bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemotyping the distribution of vitamin D metabolites in human serum
Authors: Müller Miriam J. , Stokes Caroline S. , Lammert Frank , Volmer Dietrich A.
Published: February 2016

Most studies examining the relationships between vitamin D and disease or health focus on the main 25-hydroxyvitamin D3 (25(OH)D3) metabolite, thus potentially overlooking contributions and dynamic effects of other vitamin D metabolites, the crucial roles of several of which have been previously demonstrated. The ideal assay would determine all relevant high and low-abundant vitamin D species simultaneously. We describe a sensitive quantitative assay for determining the chemotypes of vitamin D metabolites from serum after derivatisation and ultra-high performance liquid chromatography-electrospray ionisation-tandem mass spectrometry (UHPLC-ESI-MS/MS). We performed a validation according to the ‘FDA Guidance for Industry Bioanalytical Method Validation’. The proof-of-concept of the method was then demonstrated by following the metabolite concentrations in patients with chronic liver diseases (CLD) during the course of a vitamin D supplementation study. The new quantitative profiling assay provided highly sensitive, precise and accurate chemotypes of the vitamin D metabolic process rather than the usually determined 25(OH)D3 concentrations.
A Mendelian randomization study of testosterone and cognition in men
Authors: Zhao Jie V. , Lam Tai Hing , Jiang Chaoqiang , Cherny Stacey S. , Liu Bin , Cheng Kar Keung , Zhang Weisen , Leung Gabriel M. , Schooling C Mary
Published: February 2016

Testosterone replacement for older men is increasingly common, with some observations suggesting a protective effect on cognitive function. We examined the association of endogenous testosterone with cognitive function among older men in a Mendelian randomization study using a separate-sample instrumental variable (SSIV) analysis estimator to minimize confounding and reverse causality. A genetic score predicting testosterone was developed in 289 young Chinese men from Hong Kong, based on selected testosterone-related single nucleotide polymorphisms (rs10046, rs1008805 and rs1256031). The association of genetically predicted testosterone with delayed 10-word recall score and Mini-Mental State Examination (MMSE) score was assessed at baseline and follow-up using generalized estimating equation among 4,212 older Chinese men from the Guangzhou Biobank Cohort Study. Predicted testosterone was not associated with delayed 10-word recall score (−0.02 per nmol/L testosterone, 95% confidence interval (CI) −0.06–0.02) or MMSE score (0.06, 95% CI −0.002–0.12). These estimates were similar after additional adjustment for age, education, smoking, use of alcohol, body mass index and the Framingham score. Our findings do not corroborate observed protective effects of testosterone on cognitive function among older men.
Dried plum diet protects from bone loss caused by ionizing radiation
Authors: Schreurs A.-S. , Shirazi-Fard Y. , Shahnazari M. , Alwood J. S. , Truong T. A. , Tahimic C. G. T. , Limoli C. L. , Turner N. D. , Halloran B. , Globus R. K.
Published: February 2016

Bone loss caused by ionizing radiation is a potential health concern for radiotherapy patients, radiation workers and astronauts. In animal studies, exposure to ionizing radiation increases oxidative damage in skeletal tissues, and results in an imbalance in bone remodeling initiated by increased bone-resorbing osteoclasts. Therefore, we evaluated various candidate interventions with antioxidant or anti-inflammatory activities (antioxidant cocktail, dihydrolipoic acid, ibuprofen, dried plum) both for their ability to blunt the expression of resorption-related genes in marrow cells after irradiation with either gamma rays (photons, 2 Gy) or simulated space radiation (protons and heavy ions, 1 Gy) and to prevent bone loss. Dried plum was most effective in reducing the expression of genes related to bone resorption (Nfe2l2, Rankl, Mcp1, Opg, TNF-α) and also preventing later cancellous bone decrements caused by irradiation with either photons or heavy ions. Thus, dietary supplementation with DP may prevent the skeletal effects of radiation exposures either in space or on Earth.
Majorana bound states from exceptional points in non-topological superconductors
Authors: San-Jose Pablo , Cayao Jorge , Prada Elsa , Aguado Ramón
Published: February 2016

Recent experimental efforts towards the detection of Majorana bound states have focused on creating the conditions for topological superconductivity. Here we demonstrate an alternative route, which achieves fully localised zero-energy Majorana bound states when a topologically trivial superconductor is strongly coupled to a helical normal region. Such a junction can be experimentally realised by e.g. proximitizing a finite section of a nanowire with spin-orbit coupling and combining electrostatic depletion and a Zeeman field to drive the non-proximitized (normal) portion into a helical phase. Majorana zero modes emerge in such an open system without fine-tuning as a result of charge-conjugation symmetry and can be ultimately linked to the existence of ‘exceptional points’ (EPs) in parameter space, where two quasibound Andreev levels bifurcate into two quasibound Majorana zero modes. After the EP, one of the latter becomes non-decaying as the junction approaches perfect Andreev reflection, thus resulting in a Majorana dark state (MDS) localised at the NS junction. We show that MDSs exhibit the full range of properties associated to conventional closed-system Majorana bound states (zero-energy, self-conjugation, 4π-Josephson effect and non-Abelian braiding statistics), while not requiring topological superconductivity.
Exploring structural phase transitions of ion crystals
Authors: Yan L. L. , Wan W. , Chen L. , Zhou F. , Gong S. J. , Tong X. , Feng M.
Published: February 2016

