bluuebunny/crossref_metadata_2025 huggingface dataset:
Upregulation of BMSCs Osteogenesis by Positively-Charged Tertiary Amines on Polymeric Implants via Charge/iNOS Signaling Pathway
Authors: Zhang Wei , Liu Na , Shi Haigang , Liu Jun , Shi Lianxin , Zhang Bo , Wang Huaiyu , Ji Junhui , Chu Paul K.
Published: March 2015

Positively-charged surfaces on implants have a similar potential to upregulate osteogenesis of bone marrow-derived mesenchymal stem cells (BMSCs) as electromagnetic therapy approved for bone regeneration. Generally, their osteogenesis functions are generally considered to stem from the charge-induced adhesion of extracellular matrix (ECM) proteins without exploring the underlying surface charge/cell signaling molecule pathways. Herein, a positively-charged surface with controllable tertiary amines is produced on a polymer implant by plasma surface modification. In addition to inhibiting the TNF-α expression, the positively-charged surface with tertiary amines exhibits excellent cytocompatibility as well as remarkably upregulated osteogenesis-related gene/protein expressions and calcification of the contacted BMSCs. Stimulated by the charged surface, these BMSCs display high iNOS expressions among the three NOS isoforms. Meanwhile, downregulation of the iNOS by L-Can or siRNA inhibit osteogenic differentiation in the BMSCs. These findings suggest that a positively-charged surface with tertiary amines induces osteogenesis of BMSCsviathe surface charge/iNOS signaling pathway in addition to elevated ECM protein adhesion. Therefore, creating a positively-charged surface with tertiary amines is a promising approach to promote osseointegration with bone tissues.
The enhanced fluorescence properties & colloid stability of aqueous CdSe/ZnS QDs modified with N-alkylated poly(ethyleneimine)
Authors: Tang Huanjie , Zhou Changhua , Wu Ruili , Mao Mao , Shen Huaibin , Li Lin Song
Published: March 2015

Amino-functionalized hydrophilic QDs insulated with PEI(n)Cs had enhanced PL intensity and colloidal stability compared to those of PEI-QDs.
DFT and two-dimensional correlation analysis for evaluating the oxygen defect mechanism of low-density 4f (or 5f) elements interacting with Ca-Mt
Authors: Bian Liang , Song Mian-xin , Dong Fa-qin , Duan Tao , Xu Jin-bao , Li Wei-min , Zhang Xiao-yan
Published: March 2015

Existence states of f-shell electrons in Ca-Mt is calculatedviaDFT with 2D-CA techniques. Reasons of f-shell electrons influencing on electronic and optical properties are discussed. Electronic transitions are systematically analyzed.
One-dimensional Ag3PO4/TiO2 heterostructure with enhanced photocatalytic activity for the degradation of 4-nitrophenol
Authors: Zhang Mingyi , Li Lu , Zhang Xitian
Published: March 2015

A one-dimensional Ag3PO4/TiO2 heterostructure exhibits enhanced photocatalytic activity due to the good visible light absorption capability and excellent charge separation characteristics of the formed heterojunction.
A POCl3-mediated synthesis of substituted fused azoacridones derivatives
Authors: Li Xi , Gao Chunmei , Yang Ti , Zhang Bin , Tan Chunyan , Liu Hongxia , Jiang Yuyang
Published: March 2015

We provide an efficient approach to synthesize fused azoacridone derivatives, which showed broad substrate scope and good yields.
Applications of coherent Raman scattering microscopies to clinical and biological studies
Authors: Schie Iwan W. , Krafft Christoph , Popp Jürgen
Published: March 2015

This review provides an update on coherent Raman scattering microscopy of cells and tissues since 2008 including CARS and SRS.
Use of solid-state nanopores for sensing co-translocational deformation of nano-liposomes
Authors: Goyal Gaurav , Darvish Armin , Kim Min Jun
Published: March 2015

This works reports detection of electric field and hydrodynamic stress induced deformation of sub-100 nm liposomes during translocation through solid-state nanopore.
A microbial biofuel cell with an air-breathing cathode for in vivo glucose sensing applications
Authors: Lee Jin Wook
Published: March 2015

A hybrid biofuel cell employing baker's yeast and an abiotic cathode was designed and experimented.
Quantitative characterization of histone post-translational modifications using a stable isotope dimethyl-labeling strategy
Authors: Han Yanpu , Lu Congcong , Zhang Kai , Tian Shanshan , Fan Enguo , Chen Langxing , He Xiwen , Zhang Yukui
Published: March 2015

An efficient approach to quantitatively characterize histone PTMs using stable isotope dimethyl-labeling coupled with mass spectrometry analysis.
Transition-metal-free cross-coupling of thioethers with aryl(cyano)iodonium triflates: a facile and efficient method for the one-pot synthesis of thiocyanates
Authors: Zhu Dan , Chang Denghu , Shi Lei
Published: March 2015

A novel transition-metal-free method for the one-step synthesis of thiocyanates via the C–S bond cleavage of readily available thioethers was developed.
Sharp molecular-sieving of alcohol–water mixtures over phenyldiboronic acid pillared graphene oxide framework (GOF) hybrid membrane
Authors: Li Guihua , Shi Lei , Zeng Gaofeng , Li Meng , Zhang Yanfeng , Sun Yuhan
Published: March 2015

A submicron thick diboronic acid linked GOF/polyvinyl alcohol hybrid membrane was prepared for the first time.
Metal-free [3+2] cycloaddition of azides with Tf2CCH2for the regioselective preparation of elusive 4-(trifluoromethylsulfonyl)-1,2,3-triazoles
Authors: Alcaide Benito , Almendros Pedro , Lázaro-Milla Carlos
Published: March 2015

