bluuebunny/crossref_metadata_2025 huggingface dataset:
The propagation of perturbations in rewired bacterial gene networks
Authors: Baumstark Rebecca , Hänzelmann Sonja , Tsuru Saburo , Schaerli Yolanda , Francesconi Mirko , Mancuso Francesco M. , Castelo Robert , Isalan Mark
Published: December 2015

What happens to gene expression when you add new links to a gene regulatory network? To answer this question, we profile 85 network rewirings inE. coli.Here we report that concerted patterns of differential expression propagate from reconnected hub genes. The rewirings link promoter regions to different transcription factor and σ-factor genes, resulting in perturbations that span four orders of magnitude, changing up to ∼70% of the transcriptome. Importantly, factor connectivity and promoter activity both associate with perturbation size. Perturbations from related rewirings have more similar transcription profiles and a statistical analysis reveals ∼20 underlying states of the system, associating particular gene groups with rewiring constructs. We examine two large clusters (ribosomal and flagellar genes) in detail. These represent alternative global outcomes from different rewirings because of antagonism between these major cell states. This data set of systematically related perturbations enables reverse engineering and discovery of underlying network interactions.
Structural analysis of haemoglobin binding by HpuA from the Neisseriaceae family
Authors: Wong Chi T. , Xu Yingqi , Gupta Akshari , Garnett James A. , Matthews Steve J. , Hare Stephen A.
Published: December 2015

The Neisseriaceae family of bacteria causes a range of diseases including meningitis, septicaemia, gonorrhoea and endocarditis, and extracts haem from haemoglobin as an important iron source within the iron-limited environment of its human host. Herein we report crystal structures of apo- and haemoglobin-bound HpuA, an essential component of this haem import system. The interface involves long loops on the bacterial receptor that present hydrophobic side chains for packing against the surface of haemoglobin. Interestingly, our structural and biochemical analyses of Kingella denitrificans and Neisseria gonorrhoeae HpuA mutants, although validating the interactions observed in the crystal structure, show how Neisseriaceae have the fascinating ability to diversify functional sequences and yet retain the haemoglobin binding function. Our results present the first description of HpuA’s role in direct binding of haemoglobin.
Correction: Corrigendum: ChEC-seq kinetics discriminates transcription factor binding sites by DNA sequence and shape in vivo
Authors: Zentner Gabriel E. , Kasinathan Sivakanthan , Xin Beibei , Rohs Remo , Henikoff Steven
Published: December 2015

Nature Communications 6, Article number: 8733 (2015); Published 22 October 2015; Updated 16 December 2015 An incorrect version of the Supplementary Data 1, in which data in columns E, F, G, H and K of the sheet ‘Reb1’ were sorted independently from the other columns, was inadvertently published withthis Article.
HIV-1 increases TLR responses in human primary astrocytes
Authors: Serramía M Jesús , Muñoz-Fernández M Ángeles , Álvarez Susana
Published: December 2015

Astrocytes are the major glial cell within the central nervous system and have a number of important physiological properties related to brain homeostasis. They provide trophic support to neurons and are immune cells with key roles during states-of-inflammation. The potential for production of proinflammatory cytokines and its consequences has been studied in the context of HIV-1 infection of normal human astrocytes (NHA). NHA express TLR3, TLR4 and TLR5. TLR3 ligation induced the strongest proinflammatory polarizing response, characterized by generation of high levels of TNF-α, IL-6 and IL-8. HIV-1 increased the transient production of key inflammatory mediators and exposure to LPS of HIV-1-infected cells increased significantly the cytokine secretion. We confirmed that it is necessary viral gene expression from the moment of pretreatment with antiretrovirals inhibited totally HIV-1-induced TLR response. The higher response to LPS from HIV-1-infected cells did not correlate with TLR4 or MyD88 increased expression. LPS responsiveness of infected cells parallels MHC class II expression, but not CD14. HIV-1-infected NHA present increased sensitivity to the proinflammatory effects of LPS. If this phenomenon occurs in vivo, it will contribute to the immunopathogenesis of this disease and may ultimately offer novel targets for immunomodulatory therapy.
In vivo cellular imaging of various stress/response pathways using AAV following axonal injury in mice
Authors: Fujita Kosuke , Nishiguchi Koji M , Yokoyama Yu , Tomiyama Yusuke , Tsuda Satoru , Yasuda Masayuki , Maekawa Shigeto , Nakazawa Toru
Published: December 2015

Glaucoma, a leading cause of blindness worldwide, is instigated by various factors, including axonal injury, which eventually leads to a progressive loss of retinal ganglion cells (RGCs). To study various pathways reportedly involved in the pathogenesis of RGC death caused by axonal injury, seven pathways were investigated. Pathway-specific fluorescent protein-coded reporters were each packaged into an adeno-associated virus (AAV). After producing axonal injury in the eye, injected with AAV to induce RGC death, the temporal activity of each stress-related pathway was monitored in vivo through the detection of fluorescent RGCs using confocal ophthalmoscopy. We identified the activation of ATF6 and MCP-1 pathways involved in endoplasmic reticulum stress and macrophage recruitment, respectively, as early markers of RGC stress that precede neuronal death. Conversely, inflammatory responses probed by NF-κB and cell-death-related pathway p53 were most prominent in the later phases, when RGC death was already ongoing. AAV-mediated delivery of stress/response reporters followed by in vivo cellular imaging is a powerful strategy to characterize the temporal aspects of complex molecular pathways involved in retinal diseases. The identification of promoter elements that are activated before the death of RGCs enables the development of pre-emptive gene therapy, exclusively targeting the early phases of diseased cells.
Collembola at three alpine subarctic sites resistant to twenty years of experimental warming
Authors: Alatalo Juha M. , Jägerbrand Annika K. , Čuchta Peter
Published: December 2015

