bluuebunny/crossref_metadata_2025 huggingface dataset:
The genetics of feed conversion efficiency traits in a commercial broiler line
Authors: Reyer Henry , Hawken Rachel , Murani Eduard , Ponsuksili Siriluck , Wimmers Klaus
Published: November 2015

Individual feed conversion efficiency (FCE) is a major trait that influences the usage of energy resources and the ecological footprint of livestock production. The underlying biological processes of FCE are complex and are influenced by factors as diverse as climate, feed properties, gut microbiota and individual genetic predisposition. To gain an insight to the genetic relationships with FCE traits and to contribute to the improvement of FCE in commercial chicken lines, a genome-wide association study was conducted using a commercial broiler population (n = 859) tested for FCE and weight traits during the finisher period from 39 to 46 days of age. Both single-marker (generalized linear model) and multi-marker (Bayesian approach) analyses were applied to the dataset to detect genes associated with the variability in FCE. The separate analyses revealed 22 quantitative trait loci (QTL) regions on 13 different chromosomes; the integration of both approaches resulted in 7 overlapping QTL regions. The analyses pointed to acylglycerol kinase (AGK) and general transcription factor 2-I (GTF2I) as positional and functional candidate genes. Non-synonymous polymorphisms of both candidate genes revealed evidence for a functional importance of these genes by influencing different biological aspects of FCE.
Development of 1-N-11C-Methyl-l- and -d-Tryptophan for pharmacokinetic imaging of the immune checkpoint inhibitor 1-Methyl-Tryptophan
Authors: Xie Lin , Maeda Jun , Kumata Katsushi , Yui Joji , Zhang Yiding , Hatori Akiko , Nengaki Nobuki , Wakizaka Hidekatsu , Fujinaga Masayuki , Yamasaki Tomoteru , Shimoda Yoko , Higuchi Makoto , Suhara Tetsuya , Wang Feng , Zhang Ming-Rong
Published: November 2015

1-Methyl-tryptophan (1MTrp) is known as a specific inhibitor targeting the immune- checkpoint protein indoleamine-2,3-dioxygenase, in two stereoisomers of levorotary (l) and dextrorotary (d). A long-standing debate exists in immunology and oncology: which stereoisomer has the potential of antitumor immunotherapy. Herein, we developed two novel radioprobes, 1-N-11C-methyl-l- and -d-tryptophan (11C-l-1MTrp and 11C-d-1MTrp), without modifying the chemical structures of the two isomers and investigated their utility for pharmacokinetic imaging of the whole body. 11C-l-1MTrp and 11C-d-1MTrp were synthesized rapidly with radiochemical yields of 47 ± 6.3% (decay-corrected, based on 11C-CO2), a radiochemical purity of >98%, specific activity of 47–130 GBq/μmol and high enantiomeric purity. PET/CT imaging in rats revealed that for 11C-l-1MTrp, the highest distribution of radioactivity was observed in the pancreas, while for 11C-D-1MTrp, it was observed in the kidney. Ex vivo biodistribution confirmed the PET/CT results, indicating the differences in pharmacokinetics between the two isomers. Both 11C-l-1MTrp and 11C-d-1MTrp are therefore useful PET probes for delineating the distribution and action of the checkpoint inhibitor 1MTrp in vivo. This study represents the first step toward using whole-body and real-time insight to disentangle the antitumor potential of the two stereoisomers of 1MTrp and it can facilitate the development of 1MTrp immunotherapy.
Occurrence of viable, red-pigmented haloarchaea in the plumage of captive flamingoes
Authors: Yim Kyung June , Kwon Joseph , Cha In-Tae , Oh Kyung-Seo , Song Hye Seon , Lee Hae-Won , Rhee Jin-Kyu , Song Eun-Ji , Rho Jeong Rae , Seo Mi Lyu , Choi Jong-Soon , Choi Hak-Jong , Lee Sung-Jae , Nam Young-Do , Roh Seong Woon
Published: November 2015

Flamingoes (Phoenicopterus spp.) whose plumage displays elegant colors, inhabit warm regions close to the ocean throughout the world. The pink or reddish color of their plumage originates from carotenoids ingested from carotenoid-abundant food sources, since flamingoes are unable to synthesize these compounds de novo. In this study, viable red-colored archaeal strains classified as extremely halophilic archaea (i.e., haloarchaea) and belonging to the genera Halococcus and Halogeometricum were isolated from the plumage of flamingoes in captivity. Detailed analysis for haloarchaeal community structure in flamingo feathers based on metagenomic data identified several haloarchaeal genera and unclassified sequences of the class Halobacteria at the genus level. Carotenoid pigment analyses showed that a bacterioruberin precursor carotenoid in haloarchaea was identical to one of the pigments found in flamingo plumage. To the best of our knowledge, this is the first report of viable extremophilic archaea in avian plumage, thus contributing to our understanding of the ecology of haloarchaea. The potential influence of haloarchaea as an environmental factor determining avian plumage coloration should be investigated in further studies.
3D vertical nanostructures for enhanced infrared plasmonics
Authors: Malerba Mario , Alabastri Alessandro , Miele Ermanno , Zilio Pierfrancesco , Patrini Maddalena , Bajoni Daniele , Messina Gabriele C. , Dipalo Michele , Toma Andrea , Proietti Zaccaria Remo , De Angelis Francesco
Published: November 2015

