bluuebunny/crossref_metadata_2025 huggingface dataset:
Emerging role of free triiodothyronine in patients with anti-N-methyl-D-aspartate receptor encephalitis
Authors: Ji Tuo , Huang Zhi , Lian Yajun , Wang Chengze , Zhang Qiaoman
Published: March 2021

We aimed to investigate the role of free triiodothyronine (FT3) in patients with anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis. 137 consecutive inpatients (2016–2019) were registered prospectively and followed up for 12 months. 96 eligible patients were included in the study. The modified Rankin scale (mRS) score was collected, and the score of 3–6 was defined as a poor outcome. The patients were equally classified into 3 subgroups based on their FT3 levels obtained within 24 h of admission, and the subgroup differences were analyzed by parametric or nonparametric tests as appropriate. Logistic regression analysis was performed. We found that there was no difference in the mRS scores upon admission among 3 subgroups, however, patients in the low-FT3 subgroup tended to have higher disease severity during hospitalization and worse outcome in follow-up visits, represented by higher chances of intense care unit (ICU) admission (P < 0.001), longer hospital stay (P < 0.001), greater maximum mRS scores during hospitalization (P = 0.011), lower rates of getting clinical improvement within 4 weeks of starting treatment (P = 0.006), and higher percentages of poor 1-year outcome (P = 0.002). The level of FT3 was an independent factor correlated with ICU admission (P = 0.002) and might be a potential predictor for 1-year outcome. Our preliminary results suggest that the FT3 may be a risk factor involved in the evolution and progression of anti-NMDAR encephalitis, whereas the underline mechanisms remain to be explored. Attention should be paid to these patients with relatively low FT3 upon admission, which might possibly aid clinical prediction and guide clinical decision-making.
An activity-based fluorescent sensor for the detection of the phenol sulfotransferase SULT1A1 in living cells
Authors: Baglia Regina A. , Mills Kira R. , Mitra Koushambi , Tutol Jasmine N. , Ball Darby , Page Kierstin M. , Kallu Jyothi , Gottipolu Sriharika , D’Arcy Sheena , Nielsen Steven O. , Dodani Sheel C.
Published: March 2021

Here, we report the development, computational modeling, in vitro enzymology, and biological application of an activity-based fluorescent sensor for the human phenol sulfotransferase SULT1A1.
On-road emissions of Euro 6d-TEMP passenger cars on Alpine routes during the winter period
Authors: Suarez-Bertoa Ricardo , Valverde Victor , Pavlovic Jelica , Clairotte Michaël , Selleri Tommaso , Franco Vicente , Kregar Zlatko , Astorga Covadonga
Published: March 2021

Vehicles show higher emissions at cold temperature. Nevertheless, emissions during real world tests can be below Euro 6d-TEMP requirements. The relatively high PN emissions from gasoline and PHEV vehicles indicate there is still room for improvement.
Insights into the molecular composition of semi-volatile aerosols in the summertime central Arctic Ocean using FIGAERO-CIMS
Authors: Siegel Karolina , Karlsson Linn , Zieger Paul , Baccarini Andrea , Schmale Julia , Lawler Michael , Salter Matthew , Leck Caroline , Ekman Annica M. L. , Riipinen Ilona , Mohr Claudia
Published: March 2021

Molecular-level analysis of High Arctic aerosols sampled on a cruise to the North Pole shows: (1) a wide range of semi-volatile organic compounds, (2) no clear relationship between DMS oxidation products in the gas- and particle-phase
Microbial population selection in integrated fixed-film sequencing batch reactors operated with different lengths of oxic and anoxic conditions
Authors: Aqeel Hussain , Basuvaraj Mahendran , Liss Steven N.
Published: March 2021

BNR granules rich in amyloid adhesins and denitrifying bacteria were formed in the SBRs that were operated with extended anoxic conditions.
Red, orange, yellow and green luminescence by carbon dots: hydrogen-bond-induced solvation effects
Authors: Xu Xiaokai , Hu Guangqi , Mo Luoqi , Li Yadong , Wei Haopeng , Lei Bingfu , Zhang Xuejie , Hu Chaofan , Zhuang Jianle , Liu Yingliang
Published: March 2021

The surfaces of CDs are rich in hydroxyl groups, and the amino groups and carbonyl groups generate HB forces with the solvent, resulting in a regular redshift in the luminescence.
Highly efficient and stable ionic liquid-based gel electrolytes
Authors: Ma Pin , Fang Yanyan , Li Ang , Wen Boxin , Cheng Hongbo , Zhou Xiaowen , Shi Yumeng , Yang Hui Ying , Lin Yuan
Published: March 2021

Stable gel electrolytes with high ionic conductivities and diffusion are developed by incorporating rich carboxylic group-modified silica nanoparticles (COOH-SiO2) into pure ionic liquid electrolytes.
Polyolefin graft copolymers through a ring-opening metathesis grafting through approach
Authors: Wang Huiqun , Onbulak Sebla , Weigand Steven , Bates Frank S. , Hillmyer Marc A.
Published: March 2021

A series of polyethylene-g-atactic polypropylene graft copolymers were synthesized by grafting through copolymerization of a cyclooctene terminated aPP macromonomer with cyclooctene monomer and subsequent hydrogenation.
Mass production of metal-doped graphene from the agriculture waste of Quercus ilex leaves for supercapacitors: inclusive DFT study
Authors: Tatrari Gaurav , Tewari Chetna , Karakoti Manoj , Pathak Mayank , Jangra Ritu , Santhibhushan Boddepalli , Mahendia Suman , Sahoo Nanda Gopal
Published: March 2021