Phase transitions have been a research focus in many-body physics over past decades. Cold ions, under strong Coulomb repulsion, provide a repealing paradigm of exploring phase transitions in stable confinement by electromagnetic field. We demonstrate various conformations of up to sixteen laser-cooled 40Ca+ ion crystals in a home-built surface-electrode trap, where besides the usually mentioned structural phase transition from the linear to the zigzag, two additional phase transitions to more complicated two-dimensional configurations are identified. The experimental observation agrees well with the numerical simulation. Heating due to micromotion of the ions is analysed by comparison of the numerical simulation with the experimental observation. Our investigation implies very rich and complicated many-body behaviour in the trapped-ion systems and provides effective mechanism for further exploring quantum phase transitions and quantum information processing with ultracold trapped ions.
Prion infection impairs lysosomal degradation capacity by interfering with rab7 membrane attachment in neuronal cells
Authors: Shim Su Yeon , Karri Srinivasarao , Law Sampson , Schatzl Hermann M. , Gilch Sabine
Published: February 2016

Prions are proteinaceous infectious particles which cause fatal neurodegenerative disorders in humans and animals. They consist of a mostly β-sheeted aggregated isoform (PrPSc) of the cellular prion protein (PrPc). Prions replicate autocatalytically in neurons and other cell types by inducing conformational conversion of PrPc into PrPSc. Within neurons, PrPSc accumulates at the plasma membrane and in vesicles of the endocytic pathway. To better understand the mechanisms underlying neuronal dysfunction and death it is critical to know the impact of PrPSc accumulation on cellular pathways. We have investigated the effects of prion infection on endo-lysosomal transport. Our study demonstrates that prion infection interferes with rab7 membrane association. Consequently, lysosomal maturation and degradation are impaired. Our findings indicate a mechanism induced by prion infection that supports stable prion replication. We suggest modulation of endo-lysosomal vesicle trafficking and enhancement of lysosomal maturation as novel targets for the treatment of prion diseases.
A method for discrimination of processed ginger based on image color feature and a support vector machine model
Authors: Zhou Sujuan , Meng Jiang , Huang Zhanpeng , Jiang Shizhong , Tu Yongqiu
Published: February 2016

The image color feature was analysed using a support vector machine and principal component analysis to discriminate different processed products of ginger.
Monitoring biological effects of 20 nm versus 100 nm silica nanoparticles induced on a human renal cell line using Fourier transform infrared spectroscopy
Authors: Barron Emmanuelle , Passagne Isabelle , Auger Aurélien , Travo Adrian , Rascol Estelle , L'Azou Béatrice , Forfar Isabelle
Published: February 2016

A method based on FTIR spectroscopy was proposed for monitoring the biological effects induced on human renal cells with SiO2 nanoparticles (NPs).
Mass change tracking approach as collection guidelines for aerosol and vapor samples released during e-cigarette smoking
Authors: Kim Ki-Hyun
Published: February 2016

There are growing concerns about the lack of a methodological basis for the quantification of various pollutants from electronic cigarettes (ECs). In this study we use a mass change tracking (MCT) approach to explore the potent roles of key sampling variables in the quantitation of EC-produced aerosols/vapors: the sampling flow rate (or puff velocity), battery charge condition, and solution composition.
Comment on “Delivering a photosensitive transplatin prodrug to overcome cisplatin drug resistance” by H. Song, W. Li, R. Qi, L. Yan, X. Jing, M. Zheng and H. Xiao, Chem. Commun., 2015, 51, 11493
Authors: Brabec V. , Vrana O. , Novakova O. , Kasparkova J.
Published: February 2016

Transplatin is cytotoxic when irradiated by UVA light, but does not isomerize in cisplatin.
A gallic acid–succinimide co-crystal landscape: polymorphism, pseudopolymorphism, variable stoichiometry co-crystals and concomitant growth of non-solvated and solvated co-crystals
Authors: Kaur Ramanpreet , Cherukuvada Suryanarayan , Managutti Praveen B. , Row Tayur N. Guru
Published: February 2016

A design aspect for selective formation of diverse solid forms such as solvates, hydrates and anhydrous forms has been successfully investigated in a gallic acid–succinimide co-crystal landscape.
Hidden entropic contribution in the thermodynamics of molecular complexation
Authors: Evstigneev Maxim P. , Lantushenko Anastasia O. , Golovchenko Igor V.
Published: February 2016

It has become an axiom that the thermodynamic analysis of non-covalent molecular complexation is intrinsically model-dependent, i.e. the set of implicitly or explicitly introduced assumptions may strongly affect the thermodynamic parameters.
Magnetic susceptibility of actinide(iii) cations: an experimental and theoretical study
Authors: Autillo Matthieu , Guerin Laetitia , Bolvin Hélène , Moisy Philippe , Berthon Claude
Published: February 2016

Radioactive decay on magnetic susceptibility measurements by the Evans's method has been characterized on two uranium isotopes and on tritiated water. Quantum chemistry calculations have been performed to explain Pu(iii), Am(iii) and Cm(iii) magnetic susceptibilities corrected from the radioactivity effects.
3c/4e -type long-bonding competes with ω-bonding in noble-gas hydrides HNgY (Ng = He, Ne, Ar, Kr, Xe, Rn; Y = F, Cl, Br, I): a NBO/NRT perspective
Authors: Zhang Guiqiu , Li Hong , Weinhold Frank , Chen Dezhan
Published: February 2016

Novel resonance bonding for the HNgY molecule is demonstrated based on natural resonance theory analyses. Ng/Y affects the ω-bondingvs.long-bonding propensity in each of the HNgY molecules.
Graphitic carbon nitride “reloaded”: emerging applications beyond (photo)catalysis
Authors: Liu Jian , Wang Hongqiang , Antonietti Markus
Published: February 2016

