bluuebunny/crossref_metadata_2025 huggingface dataset:
Orbital free DFT versus single density equation: a perspective through quantum domain behavior of a classically chaotic system
Authors: Chakraborty Debdutta , Kar Susmita , Chattaraj Pratim Kumar
Published: May 2015

Regular to chaotic transition takes place in a driven van der Pol oscillator in both classical and quantum domains.
Surface plasmons in quantum-sized noble-metal clusters: TDDFT quantum calculations and the classical picture of charge oscillations
Authors: Weissker Hans-Christian , López-Lozano Xóchitl
Published: May 2015

The dynamics of the electronic density corresponds to a collective charge oscillation, albeit influenced by the inhomogeneity of noble metals.
Like-charge ion pairs of hydronium and hydroxide in aqueous solution?
Authors: Ghosh Manik Kumer , Choi Tae Hoon , Choi Cheol Ho
Published: May 2015

Hydroxide can form stronger like-ion pairs than hydronium in aqueous solution mostly due to its versatile coordination ability with solvents.
Adsorption of choline benzoate ionic liquid on graphene, silicene, germanene and boron-nitride nanosheets: a DFT perspective
Authors: García Gregorio , Atilhan Mert , Aparicio Santiago
Published: May 2015

This work assesses the adsorption of choline benzoate ionic liquid on the surface of different nanosheets through DFT simulations.
Assembly of near infra-red emitting upconverting nanoparticles and multiple Gd(iii)-chelates as a potential bimodal contrast agent for MRI and optical imaging
Authors: Carron Sophie , Li Qiang Ying , Vander Elst Luce , Muller Robert N. , Parac-Vogt Tatjana N. , Capobianco John A.
Published: May 2015

Linking multiple paramagnetic Gd(iii)-DO3A chelates to the surface of NaGdF4:Yb3+,Tm3+upconverting nanoparticles resulted in an assembly that has favorable properties for MRI and OI.
Utilization of mixtures of aromatic N-donor ligands of different coordination ability for the solvothermal synthesis of thiostannate containing molecules
Authors: Hilbert J. , Näther C. , Bensch W.
Published: May 2015

Combination of strong/medium or strong/weak coordinating aromatic N-donor ligands under solvothermal conditions leads to the formation of two new compounds stabilizedviaπ–π-interactions.
Stigmasterol protects against Ang II-induced proliferation of the A7r5 aortic smooth muscle cell-line
Authors: Li Chunmei , Liu Yang , Xie Zhe , Lu Qun , Luo Shaohong
Published: May 2015

Excessive proliferation of vascular smooth muscle cells is a crucial event in the pathogenesis of several cardiovascular diseases, including atherosclerosis and restenosis.
CO2, COS and CS2 adducts of N-heterocyclic olefins and their application as organocatalysts for carbon dioxide fixation
Authors: Wang Yan-Bo , Sun Dong-Sheng , Zhou Hui , Zhang Wen-Zhen , Lu Xiao-Bing
Published: May 2015

Various CO2, COS and CS2 adducts of N-heterocyclic olefins (NHOs) were synthesized and characterised by single crystal X-ray crystallography.
Direct analysis of plant leaves by EDXRF and LIBS: microsampling strategies and cross-validation
Authors: Bueno Guerra Marcelo Braga , Adame Andressa , de Almeida Eduardo , Arantes de Carvalho Gabriel Gustinelli , Stolf Brasil Marcos Augusto , Santos Jr Dário , Krug Francisco José
Published: May 2015

A novel strategy for direct analysis of dried leaves by EDXRF and LIBS aiming at plant nutrition diagnosis.
Ultrastrong composites from dopamine modified-polymer-infiltrated colloidal crystals
Authors: Liaqat F. , Tahir M. N. , Huesmann H. , Daniel P. , Kappl M. , Auernhammer G. K. , Schneider D. , Lieberwirth I. , Char K. , Fytas G. , Butt H.-J. , Tremel W.
Published: May 2015

Multilayered nanocomposites containing iron oxide nanoparticles, strongly cemented together through a dopamine modified polymer, exhibit high resistance against elastic and plastic deformation with a Young's modulus of 17 GPa and a hardness of 1.3 GPa.
New insight into high-temperature driven morphology reliant CoMoO4 flexible supercapacitors
Authors: Candler John , Elmore Tyler , Gupta Bipin Kumar , Dong Lifeng , Palchoudhury Soubantika , Gupta Ram K.
Published: May 2015

The next generation of flexible energy storage devices based on CoMoO4 for high-temperature applications were fabricated and tested.
Characterization and behaviour of ZnO-based nanocomposites designed for the control of biodeterioration of patrimonial stoneworks
Authors: Ditaranto Nicoletta , van der Werf Inez Dorothé , Picca Rosaria Anna , Sportelli Maria Chiara , Giannossa Lorena Carla , Bonerba Elisabetta , Tantillo Giuseppina , Sabbatini Luigia
Published: May 2015

Bioactive ZnO nanoparticles embedded in polymer matrices are able to exert a marked biological activity without changing their consolidant/water-repellent properties.
Truce–Smiles rearrangement of substituted phenyl ethers
Authors: Kosowan Joel R. , W'Giorgis Zemane , Grewal Ravneet , Wood Tabitha E.
Published: May 2015

This study of the Truce–Smiles rearrangement has revealed interesting tandem reactions, unprecedented systematic substituent effects, and new mechanistic insight.
A new role of curcumin: as a multicolor photoinitiator for polymer fabrication under household UV to red LED bulbs
Authors: Zhao Jiacheng , Lalevée Jacques , Lu Hongxu , MacQueen Rowan , Kable Scott H. , Schmidt Timothy W. , Stenzel Martina H. , Xiao Pu
Published: May 2015

