bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence of CT complex formation between a probe and unreacted methylimidazole in imidazolium cation based ionic liquids: sensing by functionalised 2-benzyledinemalononitrile
Authors: Tiwari Manish Kumar , Das Monika , Saha Satyen
Published: June 2019

A new sensor-based detection and estimation of unreacted methylimidazole in ionic liquids, which can corrupt the photophysical data, is presented.
Smartphone based multispectral imager and its potential for point-of-care testing
Authors: Ding Hui , Chen Chen , Zhao Haicheng , Yue Ying , Han Chunyang
Published: June 2019

A smartphone multispectral imager, containing a bio-inspired MSI chip, is designed and used to analyze skin lesions and dental plaque.
A hydrated strontium cobalt oxyhydroxide Ruddlesden–Popper phase as an oxygen electrocatalyst for aqueous lithium–oxygen rechargeable batteries
Authors: Sonoki Hidetoshi , Mori Daisuke , Taminato Sou , Takeda Yasuo , Yamamoto Osamu , Imanishi Nobuyuki
Published: June 2019

A hydrated oxyhydroxide Ruddlesden–Popper phase, Sr3Co2O5(OH)2·2H2O, enhances oxygen electrocatalytic activity in an aqueous lithium salt solution.
Carbon nitride as a ligand: edge-site coordination of ReCl(CO)3-fragments to g-C3N4
Authors: Coulson Ben , Isaacs Mark , Lari Leonardo , Douthwaite Richard E. , Duhme-Klair Anne-K.
Published: June 2019

IR spectroscopy and model structural studies show binding of ReCl(CO)3-fragments to carbon nitride (g-C3N4) occurs via κ2 N,N′ bidentate coordination.
Development of a novel ionic liquid–curcumin complex to enhance its solubility, stability, and activity
Authors: Chowdhury Md. Raihan , Moshikur Rahman Md , Wakabayashi Rie , Tahara Yoshiro , Kamiya Noriho , Moniruzzaman Muhammad , Goto Masahiro
Published: June 2019

We report a one-step emulsification and rapid freeze-drying process to develop a curcumin–ionic liquid (CCM–IL) complex that could be readily dispersed in water with a significantly enhanced solubility and half-life compared to free CCM.
Fe3O4-Encapsulating N-doped porous carbon materials as efficient oxygen reduction reaction electrocatalysts for Zn–air batteries
Authors: Li Longbin , Li Yizhe , Xiao Yingbo , Zeng Rong , Tang Xiannong , Yang Weizu , Huang Jun , Yuan Kai , Chen Yiwang
Published: June 2019

Fe3O4-Encapsulating N-doped porous carbon was synthesized for Zn–air batteries with higher energy density and better stability than Pt/C equipped devices.
Enhanced autophagy induction via the mitochondrial delivery of methylated β-cyclodextrin-threaded polyrotaxanes using a MITO-Porter
Authors: Yamada Yuma , Daikuhara Shinnosuke , Tamura Atsushi , Nishida Kei , Yui Nobuhiko , Harashima Hideyoshi
Published: June 2019

Failure of autophagy induction results in the accumulation of abnormal mitochondria to cause neurodegenerative diseases.
Chemo-, regio-, and enantioselective synthesis of allylic nitrones via rhodium-catalyzed addition of oximes to allenes
Authors: Wang Yu-Hsuan , Breit Bernhard
Published: June 2019

The first chemo-, regio-, and enantioselective rhodium-catalyzed addition of oximes to allenes is reported.
Trifunctional integrated DNA-based universal sensing platform for detection of diverse biomolecules in one-pot isothermal exponential amplification mode
Authors: Cui Yun-Xi , Feng Xue-Nan , Li Xiao-Yu , Zhang Yu-Peng , Tang An-Na , Kong De-Ming
Published: June 2019

Template constructed with only a short single-stranded DNA is necessary; it is first recognized by the target enzyme, then multiple amplification cycles are initiated, achieving ultra-high sensitivity by a one-pot isothermal reaction.
Reversible ON/OFF switching of photoluminescence from CsPbX3 quantum dots coated with silica using photochromic diarylethene
Authors: Akaishi Yuji , Pramata Azzah Dyah , Tominaga Shuhei , Kawashima Shimpei , Fukaminato Tuyoshi , Kida Tetsuya
Published: June 2019

Highly luminescent silica-coated CsPbX3 quantum dots (QDs) with good photostability were synthesized and coupled with photochromic diarylethene to modulate the QDs’ photoluminescence (PL).
Judging the feasibility of TiO2 as photocatalyst for chemical energy conversion by quantitative reactivity determinants
Authors: Dilla Martin , Moustakas Nikolaos G. , Becerikli Ahmet E. , Peppel Tim , Springer Armin , Schlögl Robert , Strunk Jennifer , Ristig Simon
Published: June 2019

Quantitative reactivity determinants imply that P25-TiO2 has limited applicability in heterogeneous photocatalytic CO2 conversion in the gas-phase.
New insights about the monomer and homodimer structures of the human AOX1
Authors: Ferreira P. , Cerqueira N. M. F. S. A. , Coelho C. , Fernandes P. A. , Romão M. J. , Ramos M. J.
Published: June 2019

We conducted MD simulations to provide a comprehensive study on the human aldehyde oxidase and on the impact that the allosteric inhibitor thioridazine and malonate ions have on its structure, particularly on the catalytic tunnel.
Adsorption of toxic gases on silicene/Ag(111)
Authors: Osborne Dale A. , Morishita Tetsuya , Tawfik Sherif Abdulkader , Yayama Tomoe , Spencer Michelle J. S.
Published: June 2019

