bluuebunny/crossref_metadata_2025_split huggingface dataset:
Robustness of structural superlubricity beyond rigid models
Authors: Feng Shizhe , Xu Zhiping 
Published: February 2022

AbstractStructural superlubricity is a theoretical concept stating that the friction force is absent between two rigid, incommensurate crystalline surfaces. However, elasticity of the contact pairs could modify the lattice registry at interfaces by nucleating local slips, favoring commeasure. The validity of structural superlubricity is thus concerned for large-scale systems where the energy cost of elastic distortion to break the lattice registry is low. In this work, we study the size dependence of superlubricity between single-crystal graphite flakes. Molecular dynamics simulations show that with nucleation and propagation of out-of-plane dislocations and strained solitons at Bernal interfaces, the friction force is reduced by one order of magnitude. Elastic distortion is much weaker for non-Bernal or incommensurate ones, remaining notable only at the ends of contact. Lattice self-organization at small twist angles perturbs the state of structural superlubricity through a reconstructed potential energy surface. Theoretical models are developed to illustrate and predict the interfacial elastoplastic behaviors at length scales beyond those in the simulations. These results validate the rigid assumption for graphitic superlubricity systems at microscale, and reveal the intrinsic channels of mechanical energy dissipation. The understandings lay the ground for the design of structural superlubricity applications.
Monolayer Graphitic Carbon Nitride as Metal-Free Catalyst with Enhanced Performance in Photo- and Electro-Catalysis
Authors: Piao Huiyan , Choi Goeun , Jin Xiaoyan , Hwang Seong-Ju , Song Young Jae , Cho Sung-Pyo , Choy Jin-Ho 
Published: February 2022

Highlights

The g-C3N4 monolayer in the perfect 2D limit was successfully realized, for the first time, by the well-defined chemical strategy based on the bottom-up process.

The most striking evidence was made from Cs–high resolution transmission electron microscopy measurements by observing directly the atomic structure of g-C3N4 unit cell, which was again supported by the corresponding high resolution transmission electron microscopy image simulation results.

We demonstrated that the newly prepared g-C3N4 monolayer showed outstanding photocatalytic activity for H2O2 generation as well as excellent electrocatalytic activity for oxygen reduction reaction.

Abstract
The exfoliation of bulk graphitic carbon nitride (g-C3N4) into monolayer has been intensively studied to induce maximum surface area for fundamental studies, but ended in failure to realize chemically and physically well-defined monolayer of g-C3N4 mostly due to the difficulty in reducing the layer thickness down to an atomic level. It has, therefore, remained as a challenging issue in two-dimensional (2D) chemistry and physics communities. In this study, an “atomic monolayer of g-C3N4 with perfect two-dimensional limit” was successfully prepared by the chemically well-defined two-step routes. The atomically resolved monolayer of g-C3N4 was also confirmed by spectroscopic and microscopic analyses. In addition, the experimental Cs-HRTEM image was collected, for the first time, which was in excellent agreement with the theoretically simulated; the evidence of monolayer of g-C3N4 in the perfect 2D limit becomes now clear from the HRTEM image of orderly hexagonal symmetry with a cavity formed by encirclement of three adjacent heptazine units. Compared to bulk g-C3N4, the present g-C3N4 monolayer showed significantly higher photocatalytic generation of H2O2 and H2, and electrocatalytic oxygen reduction reaction. In addition, its photocatalytic efficiency for H2O2 production was found to be the best for any known g-C3N4 nanomaterials, underscoring the remarkable advantage of monolayer formation in optimizing the catalyst performance of g-C3N4.
Phenotypic investigation of 4-nitrophenylacetyl- and 4-nitro-1H-imidazoyl-based compounds as antileishmanial agents
Authors: Santos Camila C. , Zhang Huaisheng , Batista Marcos M. , de Oliveira Gabriel M. , Demarque Kelly C. , da Silva Natália L. , Moreira Otacílio C. , Ogungbe Ifedayo Victor , Soeiro Maria de Nazaré Correia 
Published: February 2022