Curcumin can act as a multicolor photoinitiator in free radical photopolymerization under air upon exposure to household LED bulbs.
Organotin carboxylate catalyst in urethane formation in a polar solvent: an experimental and computational study
Authors: Devendra Ransi , Edmonds Neil R. , Söhnel Tilo
Published: May 2015

Organotin carboxylates catalyse aliphatic urethane reaction in polar solvents through an O-coordinated mechanism by forming an alkoxy derivative.
Au@Pd core–shell nanoparticles-decorated reduced graphene oxide: a highly sensitive and selective platform for electrochemical detection of hydrazine
Authors: Dutta Soumen , Ray Chaiti , Mallick Sourav , Sarkar Sougata , Roy Anindita , Pal Tarasankar
Published: May 2015

An Aucore–Pdshell-decorated reduced graphene oxide nanocomposite is successfully employed for the electrochemical detection of low-level hydrazine in an aqueous solution.
Configurable plasmonic substrates from heat-driven imprint-transferred Ag nanopatterns for enhanced photoluminescence
Authors: Jung Yeon-Ho , Sung Sang-Keun , Lee Kyung-Min , Surabhi Srivathsava , Jeong Jun-Ho , Lee Eung-sug , Choi Jun-Hyuk , Jeong Jong-Ryul
Published: May 2015

Despite substantial progress in metal nanopatterning, fabricating ultra-large-area plasmonic substrates with well-defined and well-controlled nanopatterned arrays remains a major technological challenge.
Obtaining a novel crystalline/amorphous core/shell structure in barium titanate nanocrystals by an innovative one-step approach
Authors: Ashiri Rouholah
Published: May 2015

The schematic illustration showing the formation mechanism of BTO crystalline/amorphous core/shell nanocrystals induced by ultrasonication.
Pyrazoline derivatives with a tailored third order nonlinear optical response
Authors: Papagiannouli I. , Szukalski A. , Iliopoulos K. , Mysliwiec J. , Couris S. , Sahraoui B.
Published: May 2015

In the present work the third order nonlinear optical response of a series of pyrazoline derivatives has been experimentally investigated.
LaF3-coated Li[Li0.2Mn0.56Ni0.16Co0.08]O2 as cathode material with improved electrochemical performance for lithium ion batteries
Authors: Xie Qingliang , Hu Zhibiao , Zhao Chenhao , Zhang Shuirong , Liu Kaiyu
Published: May 2015

The LaF3-coated Li1.2Mn0.56Ni0.16Co0.08O2, compared with pristine Li1.2Mn0.56Ni0.16Co0.08O2, exhibits an enormous improvement in the initial coulombic efficiency and rate capability.
Free oxoanion theory for BaMgAl10O17:Eu2+ structure decomposition during alkaline fusion process
Authors: Liu Yifan , Zhang Shengen , Liu Hu , Pan De'an , Liu Bo , Volinsky Alex A. , Chang Cheinchi
Published: May 2015

Free Oxoanion theory (FOAT) was put forward to elucidate the blue phosphor (BaMgAl10O17:Eu2+) structure decomposition during the alkaline fusion process.
Performance evaluation of phosphite NaCo(H2PO3)3·H2O as a corrosion inhibitor for aluminum in engine coolant solutions
Authors: Deyab M. A. , Essehli R. , El Bali B.
Published: May 2015

The inhibiting action of a novel inorganic compound (NaCo(H2PO3)3·H2O) (NaCoPh) synthesized in our laboratory on the corrosion of aluminum in engine coolant solutions has been studied.
Stereoselective synthesis of 3-amino-2-oxindoles from isatin imines: new scaffolds for bioactivity evaluation
Authors: Kaur Jasneet , Chimni Swapandeep Singh , Mahajan Suhel , Kumar Akshay
Published: May 2015

3-Substituted-3-aminooxindole motifs constitute the core structure of a number of natural products and drug candidates.
A new mechanistic insight on β-lactam systems formation from 5-nitroisoxazolidines
Authors: Jasiński Radomir
Published: May 2015

DFT calculations at various theory levels unequivocally show that conversion of 5-nitroisoxazolidines into β-lactams does not take place via a ring opening step (as hitherto suggested), but takes place according to a three-step, domino-type reaction.
Fabrication of high power LiNi0.5Mn1.5O4battery cathodes by nanostructuring of electrode materials
Authors: Kiani Mohammad A. , Rahmanifar Mohammad S. , El-Kady Maher F. , Kaner Richard B. , Mousavi Mir F.
Published: May 2015

Using nanoparticles, instead of microparticles, as active electrode materials in lithium ion batteries could provide a solution to slow charging rates due to long ion diffusion pathways in conventional bulk materials.
Synthesis of 2,3-disubstituted thiophenes from 2-aryl-3-nitro-cyclopropane-1,1-dicarboxylates and 1,4-dithiane-2,5-diol
Authors: Selvi Thangavel , Vanmathi Govindhraj , Srinivasan Kannupal
Published: May 2015

A two-step synthesis of 2,3-disubstituted thiophenes fromtrans-2-aryl-3-nitrocyclopropane-1,1-dicarboxylates and 1,4-dithiane-2,5-diol is described.
Consecutive C–F bond activation and C–F bond formation of heteroaromatics at rhodium: the peculiar role of FSi(OEt)3
Authors: Raza A. L. , Braun T.
Published: May 2015

