bluuebunny/crossref_metadata_2025 huggingface dataset:
On the thermodynamic path enabling a room-temperature, laser-assisted graphite to nanodiamond transformation
Authors: Gorrini F. , Cazzanelli M. , Bazzanella N. , Edla R. , Gemmi M. , Cappello V. , David J. , Dorigoni C. , Bifone A. , Miotello A.
Published: October 2016

Nanodiamonds are the subject of active research for their potential applications in nano-magnetometry, quantum optics, bioimaging and water cleaning processes. Here, we present a novel thermodynamic model that describes a graphite-liquid-diamond route for the synthesis of nanodiamonds. Its robustness is proved via the production of nanodiamonds powders at room-temperature and standard atmospheric pressure by pulsed laser ablation of pyrolytic graphite in water. The aqueous environment provides a confinement mechanism that promotes diamond nucleation and growth, and a biologically compatible medium for suspension of nanodiamonds. Moreover, we introduce a facile physico-chemical method that does not require harsh chemical or temperature conditions to remove the graphitic byproducts of the laser ablation process. A full characterization of the nanodiamonds by electron and Raman spectroscopies is reported. Our model is also corroborated by comparison with experimental data from the literature.
Nitric oxide participates in plant flowering repression by ascorbate
Authors: Senthil Kumar Rajendran , Shen Chin-Hui , Wu Pei-Yin , Suresh Kumar Subbiah , Hua Moda Sang , Yeh Kai-Wun
Published: October 2016

In Oncidium, redox homeostasis involved in flowering is mainly due to ascorbic acid (AsA). Here, we discovered that Oncidium floral repression is caused by an increase in AsA-mediated NO levels, which is directed by the enzymatic activities of nitrate reductase (NaR) and nitrite reducatase (NiR). Through Solexa transcriptomic analysis of two libraries, ‘pseudobulb with inflorescent bud’ (PIB) and ‘pseudobulb with axillary bud’ (PAB), we identified differentially expressed genes related to NO metabolism. Subsequently, we showed a significant reduction of NaR enzymatic activities and NO levels during bolting and blooming stage, suggesting that NO controlled the phase transition and flowering process. Applying AsA to Oncidium PLB (protocorm-like bodies) significantly elevated the NO content and enzyme activities. Application of sodium nitroprusside (-NO donor) on Arabidopsis vtc1 mutant caused late flowering and expression level of flowering-associated genes (CO, FT and LFY) were reduced, suggesting NO signaling is vital for flowering repression. Conversely, the flowering time of noa1, an Arabidopsis NO-deficient mutant, was not altered after treatment with L-galacturonate, a precursor of AsA, suggesting AsA is required for NO-biosynthesis involved in the NO-mediated flowering-repression pathway. Altogether, Oncidium bolting is tightly regulated by AsA-mediated NO level and downregulation of transcriptional levels of NO metabolism genes.
Purification and characterization of a novel phloretin-2′-O-glycosyltransferase favoring phloridzin biosynthesis
Authors: Zhang Tingjing , Liang Jianqiang , Wang Panxue , Xu Ying , Wang Yutang , Wei Xinyuan , Fan Mingtao
Published: October 2016

Phloretin-2′-O-glycosyltransferase (P2′GT) catalyzes the last glycosylation step in the biosynthesis of phloridzin that contributes to the flavor, color and health benefits of apples and processed apple products. In this work, a novel P2′GT of Malus x domestica (MdP2′GT) with a specific activity of 46.82 μkat/Kg protein toward phloretin and uridine diphosphate glucose (UDPG) at an optimal temperature of 30 °C and pH 8.0 was purified from the engineered Pichia pastoris broth to homogeneity by anion exchange chromatography, His-Trap affinity chromatography and gel filtration. The purified MdP2′GT was low N-glycosylated and secreted as a stable dimer with a molecular mass of 70.7 kDa in its native form. Importantly, MdP2′GT also exhibited activity towards quercetin and adenosine diphosphate glucose (ADPG), kaempferol and UDPG, quercetin and UDP-galactose, isoliquiritigenin and UDPG, and luteolin and UDPG, producing only one isoquercitrin, astragalin, hyperoside, isoliquiritin, or cynaroside, respectively. This broad spectrum of activities make MdP2′GT a promising biocatalyst for the industrial preparation of the corresponding polyphenol glycosides, preferably for their subsequent isolation and purification. Besides, MdP2′GT displayed the lowest Km and the highest kcat/Km for phloretin and UDPG compared to all previously reported P2′GTs, making MdP2′GT favor phloridzin synthesis the most.
Sleep and mood disorders in women with dry eye disease
Authors: Ayaki Masahiko , Kawashima Motoko , Negishi Kazuno , Kishimoto Taishiro , Mimura Masaru , Tsubota Kazuo
Published: October 2016

The aim of the present study was to evaluate sleep and mood disorders in women aged 30–69 with dry eye disease (DED). All subjects underwent corneal examinations, with 890 completing a questionnaire regarding symptoms of DED and 213 completing both the Pittsburgh Sleep Quality Index (PSQI) and the Hospital Anxiety and Depression Scale (HADS) questionnaires. Subjects were then divided into three groups based on age (younger [30–45 years], perimenopausal [46–55 years], and older [56–69 years]), and comparisons were made among groups in subjects with and without DED. PSQI scores were significantly worse in subjects with (6.1 ± 2.9) than without (4.9 ± 2.7) DED (P = 0.003) and, in the younger group, HADS scores were worse in those with (13.2 ± 6.0) than without DED (9.7 ± 6.0) (P = 0.020). In contrast, there were no differences in mood indices between those with and without DED in the other groups. PSQI score was significantly correlated with HADS rather than ocular findings. In conclusion, sleep quality had deteriorated in women with DED. However, mood problems contributed more to sleep quality than ocular status, especially in those with DED in the younger group.
Large spin-orbit coupling and helical spin textures in 2D heterostructure [Pb2BiS3][AuTe2]
Authors: Fang L. , Im J. , DeGottardi W. , Jia Y. , Glatz A. , Matveev K. A. , Kwok W.-K. , Crabtree G. W. , Kanatzidis M. G.
Published: October 2016

