bluuebunny/crossref_metadata_2025 huggingface dataset:
Disposable ionic liquid-coated etched stainless steel fiber for headspace solid-phase microextraction of organophosphorus flame retardants from water samples
Authors: Kang Haiyan , Mao Yanli , Wang Xianli , Zhang Yan , Wu Junfeng , Wang Hongqiang
Published: April 2015

An ionic liquid-coated etched stainless steel fiber was prepared for solid-phase microextraction of organophosphorus flame retardants from water.
Hybrid silicon nanocone–polymer solar cells based on a transparent top electrode
Authors: Kou Yanlei , Liu Kong , Wang Zhijie , Chi Dan , Lu Shudi , Yue Shizhong , Li Yanpei , Qu Shengchun , Wang Zhanguo
Published: April 2015

We utilize fully covered thin layer of transparent MoO3/Ag/ZnS as the top electrode for Si nanocone/PEDOT:PSS hybrid solar cells. By adjusting the geometrical parameters systematically, the optimized PCE was realized as 5.12%.
Direct growth of Sb2Te3 on graphene by atomic layer deposition
Authors: Zheng Li , Cheng Xinhong , Cao Duo , Wang Qian , Wang Zhongjian , Xia Chao , Shen Lingyan , Yu Yuehui , Shen Dashen
Published: April 2015

Graphene can avoid the oxidation of Sb2Te3, eliminate the generation of an interface layer and maintain the crystal structures of Sb2Te3.
Chiral liquid membrane for enantioselective separation of racemic ibuprofen by l-tartaric acid derivatives
Authors: Zhang Fan , He Lichao , Sun Wei , Cheng Yongqi , Liu Junteng , Ren Zhongqi
Published: April 2015

Use of a chiral liquid membrane is an attractive separation method for racemic ibuprofen, and the separation factor could be up to 1.38 under optimal experimental conditions.
A 3D porous interconnected NaVPO4F/C network: preparation and performance for Na-ion batteries
Authors: Xu Maowen , Cheng Chuan-Jun , Sun Qiang-Qiang , Bao Shu-Juan , Niu Yu-Bin , He Hong , Li Yutao , Song Jie
Published: April 2015

3D porous interconnected NaVPO4F/C network is fabricated by a hydrothermal method and sintering process. As a Na-ion battery cathode material, it delivers a good electrochemical performance.
Ternary composites of linear and hyperbranched polyimides with nanoscale silica for low dielectric constant, high transparency, and high thermal stability
Authors: Kim Seongku , Ando Shinji , Wang Xiaogong
Published: April 2015

A new series of ternary polyimide–silica composites was developed to obtain polymer films with low dielectric constant, high optical transparency, and good thermal stability.
NiO–ZrO2nanocomposite modified electrode for the sensitive and selective determination of efavirenz, an anti-HIV drug
Authors: Thapliyal Neeta , Osman Nadir S. E. , Patel Harun , Karpoormath Rajshekhar , Goyal Rajendra N. , Moyo Thomas , Patel Rajkumar
Published: April 2015

A highly sensitive NiO–ZrO2nanocomposite modified electrode was fabricated for trace analysis of efavirenz in pharmaceutical and biological samples.
Building cell-containing multilayered phospholipid polymer hydrogels for controlling the diffusion of a bioactive reagent
Authors: Gao Botao , Konno Tomohiro , Ishihara Kazuhiko
Published: April 2015

We developed multilayered phospholipid polymer hydrogels containing living cells and a specific bioactive reagent for the regulation of cell-fate.
Micro/nano-structured polyaniline/silver catalyzed borohydride reduction of 4-nitrophenol
Authors: Ma Bing , Wang Man , Tian Di , Pei Yanyan , Yuan Liangjie
Published: April 2015

Micro/nano-structured polyaniline/Ag composites with different morphologies were prepared. The composites were applied as a catalyst in the borohydride reduction reaction of 4-nitrophenol and showed comparable catalytic performance.
Dye-sensitized solar cells with hole-stabilizing surfaces: “inorganic” versus “organic” strategies
Authors: Hostettler Nik , Wright Iain A. , Bozic-Weber Biljana , Constable Edwin. C. , Housecroft Catherine E.
Published: April 2015

A study of organic and zinc(ii)-containing DSC sensitizers with second-generation diphenylamino-dendrons and benzothiadiazole domains shows that the organic dye has a superior performance.
Dual amplifying fluorescence anisotropy for detection of respiratory syncytial virus DNA fragments with size-control synthesized metal–organic framework MIL-101
Authors: Guo Jing Fang , Fang Rong Mei , Huang Cheng Zhi , Li Yuan Fang
Published: April 2015

Nanosized MIL-101 with negligible scattered light, synthesized by the addition of glycerol, was used to amplify FA for the detection of DNA with a dual amplification effect.
Correction: A facile hard-templating synthesis of mesoporous spinel CoFe2O4 nanostructures as promising electrocatalysts for the H2O2 reduction reaction
Authors: Ding Rui , Lv LeiLei , Qi Li , Jia Mingjun , Wang Hongyu
Published: April 2015