The exploitation of surface plasmon polaritons has been mostly limited to the visible and near infrared range, due to the low frequency limit for coherent plasmon excitation and the reduction of confinement on the metal surface for lower energies. In this work we show that 3D - out of plane - nanostructures can considerably increase the intrinsic quality of the optical output, light confinement and electric field enhancement factors, also in the near and mid-infrared. We suggest that the physical principle relies on the combination of far field and near field interactions between neighboring antennas, promoted by the 3D out-of-plane geometry. We first analyze the changes in the optical behavior, which occur when passing from a single on-plane nanostructure to a 3D out-of-plane configuration. Then we show that by arranging the nanostructures in periodic arrays, 3D architectures can provide, in the mid-IR, a much stronger plasmonic response, compared to that achievable with the use of 2D configurations, leading to higher energy harvesting properties and improved Q-factors, with bright perspective up to the terahertz range.
The effect of statins on chronic obstructive pulmonary disease exacerbation and mortality: a systematic review and meta-analysis of observational research
Authors: Cao Chao , Wu Yinfang , Xu Zhiwei , Lv Dan , Zhang Chao , Lai Tianwen , Li Wen , Shen Huahao
Published: November 2015

The objective of this study is to assess whether statin use is associated with beneficial effects on COPD outcomes. We conducted a systematic review and meta-analysis of all available studies describing the association between statin use and COPD mortality, exacerbations and cardiovascular events. Medline, Embase, Web of Science and the Cochrane Central Register of Controlled Trials were searched, with no restrictions. The hazard ratio (HR) with 95% confidence interval (CI) was estimated. Fifteen studies with a total of 238,459 patients were included. Nine articles provided data on all-cause mortality (124,543 participants) and they gave a HR of 0.62 (95% CI 0.52 to 0.73). Three studies provided data on cancer mortality (90,077 participants), HR 0.83 (0.65 to 1.08); four studies on COPD mortality (88,767 participants), HR 0.48 (0.23 to 0.99); and three studies on cardiovascular mortality (90,041 participants), HR 0.93 (0.50 to 1.72). Six articles provided data on COPD exacerbation with or without hospitalization (129,796 participants), HR 0.64 (0.55 to 0.75). Additionally, the use of statins was associated with a significant reduction risk of myocardial infarction, but not for stroke. Our systematic review showed a clear benefit of statins in patients with COPD.
Development and Effects of FTY720 Ophthalmic Solution on Corneal Allograft Survival
Authors: Liu Zhaochuan , Lin Haotian , Huang Chulong , Chen Wan , Xiang Wu , Geng Yu , Chen Weirong
Published: November 2015

Fingolimod (FTY720), a novel class of sphingosine 1-phosphate receptor modulators, has received special interest among ophthalmologists, particularly given that oral administration of FTY720 has proven to effectively treat corneal graft rejection in animal models. However, no studies have examined the performance of FTY720 as an ophthalmic solution in reducing corneal rejection in high-risk corneal rejection models and the stability and ocular irritation profile of FTY720 ophthalmic solution are also unknown. Thus, we developed 0.1%, 0.2% and 0.5% FTY720 ophthalmic solutions and evaluated their chemical stabilities under various storage conditions with high- performance liquid chromatography. To investigate the ocular irritancy of the FTY720 ophthalmic solution, New Zealand albino rabbits were subjected to the Draize test. Furthermore, classic, well-established rat allogenic penetrating keratoplasty models were used to investigate the anti-rejection efficacy of the tested FTY720 ophthalmic solutions. We found that the non-irritating 0.5% FTY720 ophthalmic solution could prolong corneal allograft survival in rats with significant efficacy for about one month. Furthermore, no significant concentration changes occurred in any of the types of FTY720 ophthalmic solutions within three months. These results revealed crucial profiles of FTY720 ophthalmic solutions and warrant further investigation and optimization of FTY720 in the anti-rejection therapy after keratoplasty.
Dihydrotanshinone-I interferes with the RNA-binding activity of HuR affecting its post-transcriptional function
Authors: D’Agostino Vito Giuseppe , Lal Preet , Mantelli Barbara , Tiedje Christopher , Zucal Chiara , Thongon Natthakan , Gaestel Matthias , Latorre Elisa , Marinelli Luciana , Seneci Pierfausto , Amadio Marialaura , Provenzani Alessandro
Published: November 2015

Post-transcriptional regulation is an essential determinant of gene expression programs in physiological and pathological conditions. HuR is a RNA-binding protein that orchestrates the stabilization and translation of mRNAs, critical in inflammation and tumor progression, including tumor necrosis factor-alpha (TNF). We identified the low molecular weight compound 15,16-dihydrotanshinone-I (DHTS), well known in traditional Chinese medicine practice, through a validated high throughput screening on a set of anti-inflammatory agents for its ability to prevent HuR:RNA complex formation. We found that DHTS interferes with the association step between HuR and the RNA with an equilibrium dissociation constant in the nanomolar range in vitro (Ki = 3.74 ± 1.63 nM). In breast cancer cell lines, short term exposure to DHTS influences mRNA stability and translational efficiency of TNF in a HuR-dependent manner and also other functional readouts of its post-transcriptional control, such as the stability of selected pre-mRNAs. Importantly, we show that migration and sensitivity of breast cancer cells to DHTS are modulated by HuR expression, indicating that HuR is among the preferential intracellular targets of DHTS. Here, we disclose a previously unrecognized molecular mechanism exerted by DHTS, opening new perspectives to therapeutically target the HuR mediated, post-transcriptional control in inflammation and cancer cells.
Tensile strain-induced softening of iron at high temperature
Authors: Li Xiaoqing , Schönecker Stephan , Simon Eszter , Bergqvist Lars , Zhang Hualei , Szunyogh László , Zhao Jijun , Johansson Börje , Vitos Levente
Published: November 2015