AbstractCutaneous leishmaniasis (CL) is a spectrum of clinical manifestations characterized by severe skin ulcerations that leads to social stigma. There are limited treatment options for CL, and the available drugs are becoming less efficacious due to drug resistance. More efficacious and safer antileishmanial drugs are needed. In this study, the biological effect of seven synthetically accessible nitroaromatic compounds was evaluated in vitro against amastigotes of Leishmania amazonensis, followed by in vivo evaluation using mouse models of CL. Two compounds (6 and 7) were active against amastigotes in vitro [half-maximal effective concentration (EC50): 4.57 ± 0.08 and 9.19 ± 0.68 μm, respectively], with selectivity indexes >50, and the other compounds were not selective. In vivo, compounds 6 and 7 (10 mg kg−1, twice a day for 14 days) failed to reduce skin lesion sizes and parasite loads determined by light microscopy of lesion imprints and quantitative polymerase chain reaction. Nevertheless, the in vitro leishmanicidal efficacy sustained their use as templates for nitroimidazole-based antileishmanial drug discovery programmes focusing on analogues with more suitable properties.
The roles of task, segment type, and attention in L2 perceptual training
Authors: Carlet Angélica , Cebrian Juli 
Published: February 2022

AbstractPrevious studies show that attention plays an important role in second language (L2) phonetic attainment. This study compares the effect of two high variability phonetic training methods (identification (ID) and categorical AX discrimination (DIS)) on specifically targeted sounds and on implicitly exposed but untargeted sounds. Four groups of Spanish/Catalan bilingual learners of English were trained on either a subset of English vowels (/iː ɪ æ ʌ ɜː/) or word-initial and word-final stops. The study also examined if the potential effect of training generalized to new stimuli and persisted two months after training. Results revealed that trainees significantly outperformed the controls in their identification of targeted sounds, and improvement generalized to new stimuli and was maintained after training, showing the efficacy of both training methodologies. However, while all trainees performed similarly with initial stops, ID trainees outperformed DIS trainees in vowel perception. Interestingly, only DIS trainees showed a significant improvement in the perception of untargeted sounds, indicating that this training method (possibly due to the absence of labels and the exposure to two physically present stimuli in each trial) may be more suited to enhance learners’ perception of both targeted and untargeted sounds.
Push, Pull, or Inform - an Empirical Taxonomy of Environmental Policy Support in Sweden
Authors: Ejelöv Emma , Harring Niklas , Hansla André , Jagers Sverker , Nilsson Andreas 
Published: February 2022

AbstractResearch on environmental policy support utilises different categorisations of policies, for example, differentiating between policies assumed to be perceived as rewarding or punishing. Do citizens’ perception of environmental policies also lend itself to this categorisation? Based on an exhaustive sample of active policies in Sweden, this study presents a taxonomy of environmental policy support in Sweden. A fairly representative Swedish sample (N = 2911) rated the acceptability of 44 environmental policies. Exploratory factor analysis indicated that participants’ acceptability of policies forms three categories: push policies consisting of regulatory and market-based disincentives, pull policies consisting mainly of market-based incentives, and informational policies, such as ecolabeling. Sociodemographics had small but consistent effects on attitudes towards the three categories, while political ideology had a larger effect across the categories. This study indicates that current academic categorisations may not adequately capture laypeople’s perceptions, and discusses the importance of research on driving mechanisms behind the current taxonomy.
Control of flexible knee joint exoskeleton robot based on dynamic model
Authors: Liu Biao , Liu YouWei , Zhou Zikang , Xie Longhan 
Published: February 2022

SummaryThe knee joint plays a significant role in ground clearness, which is a crucial subtask of normal walking and avoiding falls. While post-stroke survivors are often faced with muscle weakness during walking, which leads to inadequate knee flexion. The lack of ground clearance caused by inadequate knee flexion will severely impede walking, increase metabolic exertion, and increase the risk of falls. A compliant exoskeleton robot possesses more favorable edges than other rigid ones in lightweight, safety, sense of comfort, and so on. We developed a new type of soft exoskeleton robot to assist the knee joint to achieve desired movements with Bowden cable transmitting force and torque. With the agonist–antagonist driving method, like a group of muscles working, we have explored dual-motors structure to realize the knee flexion function. It has built a standard dynamic model to analyze stability and realize the control law. We have conducted simulation and prototype experiments to verify the feasibility and usefulness of our method. The results show that the device can compensate for the lack of the knee joint driving force and realize the reference movement. Finally, we concluded that our method is a desirable way, and the scheme could improve the knee flexion ability and clearing ground.
Stability of maritime boundaries and the challenge of geographical change: A reply to Snjólaug Árnadóttir
Authors: Lando Massimo 
Published: February 2022