This work reports a facile, eco-friendly, and cost-effective mass-scale synthesis of metal-doped graphene sheets (MDGs) using agriculture waste of Quercus ilex leaves for supercapacitor applications.
Boosting oxygen evolution reaction activity by tailoring MOF-derived hierarchical Co–Ni alloy nanoparticles encapsulated in nitrogen-doped carbon frameworks
Authors: Liu Xiaobin , Zhao Xudong , Fan Li-Zhen
Published: March 2021

The hierarchical Co2Ni@NC nanoparticles realize fast mass transfer for the oxygen evolution reaction (OER). The synergistic effect between Co and Ni can effectively adjust the binding energy tending to an optimal value, further improving the energetics for the OER.
Tunable phase transitions in NaNbO3 ceramics through bismuth/vacancy modification
Authors: Zhang Ludan , Yan Zhongna , Chen Tao , Luo Hang , Zhang Hangfeng , Khanom Taslema , Zhang Dou , Abrahams Isaac , Yan Haixue
Published: March 2021

Bi/vacancy incorporation in sodium niobate, NaNbO3, induces relaxor-like behaviour leading to higher recoverable energy storage density and efficiency, with potential use in energy storage capacitors.
Novel Cu–Mg–Ni–Zn–Mn oxide thin film electrodes for NIR photodetector applications
Authors: Wang Tzu-Hsuan , Kuo Chia-Tung , Chung Pin-Hung , Liu Chao-I , Lu You-Yan , Lee Yi-Ting , Yew Tri-Rung
Published: March 2021

CMNZM thin films generate electron–hole pairs under NIR light illumination and separate under an applied electric field.
Design and characterization of novel dirhodium coordination polymers – the impact of ligand size on selectivity in asymmetric cyclopropanation
Authors: Li Zhenzhong , Rösler Lorenz , Wissel Till , Breitzke Hergen , Hofmann Kathrin , Limbach Hans-Heinrich , Gutmann Torsten , Buntkowsky Gerd
Published: March 2021

Novel dirhodium coordination polymers are synthesized and characterized by various spectroscopic techniques. The catalysts exhibit good stability and excellent catalytic performance and selectivity in the cyclopropanation of diazooxindoles.
Sterically hindered ortho-substituted phosphatriptycenes as configurationally stable P-chirogenic triarylphosphines
Authors: Hu Lei , Mahaut Damien , Tumanov Nikolay , Wouters Johan , Collard Laurent , Robiette Raphaël , Berionni Guillaume
Published: March 2021

ortho-Substituted and unsymmetrical 9-phospha-triptycenes were synthesized via two synthetic approaches involving densely functionalized ortho-halogenated triarylmethane or phosphine precursors.
The role of rye bran and antibiotics on the digestion, fermentation process and short-chain fatty acid production and absorption in an intact pig model
Authors: Xu Yetong , Bolvig Anne Katrine , McCarthy-Sinclair Brendan , Marco Maria L. , Bach Knudsen Knud Erik , Hedemann Mette Skou , Lærke Helle Nygaard
Published: March 2021

Rye bran diet induced different DF degradation processes and SCFA profile compared with refined wheat cellulose, while antibiotics had marginal effects on digestibility and DF degradation but hampered butyrate production.
A high performance self-powered photodetector based on a 1D Te–2D WS2 mixed-dimensional heterostructure
Authors: Han Lixiang , Yang Mengmeng , Wen Peiting , Gao Wei , Huo Nengjie , Li Jingbo
Published: March 2021

Mechanically exfoliated 2D WS2 nanosheets were transferred on epitaxially grown 1D tellurium microwires. The 1D Te–2D WS2 heterostructures have potential in self-powered photodetectors and photovoltaics.
Electric field control of magnetism through modulating phase separation in (011)-Nd0.5Sr0.5MnO3/PMN-PT heterostructures
Authors: Liu Yao , Xu Zhitong , Qiao Kaiming , Shen Feiran , Xiao Andong , Wang Jing , Ma Tianyu , Hu Fengxia , Shen Baogen
Published: March 2021

Large and non-volatile electric field control of magnetization has been realized through strain mediation of both ferromagnetic and antiferromagnetic phases in Nd0.5Sr0.5MnO3/PMN-PT multiferroic heterostructures.
Preparation of hexafluoroisopropyl esters by oxidative esterification of aldehydes using sodium persulfate
Authors: León Sandoval Arturo , Politano Fabrizio , Witko Mason L. , Leadbeater Nicholas E.
Published: March 2021

A metal-free route for oxidative esterification of aldehydes using sodium persulfate and a catalytic quantity of a nitroxide.
Hydrogen bond induced high-performance quaternary organic solar cells with efficiency up to 17.48% and superior thermal stability
Authors: Li Xinrui , Zhou Lei , Lu Xi , Cao Luye , Du Xiaoyang , Lin Hui , Zheng Caijun , Tao Silu
Published: March 2021