In weakly ferromagnetic materials, already small changes in the atomic configuration triggered by temperature or chemistry can alter the magnetic interactions responsible for the non-random atomic-spin orientation. Different magnetic states, in turn, can give rise to substantially different macroscopic properties. A classical example is iron, which exhibits a great variety of properties as one gradually removes the magnetic long-range order by raising the temperature towards its Curie point of "Equation missing" = 1043 K. Using first-principles theory, here we demonstrate that uniaxial tensile strain can also destabilise the magnetic order in iron and eventually lead to a ferromagnetic to paramagnetic transition at temperatures far below "Equation missing". In consequence, the intrinsic strength of the ideal single-crystal body-centred cubic iron dramatically weakens above a critical temperature of ~500 K. The discovered strain-induced magneto-mechanical softening provides a plausible atomic-level mechanism behind the observed drop of the measured strength of Fe whiskers around 300–500 K. Alloying additions which have the capability to partially restore the magnetic order in the strained Fe lattice, push the critical temperature for the strength-softening scenario towards the magnetic transition temperature of the undeformed lattice. This can result in a surprisingly large alloying-driven strengthening effect at high temperature as illustrated here in the case of Fe-Co alloy.
Increased serum levels of sortilin are associated with depression and correlated with BDNF and VEGF
Authors: Buttenschøn H N , Demontis D , Kaas M , Elfving B , Mølgaard S , Gustafsen C , Kaerlev L , Petersen C M , Børglum A D , Mors O , Glerup S
Published: November 2015

Neurotrophic factors have been investigated in relation to depression. The aim of the present study was to widen this focus to sortilin, a receptor involved in neurotrophic signalling. The serum sortilin level was investigated in 152 individuals with depression and 216 control individuals, and eight genetic markers located within the SORT1 gene were successfully analysed for association with depression. Genotyping was performed using the Sequenom MassARRAY platform. All the individuals returned a questionnaire and participated in a semi-structured diagnostic interview. Sortilin levels were measured by immunoassay, and potential determinants of the serum sortilin level were assessed by generalized linear models. Serum levels of brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) were measured in previous studies. We identified a significant increase of serum sortilin levels in depressed individuals compared with controls (P=0.0002) and significant positive correlation between serum sortilin levels and the corresponding levels of BDNF and VEGF. None of the genotyped SNPs were associated with depression. Additional analyses showed that the serum sortilin level was influenced by several other factors. Alcohol intake and body mass index, as well as depression, serum BDNF and serum VEGF were identified as predictors of serum sortilin levels in our final multivariate model. In conclusion, the results suggest a role of circulating sortilin in depression which may relate to altered activity of neurotrophic factors.
Methodologies for the Taylor dispersion analysis for mixtures, aggregates and the mitigation of buffer mismatch effects
Authors: Latunde-Dada Seyi , Bott Rachel , Hampton Karl , Patel Jenika , Leszczyszyn Oksana Iryna
Published: November 2015

Taylor Dispersion Analysis is a fast and simple method for determining the hydrodynamic radii of mixtures.
High adsorption capacity of heavy metals on two-dimensional MXenes: an ab initio study with molecular dynamics simulation
Authors: Guo Xun , Zhang Xitong , Zhao Shijun , Huang Qing , Xue Jianming
Published: November 2015

Six lead atoms adsorb on a 3 × 3 Ti2C1H2 unit.
The impact of doping rates on the morphologies of silver and gold nanowires grown in helium nanodroplets
Authors: Volk Alexander , Thaler Philipp , Knez Daniel , Hauser Andreas W. , Steurer Johannes , Grogger Werner , Hofer Ferdinand , Ernst Wolfgang E.
Published: November 2015

The morphologies of HeN-grown gold and silver nanowires depend on the metal atom doping rates in the pickup process.
Hydroxytyrosol decreases the oxidative and nitrosative stress levels and promotes angiogenesis through HIF-1 independent mechanisms in renal hypoxic cells
Authors: Martínez-Lara Esther , Peña Ana , Calahorra Jesús , Cañuelo Ana , Siles Eva
Published: November 2015

A proposed model of action of HT-treatment in the hypoxic response of sublethally damaged renal cells is presented.
Antihypertensive effects of oleuropein-enriched olive leaf extract in spontaneously hypertensive rats
Authors: Romero M. , Toral M. , Gómez-Guzmán M. , Jiménez R. , Galindo P. , Sánchez M. , Olivares M. , Gálvez J. , Duarte J.
Published: November 2015

The effects of chronic consumption of oleuropein-enriched (15% w/w) olive leaf extract (OLE) on blood pressure, endothelial function, and vascular oxidative and inflammatory status in spontaneously hypertensive rats (SHR) were evaluated.
Synthesis and evaluation of thieno[2,3-d]pyrimidin-4(3H)-ones as potential antitubercular agents
Authors: Borate Hanumant B. , Annadate Ritesh A. , Vagh Sandip S. , Pisal Mahesh M. , Deokate Sagar B. , Arkile Manisha A. , Jadhav Nandadeep J. , Nawale Laxman U. , Sarkar Dhiman
Published: November 2015

Thieno[2,3-d]pyrimidin-4(3H)-ones with structures 11–38 were synthesized and some of them were found to be potent inhibitors of Mycobacterium tuberculosis H37Ra and/or Mycobacterium bovis BCG and non-toxic to human cell lines.
Nanocrystal size distribution analysis from transmission electron microscopy images
Authors: van Sebille Martijn , van der Maaten Laurens J. P. , Xie Ling , Jarolimek Karol , Santbergen Rudi , van Swaaij René A. C. M. M. , Leifer Klaus , Zeman Miro
Published: November 2015

