bluuebunny/crossref_metadata_2025 huggingface dataset:
Metabolic role of dipeptidyl peptidase 4 (DPP4) in primary human (pre)adipocytes
Authors: Zilleßen Pia , Celner Jennifer , Kretschmann Anita , Pfeifer Alexander , Racké Kurt , Mayer Peter
Published: March 2016

Dipeptidyl peptidase 4 (DPP4) is the target of the gliptins, a recent class of oral antidiabetics. DPP4 (also called CD26) was previously characterized in immune cells but also has important metabolic functions which are not yet fully understood. Thus, we investigated the function of DPP4 in human white preadipocytes and adipocytes. We found that both cell types express DPP4 in high amounts; DPP4 release markedly increased during differentiation. In preadipocytes, lentiviral DPP4 knockdown caused significant changes in gene expression as determined by whole-genome DNA-array analysis. Metabolic genes were increased, e.g. PDK4 18-fold and PPARγC1α (=PGC1α) 6-fold and proliferation-related genes were decreased (e.g. FGF7 5-fold). These effects, contributing to differentiation, were not inhibited by the PPARγ antagonist T0070907. Vice versa, the PPARγ agonist pioglitazone induced a different set of genes (mainly FABP4). DPP4 knockdown also affected growth factor signaling and, accordingly, retarded preadipocyte proliferation. In particular, basal and insulin-induced ERK activation (but not Akt activation) was markedly diminished (by around 60%). This indicates that DPP4 knockdown contributes to adipocyte maturation by mimicking growth factor withdrawal, an early step in fat cell differentiation. In mature adipocytes, DPP4 becomes liberated so that adipose tissue may constitute a relevant source of circulating DPP4.
Design of Advanced Photocatalysis System by Adatom Decoration in 2D Nanosheets of Group-IV and III–V Binary Compounds
Authors: Jin Hao , Dai Ying , Huang Bai-Biao
Published: March 2016

Searching for novel photocatalysts is one of the most important topic in photocatalytic fields. In the present work, we propose a feasible approach to improve the photocatalytic activities of 2D bilayers through surface decoration, i.e. hydrogenation, halogenation and hydroxylation. Our investigations demonstrate that after surface modification, the optical adsorption expands into the visible region, while a built-in electric field is induced due to the interlayer coupling, which can promote the charge separation for photogenerated electron-hole pairs. Our results show that the indirect-direct band gap transition of SiC, SnC, BN and GaN can be realised through adatom decoration. Furthermore, the surface-modified 2D bilayers have suitable VBM and CBM alignments with the oxidation and reduction potentials for water splitting, suggesting powerful potentials in energy and environmental applications.
Reconstruction of thermotolerant yeast by one-point mutation identified through whole-genome analyses of adaptively-evolved strains
Authors: Satomura Atsushi , Miura Natsuko , Kuroda Kouichi , Ueda Mitsuyoshi
Published: March 2016

Saccharomyces cerevisiae is used as a host strain in bioproduction, because of its rapid growth, ease of genetic manipulation, and high reducing capacity. However, the heat produced during the fermentation processes inhibits the biological activities and growth of the yeast cells. We performed whole-genome sequencing of 19 intermediate strains previously obtained during adaptation experiments under heat stress; 49 mutations were found in the adaptation steps. Phylogenetic tree revealed at least five events in which these strains had acquired mutations in the CDC25 gene. Reconstructed CDC25 point mutants based on a parental strain had acquired thermotolerance without any growth defects. These mutations led to the downregulation of the cAMP-dependent protein kinase (PKA) signaling pathway, which controls a variety of processes such as cell-cycle progression and stress tolerance. The one-point mutations in CDC25 were involved in the global transcriptional regulation through the cAMP/PKA pathway. Additionally, the mutations enabled efficient ethanol fermentation at 39 °C, suggesting that the one-point mutations in CDC25 may contribute to bioproduction.
Superconducting H5S2 phase in sulfur-hydrogen system under high-pressure
Authors: Ishikawa Takahiro , Nakanishi Akitaka , Shimizu Katsuya , Katayama-Yoshida Hiroshi , Oda Tatsuki , Suzuki Naoshi
Published: March 2016

Recently, hydrogen sulfide was experimentally found to show the high superconducting critical temperature (Tc) under high-pressure. The superconducting Tc shows 30–70 K in pressure range of 100–170 GPa (low-Tc phase) and increases to 203 K, which sets a record for the highest Tc in all materials, for the samples annealed by heating it to room temperature at pressures above 150 GPa (high-Tc phase). Here we present a solid H5S2 phase predicted as the low-Tc phase by the application of the genetic algorithm technique for crystal structure searching and first-principles calculations to sulfur-hydrogen system under high-pressure. The H5S2 phase is thermodynamically stabilized at 110 GPa, in which asymmetric hydrogen bonds are formed between H2S and H3S molecules. Calculated Tc values show 50–70 K in pressure range of 100–150 GPa within the harmonic approximation, which can reproduce the experimentally observed low-Tc phase. These findings give a new aspect of the excellent superconductivity in compressed sulfur-hydrogen system.
Carbonate Doping in TiO2 Microsphere: The Key Parameter Influencing Others for Efficient Dye Sensitized Solar Cell
Authors: Seddigi Zaki S. , Ahmed Saleh A. , Sardar Samim , Pal Samir Kumar
Published: March 2016