This study examined the effects of micro-scale, site and 19 and 21 years of experimental warming on Collembola in three contrasting alpine subarctic plant communities (poor heath, rich meadow, wet meadow). Unexpectedly, experimental long-term warming had no significant effect on species richness, effective number of species, total abundance or abundance of any Collembola species. There were micro-scale effects on species richness, total abundance and abundance of 10 of 35 species identified. Site had significant effect on effective number of species and abundance of six species, with abundance patterns differing between sites. Site and long-term warming gave non-significant trends in species richness. The highest species richness was observed in poor heath, but mean species richness tended to be highest in rich meadow and lowest in wet meadow. Warming showed a tendency for a negative impact on species richness. This long-term warming experiment across three contrasting sites revealed that Collembola is capable of high resistance to climate change. We demonstrated that micro-scale and site effects are the main controlling factors for Collembola abundance in high alpine subarctic environments. Thus local heterogeneity is likely important for soil fauna composition and may play a crucial role in buffering Collembola against future climate change.
Ion beam nanopatterning of III-V semiconductors: consistency of experimental and simulation trends within a chemistry-driven theory
Authors: El-Atwani O. , Norris S. A. , Ludwig K. , Gonderman S. , Allain J. P.
Published: December 2015

Several proposed mechanisms and theoretical models exist concerning nanostructure evolution on III-V semiconductors (particularly GaSb) via ion beam irradiation. However, making quantitative contact between experiment on the one hand and model-parameter dependent predictions from different theories on the other is usually difficult. In this study, we take a different approach and provide an experimental investigation with a range of targets (GaSb, GaAs, GaP) and ion species (Ne, Ar, Kr, Xe) to determine new parametric trends regarding nanostructure evolution. Concurrently, atomistic simulations using binary collision approximation over the same ion/target combinations were performed to determine parametric trends on several quantities related to existing model. A comparison of experimental and numerical trends reveals that the two are broadly consistent under the assumption that instabilities are driven by chemical instability based on phase separation. Furthermore, the atomistic simulations and a survey of material thermodynamic properties suggest that a plausible microscopic mechanism for this process is an ion-enhanced mobility associated with energy deposition by collision cascades.
Morphology-Dependent Electrochemical Performance of Zinc Hexacyanoferrate Cathode for Zinc-Ion Battery
Authors: Zhang Leyuan , Chen Liang , Zhou Xufeng , Liu Zhaoping
Published: December 2015

Zinc hexacyanoferrate (ZnHCF) which is a dimorphic (cubic or rhombohedral) Prussian blue analogue and can be intercalated by both monovalent and divalent ions,is a promising cathode material for rechargeable aqueous metal-ion batteries.In this paper, a simple co-precipitation method is developed to tune the particle morphology of ZnHCF by adjusting the dropping speed at room temperature. Three polyhedral ZnHCF particles, with cubooctahedral, truncated octahedral or octahedral shapes, are obtained at room temperature. Structural transformation from cubic phase of as-prepared ZnHCF to rhombohedral phase is observed by further dehydration of the sample at 70 °C, whereas the dehydrated ZnHCF crystals still hold the identical polyhedral shape as that of the cubic phase particles. Then the influence of shape and facets on electrochemical performance is studied for polyhedral ZnHCF with rhombohedral structure (RZnHCF). RZnHCF sample with cubooctahedral shape possesses the best rate capability and cyclic stability comparing with RZnHCF particles having truncated octahedral or octahedral shapes. Furthermore, the structure of cuboctahedron RZnHCF particles during electrochemical cycling has been monitored with ex situ X-ray diffraction to demonstrate the reversible zinc-ion intercalation mechanism.
Parallel charge sheets of electron liquid and gas in La0.5Sr0.5TiO3/SrTiO3 heterostructures
Authors: Renshaw Wang X. , Sun L. , Huang Z. , Lü W. M. , Motapothula M. , Annadi A. , Liu Z. Q. , Zeng S. W. , Venkatesan T. , Ariando
Published: December 2015

We show here a new phenomenon in La0.5Sr0.5TiO3/SrTiO3 (LSTO/STO) heterostructures; that is a coexistence of three-dimensional electron liquid (3DEL) and 2D electron gas (2DEG), separated by an intervening insulating LSTO layer. The two types of carriers were revealed through multi-channel analysis of the evolution of nonlinear Hall effect as a function of film thickness, temperature and back gate voltage. We demonstrate that the 3D electron originates from La doping in LSTO film and the 2D electron at the surface of STO is due to the polar field in the intervening insulating layer. As the film thickness is reduced below a critical thickness of 6 unit cells (uc), an abrupt metal-to-insulator transition (MIT) occurs without an intermediate semiconducting state. The properties of the LSTO layer grown on different substrates suggest that the insulating phase of the intervening layer is a result of interface strain induced by the lattice mismatch between the film and substrate. Further, by fitting the magnetoresistance (MR) curves, the 6 unit cell thick LSTO is shown to exhibit spin-orbital coupling. These observations point to new functionalities, in addition to magnetism and superconductivity in STO-based systems, which could be exploited in a multifunctional context.
Smokeless tobacco consumption impedes metabolic, cellular, apoptotic and systemic stress pattern: A study on Government employees in Kolkata, India
Authors: Biswas Sushobhan , Manna Krishnendu , Das Ujjal , Khan Amitava , Pradhan Anirban , Sengupta Aaveri , Bose Surajit , Ghosh Saurabh , Dey Sanjit
Published: December 2015