We propose a method to quickly detect and measure the nanocrystal size distribution from TEM images.
A side-chain engineering approach to solvent-resistant semiconducting polymer thin films
Authors: Guo Zi-Hao , Ai Na , McBroom Connor Ryan , Yuan Tianyu , Lin Yen-Hao , Roders Michael , Zhu Congzhi , Ayzner Alexander L. , Pei Jian , Fang Lei
Published: November 2015

Latent H-bonds in conjugated statistical copolymers rendered semiconducting thin films resistant to solvent immersion.
Pyridine-grafted graphene oxide: a reusable acid–base bifunctional catalyst for the one-pot synthesis of β-phosphonomalonates via a cascade Knoevenagel–phospha Michael addition reaction in water
Authors: Sobhani Sara , Zarifi Farzaneh
Published: November 2015

Py–GO as a new acid–base bifunctional catalyst was synthesized and employed for the one-pot synthesis of β-phosphonomalonates in water.
Continuously tuning the spectral response of chiral plasmonic patchy particles through galvanic replacement reaction
Authors: Larsen George K. , Stom Nicholas , Zhao Yiping
Published: November 2015

We demonstrate the continuous tuning of the circular dichroism spectra of chiral patchy particle arrays using the galvanic replacement reaction.
Synthesis of phosphotungstic acid-supported versatile metal–organic framework PTA@MIL-101(Fe)–NH2–Cl
Authors: Zhang Yingshi , Wan Jinquan , Wang Yan , Ma Yongwen
Published: November 2015

The catalyst PTA@MIL-101(Fe)–NH2–Cl was synthesized in various solvents and metal concentration to investigate their effect on the catalyst crystal structure. The functions of amino groups and chlorine groups were also discussed.
Ionic Diels–Alder reaction of 3-bromofuran toward the highly electron deficient cyclobuteniminium cation: a regio- and stereoselectivity, and molecular mechanism study using DFT
Authors: Emamian Saeedreza , Hosseini Seyed javad , Ravani Khadije-sadat
Published: November 2015

The ionic Diels–Alder reaction between 3-bromofuran and cyclobuteniminum cation in the presence of chloroform takes place in a complete regio- and stereoselective manner via a non-concerted two-stage one-step molecular mechanism.
Solid-state graphene formation via a nickel carbide intermediate phase
Authors: Xiong W. , Zhou Y. S. , Hou W. J. , Guillemet T. , Silvain J. F. , Gao Y. , Lahaye M. , Lebraud E. , Xu S. , Wang X. W. , Cullen D. A. , More K. L. , Jiang L. , Lu Y. F.
Published: November 2015

Direct formation of graphene with a controlled number of graphitic layers on dielectric surfaces is achieved with an in-depth understanding of the solid-state growth mechanism.
Superlubrication properties of ultra-nanocrystalline diamond film sliding against a zirconia ball
Authors: Rani Revati , Kumar N. , Kozakov A. T. , Googlev K. A. , Sankaran K. J. , Das Pankaj Kr. , Dash S. , Tyagi A. K. , Lin I-Nan
Published: November 2015

The friction and wear behavior of ultra-nanocrystalline diamond (UNCD) films are sensitive to the phase composition, mainly graphite and amorphous carbon (a-C), occupying the grain boundaries of sp3 hybridized diamond nanocrystals.
Coupling dye-integrated polymeric membranes with smartphone detection to classify bacteria
Authors: Bueno Lígia , Cottell Alison , Reddy Subrayal M. , Paixão Thiago R. L. C.
Published: November 2015

We report the use of a colorimetric plastic-based device to discriminate four pathogenic bacteria: Klebsiella pneumoniae, Proteus vulgaris, Proteus mirabilis and Escherichia coli.
Synthesis and color tuning of boron diiminate conjugated polymers with aggregation-induced scintillation properties
Authors: Tanaka Kazuo , Yanagida Takayuki , Hirose Amane , Yamane Honami , Yoshii Ryousuke , Chujo Yoshiki
Published: November 2015

We report film-type scintillators based on conjugated polymers with aggregation-induced emission (AIE) properties and the modulation of their scintillation abilities by chemical modification.
Electrodeposited nickel cobalt sulfide nanosheet arrays on 3D-graphene/Ni foam for high-performance supercapacitors
Authors: Wang Yang , Wang Lidong , Wei Bing , Miao Qinghua , Yuan Yinan , Yang Ziyue , Fei Weidong
Published: November 2015

With the synergistic effect of 3D RGO and Ni–Co–S nanosheets, a Ni–Co–S/RGO/NF electrode exhibits excellent electrochemical performance.
Fabrication of binary components based on a poly(ionic liquid) through “grafting” and “clicking” and their synergistic antifouling activity
Authors: Zhao Wenwen , Ye Qian , Hu Haiyuan , Wang Xiaolong , Zhou Feng
Published: November 2015

Grafting a binary component mPEG-poly(ionic liquid) via “grafting” and “clicking” reactions for antifouling applications.
A flow visualization and superposition rheology study of shear-banding wormlike micelle solutions
Authors: Mohammadigoushki Hadi , Muller Susan J.
Published: November 2015

In this paper, we use rheometry and flow visualization to study the dynamics of the interface between shear bands in a wormlike micellar solution sheared between concentric cylinders, i.e., in a Taylor–Couette (TC) cell, and to evaluate the stress diffusion coefficient and the stress correlation length in the Johnson–Segalman model.
Improved luminance and external quantum efficiency of red and white organic light-emitting diodes with iridium(iii) complexes with phenyl-substituted 2-phenylpyridine as a second cyclometalated ligand
Authors: Kim Hee Un , Jang Jae-Ho , Song Wook , Jung Byung Jun , Lee Jun Yeob , Hwang Do-Hoon
Published: November 2015