Correction for ‘A facile hard-templating synthesis of mesoporous spinel CoFe2O4 nanostructures as promising electrocatalysts for the H2O2 reduction reaction’ by Rui Ding et al., RSC Adv., 2014, 4, 1754–1760.
Controlled synthesis of zinc cobalt sulfide nanostructures in oil phase and their potential applications in electrochemical energy storage
Authors: Yang Jun , Zhang Yu , Sun Chencheng , Guo Guilue , Sun Wenping , Huang Wei , Yan Qingyu , Dong Xiaochen
Published: April 2015

A unique controlled synthesis of zinc cobalt sulfide nanostructures is obtained by a facile oil phase approach.
Facile preparation of a three-dimensional Fe3O4/macroporous graphene composite for high-performance Li storage
Authors: Lu Xiaoyu , Wang Ronghua , Bai Yang , Chen Jingjing , Sun Jing
Published: April 2015

Facile preparation of a 3D Fe3O4/macroporous graphene composite by self-assembly is proposed, and its superior Li storage performance against 2D Fe3O4/graphene is revealed and deeply discussed.
The position effect of an ethynyl spacer on the carrier mobility of anthracene derivatives
Authors: Zhang Xiaotao , Zhao Guangyao , Zhen Yonggang , Tu Zeyi , He Ping , Yi Yuanping , Dong Huanli , Hu Wenping
Published: April 2015

The naphthalenyl ethynyl substitution at the 1- and 2-positions of anthracene exhibits totally different film forming ability and hole mobility.
Cholesteric liquid crystals with an electrically controllable reflection bandwidth based on ionic polymer networks and chiral ions
Authors: Lu Hongbo , Hu Jinliang , Chu Yutian , Xu Wei , Qiu Longzhen , Wang Xianghua , Zhang Guobing , Hu Juntao , Yang Jiaxiang
Published: April 2015

The reflection bandwidth can be tuned dynamically by electric fields in the visible wavelength regime.
A chip-based microcavity derived from multi-component tellurite glass
Authors: Zheng Binbin , Zhao Mingxiao , Guo Qiangbing , Yu Yongze , Lu Shichao , Jiang Xiaoshun , Zhou Shifeng
Published: April 2015

Our results provide the first prototype of a chip-based optical microcavity derived from multi-component tellurite glass.
Synthesis, characterization and electromagnetic performance of nanocomposites of graphene with α-LiFeO2and β-LiFe5O8
Authors: Wu Hong , Li Huifeng , Sun Genban , Ma Shulan , Yang Xiaojing
Published: April 2015

Monodispersed Li–Fe–O nanocrystals assembled on grapheneviaa one-pot strategy exhibit excellent EM-wave absorbability, stronger than that of the corresponding Li–Fe–O nanostructures.
The effect of surface structures and compositions on the quantum yields of highly effective Zn0.8Cd0.2S nanocrystals
Authors: Chen Ya-Ching , Chen Hong-Shuo , Chung Shu-Ru , Chang Jeng-Kuei , Wang Kuan-Wen
Published: April 2015

The white light emission of ZnCdS is strongly related to the surface chemical states of Zn and Zn–O/Cd–O bonding.
Autonomous and non-autonomous roles of DNase II during cell death in C. elegans embryos
Authors: Yu Hsiang , Lai Huey-Jen , Lin Tai-Wei , Lo Szecheng J.
Published: April 2015

Generation of DNA fragments is a hallmark of cell apoptosis and is executed within the dying cells (autonomous) or in the engulfing cells (non-autonomous). The TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labelling) method is used as an in situ assay of apoptosis by labelling DNA fragments generated by caspase-associated DNase (CAD), but not those by the downstream DNase II. In the present study, we report a method of ToLFP (topoisomerase ligation fluorescence probes) for directly visualizing DNA fragments generated by DNase II in Caenorhabditis elegans embryos. ToLFP analysis provided the first demonstration of a cell autonomous mode of DNase II activity in dying cells in ced-1 embryos, which are defective in engulfing apoptotic bodies. Compared with the number of ToLFP signals between ced-1 and wild-type (N2) embryos, a 30% increase in N2 embryos was found, suggesting that the ratio of non-autonomous and autonomous modes of DNase II was ~3–7. Among three DNase II mutant embryos (nuc-1, crn-6 and crn-7), nuc-1 embryos exhibited the least number of ToLFP. The ToLFP results confirmed the previous findings that NUC-1 is the major DNase II for degrading apoptotic DNA. To further elucidate NUC-1′s mode of action, nuc-1-rescuing transgenic worms that ectopically express free or membrane-bound forms of NUC-1 fusion proteins were utilized. ToLFP analyses revealed that anteriorly expressed NUC-1 digests apoptotic DNA in posterior blastomeres in a non-autonomous and secretion-dependent manner. Collectively, we demonstrate that the ToLFP method can be used to differentiate the locations of blastomeres where DNase II acts autonomously or non-autonomously in degrading apoptotic DNA.
Linear systems with hyperbolic zero dynamics admit output regulator rejecting unknown number of unknown sinusoids
Authors: Kim Hyungjong , Shim Hyungbo
Published: April 2015

This study presents an off‐the‐shelf error feedback controller that can completely rejects the sinusoidal disturbances whose magnitudes, phases, bias, frequencies and even the number of frequencies are all unknown. A closed‐form solution is given under the assumptions that the plant has no uncertainty and has hyperbolic zero dynamics (i.e. there is no zero on the imaginary axis of the complex plane), and that the number of unknown frequencies has upper bound which is known. A non‐minimum phase plant can be dealt with. The proposed controller is tested by a simulation, which verifies its effectiveness.
Utilising stored wind energy by hydro‐pumped storage to provide frequency support at high levels of wind energy penetration
Authors: Attya Ayman Bakry Taha , Hartkopf Thomas
Published: April 2015

