bluuebunny/crossref_metadata_2025_split huggingface dataset:
High Capacity and Energy Density Organic Lithium‐Ion Battery Based on Buckypaper with Stable π‐Radical
Authors: Ito Hiroshi , Murata Tsuyoshi , Fujisaki Megumi , Tsuji Ryotaro , Morita Yasushi 
Published: January 2021

AbstractOwing to an increasing demand on high performance and rare‐metal free energy storage systems, organic rechargeable battery has attracted much attention. To increase the capacity of the whole battery, we have fabricated coin‐type buckypaper cells composed of a trioxotriangulene neutral radical derivative (H3TOT) and single‐walled carbon nanotubes as a cathode and lithium metal plate as an anode without current collector. The cells exhibited a stable charge‐discharge behavior even at a 90 wt % H3TOT content with a high‐rate performance of 10 C originating from high electrical conductivity of H3TOT. Furthermore, based on the four‐stage redox ability of H3TOT, the H3TOT 90 wt % cathode showed a high capacity of approximately 260 mAh g−1 and a high energy density of 546 Wh g−1. In view of the simple fabrication of the cathode and excellent performance, TOT‐based buckypaper will open a new strategy for the flexible cells for next‐generation energy storages.
Fluoroalkyl‐Containing 1,2‐Disubstituted Cyclobutanes: Advanced Building Blocks for Medicinal Chemistry
Authors: Demchuk Oleksandr P. , Hryshchuk Oleksandr V. , Vashchenko Bohdan V. , Trofymchuk Serhii A. , Melnykov Kostiantyn P. , Skreminskiy Artem , Volochnyuk Dmitriy M. , Grygorenko Oleksandr O. 
Published: January 2021

AbstractSynthesis of previously unavailable 1,2‐disubstituted cyclobutane building blocks bearing mono‐, di‐ and trifluoromethyl groups are disclosed. The key steps included deoxofluorination or TMAF‐mediated nucleophilic substitution in the appropriate bifunctional cyclobutanes; for the CF3‐substituted derivatives, alternative methods based on cyano‐ or azidotrifluoromethylation of cyclobutene using the Togni reagent II were also proposed. All methods provided trans diastereomers of the target primary amines and carboxylic acids (6 representatives) and were suitable for their multigram preparation. Furthermore, dissociation constants (pKa) and lipophilicity (logP) values were measured to evaluate the effect of the fluoroalkyl substituents on acidity/basicity and lipophilicity of the building blocks obtained.
KOt‐Bu‐Catalyzed Chemo‐ and Regioselective Hydroamination of Allylic Sulfones with Indoles
Authors: Kim Kundo , Park Subin , Lee Yunmi 
Published: January 2021

AbstractA highly chemo‐ and regioselective KOt‐Bu‐catalyzed addition of substituted indoles to terminal or disubstituted allylic sulfones at the indole N‐position is reported. The catalytic protocol allows for the efficient and mild synthesis of a broad range of new and versatile sulfonyl‐substituted indoles and azoles bearing various functional groups from readily available starting materials in good to excellent yields with complete regioselectivity.
Five‐Membered Nitrogen Heterocycles Synthesis through 1,3‐Dipolar Cycloaddition of Non‐Stabilized Azomethine Ylides with 2‐Pyridone Heteroaromatic Systems as Dipolarophiles
Authors: Ben Salah Sami , Sanselme Morgane , Champavier Yves , Othman Mohamed , Daïch Adam , Chataigner Isabelle , Martin Lawson Ata 
Published: January 2021

AbstractWe report an efficient 1,3‐dipolar cycloaddition involving non‐stabilized electron‐rich azomethine ylides and diversely substituted 2‐pyridones bearing two potential C=C dipolarophilic sites. The 1,3‐dipoles were prepared in situ under TFA catalysis and cycloadditions were studied according to the nature of the pyridones and position of the various substituents. These reactions occur under mild conditions, and lead to the expected cycloadducts in good yields and full control of the regioselectivity. Furthermore, mono‐ or biscycloadditions were performed, leading to the formation of polycyclic scaffolds bearing biologically relevant pyrrolidine rings, prevalent in natural products. The diastereoselectivity of the second cycloaddition was fully controlled by the first addition, leading to heterocycles with a trans relative stereochemistry of the two generated rings in the final tricyclo‐adduct.
Use of Perylene Diimides in Synthetic Photochemistry
Authors: Rosso Cristian , Filippini Giacomo , Prato Maurizio 
Published: January 2021