Two novel red Ir(iii) complexes based on cyclometalating ligands were synthesized for use in phosphorescent organic light-emitting diodes.
Modulating high-energy visible light absorption to attain neutral-state black electrochromic polymers
Authors: Neo Wei Teng , Cho Ching Mui , Shi Zugui , Chua Soo-Jin , Xu Jianwei
Published: November 2015

Neutral-state black electrochromic polymers were achieved by incorporating an additional donor to enhance the blue-absorption.
BaBi(SeO3)2Cl: a new polar material showing high second-harmonic generation efficiency enhanced by constructive alignment of chloride ions
Authors: Geng Lei , Li Qiang , Meng Chang-Yu , Dai Kai , Lu Hong-Yan , Lin Chen-Sheng , Cheng Wen-Dan
Published: November 2015

A novel polar material oxychloride BaBi(SeO3)2Cl with high SHG efficiency (∼16 × KDP) has been synthesized and characterized.
Potent irreversible P2Y12 inhibition does not reduce LPS-induced coagulation activation in a randomized, double-blind, placebo-controlled trial
Authors: Schoergenhofer Christian , Schwameis Michael , Hobl Eva-Luise , Ay Cihan , Key Nigel S. , Derhaschnig Ulla , Jilma Bernd , Spiel Alexander O.
Published: November 2015

Platelets play an important role in the activation of coagulation. P2Y12 receptor inhibition may be beneficial in inflammatory states. Prasugrel, a potent irreversible inhibitor of P2Y12 receptor-induced platelet activation may reduce activation of coagulation in a human LPS (lipopolysaccharide) model. A double-blind, randomized, crossover trial with a minimum washout period of 6 weeks was performed. Sixteen subjects were randomly assigned to a treatment group that received prasugrel or placebo 2 h before infusion of a bolus of LPS (2 ng/kg of body weight), whereas four subjects were assigned to a control group receiving prasugrel or placebo without LPS. hcDNA (histone-complexed DNA), coagulation and platelet-specific parameters were measured by enzyme immunoassay. Leucocyte aggregate formation was analysed by flow cytometry, and thromboelastometry was performed. LPS infusion markedly activated coagulation. However, prasugrel did not reduce changes in prothrombin fragments 1 and 2 (F1+2), thrombin–antithrombin complexes, microparticle-associated tissue factor, CD40 ligand, P-selectin, platelet–leucocyte aggregation, hcDNA levels or the coagulation profile measured by thromboelastometry. hcDNA plasma levels increased approximately 6-fold after LPS infusion in both treatment groups, but not in the control groups. Potent irreversible P2Y12 inhibition by prasugrel does not affect LPS-induced coagulation activation. The 6-fold increased hcDNA plasma levels after infusion of LPS indicates the formation of neutrophil extracellular traps during sterile inflammation.
Peak‐to‐peak search: fast and accurate DOA estimation method for arbitrary non‐uniform linear array
Authors: Wei Li , Shao Wei , Qi Wangdong , Chen Jianhua
Published: November 2015

A peak‐to‐peak (P‐to‐P) search‐based single source direction of arrival estimation is proposed. The P‐to‐P method aims to search only at each local minima of a least square cost function, thus quickly acquiring the global optimal solution relative to exhaustive grid search. Performance comparisons with existing methods verify that the proposed method achieves high accuracy, possesses low signal‐to‐noise ratio threshold and computational cost and can be applicable to any non‐uniform linear array.
Double space‐time transmit diversity with spatial modulation
Authors: Park Myung Chul , Jo Bong Gyun , Han Dong Seog
Published: November 2015

A hybrid scheme of the double space‐time transmit diversity (DSTTD) and spatial modulation (SM) is proposed. The spectral efficiency of proposed scheme is twice that of DSTTD. Additional bits are transmitted by transmit antenna combinations of SM without widening the bandwidth. An optimised rotated constellation is also proposed according to the antenna combination to reduce inter‐channel interference.
Near‐field time‐domain characterisation of wideband antennas
Authors: Mobashsher A.T. , Abbosh A.M.
Published: November 2015

Time‐domain characterisation is vital in verifying the suitability of wideband antennas for near‐field applications such as microwave medical imaging and sensing. To that end, a near‐field time‐domain characterisation method to calculate the near‐field transient response and the distortion of wideband antennas is proposed. The method uses a pulse merit factor, which consists of the near‐field time‐domain signal amplitude and a fidelity factor, both normalised to the highest values attained from the antennas. To verify the method, the transient responses of unidirectional and omnidirectional antennas designed for near‐field imaging are analysed. The analyses show that even though the investigated antennas cover the same band with the same average far‐field gain along the boresight direction, the unidirectional antenna exhibits 35% more pulse merit factor with less impulse distortion along the intended direction, which suggests better suitability for wideband near‐field imaging systems.
Saturation in cascaded optical amplifier free‐space optical communication systems
Authors: Bandele Oluwatosin Jeremiah , Desai Priyanka , Woolfson Malcolm. S. , Phillips Andrew Julian
Published: November 2015

