bluuebunny/crossref_metadata_2025 huggingface dataset:
Human milk oligosaccharides shorten rotavirus-induced diarrhea and modulate piglet mucosal immunity and colonic microbiota
Authors: Li Min , Monaco Marcia H , Wang Mei , Comstock Sarah S , Kuhlenschmidt Theresa B , Fahey Jr George C , Miller Michael J , Kuhlenschmidt Mark S , Donovan Sharon M
Published: February 2014

The impact of human milk oligosaccharides (HMO) on mucosal immunity, gut microbiota and response to rotavirus (RV) infection was investigated in the piglet model. Newborn piglets were fed with formula alone (FF) or formula supplemented with 4 g l−1 HMO (HMO) or a prebiotic mixture of 9:1 short-chain galactooligosaccharides (3.6 g l−1) and long-chain fructooligosaccharides (0.4 g l−1) (PRE) (n=19–21 per group) for 15 days. Piglets (n=7–8) in each dietary group were orally infected with porcine rotavirus (RV) OSU strain on d10, and stool consistency was assessed daily. Blood, small intestine and colonic contents were collected at day 15. Serum RV-specific antibody concentrations, intestinal histomorphology, RV non-structural protein-4 (NSP4) and cytokine mRNA expression were assessed. Colonic content pH, dry matter (DM) and short-chain fatty acid concentrations were measured. Ascending colonic microbiota was analyzed by 16S rRNA gene v1-3 region pyrosequencing. HMO- and PRE-fed groups had shorter duration of diarrhea than FF piglets. Infection changed intestinal histomorphology, increased serum RV-specific antibody response and intestinal RV NSP4 expression, and modulated ileal cytokine expression. HMO enhanced T helper type 1 (interferon-gamma) and anti-inflammatory (interleukin-10) cytokines in the ileum, while prebiotics promoted RV-specific immunoglobulin M response to the infection. RV infection and HMO supplementation altered intraluminal environment and gut microbiota. HMO increased pH and lowered DM of colonic contents and enhanced the abundance of unclassified Lachnospiraceae, which contains numerous butyrate-producing bacteria. In conclusion, HMO and prebiotics did not prevent the onset of RV infection but reduced the duration of RV-induced diarrhea in piglets, in part, by modulating colonic microbiota and immune response to RV infection.
Functional characterization of polysaccharide utilization loci in the marine Bacteroidetes ‘Gramella forsetii’ KT0803
Authors: Kabisch Antje , Otto Andreas , König Sten , Becher Dörte , Albrecht Dirk , Schüler Margarete , Teeling Hanno , Amann Rudolf I , Schweder Thomas
Published: February 2014

Members of the phylum Bacteroidetes are abundant in many marine ecosystems and are known to have a pivotal role in the mineralization of complex organic substrates such as polysaccharides and proteins. We studied the decomposition of the algal glycans laminarin and alginate by ‘Gramella forsetii’ KT0803, a bacteroidetal isolate from North Sea surface waters. A combined application of isotope labeling, subcellular protein fractionation and quantitative proteomics revealed two large polysaccharide utilization loci (PULs) that were specifically induced, one by alginate and the other by laminarin. These regulons comprised genes of surface-exposed proteins such as oligomer transporters, substrate-binding proteins, carbohydrate-active enzymes and hypothetical proteins. Besides, several glycan-specific TonB-dependent receptors and SusD-like substrate-binding proteins were expressed also in the absence of polysaccharide substrates, suggesting an anticipatory sensing function. Genes for the utilization of the beta-1,3-glucan laminarin were found to be co-regulated with genes for glucose and alpha-1,4-glucan utilization, which was not the case for the non-glucan alginate. Strong syntenies of the PULs of ‘G. forsetii’ with similar loci in other Bacteroidetes indicate that the specific response mechanisms of ‘G. forsetii’ to changes in polysaccharide availability likely apply to other Bacteroidetes. Our results can thus contribute to an improved understanding of the ecological niches of marine Bacteroidetes and their roles in the polysaccharide decomposition part of carbon cycling in marine ecosystems.
Direct exchange of vitamin B12 is demonstrated by modelling the growth dynamics of algal–bacterial cocultures
Authors: Grant Matthew A A , Kazamia Elena , Cicuta Pietro , Smith Alison G
Published: February 2014

The growth dynamics of populations of interacting species in the aquatic environment is of great importance, both for understanding natural ecosystems and in efforts to cultivate these organisms for industrial purposes. Here we consider a simple two-species system wherein the bacterium Mesorhizobium loti supplies vitamin B12 (cobalamin) to the freshwater green alga Lobomonas rostrata, which requires this organic micronutrient for growth. In return, the bacterium receives photosynthate from the alga. Mathematical models are developed that describe minimally the interdependence between the two organisms, and that fit the experimental observations of the consortium. These models enable us to distinguish between different mechanisms of nutrient exchange between the organisms, and provide strong evidence that, rather than undergoing simple lysis and release of nutrients into the medium, M. loti regulates the levels of cobalamin it produces, resulting in a true mutualism with L. rostrata. Over half of all microalgae are dependent on an exogenous source of cobalamin for growth, and this vitamin is synthesised only by bacteria; it is very likely that similar symbiotic interactions underpin algal productivity more generally.
Quantum phases in circuit QED with a superconducting qubit array
Authors: Zhang Yuanwei , Yu Lixian , Liang J. -Q , Chen Gang , Jia Suotang , Nori Franco
Published: February 2014