C–F activation reactions for a silyl complex gave fluorosilane and Rh pyridyl complexes. In consecutive reactions, the fluorosilane can act as a fluoride source and a regeneration of the C–F bond occurs by Si–F bond cleavage. This sets back the C–F bond cleavage reaction with consequences for the overall chemoselectivity of the activation reactions.
Graphene related magnetic materials: micromechanical exfoliation of 2D layered magnets based on bimetallic anilate complexes with inserted [FeIII(acac2-trien)]+ and [FeIII(sal2-trien)]+ molecules
Authors: Abhervé Alexandre , Mañas-Valero Samuel , Clemente-León Miguel , Coronado Eugenio
Published: May 2015

The Scotch tape method has been used for the exfoliation of layered coordination compounds formed by a 2D bimetallic anilate-based anionic network and Fe(iii) cationic complexes placed between or within the layers.
The AT-Hook motif as a versatile minor groove anchor for promoting DNA binding of transcription factor fragments
Authors: Rodríguez Jéssica , Mosquera Jesús , Couceiro Jose R. , Vázquez M. Eugenio , Mascareñas José L.
Published: May 2015

We report the development of chimeric DNA binding peptides comprising a DNA binding fragment of natural transcription factors (the basic region of a bZIP protein or a monomeric zinc finger module) and an AT-Hook peptide motif.
Formulation and preparation of stable cross-linked alginate–zinc nanoparticles in the presence of a monovalent salt
Authors: Pistone Sara , Qoragllu Dafina , Smistad Gro , Hiorth Marianne
Published: May 2015

Stable alginate nanoparticles have been prepared for the first time by ionic cross-linking with a divalent cation through a simple one-step method. The mechanism of formation was identified.
Size-exclusive and coordination-induced selective dye adsorption in a nanotubular metal–organic framework
Authors: Han Yi , Sheng Shunan , Yang Fan , Xie Yabo , Zhao Minjian , Li Jian-Rong
Published: May 2015

A nanotubular MOF, BUT-51, performs coordination-induced selective dye adsorption, which changes its stability and porosity to give a robust partner.
Facile synthesis of PdNi nanowire networks supported on reduced graphene oxide with enhanced catalytic performance for formic acid oxidation
Authors: Bin Duan , Yang Beibei , Ren Fangfang , Zhang Ke , Yang Ping , Du Yukou
Published: May 2015

The as-prepared PdNi nanowire networks/RGO catalysts exhibited efficiently the electrocatalytic activity and stability for formic acid oxidation.
Carbonaceous photonic crystals as ultralong cycling anodes for lithium and sodium batteries
Authors: Lv Weiming , Zhao Jing , Wen Fusheng , Xiang Jianyong , Li Lei , Wang Limin , Liu Zhongyuan , Tian Yongjun
Published: May 2015

Via carbonization of butterfly wings, carbonaceous photonic crystals (CPCs) were derived as anode materials for lithium and sodium ion batteries (LIB and NIB) with ultralong cycling stability.
A high-capacity Li-ion/Li–oxygen hybrid cathode
Authors: Wang Duo , Shen Yue , Hong Kunlei , Huang Qiuan , Huang Yunhui
Published: May 2015

The capacity of a conventional LiCoO2 cathode is greatly enhanced by the Li–oxygen mechanism.
An innovative 3-D nanoforest heterostructure made of polypyrrole coated silicon nanotrees for new high performance hybrid micro-supercapacitors
Authors: Aradilla David , Gaboriau Dorian , Bidan Gérard , Gentile Pascal , Boniface Maxime , Dubal Deepak , Gómez-Romero Pedro , Wimberg Jan , Schubert Thomas J. S. , Sadki Saïd
Published: May 2015

A micro-supercapacitor electrode made of polypyrrole coated silicon nanotrees.
Bioactive saccharide-conjugated polypeptide micelles for acid-triggered doxorubicin delivery
Authors: Wang Steven S.-S. , How Su-Chun , Chen Yun-Duan , Tsai Ya-Hui , Jan Jeng-Shiung
Published: May 2015

Cell-targeted, pH-sensitive saccharide-conjugated micelles exhibiting higher cell uptake led to higher drug release and cytotoxicity under pH-sensitive conditions.
Positive charge of “sticky” peptides and proteins impedes release from negatively charged PLGA matrices
Authors: Balmert Stephen C. , Zmolek Andrew C. , Glowacki Andrew J. , Knab Timothy D. , Rothstein Sam N. , Wokpetah Joseph M. , Fedorchak Morgan V. , Little Steven R.
Published: May 2015

Release kinetics of biomolecules (agents) encapsulated in negatively charged PLGA matrices are slowed by positive charge on the agents.
Synthesis and characterization of arylamino end-capped silafluorenes for blue to deep-blue organic light-emitting diodes (OLEDs)
Authors: Chen Shao Fu , Tian Yuan , Peng Jinghong , Zhang Huarong , Feng Xin Jiang , Zhang Haixia , Xu Xinjun , Li Lidong , Gao Jianhua
Published: May 2015

Silafluorene derivatives are designed for blue OLEDs and tunable efficiencies are investigated using end-capped arylamino groups and substituent groups on the silicon atom.
Di-amidosils with tunable structure, morphology and emission quantum yield: the role of hydrogen bonding
Authors: Nunes S. C. , Hümmer J. , Freitas V. T. , Ferreira R. A. S. , Carlos L. D. , Almeida P. , de Zea Bermudez V.
Published: May 2015

Di-amidosil hybrids with variable structure, morphology and photoluminescence properties were obtained using different experimental conditions. A correlation between the emission quantum yield value and the degree of order of the amide–amide hydrogen-bonded array was established for mono- and di-amidosils.
Production of centimeter-scale sub-wavelength nanopatterns by controlling the light path of adhesive photomasks
Authors: Wu Jin , Tao Kai , Miao Jianmin
Published: May 2015

Centimeter-scale sub-wavelength metal and molecular nanopatterns are generated by manipulating the light paths of adhesive polymer based photomasks.
Post-transcriptional regulation of gene expression by Unr
Authors: Ray Swagat , Catnaigh Pól Ó , Anderson Emma C.
Published: May 2015

