bluuebunny/crossref_metadata_2025 huggingface dataset:
A near infrared fluorescent probe based on ICT for monitoring mitophagy in living cells
Authors: Tang Wenqing , Dai Youzhi , Gu Biao , Liu Mengqin , Yi Zhengji , Li Zhongliang , Zhang Zhimin , He Huiyan , Zeng Rongying
Published: December 2019

Mitophagy, the process in which cells degrade dysfunctional organelles and recycle their nutrient substances by lysosomes, plays a vital role in cell metabolism and physiology.
A fast-switching electrochromic device with a surface-confined 3D metallo-organic coordination assembly
Authors: Jena Satya Ranjan , Choudhury Joyanta
Published: December 2019

Demonstrated herein is a fast (<1 s)-switching solid-state electrochromic device, fabricated with an imidazolium-linked [Fe(terpyridine)2]2+-based three-dimensional metallo-organic coordination assembly, exhibiting promising electrochromic attributes.
Photochemical fluoro-amino etherification reactions of aryldiazoacetates with NFSI under stoichiometric conditions
Authors: He Feifei , Pei Chao , Koenigs Rene M.
Published: December 2019

A photochemical three-component reaction is reported that allows the introduction of fluorine and a short polyether side chain in high efficiency under metal-free conditions.
Common structures of CO2 on structurally different coin metal surfaces
Authors: Vyshnepolsky Michael , Morgenstern Karina
Published: December 2019

A disordered spacer layer (red) allows to form an ordered CO2 layer (green), which is not influenced by the substrate.
Time-dependent DFT study of the K-edge spectra of vanadium and titanium complexes: effects of chloride ligands on pre-edge features
Authors: Yi Jun , Nakatani Naoki , Nomura Kotohiro , Hada Masahiko
Published: December 2019

X-ray absorption near edge structures (XANES) of vanadium and titanium complexes were investigated with time-dependent density functional theory (TDDFT).
Ginsenoside Rk1 induces apoptosis and downregulates the expression of PD-L1 by targeting the NF-κB pathway in lung adenocarcinoma
Authors: Hu Manling , Yang Jing , Qu Linlin , Deng Xuqian , Duan Zhiguang , Fu Rongzhan , Liang Lihua , Fan Daidi
Published: November 2019

Ginsenoside Rk1 can function as an antitumor modulator that induces apoptosis in lung adenocarcinoma cells by inhibiting NF-κB transcription and triggering cell cycle arrest.
A palladium-catalyzed oxidative aminocarbonylation reaction of alkynone O-methyloximes with amines and CO in PEG-400
Authors: Li Jianxiao , Yu Junsheng , Xiong Wenfang , Tang Hao , Hu Miao , Wu Wanqing , Jiang Huanfeng
Published: December 2019

A palladium-catalyzed oxidative aminocarbonylation of alkynone O-methyloximes with amines and CO using PEG-400 as an environmentally benign medium was accomplished.
High-performance thermoelectric silver selenide thin films cation exchanged from a copper selenide template
Authors: Chen Nan , Scimeca Michael R. , Paul Shlok J. , Hafiz Shihab B. , Yang Ze , Liu Xiangyu , Yang Fan , Ko Dong-Kyun , Sahu Ayaskanta
Published: December 2019

A high-performance n-type thermoelectric Ag2Se thin filmviacation exchange using a low-cost solution processed Cu2Se template.
Evaluating an effective electrocatalyst for the rapid determination of triptan drug (Maxalt™) from (mono and binary) transition metal (Co, Mn, CoMn, MnCo) oxides via electrochemical approaches
Authors: Muthumariappan Akilarasan , Sakthivel Kogularasu , Chen Shen-Ming , Chen Tse-Wei , Elgorban Abdallah M. , Elshikh Mohamed S. , Marraiki Najat
Published: December 2019

In this article, an ultra sensitive and selective electrochemical sensor for the detection of Rizatriptan benzoate (RZB) was reported.
High-efficiency adsorption of tetracycline by the prepared waste collagen fiber-derived porous biochar
Authors: Wei Xinxing , Zhang Renjing , Zhang Wenchao , Yuan Yue , Lai Bo
Published: November 2019

Porous biochar (PBC) derived from Cr-containing waste collagen fibers was prepared by two-step pyrolysis to 800 °C (PBC-800) and alkali activation.
Structure of Ni(OH)2 intermediates determines the efficiency of NiO-based photocathodes – a case study using novel mesoporous NiO nanostars
Authors: Wahyuono Ruri Agung , Dellith Andrea , Schmidt Christa , Dellith Jan , Ignaszak Anna , Seyring Martin , Rettenmayr Markus , Fize Jennifer , Artero Vincent , Chavarot-Kerlidou Murielle , Dietzek Benjamin
Published: November 2019

NiO nanostructures prepared from β-Ni(OH)2 intermediates exhibit favorable electronic properties for functional photocathodes for solar energy conversion devices.
The nature of G⋯E–Y σ(3c–4e) in o-MenGCH2C6H4EY (MenG = Me2N and MeE; E = O, S, Se and Te; Y = F, Cl, Br, EMe and Me) with contributions from CT and compliance constants in noncovalent G⋯E interactions
Authors: Hayashi Satoko , Nishide Taro , Nakanishi Waro , Sancineto Luca , Santi Claudio
Published: November 2019

The nature of E⋯E′ in 1-RECH2-2-R′E′C6H4 (E/E′ = O, S, Se and Te) is clarified with QTAIM approach and NBO analysis, after structural determinations.
Sequential cycloaddition and ring expansion reaction of arynes and methylenebenzothiopheneones: synthesis of a benzo-fused eight-membered ring via sulfonium ylides
Authors: Xiao Peng , Su Shikuan , Wang Wei , Cao Weiguo , Chen Jie , Li Jian , Chen Yali
Published: November 2019