Two-dimensional heterostructures with strong spin-orbit coupling have direct relevance to topological quantum materials and potential applications in spin-orbitronics. In this work, we report on novel quantum phenomena in [Pb2BiS3][AuTe2], a new 2D strong spin-orbit coupling heterostructure system. Transport measurements reveal the spin-related carrier scattering is at odds with the Abrikosov-Gorkov model due to strong spin-orbit coupling. This is consistent with our band structure calculations which reveal a large spin-orbit coupling gap of εso = 0.21 eV. The band structure is also characterized by helical-like spin textures which are mainly induced by strong spin-orbit coupling and the inversion symmetry breaking in the heterostructure system.
Hydroxysafflor yellow A alleviates myocardial ischemia/reperfusion in hyperlipidemic animals through the suppression of TLR4 signaling
Authors: Han Dan , Wei Jie , Zhang Rui , Ma Wenhuan , Shen Chen , Feng Yidong , Xia Nian , Xu Dan , Cai Dongcheng , Li Yunman , Fang Weirong
Published: October 2016

Hyperlipidemia aggravates myocardial ischemia/reperfusion (MI/R) injury through stimulating excessive inflammatory response. Therefore, blockade of inflammatory signal is a potential therapeutic management for MI/R complicated with hyperlipidemia. Hydroxysafflor yellow A (HSYA, a monomer extracted from Carthamus tinctorius L.), was studied in this article to address that the regulation of inflammatory signal would alleviate MI/R combined with hyperlipidemia injury. High-fat diet induced hyperlipidemia worsened MI/R mediated heart injury (elevation of infarct size, CK-MB and LDH activity), activated TLR4 over-expression in hearts, released inflammatory cytokines (LPS, TNF-α and IL-1β) excessively. HSYA administration suppressed the over-expression of TLR4 and alleviated heart damage caused by MI/R complicated with hyperlipidemia. Furthermore, HSYA had little influence on MI/R injury in TLR4-knockout mice, which indicated that HSYA protected MI/R through TLR4 inhibition. In vitro, hypoxia/reoxygenation (H/R) coexisting with LPS model in neonatal rat ventricular myocytes (NRVMs) induced serious damage compared with H/R injury to NRVMs. HSYA decreased excessive secretion of inflammatory cytokines, down-regulated over-expression of TLR4 and NF-κB in H/R + LPS injured NRVMs. In conclusion, HSYA alleviated myocardial inflammatory injury through suppressing TLR4, offering an alternative medication for MI/R associated with hyperlipidemia.
Feature driven classification of Raman spectra for real-time spectral brain tumour diagnosis using sound
Authors: Stables Ryan , Clemens Graeme , Butler Holly J. , Ashton Katherine M. , Brodbelt Andrew , Dawson Timothy P. , Fullwood Leanne M. , Jenkinson Michael D. , Baker Matthew J.
Published: October 2016

Spectroscopic diagnostics have been shown to be an effective tool for the analysis and discrimination of disease states from human tissue.
In vitro physiological performance factors of a catalase-based biosensor for real-time electrochemical detection of brain hydrogen peroxide in freely-moving animals
Authors: O'Riordan Saidhbhe L. , Mc Laughlin Kelly , Lowry John P.
Published: October 2016

The in vitro physiological performance factors of a catalase-based microelectrochemical biosensor, developed for real-time neurochemical monitoring of hydrogen peroxide.
Thermally rearranged (TR) bismaleimide-based network polymers for gas separation membranes
Authors: Do Yu Seong , Lee Won Hee , Seong Jong Geun , Kim Ju Sung , Wang Ho Hyun , Doherty Cara M. , Hill Anita J. , Lee Young Moo
Published: October 2016

Highly permeable thermally rearranged polymer membranes based on bismaleimide derivatives are reported for the first time. The membranes form semi-interpenetrating networks with other polymers endowing them with superior gas transport properties.
Radiosynthesis of SPECT tracers via a copper mediated 123I iodination of (hetero)aryl boron reagents
Authors: Wilson Thomas C. , McSweeney Greg , Preshlock Sean , Verhoog Stefan , Tredwell Matthew , Cailly Thomas , Gouverneur Véronique
Published: October 2016

The Cu-mediated [123I]iodination of aryl boronic pinacol esters and acids exhibits broad scope and is successfully applied to the labelling of four radiotracers, [123I]DPA-713, [123I]IMPY, [123I]MIBG and [123I]IPEB.
Alchemical screening of ionic crystals
Authors: Solovyeva Alisa , von Lilienfeld O. Anatole
Published: October 2016

We introduce alchemical perturbations as a rapid and accurate tool to estimate fundamental structural and energetic properties in pure and mixed ionic crystals.
Conformational features of the Aβ42 peptide monomer and its interaction with the surrounding solvent
Authors: Khatua Prabir , Jose Jaya C. , Sengupta Neelanjana , Bandyopadhyay Sanjoy
Published: October 2016

Heterogeneous conformational flexibility of the Aβ monomers has been found to be correlated with the corresponding non-uniform entropy gains.
Neurotrophin-mimicking peptides at the biointerface with gold respond to copper ion stimuli
Authors: Satriano C. , Forte G. , Magrì A. , Di Pietro P. , Travaglia A. , Pandini G. , Gianì F. , La Mendola D.
Published: October 2016

Gold surfaces functionalised with NGF and BDNF-derived fragments as new platforms for pH and copper ion-driven peptide loading and release.
Dynamic viscosity mapping of the oxidation of squalene aerosol particles
Authors: Athanasiadis Athanasios , Fitzgerald Clare , Davidson Nicholas M. , Giorio Chiara , Botchway Stanley W. , Ward Andrew D. , Kalberer Markus , Pope Francis D. , Kuimova Marina K.
Published: October 2016

