bluuebunny/crossref_metadata_2025 huggingface dataset:
α-Aminoazoles/azines: key reaction partners for multicomponent reactions
Authors: Imtiaz Shah , Ahmad war Jahangir , Banoo Syqa , khan Sarfaraz
Published: March 2021

Aromatic α-aminoazaheterocycles are the focus of significant investigations and exploration by researchers owing to their key role in diverse biological and physiological processes.
An efficient approach to study membrane nano-inclusions: from the complex biological world to a simple representation
Authors: Lemaalem M. , Hadrioui N. , El Fassi S. , Derouiche A. , Ridouane H.
Published: March 2021

Membrane nano-inclusions are of great interest in biophysics, materials science, nanotechnology, and medicine. In this work, We combined MD simulations and theories to reveal their physics behavior.
Efficient solution-processed deep-blue CIEy ∈ (0.05) and pure-white CIEx,y ∈ (0.34, 0.32) organic light-emitting diodes: experimental and theoretical investigation
Authors: Tagare Jairam , Yadav Rohit Ashok Kumar , Swayamprabha Sujith Sudheendran , Dubey Deepak Kumar , Jou Jwo-Huei , Vaidyanathan Sivakumar
Published: March 2021

Two bipolar non-conjugated deep-blue emitters, PICFOCz and BICFOCz, were synthesized by incorporating the charge transporting carbazole (donor/hole transporting) and imidazole (acceptor/electron transporting) moieties via a flexible alkyl spacer.
Computational and experimental characterization of the novel ECM glycoprotein SNED1 and prediction of its interactome
Authors: Vallet Sylvain D. , Davis Martin N. , Barqué Anna , Thahab Ali H. , Ricard-Blum Sylvie , Naba Alexandra
Published: March 2021

The extracellular matrix (ECM) is a complex meshwork of proteins and an essential component of multicellular life. We have recently reported the characterization of a novel ECM protein, SNED1, and showed that it promotes breast cancer metastasis and regulates craniofacial development. However, the mechanisms by which it does so remain unknown. ECM proteins exert their functions by binding to cell surface receptors and interacting with other ECM proteins, actions that we can predict using knowledge of protein's sequence, structure, and post-translational modifications. Here, we combined in-silico and in-vitro approaches to characterize the physico-chemical properties of SNED1 and infer its putative functions. To do so, we established a mammalian cell system to produce and purify SNED1 and its N-terminal fragment, which contains a NIDO domain, and demonstrated experimentally SNED1's potential to be glycosylated, phosphorylated, and incorporated into an insoluble ECM. We also determined the secondary and tertiary structures of SNED1 and its N-terminal fragment and obtained a model for its NIDO domain. Using computational predictions, we identified 114 proteins as putative SNED1 interactors, including the ECM protein fibronectin. Pathway analysis of the predicted SNED1 interactome further revealed that it may contribute to signaling through cell surface receptors, such as integrins, and participate in the regulation of ECM organization and developmental processes. Last, using fluorescence microscopy, we showed that SNED1 forms microfibrils within the ECM and partially colocalizes with fibronectin. Altogether, we provide a wealth of information on an understudied yet important ECM protein with the potential to decipher its pathophysiological functions.
Performance économique des chaînes de valeur des crevettes d’eaux douces au Bénin
Authors: Ollabodé Nouroudine , Kpadé Cokou Patrice , Montchowui Élie , Jabi Jacob Afouda
Published: March 2021

L’exportation des crevettes du Bénin pourrait se développer, mais reste quasi-inexistante en raison du non-respect des normes sanitaires exigées sur le marché international, ce qui fragilise la durabilité des chaînes de valeur de crevettes. Cette étude évalue les performances économiques des chaînes de valeur de crevettes d’eaux douces au Bénin. Les approches conceptuelle et comptable de la chaîne de valeur ont été utilisées pour identifier les acteurs, analyser les liens d’affaires et évaluer le processus de création et de redistribution de la richesse créée le long des différentes filières. Des données socio-économiques ont été collectées à travers une enquête sur un échantillon aléatoire de 204 acteurs des chaînes de valeur de crevettes dans six communes du Sud du Bénin. Les résultats obtenus montrent trois filières majeures commercialisant des produits différenciés (crevettes fraîches, fumées et frites) et dans lesquelles opèrent cinq types d’acteurs directs. L’analyse comptable révèle que les valeurs ajoutées totales, de même que les profits créés par chacune des trois filières, sont positifs, mettant ainsi en évidence que les trois sont performantes et présentent des avantages comparatifs. La chaîne de valeur de crevettes fumées est plus performante que les deux autres du point de vue de la valeur ajoutée et du profit. Des actions de soutien telles que le financement, l’appui-conseil, l’organisation des acteurs pourraient accompagner les trois filières afin de renforcer la création de valeur ajoutée dans l’industrie de la crevette au Bénin.
Präoperative Risikoevaluation und Optimierung des Patientenzustandes
Authors: Ellinger Elisabeth , Meybohm Patrick , Röder Daniel
Published: March 2021

Die präoperative Risikoevaluation spielt eine wichtige Rolle für die Sicherheit von Anästhesien. Ziel dieses Artikels ist eine Anleitung zur fokussierten Risikoevaluation und Anordnung weiterer diagnostischer und therapeutischer Maßnahmen bei erwachsenen Patienten vor elektiven, nicht herz-thoraxchirurgischen Eingriffen.
Kann das Gender-Spektrum falsch sein?
Authors: Nieder Timo O.
Published: March 2021