Efficient construction of benzo-fused eight-membered ring containing sulfur. New reaction profile with sulfonium ylides.
Hydrogen and proton exchange at carbon. Imbalanced transition state and mechanism crossover
Authors: Costentin Cyrille , Savéant Jean-Michel
Published: November 2019

Using the remarkable study of C–H oxidation of substituted fluorenyl-benzoates as an example, we have shown that a mechanism crossover takes place upon decreasing the driving force, from a CPET pathway to a PTET pathway.
Cycloserine enantiomers are reversible inhibitors of human alanine:glyoxylate aminotransferase: implications for Primary Hyperoxaluria type 1
Authors: Dindo Mirco , Grottelli Silvia , Annunziato Giannamaria , Giardina Giorgio , Pieroni Marco , Pampalone Gioena , Faccini Andrea , Cutruzzolà Francesca , Laurino Paola , Costantino Gabriele , Cellini Barbara
Published: December 2019

Peroxisomal alanine:glyoxylate aminotransferase (AGT) is responsible for glyoxylate detoxification in human liver and utilizes pyridoxal 5′-phosphate (PLP) as coenzyme. The deficit of AGT leads to Primary Hyperoxaluria Type I (PH1), a rare disease characterized by calcium oxalate stones deposition in the urinary tract as a consequence of glyoxylate accumulation. Most missense mutations cause AGT misfolding, as in the case of the G41R, which induces aggregation and proteolytic degradation. We have investigated the interaction of wild-type AGT and the pathogenic G41R variant with d-cycloserine (DCS, commercialized as Seromycin), a natural product used as a second-line treatment of multidrug-resistant tuberculosis, and its synthetic enantiomer l-cycloserine (LCS). In contrast with evidences previously reported on other PLP-enzymes, both ligands are AGT reversible inhibitors showing inhibition constants in the micromolar range. While LCS undergoes half-transamination generating a ketimine intermediate and behaves as a classical competitive inhibitor, DCS displays a time-dependent binding mainly generating an oxime intermediate. Using a mammalian cellular model, we found that DCS, but not LCS, is able to promote the correct folding of the G41R variant, as revealed by its increased specific activity and expression as a soluble protein. This effect also translates into an increased glyoxylate detoxification ability of cells expressing the variant upon treatment with DCS. Overall, our findings establish that DCS could play a role as pharmacological chaperone, thus suggesting a new line of intervention against PH1 based on a drug repositioning approach. To a widest extent, this strategy could be applied to other disease-causing mutations leading to AGT misfolding.
microRNA-217 suppressed epithelial-to-mesenchymal transition through targeting PTPN14 in gastric cancer
Authors: Chen Gen , Yang Zhangshuo , Feng Maohui , Wang Zhiliang
Published: December 2019

Background: Gastric cancer (GC) is the one of most common malignancies and its mechanism of metastasis remains unclear. The study was designed to investigate the effects of microRNA-217 on epithelial-to-mesenchymal transition. Methods: The expression levels of miR-217 in GC were assayed by real-time qPCR. Metastasis and invasion of cancer cell were assayed by transwell chamber. Double luciferase reporter gene was used to verify the target regulatory relationship between microRNA-217 and tyrosine–protein phosphatase non-receptor type 14 (PTPN14) on gastric cell lines. Epithelial-to-mesenchymal transition (EMT) markers were assayed by Western blot. Results: We found that miR-217 had a low level expression in gastric tumor tissues of 40 patients with GC, and a lower expression in the gastric tumor tissues of the patients with GC metastasis. Moreover, miR-217 markedly suppressed the metastasis and invasion of gastric cancer cell line in vitro. Furthermore, miR-217 inhibited the expression of PTPN14 by directly targeting its 3′UTR. Moreover, the down-regulation of PTPN14 reduced the metastasis and invasion, whereas up-regulation of PTPN14 led to the enhanced metastases and invasion of gastric cells. miR-217 induced the down-regulation of PTPN14 and inhibited the EMT in gastric cancer cells. Conclusion: miR-217 inhibited the EMT through directly targeting to the 3′UTR of PTPN14.
3D convolutional and recurrent neural networks for reactor perturbation unfolding and anomaly detection
Authors: Durrant Aiden , Leontidis Georgios , Kollias Stefanos
Published: November 2019

With Europe's ageing fleet of nuclear reactors operating closer to their safety limits, the monitoring of such reactors through complex models has become of great interest to maintain a high level of availability and safety. Therefore, we propose an extended Deep Learning framework as part of the CORTEX Horizon 2020 EU project for the unfolding of reactor transfer functions from induced neutron noise sources. The unfolding allows for the identification and localisation of reactor core perturbation sources from neutron detector readings in Pressurised Water Reactors. A 3D Convolutional Neural Network (3D-CNN) and Long Short-Term Memory (LSTM) Recurrent Neural Network (RNN) have been presented, each to study the signals presented in frequency and time domain respectively. The proposed approach achieves state-of-the-art results with the classification of perturbation type in the frequency domain reaching 99.89% accuracy and localisation of the classified perturbation source being regressed to 0.2902 Mean Absolute Error (MAE).
Neue Therapieansätze bei progredienter Multipler Sklerose
Authors: Faissner Simon , Gold Ralf
Published: November 2019

