bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhanced activations in syntax-related regions for multilinguals while acquiring a new language
Authors: Umejima Keita , Flynn Suzanne , Sakai Kuniyoshi L.
Published: March 2021

The neuroscientific foundation of multilingualism, a unique cognitive capacity, necessitates further elucidation. We conducted an fMRI experiment to evaluate the acquisition of syntactic features in a new language (Kazakh) for multilinguals and bilinguals. Results showed that the multilinguals who were more proficient in their second/third languages needed fewer task trials to acquire Kazakh phonology. Regarding group differences, the reduction in response times during the initial exposure to Kazakh were significantly larger for the multilinguals than the bilinguals. For the multilinguals, activations in the bilateral frontal/temporal regions were maintained at a higher level than the initial level during subsequent new grammar conditions. For the bilinguals, activations in the basal ganglia/thalamus and cerebellum decreased to the initial level each time. Direct group comparisons showed significantly enhanced activations for the multilinguals in the left ventral inferior frontal gyrus. These results indicate that both syntax-related and domain-general brain networks were more enhanced for the multilinguals. We also unexpectedly observed significant activations in the visual areas for the multilinguals, implying the use of visual representation even when listening to speech sounds alone. Because the multilinguals were able to successfully utilize acquired knowledge in an accumulated manner, the results support the cumulative-enhancement model of language acquisition.
Computational drug repurposing study elucidating simultaneous inhibition of entry and replication of novel corona virus by Grazoprevir
Authors: Behera Santosh Kumar , Vhora Nazmina , Contractor Darshan , Shard Amit , Kumar Dinesh , Kalia Kiran , Jain Alok
Published: March 2021

Outcomes of various clinical studies for the coronavirus disease 2019 (COVID-19) treatment indicated that the drug acts via inhibition of multiple pathways (targets) is likely to be more successful and promising. Keeping this hypothesis intact, the present study describes for the first-time, Grazoprevir, an FDA approved anti-viral drug primarily approved for Hepatitis C Virus (HCV), mediated multiple pathway control via synergistic inhibition of viral entry targeting host cell Angiotensin-Converting Enzyme 2 (ACE-2)/transmembrane serine protease 2 (TMPRSS2) and viral replication targeting RNA-dependent RNA polymerase (RdRP). Molecular modeling followed by in-depth structural analysis clearly demonstrated that Grazoprevir interacts with the key residues of these targets. Futher, Molecular Dynamics (MD) simulations showed stability and burial of key residues after the complex formation. Finally, Molecular Mechanics Poisson-Boltzmann Surface Area (MM-PBSA) analysis identified the governing force of drug-receptor interactions and stability. Thus, we believe that Grazoprevir could be an effective therapeutics for the treatment of the COVID-19 pandemic with a promise of unlikely drug resistance owing to multiple inhibitions of eukaryotic and viral proteins, thus warrants further clinical studies.
Effects of different prosthetic instrumentations on tibial bone resection in total knee arthroplasty
Authors: Lu Yufeng , Yuan Xuechao , Qiao Feng , Hao Yangquan
Published: March 2021

Our aim was to assess the accuracy of the obtained posterior tibial slope (PTS) with a fixed angle cutting block. 247 TKAs in 213 patients were reviewed. We included 104 Legion Prosthesis, 76 U2 Knee Prosthesis, 46 NexGen LPS-Flex Prosthesis, and 21 Vanguard Knee System products. Preoperative and postoperative PTS were measured via expanded lateral tibia radiographs. For postoperative PTS, the Legion group had significantly smaller slopes than the U2 Knee group and Vanguard group. However, there was no significant difference between the Legion and NexGen groups, and no significant difference among the NexGen, U2 Knee, and Vanguard groups. Multiple linear regression showed that the different tibial lengths and preoperative PTS had statistically significant effects on postoperative PTS. However, there were weak correlations between the tibial length and PTS, and between preoperative and postoperative PTS. For TKA, although the PTS is not completely consistent with the angle of the cutting block, using conventional tibial bone resection technology with different tibial cutting instrumentations provided by various manufacturers in TKA can obtain safe PTS.
Enhanced lipid metabolism induces the sensitivity of dormant cancer cells to 5-aminolevulinic acid-based photodynamic therapy
Authors: Nakayama Taku , Sano Tomonori , Oshimo Yoshiki , Kawada Chiaki , Kasai Moe , Yamamoto Shinkuro , Fukuhara Hideo , Inoue Keiji , Ogura Shun-ichiro
Published: March 2021

Cancer can develop into a recurrent metastatic disease with latency periods of years to decades. Dormant cancer cells, which represent a major cause of recurrent cancer, are relatively insensitive to most chemotherapeutic drugs and radiation. We previously demonstrated that cancer cells exhibited dormancy in a cell density-dependent manner. Dormant cancer cells exhibited increased porphyrin metabolism and sensitivity to 5-aminolevulinic acid-based photodynamic therapy (ALA-PDT). However, the metabolic changes in dormant cancer cells or the factors that enhance porphyrin metabolism have not been fully clarified. In this study, we revealed that lipid metabolism was increased in dormant cancer cells, leading to ALA-PDT sensitivity. We performed microarray analysis in non-dormant and dormant cancer cells and revealed that lipid metabolism was remarkably enhanced in dormant cancer cells. In addition, triacsin C, a potent inhibitor of acyl-CoA synthetases (ACSs), reduced protoporphyrin IX (PpIX) accumulation and decreased ALA-PDT sensitivity. We demonstrated that lipid metabolism including ACS expression was positively associated with PpIX accumulation. This research suggested that the enhancement of lipid metabolism in cancer cells induces PpIX accumulation and ALA-PDT sensitivity.
Kramers Weyl semimetals as quantum solenoids and their applications in spin-orbit torque devices
Authors: He Wen-Yu , Xu Xiao Yan , Law K. T.
Published: March 2021