Silicene/Ag(111) demonstrates many unique properties, and shows potential in sensing and storage applications of toxic gases such as SO2, NO2and H2S.
A microwave spectroscopic and ab initio study of keto–enol tautomerism and isomerism in the cyclohexanone–water complex
Authors: Gao Jiao , Seifert Nathan A. , Jäger Wolfgang
Published: June 2019

Experimental structure and keto–enol conversion barrier of cyclohexanone–water from microwave spectroscopy and ab initio calculations.
Isomer and conformer selective atmospheric pressure chemical ionisation of dimethyl phthalate
Authors: Michalczuk Bartosz , Moravský Ladislav , Papp Peter , Mach Pavel , Sabo Martin , Matejčík Štefan
Published: June 2019

The ionization mechanism of Atmospheric Pressure Chemical Ionization (APCI) for dimethyl phthalate isomers using an Ion Mobility Spectrometry (IMS) experiment combined with Density Functional Theory (DFT) calculations.
Tunable electronic and optical properties of the WS2/IGZO heterostructureviaan external electric field and strain: a theoretical study
Authors: Tang Hongyu , Tan Chunjian , Yang Huiru , Zheng Kai , Li Yutao , Ye Huaiyu , Chen Xianping , Fan Xuejun , Ren Tianling , Zhang Guoqi
Published: June 2019

The external mechanical strain can efficiently modulate the photoresponse of the WS2/IGZO heterostructure to the UV light and the visible light.
Correction: Maxwell–Stefan diffusion coefficient estimation for ternary systems: an ideal ternary alcohol system
Authors: Allie-Ebrahim Tariq , Zhu Qingyu , Bräuer Pierre , Moggridge Geoff D. , D'Agostino Carmine
Published: June 2019

Correction for ‘Maxwell–Stefan diffusion coefficient estimation for ternary systems: an ideal ternary alcohol system’ by Tariq Allie-Ebrahim et al., Phys. Chem. Chem. Phys., 2017, 19, 16071–16077.
Effect of mixed occupancies on the thermoelectric properties of BaCu6−xSe1−yTe6+y polychalcogenides
Authors: Jafarzadeh Parisa , Rodrigues Maegan R. , Shi Yixuan , Assoud Abdeljalil , Zou Tianze , Kycia Jan B. , Kleinke Holger
Published: June 2019

Increasing the Te amount, y in BaCu6−xSe1−yTe6+y, causes higher electrical conductivity by increasing the Cu deficiencies for steric reasons.
Investigation of the structural, optical and crystallographic properties of Bi2WO6/Ag plasmonic hybrids and their photocatalytic and electron transfer characteristics
Authors: Kavinkumar Veerappan , Verma Atul , Masilamani Sriramkumar , Kumar Sanath , Jothivenkatachalam Kandasamy , Fu Yen-Pei
Published: June 2019

We have fabricated an efficient Bi2WO6-Ag plasmonic hybrid via the photoreduction technique and the obtained materials were well characterized with sophisticated instruments.
DHA protects against monosodium urate-induced inflammation through modulation of oxidative stress
Authors: Zhang Yue , Liu Lu , Sun Dongzhe , He Yongjing , Jiang Yue , Cheng Ka-Wing , Chen Feng
Published: June 2019

DHA and DHA-rich microalgal oil protect against monosodium urate-induced inflammation via regulating oxidative stress and inhibiting NLRP3-mediated inflammatory cytokine secretion.
Charge transfer dynamics in conjugated polymer/MoS2organic/2D heterojunctions
Authors: Petoukhoff Christopher E. , Kosar Sofiia , Goto Manami , Bozkurt Ibrahim , Chhowalla Manish , Dani Keshav M.
Published: June 2019

We demonstrate electron transfer from monolayer MoS2to three different organic semiconducting conjugated polymers.
A carboxylic acid functionalized SBA-15 supported Pd nanocatalyst: an efficient catalyst for hydrogenation of nitrobenzene to aniline in water
Authors: Ganji Saidulu , Bukya Padma , Liu Zhong-Wen , Rao Kamaraju Seetha Rama , Burri David Raju
Published: June 2019

The catalytic performance of a PdNPs/SBA-COOH has been investigated for the first time in the selective hydrogenation of nitrobenzene with hydrous hydrazine at RT in water medium.
Copper-catalyzed synthesis of pyrazolo[5,1-a]isoquinoline derivatives from 2-gem-dipyrazolylvinylbromobenzenes
Authors: Zhao Wan Qiu , Qian Kun , Su Cheng Wu , Shao Lei , Zhou Wei , Cui Dong-Mei , Zhang Chen , Wang Xiu-Li
Published: June 2019

An efficient copper-catalyzed synthesis of pyrazolo[5,1-a]isoquinolines from 2-gem-dipyrazolylvinylbromobenzenes under mild conditions has been developed.
Efficient synthesis and preliminary biological evaluations of trifluoromethylated imidazo[1,2-a]pyrimidines and benzimidazo[1,2-a]pyrimidines
Authors: Jismy Badr , Akssira Mohamed , Knez Damijan , Guillaumet Gérald , Gobec Stanislav , Abarbri Mohamed
Published: June 2019

Fluoromethylated imidazo[1,2-a]pyrimidines and benzimidazo[1,2-a]pyrimidines were synthesized through Michael addition/intramolecular cyclization reaction by condensation of 2-amino imidazole derivatives with ethyl 4,4,4-trifluorobut-2-ynate and using C–O bond activation.
Preparation of a potassium chloride bridged thorium phosphinidiide complex and its reactivity towards small organic molecules
Authors: Wang Yongsong , Zhang Congcong , Zi Guofu , Ding Wanjian , Walter Marc D.
Published: June 2019

