie, in the city of Curitiba, state of Paraná, Brazil. The method of the study was exploratory-descriptive, transversal and retrospective, with a quantitative approach. We analyzed epidemiological (gender, age), clinical (life habits, pathologies, Glasgow coma scale and Hunt-Hess scale) and radiological (Fisher and modified Fisher scales) variables, and the Hunt-Hess and the Fisher scales were correlated with risk of death. The data was submitted to statistical analysis considering values of p < 0.05.

Result There was a higher prevalence of spontaneous SAH among women (69.5%), as well as among patients aged between 51 and 60 years (34.7%). Regarding the grades on the scales, there was higher prevalence of Fisher 4, Modified Fisher 4 and Hunt-Hess 2. Evolution to death was higher among women (76.4%) and patients aged between 61 and 70 years (35,2%).

Conclusion Mortality was higher among patients classified as Fisher 3, Modified Fisher 4 and Hunt-Hess ≥ 3. The Fisher scale is better than the modified Fisher scale to assess the risk of mortality.
Comparação funcional entre membro dominante e não dominante em atletas com dor inguinal
Authors: Falótico Guilherme Guadagnini , Bento André Orlandi , Goulart Luana Tossolini , Zafalon Leonardo , Arliani Gustavo Gonçalves , Cohen Móises
Published: January 2020

Objetivo Comparar a diferença do arco de movimento (ADM) entre o quadril com lesão e o não lesionado de atletas com as principais patologias femoroacetabulares. Além disso, analisar a diferença da ADM do quadril em cada patologia considerada.

Métodos Os participantes do presente estudo foram 75 atletas de diversas modalidades esportivas, sendo 56 mulheres e 19 homens, com idades entre 20 e 46 anos, os quais tinham diagnóstico de lesão do quadril. Esses indivíduos foram subdivididos em três grupos de acordo com as patologias (impacto femoroacetabular ou lesão labral, pubalgia ou lesão dos adutores e síndrome trocantérica) e as características de cada quadril foram analisadas.

Resultados Um total de 150 quadris (direito e esquerdo) foram mensurados para a presente análise. Comparou-se o ADM do quadril lesado e do quadril saudável de cada atleta e não foram encontradas diferenças estatísticas. Da mesma forma, não houve diferença significativa entre a ADM do quadril entre as principais injúrias.

Conclusão O presente estudo não encontrou diferenças no arco de movimento entre o quadril lesionado e o contralateral, bem como não houve diferença na amplitude dos movimentos entre as patologias femoroacetabulares analisadas.
Técnica de Ilizarov nas osteotomias do fêmur proximal e pélvica tripla para o tratamento da displasia do desenvolvimento do quadril em adolescentes
Authors: Teplenky Mikhail , Mekki Waleed , Oleinikov Evgenii
Published: January 2020

Objetivo A importância das osteotomias pélvicas na coxartrose desenvolvida ainda é discutível. Alguns autores acreditam que a incongruência e a osteoartrite inicial das superfícies articulares são contraindicação para a cirurgia de preservação articular e estimularão maior progressão. A visão oposta é a de que a osteotomia pélvica tripla pode ser uma alternativa à substituição articular precoce. Este estudo relata resultados de médio a longo prazo de pacientes adolescentes com coxartrose desenvolvida, tratados por osteotomias proximais do fêmur e pélvica tripla, fixados pela técnica de Ilizarov.

Métodos Revisão retrospectiva entre 2002 e 2014 do tratamento de 26 pacientes com coxartrose devido a displasia do desenvolvimento do quadril. A amostra continha 22 mulheres e 4 homens. A idade média na operação foi de 14,7 anos (variação: 12–18 anos), e o acompanhamento médio foi de 5,9 anos (variação: 3–13).