Smokeless tobacco (SLT) remains a threat amongst a large population across the globe and particularly in India. The oral use of tobacco has been implicated to cause physiological stress leading to extreme toxicological challenge. The study included 47 SLT-users and 44 non-users providing a spectrum of pathophysiological, clinico-biochemical, antioxidant parameters, cell cycle progression study of PBMC and morphological changes of red blood cells (RBC). The expressions of p53, p21, Bax, Bcl-2, IL-6, TNF- α, Cox-2, iNOS were analyzed from thirteen representative SLT-users and twelve non-users. Difference in CRP, random glucose, serum cholesterol, TG, HLDL-C, LDL-C, VLDL-C, neutrophil count, monocyte count, ESR, SOD (PBMC) and TBARS (RBC membrane) were found to be statistically significant (p < 0.05) between the studied groups. The current study confers crucial insight into SLT mediated effects on systemic toxicity and stress. This has challenged the metabolic condition leading to a rise in the inflammatory status, increased apoptosis and RBC membrane damage. The above findings were substantiated with metabolic, clinical and biochemical parameters. This is possibly the first ever in-depth report and remains an invaluable document on the fatal effects of SLT.
Photocleavable linker for the patterning of bioactive molecules
Authors: Wegner Seraphine V. , Sentürk Oya I. , Spatz Joachim P.
Published: December 2015

Herein, we report the use of a versatile photocleavable nitrobenzyl linker to micropattern a wide variety of bioactive molecules and photorelease them on demand. On one end, the linker has an NHS group that can be coupled with any amine, such as peptides, proteins or amine-linkers and on the other end an alkyne for convenient attachment to materials with an azide functional group. This linker was conjugated with NTA-amine or the cell adhesion peptide cRGD to enable straightforward patterning of His6-tagged proteins or cells, respectively, on PEGylated glass surfaces. This approach provides a practical way to control the presentation of a wide variety of bioactive molecules with high spatial and temporal resolution. The extent of photocleavage can also be controlled to tune the biomolecule density and degree of cell attachment to the surface.
The effect of exercise training on the course of cardiac troponin T and I levels: three independent training studies
Authors: van der Linden Noreen , Klinkenberg Lieke J. J. , Leenders Marika , Tieland Michael , Verdijk Lex B. , Niens Marijke , van Suijlen Jeroen D. E. , de Groot Lisette C. P. G. M. , Bekers Otto , van Loon Luc J. C. , van Dieijen-Visser Marja P. , Meex Steven J. R.
Published: December 2015

With the introduction of high-sensitive assays, cardiac troponins became potential biomarkers for risk stratification and prognostic medicine. Observational studies have reported an inverse association between physical activity and basal cardiac troponin levels. However, causality has never been demonstrated. This study investigated whether basal cardiac troponin concentrations are receptive to lifestyle interventions such as exercise training. Basal high-sensitive cardiac troponin T (cTnT ) and I (cTnI) were monitored in two resistance-type exercise training programs (12-week (study 1) and 24-week (study 2)) in older adults (≥65 years). In addition, a retrospective analysis for high sensitive troponin I in a 24-week exercise controlled trial in (pre)frail older adults was performed (study 3). In total, 91 subjects were included in the final data analyses. There were no significant changes in cardiac troponin levels over time in study 1 and 2 (study 1: cTnT −0.13 (−0.33–+0.08) ng/L/12-weeks, cTnI −0.10 (−0.33–+0.12) ng/L/12-weeks; study 2: cTnT −1.99 (−4.79–+0.81) ng/L/24-weeks, cTnI −1.59 (−5.70–+2.51) ng/L/24-weeks). Neither was there a significant interaction between training and the course of cardiac troponin in study 3 (p = 0.27). In conclusion, this study provides no evidence that prolonged resistance-type exercise training can modulate basal cardiac troponin levels.
Usefulness of serum interleukin-18 in predicting cardiovascular mortality in patients with chronic kidney disease – systems and clinical approach
Authors: Formanowicz Dorota , Wanic-Kossowska Maria , Pawliczak Elżbieta , Radom Marcin , Formanowicz Piotr
Published: December 2015

The aim of this study was to check if serum interleukin-18 (IL-18) predicts 2-year cardiovascular mortality in patients at various stages of chronic kidney disease (CKD) and history of acute myocardial infarction (AMI) within the previous year. Diabetes mellitus was one of the key factors of exclusion. It was found that an increase in serum concentration of IL-18 above the cut-off point (1584.5 pg/mL) was characterized by 20.63-fold higher risk of cardiovascular deaths among studied patients. IL-18 serum concentration was found to be superior to the well-known cardiovascular risk parameters, like high sensitivity C-reactive protein (hsCRP), carotid intima media thickness (CIMT), glomerular filtration rate, albumins, ferritin, N-terminal prohormone of brain natriuretic peptide (NT-proBNP) in prognosis of cardiovascular mortality. The best predictive for IL-18 were 4 variables, such as CIMT, NT-proBNP, albumins and hsCRP, as they predicted its concentration at 89.5%. Concluding, IL-18 seems to be important indicator and predictor of cardiovascular death in two-year follow-up among non-diabetic patients suffering from CKD, with history of AMI in the previous year. The importance of IL-18 in the process of atherosclerotic plaque formation has been confirmed by systems analysis based on a formal model expressed in the language of Petri nets theory.
Development of a mono-promoter-driven CRISPR/Cas9 system in mammalian cells
Authors: Yoshioka Shin , Fujii Wataru , Ogawa Tetsuhiro , Sugiura Koji , Naito Kunihiko
Published: December 2015