Despite being one of the oldest materials described in the chemical literature, graphitic carbon nitride (g-C3N4) has just recently experienced a renaissance as a highly active photo/electrocatalyst, and the metal-free polymer was also shown to be have diverse applications in various fields.
Copper-catalyzed oxidative carbon–heteroatom bond formation: a recent update
Authors: Zhu Xu , Chiba Shunsuke
Published: February 2016

This review updates recent advances in Cu-catalyzed (anaerobic) oxidative carbon–heteroatom bond formation on sp3- and sp2-C–H bonds as well as alkenes, classified according to the types of stoichiometric oxidants.
Direct C–H bond activation of ethers and successive C–C bond formation with benzene by a bifunctional palladium–titania photocatalyst
Authors: Tyagi Akanksha , Matsumoto Tomoya , Kato Tatsuhisa , Yoshida Hisao
Published: February 2016

Palladium-loaded titania bifunctional photocatalysts promoted a simple reaction between benzene and ethers to yield alpha-arylated ethers with high selectivity without consuming any additional chemicals or solvents under mild conditions.
White adipose tissue urea cycle activity is not affected by one-month treatment with a hyperlipidic diet in female rats
Authors: Arriarán Sofía , Agnelli Silvia , Remesar Xavier , Alemany Marià , Fernández-López José Antonio
Published: February 2016

Under high-energy diets, amino acid N is difficult to dispose of, as a consequence of the availability of alternative substrates.
A selective, efficient and environmentally friendly method for the oxidative cleavage of glycols
Authors: García Nuria , Rubio-Presa Rubén , García-García Patricia , Fernández-Rodríguez Manuel A. , Pedrosa María R. , Arnáiz Francisco J. , Sanz Roberto
Published: February 2016

An efficient and eco-friendly oxidative cleavage of glycols using DMSO as an oxidant catalyzed by dioxomolybdenum(vi) complexes has been developed.
Getting to know the extracellular vesicle glycome
Authors: Gerlach Jared Q. , Griffin Matthew D.
Published: February 2016

Extracellular vesicles (EVs) are a diverse population of complex biological particles with diameters ranging from approximately 20 to 1000 nm. EVs carry a variety of oligosaccharides and polysaccharides as well as carbohydrate-binding molecules.
Identification of immunoglobulins using Chou's pseudo amino acid composition with feature selection technique
Authors: Tang Hua , Chen Wei , Lin Hao
Published: February 2016

Immunoglobulins, also called antibodies, are a group of cell surface proteins which are produced by the immune system in response to the presence of a foreign substance (called antigen).
Silicon carbide foam as a porous support platform for catalytic applications
Authors: Duong-Viet Cuong , Ba Housseinou , El-Berrichi Zora , Nhut Jean-Mario , Ledoux Marc J. , Liu Yuefeng , Pham-Huu Cuong
Published: February 2016

This review provides an overview of the use of foam-structured SiC as a porous support platform in some typical catalytic processes both for gas-phase and liquid-phase reactions, such as H2S selective oxidation, Friedel–Crafts benzoylation and Fischer–Tropsch synthesis.
Rhodamine-modified upconversion nanoprobe for distinguishing Cu2+ from Hg2+ and live cell imaging
Authors: Xu Yanxia , Li Huifang , Meng Xianfu , Liu Jinliang , Sun Lining , Fan Xiaolin , Shi Liyi
Published: February 2016

A new organic–inorganic hybrid nanoprobe based on luminescence resonance energy transfer (LRET) from mesoporous silica coated upconversion nanoparticles to a rhodamine B derivative was prepared for distinguishing Cu2+ from Hg2+ and live cell imaging applications.
Quantitative characterization of conformational-specific protein–DNA binding using a dual-spectral interferometric imaging biosensor
Authors: Zhang Xirui , Daaboul George G. , Spuhler Philipp S. , Dröge Peter , Ünlü M. Selim
Published: February 2016

DNA-binding proteins play crucial roles in the maintenance and functions of the genome and yet, their specific binding mechanisms are not fully understood.
Self-organization of dipyridylcalix[4]pyrrole into a supramolecular cage for dicarboxylates
Authors: Kiriyama Naoaki , Ebihara Masahiro , Udagawa Taro , Miyaji Hidekazu
Published: February 2016

Cis-dipyridylcalix[4]pyrrole formed a supramolecular cage upon dimerization and coordination with Pd(ii). The cage molecule recognised suberate selectively by hydrogen bonding to the two calix[4]pyrroles.
Remediation of Cd(ii)-contaminated soil by three kinds of ferrous phosphate nanoparticles
Authors: Xu Yanzhe , Yan Xiaomin , Fan Ling , Fang Zhanqiang
Published: February 2016

Three kinds of iron phosphate nanoparticles were synthesized and they could reduce leachability and bioaccessibility of Cd effectively.
Dehydrochlorination of polyvinylchloride using Al-modified graphitic-C3N4
Authors: Bae Song Yi , Jeon Seongho , Lee Young Hoo , Lee Dong Hyun , Kye Hyoungsan , Bae Jong Wook
Published: February 2016

The increased dehydrochlorination activity for PVC over Al-modified g-C3N4is due to the larger number of basic sites and higher crystallinity of g-C3N4.
Preconcentration of sulfite from food and beverage matrices by ultrasonic assisted-cloud point extraction prior to its indirect determination by flame atomic absorption spectrometry
Authors: Altunay Nail , Gürkan Ramazan
Published: February 2016

The additives used in foods and beverages may be harmful to human health.
Stimuli-responsive cylindrical hydrogels mimic intestinal peristalsis to propel a solid object
Authors: Nistor V. , Cannell J. , Gregory J. , Yeghiazarian L.
Published: February 2016