Resultados Os resultados funcionais iniciais de acordo com o método de Merle d'Aubigné e Postel foram: dor – 4,3 ± 0,05 pontos; mobilidade – 3,6 ± 0,3 pontos; e marcha – 4 ± 0,15 pontos. O valor médio do índice da zona de carga (ZC) foi 38,7° ± 2.721°. O coeficiente acetabular (CA) foi de 162 ± 6,8, e o ângulo centro–borda (ACB) de Wiberg foi de 3° ± 0,2°. Os resultados foram acompanhados por 3 a 13 anos. No acompanhamento final, os resultados radiográficos mostraram que o valor do índice da ZC diminuiu para 8.2 ± 1.293° (0°–15°), e o CA aumentou para 249 ± 12,05. A média do ângulo cervicodiafisário (ACD) foi 115° ± 4°, a distância articulotrocantérica (DAT) foi de 8,5 ± 1,5 mm, e o ACB de Wiberg foi 28° ± 1,6° no acompanhamento final. A distribuição das articulações segundo Tönnis et al foi: grau I – 17 articulações; grau II – 8 articulações; e grau III – 1 articulação. O resultado foi bom em 14 pacientes (54%), razoável em 10 pacientes (34,5%), e ruim em 2 (11.5%).

Conclusão O tratamento da displasia do quadril na adolescência requer uma avaliação adequada do grau de displasia e a cirurgia necessária para reorientar os componentes pélvicos com o objetivo de alcançar condições adequadas para a remodelação do quadril. Nossos resultados de médio a longo prazo mostraram desfechos muito bons ao aplicarmos esses princípios usando a técnica de Ilizarov.
Skull Base Invasion Patterns of Malignant Head and Neck Tumors: A Neurosurgical Perspective
Authors: Iwami Kenichiro , Fujii Masazumi , Nishio Naoki , Maruo Takashi , Fujimoto Yasushi , Takanari Keisuke , Kamei Yuzuru , Yamada Masayuki , Ogawa Tetsuya , Osuka Koji , Saito Kiyoshi
Published: January 2020

Objective Craniofacial resection (CFR) and temporal bone resection (TBR) on malignant head and neck tumors (MHNTs) invading skull base require accurate and precise determination of the tumor invasion. We investigated tumor skull base invasion patterns and surgical results in CFR and TBR cases.

Methods We performed either CFR or TBR for 75 selected patients with the possibility of en bloc resection over the period between 2011 and 2018. The medical charts of the selected patients were reviewed.

Results Primary tumor onset site (TOS) groups were: (1) nasal cavity/ethmoid sinus, 20 cases; (2) orbit, 10 cases; (3) maxillary sinus, 28 cases; and (4) external ear/temporomandibular joint, 17 cases. Grades for tumor invasion depth (TID) included: (I) extracranial invasion and skull base bone invasion; (II) extradural invasion; or (III) intradural invasion. Patients in groups 1 and 2 had a significantly higher frequency of grade II and III invasions than patients in groups 3 and 4. The main invasion site was nasal cavity superior wall and ethmoid sinus superior wall for group 1 tumors, orbit superior wall, and lateral skull base sphenoid bone for group 2 and 3 tumors, and lateral skull base temporal bone for group 4 tumors. Positive resection margins represented a significant negative prognostic factor. TID and TOS did not affect skull base margin status.

Conclusion Skull base invasion of MHNTs exhibits certain fixed patterns in sites susceptible to invasion based on the TOS. The frequencies of extradural and intradural invasions differed, indicating the importance for accurate preoperative tumor evaluation.
Phenomenological modeling of anisotropic dielectric properties in epitaxial (Pb, Sr)TiO3 thin films
Authors: Ding Yecheng , Ma Wenhui
Published: January 2020

Strain tuning of polarization states and dielectric properties in (001) epitaxial (Pb, Sr)TiO3 (PST) films is investigated using a thermodynamic phenomenological model. We find that our calculations of anisotropic dielectric properties and their electric field tunability at various in-plane strained states are in good agreement with relevant experimental data for epitaxial Pb0.35Sr0.65TiO3 films when material constants are properly determined. Our modeling further suggests that dielectric tunability can be optimized by combined control of epitaxial strain and PST composition.
Effects of variable density on oscillatory flow around a non-conducting horizontal circular cylinder
Authors: Ashraf Muhammad , Ullah Zia
Published: January 2020

