bluuebunny/crossref_metadata_2025 huggingface dataset:
Ursachen des Hausärztemangels – ein Vergleich zwischen Frankreich und der Schweiz
Authors: Cerny Thomas , Rosemann Thomas , Tandjung Ryan , Chmiel Corinne
Published: May 2016

Zusammenfassung. Hintergrund und Fragestellung: Sowohl Frankreich als auch die Schweiz beklagen einen Hausärzte(HA)mangel. Bestehen Unterschiede/Parallelen zwischen den Ursachen in beiden Ländern? Was können wir aus einem systematischen Vergleich lernen? Methodik: Literaturreview mit qualitativer und semiquantitativer Inhaltsanalyse. Ergebnisse: Parallelen bestehen in den Kategorien Arbeitsinhalte, Arbeitsstrukturen, Ökonomie, Sozialstatus, Ausbildung, Privatleben, psychische Motive. Unterschiede bestehen in den Kategorien Biografie, soziale Selektion, medizinische Sozialisation, Weiterbildung. Letztere ist in der Schweiz nicht einheitlich strukturiert, selten institutionell organisiert, enthält wenig HA(Hausarzt)-Medizin-spezifische Inhalte. Die medizinische Sozialisierung in Frankreich überhöht im Unterschied zur Schweiz nicht nur die Spezialisten, sondern entwertet stark die HA-Medizin. Schlussfolgerungen: Durch die systematische Literatur-Analyse können beide Länder mehrfach voneinander lernen. Diese Arbeit zeigt konkrete Massnahmen vom Studium über Weiterbildung bis zur hausärztlichen Arbeitsstruktur auf, wie dem HA-Mangel aktiv entgegengewirkt werden kann.
A conserved leucine occupies the empty substrate site of LeuT in the Na+-free return state
Authors: Malinauskaite Lina , Said Saida , Sahin Caglanur , Grouleff Julie , Shahsavar Azadeh , Bjerregaard Henriette , Noer Pernille , Severinsen Kasper , Boesen Thomas , Schiøtt Birgit , Sinning Steffen , Nissen Poul
Published: May 2016

Bacterial members of the neurotransmitter:sodium symporter (NSS) family perform Na+-dependent amino-acid uptake and extrude H+ in return. Previous NSS structures represent intermediates of Na+/substrate binding or intracellular release, but not the inward-to-outward return transition. Here we report crystal structures of Aquifex aeolicus LeuT in an outward-oriented, Na+- and substrate-free state likely to be H+-occluded. We find a remarkable rotation of the conserved Leu25 into the empty substrate-binding pocket and rearrangements of the empty Na+ sites. Mutational studies of the equivalent Leu99 in the human serotonin transporter show a critical role of this residue on the transport rate. Molecular dynamics simulations show that extracellular Na+ is blocked unless Leu25 is rotated out of the substrate-binding pocket. We propose that Leu25 facilitates the inward-to-outward transition by compensating a Na+- and substrate-free state and acts as the gatekeeper for Na+ binding that prevents leak in inward-outward return transitions.
Differences in the efficacy of climate forcings explained by variations in atmospheric boundary layer depth
Authors: Davy Richard , Esau Igor
Published: May 2016

The Earth has warmed in the last century and a large component of that warming has been attributed to increased anthropogenic greenhouse gases. There are also numerous processes that introduce strong, regionalized variations to the overall warming trend. However, the ability of a forcing to change the surface air temperature depends on its spatial and temporal distribution. Here we show that the efficacy of a forcing is determined by the effective heat capacity of the atmosphere, which in cold and dry climates is defined by the depth of the planetary boundary layer. This can vary by an order of magnitude on different temporal and spatial scales, and so we get a strongly amplified temperature response in shallow boundary layers. This must be accounted for to assess the efficacy of a climate forcing, and also implies that multiple climate forcings cannot be linearly combined to determine the temperature response.
Oxygen isotope in archaeological bioapatites from India: Implications to climate change and decline of Bronze Age Harappan civilization
Authors: Sarkar Anindya , Mukherjee Arati Deshpande , Bera M. K. , Das B. , Juyal Navin , Morthekai P. , Deshpande R. D. , Shinde V. S. , Rao L. S.
Published: May 2016

The antiquity and decline of the Bronze Age Harappan civilization in the Indus-Ghaggar-Hakra river valleys is an enigma in archaeology. Weakening of the monsoon after ~5 ka BP (and droughts throughout the Asia) is a strong contender for the Harappan collapse, although controversy exists about the synchroneity of climate change and collapse of civilization. One reason for this controversy is lack of a continuous record of cultural levels and palaeomonsoon change in close proximity. We report a high resolution oxygen isotope (δ18O) record of animal teeth-bone phosphates from an archaeological trench itself at Bhirrana, NW India, preserving all cultural levels of this civilization. Bhirrana was part of a high concentration of settlements along the dried up mythical Vedic river valley ‘Saraswati’, an extension of Ghaggar river in the Thar desert. Isotope and archaeological data suggest that the pre-Harappans started inhabiting this area along the mighty Ghaggar-Hakra rivers fed by intensified monsoon from 9 to 7 ka BP. The monsoon monotonically declined after 7 ka yet the settlements continued to survive from early to mature Harappan time. Our study suggests that other cause like change in subsistence strategy by shifting crop patterns rather than climate change was responsible for Harappan collapse.
FAM83H and casein kinase I regulate the organization of the keratin cytoskeleton and formation of desmosomes
Authors: Kuga Takahisa , Sasaki Mitsuho , Mikami Toshinari , Miake Yasuo , Adachi Jun , Shimizu Maiko , Saito Youhei , Koura Minako , Takeda Yasunori , Matsuda Junichiro , Tomonaga Takeshi , Nakayama Yuji
Published: May 2016

