bluuebunny/crossref_metadata_2025 huggingface dataset:
Indium-catalyzed, novel route to β,β-disubstituted indanones via tandem Nakamura addition–hydroarylation–decarboxylation sequence
Authors: Rajesh Nimmakuri , Prajapati Dipak
Published: January 2015

An indium-catalyzed, novel method for the generation of β,β-disubstituted indanones was described. Indium(iii) trifluoromethanesulfonate is reported as the multitasking catalyst that promotes tandem Nakamura addition–hydroarylation–decarboxylation process under one-pot conditions.
Rhodium-catalysed direct C–H allylation of N-sulfonyl ketimines with allyl carbonates
Authors: Mei Shu-Tao , Wang Nan-Jin , Ouyang Qin , Wei Ye
Published: January 2015

Synthetically useful N-sulfonyl ketimines were efficiently allylated with various allyl carbonates through rhodium catalysis.
A fluorescent bistable [2]rotaxane molecular switch on SiO2nanoparticles
Authors: Cao Zhan-Qi , Miao Qi , Zhang Qi , Li Hong , Qu Da-Hui , Tian He
Published: January 2015

A fluorescent bistable [2]rotaxane was immobilized onto the surface of SiO2nanoparticles through click reaction. The shuttling motion of the macrocycle component was driven by external acid–base stimuli both in solution and on SiO2nanoparticles, accompanied by visual fluorescence changes.
Spin canting, metamagnetism, and single-chain magnetic behaviour in a cyano-bridged homospin iron(ii) compound
Authors: Shao Dong , Zhang Shao-Liang , Zhao Xin-Hua , Wang Xin-Yi
Published: January 2015

A cyano-bridged FeII compound exhibiting the coexistence of spin canting, antiferromagnetic ordering, metamagnetism and single-chain magnetism was reported.
NiO-decorated mesoporous TiO2 flowers for an improved photovoltaic dye sensitized solar cell
Authors: Zhi Jian , Chen Angran , Cui Houlei , Xie Yian , Huang Fuqiang
Published: January 2015

The flower-like porous TiO2–NiO nanoparticles, possessing a high BET surface area, are first used as a photoanode in a DSSC.
Solution vs. gas phase relative stability of the choline/acetylcholine cavitand complexes
Authors: Abdoul-Carime Hassan , Farizon Bernadette , Farizon Michel , Mulatier Jean-Christophe , Dutasta Jean-Pierre , Chermette Henry
Published: January 2015

How the information obtained from the gas phase experiments can reflect the processes in solution is a crucial question for analytical chemistry, and particularly the selective host–guest recognition mechanisms which are fundamental in biology.
A model study on the photochemical isomerization of cyclic silenes
Authors: Su Ming-Der
Published: January 2015

The photomigration reaction mechanism for a five-membered-ring silene 1 was theoretically studied using the CAS/6-311G(d) and MP2-CAS/6-311++G(3df,3pd) methods. The model computations conclude that the conical intersection mechanism plays an important role in such a photochemical reaction. That is, the conical intersection mechanism is a one-step process that has no barrier.
Structural investigation of resorcinol based symmetrical banana mesogens by XRD, NMR and polarization measurements
Authors: Kesava Reddy M. , Varathan E. , Jacintha B. , Lobo Nitin P. , Roy Arun , Narasimhaswamy T. , Ramanathan K. V.
Published: January 2015

The structural characterization of two bent-core mesogens DBPPD and DBPPDO which differ in terminal chains reveals B2 and B7 mesophases while the orientational order parameter for DBPPD is found to be 0.84 with a bent angle of 120.5°.
The mechanism of the effect of H2O on the low temperature selective catalytic reduction of NO with NH3 over Mn–Fe spinel
Authors: Xiong Shangchao , Liao Yong , Xiao Xin , Dang Hao , Yang Shijian
Published: January 2015

H2O effect on NO reduction over Mn–Fe spinel was related to the competition adsorption and the decrease in oxidation ability.
Complex magnetic behaviour of Sr2CoNb1−xTixO6(0 ≤ x ≤ 0.5) as a result of a flexible microstructure
Authors: Azcondo María Teresa , Romero de Paz Julio , Boulahya Khalid , Ritter Clemens , García-Alvarado Flaviano , Amador Ulises
Published: January 2015

We report the rich magnetic behaviour of Sr2CoNb1−xTixO6(0 ≤x≤ 0.5) oxides as a result of their complex microstructure.
Manganese borohydride; synthesis and characterization
Authors: Richter Bo , Ravnsbæk Dorthe B. , Tumanov Nikolay , Filinchuk Yaroslav , Jensen Torben R.
Published: January 2015

Three manganese borohydride polymorphs are synthesized in solution and found to be structural analogues of three magnesium borohydride polymorphs.
Synthesis, structural characterization and thermal properties of copper and silver silyl complexes
Authors: Sgro Michael J. , Piers Warren E. , Romero Patricio E.
Published: January 2015

A series of copper and silver-silyl complexes containing N-heterocyclic carbene or N-donor ligands were synthesized and characterized in the solid state. A number of different structural forms were observed and many compounds were shown to be volatile.
The materials genome in action: identifying the performance limits for methane storage
Authors: Simon Cory M. , Kim Jihan , Gomez-Gualdron Diego A. , Camp Jeffrey S. , Chung Yongchul G. , Martin Richard L. , Mercado Rocio , Deem Michael W. , Gunter Dan , Haranczyk Maciej , Sholl David S. , Snurr Randall Q. , Smit Berend
Published: January 2015

The best ZIF structure found in screening of databases containing over half a million nanoporous materials for vehicular methane storage is shown.
Effects of molybdenum on the composition and nanoscale morphology of passivated austenitic stainless steel surfaces
Authors: Maurice Vincent , Peng Hao , Klein Lorena H. , Seyeux Antoine , Zanna Sandrine , Marcus Philippe
Published: January 2015