Four key parameters namely light trapping, density of light harvesting centre, photoinduced electron injection and electron transport without self-recombination are universally important across all kinds of solar cells. In the present study, we have considered the parameters in the context of a model Dye Sensitized Solar Cell (DSSC). Our experimental studies reveal that carbonate doping of TiO2 mesoporous microspheres (doped MS) makes positive influence to all the above mentioned key parameters responsible for the enhanced solar cell efficiency. A simple method has been employed to synthesize the doped MS for the photoanode of a N719 (ruthenium dye)-based DSSC. A detail electron microscopy has been used to characterize the change in morphology of the MS upon doping. The optical absorption spectrum of the doped MS reveals significant shift of TiO2 (compared to that of the MS without doping) towards maximum solar radiance (~500 nm) and the excellent scattering in the entire absorption band of the sensitizing dye (N719). Finally and most importantly, for the first time we have demonstrated that the solar cells with doped MS offers better efficiency (7.6%) in light harvesting compared to MS without doping (5.2%) and also reveal minimum self recombination of photoelectrons in the redox chain.
Vertical Microcavity Organic Light-emitting Field-effect Transistors
Authors: Hu Yongsheng , Lin Jie , Song Li , Lu Qipeng , Zhu Wanbin , Liu Xingyuan
Published: March 2016

Organic light-emitting field-effect transistors (OLEFETs) are regarded as a novel kind of device architecture for fulfilling electrical-pumped organic lasers. However, the realization of OLEFETs with high external quantum efficiency (EQE) and high brightness simultaneously is still a tough task. Moreover, the design of the resonator structure in LED is far from satisfactory. Here, OLEFETs with EQE of 1.5% at the brightness of 2600 cdm−2 and the corresponding ON/OFF ratio and current efficiency reaches above 104 and 3.1 cdA−1, respectively, were achieved by introducing 1,4,5,8,9,12-hexaazatriphenylene-hexacarbonitrile (HAT-CN) as a charge generation layer. Moreover, a vertical microcavity based on distributed Bragg reflector (DBR) and Ag source/drain electrodes is successfully introduced into the high performance OLEFETs, which results in electroluminescent spectrum linewidth narrowing from 96 nm to 6.9 nm. The results manifest the superiority of the vertical microcavity as an optical resonator in OLEFETs, which sheds some light on achieving the electrically pumped organic lasers.
Effects of carbon-to-sulfur (C/S) ratio and nitrate (N) dosage on Denitrifying Sulfur cycle-associated Enhanced Biological Phosphorus Removal (DS-EBPR)
Authors: Yu Mei , Lu Hui , Wu Di , Zhao Qing , Meng Fangang , Wang Yudan , Hao Xiaodi , Chen Guang-Hao
Published: March 2016

In this study, the Denitrifying Sulfur cycle-associated Enhanced Biological Phosphorous Removal (DS-EBPR) with 20 mg P/L/d of the volumetric P removal rate was successfully achieved in a Sequencing Batch Reactor (SBR). The effects of carbon-to-sulfur (C/S) mass ratio and nitrate (N) dosage were investigated through two batch tests to reveal the role of wastewater compositions in DS-EBPR performance. The optimal specific P release and uptake rates (0.4 and 2.4 mg P/g VSS/h, respectively) were achieved at C/S/P/N mass ratio of 150/200/20/20, and poly-S is supplied as a potential electron and energy storage. The nitrate dosage in a range of 10–50 mg N/L had no significant influence on P uptake rates (2.1 ~ 2.4 mg P/g VSS/h), but significantly affected the storage of inclusion poly-S, the poly-S oxidation rate was increased about 16% while dosing nitrate from 20 to 30 mg N/L. It implies that nitrate is denitrified in the P uptake phase, and excess nitrate is further consumed by poly-S. Moreover, the microbial analysis showed that the functional bacteria should mostly belong to denitrifying bacteria or Unclassified genera.
Hypoxia-induced sensitisation of TRPA1 in painful dysesthesia evoked by transient hindlimb ischemia/reperfusion in mice
Authors: So Kanako , Tei Yuna , Zhao Meng , Miyake Takahito , Hiyama Haruka , Shirakawa Hisashi , Imai Satoshi , Mori Yasuo , Nakagawa Takayuki , Matsubara Kazuo , Kaneko Shuji
Published: March 2016

Dysesthesia is an unpleasant abnormal sensation, which is often accompanied by peripheral neuropathy or vascular impairment. Here, we examined the roles of transient receptor potential ankyrin 1 (TRPA1) in dysesthesia-like behaviours elicited by transient hindlimb ischemia (15–60 min) by tightly compressing the hindlimb and reperfusion by releasing the ligature. The paw-withdrawal responses to tactile stimulation were reduced during ischemia and lasted for a while after reperfusion. Hindlimb ischemia/reperfusion elicited spontaneous licking of the ischemic hindpaw that peaked within 10 min. The licking was inhibited by reactive oxygen species (ROS) scavengers, a TRPA1 antagonist, or TRPA1 deficiency, but not by TRPV1 deficiency. In human TRPA1-expressing cells as well as cultured mouse dorsal root ganglion neurons, the H2O2-evoked TRPA1 response was significantly increased by pretreatment with hypoxia (80 mmHg) for 30 min. This hypoxia-induced TRPA1 sensitisation to H2O2 was inhibited by overexpressing a catalytically-inactive mutant of prolyl hydroxylase (PHD) 2 or in a TRPA1 proline mutant resistant to PHDs. Consistent with these results, a PHD inhibitor increased H2O2-evoked nocifensive behaviours through TRPA1 activation. Our results suggest that transient hindlimb ischemia/reperfusion-evoked spontaneous licking, i.e. painful dysesthesia, is caused by ROS-evoked activation of TRPA1 sensitised by hypoxia through inhibiting PHD-mediated hydroxylation of a proline residue in TRPA1.
Novel roles for class II Phosphoinositide 3-Kinase C2β in signalling pathways involved in prostate cancer cell invasion
Authors: Mavrommati Ioanna , Cisse Ouma , Falasca Marco , Maffucci Tania
Published: March 2016

