bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectral responses of gravel beaches to tidal signals
Authors: Geng Xiaolong , Boufadel Michel C.
Published: January 2017

Tides have been recognized as a major driving forcing affecting coastal aquifer system, and deterministic modeling has been very effective in elucidating mechanisms caused by tides. However, such modeling does not lend itself to capture embedded information in the signal, and rather focuses on the primary processes. Here, using yearlong data sets measured at beaches in Alaska Prince William Sound, we performed spectral and correlation analyses to identify temporal behavior of pore-water pressure, temperature and salinity. We found that the response of the beach system was characterized by fluctuations of embedded diurnal, semidiurnal, terdiurnal and quarterdiurnal tidal components. Hydrodynamic dispersion of salinity and temperature, and the thermal conductivity greatly affected pore water signals. Spectral analyses revealed a faster dissipation of the semi-diurnal component with respect to the diurnal components. Correlation functions showed that salinity had a relatively short memory of the tidal signal when inland freshwater recharge was large. In contrast, the signature of the tidal signal on pore-water temperature persisted for longer times, up to a week. We also found that heterogeneity greatly affected beach response. The response varied from a simple linear mapping in the frequency domain to complete modulation and masking of the input frequencies.
Quantitative Fluorescence Quenching on Antibody-conjugated Graphene Oxide as a Platform for Protein Sensing
Authors: Huang Ao , Li Weiwei , Shi Shuo , Yao Tianming
Published: January 2017

We created an immunosensing platform for the detection of proteins in a buffer solution. Our sensing platform relies on graphene oxide (GO) nanosheets conjugated with antibodies to provide quantitative binding sites for analyte proteins. When analyte proteins and standard fluorescein-labelled proteins are competing for the binding sites, the assay exhibits quantitative fluorescence quenching by GO for the fluorescein-labelled proteins as determined by the analyte protein concentration. Because of this mechanism, measured fluorescence intensity from unquenched fluorescein-labelled protein was shown to increase with an increasing analyte protein concentration. As an alternative to the conventional enzyme-linked immunosorbent assay (ELISA), our method does not require an enzyme-linked second antibody for protein recognition and the enzyme for optical signal measurement. Thus, it is beneficial with its low cost and fewer systematic errors caused by the series of antigen-antibody recognition steps in ELISA. Immune globulin G (IgG) was introduced as a model protein to test our method and our results showed that the limit of detection for IgG was 4.67 pmol mL−1 in the buffer solution. This sensing mechanism could be developed into a promising biosensor for the detection of proteins, which would broaden the spectrum of GO applications in both analytical biochemistry and clinical diagnosis.
Significantly enhanced osteoblast response to nano-grained pure tantalum
Authors: Huo W. T. , Zhao L. Z. , Yu S. , Yu Z. T. , Zhang P. X. , Zhang Y. S.
Published: January 2017

Tantalum (Ta) metal is receiving increasing interest as biomaterial for load-bearing orthopedic applications and the synthetic properties of Ta can be tailored by altering its grain structures. This study evaluates the capability of sliding friction treatment (SFT) technique to modulate the comprehensive performances of pure Ta. Specifically, novel nanocrystalline (NC) surface with extremely small grains (average grain size of ≤20 nm) was fabricated on conventional coarse-grained (CG) Ta by SFT. It shows that NC surface possessed higher surface hydrophilicity and enhanced corrosion resistance than CG surface. Additionally, the NC surface adsorbed a notably higher percentage of protein as compared to CG surface. The in vitro results indicated that in the initial culture stages (up to 24 h), the NC surface exhibited considerably enhanced osteoblast adherence and spreading, consistent with demonstrated superior hydrophilicity on NC surface. Furthermore, within the 14 days culture period, NC Ta surface exhibited a remarkable enhancement in osteoblast cell proliferation, maturation and mineralization as compared to CG surface. Ultimately, the improved osteoblast functions together with the good mechanical and anti-corrosion properties render the SFT-processed Ta a promising alternative for the load-bearing bone implant applications.
Sialic Acid-Responsive Polymeric Interface Material: From Molecular Recognition to Macroscopic Property Switching
Authors: Xiong Yuting , Jiang Ge , Li Minmin , Qing Guangyan , Li Xiuling , Liang Xinmiao , Sun Taolei
Published: January 2017

Biological systems that utilize multiple weak non-covalent interactions and hierarchical assemblies to achieve various bio-functions bring much inspiration for the design of artificial biomaterials. However, it remains a big challenge to correlate underlying biomolecule interactions with macroscopic level of materials, for example, recognizing such weak interaction, further transforming it into regulating material’s macroscopic property and contributing to some new bio-applications. Here we designed a novel smart polymer based on polyacrylamide (PAM) grafted with lactose units (PAM-g-lactose0.11), and reported carbohydrate-carbohydrate interaction (CCI)-promoted macroscopic properties switching on this smart polymer surface. Detailed investigations indicated that the binding of sialic acid molecules with the grafted lactose units via the CCIs induced conformational transformation of the polymer chains, further resulted in remarkable and reversible switching in surface topography, wettability and stiffness. With these excellent recognition and response capacities towards sialic acid, the PAM-g-lactose0.11 further facilitated good selectivity, strong anti-interference and high adsorption capacity in the capture of sialylated glycopeptides (important biomarkers for cancers). This work provides some enlightenment for the development of biointerface materials with tunable property, as well as high-performance glycopeptide enrichment materials.
PSMA-targeted contrast agents for intraoperative imaging of prostate cancer,
Authors: Bao Kai , Lee Jeong Heon , Kang Homan , Park G. Kate , El Fakhri Georges , Choi Hak Soo
Published: January 2017