The CRISPR/Cas9 system has been used for spatio-temporal gene modification through the ubiquitous expression of gRNA by an RNA polymerase III promoter and the controlled expression of Cas9 using a tissue-specific or inducible promoter. However, unexpected gene disruptions indicate the necessity of a tissue-specific or inducible expression of not only Cas9 but also gRNA. In the present study, we attempted to develop a CRISPR/Cas9 system that could express functional gRNAs and Cas9 by a single RNA polymerase II promoter and induce multi-loci disruptions in specific cells. To this end, we designed vectors expressing ribozyme-flanked gRNAs (RGRs) and Cas9 mRNAs simultaneously. We showed that the mono-promoter-driven vector induces gene disruptions at the target loci in HEK 293 cells after transfection. In addition, two target loci were disrupted simultaneously by the transfection of a mono-promoter-driven vector expressing two RGRs and Cas9 mRNA. Finally, we constructed a universal vector for use in the construction of plasmids to be applied to the present mono-promoter-driven CRISPR/Cas9 system. We have thus provided a versatile tool for generating gene disruptions by the CRISPR/Cas9 system; this system should contribute to a wide range of investigations, including studies on spatio-temporal gene functions.
Evaluating the potential impact of proton carriers on syntrophic propionate oxidation
Authors: Juste-Poinapen Natacha M. S. , Turner Mark S. , Rabaey Korneel , Virdis Bernardino , Batstone Damien J.
Published: December 2015

Anaerobic propionic acid degradation relies on interspecies electron transfer (IET) between propionate oxidisers and electron acceptor microorganisms, via either molecular hydrogen, formate or direct transfers. We evaluated the possibility of stimulating direct IET, hence enhancing propionate oxidation, by increasing availability of proton carriers to decrease solution resistance and reduce pH gradients. Phosphate was used as a proton carrying anion and chloride as control ion together with potassium as counter ion. Propionic acid consumption in anaerobic granules was assessed in a square factorial design with ratios (1:0, 2:1, 1:1, 1:2 and 0:1) of total phosphate (TP) to Cl−, at 1X, 10X and 30X native conductivity (1.5 mS.cm−1). Maximum specific uptake rate, half saturation and time delay were estimated using model-based analysis. Community profiles were analysed by fluorescent in situ hybridisation and 16S rRNA gene pyrosequencing. The strongest performance was at balanced (1:1) ratios at 10X conductivity where presumptive propionate oxidisers namely Syntrophobacter and Candidatus Cloacamonas were more abundant. There was a shift from Methanobacteriales at high phosphate, to Methanosaeta at low TP:Cl ratios and low conductivity. A lack of response to TP and low percentage of presumptive electroactive organisms suggested that DIET was not favoured under the current experimental conditions.
Dimpled elastic sheets: a new class of non-porous negative Poisson’s ratio materials
Authors: Javid Farhad , Smith-Roberge Evelyne , Innes Matthew C. , Shanian Ali , Weaver James C. , Bertoldi Katia
Published: December 2015

In this study, we report a novel periodic material with negative Poisson’s ratio (also called auxetic materials) fabricated by denting spherical dimples in an elastic flat sheet. While previously reported auxetic materials are either porous or comprise at least two phases, the material proposed here is non-porous and made of a homogeneous elastic sheet. Importantly, the auxetic behavior is induced by a novel mechanism which exploits the out-of-plane deformation of the spherical dimples. Through a combination of experiments and numerical analyses, we demonstrate the robustness of the proposed concept, paving the way for developing a new class of auxetic materials that significantly expand their design space and possible applications.
Solvent transport through hard–soft segmented polymer nanocomposites
Authors: Rath Sangram K. , Edatholath Saji S. , Patro T. Umasankar , Sudarshan Kathi , Sastry P. U. , Pujari Pradeep K. , Harikrishnan G.
Published: December 2015

This article illustrates the non-barrier influence of filler on solvent transport through phase segmented block co-polymer nanocomposite.
Electronically excited states of cob(ii)alamin: insights from CASSCF/XMCQDPT2 and TD-DFT calculations
Authors: Garabato Brady D. , Kumar Neeraj , Lodowski Piotr , Jaworska Maria , Kozlowski Pawel M.
Published: December 2015

The low-lying excited states of cob(ii)alamin were investigated using time-dependent density functional theory (TD-DFT), and multiconfigurational CASSCF/XMCQDPT2 methodology, to help understand their role in B12-mediated reactions.
Pressure-induced mesoscopic disorder in protic ionic liquids: first computational study
Authors: Mariani A. , Caminiti R. , Campetella M. , Gontrani L.
Published: December 2015

The application of high pressure to protic ionic liquids with short alkyl chains induces a progressive homogenization of the structure.
A discrete {Co4(μ3-OH)4}4+cluster with an oxygen-rich coordination environment as a catalyst for the epoxidation of various olefins
Authors: Lee Sun Young , Kim Namseok , Lee Myoung Mi , Jo Young Dan , Bae Jeong Mi , Hyun Min Young , Yoon Sungho , Kim Cheal
Published: December 2015