1,2-Dipole Tf2CCH2is generatedin situfrom 2-(2-fluoro-pyridin-1-ium-1-yl)-1,1-bis[(trifluoromethyl)-sulfonyl]ethan-1-ide and immediately reacted at room temperature with azides to afford previously unknown 4-trifluoromethanesulfonyl 1,2,3-triazoles in a highly regio- and chemoselective fashion.
Two-coordinate hydrido-germylenes
Authors: Hadlington Terrance J. , Schwarze Benedikt , Izgorodina Ekaterina I. , Jones Cameron
Published: March 2015

The first structurally characterised two-coordinate hydrido-germylenes are reported (e.g.see picture), and shown to be resistant to dimerisation, due to the extreme steric bulk of their amide ligands.
Nickel-catalyzed direct thiolation of unactivated C(sp3)–H bonds with disulfides
Authors: Yan Sheng-Yi , Liu Yue-Jin , Liu Bin , Liu Yan-Hua , Zhang Zhuo-Zhuo , Shi Bing-Feng
Published: March 2015

The first nickel-catalyzed thiolation of unactivated C(sp3)–H bonds with disulfides is described.
Fe3O4NPs mediated nonenzymatic electrochemical immunosensor for the total protein of Nosema bombycis detection without addition of substrate
Authors: Xie Hua , Zhang Qiqi , Wang Qin , Chai Yaqin , Yuan Yali , Yuan Ruo
Published: March 2015

This work described an immunosensor for total protein of Nosema bombycis detection based on Fe3O4NPs as catalyst toward methylene blue with the aid of Fe3O4NPs–DNA dendrimers for signal amplification.
Facile synthesis of metal/metal oxide nanoparticles inside a nanoporous carbon matrix (M/MO@C) through the morphology-preserved transformation of metal–organic framework
Authors: Bak Woojeong , Kim Hee Soo , Chun Hyungphil , Yoo Won Cheol
Published: March 2015

Metal–organic frameworks (MOFs) undergo a simple, two-step process to form morphology-preserved metal/metal oxide@carbon composites with tunable porosity and particle sizes.
Laboratory study on OH-initiated degradation kinetics of dehydroabietic acid
Authors: Lai Chengyue , Liu Yongchun , Ma Jinzhu , Ma Qingxin , He Hong
Published: March 2015

The degradation kinetics of dehydroabietic acid by OH radicals were investigated under various environmental conditions.
Influence of Sn content on the hydrogenation of crotonaldehyde catalysed by colloidally prepared PtSn nanoparticles
Authors: Altmann Lena , Wang Xiaodong , Borchert Holger , Kolny-Olesiak Joanna , Zielasek Volkmar , Parisi Jürgen , Kunz Sebastian , Bäumer Marcus
Published: March 2015

For increasing tin concentrations PtSn nanoparticles of similar size show a monotonically increasing selectivity towards crotylalcohol and a volcano like activity.
B800–B850 coherence correlates with energy transfer rates in the LH2 complex of photosynthetic purple bacteria
Authors: Smyth Cathal , Oblinsky Daniel G. , Scholes Gregory D.
Published: March 2015

Delocalization of a model light-harvesting complex is investigated using multipartite measures inspired by quantum information science.
Design of PAMAM-COO dendron-grafted surfaces to promote Pb(ii) ion adsorption
Authors: Chong Leebyn , Dutt Meenakshi
Published: March 2015

A coarse-grained molecular dynamics study of carboxylate functionalized polyamidoamine (PAMAM-COO) dendrons grafted onto a surface for the adsorption of Pb ions.
Effects of the surface stoichiometry of seeds on GaN layer growth by hydride vapour phase epitaxy
Authors: Wang B. , Zhao Z. D. , Xu W. , Sui Y. P. , Yu G. H.
Published: March 2015

During the HVPE growth, the non-stoichiometric area on GaN seeds such as the metallic Ga layer, which acts as a mask, lowers the dislocation density of the epilayer.
Graphene-based nanomaterials for versatile imaging studies
Authors: Yoo Je Min , Kang Jin Hyoun , Hong Byung Hee
Published: March 2015

This review highlights recent applications of graphene-based nanomaterials for various types of imaging studies.
Modeling of enzymatic production of isomaltooligosaccharides: a mechanistic approach
Authors: Basu Anindya , Mutturi Sarma , Prapulla Siddalingaiya Gurudutt
Published: March 2015

In the current investigation the production of isomaltooligosaccharides (IMO) by transglucosylation of maltose using α-glucosidase was modeled by a mechanistic approach. Parameters are estimated by a genetic algorithm followed by sensitivity analysis and experimental validation.
Mechanistic study and catalyst development for selective carbon monoxide methanation
Authors: Tada S. , Kikuchi R.
Published: March 2015

As for selective CO methanation over heterogeneous catalysts, numerous investigations of the reaction mechanism and catalyst development are reviewed.
Preferential occupancy of strontium in the hydroxyapatite lattice in biphasic mixtures formed from non-stoichiometric calcium apatites
Authors: Nandha Kumar P. , Mishra Sandeep K. , Udhay Kiran R. , Kannan S.
Published: March 2015

Hydroxyapatite unit cell reflecting the preferential occupancy of Sr2+ at Ca2+ (2) site. Crystal framework represents bonding and orientation of PO43− with Ca2+ and Sr2+ and their relative OH− bonding, which proposes the thermodynamically stable configuration.
Magnesium amino-bis(phenolato) complexes for the ring-opening polymerization of rac-lactide
Authors: Devaine-Pressing Katalin , Lehr Joshua H. , Pratt Michelle E. , Dawe Louise N. , Sarjeant Amy A. , Kozak Christopher M.
Published: March 2015

Magnesium complexes capable of rac-lactide polymerization in both the melt and in solution at elevated temperatures were synthesized. End-group analysis by MALDI-TOF showed both linear and cyclic PLA.
Drinking water purity – a UK perspective
Authors: Machell John , Prior Kevin , Allan Richard , Andresen John M.
Published: March 2015