AbstractGeographical phenomena impacting the shape of coastlines may have implications for the stability of maritime boundaries delimited by agreement or judicial process. Sea level rise resulting from human-caused climate change has recently arisen as an additional phenomenon compelling the re-assessment of the stability of maritime boundaries over time. In a recent article published in this Journal, Dr. Snjólaug Árnadóttir has argued that a solution to the challenges of coastline change could be for maritime boundaries to fluctuate following the fluctuation of the baselines on which their course depends. By way of reply to Dr. Árnadóttir’s suggestion, this article argues that fluctuating boundaries have no legal basis either in the United Nations Convention on the Law of the Sea or in judicial decisions. Moreover, the delimitation process in three stages, commonly applied by international courts and tribunals since the Black Sea judgment, appears to be ill-suited for establishing fluctuating boundaries. There seems to be other solutions to the problem of coastline change, which this article also briefly explores.
Three improvements to the top-down solver
Authors: Seidl Helmut , Vogler Ralf 
Published: February 2022

AbstractThe local solver TD is a generic fixpoint engine which explores a given system of equations on demand. It has been successfully applied to the interprocedural analysis of procedural languages. The solver TD gains efficiency by detecting dependencies between unknowns on the fly. This algorithm has been recently extended to deal with widening and narrowing as well. In particular, it has been equipped with an automatic detection of widening and narrowing points. That version, however, is only guaranteed to terminate under two conditions: only finitely many unknowns are encountered, and all right-hand sides are monotonic. While the first condition is unavoidable, the second limits the applicability of the solver. Another limitation is that the solver maintains the current abstract values of all encountered unknowns instead of a minimal set sufficient for performing the iteration. By consuming unnecessarily much space, interprocedural analyses may not succeed on seemingly small programs. In the present paper, we therefore extend the top-down solver TD in three ways. First, we indicate how the restriction to monotonic right-hand sides can be lifted without compromising termination. We then show how the solver can be tuned to store abstract values only when their preservation is inevitable. Finally, we also show how the solver can be extended to side-effecting equation systems. Right-hand sides of these may not only provide values for the corresponding left-hand side unknowns but at the same time produce contributions to other unknowns. This practical extension has successfully been used for a seamless combination of context-sensitive analyses (e.g., of local states) with flow-insensitive analyses (e.g., of globals).
Bayesian vine copulas for modelling dependence in data breach losses
Authors: Liu Jia , Li Jackie , Daly Kevin 
Published: February 2022

AbstractPotentialdata breach losses represent a significant part of operational risk and can be a serious concern for risk managers and insurers. In this paper, we employ the vine copulas under a Bayesian framework to co-model incidences from different data breach types. A full Bayesian approach can allow one to select both the copulas and margins and estimate their parameters in a coherent fashion. In particular, it can incorporate process, parameter, and model uncertainties, and this is very important for applications in risk management under current regulations. We also conduct a series of sensitivity tests on the Bayesian modelling results. Using two public data sets of data breach losses, we find that the overall dependency structure and tail dependence vary significantly between different types of data breaches. The optimally selected vine structure and pairwise copulas suggest more conservative value-at-risk estimates when compared to the other suboptimal copula models.
Decrypting Log Data
Authors: Klose Maria , Steger Diana , Fick Julian , Artelt Cordula 
Published: February 2022

Abstract. Analyzing log data from digital learning environments provides information about online learning. However, it remains unclear how this information can be transferred to psychologically meaningful variables or how it is linked to learning outcomes. The present study summarizes findings on correlations between general online activity and learning outcomes in university settings. The course format, instructions to engage in online discussions, requirements, operationalization of general online activity, and publication year are considered moderators. A multi-source search provided 41 studies ( N = 28,986) reporting 69 independent samples and 104 effect sizes. The three-level random-effects meta-analysis identified a pooled effect of r = .25 p = .003, 95% CI [.09, .41], indicating that students who are more active online have better grades. Despite high heterogeneity, Q(103) = 3,960.04, p < .001, moderator analyses showed no statistically significant effect. We discuss further potential influencing factors in online courses and highlight the potential of learning analytics.
Effect of the Intensified Sub‐Thermocline Eddy on Strengthening the Mindanao Undercurrent in 2019
Authors: Azminuddin Fuad , Lee Jae Hak , Jeon Dongchull , Shin Chang‐Woong , Villanoy Cesar , Lee Seok , Min Hong Sik , Kim Dong Guk 
Published: February 2022

