bluuebunny/crossref_metadata_2025 huggingface dataset:
Discovery of potential biomarkers in exhaled breath for diagnosis of type 2 diabetes mellitus based on GC-MS with metabolomics
Authors: Yan Yanyue , Wang Qihui , Li Wenwen , Zhao Zhongjun , Yuan Xin , Huang Yanping , Duan Yixiang
Published: May 2014

Eight breath biomarkers of T2DM were discovered by a new SPME-GC-MS based metabolic profiling tool.
Step-edge induced area selective growth: a kinetic Monte Carlo study
Authors: Zhang Heng , Liu Gang , Wang Wenchong , Chi Lifeng , Yuan Shiling
Published: May 2014

Three stages of step-edge induced selective growth were proposed: step-edge induced growth, layer-by-layer growth and central nucleation growth.
High strength biocompatible PEG single-network hydrogels
Authors: Qian ShanShan , Zhou Chao , Xu LiQun , Yao Fang , Cen Lian , Fu GuoDong
Published: May 2014

A single-chain PEG hydrogel with extremely high strength was prepared via precise design and control over the molecular topology of the polymeric network.
Selectively sensing first-row transition metal ions through fluorescence enhancement
Authors: Pal Sanchari , Chatterjee Nabanita , Bharadwaj Parimal K.
Published: May 2014

Fluorescence signaling systems that give enhancement in the presence of first-row transition metal ions are discussed.
One-pot fabrication and thermoelectric properties of Ag nanoparticles–polyaniline hybrid nanocomposites
Authors: Wang Weijie , Sun Suping , Gu Shijia , Shen Hongwei , Zhang Qihao , Zhu Juanjuan , Wang Lianjun , Jiang Wan
Published: May 2014

In this context, a one-pot and in situ strategy for fabrication of AgNPs (Ag nanoparticles)/PANI (polyaniline) nanocomposites in a micellar solution of dodecylbenzene sulfonic acid (DBSA, anionic surfactant) is introduced.
Polyethyleneimine for copper absorption: kinetics, selectivity and efficiency in artificial seawater
Authors: Lindén Johan B. , Larsson Mikael , Coad Bryan R. , Skinner William M. , Nydén Magnus
Published: May 2014

Ultra-thin PEI-based coatings effectively and selectively accumulated up to 13% copper in the coatings from 200 ppb in artificial seawater.
Iron-catalyzed efficient intermolecular amination of C(sp3)–H bonds with bromamine-T as nitrene source
Authors: Wang Haiyu , Li Yuxi , Wang Zhiming , Lou Jun , Xiao Yuling , Qiu Guofu , Hu Xianming , Altenbach Hans-Josef , Liu Peng
Published: May 2014

[Fe(N4Py)(CH3CN)](ClO4)2 can efficiently catalyze intermolecular nitrene insertion of sp3 C–H bonds with bromamine-T as the nitrene source, forming the desired tosylprotected amines with NaBr as the by-product.
Cooperative manipulation and transport of microobjects using multiple helical microcarriers
Authors: Huang Tian-Yun , Qiu Famin , Tung Hsi-Wen , Peyer Kathrin E. , Shamsudhin Naveen , Pokki Juho , Zhang Li , Chen Xue-Bo , Nelson Bradley J. , Sakar Mahmut Selman
Published: May 2014

We report a cooperative transport strategy that uses engineered microbars and multiple helical microcarriers. Cooperation of microcarriers generates higher propulsive forces while application of forces at multiple locations results in motion control with multiple degrees of freedom.
Vapour solid reaction growth of SnO2 nanorods as an anode material for Li ion batteries
Authors: Hsu Kai-Chieh , Lee Chi-Young , Chiu Hsin-Tien
Published: May 2014

Via a vapour–solid reaction growth pathway, phase-segregated SnO2 nanorods were developed in a matrix of CaCl2 salt by reacting CaO particles with a flowing mixture of SnCl4 and Ar gases at elevated temperatures. A half-cell constructed from the as-fabricated SnO2 electrode and a Li foil exhibited a reversible capacity of 435 mA h g−1 after one hundred cycles at a current density of 100 mA g−1.
Effects of different dopants on the band gap and electrical conductivity of the poly(phenylene-thiazolo[5,4-d]thiazole) copolymer
Authors: Olgun U. , Gülfen M.
Published: May 2014

Band gap energy and electrical conductivity of poly(phenylene-thiazolo[5,4-d]thiazole) were compared for different dopants.
Palladium catalyzed direct allylation of azlactones with simple allylic alcohols in the absence of any activators
Authors: Zhou Hui , Yang Huameng , Yin Hongyu , Liu Muwen , Xia Chungu , Jiang Gaoxi
Published: May 2014

The first example of the readily scalable direct allylic alkylation of azlactones with simple allylic alcohols has been developed, which is catalyzed by Pd(PPh3)4 alone in the absence of any activators under neutral conditions.
Supramolecular hydrogel based on amphiphilic calix[4]arene and its application in the synthesis of silica nanotubes
Authors: Song Song , Wang Jinhua , Feng Hai-Tao , Zhu Zhi-Hua , Zheng Yan-Song
Published: May 2014

A hydrogel could be formed by leaving a suspension of novel amphiphilic calix[4]arene in aqueous media to stand at room temperature through a dissolution-reassembly process.
Solid polymer substrates and smart fibres for the selective visual detection of TNT both in vapour and in aqueous media
Authors: Pablos Jesús L. , Trigo-López Miriam , Serna Felipe , García Félix C. , García José M.
Published: May 2014

Visual detection of the explosive TNT with sensory polymer films and coated fibres.
Thermal-healable and shape memory metallosupramolecular poly(n-butyl acrylate-co-methyl methacrylate) materials
Authors: Wang Zhenhua , Fan Wenru , Tong Rui , Lu Xili , Xia Hesheng
Published: May 2014