The microscopic viscosity of squalene-based organic aerosol undergoing atmospherically relevant oxidation is investigated.
Aun (n = 1–16) clusters on the ZrO2(111) surface: a DFT+U investigation
Authors: Liang Ming-Xing , Zhao Liang , Jia Jianfeng , Wu Hai-Shun
Published: October 2016

Aun (n = 1–16) clusters supported on the monoclinic ZrO2 surface prefer quasi-planar geometries that lay flat on the surface.
Extracting nano-gold from HAuCl4 solution manipulated with electrons
Authors: Lu Y. , Wang K. , Chen F.-R. , Zhang W. , Sui M. L.
Published: October 2016

We report the migration and segregation behaviors of Au atoms in solution during real time, by exploiting a charging effect in a dilute HAuCl4 water solution under electron irradiation, to allow the growth kinetics of Au nanoparticles to be successfully controlled.
Nanoporous ionic organic networks: from synthesis to materials applications
Authors: Sun Jian-Ke , Antonietti Markus , Yuan Jiayin
Published: October 2016

This review highlights the recent progress made in the study of the synthesis of nanoporous ionic organic networks (NIONs) and their promising applications.
Kagome-type isostructural 3D-transition metal fluorosulfates with spin 3/2 and 1: synthesis, structure and characterization
Authors: Marri Subba R. , Kumar Jitendra , Panyarat Kitt , Horike Satoshi , Behera J. N.
Published: October 2016

Two isostructural kagome-type 3D metal fluorosulfates [H3O] [M(SO4)F], (where M = Co(II) for 1 and Ni(II) for 2) were synthesized and characterized. Both the compounds show antiferromagnetic interactions between the metal centers.
Photobiocatalytic alcohol oxidation using LED light sources
Authors: Rauch M. , Schmidt S. , Arends I. W. C. E. , Oppelt K. , Kara S. , Hollmann F.
Published: October 2016

The photocatalytic oxidation of NADH using a flavin photocatalyst and a simple blue LED light source is reported.
The intramolecular 5-exo, 7-endo-dig transition metal-free cyclization sequence of (2-alkynylphenyl) benzyl ethers: synthesis of seven-membered fused benzo[b]furans
Authors: Gai Rafaela , do Carmo Pinheiro Roberto , Neto José S. S. , Iglesias Bernardo A. , Acunha Thiago V. , Back Davi F. , Zeni Gilson
Published: October 2016

We present the results of the intramolecular transition metal-free cyclization of (2-alkynylphenyl) benzyl ethers promoted by sodium tert-butoxide.
Atomic spectrometry update: review of advances in the analysis of metals, chemicals and functional materials
Authors: Carter Simon , Fisher Andy , Garcia Raquel , Gibson Bridget , Marshall John , Whiteside Ian
Published: October 2016

This review covers advances in the analysis of advanced materials, metals, fuels and lubricants, nanostructures, ceramics, refractories, organic and inorganic chemicals, catalysts and nuclear materials by a range of techniques including X-ray, ICP, LIBS, mass spectrometry, synchrotron-based techniques, plus non-destructive and ablation surface techniques.
Fabrication of MnO/C composites utilizing pitch as the soft carbon source for rechargeable Li-ion batteries
Authors: Zhao Xin-Yi , Bai Xue , Yang Wei , Shen Dong , Yang Huan , Lun Ning , Qi Yong-Xin , Bai Yu-Jun
Published: October 2016

MnO nanoparticles coated with pitch-derived soft carbon exhibit greatly enhanced electrochemical performance compared to those coated with glucose-derived hard carbon.
A hybrid halobismuthate light-harvesting material with an optical band gap of 1.70 eV
Authors: Kotov Vitalii Yu. , Ilyukhin Andrey B. , Birin Kirill P. , Laurinavichyute Veronika K. , Sadovnikov Alexey A. , Dobrokhotova Zhanna V. , Kozyukhin Sergey A.
Published: October 2016

The product of Br–I substitution in 1-D (C15H14N4)BiBr5·H2O can be proposed as a promising material for solid-state solar cells.
Progress in aminosugar derived asymmetric organocatalysis
Authors: Agarwal Jyoti
Published: October 2016

This review sheds light on the effect of the structural modification of sugar amines on their catalytic efficiency and the stereoselectivity of the reaction.
Double glass transitions in exfoliated poly(methyl methacrylate)/organically modified MgAl layered double hydroxide nanocomposites
Authors: Li Xiaohai , Chen Lin , Li Qiulong , Zhang Jinjin , Su Zheng , Zhang Xian , Zheng Kang , Tian Xingyou
Published: October 2016

PMMA chains were confined at a layered material (organically modified MgAl layered double hydroxides) surface, which formed the interfacial layer between nanoparticles and the polymer matrix.
Novel dihydroisoxazoline-alkyl carbon chain hybrid artemisinin analogues (artemalogs): synthesis and antitumor activities
Authors: Liu Gang , Song Shanshan , Liu Xiaohua , Zhang Ao , Miao Zehong , Ding Chunyong
Published: October 2016

Two new series of dihydroisoxazoline-alkyl carbon chain hybrid artemisinin analogues (artemalogs) were designed and synthesized though a 1,3-dipolar cycloaddition, leading to novel analogues with dramatically improved antiproliferative effects against tumor cells.
Dynamics of proton transfer in imidazole hydrogen-bond chains
Authors: Bua-ngern Worapong , Chaiwongwattana Sermsiri , Suwannakham Parichart , Sagarik Kritsana
Published: October 2016