Unr (upstream of N-ras) is a eukaryotic RNA-binding protein that has a number of roles in the post-transcriptional regulation of gene expression. Originally identified as an activator of internal initiation of picornavirus translation, it has since been shown to act as an activator and inhibitor of cellular translation and as a positive and negative regulator of mRNA stability, regulating cellular processes such as mitosis and apoptosis. The different post-transcriptional functions of Unr depend on the identity of its mRNA and protein partners and can vary with cell type and changing cellular conditions. Recent high-throughput analyses of RNA–protein interactions indicate that Unr binds to a large subset of cellular mRNAs, suggesting that Unr may play a wider role in translational responses to cellular signals than previously thought.
Novel signalling mechanism and clinical applications of sperm-specific PLCζ
Authors: Nomikos Michail
Published: May 2015

Egg activation is the first step of embryonic development and in mammals is triggered by a series of cytoplasmic calcium (Ca2+) oscillations. Sperm–egg fusion initiates these Ca2+ oscillations by introducing a sperm-specific protein factor into the egg cytoplasm. Substantial evidence indicates that this protein is a sperm-specific phospholipase C (PLC), termed PLC-zeta (PLCζ). PLCζ stimulates cytoplasmic Ca2+ oscillations matching those at fertilization triggering early embryonic development in several mammalian species. Structurally, PLCζ is comprised of four EF-hands, a C2 domain, and X and Y catalytic domains. PLCζ is an unusual PLC since it lacks a pleckstrin homology (PH) domain. It is also distinctive in that its X–Y linker is not involved in auto-inhibition of catalytic activity, but instead binds to phosphatidylinositol 4,5-bisphosphate (PIP2). Moreover, relative to other PLC isoforms, PLCζ possesses unique potency in stimulating Ca2+ oscillations in eggs, although it does not appear to bind to plasma membrane PIP2. In contrast, PLCζ appears to interact with intracellular vesicles in eggs that contain PIP2. I discuss the recent advances in our knowledge of the intriguing biochemical and physiological properties of sperm PLCζ and postulate potential roles for PLCζ in terms of clinical diagnosis and therapy for certain forms of male infertility.
Pulmonary vein sleeve cell excitation–contraction-coupling becomes dysynchronized by spontaneous calcium transients
Authors: Rietdorf Katja , Masoud Said , McDonald Fraser , Sanderson Michael J. , Bootman Martin D.
Published: May 2015

Atrial fibrillation (AF) is the most common form of sustained cardiac arrhythmia. Substantial evidence indicates that cardiomyocytes located in the pulmonary veins [pulmonary vein sleeve cells (PVCs)] cause AF by generating ectopic electrical activity. Electrical ablation, isolating PVCs from their left atrial junctions, is a major treatment for AF. In small rodents, the sleeve of PVCs extends deep inside the lungs and is present in lung slices. Here we present data, using the lung slice preparation, characterizing how spontaneous Ca2+ transients in PVCs affect their capability to respond to electrical pacing. Immediately after a spontaneous Ca2+ transient the cell is in a refractory period and it cannot respond to electrical stimulation. Consequently, we observe that the higher the level of spontaneous activity in an individual PVC, the less likely it is that this PVC responds to electrical field stimulation. The spontaneous activity of neighbouring PVCs can be different from each other. Heterogeneity in the Ca2+ signalling of cells and in their responsiveness to electrical stimuli are known pro-arrhythmic events. The tendency of PVCs to show spontaneous Ca2+ transients and spontaneous action potentials (APs) underlies their potential to cause AF.
Alterations in late endocytic trafficking related to the pathobiology of LRRK2-linked Parkinson's disease
Authors: Rivero-Ríos Pilar , Gómez-Suaga Patricia , Fernández Belén , Madero-Pérez Jesús , Schwab Andrew J. , Ebert Allison D. , Hilfiker Sabine
Published: May 2015

Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene comprise the most common cause of familial Parkinson's disease (PD), and variants increase the risk for sporadic PD. LRRK2 displays kinase and GTPase activity, and altered catalytic activity correlates with neurotoxicity, making LRRK2 a promising therapeutic target. Despite the importance of LRRK2 for disease pathogenesis, its normal cellular function, and the mechanism(s) by which pathogenic mutations cause neurodegeneration remain unclear. LRRK2 seems to regulate a variety of intracellular vesicular trafficking events to and from the late endosome in a manner dependent on various Rab proteins. At least some of those events are further regulated by LRRK2 in a manner dependent on two-pore channels (TPCs). TPCs are ionic channels localized to distinct endosomal structures and can cause localized calcium release from those acidic stores, with downstream effects on vesicular trafficking. Here, we review current knowledge about the link between LRRK2, TPC- and Rab-mediated vesicular trafficking to and from the late endosome, highlighting a possible cross-talk between endolysosomal calcium stores and Rab proteins underlying pathomechanism(s) in LRRK2-related PD.
Determining the geometry of oligomers of the human epidermal growth factor family on cells with <10 nm resolution
Authors: Needham Sarah R. , Zanetti-Domingues Laura C. , Scherer Kathrin M. , Hirsch Michael , Rolfe Daniel J. , Roberts Selene K. , Martin-Fernandez Marisa L. , Clarke David T. , Tynan Christopher J.
Published: May 2015

There is a limited range of methods available to characterize macromolecular organization in cells on length scales from 5–50 nm. We review methods currently available and show the latest results from a new single-molecule localization-based method, fluorophore localization imaging with photobleaching (FLImP), using the epidermal growth factor (EGF) receptor (EGFR) as an example system. Our measurements show that FLImP is capable of achieving spatial resolution in the order of 6 nm.
Regulation and roles of elongation factor 2 kinase
Authors: Proud Christopher G.
Published: May 2015