Wind farms (WFs) contribution in frequency deviations curtailment is a grey area, especially when WFs replace large conventional generation capacities. This study offers an algorithm to integrate hydro‐pumped storage station (HPSS) to provide inertial and primary support, during frequency drops by utilising stored wind energy. However, wind turbines follow maximum power tracking, and do not apply frequency support methods, thus the wasted wind energy is mitigated. First, HPSS rated power and energy capacity are determined based on several givens, including wind speed and load characteristics. Thus, HPSS major aspects are estimated [e.g. pump(s), reservoir layout and generator(s)]. Second, offered algorithm coordinates energy storage, and releasing through several dynamic and static factors. HPSS output is continuously controlled through a timed approach to provide frequency support. A hypothetical system is inspired from Egyptian grid and real wind speed records at recommended locations to host WFs. Case studies examine the algorithm impact on frequency recovery, at 40% wind power penetration. The responses of thermal generation and HPSS are analysed to highlight the influence of tuning the parameters of the proposed algorithm. The assessment of several frequency metrics insures the positive role of HPSS in frequency drops curtailment. Simulation environments are MATLAB and Simulink.
Modulation and control of ac/dc matrix converter for battery energy storage application
Authors: Feng Bo , Lin Hua , Wang Xingwei
Published: April 2015

In this study, ac/dc matrix converter is applied in battery energy storage system (BESS). Aiming at reducing the dc current ripple and regulating the active and reactive power, modulation and control strategies are investigated in depth. First, a novel dc current ripple analysis approach using a geometric description of ripple vector locus is proposed. Then a simple optimal switching pattern with minimum dc current ripple under arbitrary power factor condition is developed and is compared with conventional switching patterns. On the basis of the characteristics of ac/dc matrix converter, a control scheme suitable for BESS is presented. The strategy can realise independent grid side active power control (battery charging/discharging control) and reactive power control. The simulation and experimental results verify the effectiveness of the proposed switching pattern and control strategy, and demonstrate the feasibility of applying ac/dc matrix converter in BESS.
Adaptive repetitive control with feedforward scheme for grid‐connected inverters
Authors: Abusara Mohammad , Sharkh Suleiman , Zanchetta Pericle
Published: April 2015

This study is concerned with control of grid connected inverters using odd‐harmonic repetitive scheme. Owing to the inherent long convergence period of repetitive control, a feedforward loop of the fundamental component of the grid voltage is used to make sure that the inverter's output current is bounded during the convergence period. The well‐known deficiency of repetitive control in rejecting harmonics when used with varying grid frequency has been solved by using an adaptive scheme in which the switching and sampling frequencies vary with respect to the grid frequency. The main qualities of the proposed controller are its effectiveness, simplicity and straightforwardness of implementation using a digital signal processor. Simulation and practical results are presented to demonstrate the controller capabilities.
Modified single‐carrier multilevel sinusoidal pulse width modulation for asymmetrical insulated gate bipolar transistor‐clamped grid‐connected inverter
Authors: Wu Fengjiang , Duan Jiandong , Feng Fan
Published: April 2015

Conventional sinusoidal pulse width modulation (SPWM) for single‐phase asymmetrical seven‐level insulated gate bipolar transistor (IGBT)‐clamped grid‐connected inverter (IC‐GCI) needs an additional logic operation circuit and a dead zone generation circuit, which raises cost and complicates the implementation. In addition, both added circuitries decrease the reliability. In this study, a modified single‐carrier multilevel SPWM (MSCM‐SPWM) scheme suitable for IC‐GCI is proposed. By setting one carrier, three digital signals to identify voltage zones and six equivalent modulation waves, the control signals of the switches in IC‐GCI can be generated with only one digital signal processor controller and simple logic operation. It makes the implementation of the multilevel GCI easier. The detailed spectral character of the MSCM‐SPWM is originally derived based on double‐Fourier integral theory and then compared with the conventional scheme. It proves that they own the similar spectral character. Detailed simulation and experimental results verify the accuracy and feasibility of the MSCM‐SPWM and the single‐phase IC‐GCI.
Magnetic Fe-Co films electroplated in a deep-eutectic-solvent-based plating bath
Authors: Yanai T. , Shiraishi K. , Watanabe Y. , Ohgai T. , Nakano M. , Suzuki K. , Fukunaga H.
Published: April 2015

We fabricated Fe-Co films from a deep eutectic solvent (DES)-based plating bath and investigated magnetic properties of the plated films. The plating baths were obtained by stirring the mixture of choline chloride, ethylene glycol, FeCl2·4H2O, and CoCl2·6H2O. The composition of the plated films depended on the amount of FeCl2·4H2O in the plating bath, and Fe content of the films was varied from 0 to 100 at. %. Depending on the Fe content, the saturation magnetization and the coercivity of the films varied. The Fe76Co24 film shows high saturation magnetization and smooth surface, and the change in the saturation magnetization shows good agreement with the expected change by the Slater-Pauling curve. High current efficiency (>90%) could be obtained in the wide film composition. From these results, we concluded that the DES-based plating bath is one of effective baths for the Fe-Co films with high current efficiency.
Multiple positive solutions for semilinear Schrödinger equations with critical growth in ℝN
Authors: Wang Jun , Lu Dianchen , Xu Junxiang , Zhang Fubao
Published: April 2015