Net charges, spacer length, hydrophobicity, and polarity effects on PSMA-targeted NIR fluorophores.
Investigation of K3V2(PO4)3/C nanocomposites as high-potential cathode materials for potassium-ion batteries
Authors: Han Jin , Li Guan-Nan , Liu Feng , Wang Minqiang , Zhang Yan , Hu Linyu , Dai Chunlong , Xu Maowen
Published: January 2017

Novel K3V2(PO4)3 and three-dimensional conductive network K3V2(PO4)3/C nanocomposites are successfully fabricated and further evaluated as cathode materials for potassium-ion batteries for the first time.
Multivalent dithiafulvenyl functionalization of dendritic oligo(phenylene vinylene)s with an anthraquinodimethane core
Authors: Khadem Mohammadreza , Zhao Yuming
Published: January 2017

Redox-active dithiafulvenyl endgroups were attached to dendritic oligo(phenylene vinylene)s which contain an anthraquinodimethane core. The ability of these molecules and their polymer thin films to bind with and detect nitrobenzene was demonstrated.
MALDI-imaging enables direct observation of kinetic and thermodynamic products of mixed peptide fiber assembly
Authors: Medini Karima , West Brandi , Williams David E. , Brimble Margaret A. , Gerrard Juliet A.
Published: January 2017

The first use of MALDI-imaging, as a snapshot tool to characterize multicomponent self-assembling peptide fibers.
On the multi-reference nature of plutonium oxides: PuO22+, PuO2, PuO3 and PuO2(OH)2
Authors: Boguslawski Katharina , Réal Florent , Tecmer Paweł , Duperrouzel Corinne , Gomes André Severo Pereira , Legeza Örs , Ayers Paul W. , Vallet Valérie
Published: January 2017

Orbital correlation diagrams for plutonium oxides containing oxo- and hydroxo-ligands.
The frequency-dependent response of single aerosol particles to vapour phase oscillations and its application in measuring diffusion coefficients
Authors: Preston Thomas C. , Davies James F. , Wilson Kevin R.
Published: January 2017

A new method for measuring diffusion in the condensed phase of single aerosol particles is proposed and demonstrated.
Investigations on Zr incorporation into Li3V2(PO4)3/C cathode materials for lithium ion batteries
Authors: Sun Hua-Bin , Zhou Ying-Xian , Zhang Lu-Lu , Yang Xue-Lin , Cao Xing-Zhong , Arave Hanu , Fang Hui , Liang Gan
Published: January 2017

Zr-modified Li3V2(PO4)3/C composites (LVZrP/C and LVP/C-Zr) obtained from different ways exhibit enhanced performance, in which Zr exists not only in the LVP lattice but also on the LVP surface.
TMAO and urea in the hydration shell of the protein SNase
Authors: Smolin Nikolai , Voloshin Vladimir P. , Anikeenko Alexey V. , Geiger Alfons , Winter Roland , Medvedev Nikolai N.
Published: January 2017

We performed all-atom MD simulations of the protein SNase in aqueous solution and in the presence of two major osmolytes, trimethylamine-N-oxide (TMAO) and urea, as cosolvents at various concentrations and compositions and at different pressures and temperatures.
Trapping of excess energy in a nano-layered microenvironment to promote chemical reactions
Authors: Ramakrishnan V. , Nabetani Y. , Yamamoto D. , Shimada T. , Tachibana H. , Inoue H.
Published: January 2017

Trapping of excess energy upon photo-excitation in a polyfluorinated nano-layered microenvironment through step-wise equilibration with the surrounding microenvironment.
Do grain boundaries dominate non-radiative recombination in CH3NH3PbI3perovskite thin films?
Authors: Yang Mengjin , Zeng Yining , Li Zhen , Kim Dong Hoe , Jiang Chun-Sheng , van de Lagemaat Jao , Zhu Kai
Published: January 2017

We examine grain boundaries (GBs) with respect to non-GB regions in high-quality perovskite films using fluorescence-lifetime imaging. We show that recombination happens in the non-GB regions and that GBs are not transparent to photogenerated carriers.
Metal complexes with oxygen-functionalized NHC ligands: synthesis and applications
Authors: Hameury Sophie , de Frémont Pierre , Braunstein Pierre
Published: January 2017

Hybrid NHC ligands and complexes in which an oxygen-donor type functionality is associated with the carbene donor are surveyed.
Cyclometalated platinum(ii) complexes of 2,2′-bipyridine N-oxide containing a 1,1′-bis(diphenylphosphino)ferrocene ligand: structural, computational and electrochemical studies
Authors: Shahsavari Hamid R. , Fereidoonnezhad Masood , Niazi Maryam , Mosavi S. Talaat , Habib Kazemi Sayed , Kia Reza , Shirkhan Shima , Abdollahi Aghdam Siamak , Raithby Paul R.
Published: January 2017

Two cycloplatinated rollover complexes containing dppf ligand were synthesized and characterized.
A facile and efficient route to hydrophilic ionic liquids through metathesis reaction performed in saturated aqueous solution
Authors: Chen Zhengjian , Li Zuopeng , Ma Xiaoyun , Long Panfeng , Zhou Yun , Xu Lin , Zhang Shiguo
Published: January 2017

Hydrophilic ionic liquids were easily prepared in saturated aqueous medium, with yields >90% after reaction for only 10 min.
A three dimensional in vitro glial scar model to investigate the local strain effects from micromotion around neural implants
Authors: Spencer Kevin C. , Sy Jay C. , Falcón-Banchs Roberto , Cima Michael J.
Published: January 2017