Eukaryotic elongation factor 2 kinase (eEF2K) belongs to the small family of atypical protein kinases termed α-kinases, and is the only calcium/calmodulin (Ca/CaM)-dependent member of that group. It phosphorylates and inactivates eEF2, to slow down the rate of elongation, the stage in mRNA translation that consumes almost all the energy and amino acids consumed by protein synthesis. In addition to activation by Ca/CaM, eEF2K is also regulated by an array of other regulatory inputs, which include inhibition by the nutrient- and growth-factor activated signalling pathways. Recent evidence shows that eEF2K plays an important role in learning and memory, processes that require the synthesis of new proteins and involve Ca-mediated signalling. eEF2K is activated under conditions of nutrient and energy depletion. In cancer cells, or certain tumours, eEF2K exerts cytoprotective effects, which probably reflect its ability to inhibit protein synthesis, and nutrient consumption, under starvation conditions. eEF2K is being evaluated as a potential therapeutic target in cancer.
Electrical consequences of cardiac myocyte: fibroblast coupling
Authors: McArthur Lisa , Chilton Lisa , Smith Godfrey L. , Nicklin Stuart A.
Published: May 2015

Gap junctions are channels which allow electrical signals to propagate through the heart from the sinoatrial node and through the atria, conduction system and onwards to the ventricles, and hence are essential for co-ordinated cardiac contraction. Twelve connexin (Cx) proteins make up one gap junction channel, of which there are three main subtypes in the heart; Cx40, Cx43 and Cx45. In the cardiac myocyte, gap junctions are present mainly at the intercalated discs between neighbouring myocytes, and assist in rapid electrical conduction throughout the ventricular myocardium. Fibroblasts provide the structural skeleton of the myocardium and fibroblast numbers significantly increase in heart disease. Fibroblasts also express connexins and this may facilitate heterocellular electrical coupling between myocytes and fibroblasts in the setting of cardiac disease. Interestingly, cardiac fibroblasts have been demonstrated to increase Cx43 expression in experimental models of myocardial infarction and functional gap junctions between myocytes and fibroblasts have been reported. Therefore, in the setting of heart disease enhanced cardiac myocyte: fibroblast coupling may influence the electrical activity of the myocyte and contribute to arrhythmias.
Regulation of Pannexin-1 channel activity
Authors: Taylor Kirk A. , Wright Joy R. , Mahaut-Smith Martyn P.
Published: May 2015

Pannexin-1 (Panx1) forms anion-selective channels with a permeability up to 1 kDa and represents a pathway for the release of cytosolic ATP. Several structurally similar connexin (Cx) proteins have been identified in platelets and shown to play roles in haemostasis and thrombosis. More recently, functional Panx1 channels have been demonstrated on the surface of human platelets [Taylor et al. (2014) J. Thromb. Haemost. 12, 987–998]. Since their identification in the year 2000, several mechanisms have been reported to activate Panx1 channels, including mechanical stimulation, oxygen-glucose deprivation, a rise of [Ca2+]i, caspase cleavage and phosphorylation. Within this review, the regulation of Panx1 channels is discussed, with a focus on how they may contribute to platelet function.
To beat or not to beat: degradation of Cx43 imposes the heart rhythm
Authors: Martins-Marques Tânia , Catarino Steve , Marques Carla , Pereira Paulo , Girão Henrique
Published: May 2015

The main function of the heart is to pump blood to the different parts of the organism, a task that is efficiently accomplished through proper electric and metabolic coupling between cardiac cells, ensured by gap junctions (GJ). Cardiomyocytes are the major cell population in the heart, and as cells with low mitotic activity, are highly dependent upon mechanisms of protein degradation. In the heart, both the ubiquitin-proteasome system (UPS) and autophagy participate in the fine-tune regulation of cardiac remodelling and function, either in physiological or pathological conditions. Indeed, besides controlling cardiac signalling pathways, UPS and autophagy have been implicated in the turnover of several myocardial proteins. Degradation of Cx43, the major ventricular GJ protein, has been associated to up-regulation of autophagy at the onset of heart ischemia and ischemia/reperfusion (I/R), which can have profound implications upon cardiac function. In this review, we present recent studies devoted to the involvement of autophagy and UPS in heart homoeostasis, with a particular focus on GJ.
Control of translation in the cold: implications for therapeutic hypothermia
Authors: Knight John R.P. , Willis Anne E.
Published: May 2015

Controlled whole-body cooling has been used since the 1950s to protect the brain from injury where cerebral blood flow is reduced. Therapeutic hypothermia has been used successfully during heart surgery, following cardiac arrest and with varied success in other instances of reduced blood flow to the brain. However, why reduced temperature is beneficial is largely unknown. Here we review the use of therapeutic hypothermia with a view to understanding the underlying biology contributing to the phenomenon. Interestingly, the benefits of cooling have recently been extended to treatment of chronic neurodegenerative diseases in two mouse models. Concurrently studies have demonstrated the importance of the regulation of protein synthesis, translation, to the cooling response, which is also emerging as a targetable process in neurodegeneration. Through these studies the potential importance of the rewarming process following cooling is also beginning to emerge. Altogether, these lines of research present new opportunities to manipulate cooling pathways for therapeutic gain.
Gap junctions and connexin hemichannels in the regulation of haemostasis and thrombosis
Authors: Vaiyapuri Sakthivel , Flora Gagan D. , Gibbins Jonathan M.
Published: May 2015