Potential energy curve of H-bond (2) in G4-[1](ω1=−92) is nearly identical to H-bond (1) in G2-[1](ω1=−94), the protonated H-bond (2) becomes a new precursor for the next transfer and confirms the Eigen–Zundel–Eigen mechanism.
Green method to fabricate porous microspheres for ultrasensitive SERS detection using UV light
Authors: Wang Fei , Qiu Yang , Wang Bing-Jie , Wang Hua-Lin , Long Yi-Tao
Published: October 2016

A green method to fabricate porous polymer microspheres with SERS activity for ultrasensitive SERS detection using UV light.
Simultaneous determination of dopamine and uric acid in the presence of high ascorbic acid concentration using cetyltrimethylammonium bromide–polyaniline/activated charcoal composite
Authors: Govindasamy Mani , Chen Shen-Ming , Mani Veerappan , Sathiyan Anandaraj , Merlin Johnson Princy , Al-Hemaid Fahad M. A. , Ali M. Ajmal
Published: October 2016

Simultaneous determination of dopamine and uric acid is described using CTAB–PANI/AC composite and attained detection limits of 0.06 and 0.20 μM, respectively. Practicality is demonstrated in rat brain, injection, serum and urine samples.
Applying thieno[3,2-b]thiophene as a building block in the design of rigid extended thienoacenes
Authors: Magnan François , Gabidullin Bulat , Brusso Jaclyn L.
Published: October 2016

The synthesis of rigid extended star-shaped thienoacenes that incorporate thieno[3,2-b]thiophene as a structural unit, either as the “core” or “arm” moiety, is described herein.
Simple synthesis of lithium-doped sulfated titania nanoparticles and their high visible light photocatalytic activity under negative bias electrostatic field
Authors: Guo Yu , Chen Junhua , Ding Zhijie , Guo Teng , Wei Jumeng , Ye Xiangju , Xu Weibing , Zhou Zhengfa
Published: October 2016

Li-doped TiO2/SO42− nanoparticles were successfully synthesized via a simple calcinination process in a vacuum environment using Ti(SO4)2 and LiBr as precursors, and were characterised by TEM, XRD, IR, DLS, XPS and UV-vis (DRS).
Hydrous TiO2@polypyrrole hybrid nanocomposite as an efficient selective scavenger for the defluoridation of drinking water
Authors: Parashar Kamya , Ballav Niladri , Debnath Sushanta , Pillay Kriveshini , Maity Arjun
Published: October 2016

An adsorptive process for the defluoridation of drinking water was performed using a hybrid nanocomposite of hydrous titanium oxide@polypyrrole (HTiO2@PPy), as a scavenger.
Porous boron nitride coupled with CdS for adsorption–photocatalytic synergistic removal of RhB
Authors: Li Xiaopeng , Qi Feng , Xue Yanming , Yu Chao , Jia Huichao , Bai Yinghao , Wang Sai , Liu Zhenya , Zhang Jun , Tang Chengchun
Published: October 2016

Adsorption–photocatalytic synergistic removal of organic pollutants based on porous BN coupled with a small amount of CdS.
Development of novel polymer electrolyte membranes based on a benzothiadiazole unit
Authors: Amari Shuntaro , Ando Shinji , Yamaguchi Takeo
Published: October 2016

We developed novel aromatic polymer electrolyte membranes based on the benzothiadiazole unit with high swelling resistance and proton conductivity.
Electrochemical performance of highly amorphous GeOx powders synthesized in different alcohols for use in Na- and Li-ion batteries
Authors: Kajita T. , Itoh T.
Published: October 2016

The large particle size of amorphous powders deteriorated the cycle performance of a Na-ion cell more than that of a Li-ion cell, due to large decomposition of the electrolyte.
Fluorographene nanosheets: a new carbon-based matrix for the detection of small molecules by MALDI-TOF MS
Authors: Sun Jie , Chen Suming , Liu Huihui , Xiong Caiqiao , Wang Jiyun , Xie Xiaobo , Xue Jinjuan , Chen Penglei , Nie Zongxiu
Published: October 2016

Fluorographene nanosheets (FG) was synthesized and applied as matrix for analysis of small molecules with clear background, good compatibility and homogeneity.
Preparation of diazoalkane complexes of iron(ii)
Authors: Albertin Gabriele , Antoniutti Stefano , Bortoluzzi Marco , Botter Alessandra , Castro Jesús , Sibilla Francesca
Published: October 2016

The preparation of diazoalkane complexes of iron(ii) and their reactivity toward acrylonitrile are described.
Cu2O hollow structures—microstructural evolution and photocatalytic properties
Authors: Wang Baoshun , Zhang Weiwei , Zhang Zhiyun , Li Renying , Wu Yulong , Hu Zhengguang , Wu Xiaoling , Guo Chungang , Cheng Guoan , Zheng Ruiting
Published: October 2016

Cu2O single-shelled, multi-shelled and multi-shelled porous sub-micron hollow spheres were successfully synthesized via a facile one-pot route. The Cu2O multi-shelled hollow sub-micron spheres demonstrated the best photo-catalytic property.
Nickel and cobalt nanoparticles modified hollow mesoporous carbon microsphere catalysts for efficient catalytic reduction of widely used dyes
Authors: Tian Meng , Dong Chunxu , Cui Xueliang , Dong Zhengping
Published: October 2016

We used hollow mesoporous carbon microspheres (h-MCM) as a catalyst support and designed two novel non-precious-metal-based nanocatalysts Ni/h-MCM and Co/h-MCM for efficient catalytic reduction of widely used dyes under mild reaction conditions.
Investigating the tribological performance of nanosized MoS2 on graphene dispersion in perfluoropolyether under high vacuum
Authors: Wu Xinhu , Zhao Gaiqing , Zhao Qin , Gong Kuiliang , Wang Xiaobo , Liu Weimin , Liu Weisheng
Published: October 2016