In this paper, we study the existence, multiplicity, and concentration of positive solutions for the semilinear Schrödinger equation −ε2Δu+K(x)u=Q(x)up−2u+f(u),u∈H1(RN), where ε > 0 is a small parameter, N ≥ 3 and 2
 0 small, one is concentrating on the set of minimal points of K, another is concentrating on the sets of maximal points of Q. Second of all, we investigate the relation between the number of solutions and the topology of the set of the global minima (or maxima) of the potentials (K and Q) by the Ljusternik-Schnirelmann and theory minimax theorems. Finally, we obtain some sufficient conditions for the nonexistence of positive ground state solution.
Bio-inspired mechanics of highly sensitive stretchable graphene strain sensors
Authors: Wang Wen , Yang Tingting , Zhu Hongwei , Zheng Quanshui
Published: April 2015

Graphene woven fabrics (GWFs) can sense large strain up to 10% with the highest gauge factors (105) thus far reported. This result promises key applications particularly in sensing strains of soft materials such as biological tissues, but the mechanism of such super gauge factor (SGF) property was not very clear. Through a bio-inspired Voronoi polycrystalline micromechanics model together with experimental validations, we show that the successive cracking, the “fish-scale” like network structure of GWFs, and the superlubricity between overlapped graphene flakes play crucial roles resulting in the SGF property. We also reveal the influences of overlapping width, graphene strip size, Poisson's ratio of the substrate material, size effect, interfacial resistance, and network size to the SGF property. These results can guide the design of GWFs with desired sensing performance.
A study on thermal characteristics analysis model of high frequency switching transformer
Authors: Yoo Jin-Hyung , Jung Tae-Uk
Published: April 2015

Recently, interest has been shown in research on the module-integrated converter (MIC) in small-scale photovoltaic (PV) generation. In an MIC, the voltage boosting high frequency transformer should be designed to be compact in size and have high efficiency. In response to the need to satisfy these requirements, this paper presents a coupled electromagnetic analysis model of a transformer connected with a high frequency switching DC-DC converter circuit while considering thermal characteristics due to the copper and core losses. A design optimization procedure for high efficiency is also presented using this design analysis method, and it is verified by the experimental result.
Millimeter wave complementary metal–oxide–semiconductor on-chip hexagonal nano-ferrite circulator
Authors: Chao Liu , Oukacha Hassan , Fu Enjin , Koomson Valencia Joyner , Afsar Mohammed N.
Published: April 2015

Hexagonal ferrites such as M-type BaFe12O19 and SrFe12O19 have strong uniaxial anisotropic magnetic field and remanent magnetism. The nano-sized ferrite powder exhibits high compatibility and processability in composite material. New magnetic devices using the M-type ferrite materials can work in the tens of GHz frequency range from microwave to millimeter wave without the application of strong external magnetic field. The micro- and nano-sized hexagonal ferrite can be conveniently utilized to fabricate magnetic components integrated in CMOS integrated circuits as thin as several micrometers. The micro-fabrication method of such nano ferrite device is presented in this paper. A circulator working at 60 GHz is designed and integrated into the commercial CMOS process. The circulator exhibits distinct circulation properties in the frequency range from 56 GHz to 58 GHz.
Genetic evaluation of maternal behaviour and temperament in Australian sheep
Authors: Brown D. J. , Fogarty N. M. , Iker C. L. , Ferguson D. M. , Blache D. , Gaunt G. M.
Published: April 2015

The temperament of ewes and maternal behaviour at lambing has been implicated as contributing factors to lamb survival. Some 14 054 records of maternal behaviour score (MBS, 1 = good, 5 = poor) were collected at lamb tagging from 32 breeds of sheep over several years in a variety of environments. Records for two objectively scored temperament traits, flight time from a weighing crate (FT) and agitation score in an isolation box test (IBT) were available on 19 151 and 17 159 animals, respectively. These data were pooled from three sources, which included research and commercial ram breeding flocks. The combined data were also split into three subsets based on breed groups (Merino, Maternal and Terminal) for analyses. Records of weights and number of lambs weaned (NLW), as well as pedigree information was available from the national genetic evaluation database. The heritability estimates from the combined analyses were 0.20 ± 0.02 for MBS, 0.18 ± 0.02 for FT and 0.26 ± 0.02 for IBT, with a repeatability of 0.24 ± 0.01 for MBS. There were some small differences between the breed groups in the heritability estimates. The genetic correlations between FT and MBS were negative (favourable) and consistent across the datasets (–0.47 ± 0.12, combined analysis). The genetic correlations between IBT and MBS were positive (favourable) but not significant (0.12 ± 0.11, combined analysis). The genetic correlations between IBT and FT were also favourable, but small and generally not significant. There were small favourable genetic correlations between MBS and various bodyweights (–0.17 ± 0.07, yearling) and NLW (–0.25 ± 0.07). However, there were no significant genetic relationships between the temperament and production traits. The moderate heritability and repeatability of MBS indicate maternal behaviour could be improved by selection, and that it could be a useful additional trait in breeding programs for improved reproduction.
Sexual health, alcohol and the university environment: is there a need for sexual health promotion intervention?
Authors: Burns Sharyn
Published: April 2015