This article outlines a UK-based perspective on the meaning of water purity based on relevant literature and consultation with members of the Water Science Forum of the Royal Society of Chemistry.
Antiproliferative effect of Dendrobium catenatum Lindley polypeptides against human liver, gastric and breast cancer cell lines
Authors: Zheng Qiuping , Qiu Daoshou , Liu Xiaojin , Zhang Lei , Cai Shike , Zhang Xuewu
Published: March 2015

Ten sub-peptides from Dendrobium catenatum Lindley contained in fraction A3 were separated. Fraction A3 exhibited anti-proliferative activity against cancer cells.
The p53-inducible gene 3 involved in flavonoid-induced cytotoxicity through the reactive oxygen species-mediated mitochondrial apoptotic pathway in human hepatoma cells
Authors: Zhang Qiang , Cheng Guangdong , Qiu Hongbin , Zhu Liling , Ren Zhongjuan , Zhao Wei , Zhang Tao , Liu Lei
Published: March 2015

PIG3 is a key regulator that is responsible for the prooxidant activity and apoptosis-inducing effect of flavonoids on cancer cells.
Superior peroxidase mimetic activity of carbon dots–Pt nanocomposites relies on synergistic effects
Authors: Dong Yuming , Zhang Jingjing , Jiang Pingping , Wang Guangli , Wu Xiuming , Zhao Hui , Zhang Chi
Published: March 2015

CDs–Pt nanocomposites were prepared and proposed as robust enzyme mimetics for the first time.
Gold nanoparticle–mesoporous silica sheet composites with enhanced antibody adsorption capacity
Authors: Nakanishi Kazuma , Tomita Masahiro , Masuda Yoshitake , Kato Katsuya
Published: March 2015

For the enhancement of antibody adsorption capacity, gold nanoparticle–MPS sheet composites were prepared. The dispersed gold nanoparticles were loaded onto an MPS sheetviadeposition–precipitation using HAuCl4.
Influence of noncovalent interactions on the structures of metal–organic hybrids based on a [VO2(2,6-pydc)]− tecton with cations of imidazole, pyridine and its derivatives
Authors: Koleša-Dobravc Tanja , Meden Anton , Perdih Franc
Published: March 2015

Hydrogen-bonding has a profound effect on topologies, and various 1D (band, pillar or chain), 2D and 3D hydrogen bonding networks have been observed.
The ring size of cyclic amines as a relevant feature in the activity of Ru-based complexes for ROMP
Authors: Fonseca Larissa R. , Nascimento Eduardo S. P. , Silva Sá José L. , Lima-Neto Benedito S.
Published: March 2015

The ring size of cyclic amines influences the yield, Mw and PDI values of polynorbonene obtained via ROMP using [RuCl2(PPh3)2(amine)x] as the starting complex.
Anti-epidermal growth factor receptor conjugated mesoporous zinc oxide nanofibers for breast cancer diagnostics
Authors: Ali Md. Azahar , Mondal Kunal , Singh Chandan , Dhar Malhotra Bansi , Sharma Ashutosh
Published: March 2015

We report the fabrication of an efficient, label-free, selective and highly reproducible immunosensor with unprecedented sensitivity (femto-molar) to detect a breast cancer biomarker for early diagnostics.
Participation of an additional 4′-hydroxymethyl group in the cleavage and isomerization of ribonucleoside 3′-phosphodiesters
Authors: Lain Luigi , Lönnberg Harri , Lönnberg Tuomas
Published: March 2015

The impact of an additional 4′-hydroxymethyl group on the cleavage and isomerization of an RNA model compound is modest.
A new highly conjugated crossed benzodithiophene and its donor–acceptor copolymers for high open circuit voltages polymer solar cells
Authors: Liu Deyu , Gu Chunyang , Xiao Manjun , Qiu Meng , Sun Mingliang , Yang Renqiang
Published: March 2015

What is theVoclimit of BDT and DTBT backboned photovoltaic polymers? At least 0.95 V can be achieved.!
Selective degradation in aliphatic block copolyesters by controlling the heterogeneity of the amorphous phase
Authors: Arias Veluska , Olsén Peter , Odelius Karin , Höglund Anders , Albertsson Ann-Christine
Published: March 2015

Controlling the course of the degradation of aliphatic polyesters is a key question when designing new degradable materials.
Modification of block copolymer vesicles: what will happen when AB diblock copolymer is block-extended to an ABC triblock terpolymer?
Authors: Shen Xiaoyan , Huo Fei , Kang Haijiao , Zhang Shifeng , Li Jianzhang , Zhang Wangqing
Published: March 2015

The PEG-b-PS diblock copolymer vesicles were converted into the membrane-compartmentalized vesicles of the PEG-b-PS-b-P4VP triblock terpolymer through seeded RAFT polymerization.
Efficient sodium bisulfite-catalyzed synthesis of benzothiazoles and their potential as ureases inhibitors
Authors: Pereira Araujo Débora , Santos Morais Vinicius Stefano , de Fátima Ângelo , Modolo Luzia Valentina
Published: March 2015

In this work we report the successful use of sodium bisulfite as catalyst for the synthesis of 19 benzothiazoles (BZTs) under microwave irradiation with yields from 80% to 100%.
A novel cocrystal explosive NTO/TZTN with good comprehensive properties
Authors: Wu Jin-Ting , Zhang Jian-Guo , Li Tong , Li Zhi-Min , Zhang Tong-Lai
Published: March 2015

A novel binary cocrystal explosive of NTO was discovered and it exhibits strong intermolecular hydrogen bond interaction in crystal structure.
Effect of a solid solution of AlN on the crystal structure and optical properties of LiSi2N3:Eu phosphors
Authors: Wu Quansheng , Ding Jianyan , Wang Chuang , Li Yanyan , Wang Xicheng , Mao Aijun , Wang Yuhua
Published: March 2015