We present a novel quaternary OSCs by doping SR197 and PC71BM into a host system (PM6:Y6) to achieve a PCE of up to 17.48%. And the intermolecular hydrogen bonds between materials are formed to directionally modulate the film morphology.
Enantioselective modification of sulfonamides and sulfonamide-containing drugsviacarbene organic catalysis
Authors: Song Runjiang , Liu Yingguo , Majhi Pankaj Kumar , Ng Pei Rou , Hao Lin , Xu Jun , Tian Weiyi , Zhang Long , Liu Hongmei , Zhang Xinglong , Chi Yonggui Robin
Published: March 2021

Enantioselective modification of sulfonamides and sulfonamide-containing drugsviacarbene organic catalysis is disclosed. The cation−π interaction was computationally found to play a pivotal role in modulating the reaction enantioselectivity.
Native fluorescence of tear fluid as a tool for diagnostics of glaucoma
Authors: Krajčíková Kristína , Skirková Miriama , Moravská Monika , Birková Anna , Tomečková Vladimíra
Published: March 2021

Tear fluid native fluorescence differs among patients with primary open-angle glaucoma, suspected glaucoma, ocular hypertension, and healthy subjects and could serve as a diagnostic or screening tool in future.
Nanostructured Cu foam and its derivatives: emerging materials for the heterogeneous conversion of CO2 to fuels
Authors: Bhardwaj Sakshi , Biswas Ashmita , Das Manisha , Dey Ramendra Sundar
Published: March 2021

This review provides a detailed understanding of the fundamentals, important parameters, advantages, and challenges of electrochemical CO2 reduction using copper foam and copper foam-derived materials.
Amphiphilic, thixotropic additives for extrusion-based 3D printing of silica-reinforced silicone
Authors: Suriboot Jakkrit , Marmo Alec C. , Ngo Bryan Khai D. , Nigam Aman , Ortiz-Acosta Denisse , Tai Bruce L. , Grunlan Melissa A.
Published: March 2021

Amphiphilic PEO-SA additives and silica fillers were systematically incorporated into Sylgard 184. Synergistic interactions allowed for tunable surface and rheological properties which could expand their utility in extrusion-based, DIW 3D printing.
Engineering donor–acceptor conjugated polymers for high-performance and fast-response organic electrochemical transistors
Authors: Jia Hanyu , Huang Zhen , Li Peiyun , Zhang Song , Wang Yunfei , Wang Jie-Yu , Gu Xiaodan , Lei Ting
Published: March 2021

The donor, side chain, polymerization method, and processing solvent were systematically explored for diketopyrrolopyrrole (DPP) based donor–acceptor polymers to achieve high-performance and fast-response organic electrochemical transistors.
Electromagnetic situation analysis and judgment based on deep learning
Authors: Feng Yuntian , Li Bing , Zheng Qibin , Wang Dezheng , Xu Xiong , Zhang Rongqing
Published: March 2021

The electromagnetic situation, which can promote the abilities of understanding and decision‐making for the battlefield, has attracted significant interest recently in information‐based warfare. This paper investigates the deep learning‐based electromagnetic situation analysis and judgment in a complicated battlefield environment. To comprehensively simulate the two‐sided battling process, a turn‐based confrontation strategy is proposed, and an electromagnetic situation analysis and judgment model are then designed based on the AlphaGo Zero algorithm to achieve efficient situation analysis and decision‐making. In addition, an electromagnetic situation‐based attack‐defense platform is developed to realize and evaluate this designed model. Simulation results demonstrate that this designed model achieves significant performance in electromagnetic situation analysis and judgment compared with the Monte Carlo Tree Search based baseline.
Design and DC fault clearance of modified hybrid MMC with low proportion of full‐bridge submodules
Authors: Xu Yuzhe , Zhang Zheren , Xu Zheng
Published: March 2021

The hybrid modular multilevel converter (MMC) consisting of half bridge submodules (HBSMs) and full bridge submodules (FBSMs) combines the respective advantages of both submodules. In order to further reduce the manufacture cost and power loss, this paper proposed a modified hybrid MMC with lower proportion of FBSMs than the conventional hybrid MMC. First, three main conditions for successful DC fault clearing of the hybrid MMC are analysed, which are: (1) Blocking AC fault current; (2) suppression of DC fault current; (3) capacitor voltage under threshold value. Then the topology and the DC fault clearing strategy of the proposed modified hybrid MMC are introduced. Since the installed AC current blocking switches (ACBSs) block the AC current feed during the fault, the number of FBSMs is only limited by third condition. Furthermore, the maximum capacitor voltage after the DC fault is analysed to obtain the minimum required number of FBSMs. Finally, the DC fault responses of the modified hybrid MMC are compared with the conventional hybrid MMC in a three‐terminal MMC‐HVDC test system in PSCAD/EMTDC. Simulation results demonstrate the effectiveness and feasibility of the proposed modified hybrid MMC.
Modified Convolutional Neural Networks Architecture for Hyperspectral Image Classification (Extra‐Convolutional Neural Networks)
Authors: HAMOUDA Maissa , BOUHLEL Med Salim
Published: March 2021