Thermal-induced shape memory and healing based on a metallosupramolecular polymer were realized.
An accelerated route of glycerol carbonate formation from glycerol using waste boiler ash as catalyst
Authors: Indran Vidhyaa Paroo , Syuhada Zuhaimi Nor Ain , Deraman Mohd Asyrak , Maniam Gaanty Pragas , Yusoff Mashitah Mohd. , Yun Hin Taufiq-Yap , Ab. Rahim Mohd Hasbi
Published: May 2014

New, abundant and relatively cheap waste boiler ash as catalyst for the selective transformation of glycerol into glycerol carbonate fine chemical.
Retracted Article: Light-triggered nitric oxide release and targeted fluorescence imaging in tumor cells developed from folic acid-graft-carboxymethyl chitosan nanospheres
Authors: Gui Rijun , Wan Ajun , Zhang Yalei , Li Huili , Zhao Tingting
Published: May 2014

This article reported the synthesis of CMC–FA–RBS(CQD) nanospheres and studied their potential applications for NO release and fluorescence imaging.
Synthesis of double gold nanoclusters/graphene oxide and its application as a new fluorescence probe for Hg2+ detection with greatly enhanced sensitivity and rapidity
Authors: Xiaofei Wu , Ruiyi Li , Zaijun Li , Junkang Liu , Guangli Wang , Zhiguo Gu
Published: May 2014

The paper reports a double gold nanoclusters/graphene oxide as a fluorescence probe with surprisingly enhanced sensitivity and rapidity for detection of Hg2+.
Ternary graphite nanosheet/copper phthalocyanine/sulfonated poly(aryl ether ketone) dielectric percolative composites: preparation, micromorphologies and dielectric properties
Authors: Zhang Yunhe , Zhang Gang , Xu Dan , Wang Jinfeng , Yang Xu , Jiang Zhenhua
Published: May 2014

A phthalocyanine layer was coated on the surface of acidified graphite nanosheets for improving the dielectric properties of composites.
Rapid differentiation of microbial cultures based on the analysis of headspace volatiles by atmospheric pressure chemical ionization mass spectrometry
Authors: Liang Juchao , Hang Yaping , Chingin Konstantin , Hu Longhua , Chen Huanwen
Published: May 2014

APCI-MS fingerprinting of headspace volatiles was used to differentiate microbial cultures without any sample pretreatment, chromatographic separation and wet chemistry.
Synthesis of biologically active pyridoimidazole/imidazobenzothiazole annulated polyheterocycles using cyanuric chloride in water
Authors: Pandey Anand Kumar , Sharma Rashmi , Singh Awantika , Shukla Sanjeev , Srivastava Kumkum , Puri Sunil K. , Kumar Brijesh , Chauhan Prem M. S.
Published: May 2014

An efficient and mild protocol for rapid access to N-fused polyheterocycles via Pictet–Spengler type 6-endo cyclization by cyanuric chloride in aqueous medium has been developed.
Palladium-catalyzed Suzuki cross-couplings of N′-mesyl arylhydrazines via C–N bond cleavage
Authors: Zhou He-Ping , Liu Jin-Biao , Yuan Jian-Jun , Peng Yi-Yuan
Published: May 2014

An efficient palladium-catalyzed Suzuki cross-coupling reaction of N′-mesyl arylhydrazine with aryl boronic acid is described, which affords the corresponding biaryl compounds in high yields. This transformation proceeds through C–N bond cleavage under mild conditions.
Detection of the neurotransmitter dopamine by a glassy carbon electrode modified with self-assembled perovskite LaFeO3 microspheres made up of nanospheres
Authors: Thirumalairajan S. , Girija K. , Mastelaro Valmor R. , Ganesh V. , Ponpandian N.
Published: May 2014

Glassy carbon electrode modified with LaFeO3 microspheres made up of nanospheres and having high electrocatalytic ability to detect the neurotransmitter dopamine.
Surfactant-modified chemically reduced graphene oxide for electrochemical supercapacitors
Authors: Ke Qingqing , Liu Yanqiong , Liu Huajun , Zhang Yu , Hu Yating , Wang John
Published: May 2014

An easy method to synthesize surfactant-modified graphene for a supercapacitor is demonstrated through the intercalation of graphene oxide (GO) with a triblock copolymer Pluronic F127 (F127).
Hierarchical rough surfaces formed by LBL self-assembly for oil–water separation
Authors: Li Xiaoyu , Hu Dan , Huang Kun , Yang Chuanfang
Published: May 2014

Stainless steel felt modified with hierarchically structured coatings and hydrophobicity can achieve a removal efficiency of greater than 99% for oil-in-water emulsion separation.
Cationic microporous polymer networks by polymerisation of weakly coordinating cations with CO2-storage ability
Authors: Fischer Sabrina , Schimanowitz Aneta , Dawson Robert , Senkovska Irena , Kaskel Stefan , Thomas Arne
Published: May 2014

Microporous organic polymer networks with weakly coordinating cations in their backbone have been synthesised by metal catalysed C–C bond forming reactions.
Highly stable intrinsically radiolabeled indium-111 quantum dots with multidentate zwitterionic surface coating: dual modality tool for biological imaging
Authors: Sun Minghao , Sundaresan Gobalakrishnan , Jose Purnima , Yang Likun , Hoffman David , Lamichhane Narottam , Zweit Jamal
Published: May 2014

A highly stable bimodal indium(111) radiolabeled indium QDs were synthesized for in vivo SPECT/fluorescence imaging.
Multifunctional materials for OFETs, LEFETs and NIR PLEDs
Authors: Steckler T. T. , Lee M. J. , Chen Z. , Fenwick O. , Andersson M. R. , Cacialli F. , Sirringhaus H.
Published: May 2014