Kramers Weyl semimetals are Weyl semimetals that have Weyl points pinned at the time reversal invariant momenta. Recently it has been discovered that all chiral crystals host Weyl points at time reversal invariant momenta, so metals with chiral lattice symmetry all belong to the category of Kramers Weyl semimetals. In this work, we show that due to the chiral lattice symmetry, Kramers Weyl semimetals have the unique longitudinal magnetoelectric effect in which the charge current induced spin and orbital magnetization is parallel to the direction of the current. This feature allows Kramers Weyl semimetals to act as nanoscale quantum solenoids with both orbital and spin magnetization. As the moving electrons of Kramers Weyl semimetal can generate longitudinal magnetization, Kramers Weyl semimetals can be used for new designs of spin-orbit torque devices with all electric control of magnetization switching for magnets with perpendicular magnetic anisotropy.
Atmospheric diffuse plasma jet formation from positive-pseudo-streamer and negative pulseless glow discharges
Authors: Li Jing , Lei Bingying , Wang Jing , Xu Boping , Ran Shuang , Wang Yishan , Zhang Tongyi , Tang Jie , Zhao Wei , Duan Yixiang
Published: March 2021

Atmospheric gas discharge is very likely to constrict into filaments and diffuse plasma formation is inefficient in most cases. Developing cost-efficient atmospheric diffuse plasma devices represents a significant challenge for high performance in biomedical decontamination and material processing. Here, we propose an alternative roadmap to produce a diffuse argon plasma jet by expanding and quenching the existing filamentary discharge at the initial or middle stage of streamer development. Possible mechanisms are summarized. With the gas flow velocity comparable to the ion drift one, enhancing ambipolar diffusion near the edge of the positive-streamer channel promotes the radial diffusion of newly-produced electrons, realizing the radial expansion of channel. Weakening electric field in front of the streamer head through head expansion and field offset, prevents the further development of streamer, leading to a positive-pseudo-streamer discharge. Reducing electric field in front of the negative-streamer head through ion compensation, impedes the initial growth of streamer, resulting in a negative pulseless glow discharge. The positive-pseudo-streamer and negative pulseless glow discharges function together to form the diffuse plasma jet.
Stress degradation study of bortezomib: effect of co-solvent, isolation and characterization of degradation products by UHPLC-Q-TOF-MS/MS and NMR and evaluation of the toxicity of the degradation products
Authors: Udutha Suresh , Borkar Roshan M. , Shankar G. , Sony T. , Jala Aishwarya , Vamshi Krisna E. , Kiran Kumar T. , Misra S. , Prabhakar S. , Srinivas R.
Published: March 2021

Bortezomib (BTZ) is a first-in-class, potent reversible inhibitor of proteasome used in the treatment of multiple myeloma, the second most common hematological cancer.
Hydrogen evolution of a MoS2/AOCF electrocatalyst doped with Ni element
Authors: Tao Tingxian , Lu Xiaohan , Qin Mingxing , Chen Liru , Gao Wei , Lu Siyu , Wu Zhichuan
Published: March 2021

The introduced polymers ability can replace the traditional Nafion adhesive, uniformly disperse particles and increase active sites.
Reversed selectivity of photocatalytic CO2 reduction over metallic Pt and Pt(ii) oxide cocatalysts
Authors: Wang Junyi , Li Youzi , Zhao Jiangting , Xiong Zhuo , Zhang Junying , Zhao Yongchun
Published: March 2021

The chemical state of Pt in cocatalysts has a major influence on the selectivity of the photoreduction of CO2, which was owing to the different charge transfer/separation and CO/H adsorption properties of PtO/TiO2 and Pt/TiO2.
The role of conformational heterogeneity in the excited state dynamics of linked diketopyrrolopyrrole dimers
Authors: Bradley Siobhan J. , Chi Ming , White Jonathan M. , Hall Christopher R. , Goerigk Lars , Smith Trevor A. , Ghiggino Kenneth P.
Published: March 2021

Conformational heterogeneity leads to different excited state relaxation pathways in flexibly-linked DPP-dimers.
High temperature anionic Fe(iii) spin crossover behavior in a mixed-valence Fe(ii)/Fe(iii) complex
Authors: Ouyang Zhi-Jian , Mo Xiao-Ying , Ye Jia-Qi , Yu Xiao-Xuan , Huang Shu-Yuan , Liu Xiao-Ling , Chen Wen-Bin , Gao Song , Dong Wen
Published: March 2021

Two ion-pair complexes (PPh4)[FeIII(HATD)2]·2H2O (1) and [FeII(phen)3][FeIII(HATD)2]2·3DMA·3.5H2O (2) have been synthesized and high temperature Fe(iii) spin crossover behaviour has been observed in2.
Metal–ligand cooperation behaviour of Fe and Co complexes bearing a tetradentate phenanthroline-based PNNP ligand
Authors: Nakajima Yumiko , Takeshita Tomohiro , Jheng Nai-Yuan
Published: March 2021