FAM83H is essential for the formation of dental enamel because a mutation in the FAM83H gene causes amelogenesis imperfecta (AI). We previously reported that the overexpression of FAM83H often occurs and disorganizes the keratin cytoskeleton in colorectal cancer cells. We herein show that FAM83H regulates the organization of the keratin cytoskeleton and maintains the formation of desmosomes in ameloblastoma cells. FAM83H is expressed and localized on keratin filaments in human ameloblastoma cell lines and in mouse ameloblasts and epidermal germinative cells in vivo. FAM83H shows preferential localization to keratin filaments around the nucleus that often extend to cell-cell junctions. Alterations in the function of FAM83H by its overexpression, knockdown, or an AI-causing truncated mutant prevent the proper organization of the keratin cytoskeleton in ameloblastoma cells. Furthermore, the AI-causing mutant prevents desmosomal proteins from being localized to cell-cell junctions. The effects of the AI-causing mutant depend on its binding to and possible inhibition of casein kinase I (CK-1). The suppression of CK-1 by its inhibitor, D4476, disorganizes the keratin cytoskeleton. Our results suggest that AI caused by the FAM83H mutation is mediated by the disorganization of the keratin cytoskeleton and subsequent disruption of desmosomes in ameloblasts.
Correction: Corrigendum: 3D printed cellular solid outperforms traditional stochastic foam in long-term mechanical response
Authors: Maiti A. , Small W. , Lewicki J. P. , Weisgraber T. H. , Duoss E. B. , Chinn S. C. , Pearson M. A. , Spadaccini C. M. , Maxwell R. S. , Wilson T. S.
Published: May 2016

Scientific Reports 6: Article number: 24871; Published online: 27 April 2016; Updated 25 May 2016 The Acknowledgements section in this Article is incomplete. “We would like to sincerely thank Dr. Jim Schneider of National Security Campus, MO (formerly Kansas City Plant) for giving us access to the results of their load retention study on the stochastic foam material.
Distinct doping dependence of critical temperature and critical current density in Ba1−xKxFe2As2 superconductor
Authors: Song Dongjoon , Ishida Shigeyuki , Iyo Akira , Nakajima Masamichi , Shimoyama Jun-ichi , Eisterer Michael , Eisaki Hiroshi
Published: May 2016

Since the high transition temperature (High-Tc) superconductivity was discovered in the series of materials containing iron (Fe), their potential for the applications has been extensively scrutinized. In particular, a lot of effort has been made in achieving the high current-carrying ability by revealing the vortex pinning behavior. Here, we report on the critical current density (Jc) for the pristine Ba1−xKxFe2As2 single crystals with various K concentrations (0.25 ≤ x ≤ 0.52) determined by the magnetization hysteresis loop measurements. The x-dependence of Jc is characterized by a spike-like peak at x ~ 0.30, which corresponds to the under-doped region. This behavior is distinct from a moderate Tc dome with a broad maximum spanning from x ~ 0.3 to 0.5. For the under-doped samples, with increasing magnetic field (H), a second magnetization peak in Jc is observed, whereas for the optimally- and over-doped samples, Jc monotonically decreases with H. This result emphasizes that fine tuning of doping composition is important to obtain strong flux pinning. The origin of the characteristic doping dependence of Jc is discussed in connection with the orthorhombic phase domain boundary, as well as the chemical inhomogeneity introduced by the dopant substitutions.
MicroRNA-146a suppresses ROCK1 allowing hyperphosphorylation of tau in Alzheimer’s disease
Authors: Wang Gang , Huang Yue , Wang Li-Ling , Zhang Yong-Fang , Xu Jing , Zhou Yi , Lourenco Guinevere F. , Zhang Bei , Wang Ying , Ren Ru-Jing , Halliday Glenda M. , Chen Sheng-Di
Published: May 2016

MicroRNA-146a is upregulated in the brains of patients with Alzheimer’s disease (AD). Here, we show that the rho-associated, coiled-coil containing protein kinase 1 (ROCK1) is a target of microRNA-146a in neural cells. Knockdown of ROCK1 mimicked the effects of microRNA-146a overexpression and induced abnormal tau phosphorylation, which was associated with inhibition of phosphorylation of the phosphatase and tensin homolog (PTEN). The ROCK1/PTEN pathway has been implicated in the neuronal hyperphosphorylation of tau that occurs in AD. To determine the function of ROCK1 in AD, brain tissue from 17 donors with low, intermediate or high probability of AD pathology were obtained and analyzed. Data showed that ROCK1 protein levels were reduced and ROCK1 colocalised with hyperphosphorylated tau in early neurofibrillary tangles. Intra-hippocampal delivery of a microRNA-146a specific inhibitor (antagomir) into 5xFAD mice showed enhanced hippocampal levels of ROCK1 protein and repressed tau hyperphosphorylation, partly restoring memory function in the 5xFAD mice. Our in vitro and in vivo results confirm that dysregulation of microRNA-146a biogenesis contributes to tau hyperphosphorylation and AD pathogenesis and inhibition of this microRNA could be a viable novel in vivo therapy for AD.
Composition and aggregation of extracellular polymeric substances (EPS) in hyperhaline and municipal wastewater treatment plants
Authors: Zeng Jie , Gao Jun-Min , Chen You-Peng , Yan Peng , Dong Yang , Shen Yu , Guo Jin-Song , Zeng Ni , Zhang Peng
Published: May 2016