Classification of Hyperspectral Satellite Images (HSI) is a very important technology for object detection and cartography. Several problems can be detected, which make classification difficult (large size of the images, fusion between the classes, small amount of samples, etc.). Recently, several Convolutional Neural Networks (CNN‐HSI) have been proposed for the classification of hyperspectral images. In this article, an improvement to CNN‐HSI is proposed, aiming to reduce the number of erroneous pixels during classification (due to the limited number of samples). Thus, an extra‐convolution technique (ExCNN) is proposed, where we add layers of global convolutions on the classified images, outgoing from classical CNN. The addition of 1 to 10 layers, on three real hyperspectral images, is tested. The results obtained are compared with other similar methods of the state of art, and show the effectiveness of the proposed method.
Techno‐economic‐environmental analysis of a smart multi‐energy grid utilising geothermal energy storage for meeting heat demand
Authors: Hosseini Seyed Hamid Reza , Allahham Adib , Adams Charlotte
Published: March 2021

This study presents an evaluation framework for the techno‐economic‐environmental (TEE) performance of the integrated multi‐vector energy networks (IMVENs) including geothermal energy. Geothermal energy storage (GES) offers huge potential for both energy storage and supply and can play a critical role in decarbonising the heat load of smart multi‐energy grids. The two most common types of GES, that is, high‐temperature GES (HTGES) and low‐temperature GES (LTGES), were modelled and integrated within the framework. This framework evaluates the impact of different low carbon energy sources including HTGES, LTGES, wind and Photovoltaics (PV) on the amount of energy imported from upstream, operational costs and emissions of IMVENs to meet the heat load of a region. The evaluation framework performs TEE performance analysis of any configuration of IMVEN representing future energy system pathways to provide a basis for well‐informed design choices to decarbonise heat. The TEE evaluation framework was tested on a real‐world case study, and several IMVEN configurations were designed and analysed. The results reveal that the most efficient, cost effective and least carbon‐intensive configurations for meeting the heat load of the case study are the configurations benefitting from HTGES, from high penetration of heat pumps and from LTGES, respectively.
Constitutional Characteristics of Physical Development in the Kyrgyz Population
Authors: Sakibaev Kyialbek Sh. , Nikityuk Dmitry B. , Alimbekova Aiperi A. , Mamashov Nurbek M. , Dzhumaev Ravshanbek M. , Dzholdosheva Gulay T.
Published: March 2021

Personalized medicine is one of the priorities of the development of modern medical science. The aim of this study was to identify somatotypological features of physical development in men and women of the Kyrgyz population. The physical status of 1083 men and women in the Kyrgyz population (Osh, Kyrgyzstan) was studied by the method of complex anthropometry and somatotyping. The whole complex of the conducted anatomical and anthropometric examinations corresponded to generally accepted ethical standards, with the registration of informed consent from all the examined persons. The statistical analysis included the calculation of the arithmetic mean of the indicators of their mistakes. The differences were evaluated using the Student’s method at p<0.05. The results show that among women of youth and mature age, representatives of hypersthenic and normosthenic body types predominate; women of asthenic type are a minority (classification of M. V. Chernorutsky). Women of indeterminate somatotype (scheme of I. B. Galant et al.) belong either to the normal or hypersthenic type and never to the asthenic type. In men, the abdominal somatotype corresponds to a hypersthenic, thoracic-asthenic physique; men of the muscular type-mainly normosthenics; men of indeterminate type are both hypersthenics and normosthenics. The obtained data, undoubtedly, have not only theoretical, but also significant practical significance.
21st Century: Physical Fitness of School Age Students
Authors: Lutkovskaya Olga , Minenok Elena , Antipin Nikolay , Spashchanskaya Valentina , Prokopkina Svetlana , Yushchenko Anna
Published: March 2021

Physical fitness is considered as a process of directed development of physical qualities, contributing to the formation of the necessary range of motor skills and abilities. The study of students’ physical fitness was conducted by gender. Physical fitness testing was carried out according to the guidelines developed by the Ministry of Education of the Republic of Belarus. The study of physical qualities showed that the maximum increases of the indicators of physical fitness being studied do not always coincide with the rates of puberty, however, in general, the biological development of adolescents is determined by gender differences in the dynamics of physical fitness. An integral assessment of the general physical fitness of schoolchildren showed that students of all age groups, regardless gender, are at the average level of physical fitness when they are involved in sports.
Food Engineering of Meat Bio-Products to Immunity Strengthening
Authors: Bazarnova Julia , Korzh Aleksey , Barsukova Natalya , Eliseeva Svetlana , Fedinishina Ekaterina
Published: March 2021

The mainstream of healthy nutrition during the new coronavirus pandemic is adequate and balanced nutrition based on strengthening human immunity. The authors consider the main aspects of developing theory and practice of adequate nutrition using innovative biotechnologies. Based on the St. Petersburg startup GASTROMAN.LAB there was developed new line of Bio-products enriched with probiotic cultures of microorganisms, biologically active substances of plants and prebiotics that was implemented using modern technological methods of food engineering. The recipes of original meat products of the Petersburg cuisine were used as basis for new developed recipes of bio-culinary products.
A virtual element method for the von Kármán equations
Authors: Lovadina Carlo , Mora David , Velásquez Iván
Published: March 2021

In this article we propose and analyze a Virtual Element Method (VEM) to approximate the isolated solutions of the von Kármán equations, which describe the deformation of very thin elastic plates. We consider a variational formulation in terms of two variables: the transverse displacement of the plate and the Airy stress function. The VEM scheme is conforming inH2for both variables and has the advantages of supporting general polygonal meshes and is simple in terms of coding aspects. We prove that the discrete problem is well posed forhsmall enough and optimal error estimates are obtained. Finally, numerical experiments are reported illustrating the behavior of the virtual scheme on different families of meshes.
Experimental investigation on static recrystallization behavior of a low carbon Nb–V–Ti microalloyed steel
Authors: Li Fei , Zhang Liwen , Zhang Chi , Yang Qing , Li Chaoqun , Mao Peigang
Published: March 2021