Phosphoinositide 3-kinases (PI3Ks) regulate several cellular functions such as proliferation, growth, survival and migration. The eight PI3K isoforms are grouped into three classes and the three enzymes belonging to the class II subfamily (PI3K-C2α, β and γ) are the least investigated amongst all PI3Ks. Interest on these isoforms has been recently fuelled by the identification of specific physiological roles for class II PI3Ks and by accumulating evidence indicating their involvement in human diseases. While it is now established that these isoforms can regulate distinct cellular functions compared to other PI3Ks, there is still a limited understanding of the signalling pathways that can be specifically regulated by class II PI3Ks. Here we show that PI3K-C2β regulates mitogen-activated protein kinase kinase (MEK1/2) and extracellular signal-regulated kinase (ERK1/2) activation in prostate cancer (PCa) cells. We further demonstrate that MEK/ERK and PI3K-C2β are required for PCa cell invasion but not proliferation. In addition we show that PI3K-C2β but not MEK/ERK regulates PCa cell migration as well as expression of the transcription factor Slug. These data identify novel signalling pathways specifically regulated by PI3K-C2β and they further identify this enzyme as a key regulator of PCa cell migration and invasion.
Cytokinin production by Pseudomonas fluorescens G20-18 determines biocontrol activity against Pseudomonas syringae in Arabidopsis
Authors: Großkinsky Dominik K. , Tafner Richard , Moreno María V. , Stenglein Sebastian A. , García de Salamone Inés E. , Nelson Louise M. , Novák Ondřej , Strnad Miroslav , van der Graaff Eric , Roitsch Thomas
Published: March 2016

Plant beneficial microbes mediate biocontrol of diseases by interfering with pathogens or via strengthening the host. Although phytohormones, including cytokinins, are known to regulate plant development and physiology as well as plant immunity, their production by microorganisms has not been considered as a biocontrol mechanism. Here we identify the ability of Pseudomonas fluorescens G20-18 to efficiently control P. syringae infection in Arabidopsis, allowing maintenance of tissue integrity and ultimately biomass yield. Microbial cytokinin production was identified as a key determinant for this biocontrol effect on the hemibiotrophic bacterial pathogen. While cytokinin-deficient loss-of-function mutants of G20-18 exhibit impaired biocontrol, functional complementation with cytokinin biosynthetic genes restores cytokinin-mediated biocontrol, which is correlated with differential cytokinin levels in planta. Arabidopsis mutant analyses revealed the necessity of functional plant cytokinin perception and salicylic acid-dependent defence signalling for this biocontrol mechanism. These results demonstrate microbial cytokinin production as a novel microbe-based, hormone-mediated concept of biocontrol. This mechanism provides a basis to potentially develop novel, integrated plant protection strategies combining promotion of growth, a favourable physiological status and activation of fine-tuned direct defence and abiotic stress resilience.
Geometric and electronic structures of the synthetic Mn4CaO4 model compound mimicking the photosynthetic oxygen-evolving complex
Authors: Shoji Mitsuo , Isobe Hiroshi , Shen Jian-Ren , Yamaguchi Kizashi
Published: March 2016

eg orbitals of the Mn1(III) and Mn4(III) sites in the S1 state of the PSII-OEC synthetic model.
Catalytic test reactions for the evaluation of hierarchical zeolites
Authors: Hartmann Martin , Machoke Albert Gonche , Schwieger Wilhelm
Published: March 2016

This tutorial review discusses the challenges in evaluating the catalytic performance of a hierarchical catalyst compared to its parent zeolite using the Thiele modulus and the effectiveness factor.
Reduction of MS2 bacteriophage and rotavirus in biosand filters
Authors: Wang Hanting , Li Mingming , Brockman Kazami , Nguyen Thanh H.
Published: March 2016

Biosand filter can potentially remove up 99.99% of rotavirus to provide safe drinking water to communities in developing countries.
Palladium NPs supported on novel imino-pyridine-functionalized MWCNTs: efficient and highly reusable catalysts for the Suzuki–Miyaura and Sonogashira coupling reactions
Authors: Adib Mehdi , Karimi-Nami Rahman , Veisi Hojat
Published: March 2016

In this article a new heterogeneous nanocatalyst based on palladium supported on functionalized multi-walled carbon nanotubes (MWCNTs) has been introduced.
iRGD-mediated reduction-responsive DSPE–PEG/LA–PLGA–TPGS mixed micelles used in the targeted delivery and triggered release of docetaxel in cancer
Authors: Wang Lu , Xie Xi , Liu Di , Fang Xiao-Bin , Li Peng , Wan Jian-Bo , He Cheng-Wei , Chen Mei-Wan
Published: March 2016

Reduction-sensitive micelles with crosslinked cores were developed to load the lipophilic chemotherapeutic drug docetaxel (DTX) in order to overcome the issues of toxicity, water insolubility, and rapid metabolism of DTX.
Single-cell mass spectrometry with multi-solvent extraction identifies metabolic differences between left and right blastomeres in the 8-cell frog (Xenopus) embryo
Authors: Onjiko Rosemary M. , Morris Sydney E. , Moody Sally A. , Nemes Peter
Published: March 2016

Single-cell metabolic mass spectrometry enables the discovery (untargeted) analysis of small molecules in individual cells.
Detection of low molecular weight adulterants in beverages by direct analysis in real time mass spectrometry
Authors: Sisco Edward , Dake Jeffrey
Published: March 2016