As important constituents of activated sludge flocs, extracellular polymeric substances (EPS) play significant roles in pollutants adsorption, the formation and maintenance of microbial aggregates and the protection of microbes from external environmental stresses. In this work, EPS in activated sludge from a municipal wastewater treatment plant (M-WWTP) with anaerobic/anoxic/oxic (A2/O) process and a hyperhaline wastewater treatment plant (H-WWTP) with anaerobic/oxic (A/O) process were extracted by ultrasound method. The proteins and polysaccharides contents in EPS were determined by using a modified Lowry method and anthrone colorimetry respectively to analyze the detail differences in two types of WWTPs. Fourier transform-infrared spectroscopy and three-dimensional excitation-emission matrix fluorescence spectroscopy demonstrated proteins and polysaccharides were the dominant components of the two types of EPS and the aromatic protein-like substances accounted for a larger proportion in EPS proteins. The results of the aggregation test indicated that EPS were good for the sludge aggregation and the EPS in oxic sludge were more beneficial to sludge aggregation than that in anoxic sludge. Anoxic sludge EPS in H-WWTP showed a negligible effect on sludge aggregation. Comparative study on EPS of different tanks in the M-WWTP and H-WWTP was valuable for understanding the characteristics of EPS isolated from two typical wastewater treatment processes.
Multicolour Multilevel STED nanoscopy of Actin/Spectrin Organization at Synapses
Authors: Sidenstein Sven C. , D’Este Elisa , Böhm Marvin J. , Danzl Johann G. , Belov Vladimir N. , Hell Stefan W.
Published: May 2016

Superresolution fluorescence microscopy of multiple fluorophores still requires development. Here we present simultaneous three-colour stimulated emission depletion (STED) nanoscopy relying on a single STED beam at 620 nm. Toggling the STED beam between two or more power levels (“multilevelSTED”) optimizes resolution and contrast in all colour channels, which are intrinsically co-aligned and well separated. Three-colour recording is demonstrated by imaging the nanoscale cytoskeletal organization in cultured hippocampal neurons. The down to ~35 nm resolution identified periodic actin/betaII spectrin lattices along dendrites and spines; however, at presynaptic and postsynaptic sites, these patterns were found to be absent. Both our multicolour scheme and the 620 nm STED line should be attractive for routine STED microscopy applications.
Abundance and Temperature Dependency of Protein-Protein Interaction Revealed by Interface Structure Analysis and Stability Evolution
Authors: He Yi-Ming , Ma Bin-Guang
Published: May 2016

Protein complexes are major forms of protein-protein interactions and implement essential biological functions. The subunit interface in a protein complex is related to its thermostability. Though the roles of interface properties in thermal adaptation have been investigated for protein complexes, the relationship between the interface size and the expression level of the subunits remains unknown. In the present work, we studied this relationship and found a positive correlation in thermophiles rather than mesophiles. Moreover, we found that the protein interaction strength in complexes is not only temperature-dependent but also abundance-dependent. The underlying mechanism for the observed correlation was explored by simulating the evolution of protein interface stability, which highlights the avoidance of misinteraction. Our findings make more complete the picture of the mechanisms for protein complex thermal adaptation and provide new insights into the principles of protein-protein interactions.
Coiling ultrathin tellurium nanowires into nanorings by Pickering emulsion
Authors: Yang Ye , Liu Jian-Wei , Yu Shu-Hong
Published: May 2016

Well-defined hydrophilic ultrathin tellurium nanowires (TeNWs) can be coiled into nanorings by Pickering emulsion at room temperature.
A hydrophobic three-dimensionally networked boron-doped diamond electrode towards electrochemical oxidation
Authors: He Yapeng , Lin Haibo , Wang Xue , Huang Weimin , Chen Rongling , Li Hongdong
Published: May 2016

Three-dimensionally networked boron-doped diamond with a microstructure and enhanced mass transfer showed excellent electro-oxidation ability towards contaminants.
Molecular dynamics simulations and CD spectroscopy reveal hydration-induced unfolding of the intrinsically disordered LEA proteins COR15A and COR15B from Arabidopsis thaliana
Authors: Navarro-Retamal Carlos , Bremer Anne , Alzate-Morales Jans , Caballero Julio , Hincha Dirk K. , González Wendy , Thalhammer Anja
Published: May 2016

Unfolding of intrinsically unstructured full-length LEA proteins in a differentially crowded environment can be modeled by 30 ns MD simulations in accordance with experimental data.
Photoisomerization of azobenzenes isolated in cryogenic matrices
Authors: Duarte Luís , Khriachtchev Leonid , Fausto Rui , Reva Igor
Published: May 2016

E–EandE–Zisomerization reactions were studied in azobenzene and its 2,2′ OH- and CH3-derivatives isolated in cryogenic matrices.
Hexamethyl-p-terphenyl poly(benzimidazolium): a universal hydroxide-conducting polymer for energy conversion devices
Authors: Wright Andrew G. , Fan Jiantao , Britton Benjamin , Weissbach Thomas , Lee Hsu-Feng , Kitching Elizabeth A. , Peckham Timothy J. , Holdcroft Steven
Published: May 2016

A benchmark hydroxide-conducting polymer is utilized in alkaline hydrogen fuel cell and water electrolyzer devices at 60 °C for >100 hours.
Pyroelectric control of magnetization for tuning thermomagnetic energy conversion and magnetocaloric effect
Authors: Vats Gaurav , Kumar Ashok , Ortega Nora , Bowen Chris R. , Katiyar Ram S.
Published: May 2016

