bluuebunny/crossref_metadata_2025 huggingface dataset:
Die akute HIV-Infektion darf nicht verpasst werden
Authors: Braun Dominique L. , Nemeth Johannes , Günthard Huldrych F.
Published: July 2014

Die Phase der HIV-Primoinfektion umfasst den Zeitraum der ersten drei bis sechs Monate nach Infektion. Phylogenetische Analysen des Virus weisen darauf hin, dass bis zu 50 % der Neuinfektionen durch die Übertragung von HIV von Patienten mit einer Primoinfektion zustande kommen. Die Primoinfektion manifestiert sich in 25 – 90% als akutes retrovirales Syndrom. Die häufigsten Symptome sind Fieber, Abgeschlagenheit, Halsschmerzen, Hautausschlag, Lymphknotenschwellung und Durchfall. Allerdings sind diese Symptome zu unspezifisch, um eine Primoinfektion klinisch sicher diagnostizieren zu können. In einer bedeutenden Anzahl der Fälle kann sich die Primoinfektion asymptomatisch, symptomarm oder atypisch präsentieren, so dass bei Personen mit Risiko niederschwellig ein HIV-Test veranlasst werden soll. Die heute routinemäßig verwendeten HIV-Suchtests der 4. Generation vermögen eine Primoinfektion in den meisten Fällen nach ca. zwei bis drei Wochen zu detektieren, der routinemäßige Einsatz einer HIV-PCR wird in der Praxis nicht als Suchtest empfohlen. Die aktuelle Datenlage weist darauf hin, dass eine antiretrovirale Frühtherapie den Krankheitsverlauf günstig beeinflussen kann und zusätzlich hilft, weitere Infektionen zu vermeiden. Die Frühtherapie wird heutzutage von den meisten internationalen Fachgremien empfohlen. Eine Frühtherapie sollte durch mit HIV erfahrene Ärzte initiiert werden.
Therapie und Prävention von opportunistischen Infektionen
Authors: Staehelin Cornelia , Elzi Luigia , Weber Rainer , Furrer Hansjakob
Published: July 2014

Die Inzidenz sowie auch die Morbidität und Mortalität opportunistischer Infektionen (OI) ist seit der Einführung der kombinierten antiretroviralen Therapie (ART) in den letzten 15 Jahren deutlich gesunken. Weiterhin treten OI aber auf, da 30 – 50 % der HIV-Infizierten ihren HIV-Status nicht kennen, und bei vielen von ihnen eine OI die erste Manifestation der HIV-Erkrankung ist. Bei Erstarken des Immunsystems nach Beginn der ART kann eine OI demaskiert oder in ihrer Ausprägung verschlimmert werden. Entsprechend sollten gezielte Abklärungen vor ART-Beginn getätigt werde. In der Regel muss aus demselben Grunde vor Beginn der ART der Behandlungsbeginn der OI abgewartet werden. Gewisse OI lassen sich durch gezielte präventive Maßnahmen verhindern, sobald ein CD4-Schwellenwert unterschritten wird. Die wichtigste Prävention von OI ist aber das frühzeitige Erkennen einer HIV-Erkrankung und ein entsprechend frühzeitiger Beginn der ART.
Die vertikale HIV-Infektion kann heute erfolgreich verhütet werden, bleibt aber eine Herausforderung
Authors: Nadal David , Arlettaz Romaine , Berger Christoph
Published: July 2014

Die Rate der vertikalen HIV-Übertragung von der infizierten Mutter auf das Kind liegt heute in der Schweiz bei < 1 %, wenn die Mutter erfolgreich gegen HIV behandelt und das Neugeborene sowohl eine Postexpositionsprophylaxe (PEP) erhält und nicht an der Brust ernährt wird. Die interdisziplinäre Festlegung von Anti-HIV-Therapie der Schwangeren, Geburtsmodus und PEP beim Kind sind essentiell. Beim Kind muss bei entsprechender Klinik dennoch an eine HIV-Infektion gedacht werden, da die Diagnose der HIV-Infektion bei der Mutter und somit der Übertragung zuweilen verpasst wird.
Identification Processes in Online Groups
Authors: Gabbiadini Alessandro , Mari Silvia , Volpato Chiara , Grazia Monaci Maria
Published: July 2014

Online video games are a popular leisure activity around the world; such virtual environments enable new ways for social identity to develop. This study investigated the motives affecting social identification processes in the massive multiplayer online role-playing game (MMORPG) World of Warcraft (WoW). In this video game, players interact with other players in a tridimensional virtual world through their avatar. A sample of 92 WoW players took part in a data collection Web survey. Building on the theory of social identity, we tested the predictive power of three identification motives: self-esteem enhancement, optimal distinctiveness, and uncertainty reduction. Additionally, considering previous research on MMORPGs, we added identification with the game character and membership duration as further predictors of virtual group identification. The construct of virtual group identification was analyzed at two levels: identification with the faction and guild of the character. Furthermore, the current study was a first attempt to understand whether online identification may lead to group behavior such as evaluative ingroup bias. Our results indicated that traditional motivational theories of social identity were mostly confirmed. Moreover, identification with the avatar emerged as a strong predictor of group identity. Additionally, at both levels of analysis, group attachment led to an evaluative differentiation between the ingroup and outgroup. The findings are discussed in light of modern theories of social identity and media research.
Diagnosis of Rare Inherited Diseases
Authors: Newman William G. , Black Graeme C.
Published: July 2014

