bluuebunny/crossref_metadata_2025 huggingface dataset:
STEADY-STATE ELECTRIC FIELD STRUCTURE AND DENSITY PROFILE IN A PLASMA IRRADIATED BY DOUBLE-FREQUENCY LASER
Authors: ZHU SHI-TONG  , SHEN WEN-DA  ,   (1)上海科学技术大学物理系; (2)中国科学院上海光学精密机械研究所
Published: November 2020

The analytic expressions for steady-state electric field intensity and local scale length in a plasma irradiated by doublefrequency laser are derived. It is shown that the ponderomotive force due to double-frequency laser field would lead to the local density dip near critical surface and the anamolous increase and fluctuation of the critical scale length in some region of field intensity value.
THE HARMONIC EFFECT ON EXAFS AMPLITUDE IN POLY-ELEMENT SYSTEMS
Authors: WAN JUN  , LU KUN-QUAN  , ZHAO YA-QIN  , CHANG LONG-CUN  , FANG ZHENG-ZHI  ,   (1)北京钢铁学院; (2)中国科学院物理研究所
Published: November 2020

A method to calculate the harmonic effect on EXAFS amplitude for poly-element systems is given. Results calculated and measured are presented. They are consistent with each other.
THEORETICAL INVESTIGATION OF KONDO TYPE FERROMAGNETIC SUPERCONDUCTIVITY
Authors: FENG SHI-PING  ,   北京师范大学低能核物理研究所
Published: November 2020

Assuming the BCS mechanism, we use Anderson model Hamiltonian to analyse the problem of coexistent ferromagnetic and superconducting state for Kondo type heavy fermion superconductors. Results show that the coexistent state is unstable.
THE METASTABLE PHASES FORMED IN AN AMORPHOUS Pd80Si20 ALLOY DURING CRYSTALLIZATION
Authors: WU LI-JUN  , GUO YONG-XIANG  , WU YU-KUN  , GUO KE-XIN  ,   (1)上海交通大学材料工程系; (2)中国科学院金属研究所
Published: November 2020

By tilting the crystals formed in an amorphous Pd80Si20 alloy during crystallization in a transmission electron microscope, three phases have been determined. The metastable phase P1 has a primitive orthorhombic unit cell (a = 0.46, b = 1.37, c = 1.69nm) and its possible space group is Pnmm or P(nm21). Using the data of crystal P1 the EDP of MSII and Pd9Si2 phases reported by Masumoto et al and Duhaj at el respectively can be explained. The metastable phase F has a face-centred orthorhombic unit cell with the same values of a and b as the P1 phase but c = 1.46 nm. The phase P2 crystallized at high temperature has a primitive orthorhombic unit cell (a = 0.39, b = 0.76, c = 0.54nm).
ELECTRONIC STRUCTURE IN ONE-DIMENSIONAL INCOMMENSURATELY MODULATED CHAINS WITH DISORDER
Authors: XIONG SHI-JIE  , TAN MING-QIU  ,   (1)南京大学固体物理研究所; (2)南京大学物理系
Published: November 2020

The influence of the substitution disorder and the period disorder on electronic structures of one-dimensional, nearly periodic systems is studied in terms of numerical method. The results show that the Cantor set structure of electronic spectra in the almost periodic systems is destroyed in both the disordered cases, but Ihe former may -create new impurity levels in the forbidden band, and the latter mainly broadens the original energy bands.
COEXISTENCE OF SUPERCONDUCTIVITY AND FERROMAGNETISM IN THE TRIPLET BIPOLARONIC SYSTEM
Authors: LI YAN-MIN  , ZHANG LI-YUAN  ,   (1)北京大学物理系; (2)中国科学院物理研究所
Published: November 2020

The problem of coexistence of superconductivity and ferromagnetism in the triplet bipolaro-nic system has been studied by using the symmetry-broken Hartree approximation. It is found that the ground stare of the system is the mixed state of both orders, which is different from the case of usual BCS systems. It is seen from the phase diagram obtained that in the high bipolaro-nic concentration region the system may exhibit a transition from the ferromagnetic to the mixed state on cooling, while in the low concentration region only the transition from the normal to the mixed state is possible.
LIGHT ABSORPTION AND SCATTERING OF SMALL COLLOIDAL PARTICLES IN METALLIC COLLOIDAL PARTICLES-SEMICONDUCTOR THIN FILMS
Authors: WU QUAN-DE  , XUE ZENG-QUAN  ,   北京大学无线电电子学系
Published: November 2020

Metallic colloidal particles- semiconductor thin films show special electrical, optical and photoelectric properties. The formulas for light absorption coefficient and scattering coefficient of small colloidal particles dispersed in semiconductor thin film are given in this paper. The colloidal particles may be spheroids, prolate spheroids or oblate spheroids. As an example, the effects of sizes and shapes of Ag colloidal particcles in Ag-Cs2O semiconductor thin films on light absorption and scattering are discussed. The calculated curves for relative absorption coefficient and scattering coefficient vs. wavelength λ are also presented.
INFLUENCE OF DIMENSION OF THE STEPPED HORNS WITH PIEZOELECTRIC TRANSDUCER ON THE PERFORMANCE OF THE VIBRATORS
Authors: MA YU-YING  , DING DA-CHENG  ,   陕西师范大学应用声学研究所
Published: November 2020

In this paper, we discuss two types of vibrators, that connected by a single screw and that by a strain shell, respectively. The thick-end lengths of stepped horns are varied to find out their influence on the thin-end length, the gain of displacement amplitude, and the variation of displacement amplitude at the thin end. Optimized thick-end length are then selected out. For the vibrator connected by strain shell, the displacement amplitude of the thin end and the relationships among resonant frequencies and diameter of both the thick end and the thin end are determined. The relation between the thin-end length and resonant frequencies is also studied. The method for designing improved vibrators is given.
A NEW CRITERION FOR SUPERCONDUCTIVITY OF ELEMENTS
Authors: LUO QI-GUANG  , WANG RONG-YAO  ,   (1)清华大学物理系; (2)中国科学院物理研究所
Published: November 2020