Demonstration of pyroelectric control of magnetization in ferroelectric/magnetic/ferroelectric multi-layered nanostructures for tuning thermomagnetic energy conversion efficiency and magnetocaloric effect.
A canonical correlation analysis based method for contamination event detection in water sources
Authors: Li Ruonan , Liu Shuming , Smith Kate , Che Han
Published: May 2016

In this study, a general framework integrating a data-driven estimation model is employed for contamination event detection in water sources.
A theoretical consideration of ion size effects on the electric double layer and voltammetry of nanometer-sized disk electrodes
Authors: Gao Yu , Liu Yuwen , Chen Shengli
Published: May 2016

Considering that an electric-double-layer (EDL) structure may significantly impact on the mass transport and charge transfer kinetics at the interfaces of nanometer-sized electrodes, while EDL structures could be altered by the finite sizes of electrolyte and redox ions, the possible effects of ion sizes on EDL structures and voltammetric responses of nanometer-sized disk (nanodisk) electrodes are investigated. Modified Boltzmann and Nernst–Planck (NP) equations, which include the influence of the finite ion volumes, are combined with the Poisson equation and modified Butler–Volmer equation to gain knowledge on how the finite sizes of ions and the nanometer sizes of electrodes may couple with each other to affect the structures and reactivities of a nanoscale electrochemical interface. Two typical ion radii, 0.38 nm and 0.68 nm, which could represent the sizes of the commonly used aqueous electrolyte ions (e.g., the solvated K+) and the organic electrolyte ions (e.g., the solvated TEA+) respectively, are considered. The finite size of ions can result in decreased screening of electrode charges, therefore magnifying EDL effects on the ion transport and the electron transfer at electrochemical interfaces. This finite size effect of ions becomes more pronounced for larger ions and at smaller electrodes as the electrode radii is larger than 10 nm. For electrodes with radii smaller than 10 nm, however, the ion size effect may be less pronounced with decreasing the electrode size. This can be explained in terms of the increased edge effect of disk electrodes at nanometer scales, which could relax the ion crowding at/near the outer Helmholtz plane. The conditions and situations under which the ion sizes may have a significant effect on the voltammetry of electrodes are discussed.
Complexity in structure-directed prebiotic chemistry. Unexpected compositional richness from competing reactants in tetrapyrrole formation
Authors: Deans Richard M. , Taniguchi Masahiko , Chandrashaker Vanampally , Ptaszek Marcin , Chambers Dana R. , Soares Ana R. M. , Lindsey Jonathan S.
Published: May 2016

Acyclic reactants afford “partially defective” pyrroles that interfere with chain growth of “normal” pyrroles on the path to tetrapyrrole macrocycles.
Exploiting the σ-phylic properties of cationic gold(i) catalysts in the ring opening reactions of aziridines with indoles
Authors: Rossi Elisabetta , Abbiati Giorgio , Dell'Acqua Monica , Negrato Marco , Paganoni Andrea , Pirovano Valentina
Published: May 2016

Gold(i) species catalyze the ring opening reactions of aziridines with indoles as nucleophiles for the synthesis of tryptamines and pyrroloindolines.
Synthesis and evaluation of new 2-aminothiophenes against Mycobacterium tuberculosis
Authors: Thanna Sandeep , Knudson Susan E. , Grzegorzewicz Anna , Kapil Sunayana , Goins Christopher M. , Ronning Donald R. , Jackson Mary , Slayden Richard A. , Sucheck Steven J.
Published: May 2016

New 2-aminothiophenes (2AT) were identified with MICs = 0.23–0.44 μM against drug sensitive and drug resistant strains ofMycobacterium tuberculosis.
Construction of biocompatible regenerated cellulose/SPI composite beads using high-voltage electrostatic technique
Authors: Li Chen , He Meng , Tong Zan , Li Yinping , Sheng Wen , Luo Lan , Tong Yu , Yu Hao , Huselstein Celine , Chen Yun
Published: May 2016

Regenerated cellulose/SPI composite beads fabricated by a high-voltage electrostatic technique exhibited good cytocompatibility.
A pre-lithiated phloroglucinol based 3D porous framework as a single ion conducting electrolyte for lithium ion batteries
Authors: Rohan Rupesh , Pareek Kapil , Chen Zhongxin , Cheng Hansong
Published: May 2016

We report the design and synthesis of an inherently porous single ion conducting gel electrolyte made from a pre-lithiated phloroglucinol-terephthalaldehyde 3D framework for lithium ion batteries, adopting a “bottom-up” approach.
Mechanism aspects of the hydrogenation of acrylonitrile on Ni and Pd surfaces
Authors: Ge Xin , Pan Jiongbin , Chen Xinzhi , Qian Chao , Zhou Shaodong
Published: May 2016

A combined experimental and theoretical investigation on the hydrogenation of acrylonitrile catalyzed by Ni and Pd is presented.
N-rich porous carbon with high CO2 capture capacity derived from polyamine-incorporated metal–organic framework materials
Authors: Wang Junwen , Lin Yichao , Yue Qunfeng , Tao Kai , Kong Chunlong , Chen Liang
Published: May 2016

A series of N-rich porous carbons are derived from polyamine-incorporated ZIF-70. After the carbonization process, the porous carbons exhibit greatly enhanced CO2-selective adsorption capacity compared to ZIF-70 and porous carbon derived from ZIF-70.
Tailoring the multiferroic behavior in BiFeO3nanostructures by Pb doping
Authors: Verma Kuldeep Chand , Kotnala R. K.
Published: May 2016