The performance of a free‐space optical (FSO) communication system in a turbulent atmosphere employing an optical amplifier (OA) cascade to extend reach is investigated. Analysis of both single and cascaded OA FSO communication links is given and the implications of using both adaptive (to channel state) and non‐adaptive decision threshold schemes are analysed. The benefits of amplifier saturation, for example in the form of effective scintillation reduction when a non‐adaptive decision threshold scheme is utilised at the receiver for different atmospheric turbulence regimes, are presented. Monte Carlo simulation techniques are used to model the probability distributions of the optical signal power, noise and the average bit error rate due to scintillation for the cascade. The performance of an adaptive decision threshold is superior to a non‐adaptive decision threshold for both saturated and fixed gain preamplified receivers and the ability of a saturated gain OA to suppress scintillation is only meaningful for system performance when a non‐adaptive decision threshold is used at the receiver. An OA cascade can be successfully used to extend reach in FSO communication systems and specific system implementations are presented. The optimal cascade scheme with a non‐adaptive receiver would use frequent low gain saturated amplification.
Three-parameter error analysis method based on rotating coordinates in rotating birefringent polarizer system
Authors: Cao Junjie , Jia Hongzhi
Published: November 2015

We propose error analysis using a rotating coordinate system with three parameters of linearly polarized light—incidence angle, azimuth angle on the front surface, and angle between the incidence and vibration planes—and demonstrate the method on a rotating birefringent prism system. The transmittance and angles are calculated plane-by-plane using a birefringence ellipsoid model and the final transmitted intensity equation is deduced. The effects of oblique incidence, light interference, beam convergence, and misalignment of the rotation and prism axes are discussed. We simulate the entire error model using MATLAB and conduct experiments based on a built polarimeter. The simulation and experimental results are consistent and demonstrate the rationality and validity of this method.
Nanoconfined catalytic Ångström-size motors
Authors: Colberg Peter H. , Kapral Raymond
Published: November 2015

Self-propelled chemically powered synthetic micron and nano-scale motors are being intensively studied because of the wide range of potential applications that exploit their directed motion. This paper considers even smaller Ångström-size synthetic motors. Such very small motors in bulk solution display effects arising from their self-propulsion. Recent experiments have shown that small-molecule catalysts and single enzyme molecules exhibit properties that have been attributed to their chemical activity. Molecular dynamics is used to investigate the properties of very small Ångström-size synthetic chemically powered sphere-dimer motors in a simple atomic-like solvent confined between walls separated by distances of tens of nanometers. Evidence for strong structural ordering of the motors between the walls, which reflects the finite size of solvent molecules and depends on solvent depletion forces, is provided. Dynamical properties, such as average motor velocity, orientational relaxation, and mean square displacement, are anisotropic and depend on the distance from the walls. This research provides information needed for potential applications that use molecular-scale motors in the complex confined geometries encountered in biology and the laboratory.
Quantum mechanical calculation of electric fields and vibrational Stark shifts at active site of human aldose reductase
Authors: Wang Xianwei , Zhang John Z. H. , He Xiao
Published: November 2015

Recent advance in biophysics has made it possible to directly measure site-specific electric field at internal sites of proteins using molecular probes with C = O or C≡N groups in the context of vibrational Stark effect. These measurements directly probe changes of electric field at specific protein sites due to, e.g., mutation and are very useful in protein design. Computational simulation of the Stark effect based on force fields such as AMBER and OPLS, while providing good insight, shows large errors in comparison to experimental measurement due to inherent difficulties associated with point charge based representation of force fields. In this study, quantum mechanical calculation of protein’s internal electrostatic properties and vibrational Stark shifts was carried out by using electrostatically embedded generalized molecular fractionation with conjugate caps method. Quantum calculated change of mutation-induced electric field and vibrational Stark shift is reported at the internal probing site of enzyme human aldose reductase. The quantum result is in much better agreement with experimental data than those predicted by force fields, underscoring the deficiency of traditional point charge models describing intra-protein electrostatic properties.
Plasmon resonance and perfect light absorption in subwavelength trench arrays etched in gallium-doped zinc oxide film
Authors: Hendrickson Joshua R. , Vangala Shivashankar , Nader Nima , Leedy Kevin , Guo Junpeng , Cleary Justin W.
Published: November 2015

Near-perfect light absorption in subwavelength trench arrays etched in highly conductive gallium-doped zinc oxide films was experimentally observed in the mid infrared regime. At wavelengths corresponding to the resonant excitation of surface plasmons, up to 99% of impinging light is efficiently trapped and absorbed in the periodic trenches. Scattering cross sectional calculations reveal that each individual trench acts like a vertical split ring resonator with a broad plasmon resonance spectrum. The coupling of these individual plasmon resonators in the grating structure leads to enhanced photon absorption and significant resonant spectral linewidth narrowing. Ellipsometry measurements taken before and after device fabrication result in different permittivity values for the doped zinc oxide material, indicating that localized annealing occurred during the plasma etching process due to surface heating. Simulations, which incorporate a 50 nm annealed region at the zinc oxide surface, are in a good agreement with the experimental results.
Latent fingermarks detection for La2O3:Er3+/Yb3+ phosphor material in upconversion emission mode: A comparative study
Authors: Tiwari Surya P. , Kumar Kaushal , Rai Vineet K.
Published: November 2015

The authors in this manuscript present the results on synthesis of Er3+/Yb3+ codoped La2O3 upconverting phosphor and its demonstration on the development of latent fingermarks on the surfaces of semi-porous and non-porous objects. The samples were synthesized via combustion using urea as a reducing agent and chemical precipitation methods. The annealed samples showed enough intense green emission in the 520–550 nm range on 980 nm excitation. Excellent emission property of the samples in the green region showed an advantage to use it in latent fingermarks detection. A dry powder dusting technique is used to develop latent fingermarks and the results are compared. The studies reflected the superiority of upconversion phosphor materials for the detection of latent fingermarks over the traditional downconversion luminescence methods.
Molecular and electronic structure of osmium complexes confined to Au(111) surfaces using a self-assembled molecular bridge
Authors: de la Llave Ezequiel , Herrera Santiago E. , Adam Catherine , Méndez De Leo Lucila P. , Calvo Ernesto J. , Williams Federico J.
Published: November 2015