The static recrystallization (SRX) behavior of a low carbon Nb–V–Ti microalloyed steel X70 was investigated by two-pass hot compression tests. The compression tests were carried out at deformation temperatures of 1000–1150 °C, strain rates of 0.01–5 s−1, pre-strains of 0.1–0.2 and interval times of 1–50 s. The effects of deformation parameters on SRX behavior were analyzed. The experimental results showed that deformation temperature, pre-strain and strain rate had significant influence on SRX fraction, while initial grain size had a smaller impact. The effects of deformation parameters on SRX microstructure were discussed, and the microstructure evolution process was analyzed. Higher deformation temperature, strain rate and pre-strain lead to larger SRX fraction. The kinetics and recrystallized grain size models for SRX of X70 pipeline steel were developed. Comparison between the predicted results and the experimental ones indicated that the established equations could give a reasonable description for SRX behavior of X70 pipeline steel.
Anisotropic thermal conductivity measurement of organic thin film with bidirectional 3ω method
Authors: Yamaguchi Shingi , Shiga Takuma , Ishioka Shun , Saito Tsuguyuki , Kodama Takashi , Shiomi Junichiro
Published: March 2021

Organic thin film materials with molecular ordering are gaining attention as they exhibit semiconductor characteristics. When using them for electronics, the thermal management becomes important, where heat dissipation is directional owing to the anisotropic thermal conductivity arising from the molecular ordering. However, it is difficult to evaluate the anisotropy by simultaneously measuring in-plane and cross-plane thermal conductivities of the film on a substrate because the film is typically as thin as tens to hundreds of nanometers and its in-plane thermal conductivity is low. Here, we develop a novel bidirectional 3ω system that measures the anisotropic thermal conductivity of thin films by patterning two metal wires with different widths and preparing the films on top and extracting the in-plane and cross-plane thermal conductivities using the difference in their sensitivities to the metal-wire width. Using the developed system, the thermal conductivity of spin-coated poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) with thickness of 70 nm was successfully measured. The measured in-plane thermal conductivity of PEDOT:PSS film was as high as 2.9 W m−1 K−1 presumably due to the high structural ordering, giving an anisotropy of 10. The calculations of measurement sensitivity to the film thickness and thermal conductivities suggest that the device can be applied to much thinner films by utilizing metal wires with a smaller width.
Effect of ammonium fluoride doping on the ice III to ice IX phase transition
Authors: Sharif Zainab , Shephard Jacob J. , Slater Ben , Bull Craig L. , Hart Martin , Salzmann Christoph G.
Published: March 2021

Ice III is a hydrogen-disordered phase of ice that is stable between about 0.2 and 0.35 GPa. Upon cooling, it transforms to its hydrogen-ordered counterpart ice IX within the stability region of ice II. Here, the effect of ammonium fluoride doping on this phase transition is investigated, which is followed for the first time with in situ neutron diffraction. The a and c lattice constants are found to expand and contract, respectively, upon hydrogen ordering, yielding an overall negative volume change. Interestingly, the anisotropy in the lattice constants persists when ice IX is fully formed, and negative thermal expansion is observed. Analogous to the isostructural keatite and β-spodumenes, the negative thermal expansion can be explained through the buildup of torsional strain within the a–b plane as the helical “springs” within the structure expand upon heating. The reversibility of the phase transition was demonstrated upon heating. As seen in diffraction and Raman spectroscopy, the ammonium fluoride doping induces additional residual hydrogen disorder in ice IX and is suggested to be a chemical way for the “excitation” of the configurational ice-rules manifold. Compared to ice VIII, the dopant-induced hydrogen disorder in ice IX is smaller, which suggests a higher density of accessible configurational states close to the ground state in ice IX. This study highlights the importance of dopants for exploring the water’s phase diagram and underpins the highly complex solid-state chemistry of ice.
Tuning topological phases and electronic properties of monolayer ternary transition metal chalcogenides (ABX4, A/B = Zr, Hf, or Ti; X = S, Se, or Te)
Authors: Macam Gennevieve , Sufyan Ali , Huang Zhi-Quan , Hsu Chia-Hsiu , Huang Shin-Ming , Lin Hsin , Chuang Feng-Chuan
Published: March 2021

Topological materials are very promising materials for technological applications ranging from spintronics to quantum computation. Here, based on first-principles calculations, we predict a family of two-dimensional (2D) topological materials in nine ternary transition metal chalcogenides (TTMCs) ABX4, where A/B = Zr, Hf, or Ti and X = S, Se, or Te. A total of three compounds (ZrTiTe4, HfZrTe4, and HfTiTe4) are identified to be nontrivial within a hybrid functional calculation. The nontrivial phase originated from the p-d band inversion at the Г point with spin–orbit coupling. The structural stability of these monolayers is confirmed by phonon spectrum analysis, showing no negative phonon frequencies. The diversity of TTMCs will open a wide possibility for tuning the bandgap and will provide a variety of opportunities for 2D and topological materials research.
Dielectric functions of CVD–grown boron nitride from 1.1 to 9.0 eV by spectroscopic ellipsometry
Authors: Yamada Hisashi , Kumagai Naoto , Yamada Toshikazu , Yamamoto Taiki
Published: March 2021