Die Therapie der Multiplen Sklerose hat sich in den letzten Jahren durch die Entwicklung neuer Medikamente für die schubförmige Phase der Erkrankung umfangreich gewandelt. Die Entwicklung von Medikamenten für Progression war bisher hingegen weniger erfolgreich. Neue Substanzen umfassen den in Europa und den USA zugelassenen B-Zell depletierenden Antikörper Ocrelizumab, der bei primär progredienter MS mit Krankheitsaktivität zugelassen ist, sowie den Sphingosin-1-Phosphat Modulator Siponimod, der aktuell in der Zulassungsphase für sekundär-chronisch progrediente MS ist. Progression ist durch chronische Inflammation mit Aktivierung von T- und B-Zellen sowie Mikroglia mit Freisetzung reaktiver Sauerstoffmetabolite, altersabhängige Akkumulation von Eisen und damit einhergehend neuronaler Degeneration gekennzeichnet. In dieser Arbeit soll eine Übersicht über das Verständnis der Pathogenese und vielversprechende Therapieansätze für Progression in unterschiedlichen Stadien der Entwicklung gegeben werden.
Caries Increment and Oral Hygiene Changes in 6- and 12-Year-Old Children in Riga, Latvia: A 3–Year Follow–Up Report Using ICDAS II and RADKE Criteria
Authors: Gudkina Jekaterina , Amaechi Bennett T. , Abrams Stephen. H. , Brinkmane Anda , Jelisejeva Ieva
Published: December 2019

Objectives The purpose of this study was to investigate the caries increment and oral hygiene changes over a 3-year period and also compare the sensitivity and specificity of Radke’s caries assessment method to ICDAS II among 6- and 12-year-old children in Riga, Latvia.

Materials and Methods Thirty-eight 6 and thirty-nine 12-year-old children were examined visually and with bitewing (BW) radiographs for dental caries at baseline and after a 3-year period. Decayed, missing, and filled surfaces (dmfs/DMFS) in all teeth were scored by one calibrated examiner using the Radke’s caries scoring criteria. Oral hygiene level was determined using Green-Vermillion index (G-V ind.) at baseline and after 3 years. ICDAS II was used to assess all children only at the 3rd-year time point. The parents of the 6- and 12-year-old children responded to a questionnaire on oral hygiene at baseline and at the 3-year mark.

Statistical Analysis The data were analyzed using t-test, Chi-square test, Wilcoxon test (α= 0.05), and sensitivity and specificity tests.

Results The mean (SD) values of G–V ind. and caries experience at baseline/3-year period in 6- versus 12-year-old children were as follows. G-V ind.: 1.14(0.80) /1.48(0.89) [p = 0.4768] versus 0.99(0.45)/1.45(1.22) [p = 0.0337]. DMFS: 0.72(1.02)/ 3.13(3.13) [p = 0.0000] versus 6.79(5.14)/14.79(9.86)[p = 0.0000]; dmfs: 11.26(8.71)/7.74 (4.86) [p = 0.0780] versus 3.57 (2.03)/1.5(0.71)[p = 0.3173].The sensitivity and specificity of Radke to ICDAS II of caries-affected surfaces was: in proximal surfaces–0.57 and 0.98, on occlusal surfaces–0.83 and 0.98, on buccal/lingual surfaces–0.43 and 0.99.

Conclusions The result of the present study suggests that the increased caries experience over a 3-year period among the 6- and 12-year-old children in Riga may be due to the concurrent decreased level of oral hygiene, suggesting that ICDAS II instead of Radke’s criteria should be used to detect and monitor dental caries.
Pediatric Acute Respiratory Distress Syndrome and Hypersensitivity Pneumonitis Related to E-cigarette Vaping
Authors: Phung Binh , Lam Anh
Published: November 2019

In recent years, electronic cigarettes (e-cigs) have been falsely advertised as safe alternatives to conventional smoking. We report a case involving a 16-year-old female who presented with fever, nonproductive cough, and shortness of breath after vaping e-cig/tetrahydrocannabinol dab pen. Her symptoms rapidly deteriorated and met diagnostic criteria for pediatric acute respiratory distress syndrome. Chest radiograph revealed extensive patchy airspace disease and computed tomography scan showed bilateral ground glass opacities. Bronchoalveolar lavage fluid revealed increased neutrophils, lymphocytosis, but absent eosinophilia. After the results of a comprehensive workup for infectious etiology returned negative, she was diagnosed with hypersensitivity pneumonitis and started on systemic corticosteroids.
Challenges in the early assessment and protection of refugee survivors of torture and extreme violence
Authors: Wenzel T. , Graf von Reventlow H. , Kletecka-Pulker M.
Published: December 2019

Die medizinische und psychiatrische Betreuung von Flüchtlingen ist zu einer globalen Herausforderung geworden. Spezielle Behandlung, Unterstützung und Schutz sind aufgrund der Gewalterfahrungen und den daraus resultierenden psychischen Folgen bei vielen Betroffenengruppen erforderlich. Folterüberlebende sind dabei aufgrund der oft schweren psychologischen Traumatisierung als besondere Gruppe zu berücksichtigen. Ihnen steht nach internationalen ethischen und Menschenrechtsstandards besonderer Schutz zu. Hierbei ist es nötig, Betroffene früh wäh-rend des Aufnahmeprozesses zu identifizieren, und diesen besonderen Schutz sowie weitere spezielle Hilfe zu gewähren. Dies erfordert einen interdisziplinären Ansatz unter Berücksichtigung besonderer rechtlicher und menschenrechtlicher Rahmenbedingungen. Bei der Begutachtung sind bezüglich Überlebenden von Folter besondere Aspekte zu berücksichtigen, die im „Istanbul Protokolls“ der Vereinten Nationen festgelegt sind.
Discovery of blue singlet exciton fission molecules via a high-throughput virtual screening and experimental approach
Authors: Perkinson Collin F. , Tabor Daniel P. , Einzinger Markus , Sheberla Dennis , Utzat Hendrik , Lin Ting-An , Congreve Daniel N. , Bawendi Moungi G. , Aspuru-Guzik Alán , Baldo Marc A.
Published: December 2019