The solid solutions could be the useful way to improve the luminescence intensity of LiSi2N3:Eu phosphors.
Trifluoromethyl syn- or anti-γ-amino alcohols by one-pot solvent-free Mannich-type reactions under temperature control
Authors: Fioravanti Stefania , Parise Luca , Pelagalli Alessia , Pellacani Lucio , Trulli Laura
Published: March 2015

A highly diastereoselective synthesis of fluorinated syn- or anti-γ-amino alcohols was reported by a simple and environmentally benign methodology. Unexpectedly, a strong influence of the reaction conditions on the facial selective attack was found.
C–N cross-coupling reaction catalysed by reusable CuCr2O4 nanoparticles under ligand-free conditions: a highly efficient synthesis of triarylamines
Authors: Safaei-Ghomi Javad , Akbarzadeh Zeinab , Khojastehbakht-Koopaei Bahareh
Published: March 2015

A convenient, efficient and ligand-free method for the C–N coupling reaction of anilines and aryl iodides was performed using CuCr2O4 nanoparticles.
Elevated rate capability of sulfur wrapped with thin rGO layers for lithium–sulfur batteries
Authors: Ahn Wook , Lee Dong Un , Song Hoon Sub , Yeon Sun-Hwa , Kim Kwang-Bum , Chen Zhongwei
Published: March 2015

The sulfur nanoparticle wrapped with thin layer of graphene is successfully synthesized by a facile solution impregnation method.
Synthesis of soluble poly(vinylene carbonate) by redox-initiated RAFT process in microemulsion and its aminolysis yielding snow-white polymethylol
Authors: Kumru Baris , Bicak Niyazi
Published: March 2015

The redox-initiated RAFT polymerization of VCB in microemulsion at RT yields DMF-soluble living polymer, aminolysis of which affords pure polymethylol.
Controlled fabrication of hierarchically porous Ti/Sb–SnO2anode from honeycomb to network structure with high electrocatalytic activity
Authors: Asim Sumreen , Yin Jiao , Yue Xiu , Shah Muhammad Wajid , Zhu Yunqing , Li Yingxuan , Wang Chuanyi
Published: March 2015

Hierarchically porous Ti/Sb–SnO2-honeycomb and Ti/Sb–SnO2-network anodes with high porosity, efficient electroactive sites, enlarged surface area are facilely fabricated.
Enhancement of photoluminescence emission and anomalous photoconductivity properties of Fe3O4@SiO2 core–shell microspheres
Authors: Jana S. K. , Majumder S. , Satpati B. , Mishra S. K. , Srivastava R. K. , Banerjee S.
Published: March 2015

We report the successful synthesis of both pristine Fe3O4 and the Fe3O4@SiO2 core@shell structure. The Fe3O4@SiO2 core@shell sample shows enhanced photoluminescence compared to pristine Fe3O4, while reduced and negative photoconductivity is observed in the same sample.
Fluorescence quenching in N-doped graphene derived from graphitic nitrogen
Authors: Wang Xing , Amat Miribangul , Wang Shuai , Jian Jikang
Published: March 2015

In this work, N-doped graphene (NG) has been synthesized successfully by calcination of dicyandiamide and glucose mixture in an argon atmosphere.
Correction: AIE-active mechanochromic materials based N-phenylcarbazol-substituted tetraarylethene for OLED applications
Authors: Zhao He , Wang Yang , Wang Yongtao , He Gufeng , Xue Mei , Guo Pingan , Dai Bin , Liu Zhiyong , Qi Yu
Published: March 2015

Correction for ‘AIE-active mechanochromic materials based N-phenylcarbazol-substituted tetraarylethene for OLED applications’ by He Zhao et al., RSC Adv., 2015, 5, 19176–19181.
The analysis of analogy use in the teaching of introductory quantum theory
Authors: Didiş Nilüfer
Published: March 2015

This study analyzes the analogies used in the teaching of introductory quantum theory concepts. Over twelve weeks, the researcher observed each class for a semester and conducted interviews with the students and the instructor. In the interviews, students answered questions about quantum theory concepts, which the instructor had taught them using analogies, and also discussed the effectiveness of these analogies. This study identified 48 analogies used by the instructor over the course of 53 fifty minute classes. The analysis of video recordings of the classes revealed that most of the analogies were constructed at the beginning of the semester during the teaching of the particle nature of waves, which is critical for understanding quantum theory. A large proportion of the analogies were given in verbal format; however, a limited number of pictorial and body motion elements were also used together with the analogies. The analogies were mainly positioned as an embedded activator prior to drawing conclusions about the target. It was also observed that analogies were used as an advance organizer and post synthesizer. In addition, the number of simple and enriched analogies used was similar. A limited number of analog explanations were identified and none of the analogies used indicated strategy identification. The instructor never mentioned the limitation of each analogy during their use in class as well. A large proportion of the analogies used spontaneously included both anthropomorphic and environmental characteristics. Although the presentation medium of the analogies was mainly discourse, the presentation of analogies in role play, story and brainstorming was also identified. In half of the analogy use, the instructor intended their use for clarification of the concepts; however, the use of analogies for introduction of a new topic, gaining attention, increasing participation and discriminating between classical and quantum issues was also observed, indicating a diverse use of analogies. In addition, the interviews revealed that students liked the use of analogies in their classes and believed that they had a positive effect on their understanding of new concepts.
In vivo evaluation of small-molecule thermoresponsive anticancer drugs potentiated by hyperthermia
Authors: Clavel Catherine M. , Nowak-Sliwinska Patrycja , Păunescu Emilia , Griffioen Arjan W. , Dyson Paul J.
Published: March 2015

Hyperthermia used as an adjuvant with chemotherapy is highly promising in the treatment of certain cancers.
Grafting of a redox polymer onto carbon nanotubes for high capacity battery materials
Authors: Ernould Bruno , Devos Marine , Bourgeois Jean-Pierre , Rolland Julien , Vlad Alexandru , Gohy Jean-François
Published: March 2015