A tetranuclear Co(ii) complex was active for epoxidation reactions of various olefins, and CoVO and CoIVO species were proposed to be the possible reactive intermediates.
Direct reductive amination of aldehydes with nitroarenes using bio-renewable formic acid as a hydrogen source
Authors: Zhang Qi , Li Shu-Shuang , Zhu Ming-Ming , Liu Yong-Mei , He He-Yong , Cao Yong
Published: December 2015

Direct reductive amination of aldehydes with nitroarenes can be carried out efficiently in neat water in the presence of a single phase rutile titania supported gold catalyst using FA as the hydrogen donor.
A convenient and rapid microwave-assisted synthesis of spirooxindoles in aqueous medium and their antimicrobial activities
Authors: Mali Prakash R. , Chandrasekhara Rao L. , Bangade Vikas M. , Shirsat Prashishkumar K. , George Sara A. , Jagadeesh babu N. , Meshram H. M.
Published: December 2015

An efficient, regioselective and diastereoselective synthesis of diversely functionalized spirooxindoles under microwave irradiation in aqueous medium; most of the compounds show significant antimicrobial activities.
Biosorption of copper(ii) ions by methyl-sulfonated Lagenaria vulgaris shell: kinetic, thermodynamic and desorption studies
Authors: Stanković Maja N. , Krstić Nenad S. , Mitrović Jelena Z. , Najdanović Slobodan M. , Petrović Milica M. , Bojić Danijela V. , Dimitrijević Vladimir D. , Bojić Aleksandar L.
Published: December 2015

Chemically modifiedLagenaria vulgarisshell was found to be an efficient, regenerative biosorbent to remove copper ions from wastewater models.
Influence of the terminal donor on the performance of 4,8-dialkoxybenzo[1,2-b:4,5′]dithiophene based small molecules for efficient solution-processed organic solar cells
Authors: Bagde Sushil S. , Park Hanok , Lee Song-Mi , Lee Soo-Hyoung
Published: December 2015

New dialkoxybenzo[1,2-b:4,5′]dithiophene based small molecules, BDT(PTBT)2 and BDT(TTBT)2, are designed and synthesized. BDT(TTBT)2 shows higher PCE than BDT(PTBT)2.
Green preparation of novel heptafluo-zirconate/hafnate nanocrystals at ambient temperature
Authors: He Xianghong , Cao Jinxin , Hu Ziyi
Published: December 2015

A novel method to fabricate, under ambient conditions, pure and doped heptafluo-zirconate/hafnate nanocrystalsviaa convenient complex chemical procedure.
Nanoparticles of Pt loaded on a vertically aligned TiO2 nanotube bed: synthesis and evaluation of electrocatalytic activity
Authors: Rasmi K. R. , Vanithakumari S. C. , George R. P. , Mallika C. , Mudali U. Kamachi
Published: December 2015

Pt nano particle loaded TiO2 nanotube (TiNT) electrode with excellent electrocatalytic activity was synthesized via seed mediated hydrothermal reduction method on self-aligned TiNT bed.
Enhanced biohydrogen production from beverage wastewater: process performance during various hydraulic retention times and their microbial insights
Authors: Sivagurunathan Periyasamy , Lin Chiu-Yue
Published: December 2015

This study demonstrates the feasibility of continuous hydrogen production from beverage industrial wastewater (BW) in a continuously-stirred tank reactor (CSTR) using enriched mixed microflora (EMC) under mesophilic conditions.
Piezoelectricity and excellent temperature stability in nonferroelectric Bi12TiO20–CaTiO3 polar composite ceramics
Authors: Yu Dan , Zhao Minglei , Wang Chunlei , Wang Lihai , Su Wenbin , Gai Zhigang , Wang Chunming , Li Jichao , Zhang Jialiang
Published: December 2015

After sintering at temperatures above the melting point of Bi12TiO20, both direct and converse piezoelectric effects were observed in non ferroelectric Bi12TiO20–CaTiO3 composite ceramics for the first time.
Vergleich der Kosten- und Erlössituation invasiver und konservativer kardiologischer Behandlungsfälle: Modell einer Deckungsbeitragsrechnung
Authors: Plehn G. , Oernek A. , Vormbrock J. , Maagh P. , Butz T. , Meissner A.
Published: December 2015

Ziel der Studie: Die Deckungsbeitragsrechnung ist ein Instrument zur Kostenkontrolle und bietet sich für medizinische Bereiche an, die in Form von Fallpauschalen vergütet werden. Die Gegenüberstellung von Erlösen und variablen Kosten ermöglicht es, die wirtschaftliche Attraktivität einzelner medizinischer Leistungen zu bewerten und zu vergleichen. Unter diesem Gesichtspunkt wurde ein Deckungsbeitragsmodells entwickelt und fachabteilungsbezogen auf invasive und konservative kardiologische Behandlungsfälle angewandt.

Methodik: Unsere Datenbank umfasst 7 330 stationären Behandlungsfälle eines tertiären kardiologischen Zentrums zwischen 2007 und 2011. Die betriebswirtschaftlichen Parameter wurden aus den Informationssystemen des Krankenhauses, der Materialwirtschaft und des Herzkatheterlabors generiert. Auf der Erlösseite wurden die fallbezogenen DRG-Vergütungen berücksichtigt. Der prozedurenassoziierte Ressourcenverbrauch in Form von Material-, Personal- und Wartungskosten wurde den variablen Kosten zugerechnet und detailliert analysiert. Neben dem Deckungsbeitrag I wurde eine relative Deckungsbeitragsrechnung angewandt. Zeitbezug war die stationäre Verweildauer.