The molecular and electronic structure of Os(II) complexes covalently bonded to self-assembled monolayers (SAMs) on Au(111) surfaces was studied by means of polarization modulation infrared reflection absorption spectroscopy, photoelectron spectroscopies, scanning tunneling microscopy, scanning tunneling spectroscopy, and density functional theory calculations. Attachment of the Os complex to the SAM proceeds via an amide covalent bond with the SAM alkyl chain 40° tilted with respect to the surface normal and a total thickness of 26 Å. The highest occupied molecular orbital of the Os complex is mainly based on the Os(II) center located 2.2 eV below the Fermi edge and the LUMO molecular orbital is mainly based on the bipyridine ligands located 1.5 eV above the Fermi edge.
Tungsten disulphide based all fiber Q-switching cylindrical-vector beam generation
Authors: Lin J. , Yan K. , Zhou Y. , Xu L. X. , Gu C. , Zhan Q. W.
Published: November 2015

We proposed and demonstrated an all fiber passively Q-switching laser to generate cylindrical-vector beam, a two dimensional material, tungsten disulphide (WS2), was adopted as a saturable absorber inside the laser cavity, while a few-mode fiber Bragg grating was used as a transverse mode-selective output coupler. The repetition rate of the Q-switching output pulses can be varied from 80 kHz to 120 kHz with a shortest duration of 958 ns. Attributed to the high damage threshold and polarization insensitivity of the WS2 based saturable absorber, the radially polarized beam and azimuthally polarized beam can be easily generated in the Q-switching fiber laser.
Magnetoresistance of heavy and light metal/ferromagnet bilayers
Authors: Avci Can Onur , Garello Kevin , Mendil Johannes , Ghosh Abhijit , Blasakis Nicolas , Gabureac Mihai , Trassin Morgan , Fiebig Manfred , Gambardella Pietro
Published: November 2015

We studied the magnetoresistance of normal metal (NM)/ferromagnet (FM) bilayers in the linear and nonlinear (current-dependent) regimes and compared it with the amplitude of the spin-orbit torques and thermally induced electric fields. Our experiments reveal that the magnetoresistance of the heavy NM/Co bilayers (NM = Ta, W, and Pt) is phenomenologically similar to the spin Hall magnetoresistance (SMR) of YIG/Pt, but has a much larger anisotropy of the order of 0.5%, which increases with the atomic number of the NM. This SMR-like behavior is absent in light NM/Co bilayers (NM = Ti and Cu), which present the standard anisotropic magnetoresistance expected from polycrystalline FM layers. In the Ta, W, and Pt/Co bilayers, we find an additional magnetoresistance directly proportional to the current and to the transverse component of the magnetization. This so-called unidirectional SMR, of the order of 0.005%, is largest in W and correlates with the amplitude of the antidamping spin-orbit torque. The unidirectional SMR is below the accuracy of our measurements in YIG/Pt.
Efficient nanorod-based amorphous silicon solar cells with advanced light trapping
Authors: Kuang Y. , van Lare M. C. , Veldhuizen L. W. , Polman A. , Rath J. K. , Schropp R. E. I.
Published: November 2015

We present a simple, low-cost, and scalable approach for the fabrication of efficient nanorod-based solar cells. Templates with arrays of self-assembled ZnO nanorods with tunable morphology are synthesized by chemical bath deposition using a low process temperature at 80 °C. The nanorod templates are conformally coated with hydrogenated amorphous silicon light absorber layers of 100 nm and 200 nm thickness. An initial efficiency of up to 9.0% is achieved for the optimized design. External quantum efficiency measurements on the nanorod cells show a substantial photocurrent enhancement both in the red and the blue parts of the solar spectrum. Key insights in the light trapping mechanisms in these arrays are obtained via a combination of three-dimensional finite-difference time-domain simulations, optical absorption, and external quantum efficiency measurements. Front surface patterns enhance the light incoupling in the blue, while rear side patterns lead to enhanced light trapping in the red. The red response in the nanorod cells is limited by absorption in the patterned Ag back contact. With these findings, we develop and experimentally realize a further advanced design with patterned front and back sides while keeping the Ag reflector flat, showing significantly enhanced scattering from the back reflector with reduced parasitic absorption in the Ag and thus higher photocurrent generation. Many of the findings in this work can serve to provide insights for further optimization of nanostructures for thin-film solar cells in a broad range of materials.
Demonstration of superconducting micromachined cavities
Authors: Brecht T. , Reagor M. , Chu Y. , Pfaff W. , Wang C. , Frunzio L. , Devoret M. H. , Schoelkopf R. J.
Published: November 2015

Superconducting enclosures will be key components of scalable quantum computing devices based on circuit quantum electrodynamics. Within a densely integrated device, they can protect qubits from noise and serve as quantum memory units. Whether constructed by machining bulk pieces of metal or microfabricating wafers, 3D enclosures are typically assembled from two or more parts. The resulting seams potentially dissipate crossing currents and limit performance. In this letter, we present measured quality factors of superconducting cavity resonators of several materials, dimensions, and seam locations. We observe that superconducting indium can be a low-loss RF conductor and form low-loss seams. Leveraging this, we create a superconducting micromachined resonator with indium that has a quality factor of two million, despite a greatly reduced mode volume. Inter-layer coupling to this type of resonator is achieved by an aperture located under a planar transmission line. The described techniques demonstrate a proof-of-principle for multilayer microwave integrated quantum circuits for scalable quantum computing.
Size and structure effects of PtN (N = 12 − 13) clusters for the oxygen reduction reaction: First-principles calculations
Authors: Rodríguez-Kessler P. L. , Rodríguez-Domínguez A. R.
Published: November 2015