This article gives a new criterion for superconductivity. It can be applied to all the ele-ments in periodic table. The criterion shows that the values of electronegativity of all superconducting elements concentrate in a narrow range from 1.3 to 1.9 and that the elements with values outside this region would be non-superconductive.Deepgoing studying the relation between electronegativity and superconductivity of elements will contribute to revealing the connection between electrostatic inter action of electron with crystal lattice and superconductivity, which is able to benefit further inquiries about the mechanism of superconductivity.
ELECTRONIC STRUCTURE OF CMS SURFACES ——CPA METHOD
Authors: PANG GEN-DI  , XIONG SHI-JIE  , CAI JIAN-HUA  ,   (1)南京大学固体物理研究所; (2)上海交通大学物理系,南京大学固体物理研究所
Published: November 2020

Based on tight-binding approximation, the electronic structure of CMS surfaces is discussed with the CPA method, combined with the infinite order perturbation theory. Both substitute disorder model and Anderson disorder model are included in numerical calculations.
THE LIFETIME MEASUREMENT OF THE 28Si COMPOUND STATE OF 13.095 MeV BY THE BLOCKING EFFECT
Authors: JIN WEI-GUO  , ZHAO GUO-QING  , SHAO QI-YUN  , REN YUE-HUA  , WU XIANG-JIAN  , ZHOU ZHU-YING  ,   复旦大学原子核科学系
Published: November 2020

The methods for treating the Al single crystals have been improved and high quality crystals are obtained. The experiment of radiation damage in the Al crystals is carried out and the lifetime of the 28Si compound state of 13.095 MeV, excited by the 27Al(p,a)24 Mg resonant reaction at Ep = 1565keV, is measured. The lifetime, τ = 16.3±2.4 as, is deduced by comparison with the calibration curves calculated with Monte Carlo model and "analytical" methods. The corresponding energy level widtk, Γ = 40±6eV, is in good agreement with that reported in the literature.
A STUDY OF CREEP RUPTURE IN COPPER BY MEASUREMENTS OF INTERNAL FRICTION
Authors: KONG QING-PING  , DAI YONG  ,   中国科学院固体物理研究所
Published: November 2020

On the basis of our previous work [1] on commercially pure aluminum, the change of internal friction peak of grain bound- (Ke peak) in commercially pure copper has been studied in the course of creep. Creep experiments were conducted under different conditions: (a) high temperature and low stress; (b) medium temperature and medium stress; (c) low temperature and high stress; which lead to intergranular, mixed type and transcrystalline rupture respective'y. From the changes of grain boundary peak under different creep conditions, it can be deduced that the strength of grain boundaries is changed little during creep at high temperature and low stress; somewhat increased at medium temperature and medium stress; and considerably increased at low temperature and high stress. The present work indicates that the strength of grain boundaries is changeable during creep. The extent of strengthening of grain boundaries is different under different creep conditions, which is believed to be an important roie to lead to different type of creep rupture. This provides a modification and complement of the idea of "equicohesive temperature".
A NEW APPROACH TO INVESTIGATING THE VALENCE FLUCTUATION COMPOUNDS
Authors: ZHENG HANG  ,   上海交通大学应用物理系
Published: November 2020

The ground state properties of the Sm-based valence fluctuation compounds are discussed by introducing an indirect on-site hybridization mediated by phonons, as the direct on-site hybridization is forbidden by inversion symmetry. The Hamihonian including this indirect hybridization is transformed into an effective Hamihonian of a "small polaron" type by means of a. canonical transformation. A self-consistent field approximation is used, a non-zero energy gap and the noninteger occupation of the f level have been given. The results obtained can be used to explain the small energy gap and the valence fluctuation phenomena observed in SmB6 and SmS.
THE RELATION OF SUPERCONDUCTIVITY AND STRUCTURE IN YBa2-xSrxCu3O7-δ
Authors: ZHAO YONG  , ZHANG HAN  , SUN SHI-FANG  , SUN DUN-MING  , YU DAO-QI  , YU WEI-CHAO  , CHEN ZU-YAO  , ZHANG QI-RUI  ,   (1)中国科学技术大学物理系; (2)中国科学技术大学应用化学系
Published: November 2020

The relation between superconductivity and phase structure of YBa2-xSrxCu3O7-δ system has been studied systematically. It is found that when 0c increases monotonously. The mechanism of the effect of Sr atom on Tc and superconductivity have also been discussed.
PERIOD BIFURCATIONS OF THE STANDARD MAPPING AND THE TRANSITIONS FROM THEM TO CHAOS
Authors: LIU JUN-XIAN  , CHEN GUANG-ZHI  , WANG GUANG-RUI  , CHEN SHI-GANG  ,   (1)广西师范大学; (2)应用物理与计算数学研究所
Published: November 2020

The behavior of periodic orbits of the standard mapping near their residues R =1 and R = 0 is studied. There is a sequence of period doubling bifurcations corresponding to the former, the bifurcation ratio δ and scaling factors α and βagree with those obtained from other two-dimensional area-preserving mappings. There are same period bifurcations corresponding to the latter, which is related to the antisymetric nature of the standard mapping. Moreover, by calculating Lyaponov exponents of chaotic orbits, we have found near the accumulation point k∞ of a sequence of period doubling bifurcations a scaling relation λ=λ∞+A(k-k∞)+B(k-k∞)τ with τ≈0.32, it agrees with the result τ=ln(2)/ln(δ)(δ=8.7210972…) conjectured theoretically.
CALCULATION OF ELECTRONIC STATES IN IONIC CRYSTALS USING SEMI-EMPIRICAL CNDO/INDO METHOD
Authors: CUI LI-JING  , WAN LIANG-FENG  , LIU JING-JIANG  ,   (1)南开大学化学系; (2)天津大学物理系
Published: November 2020