Surface analysis by time-of-flight secondary ion mass spectrometry, X-ray photoelectron spectroscopy and scanning tunnelling microscopy has been applied to provide new insight on Mo effects on the composition and nanostructure of the passive films grown in sulfuric acid on well-controlled Fe–17Cr–14.5Ni–2.3Mo(100) austenitic stainless steel single crystal surfaces. A duplex hydroxylated oxide matrix, 1.8–1.9 nm thick, is formed with a strong partition between Cr(iii) and Fe(iii) in the inner and outer layers, respectively. Cr(iii) is increasingly enriched by preferential iron oxide dissolution upon passivation and ageing. Ni, only present as oxide traces in the film, is enriched in the alloy underneath. Mo, mostly present as Mo(iv) in the Cr-rich inner layer prior to anodic polarisation, becomes increasingly enriched (up to 16% of cations) mostly as Mo(vi) in the Fe-rich outer layer of the passive film, with ageing promoting this effect. Metallic Mo is not significantly enriched below the passive film produced from the native oxide covered surface. Mo does not markedly impact the nanogranular morphology of the native oxide film nor its local thickness variations assigned to substrate site effects on Cr(iii) enrichment. Site specific preferential passivation still takes place at the (native) oxide-covered step edges of the alloy surface, and transient dissolution remains preferentially located on the terraces. Nanostructures, possibly Mo-containing, and healing local depressions formed by transient dissolution during passivation, appear as a specific effect of the Mo presence. Another Mo effect, observed even after 20 h of passivation, is to prevent crystallisation at least in the Fe-rich outer part of the passive film where it is concentrated mostly as Mo(vi) (i.e. molybdate) species.
High-resolution insights into the early stages of silver nucleation and growth
Authors: Völkle Cornelia M. , Gebauer Denis , Cölfen Helmut
Published: January 2015

Nucleation and growth of silver nanoparticles has already been investigated with various experimental and computational tools. However, owing to inherent problems associated with the analytical characterization of nucleation processes, there is a general lack of experimental data regarding the earliest precursors and smallest Ag(0) clusters. Here, we address this problem by the application of Synthetic Boundary Crystallization Ultracentrifugation, utilizing a multiwavelength detector for the first time, complemented by a specialized titration assay. These techniques shed new light on silver nanoparticle precursors existing in the pre-nucleation regime, and the initially nucleated ensemble of nanoclusters. For the first time, we present experimental data of UV-Vis spectra for fractionated silver clusters. These allow for unsurpassed insights into the sequence of nucleation and early growth species as well as their optical properties.
Chameleon behaviour of iodine in recovering noble-metals from WEEE: towards sustainability and “zero” waste
Authors: Serpe Angela , Rigoldi Americo , Marras Claudia , Artizzu Flavia , Laura Mercuri Maria , Deplano Paola
Published: January 2015

The peculiar properties of iodine and safe lixiviants for sustainable and effective noble-metal recovery from shredded WEEE.
A quantum Monte Carlo study on electron correlation effects in small aluminum hydride clusters
Authors: Higino Damasceno J. , Teixeira Rabelo J. N. , Cândido Ladir
Published: January 2015

Using accurate methods we calculate binding energies to discuss the electron–electron interaction in the formation of AlnHm ionic clusters.
Controlled synthesis of tower-like aniline oligomers with excellent adsorption properties
Authors: Zhou Chuanqiang , Gong Xiangxiang , Han Jie , Guo Rong
Published: January 2015

Nanoplate-based tower-like oligoaniline as a new nano-architecture was tailored via the oxidation polymerization of aniline in NaOH medium at 35 °C.
A bacteriophilic resin, synthesis and E. coli sequestration study
Authors: Lemée Frédéric , Clarot Igor , Ronin Loïc , Aranda Lionel , Mourer Maxime , Regnouf-de-Vains Jean-Bernard
Published: January 2015

The polycationic pyridinium-Merrifield resinIwas prepared and subjected to bacteria sequestration studies. Its efficiency was demonstrated by capillary electrophoresis titrations, and the effectiveness of the sequestration was shown by confocal microscopy.
Titanium complexes with octahedral geometry chelated by salen ligands adopting β-cis configuration for the ring-opening polymerisation of lactide
Authors: Gao Bo , Li Xiang , Duan Ranlong , Pang Xuan
Published: January 2015

Titanium complexes (Ti atom located in an octahedral geometry) based on quadridentate salen ligands as initiators for lactide polymerisation.
Novel energy relay dyes for high efficiency dye-sensitized solar cells
Authors: Rahman Md. Mahbubur , Ko Min Jae , Lee Jae-Joon
Published: January 2015

The incorporation of DAPI and H33342 into N719-sensitized DSSCs significantly increased the Jsc because of the net dye absorption enhancement over the entire absorption range via FRET and RET.
Reduced graphene oxide hydrogel film with a continuous ion transport network for supercapacitors
Authors: Feng Xiayu , Chen Wufeng , Yan Lifeng
Published: January 2015

In situelectrochemical reduction of the as-formed GO hydrogel film and the fabrication of a supercapactior using the obtained non-stacking ERGO hydrogel film.
Giant reversible nanoscale piezoresistance at room temperature in Sr2IrO4 thin films
Authors: Domingo Neus , López-Mir Laura , Paradinas Markos , Holy Vaclav , Železný Jakuv , Yi Di , Suresha Siriyara J. , Liu Jian , Rayan Serrao Claudy , Ramesh Ramamoorthy , Ocal Carmen , Martí Xavi , Catalan Gustau
Published: January 2015

Fully reversible giant piezoresponse on Sr2IrO4 thin films enabled by the strain dependence of its band gap under vertical compression at the nanoscale.
Cucurbiturils as supramolecular inhibitors of DNA restriction by type II endonucleases
Authors: Parente Carvalho Cátia , Norouzy Amir , Ribeiro Vera , Nau Werner M. , Pischel Uwe
Published: January 2015