A novel 3D in vitro model to probe the mechanical effects of micromotion induced strain around neural implants.
Substrate-driven selective mono- and bis-couplings of ortho-(OTf/I/Br) substituted gem-dibromovinylarenes
Authors: Rao Maddali L. N. , Dasgupta Priyabrata , Islam Sk Shamim
Published: January 2017

A one-pot approach with the substrate-driven selective and competitive reactivity ofortho-trifloxy, iodo or bromo functionalizedgem-dibromovinylarenes was studied under Pd-catalyzed conditions.
Adjusting the proportions of {0001} facets and high-index facets of ZnO hexagonal prisms and their photocatalytic activity
Authors: Liu Yu , Liu Haixia , Zhang Qing , Li Tianduo
Published: January 2017

ZnO hexagonal prisms with different proportions of {0001} facets and high-index facets were synthesized by a hydrothermal method. The proportion of {0001} facets and high-index facets was controlled by changing the amount of PEG.
Synergistic protective effect of carboxymethyl chitosan and cathodic protection of X70 pipeline steel in seawater
Authors: Feng Panpan , Wan Kai , Cai Guowei , Yang Lihui , Li Yantao
Published: January 2017

This study has investigated corrosion inhibition performance on X70 pipeline steel in seawater using carboxymethyl chitosan (CMCS) and Na2WO4 at a cathodic protection potential of −0.85 V (vs. SCE).
Hollow Sr/Rh-codoped TiO2 photocatalyst for efficient sunlight-driven organic compound degradation
Authors: Nguyen Chinh-Chien , Dinh Cao-Thang , Do Trong-On
Published: January 2017

Sunlight-driven photocatalysis has emerged as a potential technology to address organic pollutant issues.
Investigations on the effect of carriers on meta-aramid fabric dyeing properties in supercritical carbon dioxide
Authors: Zheng Huan-Da , Zhang Juan , Yan Jun , Zheng Lai-Jiu
Published: January 2017

Ecofriendly dyeing of meta-aramid was investigated with nontoxic carriers in supercritical carbon dioxide.
ZnO nanorods assembled with different porphyrins – size-tunable hybrid particles
Authors: Düring Jasmin , Gröhn Franziska
Published: January 2017

We present a fundamental study on ZnO nanorod–porphyrin assembly formation in solution, providing the key to novel tunable hybrid assemblies with potential in solar energy conversion.
Modified PLGA–PEG–PLGA thermosensitive hydrogels with suitable thermosensitivity and properties for use in a drug delivery system
Authors: Wang Puxiu , Chu Wei , Zhuo Xuezhi , Zhang Yu , Gou Jingxin , Ren Tianyang , He Haibing , Yin Tian , Tang Xing
Published: January 2017

PLGA–PEG–PLGA (PPP) triblock copolymer is the most widely studied thermosensitive hydrogel owing to its non-toxic, biocompatible, biodegradable, and thermosensitive properties.
A Clinical Evaluation of the Competing Sources of Input Hypothesis
Authors: Fey Marc E. , Leonard Laurence B. , Bredin-Oja Shelley L. , Deevy Patricia
Published: January 2017

Purpose

Our purpose was to test the competing sources of input (CSI) hypothesis by evaluating an intervention based on its principles. This hypothesis proposes that children's use of main verbs without tense is the result of their treating certain sentence types in the input (e.g.,Wasshe laughing?) as models for declaratives (e.g.,She laughing).

Method

Twenty preschoolers with specific language impairment were randomly assigned to receive either a CSI-based intervention or a more traditional intervention that lacked the novel CSI features. The auxiliaryisand the third-person singular suffix –swere directly treated over a 16-week period. Past tense –edwas monitored as a control.

Results

The CSI-based group exhibited greater improvements in use ofisthan did the traditional group (d= 1.31), providing strong support for the CSI hypothesis. There were no significant between-groups differences in the production of the third-person singular suffix –sor the control (–ed), however.

Conclusions

The group differences in the effects on the 2 treated morphemes may be due to differences in their distribution in interrogatives and declaratives (e.g.,Ishe hiding/Heishidingvs.Doeshe hide/He hides). Refinements in the intervention could address this issue and lead to more general effects across morphemes.
One‐step backtracking for occlusion detection in real‐time visual tracking
Authors: Xu Yulong , Wang Jiabao , Li Yang , Miao Zhuang , Zhang Yafei
Published: January 2017

Occlusion is a challenging problem in real‐time visual object tracking. Most state‐of‐the‐art methods learn the inaccurate appearance of the target when it becomes occluded by other objects in the scene. To address this issue, a novel one‐step backtracking (OB) tracker for occlusion detection is proposed, which backtracks to one previous frame and detects occlusion by comparing the tracking result with OB result in each frame. An adaptive learning model update scheme is further proposed by computing the peak‐to‐sidelobe ratio of the response maps to improve the tracking performance. Experiments on several benchmark sequences show that the proposed tracker outperforms state‐of‐the‐art approaches and achieves real‐time visual tracking.
Energy states aided relay selection and optimal power allocation for cognitive relaying networks
Authors: Tang Dong , Jiang Dandan , Huang Gaofei , Xia Minghua
Published: January 2017