Ergebnisse: Im Beobachtungszeitraum stiegen Fallzahlen und Jahreserlöse um ca. 20%. Pro invasivem Behandlungsfall konnten höhere Deckungsbeiträge als für nichtinvasive Fälle erwirtschaftet werden (2 097±1 590 vs. 1 614±1 105 €; p<0,001). Das relative Verhältnis von invasiven und konservativen Behandlungsfällen stellte sich über den Gesamtzeitraum unverändert dar. Zwischen 2007 und 2011 konnte eine Verkürzung der Untersuchungsdauer von 46,2±39,1 auf 36,7±33,5 min (p<0,001) beobachtet werden. Im selben Zeitraum stiegen die relativen Deckungsbeiträge von 461±306 auf 530±335 € (p<0,001).

Schlussfolgerungen: Die Deckungsbeitragsrechnung ermöglicht es, die wirtschaftliche Attraktivität einzelner medizinischer Leistungen zu vergleichen und im Verlauf zu beurteilen. Aus Sicht des Zeitmanagements ist sie besonders geeignet, um Krankenhausbereiche zu monitoren, die eine wirtschaftliche Engpasssituation darstellen.
Ion-mediated interactions between net-neutral slabs: Weak and strong disorder effects
Authors: Ghodrat Malihe , Naji Ali , Komaie-Moghaddam Haniyeh , Podgornik Rudolf
Published: December 2015

We investigate the effective interaction between two randomly charged but otherwise net-neutral, planar dielectric slabs immersed in an asymmetric Coulomb fluid containing a mixture of mobile monovalent and multivalent ions. The presence of charge disorder on the apposed bounding surfaces of the slabs leads to substantial qualitative changes in the way they interact, as compared with the standard picture provided by the van der Waals and image-induced, ion-depletion interactions. While, the latter predict purely attractive interactions between strictly neutral slabs, we show that the combined effects from surface charge disorder, image depletion, Debye (or salt) screening, and also, in particular, their coupling with multivalent ions, give rise to a more diverse behavior for the effective interaction between net-neutral slabs at nano-scale separations. Disorder effects show large variation depending on the properly quantified strength of disorder, leading either to non-monotonic effective interaction with both repulsive and attractive branches when the surface charges are weakly disordered (small disorder variance) or to a dominating attractive interaction that is larger both in its range and magnitude than what is predicted from the van der Waals and image-induced, ion-depletion interactions, when the surfaces are strongly disordered (large disorder variance).
Static and dynamic behavior of ultrathin cobalt nanowires embedded in transparent matrix
Authors: Roussigné Y. , Chérif S. M. , Stashkevich A. A. , Vidal F. , Zheng Y.
Published: December 2015

Two self-assembly of ultrathin Co nanowires (NWs) embedded in a CeO2 matrix was grown on SrTiO3(001) and oxidized Si(001) substrates. A common feature of the two arrays of NWs is the small diameter of the wires, falling in the 4–5 nm range. Combined with their length, the aspect ratio is large enough to ensure large magnetostatic anisotropy with an easy axis along the axis of the nanowires as revealed by magnetometry measurements. The Brillouin light scattering technique has been used to investigate the behavior of the spin waves under a field perpendicular to the NWs axes. The transparency of the matrix ensures the penetration of the probing light inside the sample. Importantly, Brillouin light scattering from the magnetic modes obeys the volume Bragg condition, which is characteristic of the configuration in which the observed modes are propagating along the nanowires and due to their very small diameter are nearly constant across the section. Both series of experimental results are satisfactorily analyzed by means of a single analytical model, based on a mean-field approach, assuming the presence at remanence of two populations of NWs with up and down magnetizations and including the dipolar coupling between the cylinders.
Longitudinal relaxation in dipole-coupled homonuclear three-spin systems: Distinct correlations and odd spectral densities
Authors: Chang Zhiwei , Halle Bertil
Published: December 2015

A system of three dipole-coupled spins exhibits a surprisingly intricate relaxation behavior. Following Hubbard’s pioneering 1958 study, many authors have investigated different aspects of this problem. Nevertheless, on revisiting this classic relaxation problem, we obtain several new results, some of which are at variance with conventional wisdom. Most notably from a fundamental point of view, we find that the odd-valued spectral density function influences longitudinal relaxation. We also show that the effective longitudinal relaxation rate for a non-isochronous three-spin system can exhibit an unusual inverted dispersion step. To clarify these and other issues, we present a comprehensive theoretical treatment of longitudinal relaxation in a three-spin system of arbitrary geometry and with arbitrary rotational dynamics. By using the Liouville-space formulation of Bloch-Wangsness-Redfield theory and a basis of irreducible spherical tensor operators, we show that the number of relaxation components in the different cases can be deduced from symmetry arguments. For the isochronous case, we present the relaxation matrix in analytical form, whereas, for the non-isochronous case, we employ a computationally efficient approach based on the stochastic Liouville equation.
Implications of magnetic and magnetodielectric behavior of GdCrTiO5
Authors: Basu Tathamay , Singh Kiran , Gohil Smita , Ghosh Shankar , Sampathkumaran E. V.
Published: December 2015