Cucurbiturils inactivate the restriction reaction of type II endonucleases via supramolecular interactions. This was monitored for different enzyme–DNA combinations in the absence and presence of organic macrocycles. The process can be re-activated by competitive displacement on addition of polyamines.
A configurational and conformational study of (−)-Oseltamivir using a multi-chiroptical approach
Authors: Górecki Marcin
Published: January 2015

Four chiroptical methods, i.e. electronic circular dichroism (ECD), optical rotatory dispersion (ORD), vibrational circular dichroism (VCD), and Raman optical activity (ROA) were employed to discover a set of the most probable conformations of (−)-Oseltamivir in solution.
Fractional transfer of a free unpaired electron to overcome energy barriers in the formation of Fe4+ from Fe3+ during the core contraction of macrocycles: implication for heme distortion
Authors: Liu Qiuhua , Zhou Xiaochun , Liu Haomin , Zhang Xi , Zhou Zaichun
Published: January 2015

The free unpaired electron in Fe3+ ions cannot be directly removed, and needs a transfer pathway with at least four steps to overcome the high energy barriers to form Fe4+ ions.
Expedient synthesis of tetrasubstituted pyrroles via a copper-catalyzed cascade inter-/intramolecular cyclization of 1,3-enynes carry a nitro group with amines
Authors: Bharathiraja Ganesan , Sengoden Mani , Kannan Masanam , Punniyamurthy Tharmalingam
Published: January 2015

Various tetrasubstituted pyrroles/pyrazoles have been prepared from nitro-substituted 1,3-enynes with aromatic amines/hydrazinesviaa copper-catalyzed cascade aza-Michael addition, cyclization and aromatization.
Templated polymerizations on solid supports mediated by complementary nucleoside interactions
Authors: Garcia Margarita , Kempe Kristian , Haddleton David M. , Khan Afzal , Marsh Andrew
Published: January 2015

The preparation of immobilized poly(methacryloyl nucleosides) and their abilities for template polymerizations is discussed.
8-(2-Cycloalkylphenylimino)-5,6,7-trihydro-quinolylnickel halides: polymerizing ethylene to highly branched and lower molecular weight polyethylenes
Authors: Sun Zelin , Yue Erlin , Qu Mengnan , Oleynik Irina V. , Oleynik Ivan I. , Li Kanshe , Liang Tongling , Zhang Wenjuan , Sun Wen-Hua
Published: January 2015

Cycloalkyl-modified 8-arylimino-5,6,7-trihydroquinolylnickel pre-catalysts highly polymerize ethylene into branched polyethylene waxes.
Electrochemical fabrication of Hydrangea macrophylla flower-like Pt hierarchical nanostructures and their properties for methanol electrooxidation
Authors: Wang Xia , Sun Yue , Hu Jun , Li Yong-Jun , Yeung Edward S.
Published: January 2015

Hydrangea macrophylla flower-like Pt hierarchical nanostructures were fabricated by a one-step current-directed growth method and exhibited better electrocatalytic activity and extremely strong stability toward methanol oxidation.
Effect of interactions of PVC and biomass components on the formation of polycyclic aromatic hydrocarbons (PAH) during fast co-pyrolysis
Authors: Zhou Hui , Wu Chunfei , Onwudili Jude A. , Meng Aihong , Zhang Yanguo , Williams Paul T.
Published: January 2015

Mass distribution, gas products and PAH formation from co-pyrolysis of PVC and biomass components were investigated. Biomass materials and/or bio-char can act as catalyst of PVC pyrolysis.
Proline-functionalized metal–organic frameworks and their use in asymmetric catalysis: pitfalls in the MOFs rush
Authors: Canivet Jerome , Farrusseng David
Published: January 2015

Pitfalls in the synthesis and use of chiral MOFs are presented with some best practices for the post-synthetic functionalization.
Pd nanoparticles partially embedded in the inner wall of nitrogen-doped carbon hollow spheres as nanoreactors for catalytic reduction of 4-nitrophenol
Authors: Bian Shao-Wei , Liu Si , Guo Mei-Xia , Xu Ling-Li , Chang Lan
Published: January 2015

Pd@nitrogen-doped carbon nanoreactors (Pd@NC) were synthesized by partially embedding small Pd nanoparticles in the inner wall of the nitrogen-doped carbon shells. Such embedment is critical for improving catalytic activity and stability.
Fractionation, physicochemical properties, nutritional value, antioxidant activity and ACE inhibition of palm kernel expeller protein
Authors: Zheng Yajun , Li Yan , Zhang Youlin , Zhang Runguang , Zhang Qing'an , Zhang Yufeng , Zhao Songlin
Published: January 2015

This paper provides valuable information on the nutritional quality, functional properties, antioxidative and ACE inhibition of palm kernel expeller protein fractions.
Three-dimensional graphene-wrapped PANI nanofiber composite as electrode material for supercapacitors
Authors: Wang Jiande , Xian Haiyang , Peng Tongjiang , Sun Hongjuan , Zheng Fengxian
Published: January 2015

A novel method to prepare three-dimensional graphene-wrapped PANI nanofiber composite with high supercapacitive performance is supplied in this work.
Zn-based ionic liquids as highly efficient catalysts for chemical fixation of carbon dioxide to epoxides
Authors: Liu Mengshuai , Wang Fangxiao , Shi Lei , Liang Lin , Sun Jianmin
Published: January 2015

Novel Zn-TSILs catalysts were developed, which showed high activity towards the cycloaddition of CO2 to epoxides due to synergetic effects.
A novel method of NaHCO3reduction into formic acid with N2H4·H2O over Ni catalyst
Authors: Chen Feiyan , Yao Guodong , Huo Zhibao , Jin Fangming
Published: January 2015