In this paper, we seport the coleulation of electronic states in ionic crystals in the fram-work of molecular cluster model. A convensinal CNDO/INDO program for the calculation of mole cular structure was revised to meet the requirments of calculation for electronic states of ionic crystals.The electronic states of crystals LiF, NaF, LiCl, NaCl were calculated. Width of valence band, band gap, effective ionic charge and the position of ground state louel of F-center in LiF were obtained. A comparison between our results and that proposed by other authors and experimental data has been made. Our results agree fairly good with experimental data.
THE ELECTRON PARAMAGNETIC RESONANCE STUDY OF Fe ION IN α-Al2O3 SINGLE CRYSTAL
Authors: JIN TONG-ZHENG  , HAN SHI-YING  , SUI YUN-XIA  ,   南京大学现代分析中心
Published: November 2020

The electron paramagnetic resonance of Fe3+ ion in α-Al2O3 single crystal has been studies at room temperature in x-band. It is found that Fe3+ ions occupy actually four magnetically unequivalent sites. The Fe3+ ions in two kinds of sites between adjacent planes of oxygens have same Spin Hamiltonian Parameters (SHP), but have different SHP in the sites between next adjacent planes of oxygens. Two groups of SHP are: (1) g‖=2.001, g⊥= 2.003, D= 1679×10-4 cm-1, |a| =237×l0-4cm-1, a-F = 317×10-4cm-1. (2) g‖ = 2.001, g⊥= 2.006, D=l660×10-4cm-1, |a| = 243×10-4cm-1, a-F=338×10-4cm-1.
THE BEHAVIOR OF H, He AND Kr IN TRANSITION METAL AND NOBLE METAL
Authors: LOU YONG-MING  , GU BlNG-LIN  , GAO NAI-FEI  , XIONG JIA-JIONG  , CAO BI-SONG  , YU WEI-ZHONG  ,   清华大学物理系
Published: November 2020

The electronic structures, the positron behavior and the positron annihilation lifetimes for void-H, void-He, void-Kr complex in the transitiou metals Ni, Fe, Cr and the noble metal Cu have been calculated, by means of the density functional formalism, the local density approximation based on the jellium model. It is shown that: as the size of the complex increases, the energy levels of bound state of impurity become shallower; and consequently the mean density of scattering state electron inside the complex decreases; and the probability of positron inside the complex and the positron annihilation lifetime inceases.
INVESTIGATION OF THE Cr2+(3d4) IN GaAs UNDER HYDROSTATIC PRESSURE AND AlAs ALLOYING
Authors: GU YI-MING  , HUANG MING-ZHU  , WANG KE-LING  ,   中国科学技术大学物理系
Published: November 2020

A spin-polarized version of the tight-binding Green's function scheme is developed for GaAs:Cr2+(3d4) system, which is under hydrostatic pressure and is alloyed with AlAs in different concentration. Results on the variation trends of 5E excited and 5T2 ground acceptor levels of GaAs:Cr2+ with different pressures and aluminum concentrations are reported. The theory shows that under certain pressure and Al concentration the 5E state will shift into the band gap from the bottom of conduction band. The 5E→5T2 luminescence which can not be observed in normal condition will appear in such case. Good overall agreement between theory and experiment is found. The theory also predicts that the similar luminescence process-would occur when GaAs is alloyed with Gap in certain concentration, but this still waits for experimental verification.
A STUDY ON ELASTICITY OF ACOUSTICALLY ACTIVE CRYSTALS NaBrO3 AND NaClO3
Authors: SHEN ZHI-GONG  , TAO FANG  , MA WEN-YI  , LIN QUAN  ,   中国科学院物理研究所
Published: November 2020

The dispersion curves of phonons along three crystallographic axes for isomorphous crystals NaBrO3 and NaClO3 have been measured by using coherent inelastic neutron scattering. The velocities of elastic waves along these directions and three independently elestic constants C11,C12 and C44 are deduced from the dispersion curves in the region of small wave vectars. The experimental results verified directly the prediction of portigal's theory that the velocities of left circularly polarized phonons and the right polarized ones distribute on both side of a particular average velocity v(TD) symmetrically, the value of v(TD) can be determined uniquely by the velocities on other directions or the zero-order approximative elastic constants.
SUPERSTRUCTURE FORMED BY SEGREGATION OF CARBON ON Mo(100) AND Mo(111) SURFACES
Authors: FAN YONG-NIAN  ,   中国科学院金属研究所
Published: November 2020

Carbon and oxygen on the Mo(l00) and Mo(l1l) surfaces can not be removed by bombarding the sample with argon ions at the ambient temperature. While carbon and oxygen can be reduced by bombarding the sample using nitrogen ions with primary energy of 1 keV and beam current of 6 μA for 10-15 min. This may be due to the adsorption of nitrogen reached saturation. After heating sample to 400-600℃ carbon and oxygen disappeared; at 600-650℃, Auger peak of nitrogen dropped suddenly and then decreased gradually with increasing temperature, carbon segregated simultaneously on the surface. Complete desorption of nitrogen took place at 730℃ and 775℃, A p(2×2)-C and a c(6×2)-C LEED patterns were observed respectively. After nitrogen desorbtion, the sample is cooled to room temperature, oxygen segregated on Mo(lll) surface. Repeated heating to above 650℃, carbon disappeared from the surface, nitrogen and oxygen appeared on the surface, until at 800℃ nitrogen and oxygen disappeared completely and a clean surface Mo(lll) LEED pattern was obtained. Then cooling the sample to room temperature, oxygen segregated on surface again. After bombarding the Mo(lll) surface with argon ions, carbon and nitrogen agan appeared on the surface. Heating to 700℃ and 760℃ oxygen and nitrogen disappeared and a p(6×6)-C LEED pattern was obtained.
THE FORMAL SOLUTIONS FOR FOKKER-PLANCK EQUATION WITH ZERO OR NEGATIVE DIFFUSION COEFFICIENTS AND THEIR APPLICATIONS TO QUANTUM OPTICS
Authors: TAN WEI-HAN  , LI YU-FANG  , ZHANG WEI-PING  ,   中国科学院上海光学精密机械研究所
Published: November 2020