A metal–ligand cooperation (MLC) behavior was investigated using Iron and cobalt complexes bearing a phenanthroline-based meridional PNNP ligand, demonstrating a unique long-range MLC, where the phenanthroline backbone behaves as a H2 reservoir.
Broadened bioactivity and enhanced durability of two structurally distinct metal–organic frameworks containing Zn2+ ions and thiabendazole
Authors: Kobayashi Daiya , Hamakawa Akira , Yamaguchi Yuki , Takahashi Toshiaki , Yanagita Mitsuhiro , Arai Shigebumi , Minoura Mao
Published: March 2021

Two structurally distinct TBZ-MOFs enhanced durability and biocidal spectrum compared to TBZ alone.
Charge pumping enabling Co–NC to outperform benchmark Pt catalyst for pH-universal hydrogen evolution reaction
Authors: Chen Ziliang , Qing Huilin , Wang Ruirui , Wu Renbing
Published: March 2021

A strategy for charge pumping engineering has been developed to significantly enhance the intrinsic activity of Co-based catalysts, which outperform precious Pt catalysts for the hydrogen evolution reaction over a wide pH range.
Glycothermal synthesis and photoluminescence of Mg–Si modified Ce:YAG nanophosphors
Authors: Peter Samuel , Fitzpatrick Maureen , Kitai Adrian
Published: March 2021

Influence of Mg–Si addition on absorption and emission of Ce0.03:Y2.97MgxAl5−2xSixO12 nanoparticles made using the glycothermal method.
Cryptic halogenation reactions in natural product biosynthesis
Authors: Adak Sanjoy , Moore Bradley S.
Published: March 2021

This review highlights the discovery of enzyme catalyzed cryptic halogenation reactions in building unique structural scaffolds in natural product biosynthesis.
One-pot multi-step cascade protocols toward β-indolyl sulfoximidoyl amides via intermolecular trapping of an α-indolylpalladium complex by CO
Authors: Liu Huahua , Wei Li , Chen Zhiyuan
Published: March 2021

Various β-indolyl sulfoximidoyl amides were efficiently prepared from ortho-iodoanilines, propargyl bromides, 1 atm of CO, and NH-sulfoximines, through a palladium-catalyzed indole annulation/carbonyl insertion/C–N bond formation cascade.
The transition-metal-catalyzed stereoselective ring-expansion of vinylaziridines and vinyloxiranes
Authors: Sarkar Tanumay , Talukdar Kangkan , Das Bijay Ketan , Shah Tariq A. , Debnath Bijoy , Punniyamurthy Tharmalingam
Published: March 2021

This article covers ring expansions of vinylaziridines and vinyloxiranes developed over the past five years for accessing stereochemically enriched heterocycles.
Harnessing methylation and AdoMet-utilising enzymes for selective modification in cascade reactions
Authors: Michailidou Freideriki , Rentmeister Andrea
Published: March 2021

This review summarizes the recent findings and developments in the emerging area of (chemo)-enzymatic cascades using MTases and AdoMet-generating enzymes.
Porphyrin metalation catalyzed by DNAzymes and nanozymes
Authors: Yang Hualin , Zhou Yu , Liu Juewen
Published: March 2021

In this review, DNA and nanomaterial based catalysts for porphyrin metalation reactions are summarized, including the selection of DNAzymes, choice of nanomaterials, their catalytic mechanisms, and applications of the reactions.
Synergic and coupling effect between SnO2 nanoparticles and hierarchical AlV3O9 microspheres toward emerging electrode materials for lithium-ion battery devices
Authors: Ghiyasiyan-Arani Maryam , Salavati-Niasari Masoud
Published: March 2021

Excellent functional properties were achieved for AlV3O9/SnO2 micro/nano sphere composites with high electronic and ionic conductivity due to the coupling effect, which utilized as promising candidates for Lithium storage application.
Rh(iii)-Catalyzed [3 + 2]/[4 + 2] annulation of acetophenone oxime ethers with 3-acetoxy-1,4-enynes involving C–H activation
Authors: Li Sun-Yong , Zhang Xu , Teng Fan , Li Yang , Li Jin-Heng
Published: March 2021

A novel, synthetically simple, selective rhodium(iii)-catalyzed [3 + 2]/[4 + 2] annulation cascade reaction to construct complex azafluorenone frameworks has been developed.
Nickel-catalyzed alkenylboration of alkenylarenes to access homoallylic boronic esters
Authors: Zhang Penglin , Zou Chenchen , Zhao Qian , Zhang Chun
Published: March 2021

A practical nickel-catalyzed alkenylboration of alkenylarenes with excellent chemo- and regio-selectivity has been developed.
Auditory-Perceptual Features of Speech in Children and Adults With Down Syndrome: A Speech Profile Analysis
Authors: Kent Raymond D. , Eichhorn Julie , Wilson Erin M. , Suk Youmi , Bolt Daniel M. , Vorperian Houri K.
Published: March 2021

Purpose

The aim of this study was to determine how the speech disorder profiles in Down syndrome (DS) relate to reduced intelligibility, atypical overall quality, and impairments in the subsystems of speech production (phonation, articulation, resonance, and prosody).

Method

Auditory-perceptual ratings of intelligibility, overall quality, and features associated with the subsystems of speech production were obtained from recordings of 79 children and adults with DS. Ratings were made for sustained vowels (62 of 79 speakers) and short sentences (79 speakers). The data were analyzed to determine the severity of the affected features in each speaking task and to detect patterns in the group data by means of principal components analysis.

Results

Reduced intelligibility was noted in 90% of the speakers, and atypical overall speech quality was noted in 100%. Affected speech features were distributed across the speech production subsystems. Principal components analysis revealed four components each for the vowel and sentence tasks, showing that individuals with DS are not homogeneous in the features of their speech disorder.