Singlet exciton fission is a mechanism that could potentially enable solar cells to surpass the Shockley-Queisser efficiency limit by converting single high-energy photons into two lower-energy triplet excitons with minimal thermalization loss. The ability to make use of singlet exciton fission to enhance solar cell efficiencies has been limited, however, by the sparsity of singlet fission materials with triplet energies above the bandgaps of common semiconductors such as Si and GaAs. Here, we employ a high-throughput virtual screening procedure to discover new organic singlet exciton fission candidate materials with high-energy (>1.4 eV) triplet excitons. After exploring a search space of 4482 molecules and screening them using time-dependent density functional theory, we identify 88 novel singlet exciton fission candidate materials based on anthracene derivatives. Subsequent purification and characterization of several of these candidates yield two new singlet exciton fission materials: 9,10-dicyanoanthracene (DCA) and 9,10-dichlorooctafluoroanthracene (DCOFA), with triplet energies of 1.54 eV and 1.51 eV, respectively. These materials are readily available and low-cost, making them interesting candidates for exothermic singlet exciton fission sensitization of solar cells. However, formation of triplet excitons in DCA and DCOFA is found to occur via hot singlet exciton fission with excitation energies above ∼3.64 eV, and prominent excimer formation in the solid state will need to be overcome in order to make DCA and DCOFA viable candidates for use in a practical device.
OAM crosstalk of multiple coaxial THz vortex beams propagating through an inhomogeneous unmagnetized plasma slab
Authors: Li Haiying , Ding Wei , Liu Jiawei , Bai Lu , Wu Zhensen
Published: December 2019

An investigation into the orbital angular momentum (OAM) cross talk of multiple coaxial terahertz vortex beams propagating through an inhomogeneous unmagnetized plasma slab was conducted using the vector angular spectrum expansion method. For the double Gaussian distribution model of plasma sheath, considering the incidence of coherent vortex beams with single topological charge (TC), double, and four TCs, numerical simulations of the amplitude and OAM spectra of the reflected and transmitted beams were carried out and discussed in detail. The results showed that, as an oblique incidence of vortex beams, the effects of an inhomogeneous plasma slab on the distortions of the magnitude profiles and OAM spectra of the reflected and transmitted beams were critical, and due to the effects of several reflections between interfaces, the effects on the reflected beam were more serious. The distribution of the contours of the electric fields in transverse planes was closely related to the TCs of the incident beams. For coaxial incidence of multiple coherent vortex beams, the additional mutual cross talk, which was caused by interference, decreased with the increasing difference in the TCs and needed to be considered during OAM multiplexing. The selection of the radial integral distance had an obvious impact on the weights of the primary OAM states. This work provides an important theoretical reference for terahertz OAM multiplexing technology in solving the communication blackout caused by the plasma sheath.
Improvement of proton acceleration via collisionless shock acceleration by laser-foil interaction with an external magnetic field
Authors: Xie R. , Cao L. H. , Gong J. X. , Cheng H. , Liu Z. J. , Zheng C. Y. , He X. T.
Published: December 2019

Effects of the external intense axial magnetic field on collisionless shock acceleration (CSA) are investigated by using two-dimensional particle-in-cell simulations. Proton beams accelerated by CSA show different properties when left-hand circularly polarized (LHCP) or right-hand circularly polarized (RHCP) lasers are individually applied to a foil target with or without the magnetic field. It can be attributed to the difference of the dispersion relationship for the laser propagating in a plasma. Protons achieve more efficient acceleration when magnetized plasma is irradiated by the RHCP laser compared with the LHCP laser. Furthermore, the effect of different amplitudes of the magnetic field is studied numerically. It shows that the induced electrostatic charge-separation field arises deep in the target with huge strength of the magnetic field. Protons in the upstream are accelerated before the shock arrives, leading to less efficient acceleration. As a result, an appropriate magnetic field should be applied to enhance the CSA regime.
Influence of interfacial interaction on the mechanical properties of amorphous PE/MMT nanocomposites
Authors: Wang Yulong , Zhang Xiaohong , Li Lili , Gao Junguo
Published: December 2019

We carried out molecular dynamics simulations to examine the structural, interfacial, and mechanical properties of amorphous polyethylene/montmorillonite (PE/MMT) nanocomposites loaded with 0 wt. %, 3.3 wt. %, 4.0 wt. %, and 5.1 wt. % of modified organic MMT (O-MMT). The MMT nanoparticles were simulated in two stages: first treated with octadecyl trimethyl ammonium chloride and then doped in amorphous PE. The effects of the O-MMT content on the microstructure parameters (interaction energy, free volume, and interfacial thickness) and macroscopic mechanical properties (Young’s modulus, bulk modulus, and shear modulus) were analyzed. A strong correlation between mechanical properties and interfacial thickness was observed by analyzing the obtained data from simulation, and we verified them through experiments.
Electromagnetic energy rotation along plasma-dielectric interface caused by azimuthal surface waves in isotropic cylindrical metallic waveguide
Authors: Girka Igor O. , Girka Oleksii I. , Thumm Manfred
Published: December 2019

Electromagnetic energy rotation around the axis of cylindrical metallic waveguides partially filled by isotropic plasma is studied. Angular phase velocity and angular velocity of energy transfer are analyzed as functions of the plasma waveguide parameters: plasma column radius, plasma particle density, azimuthal wavenumber, dielectric layer width and dielectric constant, and collision frequency. This study generalizes the results obtained earlier in the case of the wave propagation in two-component plasma-metal structures (cylindrical metallic waveguides entirely filled by magnetoactive plasma) to the case of three-component plasma-dielectric-metal structures.
How proteins’ negative cooperativity emerges from entropic optimisation of versatile collective fluctuations
Authors: von der Heydt Alice C. , McLeish Tom C. B.
Published: December 2019