Platelets are involved in the maintenance of haemostasis but their inappropriate activation leads to thrombosis, a principal trigger for heart attack and ischaemic stroke. Although platelets circulate in isolation, upon activation they accumulate or aggregate together to form a thrombus, where they function in a co-ordinated manner to prevent loss of blood and control wound repair. Previous report (1) indicates that the stability and functions of a thrombus are maintained through sustained, contact-dependent signalling between platelets. Given the role of gap junctions in the co-ordination of tissue responses, it was hypothesized that gap junctions may be present within a thrombus and mediate intercellular communication between platelets. Therefore studies were performed to explore the presence and functions of connexins in platelets. In this brief review, the roles of hemichannels and gap junctions in the control of thrombosis and haemostasis and the future directions for this research will be discussed.
Gap junctions–guards of excitability
Authors: Stroemlund Line Waring , Jensen Christa Funch , Qvortrup Klaus , Delmar Mario , Nielsen Morten Schak
Published: May 2015

Cardiomyocytes are connected by mechanical and electrical junctions located at the intercalated discs (IDs). Although these structures have long been known, it is becoming increasingly clear that their components interact. This review describes the involvement of the ID in electrical disturbances of the heart and focuses on the role of the gap junctional protein connexin 43 (Cx43). Current evidence shows that Cx43 plays a crucial role in organizing microtubules at the intercalated disc and thereby regulating the trafficking of the cardiac sodium channel NaV1.5 to the membrane.
CMOS phase shifter with low phase‐variation VGA for V‐band application and Ku‐band scaled design
Authors: Lee Dongho
Published: May 2015

A 90° fine tuning phase shifter design with low insertion phase‐variation a VGA for V‐band phased array systems is presented. The vector‐sum phase shifters require low phase‐variation VGAs with a gain control range of about 10 dB for good digital control performance. The measured data for discrete devices have found that a cascode has 20° better phase variation performance than a common source in the required gain control range at 50 GHz. To demonstrate the design, the Ku‐band scaled phase shifter has been fabricated in 0.13 µm standard CMOS process. It consists of 90°/0° hybrids with lumped elements and two cascode VGAs. The 91° continuous phases with the gain of 2.7 ± 0.9 dB are obtained at 13 GHz.
Video‐based facial expression recognition by removing the style variations
Authors: Mohammadian Amin , Aghaeinia Hassan , Towhidkhah Farzad
Published: May 2015

This study examines the performance of person‐independent facial expression recognition improved by adapting the system to a given person. The proposed method transfers the style of particular subjects to the semi‐style‐free space. There is no need to change the person‐independent classifier in order to improve the performance. The style transfer mapping (STM) has been proposed in image‐based classification. The challenges of employing this technique in video‐based facial expression recognition are: estimating STM from image sequences of each subject (adaptation data) and projecting new sequential data of each subject in semi‐style‐free space. A mixture of ‘binary support vector machines’ and ‘hidden Markov models’ were employed to overcome these challenges. Moreover, virtual samples generated by using the person's neutral samples were used to estimate STM. Experimental results on the CK+ database confirm the efficiency of the proposed method in recognition rate improvement.
Current estimation circuit for discontinuous conduction mode flyback pulse‐width modulation controller
Authors: Shi Ling‐Feng , Qi Yi‐Ming
Published: May 2015

Primary‐side controlled flyback converter has been widely used in low‐power and low‐voltage products for its simple structure and low cost. As most applications require constant‐current control, it is important for the integrated circuit to detect and express the output current accurately. This study proposes a novelty current detection and estimation circuit for primary‐side controlled flyback controller. The circuit transmits the output current to voltage linearly with low power consumption and small layout area. Finally, a chip based on 0.6 μm complementary metal–oxide semiconductor process is fabricated using the current detection and estimation circuit in its constant‐current loop to achieve constant output current.
Short‐term performance variations of different photovoltaic system technologies under the humid subtropical climate of Kanpur in India
Authors: Georgitsioti Tatiani , Pillai Gobind , Pearsall Nicola , Putrus Ghanim , Forbes Ian , Anand Raghubir
Published: May 2015

The study discusses the short‐term performance variations of grid‐connected photovoltaic (PV) systems installed in Kanpur, India. The analysis presents a holistic view of the performance variations of three PV array technologies [multi‐crystalline (multi‐Si), copper indium gallium diselenide and amorphous silicon] and two inverter types (high‐frequency transformer and low‐frequency transformer). The analysis considers the DC–AC conversion efficiency of the inverter, system performance through performance ratio (PR) calculations, energy variations between fixed and tracking systems and the comparison between calculated and simulated data for the examined period. The energy output difference between the tracking and fixed systems of the same PV technology show that these are dependent on differences in temperature coefficient, shading and other system related issues. The PR analysis shows the effect of temperature on the multi‐Si system. The difference between the simulated and measured values of the systems was mostly attributed to the irradiance differences. Regarding the inverter evaluation, the results showed that both inverter types underperformed in terms of the conversion efficiency compared with nameplate values.
Dynamics-based selective 2D 1H/1H chemical shift correlation spectroscopy under ultrafast MAS conditions
Authors: Zhang Rongchun , Ramamoorthy Ayyalusamy
Published: May 2015