We have carried out dc magnetization, heat-capacity, and dielectric studies down to 2 K for the compound GdCrTiO5, crystallizing in orthorhombic Pbam structure, in which well-known multiferroics RMn2O5 (R = Rare-earths) form. The points of emphasis are: (i) The magnetic ordering temperature of Cr appears to be suppressed compared with that in isostructural Nd counterpart, NdCrTiO5. This finding on the Gd compound suggests that Nd 4f hybridization plays an uncommon role in the magnetism of Cr in contrast to a proposal long ago. (ii) Dielectric constant does not exhibit any notable feature below about 30 K in the absence of external magnetic field, but a peak appears and gets stronger with the application of external magnetic fields, supporting the existence of magnetodielectric coupling. (iii) The dielectric anomalies appear even near 100 K, which can be attributed to short-range magnetic-order. We also observe a gain in spectral weight below about 150 K in Raman spectra in the frequency range 150–400 cm−1, which could be magnetic in origin, supporting short-range magnetic order. It is of interest to explore whether geometrically frustration plays any role in the dielectric properties of this family, as in the case of RMn2O5.
Silver nanoparticles on nanopatterned LiF(110) surface studied by extreme ultraviolet light scattering
Authors: Giglia Angelo , Miotti Paolo , Parisse Pietro , Nannarone Stefano
Published: December 2015

A LiF(110) surface featuring a ridge-and-valley nanopatterned structure periodic along the [−1,1,0] direction (period and height of the order of 30 nm and 10 nm, respectively) formed by [001] macrosteps exposing {100} and {010} facets was functionalized by rows of Ag nanoparticles and studied by elastic light scattering in the energy range 50–100 eV. Families of diffraction efficiencies curves were taken at grazing incidence angle and fixed photon energy as a function of scattering angle, and elastic scattering curves were taken at fixed scattering angle as a function of energy. The scattering curves presented well-defined features ascribable to the periodicities of the surface, or equivalently to the reciprocal qX vectors correlated with the power spectral density features of topological images of atomic force microscopy. Other characteristics of the functionalized surface, including the height of ridge-valley profile, the Ag nanoparticle dimensions, and the material distribution in the scattering plane, were obtained by fitting the experimental zero and first order efficiency curves to simulation results of a parameterized model. The simulations were carried out adapting an in-house code based on the electromagnetic differential method, and the different material properties were taken into account by a space dependent complex dielectric constant. Information along the direction perpendicular to the scattering plane was not accessible but morphological insights were obtained combining light diffraction with atomic force microscopy. The results indicate nanoparticles with a quasi-ellipsoidal shape prolate along the ridge direction with minor and major axes of ∼12 nm and ∼21 nm, respectively.
Quasielastic neutron scattering studies on glass-forming ionic liquids with imidazolium cations
Authors: Kofu Maiko , Tyagi Madhusudan , Inamura Yasuhiro , Miyazaki Kyoko , Yamamuro Osamu
Published: December 2015

Relaxation processes for imidazolium-based ionic liquids (ILs) were investigated by means of an incoherent quasielastic neutron scattering technique. In order to clarify the cation and anion effects on the relaxation processes, ten samples were measured. For all of the samples, we found three relaxations at around 1 ps, 10 ps, and 100 ps-10 ns, each corresponding to the alkyl reorientation, the relaxation related to the imidazolium ring, and the ionic diffusion. The activation energy (Ea) for the alkyl relaxation is insensitive to both anion and alkyl chain lengths. On the other hand, for the imidazolium relaxation and the ionic diffusion processes, Ea increases as the anion size decreases but is almost independent of the alkyl chain length. This indicates that the ionic diffusion and imidazolium relaxation are governed by the Coulombic interaction between the core parts of the cations (imidazolium ring) and the anions. This is consistent with the fact that the imidazolium-based ILs have nanometer scale structures consisting of ionic and neutral (alkyl chain) domains. It is also found that there is a clear correlation between the ionic diffusion and viscosity, indicating that the ionic diffusion is mainly associated with the glass transition which is one of the characteristics of imidazolium-based ILs.
Fourier plane colorimetric sensing using broadband imaging of surface plasmons and application to biosensing
Authors: Arora P. , Krishnan A.
Published: December 2015

We demonstrate an optical technique for refractive index and thickness sensing of sub-wavelength-thick dielectric analytes. The technique utilizes the broadband, multimode, directional leakage radiation arising from the excitation of hybrid mode surface plasmons (SP) on low aspect ratio periodic plasmonic substrates with period ≈λ. The approach requires relaxed fabrication tolerances compared to extra ordinary transmission-based sensing techniques, wherein minor shifts in the fabricated dimensions result in a very large change from the designed resonant wavelength. We show that refractive index perturbations due to about 10-nm-thick dielectric can be captured optically by the usage of carefully designed plasmonic substrates, a halogen lamp source, free-space optical components, polarizers, and a low-end, consumer-grade charge coupled device camera. The plasmonic substrates were designed for converting the signature of hybrid mode SP excitation into a transmission peak by utilizing a thin homogeneous metal layer sandwiched between the periodic plasmonic structures and the substrate. The resonance is highly sensitive to the refractive index and thickness of the analyte superstrate. The excitation of hybrid mode SP results in a polarization rotation of 90° of the leaked radiation at resonant wavelength. In order to eliminate the problem of image registration (i.e., placing the same feature in the same pixel of the image, for comparison before and after a change in refractive index) for sensing, we perform the color analysis in the Fourier plane. The change in color of the bright emitted spot with highest momentum, corresponding to the leakage of fundamental SP mode, was used to measure the changes in refractive index, whereas the number and color of spots of lower momenta, corresponding to higher-order Fabry Perot modes, was used to measure the variation in thickness. We further show that the Fourier plane analysis can also be used to sense the index of thicker dielectrics, where real plane image analysis may fail to sense index perturbations, simply due to superposition of different modes in the real plane images of such substrates. Control experiments and analysis revealed a refractive index resolution of 10–5 RIU. The results were correlated with simulations to establish the physical origin of the change in the fundamental mode and higher-order modes due to the refractive index and thickness of analyte. As a demonstration of an application and to test the limits of sensing, the substrates were used to image the surface functionalization using 2-nm-thick 11-mercaptoundecanoic acid and immobilization of 7-nm-thick mouse anti-human IgG antibody. In biological systems, where a priori knowledge about a process step is available, where accurate chemical composition testing is not necessary or possible, the presented method could be used to study the surface changes using a label-free sensing mechanism.
Advanced FeTiNbO6/poly(vinylidene fluoride) composites with a high dielectric permittivity near the percolation threshold
Authors: Fu Jing , Hou Yudong , Wei Qiaoyi , Zheng Mupeng , Zhu Mankang , Yan Hui
Published: December 2015