The fact that allostery, a nonlocal signaling between distant binding sites, can arise mainly from the entropy balance of collective thermal modes, without conformational changes, is by now well known. However, the propensity to generate negative cooperativity is still unclear. Starting from an elastic-network picture of small protein complexes, in which effector binding is modeled by locally altering interaction strengths in lieu of adding a node-spring pair, we elucidate mechanisms particularly for such negative cooperativity. The approach via a few coupled harmonic oscillators with internal elastic strengths allows us to trace individual eigenmodes, their frequencies, and their statistical weights through successive bindings. We find that the alteration of the oscillators’ couplings is paramount to covering both signs of allostery. Binding-modified couplings create a rich set of eigenmodes individually for each binding state, modes inaccessible to an ensemble of noninteracting units. The associated shifts of collective-mode frequencies, nonuniform with respect to modes and binding states, result in an enhanced optimizability, reflected by a subtle phase map of allosteric behaviors.
Atomically-smooth single-crystalline VO2 (101) thin films with sharp metal-insulator transition
Authors: Mondal Debasish , Mahapatra Smruti Rekha , Ahmed Tanweer , Podapangi Suresh Kumar , Ghosh Arindam , Aetukuri Naga Phani B.
Published: December 2019

Atomically-abrupt interfaces in transition metal oxide (TMO) heterostructures could host a variety of exotic condensed matter phases that may not be found in the bulk materials at equilibrium. A critical step in the development of such atomically-sharp interfaces is the deposition of atomically-smooth TMO thin films. Optimized deposition conditions exist for the growth of perovskite oxides. However, the deposition of rutile oxides, such as VO2, with atomic-layer precision has been challenging. In this work, we used pulsed laser deposition to grow atomically-smooth VO2 thin films on rutile TiO2 (101) substrates. We show that an optimal substrate preparation procedure followed by the deposition of VO2 films at a temperature conducive for step-flow growth mode is essential for achieving atomically-smooth VO2 films. The films deposited at optimal substrate temperatures show a step and terrace structure of the underlying TiO2 substrate. At lower deposition temperatures, there is a transition to a mixed growth mode comprised of island growth and layer-by-layer growth modes. VO2 films deposited at optimal substrate temperatures undergo a sharp metal to insulator transition, similar to that observed in bulk VO2, but at a transition temperature of ∼325K with ∼103 times increase in resistance.
The investigation of 2D monolayers as potential chelation agents in Alzheimer’s disease
Authors: Pavuluru N. , Luo X.
Published: December 2019

In this study, we conducted density functional theory calculations comparing the binding energy of the copper-amyloid-β complex to the binding energies of potential chelation materials. We used the first-coordination sphere of the truncated high-pH amyloid-β protein subject to computational limits. Binding energy and charge transfer calculations were evaluated for copper’s interaction with potential chelators: monolayer boron nitride, monolayer molybdenum disulfide, and monolayer silicene. Silicene produced the highest binding energies to copper, and the evidence of charge transfer between copper and the monolayer proves that a strong ionic bond is present. Although our three monolayers did not directly present chelation potential, the absolute differences between the binding energies of the silicene binding sites and the amyloid-β binding sites were minimal, proving that further research in silicene chelators may be useful for therapy in Alzheimer’s disease.
Temporal single-surface multipactor dynamics under obliquely incident linearly polarized electric field
Authors: Wen De-Qi , Zhang Peng , Fu Yangyang , Krek Janez , Verboncoeur John P.
Published: December 2019

It is well-known that single-surface multipactor discharges can negatively affect electromagnetic wave transmission, especially in high power microwave devices and space-based communication systems. In this work, the temporal single-surface multipactor dynamics under an obliquely incident linearly polarized electric field are investigated by particle-in-cell simulations. The results reveal that multipactor discharges highly decay by adjusting the angle, θ, between the rf electric field and the dielectric window. For plane waves with θ = 0, the number of electrons as a function of time oscillates at twice the rf frequency. However, alternative oscillations decrease in magnitude at θ=0.05π and disappear at θ=0.15π. This is because the perpendicular component of the rf electric field alternatively reinforces or reduces the restoring field and increases or decreases the secondary electron emission in half of the rf period. In addition, the electrons are forced into a few branches in the phase space of velocity and position, i.e., the electrons have a few groups of velocities at a fixed position due to the largely increased electron flight time. Finally, multipactor suppression is investigated by a simple kinetic model, by which the susceptibility diagram is obtained. This diagram shows the upper and lower boundaries gradually approach each other upon increasing θ from 0 to 0.2π, indicating reduced parameter space, in which multipactor discharge can develop.
Large bandgap tunability of GaN/ZnO pseudobinary alloys through combined engineering of anions and cations
Authors: Xian Fenglin , Xu Linhua , Zheng Gaige , Cao Zhaolou , Li Jinhua , Pei Shixin , Ye Jiandong
Published: December 2019