An efficient metal-free method of CO2reduction with N2H4·H2O over common Ni powder is proposed.
Multi-colored luminescent light-harvesting hybrids based on aminoclay and lanthanide complexes
Authors: Wang Tianren , Yu Xiaoyan , Li Zhiqiang , Wang Jin , Li Huanrong
Published: January 2015

Lanthanide(iii)-based multi-colored hybrid materials showing potential in WLEDs and self-referencing luminescent thermometers.
Water adsorption dynamics in active carbon probed by terahertz spectroscopy
Authors: Zhan Honglei , Wu Shixiang , Bao Rima , Zhao Kun , Xiao Lizhi , Ge Lina , Shi Hongjie
Published: January 2015

It is vital to characterize the adsorption dynamics in oil–gas reservoirs and pollution control industry.
pH-responsive host–guest polymerization and blending
Authors: Masseroni Daniele , Rampazzo Enrico , Rastrelli Federico , Orsi Davide , Ricci Lucia , Ruggeri Giacomo , Dalcanale Enrico
Published: January 2015

pH-responsive supramolecular polymerization and polymer blending between complementary host and guest macromolecules are driven by tetraphosphonate cavitand/N-methyl ammonium complexation.
Removal of cadmium and lead from aqueous solutions using nitrilotriacetic acid anhydride modified ligno-cellulosic material
Authors: Huang Yuanqing , Yang Chunping , Sun Zhichao , Zeng Guangming , He Huijun
Published: January 2015

The cost-effective material NTAA-LCM could be promising in the elimination of heavy metals from acidic or neutral wastewater.
A high yield, controllable process for producing tunable near infrared-absorbing gold nanoplates
Authors: James K. T. , O'Toole M. G. , Patel D. N. , Zhang G. , Gobin A. M. , Keynton R. S.
Published: January 2015

This study optimizes a new synthesis technique, DiaSynth, to produce near-infrared absorbing gold nanoplates with prescribed localized surface plasmon resonance wavelengths in high yield without the need for additional laborious purification steps.
Effect of flexible linker length in 3,4-ethylenedioxythiophene derivatives for solid state polymerization
Authors: Tusy Chuong , Peng Kai , Huang Lili , Xia Jiangbin
Published: January 2015

EDOT-linker-EDOT was chosen as a prototype model monomer for solid state polymerization. The linker length can be up to three atoms while the four-atom linker monomer failed under SSP.
Potential in vitro and in vivo colon specific anticancer activity in a HCT-116 xenograft nude mice model: targeted delivery using enteric coated folate modified nanoparticles
Authors: Khatik Renuka , Dwivedi Pankaj , Junnuthula Vijayabhaskar Reddy , Sharma Komal , Chuttani Krishna , Mishra Anil Kumar , Dwivedi Anil Kumar
Published: January 2015

ES–FA–CU–GdNP drug delivery system has been developed for specific targeting in colon cancer and has the promise to address overexpressed FRs.
Doubling of electrochemical parameters via the pre-intercalation of Na+ in layered MnO2 nanoflakes compared to α-MnO2 nanorods
Authors: Radhiyah A. A. , Izan Izwan M. , Baiju V. , Kwok Feng C. , Jamil I. , Jose R.
Published: January 2015

The pre-intercalation of Na+ ions in layered birnessite-MnO2 is shown to have a dramatic influence on its electrochemical properties.
A new high-pressure polymeric nitrogen phase in potassium azide
Authors: Zhang Meiguang , Yan Haiyan , Wei Qun , Liu Hanyu
Published: January 2015

The ELF distributions of 2D “N6” rings along thec-axis inP6/mmm-KN3(left) and 3D “N6” rings along theb-axis inC2/m-N-KN3(right).
An insight into the synthesis of novel aryl-substituted alicyclic β-amino acid derivatives through substrate-directed palladium-catalysed regio- and stereoselective cross-coupling
Authors: Nonn Melinda , Kiss Loránd , Hänninen Mikko M. , Fülöp Ferenc
Published: January 2015

Novel aryl-substituted alicyclic β-amino acid derivatives were synthesized through substrate-determined palladium-catalysed cross-coupling of aryl iodides with five- or six-membered cycloalkene β-amino esters.
Theoretical design of tetra(arenediyl)bis(allyl) derivatives as model compounds for Cope rearrangement transition states
Authors: Salvatella L.
Published: January 2015

Delocated structures bearing 2.3–2.5 Å C⋯C bonds are preferred for some tetra(arenediyl)bis(allyl) systems.
Mechanisms of graphyne-enabled cholesterol extraction from protein clusters
Authors: Zhang Liuyang , Wang Xianqiao
Published: January 2015

Functionalized graphyne provides a novel vehicle for cholesterol removal from protein clusters by molecular dynamics simulations.
Filled and peptide-modified single-walled carbon nanotubes: synthesis, characterization, and in vitro test for cancer cell targeting
Authors: Hu Zhiyuan , Zhao Jingjing , Song Zhaozheng , Yang Chunpeng
Published: January 2015

Multi-functional single-walled carbon nanotubes (SWNTs) with metal endohedral filling and a high degree of polycarboxylation on the sidewalls were synthesized without affecting the SWNTσ-framework.
Effect of HPHT processing on the structure, and thermoelectric properties of Co4Sb12 co-doped with Te and Sn
Authors: Sun Hairui , Jia Xiaopeng , Deng Le , Lv Pin , Guo Xin , Zhang Yuewen , Sun Bing , Liu Binwu , Ma Hongan
Published: January 2015

Te–Sn co-doped Co4Sb12 bulk polycrystalline materials Co4Sb11.7−xTexSn0.3 have been prepared using a high pressure and high temperature method and then characterized using X-ray diffraction.
Synthesis of a nitrogen rich (2D–1D) hybrid carbon nanomaterial using a MnO2 nanorod template for high performance Li-ion battery applications
Authors: Vinayan B. P. , Schwarzburger Nele I. , Fichtner Maximilian
Published: January 2015