In this paper, the formal solutions for Fokker-Planck equation with zero or negative diffusion coefficients in quantum optics are given. Their applications to the generation of squeezed states via degenerate parametric amplification or degenerate four wave mixing and other problems are discussed.
HIGH POWER CONTINUOUSLY TUNABLE FAR INFRARED RAMAN NH3 LASER PUMPED USING A HIGH PRESSURE TE CO2 LASER
Authors: ZHU WEN-SEN  , B. K. DEKA  , J. R. IZATT  ,   (1)美国阿拉巴马大学物理和天文系; (2)中国科学院物理研究所
Published: November 2020

A tunable far-infrared Raman transition NH3 laser with output energies up to 4 mJ (～80kW) is reported. The tuning range covered more than 70% of the emission spectrum from 90 to 93 μm, and the continuous tuning range associated with individual K-level transitions is about 30 GHz. Typical experimental results are described and discussed.
ANALYSIS OF THE COORDINATION NUMBER OF THE ATOM W IN ZnWO4 SINGLE CRYSTALS
Authors: WANG HONG  , LIU YAN  , ZHOU YA-DONG  , CHEN GANG  , HO BO-QING  , GU BEN-YUAN  ,   (1)北京工业大学; (2)中国科学院物理研究所
Published: November 2020

The coordination number Z of the atom W in scintillator ZnWO4 is analyzed based on the X-ray structural data and Raman scattering experiment results. Z is suggested to be 6 that might be more reasonable than 4. t turns out that the luminescence center in ZnWO4 locates at the configuration of the atomic group WO6, instead of WO4-2. We also present some new Raman lines expected bytheoretical analysis.
ACOUSTIC PROPERTIES OF AMORPHOUS SUPERIONIC CONDUCTOR (AgI)x(Ag4P2O7)1-x
Authors: WU KUN-YU  , DING YI  , YU WEN-HAI  ,   (1)中国科学技术大学无线电电子学系,中国科学院固体物理研究所内耗与固体缺陷实验室; (2)中国科学技术大学物理系
Published: November 2020

Amorphous superionic conductor (AgI)x(Ag4P2O7)1-x system has been obtained by means of the liquid nitrogen rapid quenching technique. The ultrasonic attenuation and velocity of longitudinal and transverse sound waves in the samples for Agl with mol concentration x = 0.50, 0.60, 0.67, 0.75, 0.80 were measured in the temperature range 77-300 K at the frequency of 2, 5, 10, 15 MHz. An anomalous strong ultrasonic absorption peak is observed at a temperature around 200-240 K with the rharacteristics of relaxation attenuation evidently. The attenuation peak was found to shifts to lower temperature and the peak attenuation value increases with increasing Agl content. In the experimental temperature region the internal friction QM-1 of longitudinal and transverse waves in the samples is almost equivalent. In the course of attenuation measurements the sound velocity, elastic moduli at room temperature and the dependence of sound velocity on Agl content were also measured. The experimental data fit satisfactorily the unified theory of low frequency fluctuation, dissipation and relaxation process (i.e. infrared divergence response theory, briefly called as IDR) proposed by Ngai. The apparent activation energy and infrared divergence exponent of the samples were presented.
EFFECT OF INTERFACIAL ROUGHNESS ON THE PLASMON MODE IN SUPERLATTICES
Authors: SHI HANG  , CAI JIAN-HUA  ,   (1)南京大学固体物理研究所; (2)上海交通大学凝聚态物理研究所
Published: November 2020

The effect of interfacial roughness on the plasmon mode in superlattices is discussed. The corresponding frequency shift, mean free path and life time of the plasmon mode have heen derived.
EFFECT OF THE PHASE ON OUTPUT PARAMETERS IN A SYNCHRONOUSLY PUMPED DYE LASER
Authors: BAO XIAO-YI  , WU CUN-KAI  ,   中国科学院安徽光学精密机械研究所
Published: November 2020

The phase contribution of asymmetry of pulse shape in a synchronously pumped dye laser is discussed. We also give the phase contribution of cavity components. The analytic expressions of the pulsewidth, peak position and amplitude are obtained in the presence of asym-metry of pulse shape and chirp.
MAXIMAL AND COMPLETE ANALYTIC EXTENSION OF A GLOBALLY REGULAR SCHWARZSCHILD BLACK HOLE
Authors: SHEN WEN-DA  , ZHU SHI-TONG  ,   (1)上海科学技术大学物理系; (2)中国高等科学技术中心(世界实验室)理论物理中心,中国科学院上海光学精密机械研究所
Published: November 2020

The maximal and complete analytic extension of a globally regular Schwarzschild black hole is given in the Kruskal coordinate. The junction conditions on null hypersurface are discussed. The asymptotic space-time stuctures of singular and nonsingular Schwarzschild black holes are compared. It is shown that a nonsingular stable black hole can exist.
THE AMORPHOUS AgxCu50-xZr50 ALLOYS AND THEIR CRYSTALLIZATION
Authors: ZHANG KANG-HOU  , ZHOU YUE-HUA  , ZHAO HUAI-ZHI  , CHEN LI-LI  ,   昆明贵金属研究所
Published: November 2020

The metallic glasses AgxCu50-xZr50 are prepared by an induction furnace followed by melt spinning in vacuum. It is found that amorphous alloys can be obtained in the range xc of the metallic glasses AgxCu50-xZr50 with x = 2, 4, 6 and 10 are obtained. The activation energys En of crystallization are determined by the Kissinger method. It is shown that the bigger is the x in metallic glasses AgxCu50-xZr50, the less stable is the glasses. A comparison of the study on the crystallization of the glasses in argon with that in the air suggests that the second exothermal peaks are oxidation peaks.
Achieving functional neuronal dendrite structure through sequential stochastic growth and retraction
Authors: Ferreira Castro André , Baltruschat Lothar , Stürner Tomke , Bahrami Amirhoushang , Jedlicka Peter , Tavosanis Gaia , Cuntz Hermann
Published: November 2020