Phthalimide–thiophene copolymers are multi-functional materials that possess reasonably high PLQEs, ambipolar mobilities, and perform extremely well as a host material for single layer NIR emitting PLEDs.
Saturable absorption and the changeover from saturable absorption to reverse saturable absorption of MoS2 nanoflake array films
Authors: Ouyang Qiuyun , Yu Hailong , Zhang Kai , Chen Yujin
Published: May 2014

MoS2 nanoflake array films on different glass substrates were fabricated by an in situ growth method. The nonlinear absorption (NLA) properties of the MoS2 nanoflake array films were investigated by an open-aperture Z-scan technique. The films exhibited different NLA properties dependent on the input energy.
Self-organized growth of metallic nanoparticles in a thin film under homogeneous and continuous-wave light excitation
Authors: Destouches Nathalie , Crespo-Monteiro Nicolas , Vitrant Guy , Lefkir Yaya , Reynaud Stéphanie , Epicier Thierry , Liu Yang , Vocanson Francis , Pigeon Florent
Published: May 2014

We show the formation and explain the optical origin of self-organized metallic photonic crystals buried in thin films.
Discovery of InsP6-kinases as InsP6-dephosphorylating enzymes provides a new mechanism of cytosolic InsP6 degradation driven by the cellular ATP/ADP ratio
Authors: Wundenberg Torsten , Grabinski Nicole , Lin Hongying , Mayr Georg W.
Published: May 2014

InsP6 (inositol hexakisphosphate), the most abundant inositol phosphate in metazoa, is pyrophosphorylated to InsP7 [5PP-InsP5 (diphosphoinositol pentakisphosphate)] by cytosolic and nuclear IP6Ks (InsP6 kinases) and to 1PP-InsP5 by another InsP6/InsP7 kinase family. MINPP1 (multiple inositol-polyphosphate phosphatase 1), the only known InsP6 phosphatase, is localized in the ER (endoplasmic reticulum) and lysosome lumina. A mechanism of cytosolic InsP6 dephosphorylation has remained enigmatic so far. In the present study, we demonstrated that IP6Ks change their kinase activity towards InsP6 at a decreasing ATP/ADP ratio to an ADP phosphotransferase activity and dephosphorylate InsP6. Enantio-selective analysis revealed that Ins(2,3,4,5,6)P5 is the main InsP5 product of the IP6K reaction, whereas the exclusive product of MINPP1 activity is the enantiomer Ins(1,2,4,5,6)P5. Whereas lentiviral RNAi-based depletion of MINPP1 at falling cellular ATP/ADP ratios had no significant impact on Ins(2,3,4,5,6)P5 production, the use of the selective IP6K inhibitor TNP [N2-(m-trifluorobenzyl),N6-(p-nitrobenzyl)purine] abolished the production of this enatiomer in different types of cells. Furthermore, by analysis of rat tissue and human blood samples all (main and minor) dephosphorylation products of InsP6 were detected in vivo. In summary, we identified IP6Ks as novel nuclear and cytosolic InsP6- (and InsP5-) dephosphorylating enzymes whose activity is sensitively driven by a decrease in the cellular ATP/ADP ratio, thus suggesting a role for IP6Ks as cellular adenylate energy ‘sensors’.
Autophagy is required and protects against apoptosis during myoblast differentiation
Authors: McMillan Elliott M. , Quadrilatero Joe
Published: May 2014

Several degradative systems assist in formation of multinucleated terminally differentiated myotubes. However, the role of autophagy in this process has not been examined. GFP–LC3B (light chain 3 beta) puncta, LC3B-II protein and LysoTracker fluorescence increased during C2C12 cell differentiation. Importantly, accumulation of LC3B-II protein occurred in CQ (chloroquine)-treated cells throughout differentiation. Furthermore, BECN1 (beclin 1), ATG7 (autophagy-related 7) and ATG12-5 protein increased, whereas SQSTM1/p62 (sequestosome 1) protein was rapidly reduced during differentiation. A transient decrease in BECN1–BCL2 association was observed from day 0.5 to 2 of differentiation. Chemical inhibition of JNK (c-Jun N-terminal kinase) during differentiation reduced LC3B-II protein and GFP–LC3B puncta and maintained BECN1–BCL2 association. Inhibition of autophagy by 3MA (3-methyladenine) or shRNA against Atg7 (shAtg7) resulted in lower myosin heavy chain expression, as well as impaired myoblast fusion and differentiation. Interestingly, 3MA treatment during differentiation increased transient CASP3 (caspase 3) activation, DNA fragmentation and the percentage of apoptotic nuclei. Similarly, shAtg7 cells had increased DNA fragmentation during differentiation compared with the controls. Collectively, these data demonstrate that autophagy increases and is required during myoblast differentiation. Moreover, autophagy protects differentiating myoblasts from apoptotic cell death.
Differential inductions of phenylalanine ammonia-lyase and chalcone synthase during wounding, salicylic acid treatment, and salinity stress in safflower,Carthamus tinctorius
Authors: Dehghan Sara , Sadeghi Mahnaz , Pöppel Anne , Fischer Rainer , Lakes-Harlan Reinhard , Kavousi Hamid Reza , Vilcinskas Andreas , Rahnamaeian Mohammad
Published: May 2014