A novel approach to synthesize a nitrogen rich few layer graphene–carbon nanotube hybrid nanomaterial for high performance Li ion battery anode electrodes.
Computational studies on structural and electronic properties of functionalized MXene monolayers and nanotubes
Authors: Zhang Xu , Ma Zhinan , Zhao Xudong , Tang Qing , Zhou Zhen
Published: January 2015

This work discloses that the electronic properties of MXenes can be controlled by rolling layers into 10 different types of nanotubes.
In situ preparation of a novel organo-inorganic 6,13-pentacenequinone–TiO2 coupled semiconductor nanosystem: a new visible light active photocatalyst for hydrogen generation
Authors: Pandit Vikram , Arbuj Sudhir , Hawaldar Ranjit , Kshirsagar Pradnya , Mulik Uttam , Gosavi Suresh , Park Chan-Jin , Kale Bharat
Published: January 2015

We investigated a new organo-inorganic hybrid semiconductor nanosystem (6, 13-pentacenequinone–TiO2) for hydrogen production.
Reduction in thrombosis and bacterial adhesion with 7 day implantation of S-nitroso-N-acetylpenicillamine (SNAP)-doped Elast-eon E2As catheters in sheep
Authors: Brisbois Elizabeth J. , Davis Ryan P. , Jones Anna M. , Major Terry C. , Bartlett Robert H. , Meyerhoff Mark E. , Handa Hitesh
Published: January 2015

Nitric oxide-releasing catheters, prepared with S-nitroso-N-acetylpenicillamine doped polymers, reduce thrombus and bacterial adhesion in a 7 day sheep model.
Efficient fiber shaped zinc bromide batteries and dye sensitized solar cells for flexible power sources
Authors: Peng Ming , Yan Kai , Hu Hsienwei , Shen Dinghan , Song Weixing , Zou Dechun
Published: January 2015

Flexible fiber shaped zinc bromide batteries and dye sensitized solar cells for a hybrid energy system with an overall efficiency of 3.4% are presented.
Effect of diselenide administration in thioacetamide-induced acute neurological and hepatic failure in mice
Authors: Stefanello Sílvio Terra , Flores da Rosa Edovando José , Dobrachinski Fernando , Amaral Guilherme Pires , Rodrigues de Carvalho Nélson , Almeida da Luz Sônia Cristina , Bender Caroline Raquel , Schwab Ricardo S. , Dornelles Luciano , Soares Félix Alexandre Antunes
Published: January 2015

Hepatic encephalopathy is a common complication of severe acute hepatic failure and has been associated with high short-term mortality rates.
Re-expression of HPV16 E2 in SiHa (human cervical cancer) cells potentiates NF-κB activation induced by TNF-α concurrently increasing senescence and survival
Authors: Prabhavathy Devan , Subramanian Chandrasekaran Karthik , Karunagaran Devarajan
Published: January 2015

Re-expression of E2 in human papillomavirus (HPV) transformed tumour cells can induce apoptosis; however, some evidences also attribute an important role to E2 in sustaining tumorigenesis. In the present paper, we studied the effects of tumour necrosis factor (TNF)-α-mediated NF-κB (nuclear factor kappa-light-chain-enhancer of activated B-cells) activation on E2-induced senescence in HPV16-integrated SiHa cells. The results show that E2 inhibits endogenous E6 gene expression and sensitizes SiHa cells to TNF-α-induced NF-κB activation. Under this condition there was an increase in the expression of senescent proteins p53, p21, p27 and p16 and senescence-associated (SA)-β-galactosidase activity indicating that TNF-α augments E2-mediated senescence. Re-expression of E2 expression with TNF-α treatment resulted in an increase in the expression of anti-apoptotic Bcl2 (B-cell lymphoma 2) protein and other pro-survival genes like cyclin D1 (cyc D1), survivin and hTERT (human telomerase reverse transcriptase). Concomitantly, E2 + TNF-α combination increased the survival of SiHa cells by positive changes in viability, proliferation and colony formation. E2-induced apoptotic tendency shifted towards senescence in presence of TNF-α by arresting the cells at both G0/G1 and G2/M phases, thus enhancing cell survival. Another observation in the present study is the significant up-regulation of key senescence messaging factors regulated by NF-κB namely interleukin (IL)-6, IL-8, high-mobility group protein A (HMGA)1 and B (HMGB)1 in E2-transfected cells treated with TNF-α. Our data provide a mechanistic basis and a new insight for the role of TNF-α and E2 in linking cellular senescence, tumorigenesis and HPV re-infection.
Highly adjustable mixer‐based UWB pulse generator architecture with leakage compensation integrated in 40 nm CMOS
Authors: Faes B. , Reynaert P. , Leroux P.
Published: January 2015

A novel highly flexible mixer‐based ultra‐wideband (UWB) pulse generator is designed. The baseband pulse generator has a controllable pulse width between 200 ps and 8 ns, while the output amplitude only varies over 80 mV in this entire range. The mixer is adjustable so that the voltage controlled oscillator leakage can be controlled and minimised. The proposed architecture gives a highly flexible UWB pulse generator for which the characteristics can be adjusted to fit the specifications of different applications and the spectral mask of the country/region of usage.
Use of equivalent nonlinearities for studying quantisation effects on sampled multicarrier signals
Authors: Guerreiro João , Dinis Rui , Montezuma Paulo
Published: January 2015

