bluuebunny/crossref_metadata_2025 huggingface dataset:
Interfacial engineering of a Mo/Hf0.3Zr0.7O2/Si capacitor using the direct scavenging effect of a thin Ti layer
Authors: Kim Se Hyun , Yu Geun Taek , Park Geun Hyeong , Lee Dong Hyun , Park Ju Yong , Yang Kun , Lee Eun Been , Lee Je In , Park Min Hyuk
Published: October 2021

The endurance of a Mo/Hf0.3Zr0.7O2/Si capacitor was improved up to 109 cycles by using a Ti layer formed prior to the atomic layer deposition of a Hf0.3Zr0.7O2 film to avoid direct exposure of Si to ozone with resulting trap density decrease.
A C3-symmetric twisted organic salt as an efficient mechano-/thermo-responsive molecule: a reusable and sensitive fluorescent thermometer
Authors: Prusti Banchhanidhi , Samanta Pralok K. , English Niall J. , Chakravarty Manab
Published: October 2021

C
3-Symmetric thermally stable twisted phenothiazine-based organic salt is recognised as a mechano-/thermo-fluorochromic material and used as reusable molecular thermometer to detect the temperature range of 130–170 °C.
Molecular rotors as reporters for viscosity of solutions of collagen like peptides
Authors: McTiernan Christopher D. , Zuñiga-Bustos Matias , Rosales-Rojas Roberto , Barrias Pablo , Griffith May , Poblete Horacio , Sherin Peter S. , López-Duarte Ismael , Kuimova Marina K. , Alarcon Emilio I.
Published: October 2021

A BODIPY molecular rotor can be used to evaluate the viscosity of collagen-like peptide-PEG solutions.
Shape selectivity effects in the hydroconversion of perhydrophenanthrene over bifunctional catalysts
Authors: Brito Larissa , Pirngruber Gerhard D. , Perez-Pellitero Javier , Guillon Emmanuelle , Albrieux Florian , Martens Johan A.
Published: October 2021

The zeolite pore structure dictates the formation of isomers, which in turn influences the preferred ring opening products and the distribution of cracking products.
Graphitic carbon nitride photocatalysis: the hydroperoxyl radical role revealed by kinetic modelling
Authors: Velo-Gala Inmaculada , Torres-Pinto André , Silva Cláudia G. , Ohtani Bunsho , Silva Adrián M. T. , Faria Joaquim L.
Published: October 2021

The behaviour of graphitic carbon nitride photocatalysis for phenol removal and H2O2 evolution was fully analysed by kinetic modelling, rediscovering the contribution of oxygen, reactive oxygen species, photogenerated holes and intermediate products.
Three types of charged ligand-based neutral phosphorescent iridium(iii) complexes featuring nido-carborane: synthesis, structures, and solution processed organic light-emitting diode applications
Authors: Li Qiuxia , Shi Chao , Huang Manli , Zhang Xinghua , Sun Fangxiang , Zheng Ying , Yan Hong , Yang Chuluo , Yuan Aihua
Published: October 2021

A novel family of three types of charged ligand (0, −1, and −2) based neutral phosphorescent iridium(iii) complexes featuring nido-carborane have been prepared and their structures and photophysical properties have been studied.
A new broad-band infrared window material CdPbOCl2 with excellent comprehensive properties
Authors: Bai Chen , Cheng Bingliang , Zhang Kewang , Zhang Min , Pan Shilie , Li Junjie
Published: October 2021

A new infrared window material CdPbOCl2, with wide infrared transmission regions and excellent comprehensive properties, was rationally designed and fabricated.
Novel polynitro azoxypyrazole-based energetic materials with high performance
Authors: Yang Pengju , Yang Hongwei , Zhao Ying , Tang Jie , Cheng Guangbin
Published: October 2021

Novel polynitro azoxypyrazole-based energetic compounds 1,2-bis (4-nitro-1H-pyrazol-5-yl) diazene 1-oxide (3) and 1,2-bis (1,4-dinitro-1H-pyrazol-3-yl) diazene 1-oxide (4) were synthesized from 5-amino-pyrazole-4-carbonitrile by optimized reactions.
Atomically dispersed Pd sites on Ti-SBA-15 for efficient catalytic combustion of typical gaseous VOCs
Authors: Wen Meicheng , Song Shengnan , Zhao Weina , Liu Qiuxia , Chen Jiangyao , Li Guiying , An Taicheng
Published: October 2021

An atomically dispersed Pd site catalyst with 0.04 wt% Pd loading amount has been prepared for catalytic combustion of typical gaseous VOCs with high catalytic activity and stability.
Phosphorus solubilization in stormwater ponds: rapid field assessment to identify ponds with excessive total phosphorus concentrations
Authors: Austin David , Liao Hehuan , Scharf Roger
Published: October 2021

Wet stormwater ponds are sedimentation basins used for phosphorus (P) removal in urban watersheds.
Mechanistic understanding of the catalytic hydrogenation of bio-derived aromatics
Authors: Yu Iris K. M.
Published: October 2021

The pressing need for “zero carbon” calls for a transition from the petroleum refinery to biorefinery of renewable feedstocks. This review addresses the kinetic and thermodynamic understanding in the hydrogenative upgrading of bio-derived aromatics.
Development of S4A–BSA–Au NPs for enhanced anti-tumor therapy of canine breast cancer
Authors: Chen Qi , Xu Chengfang , Sun Zhonghao , Yang Jingjing , Chen Fan , Lin Zixiang , Lin Degui , Jiang Yanyan , Lin Jiahao
Published: October 2021

