bluuebunny/crossref_metadata_2025 huggingface dataset:
Fabrication of AgCl/Ag3PO4/graphitic carbon nitride heterojunctions for enhanced visible light photocatalytic decomposition of methylene blue, methylparaben and E. coli
Authors: Li Haishuai , Cai Linlin , Wang Xin , Shi Huixian
Published: February 2021

A noval ternary nanocomposite AgCl/Ag3PO4/g-C3N4 was successfully synthesized for photocatalytic degradation of methylene blue, methylparaben and inactivation of E. coli under visible light irradiation, showing excellent photocatalytic degradation performance and stability.
Breaking the bottleneck: stilbene as a model compound for optimizing 6π e− photocyclization efficiency
Authors: Seylar Joshua , Stasiouk Dmytro , Simone Davide L. , Varshney Vikas , Heckler James E. , McKenzie Ruel
Published: February 2021

TEMPO is more effective than iodine in free-radical mediated, photochemical oxidative cyclization of stilbenes at elevated concentrations.
Synthesis of amino alcohols, cyclic urea, urethanes, and cyclic carbonates and tandem one-pot conversion of an epoxide to urethanes using a Zn–Zr bimetallic oxide catalyst
Authors: More Ganesh Sunil , Srivastava Rajendra
Published: February 2021

The one-pot tandem synthesis of urethanes directly from an epoxide, with urea in solvent-free condition using Zn2ZrOx is demonstrated. The catalyst exhibits excellent activity in cyclic urea, urethane, and cyclic carbonate production in neat conditions.
Low-temperature sprayed carbon electrode in modular HTL-free perovskite solar cells: a comparative study on the choice of carbon sources
Authors: Chen Ransheng , Feng Yulin , Jing Liu , Wang Minhuan , Ma Hongru , Bian Jiming , Shi Yantao
Published: February 2021

Among the three carbon sources (MWCNT, CNC, and graphene), MWCNT was identified as the best candidate for application as the back electrode in HTL-free C-PSCs. Ultimately, an improved PCE of 11.2% was achieved for modular MWCNT-based PSCs.
Design of one-dimensional organic semiconductors with high intrinsic electron mobilities: lessons from computation
Authors: Xie Wenjun , Huang Weicong , Tu Lingzhi , Shi Hu , Liu Hongguang
Published: February 2021

A bottom-up design strategy for one-dimensional organic semiconductors with high intrinsic electron mobilities is proposed.
Computational study of 1,2,3-triazol-5-ylidenes with p-block element substituents
Authors: Huang Shiqing , Wang Yedong , Hu Chubin , Yan Xiaoyu
Published: February 2021

1,2,3-Triazol-5-ylidenes with p-block element substituents have been investigated by DFT calculations, which show tunable electronic properties.
PKCα/ERK/C7ORF41 axis regulates epidermal keratinocyte differentiation through the IKKα nuclear translocation
Authors: Yan Feng-Juan , Wang Yong-Jian , Wang Song-En , Hong Hai-Ting
Published: February 2021

Aberrant differentiation of keratinocytes disrupts the skin barrier and causes a series of skin diseases. However, the molecular basis of keratinocyte differentiation is still poorly understood. In the present study, we examined the expression of C7ORF41 using tissue microarrays by immunohistochemistry and found that C7ORF41 is specifically expressed in the basal layers of skin epithelium and its expression is gradually decreased during keratinocytes differentiation. Importantly, we corroborated the pivotal role of C7ORF41 during keratinocyte differentiation by C7ORF41 knockdown or overexpression in TPA-induced Hacat keratinocytes. Mechanismly, we first demonstrated that C7ORF41 inhibited keratinocyte differentiation mainly through formatting a complex with IKKα in the cytoplasm, which thus blocked the nuclear translocation of IKKα. Furthermore, we also demonstrated that inhibiting the PKCα/ERK signaling pathway reversed the reduction in C7ORF41 in TPA-induced keratinocytes, indicating that C7ORF41 expression could be regulated by upstream PKCα/ERK signaling pathway during keratinocyte differentiation. Collectively, our study uncovers a novel regulatory network PKCα/ERK/C7ORF41/IKKα during keratinocyte differentiation, which provides potential therapeutic targets for skin diseases.
Wildlife crime in Australia
Authors: Linacre Adrian
Published: February 2021

Wildlife crime is on a massive scale by whatever metric is used. The illegal trade in wildlife and related products is leading to the decline and extinction of many iconic species from rhino to tigers. Almost all countries are signatures to CITES and therefore should enforce national legislation if alleged infringements of trade of wildlife occur. No country is immune from this illegal trade although countries like Australia have their own specific wildlife crimes. Australia is home to many reptilian, amphibian and avian species that are highly prized, predominantly as pets. Collection of protected species from the wild is illegal in all jurisdictions yet policing remote areas of the outback, where so much of the native endemic fauna and flora lives, is nearly impossible. The illegal international trade in these species is highlighted by two case studies provided in this review. A further case highlights the issues of each of the six states of Australia having separate legislation, which is compounded when wildlife crime can be inter-state crime. Australia is one of the few countries having an institute, based at the Australian Museum, with an accredited wildlife forensic science laboratory and therefore the capability to undertake forensic testing of seized samples. One way to reduce wildlife crime may be by educating those who buy illegally seized products that there is a direct connection between the dead animal from which it came and the devasting effect this purchase has on the environment.
Expressive Verb Morphology Deficits in Arabic-Speaking Children With Developmental Language Disorder
Authors: Taha Juhayna , Stojanovik Vesna , Pagnamenta Emma
Published: February 2021

Purpose

This study investigated the production of tense and subject–verb agreement in Palestinian Arabic–speaking children with developmental language disorder (DLD) in comparison to their typically developing (TD) peers in terms of (a) performance accuracy and (b) error patterns.