The steric and electronic properties of the coordinated ligands modulate the reactivity of thorium phosphinidene complexes.
Reliable detection of o-nitrophenol and p-nitrophenol based on carbon nanotubes covalently functionalized with ferrocene as an inner reference
Authors: Pang Shasha , Kan Xianwen
Published: June 2019

Developing an accurate and sensitive method for the detection of environmental pollutants is of great significance.
Transforming layered MoS2 into functional MoO2 nanowires
Authors: Vogl Lilian M. , Schweizer Peter , Wu Mingjian , Spiecker Erdmann
Published: June 2019

A new in situ synthesis method for the growth of MoO2 nanowires via the controlled thermal oxidation of MoS2 flakes is presented and the electrical, field emission and mechanical properties of single nanowires are studied.
Nature-inspired salt resistant polypyrrole–wood for highly efficient solar steam generation
Authors: Huang Wei , Hu Gaoyue , Tian Cheng , Wang Xiaohong , Tu Jinchun , Cao Yang , Zhang Kexi
Published: June 2019

Solar steam generation has emerged as a promising and sustainable method of addressing the water shortage issue. The fabricated PPy–wood exhibits high solar energy conversion efficiency and excellent salt resistant performance.
NiS–MoS2 hetero-nanosheet array electrocatalysts for efficient overall water splitting
Authors: Guan Shundong , Fu Xiuli , Lao Zhezhu , Jin Chuanhong , Peng Zhijian
Published: June 2019

A facile synthesis method to optimize the synergistic catalytic effect between NiS and MoS2 for highly efficient overall water splitting performance.
Nonequilibrium Monte Carlo simulations of entangled polymer melts under steady shear flow
Authors: Roh Eun Jung , Baig Chunggi
Published: June 2019

Atomistic snapshots of a C400H802entangled polyethylene melt system at equilibrium and nonequilibrium states in shear flow, as generated by the GENERIC Monte Carlo method based on expanded nonequilibrium thermodynamic formalism.
Association of STAT3 and STAT4 polymorphisms with susceptibility to chronic hepatitis B virus infection and risk of hepatocellular carcinoma: a meta-analysis
Authors: Shi Han , He Hongyan , Ojha Suvash Chandra , Sun Changfeng , Fu Juan , Yan Mao , Deng Cunliang , Sheng Yunjian
Published: June 2019

Background: It has been reported that polymorphisms of signal transducer and activator of transcription (STAT) 3 and STAT4 might be associated with susceptibility to hepatitis B virus (HBV) infection and risk of chronic hepatocellular carcinoma (HCC). Owing to limitation of sample size and inconclusive results, we conducted a meta-analysis to clarify the association. Methods: We identified relevant studies by a systematic search of Medline/PubMed, Embase, Web of Science and the Cochrane Library up to 20 February 2019. The strength of the association measured by odds ratios (OR) with 95% confidence intervals (CIs) was studied. All the statistical analyses were conducted based on Review Manager 5.3 software. Results: A total of 5242 cases and 2717 controls from five studies were included for the STAT3 polymorphism, 5902 cases and 7867 controls from nine studies for the STAT4 polymorphism. Our results suggested that STAT3 rs1053004 polymorphism was a significant risk factor of chronic HBV infection (C vs. T: OR = 1.17, 95% CI: 1.07–1.29, PA=0.0007; CC + CT vs. TT: OR = 1.38, 95% CI: 1.09–1.76, PA=0.008). Validation with all the genetic models revealed that rs7574865 polymorphism of STAT4 gene was closely associated with chronic HBV infection (PA<0.01) and chronic hepatitis B (CHB)-related HCC (PA<0.05). Meanwhile, the authenticity of the above meta-analysis results was confirmed by trial sequential analysis (TSA). Conclusions: The meta-analysis showed that STAT3 rs1053004 polymorphism may be the risk for developing chronic HBV infection but not associated with HCC. The present study also indicates that STAT4 rs7574865 polymorphism increased the risk of chronic HBV infection and HCC.
Near-Earth asteroids spectroscopic survey atIsaac NewtonTelescope
Authors: Popescu M. , Vaduvescu O. , de León J. , Gherase R. M. , Licandro J. , Boacă I. L. , Şonka A. B. , Ashley R. P. , Močnik T. , Morate D. , Predatu M. , De Prá M. , Fariña C. , Stoev H. , Díaz Alfaro M. , Ordonez-Etxeberria I. , López-Martínez F. , Errmann R.
Published: June 2019

Context.The population of near-Earth asteroids (NEAs) shows a large variety of objects in terms of physical and dynamical properties. They are subject to planetary encounters and to strong solar wind and radiation effects. Their study is also motivated by practical reasons regarding space exploration and long-term probability of impact with the Earth.

Aims.We aim to spectrally characterize a significant sample of NEAs with sizes in the range of ~0.25–5.5 km (categorized as large), and search for connections between their spectral types and the orbital parameters.

Methods.Optical spectra of NEAs were obtained using theIsaac NewtonTelescope (INT) equipped with the IDS spectrograph. These observations are analyzed using taxonomic classification and by comparison with laboratory spectra of meteorites.