Nanosized MoS2 on graphene was firstly investigated in the lubrication field and exhibited excellent tribological performance in perfluoroalkylpolyether under high vacuum.
Microstructure evolution and enhanced bioactivity of Ti–Nb–Zr alloy by bioactive hydroxyapatite fabricated via spark plasma sintering
Authors: He Y. H. , Zhang Y. Q. , Jiang Y. H. , Zhou R.
Published: October 2016

The crystalline phases and bioactivity of materials play crucial factors in determining the biological interactions and osseointegration process of orthopaedic replacements or implants.
Study on the simultaneous reduction of diesel engine soot and NO with nano-CeO2catalysts
Authors: Huang He , Liu Junheng , Sun Ping , Ye Song
Published: October 2016

Nano-CeO2catalysts simultaneously reduce diesel soot and nitric oxide on a catalytic activity evaluation platform.
Half-cell and full-cell applications of horizontally aligned reduced oxide graphene/V2O5 sheets as cathodes for high stability lithium-ion batteries
Authors: Xu Na , Liang Jiaqi , Qian Tao , Yang Tingzhou , Yan Chenglin
Published: October 2016

2D hybrid sheets of V2O5 and reduced graphene oxide (rGO/V2O5) have been synthesized using a hydrothermal method.
A metal-mediated base pair that discriminates between the canonical pyrimidine nucleobases
Authors: Jash Biswarup , Scharf Philipp , Sandmann Nikolas , Fonseca Guerra Célia , Megger Dominik A. , Müller Jens
Published: October 2016

A molecular beacon has been developed that depends on the formation of a metal-mediated base pair.
Nanospace-confined synthesis of oriented porous carbon nanosheets for high-performance electrical double layer capacitors
Authors: Wang Ya , Dou Hui , Ding Bing , Wang Jie , Chang Zhi , Xu Yunling , Hao Xiaodong
Published: October 2016

A symmetric capacitor based on facilely synthesized three-dimensional oriented porous carbon nanosheets delivers high energy density.
Bridged bisnitramide-substituted furazan-based energetic materials
Authors: Zhang Jiaheng , Dharavath Srinivas , Mitchell Lauren A. , Parrish Damon A. , Shreeve Jean'ne M.
Published: October 2016

A series of bisnitramide-bridging energetic compounds was designed and synthesized based on amino/nitro-functionalized furazans with methyl-NNO-azoxy, 1,2,4-oxadiazol and 3-hydrazino(imino)methyl side-chain groups.
Colonic acetate in obesity: location matters!
Authors: Bindels Laure B. , Leclercq Isabelle
Published: October 2016

Gut micro-organisms are recognized as crucial regulators of host immunity and the microbiota has been implicated in several inflammatory, immune, inflammatory or even psychiatric disorders. Therefore the analysis of the complex interactions between gut microbiota and the host is currently under intense investigation. Most of our knowledge stems from the study of animal models while translational research and data in humans are necessary to move the field forward and to evolve to diagnostic and therapeutic application. Amongst the microbial by-products, short chain fatty acids such as acetate yielded by fermentation of non-digestible fibers, were pointed as metabolic modulators. Here we highlight a study evaluating the effects of colonic infusion of one of the short chain fatty acids, acetate, in a cohort of overweight and obese normoglycaemic subjects.
Design of a digital holography system for PFC erosion measurements on Proto-MPEX
Authors: Thomas C. E. (Tommy) , Biewer T. M. , Baylor L. R. , Combs S. K. , Meitner S. J. , Rapp J. , Hillis D. L. , Granstedt E. M. , Majeski R. , Kaita R.
Published: October 2016

A project has been started at ORNL to develop a dual-wavelength digital holography system for plasma facing component erosion measurements on prototype material plasma exposure experiment. Such a system will allow in situ real-time measurements of component erosion. Initially the system will be developed with one laser, and first experimental laboratory measurements will be made with the single laser system. In the second year of development, a second CO2 laser will be added and measurements with the dual wavelength system will begin. Adding the second wavelength allows measurements at a much longer synthetic wavelength.
Superconducting nanowire detector jitter limited by detector geometry
Authors: Calandri Niccolò , Zhao Qing-Yuan , Zhu Di , Dane Andrew , Berggren Karl K.
Published: October 2016

Detection jitter quantifies variance introduced by the detector in the determination of photon arrival time. It is a crucial performance parameter for systems using superconducting nanowire single photon detectors (SNSPDs). In this work, we have demonstrated that the detection timing jitter is limited in part by the spatial variation of the photon detection events along the length of the wire. We define this jitter source as a geometric jitter since it is related to the length and area of the SNSPD. To characterize the geometric jitter, we have constructed a differential cryogenic readout with less than 7 ps of an electronic jitter that can amplify the pulses generated from the two ends of an SNSPD. By differencing the measured arrival times of the two electrical pulses, we were able to partially cancel out the difference of the propagation times and thus reduce the uncertainty of the photon arrival time. We proved that the variation of the differential propagation time was a few ps for a 3 μm × 3 μm device, while it increased up to 50 ps for a 20 μm × 20 μm device. In a 20 μm × 20 μm large SNSPD, we achieved a 20% reduction in the overall detection timing jitter for detecting the telecom-wavelength photons by using the differential cryogenic readout.
Drop generation from a vibrating nozzle in an immiscible liquid-liquid system
Authors: Bertrandias A. , Duval H. , Casalinho J. , Giorgi M. L.
Published: October 2016