Circuit QED on a chip has become a powerful platform for simulating complex many-body physics. In this report, we realize a Dicke-Ising model with an antiferromagnetic nearest-neighbor spin-spin interaction in circuit QED with a superconducting qubit array. We show that this system exhibits a competition between the collective spin-photon interaction and the antiferromagnetic nearest-neighbor spin-spin interaction and then predict four quantum phases, including: a paramagnetic normal phase, an antiferromagnetic normal phase, a paramagnetic superradiant phase and an antiferromagnetic superradiant phase. The antiferromagnetic normal phase and the antiferromagnetic superradiant phase are new phases in many-body quantum optics. In the antiferromagnetic superradiant phase, both the antiferromagnetic and superradiant orders can coexist and thus the system possesses "Equation missing" symmetry. Moreover, we find an unconventional photon signature in this phase. In future experiments, these predicted quantum phases could be distinguished by detecting both the mean-photon number and the magnetization.
On-line flow injection solid phase extraction using oxidised carbon nanotubes as the substrate for cold vapour-atomic absorption determination of Hg(ii) in different kinds of water
Authors: Parodi Belén , Londonio Agustín , Polla Griselda , Savio Marianela , Smichowski Patricia
Published: February 2014

To surmount particle agglomeration when columns filled with CNTs are used in flow sorptive systems, we propose to mix CNTs with a low molecular weight polyethylene.
Gold-catalysed cyclisation of N-propargylic β-enaminones to form 3-methylene-1-pyrroline derivatives
Authors: Goutham Kommuru , Mangina N. S. V. M. Rao , Suresh Surisetti , Raghavaiah Pallepogu , Karunakar Galla V.
Published: February 2014

A gold(i) catalysed reaction between N-propargylic β-enaminones and arynes was developed to access 3-methylene-1-pyrrolines. The title compounds were obtained in 57–78% yields.
Roles of carboxylate donors in O–O bond scission of peroxodi-iron(iii) to high-spin oxodi-iron(iv) with a new carboxylate-containing dinucleating ligand
Authors: Kodera Masahito , Tsuji Tomokazu , Yasunaga Tomohiro , Kawahara Yuka , Hirano Tomoya , Hitomi Yutaka , Nomura Takashi , Ogura Takashi , Kobayashi Yoshio , Sajith P. K. , Shiota Yoshihito , Yoshizawa Kazunari
Published: February 2014

Carboxylate donor stabilizes the peroxo state in dioxygen activation via reversible O–O bond scission of peroxodi-iron(iii) to high spin oxodi-iron(iv).
Ultrathin nanosheets of feroxyhyte: a new two-dimensional material with robust ferromagnetic behavior
Authors: Chen Pengzuo , Xu Kun , Li Xiuling , Guo Yuqiao , Zhou Dan , Zhao Jiyin , Wu Xiaojun , Wu Changzheng , Xie Yi
Published: February 2014

A new two dimensional nanomaterial with robust room-temperature ferromagnetic behavior has been synthesizedviaan atomic-scale topochemical transformation strategy.
The gas sensing properties of zeolite modified zinc oxide
Authors: Pugh D. C. , Newton E. J. , Naik A. J. T. , Hailes S. M. V. , Parkin I. P.
Published: February 2014

The illicit manufacture of drugs in the 21stcentury presents a danger to first responders, bystanders and the environment, making its detection important.
Detonation nanodiamonds tailor the structural order of PEDOT chains in conductive coating layers of hybrid nanoparticles
Authors: Tamburri Emanuela , Guglielmotti Valeria , Matassa Roberto , Orlanducci Silvia , Gay Stefano , Reina Giacomo , Terranova Maria Letizia , Passeri Daniele , Rossi Marco
Published: February 2014

Conductive coatings made of template-free polymerized PEDOT/ND nanoparticles with peculiar enhancement of mechanical properties and endurance to electron damage.
Au nanorod plasmonic superstructures obtained by a combined droplet evaporation and stamping method
Authors: Schopf Carola , Martín Alfonso , Burke Mícheál , Jones Daniel , Pescaglini Andrea , O'Riordan Alan , Quinn Aidan J. , Iacopino Daniela
Published: February 2014

Au nanorod plasmonic superstructures with a high degree of optical anisotropy were used for demonstration of a novel plasmonic encoding system.
A disordered silver nanowires membrane for extraction and surface-enhanced Raman spectroscopy detection
Authors: Shi Yu-e , Li Limei , Yang Min , Jiang Xiaohong , Zhao Quanqin , Zhan Jinhua
Published: February 2014

A disordered silver nanowires membrane combining solid-phase extraction with surface-enhanced Raman spectroscopy was used for the rapid collection and detection of food contaminants.
A highly sensitive sensor for the detection of nitrite based on a nanoporous Fe2O3–CoO composite
Authors: Wang Jinping , Zhao Dianyun , Zhang Yu , Li Juefei , Xu Caixia
Published: February 2014

A nanoporous (NP) Fe2O3–CoO composite, with an open three-dimensional bicontinuous nanoparticle architecture, was easily fabricated by selectively dealloying Fe5Co5Al90, exhibiting great sensing performance, structure stability, and analytical utility for nitrite sensing.
Dimensionality variations in new zirconium iodates: hydrothermal syntheses, structural determination, and characterization of BaZr(IO3)6 and K2Zr(IO3)6
Authors: Ahn Hyun Sun , Lee Dong Woo , Ok Kang Min
Published: February 2014

While BaZr(IO3)6 reveals a unidimensional band structure, K2Zr(IO3)6 exhibits a zero-dimensional molecular geometry. The dimensionality variations are attributable to the flexible coordination numbers of Zr4+ cations with large ionic radii as well as the number of counter cations.
Reactivity and catalytic activity of tert-butoxy-aluminium hydride reagents
Authors: Less Robert J. , Simmonds Hayley R. , Wright Dominic S.
Published: February 2014