Discussion

The speech disorder in DS is complex in its perceptual features and reflects impairments across the subsystems of speech production, but the pattern is not uniform across individuals, indicating that attention must be given to individual variation in designing treatments.
Seeking the origins of a mysteriously large decay length in electrolytes
Authors: Bandari Anashe
Published: March 2021

Researchers aim to corroborate experimental evidence of long-range decay with theory and simulations of primitive model electrolytes.
Characterizing the coverage of anti-soiling coatings on photovoltaic modules
Authors: Bandari Anashe
Published: March 2021

Anti-soiling coatings help protect solar modules against dust deposition. Tapping mode atomic force microscopy phase imaging can be used to ensure these coatings have ample coverage.
Game dynamics of emotion evolution based on the Moran process
Authors: Dai Ya-yun , Zhan Guang-jie , Ye Ye , Bao Wei , Wen Tao , Cheong Kang Hao , Xie Neng-gang
Published: March 2021

In this paper, emotions are classified into four types, namely, respect for the strong, envying the strong, sympathy for the weak, and bullying the weak. The corresponding relationship between the four emotion types and the two behaviors of competition and cooperation is then defined. The payoff matrices of the game based on emotions are obtained and the evolutionary dynamics of the four emotion types in a finite population based on the Moran process are studied. Next, we derive the absorption probabilities of a 4×4 symmetric evolutionary game of the population. The influence of the payoff parameters and the natural selection intensity on the result of the group evolution are then analyzed. The calculations indicate that there are differences in the absorption probabilities of the four absorption states of the system. At a steady state, individuals of the types envying the strong and bullying the weak have the highest probability of occupying the entire population, and individuals of the type respect for the strong and sympathy for the weak have the lowest one. By comparing the level of cooperation and average payoffs at a steady state, we observe that the level of cooperation and average payoffs based on the proposed model are better than those of the prisoner’s dilemma game with two behaviors. Therefore, emotional evolution can promote cooperation and achieve better group fitness.
Surface roughness mediated specularity parameter of thin Cu films
Authors: Konar Aniruddha , Shin Keun Wook , Byun Kyung-Eun , Shinde Prashant P. , Adiga Shashishekar P. , Subramanya Mayya K. , Cho Yeonchoo , Shin Hyeon-Jin , Park Seongjun
Published: March 2021

Roughness-induced resistivity variation of thin metal films is conveniently described by the Fuchs–Sondheimer model, where the phenomenological parameter p is used to quantify the extent of specular scattering at surfaces. However, p is a lumped parameter and does not include microscopic information that characterizes roughness, viz., auto-correlation function, root-mean-square height, and correlation length. In this work, we extract these roughness parameters for Cu films of thickness ranging from 31 nm to 95 nm. We find that the roughness–roughness correlation function is an exponential with a characteristic correlation length that increases monotonically with the film thickness. Using this, we predict the roughness parameter-dependent specularity coefficient, which has an implicit thickness dependency. This alters the resistivity scaling compared to the prevailing model of resistivity scaling, where p is assumed to be a constant.
Joint-velocity scalar energy probability density function method for large eddy simulations of compressible flow
Authors: Almeida Y. , Navarro-Martinez S.
Published: March 2021

The combination of large eddy simulation (LES) and probability density function (PDF) methods is a general framework to model turbulent reactive flows. The coupled approach provides direct closures for the nonlinear subgrid source terms typical of chemically reacting flows. LES-PDF methods have a wide range of applicability and they are started to be used in high-speed flows with strong compressibility effects. However, PDF formulations are more complex in compressible flows, where mechanical and thermodynamic contributions are more coupled. The paper presents a novel PDF framework that uses a full thermodynamic closure (scalar-energy-density-velocity) with the Eulerian Monte Carlo stochastic field approach. The work uses simple closures for the subgrid terms using the advantages of the Eulerian formulation and recasts the stochastic equations in a pseudoconservative form. The resultant formulation is applied to three canonical compressible flows: turbulent shock-tubes, compressible homogeneous turbulence, and a reactive free-moving premixed flame. All cases show large density and pressure fluctuations. The effects of underlying numerical schemes and PDF closures to represent compressible effects are investigated along with the statistical convergence of the method.
Self-starting harmonic comb emission in THz quantum cascade lasers
Authors: Forrer Andres , Wang Yongrui , Beck Mattias , Belyanin Alexey , Faist Jérôme , Scalari Giacomo
Published: March 2021

Harmonic comb states have proven to be ubiquitous in mid-IR quantum cascade lasers. We report here on robust, pure, self-starting harmonic mode locking in Copper-based double-metal THz quantum cascade lasers. Different harmonic orders can be excited in the same laser cavity depending on the pumping condition, and stable harmonic combs spanning more than 600 GHz at 80 K are reported. Such devices can be RF injected, and the free running coherence is assessed by means of a self-mixing technique performed at 50 GHz. A theoretical model based on Maxwell-Bloch equations including an asymmetry in the gain profile is used to interpret the data.
Thermal bi-stability and hysteresis in hetero-phase molybdenum di-selenide
Authors: Malavika C. , Anu Roshini R. , Kannan E. S.
Published: March 2021