The large dynamic range of multicarrier signals make them very sensitive to quantisation effects. Owing to the non‐continuous nature of quantisation curves, conventional analytical methods used to characterise the distortion effects of quantisation signals are very complex, and can and even have convergence and/or accuracy problems. A simple and accurate analytical method for performance evaluation of quantisation effects on sampled multicarrier signals is presented.
Low‐power transformer‐based current‐reuse injection‐locked frequency divider
Authors: Ha Keum‐Won , Sung Eun‐Taek , Baek Donghyun
Published: January 2015

A novel low‐power injection‐locked frequency divider (ILFD) is proposed, in which a complementary Gm‐boosted Colpitts oscillator core is employed to improve negative transconductance (Gm) and the current‐reuse technique using a single transformer is applied to reduce the power consumption. The proposed ILFD exhibits a self‐resonant frequency of 4.93 GHz with a maximum locking range of 870 MHz at 0 dBm of input power. The phase noises of the input and output signals are −128.54 and −134.53 dBc/Hz, respectively. The ILFD consumes 1.37 and 2.5 mW at 1.15 and 1.3 V, respectively. The chip area is 715.5 × 468 μm2 in a 0.13 μm CMOS process. To the authors’ knowledge, this is the first demonstration of the current‐reuse ILFD.
The fast multipole method and point dipole moment polarizable force fields
Authors: Coles Jonathan P. , Masella Michel
Published: January 2015

We present an implementation of the fast multipole method for computing Coulombic electrostatic and polarization forces from polarizable force-fields based on induced point dipole moments. We demonstrate the expected O(N) scaling of that approach by performing single energy point calculations on hexamer protein subunits of the mature HIV-1 capsid. We also show the long time energy conservation in molecular dynamics at the nanosecond scale by performing simulations of a protein complex embedded in a coarse-grained solvent using a standard integrator and a multiple time step integrator. Our tests show the applicability of fast multipole method combined with state-of-the-art chemical models in molecular dynamical systems.
A new phase difference measurement algorithm for extreme frequency signals based on discrete time Fourier transform with negative frequency contribution
Authors: Shen Ting’ao , Tu Yaqing , Li Ming , Zhang Haitao
Published: January 2015

For the ultralow frequency signals or adjacent Nyquist frequency signals, which widely exist in vibration engineering domain, the traditional discrete time Fourier transform (DTFT) algorithms show poor performance for phase difference measurement. To improve the accuracy of phase difference measurement for these extreme frequency signals, the phase difference measurement error of DTFT algorithm is analyzed, which indicates that the negative frequency contribution is the main cause of the bias. By considering the negative frequency contribution, a new phase difference measurement algorithm for extreme frequency signals is proposed based on DTFT, and the new formulas for phase difference calculation with different windows are derived in detail. The new algorithm has stronger inhibition of spectrum leakage and has a higher accuracy than traditional DTFT algorithms. Simulation and experimental results show that the proposed algorithm has better performance than the other DTFT algorithms.
Two-color two-photon excited fluorescence of indole: Determination of wavelength-dependent molecular parameters
Authors: Herbrich Sebastian , Al-Hadhuri Tawfik , Gericke Karl-Heinz , Shternin Peter S. , Smolin Andrey G. , Vasyutinskii Oleg S.
Published: January 2015

We present a detailed study of two-color two-photon excited fluorescence in indole dissolved in propylene glycol. Femtosecond excitation pulses at effective wavelengths from 268 to 293.33 nm were used to populate the two lowest indole excited states 1La and 1Lb and polarized fluorescence was then detected. All seven molecular parameters and the two-photon polarization ratio Ω containing information on two-photon absorption dynamics, molecular lifetime τf, and rotation correlation time τrot have been determined from experiment and analyzed as a function of the excitation wavelength. The analysis of the experimental data has shown that 1Lb–1La inversion occurred under the conditions of our experiment. The two-photon absorption predominantly populated the 1La state at all excitation wavelengths but in the 287–289 nm area which contained an absorption hump of the 1Lb state 0-0 origin. The components of the two-photon excitation tensor S were analyzed giving important information on the principal tensor axes and absorption symmetry. The results obtained are in a good agreement with the results reported by other groups. The lifetime τf and the rotation correlation time τrot showed no explicit dependence on the effective excitation wavelength. Their calculated weighted average values were found to be τf = 3.83 ± 0.14 ns and τrot = 0.74 ± 0.06 ns.
Instrument for in-situ orientation of superconducting thin-film resonators used for electron-spin resonance experiments
Authors: Mowry Andrew , Chen Yiming , Kubasek James , Friedman Jonathan R.
Published: January 2015

When used in electron-spin resonance measurements, superconducting thin-film resonators must be precisely oriented relative to the external magnetic field in order to prevent the trapping of magnetic flux and the associated degradation of resonator performance. We present a compact design solution for this problem that allows in-situ control of the orientation of the resonator at cryogenic temperatures. Tests of the apparatus show that when proper alignment is achieved, there is almost no hysteresis in the field dependence of the resonant frequency.
Optical and structural properties of plasma-treated Cordyceps bassiana spores as studied by circular dichroism, absorption, and fluorescence spectroscopy
Authors: Lee Geon Joon , Sim Geon Bo , Choi Eun Ha , Kwon Young-Wan , Kim Jun Young , Jang Siun , Kim Seong Hwan
Published: January 2015