The reactivity and catalytic activity of thetert-butoxy aluminium hydride reagents [(tBuO)xAlH3−x] [x= 1 (1), 2 (2)] and (L)Li[(tBuO)2AlH2] [L = THF (3), 1,4-dioxane (4)] were investigated. These reagents exhibit interesting reactivity and catalyse the dehydrocoupling reaction of the amine–borane Me2NHBH3into the ring compound [Me2NBH2]2.
Layered germanium tin antimony tellurides: element distribution, nanostructures and thermoelectric properties
Authors: Welzmiller Simon , Rosenthal Tobias , Ganter Pirmin , Neudert Lukas , Fahrnbauer Felix , Urban Philipp , Stiewe Christian , de Boor Johannes , Oeckler Oliver
Published: February 2014

Layered compounds containing Ge/Sb/Te show improved thermoelectric properties upon doping with Sn. The structures were refined using resonant X-ray diffraction; structure models were confirmed by TEM.
Multiplying the electron storage capacity of a bis-tetrazine pincer ligand
Authors: Benson Christopher R. , Hui Alice K. , Parimal Kumar , Cook Brian J. , Chen Chun-Hsing , Lord Richard L. , Flood Amar H. , Caulton Kenneth G.
Published: February 2014

A new nitrogen-rich pincer ligand is the key to develop quantitatively rich “redox non-innocent” reductive chemistry when complexed to Fe(2+), as illustrated.
DMAP-promoted domino annulation of β-ketothioamides with internal alkynes: a highly regioselective access to functionalized 1,3-thiazolidin-4-ones at room temperature
Authors: Verma Girijesh Kumar , Shukla Gaurav , Nagaraju Anugula , Srivastava Abhijeet , Raghuvanshi Keshav , Singh Maya Shankar
Published: February 2014

One-pot DMAP-mediated regioselective access to functionalized 1,3-thiazolidin-4-ones has been achievedviaannulation of β-ketothioamides with internal alkynes.
Oxidation modifies the structure and function of the extracellular matrix generated by human coronary artery endothelial cells
Authors: Chuang Christine Y. , Degendorfer Georg , Hammer Astrid , Whitelock John M. , Malle Ernst , Davies Michael J.
Published: February 2014

ECM (extracellular matrix) materials, such as laminin, perlecan, type IV collagen and fibronectin, play a key role in determining the structure of the arterial wall and the properties of cells that interact with the ECM. The aim of the present study was to investigate the effect of peroxynitrous acid, an oxidant generated by activated macrophages, on the structure and function of the ECM laid down by HCAECs (human coronary artery endothelial cells) in vitro and in vivo. We show that exposure of HCAEC-derived native matrix components to peroxynitrous acid (but not decomposed oxidant) at concentrations >1 μM results in a loss of antibody recognition of perlecan, collagen IV, and cell-binding sites on laminin and fibronectin. Loss of recognition was accompanied by decreased HCAEC adhesion. Real-time PCR showed up-regulation of inflammation-associated genes, including MMP7 (matrix metalloproteinase 7) and MMP13, as well as down-regulation of the laminin α2 chain, in HCAECs cultured on peroxynitrous acid-treated matrix compared with native matrix. Immunohistochemical studies provided evidence of co-localization of laminin with 3-nitrotyrosine, a biomarker of peroxynitrous acid damage, in type II–III/IV human atherosclerotic lesions, consistent with matrix damage occurring during disease development in vivo. The results of the present study suggest a mechanism through which peroxynitrous acid modifies endothelial cell-derived native ECM proteins of the arterial basement membrane in atherosclerotic lesions. These changes to ECM and particularly perlecan and laminin may be important in inducing cellular dysfunction and contribute to atherogenesis.
Crystallographic structure of the turbine C-ring from spinach chloroplast F-ATP synthase
Authors: Balakrishna Asha Manikkoth , Seelert Holger , Marx Sven-Hendric , Dencher Norbert A. , Grüber Gerhard
Published: February 2014

In eukaryotic and prokaryotic cells, F-ATP synthases provide energy through the synthesis of ATP. The chloroplast F-ATP synthase (CF1FO-ATP synthase) of plants is integrated into the thylakoid membrane via its FO-domain subunits a, b, b’ and c. Subunit c with a stoichiometry of 14 and subunit a form the gate for H+-pumping, enabling the coupling of electrochemical energy with ATP synthesis in the F1 sector.

Here we report the crystallization and structure determination of the c14-ring of subunit c of the CF1FO-ATP synthase from spinach chloroplasts. The crystals belonged to space group C2, with unit-cell parameters a=144.420, b=99.295, c=123.51 Å, and β=104.34° and diffracted to 4.5 Å resolution. Each c-ring contains 14 monomers in the asymmetric unit. The length of the c-ring is 60.32 Å, with an outer ring diameter 52.30 Å and an inner ring width of 40 Å.
Diversity analysis of distributed linear convolutive space‐time codes for time–frequency asynchronous cooperative networks
Authors: Liu Yi , Li Yongzhao , Li Danping , Ma Qi , Zhang Hailin
Published: February 2014

This study analyses the achievable cooperative diversity order of the distributed linear convolutional space‐time coding (DLC‐STC) scheme for time–frequency asynchronous cooperative networks. The authors first prove that perfect time or frequency synchronisation is impractical for cooperative networks with multiple relays serving multiple destinations even when the relays know all accurate time delays and frequency offsets. Then the DLC‐STC scheme, in which the exact time synchronisation at the relay nodes is unnecessary, is introduced into this type of cooperative networks. This study proves that the achievable time–frequency asynchronous cooperative diversity order of the DLC‐STC scheme with maximum‐likelihood receivers is equal to the number of relays. Simulation results verify the analysis.
Implementation of four‐leg distribution static compensator
Authors: Singh Bhim , Arya Sabha Raj , Jain Chinmay , Goel Sagar
Published: February 2014