The emerging field of soft robotics relies on soft, stimuli-responsive materials to enable load transport, manipulation, and mobility in complex unconstrained environments.
Assembly of nothing: equilibrium fluids with designed structured porosity
Authors: Lindquist Beth A. , Jadrich Ryan B. , Truskett Thomas M.
Published: February 2016

Inverse design was used to discover an isotropic pair interaction that assembles particles into an inhomogeneous fluid matrix surrounding pores of prescribed size and morphology.
Preparation of fine particles of sheelite-monoclinic phase BiVO4via an aqueous chelating method for efficient photocatalytic oxygen evolution under visible-light irradiation
Authors: Okunaka Sayuri , Tokudome Hiromasa , Hitomi Yutaka , Abe Ryu
Published: February 2016

Efficient photocatalytic O2 evolution is demonstrated under visible-light on BiVO4 fine particles prepared via a newly developed aqueous chelating method.
On the electrochemical deposition of metal–organic frameworks
Authors: Campagnol Nicolò , Van Assche Tom R. C. , Li Minyuan , Stappers Linda , Dincă Mircea , Denayer Joeri F. M. , Binnemans Koen , De Vos Dirk E. , Fransaer Jan
Published: February 2016

In this paper we study and compare the anodic and cathodic electrodeposition of Metal–Organic Frameworks (MOFs) and suggest guidelines for the electrodeposition of new MOFs with this technique. KHUST-1 was electrodeposited both anodically and cathodically and a four step mechanism is proposed to explain the anodic synthesis.
A bodipy based fluorescent probe for evaluating and identifying cancer, normal and apoptotic C6 cells on the basis of changes in intracellular viscosity
Authors: Gupta Neha , Reja Shahi Imam , Bhalla Vandana , Gupta Muskan , Kaur Gurcharan , Kumar Manoj
Published: February 2016

A bodipy based probe 1 has been explored for the identification of diseased cell population out of normal cells on the basis of changes in intracellular viscosity.
Recent advances in twisted intramolecular charge transfer (TICT) fluorescence and related phenomena in materials chemistry
Authors: Sasaki Shunsuke , Drummen Gregor P. C. , Konishi Gen-ichi
Published: February 2016

Twisted intramolecular charge transfer (TICT) is an electron transfer process that occurs upon photoexcitation in molecules that usually consist of a donor and acceptor part linked by a single bond.
High spatial and temporal resolution cell manipulation techniques in microchannels
Authors: Novo Pedro , Dell'Aica Margherita , Janasek Dirk , Zahedi René P.
Published: February 2016

Reviewing latest developments on lab on chips for enhanced control of cells’ experiments.
Recent progress in chromogenic and fluorogenic chemosensors for hypochlorous acid
Authors: Yue Yongkang , Huo Fangjun , Yin Caixia , Escobedo Jorge O. , Strongin Robert M.
Published: February 2016

Due to the biological and industrial importance of hypochlorous acid, the development of optical probes for HOCl has been an active research area.
Pincer-CNC mononuclear, dinuclear and heterodinuclear Au(iii) and Pt(ii) complexes supported by mono- and poly-N-heterocyclic carbenes: synthesis and photophysical properties
Authors: Gonell S. , Poyatos M. , Peris E.
Published: February 2016

The photophysical properties of a family of cyclometallated Au(iii) and Pt(ii) complexes containing a CNC-pincer ligand supported by pyrene-based mono- or bis-NHC ligands are described, and compared with those shown by related dimetallic complexes of Pt/Au and Ru2.
Advances in electroanalysis, sensing and monitoring in molten salts
Authors: Corrigan Damion K. , Elliott Justin P. , Blair Ewen O. , Reeves Simon J. , Schmüser Ilka , Walton Anthony J. , Mount Andrew R.
Published: February 2016

Microelectrodes have a number of advantages over macroelectrodes for quantitative electroanalysis and monitoring, including reduced iR drop, a high signal-to-noise ratio and reduced sensitivity to convection. Their use in molten salts has been generally precluded by the combined materials challenges of stresses associated with thermal cycling and physical and corrosive chemical degradation at the relatively high temperatures involved. We have shown that microfabrication, employing high precision photolithographic patterning in combination with the controlled deposition of materials, can be used to successfully address these challenges. The resulting molten salt compatible microelectrodes (MSMs) enable prolonged quantitative microelectrode measurements in molten salts (MSs). This paper reports the fabrication of novel MSM disc electrodes, chosen because they have an established ambient analytical response. It includes a detailed set of electrochemical characterisation studies which demonstrate both their enhanced capability over macroelectrodes and over commercial glass pulled microelectrodes, and their ability to extract quantitative electroanalytical information from MS systems. MSM measurements are then used to demonstrate their potential for shedding new light on the fundamental properties of, and processes in, MSs, such as mass transport, charge transfer reaction rates and the selective plating/stripping and alloying reactions of liquid Bi and other metals; this will underpin the development of enhanced MS industrial processes, including pyrochemical spent nuclear fuel reprocessing.
Electrochemical imaging for microfluidics: a full-system approach
Authors: Kara Adnane , Reitz Arnaud , Mathault Jessy , Mehou-Loko Syllia , Amirdehi Mehran Abbaszadeh , Miled Amine , Greener Jesse
Published: February 2016

Electrochemical imaging is developed as a new chemical imaging modality for microfluidics and applied to laminar flow micropatterns.
Self-assembled particle membranes for in situ concentration and chemostat-like cultivation of microorganisms on a chip
Authors: Lee Jongwan , Kim Minseok , Park Jungyul , Kim Taesung
Published: February 2016