S4A–BSA–Au NPs were prepared by ethanol-induced self-assembly with BSA and B-BANC-NPs (BANCs) as precursors achieving an excellent anticancer effect after loading with S4A.
Design for dynamic hydrogen bonding in a double network structure to improve the mechanical properties of sodium alginate fibers
Authors: Yan Ming , Shi Junfeng , Tang Song , Zhou Guohang , Zeng Jiexiang , Zhang Yixin , Zhang Hong , Yu Yue , Guo Jing
Published: October 2021

The SA/PAA-VSNP fiber was obtained using dynamic wet spinning through dynamic hydrogen bonding in the double network structure.
Cyclopentadienylmetal group 6 metal carbonyl derivatives with 2-propanoneoximato and related ligands
Authors: Dănescu Theodor M. , Silaghi-Dumitrescu Radu , Lupan Alexandru , King R. Bruce
Published: October 2021

The experimental NO-dihapto (Me2CNO)Mo(CO)2Cp dicarbonyl structure is found by density functional theory to be the lowest energy isomer by a substantial margin. The lowest energy structures for the corresponding monocarbonyls are of the type (Me2CN)M(O)(CO)Cp with separate dimethylimino and oxo ligands.
Radical-mediated aerobic oxidation of substituted styrenes and stilbenes
Authors: Aman Hasil , Chiu Wei-Hua , Liu Pin-Heng , Chuang Gary Jing
Published: October 2021

A 2,2-azobis(isobutyronitrile)-catalyzed oxidative cleavage of alkenes with molecular oxygen as the oxidant was described.
Effect of vacancy concentration on the lattice thermal conductivity of CH3NH3PbI3: a molecular dynamics study
Authors: Hong Song-Nam , Yu Chol-Jun , Jong Un-Gi , Choe Song-Hyok , Kye Yun-Hyok
Published: October 2021

Molecular dynamics simulations with the MYP force field were performed to determine the thermal conductivity of perfect and defective bulk MAPbI3. Thermal conductivity was found to decrease overall as the vacancy concentration increased.
A highly selective pyridoxal-based chemosensor for the detection of Zn(ii) and application in live-cell imaging; X-ray crystallography of pyridoxal-TRIS Schiff-base Zn(ii) and Cu(ii) complexes
Authors: Hussain Anwar , Mariappan Kadarkaraisamy , Cork Dawson C. , Lewandowski Luke D. , Shrestha Prem K. , Giri Samiksha , Wang Xuejun , Sykes Andrew G.
Published: October 2021

The synthesis, characterization, X-ray crystallography, and live-cell imaging of pyridoxal-TRIS Schiff-base ligand which is selective as a luminescence sensor to detect Zn(ii) ion, and the corresponding Zn(ii) and Cu(ii) complexes are described.
Comparative study on interfacial and foaming properties of glycolipids in relation to the gas applied for foam generation
Authors: Hollenbach Rebecca , Oeppling Sophie , Delavault André , Völp Annika R. , Willenbacher Norbert , Rudat Jens , Ochsenreither Katrin , Syldatk Christoph
Published: October 2021

Enzymatically tailor-made glycolipids, as well as certain microbial glycolipids provide an efficient, powerful alternative to petroleum-based surfactants concerning foaming properties.
A hybrid bipy–NHC ligand for the construction of group 11 mixed-metal bimetallic complexes
Authors: Kariuki Benson M. , Platts James A. , Newman Paul D.
Published: October 2021

A ditopic bipy–NHC ligand has been used to construct hetero-bimetallic complexes of the monovalent group 11 metals.
Synthesis of dithienofurans via cascade copper catalysed dual C–S coupling and ring closure reactions under mild conditions
Authors: Zhou Lu , Chen Zhaopeng , Li Jiahui , Li Baolin
Published: October 2021

We have developed a mild catalytic approach for the synthesis of new dithienofuran compounds via cascade copper catalysed dual C–S coupling and subsequent ring closure reactions. This strategy shows broad substrate scope.
Polymer looping kinetics in active heterogeneous environments
Authors: Zhang Bingjie , Tan Fei , Zhao Nanrong
Published: October 2021

We reveal novel phenomena of polymer looping kinetics induced by the interplay of heterogeneity, crowdedness and activity features of the media. A perplexing facilitation–inhibition transition is clarified and the underlying mechanism is unravelled.
Accelerated Li-ion transport through a zwitterion-anchored separator for high-performance Li–S batteries
Authors: Lee Jun Hyuk , Yeon Jeong Seok , Kim Jihoon , Park Jeong Hee , Yoo Seong Soo , Hong Sunghwan , Kim Minjun , Park Moon Jeong , Park Ho Seok , Yoo Pil J.
Published: October 2021

Zwitterionic sulfobetaine moieties were anchored on a separator surface to concurrently facilitate selective Li-ion transport and polysulfide conversion, finally resulting in significantly enhanced performance for durable Li–S battery operation.
Effect of electric hysteresis on fatigue behavior in antiferroelectric bulk ceramics under bipolar loading
Authors: Mohapatra Pratyasha , Johnson Duane D. , Cui Jun , Tan Xiaoli
Published: October 2021