Results.A total number of 76 NEAs were observed. We spectrally classified 44 of them as Q/S-complex, 16 as B/C-complex, eight as V-types, and another eight belong to the remaining taxonomic classes. Our sample contains 27 asteroids categorized as potentially hazardous and 31 possible targets for space missions including (459872) 2014 EK24, (436724) 2011 UW158, and (67367) 2000 LY27. The spectral data corresponding to (276049) 2002 CE26 and (385186) 1994 AW1 shows the 0.7μm feature which indicates the presence of hydrated minerals on their surface. We report that Q-types have the lowest perihelia (a median value and absolute deviation of 0.797 ± 0.244 AU) and are systematically larger than the S-type asteroids observed in our sample. We explain these observational evidences by thermal fatigue fragmentation as the main process for the rejuvenation of NEA surfaces.

Conclusions.In general terms, the taxonomic distribution of our sample is similar to the previous studies and matches the broad groups of the inner main belt asteroids. Nevertheless, we found a wide diversity of spectra compared to the standard taxonomic types.
Umgang mit Spannungen und Krisen in der therapeutischen Beziehung: Erste Erfahrungen mit einem handlungsorientierten Ausbildungs- und Supervisionskonzept
Authors: Gumz Antje , Reuter Laurence , Flückiger Christoph , Marx Christopher , Rugenstein Kai , Schlipfenbacher Carina , Schmidt Lisa , Munder Thomas
Published: June 2019

Ziele Das allianzfokussierte Training (AFT) 1 schult therapeutische Kompetenzen, die für den Umgang mit Spannungen und Krisen in der therapeutischen Beziehung hilfreich sind unter Einsatz von Videoaufzeichnungen und Rollenspielen. Ziel der von der Heigl-Stiftung geförderten Pilotstudie war es, erste klinische Erfahrungen und Ergebnisse mit AFT im deutschsprachigen Raum vorzustellen und eine RCT-Folgestudie vorzubereiten.

Methoden 7 Ausbildungskandidaten nahmen teil. Therapien von 15 Patienten mit depressiver Störung wurden analysiert.

Ergebnisse und Schlussfolgerung AFT wurde als sehr hilfreich für die professionelle Entwicklung und den Umgang mit Spannungen und Krisen erlebt. Die therapeutische Kompetenz verbesserte sich signifikant im Selbsterleben und aus Beobachterperspektive. Die Ergebnisse sprechen dafür, dass AFT eine vielversprechende Möglichkeit zur Verbesserung der Psychotherapieausbildung ist und sich die Durchführung eines RCT zum Nachweis der Wirksamkeit lohnt.
Nonthyroidal Illness Syndrome in Ischaemic Stroke Patients is
Associated with Increased Mortality
Authors: Taroza Saulius , Rastenytė Daiva , Podlipskytė Aurelija , Kazlauskas Henrikas , Mickuvienė Narseta
Published: June 2019

Background Results of studies on associations between triiodothyronine
serum levels and mortality after acute ischemic stroke (AIS) are inconsistent.
Therefore, the aim of this prospective study was to evaluate links between serum
levels of thyroid axis associated hormones and all-cause mortality during 1 year
after AIS.

Methods and results This study involved 255 patients with AIS. Patients
were divided into two groups: those who survived 1 year after their index stroke
and those who not, and by quartiles of free triiodothyronine (FT3) and
ΔFT3 (difference between basal FT3 and repeated FT3 on discharge)
hormone serum concentrations. To assess serum levels of thyroid stimulating
hormone (TSH), FT3 and free tetraiodothyronine (FT4), venous blood was taken
from all included patients on admission to hospital. On discharge, blood tests
were repeated for 178 (69.8%) patients. Study endpoints were overall
mortality within 30, 90 and 365 days after AIS.

Results Compared with the survivals, those who died had significantly
lower mean FT3, FT3/FT4 ratio in all periods and lower median TSH within
30 days. Higher FT3 serum levels versus lower, even after adjustment for
included important variables, remained significant for lower odds of death
within 365 days after AIS (OR=0.57; 95% CI: 0.33–0.97,
p=0.04), but added insignificant additional predictive value
to the NIHSS score or age. Kaplan–Meier survival curves demonstrated
that the first FT3 quartile was significantly associated with increased
mortality compared with all other quartiles within 365 days after AIS. With
ΔFT3 quartiles no such association was found.

Conclusions. Higher FT3 levels on admission versus lower are
significantly associated with lower mortality within 365 days after AIS. FT3
serum levels changes over time didn’t show any association with
mortality within first year.
Supporting the Development of Clinical Reasoning of Preprofessional Novices in Dysphagia Management
Authors: Doeltgen Sebastian , Attrill Stacie , Murray Joanne
Published: June 2019

Proficient clinical reasoning is a critical skill in high-quality, evidence-based management of swallowing impairment (dysphagia). Clinical reasoning in this area of practice is a cognitively complex process, as it requires synthesis of multiple sources of information that are generated during a thorough, evidence-based assessment process and which are moderated by the patient's individual situations, including their social and demographic circumstances, comorbidities, or other health concerns. A growing body of health and medical literature demonstrates that clinical reasoning skills develop with increasing exposure to clinical cases and that the approaches to clinical reasoning differ between novices and experts. It appears that it is not the amount of knowledge held, but the way it is used, that distinguishes a novice from an experienced clinician. In this article, we review the roles of explicit and implicit processing as well as illness scripts in clinical decision making across the continuum of medical expertise and discuss how they relate to the clinical management of swallowing impairment. We also reflect on how this literature may inform educational curricula that support SLP students in developing preclinical reasoning skills that facilitate their transition to early clinical practice. Specifically, we discuss the role of case-based curricula to assist students to develop a meta-cognitive awareness of the different approaches to clinical reasoning, their own capabilities and preferences, and how and when to apply these in dysphagia management practice.
Management of Guillain-Barré Syndrome
Authors: Gopalakrishna Kadarapura N. , Ramesh Venkatapura J.
Published: June 2019