Aus einer teils persönlich argumentierten, teils zeitgeschichtlichen Perspektive von mehreren Jahrzehnten setzt sich Düring in ihrem Beitrag (2021, in diesem Heft) mit der zunehmenden Prävalenz von trans* Personen vor allem im Jugendalter und mit den sich für diese Lebensphase verändernden Geschlechterverhältnissen auseinander. Der vorliegende Kommentar erkennt die wissenschaftlich wie klinisch fraglos relevante Fragestellung an und kritisiert die tendenziöse Ausrichtung des Textes. Im Mittelpunkt der Kritik stehen die fehlende Abgrenzung unterschiedlicher Konzepte und der Umgang mit der vorhandenen Empirie. So argumentiert der Kommentar sowohl für eine empirisch informierte und damit ausgewogenere Diskussion zu diesen komplexen Fragestellungen als auch für ein dialektisches Vorgehen in Forschung und Therapie, das weder das Gender-Spektrum idealisiert noch die zunehmenden Prävalenzen im Kontext von Trans* dämonisiert.
Arzneimittelversorgung für Menschen in prekären Lebenssituationen – Schriftliche Befragung von medizinischen Hilfen
Authors: Fey Andreas
Published: March 2021

Hintergrund Obwohl der weit überwiegende Teil der in Deutschland lebenden Bevölkerung Zugang zur gesundheitlichen Regelversorgung hat, trifft dies für einen Teil nicht zu. Um die Not zu lindern, haben sich auf Ehrenamt fußende medizinische Hilfen gebildet, die für eine rudimentäre medizinische Versorgung sorgen. Während darüber bereits vereinzelt berichtet wurde, gibt es bislang zur Arzneimittelversorgung von nicht abgesicherten Menschen so gut wie keine Kenntnisse. Hier will der vorliegende Bericht Anstoß geben, genauer hinzuschauen und Lösungen zum Abbau der Not zu entwickeln.

Methodik Mithilfe eines Fragebogens wurden mittels Internetrecherche auffindbare medizinische Hilfen gefragt, wie die Arzneimittelversorgung organisiert ist, ob der Bedarf gedeckt werden kann und welche Arzneimittel hauptsächlich zum Einsatz kommen.

Ergebnisse In erster Linie werden Arzneimittel auf Privatrezept verordnet und über Spenden finanziert. Zum Teil werden auch nicht regelkonforme Lösungen gefunden. Arzneimittel zur Behandlung von Infektionskrankheiten, psychischen und Hauterkrankungen sowie Schmerzmittel und – im Rahmen der Selbstmedikation – Erkältungsmittel werden am häufigsten angewendet. Chronische Erkrankungen können in der Regel dauerhaft nicht behandelt werden.

Diskussion Die Akutversorgung mit Arzneimitteln über medizinische Hilfen scheint weitgehend gewährleistet zu sein, die Behandlung chronischer Erkrankungen jedoch meist nicht. Da nur über das Internet verfügbare Informationen genutzt wurden, um deutschlandweit bestehende Einrichtungen zu finden, kann diese Untersuchung nur einen ersten Einblick zur Arzneimittelversorgung der betroffenen Personengruppen liefern. Zudem waren oftmals nur Abschätzungen möglich, da in den Einrichtungen die behandelten Fälle nicht ausreichend dokumentiert wurden.

Schlussfolgerungen Die im Rahmen dieser Untersuchung aufgefundene Arzneimittelversorgung ist defizitär. Es fehlt an (Spenden-)Geldern, um den Bedarf an Akut-, insbesondere aber Dauermedikation zu decken und die Versorgung auf dem üblichen hohen Niveau zu gewährleisten. Weitere Untersuchungen sind notwendig, um die Defizite genauer quanti- und qualifizieren zu können. Zudem müssen Wege gefunden werden, wie eine Regelversorgung für diese Menschen realisiert werden kann.
MSProDiscuss – Entwicklung eines digitalen Tools zur
standardisierten Patientenanamnese, um Progredienz bei Multipler Sklerose zu
identifizieren
Authors: Inojosa Hernan , Akgün Katja , Haacke Katrin , Ziemssen Tjalf
Published: March 2021