We disclose a strategy towards grafting of nitroxide-bearing polymer brushes on multi-walled carbon nanotubes as a material for organic radical batteries.
Multiferroic properties of the layered perovskite-related oxide La6(Ti0.67Fe0.33)6O20
Authors: Cheng Xiangyi , Wang Xiaoxiong , Yang Hongshun , Ruan Keqing , Li Xiaoguang
Published: March 2015

The layered perovskite-related oxide, La6(Ti0.67Fe0.33)6O20, with two competing magnetic interactions presents multiferroic behavior.
Stability and electronic properties of silicene on WSe2
Authors: Zhu Jiajie , Schwingenschlögl Udo
Published: March 2015

The Dirac physics of silicene is preserved on the WSe2 substrate with a sufficiently large band gap to withstand thermal fluctuations.
Metabolomics reveals disturbed metabolic pathways in human lung epithelial cells exposed to airborne fine particulate matter
Authors: Huang Qingyu , Zhang Jie , Luo Lianzhong , Wang Xiaofei , Wang Xiaoxue , Alamdar Ambreen , Peng Siyuan , Liu Liangpo , Tian Meiping , Shen Heqing
Published: March 2015

Airborne PM2.5 exposure disturbs citrate cycle, amino acid biosynthesis and metabolism, and glutathione metabolism in A549 cells.
Cyanobacterially generated peloids in laminated, organic‐matter rich, limestones: an unobtrusive presence
Authors: Tribovillard Nicolas‐Pierre
Published: March 2015

The late‐Kimmeridgian Southern Jura (France) is a carbonate platform where laminated limestones accumulated locally (notably at Orbagnoux). The two types of laminations encountered result either from particle settling in a very quiet environment or from bacterial mat growth. In the latter case, as revealed by acid etching, the dark‐coloured laminae result from filamentous cyanobacteria developments, whereas the light‐coloured laminae appear, surprisingly, to comprise packed peloids. These peloids are interpreted as originating from the in vivo or shortly post mortem calcification of sheaths of coccoid cyanobacteria in an environment loaded by temporary excess alkalinity (and possible H2S emissions). Thus, a simple etching treatment reveals the unsuspected, albeit prominent, role of cyanobacteria in the genesis of the limestones from Orbagnoux. As such facies are widespread in Late Jurassic records, the role of cyanobacteria in their formation deserves re‐evaluation.
High friction on ice provided by elastomeric fiber composites with textured surfaces
Authors: Rizvi R. , Naguib H. , Fernie G. , Dutta T.
Published: March 2015

Two main applications requiring high friction on ice are automobile tires and footwear. The main motivation behind the use of soft rubbers in these applications is the relatively high friction force generated between a smooth rubber contacting smooth ice. Unfortunately, the friction force between rubber and ice is very low at temperatures near the melting point of ice and as a result we still experience automobile accidents and pedestrian slips and falls in the winter. Here, we report on a class of compliant fiber-composite materials with textured surfaces that provide outstanding coefficients of friction on wet ice. The fibrous composites consist of a hard glass-fiber phase reinforcing a compliant thermoplastic polyurethane matrix. The glass-fiber phase is textured such that it is aligned transversally and protruding out of the elastomer surface. Our analysis indicates that the exposed fiber phase exhibits a “micro-cleat” effect, allowing for it to fracture the ice and increase the interfacial contact area thereby requiring a high force to shear the interface.
Existence of a lower bound for the distance between point masses of relative equilibria for generalised quasi-homogeneous n-body problems and the curved n-body problem
Authors: Tibboel Pieter
Published: March 2015

We prove that if for relative equilibrium solutions of a generalisation of quasi-homogeneous n-body problems the masses and rotation are given, then the minimum distance between the point masses of such a relative equilibrium has a universal lower bound that is not equal to zero. We furthermore prove that the set of such relative equilibria is compact and prove related results for n-body problems in spaces of constant Gaussian curvature.
Ultrafast phosphate hydration dynamics in bulk H2O
Authors: Costard Rene , Tyborski Tobias , Fingerhut Benjamin P. , Elsaesser Thomas
Published: March 2015

Phosphate vibrations serve as local probes of hydrogen bonding and structural fluctuations of hydration shells around ions. Interactions of H2PO4− ions and their aqueous environment are studied combining femtosecond 2D infrared spectroscopy, ab-initio calculations, and hybrid quantum-classical molecular dynamics (MD) simulations. Two-dimensional infrared spectra of the symmetric (νS(PO2−)) and asymmetric (νAS(PO2−)) PO2− stretching vibrations display nearly homogeneous lineshapes and pronounced anharmonic couplings between the two modes and with the δ(P-(OH)2) bending modes. The frequency-time correlation function derived from the 2D spectra consists of a predominant 50 fs decay and a weak constant component accounting for a residual inhomogeneous broadening. MD simulations show that the fluctuating electric field of the aqueous environment induces strong fluctuations of the νS(PO2−) and νAS(PO2−) transition frequencies with larger frequency excursions for νAS(PO2−). The calculated frequency-time correlation function is in good agreement with the experiment. The ν(PO2−) frequencies are mainly determined by polarization contributions induced by electrostatic phosphate-water interactions. H2PO4−/H2O cluster calculations reveal substantial frequency shifts and mode mixing with increasing hydration. Predicted phosphate-water hydrogen bond (HB) lifetimes have values on the order of 10 ps, substantially longer than water-water HB lifetimes. The ultrafast phosphate-water interactions observed here are in marked contrast to hydration dynamics of phospholipids where a quasi-static inhomogeneous broadening of phosphate vibrations suggests minor structural fluctuations of interfacial water.
Wavelength dependent resonance Raman band intensity of broadband stimulated Raman spectroscopy of malachite green in ethanol
Authors: Cen Qiongyan , He Yuhan , Xu Mei , Wang Jingjing , Wang Zhaohui
Published: March 2015