Drop generation from an axially vibrating nozzle exhibits a transition in drop diameter when varying the vibration amplitude. Below a threshold amplitude, forcing has essentially no effect on drop size and drops form in dripping mode. Above the threshold, drop size is controlled by forcing: drops detach at resonance, i.e., when the first eigenfrequency of the growing drop coincides with the forcing frequency. We experimentally study the impact of the nozzle inner diameter, dispersed phase flow rate, interfacial tension, and dispersed phase viscosity on this transition. Drop diameter is well correlated to the mode 1 eigenfrequency of Strani and Sabetta for a drop in partial contact with a spherical bowl. We propose a transient model to describe drop dynamics until detachment. The drop is modelled as a linearly forced harmonic oscillator, with the eigenfrequency of Strani and Sabetta. Since the dispersed phase does not wet the nozzle tip, an additional damping coefficient is introduced to account for the viscous dissipation in the film of continuous phase between the drop and nozzle surface. The model adequately reproduces the effect of the different parameters on the threshold amplitude.
Digital holographic interferometry employing Fresnel transform reconstruction for the study of flow shear stabilized Z-pinch plasmas
Authors: Ross M. P. , Shumlak U.
Published: October 2016

The ZaP-HD flow Z-pinch project provides a platform to explore how shear flow stabilized Z-pinches could scale to high-energy-density plasma (plasma with pressures exceeding 1 Mbar) and fusion reactor conditions. The Z-pinch is a linear plasma confinement geometry in which the plasma carries axial electric current and is confined by its self-induced magnetic field. ZaP-HD generates shear stabilized, axisymmetric Z-pinches with stable lifetimes approaching 60 μs. The goal of the project is to increase the plasma density and temperature compared to the previous ZaP project by compressing the plasma to smaller radii (≈1 mm). Radial and axial plasma electron density structure is measured using digital holographic interferometry (DHI), which provides the necessary fine spatial resolution. ZaP-HD’s DHI system uses a 2 ns Nd:YAG laser pulse with a second harmonic generator (λ = 532 nm) to produce holograms recorded by a Nikon D3200 digital camera. The holograms are numerically reconstructed with the Fresnel transform reconstruction method to obtain the phase shift caused by the interaction of the laser beam with the plasma. This provides a two-dimensional map of line-integrated electron density, which can be Abel inverted to determine the local number density. The DHI resolves line-integrated densities down to 3 × 1020 m−2 with spatial resolution near 10 μm. This paper presents the first application of Fresnel transform reconstruction as an analysis technique for a plasma diagnostic, and it analyzes the method’s accuracy through study of synthetic data. It then presents an Abel inversion procedure that utilizes data on both sides of a Z-pinch local number density profile to maximize profile symmetry. Error estimation and Abel inversion are applied to the measured data.
Photodetectors with zigzag and armchair graphene nanoribbon channels and asymmetric source and drain contacts: Detectors for visible and solar blind applications
Authors: Ostovari Fatemeh , Moravvej-Farshi Mohammad Kazem
Published: October 2016

Employing the non-equilibrium Green's function with the third order tight binding Hamiltonian, we show that 12.7 nm long and 1.11 nm wide zigzag and armchair graphene nanoribbons (ZGNR and AGNR) in contact with asymmetric source and drain, consisting of graphene topped with Au and Ti, respectively, can operate as visible and solar blind photodetectors under zero externally applied biases. The carbon atoms at the channels' edges are considered to be hydrogen passivated. Numerical simulations show that the unbiased Au-ZGNR-Ti and Au-AGNR-Ti photodetectors can detect photons of energies 2.72 eV (456 nm, visible reign) and 5.02 eV (247 nm, solar blind reign), respectively, with the corresponding quantum efficiencies as high as 90% and 60% and responsivities of 93.8 and 13.4 A/mW. We also show that in Au-ZGNR-Ti the local photocurrents are distributed more around the ZGNR edges in regions near the source and drain sides of the channel, for the zero gate-source voltage (VGS = 0), whereas in Au-AGNR-Ti for the same biasing condition, the local photocurrents are distributed far from the AGNR edges within regions near the source and drain sides of the channel. As the applied gate voltage moves away from the Dirac point, the peaks of the local photocurrents move away from the source and drain sides of the channel in opposite directions, in either asymmetric photodetector. Polarities of the local photocurrents are altered, as the gate-source voltage approaches the Dirac point, where the total photocurrent is maximized for both asymmetric photodetectors.
Enhanced photoluminescence in air-suspended carbon nanotubes by oxygen doping
Authors: Chen Jihan , Dhall Rohan , Hou Bingya , Yang Sisi , Wang Bo , Kang Daejing , Cronin Stephen B.
Published: October 2016

We report photoluminescence (PL) imaging and spectroscopy of air-suspended carbon nanotubes (CNTs) before and after exposure to a brief (20 s) UV/ozone treatment. These spectra show enhanced PL intensities in 10 out of 11 nanotubes that were measured, by as much as 5-fold. This enhancement in the luminescence efficiency is caused by oxygen defects which trap excitons. We also observe an average 3-fold increase in the D-band Raman intensity further indicating the creation of defects. Previous demonstrations of oxygen doping have been carried out on surfactant-coated carbon nanotubes dissolved in solution, thus requiring substantial longer ozone/UV exposure times (∼15 h). Here, the ozone treatment is more efficient because of the surface exposure of the air-suspended CNTs. In addition to enhanced PL intensities, we observe narrowing of the emission linewidth by 3–10 nm. This ability to control and engineer defects in CNTs is important for realizing several optoelectronic applications such as light-emitting diodes and single photon sources.
A high-performance wave guide cryogenic thermal break
Authors: Melhuish S. J. , McCulloch M. A. , Piccirillo L. , Stott C.
Published: October 2016

We describe a high-performance wave guide cryogenic thermal break. This has been constructed both for Ka band, using WR28 wave guide, and Q band, using WR22 wave guide. The mechanical structure consists of a hexapod (Stewart platform) made from pultruded carbon fibre tubing. We present a tentative examination of the cryogenic Young’s modulus of this material. The thermal conductivity is measured at temperatures above the range explored by Runyan and Jones, resulting in predicted conductive loads through our thermal breaks of 3.7 mW to 3 K and 17 μK to 1 K.
Understanding the plasmonics of nanostructured atomic force microscopy tips
Authors: Sanders A. , Bowman R. W. , Zhang L. , Turek V. , Sigle D. O. , Lombardi A. , Weller L. , Baumberg J. J.
Published: October 2016