Die Mehrheit der Patienten mit schubförmiger remittierender Multipler
Sklerose (RRMS) konvertiert im langfristigen Verlauf ihrer Erkrankung zu einer
sekundär-progredienten Verlaufsform (SPMS), die durch eine
schubunabhängige Behinderungszunahme charakterisiert und mit einer
deutlich schlechteren Prognose assoziiert ist. Aufgrund der
Heterogenität der SPMS-Transition ist dieser Übergang nur schwer
feststellbar, daher wird in der Regel eine SPMS-Diagnose nur retrospektiv und
oft mit mehrjähriger Verzögerung gestellt. In dieser
Übersichtsarbeit stellen wir Ansätze für eine
frühere SPMS-Diagnose wie das SPMS-Nomogramm, den MS Prediction Score
oder den Best Definition Ansatz vor, die beitragen könnten, die Phase
der diagnostischen Unsicherheit zu verkürzen. Im Fokus dieser
Übersichtsarbeit steht die Entwicklung von MSProDiscuss, einem neuen
webbasierten Tool, durch das der Arzt systematisch und während der
Routineanamnese alle progressionsrelevanten Parameter der
Krankheitsaktivität, Symptomatik und täglichen
Beeinträchtigungen aus Patientenperspektive erheben kann. In einer
aktuellen Validierungsstudie zeigte MSProDiscuss eine hohe Sensitivität,
Spezifität und Interrater-Reliabilität bei der Identifizierung
von SPMS-Patienten und Patienten im SPMS-Übergang. Da MSProDiscuss
aufgrund des geringen Zeitbedarfs zu keiner Mehrbelastung des behandelnden
Neurologen führt und sein Ergebnis mittels eines einfachen Ampelsystems
leicht interpretiert werden kann, wurde es in ersten Usability-Tests als
äußerst hilfreiches diagnostisches Werkzeug für die
neurologische Praxis bewertet. Die frühzeitige Identifizierung von
signifikanter klinischer Progression durch diagnostische Tools wie MSProDiscuss
könnte beitragen, ein Zeitfenster für mögliche
therapeutische Interventionen zu öffnen.
Aufbau und Entwicklung eines interdisziplinären Zentrums für hereditäre hämorrhagische Teleangiektasie
Authors: Droege Freya , Dingemann Julia , Thangavelu Kruthika , Kuerten Cornelius H. L. , Dahlfrancis Philipp Marius , Kaiser Christina , Kaster Friederike , Zioga Eleni , Meyer Corinna , Lueb Carolin , Sure Ulrich , Lang Stephan , Geisthoff Urban
Published: March 2021

Hintergrund Die hereditäre hämorrhagische Teleangiektasie (HHT) ist eine seltene, systemische Erbkrankheit, die durch mukokutane und viszerale Gefäßmalformationen gekennzeichnet ist. Ein interdisziplinäres Behandlungskonzept in HHT-Zentren wird empfohlen.

Material und Methoden In einer retrospektiven Studie wurden Strukturen, Prozesse und die Daten aller Patienten analysiert, die von April 2014 bis August 2019 in unserem neu gegründeten HHT-Zentrum behandelt wurden.

Ergebnisse Innerhalb des Universitätsklinikums Essen wurde zunächst ein Netzwerk von über 20 verschiedenen Fachabteilungen zur Behandlung von Patienten mit HHT aufgebaut. Von den 282 Patienten, die sich seit der Zentrumsgründung mit möglicher HHT im Westdeutschen Morbus-Osler-Zentrum vorstellten, wurde bei 261 Patienten (93 %) die Diagnose als möglich angesehen. Die meisten Patienten wiesen multiple Symptome auf (Epistaxis und/oder Teleangiektasien: je > 80 %, viszerale Beteiligung: 65 %), welche häufiger eine Behandlung im interdisziplinären Rahmen erforderten. Über 900 E-Mails fielen jährlich für die direkte Behandlung der Patienten mit HHT, deren Koordination, Kooperationen und Öffentlichkeitsarbeit an. Durch den internationalen Austausch innerhalb des Europäischen Referenznetzwerks für multisystemische vaskuläre Erkrankungen (VASCERN) ist eine Behandlung auf aktuellem Stand auch bei komplexen Fragestellungen gewährleistet.

Schlussfolgerungen Ein HHT-Zentrum beinhaltet ein interdisziplinäres Netzwerk von medizinischen Fachrichtungen, bei denen die Abläufe durch Prozesse definiert und durch eine wirksame Öffentlichkeitsarbeit, Schulungs- und Veröffentlichungstätigkeit gekennzeichnet sind.
Endovascular Treatment of a Ruptured Distal Anterior Cerebral Artery Aneurysm Using Coils and N-Butyl-Cyanoacrylate in a 5-Month-Old Baby
Authors: Saal-Zapata Giancarlo , Flores Jesús , Vallejos Ricardo , Valer Dante , Durand Walter , Rodriguez Rodolfo
Published: March 2021

Intracranial aneurysms in pediatric population are rare and differ in several features with their adult counterpart. Clipping and endovascular therapy have both demonstrated favorable clinical outcomes with reconstructive and deconstructive techniques. We present the case of a 5-month-old infant who was admitted to the emergency with interhemispheric and sylvian subarachnoid hemorrhage. CT angiography and three-dimensional digital subtraction angiography revealed a ruptured left pericallosal aneurysm with morphological features of a dissecting aneurysm. Coiling and N-butyl-cyanoacrylate administration were employed to occlude the aneurysm without complications. Endovascular therapy is an effective and safe option in cases of ruptured intracranial aneurysms in pediatric patients with favorable clinical and radiological outcomes.
A Hybrid Approach for Treating Recurrent Renal Cell Carcinoma (RCC) in a Single Kidney with a Tethered Ureter
Authors: Carter Nicole , Al-Shawi Modher , Royce Peter , O’Brien Andrew , Clements Warren
Published: March 2021

This case highlights a hybrid treatment model used successfully in a patient with complicated recurrent renal cell carcinoma (RCC), following partial nephrectomy, in the context of a single kidney. Scar tissue from previous surgery tethered the ureter to the margin of the lesion and combined with obesity, rendered simple percutaneous intervention challenging. The patient was ultimately successfully treated using a hybrid approach of open surgical access, ureterolysis, and intraoperative ultrasound-guided radiofrequency ablation. This approach optimized the volume of conserved normal renal parenchyma and eliminated the need for postoperative dialysis treatment, with no recurrence at 13 months follow-up.
Alternative Combined Retrograde–Antegrade Use of a Re-entry Device in the Revascularization of a Surgically Ligated Superficial Femoral Artery Occlusion
Authors: Gandini Roberto , Raso Armando , Di Martino Arezia , Salimei Fabio , Morosetti Daniele
Published: March 2021