The analysis of the oscillatory mixed convection flow of electrically conducting fluid along a nonconducting horizontal circular cylinder in the presence of variable density is performed. The density of electrically conducting fluid is assumed to be an exponential function of temperature. The governing boundary layer equations are transformed by adopting primitive variable transformation, which is integrated numerically by employing the finite difference method. The influence of the various physical parameters, density/temperature parameter m, mixed-convection parameter λ, magnetic force parameter ξ, magnetic Prandtl number γ, and Prandtl number Pr, is interpreted graphically and numerically. The impact of these pertinent parameters on velocity, temperature, and magnetic field profiles at positions α=π/6,π/3, and π on the surface of a nonconducting cylinder is examined and then used to compute oscillatory skin friction, heat transfer, and current density. From these results, it is concluded that an increase in the density/temperature parameter m means an increase in the velocity of the fluid particles due to an increase in the buoyancy forces. Due to this reason, a good response in steadiness and amplitude of oscillation is noted at an angle π/3 for heat transfer and current density and velocity field at π/6. Furthermore, it is noticed that the decrease in the density parameter m leads to a sharp increase in the velocity of fluid at the position α=π/6 for a lower Prandtl number Pr = 0.1.
Charge trapping analysis in sputtered BixSe1-x based accumulation-mode FETs
Authors: Sahu Protyush , Chen Jun-Yang , Wang Jian-Ping
Published: January 2020

Topological materials have attracted a lot of attention in the field of beyond Complementary Metal Oxide Semiconductor (CMOS) devices. Topological Insulators (TI) have been proposed for future high electron mobility field effect transistor (FET) devices that make the physics of operation and especially the oxide-film interface extremely crucial to understand. The effects of the gate voltage on the charge trapping in TI-based FET devices are reported in this work. Sputtered BixSe1-x was chosen as the TI material. The interfacial chemistry was characterized using X-ray photoelectron spectroscopy (XPS), which shows a presence of Mg2+ and oxygen impurities. A unique hysteresis behavior was found for the gate transfer characteristics, with respect to the gate voltage. This was attributed to the charge trapping in the gate oxide and across the SiO2/BixSe1-x interface. We simulated the effects of charge fluctuations on the resistivity of the film. These devices operate under accumulation mode rather inversion mode. Application of positive gate voltage results in accumulation of electrons in the “n-type” BixSe1-x layer resulting in an increase of conductivity. In order to explain the drain current-gate voltage behavior, we used a simple polynomial model to describe the change in the device characteristics due to charge traps. The model was fitted with our experimental results. We further analyzed the gate leakage current, which showed a good match with trap-assisted tunneling (TAT) process that was used to derive trap parameters. The obtained trap parameters show the presence of ultra-deep charge traps contributing to the hysteretic behavior.
Molecular dynamics simulations of the response of pre-damaged SrTiO3 and KTaO3 to fast heavy ions
Authors: Zarkadoula Eva , Zhang Yanwen , Weber William J.
Published: January 2020

We investigate the energy dissipation and track formation due to ion irradiation in SrTiO3 and KTaO3. We use molecular dynamics simulations combined with the inelastic thermal spike model to simulate 21 MeV Ni ion irradiation in pristine and predamaged samples. The results are validated against experimental findings, showing that the level of initial disorder affects the electron-phonon interactions and the energy dissipation and deposition to the atoms. It is predicted that the ion track size increases linearly for low disorder levels, while its size saturates for high levels of disorder.
Scientists define the characteristics of trigatron plasma jet
Authors: Kish Stacy W.
Published: January 2020

Researchers model the step-by-step progression of the spark gap to define the plasma jet characteristics as it grows and dissipates.
Channelization cascade in landscape evolution
Authors: Bonetti Sara , Hooshyar Milad , Camporeale Carlo , Porporato Amilcare
Published: January 2020

The hierarchy of channel networks in landscapes displays features that are characteristic of nonequilibrium complex systems. Here we show that a sequence of increasingly complex ridge and valley networks is produced by a system of partial differential equations coupling landscape evolution dynamics with a specific catchment area equation. By means of a linear stability analysis we identify the critical conditions triggering channel formation and the emergence of characteristic valley spacing. The ensuing channelization cascade, described by a dimensionless number accounting for diffusive soil creep, runoff erosion, and tectonic uplift, is reminiscent of the subsequent instabilities in fluid turbulence, while the structure of the simulated patterns is indicative of a tendency to evolve toward optimal configurations, with anomalies similar to dislocation defects observed in pattern-forming systems. The choice of specific geomorphic transport laws and boundary conditions strongly influences the channelization cascade, underlying the nonlocal and nonlinear character of its dynamics.
Investigation of gate oxide traps effect on NAND flash memory by TCAD simulation*
Authors: Zhang He-Kun , Tian Xuan , He Jun-Peng , Song Zhe , Yu Qian-Qian , Li Liang , Li Ming , Zhao Lian-Cheng , Gao Li-Ming
Published: January 2020