Method

Participants were 14 children with DLD aged 4;0–7;10 and 32 TD children aged 3;0–8;0 matched on nonverbal abilities. Children were asked to complete a picture-based verb elicitation task. The task was designed to measure the production accuracy of tense and subject–verb agreement inflections in Arabic.

Results

The DLD group scored significantly lower than the TD group on the verb elicitation task. The DLD group was significantly less accurate than the TD group in marking tense, specifically present tense. They were also less accurate in marking agreement in general, with specific difficulty in using feminine verb forms. The DLD and TD groups differed in their tense error patterns, but not in agreement error patterns.

Conclusions

The acquisition of verb morphology in Palestinian Arabic–speaking children with DLD appears to be delayed and possibly different from their TD peers. The DLD group found the production of marked verb forms more challenging than less marked ones. These results are discussed in light of the structural characteristics of Arabic. Future studies would need to include larger sample sizes; investigate other aspects of verb morphology, including both production and comprehension; include other language domains; and consider longitudinal designs to provide more in-depth knowledge of Arabic language acquisition.
Blockchain‐assisted secure UAV communication in 6G environment: Architecture, opportunities, and challenges
Authors: Gupta Rajesh , Nair Anuja , Tanwar Sudeep , Kumar Neeraj
Published: February 2021

From the past few years, Unmanned Aerial Vehicles (UAVs) has proved an immense potential in providing the cost and time‐efficient solutions to the various societal applications such as healthcare, supply chain, and video & surveillance. It has many data security and privacy issues, and researchers across the globe have given many solutions to protect data from cyber‐attacks. Many of them have suggested cryptographic‐based solutions, which is very compute extensive. Very few researchers have suggested Blockchain (BC)‐based solutions, but their solutions may suffer from high data storage cost as well as network latency, reliability, and bandwidth issues. To overcome the above‐mentioned issues, this paper proposed an InterPlanetary File System and BC‐based secure UAV communication scheme over the 6G network. This proposed scheme ensures data security and privacy, reduces data storage cost, and enhances network performance. Then, the research challenges and future directions for further improvement of the proposed system have been presented.
Survival in an extreme environment: Which is the closest globular cluster to the Galactic centre?
Authors: Minniti D. , Fernández-Trincado J. G. , Smith L. C. , Lucas P. W. , Gómez M. , Pullen J. B.
Published: February 2021

Context. Globular clusters (GCs) are interesting probes of the Milky Way, and can be used to test different dynamical galaxy-wide processes. In particular, the inner regions of the Galaxy pose important challenges for the long-term survival of GCs, as threatening effects like dynamical friction accelerate their demise.

Aims. Our main goal is to search for the closest known GC to the Galactic centre using the VVV ESO Public Survey near-infrared database.

Methods. We investigate recently published GC candidates in a region within 2.5° from the Galactic centre using the preliminary update to the VVV Infrared Astrometric Catalogue, point-spread function photometry, and proper motions. In particular, VVV-CL002 and VVV-CL003 are located at a projected angular distance of 1.1 and 1.7° from the Galactic centre, much closer in projection than all other previously known GCs.

Results. The colour–magnitude diagrams and luminosity functions for VVV-CL002 and VVV-CL003 exhibit well-defined red giant branches and red clump peaks, and provide confirmation that both objects are metal-rich GCs. We measure their mean proper motions and distances, estimate their total luminosities, and model the orbits. In particular, we obtain D = 8.6 ± 0.6 kpc and D = 13.2 ± 0.8 kpc for VVV-CL002 and VVV-CL003, respectively.

Conclusions. We conclude that VVV-CL002 is a low-luminosity bulge GC, whereas VVV-CL003 is a distant background GC. Also, VVV-CL002 is the closest known GC to the centre of the Galaxy. For this cluster, the effect of dynamical friction is minimised because of the large cluster velocity, V > 400 km s−1, allowing the long-term survival of this GC in such a high-stellar-density medium. Furthermore, this GC has traversed through the Galactic plane very recently (∼3.5 × 105 yr ago). There are many other GC candidates located within 2.5° of the Galactic centre that remain to be studied in detail: VVV-CL154, Camargo 1105, 1107, 1108, and 1109, and Minniti 20, 39, 40, 46, 47, 54, 55, 56, 57, 58, 59, and 60.
Development of research capacities in space weather: a successful international cooperation
Authors: Amory-Mazaudier Christine , Radicella Sandro , Doherty Patricia , Gadimova Sharafat , Fleury Rolland , Nava Bruno , Anas Emran , Petitdidier Monique , Migoya-Orué Yenca , Alazo-Cuartas Katy , Shiokawa Kazuo
Published: February 2021

This paper presents an international cooperation which has successfully developed research capacities in the scientific disciplines of sun–earth relations and space weather in many countries over the world during the past decades. This success was based on the deployment of scientific instruments in countries that did not have them, on the sharing of knowledge and research tools, on thesis supervision and on the integration of researchers trained in their country. This article will only focus on aspects of training conducted by ICTP, Boston College, ICG, SCOSTEP and GIRGEA. We will highlight what has been enhanced in international cooperation to achieve this success and what remains to be done.
Wie lässt sich die praktische Ausbildung für ärztliche und pflegerische Einsteiger in der Endoskopie optimieren?
Authors: Engelke Monika , Schilling Dieter
Published: February 2021