We report a case of a diabetic patient with critical limb ischemia, who previously underwent thromboendarterectomy at the right lower extremity, resulting in surgical ligation at the proximal third of the right superficial femoral artery (SFA). Twenty months later, the patient developed foot ulcers; endovascular treatment was therefore performed. After obtaining a retrograde right SFA subintimal access, directly puncturing the occluded segment of the artery, a re-entry intravascular ultrasound-guided catheter was used to gain proximal re-entry. Then, the same device was used again, in antegrade fashion, to obtain re-entry into the patent popliteal artery. A covered stent was deployed in the site of the surgical closure. In the following 3 months, foot ulcers healed.
Effectiveness of Nurse-Driven Discharge Teaching Using Mobile Application for Home-Based Health Care Practices among Postoperative Neurosurgical Patients or Caregivers in a Tertiary Care Hospital, New Delhi: A Randomized Control Study
Authors: Metilda C.J. , Sharma Kamlesh K. , Sinha Aditi P. , Agrawal Deepak
Published: March 2021

Introduction Considering the increased access to mobile use even in the remote areas, it may be feasible to utilize mobile application (App)-based education among neurosurgical patients and caregivers for home-based care.

Objective This study was aimed to assess the effectiveness of nurse-driven discharge teaching using mobile App for home-based health care practices in terms of discharge advice compliances, revisits, and satisfaction among postoperative neurosurgical patients.

Materials and Methods This randomized control trial was conducted among 100 (50 in each arm) postoperative neurosurgical patients admitted to Neurosurgery department, All India Institute of Medical Sciences (AIIMS), New Delhi. The experimental group received mobile App–based discharge teaching additional to the routine paper-based discharge teaching received by the control group. Data were collected at baseline, during first (within 30th day) and second (within 60th day) routine follow-up visits using adherence to refills and medications scale (ARMS) questionnaire (medication compliance), self-developed structured questionnaires (lifestyle practices like tracheostomy tube (TT) catheter care, exercises and diet changes, revisits, and satisfaction) and computerized log record from App. Data were analyzed using descriptive and inferential statistics.

Results The demographic and clinical profiles of both groups were comparable. There was no statistically significant difference in medication compliance between the experimental group and control group (p = 0.35 and 0.53) in first and second posttests, respectively. The level of confidence to perform lifestyle practices was high among experimental group. The subgroup analysis showed that patients in experimental arm were more compliant to medications as compared with control group (p = 0.001). Both the groups were comparable in terms of revisits (p = 0.26). However, the overall satisfaction of experimental group was reported to be highly using mobile App based teaching than control group with routine paper-based discharge teaching (p = 0.001).

Conclusion Nurse-driven discharge teaching using mobile App is an effective method for neurosurgical patients to adhere to home-based discharge teachings. Use of technology like mobile Apps in vernacular language can bridge the gap for improving home-based care and follow-up among patients in resource constrained settings.
Gastric Outlet Obstruction in the Current Era–A Pictorial Review on Computed Tomography Imaging
Authors: Rastogi Ashita , Singh Somesh , Yadav Rajanikant
Published: March 2021

Gastric outlet obstruction is a pathophysiological entity characterized by mechanical impediment of gastric emptying, which may occur due to a variety of intrinsic or extrinsic causes affecting the antrum or pylorus or duodenum. The obstruction may be benign or malignant or secondary to a motility disorder. Imaging in gastric outlet obstruction identifies majority of these causes and may indirectly even point toward motility disorders. The advent of computed tomography imaging and its subsequent advances have allowed it to become the mainstay of evaluation of stomach, particularly in gastric outlet obstruction. In this pictorial review, a few causes of gastric outlet obstruction are exhibited.
Towards an intelligent blended system of learning activities model for New Zealand institutions: an investigative approach
Authors: Adel Amr , Dayan Joshua
Published: March 2021

COVID-19 has accelerated the uptake of blended learning approaches all over the world. The need to restrict human interaction to reduce the possibility of infection has led to a full lockdown of all educational institutions. Blended learning is a new teaching style combining traditional and modern learning models, where the digital methods of teaching students do not completely replace the ways in which the traditional teachers used to interact with and teach the students. However, there are several challenges associated with the understanding of blended learning models and their implementation in an educational institution. With the development of these blended learning models, there have also been several challenges associated with the different ways of accepting the learning models and using them in combination. This is why this paper proposes a design for a system of blended learning activities that would provide students with a total learning model, which has not replaced the traditional learning models but has successfully utilized digital technologies and blended them with traditional learning. Therefore, they can be used along with the old way of teaching a student, evaluating how the student is performing and also how the staff are performing as teachers. This paper focuses on the development of this model for students in New Zealand.
“These are the realities”: insights from facilitating researcher-policymaker engagement in Nigeria’s household energy sector
Authors: Sesan Temilade , Siyanbola Willie
Published: March 2021