Direct Analysis in Real Time Mass Spectrometry (DART-MS) has been used to detect the presence of non-narcotic adulterants in beverages.
Laser-assisted crystallization of CH3NH3PbI3 films for efficient perovskite solar cells with a high open-circuit voltage
Authors: Li Faming , Zhu Weidong , Bao Chunxiong , Yu Tao , Wang Yangrunqian , Zhou Xiaoxin , Zou Zhigang
Published: March 2016

The pristine film of CH3NH3I·PbI2·DMSO was crystallized via continuous laser irradiation at 450 nm.
Design of a plasmonic micromotor for enhanced photo-remediation of polluted anaerobic stagnant waters
Authors: Zhang Zhijun , Zhao Andong , Wang Faming , Ren Jinsong , Qu Xiaogang
Published: March 2016

A motor plasmonic photocatalyst (MPP) is developed to promote photocatalysis in an anaerobic stagnant environment.
Single molecule study of initial structural features on the amyloidosis process
Authors: Hu Yong-Xu , Ying Yi-Lun , Gu Zhen , Cao Chan , Yan Bing-Yong , Wang Hui-Feng , Long Yi-Tao
Published: March 2016

We employed an α-hemolysin (α-HL) nanopore as a single-molecule tool to investigate the effects of initial structure on the amyloidosis process.
Supramolecular ordering of difuryldiketopyrrolopyrrole: the effect of alkyl chains and inter-ring twisting
Authors: Fu Chaoying , Bélanger-Gariépy Francine , Perepichka Dmitrii F.
Published: March 2016

Combined XRD, STM and DFT studies reveal the details of supramolecular ordering of difuryldiketopyrrolopyrrole in monolayers and 3D crystals.
Glass polymorphism in glycerol–water mixtures: I. A computer simulation study
Authors: Jahn David A. , Wong Jessina , Bachler Johannes , Loerting Thomas , Giovambattista Nicolas
Published: March 2016

Computer simulations of glassy water–glycerol mixtures: molecular structure and density during the pressure-induced amorphous–amorphous (LDA–HDA) transformation.
On the Cl⋯C halogen bond: a rotational study of CF3Cl–CO
Authors: Caminati Walther , Evangelisti Luca , Feng Gang , Giuliano Barbara M. , Gou Qian , Melandri Sonia , Grabow Jens-Uwe
Published: March 2016

A Cl⋯C halogen bond links CF3Cl to CO in their symmetric top 1 : 1 adduct.
Unusual effect of cobalt on Cu–MgO catalyst for the synthesis of γ-butyrolactone and aniline via coupling reaction
Authors: Kannapu Hari Prasad Reddy , Neeli Chinna Krishna Prasad , Rama Rao Kamaraju Seetha , Kalevaru Venkat Narayana , Martin Andreas , Burri David Raju
Published: March 2016

Addition of cobalt to Cu–MgO catalyst elevated the yields of γ-butyrolactone and aniline significantly from 1,4-butanediol and nitrobenzene via hydrogenation and dehydrogenation coupling process.
Copper complexes as catalyst precursors in the electrochemical hydrogen evolution reaction
Authors: Kügler Merle , Scholz Julius , Kronz Andreas , Siewert Inke
Published: March 2016

Two copper complexes were investigated with respect to their activity in the electrocatalysed hydrogen evolution reaction. The complexes are precursors for highly active copper(0) and Cu2O deposits.
Bimetallic rare-earth/platinum complexes ligated by phosphinoamides
Authors: Völcker Franziska , Roesky Peter W.
Published: March 2016

The heterometallic early-late 5d/4f binuclear phosphinoamido Ln/Pt(0) complexes [(Ph2PNHPh)Pt{μ-(Ph2PNPh)}3Ln(μ-Cl)Li(THF)3] (Ln = Y, Lu) and [(Ph2PNHPh)Pt{μ-(Ph2PNPh)}3Ln{η2-(Ph2PNPh)}][Li(THF)4] (Ln = Y, Lu) are reported.
When two are better than one: bright phosphorescence from non-stereogenic dinuclear iridium(iii) complexes
Authors: Daniels Ruth E. , Culham Stacey , Hunter Michael , Durrant Marcus C. , Probert Michael R. , Clegg William , Williams J. A. Gareth , Kozhevnikov Valery N.
Published: March 2016

Tridentate N^C^N-coordinating ligands in combination with bis-N^C-bridging ligands give rise to achiral dinuclear iridium complexes displaying exceptionally high radiative rate constants.
Impact of microbial activities and hydraulic retention time on the production and profile of long chain fatty acids in grease interceptors: a laboratory study
Authors: He Xia , Yan Tao
Published: March 2016

Fat, oil and grease (FOG) deposits are a major cause of sanitary sewer overflows (SSOs), and calcium salts of long chain fatty acids (LCFAs) have recently been identified as key components of FOG deposits in sewer systems.
The development of effective CaO-based CO2 sorbents via a sacrificial templating technique
Authors: Naeem Muhammad Awais , Armutlulu Andac , Broda Marcin , Lebedev Dmitry , Müller Christoph R.
Published: March 2016

A carbon-based sacrificial templating approach was employed to realize single-pot synthesis of cyclically stable CaO-based CO2 sorbents. The sacrificial carbonaceous template was formed through resorcinol–formaldehyde polymerization reaction. The resultant sorbents following the thermal decomposition of the carbonaceous template featured an inverse opal-like macrostructure composed of a highly porous nanostructured backbone. In addition to pure CaO, sorbents supported with Al2O3, MgO, Y2O3, and ZrO2 were synthesized. SEM and XRD were utilized to characterize the morphology and the chemical composition of the synthetic CO2 sorbents, respectively. The cyclic CO2 uptake performance of the synthetic sorbents was assessed by TGA and compared to limestone. All of the synthetic sorbents exhibited an improved CO2 uptake performance when compared to limestone. The performance enhancement became more pronounced in the case of supported sorbents. The sorbent with the best CO2 uptake performance was supported by a mixture of Al2O3 and Y2O3, and exhibited a CO2 uptake of 0.61 g CO2/g CaO after 10 cycles of calcination and carbonation under practically relevant operating temperatures, which exceeded the CO2 uptake of limestone by more than 350%.
An embedded microretroreflector-based microfluidic immunoassay platform
Authors: Raja Balakrishnan , Pascente Carmen , Knoop Jennifer , Shakarisaz David , Sherlock Tim , Kemper Steven , Kourentzi Katerina , Renzi Ronald F. , Hatch Anson V. , Olano Juan , Peng Bi-Hung , Ruchhoeft Paul , Willson Richard
Published: March 2016