Guillain-Barré syndrome (GBS) is the most common, immune-mediated acute polyneuropathy characterized by variable degree of motor weakness, often presenting with quadriparesis. GBS with respiratory failure requiring endotracheal intubation with mechanical ventilation is common, affecting approximately 30% of patients. In addition, they present with sensory features, cranial nerve involvement, and autonomic disturbance. The majority of GBS patients have preceding respiratory tract infection or gastroenteritis. The diagnosis of GBS is based on clinical features supported by cerebrospinal fluid (CSF) examination and nerve conduction studies. Early course of the GBS requires meticulous monitoring and early initiation of immunotherapy. Plasma exchange (PE) and intravenous immunoglobulin (IVIg) are the proven therapies, and both have been shown to be equally effective. General supportive care is an important part of management of GBS. A multidisciplinary approach to prevent and manage potential complications in rapidly progressing GBS is important to reduce morbidity and mortality.
Clinical Decision Making with Head and Neck Cancer Patients with Dysphagia
Authors: Starmer Heather , Edwards Jeffrey
Published: June 2019

Dysphagia is a common challenge faced by patients with head and neck cancer. Management of these patients is quite distinct from many other dysphagia etiologies due to the nature of surgical removal of organs critical to swallowing, the ability to provide preventative therapies, and the variable risk for complications related to dysphagia. Thus, clinicians providing care to the head and neck cancer population need to understand these differences when employing clinical decision making. In addition, changes in the demographics of head and neck cancer, related predominantly to the epidemic of oropharyngeal cancer associated with the human papillomavirus, have further transformed both the types of patients and the types of treatments offered. These epidemiologic factors further complicate the decision-making process for clinicians. This article provides a framework for decision making in the surgical and nonsurgical patient with head and neck cancer.
Cannabis auf Rezept zur Schmerztherapie
Authors: Herz Mona
Published: June 2019

Seit März 2017 können Ärzte Cannabisblüten oder -extrakte Patienten verordnen,
die an einer schwerwiegenden Erkrankung leiden. Das Gesetz legitimiert die
Hanftherapie, wenn diese den Krankheitsverlauf verbessern und
Symptome lindern kann. Doch nicht jeder ist für den Medizinalhanf geeignet.
Microstructural evolution of single-crystal magnesium under elevated temperature and ultra-high strain rate
Authors: Wang Shengtao , Pan Hao , Wang Pei , Zhang Fengguo
Published: June 2019

Despite numerous studies of the deformation behavior of magnesium (Mg), its microstructural evolution at different temperatures and strain rates remains largely unexplored. In this paper, the evolution of dislocations and amorphous regions in single-crystal Mg under compressive loading along the c-axis is investigated using molecular dynamics simulations, and temperature and strain-rate dependence of the microstructural evolution is revealed. At a strain rate of 107 s−1, the dislocations are low in density, and they slip and evolve unevenly as the strain in the single crystal increases. Consequently, the stress in the single crystal varies in a zigzag manner with increasing strain. The dislocation density is higher at strain rates of 108 s−1 and 109 s−1, resulting in relatively smooth deformation and stress–strain curves. At a strain rate of 1010 s−1, the amorphous regions achieve a very high fraction during deformation, contributing to softening and smoother deformation of the single crystal. The fraction of amorphous regions also increases with increasing temperature, which is an important cause of the temperature softening effect. Furthermore, the initiation of dislocations and amorphous regions is also studied at different strain rates and temperatures.
Theory of electron transport and emission from a semiconductor nanotip
Authors: Piryatinski Andrei , Huang Chengkun , Kwan Thomas J. T.
Published: June 2019

An effective mass based model accounting for the conduction band quantization in a high aspect ratio semiconductor nanotip is developed to describe injected electron transport and subsequent electron emission from the nanotip. A transfer matrix formalism is used to treat electron scattering induced by the variation in the tip diameter and in the electron emission. Numerical analysis of the scattering and emission probabilities is performed for the diamond parametrized nanotip model. Our scattering and emission models are further combined with a Monte Carlo (MC) approach to simulate electron transport through the nanotip. The MC simulations, also accounting for the electron-phonon scattering and externally applied electric field, are performed for a minimal nanotip model and an equivalent width diamond slab. An effect of the level quantization, electron scattering due to the nanotip diameter variation, and electron-phonon scattering on the nanotip emission properties are identified and compared with the case of a bulk slab.
On the stem diameter under positive impulses in long air gaps
Authors: Xiao Pei , He Junjia , Zhao Xiangen , Yang Yongchao , shah Wahab Ali
Published: June 2019

The diameter of a stem, a common origin point for streamers where the transition from the streamer to the leader takes place, has a significant effect on the simulation of streamer-to-leader transition. To measure the diameter of the stem, a schlieren system was established with the temporal and spatial resolutions of 5 μs and 70 μm, respectively. Experiments were conducted under positive lightning and switching impulses; the applied voltage, discharge current, and schlieren images were recorded synchronously. A method was proposed to measure the diameter of the stem based on the schlieren images, with which the stem diameter as a function of time was obtained. Moreover, the initial diameters of the stem under different conditions were obtained through the linear fitting. At last, a relation between the initial cross-sectional area of the stem and the discharge current was given within a certain range.
Explicitly correlated renormalized second-order Green’s function for accurate ionization potentials of closed-shell molecules
Authors: Teke Nakul K. , Pavošević Fabijan , Peng Chong , Valeev Edward F.
Published: June 2019