Recently, microparticles have been used as nanoporous membranes in microfluidic devices, contributing to various bioassays on a chip.
Recent advances in transition metal-catalysed hydroacylation of alkenes and alkynes
Authors: Ghosh Avipsa , Johnson Kirsten F. , Vickerman Kevin L. , Walker James A. , Stanley Levi M.
Published: February 2016

This highlight presents advances in transition metal-catalysed alkene and alkyne hydroacylation over the past three years.
Ultra-rapid pattern formation of block copolymers with a high-χ parameter in immersion annealing induced by a homopolymer
Authors: Kim Myung Jin , Park Woon Ik , Choi Young Joong , Jung Yun Kyung , Kim Kwang Ho
Published: February 2016

Ultra-rapid pattern formation of homopolymer/BCP blend is demonstrated. A highly ordered dot pattern can be achieved for an extremely short immersion time (10 s) by controlling the annealing temperature and mixing ratio of binary solvent.
An improved miniprotein host for fluorogenic supramolecular assembly on the surface of living cells
Authors: Xu Bi , Zhou Xinqi , Stains Cliff I.
Published: February 2016

A new host–guest pair produces a significant increase in the brightness of supramolecular complexes on the surface of living cells.
Correction: Understanding and controlling the release mechanism of Escherichia coli in double W1/O/W2 emulsion globules in the presence of NaCl in the W2 phase
Authors: El Kadri Hani , Overton Tim , Bakalis Serafim , Gkatzionis Konstantinos
Published: February 2016

Correction for ‘Understanding and controlling the release mechanism of Escherichia coli in double W1/O/W2 emulsion globules in the presence of NaCl in the W2 phase’ by Hani El Kadri et al., RSC Adv., 2015, 5, 105098–105110.
Correction: Towards the use of metal–organic frameworks for water reuse: a review of the recent advances in the field of organic pollutants removal and degradation and the next steps in the field
Authors: Dias Elton M. , Petit Camille
Published: February 2016

Correction for ‘Towards the use of metal–organic frameworks for water reuse: a review of the recent advances in the field of organic pollutants removal and degradation and the next steps in the field’ by Elton M. Dias et al., J. Mater. Chem. A, 2015, 3, 22484–22506.
Coupled electric–magnetic–thermal–mechanical modelling of busbars under short‐circuit conditions
Authors: Kadkhodaei Gholamreza , Sheshyekani Keyhan , Hamzeh Mohsen
Published: February 2016

This study presents a coupled electric–magnetic–thermal–mechanical analysis of busbar systems under short‐circuit currents. The analysis is carried out by making use of the finite‐element method, which enables one to closely model two‐way interactions among separate continuum physics. In contrast to previous works, which only consider the peak value of the short‐circuit current, this method evaluates the magnetic force, the temperature rise, the mechanical displacement and their interactions over the simulation time of interest. The mechanical displacements are obtained by means of a three‐dimensional analysis. It is found that the type of busbar support can markedly affect the conductor displacement during the short‐circuit current. The temperature rise due to the short‐circuit current flows is found to have a slight effect on the displacement of busbar conductors.
Synthesis of spherical amorphous selenium nano and microparticles with tunable sizes
Authors: Bartůněk Vilém , Junková Jiřina , Babuněk Mario , Ulbrich Pavel , Kuchař Martin , Sofer Zdeněk
Published: February 2016

Spherical amorphous nano and microparticles of elemental selenium have been prepared by simple reduction method. For surface stabilisation, sodium dodecyl sulphate (SDS), polysorbate 80 and tryptone have been used. ZetaSizer and transmission electron microscopy measurements were used for characterisation of the size and shape of prepared particles and X‐ray diffraction measurements to confirm their amorphous nature. The sizes of the nanoparticles stabilised by SDS can be controlled by varying of the surfactant concentration. Particles stabilised by tryptone have microdimensions and could be therefore applied where nanodimensions are not suitable.
Preparation of multi‐walled carbon nanotubes/SiO2 core–shell nanocomposites by a two‐step Stöber process
Authors: Sun Chang , Sun Kangning
Published: February 2016

The surface modification and functionalisation of multi‐walled carbon nanotubes (MWNTs) could provide enhanced properties to MWNTs for highly specific applications which often require solubilisation and dispersion, promotion of functionality, biocompatibility or lower toxicity of MWNTs. Herein, a novel nanocomposite consisting of MWNTs as a core and amorphous silica (SiO2) as a shell is developed. First, the functionalisation of MWNTs with carboxylic functional group (MWNTs‐COOH) was obtained via oxidation using the concentrated sulphuric acid/nitric acid mixture (3:1 v/v) treatment. Second, a silica uniform layer was grown on MWNTs‐COOH by a two‐step Stöber process. The core–shell nanostructure is characterised by Fourier‐transform infrared spectroscopy, X‐ray powder diffraction, transmission electron microscopy, and energy dispersive spectrometer. Experimental results show that a SiO2 shell was uniformly coated on the surface of MWNTs with a thickness of 5–10 nm. The results can have important implications for the preparation of carbon nanotube core–shell nanocomposites in general.
High-pressure stability and ambient metastability of marcasite-type rhodium pernitride
Authors: Niwa K. , Terabe T. , Suzuki K. , Shirako Y. , Hasegawa M.
Published: February 2016