Safflower (Carthamus tinctorius L.) serves as a reference dicot for investigation of defence mechanisms in Asteraceae due to abundant secondary metabolites and high resistance/tolerance to environmental stresses. In plants, phenylpropanoid and flavonoid pathways are considered as two central defence signalling cascades in stress conditions. Here, we describe the isolation of two major genes in these pathways, CtPAL (phenylalanine ammonia-lyase) and CtCHS (chalcone synthase) in safflower along with monitoring their expression profiles in different stress circumstances. The aa (amino acid) sequence of isolated region of CtPAL possesses the maximum identity up to 96% to its orthologue in Cynara scolymus, while that of CtCHS retains the highest identity to its orthologue in Callistephus chinensis up to 96%. Experiments for gene expression profiling of CtPAL and CtCHS were performed after the treatment of seedlings with 0.1 and 1 mM SA (salicylic acid), wounding and salinity stress. The results of semi-quantitative RT–PCR revealed that both CtPAL and CtCHS genes are further responsive to higher concentration of SA with dissimilar patterns. Regarding wounding stress, CtPAL gets slightly induced upon injury at 3 hat (hours after treatment) (hat), whereas CtCHS gets greatly induced at 3 hat and levels off gradually afterward. Upon salinity stress, CtPAL displays a similar expression pattern by getting slightly induced at 3 hat, but CtCHS exhibits a biphasic expression profile with two prominent peaks at 3 and 24 hat. These results substantiate the involvement of phenylpropanoid and particularly flavonoid pathways in safflower during wounding and especially salinity stress.
Ghost stochastic resonance in FitzHugh–Nagumo circuit
Authors: Bordet M. , Morfu S. , Marquié P.
Published: May 2014

The response of a neural circuit submitted to a bi‐chromatic stimulus and corrupted by noise is investigated. In the presence of noise, when the spike firing of the circuit is analysed, a frequency not present at the circuit input appears. For a given range of noise intensities, it is shown that this ghost frequency is almost exclusively present in the interspike interval distribution. This phenomenon is for the first time shown experimentally in a FitzHugh–Nagumo circuit.
Distributed range‐free localisation algorithm for wireless sensor networks
Authors: Chen Liangyin , Li Miao , Liu Kai , Liu Zhenlei , Zhang Jingyu , Peng Tong , Liu Yan , Xu Yongjun , Luo Qian , He Tian
Published: May 2014

A novel distributed range‐free localisation algorithm to accurately locate regular nodes in wireless sensor networks is presented. Existing methods reduce the possible area where a regular node would be located by using anchors (i.e. nodes with known locations) only. These methods are effective only when anchor density is high. In contrast, the work presented here reduces the possible area of a regular node iteratively, using both anchor node locations and the possible areas of its neighbouring and non‐neighbouring ‘regular’ nodes from early iteration. This allows a significant improvement in the localisation accuracy. Simulations verify the advantage of the proposed algorithm and show that the localisation error can be controlled within 15% with off‐the‐shelf devices.
Structured compressive sensing based superimposed pilot design in downlink large‐scale MIMO systems
Authors: Gao Zhen , Dai Linglong , Wang Zhaocheng
Published: May 2014

Large‐scale multiple‐input multiple‐output (MIMO) with high spectrum and energy efficiency is a very promising key technology for future 5G wireless communications. For large‐scale MIMO systems, accurate channel state information (CSI) acquisition is a challenging problem, especially when each user has to distinguish and estimate numerous channels coming from a large number of transmit antennas in the downlink. Unlike the conventional orthogonal pilots whose pilot overhead prohibitively increases with the number of transmit antennas, a spectrum‐efficient superimposed pilot design for downlink large‐scale MIMO scenarios is proposed, where frequency‐domain pilots of different transmit antennas occupy completely the same subcarriers in the frequency domain. Meanwhile, spatial–temporal common sparsity of large‐scale MIMO channels motivates us to exploit the emerging theory of structured compressive sensing (CS) for reliable MIMO channel estimation, which is realised by the proposed structured subspace pursuit (SSP) algorithm to simultaneously recover multiple channels with low pilot overhead. Simulation results demonstrate that the proposed scheme performs well and can approach the performance bound.
Assessing flexibility requirements in power systems
Authors: Dvorkin Yury , Kirschen Daniel S. , Ortega‐Vazquez Miguel A.
Published: May 2014

This study proposes a methodology to assess the effect of wind power production on the flexibility requirements of a power system. First, the study describes the probabilistic characteristics of the intra‐hour net load variability and demonstrates that they are best captured by non‐parametric statistics. Then, this non‐parametric approach is used to determine simultaneously the hourly flexibility requirements at a given probability level for large and small, continuous and discrete disturbances. This approach allocates the required flexibility among primary, secondary and tertiary regulation intervals. The usefulness of this method is then illustrated using actual 1 min resolution net load data, which has been clustered to take advantage of seasonal and daily differences in flexibility requirements.
Optimal scheduling of a microgrid with demand response resources
Authors: Carpinelli Guido , Mottola Fabio , Proto Daniela
Published: May 2014

A larger penetration of plug‐in electric vehicle (EV) fleets and of data centres in the microgrids (µGs) is foreseeable in the near future. Their presence and the presence of distributed generation (DG) units represent a challenge for system operators in that they must identify approaches for using these distributed resources that allow them to operate the grid in a more efficient and economical way. With particular reference to EVs and data centres, it must be noted that they are equipped with storage devices that potentially could result in the modification of the daily load profile of µGs by shifting peak demand away from the high‐cost periods. This study is focused on the use of data centres and EV aggregators as demand‐response resources, and a new model for the operation of a µG that includes DG units, EV fleets and the data centre's storage systems has been proposed. The procedure is based on a non‐linear, constrained, optimisation model with the aim of minimising the total cost of energy and simultaneously shaving peak power. The effectiveness of the proposed strategy was demonstrated by means of numerical applications to a low‐voltage, test µG.
Investigation of synchronous generator in reactive power market – an accurate view
Authors: Homaee Omid , Jadid Shahram
Published: May 2014

This study addresses clarification regarding total payment function calculation in reactive power market. One of the main sources of reactive power in transmission network is synchronous generator. Capability curves of reactive power produced by synchronous generators are surveyed in this study. Meanwhile, using these curves, all the costs of one synchronous generator to inject or absorb reactive power are calculated. These costs include an availability cost and cost of losses as well as cost of losing the sale opportunity of electrical energy because of production or absorption of reactive power. The IEEE 24‐bus reliability test system is used to illustrate the proposed cost calculation technique in reactive power market.
Diagnosis of diabetic retinopathy by employing image processing technique to detect exudates in retinal images
Authors: Franklin Sundararaj Wilfred , Rajan Samuelnadar Edward
Published: May 2014