We present an energy-dependent explicitly correlated (F12) formalism for the nondiagonal renormalized second-order (NR2) Green’s function method of closed-shell molecules. For a test set of 21 small molecules, the mean basis set error in IP computed using NR2-F12 with aug-cc-pVTZ basis is 0.028 eV, compared to 0.044 eV for NR2 with aug-cc-pV5Z basis. Similarly, for a set of 24 medium-sized organic electron acceptor molecules (OAM24), the mean basis set errors are 0.015 eV for NR2-F12 with aug-cc-pVTZ basis compared to 0.067 eV for NR2 with aug-cc-pVQZ basis. Hence, NR2-F12 facilitates accurate calculation of IP at a lower cost compared to the NR2 method. NR2-F12 has O(N6)/O(N5) noniterative/iterative costs with system size. At a small basis, the performance of NR2-F12 for 21 small molecules and OAM24 dataset is comparable to equation-of-motion ionized coupled-cluster singles and doubles, whose cost is iterative O(N6).
Single-photon light-emitting diodes based on preselected quantum dots using a deterministic lithography technique
Authors: Sartison Marc , Seyfferle Simon , Kolatschek Sascha , Hepp Stefan , Jetter Michael , Michler Peter , Portalupi Simone Luca
Published: June 2019

In the present study, we developed a deterministic fabrication process for an electrically driven single-photon light-emitting diode based on InP quantum dots (QDs) emitting in the red spectral range, where the wavelength of interest coincides with the high efficiency window of most commonly available standard Si avalanche photodiodes (APDs). A deterministic lithography technique allowed for the preselection of a suitable QD, here exclusively operated under electrical carrier injection. The final device was characterized under micro-electroluminescence in the direct current as well as in pulsed excitation mode. In particular, under pulsed excitation of one device, single-photon emission has been observed with graw(2)(0)=0.42 ± 0.02, where the nonzero g(2)-value is mainly caused by background contribution in the spectrum and re-excitation processes due to the electrical pulse length. The obtained results constitute an important step forward in the fabrication of electrically driven single-photon sources, where deterministic lithography techniques can be used to sensibly improve the device performances. In principle, the developed process can be extended to any desired emitter wavelength above 600 nm up to the telecom bands.
High-pressure deformation and amorphization in boron carbide
Authors: Awasthi Amnaya P. , Subhash Ghatu
Published: June 2019

Icosahedral boron-rich solids fall second in hardness to diamondlike structures and have been the subject of intense investigations over the past two decades, as they possess low density, high thermal, and mechanical stability at high temperatures, and superior industrial manufacturability. A common deleterious feature called “presssure-induced amorphization,” limits their performance in high-velocity projectile applications. This article discusses spectral characteristics of amorphized states of boron carbide, a common icosahedral boron-rich ceramic, with the goal of understanding the mechanistic layout of pressure-induced amorphization. Mystery has surrounded the appearance of new peaks in Raman spectrum of pressure-induced amorphized boron carbide, but to date, no convincing explanation exists on their origin. Shock studies of boron carbide have proposed phase transformation at high pressures, but to date, no conclusive evidence has been corroborative to prove the existence of new high-pressure phases. We propose a new rationale toward deciphering the amorphization phenomenon in boron carbide centered on a thermodynamic approach to explain atomic interactions in amorphous islands. Quantum mechanical simulations are utilized to understand the impact of stresses on Raman spectra, while results from molecular dynamics (MD) simulations of volumetric compression are used to understand thermodynamic aspects of amorphization. Atomic-level nonbonded interactions from the MD potential are utilized to demonstrate origins of the residual pressure. Combining these efforts, the present study deciphers the connection between deformation behavior of boron carbide at high pressure and its mysterious amorphous Raman spectrum. The approach highlights the importance of meticulously incorporating multiscale modeling considerations in determining accurate material behavior of ultrahard materials.
Ultrastable and polyamorphic states of vapor-deposited 2-methyltetrahydrofuran
Authors: Riechers Birte , Guiseppi-Elie A. , Ediger M. D. , Richert Ranko
Published: June 2019

This work reports results gained from dielectric spectroscopy on the organic molecular glass-former 2-methyltetrahydrofuran (MTHF), which was deposited onto an interdigitated electrode device by physical vapor deposition. By a suitable selection of preparation parameters (deposition temperature, deposition rate, and annealing conditions), various states of MTHF could be created: ultrastable glass, a liquid state with unusual dielectric properties, or the ordinary liquid state as obtained by supercooling. Observations on kinetic stability as well as on the suppression of dielectric loss in the ultrastable state resemble previous findings for other molecular glass-formers. Remarkably, after annealing just above Tg, all vapor-deposited films of MTHF display a static dielectric constant in the liquid state (εs) that is up to a factor of two below that of the ordinary bulk liquid. A structural transition to the ordinary liquid-cooled state of MTHF occurs at temperatures far above its conventional Tg, indicative of polyamorphism: the formation of an unusual structure that is achieved by physical vapor deposition and that differs from the ordinary liquid state obtained by supercooling. The present results also reveal that the dielectric constant of the as deposited glass (ε∞) is reduced to practically the value of the squared refractive index, n2.
Screening billions of candidates for solid lithium-ion conductors: A transfer learning approach for small data
Authors: Cubuk Ekin D. , Sendek Austin D. , Reed Evan J.
Published: June 2019