An implementation of a four‐leg distribution static compensator (DSTATCOM) using an adaptive neural network‐based control algorithm for compensation of linear/non‐linear loads using voltage source converter is presented here. The proposed control algorithm, which is based on adaptive neural network, is used for extraction of fundamental active and reactive power components of load currents which are major components in the estimation of reference supply currents. This control algorithm is implemented on a developed four‐leg DSTATCOM for reactive power compensation, harmonics elimination, load balancing and neutral current mitigation under linear and non‐linear loads. The performance of DSTATCOM is observed quite satisfactory under various linear and non‐linear loads.
Time–frequency method to reduce contamination by ionospheric fast frequency modulation for HF skywave radars
Authors: Chengyu Hou , Tian Xia , Qian Bao
Published: February 2014

The unstable and time‐varying property of the ionosphere causes a frequency modulation on the high frequency sky‐wave radar echo signals. When the modulation period is of 10 s or smaller, it is called the fast phase‐path modulation. This sort of modulation will result in the broadening, the splitting and even the overlapping of the spectra, which makes target detection and sea‐state remote sensing hard. Hence, it is necessary to decontaminate the echo signals before the coherent integration process. In this study, the pseudo Wigner‐Ville distribution is proposed as a means of estimating the ionospheric frequency modulation. A frequency weighting method is used to obtain the instantaneous frequency (IF) from the time–frequency distribution and an adaptive low‐pass filter is introduced to purify the IF. Then, the amplitude difference between the two first‐order Bragg peaks is adopted in the weighting process to obtain the phase compensation function. To improve the compensation effect, an optimising process is proposed. The simulation results show that the method can improve the quality of the spectra for the target detection and remote sensing efficiently even in the cases of a high sea‐state.
Research on pulse electrodeposition of Fe-Ni alloy
Authors: Peng Yongsen , Zhu Zengwei , Chen Jiangbo , Ren Jianhua , Han Taojie
Published: February 2014

Fe-Ni alloys were fabricated on steel substrates by means of pulse electrodeposition in sulfate solutions. The layers were electrodeposited using different peak current densities, duty cycles and frequencies. Fe contents, microhardnesses and crystalline phases were examined systematically. The Fe content in the deposit decreased and the microhardness increased with increasing duty cycle and peak current density. The pulse frequency had little effect on Fe content but led to a slight decrease in microhardness. X-ray diffraction patterns show that the crystalline phases vary with changes in peak current density and duty cycle but are barely influenced by frequency. When the peak current density or duty cycle is relatively low, crystalline Fe-Ni alloy and pure Fe phases coexist; the pure Fe phases disappear as the peak current density or duty cycle increases. At still larger peak current densities or duty cycles, crystalline Fe-Ni alloy and pure Ni phases coexist.
Miniaturized overlapped LC phase delay line
Authors: Guo Xin , Li Ling , Zhao Chenxu , Liu Zewen
Published: February 2014

A novel miniaturized ultra-wide bandwidth (DC–35 GHz) LC phase delay line (PDL) based on overlapped meander inductors and air-bridge capacitors is proposed and fabricated. Two 45º and 90º PDLs were designed using a semi-lumped model, and the parameters were calculated and optimized based on transmission line theory and 3D simulations. The lengths of the 45º and 90º delay lines are 110 μm and 286 μm, respectively, which represent respective length reductions of 50% and 75% when compared with the corresponding conventional transmission lines. Over the entire operating band, the phase error is less than 0.6º for the 45º PDL and 2.5º for the 90º PDL. The return loss (S11) for both PDLs is better than 15.5 dB, while the insertion loss (S21) is less than 0.62 dB for both devices. Measured results show perfect consistency with the simulation results for these PDLs, and demonstrate the validity of the corresponding model.
Magnetic detectability of a finite size paramagnet/superconductor cylindrical cloak
Authors: Yampolskii S. V. , Genenko Y. A.
Published: February 2014

Cloaking of static magnetic fields by a finite thickness type-II superconductor tube surrounded by a coaxial paramagnet shell is studied. On the basis of exact solutions to the London and Maxwell equations, it is shown that perfect cloaking is realizable for arbitrary geometrical parameters including the thin film case for both constituents. In contrast to the previous approximate studies assuming perfect diamagnetism of the superconductor constituent, it is proven that cloaking provides simultaneously full undetectability, that is the magnetic moment of the structure completely vanishes as well as all high-order multipole moments as soon as the uniform field outside remains unaffected.
Heteroepitaxy of GaSb on Si(111) and fabrication of HfO2/GaSb metal-oxide-semiconductor capacitors
Authors: Ohtake Akihiro , Mano Takaaki , Miyata Noriyuki , Mori Takahiro , Yasuda Tetsuji
Published: February 2014

The (111)A-oriented GaSb films are two-dimensionally grown on the Si(111) substrate. We found that the insertion of a thin interface layer of InAs between GaSb and Si is very effective to obtain high-quality GaSb films. Using the GaSb/InAs/Si heterostructure, we have fabricated HfO2/GaSb metal-oxide-semiconductor (MOS) capacitors. The MOS capacitors show electrical characteristics comparable to those fabricated on GaSb(001) substrates, making itself suitable for realizing the integration of Sb-based MOS devices with Si substrates.
Magnetic field reversal of electric polarization and magnetoelectric phase diagram of the hexaferrite Ba1.3Sr0.7Co0.9Zn1.1Fe10.8Al1.2O22
Authors: Shen Shipeng , Yan Liqin , Chai Yisheng , Cong Junzhuang , Sun Young
Published: February 2014