In this paper, we demonstrate thermal bi-stability and hysteresis in hetero-phase molybdenum diselenide (h-MoSe2) consisting of 2H semiconducting MoSe2 and molybdenum oxide (MoOx) phases. h-MoSe2 exhibits pinched hysteresis in the current-voltage characteristics, with the lobe area increasing with decreasing temperature. High and low resistance states were encoded into the sample by thermal manipulation. Cooling the sample below room temperature (RT) drives it to a low resistance state (“1” state), whereas heating above RT switches it to a high resistance state (“0” state). The ratio between “1” and “0” resistance states was found to be greater than 2000 with arbitrary long retention time at room temperature. The results are discussed in terms of temperature-induced adsorption/desorption of water vapor and its interplay with the charge transfer in MoSe2. Our study indicates that h-MoSe2 can be a potential candidate for application in alternate memory devices such as thermal memory and memristors.
Direct numerical simulation of turbulent dispersion of evaporative aerosol clouds produced by an intense expiratory event
Authors: Fabregat Alexandre , Gisbert Ferran , Vernet Anton , Ferré Josep Anton , Mittal Ketan , Dutta Som , Pallarès Jordi
Published: March 2021

Airborne particles are a major route for transmission of COVID-19 and many other infectious diseases. When a person talks, sings, coughs, or sneezes, nasal and throat secretions are spewed into the air. After a short initial fragmentation stage, the expelled material is mostly composed of spherical particles of different sizes. While the dynamics of the largest droplets are dominated by gravitational effects, the smaller aerosol particles, mostly transported by means of hydrodynamic drag, form clouds that can remain afloat for long times. In subsaturated air environments, the dependence of pathogen-laden particle dispersion on their size is complicated due to evaporation of the aqueous fraction. Particle dynamics can significantly change when ambient conditions favor rapid evaporation rates that result in a transition from buoyancy-to-drag dominated dispersion regimes. To investigate the effect of particle size and evaporation on pathogen-laden cloud evolution, a direct numerical simulation of a mild cough was coupled with an evaporative Lagrangian particle advection model. The results suggest that while the dispersion of cough particles in the tails of the size distribution are unlikely to be disrupted by evaporative effects, preferential aerosol diameters (30–40 μm) may exhibit significant increases in the residence time and horizontal range under typical ambient conditions. Using estimations of the viral concentration in the spewed fluid and the number of ejected particles in a typical respiratory event, we obtained a map of viral load per volume of air at the end of the cough and the number of virus copies per inhalation in the emitter vicinity.
The nuclear to cytoplasmic ratio directly regulates zygotic transcription in
Drosophila
through multiple modalities
Authors: Syed Sahla , Wilky Henry , Raimundo João , Lim Bomyi , Amodeo Amanda A.
Published: March 2021

Significance

At the mid-blastula transition, rapid cell divisions are slowed down and global activation of zygotic genes occur, preparing the early embryo for differentiation and further development. Using live imaging of embryos with reduced ploidy and cell cycle lengths, we examined the effects of the nuclear content to cytoplasm (N/C) ratio on the timing of zygotic genome activation. While some genes are predominantly affected by the N/C ratio–dependent changes in cell cycle durations, other genes demonstrate direct regulation by the N/C ratio through changes in the transcriptional kinetics and in the probability of gene activation.
Self-shaping liquid crystal droplets by balancing bulk elasticity and interfacial tension
Authors: Peddireddy Karthik , Čopar Simon , Le Khoa V. , Muševič Igor , Bahr Christian , Jampani Venkata. S. R.
Published: March 2021

Significance

Liquid crystal (LC) research is rapidly expanding to include studies of curved and topologically nontrivial structures. Here, we explore the role of the bulk LC elasticity and interfacial free energy under weak thermal stimuli to achieve structural transformations in LC emulsions using two different surfactants. Our method is universal and could be used for any LC material or phase. A theoretical model for transforming LC emulsions into uniform fibers and vice versa is presented. We also show the self-shaping of smectic vesicle structures and monodispersed droplet formation at the nematic–smectic transition, utilizing the LC bulk elasticity. This work shows the potential to obtain the controllable shape of complex curved structures for a constant volume of different LCs and other soft materials.
Climate change and state evolution
Authors: Benati Giacomo , Guerriero Carmine
Published: March 2021

Despite the vast evidence on the short-run effects of adverse climate shocks on the economy, our understanding of their long-run impact on institutions is limited. To tackle such a key issue, a vast body of research has focused on ancient societies because of the limited complexity of their economies and their unparalleled experience with environmental and institutional change. Notably, the “collapse archaeology” literature has reported countless correlations consistent with the mantra that severe droughts are bound to trigger institutional crises. This conclusion, however, has been recently challenged by a stream of papers that, building on more detailed data on Bronze Age Mesopotamia and a more credible theory-based empirical strategy, have yielded the following two results. First, severe droughts pushed the elites to grant strong political and property rights to the nonelites to convince them that a sufficient part of the returns on joint investments would be shared via public good provision and, thus, to cooperate and accumulate a culture of cooperation. Second, a more favorable climate allowed the elites to elicit cooperation under less inclusive political regimes as well as a weaker culture of cooperation and, possibly, incomplete property rights. These patterns emphasize the importance of considering the asymmetric effect of droughts and, more generally, combining natural and social sciences for the evaluation of climate-related policies.
Skew-symmetric endomorphisms in

M1,n

: a unified canonical form with applications to conformal geometry
Authors: Mars Marc , Peón-Nieto Carlos
Published: March 2021

We show the existence of families of orthonormal, future directed bases which allow to cast every skew-symmetric endomorphism of

M

1
,
n

(

S
k
e
w
E
n
d

M

1
,
n

) in a single canonical form depending on a minimal number of parameters. This canonical form is shared by every pair of elements in