Machine learning (ML) methods have the potential to revolutionize materials design, due to their ability to screen materials efficiently. Unlike other popular applications such as image recognition or language processing, large volumes of data are not available for materials design applications. Here, we first show that a standard learning approach using generic descriptors does not work for small data, unless it is guided by insights from physical equations. We then propose a novel method for transferring such physical insights onto more generic descriptors, allowing us to screen billions of unknown compositions for Li-ion conductivity, a scale which was previously unfeasible. This is accomplished by using the accurate model trained with physical insights to create a large database, on which we train a new ML model using the generic descriptors. Unlike previous applications of ML, this approach allows us to screen materials which have not necessarily been tested before (i.e., not on ICSD or Materials Project). Our method can be applied to any materials design application where a small amount of data is available, combined with high details of physical understanding.
Fluid dynamics of oscillatory flow in three-dimensional branching networks
Authors: Pradhan Kaustav , Guha Abhijit
Published: June 2019

The present study is aimed at understanding and thoroughly documenting the complex unsteady fluid dynamics in six generations of a model human bronchial tree, comprising 63 straight sections and 31 bifurcation modules, during a complete breathing cycle. The computational task is challenging since the complexity of an elaborate network is augmented with adopted stringent criteria for spatial and temporal accuracy and convergence at each time step (10−8 for each scaled residual). The physical understanding of the fluid dynamics of steady expiratory flow is taken to a similar level of fine details that have been previously established for steady inspiratory flow in earlier publications of the authors. The effects of three-dimensional arrangement of the same branches on the oscillatory flow structure are determined. It is found that the quasisteady assumption is approximately valid in the neighborhood of the peak flow rate, both during inspiration and expiration. Unsteady effects are at their maximum during the changeover from expiration to inspiration and inspiration to expiration. At these time instants, regions of bidirectional flow are observed in all branches with significant secondary motion at various cross sections (none of these features can be predicted by steady state simulations). It is described how the symmetry of the solution with respect to both space and time—found in the oscillating, fully developed flow in a pipe—are destroyed in the unsteady effects that occur in the oscillating flow in a branching network. As the Womersley number is increased, the unsteady effects at all branches increase, and bidirectional flow exists over a greater portion of a cycle. The flow division at a bifurcation module during inspiratory flow generates large asymmetry in the flow field with nonuniform mass flow distribution among the branches of a generation (even in a geometrically symmetric network), whereas flow combination at the same bifurcation module during expiratory flow tends to produce more symmetry in the flow field, displaying essential irreversibility of fluid dynamics.
Simulations of water structure and the possibility of ice nucleation on selected crystal planes of K-feldspar
Authors: Soni Abhishek , Patey G. N.
Published: June 2019

Molecular dynamics simulations are employed to investigate the structure of supercooled water (230 K) in contact with the (001), (010), and (100) surfaces of potassium feldspar (K-feldspar) in the microcline phase. Experimentally, K-feldspar and other feldspar minerals are known to be good ice-nucleating agents, which play a significant role in atmospheric science. Therefore, a principal purpose of this work is to evaluate the possibility that the K-feldspar surfaces considered could serve as likely sites for ice nucleation. The (001) and (010) surfaces were selected for study because they are perfect cleavage planes of feldspar, with (001) also being an easy cleavage plane. The (100) surface is considered because some experiments have suggested that it is involved in ice nucleation. Feldspar is modeled with the widely used CLAYFF force field, and the TIP4P/Ice model is employed for water. We do not observe ice nucleation on any of the K-feldspar surfaces considered; moreover, the density profiles and the structure of water near these surfaces do not exhibit any particularly icelike features. Our simulations indicate that these surfaces of K-feldspar are likely not responsible for its excellent ice nucleating ability. This suggests that one must look elsewhere, possibly at water-induced surface rearrangements or some other “defect” structure, for an explanation of ice nucleation by K-feldspar.
Structural and electronic properties of two-dimensional atomically thick (100) diamond nanofilms by first-principles calculations
Authors: Sun Zhaolong , Qiu Dongchao , Gao Nan , Li Hongdong
Published: June 2019

In this work, the structural and electronic properties of two-dimensional (2D) atomically thick (100) diamond nanofilms are investigated by first-principles calculations. The results of phonon dispersion curves and ab initio molecular dynamics simulations indicate that the nanofilms are dynamically and thermally stable with three types of reconstructed surfaces (named 5-MR, 5-7-MR, and 5/5-7-MR). The bandgaps (Eg) of the nanofilms with 5-MR and 5-7-MR patterns are in regions of 1.02–1.40 eV and 0.32–0.55 eV, respectively, and an oscillatory phenomenon of Eg appears related to parity of the layer number. The nanofilms with the 5/5-7-MR pattern show a metallic feature. The variations in Eg are determined by surface states with different configurations. These novel diamond-based structures may be useful for applications such as 2D semiconductors in diamond-based electronic devices.
Equation of state and phase evolution of U-7.7Nb with implications for the understanding of dynamic behavior of U-Nb alloys
Authors: Zhang Jianzhong , Hackenberg Robert E. , Vogel Sven C. , Brown Donald W.
Published: June 2019

In this work, we conducted in-situ high P-T neutron diffraction experiments on U-7.7Nb. Our results show that the tetragonal γo phase is substantially more compressible than the monoclinic α′′ phase. As the pressure increases, this leads to increased volume collapse and stress relaxation for the reverse martensitic transformation, α′′ → γo. At moderately elevated temperatures, a substantial strain-induced stabilization against transformation into a body centered cubic γ phase was observed in the γo phase. We also found that the ability to retain the metastable γ phase, formed from rapid heating of thermally reset γo, has subtle dependence on the austenitization temperature. The present findings provide a direct test for the hypotheses proposed to explain the low-pressure shock behaviors of the U-Nb alloys.
Bowling water drops on water surface
Authors: Law Kiat Li , Chu Hong-Yu
Published: June 2019