Die praktische Ausbildung von Pflegenden, Medizinischen Fachangestellten (MFA), Operationstechnischen Assistenten (OTA) und Ärzten läuft in der Endoskopie zum jetzigen Zeitpunkt häufig mithilfe der klassischen Schulung am Arbeitsplatz im laufenden Programm. Der Artikel soll aufzeigen, welche Einschränkungen und Nachteile dadurch entstehen und welche Möglichkeiten es gibt, die Ausbildungssituation für alle Mitwirkenden sinnvoller und für den Patienten sicherer zu gestalten.
Endocannabinoidsystem und Stress
Authors: Spohrs Jennifer , Ulrich Martin , Abler Birgit
Published: February 2021

Das wissenschaftliche Interesse am Endocannabinoidsystem hat in den vergangenen Jahren aufgrund der zunehmenden Legalisierung von medizinischem Cannabis und seiner anxiolytischen Wirkung eine breite Basis von Tierexperimenten und erste translationale Studien zu biologischen, genetischen und neurobiologischen Befunden generiert. Besonders die modulatorische Rolle von Endocannabinoiden im Rahmen von Stress- und Angsterkrankungen steht im Vordergrund und weist auf mögliche Interventionspunkte hin, um vorhandene Therapien zu verbessern. Es fehlen jedoch weiterhin Erkenntnisse und Studien zur Wirkweise am Menschen, um die Implementierung dieser therapeutischen Anknüpfungspunkte umzusetzen. Die folgende Arbeit stellt eine Übersicht mit Schwerpunkt auf der Grundlagenforschung zum Endocannabinoidsystem im Rahmen von stressbezogenen Prozessen dar.
Traumatic Gallbladder Perforation in Children – Case Report and Review
Authors: Le Melanie Thanh Phuong , Herrmann Jochen , Groth Michael , Reinshagen Konrad , Boettcher Michael
Published: February 2021

Background Gallbladder perforation is a very rare finding in children. Clinical and radiografic presentations are often vague. Hence it is a challenging diagnosis, often missed during initial evaluation with potentially fatal consequences. The aim of this case report and review was to identify factors that might help to diagnose and manage future cases.

Methods We present a case of gallbladder perforation in an 8-year-old child after blunt abdominal trauma caused by a handlebar in which imaging modalities such as ultrasound and magnetic resonance imaging (MRI) helped us to determine proper management. We identified and evaluated comparable cases for isolated traumatic gallbladder injury. A review of the recent literature was performed by online search in Pubmed and Google Scholar using “gallbladder injury in children”, “gallbladder perforation children”, “blunt abdominal trauma children” as keywords. We focused on articles exclusively in the pediatric section. The literature from the period 2000–2020 was taken into account to review the state of the art in diagnosis and management.

Results and Conclusion Recent literature for gallbladder injury in pediatrics is sparse compared to the adult counterpart. Only eight published cases of isolated gallbladder injury in children were identified. Since the onset of symptoms may not develop acutely and often develops in an indistinct manner, radiografic examinations play an important role in the diagnostic progress. The authors advise caution in cases of blunt abdominal trauma especially involving handlebars, intraperitoneal free fluid, and severe abdominal pain. We advocate high suspicion of gallbladder perforation if the gallbladder wall displays discontinuation or cannot be definitively differentiated in sonografic examination. Echogenic fluid within the gallbladder should always lead to suspicion of intraluminal bleeding. Repeated clinical and imaging examinations are mandatory since the onset of signs and symptoms may be delayed.

Key Points: 

Citation Format
Automatic, log file-based process analysis of a clinical 1.5T MR scanner: a proof-of-concept study
Authors: Frydrychowicz Alex , Boppel Tobias , Sieber Victoria , Schmidt Joachim D. , Borgert Jörn , Schramm Peter , Barkhausen Jörg , Amthor Thomas
Published: February 2021

Purpose In light of the steadily increasing need for economical efficacy and capacity utilization it was the aim of this proof-of-concept work to implement an automated logfile-based analysis tool for MRI scanner utilization and to establish a process analysis. As a primary step, analyses of scanner and protocol utilization, parametrization of protocol processes, their durations, age dependency, and scan efficacy were to be tested.

Materials and Methods Logfiles were continuously extracted from a 1.5 T MR scanner (Philips Achieva) and automatically explored for relevant scan parameters. Parameters were extracted into a database and logically combined to protocol parameters. Visualization was achieved using PowerBI (Microsoft, USA). Data aggregation comprised a day-based and protocol-based strategy. In addition, age- and regional-based testing was performed. The frequency of protocol usage was evaluated and those protocols with frequent usage compared regarding efficacy to those rarely used.

Results After successful technical implementation, 3659 MR exams were available for further analysis. Out of a plethora of parameters, those relevant to the understanding of the scan process were identified. The initial results mirror the daily scanner usage and allow identifying, e. g., shortened scanner usage on Fridays or longer examination times in children. A scan efficacy of 69.6 ± 17.6 % excluding preparation process was identified as a parameter with high potential to be optimized in daily routine.

Conclusion The logfile-based analysis of MR scanner processes was successfully introduced and holds the promise to be extended into a comprehensive analytic tool for the analysis and optimization of scanner processes. In combination with other variables from the departmental or institutional infrastructure or patient-specific information such tool may be developed into a intelligent steering tool.