To understand the killing mechanism of fungal spores by plasma treatment, the optical, structural, and biological properties of the insect pathogenic fungus Cordyceps bassiana spores were studied. A nonthermal atmospheric-pressure plasma jet (APPJ) was used to treat the spores in aqueous solution. Optical emission spectra of the APPJ acquired in air indicated emission peaks corresponding to hydroxyl radicals and atomic oxygen. When the APPJ entered the aqueous solution, additional reactive species were derived from the interaction of plasma radicals with the aqueous solution. Fluorescence and absorption spectroscopy confirmed the generation of hydroxyl radicals and hydrogen peroxide in the plasma-activated water (PAW). Spore counting showed that plasma treatment significantly reduced spore viability. Absorption spectroscopy, circular dichroism (CD) spectroscopy, and agarose gel electrophoresis of the DNA extracted from plasma-treated spores showed a reduction in spore DNA content. The magnitude of the dip in the CD spectrum was lower in the plasma-treated spores than in the control, indicating that plasma treatment causes structural modifications and/or damage to cellular components. Tryptophan fluorescence intensity was lower in the plasma-treated spores than in the control, suggesting that plasma treatment modified cell wall proteins. Changes in spore viability and DNA content were attributed to structural modification of the cell wall by reactive species coming from the APPJ and the PAW. Our results provided evidence that the plasma radicals and the derived reactive species play critical roles in fungal spore inactivation.
Atom-diatom scattering dynamics of spinning molecules
Authors: Eyles C. J. , Floß J. , Averbukh I. Sh. , Leibscher M.
Published: January 2015

We present full quantum mechanical scattering calculations using spinning molecules as target states for nuclear spin selective atom-diatom scattering of reactive D+H2 and F+H2 collisions. Molecules can be forced to rotate uni-directionally by chiral trains of short, non-resonant laser pulses, with different nuclear spin isomers rotating in opposite directions. The calculations we present are based on rotational wavepackets that can be created in this manner. As our simulations show, target molecules with opposite sense of rotation are predominantly scattered in opposite directions, opening routes for spatially and quantum state selective scattering of close chemical species. Moreover, two-dimensional state resolved differential cross sections reveal detailed information about the scattering mechanisms, which can be explained to a large degree by a classical vector model for scattering with spinning molecules.
Note: A pulsed laser ion source for linear induction accelerators
Authors: Zhang H. , Zhang K. , Shen Y. , Jiang X. , Dong P. , Liu Y. , Wang Y. , Chen D. , Pan H. , Wang W. , Jiang W. , Long J. , Xia L. , Shi J. , Zhang L. , Deng J.
Published: January 2015

We have developed a high-current laser ion source for induction accelerators. A copper target was irradiated by a frequency-quadrupled Nd:YAG laser (266 nm) with relatively low intensities of 108 W/cm2. The laser-produced plasma supplied a large number of Cu+ ions (∼1012 ions/pulse) during several microseconds. Emission spectra of the plasma were observed and the calculated electron temperature was about 1 eV. An induction voltage adder extracted high-current ion beams over 0.5 A/cm2 from a plasma-prefilled gap. The normalized beam emittance measured by a pepper-pot method was smaller than 1 π mm mrad.
Remarks on a convergent flow for marginally trapped surfaces in Lorentz-Minkowski space
Authors: Palmer Bennett
Published: January 2015

We study a flow for a class of spacelike marginally trapped surfaces in Lorentz-Minkowski space under which the surface converges to a spacelike surface with zero mean curvature. The flow decreases the area monotonically. An analogous flow is constructed for marginally trapped surfaces in an arbitrary four dimensional Lorentzian manifold which satisfies the null convergence condition.
Enhanced magnetism of Cun clusters capped with N and endohedrally doped with Cr
Authors: Datta Soumendu , Banerjee Radhashyam , Mookerjee Abhijit
Published: January 2015

The focus of our work is on the production of highly magnetic materials out of Cu clusters. We have studied the relative effects of N-capping as well as N mono-doping on the structural stability and electronic properties of the small Cu clusters using first principles density functional theory based electronic structure calculations. We find that the N-capped clusters are more promising in producing giant magnetic moments, such as 14 μB for the Cu6N6 cluster and 29 μB for the icosahedral Cu13N12 cluster. This is accompanied by a substantial enhancement in their stability. We suggest that these giant magnetic moments of the capped Cun clusters have relevance to the observed room temperature ferromagnetism of Cu doped GaN. For cage-like hollow Cu-clusters, an endohedral Cr-doping together with the N-capping appears as the most promising means to produce stable giant magnetic moments in the copper clusters.
Sodium doping in ZnO crystals
Authors: Parmar N. S. , Lynn K. G.
Published: January 2015

ZnO bulk single crystals were doped with sodium by thermal diffusion. Positron annihilations spectroscopy confirms the filling of zinc vacancies, to >6 μm deep in the bulk. Secondary-ion mass spectrometry measurement shows the diffusion of sodium up to 8 μm with concentration (1–3.5) × 1017 cm−3. Broad photoluminescence excitation peak at 3.1 eV, with onset appearance at 3.15 eV in Na:ZnO, is attributed to an electronic transition from a NaZn level at ∼(220–270) meV to the conduction band. Resistivity in Na doped ZnO crystals increases up to (4–5) orders of magnitude at room temperature.
1H nuclear magnetic resonance study of hydrated water dynamics in perfluorosulfonic acid ionomer Nafion
Authors: Han Jun Hee , Lee Kyu Won , Jeon G. W. , Lee Cheol Eui , Park W. K. , Choi E. H.
Published: January 2015

We have studied the dynamics of hydrated water molecules in the proton exchange membrane of Nafion by means of high-resolution 1H nuclear magnetic resonance (NMR) measurements. “Bound” and “free” states of hydrated water clusters as well as the exchange protons were identified from the NMR chemical shift measurements, and their activation energies were obtained from the temperature-dependent laboratory- and rotating-frame spin-lattice relaxation measurements. Besides, a peculiar motional transition in the ultralow frequency region was observed at 373 K for the “free” hydrated water from the rotating-frame NMR spin-lattice relaxation time measurements.
Amorphous indium-tin-zinc oxide films deposited by magnetron sputtering with various reactive gases: Spatial distribution of thin film transistor performance
Authors: Jia Junjun , Torigoshi Yoshifumi , Kawashima Emi , Utsuno Futoshi , Yano Koki , Shigesato Yuzo
Published: January 2015

