bluuebunny/crossref_metadata_2025_split huggingface dataset:
Torpedo californica acetylcholinesterase is stabilized by binding of a divalent metal ion to a novel and versatile 4D motif
Authors: Silman Israel , Shnyrov Valery L. , Ashani Yacov , Roth Esther , Nicolas Anne , Sussman Joel L. , Weiner Lev 
Published: March 2021

AbstractStabilization of Torpedo californica acetylcholinesterase by the divalent cations Ca+2, Mg+2, and Mn+2 was investigated. All three substantially protect the enzyme from thermal inactivation. Electron paramagnetic resonance revealed one high‐affinity binding site for Mn+2 and several much weaker sites. Differential scanning calorimetry showed a single irreversible thermal transition. All three cations raise both the temperature of the transition and the activation energy, with the transition becoming more cooperative. The crystal structures of the Ca+2 and Mg+2 complexes with Torpedo acetylcholinesterase were solved. A principal binding site was identified. In both cases, it consists of four aspartates (a 4D motif), within which the divalent ion is embedded, together with several water molecules. It makes direct contact with two of the aspartates, and indirect contact, via waters, with the other two. The 4D motif has been identified in 31 acetylcholinesterase sequences and 28 butyrylcholinesterase sequences. Zebrafish acetylcholinesterase also contains the 4D motif; it, too, is stabilized by divalent metal ions. The ASSAM server retrieved 200 other proteins that display the 4D motif, in many of which it is occupied by a divalent cation. It is a very versatile motif, since, even though tightly conserved in terms of RMSD values, it can contain from one to as many as three divalent metal ions, together with a variable number of waters. This novel motif, which binds primarily divalent metal ions, is shared by a broad repertoire of proteins. An animated Interactive 3D Complement (I3DC) is available in Proteopedia at http://proteopedia.org/w/Journal:Protein_Science:3.
A novel method to objectively assess robotic assistance in laparoscopic colorectal surgery
Authors: Ngu James Chi‐Yong , Teo Nan‐Zun 
Published: March 2021

AbstractObjectiveAn objective assessment of robotic assistance in colorectal surgery.BackgroundThere is a lack of objective evidence behind the claims of superior optics and improved ergonomics with robotics. This study introduces a novel method of assessing how robotics facilitates colorectal surgery.MethodsOperative videos of laparoscopic and robotic surgeries were reviewed. Two components were evaluated—scope‐holder performance was assessed using a transparent overlay to partition the video image and provide lines for measurement; assistant instrument performance was measured using a separate matrix of movement episodes and time.ResultsThe views achieved in robotic surgery were superior and less dependent on the assistant. The degree of assistance provided by the robotic system was more than that of the human assistant.ConclusionsThe use of robotics allows a trained operator to project his skills threefold—as a scope holder, operator and assistant—providing superior visualization and dynamic assistance throughout surgery.
Protocol‐based H∞ filtering for piecewise linear systems: A measurement‐dependent equivalent reduction approach
Authors: Li Jiajia , Wei Guoliang , Ding Derui , Tian Engang 
Published: March 2021

AbstractIn this article, a protocol‐based H∞ filtering problem is investigated for piecewise linear (PWL) systems with mixed delays. Stochastic access protocol (SAP) is utilized to schedule the signal transmission via a constrained communication channel, under which only one measurement value can be transmitted to the filter at each time instant following a Markov process. When SAP is applied to PWL systems, only a part of system modes can be observed due to the incomplete measurement information. Therefore, a measurement‐dependent parameter storage rule with a certain probability distribution is introduced to overcome the difficulties coming from SAP‐induced incomplete information. By resorting to the proposed mode storage rule, a novel measurement‐dependent asynchronous H∞ filter model is constructed and the problem is converted into a new switching process of a larger state space following a reconstructed Markov process. Subsequently, a sufficient condition is established to guarantee the H∞ performance, and the probability‐dependent filter parameters are obtained by applying the stochastic analysis technique. Finally, a numerical example is given to show the effectiveness of the design approach.
Development and Characterization of Drug‐Loaded PVP/PAN/Gr Electrospun Fibers for Drug Delivery Systems
Authors: Maşlakcı Neslihan Nohut 
Published: March 2021