Class I ventral posterior dendritic arborisation (c1vpda) proprioceptive sensory neurons respond to contractions in theDrosophilalarval body wall during crawling. Their dendritic branches run along the direction of contraction, possibly a functional requirement to maximise membrane curvature during crawling contractions. Although the molecular machinery of dendritic patterning in c1vpda has been extensively studied, the process leading to the precise elaboration of their comb-like shapes remains elusive. Here, to link dendrite shape with its proprioceptive role, we performed long-term, non-invasive, in vivo time-lapse imaging of c1vpda embryonic and larval morphogenesis to reveal a sequence of differentiation stages. We combined computer models and dendritic branch dynamics tracking to propose that distinct sequential phases of stochastic growth and retraction achieve efficient dendritic trees both in terms of wire and function. Our study shows how dendrite growth balances structure–function requirements, shedding new light on general principles of self-organisation in functionally specialised dendrites.
A survey of research quality in core facilities
Authors: Kos-Braun Isabelle C , Gerlach Björn , Pitzer Claudia
Published: November 2020

Core facilities are an effective way of making expensive experimental equipment available to a large number of researchers, and are thus well placed to contribute to efforts to promote good research practices. Here we report the results of a survey that asked core facilities in Europe about their approaches to the promotion of good research practices, and about their interactions with users from the first contact to the publication of the results. Based on 253 responses we identified four ways that good research practices could be encouraged: (i) motivating users to follow the advice and procedures for best research practice; (ii) providing clear guidance on data-management practices; (iii) improving communication along the whole research process; and (iv) clearly defining the responsibilities of each party.
A novel haemocytometric COVID-19 prognostic score developed and validated in an observational multicentre European hospital-based study
Authors: Linssen Joachim , Ermens Anthony , Berrevoets Marvin , Seghezzi Michela , Previtali Giulia , van der Sar-van der Brugge Simone , Russcher Henk , Verbon Annelies , Gillis Judith , Riedl Jürgen , de Jongh Eva , Saker Jarob , Münster Marion , Munnix Imke CA , Dofferhof Anthonius , Scharnhorst Volkher , Ammerlaan Heidi , Deiteren Kathleen , Bakker Stephan JL , Van Pelt Lucas Joost , Kluiters-de Hingh Yvette , Leers Mathie PG , van der Ven Andre J
Published: November 2020

COVID-19 induces haemocytometric changes. Complete blood count changes, including new cell activation parameters, from 982 confirmed COVID-19 adult patients from 11 European hospitals were retrospectively analysed for distinctive patterns based on age, gender, clinical severity, symptom duration, and hospital days. The observed haemocytometric patterns formed the basis to develop a multi-haemocytometric-parameter prognostic score to predict, during the first three days after presentation, which patients will recover without ventilation or deteriorate within a two-week timeframe, needing intensive care or with fatal outcome. The prognostic score, with ROC curve AUC at baseline of 0.753 (95% CI 0.723–0.781) increasing to 0.875 (95% CI 0.806–0.926) on day 3, was superior to any individual parameter at distinguishing between clinical severity. Findings were confirmed in a validation cohort. Aim is that the score and haemocytometry results are simultaneously provided by analyser software, enabling wide applicability of the score as haemocytometry is commonly requested in COVID-19 patients.
Prevalence of Bacterial Leaf Spot of Bottle Gourd and Pumpkin in Subtropical Zone of Himachal Pradesh
Authors: Jarial Kumud , Kumari Sujata , Jarial R. S. , Jandaik Savita , Sharma Deepa
Published: November 2020

To assess the prevalence and severity of bacterial leaf spot on bottle gourd and pumpkin, a survey was conducted in Hamirpur, Una and Bilaspur districts of sub tropical zone of Himachal Pradesh, India during the years 2018 and 2019. Data were recorded in terms of disease severity and fruit rot incidence. The associated pathogen from bottle gourd and pumpkin was isolated on nutrient sodium chloride agar medium and identified on the basis of morphological, biochemical and pathogenicity tests on bottle gourd and pumpkin seedlings. Disease was found to be prevalent at all the locations surveyed exhibiting a mean disease severity from 24.70 to 87.55 and 5.30 to 52.92 per cent in bottle gourd and pumpkin, respectively. Fruits of bottle gourd were recorded to be affected badly exhibiting a mean fruit rot incidence of 10.23 to 95.32 to per cent, while, no fruit rot incidence was recorded in pumpkin fruits. The colonies of the isolated bacterium were mucoid, circular, smooth textured and yellow in colour having a diameter of 2-4 mm. The pathogen was found to be Gram–ve and tested positive for esculin hydrolysis as well as protein digestion test. During pathogenicity tests, incubation period of 2 and 4 days was recorded on bottle gourd and pumpkin, respectively. Based on these studies, the identity of the pathogen was confirmed to be Xanthomonas cucurbitae(ex Bryan) Vauterin et al.
Effect of dental metal artifact conversion volume on dose distribution in head‐and‐neck volumetric‐modulated arc therapy
Authors: Kitagawa Kenta , Ikushima Hitoshi , Sasaki Motoharu , Furutani Shunsuke , Kawanaka Takashi , Kubo Akiko , Tonoiso Chisato , Kudoh Takaharu , Kano Yosuke , Tsuzuki Akira
Published: November 2020

Purpose

During treatment planning for head‐and‐neck volumetric‐modulated arc therapy (VMAT), manual contouring of the metal artifact area of artificial teeth is done, and the area is replaced with water computed tomography (CT) values for dose calculation. This contouring of the metal artifact areas, which is performed manually, is subject to human variability. The purpose of this study is to evaluate and analyze the effect of inter‐observer variation on dose distribution.

Methods

The subjects were 25 cases of cancer of the oropharynx for which VMAT was performed. Six radiation oncologists (ROs) performed metal artifact contouring for all of the cases. Gross tumor volume, clinical target volume, planning target volume (PTV), and oral cavity were evaluated. The contouring of the six ROs was divided into two groups, small and large groups. A reference RO was determined for each group and the dose distribution was compared with those of the other radiation oncologists by gamma analysis (GA).