Low magnetic field reversal of electric polarization has been demonstrated in the multiferroic Y-type hexaferrite Ba1.3Sr0.7Co0.9Zn1.1Fe10.8Al1.2O22 single crystal. The maximum magnetoelectric coefficient at 200 K reaches 1065 ps/m near zero magnetic field. By a systematic investigation of magnetic field dependence of magnetic and dielectric responses at various temperatures, we obtained the magnetoelectric phase diagram describing the detailed evolution of the spin-induced ferroelectric phases with temperature and magnetic field. Below 225 K, the transverse spin cone can be stabilized at zero magnetic field, which is responsible for the reversal behavior of electric polarization. Our study reveals how to eventually achieve magnetic field reversal of electric polarization in hexaferrites at room temperature.
Negative differential resistance phenomena in colloidal quantum dots-based organic light-emitting diodes
Authors: Yang Shengyi , Liu Peng , Guo Sanwei , Zhang Li , Yang Dan , Jiang Yurong , Zou Bingsuo
Published: February 2014

The influence of ligands on the electrical behavior of CdSe/ZnS core-shell colloidal quantum dots (CQDs)-based organic light-emitting diodes is presented. Negative differential resistance (NDR) phenomena at room temperature are observed from single-layer device ITO/poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS)/CQDs/Al in which the original capping ligand tri-n-octylphosphine oxide (TOPO) of CQDs is exchanged with oleylamine, as well as in both bilayer device ITO/PEDOT:PSS/CQDs/BCP(10 nm)/Al and trilayer device ITO/PEDOT:PSS/CQDs/BCP(10 nm)/Alq3(10 nm)/Al. However, such a kind of NDR phenomenon disappears if TOPO is exchanged with hexadecylamine. Therefore, NDR phenomenon depends greatly on the ligands of the CQDs, and the origin of NDR from these devices is discussed.
Elongated unique DNA strand deposition on microstructured substrate by receding meniscus assembly and capillary force
Authors: Charlot B. , Bardin F. , Sanchez N. , Roux P. , Teixeira S. , Schwob E.
Published: February 2014

Ordered deposition of elongated DNA molecules was achieved by the forced dewetting of a DNA solution droplet over a microstructured substrate. This technique allows trapping, uncoiling, and deposition of DNA fragments without the need of a physicochemical anchoring of the molecule and results in the combing of double stranded DNA from the edge of microwells on a polydimethylsiloxane (PDMS) substrate. The technique involves scanning a droplet of DNA solution caught between a movable blade and a PDMS substrate containing an array of microwells. The deposition and elongation appears when the receding meniscus dewets microwells, the latter acting here as a perturbation in the dewetting line forcing the water film to break locally. Thus, DNA molecules can be deposited in an ordered manner and elongated conformation based solely on a physical phenomenon, allowing uncoiled DNA molecules to be observed in all their length. However, the exact mechanism that governs the deposition of DNA strands is not well understood. This paper is an analysis of the physical phenomenon occurring in the deposition process and is based on observations made with the use of high frame/second rate video microscopy.
Base norms and discrimination of generalized quantum channels
Authors: Jenčová A.
Published: February 2014

We introduce and study norms in the space of hermitian matrices, obtained from base norms in positively generated subspaces. These norms are closely related to discrimination of so-called generalized quantum channels, including quantum states, channels, and networks. We further introduce generalized quantum decision problems and show that the maximal average payoffs of decision procedures are again given by these norms. We also study optimality of decision procedures, in particular, we obtain a necessary and sufficient condition under which an optimal 1-tester for discrimination of quantum channels exists, such that the input state is maximally entangled.
Plasmon-enhanced terahertz emission in self-assembled quantum dots by femtosecond pulses
Authors: Carreño F. , Antón M. A. , Melle Sonia , Calderón Oscar G. , Cabrera-Granado E. , Cox Joel , Singh Mahi R. , Egatz-Gómez A.
Published: February 2014

A scheme for terahertz (THz) generation from intraband transition in a self-assembled quantum dot (QD) molecule coupled to a metallic nanoparticle (MNP) is analyzed. The QD structure is described as a three-level atom-like system using the density matrix formalism. The MNP with spherical geometry is considered in the quasistatic approximation. A femtosecond laser pulse creates a coherent superposition of two subbands in the quantum dots and produces localized surface plasmons in the nanoparticle which act back upon the QD molecule via dipole-dipole interaction. As a result, coherent THz radiation with a frequency corresponding to the interlevel spacing can be obtained, which is strongly modified by the presence of the MNP. The peak value of the terahertz signal is analyzed as a function of nanoparticle's size, the MNP to QD distance, and the area of the applied laser field. In addition, we theoretically demonstrate that the terahertz pulse generation can be effectively controlled by making use of a train of femtosecond laser pulses. We show that by a proper choice of the parameters characterizing the pulse train a huge enhancement of the terahertz signal is obtained.
From toroidal to rod-like condensates of semiflexible polymers
Authors: Hoang Trinh Xuan , Giacometti Achille , Podgornik Rudolf , Nguyen Nhung T. T. , Banavar Jayanth R. , Maritan Amos
Published: February 2014