S
k
e
w
E
n
d

M

1
,
n

differing by an orthochronous Lorentz transformation, i.e. it defines the orbits of the orthochronous Lorentz group O
+(1, n) under the adjoint action on its algebra. Using this form, we obtain the quotient topology of

S
k
e
w
E
n
d

M

1
,
n

/

O

+

(

1
,
n

)

. From known relations between

S
k
e
w
E
n
d

M

1
,
n
+
1

and the conformal Killing vector fields (CKVFs) of the sphere

S

n

, a canonical form for CKVFs follows immediately. This form is used to find adapted coordinates to an arbitrary CKVF that covers all cases at the same time. We do the calculation for even n and obtain the case of odd n as a consequence. Finally, we employ the adapted coordinates to obtain a wide class of TT-tensors for n = 3, which provide Cauchy data at conformally flat null infinity

I

. Specifically, this class of data is characterized for generating Λ > 0-vacuum spacetimes with two-symmetries, one of which axial, admitting a conformally flat

I

. The class of data is infinite dimensional, depending on two arbitrary functions of one variable as well as a number of constants. Moreover, it contains the data for the Kerr–de Sitter spacetime, which we explicitly identify within.
Optoelectrical switching behavior based on a composite of a fullerene acceptor and carbazole donor
Authors: Zhao Enming , Liu Guangyu , Xing Chuanxi , Liu Xiaodan , Wang Chen , Zhu Xiaodong , Yang Yanting , Liu Shuo , Huang Yi
Published: March 2021

An electron donor–acceptor system composed of a C60 fullerene acceptor and poly(9-vinylcarbazole) (PVK) as the donor has been constructed. This material can respond to both electrical and optical stimuli. Using the C60:PVK blends as the active layer, a solution-processed active layer with a configuration of indium tin oxid (ITO)/C60:PVK/Al is fabricated. Interestingly, when the applied voltages varied from 0 to −0.8 V, the as-fabricated device exhibits both photo-induced resistive state changes and volatile photo-response characteristics in the broadband visible region. The light illumination gives rise to a significant decrease in the device resistance. Furthermore, it is also found that, when the sweep-voltage applied to the device is changed from 0 to ±4 V, this device shows a typical nonvolatile rewritable memory performance in the dark. Upon illumination with different wavelengths of light, both the switching-on voltage and the ON/OFF ratio of the ITO/C60:PVK/Al device are found to be greatly decreased. This work opens up a pathway to the integration of information storage and modulating and demodulating functions in an optoelectronic device.
Tissue differentiation using optical emission spectroscopy for gastric mucosal devitalisation
Authors: Hillebrand Bastian , Jurjut Ovidiu , Schuhmann Tim , Schürmann Mirjam , Neugebauer Alexander , Kemen Matthias , Awakowicz Peter , Enderle Markus
Published: March 2021

Argon plasma coagulation is a promising new approach to combat obesity. During the procedure, a large area of the gastric lamina mucosae and the parietal cells that are located in this layer are ablated. This reduces the secretion of the hormone ghreline, which is known to play a major role in inducing appetite. One hypothesis is that this procedure partly suppresses the feeling of hunger which lowers the food-intake and body weight effectively. To rule out side effects, the treatment of other structures of the gastric wall that are much more sensitive to thermal injury, such as the tela submucosa and the lamina muscularis propria, needs to be avoided. The possibility of layer specific tissue differentiation is explored in this work using optical emission spectroscopy on ex vivo human stomach tissue. The optical emission generated during the plasma treatment of each layer is measured with two different spectrometers. The three main layers of the gastric wall can be differentiated by specific emissions lines of electrolytic ions and trace elements. In order to evaluate the diagnostic quality of this method a linear support vector classifier is used to differentiate the three layers against each other on the basis of these emission lines of these elements. This differentiation between ‘mucosa’ and ‘submucosa’ results in a sensitivity of up to 82% and specificity of up to 92%. However, a lower sensitivity and specificity is found for a classification between ‘submucosa’ and ‘muscularis’ which implies that a classification between ‘mucosa’ and ‘not mucosa’ would be a much more suitable classification for a later clinical application.
Large linear sensitivity of asymmetric structured giant magnetoresistive device with metastable bcc-Cu spacer and auxiliary biquadratic coupling through Rh spacer
Authors: Taparia Dolly , Fathoni Kresna Bondan , Kulkarni Prabhanjan Dilip , Srinivasan Ananthakrishnan , Alagarsamy Perumal , Sakuraba Yuya , Nakatani Tomoya , Sasaki Taisuke , Hono Kazuhiro
Published: March 2021

Large magnetoresistance (MR) with a linear response to the magnetic field is an important feature in MR devices for magnetic sensor applications. Following the largest MR ratio realized in a current-in-plane (CIP) giant magnetoresistance (GMR) device using a metastable body-centered cubic (bcc)-Cu spacer, we developed a new CIP-GMR device with a combination of two spacer materials, i.e. CoFe/Rh/CoFe (sensing layer)/bcc-Cu/CoFe asymmetric structure and realized a large linear sensitivity due to large MR ratio (21%) and linear response through a biquadratic coupling, high sensitivity of 0.047% mT−1, reduced nonlinearity of 0.98% full scale along with a substantially wider operation field range of 220 mT. Our numerical simulation analyses of magnetization curves clearly establish that the middle CoFe sensing layer is well-controlled by interlayer exchange coupling through the Rh spacer, giving rise to a linear response without losing the high MR ratio through the bcc-Cu spacer. These findings demonstrate that CIP-GMR devices are promising for wide dynamic range magnetic sensors.
Enhanced luminescence of Si(111) surface by localized surface plasmons of silver islands
Authors: Zhou Xinxin , Guo Cong , Wang Zhongping , Fu Mingming , Wei Sheng , Liu Xiaoqing , Wu Sanqin , Wang Li
Published: March 2021