The fatigue behavior of antiferroelectric ceramics with different electric hysteresis are comparatively studied. The ceramic with small hysteresis displays not only a high energy efficiency, but also a much more stable performance and longer life.
Enhancing the brightness of CsPbBr3 quantum dot electroluminescence light-emitting diodes by manipulation of PEDOT:PSS films
Authors: Wang Zhen , Peng Yue , Lu Yongsheng , Tang Xiaosheng , Tan Xing , Liang Zhenshan , Huang Qiang , Qi Fei , Zhang Nan , Chen Weiwei
Published: October 2021

This work outlines the manipulation of the hole transport layer PEDOT:PSS films of QLED devices by three methods, air annealing, toluene vapor annealing, and EG washing to improve device performance.
Intelligent host engineering for metabolic flux optimisation in biotechnology
Authors: Munro Lachlan J. , Kell Douglas B.
Published: October 2021

Optimising the function of a protein of length N amino acids by directed evolution involves navigating a ‘search space’ of possible sequences of some 20N. Optimising the expression levels of P proteins that materially affect host performance, each of which might also take 20 (logarithmically spaced) values, implies a similar search space of 20P. In this combinatorial sense, then, the problems of directed protein evolution and of host engineering are broadly equivalent. In practice, however, they have different means for avoiding the inevitable difficulties of implementation. The spare capacity exhibited in metabolic networks implies that host engineering may admit substantial increases in flux to targets of interest. Thus, we rehearse the relevant issues for those wishing to understand and exploit those modern genome-wide host engineering tools and thinking that have been designed and developed to optimise fluxes towards desirable products in biotechnological processes, with a focus on microbial systems. The aim throughput is ‘making such biology predictable’. Strategies have been aimed at both transcription and translation, especially for regulatory processes that can affect multiple targets. However, because there is a limit on how much protein a cell can produce, increasing kcat in selected targets may be a better strategy than increasing protein expression levels for optimal host engineering.
Development and prospects of metamaterial in wireless power transfer
Authors: Huang Xiutao , Zhang Chunbo , Cong Lin , Cai Rufeng , Yang Fan , Lu Conghui
Published: October 2021

As a unique group of advanced artificial materials, metamaterials have found many interesting applications in various devices due to the ability to control electromagnetic fields. The metamaterial provides the prospect of new opportunities for the wireless power transfer (WPT) system to improve efficiency and reduce magnetic flux density. This review paper evaluates the performance of the WPT system with metamaterial from both principles and functions aspects. The objectives of this review include: (1) to present the research process and bottlenecks of metamaterial in the WPT system; (2) to clarify the design solution and checking method of the metamaterial and (3) to identify the challenges and opportunities based on the functional of the WPT system integration with metamaterial. Therefore, the process on metamaterial design, working principle of metamaterial, optimal method, equivalent model, and experimental method are reviewed. The recent efforts of the WPT system with metamaterial in efficiency enhancement, misalignments, magnetic field reduction are illustrated. Finally, the challenges and prospects of metamaterial based on the WPT system are concluded.
Dust entrainment in photoevaporative winds: Densities and imaging
Authors: Franz R. , Ercolano B. , Casassus S. , Picogna G. , Birnstiel T. , Pérez S. , Rab Ch. , Sharma A.
Published: October 2021

Context.X-ray- and extreme-ultraviolet- (together: XEUV-) driven photoevaporative winds acting on protoplanetary disks around young T-Tauri stars may crucially impact disk evolution, affecting both gas and dust distributions.

Aims.We constrain the dust densities in a typical XEUV-driven outflow, and determine whether these winds can be observed at μm-wavelengths.

Methods.We used dust trajectories modelled atop a 2D hydrodynamical gas model of a protoplanetary disk irradiated by a central T-Tauri star. With these and two different prescriptions for the dust distribution in the underlying disk, we constructed wind density maps for individual grain sizes. We used the dust density distributions obtained to synthesise observations in scattered and polarised light.

Results.For an XEUV-driven outflow around aM*= 0.7M⊙T-Tauri star withLX= 2 × 1030erg s−1, we find a dust mass-loss rateṀdust≲ 4.1 × 10−11M⊙yr−1for an optimistic estimate of dust densities in the wind (compared toṀgas≈ 3.7 × 10−8M⊙yr−1). The synthesised scattered-light images suggest a distinct chimney structure emerging at intensitiesI∕Imax< 10−4.5(10−3.5) atλobs= 1.6 (0.4) μm, while the features in the polarised-light images are even fainter. Observations synthesised from our model do not exhibit clear features for SPHERE IRDIS, but show a faint wind signature for JWST NIRCam under optimal conditions.

Conclusions.Unambiguous detections of photoevaporative XEUV winds launched from primordial disks are at least challenging with current instrumentation; this provides a possible explanation as to why disk winds are not routinely detected in scattered or polarised light. Our calculations show that disk scale heights retrieved from scattered-light observations should be only marginally affected by the presence of an XEUV wind.
Towards modelling active sound localisation based on Bayesian inference in a static environment
Authors: McLachlan Glen , Majdak Piotr , Reijniers Jonas , Peremans Herbert
Published: October 2021

Over the decades, Bayesian statistical inference has become a staple technique for modelling human multisensory perception. Many studies have successfully shown how sensory and prior information can be combined to optimally interpret our environment. Because of the multiple sound localisation cues available in the binaural signal, sound localisation models based on Bayesian inference are a promising way of explaining behavioural human data. An interesting aspect is the consideration of dynamic localisation cues obtained through self-motion. Here we provide a review of the recent developments in modelling dynamic sound localisation with a particular focus on Bayesian inference. Further, we describe a theoretical Bayesian framework capable to model dynamic and active listening situations in humans in a static auditory environment. In order to demonstrate its potential in future implementations, we provide results from two examples of simplified versions of that framework.
Arbeitsperspektiven für Menschen mit psychischen Erkrankungen unter Corona-Bedingungen: Eine explorative Kurzumfrage
Authors: Dehn Lorenz B. , Böske Nils , Beblo Thomas , Steinhart Ingmar , Stengler Katarina , Driessen Martin
Published: October 2021

Ziel der Studie Explorative Untersuchung der coronabedingten Auswirkungen auf die beruflichen Perspektiven von Menschen mit psychischen Erkrankungen auf dem ersten Arbeitsmarkt.