The competition between toroidal and rod-like conformations as possible ground states for DNA condensation is studied as a function of the stiffness, the length of the DNA, and the form of the long-range interactions between neighboring molecules, using analytical theory supported by Monte Carlo simulations. Both conformations considered are characterized by a local nematic order with hexagonal packing symmetry of neighboring DNA molecules, but differ in global configuration of the chain and the distribution of its curvature as it wraps around to form a condensate. The long-range interactions driving the DNA condensation are assumed to be of the form pertaining to the attractive depletion potential as well as the attractive counterion induced soft potential. In the stiffness-length plane we find a transition between rod-like to toroid condensate for increasing stiffness at a fixed chain length L. Strikingly, the transition line is found to have a L1/3 dependence irrespective of the details of the long-range interactions between neighboring molecules. When realistic DNA parameters are used, our description reproduces rather well some of the experimental features observed in DNA condensates.
Tuning of the spin pumping in yttrium iron garnet/Au bilayer system by fast thermal treatment
Authors: Jin Lichuan , Zhang Dainan , Zhang Huaiwu , Yang Qinghui , Tang Xiaoli , Zhong Zhiyong , Xiao John Q.
Published: February 2014

In this Letter, we investigated the influence of the fast thermal treatment on the spin pumping in ferromagnetic insulator yttrium iron garnet (YIG)/normal metal Au bilayer system. The YIG/Au bilayer thin films were treated by fast annealing process with different temperatures from 0 to 800 °C. The spin pumping was studied using ferromagnetic resonance. The surface evolution was investigated using a high resolution scanning microscopy and an atomic force microscopy. A strong thermal related spin pumping in YIG/Au bilayer system has been revealed. It was found that the spin pumping process can be enhanced by using fast thermal treatment due to the thermal modifications of the Au surface. The effective spin-mixing conductance of the fast thermal treated YIG/Au bilayer has been obtained.
Outstanding problems in nuclear astrophysics: recent progress at TRIUMF
Authors: Davids B.
Published: February 2014

Recent experimental and theoretical efforts at TRIUMF on nuclear reactions relevant to big bang nucleosynthesis, quiescent stellar fusion, classical novae, and Type I X-ray bursts are described.
Transport and dielectric properties of water and the influence of coarse-graining: Comparing BMW, SPC/E, and TIP3P models
Authors: Braun Daniel , Boresch Stefan , Steinhauser Othmar
Published: February 2014

Long-term molecular dynamics simulations are used to compare the single particle dipole reorientation time, the diffusion constant, the viscosity, and the frequency-dependent dielectric constant of the coarse-grained big multipole water (BMW) model to two common atomistic three-point water models, SPC/E and TIP3P. In particular, the agreement between the calculated viscosity of BMW and the experimental viscosity of water is satisfactory. We also discuss contradictory values for the static dielectric properties reported in the literature. Employing molecular hydrodynamics, we show that the viscosity can be computed from single particle dynamics, circumventing the slow convergence of the standard approaches. Furthermore, our data indicate that the Kivelson relation connecting single particle and collective reorientation time holds true for all systems investigated. Since simulations with coarse-grained force fields often employ extremely large time steps, we also investigate the influence of time step on dynamical properties. We observe a systematic acceleration of system dynamics when increasing the time step. Carefully monitoring energy/temperature conservation is found to be a sufficient criterion for the reliable calculation of dynamical properties. By contrast, recommended criteria based on the ratio of fluctuations of total vs. kinetic energy are not sensitive enough.
Real-time, sensitive electrical detection of Cryptosporidium parvum oocysts based on chemical vapor deposition-grown graphene
Authors: It Wong Jen , Wang Lu , Shi Yumeng , Palacios Tomás , Kong Jing , Dong Xiaochen , Ying Yang Hui
Published: February 2014

Cryptosporidium parvum is a common intestinal parasitic protozoan that causes gastroenteritis in man and animals. It poses high risks to drinking water supply because of its ubiquitous distribution in water and their oocysts are resistant to harsh environment conditions. In this work, we demonstrated the use of large-size chemical vapor deposition (CVD) grown graphene films configured as field-effect device for rapid electrical detection of Cryptosporidium parvum oocysts (Cp. oocysts). The presence of Cp. oocysts causes the change in the transport characteristics of the antibody-functionalized graphene device, which can be measured in terms of the dependence of the drain current on the sweep of the gate voltage or the real-time drain current data under a constant gate voltage. The high sensor sensitivity of 25 oocysts per milliliter solution and good specificity were evaluated, indicating it a promising candidate for detecting waterborne pathogens in water quality control.
Hot spots in energetic materials generated by infrared and ultrasound, detected by thermal imaging microscopy
Authors: Chen Ming-Wei , You Sizhu , Suslick Kenneth S. , Dlott Dana D.
Published: February 2014

We have observed and characterized hot spot formation and hot-spot ignition of energetic materials (EM), where hot spots were created by ultrasonic or long-wavelength infrared (LWIR) exposure, and were detected by high-speed thermal microscopy. The microscope had 15–20 μm spatial resolution and 8.3 ms temporal resolution. LWIR was generated by a CO2 laser (tunable near 10.6 μm or 28.3 THz) and ultrasound by a 20 kHz acoustic horn. Both methods of energy input created spatially homogeneous energy fields, allowing hot spots to develop spontaneously due to the microstructure of the sample materials. We observed formation of hot spots which grew and caused the EM to ignite. The EM studied here consisted of composite solids with 1,3,5-trinitroperhydro-1,3,5-triazine crystals and polymer binders. EM simulants based on sucrose crystals in binders were also examined. The mechanisms of hot spot generation were different with LWIR and ultrasound. With LWIR, hot spots were most efficiently generated within the EM crystals at LWIR wavelengths having longer absorption depths of ∼25 μm, suggesting that hot spot generation mechanisms involved localized absorbing defects within the crystals, LWIR focusing in the crystals or LWIR interference in the crystals. With ultrasound, hot spots were primarily generated in regions of the polymer binder immediately adjacent to crystal surfaces, rather than inside the EM crystals.
Methods and preliminary measurement results of liquid Li wettability
Authors: Zuo G. Z. , Hu J. S. , Ren J. , Sun Z. , Yang Q. X. , Li J. G. , Zakharov L. E. , Mansfield D. K.
Published: February 2014