The role of silver localized surface plasmons (LSPs) on the luminescence of a Si(111)-(7 × 7) surface has been investigated by scanning tunneling microscopy (STM) with a silver tip at 77 K. On a bare Si(111)-(7 × 7) surface, a characteristic peak at 1.85 eV dominates the STM-induced luminescence spectrum, although the luminescence intensity is extremely weak. Once Ag atoms are deposited onto the Si surface to form islands with a few atomic layers, it is found that the intensity of the characteristic peak from the Si surface underneath the Ag islands is significantly enhanced by about one order. In addition to the luminescence from the Si surface, light emission originating from the irradiation decay of the Ag plasmons is also detected. Such great enhancement of the luminescence from the Si surface is attributed to the strong coupling between the surface states of the Si and the LSPs of the Ag islands.
Nonlinear dynamic control of GaAs nanomechanical resonators using lasers
Authors: Jin Leisheng , Zhao Hao , Li Zhi , Jiang Zongqing , Li Lijie , Yan Xiaohong
Published: March 2021

The ability to control, manipulate, and read out nanomechanical resonators is of great significance for many applications. In this work, we start by constructing a nonlinear dynamic model that is deduced from the fundamental beam-photon–electron interaction and energy band theories, with the aim of describing a complicated cavity-free optomechanical coupling process. Based on the model established, we first reveal the manipulation of a resonator’s response, including softening and hardening effects due to laser injection. By driving the laser parametrically, we comprehensively investigate the control of the resonator’s dynamics, in particular, in the nonlinear regime. It is found that both the laser power and frequency can be used to directly manipulate the NEMS resonator’s dynamics, e.g., by amplitude amplification, periodicity changes, and periodic–chaotic state conversion. We then provide bifurcation diagrams, which evidence a deterministic evolution of dynamics. Finally, we perform a special study of the control of chaotic states of the nanomechanical resonator using laser parametric driving. The maximal Lyapunov exponents together with time series calculation show that the chaotic states can be controlled at a few specific frequency points of the injecting laser. This work not only provides guidance for using lasers to control nanoscale resonators, but also sheds light on the exploration of novel applications based on nonlinear NEMS resonators.
Effect and mechanism of action in vitro of cyclodextrin derivative nanoparticles loaded with tyroserleutide on hepatoma
Authors: Wu Xiaoyan , Hua Yingying , Wei Tiantian , Ma Chenjun , Wang Zhongjie , Zhang Liefeng , Wang Jing
Published: March 2021

In this study, a cyclodextrin derivative (R6RGD-CMβCD) nanoparticle with tumor targeting and cell penetration ability was successfully synthesized and loaded with tyroserleutide (YSL) to obtain YSL-loaded nanoparticles (YSL/R6RGD-CMβCD NPs). The characterization of these NPs revealed a smooth surfaces and an average diameter of approximately 170 nm. YSL/R6RGD-CMβCD NPs increased the NP uptake in Caco-2 cells. As regard the mechanism of action, the cell uptake was related to endocytosis mediated by reticulin and megacytosis. In addition, YSL/R6RGD-CMβCD NPs induced significantly higher cytotoxicity on tumor cells and better tumor targeting compared with the effect of CMβCD NPs. Most importantly, the good anti-cancer effect of YSL/R6RGD-CMβCD NPs might be due to the interference with the function of mitochondria. On the other hand, YSL/R6RGD-CMβCD NPs were not toxic for normal cells. Taken together, our results indicated that R6RGD-CMβCD could be considered as a nanopharmaceutical material with good tumor targeting abilities, and their combination with YSL could represent an effective anti-cancer system.
Laser-assisted graphene growth directly on silicon
Authors: Vishwakarma Riteshkumar , Zhu Rucheng , Mewada Ashmi , Umeno Masayoshi
Published: March 2021

Controlled graphene growth on a substrate without the use of catalysts is of great importance for industrial applications. Here, we report thickness-controlled graphene growth directly on a silicon substrate placed in a low-density microwave plasma environment using a laser. Graphene is relatively easy to grow in high-density plasma; however, low-density plasma lacks the sufficient energy and environment required for graphene synthesis. This study reports that laser irradiation on silicon samples in a low-density plasma region nucleates graphene, and growth is controlled with laser exposure time and power. A graphene–silicon junction is thus formed and shows an enhanced (1.7 mA) short-circuit current as compared to one grown in high-density plasma (50 μA) without the laser effects. Synthesized graphene is characterized by Raman spectroscopy, atomic force microscopy to investigate surface morphology and Hall effect measurements for electronic properties. The key aspect of this report is the use of a laser to grow graphene directly on the silicon substrate by ensuring that the bulk resistance of the silicon is unaffected by ion bombardment. Additionally, it is observed that graphene grain size varies in proportion to laser power. This report can help in the growth of large-area graphene directly on silicon or other substrates at reduced substrate temperatures with advanced electronic properties for industrial applications.
Effects of equilibrium radial electric field on ion temperature gradient instability in the scrape-off layer of a field-reversed configuration
Authors: Wang W H , Bao J , Wei X S , Lin Z , Choi G J , Dettrick S , Kuley A , Lau C , Liu P F , Tajima T
Published: March 2021