Background
Young university students participate in hazardous drinking and risky sexual health behaviours, however there are few comprehensive interventions targeting this group. Methods: Undergraduate university students aged 18–24 years (n = 2466) were recruited to complete an online survey to investigate the association between levels of alcohol consumption, gender and experienced, second-hand and witnessed sexual health behaviours and situations. Results: Male students and hazardous drinkers were most likely to participate in unprotected sex and regretted sex. Female students and hazardous drinkers were most likely to experience an unwanted sexual advance. Conclusions: Integrated and comprehensive interventions targeting young people in the university setting are needed.
A critique of Vihvelin’s Three-fold Classification
Authors: Mickelson Kristin
Published: April 2015

In this essay, I argue for the rejection of Vihvelin’s ‘Three-fold Classification’ (3-FC), a nonstandard taxonomy of free-will compatibilism, incompatibilism, and impossibilism. Vihvelin is right that the standard taxonomy of these views is inadequate, and that a new taxonomy is needed to clarify the free-will debate. Significantly, Vihvelin notes that the standard formal definition of ‘incompatibilism’ does not capture the historically popular view that deterministic laws pose a threat to free will. Vihvelin’s proposed solution is to redefine ‘incompatibilism.’ However, Vihvelin’s formal definition of ‘incompatibilism’ is flawed according to her own arguments. In addition, Vihvelin’s characterization of ‘compatibilism’ is (at best) incomplete, and at least two important free-will views are missing from her proposed taxonomy. Given the problems with Vihvelin’s arguments for 3-FC, her novel view of the dialectic between the major free-will views lacks support.
Harvesting the Beach Clam Tivela mactroides: Short- and Long-Term Dynamics
Authors: Denadai Márcia Regina , Pombo Maíra , Bernadochi Ligia Coletti , Turra Alexander
Published: April 2015

Small-scale fisheries are frequently overlooked for research and management, and their social and environmental impacts are often overlooked as well, preventing the implementation of appropriate actions for their sustainability. Additionally, the dynamics of beach clam fisheries and their importance for local communities are not well understood. A study on the population biology of the clam Tivela mactroides in Caraguatatuba Bay, southeastern Brazil, revealed intense harvesting of this resource by both residents and tourists. To assess the extent and dynamics of clamming, the number of harvesters was recorded during the course of the day in vacation and nonvacation periods throughout 2003–2005 and 2007–2008; the number of other beach users, weather conditions, and tide height were also recorded. The overall amount of clams harvested was estimated based on censuses of clammers and interviews to calculate the amount of clams harvested per collecting event. The intensity and dynamics of the harvesting activity varied on all the temporal scales evaluated. The estimated amount of clams harvested per year decreased from the first (24.6 kg/year) to the second (8.8 kg/year) group of sampling years, presumably due to clam mass-mortality events and smaller shell sizes in 2007–2008, although clam abundance increased enormously. Vacation periods (presence of tourists) influenced the number of harvesters and the daily dynamics of clamming activity, although this relationship was only evident during 2003–2004. The number of harvesters increased with the number of tourists, except in periods of very high tourist activity, when harvesting decreased. Clamming was more widespread during the day under high tourist activity but during nonvacation times was concentrated in morning low-tide periods. Weather had a partial influence on clamming, with harvesters absent only during intense rain occasions. The understanding of the dynamics of this Tivela mactroides fishery highlights key points for planning and implementing management measures, which will involve continuous monitoring of stocks, harvesting, and food safety.

Received February 4, 2014; accepted December 21, 2014
Targeting the late component of the cardiac L-type Ca2+ current to suppress early afterdepolarizations
Authors: Madhvani Roshni V. , Angelini Marina , Xie Yuanfang , Pantazis Antonios , Suriany Silvie , Borgstrom Nils P. , Garfinkel Alan , Qu Zhilin , Weiss James N. , Olcese Riccardo
Published: April 2015

Early afterdepolarizations (EADs) associated with prolongation of the cardiac action potential (AP) can create heterogeneity of repolarization and premature extrasystoles, triggering focal and reentrant arrhythmias. Because the L-type Ca2+ current (ICa,L) plays a key role in both AP prolongation and EAD formation, L-type Ca2+ channels (LTCCs) represent a promising therapeutic target to normalize AP duration (APD) and suppress EADs and their arrhythmogenic consequences. We used the dynamic-clamp technique to systematically explore how the biophysical properties of LTCCs could be modified to normalize APD and suppress EADs without impairing excitation–contraction coupling. Isolated rabbit ventricular myocytes were first exposed to H2O2 or moderate hypokalemia to induce EADs, after which their endogenous ICa,L was replaced by a virtual ICa,L with tunable parameters, in dynamic-clamp mode. We probed the sensitivity of EADs to changes in the (a) amplitude of the noninactivating pedestal current; (b) slope of voltage-dependent activation; (c) slope of voltage-dependent inactivation; (d) time constant of voltage-dependent activation; and (e) time constant of voltage-dependent inactivation. We found that reducing the amplitude of the noninactivating pedestal component of ICa,L effectively suppressed both H2O2- and hypokalemia-induced EADs and restored APD. These results, together with our previous work, demonstrate the potential of this hybrid experimental–computational approach to guide drug discovery or gene therapy strategies by identifying and targeting selective properties of LTCC.
Mechanism for phosphoinositide selectivity and activation of TRPV1 ion channels
Authors: Ufret-Vincenty Carmen A. , Klein Rebecca M. , Collins Marcus D. , Rosasco Mario G. , Martinez Gilbert Q. , Gordon Sharona E.
Published: April 2015