Diabetic retinopathy (DR) is a microvascular complication of long‐term diabetes and it is the major cause of visual impairment because of changes in blood vessels of the retina. Major vision loss because of DR is highly preventable with regular screening and timely intervention at the earlier stages. The presence of exudates is one of the primitive signs of DR and the detection of these exudates is the first step in automated screening for DR. Hence, exudates detection becomes a significant diagnostic task, in which digital retinal imaging plays a vital role. In this study, the authors propose an algorithm to detect the presence of exudates automatically and this helps the ophthalmologists in the diagnosis and follow‐up of DR. Exudates are normally detected by their high grey‐level variations and they have used an artificial neural network to perform this task by applying colour, size, shape and texture as the features. The performance of the authors algorithm has been prospectively tested by using DIARETDB1 database and evaluated by comparing the results with the ground‐truth images annotated by expert ophthalmologists. They have obtained illustrative results of mean sensitivity 96.3%, mean specificity 99.8%, using lesion‐based evaluation criterion and achieved a classification accuracy of 99.7%.
Indium nitride humidity sensing devices with microwave resonant property
Authors: Yang Chih Chin
Published: May 2014

An effective microstructure indium nitride (InN) humidity sensing (INHUSE) device has been developed after InN compound was appropriately annealed with nitrogen source compensation. An X‐ray diffraction spectrum of the as‐synthesised structure shows one strong peak at 30.5° corresponding to the (0002) atomic plane of the InN hexagonal compound. The InN compound of p‐type is exhibited to reach an average Hall coefficient of 2.270 × 107 m2/C, which can be conjugated with the n‐type substrate to construct the p–n sensing device with a resonant tunnelling property. The Raman spectrum reveals the longitudinal optical phonon mode A1(LO) (polar mode), transverse optical phonon mode A1(TO) (polar mode) and transverse optical phonon mode E1(TO) of the InN‐based INHUSE device in 582, 437 and 473 cm−1, respectively. The negative differential resistance effect of the INHUSE device with an excellent peak current density in 13.2 kA/cm2 and an outstanding peak to valley current ratio of about 3.36 is exhibited. Experimental moisture examination of the INHUSE device from RH30 to 90% in accordance with the calculation of the microwave resonant property up to GHz is completed. The linear region of relative humidity measurement is from RH40 to 70% in resistance value, reached as the measured resistance value at about 31 Ω. The sensitivity of the INHUSE device is about 50 kHz/RH% for the self‐resonant frequency and 2.5 MHz/RH% for the resistive cutoff frequency.
Remarkable Triple Pleomorphic Adenoma Affecting both Parotid and Submandibular Glands
Authors: Pingarrón-Martín Lorena , Arias-Gallo L. J. , Demaría-Martínez G. , Chamorro Pons M.
Published: May 2014

The objective of this article is to present the first case reported in the literature of metachronous pleomorphic adenoma of bilateral parotid glands and submaxillary gland. The authors report the case of a 27-year-old female with metachronous mixed tumors in her right parotid and submandibular glands. The patient has no history of previous radiotherapy. All three lesions were diagnosed by fine-needle aspiration. The histopathologic evaluation of all three major salivary gland masses demonstrated pleomorphic adenomas, with no occult malignancy observed on serial sections. The presentation of pleomorphic adenomas in the parotids and submandibular glands probably represents three unrelated primary sites of tumor, yet the possibility of metastasis from one gland to the other cannot be excluded.
Dynamic temperature response of electrocaloric multilayer capacitors
Authors: Kwon Beomjin , Roh Im-Jun , Baek Seung-Hyub , Keun Kim Seong , Kim Jin-Sang , Kang Chong-Yun
Published: May 2014

We measure and model the dynamic temperature response of electrocaloric (EC) multilayer capacitors (MLCs) which have been recently highlighted as novel solid-state refrigerators. The MLC temperature responses depend on the operation voltage waveform, thus we consider three types of voltage waveforms, which include square, triangular, and trapezoidal. Further, to implement an effective refrigeration cycle, the waveform frequency and duty cycle should be carefully chosen. First, our model is fitted to the measurements to evaluate an effective EC power and thermal properties, and calculates an effective cooling power for an EC MLC. The prediction shows that for a MLC with a thermal relaxation time for cooling, trc, a square voltage waveform with a duty cycle of 0 < d ≤ 0.3 and a period of trc < P ≤ 1.4trc provides the maximum cooling power. This work will help to improve the implementing methods for EC refrigeration cycles.
Alkyl chain length-dependent surface reaction of dodecahydro-N-alkylcarbazoles on Pt model catalysts
Authors: Gleichweit Christoph , Amende Max , Bauer Udo , Schernich Stefan , Höfert Oliver , Lorenz Michael P. A. , Zhao Wei , Müller Michael , Koch Marcus , Bachmann Philipp , Wasserscheid Peter , Libuda Jörg , Steinrück Hans-Peter , Papp Christian
Published: May 2014