Substituting Pb2+for Bi3+in BiFeO3can induce lattice distortions and structural transitions to tune the lone-pair activity for ferroelectricity and neutralized oxygen vacancies to valence Fe2+/Fe3+ions for ferromagnetism.
Correction: Bovine glutamate dehydrogenase immobilization on magnetic nanoparticles: conformational changes and catalysis
Authors: Marques Netto Caterina G. C. , da Silva Delmárcio G. , Toma Sergio H. , Andrade Leandro H. , Nakamura Marcelo , Araki Koiti , Toma Henrique E.
Published: May 2016

Correction for ‘Bovine glutamate dehydrogenase immobilization on magnetic nanoparticles: conformational changes and catalysis’ by Caterina G. C. Marques Netto et al., RSC Adv., 2016, 6, 12977–12992.
Foxa2 and Hif1ab regulate maturation of intestinal goblet cells by modulating agr2 expression in zebrafish embryos
Authors: Lai Yun-Ren , Lu Yu-Fen , Lien Huang-Wei , Huang Chang-Jen , Hwang Sheng-Ping L.
Published: May 2016

Mammalian anterior gradient 2 (AGR2), an endoplasmic reticulum (ER) protein disulfide-isomerase (PDI), is involved in cancer cell growth and metastasis, asthma and inflammatory bowel disease (IBD). Mice lacking Agr2 exhibit decreased Muc2 protein in intestinal goblet cells, abnormal Paneth cell development, ileitis and colitis. Despite its importance in cancer biology and inflammatory diseases, the mechanisms regulating agr2 expression in the gastrointestinal tract remain unclear. In the present study, we investigated the mechanisms that control agr2 expression in the pharynx and intestine of zebrafish by transient/stable transgenesis, coupled with motif mutation, morpholino knockdown, mRNA rescue and ChIP. A 350 bp DNA sequence with a hypoxia-inducible response element (HRE) and forkhead-response element (FHRE) within a region −4.5 to −4.2 kbp upstream of agr2 directed EGFP expression specifically in the pharynx and intestine. No EGFP expression was detected in the intestinal goblet cells of Tg(HREM:EGFP) or Tg(FHREM:EGFP) embryos with mutated HRE or FHRE, whereas EGFP was expressed in the pharynx of Tg(HREM:EGFP), but not Tg(FHREM:EGFP), embryos. Morpholino knockdown of foxa1 (forkhead box A1) reduced agr2 levels in the pharynx, whereas knockdown of foxa2 or hif1ab decreased intestinal agr2 expression and affected the differentiation and maturation of intestinal goblet cells. These results demonstrate that Foxa1 regulates agr2 expression in the pharynx, whereas both Foxa2 and Hif1ab control agr2 expression in intestinal goblet cells to regulate maturation of these cells.
Mutual coupling reduction between closely spaced microstrip antennas by means of H‐shaped conducting wall
Authors: Park C.‐H. , Son H.‐W.
Published: May 2016

This Letter presents a novel H‐shaped conducting wall structure that effectively suppresses the mutual coupling between two closely spaced microstrip antennas (MSAs). The wall consists of an H‐shaped copper strip printed on a dielectric substrate, and a row of periodic vias through which the strip is connected to a ground plane. The wall is inserted between the MSAs and surrounds half the periphery of each antenna. Measurements of a prototype show that the high isolation of about 51 dB is achieved between two MSAs separated by the edge‐to‐edge distance of 0.052 λ0 at 5.2 GHz. The proposed structure greatly improves the isolation without causing any significant degradation of the antenna bandwidth, gain, or front‐to‐back ratio, unlike other isolation structures based on resonators or defected ground structures.
Second‐order VCO‐based ΔΣ ADC using a modified DPLL
Authors: Sanyal A. , Sun N.
Published: May 2016

A novel purely VCO‐based architecture for a second‐order ΔΣ ADC is presented. The proposed architecture achieves in‐band second‐order quantisation noise shaping. The proposed ADC is highly digital and well suited for design in scaled technologies. The architecture has been validated with MATLAB Simulink based models.
DC‐side fault detection for photovoltaic energy conversion system using fractional‐order dynamic‐error‐based fuzzy Petri net integrated with intelligent meters
Authors: Chen Jian‐Liung , Kuo Chao‐Lin , Chen Shi‐Jaw , Kao Chih‐Cheng , Zhan Tung‐Sheng , Lin Chia‐Hung , Chen Ying‐Shin
Published: May 2016

Fault occurrence or voltage disturbance, such as mismatch operations or electrical faults caused by structural changes in photovoltaic (PV) panels, local/remote faults, or heavy load operation, can disturb a PV energy conversion system (PVECS) on both the DC and AC sides. On the AC side, any serious disturbance can be isolated using power fuses, overcurrent protection and ground‐fault protection devices. Therefore, the authors propose the use of fractional‐order dynamic‐error‐based fuzzy Petri net (FPN) to detect disturbance events in a microdistribution system. PV energy conversion depends on solar radiation and temperature, and a maximum power point tracking control is used to maintain stable output power and voltage to microdistribution loads. When the desired maximum power is estimated, a bisection approach algorithm is used to regulate the output voltage of the PVECS by adjusting the duty ratios of a buck–boost converter. The maximum power drops, which are compared with meter‐reading power from intelligent meters, are used to detect faults on the DC side. Then, fractional‐order dynamic errors between the desired and estimated powers and a FPN are employed to detect faults. For a small‐scale PVECS, computer simulations are conducted to show the effectiveness of the proposed model.
Multi-dimensional rheology-based two-phase model for sediment transport and applications to sheet flow and pipeline scour
Authors: Lee Cheng-Hsien , Low Ying Min , Chiew Yee-Meng
Published: May 2016