A test of lithium wettability was performed in high vacuum (< 3 × 10−4 Pa). High magnification images of Li droplets on stainless steel substrates were produced and processed using the MATLAB® program to obtain clear image edge points. In contrast to the more standard “θ/2” or polynomial fitting methods, ellipse fitting of the complete Li droplet shape resulted in reliable contact angle measurements over a wide range of contact angles. Using the ellipse fitting method, it was observed that the contact angle of a liquid Li droplet on a stainless steel substrate gradually decreased with increasing substrate temperature. The critical wetting temperature of liquid Li on stainless steel was observed to be about 290 °C.
A direct tensile device to investigate the critical current properties in superconducting tapes
Authors: Zhang Xingyi , Liu Wei , Zhou Jun , Yue Donghua , Wang Jun , Liu Cong , Huang Yi , Liu Yong , Zhou Youhe
Published: February 2014

We construct an instrument to study the behavior of the critical current in superconducting tapes as a function of magnetic field and axial tension strain. The apparatus combines a material testing machine made by the non-magnetic stainless steel, which is capable of producing mechanical forces up to 1000 N and magnetic field up to 5 T with a homogeneous range of Φ150 × 110 mm. Moreover, the apparatus allows the automatic measurement of time dependence of voltage (V-t) under different magnetic fields and applied strains, which can be used to investigate the vortex instability and its time effect in the superconducting tapes. As an example, the simultaneous measurements of critical current and voltage relaxation with time at various strains and magnetic fields for the YaBa2Cu3O7−x coated conductors are carried out. Comparisons are made with the earlier reports in literature; the strain and magnetic field dependence of critical current indicate consistent behavior of this instrument.
Note: A high-sensitivity current sensor based on piezoelectric ceramic Pb(Zr,Ti)O3 and ferromagnetic materials
Authors: He Wei , Li Ping , Wen Yumei , Zhang Jitao , Yang Aichao , Lu Caijiang
Published: February 2014

An electric current sensor using piezoelectric ceramic Pb(Zr,Ti)O3 (PZT) sandwiched between two high permeability cuboids and two NdFeB magnets is presented. The magnetic field originating from an electric wire is augmented by the high permeability cuboids. The PZT plate experiences an enhanced magnetic force and generates voltage output. When placed with a distance of d = 5.0 mm from the wire, the sensor shows a flat sensitivity of ∼5.7 mV/A in the frequency range of 30 Hz–80 Hz and an average sensitivity of 5.6 mV/A with highly linear behavior in the current range of 1 A–10 A at 50 Hz.
Note: Three wavelengths near-infrared spectroscopy system for compensating the light absorbance by water
Authors: Bhutta M. Raheel , Hong Keum-Shik , Kim Beop-Min , Hong Melissa Jiyoun , Kim Yun-Hee , Lee Se-Ho
Published: February 2014

Given that approximately 80% of blood is water, we develop a wireless functional near-infrared spectroscopy system that detects not only the concentration changes of oxy- and deoxy-hemoglobin (HbO and HbR) during mental activity but also that of water (H2O). Additionally, it implements a water-absorption correction algorithm that improves the HbO and HbR signal strengths during an arithmetic task. The system comprises a microcontroller, an optical probe, tri-wavelength light emitting diodes, photodiodes, a WiFi communication module, and a battery. System functionality was tested by means of arithmetic-task experiments performed by healthy male subjects.
Room-temperature mid-infrared “M”-type GaAsSb/InGaAs quantum well lasers on InP substrate
Authors: Chang Chia-Hao , Li Zong-Lin , Pan Chien-Hung , Lu Hong-Ting , Lee Chien-Ping , Lin Sheng-Di
Published: February 2014

We have demonstrated experimentally the InP-based “M”-type GaAsSb/InGaAs quantum-well (QW) laser lasing at 2.41 μm at room temperature by optical pumping. The threshold power density per QW and extracted internal loss were about 234 W/cm2 and 20.5 cm−1, respectively. The temperature-dependent photoluminescence (PL) and lasing spectra revealed interesting characteristics for this type of lasers. Two distinct regions in the temperature dependent threshold behavior were observed and the transition temperature was found to coincide with the cross over point of the PL and lasing emission peaks. The current-voltage characteristic of “M”-type QW laser was superior to the inverse “W”-type one due to its thinner barrier for holes. Further improvement of the “M”-type QW structure could lead to a cost-effective mid-infrared light source.
Magnetic properties of the anisotropic MnBi/Sm2Fe17Nx hybrid magnet
Authors: Yang Y. B. , Wei J. Z. , Peng X. L. , Xia Y. H. , Chen X. G. , Wu R. , Du H. L. , Han J. Z. , Wang C. S. , Yang Y. C. , Yang J. B.
Published: February 2014

In order to improve the magnetic properties of MnBi compound, anisotropic MnBi/Sm2Fe17Nx hybrid magnet was prepared by grinding of high purity MnBi ribbons and Sm2Fe17Nx particles together. The smooth hysteresis loops of the hybrid magnets indicated that the mixture of the hard/hard phase magnetic components was well exchange coupled. As compared to the single MnBi phase magnet, the remanent magnetization and maximum energy product (BH)max of the composited magnets were improved. As an optimized result, the exchange coupled magnet of MnBi/Sm2Fe17Nx = 3/7 yielded both high remanence and coercivity from 250 K to 380 K. A maximum energy product (BH)max of 18 MGOe was achieved at 300 K, and remained 10 MGOe at 380 K, implying the MnBi/Sm2Fe17Nx magnets can be specially utilized in the high temperature environment.
Interfacial spin cluster effects in exchange bias systems
Authors: Carpenter R. , Vallejo-Fernandez G. , O'Grady K.
Published: February 2014