Resonance broadband stimulated Raman spectroscopy of malachite green in ethanol has been performed. With a tuning picosecond visible laser source and a broadband Raman probe, the Raman gain and loss spectra have been measured simultaneously. By scanning the Raman pump across the first absorption band of the molecule, we found that the resonant Raman bands could be only seen when the pump laser tuned in the range of the red edge of the S1←S0 transition. Dispersive lineshapes of resonant Raman bands have been observed in the Raman loss spectra, while the line shape is normal (same as spontaneous Raman) in the Raman gain spectra. Although, the resonant bands in the loss spectrum are usually stronger than that in the gain spectrum, the band intensities of both loss and gain linearly increase with the pump energy. The relative magnitude of each corresponding resonant band in the Raman loss and gain varies with the pump wavelength. Mode specified Raman excitation profiles have been obtained through broadband stimulated Raman measurement.
Molecular dynamics study of two-dimensional sum frequency generation spectra at vapor/water interface
Authors: Ishiyama Tatsuya , Morita Akihiro , Tahara Tahei
Published: March 2015

Two-dimensional heterodyne-detected vibrational sum frequency generation (2D HD-VSFG) spectra at vapor/water interface were studied by molecular dynamics (MD) simulation with a classical flexible and nonpolarizable model. The present model well describes the spectral diffusion of 2D infrared spectrum of bulk water as well as 2D HD-VSFG at the interface. The effect of isotopic dilution on the 2D HD-VSFG was elucidated by comparing the normal (H2O) water and HOD water. We further performed decomposition analysis of 2D HD-VSFG into the hydrogen-bonding and the dangling (or free) OH vibrations, and thereby disentangled the different spectral responses and spectral diffusion in the 2D HD-VSFG. The present MD simulation demonstrated the role of anharmonic coupling between these modes on the cross peak in the 2D HD-VSFG spectrum.
3D RISM theory with fast reciprocal-space electrostatics
Authors: Heil Jochen , Kast Stefan M.
Published: March 2015

The calculation of electrostatic solute-solvent interactions in 3D RISM (“three-dimensional reference interaction site model”) integral equation theory is recast in a form that allows for a computational treatment analogous to the “particle-mesh Ewald” formalism as used for molecular simulations. In addition, relations that connect 3D RISM correlation functions and interaction potentials with thermodynamic quantities such as the chemical potential and average solute-solvent interaction energy are reformulated in a way that calculations of expensive real-space electrostatic terms on the 3D grid are completely avoided. These methodical enhancements allow for both, a significant speedup particularly for large solute systems and a smoother convergence of predicted thermodynamic quantities with respect to box size, as illustrated for several benchmark systems.
An elementary singularity-free Rotational Brownian Dynamics algorithm for anisotropic particles
Authors: Ilie Ioana M. , Briels Wim J. , den Otter Wouter K.
Published: March 2015

Brownian Dynamics is the designated technique to simulate the collective dynamics of colloidal particles suspended in a solution, e.g., the self-assembly of patchy particles. Simulating the rotational dynamics of anisotropic particles by a first-order Langevin equation, however, gives rise to a number of complications, ranging from singularities when using a set of three rotational coordinates to subtle metric and drift corrections. Here, we derive and numerically validate a quaternion-based Rotational Brownian Dynamics algorithm that handles these complications in a simple and elegant way. The extension to hydrodynamic interactions is also discussed.
Using fast moving electrode to achieve overvoltage breakdown of gas switch stressed with high direct voltages
Authors: Zou X. B. , Shi H. T. , Xie H. , Wang Xinxin , Zhang Guixin
Published: March 2015

A small-scale fast risetime gas switch attached to a 50 Ω pulse forming line is tested. It includes a fast moving electrode and a fixed electrode. For the applied direct voltages, such as 2.8 kV, 2.0 kV, and 1.0 kV, the risetimes of this switch are tested to be ∼3.8 ns, ∼2.3 ns, and ∼1.1 ns, respectively, while the risetimes of a switch with two fixed electrodes are about ∼10.1 ns, ∼9.0 ns, and ∼3.6 ns. The results of high-speed photography and laser interferometry reveal that the moving electrode will obviously shorten discharge spark length but almost will not change the inter-electrodes gas pressure. The reason of shortening spark length is the existence of the discharge time delay of gas switch. After moving to the static breakdown spacing, the fast moving electrode will move on for an additional distance within the discharge time delay, which makes gas switch achieve overvoltage breakdown under high direct voltages and therefore leads to shorter spark length and faster switch risetime.
Polymers encapsulated in short single wall carbon nanotubes: Pseudo-1D morphologies and induced chirality
Authors: Kumar Sunil , Pattanayek Sudip K. , Pereira Gerald G.
Published: March 2015

Molecular dynamics simulations are performed to investigate the stable morphologies of semi-flexible polymer chains within a single wall carbon nanotube (CNT). We characterize these morphologies with a variety of measures. Due to the different curvature inside the CNT to outside, there are increased numbers of polymer-CNT bead contacts for polymers which reside inside the CNT. A sufficiently long polymer chain first adsorbs on the exterior of the nanotube and subsequently moves inside the cavity of the nanotube. At equilibrium, the polymer configuration consists of a central stem surrounded by helically wrapped layers. Sections of the polymer outside the CNT have helical conformations (for CNTs of small radius) or circular arrangements (for CNTs of larger radius). Polymers encapsulated within the CNT have an increased chirality due to packing of the beads and this chirality is further enhanced for moderately stiff chains.
Tunable beam displacer
Authors: Salazar-Serrano Luis José , Valencia Alejandra , Torres Juan P.
Published: March 2015

We report the implementation of a tunable beam displacer, composed of a polarizing beam splitter (PBS) and two mirrors, that divides an initially polarized beam into two parallel beams whose separation can be continuously tuned. The two output beams are linearly polarized with either vertical or horizontal polarization and no optical path difference is introduced between them. The wavelength dependence of the device as well as the maximum separation between the beams achievable is limited mainly by the PBS characteristics.
On the analysis of inhomogeneous magnetic field spectrometer for laser-driven ion acceleration
Authors: Jung D. , Senje L. , McCormack O. , Yin L. , Albright B. J. , Letzring S. , Gautier D. C. , Dromey B. , Toncian T. , Fernandez J. C. , Zepf M. , Hegelich B. M.
Published: March 2015