Methode Kurzumfrage mit quantitativen und qualitativen Fragen unter Mitarbeitenden aus der beruflichen Rehabilitation und Wiedereingliederung.

Ergebnisse Von den n = 76 Teilnehmenden gaben über 90 % an, dass sich die Situation beim beruflichen Wiedereinstieg bzw. der Arbeitsplatzsuche coronabedingt (deutlich) verschlechtert habe. 75 % sahen auch auf längere Sicht hin negative Aussichten für die berufliche Rehabilitation. Offene Antworten zu Schwierigkeiten verwiesen neben dem Hauptproblem fehlender Stellenangebote u. a. auf erhöhte psychische Belastungen bei den Betroffenen sowie Probleme bei der Erreichbarkeit von Ansprechpersonen oder bei Online-Prozessen.

Schlussfolgerung Durch die Corona-Situation ist es zu einer zusätzlichen Verschlechterung der beruflichen Perspektiven und Teilhabechancen von Menschen mit psychischen Erkrankungen gekommen.
Percutaneous Aspiration Thrombectomy for Arterial Thromboembolic Occlusion Following Percutaneous Transluminal Angioplasty: Technical Success Rates and Clinical Outcomes
Authors: Schicho Andreas , Bäumler Wolf , Verloh Niklas , Beyer Lukas Philipp , Schierling Wilma , Uller Wibke , Gößmann Holger , Stroszczynski Christian , Dollinger Marco
Published: October 2021

Purpose We aimed to analyze the technical success rate of manual percutaneous aspiration thrombectomy (PAT) in patients with peripheral arterial thromboembolism as a complication of infrainguinal percutaneous transluminal angioplasty (PTA) and we sought to evaluate the 30-day postintervention clinical outcome.

Materials and Methods We retrospectively identified 29 patients (men/women, 18/11; mean age, 74 years) who underwent infrainguinal PAT to treat thromboembolic complications of infrainguinal PTA. Primary and secondary technical successes were defined as residual stenosis of < 50 % of the vessel diameter after PAT alone and PAT with additional PTA, respectively. Clinical outcome parameters (e. g., amputation, need for further intervention) were evaluated during the first 30 days after intervention.

Results The primary and secondary technical success rates were 58.6 % (17/29) and 79.3 % (23/29), respectively. Clinical outcome data were available for 93.1 % (27/29) of patients. No further intervention was required within 30 days in 81.5 % (22/27) of patients. Four patients underwent minor amputations owing to preexisting ulcerations (Rutherford Category 5), and no patients underwent major amputations (Rutherford Category 6). Revascularization of the previously treated vessel segment with PTA was necessary on the first postintervention day in one patient.

Conclusion Manual PAT, with PTA if needed, has a good technical success rate and satisfactory early clinical outcome in patients with iatrogenic thromboembolic complications after infrainguinal PTA.

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Citation Format
Comparison of Dentinal Tubule Penetration between a Calcium Silicate-Based Sealer with Ultrasonic Activation and an Epoxy Resin-Based Sealer: A Study Using Confocal Laser Scanning Microscopy
Authors: Song Dani , Yang Sung-Eun
Published: October 2021

Objective The aim of this study was to compare the degree of dentinal penetration between an epoxy resin-based sealer applied by using two different filling methods and an ultrasonically activated calcium silicate-based sealer via confocal laser scanning microscopy (CLSM).

Materials and Methods Forty-five extracted permanent maxillary premolars with type II canals (Vertucci’s classification) were subjected to the experiment. The root canals were instrumented and distributed randomly into the following three groups: AH Plus + continuous wave technique (AHC group); AH Plus + single cone technique (AHS group); and Endoseal MTA + single cone technique with ultrasonic activation (EMS) group. Each sealer was labeled with rhodamine B dye to allow visualization under CLSM. The sealer penetration depth in each sample was observed at 2 mm and 5 mm from the apex by using CLSM. The data were statistically analyzed by using analysis of variance or Kruskal–Wallis H test according to normality of variable (α = 0.05).

Results In all groups, the maximum sealer penetration depth, mean fluorescence intensity, and sum fluorescence intensity values were higher at the 5-mm level than at the 2-mm level. At the 5-mm level, the EMS group showed the lowest value (p = 0.02). At the 2-mm level, there were no statistically significant differences among any of the groups. The AHC group showed higher values than the other groups, but there was no statistically significant difference in the apical area where access of instruments was difficult.

Conclusion The AHC group showed the highest dentinal tubule penetration, but had questionable filing efficacy in the apical area, which is of particular importance for the success of root canal treatment. Therefore, in areas such as the apical 2 mm of premolars with type II canals, which are difficult to access by using instruments such as heat carriers, other appropriate approaches may be required accordingly.
SARS-CoV-2 Genome Analysis of Pediatric Patients in Konya Region, Turkey
Authors: Tasbent Fatma Esenkaya , Özdemir Mehmet , Akcan Özge M. , Kurt Esma K.
Published: October 2021

Objective Genome sequencing is useful for following the change in mutation and variants in viral agent during pandemics. In this study, we performed next-generation sequencing of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) complete genomes on pediatric patients.