Energy has been a key focus of government policy in Nigeria for decades, yet little improvement has been seen in rates of access among the population. Our paper assesses the inputs to policymaking in this context and interrogates the role of scientific evidence and knowledge co-production in the process. Through key informant interviews and participatory workshops with stakeholders, we addressed the practical question of how to strengthen the contribution of evidence to national energy policymaking processes. Two windows of opportunity were identified for this: the critical stage of problem definition; and the time lag between policy adoption and implementation. By engaging proactively with policymakers on these fronts, academic researchers working in knowledge co-production arrangements can make quick inroads into a policy space that has largely excluded them to date. This case is instructive for academics and knowledge brokers in similar contexts where a diminished status for scientific evidence might make more ambitious exchanges with policy difficult, to begin with.
The effect of energetic plasma on 2D semiconductor materials
Authors: McConnon Aili
Published: March 2021

An investigation of 2D heterostructures made of boron nitride and molybdenum disulfide and the effect of varying plasma exposure duration
Mechanism for truncating power-frequency continuation and reburning by means of a super-strong arc-extinguishing gas
Authors: Wang Yanlei , Huang Ping , Luo Yaojing , Chen Yuning , Wang Jufeng
Published: March 2021

The process of arc suppression with a super-strong arc-extinguishing gas (AEG) includes arc truncation and reburning suppression. In this paper, the plasma mechanics, the mechanics of the super-strong AEG, and the arc-reburning suppression by the AEG are all modeled. Combined with test data, the characteristics of arc truncation, pressure characteristics, and time characteristics of the AEG are analyzed, and the law of medium recovery and reignition suppression of arc fracture under the action of the super-strong AEG are discussed. The test results show that with a super-strong AEG, the arc-extinguishing threshold and time are 40 kA and less than 0.5 ms, respectively.
Sex differences in the blood–brain barrier and neurodegenerative diseases
Authors: Weber Callie M. , Clyne Alisa Morss
Published: March 2021

The number of people diagnosed with neurodegenerative diseases is on the rise. Many of these diseases, including Alzheimer's disease, Parkinson's disease, multiple sclerosis, and motor neuron disease, demonstrate clear sexual dimorphisms. While sex as a biological variable must now be included in animal studies, sex is rarely included in in vitro models of human neurodegenerative disease. In this Review, we describe these sex-related differences in neurodegenerative diseases and the blood–brain barrier (BBB), whose dysfunction is linked to neurodegenerative disease development and progression. We explain potential mechanisms by which sex and sex hormones affect BBB integrity. Finally, we summarize current in vitro BBB bioengineered models and highlight their potential to study sex differences in BBB integrity and neurodegenerative disease.
Ferroelastic domain hierarchy in the intermediate state of
PbZr0.98Ti0.02O3 single crystal
Authors: An Zheyi , Xie Shanshan , Zhang Nan , Zhuang Jian , Glazer A. M. , Ren Wei , Ye Zuo-Guang
Published: March 2021

PbZrO3-based antiferroelectric crystals are of great interest in both fundamental and applied research, not only because of the antiferroelectric feature at room temperature but also because of the existence of a peculiar intermediate state at elevated temperatures. Here, we report a detailed description of domain structure change at the temperature-induced antiferroelectric-to-ferroelectric phase transition. A complex process of different types of domains is revealed to appear at different stages of the phase transition. A hierarchical ferroelastic domain structure forms in the stabilized intermediate state, where the dense domain walls show potential impact on the physical properties of the crystal.
Tribological behavior of PTFE/Kevlar fabric under different contact stresses
Authors: Tan Deqiang , Li Rui , Yang Xiaoqiang , He Qiang , Gao Huiying
Published: March 2021

The tribological behavior of polytetrafluoroethylene/Kevlar (PTFE/Kevlar) fabric was investigated under different contact stress loads. The prepared PTFE/Kevlar fabric and GCr15 steel were used to form a friction pair, and the tribological properties of the material were tested using a reciprocating friction and wear tester. A stereo microscope, a three-dimensional optical profiler, a field emission scanning electron microscope, and an energy dispersive spectrometer were used to conduct macro- and micro-analysis on the fabric’s wear scar. The results indicated that the friction factor of the PTFE/Kevlar material decreased and then increased as the load increased. The material showed the best tribological performance when the maximum contact stress was 84 MPa (2 N). The friction behavior between the fabric and the GCr15 steel consisted of continuous production, peeling, and regeneration of the PTFE transfer film as the load increased. The wear surface of the fabric showed fiber abrasion and significant wear damage at a contact stress of 143 MPa (10 N). The wear mechanism of the fabric consisted of fatigue wear, abrasive wear, and some oxidative wear.
First-passage time theory of activated rate chemical processes in electronic molecular junctions
Authors: Preston Riley J. , Gelin Maxim F. , Kosov Daniel S.
Published: March 2021

Confined nanoscale spaces, electric fields, and tunneling currents make the molecular electronic junction an experimental device for the discovery of new out-of-equilibrium chemical reactions. Reaction-rate theory for current-activated chemical reactions is developed by combining the Keldysh nonequilibrium Green’s function treatment of electrons, Fokker–Planck description of the reaction coordinate, and Kramers first-passage time calculations. The nonequilibrium Green’s functions (NEGF) provide an adiabatic potential as well as a diffusion coefficient and temperature with local dependence on the reaction coordinate. Van Kampen’s Fokker–Planck equation, which describes a Brownian particle moving in an external potential in an inhomogeneous medium with a position-dependent friction and diffusion coefficient, is used to obtain an analytic expression for the first-passage time. The theory is applied to several transport scenarios: a molecular junction with a single reaction coordinate dependent molecular orbital and a model diatomic molecular junction. We demonstrate the natural emergence of Landauer’s blowtorch effect as a result of the interplay between the configuration dependent viscosity and diffusion coefficients. The resultant localized heating in conjunction with the bond-deformation due to current-induced forces is shown to be the determining factors when considering chemical reaction rates, each of which results from highly tunable parameters within the system.
Data sharing among protected areas shows advantages in habitat suitability modelling performance
Authors: Falaschi Mattia , Scali Stefano , Sacchi Roberto , Mangiacotti Marco
Published: March 2021