Although PI(4,5)P2 is believed to play an essential role in regulating the activity of numerous ion channels and transporters, the mechanisms by which it does so are unknown. Here, we used the ability of the TRPV1 ion channel to discriminate between PI(4,5)P2 and PI(4)P to localize the region of TRPV1 sequence that interacts directly with the phosphoinositide. We identified a point mutation in the proximal C-terminal region after the TRP box, R721A, that inverted the selectivity of TRPV1. Although the R721A mutation produced only a 30% increase in the EC50 for activation by PI(4,5)P2, it decreased the EC50 for activation by PI(4)P by more than two orders of magnitude. We used chemically induced and voltage-activated phosphatases to determine that PI(4)P continued to support TRPV1 activity even after depletion of PI(4,5)P2 from the plasma membrane. Our data cannot be explained by a purely electrostatic mechanism for interaction between the phosphoinositide and the protein, similar to that of the MARCKS (myristoylated alanine-rich C kinase substrate) effector domain or the EGF receptor. Rather, conversion of a PI(4,5)P2-selective channel to a PI(4)P-selective channel indicates that a structured phosphoinositide-binding site mediates the regulation of TRPV1 activity and that the amino acid at position 721 likely interacts directly with the moiety at the 5′ position of the phosphoinositide.
CaV1.2/CaV3.x channels mediate divergent vasomotor responses in human cerebral arteries
Authors: Harraz Osama F. , Visser Frank , Brett Suzanne E. , Goldman Daniel , Zechariah Anil , Hashad Ahmed M. , Menon Bijoy K. , Watson Tim , Starreveld Yves , Welsh Donald G.
Published: April 2015

The regulation of arterial tone is critical in the spatial and temporal control of cerebral blood flow. Voltage-gated Ca2+ (CaV) channels are key regulators of excitation–contraction coupling in arterial smooth muscle, and thereby of arterial tone. Although L- and T-type CaV channels have been identified in rodent smooth muscle, little is known about the expression and function of specific CaV subtypes in human arteries. Here, we determined which CaV subtypes are present in human cerebral arteries and defined their roles in determining arterial tone. Quantitative polymerase chain reaction and Western blot analysis, respectively, identified mRNA and protein for L- and T-type channels in smooth muscle of cerebral arteries harvested from patients undergoing resection surgery. Analogous to rodents, CaV1.2 (L-type) and CaV3.2 (T-type) α1 subunits were expressed in human cerebral arterial smooth muscle; intriguingly, the CaV3.1 (T-type) subtype present in rodents was replaced with a different T-type isoform, CaV3.3, in humans. Using established pharmacological and electrophysiological tools, we separated and characterized the unique profiles of Ca2+ channel subtypes. Pressurized vessel myography identified a key role for CaV1.2 and CaV3.3 channels in mediating cerebral arterial constriction, with the former and latter predominating at higher and lower intraluminal pressures, respectively. In contrast, CaV3.2 antagonized arterial tone through downstream regulation of the large-conductance Ca2+-activated K+ channel. Computational analysis indicated that each Ca2+ channel subtype will uniquely contribute to the dynamic regulation of cerebral blood flow. In conclusion, this study documents the expression of three distinct Ca2+ channel subtypes in human cerebral arteries and further shows how they act together to orchestrate arterial tone.
Role Played by Prx1‐Dependent Extracellular Matrix Properties in Vascular Smooth Muscle Development in Embryonic Lungs
Authors: Ihida‐Stansbury Kaori , Ames Juliana , Chokshi Mithil , Aiad Norman , Sanyal Sonali , Kawabata Kimihito C. , Levental Ilya , Sundararaghavan Harini G. , Burdick Jason A. , Janmey Paul , Miyazono Kohei , Wells Rebecca G. , Jones Peter L.
Published: April 2015

Although there are many studies focusing on the molecular pathways underlying lung vascular morphogenesis, the extracellular matrix (ECM)–dependent regulation of mesenchymal cell differentiation in vascular smooth muscle development needs better understanding. In this study, we demonstrate that the paired related homeobox gene transcription factor Prx1 maintains the elastic ECM properties, which are essential for vascular smooth muscle precursor cell differentiation. We have found that Prx1null mouse lungs exhibit defective vascular smooth muscle development, downregulated elastic ECM expression, and compromised transforming growth factor (TGF)–β localization and signaling. Further characterization of ECM properties using decellularized lung ECM scaffolds derived from Prx1 mice demonstrated that Prx1 is required to maintain lung ECM stiffness. The results of cell culture using stiffness‐controlled 2‐D and 3‐D synthetic substrates confirmed that Prx1‐dependent ECM stiffness is essential for promotion of smooth muscle precursor differentiation for effective TGF‐β stimulation. Supporting these results, both decellularized Prx1null lung ECM and Prx1WT (wild type) ECM scaffolds with blocked TGF‐β failed to support mesenchymal cell to 3‐D smooth muscle cell differentiation. These results suggest a novel ECM‐dependent regulatory pathway of lung vascular development wherein Prx1 regulates lung vascular smooth muscle precursor development by coordinating the ECM biophysical and biochemical properties.
Integrative analysis of RNA, translation and protein levels reveals distinct regulatory variation across humans
Authors: Cenik Can , Sarinay Cenik Elif , Byeon Gun W , Grubert Fabian , Candille Sophie I , Spacek Damek , Alsallakh Bilal , Tilgner Hagen , Araya Carlos L , Tang Hua , Ricci Emiliano , Snyder Michael P
Published: April 2015