We present a microfluidic immunoassay platform based on linear microretroreflectors as the sensing modality and magnetic microparticles as light-blocking labels.
Selective plane illumination microscopy on a chip
Authors: Paiè Petra , Bragheri Francesca , Bassi Andrea , Osellame Roberto
Published: March 2016

A high-throughput on-chip light sheet microscope allowing 3D reconstructions of large populations of samples, even with standard microscopes, is presented.
Acoustic force mapping in a hybrid acoustic-optical micromanipulation device supporting high resolution optical imaging
Authors: Thalhammer Gregor , McDougall Craig , MacDonald Michael Peter , Ritsch-Marte Monika
Published: March 2016

We demonstrate combined acoustic-optical trapping with transparent piezoelectric transducers supporting high-resolution imaging and acoustic force mapping.
Catalytic asymmetric synthesis of enantioenriched β-nitronitrile bearing a C-CF3stereogenic center
Authors: Jakhar Ajay , Kumari Prathibha , Nazish Mohd , Khan Noor-ul H. , Kureshy Rukhsana I. , Abdi Sayed H. R. , Suresh E.
Published: March 2016

CF3substituted β-nitronitriles with an all-carbon quaternary stereogenic center have been synthesizedviaasymmetric cyanation reaction.
A selective and economic carbon catalyst from waste for aqueous conversion of fructose into 5-hydroxymethylfurfural
Authors: Deng Tiansheng , Li Jiangong , Yang Qiqi , Yang Yongxing , Lv Guangqiang , Yao Ying , Qin Limin , Zhao Xianlong , Cui Xiaojing , Hou Xianglin
Published: March 2016

A selective aqueous conversion of fructose to HMF using carbon catalysts from pulping waste sodium ligninsulfonate.
Exploration of 6,7-dimethoxyquinazoline derivatives as dual acting α1- and AT1-receptor antagonists: synthesis, evaluation, pharmacophore & 3D-QSAR modeling and receptor docking studies
Authors: Agrawal Neetesh , Machhi Jatin , Rathwa Virendra , Kanhed Ashish M. , Patel Sagar , Murumkar Prashant , Gandhi Hardik , Yadav Mange Ram
Published: March 2016

The 6,7-dimethoxyquinazoline scaffold was further explored to provide dual acting α1- and AT1-receptor antagonists by synthesizing a series of derivatives and biologically evaluating the newly synthesized compounds.
A non-destructive, rapid and inexpensive methodology based on digital images for the classification of natural tannin extracts
Authors: Grasel F. S. , Marcelo M. C. A. , Ferrão M. F.
Published: March 2016

In this study a methodology was developed for the identification and classification, by type of plant, of six commercial tannin extracts using multivariate analysis of digital images acquired through a commercial scanner.
Selective oxidation of organic sulfides to sulfoxides using sugar derived cis-dioxo molybdenum(vi) complexes: kinetic and mechanistic studies
Authors: Baig Noorullah , Madduluri Vimal Kumar , Sah Ajay K.
Published: March 2016

Sixcis-dioxo molybdenum(vi) complexes ofd-glucose derived ligands have been applied as catalysts for the selective transformation of organic sulfides to sulfoxides, and kinetics as well as mechanistic aspects of this reaction have been explored.
Highly flexible transparent electrodes using a silver nanowires-embedded colorless polyimide film via chemical modification
Authors: Lee Dasom , Youn Doo-Young , Luo Zhenhao , Kim Il-Doo
Published: March 2016

AgNWs-embedded colorless polyimide encapsulated by a ZnO layer via chemical modification of a CPI film. The ZnO/AgNWs-embedded CPI substrate exhibited a low sheet resistance of 24 Ω sq−1 while maintaining a high optical transparency of 81%.
Enantioselective synthesis of seven-membered carbo- and heterocyles by organocatalyzed intramolecular Michael addition
Authors: Guevara-Pulido James O. , Andrés José M. , Ávila Deisy P. , Pedrosa Rafael
Published: March 2016

Enantioenriched seven membered rings have been prepared in high yields and stereoselectivities by intramolecular Michael addition of functionalized enals catalyzed by Jorgensen–Hayashi catalyst.
Non-covalent hydrophilization of reduced graphene oxide used as a paclitaxel vehicle
Authors: Liu Yu , Zhong Han , Qin Yu , Zhang Yan , Liu Xinfeng , Zhang Tao
Published: March 2016

Phosphorylcholine oligomer grafted perylene (Perylene-PCn) was synthesized. By π–π stacking interaction of reduced graphene oxide (RGO) and perylene moiety, water dispersible RGO/Perylene-PCn composites were prepared and used as paclitaxel vehicle.
Conducting polymer and metal–complex composites formed by complexation of the ligands from the vapour phase
Authors: Mayevsky David , Winther-Jensen Orawan , Winther-Jensen Bjorn
Published: March 2016