Methods Six pediatric patients aged 0 to 18 years who were positive for SARS-CoV-2 by reverse transcription polymerase chain reaction were included in this study. SARS-CoV-2 genome sequencing was performed using Oxford Nanopore Technologies MinION, following the ARTIC Network protocols. Sequencing data were obtained using the FASTQ program and quality assessment was evaluated. The sequence information of all samples was uploaded to the Global Initiative on Sharing All Influenza Data (GISAID) database. Genome, variant, clade, and phylogenetic tree analyses were performed with bioinformatic analysis.

Results Two of these six samples were at 20A, two were at 20B, and two were at 19A in the nextstrain clade. According to Pango lineages, B.1.36, B.1.218, B.1, and B.1.260 lineages were detected. A total of 84 mutations were observed in all samples. None of the variants were classified as variants of concern (VOC) nor variants of interest (VOI) according to the Pango database.

Conclusion This study is the first comprehensively sequence analysis registered in the GISAID database reported from the Konya region in Turkey. Similar studies will be informative to track changes in the virus genome, obtain epidemiological data, guide studies on diagnosis and treatment, and evaluate vaccine efficacy.
The Impact of Altitude at Birth on Perinatal Respiratory Support for Neonates with Trisomy 21
Authors: Bloom Jessica L. , Furniss Anna , Suresh Krithika , Fuhlbrigge Robert C. , Lamb Molly M. , Rosenberg Sophie , Edwards Anastasia , O'Leary Sean T.
Published: October 2021

Objective Both high altitude and trisomy 21 (T21) status can negatively impact respiratory outcomes. The objective of this study was to examine the association between altitude and perinatal respiratory support in neonates with T21 compared with those without T21.

Study Design This retrospective cohort study used the United States all-county natality files that included live, singleton, in-hospital births from 2015 to 2019. Descriptive statistics for neonates with and without the primary outcome of sustained assisted ventilation (>6 hours) were compared using t-tests and Chi-squared analyses. Multivariable logistic regression was used to determine the association between respiratory support and the presence of T21, and included an interaction term to determine whether the association between respiratory support and the presence of T21 was modified by elevation at delivery.

Results A total of 17,939,006 neonates, 4,059 (0.02%) with T21 and 17,934,947 (99.98%) without, were included in the study. The odds of requiring sustained respiratory support following delivery were 5.95 (95% confidence interval [CI]: 5.31, 6.66), 4.06 (95% CI: 2.39, 6.89), 2.36 (95% CI: 1.64, 3.40), and 5.04 (95% CI: 1.54, 16.54) times as high for neonates with T21 than without T21 when born at low, medium, high, and very high elevations, respectively. The odds of requiring immediate ventilation support following delivery were 5.01 (95% CI: 4.59, 5.46), 5.90 (95% CI: 4.16, 8.36), 2.86 (95% CI: 2.15, 3.80), and 12.08 (95% CI: 6.78, 21.51) times as high for neonates with T21 than without T21 when born at low, medium, high, and very high elevation, respectively.

Conclusion Neonates with T21 have increased odds of requiring respiratory support following delivery when compared with neonates without T21 at all categories of altitude. However, the odds ratios did not increase monotonically with altitude which indicates additional research is critical in understanding the effects of altitude on neonates with T21.

Key Points
Spatiotemporal characteristics in systems of diffusively coupled excitable slow–fast FitzHugh–Rinzel dynamical neurons
Authors: Mondal Arnab , Mondal Argha , Kumar Sharma Sanjeev , Kumar Upadhyay Ranjit , Antonopoulos Chris G.
Published: October 2021

In this paper, we study an excitable, biophysical system that supports wave propagation of nerve impulses. We consider a slow–fast, FitzHugh–Rinzel neuron model where only the membrane voltage interacts diffusively, giving rise to the formation of spatiotemporal patterns. We focus on local, nonlinear excitations and diverse neural responses in an excitable one- and two-dimensional configuration of diffusively coupled FitzHugh–Rinzel neurons. The study of the emerging spatiotemporal patterns is essential in understanding the working mechanism in different brain areas. We derive analytically the coefficients of the amplitude equations in the vicinity of Hopf bifurcations and characterize various patterns, including spirals exhibiting complex geometric substructures. Furthermore, we derive analytically the condition for the development of antispirals in the neighborhood of the bifurcation point. The emergence of broken target waves can be observed to form spiral-like profiles. The spatial dynamics of the excitable system exhibits two- and multi-arm spirals for small diffusive couplings. Our results reveal a multitude of neural excitabilities and possible conditions for the emergence of spiral-wave formation. Finally, we show that the coupled excitable systems with different firing characteristics participate in a collective behavior that may contribute significantly to irregular neural dynamics.
In situ nanoelectromechanical characterization of phase
transformation in Si phononic crystal during nanoindentation
Authors: Fujikane Masaki , Takahashi Kouhei , Tambo Naoki , Kozaki Takashi , Nagao Shijo
Published: October 2021