Key Points: 

Citation Format
Deszendierende nekrotisierende Mediastinitis: Wahl der Drainage
Authors: Safranek Jarmil , Skala Martin , Vejvodova Sarka , Hosek Petr
Published: February 2021

Einleitung Die deszendierende nekrotisierende Mediastinitis (DNM) ist ein seltener, aber sehr schwerwiegender septischer Zustand, der durch das Übertreten einer Infektion aus dem Hals ins Mediastinum hervorgerufen wird. Verzögerung in der Diagnostik und ein unzureichender chirurgischer Eingriff bedeuten für den Kranken einen lebensbedrohenden Zustand.

Material und Methode Wir beurteilen retrospektiv eine Patientengruppe, bei der in unserer Abteilung die DNM durch eine Drainage in den letzten 10 Jahren (2010 – 2019) therapiert wurde. Bei allen Patienten war eine der folgenden Mediastinumdrainagen erforderlich: zervikomediastinale, mediastinothorakale oder zervikomediastinothorakale „Rendevouz“-Drainage (ZMT-D). Wir beurteilten in der Gruppe die Infektionsquelle, den mikrobiologischen Kultivierungsbefund, die Art der Mediastinumdrainage, den Krankenhausaufenthalt, die Beatmungsdauer und die Laborentzündungsparameter.

Ergebnisse Insgesamt wurden 22 Patienten mit DNM behandelt, 14 Männer und 8 Frauen im Alter von 23 bis 85 Jahren, Durchschnittsalter 54,1 Jahre. Durch weitere Ausbreitung der Entzündung musste in 8 Fällen der zervikomediastinalen Drainage eine der transthorakalen Drainagemethoden folgen. Letztendlich wurde in 8 Fällen von Mediastinitis eine Spüldrainage aus dem Halszugang, in 6 Fällen durch Thorakotomie und in 8 Fällen durch die Spül-ZMT-D durchgeführt. Die Art der Drainage wurde nach den ersten CT-Befunden ausgewählt, weitere Interventionen nach CT-Kontrollen während der Behandlung. Im Zusammenhang mit DNM starben 4 Patienten (Mortalität 18,2%). Bei 15 Patienten wurde eine Tonsillitis als Ursache einer DNM festgestellt, bei 6 Patienten eine odontogene Infektion und bei 1 Patient blieb die Ursache unklar. Obwohl wir die Methode immer individuell und die ZMT-D für die schwierigeren Fälle auswählten, gab es keine statistisch signifikanten (p < 0,05) Unterschiede
zwischen den bewerteten Parametern. Im Vergleich waren der Krankenhausaufenthalt und die Beatmungsdauer bei der ZMT-D kürzer als bei den anderen Drainagemethoden (nicht signifikant).

Schlussfolgerung Insbesondere bei einer Infektion der distalen Bereiche des Mediastinums halten wir ZMT-D für eine ideale Art der Drainage. Es handelt sich um einen genügend radikalen Behandlungsansatz. Sowohl die Behandlungszeit als auch die Mortalität sind nach Einschätzung in unserer Gruppe trotz des Schweregrads der Erkrankung positiv ausgefallen.
Traumatic Dental Injuries, Treatment, and Complications in Children and Adolescents: A Register-Based Study
Authors: Antipovienė Austė , Narbutaitė Julija , Virtanen Jorma I.
Published: February 2021

Objective Traumatic dental injury (TDI) is a common dental concern among children worldwide. We performed a retrospective patient register study among children under 18 years to investigate TDIs with respect to causes, treatment, and complications.

Materials and Methods  We collected information on TDIs from the original patient records of 407 child patients visiting dental clinic of Lithuanian University of Health Sciences, Kaunas, Lithuania. We analyzed all child patients’ (n = 407) background, cause, type of TDI, treatment, complications, and time elapsed from injury to visit to the dentist.

Statistical Analysis The χ
2-test, analysis of variance (ANOVA), and Kruskal–Wallis and Mann–Whitney tests served in the statistical analyses.

Results A total of 579 TDI cases occurred during 2010 to 2016. Lateral luxation (19.8%) and intrusion (14.8%) occurred more often in the primary than the permanent dentition (p < 0.05). The most common cause of TDI was falling (56%). Avulsion occurred in approximately 10% of cases. Follow-up (44.5%) and tooth extraction (48.3%) were the most frequent treatments in the primary and splinting (25.3%) in the permanent teeth. Pulp necrosis was the most frequent complication in primary (92%) and permanent (54%) dentition. About 1% of the patients obtained dental care during the first hour after injury.

Conclusion The most frequent TDIs included lateral luxation in primary teeth and enamel-dentine fractures in permanent teeth. We observed a delay in patients obtaining emergency dental care.
Men’s Sheds in Scotland: the potential for improving the health of men
Authors: Kelly Danielle , Teasdale Simon , Steiner Artur , Mason Helen
Published: February 2021

Recent policy focus is on the ‘non-obvious’ role of community-based organisations in tackling causes of poor health, such as social exclusion. Men’s Sheds are a type of community-based organisation offering health and wellbeing benefits to men, despite this not being the explicit reason they exist. A qualitative study was conducted in Scotland to identify sustainability challenges that impact on the ability of Sheds to become a formal healthcare service. Findings showed that a reliance on ageing and retired volunteers to undertake operational tasks and generate income to fund activities affected the ability of Sheds to sustain and develop. Further, members preferred their Sheds to remain informal and flexible to fit their specific needs. Although Sheds are recognised for their health and wellbeing benefits to men, policymakers must recognise that formalising their activities might detract from the Shed’s primary aims. This paper summarises specific policy implications and recommendations, taking into consideration tensions between the expectations placed on Sheds to expand into formal healthcare delivery, and the needs of Shed users.