The concept of liquid organic hydrogen carriers (LOHC) holds the potential for large scale chemical storage of hydrogen at ambient conditions. Herein, we compare the dehydrogenation and decomposition of three alkylated carbazole-based LOHCs, dodecahydro-N-ethylcarbazole (H12-NEC), dodecahydro-N-propylcarbazole (H12-NPC), and dodecahydro-N-butylcarbazole (H12-NBC), on Pt(111) and on Al2O3-supported Pt nanoparticles. We follow the thermal evolution of these systems quantitatively by in situ high-resolution X-ray photoelectron spectroscopy. We show that on Pt(111) the relevant reaction steps are not affected by the different alkyl substituents: for all LOHCs, stepwise dehydrogenation to NEC, NPC, and NBC is followed by cleavage of the C–N bond of the alkyl chain starting at 380–390 K. On Pt/Al2O3, we discern dealkylation on defect sites already at 350 K, and on ordered, (111)-like facets at 390 K. The dealkylation process at the defects is most pronounced for NEC and least pronounced for NBC.
High-density carbon ablator experiments on the National Ignition Facility
Authors: MacKinnon A. J. , Meezan N. B. , Ross J. S. , Le Pape S. , Berzak Hopkins L. , Divol L. , Ho D. , Milovich J. , Pak A. , Ralph J. , Döppner T. , Patel P. K. , Thomas C. , Tommasini R. , Haan S. , MacPhee A. G. , McNaney J. , Caggiano J. , Hatarik R. , Bionta R. , Ma T. , Spears B. , Rygg J. R. , Benedetti L. R. , Town R. P. J. , Bradley D. K. , Dewald E. L. , Fittinghoff D. , Jones O. S. , Robey H. R. , Moody J. D. , Khan S. , Callahan D. A. , Hamza A. , Biener J. , Celliers P. M. , Braun D. G. , Erskine D. J. , Prisbrey S. T. , Wallace R. J. , Kozioziemski B. , Dylla-Spears R. , Sater J. , Collins G. , Storm E. , Hsing W. , Landen O. , Atherton J. L. , Lindl J. D. , Edwards M. J. , Frenje J. A. , Gatu-Johnson M. , Li C. K. , Petrasso R. , Rinderknecht H. , Rosenberg M. , Séguin F. H. , Zylstra A. , Knauer J. P. , Grim G. , Guler N. , Merrill F. , Olson R. , Kyrala G. A. , Kilkenny J. D. , Nikroo A. , Moreno K. , Hoover D. E. , Wild C. , Werner E.
Published: May 2014

High Density Carbon (HDC) is a leading candidate as an ablator material for Inertial Confinement Fusion (ICF) capsules in x-ray (indirect) drive implosions. HDC has a higher density (3.5 g/cc) than plastic (CH, 1 g/cc), which results in a thinner ablator with a larger inner radius for a given capsule scale. This leads to higher x-ray absorption and shorter laser pulses compared to equivalent CH designs. This paper will describe a series of experiments carried out to examine the feasibility of using HDC as an ablator using both gas filled hohlraums and lower density, near vacuum hohlraums. These experiments have shown that deuterium (DD) and deuterium-tritium gas filled HDC capsules driven by a hohlraum filled with 1.2 mg/cc He gas, produce neutron yields a factor of 2× higher than equivalent CH implosions, representing better than 50% Yield-over-Clean (YoC). In a near vacuum hohlraum (He = 0.03 mg/cc) with 98% laser-to-hohlraum coupling, such a DD gas-filled capsule performed near 1D expectations. A cryogenic layered implosion version was consistent with a fuel velocity = 410 ± 20 km/s with no observed ablator mixing into the hot spot.
Progress in hohlraum physics for the National Ignition Facility
Authors: Moody J. D. , Callahan D. A. , Hinkel D. E. , Amendt P. A. , Baker K. L. , Bradley D. , Celliers P. M. , Dewald E. L. , Divol L. , Döppner T. , Eder D. C. , Edwards M. J. , Jones O. , Haan S. W. , Ho D. , Hopkins L. B. , Izumi N. , Kalantar D. , Kauffman R. L. , Kilkenny J. D. , Landen O. , Lasinski B. , LePape S. , Ma T. , MacGowan B. J. , MacLaren S. A. , Mackinnon A. J. , Meeker D. , Meezan N. , Michel P. , Milovich J. L. , Munro D. , Pak A. E. , Rosen M. , Ralph J. , Robey H. F. , Ross J. S. , Schneider M. B. , Strozzi D. , Storm E. , Thomas C. , Town R. P. J. , Widmann K. L. , Kline J. , Kyrala G. , Nikroo A. , Boehly T. , Moore A. S. , Glenzer S. H.
Published: May 2014

Advances in hohlraums for inertial confinement fusion at the National Ignition Facility (NIF) were made this past year in hohlraum efficiency, dynamic shape control, and hot electron and x-ray preheat control. Recent experiments are exploring hohlraum behavior over a large landscape of parameters by changing the hohlraum shape, gas-fill, and laser pulse. Radiation hydrodynamic modeling, which uses measured backscatter, shows that gas-filled hohlraums utilize between 60% and 75% of the laser power to match the measured bang-time, whereas near-vacuum hohlraums utilize 98%. Experiments seem to be pointing to deficiencies in the hohlraum (instead of capsule) modeling to explain most of the inefficiency in gas-filled targets. Experiments have begun quantifying the Cross Beam Energy Transfer (CBET) rate at several points in time for hohlraum experiments that utilize CBET for implosion symmetry. These measurements will allow better control of the dynamic implosion symmetry for these targets. New techniques are being developed to measure the hot electron energy and energy spectra generated at both early and late time. Rugby hohlraums offer a target which requires little to no CBET and may be less vulnerable to undesirable dynamic symmetry “swings.” A method for detecting the effect of the energetic electrons on the fuel offers a direct measure of the hot electron effects as well as a means to test energetic electron mitigation methods. At higher hohlraum radiation temperatures (including near vacuum hohlraums), the increased hard x-rays (1.8–4 keV) may pose an x-ray preheat problem. Future experiments will explore controlling these x-rays with advanced wall materials.
Regularity criteria and uniform estimates for the Boussinesq system with temperature-dependent viscosity and thermal diffusivity
Authors: Fan Jishan , Li Fucai , Nakamura Gen
Published: May 2014