AbstractPerylene diimides (PDIs) are valuable organic chromophores that stand out for their outstanding optical and redox properties. Owing to these features, PDIs have emerged as prominent dyes capable of acting as photocatalysts for numerous relevant organic transformations. This Minireview highlights the recent advances in the application of PDIs in organic photocatalysis. The various mechanistic pathways of the photo‐reduction reaction of aryl halides, recently proposed in independent studies, are discussed with an eye to unsolved challenges and forward‐looking opportunities regarding the use of PDIs within this field.
SO‐VMEC: Service offloading in virtual mobile edge computing using deep reinforcement learning
Authors: Laroui Mohammed , Ibn‐Khedher Hatem , Ali Cherif Moussa , Moungla Hassine , Afifi Hossam , Kamel Ahmed E. 
Published: January 2021

AbstractService offloading poses interesting challenges in current and next‐generation networks. The classical network optimization algorithms are still painstakingly tune heuristics to get a sufficient solution. Classical approaches use data as input in order to output near‐optimal solutions. These techniques show exponential computational time and deal only with small network scale. Therefore, we are motivated by replacing this tedious process with recent learning techniques to learn the behavior of the classical optimization algorithms while enhancing both the quality of service and satisfying the resources requirements of next‐generation applications. Deep reinforcement learning (DRL) and machine learning (ML) can improve service offloading and network caching. An optimal service offloading in virtual mobile edge computing (SO‐VMEC) use case algorithm is proposed using integer linear programming (ILP). Moreover, a service offloading protocol is presented to support the use case. We leverage software defined networking (SDN) and network function virtualization (NFV) concepts to control and virtualize network components. Then, a DRL‐based offloading is proposed to deal with dense Internet of Things (IoT) networks. Extensive evaluations and comparison to state of the art techniques are carried out. Results show the efficiency of the proposed algorithms in terms of service offloading, resource utilization, and networking.
Can we learn lessons from the past? COVID‐19 crisis and corporate governance responses
Authors: Jebran Khalil , Chen Shihua 
Published: January 2021

AbstractThe coronavirus (COVID‐19) pandemic has seriously threatened the lives of the people. The pandemic has also threatened the survival of the firms, which has drawn the attention of policymakers and corporate governance practitioners around the world. In this study, we focus on how corporate governance practices can help firms to survive during COVID‐19 crisis. For this purpose, we take insights from prior crises by reviewing leading business journals articles and identify key corporate governance mechanisms that could potentially be effective in the ongoing COVID‐19 crisis. Our review of a large body of literature highlights several governance mechanisms that may help firms to cope with COVID‐19 crisis. These governance attributes include risk management committees, board diversity, independent directors, foreign investors, institutional ownership, ownership concentration, CEO's dual roles, block ownership, and family ownership. We provide several policy implications after reviewing the corporate governance literature. Our review illustrates that firms may be subject to at least one of the identified governance mechanisms and they may learn how these governance attributes can be effective in the COVID‐19 crisis. Our review illustrates that independent risk management committees, institutional ownership, board independence, blockholders, and family ownership are some of the essential and effective governance mechanisms compared to other governance attributes during COVID‐19 crisis.
Debt financing and technology investment Kuznets curve: Evidence from China
Authors: Shahzad Umeair , Luo Fukai , Liu Jing 
Published: January 2021

AbstractThe nexus of debt financing and enterprise innovation is the most arguable debate in the modern literature of corporate finance. The subject of external debts and a smooth innovative environment is one of the common puzzles for high‐tech firms. We attempt to address this puzzle and explore the impact of efficient utilization of debt on the linkage between R&D intensity and technology investment. Patent count data are used to measure enterprise innovation, therefore, negative binomial and Poisson regression is applied for empirical analysis. The estimations validate that the linkage between debt financing and corporate innovation is inverted U‐shaped which approves the Kuznets curve hypothesis. Technology firms tend to decline debt undertaking after achieving a specific level, it is assumed as an optimum debt point, higher in incremental and lower in radical innovation. The mediation role of debt financing in the linkage between R&D intensity and technology investment is negative. However, efficient debt undertaking which remains under the optimum level improves the association between R&D intensity and enterprise innovation. High‐tech firms should be cautious on external financing because abundant debt undertaking worsens a smooth innovative environment.
Antimicrobial, cytotoxic, antioxidants, enzyme inhibition activities, and scanning electron microscopy of Lactuca orientalis (Boiss.) Boiss. seeds
Authors: Zahra Syeda Anber , Iqbal Javed , Abbasi Banzeer Ahsan , Shahbaz Amir , Kanwal Sobia , Shah Syed Lal , Ahmad Parvaiz , Mahmood Tariq 
Published: January 2021