Abstract Context Most of the effort dedicated to the conservation of biodiversity in the European Union is applied through the establishment and maintenance of the Natura 2000 network, the world’s most extensive network of conservation areas. European Member State must actively manage these sites and report the state of the species listed in the Annexes of the Habitat and Birds Directives. Fulfilling these duties is a challenging task, especially when money available for conservation is limited. Consequently, how to optimise the use of the available economic resources is a primary goal for reserve managers. Aims In the present study, we focussed on data-sharing, and we analysed whether data-sharing among institutions may boost the performance of habitat suitability models (HSMs). Methods We collected presence data about three species of reptiles in three different protected areas of northern Italy. Then, we built HSMs under the following two different data-sharing policies: data-sharing of species’ occurrence among the different managers of the protected areas, and not sharing the occurrence data among the different managers. To evaluate how sharing the occurrence data influences the reliability of HSMs in various situations, we compared model performances under several sampling-effort levels. Key results Results show that data-sharing is usually the best strategy. In most cases, models built under the data-sharing (DS) strategy showed better performance than did data-un-sharing (DU) models. The data-sharing strategy showed advantages in model performance, notably at low levels of sampling effort. Conclusions Overcoming administrative barriers and share data among different managers of protected areas allows obtaining more biologically meaningful results. Implications Data-sharing among protected areas could allow improving the reliability of future management actions within the Natura 2000 network.
Attention recruits frontal cortex in human infants
Authors: Ellis Cameron T. , Skalaban Lena J. , Yates Tristan S. , Turk-Browne Nicholas B.
Published: March 2021

Significance

Infants are capable of deftly allocating attention to new information. However, the brain regions that support attention in adults are thought to be immature early in life. We tested awake behaving infants in their first year using gaze coding and fMRI to collect simultaneous behavioral and neural measures of attentional cuing. We found a robust validity effect in behavior from all infants, accompanied by engagement of portions of the brain networks that support attention in adults, notably, regions of frontal cortex. This evidence of maturity is compatible with the importance of attention in scaffolding learning and understanding. This study also highlights the opportunities and challenges of awake infant fMRI, including limitations in experimental design, data collection, and data analysis.
Simple and complex cognitive modelling in oblique translation strategies in a corpus of English–Spanish drama film titles
Authors: Peña-Cervel María Sandra , Ovejas-Ramírez Carla
Published: March 2021

This article provides a quantitative and qualitative analysis of the translation of English drama film titles into Peninsular Spanish, drawing on cognitive modelling and following preliminary findings inPeña-Cervel (2016). Our study is consistent with the epistemological and ontological grounding of Cognitive Linguistics (Samaniego-Fernández 2007) and contributes to satisfying one of the major challenges Rojo-López and Ibarretxe-Antuñano (2013a, 10) identify for present-day Translation Studies: To reveal the conceptual substratum that guides the translation process. Our approach does not rely on an exhaustive classification of clear-cut and well-defined translation techniques, but rather on a broad distinction between direct and oblique strategies. We demonstrate how the notion of cognitive operation, as proposed byRuiz de Mendoza-Ibáñez and Galera-Masegosa (2014), can help elucidate the sometimes seemingly arbitrary relationship between original English titles and their counterparts in Spanish, especially in cases of traditionally so-called free translations. Stands-for relations, such as expansion and reduction, are shown to play a fundamental role in the translation process and the fruitful combination of cognitive operations into conceptual complexes is explored. Our study attempts to go beyond descriptive adequacy in order to achieve explanatory adequacy.
Grass-legume intercropping for sustainability animal production in the tropics
Authors: Rusdy Muhammad
Published: March 2021

Seasonal and low forage availability and quality, shrinking of grassland area, and poor grassland management are the main causes of low soil fertility and animal production in tropical grasslands. One sustainable way to overcome the problems is through establishment of grass-legume intercropping in tropical grassland. Results revealed that grass-legume intercropping improved soil health and fertility, forage yield, and stability and reduced weed invasion. Besides, it improves forage nutritive value and animal production. To enhance grass-legume intercropping, the selected grass and legume species should be matched with local environmental conditions followed by good management.
All possible paths: bringing quantum electrodynamics to classrooms
Authors: Choudhary Rahul , Blair David
Published: March 2021