Dynamics plays important roles in determining the physical, chemical, and functional properties of a variety of chemical and biological materials. However, a material (such as a polymer) generally has mobile and rigid regions in order to have high strength and toughness at the same time. Therefore, it is difficult to measure the role of mobile phase without being affected by the rigid components. Herein, we propose a highly sensitive solid-state NMR approach that utilizes a dipolar-coupling based filter (composed of 12 equally spaced 90° RF pulses) to selectively measure the correlation of 1H chemical shifts from the mobile regions of a material. It is interesting to find that the rotor-synchronized dipolar filter strength decreases with increasing inter-pulse delay between the 90° pulses, whereas the dipolar filter strength increases with increasing inter-pulse delay under static conditions. In this study, we also demonstrate the unique advantages of proton-detection under ultrafast magic-angle-spinning conditions to enhance the spectral resolution and sensitivity for studies on small molecules as well as multi-phase polymers. Our results further demonstrate the use of finite-pulse radio-frequency driven recoupling pulse sequence to efficiently recouple weak proton-proton dipolar couplings in the dynamic regions of a molecule and to facilitate the fast acquisition of 1H/1H correlation spectrum compared to the traditional 2D NOESY (Nuclear Overhauser effect spectroscopy) experiment. We believe that the proposed approach is beneficial to study mobile components in multi-phase systems, such as block copolymers, polymer blends, nanocomposites, heterogeneous amyloid mixture of oligomers and fibers, and other materials.
Power supply and impedance matching to drive technological radio-frequency plasmas with customized voltage waveforms
Authors: Franek James , Brandt Steven , Berger Birk , Liese Martin , Barthel Matthias , Schüngel Edmund , Schulze Julian
Published: May 2015

We present a novel radio-frequency (RF) power supply and impedance matching to drive technological plasmas with customized voltage waveforms. It is based on a system of phase-locked RF generators that output single frequency voltage waveforms corresponding to multiple consecutive harmonics of a fundamental frequency. These signals are matched individually and combined to drive a RF plasma. Electrical filters are used to prevent parasitic interactions between the matching branches. By adjusting the harmonics’ phases and voltage amplitudes individually, any voltage waveform can be approximated as a customized finite Fourier series. This RF supply system is easily adaptable to any technological plasma for industrial applications and allows the commercial utilization of process optimization based on voltage waveform tailoring for the first time. Here, this system is tested on a capacitive discharge based on three consecutive harmonics of 13.56 MHz. According to the Electrical Asymmetry Effect, tuning the phases between the applied harmonics results in an electrical control of the DC self-bias and the mean ion energy at almost constant ion flux. A comparison with the reference case of an electrically asymmetric dual-frequency discharge reveals that the control range of the mean ion energy can be significantly enlarged by using more than two consecutive harmonics.
A permutationally invariant full-dimensional ab initio potential energy surface for the abstraction and exchange channels of the H + CH4 system
Authors: Li Jun , Chen Jun , Zhao Zhiqiang , Xie Daiqian , Zhang Dong H. , Guo Hua
Published: May 2015

We report a permutationally invariant global potential energy surface (PES) for the H + CH4 system based on ∼63 000 data points calculated at a high ab initio level (UCCSD(T)-F12a/AVTZ) using the recently proposed permutation invariant polynomial-neural network method. The small fitting error (5.1 meV) indicates a faithful representation of the ab initio points over a large configuration space. The rate coefficients calculated on the PES using tunneling corrected transition-state theory and quasi-classical trajectory are found to agree well with the available experimental and previous quantum dynamical results. The calculated total reaction probabilities (Jtot = 0) including the abstraction and exchange channels using the new potential by a reduced dimensional quantum dynamic method are essentially the same as those on the Xu-Chen-Zhang PES [Chin. J. Chem. Phys. 27, 373 (2014)].
Theoretical analysis of co-solvent effect on the proton transfer reaction of glycine in a water–acetonitrile mixture
Authors: Kasai Yukako , Yoshida Norio , Nakano Haruyuki
Published: May 2015

The co-solvent effect on the proton transfer reaction of glycine in a water–acetonitrile mixture was examined using the reference interaction-site model self-consistent field theory. The free energy profiles of the proton transfer reaction of glycine between the carboxyl oxygen and amino nitrogen were computed in a water–acetonitrile mixture solvent at various molar fractions. Two types of reactions, the intramolecular proton transfer and water-mediated proton transfer, were considered. In both types of the reactions, a similar tendency was observed. In the pure water solvent, the zwitterionic form, where the carboxyl oxygen is deprotonated while the amino nitrogen is protonated, is more stable than the neutral form. The reaction free energy is −10.6 kcal mol−1. On the other hand, in the pure acetonitrile solvent, glycine takes only the neutral form. The reaction free energy from the neutral to zwitterionic form gradually increases with increasing acetonitrile concentration, and in an equally mixed solvent, the zwitterionic and neutral forms are almost isoenergetic, with a difference of only 0.3 kcal mol−1. The free energy component analysis based on the thermodynamic cycle of the reaction also revealed that the free energy change of the neutral form is insensitive to the change of solvent environment but the zwitterionic form shows drastic changes. In particular, the excess chemical potential, one of the components of the solvation free energy, is dominant and contributes to the stabilization of the zwitterionic form.
Response measurement of single-crystal chemical vapor deposition diamond radiation detector for intense X-rays aiming at neutron bang-time and neutron burn-history measurement on an inertial confinement fusion with fast ignition
Authors: Shimaoka T. , Kaneko J. H. , Arikawa Y. , Isobe M. , Sato Y. , Tsubota M. , Nagai T. , Kojima S. , Abe Y. , Sakata S. , Fujioka S. , Nakai M. , Shiraga H. , Azechi H. , Chayahara A. , Umezawa H. , Shikata S.
Published: May 2015