Structured metallic tips are increasingly important for optical spectroscopies such as tip-enhanced Raman spectroscopy, with plasmonic resonances frequently cited as a mechanism for electric field enhancement. We probe the local optical response of sharp and spherical-tipped atomic force microscopy (AFM) tips using a scanning hyperspectral imaging technique to identify the plasmonic behaviour. Localised surface plasmon resonances which radiatively couple with far-field light are found only for spherical AFM tips, with little response for sharp AFM tips, in agreement with numerical simulations of the near-field response. The precise tip geometry is thus crucial for plasmon-enhanced spectroscopies, and the typical sharp cones are not preferred.
Note: Efficient, low-cost cooling system for gloveboxes
Authors: Möller A. , Marioneck T. , Dronskowski R.
Published: October 2016

Cooling within gloveboxes is often restricted to expensive refrigerated bath circulators or small temperature differences. Here, we present a sturdy, inexpensive cooling system which matches various glovebox types and can be readily fabricated by a mechanical workshop in a few days. The system is suitable for cold plates of areas up to 150 cm2 and temperatures as low as −100 °C.
Increase in elastic anisotropy of single crystal tungsten upon He-ion implantation measured with laser-generated surface acoustic waves
Authors: Duncan R. A. , Hofmann F. , Vega-Flick A. , Eliason J. K. , Maznev A. A. , Every A. G. , Nelson K. A.
Published: October 2016

We report the experimental observation of an increase in the elastic anisotropy of tungsten upon He-ion implantation, probed optically using transient grating spectroscopy. Surface acoustic wave (SAW) velocity measurements were performed on a (110) oriented tungsten single crystal as a function of in-plane propagation direction for unimplanted and implanted samples. Our measurements allow us to finely resolve the remarkably small elastic anisotropy of the samples investigated. SAW velocity calculations are used to interpret the experimental data and to extract the Zener anisotropy parameter η and the elastic constant C44. Upon ion implantation, we observe an increase in the quantity (η−1) by a factor of 2.6. The surprising increase in elastic anisotropy agrees with previous theoretical predictions based on ab initio calculations of the effect of self-interstitial atoms and He-filled vacancy defects on the elastic properties of tungsten.
Dynamic analysis of immune and cancer cell interactions at single cell level in microfluidic droplets
Authors: Sarkar S. , Sabhachandani P. , Stroopinsky D. , Palmer K. , Cohen N. , Rosenblatt J. , Avigan D. , Konry T.
Published: October 2016

Cell-cell communication mediates immune responses to physiological stimuli at local and systemic levels. Intercellular communication occurs via a direct contact between cells as well as by secretory contact-independent mechanisms. However, there are few existing methods that allow quantitative resolution of contact-dependent and independent cellular processes in a rapid, precisely controlled, and dynamic format. This study utilizes a high-throughput microfluidic droplet array platform to analyze cell-cell interaction and effector functions at single cell level. Controlled encapsulation of distinct heterotypic cell pairs was achieved in a single-step cell loading process. Dynamic analysis of dendritic cell (DC)-T cell interactions demonstrated marked heterogeneity in the type of contact and duration. Non-stimulated DCs and T cells interacted less frequently and more transiently while antigen and chemokine-loaded DCs and T cells depicted highly stable interactions in addition to transient and sequential contact. The effector function of CD8+ T cells was assessed via cytolysis of multiple myeloma cell line. Variable cell conjugation periods and killing time were detected irrespective of the activation of T cells, although activated T cells delivered significantly higher cytotoxicity. T cell alloreactivity against the target cells was partially mediated by secretion of interferon gamma, which was abrogated by the addition of a neutralizing antibody. These results suggest that the droplet array-based microfluidic platform is a powerful technique for dynamic phenotypic screening and potentially applicable for evaluation of novel cell-based immunotherapeutic agents.
Modeling and simulation of plasma gas flow driven by a single nanosecond-pulsed dielectric barrier discharge
Authors: Xu S. Y. , Cai J. S. , Li J.
Published: October 2016

A simplified (7 species and 9 processes) plasma kinetic model is proposed to investigate the mechanism of the plasma aerodynamic actuation driven by nanosecond-pulsed dielectric barrier discharge (NS-DBD). The governing equations include conservation equations for each species, the Poisson equation for the electric potential, and Navier-Stokes equations for the gas dynamic flow. Numerical simulations of plasma discharge and flow actuation on NS-DBD plasma actuators have been carried out. Key discharge characteristics and the responses of the quiescent air were reproduced and compared to those obtained in experiments and numerical simulations. Results demonstrate that the reduced plasma kinetic model is able to capture the dominant species and reactions to predict the actuation in complicated hydrodynamics. For the one-dimensional planar and two-dimensional symmetric NS-DBD, the forming of the sheath collapse is mainly due to the charge accumulation and secondary emission from the grounded electrode. Rapid species number density rise and electric field drop occur at the edge of the plasma sheath, where the space charge density gradient peaks. For the aerodynamic actuation with typical asymmetry electrodes, discharge characteristics have a core area on the right edge of the upper electrode, where the value can be much higher. The formation and propagation of the compression waves generated through rapid heating have also been performed and compared to those measured in a recent experiment. Energy release leads to gas expansion and forms a cylindrical shock wave, centering at the upper electrode tip with low gas acceleration. For the present single pulsed 12 kV case, the mean temperature of gas heating reaches about 575 K at 1 μs and decreases to about 460 K at 10 μs.
A bilayer small diameter in vitro vascular model for evaluation of drug induced vascular injury
Authors: Hoganson David M. , Finkelstein Eric B. , Owens Gwen E. , Hsiao James C. , Eng Kurt Y. , Kulig Katherine M. , Kim Ernest S. , Kniazeva Tatiana , Pomerantseva Irina , Neville Craig M. , Turk James R. , Fermini Bernard , Borenstein Jeffrey T. , Vacanti Joseph P.
Published: October 2016