Quantum electrodynamics was described by Feynman as the ‘jewel of physics’ [1985 QED: The Strange Theory of Light and Matter (Alix G. Mautner Memorial Lectures) (Princeton, NJ: Princeton University Press)] because of its ability to precisely describe the interaction of light and matter. It embodies the key concepts of quantum physics and yet also describes classical optics. It is normally considered to be too advanced for use in schools. Here we show that through the use of novel learning tools called phasor wheels, it is possible to make quantum electrodynamics accessible to students from middle school and higher. Our graphical approach is based on the summation of all possible paths (formally known as Feynman path integrals). It uses graphical vector addition, and gives students a deep understanding of vectors. It offers insights into the quantum world in which observations represent quantum probability density, while correctly describing the laws of classical optics. The phasor wheel is a tactile tool that allows students to compute the probability of photons arriving at a point in space and to explore phenomena such as matter–wave interference, diffraction, and reflection without any distinction between quantum or classical. To make it accessible, we combine the phasor tool with real-life analogies, and videos of single quanta interference. Needing only elementary mathematics, the approach is suitable for middle/upper secondary schools as well early undergraduate students.
Coordinating vector field equations and diagrams with a serious game in introductory physics
Authors: Klein P , Burkard N , Hahn L , Dahlkemper M N , Eberle K , Jaeger T , Herrlich M
Published: March 2021

Mathematical reasoning with algebraic and graphical representations is important for a throughout understanding of physics problems and concepts. Many problems require students to fluently move between algebraic and graphical representations. We developed a freely available serious game to challenge the representational fluency of introductory students regarding vector fields. Within the game, interactive puzzles are solved using different types of vector fields that must be configured with the correct mathematical parameters. A reward system implemented in the game prevents from using trial-and-error approaches and instead encourages the player to establish a mental connection between the graphical representation of the vector field and the (algebraic) equation before taking any action. For correct solutions, the player receives points and can unlock further levels. The graphics implemented in the game make the effects of changing the direction of a field or its magnitude visible and thus can help the learner gain a throughout understanding of vector fields. We report about the aim of the game from an educational perspective, describe potential learning scenarios and put in perspective the use of the game in the classroom.
Wavepacket-interference view of optical excitation
Authors: Lü Ling-Jie
Published: March 2021

Excitation mechanisms using intense lasers are described as being either a multiphoton or tunneling process, based on whether the Keldysh parameter γ is greater than or less than unity. However, the lack of intrinsic connection between these two excitation mechanisms fetters the cognizance of dynamics in strong field ionization under typical experimental conditions. In this paper, quantum tunneling and the multiphoton process are connected by an intuitive picture of wavepacket interference. In this view, the transition from multiphoton resonance to tunneling is recognized as a decoherence process of tunneling electrons. We reveal this decoherence in crystals and gases when the Keldysh parameter decreases. In this process, the characteristics of driving fields, frequent scattering in crystals and localization play an important role. Moreover, once this understanding of multiphoton resonance is obtained, additional means are provided for coherent control in electron excitations. We find that the interference of tunneling electrons leads to novel performances of the transition rate in subcycles, and provides a theoretical method of attosecond-resolved quantum interference control. Our work opens up a new prospect of electron ultrafast control.
Bound states in the continuum on perfect conducting reflection gratings*
Authors: Huang Jianfeng , Song Qianju , Hu Peng , Xiang Hong , Han Dezhuan
Published: March 2021

Bound states can be supported on the surface of a periodically corrugated perfect conductor known as spoof surface plasmon polaritons with their dispersion curves reside below the light line. Here we show that bound states in the continuum (BICs) can also be achieved in such systems. Two types of grating structures are proposed to suppress the radiation leakage and hence generate bound states. The first one is a simple grating with broad grooves in which multiple cavity modes are accommodated. Due to the symmetry incompatibility and the destructive interaction mainly from the TM0 and TM1 modes, BICs at the Γ point and at off-Γ points are both realized. The second one is a dimerized grating with two grooves in each unit cell. The destructive interaction between the modes in the two grooves can suppresses the radiation and BICs at the Γ point are observed. The Q factors of the whole bands can be further tuned by the dimerization strength effectively. This work may offer new opportunity for the applications of metallic grating in the low frequency bands.
Theoretical study of reactive melt infiltration to fabricate Co-Si/C composites
Authors: Shahzad Saqib , Iqbal Khurram , Uddin Zaheer
Published: March 2021

Cobalt-silicon based carbon composites (Co–Si/C) have established a noteworthy consideration in recent years as a replacement for conventional materials in the automotive and aerospace industries. To achieve the composite, a reactive melt infiltration process (RMI) is used, in which a melt impregnates a porous preform by capillary force. This method promises a high-volume fraction of reinforcement and can be steered in such a way to get the good “near-net” shaped components. A mathematical model is developed using reaction-formed Co–Si alloy/C composite as a prototype system for this process. The wetting behavior and contact angle are discussed; surface tension and viscosity are calculated by Wang’s and Egry’s equations, respectively. Pore radii of 5 μm and 10 μm are set as a reference on highly oriented pyrolytic graphite. The graphs are plotted using the model, to study some aspects of the infiltration dynamics. This highlights the possible connections among the various processes. In this attempt, the Co–Si (62.5 at.% silicon) alloy’s maximum infiltration at 5 μm and 10 μm radii are found as 0.05668 m at 125 s and 0.22674 m at 250 s, respectively.
A strategy to improve the electrochemical performance of Ni-rich positive electrodes: Na/F-co-doped LiNi0.6Mn0.2Co0.2O2
*
Authors: Wan Hui , Liu Zhixiao , Liu Guangdong , Yi Shuaiyu , Gao Fei , Deng Huiqiu , Yuan Dingwang , Hu Wangyu
Published: March 2021