AbstractThe objective of the present study is to evaluate the pH‐dependent drug release from polyvinylpyrrolidone (PVP)/polyacrylonitrile (PAN)/graphene (Gr) (P1) fibers using a quartz crystal microbalance (QCM). Electrospun fibers for poorly water‐soluble drugs were prepared on the QCM electrode surface through the electrospinning with P1 as the fiber‐forming polymer and drug carrier system and ibuprofen (Ibu) as the model drug. Characterization of the fibers is practiced by X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy in combination with energy‐dispersive X‐ray spectroscopy (SEM‐EDX), thermogravimetric analysis (TGA)‐differential scanning calorimetry (DSC), and water contact angle measurements. The in vitro release kinetic studies of the Ibu were studied using QCM and UV‐vis spectroscopy. The drug delivery properties of the fibers of PVP/PAN/Gr with 5 wt % Ibu (P2) and PVP/PAN/Gr with 10 wt % Ibu (P3) were measured at pH 5.4 and 7.4. In pH 5.4, the cumulative drug release of 19.5 % was procured from the P3 fiber within 24 h, on the other hand; the cumulative drug release of 16 % was acquired in pH 7.4.
Synthesis, Dynamic Mechanical Properties, and Shape Memory Effect of Poly(benzoxazine‐ether‐urethane)s
Authors: Wang Chang , Li Zhiyun , Lu Guosheng , Zhen Hecheng , Liu Yanfang , Run Mingtao 
Published: March 2021

AbstractTwo series of poly(benzoxazine‐ether‐urethane)s (PBEUs) are prepared through thermally activated ring‐opening polymerization (ROP) of bi‐functional benzoxazines containing ether‐urethane moieties. The bi‐functional benzoxazines are synthesized through coupling reaction of hydroxyl‐containing mono‐functional monomers based on phenol,o‐allylphenol,o‐cresol,p‐cresol, diglycolamine, and paraformaldehyde with 1,6‐hexamethylene diisocyanate (HDI) and 2,4‐toluene diisocyanate (TDI), respectively. The ROP temperature of each HDI‐based benzoxazine is higher than that of the counterpart based on TDI, and they are in descending orderortho‐,para‐, and unsubstituted phenol for both series. Due to the difference in structure symmetry between the two series monomers, the variation of polymerization rate with temperature of each TDI‐based benzoxazine is different from that of the counterpart based on HDI. Theortho‐ andpara‐substituted‐phenol‐based PBEUs show lower glass transition temperatures than that of the phenol‐based counterpart. In the vicinity of the glass transition temperature, the HDI‐based PBEUs exhibit thermally induced one‐way dual‐shape memory effect.
Laccase‐Mimicking Syntheses of Phenoxazinones by Aerobic Oxidative Homo‐ and Hetero‐Dimerizations of Aminophenols
Authors: Duan Wenxue , Li Wenhao , Tang Qingxuan , Zhao Yiyang , Guo Xianji , Yang Guanyu 
Published: March 2021

AbstractTo pursue a sustainable enzyme‐liking approach, a laccase‐mimicking model that utilized natural low‐toxic gallic acid as an organocatalyst was developed for efficient aerobic oxidative homo‐ and hetero‐dimerizations of various 2‐aminophenols to afford 2‐aminophenoxazin‐3‐ones with moderate to high isolated yields at room temperature in water.
Polymeric Carbon Nitride‐Derived Photocatalysts for Water Splitting and Nitrogen Fixation
Authors: Zhang Deliang , He Wen , Ye Jiamin , Gao Xing , Wang Debao , Song Jibin 
Published: March 2021

AbstractPhotocatalysis is a promising energy conversion and environmental restoration technology. The main focus of photocatalysis is the development and manufacture of highly efficient photocatalysts. Semiconductor‐based photocatalysis technology based on harnessing solar energy is considered as an attractive approach to solve the problems of global energy shortage and environmental pollution. Since 2009 pioneering work has been carried out on polymeric carbon nitride (PCN) for visible photocatalytic water splitting, thus PCN‐based photocatalysis has become a hot research topic, demanding significant research attention. This article reviews the physical and chemical properties, synthesis methods, and the methods to control the morphology, heteroatom doping, and construction of heterojunctions to improve the performance of PCN‐based photocatalysts in water splitting and nitrogen fixation. Through different design strategies, the photo‐generated electron‐hole pair separation efficiency of PCN materials can be effectively improved, thereby improving their photocatalytic performance. Finally, the challenges of PCN‐based photocatalysts in water splitting and nitrogen fixation applications are discussed herein. It is strongly believed that through different design strategies, efficient PCN‐based photocatalysts can be constructed for both water splitting and nitrogen reduction. These excellent modification strategies can be used as a guiding theory for photocatalytic reactions of other promising catalysts and further promote the development of photocatalysis.
Maximized Schottky Effect: The Ultrafine V2O3/Ni Heterojunctions Repeatedly Arranging on Monolayer Nanosheets for Efficient and Stable Water‐to‐Hydrogen Conversion
Authors: Zhang Qi , Liu Bingqiu , Li Lu , Ji Yue , Wang Chungang , Zhang Lingyu , Su Zhongmin 
Published: March 2021