The effects of gate oxide traps on gate leakage current and device performance of metal–oxide–nitride–oxide–silicon (MONOS)-structured NAND flash memory are investigated through Sentaurus TCAD. The trap-assisted tunneling (TAT) model is implemented to simulate the leakage current of MONOS-structured memory cell. In this study, trap position, trap density, and trap energy are systematically analyzed for ascertaining their influences on gate leakage current, program/erase speed, and data retention properties. The results show that the traps in blocking layer significantly enhance the gate leakage current and also facilitates the cell program/erase. Trap density ∼ 1018 cm−3 and trap energy ∼ 1 eV in blocking layer can considerably improve cell program/erase speed without deteriorating data retention. The result conduces to understanding the role of gate oxide traps in cell degradation of MONOS-structured NAND flash memory.
Enhancement of radiation hardness of InP-based HEMT with double Si-doped plane*
Authors: Zhong Ying-Hui , Yang Bo , Chang Ming-Ming , Ding Peng , Ma Liu-Hong , Li Meng-Ke , Duan Zhi-Yong , Yang Jie , Jin Zhi , Wei Zhi-Chao
Published: January 2020

An anti-radiation structure of InP-based high electron mobility transistor (HEMT) has been proposed and optimized with double Si-doped planes. The additional Si-doped plane under channel layer has made a huge promotion in channel current, transconductance, current gain cut-off frequency, and maximum oscillation frequency of InP-based HEMTs. Moreover, direct current (DC) and radio frequency (RF) characteristic properties and their reduction rates have been compared in detail between single Si-doped and double Si-doped structures after 75-keV proton irradiation with dose of 5 × 1011 cm−2, 1 × 1012 cm−2, and 5 × 1012 cm−2. DC and RF characteristics for both structures are observed to decrease gradually as irradiation dose rises, which particularly show a drastic drop at dose of 5 × 1012 cm−2. Besides, characteristic degradation degree of the double Si-doped structure is significantly lower than that of the single Si-doped structure, especially at large proton irradiation dose. The enhancement of proton radiation tolerance by the insertion of another Si-doped plane could be accounted for the tremendously increased native carriers, which are bound to weaken substantially the carrier removal effect by irradiation-induced defects.
Lump and interaction solutions to the (3+1)-dimensional Burgers equation*
Authors: Liu Jian , Wu Jian-Wen
Published: January 2020

The (3+1)-dimensional Burgers equation, which describes nonlinear waves in turbulence and the interface dynamics, is considered. Two types of semi-rational solutions, namely, the lump–kink solution and the lump–two kinks solution, are constructed from the quadratic function ansatz. Some interesting features of interactions between lumps and other solitons are revealed analytically and shown graphically, such as fusion and fission processes.
Evaluation of polarization field in InGaN/GaN multiple quantum well structures by using electroluminescence spectra shift*
Authors: Chen Ping , Zhao De-Gang , Jiang De-Sheng , Yang Jing , Zhu Jian-Jun , Liu Zong-Shun , Liu Wei , Liang Feng , Liu Shuang-Tao , Xing Yao , Zhang Li-Qun
Published: January 2020

In order to investigate the inherent polarization intensity in InGaN/GaN multiple quantum well (MQW) structures, the electroluminescence (EL) spectra of three samples with different GaN barrier thicknesses of 21.3 nm, 11.4 nm, and 6.5 nm are experimentally studied. All of the EL spectra present a similar blue-shift under the low-level current injection, and then turns to a red-shift tendency when the current increases to a specific value, which is defined as the turning point. The value of this turning point differs from one another for the three InGaN/GaN MQW samples. Sample A, which has the GaN barrier thickness of 21.3 nm, shows the highest current injection level at the turning point as well as the largest value of blue-shift. It indicates that sample A has the maximum intensity of the polarization field. The red-shift of the EL spectra results from the vertical electron leakage in InGaN/GaN MQWs and the corresponding self-heating effect under the high-level current injection. As a result, it is an effective approach to evaluate the polarization field in the InGaN/GaN MQW structures by using the injection current level at the turning point and the blue-shift of the EL spectra profiles.
Single crystal growth, structural and transport properties of bad metal RhSb2*
Authors: Wu D S , Qian Y T , Liu Z Y , Wu W , Li Y J , Na S H , Shao Y T , Zheng P , Li G , Cheng J G , Weng H M , Luo J L
Published: January 2020