Highlights:

Men’s Shed are known for their ability to contribute to men’s health and wellbeing.

The potential of Shed to take on a formal healthcare role is questionable because of a reliance on ageing and retired volunteers and a preference to remain informal.

Policymakers must recognise that although Sheds might be well placed to offer formal health care this may detract from their primary aims.
Bubble dynamics and pressure field characteristics of underwater detonation gas jet generated by a detonation tube
Authors: Liu Wei , Li Ning , Weng Chun-sheng , Huang Xiao-long , Kang Yang
Published: February 2021

An underwater detonation tube (DT) experiment is carried out in a water tank to investigate the bubble dynamics and pressure field characteristics of an underwater detonation gas jet. In the experiment, a 0.78 liter DT filled with a 0.29 MPa methane–oxygen mixture (equivalent to 0.85 mg of TNT, trinitrotoluene) is detonated. By means of high-speed photography and pressure field measurements, the jet process is divided into four different stages. The evolution patterns and features of the four stages are characterized according to the morphology of the detonation gas bubble, and the dimensionless parameters of the bubble dynamics are defined and calculated using image post-processing. The transmitted shock wave and pressure pulsations of the bubble oscillations are extracted using a low-pass filter with a cutoff frequency of 1000 Hz. The time intervals between consecutive pressure peaks are compared with the oscillation periods obtained from parameter studies of bubble dynamics. The bubble dynamics generated by the sudden release of detonation products in the first oscillation are found to be similar to those of underwater explosions. An expansion-necking structure is observed, formed by the impulsive release of the remaining detonation gas from the DT. A numerical simulation is conducted under the same filling conditions as the experiment to supplement the experimental results. The experiment demonstrates the feasibility of underwater detonation gas jets, which could provide an alternative means of generating pulsation bubbles.
Evidence of improvement in thermoelectric parameters of n-type Bi2Te3/graphite nanocomposite
Authors: Singha P. , Das Subarna , Kulbachinskii V. A. , Kytin V. G. , Apreleva A. S. , Voneshen D. J. , Guidi T. , Powell Anthony V. , Chatterjee S. , Deb A. K. , Bandyopadhyay S. , Banerjee Aritra
Published: February 2021

Improvement in thermoelectric parameters is reported with graphite incorporation in n-type Bi2Te3/graphite nanocomposite systems. In-depth thermoelectric properties of nanostructured Bi2Te3/graphite composites are probed both microscopically and macroscopically using x-ray diffraction, Raman spectroscopy, inelastic neutron scattering, and measurement of the temperature dependence of thermal conductivity κ, Seebeck coefficient S, resistivity ρ, and carrier concentration nH. Raman spectroscopic analysis confirms that graphite introduces defects and disorder in the system. Graphite addition induces a large (∼17%) decrease of κ, originating from a strong phonon scattering effect. A low lattice thermal conductivity, κL, value of 0.77 W m−1 K−1, approaching the κmin value, estimated using the Cahill–Pohl model, is reported for Bi2Te3 + 1.0 wt. % graphite sample. Graphite dispersion alters the low-energy inelastic neutron scattering spectrum providing evidence for modification of the Bi2Te3 phonon density of states. Improvement in other thermoelectric parameters, viz., Seebeck coefficient and resistivity, is also reported. Theoretical modeling of electrical and thermal transport parameters is carried out and a plausible explanation of the underlying transport mechanism is provided assuming a simple model of ballistic electron transport in 1D contact channels with two different energies.
The other model antiferroelectric: PbHfO3 thin films from ALD precursors
Authors: Hanrahan Brendan , Milesi-Brault Cosme , Leff Asher , Payne Alexis , Liu Shi , Guennou Mael , Strnad Nicholas
Published: February 2021

Antiferroelectric PbHfO3 is grown from atomic layer deposition precursors lead bis(dimethylaminomethylpropanolate) and tetrakis dimethylamino hafnium with H2O and O3 oxidizers in thicknesses from 20 nm to 200 nm at a substrate temperature of 250 °C. X-ray analysis shows an as-grown crystalline PbO phase that diffuses into an amorphous HfO2 matrix upon annealing to form a randomly oriented, orthorhombic PbHfO3 thin film. Electrical characterization reveals characteristic double hysteresis loops with maximum polarizations of around 30 µC/cm2 and transition fields of 350 kV/cm–500 kV/cm depending on the thickness. Temperature-dependent permittivity and polarization testing show a phase transition at 185 °C, most probably to the paraelectric phase, but give no clear evidence for the intermediate phase known from bulk PbHfO3. The energy storage density for the films reaches 16 J/cm3 at 2 MV/cm. A dielectric tunability of 221% is available within 1 V for the thinnest film. These results highlight the unique spectrum of properties available for thin film perovskite antiferroelectrics.
Thin-film evolution and fingering instability of self-rewetting films flowing down an inclined plane
Authors: Ma Chicheng , Liu Jianlin
Published: February 2021