AbstractLactuca orientalis (Boiss.) Boiss. is one of the most frequently used ethnomedicinal plant. This research study was designed to decipher the phytochemical screening, pharmacological potential and implementation of scanning electron microscope (SEM). Six different solvents were used to prepare L. orientalis (LO) seed extracts. Phytochemical and antioxidant activities were determined calorimetrically. To investigate antidiabetic, α‐amylase inhibition assay was performed. Brine shrimp assay was performed for cytotoxicity and anti‐leishmanial via MTT assay. Disc‐diffusion assay was performed to detect protein kinase inhibitory, antibacterial and antifungal activities. SEM was used as identification tool. Significant amount of phenolic and flavonoid content were identified in methanol extract (LOSM) (95.76 ± 3.71 GAE/mg) and (77 ± 3.60 QE/mg). Highest DPPH scavenging potential (82%) was reported for LOSM. Significant total antioxidant capacity (90.60 ± 1.55 AAE/mg) and total reducing power (94.44 ± 1.38 AAE/mg) were determined for LOSM. Highest α‐amylase inhibition was found in LOSM (78.20 ± 1.58%). The highest LD50 of brine shrimp was found for n‐Hexane extract (LOSH) 13.03 𝜇g/ml. All extracts showed strong anti‐leishmanial activity except LOSH. L. orientalis seeds showed significant protein kinase inhibition, antibacterial and antifungal activities. The seeds of L. orientalis were seen to be oblong to obovate, projections, wavy slightly straight, anticlinal wall was raised with apex acuminate. The outer‐periclinal wall convex with fine texture. In conclusion, our findings scientifically support ethnomedicinal and biological potentials of L. orientalis seeds. In future, L. orientalis seeds need to be explored for identification and isolation of bioactive compounds. The results obtained necessitate further in vivo studies to evaluate their pharmacological potentials.
Raman spectroscopic and quantum chemical investigation of the effects of trimethylamine N‐oxide on hydrated guanidinium and hydrogen‐bonded water networks
Authors: Verville Genevieve A. , Byrd Mary Hannah , Kamischke Andrew , Smith Shelly A. , Magers David H. , Hammer Nathan I. 
Published: January 2021

AbstractThe effects of trimethylamine N‐oxide (TMAO) on guanidinium chloride and hydrogen‐bonded networks of water are explored in this joint Raman spectroscopic and quantum chemical study. Both TMAO and guanidinium are osmolytes that affect the stability of proteins, as TMAO is known to stabilize and counteract the destabilizing effects of guanidinium. While guanidinium is very similar in chemical structure to urea, the exact mechanisms of the molecular interactions between guanidinium, TMAO, and proteins continue to be investigated. Herein, we use Raman spectroscopy to elucidate the physical interactions between TMAO and guanidinium in aqueous solutions to better understand how these important osmolytes interact with each other and affect adjacent hydrogen‐bonding networks of water. Comparing experiment to theory yields good agreement and allows for the identification and tracking of different vibrational modes. It was determined that adding TMAO into an aqueous solution of guanidinium induces a blue shift (shift to higher energy) in guanidinium's H‐N‐H bending modes, which is indicative of direct interactions between the two osmolytes and similar to the earlier results observed for TMAO interacting with urea.
LncRNA TP73‐AS1 regulates miR‐495 expression to promote migration and invasion of nasopharyngeal carcinoma cells through junctional adhesion molecule A
Authors: Dai Bao‐Qiang , Jiang Xue , Feng Li‐Chun 
Published: January 2021