We have successfully grown an arsenopyrite marcasite type RhSb2 single crystal, and systematically investigated its crystal structure, electrical transport, magnetic susceptibility, heat capacity, and thermodynamic properties. We found that the temperature-dependent resistivity exhibits a bad metal behavior with a board peak around 200 K. The magnetic susceptibility of RhSb2 shows diamagnetism from 300 K to 2 K. The low-temperature specific heat shows a metallic behavior with a quite small electronic specific-heat coefficient. No phase transition is observed in both specific heat and magnetic susceptibility data. The Hall resistivity measurements show that the conduction carriers are dominated by electrons with n
e = 8.62 × 1018 cm−3 at 2 K, and the electron carrier density increases rapidly above 200 K without change sign. Combining with ab-initio band structure calculations, we showed that the unusual peak around 200 K in resistivity is related to the distinct electronic structure of RhSb2. In addition, a large thermopower S(T) about –140 μV/K is observed around 200 K, which might be useful for future thermoelectric applications.
Forestland-peatland hydrologic connectivity in water-limited environments: hydraulic gradients often oppose topography
Authors: Hokanson K J , Peterson E S , Devito K J , Mendoza C A
Published: January 2020

It is common to conceptualize the water table as a subdued replica of surface topography, where groundwater recharges at, and flows from, topographic highs and flows to, and discharges at, topographic lows, in humid (i.e. wetter) environments. This concept is also regularly applied to peatland hydrology, where hydraulic gradients are shown to be towards the peatland. However, this may not be a realistic representation of hydrology for low-relief and sub-humid regions. While it is widely accepted that peatlands maintain internal water tables in drought conditions through a system of autogenic negative feedback loops, there is a general lack of knowledge concerning the controls on, and patterns of, forestland hydrologic process that drive the hydraulic gradients between wetlands and their adjacent forestlands in water-limited conditions in low-relief areas. This study identifies the hydrologic function (i.e. source or sink of water) of forested uplands and peatlands in the Boreal Plains region of Canada and demonstrates that during a mesic (non-drought) year most peatlands are, in fact, potential sources of groundwater to adjacent forestlands. Sixteen forestland-peatland pairs were selected to represent a spectrum of forested hummock and peatland morphometries, topographic positions, and geologic settings. Hydraulic gradients determined for each well pair during the ice-off season demonstrate that the dominant gradient under mesic climatic conditions is from peatlands to adjacent forestlands, opposite of the topographic gradient, and that the sink-source function of each land unit does not change seasonally. Water table depressions under each forested hummock indicate that boreal forestlands are not reliable sources of groundwater recharge, spatially or temporally, which supports previous research showing that peatlands are the primary water source for runoff; illustrating the need for alternative conceptualizations of catchment hydrology in water limited regions of the boreal. Social Media Summary. Forests are poor sources of water to boreal peatlands and landscapes due to water table depressions.
Influence of soil tillage, fertilizers and biostimulants on the yield of spring wheat in the forest-steppe of the Middle Volga
Authors: Vasin V G , Vasin A V , Burunov A N , Vasina N V , Kozhevnikova O P
Published: January 2020

A three-factor field experiment (tillage and fertilizer systems, biostimulants) was carried out in the Samara region in 2016 and 2017 on two experimental fields in crop rotation: bare fallow – winter wheat – spring wheat – sunflower. There were two main tillage systems: minimum tillage and No-Till; two soil fertilizer systems: without and with fertilizer (N12P52); liquid mineral fertilizer and biostimulants: control, Megamix N10, Aminocat 10% + Raykat Growth. In 2016, the yield of spring wheat on plots with No-Till was 10% higher, and in wet and cool 2017 it was 5% lower than in wheat crops with minimal tillage. In 2017 in experiments with soil fertilizer (N12P52) the grain number per spike increased by 37% (No-Till), and grain yield of spring wheat – by 23% (minimum tillage), in 2016 respectively by 13-15% and 14% (No-Till and minimum tillage) compared to plots without soil fertilizer. In 2017 (2016) in experiments with Megamix N10 the number of productive tillers per plant increased by 5 (2)%, thousand grain weight by 12 (2)%, grain yield by 12 (6)%; with Aminocat + Raykat Growth by 7 (10)%, 22 (4)% and 44 (14)%, respectively, compared to plots without their use. Minimum soil tillage and No-Till create favorable conditions for the development of weeds, diseases and pests in spring wheat crops. This necessitates the use of herbicides, fungicides and insecticides in its cultivation.
Festulolium seed productivity depending on sowing methods and seeding rates
Authors: Obraztsov V N , Shchedrina D I , Kadyrov S V
Published: January 2020