Coordinating ligands to metal-ions inside a conducting polymer matrix via complexation from the vapour phase was shown for the first time.
Ce3+ and Tb3+-doped lutetium-containing silicate phosphors: synthesis, structure refinement and photoluminescence properties
Authors: Li Kai , Liang Sisi , Lian Hongzhou , Shang Mengmeng , Xing Bengang , Lin Jun
Published: March 2016

A series of Ce3+ and Tb3+-doped BaLu2Si3O10 (BLSO) phosphors synthesized via the high-temperature solid-state reaction method were investigated.
Fairness enhanced dynamic routing and spectrum allocation in elastic optical networks
Authors: Xiong Yu , Fan Xue , Liu Shuming
Published: March 2016

The finer spectrum granularity unit in elastic optical networks makes wider spectrum services more likely to be restricted by the constraints of spectrum continuity and spectrum contiguity (2SC), leading to higher blocking probability (BP). Obviously, it would deteriorate the fairness among multi‐granularity services. Therefore, a fair dynamic routing and spectrum allocation algorithm is proposed. By virtualising the network resources as a ‘resource pool’, a two‐dimensional rectangle packing model in combination with service holding‐time is introduced to satisfy the 2SC constraints and to optimise the allocation of the ‘resource pool’ for dynamic multi‐granularity services. Besides multi‐granularity service fairness is achieved by tackling heterogeneous‐size services together. Simulation results show that the benefit in terms of fairness can be reaped. Meanwhile, the authors also investigate the proposed algorithm's impact on performance metrics: namely, spectrum resource utilisation and BP. The results indicate that the proposed algorithm can achieve lower BP and higher spectrum efficiency.
Reliable routing in wireless sensor networks based on coalitional game theory
Authors: Feng Renjian , Li Tongling , Wu Yinfeng , Yu Ning
Published: March 2016

Nodes in wireless sensor networks (WSNs) have the potential to be selfish without transmitting packets in routing. This study mainly focuses on the problem of reliable delivery mechanism in WSNs, and the authors’ objective is to ensure stable cooperation among nodes for packets delivery and minimum routing cost at the same time. Based on the performance metrics in terms of the rate of packets forwarding, correctly reporting event, and energy remain, the authors present a coalitional game model with a characteristic function to be shared among coalition members. Then an efficient and fast convergence coalition formation algorithm is proposed to obtain the stable coalition partition in the game. Finally, on the basis of the coalitional game model, the authors design a reliable coalition formation routing (RCFR) protocol, which selects route according to the principle of lowest cost. Simulation experiments are conducted to analyse the performance of RCFR, compared with original ad hoc on‐demand distance vector routing and the method proposed by Kazemeyni. The results show that RCFR effectively enhances packet delivery ratio, decreases routing establishing time, balances energy consumption, and reduces average signalling overhead.
Cross‐layer aware joint design of sensing and frame durations in cognitive radio networks
Authors: Zhang Shaojie , Hafid Abdelhakim Senhaji , Zhao Haitao , Wang Shan
Published: March 2016

The tradeoff between increasing secondary users’ (SUs’) throughput and decreasing interferences to primary user (PU) is an important problem in cognitive radio networks. Joint design of sensing duration and frame duration has a crucial impact on both these two conflicting attributes but has not been studied yet. In this study, using a cross‐layer approach, the authors investigate joint design of sensing duration and frame duration for the tradeoff. Specially, they consider that PU's traffic randomly changes within a secondary frame and multiple SUs contend to use the licensed channel based on widely used large/small‐scale‐backoff‐based MAC protocols. By modelling more realistic PU's traffic, imperfect spectrum sensing in PHY and multiple SUs’ access contention in MAC, the authors reformulate the sensing‐throughput tradeoff problem to maximise SUs’ throughput while restricting interference probability to PU under a tolerable level. Moreover, the optimal solution is analysed and a bi‐dimensional search algorithm is presented. Simulation results show that the authors’ proposal achieves better throughput performance than conventional approaches. They also show how the optimal solution varies with received PU's signal‐to‐noise ratio and PU's traffic distribution.
Design and experimentation of an observer‐based linear adaptive control applied to an electropneumatic actuator
Authors: Boubakir Ahsene , Plestan Franck , Labiod Salim , Boudjema Fares
Published: March 2016

This study proposes an observer‐based linear adaptive control scheme for the position control of a pneumatic actuator system. The proposed controller does not rely on a physical model of the pneumatic actuator system to be controlled; it only needs the position measurement for its implementation, which is really a novelty in the field of such applications. First, based on the implicit function theory, the existence of an ideal position controller is demonstrated. Then, the objective is to construct this unknown ideal position controller using a linear control with a stable adaptation law and an extended observer. This latter is used to estimate both the tracking error vector and an unknown function of the error between the implicit ideal control and the actual control which is used in the adaptation mechanism. The stability of the overall closed‐loop system is studied by using singular perturbation theory and Tikhonov's theorem. Finally, real‐time experimental results are provided to show the performances of the proposed control scheme.
Initial measurements of two- and three-dimensional ordering, waves, and plasma filamentation in the Magnetized Dusty Plasma Experiment
Authors: Thomas Edward , Konopka Uwe , Merlino Robert L. , Rosenberg Marlene
Published: March 2016

The Magnetized Dusty Plasma Experiment at Auburn University has been operational for over one year. In that time, a number of experiments have been performed at magnetic fields up to B = 2.5 T to explore the interaction between magnetized plasmas and charged, micron-sized dust particles. This paper reports on the initial results from studies of: (a) the formation of imposed, ordered structures, (b) the properties of dust wave waves in a rotating frame, and (c) the generation of plasma filaments.
Collisional transport across the magnetic field in drift-fluid models
Authors: Madsen J. , Naulin V. , Nielsen A. H. , Rasmussen J. Juul
Published: March 2016