AbstractThe Mott–Schottky heterojunction formed at the interface of ultrafine metallic Ni and semiconducting V2O3 nanoparticles is constructed, and the heterojunctions are “knitted” into the tulle‐like monolayer nanosheets on nickel foam (NF). The greatly reduced particle sizes of both Ni and V2O3 on the Mott–Schottky heterojunction highly enhance the number of Schottky heterojunctions per unit area of the materials. Moreover, arranging the heterojunctions into the monolayer nanosheets makes the heterojunctions repeat and expose to the electrolyte sufficiently. The Schottky heterojunctions are like countless self‐powered charge transfer workstations embedded in the tulle‐like monolayer nanosheets, promoting maximum of the materials to participate into the electron transfer and become catalytic active sites. In addition, the tulle‐like monolayer nanosheet structure can assist in pumping liquid phase electrolyte to the surface of catalysts, owing to the capillary force. The V2O3/Ni/NF Mott–Schottky catalyst exhibits excellent hydrogen evolution reaction (HER) performance with a low η10 of 54 mV and needs −107 mV to get the current density of −100 mA cm−2. Furthermore, V2O3/Ni/NF Schottky electrocatalyst exhibits excellent urea oxidation reaction activity: 1.40, 1.51, and 1.61 V versus reversible hydrogen electrode (RHE) voltage are required to reach a current density of 100, 500, and 1000 mA cm−2, respectively.
Reduced Fracture Strength of 2D Materials Induced by Interlayer Friction
Authors: Zhan Hao , Tan Xinfeng , Xie Guoxin , Guo Dan 
Published: March 2021

AbstractThe potential applications of 2D layered materials (2DLMs) as the functional membranes in flexible electronics and nano‐electromechanical systems emphasize the role of the mechanical properties of these materials. Interlayer interactions play critical roles in affecting the mechanical properties of 2DLMs, and nevertheless the understanding of their relationship remains incomplete. In the present work, it is reported that the fracture strength of few‐layer (FL) WS2 can be weakened by the interlayer friction among individual layers with the assistance of finite element simulations and density functional theory (DFT) calculations. The reduced fracture strength can be also observed in FL WSe2 but with a lesser extent, which is attributed to the difference in the interlayer sliding energies of WS2 and WSe2 as confirmed by DFT calculations. Moreover, the tip‐membrane friction can give rise to the underestimation of the Young's modulus except for the membrane nonlinearity. These results give deep insights into the influence of interfacial interactions on the mechanical properties of 2DLMs, and suggest that importance should be also attached to the interlayer interactions during the design of nanodevices with 2DLMs as the functional materials.
Modulation of Self‐Assembly Enhances the Catalytic Activity of Iron Porphyrin for CO2 Reduction
Authors: Tasaki Masahiro , Okabe Yuki , Iwami Hikaru , Akatsuka Chiharu , Kosugi Kento , Negita Kohei , Kusaka Sinpei , Matsuda Ryotaro , Kondo Mio , Masaoka Shigeyuki 
Published: March 2021

AbstractElectrochemical reduction of CO2 in aqueous media is an important reaction to produce value‐added carbon products in an environmentally and economically friendly manner. Various molecule‐based catalytic systems for the reaction have been reported thus far. The key features of state‐of‐the‐art catalytic systems in this field can be summarized as follows: 1) an iron‐porphyrin‐based scaffold as a catalytic center, 2) a dinuclear active center for the efficient activation of a CO2 molecule, and 3) a hydrophobic channel for the accumulation of CO2. This article reports a novel approach to construct a catalytic system for CO2 reduction with the aforementioned three key substructures. The self‐assembly of a newly designed iron‐porphyrin complex bearing bulky substituents with noncovalent interaction ability forms a highly ordered crystalline solid with adjacent catalytically active sites and hydrophobic pores. The obtained crystalline solid serves as an electrocatalyst for CO2 reduction in aqueous media. Note that a relevant iron‐porphyrin complex without bulky substituents cannot form a porous structure with adjacent active sites, and the catalytic performance of the crystals of this relevant iron‐porphyrin complex is substantially lower than that of the newly developed catalytic system. The present study provides a novel strategy for constructing porous crystalline solids for small‐molecule conversions.
Interplay of Bright Triplet and Dark Excitons Revealed by Magneto‐Photoluminescence of Individual PbS/CdS Quantum Dots
Authors: Kim Younghee , Hu Zhongjian , Avdeev Ivan D. , Singh Ajay , Singh Amita , Chandrasekaran Vigneshwaran , Nestoklon Mikhail O. , Goupalov Serguei V. , Hollingsworth Jennifer A. , Htoon Han 
Published: March 2021