As an additional experiment, we changed the contouring of each dental metal artifact area, creating enlarged contours (L), reduced contours (S), and undrawn contours (N) based on the contouring by the six ROs and compared these structure sets.

Results

The evaluation of inter‐observer variation showed no significant difference between the large and small groups, and the GA pass rate was 100%. Similar results were obtained comparing structure sets L and S, but in the comparison of structure sets L and N, there were cases with pass rates below 70%.

Conclusions

The results show that the artificial variability of manual artificial tooth metal artifact contouring has little effect on the dose distribution of VMAT. However, it should be noted that the dose distribution may change depending on the contouring method in cases where the overlap between PTV and metal artifact areas is large.
Batch Culture Formulation of Live Biotherapeutic Products
Authors: Qiu Kunyu , Anselmo Aaron C.
Published: November 2020

Live biotherapeutic products (LBPs) are an emerging therapeutic modality that have been clinically investigated for treating pathogenic infections and inflammatory diseases. A major class of LBPs are feces‐derived microbial consortiums which require numerous process development steps (e.g., separation, purification, blending) to facilitate LBP formulation into oral dosage forms. A subset of these LBPs circumvents the need for continuous fecal processing by batch culture for individual strains of microbes that are rationally defined and combined in the final LBP formulation. Separately, delivery formulations (e.g., polymer encapsulation) are being developed for LBPs to improve storage and intestinal engraftment; however, formulation requires additional manufacturing processes distinct from fecal processing or batch culture. Here, a streamlined approach termed batch culture formulation (BCF) is developed to combine the individual batch culture and formulation processes into a single‐step process. Based on a previously described polymeric film formulation that encapsulates LBPs, BCF is shown to reduce the number of required processes to formulate LBP‐films without altering LBP phenotype, function, or storage profiles compared to the standard LBP‐film formulation approach. Additionally, it is demonstrated that BCF facilitates scaled‐fabrication from the milligram to gram scale with predictable loading, highlighting the potential that BCF has for clinical translation.
Fast Proton Insertion in Layered H2W2O7 via Selective Etching of an Aurivillius Phase
Authors: Wang Ruocun , Sun Yangyunli , Brady Alexander , Fleischmann Simon , Eldred Tim B. , Gao Wenpei , Wang Hsiu‐Wen , Jiang De‐en , Augustyn Veronica
Published: November 2020

H2W2O7, a metastable material synthesized via selective etching of the Aurivillius‐related Bi2W2O9, is demonstrated as an electrode for high power proton‐based energy storage. Comprehensive structural characterization is performed to obtain a high‐fidelity crystal structure of H2W2O7 using an iterative approach that combines X‐ray diffraction, neutron pair distribution function, scanning transmission electron microscopy, Raman spectroscopy, and density functional theory modeling. Electrochemical characterization shows a capacity retention of ≈80% at 1000 mV s–1 (1.5‐s charge/discharge time) as compared to 1 mV s–1 (≈16‐min charge/discharge time) with cyclability for over 100 000 cycles. Energetics from density functional theory calculations indicate that proton storage occurs at the terminal oxygen sites within the hydrated interlayer. Last, optical micrographs collected during in situ Raman spectroscopy show reversible, multicolor electrochromism, with color changes from pale yellow to blue, purple, and last, orange as a function of proton content. These results highlight the use of selective etching of layered perovskites for the synthesis of metastable transition metal oxide materials and the use of H2W2O7 as an anode material for proton‐based energy storage or electrochromic applications.
BF3 ⋅ OEt2 Catalyzed Synthesis of 1,3‐Thiazines/‐Selenazines
Authors: Muthusamy Sengodagounder , Malarvizhi Muthukumar , Suresh Eringathodi
Published: November 2020

An efficient strategy for the synthesis of 3,4‐dihydro‐2H‐1,3‐thiazines / 3,4‐dihydro‐2H‐1,3‐selenazines from propargylic alcohols and thioamides/thiosemicarbazones/selenamides is described. The reaction is accomplished in moderate to excellent yield under mild conditions that did not require the exclusion of air or moisture and offers an operationally simplistic and convenient route to the synthetically useful six‐membered N,S/Se‐heterocycles.
Why More Arbitral Filings Has Meant Alternative Dispute Resolution Irony
Authors: Jacobs Roger B.
Published: November 2020

Arbitration is intended to be a simpler remedy than going to court.
Gold‐Catalyzed [3+2]‐Annulations of α‐Aryl Diazoketones with the Tetrasubstituted Alkenes of Cyclopentadienes: High Stereoselectivity and Enantioselectivity
Authors: Chen Ching‐Nung , Cheng Wei‐Min , Wang Jian‐Kai , Chao Tzu‐Hsuan , Cheng Mu‐Jeng , Liu Rai‐Shung
Published: November 2020

This work reports gold‐catalyzed [3+2]‐annulations of α‐diazo ketones with highly substituted cyclopentadienes, affording bicyclic 2,3‐dihydrofurans with high regio‐ and stereoselectivity. The reactions highlights the first success of tetrasubstituted alkenes to undergo [3+2]‐annulations with α‐diazo carbonyls. The enantioselective annulations are also achieved with high enantioselectivity using chiral forms of gold and phosphoric acid. Our mechanistic analysis supports that cyclopentadienes serve as nucleophiles to attack gold carbenes at the more substituted alkenes, yielding gold enolates that complex with chiral phosphoric acid to enhance the enantioselectivity.
The Electron Transfer Process in Mixed Valence Compounds with a Low‐lying Energy Bridge in Different Oxidation States
Authors: Yang Yu‐Ying , Zhu Xiao‐Quan , Launay Jean‐Pierre , Hong Cheng‐Bin , Su Shao‐Dong , Wen Yue‐Hong , Wu Xin‐Tao , Sheng Tian‐Lu
Published: November 2020