This paper examines the evolution patterns and essential mechanisms of flow instability of a self-rewetting fluid (SRF) coating on an inclined plane. Considering that the self-rewetting liquid has an anomalous surface tension with temperature change, some interesting phenomena will be found and should be explained. Using the thin-film model, the evolution equation of the air–liquid interface is derived, and the thickness of the liquid film is determined by a fourth-order partial differential equation. Taking T0 (temperature corresponding to the minimum of surface tension) as a cutoff point, two representative cases of the nonlinear flow are comprehensively discussed. One is the case of Ti > T0, and the other is Ti < T0 (interfacial temperature Ti). Based on traveling wave solutions, linear stability analysis (LSA) of the small perturbation applied to the initial condition is given, and the results of LSA are confirmed and explained by the numerical simulations. Results show that the inclined angle and the Weber number always stabilize the free surface, while the Marangoni effect and the Biot number play different roles for the two cases. As Ti − T0 varies from a negative value to a positive value, the Marangoni effect switches to the reverse Marangoni effect. With Ti − T0 < 0, the Marangoni effect enhances the fingering instability, while the Marangoni effect makes the flow more stable if Ti − T0 > 0. The Biot number Bi = 1 corresponds to the most unstable state for Ti < T0 and to the most stable state for Ti > T0.
Calculating vibrational excitation energies using tensor-decomposed vibrational coupled-cluster response theory
Authors: Madsen Niels Kristian , Jensen Rasmus Berg , Christiansen Ove
Published: February 2021

The first implementation of tensor-decomposed vibrational coupled cluster (CP-VCC) response theory for calculating vibrational excitation energies is presented. The CP-VCC algorithm, which has previously been applied to solving the vibrational coupled cluster (VCC) ground-state equations without explicitly constructing any tensors of order three or higher, has been generalized to allow transformations with the Jacobian matrix necessary for computation of response excitation energies by iterative algorithms. A new eigenvalue solver for computing CP-VCC excitation energies is introduced, and the different numerical thresholds used for controlling the accuracy of the obtained eigenvalues are discussed. Numerical results are presented for calculations of the 20 lowest eigenvalues on a set of 10 four-atomic molecules, as well as for a number of polycyclic aromatic hydrocarbons (PAHs) of increasing size, up to PAH8 with 120 modes. It is shown that the errors introduced by the tensor decomposition can be controlled by the choice of numerical thresholds. Furthermore, all thresholds can be defined relative to the requested convergence threshold of the equation solver, which allows black-box calculations with minimal user input to be performed. Eigenstates of PAHs were efficiently computed without any explicitly constructed tensors, showing improvements in both memory and central processing unit time compared to the existing full-tensor versions.
Determination of the energetic resolution of Schottky barrier visualization via interface band structure and parallel momentum conservation
Authors: Rogers Jack , Nolting Westly , Durcan Chris , Balsano Robert , LaBella Vincent P.
Published: February 2021

The energetic resolution of Schottky barrier visualization is determined by utilizing differences in interface band structures between the Au/Si(001) and Au/Si(111) non-epitaxial interfaces and parallel momentum conservation of the carriers. The visualization technique is based on ballistic electron emission microscopy and spectroscopy, where tens of thousands of spectra are collected on a grid and then fit to extract a spatially resolved map and histogram of the electrostatic barrier height. A resolution of 10 meV is determined from the minimal splitting and eventual merging of the histograms as the gold thickness decreases for the Au/Si(001) and Au/Si(111) samples. This splitting is below previously measured differences in barrier heights extracted from computational modeling of measured barrier height distributions from other interfaces.
Non-normal effect of the velocity gradient tensor and the relevant subgrid-scale model in compressible turbulent boundary layer
Authors: Yu Jia-Long , Zhao Zhiye , Lu Xi-Yun
Published: February 2021

The non-normal effects of the velocity gradient tensor (VGT) in a compressible turbulent boundary layer are studied by means of the Schur decomposition of the VGT into its normal and non-normal parts. Based on the analysis of the relative importance of them, it is found that the non-normal part significantly affects the dynamics of the VGT in the wall-bounded turbulent flow and the relevant non-normal effect has a dominant influence on the enstrophy and dissipation. It is revealed that the deviatoric part of the pressure Hessian is associated with the non-normal effect and the isotropic part is associated with the normal effect. The pressure Hessian significantly influences the vortex stretching. The non-normal effect reinforces the preferences for the vorticity vector to align with the intermediate strain-rate eigenvector and to be perpendicular to the extensive and compressive strain-rate eigenvector in the near-wall region. The non-normal effect also reduces the intermediate eigenvalue of the strain-rate tensor. Furthermore, a subgrid scale (SGS) model that separately considers the normal and non-normal effects is proposed based on the above characters and is verified to give a better prediction of the SGS dissipations in the wall-bounded turbulent flow.
A compression strategy for particle mesh Ewald theory
Authors: Simmonett Andrew C. , Brooks Bernard R.
Published: February 2021

Particle Mesh Ewald (PME) has become a standard method for treating long-range electrostatics in molecular simulations. Although the method has inferior asymptotic computational complexity to its linear scaling competitors, it remains enormously popular due to its high efficiency, which stems from the use of fast Fourier transforms (FFTs). This use of FFTs provides great challenges for scaling the method up to massively parallel systems, in large part because of the need to transfer large amounts of data. In this work, we demonstrate that this data transfer volume can be greatly reduced as a natural consequence of the structure of the PME equations. We also suggest an alternative algorithm that supplants the FFT with a linear algebra approach, which further decreases communication costs at the expense of increased asymptotic computational complexity. This linear algebra based approach is demonstrated to have great potential for latency hiding by interleaving communication and computation steps of the short- and long-range electrostatic terms.
Microstructure analysis of electrospun La0.8Sr0.2MnO3 nanowires using electron microscopy and electron backscatter diffraction (EBSD)
Authors: Koblischka-Veneva Anjela , Koblischka Michael R. , Zeng XianLin , Schmauch Jörg
Published: February 2021