High-pressure stability, ambient metastability, and high-pressure crystal chemistry of chemical bonds of marcasite-type RhN2 have been investigated using a laser-heated diamond-anvil cell up to a pressure of 70.6 GPa. High-pressure in-situ X-ray diffraction and Raman scattering measurements revealed that the marcasite-type RhN2 structure is stable up to 70.6 GPa and exhibited an order of axial compressibility of βc > βb > βa. This indicates that single bonded nitrogen dimer (N-N) plays an important role in the incompressibility of a- and b-axes than in that of the c-axis and stabilizes the marcasite-type structure at high-pressure. Field emission scanning electron microscopic analysis in combination with the energy dispersive X-ray spectroscopic measurements and the result of our previous study indicates that the marcasite-type RhN2 can be quenched to ambient pressure when the grain size is less than 100 nm. Our study together with other previous studies indicates that the ambient metastability of 4d platinum group pernitrides (RuN2, RhN2, and PdN2) decreases from ruthenium to palladium.
Measuring the local electrical conductivity of human brain tissue
Authors: Akhtari M. , Emin D. , Ellingson B. M. , Woodworth D. , Frew A. , Mathern G. W.
Published: February 2016

The electrical conductivities of freshly excised brain tissues from 24 patients were measured. The diffusion-MRI of the hydrogen nuclei of water molecules from regions that were subsequently excised was also measured. Analysis of these measurements indicates that differences between samples' conductivities are primarily due to differences of their densities of solvated sodium cations. Concomitantly, the sample-to-sample variations of their diffusion constants are relatively small. This finding suggests that non-invasive in-vivo measurements of brain tissues' local sodium-cation density can be utilized to estimate its local electrical conductivity.
Water adsorption on the LaMnO3 surface
Authors: Billman Chris R. , Wang Yan , Cheng Hai-Ping
Published: February 2016

Studying the adsorption of water on the metallic LaMnO3 surface can provide insight into this complicated surface-adsorbate interaction. Using density functional theory, we investigated the adsorption of a water monomer, dimer, trimer, and a monolayer on the surface. The electronic structure of ground state configurations is explored using analysis of density of states, charge density, and crystal orbital overlap populations. We found that the interaction between the surface and water molecules is stronger than hydrogen bonding between molecules, which facilitates wetting of the surface. Adsorbed water molecules form very strong hydrogen bonds, with substantially shifted OH stretch modes. For the monolayer of adsorbed water, a hint of a bilayer is observed with a height separation of only 0.2 A˚. However, simulated scanning tunneling microscopy images and vibrational spectra suggest a significant difference between the two layers due to intermolecular bonding and interaction with the substrate.
Nonlinear Alfvén waves in extended magnetohydrodynamics
Authors: Abdelhamid Hamdi M. , Yoshida Zensho
Published: February 2016

Large-amplitude Alfvén waves are observed in various systems in space and laboratories, demonstrating an interesting property that the wave shapes are stable even in the nonlinear regime. The ideal magnetohydrodynamics (MHD) model predicts that an Alfvén wave keeps an arbitrary shape constant when it propagates on a homogeneous ambient magnetic field. However, such arbitrariness is an artifact of the idealized model that omits the dispersive effects. Only special wave forms, consisting of two component sinusoidal functions, can maintain the shape; we derive fully nonlinear Alfvén waves by an extended MHD model that includes both the Hall and electron inertia effects. Interestingly, these “small-scale effects” change the picture completely; the large-scale component of the wave cannot be independent of the small scale component, and the coexistence of them forbids the large scale component to have a free wave form. This is a manifestation of the nonlinearity-dispersion interplay, which is somewhat different from that of solitons.
A time-dependent formulation of multi-reference perturbation theory
Authors: Sokolov Alexander Yu. , Chan Garnet Kin-Lic
Published: February 2016

We discuss the time-dependent formulation of perturbation theory in the context of the interacting zeroth-order Hamiltonians that appear in multi-reference situations. As an example, we present a time-dependent formulation and implementation of second-order n-electron valence perturbation theory. The resulting time-dependent n-electron valence second-order perturbation theory (t-NEVPT2) method yields the fully uncontracted n-electron valence perturbation wavefunction and energy, but has a lower computational scaling than the usual contracted variants, and also avoids the construction of high-order density matrices and the diagonalization of metrics. We present results of t-NEVPT2 for the water, nitrogen, carbon, and chromium molecules and outline directions for the future.
Using forbidden ordinal patterns to detect determinism in irregularly sampled time series
Authors: Kulp C. W. , Chobot J. M. , Niskala B. J. , Needhammer C. J.
Published: February 2016

It is known that when symbolizing a time series into ordinal patterns using the Bandt–Pompe (BP) methodology, there will be ordinal patterns called forbidden patterns that do not occur in a deterministic series. The existence of forbidden patterns can be used to identify deterministic dynamics. In this paper, the ability to use forbidden patterns to detect determinism in irregularly sampled time series is tested on data generated from a continuous model system. The study is done in three parts. First, the effects of sampling time on the number of forbidden patterns are studied on regularly sampled time series. The next two parts focus on two types of irregular-sampling, missing data and timing jitter. It is shown that forbidden patterns can be used to detect determinism in irregularly sampled time series for low degrees of sampling irregularity (as defined in the paper). In addition, comments are made about the appropriateness of using the BP methodology to symbolize irregularly sampled time series.
Note: Differential configurations for the mitigation of slow fluctuations limiting the resolution of digital lock-in amplifiers
Authors: Carminati M. , Gervasoni G. , Sampietro M. , Ferrari G.
Published: February 2016

The resolution of digital lock-in amplifiers working with a narrow bandwidth (<100 Hz) is limited by slow fluctuations, which can be two orders of magnitude larger (μV range) than the noise of the input amplifier (tens of nV). In order to tackle this issue, affecting state-of-the-art laboratory instrumentation and here systematically quantified, three differential sensing configurations are presented. They adapt to different setup conditions and are based on manual and automatic tuning of dummy references, allowing a 25-fold resolution improvement for enhanced long-term tracking of impedance sensors.
Defect density dependent photoluminescence yield and triplet diffusion length in rubrene
Authors: Irkhin Pavel , Biaggio Ivan , Zimmerling Tino , Döbeli Max , Batlogg Bertram
Published: February 2016