In this paper, we establish some regularity criteria for the 3D Boussinesq system with the temperature-dependent viscosity and thermal diffusivity. We also obtain some uniform estimates for the corresponding 2D case when the fluid viscosity coefficient is a positive constant.
Atomic imaging and modeling of H2O2(g) surface passivation, functionalization, and atomic layer deposition nucleation on the Ge(100) surface
Authors: Kaufman-Osborn Tobin , Chagarov Evgueni A. , Kummel Andrew C.
Published: May 2014

Passivation, functionalization, and atomic layer deposition nucleation via H2O2(g) and trimethylaluminum (TMA) dosing was studied on the clean Ge(100) surface at the atomic level using scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS). Chemical analysis of the surface was performed using x-ray photoelectron spectroscopy, while the bonding of the precursors to the substrate was modeled with density functional theory (DFT). At room temperature, a saturation dose of H2O2(g) produces a monolayer of a mixture of –OH or –O species bonded to the surface. STS confirms that H2O2(g) dosing eliminates half-filled dangling bonds on the clean Ge(100) surface. Saturation of the H2O2(g) dosed Ge(100) surface with TMA followed by a 200 °C anneal produces an ordered monolayer of thermally stable Ge–O–Al bonds. DFT models and STM simulations provide a consistent model of the bonding configuration of the H2O2(g) and TMA dosed surfaces. STS verifies the TMA/H2O2/Ge surface has an unpinned Fermi level with no states in the bandgap demonstrating the ability of a Ge–O–Al monolayer to serve as an ideal template for further high-k deposition.
The adsorption-desorption transition of double-stranded DNA interacting with an oppositely charged dendrimer induced by multivalent anions
Authors: Jiang Yangwei , Zhang Dong , Zhang Yaoyang , Deng Zhenyu , Zhang Linxi
Published: May 2014

The adsorption-desorption transition of DNA in DNA-dendrimer solutions is observed when high-valence anions, such as hexavalent anions, are added to the DNA-dendrimer solutions. In the DNA-dendrimer solutions with low-valence anions, dendrimers bind tightly with the V-shaped double-stranded DNA. When high-valence anions, such as pentavalent or hexavalent anions, are added to the DNA-dendrimer solutions, the double-stranded DNA chains can be stretched straightly and the dendrimers are released from the double-stranded DNA chains. In fact, adding high-valence anions to the solutions can change the charge spatial distribution in the DNA-dendrimer solutions, and weaken the electrostatic interactions between the positively charged dendrimers and the oppositely charged DNA chains. Adsorption-desorption transition of DNA is induced by the overcharging of dendrimers. This investigation is capable of helping us understand how to control effectively the release of DNA in gene/drug delivery because an effective gene delivery for dendrimers includes non-covalent DNA-dendrimer binding and the effective release of DNA in gene therapy.
Multiphoton ionization of large water clusters
Authors: Apicella B. , Li X. , Passaro M. , Spinelli N. , Wang X.
Published: May 2014

Water clusters are multimers of water molecules held together by hydrogen bonds. In the present work, multiphoton ionization in the UV range coupled with time of flight mass spectrometry has been applied to water clusters with up to 160 molecules in order to obtain information on the electronic states of clusters of different sizes up to dimensions that can approximate the bulk phase. The dependence of ion intensities of water clusters and their metastable fragments produced by laser ionization at 355 nm on laser power density indicates a (3+1)-photon resonance-enhanced multiphoton ionization process. It also explains the large increase of ionization efficiency at 355 nm compared to that at 266 nm. Indeed, it was found, by applying both nanosecond and picosecond laser ionization with the two different UV wavelengths, that no water cluster sequences after n = 9 could be observed at 266 nm, whereas water clusters up to m/z 2000 Th in reflectron mode and m/z 3000 Th in linear mode were detected at 355 nm. The agreement between our findings on clusters of water, especially true in the range with n > 10, and reported data for liquid water supports the hypothesis that clusters above a critical dimension can approximate the liquid phase. It should thus be possible to study clusters just above 10 water molecules, for getting information on the bulk phase structure.
Spin-dependent thermoelectronic transport of a single molecule magnet Mn(dmit)2
Authors: Su Zhongbo , An Yipeng , Wei Xinyuan , Yang Zhongqin
Published: May 2014

We investigate spin-dependent thermoelectronic transport properties of a single molecule magnet Mn(dmit)2 sandwiched between two Au electrodes using first-principles density functional theory combined with nonequilibrium Green's function method. By applying a temperature difference between the two Au electrodes, spin-up and spin-down currents flowing in opposite directions can be induced due to asymmetric distribution of the spin-up and spin-down transmission spectra around the Fermi level. A pure spin current and 100% spin polarization are achieved by tuning back-gate voltage to the system. The spin caloritronics of the molecule with a perpendicular conformation is also explored, where the spin-down current is blocked strongly. These results suggest that Mn(dmit)2 is a promising material for spin caloritronic applications.
Dynamics of the time-resolved stimulated Raman scattering spectrum in presence of transient vibronic inversion of population on the example of optically excited trans-β-apo-8′-carotenal
Authors: Kardaś T. M. , Ratajska-Gadomska B. , Lapini A. , Ragnoni E. , Righini R. , Di Donato M. , Foggi P. , Gadomski W.
Published: May 2014

We have studied the effect of transient vibrational inversion of population in trans-β-apo-8′-carotenal on the time-resolved femtosecond stimulated Raman scattering (TR-FSRS) signal. The experimental data are interpreted by applying a quantum mechanical approach, using the formalism of projection operators for constructing the theoretical model of TR-FSRS. Within this theoretical frame we explain the presence of transient Raman losses on the Stokes side of the TR-FSRS spectrum as the effect of vibrational inversion of population. In view of the obtained experimental and theoretical results, we conclude that the excited S2 electronic level of trans-β-apo-8′-carotenal relaxes towards the S0 ground state through a set of four vibrational sublevels of S1 state.
Rotation-induced nonlinear wavepackets in internal waves
Authors: Whitfield A. J. , Johnson E. R.
Published: May 2014