Sediment transport is fundamentally a two-phase phenomenon involving fluid and sediments; however, many existing numerical models are one-phase approaches, which are unable to capture the complex fluid-particle and inter-particle interactions. In the last decade, two-phase models have gained traction; however, there are still many limitations in these models. For example, several existing two-phase models are confined to one-dimensional problems; in addition, the existing two-dimensional models simulate only the region outside the sand bed. This paper develops a new three-dimensional two-phase model for simulating sediment transport in the sheet flow condition, incorporating recently published rheological characteristics of sediments. The enduring-contact, inertial, and fluid viscosity effects are considered in determining sediment pressure and stresses, enabling the model to be applicable to a wide range of particle Reynolds number. A k − ε turbulence model is adopted to compute the Reynolds stresses. In addition, a novel numerical scheme is proposed, thus avoiding numerical instability caused by high sediment concentration and allowing the sediment dynamics to be computed both within and outside the sand bed. The present model is applied to two classical problems, namely, sheet flow and scour under a pipeline with favorable results. For sheet flow, the computed velocity is consistent with measured data reported in the literature. For pipeline scour, the computed scour rate beneath the pipeline agrees with previous experimental observations. However, the present model is unable to capture vortex shedding; consequently, the sediment deposition behind the pipeline is overestimated. Sensitivity analyses reveal that model parameters associated with turbulence have strong influence on the computed results.
Modified Newton-Raphson GRAPE methods for optimal control of spin systems
Authors: Goodwin D. L. , Kuprov Ilya
Published: May 2016

Quadratic convergence throughout the active space is achieved for the gradient ascent pulse engineering (GRAPE) family of quantum optimal control algorithms. We demonstrate in this communication that the Hessian of the GRAPE fidelity functional is unusually cheap, having the same asymptotic complexity scaling as the functional itself. This leads to the possibility of using very efficient numerical optimization techniques. In particular, the Newton-Raphson method with a rational function optimization (RFO) regularized Hessian is shown in this work to require fewer system trajectory evaluations than any other algorithm in the GRAPE family. This communication describes algebraic and numerical implementation aspects (matrix exponential recycling, Hessian regularization, etc.) for the RFO Newton-Raphson version of GRAPE and reports benchmarks for common spin state control problems in magnetic resonance spectroscopy.
Combined theoretical and experimental study of the valence, Rydberg and ionic states of fluorobenzene
Authors: Palmer Michael H. , Ridley Trevor , Vrønning Hoffmann Søren , Jones Nykola C. , Coreno Marcello , de Simone Monica , Grazioli Cesare , Zhang Teng , Biczysko Malgorzata , Baiardi Alberto , Peterson Kirk A.
Published: May 2016

New photoelectron spectra (PES) and ultra violet (UV) and vacuum UV (VUV) absorption spectra of fluorobenzene recorded at higher resolution than previously, have been combined with mass-resolved (2 + 1) and (3 + 1) resonance enhanced multiphoton ionization (REMPI) spectra; this has led to the identification of numerous Rydberg states. The PES have been compared with earlier mass-analyzed threshold ionization and photoinduced Rydberg ionization (PIRI) spectra to give an overall picture of the ionic state sequence. The analysis of these spectra using both equations of motion with coupled cluster singles and doubles (EOM-CCSD) configuration interaction and time dependent density functional theory (TDDFT) calculations have been combined with vibrational analysis of both the hot and cold bands of the spectra, in considerable detail. The results extend several earlier studies on the vibronic coupling leading to conical intersections between the X2B1 and A2A2 states, and a further trio (B, C, and D) of states. The conical intersection of the X and A states has been explicitly identified, and its structure and energetics evaluated. The energy sequence of the last group is only acceptable to the present study if given as B2B2<C2B1<D2A1, a conclusion which is in agreement with most previous EOM-CCSD and other calculations. However, this symmetry ordering of the B and C states forces reconsideration of the nature of the PIRI spectrum. The coupling between these two states is induced by the a2 modes, ν12 and ν14 and we propose that the 141 band is observed in the B2B2 band in the PES for the first time, because of the improved resolution. This same assignment is given to the lowest energy band in the PIRI spectrum which was previously assigned as the origin band and further conclude that the entire PIRI spectrum is induced by ν12 and ν14. The relative intensities of the various Rydberg state peaks in the VUV absorption and REMPI spectra of fluorobenzene are very similar to those observed in the equivalent spectra of benzene.
Computing bulk and shear viscosities from simulations of fluids with dissipative and stochastic interactions
Authors: Jung Gerhard , Schmid Friederike
Published: May 2016

Exact values for bulk and shear viscosity are important to characterize a fluid, and they are a necessary input for a continuum description. Here we present two novel methods to compute bulk viscosities by non-equilibrium molecular dynamics simulations of steady-state systems with periodic boundary conditions — one based on frequent particle displacements and one based on the application of external bulk forces with an inhomogeneous force profile. In equilibrium simulations, viscosities can be determined from the stress tensor fluctuations via Green-Kubo relations; however, the correct incorporation of random and dissipative forces is not obvious. We discuss different expressions proposed in the literature and test them at the example of a dissipative particle dynamics fluid.
Real-time diamagnetic flux measurements on ASDEX Upgrade
Authors: Giannone L. , Geiger B. , Bilato R. , Maraschek M. , Odstrčil T. , Fischer R. , Fuchs J. C. , McCarthy P. J. , Mertens V. , Schuhbeck K. H.
Published: May 2016