In this work, the effect of exchange bias on the hysteresis loop of CoFe is observed. The evolution of the coercivities and the shift of the hysteresis loop during the annealing process has been measured for films deposited on NiCr and Cu seed layers. Through comparison of the as deposited and field annealed loops, it is clear that for an exchange biased material, the two coercivities are due to different reversal processes. This behaviour is attributed to spin clusters at the ferromagnet/antiferromagnet interface, which behave in a similar manner to a fine particle system.
Composition and crystallinity in electrochemically deposited magnetostrictive galfenol (FeGa)
Authors: Estrine Eliot C. , Hein Matt , Robbins William P. , Stadler Bethanie J. H.
Published: February 2014

Here, we report the first measurements of magnetostriction as a function of composition for electrodeposited iron-gallium alloys, also known as galfenol. Galfenol is an exciting material due to its large magnetostriction constant (up to 400 ppm) and robust mechanical properties. A wide range of sensors, actuators, and other transducers can be fabricated by taking advantage of galfenol's unique mix of magnetic and mechanical properties. Electrodeposition allows galfenol to be easily integrated into a variety of applications, such as toque sensors with conformal, monolithic active layers. In this work, we examine the underlying factors that influence magnetostriction in electrodeposited galfenol, including crystallinity and composition. Here, we have controlled the film composition, as measured by energy dispersive x-ray spectroscopy, over the range of 5–25% gallium using a single plating bath by varying deposition parameters. This composition range corresponds to the region of largest expected magnetostriction for iron gallium alloys. However, our measured magnetostriction values were significantly lower than the values for single crystal galfenol from literature. The electrodeposited films in this work appeared polycrystalline when measured using x-ray diffraction. When the texture of the film is taken into account, the magnetostriction results closely matched the predicted values. These results show that it is possible to achieve magnetostrictive galfenol thin films over a wide range of compositions using electrodeposition.
Enhanced light extraction in n-GaN-based light-emitting diodes with three-dimensional semi-spherical structure
Authors: Yin Hong-Xing , Zhu Chuan-Rui , Shen Yan , Yang Hai-Fang , Liu Zhe , Gu Chang-Zhi , Liu Bao-Li , Xu Xian-Gang
Published: February 2014

Three-dimensional (3D) periodic micro/nanostructures can have a remarkable enhancement effect on light-emitting diodes (LEDs). However, simple, high-throughput and large-area fabrication of 3D periodic micro/nanostructures with a high duty ratio is difficult. In this Letter, high-duty-ratio 3D semi-spherical structures were fabricated on the surface of n-GaN-based vertical-structure LEDs by under-exposure ultraviolet lithography and dry etching. The resulting LEDs provide about 200% more light output power than those with a flat surface. This method of fabricating high-duty-ratio 3D semi-spherical structures could be used in other optical devices and shows potential for industrial production and commercialization.
Cross-polarization detecting surface-plasmon resonance of near-field transducer
Authors: Peng Chubing
Published: February 2014

Surface-plasmon resonance of a lollipop near-field transducer integrated in a planar solid immersion mirror for heat-assisted magnetic recording has been characterized by measuring the amount of transmitted light in the polarization state orthogonal to the illumination in the far field. This resonance is compared to that probed with a photothermal measurement in near-field. The difference in peak wavelength between the two measures is only about 20 nm.
Influence of Nd and Cu content on the microstructural and magnetic properties of NdFeB thick films
Authors: Gunduz Akdogan N. , Dempsey N. M. , Givord D. , Manabe A. , Shoji T. , Yano M. , Kato A.
Published: February 2014

In this study, Nd(Cu)-Fe-B single layer thick films (up to 5 μm) have been prepared by triode sputtering and the effect of excess Nd and Cu content on the magnetic properties and microstructures have been investigated. The films were deposited at 450 °C and depending on the Nd and Cu content, they are either amorphous or crystalline in the as-deposited state. All films were submitted to an ex-situ rapid thermal annealing (500 °C/10 min). While films with a lower Nd and Cu content are characterized by a homogeneous microstructure, those with a higher Nd-Cu content have a wide distribution in grain size (in some cases, peculiar flower-like structures are formed close to the substrate). The inhomogeneous microstructure, together with direct crystallization in the as-deposited state in high Nd-Cu containing films, is attributed to an exothermic reaction. The highest coercivity (2.75 T) is achieved for the lower Nd (17.5 at. %)-Cu (1.5 at. %) content, higher Nd (up to 35 at. %)-Cu (up to 3 at. %) content leading to a reduction in both coercivity and degree of texture.
A simple electrical test method to isolate viscoelasticity and creep in capacitive microelectromechanical switches
Authors: Ryan C. , Olszewski Z. , Houlihan R. , O'Mahony C. , Duane R.
Published: February 2014

A bipolar hold-down voltage was used to study mechanical degradation in radio-frequency microelectromechanical capacitive shunt switches. The bipolar signal was used to prevent the occurrence of dielectric charging and to isolate mechanical effects. The characteristics of material stress relaxation and recovery were monitored by recording the change of the pull-in voltage of a device. The creep effect in movable components was saturated by repeated actuation to the pulled-in position, while comparison with a theoretical model confirmed the presence of linear viscoelasticity in the devices.