Drift ordered fluid models are widely applied in studies of low-frequency turbulence in the edge and scrape-off layer regions of magnetically confined plasmas. Here, we show how collisional transport across the magnetic field is self-consistently incorporated into drift-fluid models without altering the drift-fluid energy integral. We demonstrate that the inclusion of collisional transport in drift-fluid models gives rise to diffusion of particle density, momentum, and pressures in drift-fluid turbulence models and, thereby, obviates the customary use of artificial diffusion in turbulence simulations. We further derive a computationally efficient, two-dimensional model, which can be time integrated for several turbulence de-correlation times using only limited computational resources. The model describes interchange turbulence in a two-dimensional plane perpendicular to the magnetic field located at the outboard midplane of a tokamak. The model domain has two regions modeling open and closed field lines. The model employs a computational expedient model for collisional transport. Numerical simulations show good agreement between the full and the simplified model for collisional transport.
Atomically resolved structure of ligand-protected Au9 clusters on TiO2 nanosheets using aberration-corrected STEM
Authors: Al Qahtani Hassan S. , Kimoto Koji , Bennett Trystan , Alvino Jason F. , Andersson Gunther G. , Metha Gregory F. , Golovko Vladimir B. , Sasaki Takayoshi , Nakayama Tomonobu
Published: March 2016

Triphenylphosphine ligand-protected Au9 clusters deposited onto titania nanosheets show three different atomic configurations as observed by scanning transmission electron microscopy. The configurations observed are a 3-dimensional structure, corresponding to the previously proposed Au9 core of the clusters, and two pseudo-2-dimensional (pseudo-2D) structures, newly found by this work. With the help of density functional theory (DFT) calculations, the observed pseudo-2D structures are attributed to the low energy, de-ligated structures formed through interaction with the substrate. The combination of scanning transmission electron microscopy with DFT calculations thus allows identifying whether or not the deposited Au9 clusters have been de-ligated in the deposition process.
Formation of hierarchical macro porous YAlO:Ce multifunctional nanophosphors
Authors: Jayanthi Rajan K. , Manorama Sunkara V.
Published: March 2016

Hierarchically macro-porous lumino-magnetic yttrium aluminium oxide (YAlO:- YAT: tetragonal; YAG: garnet; YAM: monoclinic) ceramic nanophosphors doped with trivalent cerium (Ce) ions have been synthesized by a novel and versatile self assembly route without the need of any external templates. X-ray diffraction and X-ray photoelectron spectroscopy studies confirm the presence of dopant and its valence state. Room temperature ferromagnetism in undoped and YAlO:Ce suggest an intrinsic nature of ferromagnetism dependent on host lattice imperfection along with yellow photoluminescence emission explicitly arising due to Ce doping established the non-interfering character of the two phenomena. Such a porous morphology has the potential of the biocarriers and could be engineered to make it suitable for spintronic applications by incorporation of dielectric into the pores and in conjunction with blue light emitting devices which could be used to obtain white light.
Antenna induced hot restrike of a ceramic metal halide lamp recorded by high-speed photography
Authors: Hermanns P. , Hoebing T. , Bergner A. , Ruhrmann C. , Awakowicz P. , Mentel J.
Published: March 2016

The hot restrike is one of the biggest challenges in operating ceramic metal halide lamps with mercury as buffer gas. Compared to a cold lamp, the pressure within a ceramic burner is two orders of magnitude higher during steady state operation due to the high temperature of the ceramic tube and the resulting high mercury vapour pressure. Room temperature conditions are achieved after 300 s of cooling down in a commercial burner, enclosed in an evacuated outer bulb. At the beginning of the cooling down, ignition voltage rises up to more than 14 kV. A significant reduction of the hot-restrike voltage can be achieved by using a so called active antenna. It is realized by a conductive sleeve surrounding the burner at the capillary of the upper electrode. The antenna is connected to the lower electrode of the lamp, so that its potential is extended to the vicinity of the upper electrode. An increased electric field in front of the upper electrode is induced, when an ignition pulse is applied to the lamp electrodes. A symmetrically shaped ignition pulse is applied with an amplitude, which is just sufficient to re-ignite the hot lamp. The re-ignition, 60 s after switching off the lamp, when the mercury pressure starts to be saturated, is recorded for both polarities of the ignition pulse with a high-speed camera, which records four pictures within the symmetrically shaped ignition pulse with exposure times of 100 ns and throws of 100 ns. The pictures show that the high electric field and its temporal variation establish a local dielectric barrier discharge in front of the upper electrode inside the burner, which covers the inner wall of the burner with a surface charge. It forms a starting point of streamers, which may induce the lamp ignition predominantly within the second half cycle of the ignition pulse. It is found out that an active antenna is more effective when the starting point of the surface streamer in front of the sleeve is a negative surface charge on the inner tube wall. The high-speed photos show that the ignition process is very similar in lamps with Hg or Xe as buffer gas.
Three-dimensional indium distribution in electron-beam irradiated multiple quantum wells of blue-emitting InGaN/GaN devices
Authors: Jung Woo-Young , Seol Jae-Bok , Kwak Chan-Min , Park Chan-Gyung
Published: March 2016