The microstructural properties of electrospun La0.8Sr0.2MnO3 (LSMO) nanofibers were investigated using electron microscopy and electron backscatter diffraction (EBSD). By means of EBSD, it is possible to measure the crystallographic orientation of the LSMO grains within an individual nanofiber. As the LSMO grains within the nanofibers are in the 10-nm range, we employ here parts of the recently developed transmission Kikuchi diffraction technique in order to enhance the Kikuchi pattern quality to enable an automated mapping of the crystallographic data. The diffraction results demonstrate that the grain orientation is not random, but there is a texture induced by the shape of the polymer nanofiber formed after the electrospinning step. Within an individual nanofiber section, the dominating grain boundaries are high-angle ones, which play an important role in the current flow through the sample (low- and high field magnetoresistance). The data obtained allow further an analysis of the grain shape aspect ratio, and elucidate the grain and grain boundary arrangement within electrospun LSMO nanofibers.
Logical complexity of induced subgraph isomorphism for certain families of graphs
Authors: Zhukovskii M. E. , Kudryavtsev E. D. , Makarov M. V. , Shlychkova A. S.
Published: February 2021

We investigate the problem of the most efficient first-order definition of the property of containing an induced subgraph isomorphic to a given pattern graph, which is closely related to the time complexity of the decision problem for this property.

We derive a series of new bounds for the minimum quantifier depth of a formula defining this property for pattern graphs on five vertices, as well as for disjoint unions of isomorphic complete multipartite graphs. Moreover, we prove that for any

there exists a graph on

vertices and a first-order formula of quantifier depth at most

that defines the property of containing an induced subgraph isomorphic to this graph.

Bibliography: 12 titles.
T-cell responses to hybrid insulin peptides prior to type 1 diabetes development
Authors: Mitchell Angela M. , Alkanani Aimon A. , McDaniel Kristen A. , Pyle Laura , Waugh Kathleen , Steck Andrea K. , Nakayama Maki , Yu Liping , Gottlieb Peter A. , Rewers Marian J. , Michels Aaron W.
Published: February 2021

Significance

Immune responses to modified self-proteins are involved in the pathogenesis of a number of autoimmune diseases. Type 1 diabetes (T1D) is a prototypical organ-specific autoimmune disease that results from the T-cell–mediated destruction of insulin-producing β-cells within pancreatic islets. The stages of T1D development allow for the measurement of immune responses prior to clinical symptom onset. In our study, we measured T-cell responses from genetically at-risk individuals to both naturally occurring insulin and hybrid insulin peptides, novel neo-epitopes implicated in T1D pathogenesis. Our results have important implications to stratify the risk of developing T1D and identifying individuals who may benefit from immune intervention studies.
Pandemic precarity: COVID-19 is exposing and exacerbating inequalities in the American heartland
Authors: Perry Brea L. , Aronson Brian , Pescosolido Bernice A.
Published: February 2021

Significance

The 2008 Great Recession widened socioeconomic inequities among young adults, people of color, and those without a college degree. The COVID-19 pandemic raises renewed concerns about inequality. Leveraging pre–post data from a population-representative sample of Indiana residents, we examine employment and food, housing, and financial insecurity. Comparing data before COVID-19 reached the state and during the initial stay-at-home orders, we find socioeconomic shocks disproportionately affecting vulnerable groups, controlling for prepandemic status. Findings are consistent with patterns of inequality observed following other disasters, including Hurricane Katrina, the Chicago Heatwave, the Buffalo Creek Flood, and the Great Recession. As with these disasters, additional surges are likely to escalate short-term hardships, revealing the axes of social devastation that translate into durable inequality.
Struggles over value: corporate–state suppression of locally led mining mechanisation in the Democratic Republic of the Congo
Authors: Radley Ben , Geenen Sara
Published: February 2021

The analytical framework deployed by the extensive global value chain (GVC) literature on African mining fails to consider how and from whom value is transferred within the process of establishing foreign corporate-led mining GVCs, and with what consequences. The authors explore these questions through a case study of the gold value chain in the Democratic Republic of the Congo. In this context, they argue that a coalition between transnational capital and the Congolese state has marginalised and held back locally led processes of capital accumulation and mining mechanisation. Based on the findings, the developmental potential of domestically embedded networks of African production is highlighted.
The involvement of leucine-rich α-2 glycoprotein in the progression of skin and lung fibrosis in bleomycin-induced systemic sclerosis model
Authors: Nakajima Hideki , Nakajima Kimiko , Serada Satoshi , Fujimoto Minoru , Naka Tetsuji , Sano Shigetoshi
Published: February 2021

Objective

Systemc sclerosis (SSc) is an autoimmune disorder characterized by fibrosis of the skin and internal organs. Recently, it has been shown that leucine-rich α-2 glycoprotein (LRG) functions as a modulator of transforming growth factor-β (TGF-β) signaling in fibrosis. We aimed to characterize the effect of LRG in SSc model and SSc patients.

Methods

Histological analysis was performed on LRG knockout (KO) and wild type (WT) mouse in the skin and the lung after bleomycin administration. Serum LRG levels were measured during the injection period. Gene expression analysis of the skin and lung tissue from LRG KO and WT mice was performed. In addition, serum LRG levels were determined in SSc patients and healthy controls.