The long time effect of weak rotation on an internal solitary wave is the decay into inertia-gravity waves and the eventual formation of a localised wavepacket. Here this initial value problem is considered within the context of the Ostrovsky, or the rotation-modified Korteweg-de Vries (KdV), equation and a numerical method for obtaining accurate wavepacket solutions is presented. The flow evolutions are described in the regimes of relatively-strong and relatively-weak rotational effects. When rotational effects are relatively strong a second-order soliton solution of the nonlinear Schrödinger equation accurately predicts the shape, and phase and group velocities of the numerically determined wavepackets. It is suggested that these solitons may form from a local Benjamin-Feir instability in the inertia-gravity wave-train radiated when a KdV solitary wave rapidly adjusts to the presence of strong rotation. When rotational effects are relatively weak the initial KdV solitary wave remains coherent longer, decaying only slowly due to weak radiation and modulational instability is no longer relevant. Wavepacket solutions in this regime appear to consist of a modulated KdV soliton wavetrain propagating on a slowly varying background of finite extent.
Size-exclusion partitioning of neutral solutes in crosslinked polymer networks: A Monte Carlo simulation study
Authors: Quesada-Pérez Manuel , Adroher-Benítez Irene , Maroto-Centeno José Alberto
Published: May 2014

In this work, the size-exclusion partitioning of neutral solutes in crosslinked polymer networks has been studied through Monte Carlo simulations. Two models that provide user-friendly expressions to predict the partition coefficient have been tested over a wide range of volume fractions: Ogston's model (especially devised for fibrous media) and the pore model. The effects of crosslinking and bond stiffness have also been analyzed. Our results suggest that the fiber model can acceptably account for size-exclusion effects in crosslinked gels. Its predictions are good for large solutes if the fiber diameter is assumed to be the effective monomer diameter. For solutes sizes comparable to the monomer dimensions, a smaller fiber diameter must be used. Regarding the pore model, the partition coefficient is poorly predicted when the pore diameter is estimated as the distance between adjacent crosslinker molecules. On the other hand, our results prove that the pore sizes obtained from the pore model by fitting partitioning data of swollen gels are overestimated.
Understanding the role of ultra-thin polymeric interlayers in improving efficiency of polymer light emitting diodes
Authors: Bailey Jim , Wright Edward N. , Wang Xuhua , Walker Alison B. , Bradley Donal D. C. , Kim Ji-Seon
Published: May 2014

Insertion of ultra-thin polymeric interlayers (ILs) between the poly(3,4-ethylenedioxythiophene):polystyrene sulphonate hole injection and poly(9,9-dioctylfluorene-alt-benzothiadiazole) (F8BT) light emission layers of polymer light emitting diodes (PLEDs) can significantly increase their efficiency. In this paper, we investigate experimentally a broad range of probable causes of this enhancement with an eye to determining which IL parameters have the most significant effects. The importance of hole injection and electron blocking was studied through varying the IL material (and consequently its electronic energy levels) for both PLED and hole-only diode structures. The role of IL conductivity was examined by introducing a varying level of charge-transfer doping through blending the IL materials with a strong electron-accepting small molecule in concentrations from 1% to 7% by weight. Depositing ILs with thicknesses below the exciton diffusion length of ∼15 nm allowed the role of the IL as a physical barrier to exciton quenching to be probed. IL containing PLEDs was also fabricated with Lumation Green Series 1300 (LG 1300) light emission layers. On the other hand, the PLEDs were modeled using a 3D multi-particle Kinetic Monte Carlo simulation coupled with an optical model describing how light is extracted from the PLED. The model describes charge carrier transport and interactions between electrons, holes, singlets, and triplets, with the current density, luminance, and recombination zone (RZ) locations calculated for each PLED. The model shows F8BT PLEDs have a narrow charge RZ adjacent to the anode, while LG 1300 PLEDs have a wide charge RZ that is evenly distributed across the light emitting layer. Varying the light emitting layer from F8BT to Lumation Green Series 1300, we therefore experimentally examine the dependence of the IL function, specifically in regard to anode-side exciton quenching, on the location of the RZ. We found an exponential dependence of F8BT PLED luminance on the difference, δ, in the highest occupied to lowest unoccupied molecular orbital energy gap between the light emitting polymer and a semiconducting polymeric IL, with δ consequently the most important parameter determining efficiency. Understanding the exponential effect that wider energy gap IL materials have on exciton quenching may allow δ to be used to better guide PLED structure design.
In-operando hard X-ray photoelectron spectroscopy study on the impact of current compliance and switching cycles on oxygen and carbon defects in resistive switching Ti/HfO2/TiN cells
Authors: Sowinska Malgorzata , Bertaud Thomas , Walczyk Damian , Thiess Sebastian , Calka Pauline , Alff Lambert , Walczyk Christian , Schroeder Thomas
Published: May 2014

In this study, direct experimental materials science evidence of the important theoretical prediction for resistive random access memory (RRAM) technologies that a critical amount of oxygen vacancies is needed to establish stable resistive switching in metal-oxide-metal samples is presented. In detail, a novel in-operando hard X-ray photoelectron spectroscopy technique is applied to non-destructively investigates the influence of the current compliance and direct current voltage sweep cycles on the Ti/HfO2 interface chemistry and physics of resistive switching Ti/HfO2/TiN cells. These studies indeed confirm that current compliance is a critical parameter to control the amount of oxygen vacancies in the conducting filaments in the oxide layer during the RRAM cell operation to achieve stable switching. Furthermore, clear carbon segregation towards the Ti/HfO2 interface under electrical stress is visible. Since carbon impurities impact the oxygen vacancy defect population under resistive switching, this dynamic carbon segregation to the Ti/HfO2 interface is suspected to negatively influence RRAM device endurance. Therefore, these results indicate that the RRAM materials engineering needs to include all impurities in the dielectric layer in order to achieve reliable device performance.