Elucidating the consequences of genetic differences between humans is essential for understanding phenotypic diversity and personalized medicine. Although variation in RNA levels, transcription factor binding and chromatin have been explored, little is known about global variation in translation and its genetic determinants. We used ribosome profiling, RNA sequencing, and mass spectrometry to perform an integrated analysis in lymphoblastoid cell lines from a diverse group of individuals. We find significant differences in RNA, translation, and protein levels suggesting diverse mechanisms of personalized gene expression control. Combined analysis of RNA expression and ribosome occupancy improves the identification of individual protein level differences. Finally, we identify genetic differences that specifically modulate ribosome occupancy - many of these differences lie close to start codons and upstream ORFs. Our results reveal a new level of gene expression variation among humans and indicate that genetic variants can cause changes in protein levels through effects on translation.
Technology-sourcing investment abroad as an enhancer of Chinese MNEs’ innovative capabilities
Authors: Gugler Philippe , Vanoli Laura
Published: April 2015

Purpose

– The purpose of this paper is to focus on Chinese firms’ innovation processes that are induced by foreign direct investment abroad. The study uses a patent and citation analysis to examine the extent to which investments abroad contribute to enhancing these firms’ innovative capabilities. More specifically, this study focusses on the role of foreign location competitiveness as an asset to provide technological capabilities to Chinese affiliates.

Design/methodology/approach

– Patents are good indicators of firms’ innovative capabilities. Moreover, patents allow to track the inter-firm knowledge transfer through the citations of patents on which they are based. The authors use an OECD patent database called “OECD REGPAT July 2013” that compiles patents registered with the European Patent Office (EPO) over the period from 1986 to 2013. The authors focus the analysis on patents registered by Chinese multinational enterprises’ (MNEs) based in Europe because the authors assume inter alia that innovations patented by Chinese affiliates in Europe are registered with the EPO. The sample comprises 3,010 patents involving 5,749 citations that the authors have individually examined.

Findings

– The findings suggest that Chinese MNEs ability to generate innovation based on their own knowledge is low, with a self-citation rate of approximately 4 percent. Patents by Chinese MNEs are largely based on foreign patents, especially from developed economies (at least 90 percent). The citation analysis also suggests that 39.2 percent of citations represent domestic firms in the local recipient country. This subgroup of citations is categorized as follows: 1.04 percent are M&A linkages, 13.8 percent are cluster linkages, and 24.36 percent are localization linkages. The remaining 60.8 percent of the total sample demonstrates that firms do not necessarily need to be collocated in foreign locations with domestic firms to exchange assets.

Research limitations/implications

– Patent and citation analysis considers only a part of the inter-firm knowledge diffusion. Some innovations are not patented and tacit knowledge diffusion is not observable. Moreover, the analysis focusses only on Chinese outward foreign direct investment to Europe, but a large part of knowledge is accumulated in China thanks to inward foreign direct investment.

Originality/value

– Many scholars have scrutinized emerging markets multinational enterprises’ strategic asset-seeking investments abroad that are designed to upgrade the companies’ technological capabilities (Cui and Jiang, 2009; Zhang and Filippov, 2009; Huang and Wang, 2013; Amighiniet al., 2014; De Beuleet al., 2014; Nicolas, 2014). However, few studies analyze the results of these strategies in terms of innovation output.
Interorganizational network and innovation: a bibliometric study and proposed research agenda
Authors: Dagnino Giovanni Battista , Levanti Gabriella , Minà Anna , Picone Pasquale Massimo
Published: April 2015

Purpose

– This paper aims to explore the latent structure of the literature on interorganizational network and innovation as well as to map the main themes and empirical advances in this research stream.

Design/methodology/approach

– Using bibliometric coupling, the authors analyze the citation patterns in 67 management studies regarding innovation networks, published in ISI-journals from January 1996 to October 2012.

Findings

– The authors identify the conceptual orientations that studies share. Bibliometric analysis allows us to draw an overview of how this field of research has developed, recognizing in essence six main clustered research themes: networks as a framework that sustains firm innovativeness in specific contexts; network dimensions and knowledge processes; networks as a means to access and share resources/knowledge; the interplay between firm and network characteristics and its effects on innovative processes; empirical research on networks in highly dynamic industries; and the influence of industry knowledge domain’s peculiarities on network dimensions and characteristics.

Research limitations/implications

– By providing a comprehensive survey of current trends in the literature on interorganizational network and innovation, the authors eventually identify the major gaps in our knowledge and help refocusing the current research agenda in this increasingly relevant research stream.

Practical implications

– The systematic introduction to the field of innovation networks is of notable interest to scholars and practitioners, who have (or desire to have) some awareness in the topic. Here, practitioners may find their compass to acquire some knowledge on innovation networks and orient their choices.