The size dependence of Young’s modulus and the critical pressure for phase transformation from the diamond structure at ambient pressure to a metallic β-Sn structure at high pressure was studied in a Si phononic crystal. We used dynamic mechanical analysis and in situ electrical characterization with an electrically conducting diamond nanoindentation tip. Experiments on several phononic periodic sizes enabled us to establish that the Young’s modulus and critical phase-transformation pressure decreased as the neck width (periodic structure) of the phononic crystal shrank. The finding enables us to understand the reduction in the thermal conductivity of the Si phononic crystal at the local neck between the nanoholes.
Epitaxial ferroelectric interfacial devices
Authors: Vaz C. A. F. , Shin Y. J. , Bibes M. , Rabe K. M. , Walker F. J. , Ahn C. H.
Published: October 2021

Ferroelectric interfacial devices consist of materials systems whose interfacial electronic properties (such as a 2D electron gas or an interfacial magnetic spin configuration) are modulated by a ferroelectric layer set in its immediate vicinity. While the prototypical example of such a system is the ferroelectric field effect transistor first proposed in the 1950s, only with the recent advances in the controlled growth of epitaxial thin films and heterostructures, and the recent physical understanding down to the atomic scale of screening processes at ferroelectric-semiconducting and -metallic interfaces made possible by first principles calculations, have the conditions been met for a full development of the field. In this review, we discuss the recent advances in ferroelectric interfacial systems with emphasis on the ferroelectric control of the electronic properties of interfacial devices with well ordered (epitaxial) interfaces. In particular, we consider the cases of ferroelectric interfacial systems aimed at controlling the correlated state, including superconductivity, Mott metallic-insulator transition, magnetism, charge, and orbital order, and charge and spin transport across ferroelectric tunnel junctions. The focus is on the basic physical mechanisms underlying the emergence of interfacial effects, the nature of the ferroelectric control of the electronic state, and the role of extreme electric field gradients at the interface in giving rise to new physical phenomena. Such understanding is key to the development of ferroelectric interfacial systems with characteristics suitable for next generation electronic devices based on controlling the correlated state of matter.
Exploring human-guided strategies for reaction network exploration: Interactive molecular dynamics in virtual reality as a tool for citizen scientists
Authors: Shannon Robin J. , Deeks Helen M. , Burfoot Eleanor , Clark Edward , Jones Alex J. , Mulholland Adrian J. , Glowacki David R.
Published: October 2021

The emerging fields of citizen science and gamification reformulate scientific problems as games or puzzles to be solved. Through engaging the wider non-scientific community, significant breakthroughs may be made by analyzing citizen-gathered data. In parallel, recent advances in virtual reality (VR) technology are increasingly being used within a scientific context and the burgeoning field of interactive molecular dynamics in VR (iMD-VR) allows users to interact with dynamical chemistry simulations in real time. Here, we demonstrate the utility of iMD-VR as a medium for gamification of chemistry research tasks. An iMD-VR “game” was designed to encourage users to explore the reactivity of a particular chemical system, and a cohort of 18 participants was recruited to playtest this game as part of a user study. The reaction game encouraged users to experiment with making chemical reactions between a propyne molecule and an OH radical, and “molecular snapshots” from each game session were then compiled and used to map out reaction pathways. The reaction network generated by users was compared to existing literature networks demonstrating that users in VR capture almost all the important reaction pathways. Further comparisons between humans and an algorithmic method for guiding molecular dynamics show that through using citizen science to explore these kinds of chemical problems, new approaches and strategies start to emerge.
The microscopic origin of the anomalous isotopic properties of ice relies on the strong quantum anharmonic regime of atomic vibration
Authors: Cherubini Marco , Monacelli Lorenzo , Mauri Francesco
Published: October 2021

Water ice is a unique material presenting intriguing physical properties, such as negative thermal expansion and anomalous volume isotope effect (VIE). They arise from the interplay between weak hydrogen bonds and nuclear quantum fluctuations, making theoretical calculations challenging. Here, we employ the stochastic self-consistent harmonic approximation to investigate how thermal and quantum fluctuations affect the physical properties of ice XI with ab initio accuracy. Regarding the anomalous VIE, our work reveals that quantum effects on hydrogen are so strong to be in a nonlinear regime: When progressively increasing the mass of hydrogen from protium to infinity (classical limit), the volume first expands and then contracts, with a maximum slightly above the mass of tritium. We observe an anharmonic renormalization of about 10% in the bending and stretching phonon frequencies probed in IR and Raman experiments. For the first time, we report an accurate comparison of the low-energy phonon dispersion with the experimental data, possible only thanks to high-level accuracy in the electronic correlation and nuclear quantum and thermal fluctuations, paving the way for the study of thermal transport in ice from first-principles and the simulation of ice under pressure.
Global conservative weak solutions for the two-component Novikov equation
Authors: He Cheng , Qu Changzheng
Published: October 2021

In this paper, we study the existence of global conservative solutions to a two-component Novikov system. The system is an integrable multi-component extension of the Novikov integrable equation. We develop the method of constructing global conservative solutions of the Camassa–Holm equation due to Bressan and Constantin to a two-component case with genuine nonlinear interactions. Our approach is based on the formulation of Bressan and Constantin and additional estimates relating to the new conservation laws of the system.
Suppressing exciton deconfinement and dissociation for efficient thermally activated delayed fluorescence OLEDs
Authors: Hauenstein C. , de Vries X. , Weijtens C. H. L. , Imbrasas P. , Will P.-A. , Lenk S. , Ortstein K. , Reineke S. , Bobbert P. A. , Coehoorn R. , van Eersel H.
Published: October 2021