Energy harvesting (EH) is a promising technique for cognitive relaying transmission (CRT) where secondary users (SUs) and relaying nodes do not have a constant power supply each. Unlike conventional CRT where the end‐to‐end data rate is usually maximised without taking into account the energy consumption at the source and relay, in this study, the energy consumption is characterised by means of energy efficiency, defined as the achievable data rate per Joule. In particular, the energy states at each node (either at a SU or a relay) is modelled as a finite‐state Markov chain and the transmit power at a node is optimally allocated by jointly accounting for the interference threshold prescribed by primary users (PUs), the maximum allowable transmit power and the harvested energy at the node. To maximise the energy efficiency, a best relay selection criterion is proposed and the subsequent optimal transmit power allocation is initially formulated as a non‐linear fractional programming problem and, then, equivalently transformed into a parametric programming problem and, finally, solved analytically by using the classic Karush–Kuhn–Tucker conditions. With extensive Monte‐Carlo simulation results, the effectiveness of the proposed relay selection algorithm and corresponding optimal power allocation strategy are corroborated.
Voltage stability assessment and identification of important nodes in power transmission network through network response structural characteristics
Authors: Adebayo Isaiah , Jimoh Adisa A. , Yusuff Adedayo
Published: January 2017

Electrical power grids are often susceptible to voltage instability and have been a growing concern. In this study, the authors propose techniques based on network response structural characteristics for voltage stability assessment and for the identification of important nodes in electrical power grids. First, the network response structural characteristic indices (NRSCIs) which are inherent in the conventional power grids in terms of the Kirchhoff matrix is formulated. The eigenvalue decomposition (ED) technique is then applied to a submatrix of the Kirchhoff matrix to determine the topological strength of the electrical network graph. The vertex (node) that has a minimum eigenvalue is taken as the critical mode, from which its contributions to the entire graph is identified using the proposed network response structural characteristics theory participation factor (NRSCTPF). To demonstrate the magnitude of the concept formulated, the known degree centrality is modified in terms of the established NRSCI, which are then used to determine the important nodes of the network graph. The results obtained show that the proposed NRSCTPF and the degree centrality based on the NRSCI can be used for voltage stability assessment and identification of important nodes. The proposed approach is also less computationally intensive compared with the traditional approach.
LSTM network: a deep learning approach for short‐term traffic forecast
Authors: Zhao Zheng , Chen Weihai , Wu Xingming , Chen Peter C. Y. , Liu Jingmeng
Published: January 2017

Short‐term traffic forecast is one of the essential issues in intelligent transportation system. Accurate forecast result enables commuters make appropriate travel modes, travel routes, and departure time, which is meaningful in traffic management. To promote the forecast accuracy, a feasible way is to develop a more effective approach for traffic data analysis. The availability of abundant traffic data and computation power emerge in recent years, which motivates us to improve the accuracy of short‐term traffic forecast via deep learning approaches. A novel traffic forecast model based on long short‐term memory (LSTM) network is proposed. Different from conventional forecast models, the proposed LSTM network considers temporal–spatial correlation in traffic system via a two‐dimensional network which is composed of many memory units. A comparison with other representative forecast models validates that the proposed LSTM network can achieve a better performance.
A deconvolution technique to correct deep images of galaxies from instrumental scattered light
Authors: Karabal E. , Duc P.-A. , Kuntschner H. , Chanial P. , Cuillandre J.-C. , Gwyn S.
Published: January 2017

Deep imaging of the diffuse light that is emitted by stellar fine structures and outer halos around galaxies is often now used to probe their past mass assembly. Because the extended halos survive longer than the relatively fragile tidal features, they trace more ancient mergers. We use images that reach surface brightness limits as low as 28.5−29 mag arcsec-2 (g-band) to obtain light and color profiles up to 5–10 effective radii of a sample of nearby early-type galaxies. These were acquired with MegaCam as part of the CFHT MATLAS large programme. These profiles may be compared to those produced using simulations of galaxy formation and evolution, once corrected for instrumental effects. Indeed they can be heavily contaminated by the scattered light caused by internal reflections within the instrument. In particular, the nucleus of galaxies generates artificial flux in the outer halo, which has to be precisely subtracted. We present a deconvolution technique to remove the artificial halos that makes use of very large kernels. The technique, which is based on PyOperators, is more time efficient than the model-convolution methods that are also used for that purpose. This is especially the case for galaxies with complex structures that are hard to model. Having a good knowledge of the point spread function (PSF), including its outer wings, is critical for the method. A database of MegaCam PSF models corresponding to different seeing conditions and bands was generated directly from the deep images. We show that the difference in the PSFs in different bands causes artificial changes in the color profiles, in particular a reddening of the outskirts of galaxies having a bright nucleus. The method is validated with a set of simulated images and applied to three representative test cases: NGC 3599, NGC 3489, and NGC 4274, which exhibits a prominent ghost halo for two of them. This method successfully removes this.
CAFM-Systeme: Eine Frage der Wirtschaftlichkeit
Authors: Pieper Ulrich , Göcke Andreas , Opić Marko
Published: January 2017

Die Digitalisierung wird die Krankenhäuser zwingen, sich mit der Einführung oder Optimierung von CAFM-Systemen zu beschäftigen. Nur so lassen sich interessante Innovationen nutzen. Die jüngst aktualisierte Gefma-Richtlinie 460 hilft, die Wirtschaftlichkeit zu betrachten.
Änderung der Medizinprodukte-Betreiberverordnung: Null Reaktionszeit
Authors: Thalmayr Maria
Published: January 2017

Ende September 2016 stimmte der Bundestag von den Gesundheitseinrichtungen weitgehend unbemerkt der zweiten Verordnung zur Änderung medizinprodukterechtlicher Vorschriften zu. Diese fasst die Medizinprodukte-Betreiberverordnung in wesentlichen Teilen neu. Die Umsetzung der Neuerungen verlangt/e Sportlichkeit. Sie traten nämlich bereits am 1. Januar 2017 in Kraft.
36. Tagung „Technik im Krankenhaus“: TK 2016: E-Health, Big Data und IT
Authors: Brüning Cord
Published: January 2017