A neutron bang time and burn history monitor in inertial confinement fusion with fast ignition are necessary for plasma diagnostics. In the FIREX project, however, no detector attained those capabilities because high-intensity X-rays accompanied fast electrons used for plasma heating. To solve this problem, single-crystal CVD diamond was grown and fabricated into a radiation detector. The detector, which had excellent charge transportation property, was tested to obtain a response function for intense X-rays. The applicability for neutron bang time and burn history monitor was verified experimentally. Charge collection efficiency of 99.5% ± 0.8% and 97.1% ± 1.4% for holes and electrons were obtained using 5.486 MeV alpha particles. The drift velocity at electric field which saturates charge collection efficiency was 1.1 ± 0.4 × 107 cm/s and 1.0 ± 0.3 × 107 cm/s for holes and electrons. Fast response of several ns pulse width for intense X-ray was obtained at the GEKKO XII experiment, which is sufficiently fast for ToF measurements to obtain a neutron signal separately from X-rays. Based on these results, we confirmed that the single-crystal CVD diamond detector obtained neutron signal with good S/N under ion temperature 0.5–1 keV and neutron yield of more than 109 neutrons/shot.
Quantum scattering calculations for ro-vibrational de-excitation of CO by hydrogen atoms
Authors: Song Lei , Balakrishnan N. , van der Avoird Ad , Karman Tijs , Groenenboom Gerrit C.
Published: May 2015

We present quantum-mechanical scattering calculations for ro-vibrational relaxation of carbon monoxide (CO) in collision with hydrogen atoms. Collisional cross sections of CO ro-vibrational transitions from v = 1, j = 0 − 30 to v′ = 0, j′ are calculated using the close coupling method for collision energies between 0.1 and 15 000 cm−1 based on the three-dimensional potential energy surface of Song et al. [J. Phys. Chem. A 117, 7571 (2013)]. Cross sections of transitions from v = 1, j ≥ 3 to v′ = 0, j′ are reported for the first time at this level of theory. Also calculations by the more approximate coupled states and infinite order sudden (IOS) methods are performed in order to test the applicability of these methods to H–CO ro-vibrational inelastic scattering. Vibrational de-excitation rate coefficients of CO (v = 1) are presented for the temperature range from 100 K to 3000 K and are compared with the available experimental and theoretical data. All of these results and additional rate coefficients reported in a forthcoming paper are important for including the effects of H–CO collisions in astrophysical models.
Photoinduced reduction of surface states in Fe:ZnO
Authors: Knut R. , Lagerqvist U. , Palmgren P. , Pal P. , Svedlindh P. , Pohl A. , Karis O.
Published: May 2015

We report on the electronic structure of nano-crystalline Fe:ZnO, which has recently been found to be an efficient photocatalyst. Using resonant photoemission spectroscopy, we determine the binding energy of Fe 3d states corresponding to different valencies and coordination of the Fe atoms. The photo-activity of ZnO reduces Fe from 3+ to 2+ in the surface region of the nano-crystalline material due to the formation of oxygen vacancies. Electronic states corresponding to low-spin Fe2+ are observed and attributed to crystal field modification at the surface. These states are potentially important for the photocatalytic sensitivity to visible light due to their location deep in the ZnO bandgap. X-ray absorption and x-ray photoemission spectroscopy suggest that Fe is only homogeneously distributed for concentrations up to 3%. Increased concentrations does not result in a higher concentration of Fe ions in the surface region. This is limiting the photocatalytic functionality of ZnO, where the most efficient Fe doping concentration has been shown to be 1%-4%.
Properties of three-dimensional structures prepared by Ge dewetting from Si(111) at high temperatures
Authors: Shklyaev Alexander , Bolotov Leonid , Poborchii Vladimir , Tada Tetsuya
Published: May 2015

The formation of three-dimensional (3D) structures during Ge deposition on Si(111) at about 800 °C is studied with scanning tunneling, Kelvin probe and electron microscopies, and scanning tunneling and Raman spectroscopies. The observed surface morphology is formed by dewetting of Ge from Si(111), since it occurs mainly by means of minimization of surface and interfacial energies. The dewetting proceeds through massive Si eroding around growing 3D structures, providing them to be composed of SiGe with about a 30% Ge content, and leads to the significant reduction of the SiGe/Si interface area. It is found that the SiGe top component of 3D structures forms sharp interfaces with the underlying Si. The minimization of interfacial and strain energies occurs on the way that the 3D structures appear to get the dendrite-like shape. The Ge distribution in the 3D SiGe structures is inhomogeneous in the lateral dimension with a higher Ge concentration in their central areas and Ge segregation on their surface.
Temperature dependence of equilibrium separation and lattice parameters of nematic boojum-colloids
Authors: Zuhail K. P. , Dhara Surajit
Published: May 2015

We report experimental studies on the temperature dependence of equilibrium separation of a pair of nematic boojum colloids. The interparticle separation is linearly proportional to the elastic anisotropy and the orientation angle with respect to the rubbing direction. The latter result is in agreement with the recent prediction of computer simulations. We prepared two-dimensional colloidal crystals assisted by a laser tweezer and measured the temperature dependence of the lattice parameters. We observe a structural transition in boojum colloidal crystal across the N-SmA transition. The structural transition is mediated by the transformation of boojum defects into focal conic lines across the phase transition. The hexagonal close pack structure of the colloidal crystal in the SmA phase could be useful for designing photonic crystal.
How plasma parameters fluctuations influence emissive probe measurements
Authors: Bousselin G. , Plihon N. , Lemoine N. , Cavalier J. , Heuraux S.
Published: May 2015

Relationship between the floating potential of an emissive probe and plasma potential oscillations is studied in the case of controlled oscillations of plasma parameters. This relationship is compared to a quasi-static model for floating potential oscillations that assumes a constant emission current and includes the fluctuations of plasma parameters (density and electron temperature). Two different plasma regimes are considered. In the first one, the model is coherent with experimental results. In the second, the model does not fulfill one of the assumption due to the evidence of emission current oscillations when the mean emission current exceeds a given threshold. This second regime highlights the importance of taking into account emission current oscillations in the interpretation of emissive probe measurements. Nevertheless, discrepancies are still observed between emissive probe floating potential and plasma potential oscillations.