Mixed‐valence compounds with the iso‐cyanidometal‐ligand bridge in different oxidation states are used as models for the investigation of the electron‐transfer process. We synthesized a series of trimetallic isocyanidometal‐bridged compounds with [Fe–CN–Ru–NC–Fe]n+ (n=2–4), in which the one‐electron oxidation product (N3+) and two‐electron oxidation product (N4+) compounds possess an isocyanidometal bridge whose energy is, respectively lower and slightly higher than the terminal metal centers energies. For the N3+ compounds, the bridge state (FeII–RuIII–FeII) and mixed‐valence states (FeIII–RuII–FeII or FeII–RuII–FeIII) could be simultaneously observed on the IR timescale. For the N4+ compounds, as the donor becomes stronger the electron transfer bridge excited state (FeIII–RuII–FeIII) becomes more and more stable, and even becomes ground state due to the strong electronic coupling between Fe and Ru.
Design and discovery of new 1,2,4‐triazolo[4,3‐c]quinazolines as potential DNA intercalators and topoisomerase II inhibitors
Authors: Alesawy Mohamed S. , Al‐Karmalawy Ahmed A. , Elkaeed Eslam B. , Alswah Mohamed , Belal Ahmed , Taghour Mohammed S. , Eissa Ibrahim H.
Published: November 2020

A new series of 1,2,4‐triazolo[4,3‐c]quinazoline derivatives was designed and synthesized as Topo II inhibitors and DNA intercalators. The cytotoxic effect of the new members was evaluated in vitro against a group of cancer cell lines including HCT‐116, HepG‐2, and MCF‐7. Compounds 14c, 14d, 14e, 14e, 15b, 18b, 18c, and 19b exhibited the highest activities with IC50 values ranging from 5.22 to 24.24 µM. Furthermore, Topo II inhibitory activities and DNA intercalating affinities of the most promising candidates were evaluated as a possible mechanism for the antiproliferative effect. The results of the Topo II inhibition and DNA binding tests were coherent with that of in vitro cytotoxicity. Additionally, the most promising compound 18c was analyzed in HepG‐2 cells for its apoptotic effect and cell cycle arrest. It was found that 18c can induce apoptosis and arrest the cell cycle at the G2–M phase. Finally, molecular docking studies were carried out for the designed compounds against the crystal structure of the DNA−Topo II complex as a potential target to explore their binding modes. On the basis of these studies, it was hypothesized that the DNA binding and/or Topo II inhibition would participate in the noted cytotoxicity of the synthesized compounds.
Novel N‐benzylpiperidine derivatives of 5‐arylisoxazole‐3‐carboxamides as anti‐Alzheimer's agents
Authors: Saeedi Mina , Felegari Peyman , Iraji Aida , Hariri Roshanak , Rastegari Arezoo , Mirfazli S. Sara , Edraki Najmeh , Firuzi Omidreza , Mahdavi Mohammad , Akbarzadeh Tahmineh
Published: November 2020

The complex pathophysiology of Alzheimer's disease (AD) has prompted researchers to develop multitarget‐directed molecules to find an effective therapy against the disease. In this context, a novel series of N‐(1‐benzylpiperidin‐4‐yl)‐5‐arylisoxazole‐3‐carboxamide derivatives were designed, synthesized, and evaluated against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). In vitro biological evaluation demonstrated that compound 4e was the best AChE (IC50 = 16.07 μM) and BuChE inhibitor (IC50 = 15.16 μM). A kinetic study of 4e was also conducted, which presented a mixed‐type inhibition for both enzymes. Molecular docking studies revealed that compound 4e fitted well into the active sites of AChE and BuChE, forming stable and strong interactions with key residues Glu199, Trp84, Asp72, Tyr121, and Phe288 in AChE and His438, Trp82, Ala328, Tyr332, Phe329, Thr120, and Pro285 in BuChE. Besides, the inhibition of BACE1 by 4e and the biometal chelation activity of 4e were measured. The neuroprotective assessment revealed that 4e exhibited 23.2% protection at 50 µM toward amyloid‐beta‐induced PC12 neuronal cells. Overall, this study exhibited that compound 4e was a promising compound targeting multiple factors associated with AD.
Unravelling the Role of Speciation in Glyme:Ionic Liquid Hybrid Electrolytes for Na−O2 Batteries
Authors: Garcia‐Quintana Laura , Chen Fangfang , Ortiz‐Vitoriano Nagore , Zhang Yafei , O'Dell Luke A. , MacFarlane Douglas R. , Forsyth Maria , Bond Alan M. , Howlett Patrick C. , Pozo‐Gonzalo Cristina
Published: November 2020

The morphology and size of the discharge products in Na−O2 batteries are largely dominated by the interactions of the electrolyte with superoxide and sodium ions; therefore, an in‐depth understanding is essential for achieving high performance batteries. Herein, we report a framework designed to understand solvation and coordination in the recently discovered hybrid electrolytes, based on glyme and a pyrrolidinium ionic liquid. FTIR and NMR spectroscopic techniques, coupled with molecular dynamics simulations, have been used to characterize these systems. We demonstrate that the presence of ionic liquid in the hybrid electrolyte affects the superoxide coordination environment by weakening the glyme‐Na+ interactions, and generating solvent separated ion pairs. All these factors lead to different deposition mechanisms, which will determine the battery performance. The Na+ solvation shell compositions, anion conformers and relative free glyme content are also evaluated. The combinatorial approach used in this study‐experimental and computational – can be applied for further design of these hybrid electrolytes and other metal – O2 chemistries and electrochemical systems.
Optimization of a transient antibody expression platform towards high titer and efficiency
Authors: Greene Elizabeth , Cazacu Daniela , Tamot Ninkka , Castellano Steven , Datar Akshita , Kronkaitis Anthony , Gebhard Douglas , Reed Jon , Mawson Paul , Florin Lore , Rossi Nicholas , Lauer Anthony , Juckem Laura , Nixon Andrew , Wenger Till , Sen Saurabh
Published: November 2020