AbstractThe northward‐flowing Mindanao Undercurrent (MUC) was directly measured by acoustic Doppler current profilers from a subsurface mooring at about 8°N, 127°E during 2 years (November 2017–December 2019). Its depth covers a range from 400 m to deeper than 1,000 m with its core appearing at around 900 m. The mean velocity of MUC's core was approximately 5.8 cm s−1 with a maximum speed of about 47.6 cm s−1. The MUC was observed as a quasi‐permanent current with strong intraseasonal variability (ISV) with a period of 70–80 days. Further analyses with an eddy‐resolving circulation model output suggest that the ISV is closely related to sub‐thermocline eddies (SEs). In this study, two types of SEs near the Philippine coast are disclosed: the westward propagating SE (SE‐1) and the quasi‐stational SE southeast of Mindanao Island (SE‐2). The SE‐1 has both cyclonic and anticyclonic polarities with the propagation speed of 7–8 cm s−1, while the SE‐2 is an anticyclonic eddy that moves erratically within 4–8°N, 127–130°E with the mean translation speed of about 11 cm s−1. Even though the SE‐1 plays an important role in modulating the MUC, our results show that the observed strong MUC event (May–July 2019) is evidently induced by the intensified SE‐2 that moves northwestward. This study emphasizes that the SE‐2 when intensified, receives more energy from the strengthened New Guinea Coastal Undercurrent and loses the energy northward along the Philippine coast by intensifying the MUC.
Reduced expression of the psychiatric risk gene DLG2 (PSD93) impairs hippocampal synaptic integration and plasticity
Authors: Griesius Simonas , O’Donnell Cian , Waldron Sophie , Thomas Kerrie L. , Dwyer Dominic M. , Wilkinson Lawrence S. , Hall Jeremy , Robinson Emma S. J. , Mellor Jack R. 
Published: February 2022

AbstractCopy number variants indicating loss of function in the DLG2 gene have been associated with markedly increased risk for schizophrenia, autism spectrum disorder, and intellectual disability. DLG2 encodes the postsynaptic scaffolding protein DLG2 (PSD93) that interacts with NMDA receptors, potassium channels, and cytoskeletal regulators but the net impact of these interactions on synaptic plasticity, likely underpinning cognitive impairments associated with these conditions, remains unclear. Here, hippocampal CA1 neuronal excitability and synaptic function were investigated in a novel clinically relevant heterozygous Dlg2+/− rat model using ex vivo patch-clamp electrophysiology, pharmacology, and computational modelling. Dlg2+/− rats had reduced supra-linear dendritic integration of synaptic inputs resulting in impaired associative long-term potentiation. This impairment was not caused by a change in synaptic input since NMDA receptor-mediated synaptic currents were, conversely, increased and AMPA receptor-mediated currents were unaffected. Instead, the impairment in associative long-term potentiation resulted from an increase in potassium channel function leading to a decrease in input resistance, which reduced supra-linear dendritic integration. Enhancement of dendritic excitability by blockade of potassium channels or activation of muscarinic M1 receptors with selective allosteric agonist 77-LH-28-1 reduced the threshold for dendritic integration and 77-LH-28-1 rescued the associative long-term potentiation impairment in the Dlg2+/− rats. These findings demonstrate a biological phenotype that can be reversed by compound classes used clinically, such as muscarinic M1 receptor agonists, and is therefore a potential target for therapeutic intervention.
Selective induction of human gut-associated acetogenic/butyrogenic microbiota based on specific microbial colonization of indigestible starch granules
Authors: Nagara Yusuke , Fujii Daichi , Takada Toshihiko , Sato-Yamazaki Mikiko , Odani Toru , Oishi Kenji 
Published: February 2022