FeTiNbO6 (denoted as FTN) is a recently discovered giant dielectric material with high Curie temperature (550 K). In this work, well dispersive FTN particles with mean particle size about 500 nm were synthesized by the improved solid-state reaction method. Using FTN particles as fillers and poly(vinylidene fluoride) (denoted as PVDF) polymer as matrix, multi-volume ratio (0%–60%) homogeneous ceramic/polymer composites have been prepared through a hot-pressing technology. At the same filling content, the FTN/PVDF composites display higher dielectric permittivity compared to the normal reported BaTiO3/PVDF composites, even larger than that of PVDF based composites using giant dielectric CaCu3Ti4O12 as filler. Especially, for 40 vol. % FTN/PVDF composites, the dielectric permittivity is as high as 181 measured at 100 Hz and 25 °C. Through the theoretical analysis correlated with structure evolution observation, it is deduced that the high dielectric performance originates from the combined effect of a variety of factors, such as giant dielectric semiconducting FTN particles, the micro-capacitor structure, and percolation phenomenon at appropriate volume fraction of FTN. Moreover, FTN/PVDF composites present strong dielectric relaxation behavior, which results from the superposition of the dielectric relaxation between PVDF and FTN. These flexible, easy processing FTN/PVDF composites with large dielectric permittivity values could find applications as new generational embedded capacitors.
Printing low-voltage dielectric elastomer actuators
Authors: Poulin Alexandre , Rosset Samuel , Shea Herbert R.
Published: December 2015

We demonstrate the fabrication of fully printed thin dielectric elastomer actuators (DEAs), reducing the operation voltage below 300 V while keeping good actuation strain. DEAs are soft actuators capable of strains greater than 100% and response times below 1 ms, but they require driving voltage in the kV range, limiting the possible applications. One way to reduce the driving voltage of DEAs is to decrease the dielectric membrane thickness, which is typically in the 20–100 μm range, as reliable fabrication becomes challenging below this thickness. We report here the use of pad-printing to produce μm thick silicone membranes, on which we pad-print μm thick compliant electrodes to create DEAs. We achieve a lateral actuation strain of 7.5% at only 245 V on a 3 μm thick pad-printed membrane. This corresponds to a ratio of 125%/kV2, by far the highest reported value for DEAs. To quantify the increasing stiffening impact of the electrodes on DEA performance as the membrane thickness decreases, we compare two circular actuators, one with 3 μm- and one with 30 μm-thick membranes. Our experimental measurements show that the strain uniformity of the 3 μm-DEA is indeed affected by the mechanical impact of the electrodes. We developed a simple DEA model that includes realistic electrodes of finite stiffness, rather than assuming zero stiffness electrodes as is commonly done. The simulation results confirm that the stiffening impact of the electrodes is an important parameter that should not be neglected in the design of thin-DEAs. This work presents a practical approach towards low-voltage DEAs, a critical step for the development of real world applications.
Oblique solitary waves in a five component plasma
Authors: Sijo S. , Manesh M. , Sreekala G. , Neethu T. W. , Renuka G. , Venugopal C.
Published: December 2015

We investigate the influence of a second electron component on oblique dust ion acoustic solitary waves in a five component plasma consisting of positively and negatively charged dust, hydrogen ions, and hotter and colder electrons. Of these, the heavier dust and colder photo-electrons are of cometary origin while the other two are of solar origin; electron components are described by kappa distributions. The K-dV equation is derived, and different attributes of the soliton such as amplitude and width are plotted for parameters relevant to comet Halley. We find that the second electron component has a profound influence on the solitary wave, decreasing both its amplitude and width. The normalized hydrogen density strongly influences the solitary wave by decreasing its width; the amplitude of the solitary wave, however, increases with increasing solar electron temperatures.
Features in the ion emission of Cu, Al, and C plasmas produced by ultrafast laser ablation
Authors: Kelly T. J. , Butler T. , Walsh N. , Hayden P. , Costello J. T.
Published: December 2015

The bi-modal nature of charge integrated ion kinetic energy distributions, which result from ultrafast laser produced plasmas, is discussed in this paper. A negatively biased Faraday cup was used as a charge collector to measure ion distributions from three different solid targets that had been irradiated with an ultrafast laser in the fluence range 0.1–1 J/cm2. A bi-modal time of flight distribution is found for all three targets (C, Al, and Cu). In the case of the metallic targets (Al and Cu), high- and low-kinetic energy peaks exhibit quite different dependencies on laser fluence, whereas for the semi-metallic target (C), both peaks scale similarly with ultrafast laser fluence. The results are discussed within the framework of a one dimensional capacitor model resulting in ion acceleration.