We investigate how excitonic processes in rubrene single crystals are affected by a deliberately implanted defect gradient induced by proton irradiation. Spatially resolved measurements show a gradually reduced photoluminescence quantum yield and triplet exciton diffusion length along the defect gradient. Both effects are caused by a decrease in the average triplet lifetime due to interaction with the implanted defects. The triplet lifetime was reduced by almost two orders of magnitude at the highest implanted defect density of 1017 cm–3. The strong sensitivity of the photoluminescence quantum yield to the defect density that is observed already at moderate excitation densities is caused by the combination of two effects: the dominant contribution of triplet-fusion to the observed photoluminescence and the long-range diffusion of triplet excitons.
Communication: Real time observation of unimolecular decay of Criegee intermediates to OH radical products
Authors: Fang Yi , Liu Fang , Barber Victoria P. , Klippenstein Stephen J. , McCoy Anne B. , Lester Marsha I.
Published: February 2016

In the atmosphere, a dominant loss process for carbonyl oxide intermediates produced from alkene ozonolysis is also an important source of hydroxyl radicals. The rate of appearance of OH radicals is revealed through direct time-domain measurements following vibrational activation of prototypical methyl-substituted Criegee intermediates under collision-free conditions. Complementary theoretical calculations predict the unimolecular decay rate for the Criegee intermediates in the vicinity of the barrier for 1,4 hydrogen transfer that leads to OH products. Both experiment and theory yield unimolecular decay rates of ca. 108 and 107 s−1 for syn-CH3CHOO and (CH3)2COO, respectively, at energies near the barrier. Tunneling through the barrier, computed from high level electronic structure theory and experimentally validated, makes a significant contribution to the decay rate. Extension to thermally averaged unimolecular decay of stabilized Criegee intermediates under atmospheric conditions yields rates that are six orders of magnitude slower than those evaluated directly in the barrier region.
Improved conversion efficiency of InN/p-GaN heterostructure solar cells with embedded InON quantum dots
Authors: Ke Wen-Cheng , Liang Zhong-Yi , Yang Cheng-Yi , Chan Yu-Teng , Jiang Chi-Yung
Published: February 2016

An indium oxynitride (InON) quantum dot (QD) layer was inserted between the indium nitride (InN) and p-type gallium nitride (GaN) films for improving the conversion efficiency of the heterostructure solar cells. The InN/InON QD/p-GaN heterostructure solar cells exhibited a high open-circuit voltage of 2.29 V, short-circuit current density of 1.64 mA/cm2, and conversion efficiency of 1.12% under AM 1.5G illumination. Compared with samples without InON QDs, the power conversion efficiency of sample with InON QDs increased twofold; this increase was attributed to the increase in short-current density. The external quantum efficiency of 250-nm-thick InN/p-GaN heterostructure solar cells has a highest value of 6.5% in the wavelength range of 700–1100 nm. The photogenerated holes separated in the depletion region of InN thin films is difficult to transport across the energy barrier between the InN and p-GaN layers. The oxygen vacancy assisted carrier transport in the InN/InON QD/p-GaN sample, which was evidenced in its current–voltage (I–V) and capacitance–voltage (C–V) characteristics. The dark I–V characteristic curves in the bias range of −2 to 2 V exhibited ohmic behavior, which indicated the absence of a transport barrier between the InN and p-GaN layers. In addition, a shoulder peak at −0.08 V was observed in the high-frequency (60–100 kHz) C–V characteristic curves corresponding to carrier capture and emission in the shallow defect state of oxygen vacancy in the InON QDs. The oxygen vacancy exists inside the InON QDs and generates the interface states in the InON QD/p-GaN interface to form a carrier transport path. Thus, more photogenerated holes can transport via the InON QDs into the p-GaN layer, contributing to the photocurrent and resulting in high conversion efficiency for the InN/InON QD/p-GaN heterostructure solar cells.
Influence of nanoparticle formation on discharge properties in argon-acetylene capacitively coupled radio frequency plasmas
Authors: Wegner Th. , Hinz A. M. , Faupel F. , Strunskus T. , Kersten H. , Meichsner J.
Published: February 2016

This contribution presents experimental results regarding the influence of nanoparticle formation in capacitively coupled radio frequency (13.56 MHz) argon-acetylene plasmas. The discharge is studied using non-invasive 160 GHz Gaussian beam microwave interferometry and optical emission spectroscopy. Particularly, the temporal behavior of the electron density from microwave interferometry is analyzed and compared with the changing plasma emission and self-bias voltage caused by nanoparticle formation. The periodic particle formation with a cycle duration between 30 s and 140 s starts with an electron density drop over more than one order of magnitude below the detection limit (8 × 1014 m−3). The electron density reduction is the result of electron attachment processes due to negative ions and nanoparticle formation. The onset time constant of nanoparticle formation is five times faster compared to the expulsion of the particles from the plasma due to multi-disperse size distribution. Moreover, the intensity of the argon transition lines increases and implies a rising effective electron temperature. The cycle duration of the particle formation is affected by the total gas flow rate and exhibits an inverse proportionality to the square of the total gas flow rate. The variation in the total gas flow rate influences the force balance, which determines the confinement time of the nanoparticles. As a further result, the cycle duration is dependent on the axial position of the powered electrode, which also corresponds to different distances relative to the fixed optical axis of the microwave interferometer.
Temperature-dependent polarization characteristics in Al0.25Ga0.75N/AlN/GaN heterostructure
Authors: Xiang Yong , Chen Xinjuan , Ji Cheng , Yang Xuelin , Xu Fujun , Yang Zhijian , Kang Xiangning , Shen Bo , Zhang Guoyi , Yu Tongjun
Published: February 2016