AbstractThe main obstacle to the treatment of nasopharyngeal carcinoma (NPC) is metastasis. Long non‐coding RNAs (lncRNAs) and microRNAs (miRNAs) are highly involved in the progression of NPC. In this study, we aimed to explore the regulatory role of lncRNA P73 antisense RNA 1 T (TP73‐AS1) and miR‐495 in migration and invasion of NPC cells. The expression levels of TP73‐AS1, miR‐495, and junctional adhesion molecule A (JAM‐A) in NPC tissue samples and cell lines were examined by quantitative real‐time PCR (qRT‐PCR) and/or Western blot. NPC cells were transfected with vectors overexpressing TP73‐AS1, short hairpin RNA (shRNA) against TP73‐AS1, shRNA against JAM‐A, miR‐495 mimics, miR‐495 inhibitor, and their corresponding negative controls as designated. The MTT assay, cell migration assay, and transwell assay were performed to detect cell viability, migration, and invasion, respectively. Dual‐luciferase reporter assay was performed to confirm the binding of TP73‐AS1 and miR‐495, and miR‐495 and JAM‐A. TP73‐AS1 and JAM‐A were significantly upregulated while miR‐495 was markedly downregulated in NPC tissues and cell lines compared to normal controls. The overexpression of TP73‐AS1 promoted migration and invasion of NPC cell line CNE‐2. TP73‐AS1 targeted miR‐495 and negatively regulated its expression. TP73‐AS1 upregulated the expression of JAM‐A through miR‐495. TP73‐AS1 mediated migration and invasion of CNE‐2 cells via upregulating JAM‐A. LncRNA TP73‐AS1, miR‐495, and JAM‐A are involved in migration and invasion of NPC cells. The TP73‐AS1/miR‐495/JAM‐A axis may serve as a therapeutic target for the treatment of NPC.
A pattern‐ and frequency‐reconfigurable antenna using liquid metal
Authors: Zhang Yuwei , Lin Shu , Yang Zhiqin , Li Bingqing , Cui Jingxuan , Jiao Jianlin 
Published: January 2021

AbstractThis article presents a pattern‐and frequency‐reconfigurable antenna based on movable liquid metal. The proposed antenna mainly consists of a printed three‐element Yagi‐Uda structure whose two parasitic elements are loaded with slots in the middle. Six movable liquid metal poles are filled in the microfluidic channels, which adhered to the surface of the three radiating arms of the Yagi‐Uda antenna. By moving these liquid metal poles, the slots can be shorted or opened and the equivalent electrical lengths of the director and fed‐dipole can be changed, thus adjusting the antenna in radiation pattern and frequency. As a result, this antenna can work at different states, which are mainly classified into five modes. To verify this design concept, a prototype of the proposed antenna is fabricated and measured. The measured results indicate that the antenna can operate in the frequency range from 1.52 to 3.2 GHz, and the peak gain can reach 7.3 dBi.
Design of wideband directional coupler based on secondary stage coupled structure
Authors: Liao Dun Wei , Fu Yun Qi 
Published: January 2021

AbstractA wideband directional coupler based on secondary coupled structure is presented and implemented in this paper. The proposed coupler is formed by two stepped‐impedance shaped microstrip and parallel coupled‐lines with a stepped rectangular slot in a common ground plane. The phase velocity differences between the even‐ and odd‐modes of the coupler are compensated by introducing broadside principal coupling and parallel‐line secondary coupling structures, which can achieve a flat coupling without any enlarging the size of the coupler. The simulation results show that the designed device exhibit a coupling of 3 ± 1 dB across the 2.3–11.8 GHz band, which obtained a wideband over 5‐octave wider than other couplers. In order to demonstrate the effectiveness of the design, a prototype is fabricated and measured. The measured results reveal a coupling of 3 ± 1 dB across the 2.7–11.1 GHz band, which also show good performance.
Time‐resolved model for geothermal engineering in high porosity Slochteren sandstone
Authors: Singh Aditya , Fokker Peter A. 
Published: January 2021

AbstractThis work is an extension of the time‐resolved poro‐elasto‐plastic Mohr‐Coulomb model by Fokker et al to include a more realistic constitutive model. Experiments on Slochteren sandstone revealed that the inelastic deformation contributes significantly in compressive deformation almost in all stages of loading and instigated the development of a Cam‐Clay‐like model to reproduce the Slochteren sandstone behavior. This model was adopted for the current extension. A typical behavior of this model is that the presence of a borehole causes both elastic and inelastic deformation everywhere in the reservoir, as opposed to the conventional philosophy with plastic and elastic zones.Our solution handles the spatial and temporal evolution of pressures, permeability, elastic and plastic properties under the assumption of symmetric loading. The applicability of the approach is demonstrated through a number of cases, like fluid injection, shut‐in, production, stimulation, and an injection‐production sequence.
SnO2/Sn/Carbon nanohybrid lithium‐ion battery anode with high reversible capacity and excellent cyclic stability
Authors: Wang Xiaoyan , Zheng Tianle , Cheng Ya‐Jun , Yin Shanshan , Xia Yonggao , Ji Qing , Xu Zhuijun , Liang Suzhe , Ma Liujia , Zuo Xiuxia , Meng Jian‐Qiang , Zhu Jin , Müller‐Buschbaum Peter 
Published: January 2021