Bandgap engineering of gallium zinc oxynitride (GaZnON) thin films has been performed by the GaN/ZnO pseudobinary alloying in a periodical superlattice order through the pulsed laser deposition technique. By tuning the growth temperature, the combined engineering of anions and cations in GaZnON quaternary alloys leads to a large tunability of the optical bandgap from 1.80 to 4.34 eV. In terms of the enthalpy of formation and kinetic dynamics of reactant species, nitrogen incorporation is effective to form Zn3N2-rich GaZnON quaternary alloys at low-temperature (<100 °C) conditions far from the equilibrium, while amorphous nitrogen deficient GaZnON is formed at high temperatures with ZnGa2O4 and β-Ga2O3 nanocrystalline structures embedded. The conduction band (CB) and valence band (VB) of GaZnON are determined by Zn 4s orbital electrons and the hybridization of N 2p and O 2p electrons, respectively, while the Ga 4s and O 2p are predominant to construct the CB and VB of O-rich GaON due to the low solubility of N at high temperature. The asymmetric band bowing effect of GaZnON quaternary alloy demonstrates a large bandgap tunability down to the visible spectral range, which provides significant potential applications in the harvest of solar energy technologies.
Recombination rates in green-yellow InGaN-based multiple quantum wells with AlGaN interlayers
Authors: Al Muyeed Syed Ahmed , Sun Wei , Peart Matthew R. , Lentz Rebecca M. , Wei Xiongliang , Borovac Damir , Song Renbo , Tansu Nelson , Wierer Jonathan J.
Published: December 2019

The recombination rates in InGaN/AlGaN/GaN multiple quantum wells (MQWs) emitting in the green-yellow and grown with different Al compositions in the AlGaN interlayer (IL) are shown. By transforming measurements on radiative efficiency, absorption, and differential carrier lifetime, the radiative and nonradiative rates are determined. The IL Al composition controls lattice relaxation of the MQWs, as determined by X-ray reciprocal space mapping, and, therefore, defect formation. For the most pseudomorphic MQWs, the Shockley-Read-Hall (SRH) A coefficient is minimized and is similar to reports at shorter (blue and green) wavelengths. It is an order of magnitude smaller than a conventional InGaN/GaN MQW and is the most significant factor behind the improvement in radiative efficiency using the IL. The radiative B coefficient is also reduced and a minimum for the most pseudomorphic MQWs due to a reduction in the electron-hole wavefunction overlap. However, the decrease in A is more significant and leads to an overall improvement in the radiative efficiency. These recombination rate measurements confirm that if the SRH recombination is controlled, then the severe reduction of radiative recombination with an increased emitting wavelength is one of the main challenges in realizing high efficiency, long-wavelength InGaN-based MQW emitters operating at low to moderate current densities.
Nonadiabatic excited-state intramolecular proton transfer in 3-hydroxyflavone: S2 state involvement via multi-mode effect
Authors: Anand Neethu , Welke Kai , Irle Stephan , Vennapusa Sivaranjana Reddy
Published: December 2019

The excited-state intramolecular proton transfer process in 3-hydroxyflavone is investigated based on the computed structural parameters and energetics of stationary points of vibronically coupled S1-S2 potential energy surfaces. A conical intersection close to the Franck-Condon point on S1 is identified. The minimum energy of the conical intersection is found to be near-degenerate with the equilibrium minimum of S2. Quantum nuclear wavepacket simulations revealed a small population transfer from the “bright” S1 to “dark” S2 on a time scale shorter than the O—H stretching vibrational period. Such a nonadiabatic transition opens up the possibility of new photophysical and photochemical pathways, including the proton transfer via S2.
Development of a new high temperature oven for the production of intense
metal ion beams with ECR ion sources
Authors: Huang W. , Xie D. Z. , Sun L. T.
Published: December 2019

High Temperature Ovens (HTOs) have widely been used to evaporate refractory materials in electron cyclotron resonance ion sources to produce hundreds of microamperes of multiply and highly charged metal ion beams. To meet the demands of milliamperes of multiply charged uranium and other heavy metal ion beams for future accelerators, a new and low-cost HTO is under development at Lawrence Berkeley National Laboratory for better long-term stability at high evaporation rates. ANSYS simulations have been carried out to optimize the new HTO with low heating current to reduce the electromagnetic forces as an HTO is immersed in the strong ECRIS magnetic fields. A larger loading volume is employed to deal with higher material consumption. Off-line tests have shown that the unloaded new HTO operates stably up to 1800–1900 °C with low temperature gradients and good repeatability. This paper presents and discusses the conceptual design features of the new HTO and off-line tests.
Collisional resonance function in discrete-resonance quasilinear plasma systems
Authors: Duarte V. N. , Gorelenkov N. N. , White R. B. , Berk H. L.
Published: December 2019

A method is developed to analytically determine the resonance broadening function in quasilinear theory from first principles, due to either Krook or Fokker-Planck scattering collisions of marginally unstable plasma systems where discrete resonance instabilities are excited without any mode overlap. It is demonstrated that a quasilinear system that employs the calculated broadening functions reported here systematically recovers the growth rate and mode saturation levels for near-threshold plasmas previously calculated from nonlinear kinetic theory. The distribution function is also calculated, which enables precise determination of the characteristic collisional resonance width.
Tomography reconstruction of beams extracted from an ion source
Authors: Saminathan S. , Ames F. , Baartman R. , Marchetto M. , Lailey O. , Mahon A.
Published: December 2019

Commissioning of the CANREB (CANadian Rare isotope facility with Electron Beam ion source) system and its associated beamlines has recently begun at TRIUMF. At the head of this beamline is an ion source used to produce stable alkaline ions with energy up to 60 keV for the CANREB system. Throughout commissioning, it is essential to have a means of verifying beam quality and ensuring that the required beam parameters along the beamline are met. This is accomplished using tomography reconstruction, which consists of taking one-dimensional scans at different projections and reconstructing an image of the beam in two dimensions using the maximum entropy algorithm. Tomography enables the visualization of the shape of the beam as well as the investigation into the possible presence of aberrations. Initially, tomography reconstruction is performed by using simulated beam profiles at the measurement locations and is then performed by using measured beam profiles. Additionally, these measurements are benchmarked by fitting the initial beam parameters in our beam optics model, and the results are presented.
Efficacy of two adjuvant systems to promote humoral immunity to the pre-proghrelin peptide obestatin in pigs: consequences for the growth of piglets to weaning
Authors: Geale P. F. , Sheehy P. A. , Giles C. , Thomson P. C. , Wynn P. C.
Published: December 2019