The characteristics of polarizations, including spontaneous polarization (PSP) and piezoelectric polarization (PPE) in Al0.25Ga0.75N/AlN/GaN were obtained by temperature-dependent x-ray diffraction measurements of AlN and GaN layers, and the sheet carrier density (ns) in 20-nm-thick barrier Al0.25Ga0.75N/AlN/GaN heterostructure was studied by Hall measurement at different temperatures from 300 K to 600 K. It is found that the PSP/e (∼1 × 1013 cm−2, e is the electron charge) is larger than PPE/e (∼7 × 1012 cm−2). Excluding the influence of background carrier density, the change of PSP/e with temperature is similar to that of ns, while the tendency of PPE/e is opposite. The contributions to ns change by PSP and PPE are ∼−7.3 × 1011 cm−2 and ∼1.9 × 1011 cm−2, respectively. Therefore, the total variation of PSP and PPE is ∼−5.4 × 1011 cm−2, which is close to the value ∼−5.5 × 1011 cm−2 obtained by Hall data. All these results demonstrate that the PSP is dominant in temperature-dependent properties of two-dimensional electron gas. Moreover, the reduction of PSP with increasing temperature might aggravate current collapse in high electron mobility transistors devices.
Novel secret key generation techniques using memristor devices
Authors: Abunahla Heba , Shehada Dina , Yeun Chan Yeob , Mohammad Baker , Jaoude Maguy Abi
Published: February 2016

This paper proposes novel secret key generation techniques using memristor devices. The approach depends on using the initial profile of a memristor as a master key. In addition, session keys are generated using the master key and other specified parameters. In contrast to existing memristor-based security approaches, the proposed development is cost effective and power efficient since the operation can be achieved with a single device rather than a crossbar structure. An algorithm is suggested and demonstrated using physics based Matlab model. It is shown that the generated keys can have dynamic size which provides perfect security. Moreover, the proposed encryption and decryption technique using the memristor based generated keys outperforms Triple Data Encryption Standard (3DES) and Advanced Encryption Standard (AES) in terms of processing time. This paper is enriched by providing characterization results of a fabricated microscale Al/TiO2/Al memristor prototype in order to prove the concept of the proposed approach and study the impacts of process variations. The work proposed in this paper is a milestone towards System On Chip (SOC) memristor based security.
Scotch tape induced strains for structural variation of FeTe0.5Se0.5 and Fe1.05Te single crystals
Authors: Wang Weike , Wang Xuefei , Zhang Lei , Yang Jiyong , Chen Xuliang , Zhang Zhitao , Tian Mingliang , Yang Zhaorong , Zhang Yuheng
Published: February 2016

We have recently reported that the superconducting transition temperature of FeTe0.5Se0.5 flakes attached onto commercial Scotch tape can be enhanced by about 1-2 K due to a thermal-mismatch induced compressive strain. In this work, we further investigated the Scotch tape effect on structural variation of FeTe0.5Se0.5 and Fe1.05Te flakes by X-ray diffraction measurements. We show that for FeTe0.5Se0.5, the lattice constant c of taped flakes is elongated by about 0.5% at 15 K as compared with bulk crystal. Upon warming from 15 K, the lattice constant c of the taped flakes first levels off then displays negative thermal expansion followed by monotonic increase at temperatures above 100 K. For antiferromagnetic Fe1.05Te, the structural transition around 70 K is remarkably broadened by about 2 K. The present results demonstrate that the Scotch tape is a simple and effective tool to probe structure sensitive physical properties of layered materials.
Valley and spin resonant tunneling current in ferromagnetic/nonmagnetic/ferromagnetic silicene junction
Authors: Hajati Yaser , Rashidian Zeinab
Published: February 2016

We study the transport properties in a ferromagnetic/nonmagnetic/ferromagnetic (FNF) silicene junction in which an electrostatic gate potential, U, is attached to the nonmagnetic region. We show that the electrostatic gate potential U is a useful probe to control the band structure, quasi-bound states in the nonmagnetic barrier as well as the transport properties of the FNF silicene junction. In particular, by introducing the electrostatic gate potential, both the spin and valley conductances of the junction show an oscillatory behavior. The amplitude and frequency of such oscillations can be controlled by U. As an important result, we found that by increasing U, the second characteristic of the Klein tunneling is satisfied as a result of the quasiparticles chirality which can penetrate through a potential barrier. Moreover, it is found that for special values of U, the junction shows a gap in the spin and valley-resolve conductance and the amplitude of this gap is only controlled by the on-site potential difference, Δz. Our findings of high controllability of the spin and valley transport in such a FNF silicene junction may improve the performance of nano-electronics and spintronics devices.
Current WHO protocols for mass drug administration in helminth control
Authors: Bradbury Richard S , Graves Patricia M
Published: February 2016

Soil transmitted helminths (STH), comprising Ascaris, Trichuris, Strongyloides and the hookworms remain a significant cause of morbidity amongst people in many parts of the world, including Australia. Other important helminth infections include lymphatic filariasis (LF), schistosomiasis and onchocerciasis. Preventive chemotherapy (mass drug administration [MDA]) campaigns are frequently conducted for these helminth infections in endemic areas, but the target population groups, duration of campaigns, cointerventions (e.g. vector control) criteria for inclusion, drugs used and doses of drugs differ.