AbstractUltrafine SnO2/Sn nanoparticles encapsulated into the adjustable mesoporous carbon matrix has been successfully fabricated by a facile route. The mesoporous carbon effectively improve the conductivity of the SnO2/Sn, prevent the aggregation, accommodate the strain of volume change and provide high interface area with the electrolyte, thus resulting in excellent cycling performance. A reversible capacity of 1105 mAh g–1 still retained after 290 cycles at 200 mA g–1, and the capacity still can keep at 107 mAh g–1 at high current density of 10 A g–1. The porous structures by the in situ SiOx template provide an appropriate specific surface area, which contributes to a relatively high capacitive contribution.
Deciding feasibility of a booking in the European gas market on a cycle is in P for the case of passive networks
Authors: Labbé Martine , Plein Fränk , Schmidt Martin , Thürauf Johannes 
Published: January 2021

AbstractWe show that the feasibility of a booking in the European entry‐exit gas market can be decided in polynomial time on single‐cycle networks that are passive, i.e., do not contain controllable elements. The feasibility of a booking can be characterized by solving polynomially many nonlinear potential‐based flow models for computing so‐called potential‐difference maximizing load flow scenarios. We thus analyze the structure of these models and exploit both the cyclic graph structure as well as specific properties of potential‐based flows. This enables us to solve the decision variant of the nonlinear potential‐difference maximization by reducing it to a system of polynomials of constant dimension that is independent of the cycle's size. This system of fixed dimension can be handled with tools from real algebraic geometry to derive a polynomial‐time algorithm. The characterization in terms of potential‐difference maximizing load flow scenarios then leads to a polynomial‐time algorithm for deciding the feasibility of a booking. Our theoretical results extend the existing knowledge about the complexity of deciding the feasibility of bookings from trees to single‐cycle networks.
BMI and Risk for Severe COVID‐19 Among Veterans Health Administration Patients
Authors: Breland Jessica Y. , Wong Michelle S. , Steers W. Neil , Yuan Anita H. , Haderlein Taona P. , Washington Donna L. 
Published: January 2021

ObjectiveThe purpose of this study was to assess associations between BMI and severe coronavirus disease 2019 (COVID‐19) outcomes: hospitalization, intensive care unit (ICU) admission, and mortality. A secondary aim was to investigate whether associations varied by age.MethodsThe cohort comprised patients in the Veterans Health Administration (VHA) who tested positive for COVID‐19 (N = 9,347). For each outcome, we fit piecewise logistic regression models with restricted cubic splines (knots at BMI of 23, 30, and 39), adjusting for age, sex, comorbidities, VHA nursing home residence, and race/ethnicity. Supplemental analyses included age‐by‐BMI interaction terms (α = 0.05).ResultsWe found evidence of a nonlinear J‐curve association between BMI and likelihood of hospitalization and mortality. BMI was associated with increased odds for hospitalization, ICU admission, and mortality among patients with BMI 30 to 39 but decreased odds of hospitalization and mortality for patients with BMI 23 to 30. Patients under age 75 with BMI between 30 and 39 had increased odds for mortality with increasing BMI.ConclusionsOdds for severe outcomes with COVID‐19 infection increased with increasing BMI for people with, but not without, obesity. This nonlinear relationship should be tested in future research. COVID‐19 public health messages in VHA, and broadly, should incorporate information about risks associated with all classes of obesity, particularly for those under age 75.
Future and the past of polymeric antioxidants
Authors: Filippov Sergey K. , Domnina Nina , Vol'eva Violetta 
Published: January 2021

AbstractHybrid macromolecular antioxidants has evolved into a mature research field last three decades. The main concept of this area was to design polymer conjugates that combine in one structure the hydrophilic properties of a polymer backbone and biological efficiency of hydrophobic antioxidants. Over the years, the understanding of different aspects of such approach has grown. In general, meticulous selection of each component is essential to obtain the conjugate with required properties. This review overview a plethora of hybrid macromolecular antioxidants synthesized over the last 20 years, together with the discussion their physicochemical properties and application for biomedical purposes.