Als die WGKT im Herbst 2015 das Thema „E-Health, Big Data und IT – Herausforderungen für die Krankenhaustechnik“ für TK 2016 veröffentlicht hat, war noch nicht absehbar, dass die WGKT damit so ins Schwarze treffen würde. Über 100 Teilnehmer sorgten schon bei der Eröffnung für vollbesetzte Reihen in der Kongresshalle am Zoo in Leipzig und zeigten, dass sich Technikverantwortliche der Tragweite der Digitalisierung auch in der Krankenhaustechnik bewusst sind. Sie wissen genau, dass heute die entscheidenden strategischen Weichen gestellt werden müssen.
Rentendebatte: Arbeit im Alter bedeutet meistens mehr Lebensqualität
Authors: Gerster Florian
Published: January 2017

Parteipolitischer Streit droht im Bundestagswahljahr 2017 um die Zukunft der gesetzlichen Rentenversicherung. Bundessozialministerin Andrea Nahles möchte „Haltelinien“ für das Rentenniveau – um zu verhindern, dass die Renten deutlich langsamer steigen als Löhne und Gehälter. Aber auch die Beiträge von Arbeitnehmern und Arbeitgebern sollen im sozial und volkswirtschaftlich vertretbaren Rahmen bleiben.
Glaukomdrainageimplantate und ihre Bedeutung: Tube-versus-Trabekulektomie-Studie
Authors: Rosentreter A. , Strzalkowski P. , Bula A. , Alnawaiseh M.
Published: January 2017

Während die Trabekulektomie mit Mitomycin C zu einem früheren Zeitpunkt die Goldstandardmethode in der penetrierenden Glaukomchirurgie darstellte, sind Glaukomdrainageimplantate im Zuge der Tube-versus-Trabekulektomie-Studie (TVT-Studie) immer mehr in den Fokus eines früheren Einsatzes innerhalb der Glaukomchirurgie gerückt. Einerseits bedingt durch gewebsverträglichere Materialien, aber auch durch optimierte Operationsmethoden werden Glaukomdrainageimplantate nun auch schon zu einem früheren Zeitpunkt eingesetzt, während in der Vergangenheit der Einsatz solcher Implantate oftmals erst nach multiplen Voroperationen erfolgte. Typischerweise werden die Glaukomdrainageimplantate jedoch weiterhin am pseudophaken Auge eingesetzt, an dem schon 1–2 Glaukomvoroperationen (z. B. Trabekulektomie) durchgeführt wurden.
Visusverlust nach Silikonölchirurgie
Authors: Lappas A. , Dietlein T. , Rosentreter A. , Foerster A. , Hedergott A. , Kirchhof B.
Published: January 2017

In der Therapie komplizierter Netzhautablösungen kommt dem Silikonöl als intraokularer Tamponade eine wichtige Funktion zu. Es ist durch seine Langzeitwirkung in der Lage, die Wiederanlagerate der Retina nach deren Ablösung zu erhöhen und damit die Visusprognose zu verbessern. Abweichend von diesen Erwartungen werden in den letzten Jahren Fälle von Visusminderungen nach Silikonölchirurgie beobachtet, die irreversibel verlaufen und deren Genese unklar bleibt. Diese Arbeit bezweckt, einen Überblick über die Erkenntnisse, die bisher zu diesem Phänomen existieren, zu geben. Die Hinweise auf solche unglücklichen Verläufe mehren sich derart, dass die Retinologische Gesellschaft mit der Unterstützung des Retinanet (http://retina-net.uni-koeln.de) eine laufende Datensammlung realisiert hat in Zusammenarbeit mit der Augenklinik der Uniklinik Köln. Klinische Daten zu Patienten sollen gesammelt werden, um die Verläufe besser charakterisieren zu können und mögliche Ursachen zu finden. Behandelnde Augenärzte können Fälle unklarer Visusminderungen nach Silikonölchirurgie anonym melden. Eine Kontaktaufnahme hierfür ist über das Zentrum für Klinische Studien der Uniklinik Köln oder über die E-Mail-Adresse augenklinik-silikonoel@uk-koeln.de möglich.
Interessantes aus der Kataraktchirurgie
Authors: Dick H. , Schultz T.
Published: January 2017

Die Kataraktchirurgie hat in jüngster Zeit eine Vielzahl bemerkenswerter technischer Neuerungen erfahren. Neue Visualisierungssysteme wie das Rescan 700 OCT-System, das iOCT und das IOL Compass Pro erlauben eine Überprüfung der Implantatposition (und -qualität) in Echtzeit, was vor allem bei der Implantation torischer Linsen wertvoll ist. Diese kann auch durch eine mit dem Femtosekundenlaser vorgenommene intrastromale Zielachsenmarkierung zuverlässiger gehandhabt werden. Die Femtosekundenlasertechnologie kommt in verstärktem Maße auch bei Patienten mit einer markanten Ausgangssituation erfolgreich zum Einsatz, wie solche mit pädiatrischen oder hypermaturen Katarakten. Eine mit dem Femtosekundenlaser vorgenommene primäre posteriore Kapsulotomie hat das Potenzial, die Nachstarinzidenz zu reduzieren. Die Laserapplikation geht, wie in mehreren Arbeiten nachgewiesen wurde, mit einer Prostaglandinfreisetzung am Vorderabschnitt einher. Zur Prophylaxe der von dem Prostaglandinanstieg mitunter ausgelösten Miosis wird die präoperative Applikation von nicht steroidalen Entzündungshemmern empfohlen. Gutes Sehen im Fern-, Intermediär- und Nahbereich sollen EDOF-Intraokularlinsen (EDOF: extended depth of focus) ermöglichen. Die ersten und noch zahlenmäßig sehr begrenzten klinischen Erfahrungen deuten auf gute Ergebnisse bei manchen, wenn auch nicht allen Patienten hin – „Brillenfreiheit“ auf alle Distanzen bleibt wohl weiter eine Schimäre. Einen wichtigen Beitrag zur Behandlung von Glaukompatienten kann der bei einer Kataraktoperation implantierte Drucksensor Eyemate leisten, der kontinuierlich den IOD misst und vom Patienten leicht zu bedienen ist – erste Erfahrungen sind sehr ermutigend. Versuche, mit nutritiven oder pharmakologischen Mitteln die Kataraktentstehung zu beeinflussen, sind nicht neu – auch wenn gerade einmal wieder angeblich protektive Substanzen ins Gespräch gebracht werden.
Observation of coherent electron transport in self-catalysed InAs and InAs1–xSbx nanowires grown on silicon
Authors: Sourribes M. J. L. , Isakov I. , Panfilova M. , Warburton P. A.
Published: January 2017