This work presents the spatial distribution of electrical characteristics of amorphous indium-tin-zinc oxide film (a-ITZO), and how they depend on the magnetron sputtering conditions using O2, H2O, and N2O as the reactive gases. Experimental results show that the electrical properties of the N2O incorporated a-ITZO film has a weak dependence on the deposition location, which cannot be explained by the bombardment effect of high energy particles, and may be attributed to the difference in the spatial distribution of both the amount and the activity of the reactive gas reaching the substrate surface. The measurement for the performance of a-ITZO thin film transistor (TFT) also suggests that the electrical performance and device uniformity of a-ITZO TFTs can be improved significantly by the N2O introduction into the deposition process, where the field mobility reach to 30.8 cm2 V–1 s–1, which is approximately two times higher than that of the amorphous indium-gallium-zinc oxide TFT.
High-resolution dichroic imaging of magnetic flux distributions in superconductors with scanning x-ray microscopy
Authors: Ruoß S. , Stahl C. , Weigand M. , Schütz G. , Albrecht J.
Published: January 2015

The penetration of magnetic flux into high-temperature superconductors has been observed using a high-resolution technique based on x-ray magnetic circular dichroism. Superconductors coated with thin soft-magnetic layers are observed in a scanning x-ray microscope under the influence of external magnetic fields. Resulting electric currents in the superconductor create an inhomogeneous magnetic field distribution above the superconductor and lead to a local reorientation of the ferromagnetic layer. Measuring the local magnetization of the ferromagnet by x-ray absorption microscopy with circular-polarized radiation allows the analysis of the magnetic flux distribution in the superconductor with a spatial resolution on the nanoscale.
Pseudo Jahn–Teller effect in the origin of enhanced flexoelectricity
Authors: Bersuker I. B.
Published: January 2015

The controversy between the theory and experiment in explaining the origin of enhanced flexoelectricity is removed by taking into account the pseudo Jahn-Teller effect (PJTE) which, under certain conditions, creates local dipolar distortions of dynamic nature, resonating between two or more equivalent orientations. The latter become nonequivalent under a strain gradient thus producing enhanced flexoelectricity: it is much easier to orient ready-made dipoles than to polarize an ionic solid. For BaTiO3, the obtained earlier numerical data for the adiabatic potential energy surface in the space of dipolar displacements in the Ti centers were used to estimate the flexoelectric coefficient f in the paraelectric phase in a one-dimensional model with the strain gradient along the [111] direction: f = −0.43 × 10−6 Cm−1. This eliminates the huge contradiction between the experimental data of f ∼ μ Cm−1 for this case and the theoretical predictions (without the PJTE) of 3–4 orders-of-magnitude smaller values. Enhanced flexoelectricity is thus expected in solids with a sufficient density of centers that have PJTE induced dipolar instabilities. It explains also the origin of enhanced flexoelectricity observed in other solids, noticeable containing Nb perovskite centers which are known to have a PJTE instability, similar to that of Ti centers. The SrTiO3 crystal as a virtual ferroelectric in which the strain gradient eases the condition of PJTE polar instability is also discussed.
Capping layer-tailored interface magnetic anisotropy in ultrathin Co2FeAl films
Authors: Belmeguenai M. , Gabor M. S. , Petrisor T. , Zighem F. , Chérif S. M. , Tiusan C.
Published: January 2015

Co2FeAl (CFA) thin films of various thicknesses (2 nm ≤ d ≤ 50 nm) have been grown on (001) MgO single crystal substrates and then capped with Cr, V, and Ta. Their magnetic and structural properties have been studied by x-ray diffraction (XRD), vibrating sample magnetometry, and broadband microstrip ferromagnetic resonance (MS-FMR). The XRD revealed that the films are epitaxial with the cubic [001] CFA axis normal to the substrate plane and that the chemical order varies from the B2 phase to the A2 phase when decreasing the thickness. The deduced lattice parameters showed that the Cr-capped films exhibit a larger tetragonal distortion, as compared with the films capped with V or Ta. The presence of magnetic dead layers has been observed in CFA samples capped with V and Ta but not in the case of the Cr-capped ones. The effective magnetization, deduced from the fit of MS-FMR measurements, increases (decreases) linearly with the CFA inverse thickness (1/d) for the Cr-capped (Ta-capped) films while it is constant for the V-capped ones. This allows quantifying the perpendicular surface anisotropy coefficients of −0.46 erg/cm2 and 0.74 erg/cm2 for Cr and Ta-capped films, respectively. Moreover, the fourfold and the uniaxial anisotropy fields, measured in these films, showed different trends with a respect to the CFA inverse thickness. This allows inferring that a non-negligible part of the fourfold magnetocrystalline term is of interfacial origin.
Azimuthal-spin-wave-mode-driven vortex-core reversals
Authors: Yoo Myoung-Woo , Kim Sang-Koog
Published: January 2015

We studied, by micromagnetic numerical calculations, asymmetric vortex-core reversals driven by the m = −1 and m = +1 azimuthal spin-wave modes' excitations in soft magnetic circular nano-disks. We addressed the similarities and differences between the asymmetric core reversals in terms of the temporal evolutions of the correlated core-motion speed, locally concentrated perpendicular gyrofield, and magnetization dip near the original vortex core. The criterion for the core reversals was found to be the magnetization dip that must reach the out-of-plane magnetization component, mz = −p, with the initial polarization p, where p = +1 (−1) for the upward (downward) core magnetization. The core-motion speed and the associated perpendicular gyrofield, variable and controllable with static perpendicular field, Hz, applied perpendicularly to the disk plane, must reach their threshold values to meet the ultimate core-reversal criterion. Also, we determined the Hz strength and direction dependence of the core-switching time and threshold exciting field strength required for the core reversals, whose parameters are essential in the application aspect. This work offers deeper insights into the azimuthal spin-wave-driven core-reversal dynamics as well as an efficient means of controlling the azimuthal-modes-driven core reversals.