The poor antigenicity of peptide antigens demands the selection of effective adjuvants to induce humoral immunity. The peptides obestatin and ghrelin from the pro-hormone pre-proghrelin were initially identified as antagonistic in regulating feeding behaviour, with obestatin being suppressive. The efficacy of two adjuvant systems, DEAE with the oil polysorbate emulsion of BP85:Span80 and the surfactant-oil system Montanide (ISA 50v) were therefore assessed with an obestatin-ovalbumin conjugate injected into late pregnant sows. This enabled the supply of antibodies directed against obestatin to newborn piglets through colostrum with the objective of promoting ghrelin secretion and therefore increasing feeding behaviour. Pregnant Landrace × Large White sows (n = 28) were immunised with 0.5 mg obestatin-ovalbumin in 2 mL DEAE:BP85:Span80 (DEAE; n = 14) or with 2 mL Montanide (ISA 50v: n = 14) as adjuvants at days 91 and 105 of gestation. After farrowing, piglets remained with their mothers during the lactation period and were weighed after weaning at Day 28. Antibody titres (unitless) in colostrum were assessed by ELISA as 5543 ± 2388 and 3139 ± 1151 for the DEAE and Montanide adjuvants respectively. These were associated with total IgG of 67.7 ± 3 and 82.3 ± 4.8 mg/mL respectively (P = 0.018). Piglet plasma titres were 5100 ± 1576 and 5762 ± 1688 for DEAE and Montanide respectively at Day 5 postpartum. These titres were still detectable through to Day 28 (titres of 1213 ± 389 and 665 ± 203 respectively (P = 0.176). However, sow colostral antibody titres were not related to piglet antibody concentrations on D5 (r = –0.225, P = 0.341). Sow plasma antibody titres were not related to titres at Day 28 in piglets across treatments (r = 0.198, P = 0.402). The concentration of ghrelin in colostrum was 672 ± 78 and 666 ± 39 pg/mL for the DEAE and Montanide groups, respectively, leading to piglet plasma concentrations on Day 5 of 1105 ± 164 and 530 ± 84 pg/mL (P = 0.002). Animals grew from birthweights of 1.7 ± 0.1 and 1.8 ± 0.1 (P = 0.993) to 7.7 ± 1.2 and 7.8 ± 1.0 kg (P = 0.295) at weaning, representing growth rates of 200.5 ± 52.9 and 225.5 ± 53.4 g/day (P = 0.181). There was a significant negative correlation between piglet D28 antibody titre and growth rate to weaning with the Montanide adjuvant (r = 0.116, P = 0.035) but not for the DEAE (r = –0.118, P = 0.411). Although both adjuvants were capable of generating high antibody titres, the DEAE dextran was likely to be the most effective adjuvant to induce a humoral immune response to develop further with a commercial vaccine.
A review of the adequacy of reporting to the Ramsar Convention on change in the ecological character of wetlands
Authors: Davidson N. C. , Dinesen L. , Fennessy S. , Finlayson C. M. , Grillas P. , Grobicki A. , McInnes R. J. , Stroud D. A.
Published: December 2019

We review the mechanisms established by the Ramsar Convention for reporting on the status and change in the ecological character of wetlands. We assess the extent of their implementation and compliance, but not issues of the adequacy of their design nor the consequences of their extent of implementation. We conclude that, with the exception of qualitative national-scale reporting in triennial Contracting Party National Reports, there is inadequate implementation and compliance with most of these mechanisms, notably concerning required reporting under Article 3.2 of the Convention and the updating of the Information Sheet on Ramsar Wetlands (RIS). This limits the ability of the Convention to assess the status, and trends in status, of designated Wetlands of International Importance (Ramsar Sites), and to inform future decision-making and priority-setting for the wise use of all wetlands. As has been recognised by the Ramsar Convention, unless compliance with these mechanisms is improved, sufficient information will not be gathered through the mechanisms of Ramsar Convention to assess fully the Sustainable Development Goal 6.6.1 indicator supported by the Convention on change in the extent of water-related ecosystems over time.
B cell receptor ligation induces display of V-region peptides on MHC class II molecules to T cells
Authors: Huszthy Peter Csaba , Gopalakrishnan Ramakrishna Prabhu , Jacobsen Johanne Tracey , Haabeth Ole Audun Werner , Løset Geir Åge , Braathen Ranveig , Schenck Karl , Tveita Anders Aune , Munthe Ludvig Andre , Bogen Bjarne
Published: December 2019

The B cell receptors (BCRs) for antigen express variable (V) regions that are enormously diverse, thus serving as markers on individual B cells. V region-derived idiotypic (Id) peptides can be displayed as pId:MHCII complexes on B cells for recognition by CD4+T cells. It is not known if naive B cells spontaneously display pId:MHCII in vivo or if BCR ligation is required for expression, thereby enabling collaboration between Id+B cells and Id-specific T cells. Here, using a mouse model, we show that naive B cells do not express readily detectable levels of pId:MHCII. However, BCR ligation by Ag dramatically increases physical display of pId:MHCII, leading to activation of Id-specific CD4+T cells, extrafollicular T–B cell collaboration and some germinal center formation, and production of Id+IgG. Besides having implications for immune regulation, the results may explain how persistent activation of self-reactive B cells induces the development of autoimmune diseases and B cell lymphomas.
Young children spontaneously recreate core properties of language in a new modality
Authors: Bohn Manuel , Kachel Gregor , Tomasello Michael
Published: December 2019