Linear and nonlinear effects of the equilibrium radial electric field on the ion temperature gradient (ITG) instability in the scrape-off layer (SOL) of a field-reversed configuration have been studied using gyrokinetic particle simulations for a single toroidal mode. Linear simulations with adiabatic electrons find that the

E
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flow shear reduces the growth rate and causes a radial tilting of the mode structure on the toroidal plane. Nonlinear simulations find that the

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flow shear significantly decreases ITG saturation amplitude and ion heat transport in the SOL by reducing both turbulence intensity and eddy size. The turbulence intensity is determined by fluid eddy rotation, which is the dominant saturation mechanism for the SOL ITG instability with a single toroidal mode number. On the other hand, parallel wave-particle decorrelation is the dominant mechanism for the SOL ITG turbulent transport. A random walk model using the guiding center radial excursion as the characteristic length scale and the eddy turnover time as the characteristic time scale fits very well to the scaling of ion heat conductivity with the

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flow shear.
Influence of vehicle body vibration induced by road excitation on the performance of a vehicle-mounted piezoelectric-electromagnetic hybrid energy harvester
Authors: Li Zhiyuan , Li Xia , Liu Benxue , Wang Junlei
Published: March 2021

In order to study the influence of vehicle body vibration caused by road excitation on the output performance of a vehicle piezoelectric electromagnetic hybrid energy harvester, the theoretical analysis of the energy harvester is carried out, and a corresponding electromechanical coupling model is established. The hybrid energy harvester includes a flutter piezoelectric energy harvester (FPEH) and an electromagnetic vibration energy harvester (EVEH). Sweep frequency experiments and wind tunnel experiments were carried out to verify the correctness of the coupling model. By establishing the road-vehicle coupling differential equations solving module, the vehicle body vibration under different road surfaces was simulated, and the influence of different roads on output performance is analyzed. The results show that when vehicle body vibration is not considered, the cut-in speed of the harvester is 32 km h−1. When the vehicle speed is higher than 32 km h−1, vehicle body vibration caused by road roughness will suppress the overall output performance. When the vehicle speed is less than 32 km h−1, the vibration of the vehicle body will cause the energy harvester to have no obvious cut-in wind speed. And the higher the road level, the stronger the body vibration, and the better the output performance when the vehicle speed is less than 32 km h−1. Under E-class road with vehicle body vibration considered, it has already power output at a vehicle speed of 20 km h−1. When the vehicle speed reaches 57 km h−1, the output power of hybrid FPEH and EVEH reach 1.74 and 2.51 mW under E-class road (2.88 and 3.25 mW under A-class road), respectively.
Approximate nonlinear wave solutions of the coupled two-component Gross–Pitaevskii equations with spin–orbit interaction
Authors: Belobo D Belobo , Meier T
Published: March 2021

Recent experimental observations of spin–orbit coupling (SOC) in Bose–Einstein condensates (BECs) open the way for investigating novel physics of nonlinear waves with promising applications in atomic physics and condensed matter physics. The interplay between atomic interactions and SOC are crucial for the understanding of the dynamics of nonlinear waves in BECs with SOC. Here, in the small linear coupling regime, an approach is presented which allows us to derive an infinite number of novel approximate solutions of the Gross–Pitaevskii equations (GPEs) in one and two dimensions including SOCs, time-dependent external potentials, and nonlinearities leading to breathers and periodic as well as quasiperiodic nonlinear waves. To verify the theoretical predictions we perform numerical simulations which show for several cases a very good agreement with the analytics. For the case of one spatial dimension, it is shown that functions describing the external potential and nonlinearities cannot be chosen independently. The management of the solutions is clarified along with some important physical properties such as Josephson oscillations and Rosen–Zener oscillations.
Exploring multi-level Rydberg excitation schemes for suppressing motional dephasing in optically trapped Cs atom qubits
Authors: Raina Parth , Santra Bodhaditya
Published: March 2021

We analyse in detail various multi-level Rydberg excitation schemes which can be used to suppress motional dephasing in optically trapped Cesium atom qubits in the context of quantum information processing. To explore the dephasing mechanism on a quantitative level, we analyse the time evolution of the atom’s wavefunction, under the application of a composite pulse sequence (π − 4π − π), taking into account controllable experimental parameters like the Rabi frequency and temperature. Our study determines the characteristics of a three level system that can be used with this pulse sequence for eliminating motional dephasing. Such systems can hence be directly employed in state-of-the-art quantum simulation and quantum computation experiments to reduce the trap induced decoherence. This paves the way towards the realization of large scale quantum information processing architecture using optically trapped alkali atom qubits.
Shannon, Rényi entropies, and Fisher information calculations of the Li1+ and Be2+ ions screened by the ion-sphere plasma model
Authors: Martínez-Flores César , Zeama Mostafa , Nasser Ibraheem
Published: March 2021

We show results for the Shannon entropy, Rényi entropy, Fisher information, and their relative relations in the position space for the Li1+ and Be2+ ions embedded in a strong plasma. This medium is simulated by the ion-sphere screening model as a function of the plasma electron density, N

e
. We solve the Hartree–Fock equations using a numerical grid method in a self-consisting manner and the simple Hylleraas-type correlated wave function is applied. Our findings show a reduction of the total energy for both ions as the electron density is increased reaching the ionization limit. We find interesting features in the description of the Shannon entropy and Fisher information where the correlation effects of the embedded ions are relevant. The Shannon-Fisher product results indicate that the electron-electron correlation decreases as N

e
increases and similar behavior is found for the Rényi-Fisher product. Finally, in the absence of the plasma medium, our results are in excellent agreement with those available in the literature.