The effectiveness of animal husbandry depends on stable provision of animals with high-quality and inexpensive feed. The most affordable source of feed is perennial grasses. New varieties of forage grasses with improved characteristics are an important reserve for fodder production. The intergeneric festulolium hybrid is a valuable forage crop for field and meadow grass sowing which can be used for green fodder, hay, silage, haylage, cultivated hayfields and pastures. The scientific development of cultivation techniques is required to ensure high and sustainable seed yields. An important element of the cultivating technology is the rate of sowing seeds and the method of sowing. In the studies conducted in 2006–2009, the biological characteristics and seed productivity of festulolium were studied at different seeding rates. According to the results of the studies, it can be noted that sowing of festulolium by traditional (15 cm) or inter-row (30 cm) methods at a seed rate of 6.0 kg/ha allows for the formation of a sparse and weakly lodging grass stand. The photosynthetic apparatus of festulolium assimilated most productively when using conventional and inter-row methods of sowing at seeding rates of 6.0 and 9.0 kg/ha, as evidenced by the maximum value of the photosynthetic potential - 1029-1090 thousand m2×day/ha. Excessive thickening of crops (12.0 kg/ha) adversely affects the formation of elements of the crop structure and reduces their productivity. It was found that the highest yield of festulolium seeds with the traditional (604.3 kg/g) and inter-row (652.3 kg/ha) sowing methods were obtained at a seeding rate of 6.0 kg/ha and plant density of 130–133 pcs/m2.
Influence of biological preparations based on associative on the yield of winter triticale in the conditions of the south-east Central Chernozemic Area
Authors: Sautkina M Yu , Cheverdin Yu I
Published: January 2020

The article presents the results of field studies to study the effectiveness of biological preparations based on associative microorganisms in the crops of winter triticale on ordinary chernozem in 2012-2015 years. The method of application of biological preparations is pre-sowing inoculation of seeds. The experimental design included studies on a natural background and when nitrogen fertilizers were applied at a dose of 30 kg/ha of the active substance. According to the results of four years of research, the high efficiency of the use of biological products for presowing treatment of seeds of winter triticale in the conditions of the southeast of Central Chernozemic Area is shown. The productivity of winter triticale increased on average by 1.5-5.5 c/ha. The maximum yield growth was detected using strain 18-5. Mineral fertilizers in the form of nitrogen at a dose of N30 in combination with presowing inoculation of seeds did not contribute to a stable increase in the productivity of cultivated crops. In the technologies of cultivation of winter triticale, it is possible to exclude presowing introduction of nitrogen at a dose of N30 and replace it with biological products based on associative microorganisms.
A model for predicting microbiological and organoleptic indicators of salads during storage with the use of chitosan
Authors: Bugayets N A , Usatikov S V , Lyubimova L V , Tereshchenko I V , Shantyz A KH , Miroshnichenko P V
Published: January 2020

The authors theoretically substantiated and experimentally confirmed the feasibility of using high-molecular acid-soluble chitosan (HAC), which inhibits the growth of microbial flora in the production of salads, to extend the expiration date of salads and ensure the quality and safety indicators of products during storage. The effect of «cold pasteurization» of HAC on the microflora of salads was established. Regression models were obtained that adequately describe the effect of HAC on the microbiological and organoleptic indicators of salads. A method for multi-criteria optimization of the technological mode of production of salads using chitosan according to microbiological and organoleptic indicators to extend their expiration date is proposed. A method for the introduction of HAC in the production of salads in the composition of the dressing – in the form of a 1 % solution in 3 % acetic acid. Salad dressing recipe using HAC was developed. The efficiency of the production technology of salads with the use of HAC was confirmed, which allows one to extend their expiration date at a storage temperature of (4 ± 2) °C from 12 to 78 h.