How the world’s 6,000+ natural languages have arisen is mostly unknown. Yet, new sign languages have emerged recently among deaf people brought together in a community, offering insights into the dynamics of language evolution. However, documenting the emergence of these languages has mostly consisted of studying the end product; the process by which ad hoc signs are transformed into a structured communication system has not been directly observed. Here we show how young children create new communication systems that exhibit core features of natural languages in less than 30 min. In a controlled setting, we blocked the possibility of using spoken language. In order to communicate novel messages, including abstract concepts, dyads of children spontaneously created novel gestural signs. Over usage, these signs became increasingly arbitrary and conventionalized. When confronted with the need to communicate more complex meanings, children began to grammatically structure their gestures. Together with previous work, these results suggest that children have the basic skills necessary, not only to acquire a natural language, but also to spontaneously create a new one. The speed with which children create these structured systems has profound implications for theorizing about language evolution, a process which is generally thought to span across many generations, if not millennia.
Homeobox protein Hhex negatively regulates Treg cells by inhibiting Foxp3 expression and function
Authors: Jang Sung Woong , Hwang Soo Seok , Kim Hyeong Su , Kim Min Kyung , Lee Woo Ho , Hwang Soh Un , Gwak Jinu , Yew Si Kyoung , Flavell Richard A. , Lee Gap Ryol
Published: December 2019

Regulatory T (Treg) cells play an essential role in maintaining immune homeostasis, but the suppressive function of Treg cells can be an obstacle in the treatment of cancer and chronic infectious diseases. Here, we identified the homeobox protein Hhex as a negative regulator of Treg cells. The expression of Hhex was lower in Treg cells than in conventional T (Tconv) cells. Hhex expression was repressed in Treg cells by TGF-β/Smad3 signaling. Retroviral overexpression of Hhex inhibited the differentiation of induced Treg (iTreg) cells and the stability of thymic Treg (tTreg) cells by significantly reducing Foxp3 expression. Moreover, Hhex-overexpressing Treg cells lost their immunosuppressive activity and failed to prevent colitis in a mouse model of inflammatory bowel disease (IBD).
Hhex
expression was increased; however,
Foxp3
expression was decreased in Treg cells in a delayed-type hypersensitivity (DTH) reaction, a type I immune reaction. Hhex directly bound to the promoters of
Foxp3
and other Treg signature genes, including
Il2ra
and
Ctla4
, and repressed their transactivation. The homeodomain and N-terminal repression domain of Hhex were critical for inhibiting Foxp3 and other Treg signature genes. Thus, Hhex plays an essential role in inhibiting Treg cell differentiation and function via inhibition of Foxp3.
Targeting liver aldehyde dehydrogenase-2 prevents heavy but not moderate alcohol drinking
Authors: Guillot Adrien , Ren Tianyi , Jourdan Tony , Pawlosky Robert J. , Han Elaine , Kim Seung-Jin , Zhang Li , Koob George F. , Gao Bin
Published: December 2019

Significance

It is generally accepted that ethanol and its metabolite acetaldehyde are primarily metabolized in the liver via the alcohol dehydrogenase and the aldehyde dehydrogenase-2 (ALDH2), respectively. However, by using tissue-specific
Aldh2
knockout mice, we demonstrated that the liver ALDH2 is only responsible for approximately half of circulating acetaldehyde clearance after acute alcohol intake. Thus, cumulative ALDH2 activity from multiple organs may contribute to circulating acetaldehyde clearance. The present study shows that, although the liver ALDH2 only partially contributes to acetaldehyde clearance, genetic deletion or knockdown of the liver
Aldh2
decreases excessive but not light to moderate alcohol drinking. Our results suggest that liver-specific ALDH2 inhibition may be an effective strategy for the treatment of alcohol user disorder with excessive drinking.
The influence of the global electric power system on terrestrial biodiversity
Authors: Holland Robert A. , Scott Kate , Agnolucci Paolo , Rapti Chrysanthi , Eigenbrod Felix , Taylor Gail
Published: December 2019

Significance

Understanding the relationship between the global electric power sector and biodiversity is central to identifying sustainable pathways to decarbonization. This study examines the relationship between the global electric power sector and threats to biodiversity. The biodiversity footprint of the electric power sector is primarily within the territory where demand for power resides, although substantial regional differences exist. The relationship between supply technologies and threats to biodiversity indicates that a shift to some nonfossil sources could reduce pressures on biodiversity, although there is uncertainty in how threats will scale given current deployment levels of nonfossil sources. The strong territorial link between electric power demand and biodiversity threat provides clear routes for governments to effectively manage biodiversity impacts of electric power transitions.
Insect-damaged
Arabidopsis
moves like wounded
Mimosa pudica
Authors: Kurenda Andrzej , Nguyen Chi Tam , Chételat Aurore , Stolz Stéphanie , Farmer Edward E.
Published: December 2019

Significance

Leaves display constant and complex movements. We found that the petioles of undamaged leaves of
Arabidopsis thaliana
undergo minute deformations when insects fed on other leaves. These deformations reported in real time the arrival and architecture of damage-triggered electrical signals called slow wave potentials. Mutants affecting cell walls in xylem vessels altered these petiole deformations, suggesting that water fluxes coincide with the passage of the electrical signals through tissues. Further analyses revealed that whole leaves distal to wounds displayed slow downward motions following the arrival of electrical signals. Monitoring insect-triggered tissue deformations in different genetic backgrounds can yield mechanistic insights into electrical signalling and may increase our understanding of the basis of plant movement.