Real-time diamagnetic flux measurements are now available on ASDEX Upgrade. In contrast to the majority of diamagnetic flux measurements on other tokamaks, no analog summation of signals is necessary for measuring the change in toroidal flux or for removing contributions arising from unwanted coupling to the plasma and poloidal field coil currents. To achieve the highest possible sensitivity, the diamagnetic measurement and compensation coil integrators are triggered shortly before plasma initiation when the toroidal field coil current is close to its maximum. In this way, the integration time can be chosen to measure only the small changes in flux due to the presence of plasma. Two identical plasma discharges with positive and negative magnetic field have shown that the alignment error with respect to the plasma current is negligible. The measured diamagnetic flux is compared to that predicted by TRANSP simulations. The poloidal beta inferred from the diamagnetic flux measurement is compared to the values calculated from magnetic equilibrium reconstruction codes. The diamagnetic flux measurement and TRANSP simulation can be used together to estimate the coupled power in discharges with dominant ion cyclotron resonance heating.
Kinetic theory of diffusion-limited nucleation
Authors: Philippe T. , Bonvalet M. , Blavette D.
Published: May 2016

We examine binary nucleation in the size and composition space {R,c} using the formalism of the multivariable theory [N. V. Alekseechkin, J. Chem. Phys. 124, 124512 (2006)]. We show that the variable c drops out of consideration for very large curvature of the new phase Gibbs energy with composition. Consequently nuclei around the critical size have the critical composition, which is derived from the condition of criticality for the canonical variables and is found not to depend on surface tension. In this case, nucleation kinetics can be investigated in the size space only. Using macroscopic kinetics, we determine the general expression for the condensation rate when growth is limited by bulk diffusion, which accounts for both diffusion and capillarity and exhibits a different dependence with the critical size, as compared with the interface-limited regime. This new expression of the condensation rate for bulk diffusion-limited nucleation is the counterpart of the classical interface-limited result. We then extend our analysis to multicomponent solutions.
An instrument to measure fast gas phase radical kinetics at high temperatures and pressures
Authors: Stone Daniel , Blitz Mark , Ingham Trevor , Onel Lavinia , Medeiros Diogo J. , Seakins Paul W.
Published: May 2016

Fast radical reactions are central to the chemistry of planetary atmospheres and combustion systems. Laser-induced fluorescence is a highly sensitive and selective technique that can be used to monitor a number of radical species in kinetics experiments, but is typically limited to low pressure systems owing to quenching of fluorescent states at higher pressures. The design and characterisation of an instrument are reported using laser-induced fluorescence detection to monitor fast radical kinetics (up to 25 000 s−1) at high temperatures and pressures by sampling from a high pressure reaction region to a low pressure detection region. Kinetics have been characterised at temperatures reaching 740 K and pressures up to 2 atm, with expected maximum operational conditions of up to ∼900 K and ∼5 atm. The distance between the point of sampling from the high pressure region and the point of probing within the low pressure region is critical to the measurement of fast kinetics. The instrumentation described in this work can be applied to the measurement of kinetics relevant to atmospheric and combustion chemistry.
Specification and thermodynamical properties of semigroup actions
Authors: Rodrigues Fagner B. , Varandas Paulo
Published: May 2016

In the present paper, we study the thermodynamical properties of finitely generated continuous subgroup actions. We propose a notion of topological entropy and pressure functions that do not depend on the growth rate of the semigroup and introduce strong and orbital specification properties, under which the semigroup actions have positive topological entropy and all points are entropy points. Moreover, we study the convergence and Lipschitz regularity of the pressure function and obtain relations between topological entropy and exponential growth rate of periodic points in the context of semigroups of expanding maps, obtaining a partial extension of the results obtained by Ruelle for ℤd-actions [D. Ruelle, Trans. Am. Math. Soc., 187, 237–251 (1973)]. The specification properties for semigroup actions and the corresponding one for its generators and the action of push-forward maps are also discussed.
Analysis of short circuit current loss in rear emitter crystalline Si solar cell
Authors: Watahiki Tatsuro , Kobayashi Yumiko , Morioka Takayuki , Nishimura Shinya , Niinobe Daisuke , Nishimura Kunihiko , Tokioka Hidetada , Yamamuka Mikio
Published: May 2016

Short circuit current (Jsc) loss in rear emitter crystalline Si solar cell is analyzed in detail by a 2D device simulation and compared with the experimental results. There is a significant loss in Jsc for the rear emitter n-Si solar cell with an n-type doped front surface field (FSF) when the base substrate resistivity is low. It is due to an increase in recombination in the FSF region led by a less barrier height for minority carriers with a lower substrate resistivity. The barrier height less than 0.1 eV causes large loss in Jsc. To achieve higher Jsc for the cells with FSF, the control of the doping concentration in FSF, the substrate thickness, and the barrier height for the minority carriers are important. A rear emitter heterojunction Si solar cell with an amorphous Si passivation layer shows no substrate resistivity dependence on Jsc since an amorphous Si possess a higher barrier height and a long bulk lifetime of more than a few milliseconds.
AlN and Al oxy-nitride gate dielectrics for reliable gate stacks on Ge and InGaAs channels
Authors: Guo Y. , Li H. , Robertson J.
Published: May 2016

AlN and Al oxy-nitride dielectric layers are proposed instead of Al2O3 as a component of the gate dielectric stacks on higher mobility channels in metal oxide field effect transistors to improve their positive bias stress instability reliability. It is calculated that the gap states of nitrogen vacancies in AlN lie further away in energy from the semiconductor band gap than those of oxygen vacancies in Al2O3, and thus AlN might be less susceptible to charge trapping and have a better reliability performance. The unfavourable defect energy level distribution in amorphous Al2O3 is attributed to its larger coordination disorder compared to the more symmetrically bonded AlN. Al oxy-nitride is also predicted to have less tendency for charge trapping.
Ultrasound acoustic metamaterials with double-negative parameters
Authors: Chen Huaijun , Li Hui , Zhai Shilong , Ding Changlin , Li Jiamao , Luo Chunrong , Zhao Xiaopeng
Published: May 2016