We report the observation of phase coherent transport in catalyst-free InAs and InAs1–xSbx nanowires grown by molecular beam epitaxy on silicon (111) substrates. We investigate three different methods to gain information on the phase coherence length of the nanowires: first through the study of universal conductance fluctuations as a function of both magnetic field and gate voltage and then through localisation effects. The analysis of these different quantum effects gave consistent results and a phase-coherence length in the hundred nanometre range was extracted for all nanowires below 10 K. This demonstrates the potential of catalyst-free nanowires as building blocks for future quantum electronics devices directly integrated with silicon circuits.
Magnonic interferometric switch for multi-valued logic circuits
Authors: Balynsky Michael , Kozhevnikov Alexander , Khivintsev Yuri , Bhowmick Tonmoy , Gutierrez David , Chiang Howard , Dudko Galina , Filimonov Yuri , Liu Guanxiong , Jiang Chenglong , Balandin Alexander A. , Lake Roger , Khitun Alexander
Published: January 2017

We investigated a possible use of the magnonic interferometric switches in multi-valued logic circuits. The switch is a three-terminal device consisting of two spin channels where input, control, and output signals are spin waves. Signal modulation is achieved via the interference between the source and gate spin waves. We report experimental data on a micrometer scale prototype based on the Y3Fe2(FeO4)3 structure. The output characteristics are measured at different angles of the bias magnetic field. The On/Off ratio of the prototype exceeds 13 dB at room temperature. Experimental data are complemented by the theoretical analysis and the results of micro magnetic simulations showing spin wave propagation in a micrometer size magnetic junction. We also present the results of numerical modeling illustrating the operation of a nanometer-size switch consisting of just 20 spins in the source-drain channel. The utilization of spin wave interference as a switching mechanism makes it possible to build nanometer-scale logic gates, and minimize energy per operation, which is limited only by the noise margin. The utilization of phase in addition to amplitude for information encoding offers an innovative route towards multi-state logic circuits. We describe possible implementation of the three-value logic circuits based on the magnonic interferometric switches. The advantages and shortcomings inherent in interferometric switches are also discussed.
Experimental evidence for pressure-induced first order transition in cerium nitride from B1 to B10 structure type
Authors: Nielsen Morten B. , Ceresoli Davide , Jørgensen Jens-Erik , Prescher Clemens , Prakapenka Vitali B. , Bremholm Martin
Published: January 2017

The crystal structure of CeN was investigated up to pressures of 82 GPa, using diamond anvil cell powder X-ray diffraction in two experiments with He and Si-oil as the pressure transmitting media. In contrast to previous reports, we do not observe the B2 (CsCl type) structure at high pressure. Instead, the structural phase transition, starting at 65 GPa, from the ambient rock salt B1 structure results in a distorted CsCl-like B10 structure, irrespective of the pressure medium. Our result unambiguously confirms two recent density functional theory (DFT) studies predicting the B10 phase to be stable at these pressures, rather than the B2 (CsCl type) phase previously reported. The B10 structure appears to approach the B2 structure as pressure is increased further, but DFT calculations indicate that an L10 structure (AuCu type) is energetically favored.
Interferometrically stable, enclosed, spinning sample cell for spectroscopic experiments on air-sensitive samples
Authors: Baranov Dmitry , Hill Robert J. , Ryu Jisu , Park Samuel D. , Huerta-Viga Adriana , Carollo Alexa R. , Jonas David M.
Published: January 2017

In experiments with high photon flux, it is necessary to rapidly remove the sample from the beam and to delay re-excitation until the sample has returned to equilibrium. Rapid and complete sample exchange has been a challenge for air-sensitive samples and for vibration-sensitive experiments. Here, a compact spinning sample cell for air and moisture sensitive liquid and thin film samples is described. The principal parts of the cell are a copper gasket sealed enclosure, a 2.5 in. hard disk drive motor, and a reusable, chemically inert glass sandwich cell. The enclosure provides an oxygen and water free environment at the 1 ppm level, as demonstrated by multi-day tests with sodium benzophenone ketyl radical. Inside the enclosure, the glass sandwich cell spins at ≈70 Hz to generate tangential speeds of 7-12 m/s that enable complete sample exchange at 100 kHz repetition rates. The spinning cell is acoustically silent and compatible with a ±1 nm rms displacement stability interferometer. In order to enable the use of the spinning cell, we discuss centrifugation and how to prevent it, introduce the cycle-averaged resampling rate to characterize repetitive excitation, and develop a figure of merit for a long-lived photoproduct buildup.
Isomorphism between the multi-state Hamiltonian and the second-quantized many-electron Hamiltonian with only 1-electron interactions
Authors: Liu Jian
Published: January 2017