The optical properties of CVD-grown hexagonal boron nitride (h-BN) and turbostratic BN (t-BN) layers on Al2O3 substrates are investigated by spectroscopic ellipsometry in the range from 1.1 to 9.0 eV at room temperature. The absorption spectra and dielectric functions (DFs) are characterized for analyzing critical points from near and above the bandgap (Eg) by analyzing the multilayer optical model. The real part ε1 and imaginary part ε2 of DFs for the BN layers are derived from the B–spline function under the Kramers–Kronig relation. The DFs show a significant difference between the h-BN and t-BN layers. The h-BN layer presents stronger and sharper spectra of DFs compared to the t-BN layer. Judging from extended Tauc's plot, the indirect Eg value of the h-BN layer is determined to be 5.97 eV, which is 0.15 eV larger than that of the t-BN layer.
A-site substitution induced diffuse phase transition for high tunability in Ba1-xCaxTi0.85Sn0.15O3 thin films with a low bias electric field
Authors: Wu Chenjing , Yao Manwen , Yao Xi
Published: March 2021

We fabricate BaTi0.85Sn0.15O3 thin films with various Ca doping contents on Pt(100)/Ti/SiO2/Si substrates by a sol-gel and spin-coating method to investigate the effects on dielectric tunable properties. The results show that the greater tunability under a low bias electric field can be achieved compared with undoped BaTi0.85Sn0.15O3 thin films. In particular, the 0.1 mol. % Ca-doped BaTi0.85Sn0.15O3 thin films achieve the highest tunability of 50.9% and the highest FOM value of 23.1 at 16 kV/mm, surpassing most values reported previously for the dielectric tunability of BTS thin films. The use of a low bias electric field avoids the need for a high voltage, thus reducing safety hazards. These outstanding properties are attributed to the broadening of the Curie peak near room temperature, which indicates the existence of diffuse ferroelectric phase transition behavior, a larger grain size, and the suppression of electron hopping between Sn2+ and Sn4+. The results show the great potential of Ca-doped BaTi0.85Sn0.15O3 thin films for dielectric tunable applications.
GaN buffer growth temperature and efficiency of InGaN/GaN quantum wells: The critical role of nitrogen vacancies at the GaN surface
Authors: Chen Yao , Haller Camille , Liu Wei , Karpov Sergey Yu , Carlin Jean-François , Grandjean Nicolas
Published: March 2021

An indium-containing layer positioned underneath the InGaN/GaN quantum well (QW) active region is commonly used in high efficiency blue light-emitting diodes. Recent studies proposed that the role of this underlayer is to trap surface defects (SDs), which, otherwise, generate non-radiative recombination centers in the QWs. However, the origin and the nature of these defects remain unknown. Our previous study revealed that high-temperature growth of GaN promotes SD creation. In this work, we investigate the impact of the GaN-buffer growth temperature on the InGaN/GaN QW efficiency. We show that the 300 K photoluminescence decay time of a single QW deposited on 1-μm-thick GaN buffer dramatically decreases from few ns to less than 100 ps when the GaN buffer growth temperature is increased from 870 °C to 1045 °C. This internal quantum efficiency collapse is ascribed to the generation of SDs in the GaN buffer. A theoretical study of temperature-dependent defect formation energy in GaN suggests that these SDs are most likely nitrogen vacancies. Finally, we investigate the formation dynamics of SDs and show that they are mainly generated at the early stage of the GaN growth, i.e., within 50 nm, and then reach a steady state concentration mainly fixed by the GaN growth temperature.
Photoswitchable high-dimensional CoII–[WV(CN)8] networks: Past, present, and future
Authors: Stefańczyk Olaf , Ohkoshi Shin-ichi
Published: March 2021

The research and development of novel bistable magnetic materials is one of the most expanding areas of molecular magnetism. These materials are potentially suitable to be utilized in the construction of modern detectors, high-density data carriers, and devices for energy conversion. Until now, the greatest successes in this field have been achieved for magnetic cyanido-bridged metal assemblies. Among them, the greatest recognition is related to high-dimensional octacyanidometallate-based networks. In this Perspective, two- and three-dimensional cyanido-bridged CoII–[WV(CN)8] networks, exhibiting nontrivial magnetic properties (e.g., electron-transfer-coupled spin transition with broad thermal hysteresis and photoinduced spontaneous magnetization with relatively high Curie temperatures and large magnetic hysteresis loops) and other physicochemical properties (e.g., THz absorption and humidity sensitivity), are collected. All of them are model systems for development of bistable systems due to the presence of wide thermal hysteresis, and the formation of photoinduced metastable state tuned by temperature and wavelength of used light. Additionally, we summarized magnetostructural correlations within them, and we offered some guidelines for the improvement of their performances and the introduction of new functionalities and physicochemical cross-effects.
Determining the angle-of-arrival of a radio-frequency source with a Rydberg atom-based sensor
Authors: Robinson Amy K. , Prajapati Nikunjkumar , Senic Damir , Simons Matthew T. , Holloway Christopher L.
Published: March 2021