Size and structure effects on the oxygen reduction reaction on PtN clusters with N = 12–13 atoms have been investigated using periodic density functional theory calculations with the generalized gradient approximation. To describe the catalytic activity, we calculated the O and OH adsorption energies on the cluster surface. The oxygen binding on the 3-fold hollow sites on stable Pt12−13 cluster models resulted more favorable for the reaction with O, compared with the Pt13(Ih) and Pt55(Ih) icosahedral particles, in which O binds strongly. However, the rate-limiting step resulted in the removal of the OH species due to strong adsorptions on the vertex sites, reducing the utility of the catalyst surface. On the other hand, the active sites of Pt12−13 clusters have been localized on the edge sites. In particular, the OH adsorption on a bilayer Pt12 cluster is the closest to the optimal target; with 0.0-0.2 eV weaker than the Pt(111) surface. However, more progress is necessary to activate the vertex sites of the clusters. The d-band center of PtN clusters shows that the structural dependence plays a decisive factor in the cluster reactivity.
Study on the size effect in Hf0.5Zr0.5O2 films thinner than 8 nm before and after wake-up field cycling
Authors: Park Min Hyuk , Kim Han Joon , Kim Yu Jin , Lee Young Hwan , Moon Taehwan , Kim Keum Do , Hyun Seung Dam , Hwang Cheol Seong
Published: November 2015

The effects of film thickness and wake-up field cycling on the ferroelectricity in Hf0.5Zr0.5O2 films thinner than 8 nm were carefully examined. The Hf0.5Zr0.5O2 films became more antiferroelectric-like with decreasing film thickness in pristine state, whereas all the Hf0.5Zr0.5O2 films showed ferroelectric characteristics after wake-up process. The decrease in the coercive field with decreasing film thickness could be understood based on the depolarization correction. From the temperature-dependent characterization, the tetragonal-to-orthorhombic phase transition during wake-up process is believed to be a thermally activated process, and the estimated activation energy was ∼3.42 ± 0.17 kJ/mol.
Investigation of optimal hydrogen sensing performance in semiconducting carbon nanotube network transistors with palladium electrodes
Authors: Choi Bongsik , Lee Dongil , Ahn Jae-Hyuk , Yoon Jinsu , Lee Juhee , Jeon Minsu , Kim Dong Myong , Kim Dae Hwan , Park Inkyu , Choi Yang-Kyu , Choi Sung-Jin
Published: November 2015

The work function of palladium (Pd) is known to be sensitive to hydrogen (H2) via the formation of a surface dipole layer or Pd hydride. One approach to detect such a change in the work function is based on the formation of a Schottky barrier between Pd and a semiconductor. Here, we demonstrate a H2 sensor operable at room temperature by assembling solution-processed, pre-separated semiconducting single-walled carbon nanotube (SWNT) network bridged by Pd source/drain (S/D) electrodes in a configuration of field-effect transistors (FETs) with a local back-gate electrode. To begin with, we observed that the H2 response of the fabricated SWNT FETs can be enhanced in the linear operating regime, where the change in the work function of the Pd S/D electrodes by H2 can be effectively detected. We also explore the H2 responses in various SWNT FETs with different physical dimensions to optimize the sensing performance.
Tuning molecule-substrate coupling via deposition of metal adatoms
Authors: Yang Hung-Hsiang , Tsai Hsu-Han , Ying Chi-Feng , Yang Tsung-Han , Kaun Chao-Cheng , Chen Chun-hsien , Lin Minn-Tsong
Published: November 2015

Organic-inorganic hybrids constitute an important class of functional materials. The fundamentals at the molecular levels are, however, relatively unexplored. PTCDA (perylene-3,4,9,10-tetracarboxylic dianhydride) is a colorant and extensively applied in organic-based optoelectronic devices. PTCDA/Cu(111) and Fe-PTCDA/Cu(111) metal-organic hybrid monolayers are studied by low temperature scanning tunneling microscopy and spectroscopy (STS) and density functional theory (DFT). The former exhibits Moiré pattern-modulated molecular density of states while the latter adapts a commensurate adlattice. Both imaging and spectroscopic results suggest a strong hybridization between PTCDA molecules and Cu(111) substrate. Weak PTCDA-Cu(111) coupling can be obtained by the introduction of Fe adatoms. Compared to PTCDA/Cu(111), STS spectra of Fe-PTCDA/Cu(111) exhibit a higher energy and sharper features of the frontier orbitals. Together with the DFT results, we found that the PTCDA-Cu(111) coupling is attenuated by the presence of Fe adatoms and Fe-PTCDA coordination.
Carborane-Containing Hydroxyamidine Scaffolds as Novel Inhibitors of Indoleamine 2,3-Dioxygenase 1 (IDO1)
Authors: Austin Christopher J. D. , Moir Michael , Kahlert Jan , Smith Jason R. , Jamie Joanne F. , Kassiou Michael , Rendina Louis M.
Published: November 2015

Two new carborane-containing hydroxyamidines were prepared as potential inhibitors of the indoleamine 2,3-dioxygenase 1 (IDO1) enzyme. One compound (3) displayed low micromolar (1.90 μM) inhibition of IDO1, with the related compound (4) displaying >5-fold lower inhibitory activity, i.e. subtle differences in structure between the two carborane compounds led to dramatic changes in inhibitor binding. In silico docking experiments unravel a possible molecular mechanism that is consistent with the observed difference in IDO1 binding for 3 and 4 and also for the phenyl bioisosteres 1 and 2.