We introduce the isomorphism between an multi-state Hamiltonian and the second-quantized many-electron Hamiltonian (with only 1-electron interactions). This suggests that all methods developed for the former can be employed for the latter, and vice versa. The resonant level (Landauer) model for nonequilibrium quantum transport is used as a proof-of-concept example. Such as the classical mapping models for the multi-state Hamiltonian proposed in our previous work [J. Liu, J. Chem. Phys. 145, 204105 (2016)] lead to exact results for this model problem. We further demonstrate how these methods can also be applied to the second-quantized many-electron Hamiltonian even when 2-electron interactions are included.
Miniaturized two-stack Blumlein pulser with a variable repetition-rate for non-thermal irreversible-electroporation experiments
Authors: Min Sun-Hong , Kwon Ohjoon , Sattorov Matlabjon , Baek In-Keun , Kim Seontae , Jeong Jin-Young , Hong Dongpyo , Park Seunghyuk , Park Gun-Sik
Published: January 2017

Non-thermal irreversible electroporation (NTIRE) to avoid thermal damage to cells during intense DC ns pulsed electric fields (nsPEFs) is a recent modality for medical applications. This mechanism, related to bioelectrical dynamics of the cell, is linked to the effect of a DC electric field and a threshold effect with an electrically stimulated membrane for the charge distribution in the cell. To create the NTIRE condition, the pulse width of the nsPEF should be shorter than the charging time constant of the membrane related to the cell radius, membrane capacitance, cytoplasm resistivity, and medium resistivity. It is necessary to design and fabricate a very intense nanosecond DC electric field pulser that is capable of producing voltages up to the level of 100 kV/cm with an artificial pulse width (∼ns) with controllable repetition rates. Many devices to generate intense DC nsPEF using various pulse-forming line technologies have been introduced thus far. However, the previous Blumlein pulse-generating devices are clearly inefficient due to the energy loss between the input voltage and the output voltage. An improved two-stage stacked Blumlein pulse-forming line can overcome this limitation and decrease the energy loss from a DC power supply. A metal oxide silicon field-effect transistor switch with a fast rise and fall time would enable a high repetition rate (max. 100 kHz) and good endurance against very high voltages (DC ∼ 30 kV). The load is designed to match the sample for exposure to cell suspensions consisting of a 200 Ω resistor matched with a Blumlein circuit and two electrodes without the characteristic RC time effect of the circuit (capacitance =0.174 pF).
Lithium ion micrometer diffusion in a garnet-type cubic Li7La3Zr2O12 (LLZO) studied using 7Li NMR spectroscopy
Authors: Hayamizu Kikuko , Seki Shiro , Haishi Tomoyuki
Published: January 2017

Mobile lithium ions in a cubic garnet Li7La3Zr2O12 (Al-stabilized) were studied using 7Li NMR spectroscopy for membrane and powder samples, the latter of which was ground from the membrane. Lithium diffusion in a micrometer space was measured using the pulsed-gradient spin-echo 7Li NMR method between 70 and 130 °C. When the observation time (Δ) was shorter than 20 ms, the echo attenuation showed diffusive diffraction patterns, indicating that the Li+ diffusing space is not free but restricted. For longer Δ, the values of apparent diffusion constant (Dapparent) became gradually smaller to approach an equilibrated value (close to a tracer diffusion constant). In addition, the Dapparent depends on the pulse field gradient strength (g) and became smaller as g became larger. These experimental results suggest that the lithium ions diffuse through Li+ pathways surrounded by stationary anions and lithium ions, and are affected by collisions and diffractions. One-dimensional profiles of the membrane sample of thickness 0.5 mm were observed from 65 to 110 °C and the area intensity, as well as the lithium occurrence near the surface, increased with the increase in temperature. The temperature-dependent area intensity showed a correspondence to the number of Li+ carrier ions estimated from the ionic conductivity and the equilibrated diffusion constant through the Nernst-Einstein relationship.
Safety considerations during production and consumption of hydrogen using proton exchange membrane electrolysis
Authors: Abdalla S. , Al-Marzouki Fahd , Obaid A.
Published: January 2017

Hydrogen (H2) cross-over through a membrane electrolyte is a critical safety issue in proton exchange membrane (PEM) electrolysis. Permeated H2 tends to be consumed by oxidation or recombination at the anode. In this study, the contribution of oxidation/recombination to the reduction of the H2 content in the anode compartment was quantitatively evaluated by measuring the H2 content during the electrolysis operation of a unitized reversible fuel cell stack in which the anode catalyst layer (CL) contained platinum (Pt). The results of fitting calculation indicated that over 70% of permeated H2 flux through the membrane was consumed at the anode by oxidation or recombination when the cathode pressure was under 10 bars. Therefore, promoting H2 consumption due to the addition of Pt in either the CL or current collector is critical for safe PEM electrolysis. Furthermore, optimization of the electrode structure is also important not only to increase the Faraday (current) efficiency but also to reduce the H2 content in the anode.