We present a detailed study of the use of a non-parallel, inhomogeneous magnetic field spectrometer for the investigation of laser-accelerated ion beams. Employing a wedged yoke design, we demonstrate the feasibility of an in-situ self-calibration technique of the non-uniform magnetic field and show that high-precision measurements of ion energies are possible in a wide-angle configuration. We also discuss the implications of a stacked detector system for unambiguous identification of different ion species present in the ion beam and explore the feasibility of detection of high energy particles beyond 100 MeV/amu in radiation harsh environments.
Magneto-optical Kramers-Kronig analysis
Authors: Levallois Julien , Nedoliuk Ievgeniia O. , Crassee Iris , Kuzmenko Alexey B.
Published: March 2015

We describe a simple magneto-optical experiment and introduce a magneto-optical Kramers-Kronig analysis (MOKKA) that together allow extracting the complex dielectric function for left- and right-handed circular polarizations in a broad range of frequencies without actually generating circularly polarized light. The experiment consists of measuring reflectivity and Kerr rotation, or alternatively transmission and Faraday rotation, at normal incidence using only standard broadband polarizers without retarders or quarter-wave plates. In a common case, where the magneto-optical rotation is small (below ∼0.2 rad), a fast measurement protocol can be realized, where the polarizers are fixed at 45∘ with respect to each other. Apart from the time-effectiveness, the advantage of this protocol is that it can be implemented at ultra-high magnetic fields and in other situations, where an in-situ polarizer rotation is difficult. Overall, the proposed technique can be regarded as a magneto-optical generalization of the conventional Kramers-Kronig analysis of reflectivity on bulk samples and the Kramers-Kronig constrained variational analysis of more complex types of spectral data. We demonstrate the application of this method to the textbook semimetals bismuth and graphite and also use it to obtain handedness-resolved magneto-absorption spectra of graphene on SiC.
Characteristics of bowl-shaped coils for transcranial magnetic stimulation
Authors: Yamamoto Keita , Suyama Momoko , Takiyama Yoshihiro , Kim Dongmin , Saitoh Youichi , Sekino Masaki
Published: March 2015

Transcranial magnetic stimulation (TMS) has recently been used as a method for the treatment of neurological and psychiatric diseases. Daily TMS sessions can provide continuous therapeutic effectiveness, and the installation of TMS systems at patients' homes has been proposed. A figure-eight coil, which is normally used for TMS therapy, induces a highly localized electric field; however, it is challenging to achieve accurate coil positioning above the targeted brain area using this coil. In this paper, a bowl-shaped coil for stimulating a localized but wider area of the brain is proposed. The coil's electromagnetic characteristics were analyzed using finite element methods, and the analysis showed that the bowl-shaped coil induced electric fields in a wider area of the brain model than a figure-eight coil. The expanded distribution of the electric field led to greater robustness of the coil to the coil-positioning error. To improve the efficiency of the coil, the relationship between individual coil design parameters and the resulting coil characteristics was numerically analyzed. It was concluded that lengthening the outer spherical radius and narrowing the width of the coil were effective methods for obtaining a more effective and more uniform distribution of the electric field.
Low frequency noise elimination technique for 24-bit Σ-Δ data acquisition systems
Authors: Qu Shao-Bo , Robert Olivier , Lognonné Philippe , Zhou Ze-Bing , Yang Shan-Qing
Published: March 2015

Low frequency 1/f noise is one of the key limiting factors of high precision measurement instruments. In this paper, digital correlated double sampling is implemented to reduce the offset and low frequency 1/f noise of a data acquisition system with 24-bit sigma delta (Σ-Δ) analog to digital converter (ADC). The input voltage is modulated by cross-coupled switches, which are synchronized to the sampling clock, and converted into digital signal by ADC. By using a proper switch frequency, the unwanted parasitic signal frequencies generated by the switches are avoided. The noise elimination processing is made through the principle of digital correlated double sampling, which is equivalent to a time shifted subtraction for the sampled voltage. The low frequency 1/f noise spectrum density of the data acquisition system is reduced to be flat down to the measurement frequency lower limit, which is about 0.0001 Hz in this paper. The noise spectrum density is eliminated by more than 60 dB at 0.0001 Hz, with a residual noise floor of (9 ± 2) nV/Hz1/2 which is limited by the intrinsic white noise floor of the ADC above its corner frequency.
Inertial shear bands in granular materials
Authors: Berzi Diego , Jenkins James T.
Published: March 2015

We provide numerical solutions to the momentum and energy balance of a kinetic theory for the steady, collisional shearing of identical, inelastic, frictional spheres between two different types of boundaries—rigid-bumpy and erodible, in the absence of gravity. A rigid-bumpy boundary is a source of fluctuation energy for the flow, an erodible boundary is a sink. As a consequence, the characteristics of shearing between two rigid-bumpy boundaries, two erodible boundaries, and a rigid-bumpy and an erodible boundary are all different. Here, we display these differences and relate them to measurements of inhomogeneous shearing and the development of shear bands in laboratory experiments.
Magneto-reactance based detection of MnO nanoparticle-embedded Lewis lung carcinoma cells
Authors: Devkota J. , Howell M. , Mukherjee P. , Srikanth H. , Mohapatra S. , Phan M. H.
Published: March 2015