In this work, we demonstrate the use of a Rydberg atom-based sensor for determining the angle of arrival of an incident radio frequency (RF) wave or signal. The technique uses electromagnetically induced transparency in Rydberg atomic vapor in conjunction with a heterodyne Rydberg atom-based mixer. The Rydberg atom mixer measures the phase of the incident RF wave at two different locations inside an atomic vapor cell. The phase difference at these two locations is related to the direction of arrival of the incident RF wave. To demonstrate this approach, we measure phase differences of an incident 19.18 GHz wave at two locations inside a vapor cell filled with cesium atoms for various incident angles. Comparisons of these measurements with both the full-wave simulation and the plane wave theoretical model show that these atom-based sub-wavelength phase measurements can be used to determine the angle of arrival of an RF field.
Revealing the many-body interactions and valley-polarization behavior in Re-doped MoS2 monolayers
Authors: Zhu Xiaoli , Ding Siting , Li Lihui , Jiang Ying , Zheng Biyuan , Sun Xingxia , Xu Zheyuan , You Wenxia , Liu Huawei , Liang Delang , Zhao Haipeng , Qu Junyu , Zheng Weihao , Li Dong , Pan Anlian
Published: March 2021

Substitutional doping has proved to be one of the most important approaches to tune and improve the opto-electronic performance of traditional semiconductors. Similarly, controllable substitution of cations in two-dimensional layered materials can effectively modify and manipulate the band structures, which help to explore sciences and broaden the related applications. In this paper, the salt-assisted one-step chemical vapor deposition method was used to achieve Re substitution in MoS2 monolayers. High-resolution scanning transmission electron microscopy confirms the substitution of Re atoms in Mo sites. X-ray photoelectron spectroscopy and micro-photoluminescence (PL) characterization studies suggest that the Re substitution introduces typical n-type doping in MoS2 monolayers, resulting in the distinct many-body interactions in the doped sample with a higher trion ratio than in the pristine sample in the wide temperature window. The result is further confirmed by the shorter recombination lifetime observed in the Re-doped sample acquired by time-resolved PL measurements. More intriguingly, the circularly polarized PL characterization studies demonstrate that Re doping can improve the valley polarization of the MoS2 monolayer. Our work provides a deep understanding of the optical properties and the associated many-body interactions in the Re-doped MoS2 system and offers a potential way to enhance the valley polarization for spin-/valley-photonic applications.
Quantum antiferromagnets near SU(N) symmetry
Authors: Zavertanyi T. , Kolezhuk A.
Published: March 2021

We study antiferromagnetic systems with enhanced “nearly-SU(N)” symmetry, which can be realized in systems of ultracold spinor atoms in optical lattices. Examples of N = 3 (for S = 1 bosons) and N = 4 (for S=32 fermions) are considered. Near the SU(N) point, the low-energy physics can be described by the CPN−1 model with an additional symmetry-breaking term lowering the symmetry down to SU(2) and favoring the Néel ordering. We show that the effective theory of such systems can be cast in the form of a nonlinear sigma model with the SO(3) matrix-valued field, which is typically obtained for frustrated magnets with non-collinear order. Further, we show that those systems possess a peculiar effect of topological binding: for a system with the underlying spin S, lowering of the symmetry from SU(2S + 1) to SU(2) leads to binding of topological unit-charge excitations of the CP2S model (skyrmions for space dimension d = 2, instantons for d = 1, and hedgehogs for d = 3) into 2S-multiplets.
‘The horror stories put me off!’: exploring women’s acceptability of the Levonorgestrel IntraUterine System (LNG-IUS) for endometrial protection
Authors: Henry Claire , Ekeroma Alec , Dowell Anthony , Filoche Sara
Published: March 2021

ABSTRACT INTRODUCTION There are few studies of user perceptions of the Levonorgestrel Intrauterine System (LNG-IUS; Mirena™), which now has the potential to play an important role in the treatment of women with hyperplasia or early stage endometrial cancer. There is limited evidence on how well the Mirena™ is perceived and accepted by women in this context. AIM To gain an understanding of New Zealand women’s views on the use of the Mirena™ contraceptive device to inform policies in endometrial cancer prevention. METHODS An online survey platform (Qualtrics™) was disseminated over social media sites such as Facebook once a week for 3 weeks. The survey used mixed methods (closed questions, multiple choice and open-ended questions) and covered topics relating to the knowledge and use of the Mirena™ for endometrial protection. Data were collected and explored using content and thematic analysis. RESULTS In total, 89 women responded to the survey. Half (42/89) of respondents had never used a Mirena™ in their life. Most women (79/89) did not know anyone who had had endometrial cancer. The frequency of negative comments about the Mirena™ was higher than positive comments (42 and 26 respectively), largely attributed to personal or reported poor experiences with other contraceptives (including the copper intrauterine device). DISCUSSION Although health-care providers may view the Mirena™ favourably, this view was not reciprocated in this community sample.
Compounding inequity: a qualitative study of gout management in an urban marae clinic in Auckland
Authors: Te Karu Leanne , Harwood Matire , Bryant Linda , Kenealy Tim , Arroll Bruce
Published: March 2021