The efficiency of organic light-emitting diodes that utilize the principle of thermally activated delayed fluorescence (TADF) depends sensitively on the host material in which the TADF emitter molecules (guests) are embedded. Potential loss processes are “deconfinement,” the transfer of excitons from the guest to the host, and “dissociation,” the formation of intermolecular charge-transfer states. We investigate how both processes can be suppressed by studying the photoluminescence efficiency, emission spectrum, and time-resolved emission intensity of eight thin-film systems in which 5 mol. % of the sky-blue TADF emitter 4-carbazolyl-methylphthalimide (abbreviated here as CzPIMe) is embedded in various host materials. Deconfinement is found to be entirely suppressed if the triplet energy of the host is 0.25 eV or more above that of the guest. For systems allowing for deconfinement, the dependence on the energy difference is consistent with a recent theoretical analysis [C. Hauenstein et al., J. Appl. Phys. 128, 075501 (2020)]. Dissociation, due to hole transfer to a host molecule, is found to be suppressed if the host’s highest occupied molecular orbital energy is not more than about 0.2 eV higher than that of the guest. Otherwise, we observe an efficiency loss, a spectral redshift, and the disappearance of distinct prompt and delayed emission regimes. A comprehensive rate-equation model is developed from which we study the sensitivity of these observations to the energy level structure, the intermolecular interaction rates, and the photophysical rates that follow from a fit to the experimental data for the CzPIMe:TCTA[tris(4-carbazoyl-9-ylphenyl)amine] system.
Complex interferometry of magnetized plasma: Accuracy and limitations
Authors: Kochetkov Iu. , Pisarczyk T. , Kalal M. , Chodukowski T. , Zaraś-Szydłowska A. , Rusiniak Z. , Dudzak R. , Dostal J. , Krupka M. , Juha L. , Korneev Ph.
Published: October 2021

Expanding laser plasmas, produced by high energy laser radiation, possess both high thermal and magnetic field energy densities. Characterization of such plasma is challenging but may provide essential information needed for understanding its physical behavior. Among the standard experimental techniques used for plasma diagnostics, conventional interferometry is one of the most convenient, informative, and accurate. Attempts to extract more information from each laser shot on large facilities have led to development of complex interferometry, which allows us to reconstruct both plasma electron density and magnetic field distributions from a single data object. However, such a benefit requires more accurate processing, critically important in some situations. This work focuses on quasi-axisymmetric interaction geometry. Starting from basic principles, we present a general analysis, consider main error sources, and obtain plasma density and magnetic field distributions with their derived error bars. A regularization procedure, significantly decreasing an error near the plasma symmetry axis, is proposed and analyzed in detail. With use of synthetic datasets, the presented analysis is generally universal for quasi-axisymmetric plasmas.
Accurate parameterization of the kinetic energy functional for calculations using exact-exchange
Authors: Kumar Shashikant , Sadigh Babak , Zhu Siya , Suryanarayana Phanish , Hamel Sebastian , Gallagher Brian , Bulatov Vasily , Klepeis John , Samanta Amit
Published: October 2021

Electronic structure calculations based on Kohn–Sham density functional theory (KSDFT) that incorporate exact-exchange or hybrid functionals are associated with a large computational expense, a consequence of the inherent cubic scaling bottleneck and large associated prefactor, which limits the length and time scales that can be accessed. Although orbital-free density functional theory (OFDFT) calculations scale linearly with system size and are associated with a significantly smaller prefactor, they are limited by the absence of accurate density-dependent kinetic energy functionals. Therefore, the development of accurate density-dependent kinetic energy functionals is important for OFDFT calculations of large realistic systems. To this end, we propose a method to train kinetic energy functional models at the exact-exchange level of theory by using a dictionary of physically relevant terms that have been proposed in the literature in conjunction with linear or nonlinear regression methods to obtain the fitting coefficients. For our dictionary, we use a gradient expansion of the kinetic energy nonlocal models proposed in the literature and their nonlinear combinations, such as a model that incorporates spatial correlations between higher order derivatives of electron density at two points. The predictive capabilities of these models are assessed by using a variety of model one-dimensional (1D) systems that exhibit diverse bonding characteristics, such as a chain of eight hydrogens, LiF, LiH, C4H2, C4N2, and C3O2. We show that by using the data from model 1D KSDFT calculations performed using the exact-exchange functional for only a few neutral structures, it is possible to generate models with high accuracy for charged systems and electron and kinetic energy densities during self-consistent field iterations. In addition, we show that it is possible to learn both the orbital dependent terms, i.e., the kinetic energy and the exact-exchange energy, and models that incorporate additional nonlinearities in spatial correlations, such as a quadratic model, are needed to capture subtle features of the kinetic energy density that are present in exact-exchange-based KSDFT calculations.
Assessing time series irreversibility through micro-scale trends
Authors: Zanin Massimiliano
Published: October 2021

Time irreversibility, defined as the lack of invariance of the statistical properties of a system or time series under the operation of time reversal, has received increasing attention during the last few decades, thanks to the information it provides about the mechanisms underlying the observed dynamics. Following the need of analyzing real-world time series, many irreversibility metrics and tests have been proposed, each one associated with different requirements in terms of, e.g., minimum time series length or computational cost. We here build upon previously proposed tests based on the concept of permutation patterns but deviating from them through the inclusion of information about the amplitude of the signal and how this evolves over time. We show, by means of synthetic time series, that the results yielded by this method are complementary to the ones obtained by using permutation patterns alone, thus suggesting that “one irreversibility metric does not fit all.” We further apply the proposed metric to the analysis of two real-world data sets.
Steric interactions and out-of-equilibrium processes control the internal organization of bacteria
Authors: Miangolarra A. Movilla , Li Sophia Hsin-Jung , Joanny Jean-François , Wingreen Ned S. , Castellana Michele
Published: October 2021