Originality/value

– First, the spatially organized picture of the intellectual structure of the literature the authors offer is the initial thought-out comprehensive introduction to the field of on interorganizational network and innovation. Second, by developing a thorough bibliometric analysis of the extant bulk of the innovation networks literature, the authors develop specific methodological contribution. Third, we are able to map the intellectual structure in a two-dimensional space to visualize spatial distances between intellectual themes.
Innovative and networked business functions: customer-driven procurement
Authors: Tunisini Annalisa , Sebastiani Roberta
Published: April 2015

Purpose

– This paper aims to highlight the evolving and articulated role of purchasing as a “mediator” between the company’s customers and suppliers, thus showing the opportunities connected to the evolution of purchasing from a business function to a strategic business for companies.

Design/methodology/approach

– The paper reports on an in-depth analysis to investigate the case of IBM, which turned to the offering of services to transform itself from a pure product manufacturer into an outstanding service provider.

Findings

– The paper shows that as the company’s business strategy becomes focused on client value, its success is strongly dependent on the development of a customer-driven procurement. The evolution of the role of procurement is accompanied by the growing integration between the company’s procurement and sales functions, as well as by the growing interconnection and interaction between the procurement function and the company’s clients.

Originality/value

– The paper applies the conceptual approach and theoretical tools connected to servitization and procurement development processes to an innovative case study. The results make possible original suggestions both for literatures and management practices.
Knowledge transfer between actors in the innovation system: a study of higher education institutions (HEIS) and SMES
Authors: Corral de Zubielqui Graciela , Jones Janice , Seet Pi-Shen , Lindsay Noel
Published: April 2015

Purpose

– The purpose of this paper is to understand how and why small to medium enterprises (SMEs) access knowledge from external actors in general and from higher education institutions (HEIs) in particular and what is the extent to which these knowledge access pathways affect SME innovativeness.

Design/methodology/approach

– The paper involved both quantitative and qualitative approaches: a survey of 1,226 SMEs and a mini case study to follow-up on issues arising from the survey analysis. Survey data were analysed using both non-parametric and multivariate Poisson regression analysis. The case study was based on a medium-sized manufacturing firm in South Australia.

Findings

– While there are significant differences between the micro-, small- and medium-sized enterprises, the evidence suggests that SMEs generally use “generic” university–industry knowledge transfer pathways (e.g. published research results) rather than university–industry links with high “relational” involvement. More significantly, the results indicate that SMEs are more likely to rely on organisations other than universities and related R&D enterprises for knowledge acquisition like clients/customers or suppliers. While collaboration is most likely to occur within the same state/territory, or Australia, many SMEs also collaborate internationally, usually as part of normal supplier–customer relationships, reinforcing knowledge acquisition from organisationally proximate partners. These findings are also supported by the case study.

Research limitations/implications

– This research was limited to surveying SMEs in one geographic (metropolitan) region in Australia. It also does not account for the different patterns of HEI–SME interactions in different industry sectors. There is also only one case study.

Originality/value

– First, the research adds to the few field studies that have investigated accessing knowledge for innovation among SMEs. Specifically, the research contributes to an understanding of the heterogeneous roles that different actors play in facilitating knowledge access for improving innovative SMEs outcomes. Second, the research does not treat all SMEs similarly in terms of size effects but instead accounts for differing SME sizes and how this affects their selection of knowledge access pathways. Third, the research contributes to a small number of studies that attempt to understand how HEIs and SMEs can work better together in the context of a regional innovation system, especially one that is relatively less competitive to the larger economy.
Drivers of institutional innovation in networks: unleashing the innovation potential of domesticated markets
Authors: Van Bockhaven Wouter MG , Matthyssens Paul , Vandenbempt Koen
Published: April 2015

Purpose

– This paper aims to apply innovation networks (INs) theory to the context of domesticated markets, where innovation triggers deinstitutionalization. In such contexts, the success of INs depends on their capacity to transform the business field in which they are embedded, so that it accommodates innovative business models. Such “institutional INs” beget a meso-level finality, and this poses different requirement on their effectiveness. The purpose of this paper is to confront extant models of collaborative innovation in networks with this specific context to offer exploratory insights into how innovation can be achieved in domesticated contexts and what the differential implications are for network configurations and strategic “reinstitutionalization” practices.

Design/methodology/approach

– Based on an illustrative embedded case study in the Dutch steel industry, a framework offering indications on the effectiveness of discrete configurational dimensions and their fit with reinstitutionalization practices for institutional INs is suggested. The case builds on 26 semi-structured interviews and 4 focus groups with top managers in the industry. As the aim is to extend theoretical models of INs to this under-researched context, an abductive approach to theorizing, consistent with the extended case method, is adopted.

Findings

– Findings suggest that collaborating to redesign an institutionalized business field collectively implies a more explicit attention to interdependencies within the business field.

Practical implications

– Besides suggesting modifications to extant frames regarding heterogeneity in and the configuration of networks, this paper has some practical implications. The framework proposed offers managers some support in the largely ignored issue of developing a collective action network. With these findings, we aspire to stimulate further research into this relevant, yet underdeveloped, topic.

Originality/value

– The study extends IN theory toward innovation realization in domesticated contexts. In such contexts, IN’s success depends on their capacity to transform the business field in which they are embedded, so that it enables innovative ways of creating end-customer value. Besides suggesting a new area for theorizing about innovation networks, institutional innovation networks are also a useful template for institutional innovation and collective action research. The paper offers a framework to support managers in the largely ignored challenge of developing a collective action network. In an increasingly transparent, connected and consolidated business environment, such a challenge becomes ever more essential.