The compositional distribution of In atoms in InGaN/GaN multiple quantum wells is considered as one of the candidates for carrier localization center, which enhances the efficiency of the light-emitting diodes. However, two challenging issues exist in this research area. First, an inhomogeneous In distribution is initially formed by spinodal decomposition during device fabrication as revealed by transmission electron microscopy. Second, electron-beam irradiation during microscopy causes the compositional inhomogeneity of In to appear as a damage contrast. Here, a systematic approach was proposed in this study: Electron-beam with current density ranging from 0 to 20.9 A/cm2 was initially exposed to the surface regions during microscopy. Then, the electron-beam irradiated regions at the tip surface were further removed, and finally, atom probe tomography was performed to run the samples without beam-induced damage and to evaluate the existence of local inhomegenity of In atoms. We proved that after eliminating the electron-beam induced damage regions, no evidence of In clustering was observed in the blue-emitting InGaN/GaN devices. In addition, it is concluded that the electron-beam induced localization of In atoms is a surface-related phenomenon, and hence spinodal decomposition, which is typically responsible for such In clustering, is negligible for biaxially strained blue-emitting InGaN/GaN devices.
Optimizing array spectroradiometer readings using adaptative bracketing
Authors: Deniel Jean-Marc
Published: March 2016

Single monochromator array spectroradiometers are convenient instruments for measuring spectral quantities in the UV-Vis-NIR range. They monitor the sensor array signal based on the same integration time for all wavelengths. However, the signal-to-noise ratio may be too low to provide useful readings at weaker signal wavelengths. The so-called “bracketing” technique overcomes this drawback by performing successive retrievals using different integration times, thereby ensuring that sufficiently high signal-to-noise ratio signals are recorded and non-relevant and low ratio signals are ignored. This paper proposes the use of an automated bracketing method based on the currently used array spectroradiometer noise models and analysis of retrieved spectra. Integration time at each array pixel fits spectral signal distribution with respect to a user-defined accuracy criterion and relevance constraints for the spectroradiometer used.
Quantum random flip-flop and its applications in random frequency synthesis and true random number generation
Authors: Stipčević Mario
Published: March 2016

In this work, a new type of elementary logic circuit, named random flip-flop (RFF), is proposed, experimentally realized, and studied. Unlike conventional Boolean logic circuits whose action is deterministic and highly reproducible, the action of a RFF is intentionally made maximally unpredictable and, in the proposed realization, derived from a fundamentally random process of emission and detection of light quanta. We demonstrate novel applications of RFF in randomness preserving frequency division, random frequency synthesis, and random number generation. Possible usages of these applications in the information and communication technology, cryptographic hardware, and testing equipment are discussed.
Dynamic yielding and fracture of grade 4 titanium in plate impact experiments
Authors: Whelchel R. L. , Mehoke D. S. , Iyer K. A. , Sanders T. H. , Thadhani N. N.
Published: March 2016

The dynamic yielding and fracture (spalling) of commercially pure (grade 4) titanium are investigated using symmetric plate impact experiments for a peak stress range of 5.6 GPa–12.5 GPa. Velocity interferometry system for any reflector rear free surface velocity profiles display both a Hugoniot elastic limit (HEL) and a velocity pullback, which are indicative of dynamic compressive yielding and tensile fracture (spalling), respectively. The HEL decreases with peak stress from 2.2 GPa for 5.6 GPa peak stress to 2.0 GPa for 12.5 GPa peak stress. The decrease in the HEL corresponded to an increase in twinning observed in recovered samples. The spall strength increases with peak stress from 3.3 GPa to 3.8 GPa over the measured peak stress range and shows a good power law fit with the decompression strain rate. The differences in the dynamic yield and fracture behavior indicate that void nucleation is the dominant mechanism affecting the spall strength of grade 4 titanium.
Field transients of coherent terahertz synchrotron radiation accessed via time-resolving and correlation techniques
Authors: Pohl A. , Semenov A. , Hübers H.-W. , Hoehl A. , Ries M. , Wüstefeld G. , Ulm G. , Ilin K. , Thoma P. , Siegel M.
Published: March 2016

Decaying oscillations of the electric field in repetitive pulses of coherent synchrotron radiation in the terahertz frequency range was evaluated by means of time-resolving and correlation techniques. Comparative analysis of real-time voltage transients of the electrical response and interferograms, which were obtained with an ultrafast zero-bias Schottky diode detector and a Martin-Puplett interferometer, delivers close values of the pulse duration. Consistent results were obtained via the correlation technique with a pair of Golay Cell detectors and a pair of resonant polarisation-sensitive superconducting detectors integrated on one chip. The duration of terahertz synchrotron pulses does not closely correlate with the duration of single-cycle electric field expected for the varying size of electron bunches. We largely attribute the difference to the charge density oscillations in electron bunches and to the low-frequency spectral cut-off imposed by both the synchrotron beamline and the coupling optics of our detectors.
The effect of basis set and exchange-correlation functional on time-dependent density functional theory calculations within the Tamm-Dancoff approximation of the x-ray emission spectroscopy of transition metal complexes
Authors: Roper Ian P. E. , Besley Nicholas A.
Published: March 2016

The simulation of X-ray emission spectra of transition metal complexes with time-dependent density functional theory (TDDFT) is investigated. X-ray emission spectra can be computed within TDDFT in conjunction with the Tamm-Dancoff approximation by using a reference determinant with a vacancy in the relevant core orbital, and these calculations can be performed using the frozen orbital approximation or with the relaxation of the orbitals of the intermediate core-ionised state included. Both standard exchange-correlation functionals and functionals specifically designed for X-ray emission spectroscopy are studied, and it is shown that the computed spectral band profiles are sensitive to the exchange-correlation functional used. The computed intensities of the spectral bands can be rationalised by considering the metal p orbital character of the valence molecular orbitals. To compute X-ray emission spectra with the correct energy scale allowing a direct comparison with experiment requires the relaxation of the core-ionised state to be included and the use of specifically designed functionals with increased amounts of Hartree-Fock exchange in conjunction with high quality basis sets. A range-corrected functional with increased Hartree-Fock exchange in the short range provides transition energies close to experiment and spectral band profiles that have a similar accuracy to those from standard functionals.