Significance

Self-organizing processes and structures lie at the heart of biology. Here, we study compaction and localization of DNA inside cells of the bacterium
Escherichia coli
. We explain the physics behind this phenomenon based on excluded-volume interactions, by which the DNA spontaneously phase separates from other intracellular crowders. We then explore the rich phenomenology that arises when these interactions are coupled to out-of-equilibrium cellular processes, such as the transcription and degradation of messenger RNAs. The results agree well with recent experimental observations of the size, positioning, and dynamical splitting of
E. coli
’s DNA, providing an example of the tight control that cells exert over their internal organization by means of out-of-equilibrium processes.
Acute Csk inhibition hinders B cell activation by constraining the PI3 kinase pathway
Authors: Lu Wen , Skrzypczynska Katarzyna M. , Weiss Arthur
Published: October 2021

Significance

B lymphocytes recognize pathogenic antigens and become activated via their B cell receptors (BCR). This BCR-dependent activation is controlled by Src-family kinases (SFKs). It is unclear how B cells tolerate the fluctuations of SFK activities and maintain unresponsiveness in the absence of foreign antigens. Using a chemical-genetic system, we acutely inhibited C-terminal Src kinase to enhance the SFK activity in mouse B cells. Surprisingly, we observed marked inhibition of BCR-downstream signaling due to associated impairment of the phosphatidylinositol-trisphosphate pathway. These results reveal the critical importance of maintaining a proper amount of SFK activity in quiescent B cells for appropriate BCR-dependent responses, which may be critical for naïve B cell unresponsiveness to self-antigens to maintain peripheral tolerance.
Cannabis and Binge Alcohol use among Older Individuals with Major Depressive Episode
Authors: Choi Namkee G. , DiNitto Diana M. , Marti C. Nathan , Choi Bryan Y.
Published: October 2021

Background: Research shows significant associations of major depression with cannabis and binge alcohol use. However, despite increasing cannabis and binge alcohol use rates among the 50+ age group, research on this age group is scant. Methods: We used the 2015–2019 National Survey on Drug Use and Health data ( n = 44,007 age 50+) and multinomial logistic regression models to examine associations of a major depressive episode (MDE) with cannabis and binge alcohol use and co-use and associations of binge alcohol use with nonmedical and medical cannabis use. Results: Of individuals age 50+, 89.6% had no history of MDE, 5.7% had prior-to-past-year MDE, and 4.7% had past-year MDE. The rates of past-month cannabis use were 4.3%, 7.7%, and 11.6% and binge alcohol use were 17.3%, 18.7%, and 19.9% among those with no MDE history, prior-to-past-year MDE, and past-year MDE, respectively. Compared to no MDE history, prior-to-past-year MDE (RRR = 1.70, 95% CI = 1.30–2.23) and past-year MDE (RRR = 1.80, 95% CI = 1.27–2.55) were significantly associated with past-month cannabis use (with or without binge alcohol use). However, MDE status was not associated with past-month binge alcohol use. Among cannabis users, binge alcohol use was significantly associated with nonmedical cannabis use only (RRR = 2.50, 95% CI = 1.95–3.21). Users of cannabis and/or binge alcohol also had a higher likelihood of using tobacco products and illicit drugs. Conclusions: Healthcare professionals treating individuals age 50+ with depression should screen for substance use, provide education on the potential adverse effects of polysubstance use, and help them access treatment for co-occurring depression and substance use problems.
Study of optical, thermal and radio frequency properties of low emissivity coatings with frequency selective surfaces
Authors: Alcain R , Carretero E , Chueca R , Heras C , Salinas I
Published: October 2021

The use of frequency selective surfaces (FSSs) defined on railcar windows with a metallic low-e coating to improve the reception of mobile communications signals is becoming ever more common. The proximity of the glass to the passenger in this scenario has introduced a new parameter to consider, aesthetics. This paper presents a complete study of the development of a FSS defined by laser ablation, considering all current requirements. The fabricated samples will be characterized in the optical and radiofrequency ranges of the spectrum. Also, by means of an electron microscope, the chemical elements of each area of the samples will be quantified, in order to study the ablation process. New samples will be made using these parameters, and its performance according to specifications verified. These data will be correlated, using digital image processing, to the aesthetic impact of the engraved FSS, as confirmation of the optimal laser configuration.
Temperature distribution inside a porous silicon photonic mirror
Authors: Estrada-Wiese D , Balbuena-Ortega A , del Río J A
Published: October 2021

Photonic devices require precise and high-cost procedures to evaluate their performance which is related to their temperature increase. The fundamental understanding of thermal phenomena, ergo measurement of temperature, inside radiation controlling devices is of great relevance to study their performance. In this paper, we carry out a comprehensive campaign of experiments to study the temperature profile inside a porous silicon multilayer 1D photonic structure by using a thermographic camera. In particular, we have analyzed broad-range reflective devices and found that the electromagnetic radiation does not travel beyond the photonic structure showing a clear maximum inside of it. We have compared this result with a pure silicon wafer under the interaction with the same radiation. To compare these samples, we used a normalization procedure that can be implemented on many microstructured devices to simplify their performance evaluation.