In our daily experience, the drops falling on a water pool usually immediately merge into water. The liquid drops floating at different environments are fascinating but attract less attention. Here, we report that the water drops are capable of floating on a water surface without heating, shearing, or oscillating the water pool. Water drops are generated from a beveled needle and fall on the clean water in an acrylic container. Water drops released from a beveled needle are found to travel on the water surface in a speed of tens of millimeter/second for several centimeters, which can be adjusted by the injection rate. A particle image velocimetry (PIV) technique is employed on the air, water drop, and water pool to confirm the rotation-induced shear effect for the delay coalescence. TiO2 particles and water aerosols served as visualized particles for PIV measurements in air, drop, and water pool. We show that the water drop can float on the water surface if it rotates or slides fast enough. The relative motion of the drop and the underneath surface plays an important role in the delay coalescence. The flow in the air layer between the drop and water pool not only shears the drop but also replenishes the loss of squeeze-out air in the thin layer.
Optically tailored trapping geometries for ultracold atoms on a type-II superconducting chip
Authors: Tosto Francesca , Baw Swe Phyo , Nguyen Nghia Tin , Hufnagel Christoph , Martínez Valado María , Prigozhin Leonid , Sokolovsky Vladimir , Dumke Rainer
Published: June 2019

Superconducting atom chips have very significant advantages in realizing trapping structures for ultracold atoms compared to conventional atom chips. We extend these advantages further by developing the ability to dynamically tailor the superconducting trap architecture. Heating the chosen parts of a superconducting film by transferring optical images onto its surface, we are able to modify the current density distribution and create desired trapping potentials. This method enables us to change the shape and structure of magnetic traps, enabling versatile applications in atomtronics.
Interaction mechanism between the focused ultrasound and lipid membrane at the molecular level
Authors: Man Viet Hoang , Li Mai Suan , Wang Junmei , Derreumaux Philippe , Nguyen Phuong H.
Published: June 2019

Focused ultrasound (FUS) has a wide range of medical applications. Nowadays, the diagnostic and therapeutic ultrasound procedures are routinely used; effects of ultrasound on biological systems at the molecular level are, however, not fully understood. Experimental results on the interaction of the cell membrane, a simplest but important system component, with ultrasound are controversial. Molecular dynamics (MD) simulations could provide valuable insights, but there is no single study on the mechanism of the FUS induced structural changes in cell membranes. With this in mind, we develop a simple method to include FUS into a standard MD simulation. Adopting the 1,2-dioleoyl-sn-glycero-3-phosphocholine lipid membrane as a representative model described by the MARTINI coarse-grained force field, and using experimental values of the ultrasound frequency and intensity, we show that the heat and bubble cavitation are not the primary direct mechanisms that cause structural changes in the membrane. The spatial pressure gradients between the focused and free regions and between the parallel and perpendicular directions to the membrane are the origin of the mechanism. These gradients force lipids to move out of the focused region, forming a lipid flow along the membrane diagonal. Lipids in the free region move in the opposite direction due to the conservation of the total momentum. These opposite motions create wrinkles along the membrane diagonal at low FUS intensities and tear up the membrane at high FUS intensities. Once the membrane is torn up, it is not easy to reform. The implication of our findings in the FUS-induced drug delivery is discussed in some detail.
Borders and boundaries in the state-making of Eritrea: revisiting the importance of territorial integrity in the rapprochement between Eritrea and Ethiopia
Authors: Müller Tanja R.
Published: June 2019

In this article, the author analyses Eritrean state-making and its foreign policy as driven by the quest for territorial integrity. The article first demonstrates the importance of creating a territorial nation-state for Eritrean nationalism. It subsequently provides an interpretation of Eritrean foreign policy through the lens of the importance of territorial integrity. The article then reflects on how this has underpinned the recent rapprochement between Eritrea and Ethiopia. It ends with some thoughts on what these developments might mean for the future of Eritrea and the wider geopolitical environment of the Horn.
Reactive knee stiffening strategies between various conditioning histories
Authors: Oates D Craig , Needle Alan R. , Kaminski Thomas W. , Royer Todd D. , Swanik C Buz
Published: June 2019

Optimizing joint stiffness through appropriate muscular activation is crucial for maintaining stability and preventing injury. Conditioning techniques may affect joint stability by increasing joint stiffness and altering neuromuscular control; however no studies have assessed this in a controlled setting. Fifteen endurance athletes, 12 power athletes, and 15 control subjects sat on a stiffness device that generated a rapid knee flexion perturbation and were instructed to react to the perturbation. Main outcome measures included short‐range (0–4°) and long range (0–40°) stiffness and muscle activation from quadriceps and hamstring muscles. Stiffness results revealed greater short‐range stiffness in endurance athletes (0.057 ± 0.012 Nm/deg/kg) than controls (0.047 ± 0.008 Nm/deg/kg, p = 0.021); while passive long‐range stiffness was greater in power (0.0020 ± 0.001 nm/deg/kg) than endurance athletes (0.0016 ± 0.001 nm/deg/kg, p = 0.016). Endurance athletes had greater reactive stiffness (0.051 ± 0.017 nm/deg/kg) than control (0.033 ± 0.011 nm/deg/kg, p = 0.001) and power (0.037 ± 0.015 nm/deg/kg, p = 0.044) groups. Endurance athletes also displayed greater quadriceps activity during passive and reactive conditions (p < 0.050) compared to power athletes and controls. These findings suggest that power‐based training history may be associated with greater passive joint stiffness across the full range of motion, while endurance‐based training could positively influence reactive muscular characteristics, as well as resting muscle tone. These unique variations in stiffness regulation could be beneficial to programmes for prevention and rehabilitation of joint injury.