AbstractA low‐temperature polarization‐resolved magneto‐photoluminescence experiment is performed on individual PbS/CdS core/shell quantum dots (QDs). The experiment enables a direct measurement of the exciton Landé g factor and the anisotropic zero‐field splitting of the lowest emissive bright exciton triplet in PbS/CdS QDs. While anisotropic splittings of individual QDs distribute randomly in 104—325 μeV range, the exciton Landé g factors increase from 0.95 to 2.70 as the emission energy of the QD increases from 1.0 to 1.2 eV. The tight‐binding calculations allow to rationalize these trends as a direct consequence of reducing a cubic symmetry of QD via addition/removal of a few (<70) atoms from the surfaces of the PbS core. Furthermore, it is observed that while right (σ  +) and left (σ   −) circularly polarized photoluminescence (PL) peaks split linearly with magnetic field as expected for Zeeman effect, the energy splitting between X and Y linearly polarized PL peaks remains nearly unchanged. The theoretical study reveals rich and complex magnetic field‐induced interplay of bright triplet and dark exciton states explaining this puzzling behavior. These findings fill the missing gaps in the understanding of lead salt QDs and provide foundation for development of classical and quantum light sources operating at telecommunication wavelengths.
Suppressing Water Dissociation via Control of Intrinsic Oxygen Defects for Awakening Solar H2O‐to‐H2O2 Generation
Authors: Wang Luyang , Lu Yuan , Han Nannan , Dong Chaoran , Lin Cheng , Lu Siyu , Min Yulin , Zhang Kan 
Published: March 2021

AbstractBiVO4 theoretically has a thermodynamic activity trend toward highly selective water oxidative H2O2 formation, but it is more inclined to generate O2 in practical. The influence of intrinsic oxygen vacancy (Ovac), especially, on surface reactivity, has never been considered as a possible activity loss mechanism in the synthetic BiVO4. In this work, it is theoretically and experimentally demonstrated that the intrinsic surface Ovac is responsible for lower H2O2 evolution activity via promoting water dissociation to form intermediate. Through an annealing process under a V2O5 rich atmosphere, the surface Ovac can be eliminated that awakens the photoelectrochemical (PEC) water oxidative H2O2 activity in a NaHCO3 electrolyte, which achieves an average of 58.4%, and increases by up to 4.28 times of the one annealed in air. This work offers a general understanding of catalytic activity loss and may be extended to other photo or electrocatalysts for catalytic selectivity regulation.
Tentative sensitivity of future 0νββ-decay experiments to neutrino masses and Majorana CP phases
Authors: Huang Guo-yuan , Zhou Shun 
Published: March 2021

Abstract
In the near future, the neutrinoless double-beta (0νββ) decay experiments will hopefully reach the sensitivity of a few meV to the effective neutrino mass |mββ|. In this paper, we tentatively examine the sensitivity of future 0νββ-decay experiments to neutrino masses and Majorana CP phases by following the Bayesian statistical approach. Provided experimental setups corresponding to the experimental sensitivity of |mββ| ≃ 1 meV, the null observation of 0νββ decays in the case of normal neutrino mass ordering leads to a very competitive bound on the lightest neutrino mass m1. Namely, the 95% credible interval in the Bayesian approach turns out to be 1.6 meV ≲ m1 ≲ 7.3 meV or 0.3 meV ≲ m1 ≲ 5.6 meV when the uniform prior on m1/eV or on log10(m1/eV) is adopted. Moreover, one of two Majorana CP phases is strictly constrained, i.e., 140° ≲ ρ ≲ 220° for both scenarios of prior distributions of m1. In contrast, if a relatively worse experimental sensitivity of |mββ| ≃ 10 meV is assumed, the constraint on the lightest neutrino mass becomes accordingly 0.6 meV ≲ m1 ≲ 26 meV or 0 ≲ m1 ≲ 6.1 meV, while two Majorana CP phases will be essentially unconstrained. In the same statistical framework, the prospects for the determination of neutrino mass ordering and the discrimination between Majorana and Dirac nature of massive neutrinos in the 0νββ-decay experiments are also discussed. Given the experimental sensitivity of |mββ| ≃ 10 meV (or 1 meV), the strength of evidence to exclude the Majorana nature under the null observation of 0νββ decays is found to be inconclusive (or strong), no matter which of two priors on m1 is taken.
A new spin on the Weak Gravity Conjecture
Authors: Aalsma Lars , Cole Alex , Loges Gregory J. , Shiu Gary 
Published: March 2021