Results

LRG KO mice display an inhibition of fibrosis in the skin in association with a decrease of dermal thickness, collagen deposition, and phospho-Smad3 expression after bleomycin. Serum LRG concentration significantly increased in WT mice after bleomycin. There was also a suppression of inflammation and fibrosis in the LRG KO mouse lung indicated by a reduction of lung weight, collagen content, and phospho-Smad3 expression after bleomycin. Gene expressions of TGF-β and Smad2/3 were significantly reduced in LRG KO mice. Serum LRG levels in SSc patients were significantly higher than those in controls.

Conclusion

LRG promotes fibrotic processes in SSc model through TGF-β-Smad3 signaling, and LRG can be a biomarker for SSc in humans and also a potential therapeutic target for SSc.
Dendritic cell actin dynamics control contact duration and priming efficiency at the immunological synapse
Authors: Leithner Alexander , Altenburger Lukas M. , Hauschild Robert , Assen Frank P. , Rottner Klemens , Stradal Theresia E.B. , Diz-Muñoz Alba , Stein Jens V. , Sixt Michael
Published: February 2021

Dendritic cells (DCs) are crucial for the priming of naive T cells and the initiation of adaptive immunity. Priming is initiated at a heterologous cell–cell contact, the immunological synapse (IS). While it is established that F-actin dynamics regulates signaling at the T cell side of the contact, little is known about the cytoskeletal contribution on the DC side. Here, we show that the DC actin cytoskeleton is decisive for the formation of a multifocal synaptic structure, which correlates with T cell priming efficiency. DC actin at the IS appears in transient foci that are dynamized by the WAVE regulatory complex (WRC). The absence of the WRC in DCs leads to stabilized contacts with T cells, caused by an increase in ICAM1-integrin–mediated cell–cell adhesion. This results in lower numbers of activated and proliferating T cells, demonstrating an important role for DC actin in the regulation of immune synapse functionality.
A Q-switched fiber laser using a Ti2AlN-based saturable absorber
Authors: Kwon SuhYoung , Lee Jinho , Lee Ju Han
Published: February 2021

We experimentally demonstrate the fabrication of a polarization-insensitive Ti2AlN-based, fiberized saturable absorber (SA) for Q-switching of a fiber laser. The fabrication procedure for the SA is as follows. A mixture of Ti2AlN/polyvinyl alcohol (PVA) composite solution was deposited onto a slide glass and spread evenly. After the spread Ti2AlN/PVA composite dried, the formed film was stripped off the slide glass and transferred onto the flat end of a fiber connection/angled physical contact fiber ferrule. The modulation depth and saturation intensity of the resulting SA were measured to be ∼3.2% and ∼3.4 MW cm−2, respectively. The sandwich-structured SA was successfully used to generate Q-switched pulses from an erbium-doped-fiber ring cavity. The temporal width of the Q-switched pulses with a repetition rate of 41.55 kHz was ∼2.52 μs at a wavelength ∼1557 nm.
Towards absorption spectroscopy by means of mid-infrared supercontinuum generation in a step index tellurite fiber
Authors: Lemière Arnaud , Maldonado Anthony , Désévédavy Frédéric , Kibler Bertrand , Mathey Pierre , Gadret Grégory , Jules Jean-Charles , Hoa Nguyen Phuoc Trung , Suzuki Takenobu , Ohishi Yasutake , Smektala Frédéric
Published: February 2021

We report on mid-infrared gas spectroscopy measurements by means of the supercontinuum (SC) absorption spectroscopy method. We developed a 80 MHz-repetition-rate mid-infrared SC light source with an average power of 40 mW generated through nonlinear propagation of 200 fs pulses in a 10 cm-long segment of step-index tellurite fiber. A compact multipass cell is used for analyzing absorption of CO2 and CH4 gases and their mixture in the 2–3.5 µm spectral range. Experimental results are compared to the HITRAN database.
Raman investigation of hydration structure of iodide and iodate*
Authors: Liu Zhe , Zhao Hong-Liang , Lang Hong-Zhi , Wang Ying , Li Zhan-Long , Men Zhi-Wei , Wang Sheng-Han , Sun Cheng-Lin
Published: February 2021

In the troposphere, the destruction of ozone and the formation of new particles are closely related to the iodine content, which mainly comes from iodide (I−) and iodate (

IO

3
−

) in the seawater. Therefore, understanding the interactions between I−,

IO

3
−

and water molecules plays a certain role in alleviating the destruction of the ozone layer. Raman spectroscopy is commonly used to obtain the information of the interaction between I−,

IO

3
−

and water molecules quickly and accurately. Herein, the effect of I− and

IO

3
−

on the change in Raman band characteristics of water is investigated to reflect the associated intermolecular interactions change. With the addition of the two ions, the Raman band corresponding to OH stretching vibration moves towards the high wavenumber, indicating the formation of hydration structure. The narrowing of the Raman band from OH stretching vibration under weak hydrogen bond agrees well with the hydrogen bond variation, while the abnormal broadening of the Raman band from OH stretching vibration under strong hydrogen bond indicates the formation of H-down structure. With the increase of ions concentration, the frequency shift of the Raman band from OH stretching vibration under both weak and strong hydrogen bonds becomes more apparent. Meanwhile, the frequency shift of I− is more obvious than that of

IO

3
−

, which indicates that I− is more likely to form the hydration structure with water than

IO

3
−

. These results contribute to analyzing the different interactions between I−–water and

IO

3
−

–water, then helping to prevent ozone depletion.