AbstractPrediction of individualized responses is one of biggest challenges in dietary intervention to modulate human gut microbiota. Bacterial interspecies competition for dietary factors should underlie the inter-subject heterogeneity of microbial responses. Microscale localization of bacterial species around intestinal food structures could provide direct evidence for understanding this, however, little information is currently available. Here we analyzed human fecal sections and found multiple types of bacterial colonization of food structures. The most eminent one was dense and frequent colonization of starch granules by Bifidobacterium adolescentis. After intake of raw potato starch (pSt), B. adolescentis dramatically increased in every carrier of the species, accompanied by an increase in bifidobacterial metabolite acetate. In the other subjects, Eubacterium rectale and its metabolite butyrate increased, but it was suppressed in B. adolescentis carriers. A correlation analysis indicated the contribution of these species to respective metabolites. In vitro analyses of isolates of major gut bacterial species confirmed that these species are major colonizers of pSt and that B. adolescentis can colonize pSt even in the presence of the known starch granule–degrading bacterium Ruminococcus bromii. Collectively, we propose that specific binding of B. adolescentis or E. rectale to pSt selectively induces acetogenic or butyrogenic response of gut microbiota, where the former determines the response of the latter.
Compromised mammillary body connectivity and psychotic symptoms in mice with di- and mesencephalic ablation of ST8SIA2
Authors: Küçükerden Melike , Schuster Ute E. , Röckle Iris , Alvarez-Bolado Gonzalo , Schwabe Kerstin , Hildebrandt Herbert 
Published: February 2022

AbstractAltered long-range connectivity is a common finding across neurodevelopmental psychiatric disorders, but causes and consequences are not well understood. Genetic variation in ST8SIA2 has been associated with schizophrenia, autism, and bipolar disorder, and St8sia2−/− mice show a number of related neurodevelopmental and behavioral phenotypes. In the present study, we use conditional knockout (cKO) to dissect neurodevelopmental defects and behavioral consequences of St8sia2 deficiency in cortical interneurons, their cortical environment, or in the di- and mesencephalon. Neither separate nor combined cortical and diencephalic ablation of St8sia2 caused the disturbed thalamus-cortex connectivity observed in St8sia2−/− mice. However, cortical ablation reproduced hypoplasia of corpus callosum and fornix and mice with di- and mesencephalic ablation displayed smaller mammillary bodies with a prominent loss of parvalbumin-positive projection neurons and size reductions of the mammillothalamic tract. In addition, the mammillotegmental tract and the mammillary peduncle, forming the reciprocal connections between mammillary bodies and Gudden’s tegmental nuclei, as well as the size of Gudden’s ventral tegmental nucleus were affected. Only mice with these mammillary deficits displayed enhanced MK-801-induced locomotor activity, exacerbated impairment of prepulse inhibition in response to apomorphine, and hypoanxiety in the elevated plus maze. We therefore propose that compromised mammillary body connectivity, independent from hippocampal input, leads to these psychotic-like responses of St8sia2-deficient mice.
LINC01123 promotes immune escape by sponging miR-214-3p to regulate B7–H3 in head and neck squamous-cell carcinoma
Authors: Li Huan , Yang Zihui , Yang Xiangming , Zhang Fengrui , Wang Jun , Wu Zhongming , Wanyan Chaojie , Meng Qingzhe , Gao Wanpeng , Yang Xinjie , Wei Jianhua 
Published: February 2022

AbstractNumerous studies have shown that long noncoding RNAs (LncRNAs) are involved in the development and immune escape of head and neck squamous-cell carcinoma (HNSCC). However, the specific regulatory mechanisms by which LINC01123 regulates HNSCC and its correlation with immunity remain unclear. Therefore, this study’s primary purpose was to explore the mechanisms by which LINC01123 regulates the immune escape and progression of HNSCC. This study confirmed that LINC01123 is competitively bound to miR-214-3p, and miR-214-3p specifically targets B7–H3. The effects of LINC01123, B7–H3, and miR-214-3p on tumor progression, CD8+T-cell-mediated immune response, and the tumorigenicity of HNSCC in vitro and in vivo were examined through the downregulation or upregulation of LINC01123, B7–H3, and miR-214-3p. Our results indicated that LINC01123 and B7–H3 were highly expressed in HNSCC and are associated with poor prognosis in patients. Notably, overexpression of LINC01123 or B7–H3 or downregulation of miR-214-3p inhibited the function of CD8+T cells and promoted the progression of HNSCC. Therefore, LINC01123 acts as a miR-214-3p sponge to inhibit the activation of CD8+T cells and promote the progression of HNSCC by upregulating B7–H3.