Abstract
The mild form of the Weak Gravity Conjecture states that quantum or higher-derivative corrections should decrease the mass of large extremal charged black holes at fixed charge. This allows extremal black holes to decay, unless protected by a symmetry (such as supersymmetry). We reformulate this conjecture as an integrated condition on the effective stress tensor capturing the effect of quantum or higher-derivative corrections. In addition to charged black holes, we also consider rotating BTZ black holes and show that this condition is satisfied as a consequence of the c-theorem, proving a spinning version of the Weak Gravity Conjecture. We also apply our results to a five-dimensional boosted black string with higher-derivative corrections. The boosted black string has a BTZ×S2 near-horizon geometry and, after Kaluza-Klein reduction, describes a four-dimensional charged black hole. Combining the spinning and charged Weak Gravity Conjecture we obtain positivity bounds on the five-dimensional Wilson coefficients that are stronger than those obtained from charged black holes alone.
Overlaps and fermionic dualities for integrable super spin chains
Authors: Kristjansen Charlotte , Müller Dennis , Zarembo Konstantin 
Published: March 2021

Abstract
The $$ \mathfrak{psu}\left(2,\left.2\right|4\right) $$
psu

2

2

4

integrable super spin chain underlying the AdS/CFT correspondence has integrable boundary states which describe set-ups where k D3-branes get dissolved in a probe D5-brane. Overlaps between Bethe eigenstates and these boundary states encode the one-point functions of conformal operators and are expressed in terms of the superdeterminant of the Gaudin matrix that in turn depends on the Dynkin diagram of the symmetry algebra. The different possible Dynkin diagrams of super Lie algebras are related via fermionic dualities and we determine how overlap formulae transform under these dualities. As an application we show how to consistently move between overlap formulae obtained for k = 1 from different Dynkin diagrams.
Non-relativistic limit of gravity theories in the first order formalism
Authors: Guerrieri Amanda , Sobreiro Rodrigo F. 
Published: March 2021

Abstract
We consider the non-relativistic limit of gravity in four dimensions in the first order formalism. First, we revisit the case of the Einstein-Hilbert action and formally discuss some geometrical configurations in vacuum and in the presence of matter at leading order. Second, we consider the more general Mardones-Zanelli action and its non-relativistic limit. The field equations and some interesting geometries, in vacuum and in the presence of matter, are formally obtained. Remarkably, in contrast to the Einstein-Hilbert limit, the set of field equations is fully determined because the boost connection appears in the action and field equations. It is found that the cosmological constant must disappear in the non-relativistic Mardones-Zanelli action at leading order. The conditions for Newtonian absolute time be acceptable are also discussed. It turns out that Newtonian absolute time can be safely implemented with reasonable conditions.
R-catcher, a potent molecular tool to unveil the arginylome
Authors: Seo Taewook , Kim Jihyo , Shin Ho-Chul , Kim Jung Gi , Ju Shinyeong , Nawale Laxman , Han Goeun , Lee Hye Seon , Bang Geul , Kim Jin Young , Bang Jeong Kyu , Lee Kyung Ho , Soung Nak-Kyun , Hwang Joonsung , Lee Cheolju , Kim Seung Jun , Kim Bo Yeon , Cha-Molstad Hyunjoo 
Published: March 2021

AbstractProtein arginylation is a critical regulator of a variety of biological processes. The ability to uncover the global arginylation pattern and its associated signaling pathways would enable us to identify novel disease targets. Here, we report the development of a tool able to capture the N-terminal arginylome. This tool, termed R-catcher, is based on the ZZ domain of p62, which was previously shown to bind N-terminally arginylated proteins. Mutating the ZZ domain enhanced its binding specificity and affinity for Nt-Arg. R-catcher pulldown coupled to LC–MS/MS led to the identification of 59 known and putative arginylated proteins. Among these were a subgroup of novel ATE1-dependent arginylated ER proteins that are linked to diverse biological pathways, including cellular senescence and vesicle-mediated transport as well as diseases, such as Amyotrophic Lateral Sclerosis and Alzheimer’s disease. This study presents the first molecular tool that allows the unbiased identification of arginylated proteins, thereby unlocking the arginylome and provide a new path to disease biomarker discovery.