Transient gene expression (TGE) using mammalian cells is an extensively used technology for the production of antibodies and recombinant proteins and has been widely adopted by both academic and industrial labs. Chinese Hamster Ovary (CHO) cells have become one of the major workhorses for TGE of recombinant antibodies due to their attractive features: post‐translational modifications, adaptation to high cell densities, and use of serum‐free media. In this study, we describe the optimization of parameters for TGE for antibodies from CHO cells. Through a matrix evaluation of multiple factors including inoculum, transfection conditions, amount and type of DNA used, and post‐transfection culture conditions, we arrived at an uniquely optimized process with higher titer and reduced costs and time, thus increasing the overall efficiency of early antibody material supply. We further investigated the amount of coding DNA used in TGE and the influence of kinetics and size of the transfection complex on the in vitro efficiency of the transfection. We present here the first report of an optimized TGE platform using Filler DNA in an early drug discovery setting for the screening and production of therapeutic mAbs.
How to assess visual function in acquired brain injury—Asking is not enough
Authors: Berthold‐Lindstedt Märta , Johansson Jan , Ygge Jan , Borg Kristian
Published: November 2020

Background

Acquired brain injury affects many brain areas and causes a range of dysfunctions including vision‐related issues. These issues can have negative impacts on rehabilitation progress and activities of daily life but may easily be overlooked. There is no common recommendation about how to assess visual impairments after ABI. The purpose of this study was to estimate the frequency of objectively measures oculomotor dysfunctions, and also how these findings are related to two inventories intended to support detection of visual impairment.

Methods

The study was cross‐sectional and included 73 outpatients. In addition to the standard evaluation program, the patients went through a comprehensive optometric examination. The inventories used were the Vision Interview (VI) and the Convergence Insufficiency Symptom Survey (CISS).

Results

All three types of examinations showed a high proportion vision‐related symptoms. Fusion vergence was the most common objectively measured finding, 83%. There were seven statistically significant associations between five VI items and five visual deficits. The strength of associations was moderate (Phi 0.261–0.487, p < .05). The sensitivity and specificity of the CISS were moderate.

Conclusion

We found high percentages of the patients with visual symptoms and dysfunctions. Due to the complexity of visual symptoms and functional deficits in ABI, we find it necessary to combine both symptom assessment and vision examination in order to capture visual function issues.
Catheter directed embolectomy of right atrial clot in transit‐A case series
Authors: Verma Isha , Chang Eric Y , Kumar Gautam , Sachdeva Rajesh
Published: November 2020

In the previous literature, the prevalence of right atrial (RA) clot‐in‐transit associated with pulmonary embolism is around 4–18% with an associated mortality of 80–100% in untreated cases. Surgical thrombo‐embolectomy has been the mainstay of treatment for stable patients but the data for percutaneous thrombo‐embolectomy is lacking in the literature. We present a series of three cases of right atrium clot‐in‐transit treated with catheter‐based therapies with Inari FlowTriever® (Inari Medical, Irvine, CA). Our three patients had different clinical profiles and presentations of right atrial clot‐in‐transit. All of the subjects had contraindications to surgical thrombo‐embolectomy and thrombolytic therapy. Catheter based embolectomy using Inari FlowTriever® was successfully performed in all the patients. As the data on this intervention is sparse, our case series highlights successful catheter based thrombo‐embolectomies in high‐risk individuals with right atrial clot in‐transit with or without pulmonary embolism.
Stable N,N’‐Diarylated Dihydrodiazaacene Radical Cations
Authors: Xie Gaozhan , Bojanowski N. Maximilian , Brosius Victor , Wiesner Thomas , Rominger Frank , Freudenberg Jan , Bunz Uwe H. F.
Published: November 2020

Three stable N,N’‐diarylated dihydroazaacene radical cations were prepared by oxidation of neutral N,N’‐diarylated dihydroazaacenes synthesized via palladium‐catalyzed Buchwald‐Hartwig aminations of aryl iodides with N,N’‐dihydroazaacenes. Both neutral as well as oxidized species were investigated via UV‐vis spectroscopy, single crystal analysis, and DFT calculations. All the radical cations are surprisingly stable—their absorption spectra in dichloromethane remain unchanged in ambient conditions for at least 24 hours.
Dynamic Ion Speciation during the Hydrolysis of Aryltrifluoroborates**
Authors: Omari Isaac , Yunker Lars P. E. , Penafiel Johanne , Gitaari Darlene , San Roman Atzin , McIndoe J. Scott
Published: November 2020

Organotrifluoroborates serve as coupling partners during transmetalation in the Suzuki–Miyaura reaction but require hydrolysis prior to the coupling reaction. Their anionic nature allows study of their hydrolysis by electrospray ionization mass spectrometry (ESI‐MS) through real‐time monitoring, complemented by pH analysis. The induction period varied according to the borates employed, and a dynamic series of equilibria for numerous ions was observed during hydrolysis. We found that the induction periods and reaction rates were sensitive to the R group of the borates, the shape of the reaction vessel, and stir rate.
Phosphorus Ligands from the Zhang Lab: Design, Asymmetric Hydrogenation, and Industrial Applications
Authors: Wan Feng , Tang Wenjun
Published: November 2020

Chiral phosphorus ligands have played a crucial role for the recent advances in asymmetric catalysis. This review summarizes chiral phosphorus ligands developed from the Laboratory of Professor Xumu Zhang in the latest 25 years. A number of iconic phosphorus ligands including bisphosphorus ligands with rigid chiral backbone such as BICP, PennPhos, TunePhos, and f‐Binaphane, P‐chiral bisphosphorus ligands TangPhos, Binapine, and DuanPhos, phosphine‐phosphoramidte ligand YanPhos, noncovalent interaction‐assisted ferrocenyl phosphorus ligand ZhaoPhos and WudaPhos, and tridentate ferrocenyl phosphorus ligands f‐amphox are introduced, and their applications in asymmetric hydrogenation are emphasized.