ABSTRACT INTRODUCTION Gout remains a health equity issue; Māori and Pacific peoples are disproportionately afflicted, with increased burden and loss of quality of life, yet are less likely to receive appropriate management, which mainly occurs in primary care. AIM This study aims to understand the perspectives of the mainly Māori and Pacific clinicians and staff at an urban marae practice about barriers and challenges to delivering effective care to a Māori and Pacific community with high burden of gout. METHODS Semi-structured interviews were conducted with 10 staff members delivering health care to a mostly Indigenous community. Interviews sought to ascertain staff views of enablers and barriers to optimal gout management and analyse them thematically. RESULTS Three themes were identified: community disadvantage; demands unique to Indigenous providers; and challenges and opportunities for optimising gout management. High prevalence and heavy impact of gout on wellbeing in the community was intertwined with socioeconomic disadvantage, precariousness of employment and entrenched inaccurate (yet pliable) patient views on gout, to the detriment of focused, effective care. Structural and funding demands on providers inhibited staff focus on the clear community need. Providers saw the culturally safe and competent approach necessary for improvement as requiring community empowerment with appropriate clinical tools and adequate resourcing. DISCUSSION Despite provider intent to deliver culturally appropriate and safe care and equitable health outcomes for patients suffering from gout, general practice initiatives without aligned resourcing or incentives are inhibited when inequity is pervasive. Simply asking Māori providers to do more for the same amount of resource may not be effective.
The more the merrier: using environmental flows to improve floodplain vegetation condition
Authors: Campbell Cherie Joy , Freestone Fiona Linda , Duncan Richard P. , Higgisson Will , Healy Sascha Jade
Published: March 2021

Environmental flows are increasingly being used to restore degraded floodplain vegetation; however, the type of flow regime required for recovery to healthy condition can vary depending on the extent of degradation before restoration. Regulation of the River Murray has affected floodplain ecosystems at many locations, including Bottle Bend Reserve, in south-western New South Wales, Australia. Within Bottle Bend Reserve, tangled lignum (Duma florulenta) dominates sections of the higher floodplain elevations. Lignum is an important and widely distributed Australian shrub occurring in arid and semiarid river systems within the Murray–Darling and Lake Eyre Basins. In an effort to restore floodplain vegetation, three environmental flows were delivered to Bottle Bend Reserve between 2013 and 2016. Flows varied in magnitude, leading to a mosaic of different regimes across the area. Condition surveys were undertaken over 1 year, namely, before, during and after delivery of the September 2016 environmental flow. This study found that the greatest response occurred in lignum plants with no recent environmental water, although lignum plants with one or two recent environmental flows still responded relative to the control. Lignum was in a better condition at sites that received more environmental flows, demonstrating the value of increased frequency of flows in recovering vegetation health.
Delayed HIV testing and treatment seeking, and associated support needs among people living with HIV in Malaysia: a qualitative study
Authors: Chong Susan C. S. , Kamarulzaman Adeeba , Azwa Iskandar , Ng Rong-Xiang , Chong Meng-Li , Raman Nishaan , Bourne Adam
Published: March 2021

Background By the end of 2017, an estimated 83% of people living with HIV in Malaysia knew their serostatus. However, the Ministry of Health reported a high proportion of those newly diagnosed had low CD4 counts <200 cells/µL, indicating late presentation for testing may be pervasive. Methods: A qualitative study was conducted to explore the context and experiences of people at risk of HIV infection testing and seeking treatment later in the course of their infection. Participants recruited (n = 20) were HIV positive, aged >18 years who fit the description of late presentation (World Health Organization defined as CD4 cell count <350 cells/µL). Semi-structured interviews were conducted, and a framework approach was used to interrogate the data. Results: Many participants perceived themselves at low risk of HIV infection and did not undergo routine voluntary testing; rather, they were diagnosed when seeking treatment for serious illness or as part of mandatory employment-related testing. Perceived lack of confidentiality and potential discriminatory behaviour at public health facilities were significant deterrents to testing. Participants were satisfied with HIV treatment, but rarely sought psychosocial support in order to ‘protect’ their privacy. Conclusion: Unless drivers of HIV infection are effectively addressed, including stigmatising and discriminatory practices, and low health literacy, the occurrence of late presentation will persist. Their collective impact will not only jeopardise efforts to improve the treatment cascade, but may also impact engagement with other biomedical prevention and care technologies.
Effects of altered fire intervals on critical timber production and conservation values
Authors: Cary Geoffrey J. , Blanchard Wade , Foster Claire N. , Lindenmayer David B.
Published: March 2021

Forests exhibit thresholds in disturbance intervals that influence sustainability of production and natural values including sawlog production, species existence and habitat attributes. Fire is a key disturbance agent in temperate forests and frequency of fire is increasing, threatening sustainability of these forest values. We used mechanistically diverse, theoretical fire interval distributions for mountain ash forest in Victoria, Australia, in the recent past and future to estimate the probability of realising: (i) minimum sawlog harvesting rotation time; (ii) canopy species maturation; and (iii) adequate habitat hollows for fauna. The likelihood of realising fire intervals exceeding these key stand age thresholds diminishes markedly for the future fire regime compared with the recent past. For example, we estimate that only one in five future fire intervals will be sufficiently long (~80 years) to grow sawlogs in this forest type, and that the probability of forests developing adequate habitat hollows (~180 years) could be as low as 0.03 (3% of fire intervals). Therefore, there is a need to rethink where sawlogs can be sourced sustainably, such as from fast-growing plantations that can be harvested and then regrown rapidly, and to reserve large areas of existing 80-year-old forest from timber harvesting.