We demonstrate the capacity of detecting magnetically weak manganese oxide (MnO) nanoparticles and the Lewis lung carcinoma (LLC) cancer cells that have taken up these nanoparticles using a novel biosensor based on the magneto-reactance (MX) effect of a soft ferromagnetic amorphous ribbon with a microhole-patterned surface. While the magnetic moment of the MnO nanoparticles is relatively small, and a magneto-impedance based sensor fails to detect them in solution (0.05 mg/ml manganese oxide lipid micellar nanoparticles) and inside cells at low concentrations (8.25 × 104 cells/ml), the detection of these nanoparticles and the LLC cells containing them is achieved with the MX-based sensor, which, respectively, reaches the detection sensitivity of ∼3.6% and 2.8% as compared to the blank cells. Since the MnO nanoparticles are a promising contrast agent for magnetic resonance imaging (MRI) of lung cells, the MX-based biosensing technique can be developed as a pre-detection method for MRI of lung cancer cells.
Angular dependence of hysteresis scaling and coercivity for anisotropically distributed ferromagnetic nanoparticles in paramagnetic matrix
Authors: Miura Kodai , Kobayashi Satoru , Onuki Yusuke , Szpunar Jerzy A. , Kamada Yasuhiro
Published: March 2015

We have investigated anisotropy behavior of coercivity and scaling law for nano-scale ferromagnetic phases embedded in a paramagnetic matrix of an austenitic stainless steel. Small ferromagnetic martensites are induced by uniaxial tensile deformation. A scaling-law relationship between the hysteresis loss and remanence, with a power law exponent of 1.47 ± 0.09, has been found, irrespective of stress, martensite volume fraction, and angle between the magnetization and tensile directions. A coefficient of the scaling law decreases with volume fraction, whereas it increases with increasing the angle and maximizes when the magnetization direction is perpendicular to that of the tensile. This trend is opposite to that of coercivity. The behavior of the coefficient and the coercivity was discussed from the viewpoint of morphology of martensite particles.
Temperature dependent c-axis hole mobilities in rubrene single crystals determined by time-of-flight
Authors: Pundsack Tom J. , Haugen Neale O. , Johnstone Lucas R. , Daniel Frisbie C. , Lidberg Russell L.
Published: March 2015

Hole mobilities (μ) in rubrene single crystals (space group Cmca) along the crystallographic c-axis have been investigated as a function of temperature and applied electric field by the time-of-fight method. Measurements demonstrate an inverse power law dependence on temperature, namely, μ=μ0T−n with n = 1.8, from room temperature down to 180 K. At 296 K, the average value of μ was found to be 0.29 cm2/Vs increasing to an average value of 0.70 cm2/Vs at 180 K. Below 180 K a decrease in mobility is observed with further cooling. Overall, these results confirm the anisotropic nature of transport in rubrene crystals as well as the generality of the inverse power law temperature dependence that is observed for field effect mobility measurements in the a-b crystal plane.
Mechanism of β-FeSi2 precipitates growth-and-dissolution and pyramidal defects' formation during oxidation of Fe-contaminated silicon wafers
Authors: De Luca Anthony , Texier Michaël , Portavoce Alain , Burle Nelly , Grosjean Catherine , Morata Stéphane , Michel Fabrice
Published: March 2015

Fe-implanted Si-wafers have been oxidized at 900 °C and 1100 °C in order to investigate the behaviour of Fe atoms at the growing SiO2/Si interface and the impact on the integrity of microelectronic devices of an involuntary Fe contamination before or during the oxidation process. As-implanted and oxidized wafers have been characterized using secondary ion mass spectroscopy, atom probe tomography, and high-resolution transmission electron microscopy. Experimental results were compared to calculated implantation profiles and simulated images. Successive steps of iron disilicide precipitation and oxidation were evidenced during the silicon oxidation process. The formation of characteristic pyramidal-shaped defects, at the SiO2/Si interface, was notably found to correlate with the presence of β-FeSi2 precipitates. Taking into account the competitive oxidation of these precipitates and of the surrounding silicon matrix, dynamic mechanisms are proposed to model the observed microstructural evolution of the SiO2/Si interface, during the growth of the silicon oxide layer.
Effect of spacer layer on the magnetization dynamics of permalloy/rare-earth/permalloy trilayers
Authors: Luo Chen , Yin Yuli , Zhang Dong , Jiang Sheng , Yue Jinjin , Zhai Ya , Du Jun , Zhai Hongru
Published: March 2015

The permalloy/rare-earth/permalloy trilayers with different types (Gd and Nd) and thicknesses of spacer layer are investigated using frequency dependence of ferromagnetic resonance (FMR) measurements at room temperature, which shows different behaviors with different rare earth spacer layers. By fitting the frequency dependence of the FMR resonance field and linewidth, we find that the in-plane uniaxial anisotropy retains its value for all samples, the perpendicular anisotropy remains almost unchanged for different thickness of Gd layer but the values are tailored by different thicknesses of Nd layer. The Gilbert damping is almost unchanged with different thicknesses of Gd; however, the Gilbert damping is significantly enhanced from 8.4×10−3 to 20.1×10−3 with 6 nm of Nd and then flatten out when the Nd thickness rises above 6 nm.
Site selectivity on chalcogen atoms in superconducting La(O,F)BiSSe
Authors: Tanaka Masashi , Yamaki Takuma , Matsushita Yoshitaka , Fujioka Masaya , Denholme Saleem J. , Yamaguchi Takahide , Takeya Hiroyuki , Takano Yoshihiko
Published: March 2015

Single crystals of La(O,F)BiSSe were grown by using a CsCl flux method. Single crystal X-ray structural analysis reveals that the crystal structure is isostructural to the BiS2- or BiSe2-based compounds crystallizing with space group P4/nmm (lattice parameters a = 4.1110(2) Å, c = 13.6010(7) Å). However, the S atoms are selectively occupied at the apical site of the Bi-SSe pyramids in the superconducting layer. The single crystals show a superconducting transition at around 4.2 K in the magnetic susceptibility and resistivity measurements. The superconducting anisotropic parameter is determined to be 34–35 from its upper critical magnetic field. The anisotropy is in the same range with that of other members of the La(O,F)BiCh2 (Ch = S, Se) family under ambient pressure.