At the request of the Editors-in-Chief and AIP Publishing this article is being retracted. The article had a high degree of overlap with an article published in the International Journal of Hydrogen Energy. The article is retracted from the scientific record effective 30 June 2017.
Generalized approach to design multi-layer stacks for enhanced optical detectability of ultrathin layers
Authors: Hutzler A. , Matthus C. D. , Rommel M. , Frey L.
Published: January 2017

The optical detectability of ultrathin conductive films (down to one atomic layer) can be enhanced by choosing distinct layer-stacks. A simple analytical approach using the transfer matrix method is applied for calculating the reflectance of arbitrary multi-layer stack systems with and without the ultrathin layer of interest on top in a wide wavelength range, including both the visible spectrum and the ultraviolet spectrum. Then, the detectability defined by the Michelson contrast was calculated. Performing these calculations for thickness variations of the individual layers in the stack allows determining optimum layer thicknesses, e.g., maximum overall contrast or maximum contrast for a given wavelength. To demonstrate the validity of the methodology, two thin film stacks were investigated, which use p-type silicon as a substrate material and partially covered by a single-layer graphene as a top layer. For each stack, two samples with different layer thicknesses were fabricated and their experimentally determined reflectance was compared to the calculated values. The first system consists of a single SiO2 layer with a thickness of 147 nm and 304 nm, respectively, and the second is a double layer stack consisting of a Si3N4 layer with a thickness of 54 nm and 195 nm, respectively, on top of an 11 nm SiO2 film. The Michelson contrast of single-layer graphene flakes on the latter layer stacks becomes very high (absolute value of more than 0.3) in the visible wavelength range. Additionally, in the UV-B range a large difference in the reflection of selected SiO2 layer thicknesses on silicon substrates with and without single-layer graphene on top is found with a decrease in the measured reflectance of up to 33%. The measured and calculated values showed a high conformity suggesting this approach usable for the calculation of reflectance and transmittance properties of arbitrary layer stack systems including thin conductive layers.
Two-beam femtosecond coherent anti-Stokes Raman scattering for thermometry on CO2
Authors: Kerstan M. , Makos I. , Nolte S. , Tünnermann A. , Ackermann R.
Published: January 2017

We show that two-beam femtosecond coherent anti-Stokes Raman scattering can be effectively used for thermometry on CO2 for temperatures between ∼100 °C and ∼600 °C at a maximum pressure of 8.5 bar. The temperature measurement is based on probing the vibrationally excited states of CO2, using a ∼7 fs pump/Stokes pulse and a narrowband (∼0.3 nm) probe pulse. The temperatures can be derived from a single spectrum, obviating the need for a delay scan or a chirped probe pulse.
Comparison of the surface dielectric barrier discharge characteristics under different electrode gaps
Authors: Gao Guoqiang , Dong Lei , Peng Kaisheng , Wei Wenfu , Li Chunmao , Wu Guangning
Published: January 2017

Currently, great interests are paid to the surface dielectric barrier discharge due to the diverse and interesting application. In this paper, the influences of the electrode gap on the discharge characteristics have been studied. Aspects of the electrical parameters, the optical emission, and the discharge induced gas flow were considered. The electrode gap varied from 0 mm to 21 mm, while the applied AC voltage was studied in the range of 17 kV–27 kV. Results indicate that with the increase of the electrode gap, the variation of discharge voltage exhibits an increasing trend, while the other parameters (i.e., the current, power, and induced flow velocity) increase first, and then decrease once the gap exceeded the critical value. Mechanisms of the electrode gap influencing these key parameters were discussed from the point of equivalent circuit. The experimental results reveal that an optimal discharge gap can be obtained, which is closely related to the applied voltage. Visualization of the induced flow with different electrode gaps was realized by the Schlieren diagnostic technique. Finally, the velocities of induced gas flow determined by the pitot tube were compared with the results of intensity-integral method, and good agreements were found.
Electromagnetic theory of turbulent acceleration of parallel flow and momentum conservation
Authors: Peng Shuitao , Wang Lu
Published: January 2017

Intrinsic flow in plasma physics is a long-standing puzzle, since it is difficult to understand its origin without contradiction to momentum conservation in conventional wisdom. It is proved that the electromagnetic turbulent acceleration as a candidate for intrinsic parallel flow generation driven by pressure gradient along the total magnetic field line does not contradict the momentum conservation. The conserved quantity corresponding to axial symmetry is the total gyrocenter parallel canonical momentum carried by both species or the total gyrocenter parallel momentum including the ion gyrocenter kinematic momentum and electromagnetic fields momentum, but not the ion kinematic momentum, or even the ion parallel flow. A conservation equation of total parallel momentum including the ion particles' kinematic momentum and electromagnetic fields momentum is also presented.
Preparation of tunable-sized iron nanoparticles based on magnetic manipulation in inert gas condensation (IGC)
Authors: Xing Lijuan , ten Brink Gert H. , Kooi Bart J. , Palasantzas George
Published: January 2017

Iron nanoparticles (NPs) prepared by inert gas condensation were studied using high resolution transmission electron microscopy and Wulff construction shape analysis. The NP size and shape show strong dependence on the magnetic field above the target surface. The effect of the magnetic field could be tuned by adjusting the thickness of the protective backing plate positioned in-between the target and the magnetron head. With increasing backing plate thickness, the particle size decreases and the NP morphologies evolve from faceted to close-to-spherical polyhedral shapes. Moreover, with changes in size and shape, the particle structure also varies so that the NPs exhibit: (i) a core-shell structure for the faceted NPs with size ∼15–24 nm; (ii) a core-shell structure for the close-to-spherical NPs with size ∼8–15 nm; and (iii) a fully oxidized uniform structure for NPs with sizes less than ∼8 nm having a void in the center due to the Kirkendall effect. The decrease of NP size with the increasing backing plate thickness can be attributed to a reduced magnetic field strength above the iron target surface combined with a reduced magnetic field confinement. These results pave the way to drastically control the NP size and shape in a simple manner without any other adjustment of the aggregation volume within the deposition system.