Ni-rich layered lithium transition metal oxides LiNi
x
Mn
y
Co
z
O2 (1 – y – z ≥ 0.6) are promising candidates for cathode materials, but their practical applications are hindered by high-voltage instability and fast capacity fading. Using density functional theory calculations, we demonstrate that Na-, F-doping, and Na/F-co-doping can stabilize the structure and result into a higher open circuit voltage than pristine LiNi0.6Mn0.2Co0.2O2 (NMC622) during the charging process, which may attain greater discharge capacity. F doping may inhibit the diffusion of Li ions at the beginning and end of charging; Na doping may improve Li ion diffusion due to the increase in Li layer spacing, consistent with prior experiments. Na/F-co-doping into NMC622 promotes rate performance and reduces irreversible phase transitions for two reasons: (i) a synergistic effect between Na and F can effectively restrain the Ni/Li mixing and then enhances the mobility of Li ions and (ii) Ni/Li mixing hinders the Ni ions to migrate into Li layers and thus, stabilizes the structure. This study proposes that a layer cathode material with high electrochemical performance can be achieved via rational dopant modification, which is a promising strategy for designing efficient Li ion batteries.
Differentiable programming and density matrix based Hartree–Fock method*
Authors: Ren Hong-Bin , Wang Lei , Dai Xi
Published: March 2021

Differentiable programming is an emerging programming paradigm that allows people to take derivative of an output of arbitrary code snippet with respect to its input. It is the workhorse behind several well known deep learning frameworks, and has attracted significant attention in scientific machine learning community. In this paper, we introduce and implement a density matrix based Hartree–Fock method that naturally fits into the demands of this paradigm, and demonstrate it by performing fully variational ground state calculation on several representative chemical molecules.
Pyramid scheme in stock market: A kind of financial market simulation*
Authors: Shi Yong , Li Bo , Du Guang-Le
Published: March 2021

Artificial stock market simulation based on agent is an important means to study financial market. Based on the assumption that the investors are composed of a main fund, small trend and contrarian investors characterized by four parameters, we simulate and research a kind of financial phenomenon with the characteristics of pyramid schemes. Our simulation results and theoretical analysis reveal the relationships between the rate of return of the main fund and the proportion of the trend investors in all small investors, the small investors’ parameters of taking profit and stopping loss, the order size of the main fund and the strategies adopted by the main fund. Our work is helpful to explain the financial phenomenon with the characteristics of pyramid schemes in financial markets, design trading rules for regulators and develop trading strategies for investors.
Influences of spin–orbit interaction on quantum speed limit and entanglement of spin qubits in coupled quantum dots
Authors: Harouni M Bagheri
Published: March 2021

Quantum speed limit and entanglement of a two-spin Heisenberg XYZ system in an inhomogeneous external magnetic field are investigated. The physical system studied is the excess electron spin in two adjacent quantum dots. The influences of magnetic field inhomogeneity as well as spin–orbit coupling are studied. Moreover, the spin interaction with surrounding magnetic environment is investigated as a non-Markovian process. The spin–orbit interaction provides two important features: the formation of entanglement when two qubits are initially in a separated state and the degradation and rebirth of the entanglement.
Excitation energy transfer model for Ne-CO2 and Ne-N2 mixtures
Authors: Şahin Ö.
Published: March 2021

The excited states of neon are capable of ionizing the CO2 and N2 molecules through Penning energy transfer mechanisms. Probability of such additional ionizations can be calculated from the measured gas gain fits. In the present work, Penning ionization processes for Ne-CO2 and Ne-N2 mixtures have been investigated with a newly developed model. The decreases in the transfer rates observed at high molecular gas concentrations indicate the existence of a remarkably interesting transfer mechanism for the excited neon atoms.
Attribution of production-stage methane emissions to assess spatial variability in the climate intensity of US natural gas consumption
Authors: Burns Diana , Grubert Emily
Published: March 2021

Although natural gas is often viewed as a commodity fuel with limited variability due to standardization for pipeline transportation, life cycle impacts of natural gas vary substantially. Greenhouse gas (GHG) intensity is one of the most policy-relevant environmental characteristics of natural gas, particularly as decarbonization efforts proceed. Given that natural gas is mostly methane, a powerful GHG, methane emissions from the natural gas system contribute substantially to the GHG intensity of natural gas. Research has established that methane emissions from natural gas systems are climatically relevant and higher than long understood, in part due to variation in production-stage emissions by basin. This work combines recent estimates of basin-level US production-stage methane emissions, data on US natural gas production, consumption, and trade, and a spatial evaluation of pipeline connections between production basins and consumer states to generate first-order estimates of the production-stage methane emissions intensity of natural gas consumed in the United States. Although natural gas is a commodity product, the environmental footprint of a given unit of natural gas varies based on its origin and infrastructural needs. We find that production-stage methane emissions intensity of delivered natural gas by state varies from 0.9% to 3.6% (mass methane emitted from natural gas production sites per mass methane withdrawn). These production-stage emissions add 16%–65% (global warming potential (GWP)-100; 38%–157%, GWP-20) to combustion carbon dioxide emissions. Other sources of life cycle methane emissions downstream of production can be similar in magnitude. Natural gas consumed in Arizona, Kansas, and New Mexico has the highest estimated production-stage methane emissions intensity, largely due to reliance on high-emission basins. Limitations include emissions-related data gaps and sensitivity to allocation approaches, but results demonstrate decision-relevant variability in the GHG impact of natural gas.