We experimentally demonstrate a double-negative acoustic metamaterial (AM) that combines a hollow tube and a split hollow sphere into a structurally simple perforated hollow tube with the ability to generate simultaneous resonances in water. The effective acoustic parameters extracted from the transmission and reflection coefficients confirmed that negative effective mass density and modulus were achieved from 36.68 kHz to 36.96 kHz, and the effective index was also negative in the same frequency range. In addition, further experimental measurements confirmed that the well-designed AM could realize slab focusing phenomenon. With the unique properties, the proposed AM presents potential applications in sub-wavelength imaging and medical ultrasound treatment.
Self-aligned grating couplers on template-stripped metal pyramids via nanostencil lithography
Authors: Klemme Daniel J. , Johnson Timothy W. , Mohr Daniel A. , Oh Sang-Hyun
Published: May 2016

We combine nanostencil lithography and template stripping to create self-aligned patterns about the apex of ultrasmooth metal pyramids with high throughput. Three-dimensional patterns such as spiral and asymmetric linear gratings, which can couple incident light into a hot spot at the tip, are presented as examples of this fabrication method. Computer simulations demonstrate that spiral and linear diffraction grating patterns are both effective at coupling light to the tip. The self-aligned stencil lithography technique can be useful for integrating plasmonic couplers with sharp metallic tips for applications such as near-field optical spectroscopy, tip-based optical trapping, plasmonic sensing, and heat-assisted magnetic recording.
Dopant-controlled single-electron pumping through a metallic island
Authors: Wenz Tobias , Hohls Frank , Jehl Xavier , Sanquer Marc , Barraud Sylvain , Klochan Jevgeny , Barinovs Girts , Kashcheyevs Vyacheslavs
Published: May 2016

We investigate a hybrid metallic island/single dopant electron pump based on fully depleted silicon-on-insulator technology. Electron transfer between the central metallic island and the leads is controlled by resonant tunneling through single phosphorus dopants in the barriers. Top gates above the barriers are used to control the resonance conditions. Applying radio frequency signals to the gates, non-adiabatic quantized electron pumping is achieved. A simple deterministic model is presented and confirmed by comparing measurements with simulations.
Reconstruction of the modified discrete Langevin equation from persistent time series
Authors: Czechowski Zbigniew
Published: May 2016

The discrete Langevin-type equation, which can describe persistent processes, was introduced. The procedure of reconstruction of the equation from time series was proposed and tested on synthetic data, with short and long-tail distributions, generated by different Langevin equations. Corrections due to the finite sampling rates were derived. For an exemplary meteorological time series, an appropriate Langevin equation, which constitutes a stochastic macroscopic model of the phenomenon, was reconstructed.
Molecular electric moments calculated by using natural orbital functional theory
Authors: Mitxelena Ion , Piris Mario
Published: May 2016

The molecular electric dipole, quadrupole, and octupole moments of a selected set of 21 spin-compensated molecules are determined employing the extended version of the Piris natural orbital functional 6 (PNOF6), using the triple-ζ Gaussian basis set with polarization functions developed by Sadlej, at the experimental geometries. The performance of the PNOF6 is established by carrying out a statistical analysis of the mean absolute errors with respect to the experiment. The calculated PNOF6 electric moments agree satisfactorily with the corresponding experimental data and are in good agreement with the values obtained by accurate ab initio methods, namely, the coupled-cluster single and doubles and multi-reference single and double excitation configuration interaction methods.
Bunker probe: A plasma potential probe almost insensitive to its orientation with the magnetic field
Authors: Costea S. , Fonda B. , Kovačič J. , Gyergyek T. , Schneider B. S. , Schrittwieser R. , Ionita C.
Published: May 2016

Due to their ability to suppress a large part of the electron current and thus measuring directly the plasma potential, ion sensitive probes have begun to be widely tested and used in fusion devices. For these probes to work, almost perfect alignment with the total magnetic field is necessary. This condition cannot always be fulfilled due to the curvature of magnetic fields, complex magnetic structure, or magnetic field reconnection. In this perspective, we have developed a plasma potential probe (named Bunker probe) based on the principle of the ion sensitive probe but almost insensitive to its orientation with the total magnetic field. Therefore it can be used to measure the plasma potential inside fusion devices, especially in regions with complex magnetic field topology. Experimental results are presented and compared with Ball-Pen probe measurements taken under identical conditions. We have observed that the floating potential of the Bunker probe is indeed little affected by its orientation with the magnetic field for angles ranging from 90° to 30°, in contrast to the Ball-Pen probe whose floating potential decreases towards that of a Langmuir probe if not properly aligned with the magnetic field.
A method for suppression of spurious fundamental-harmonic waves in gyrotrons operating at the second cyclotron harmonic
Authors: Kalynov Yu. K. , Osharin I. V. , Savilov A. V.
Published: May 2016

A typical problem of gyrotrons operating at high harmonics of the electron cyclotron frequency is the suppression of parasitic near-cutoff waves excited at lower harmonics. In this paper, a method for a significant improvement of the selectivity of the second-harmonic gyrotrons is proposed. This method is based on the use of quasi-regular cavities with short irregularities, which provide different effects on the process of excitation of the operating second-harmonic wave and the spurious fundamental-harmonic wave by the electron beam.