In pre-clinical safety studies, drug-induced vascular injury (DIVI) is defined as an adverse response to a drug characterized by degenerative and hyperplastic changes of endothelial cells and vascular smooth muscle cells. Inflammation may also be seen, along with extravasation of red blood cells into the smooth muscle layer (i.e., hemorrhage). Drugs that cause DIVI are often discontinued from development after considerable cost has occurred. An in vitro vascular model has been developed using endothelial and smooth muscle cells in co-culture across a porous membrane mimicking the internal elastic lamina. Arterial flow rates of perfusion media within the endothelial chamber of the model induce physiologic endothelial cell alignment. Pilot testing with a drug known to cause DIVI induced extravasation of red blood cells into the smooth muscle layer in all devices with no extravasation seen in control devices. This engineered vascular model offers the potential to evaluate candidate drugs for DIVI early in the discovery process. The physiologic flow within the co-culture model also makes it candidate for a wide variety of vascular biology investigations.
Ultrafast demagnetization by hot electrons: Diffusion or super-diffusion?
Authors: Salvatella G. , Gort R. , Bühlmann K. , Däster S. , Vaterlaus A. , Acremann Y.
Published: October 2016

Ultrafast demagnetization of ferromagnetic metals can be achieved by a heat pulse propagating in the electron gas of a non-magnetic metal layer, which absorbs a pump laser pulse. Demagnetization by electronic heating is investigated on samples with different thicknesses of the absorber layer on nickel. This allows us to separate the contribution of thermalized hot electrons compared to non-thermal electrons. An analytical model describes the demagnetization amplitude as a function of the absorber thickness. The observed change of demagnetization time can be reproduced by diffusive heat transport through the absorber layer.
Sward structure and relationship between canopy height and light interception for tropical C4 grasses growing under trees
Authors: Baldissera Tiago Celso , Pontes Laíse da Silveira , Giostri André Faé , Barro Raquel Santiago , Lustosa Sebastião Brasil Campos , de Moraes Aníbal , Carvalho Paulo César de Faccio
Published: October 2016

The canopy height (CH) at 95% light interception (LI) is a valuable defoliation frequency strategy used to handle variability in herbage accumulation throughout the year, mainly in C4 grasses. Such a strategy has been adopted as an open pasture management index, but defoliation frequency and intensity remain unsolved issues for shade-grown forages. A field experiment was conducted for 2 years to determine the influence of tree canopy (Eucalyptus dunnii) shading and nitrogen availability (0 and 300 kg N ha–1 year–1) on CH at 95% LI of six perennial tropical forage species. The plots were cut at 95% LI, and the height of the residual sward was kept at 50% of the corresponding CH at 95% LI. The shade level ranged from ~40% at the beginning of the experiment to ~60% at the end of summer 2013. Variations in CH at 95% LI occurred because of shading and across seasons. The range of these variations was species-dependent. Overall, species growing under trees showed higher CH, except for Paspalum notatum and Megathyrsus maximus in the first year. There was a significant increase in the length of the sheaths and leaves, as well as a decrease in tiller density and leaf : stem ratio in plants growing under trees. Nitrogen also had an impact on CH; however, its application did not compensate the shade effect on CH. Therefore, our results suggest that greater CH should be considered in case of defoliated, shade-grown plants and that such strategy might change throughout seasons.
Responses of woody Cerrado species to rising atmospheric CO2 concentration and water stress: gains and losses
Authors: Souza João Paulo , Melo Nayara M. J. , Pereira Eduardo G. , Halfeld Alessandro D. , Gomes Ingrid N. , Prado Carlos Henrique B. A.
Published: October 2016

The rise in atmospheric CO2 concentration ([CO2]) has been accompanied by changes in other environmental factors of global climate change, such as drought. Tracking the early growth of plants under changing conditions can determine their ecophysiological adjustments and the consequences for ecosystem functions. This study investigated long-term ecophysiological responses in three woody Cerrado species: Hymenaea stigonocarpa Mart. ex Hayne, Solanum lycocarpum A. St.-Hil. and Tabebuia aurea (Silva Manso) Benth. and Hook. f. ex S. Moore, grown under ambient and elevated [CO2]. Plants were grown for 515 days at ambient (430 mg dm–3) or elevated [CO2] (700 mg dm–3). Some plants were also subjected to water stress to investigate the synergy between atmospheric [CO2] and soil water availability, and its effect on plant growth. All three species showed an increase in maximum net photosynthesis (PN) and chlorophyll index under high [CO2]. Transpiration decreased in some species under high [CO2] despite daily watering and a corresponding increase in water use efficiency was observed. Plants grown under elevated [CO2] and watered daily had greater leaf area and total biomass production than plants under water stress and ambient [CO2]. The high chlorophyll and PN in cerrado plants grown under elevated [CO2] are an investment in light use and capture and higher Rubisco carboxylation rate, respectively. The elevated [CO2] had a positive influence on biomass accumulation in the cerrado species we studied, as predicted for plants under high [CO2]. So, even with water stress, Cerrado species under elevated [CO2] had better growth.
In vivo optical imaging of physiological responses to photostimulation in human photoreceptors
Authors: Hillmann Dierck , Spahr Hendrik , Pfäffle Clara , Sudkamp Helge , Franke Gesa , Hüttmann Gereon
Published: October 2016

Significance

Using a full-field optical coherence tomography system, we measured changes in the time that light requires to pass through photoreceptor outer segments, when the retina is stimulated by a light pulse. This effect can be used to monitor the activity of single cones in the living human eye. Objective monitoring of photoreceptor activity using such intrinsic optical signals could have important diagnostic applications in ophthalmology and neurology and might provide insight to facilitate basic research.