Delineation of the genetic basis of rare inherited diseases can provide diagnostic certainty and risk assessment for affected individuals and their families. Determination of the genes that are mutated in such conditions can not only provide important insights into disease pathogenesis, but have frequently been shown to shed important light on the molecular pathology of common complex disorders, which share similar features. Crucially, disease gene identification represents the starting point for the development of novel therapeutics. This chapter describes the different types of genetic disorders – both chromosomal and monogenic – and the advances in technology, including next generation sequencing and microarrays that are driving the discovery of novel genetic mechanisms underlying human disease.
The Challenges of Conducting Clinical Trials in Diseases with Small Target Populations
Authors: Arkin Steven
Published: July 2014

Scientific advances are creating enhanced opportunities for development of new therapeutics to treat rare diseases. Regulatory incentives provide added impetus for allocation of sponsor research and development resources to development of treatments for rare diseases. Despite incentives and enablers, development of therapeutics for rare diseases remains a significant undertaking. Drugs for rare diseases are subjected to the same rigour in the assessment of safety and efficacy as drugs developed for more common diseases, usually with the same requirement for clinical data from randomised and well controlled clinical studies. To meet requirements for market authorisation, investigations must overcome challenges that include incomplete understanding of the disease course, lack of validated measures of disease progression or end points to support regulatory approval, incomplete understanding of the standard of care and difficulty accessing sufficient sample size to support hypothesis testing. Tools available to meet these challenges include natural history data, patient registries, clinical trial data repositories, clinical study enrichment strategies, innovative statistical models, use of external control groups and advocacy groups or established clinical networks as partners to facilitate enrolment. Examples of how these tools may be used are provided in this chapter and in the detailed case studies presented in subsequent chapters.
Pharmacological Chaperones to Correct Enzyme Folding, Cellular Trafficking and Lysosomal Activity
Authors: Boyd Robert E. , Valenzano Kenneth J.
Published: July 2014

A variety of unwanted cellular waste materials and macromolecules (e.g. glycosphingolipids, oligosaccharides, glycoproteins, glycogen, peptides, cholesterol, etc.) are enzymatically degraded in a cellular organelle known as the lysosome, with the resulting products recycled into various biosynthetic pathways. Genetic defects that reduce the activity for any one of the enzymes that are responsible for these processes can result in accumulation of one or more substrates, compromised cellular function, and disease pathology. Over the last 10 to 20 years there have been significant advances in understanding the basic biochemistry and cell biology that underlie these diseases, which are known collectively as lysosomal storage diseases (LSDs). In turn, this has led to several treatment options, where virtually none had previously existed. A relatively new and promising therapeutic approach involves pharmacological chaperones (PCs), small molecules that are designed to bind and stabilise mutant lysosomal enzymes, and to improve trafficking to their proper cellular destination, the lysosome, where increased activity can aid in the clearance of storage material. This chapter will outline the mechanism of action of PCs, and describe how such molecules are identified and characterised pre-clinically using biochemical and cell-based assays, as well as animal models of LSDs.
Discovery and Development of Ilaris® for the Treatment of Cryopyrin-Associated Periodic Syndromes
Authors: Gram Hermann
Published: July 2014

Canakinumab is a human anti-human IL-1β monoclonal antibody which is therapeutically applied to neutralise the bioactivity of IL-1β produced in acute and chronic inflammatory conditions. IL-1β is part of the innate immune response to bacterial pathogens, but has a prominent role in a number of biological responses and processes in mammals, such as the fever response, insulin metabolism, pain sensitisation, endothelial activation and orchestration of the neutrophil response, reproduction, tissue remodelling, and the induction of cytokines and chemokines. Canakinumab is marketed under the trade name ILARIS® and is indicated for the treatment of cryopyrin associated periodic syndrome (CAPS). CAPS is an extremely rare monogenetic disease with an incidence of about 1 per million and is caused by a functional defect in the NLRP3 protein, a component of the inflammasome, which controls the release of mature and active IL-1β from phagocytes. Chronic overproduction of IL-1β in these patients leads to high spiking fever attacks, urticaria, fatigue, arthralgia, and in the long term to amyloidosis and sensoneuronal hearing loss. Canakinumab is particularly well suited for the treatment of CAPS, as it specifically targets the critical effector molecule, IL-1β, responsible for the clinical pathology of this disease. Treatment with canakinumab provides a rapid and sustained remission of clinical symptoms and biochemical markers of inflammation in CAPS patients, while it is generally well tolerated.
Drug Discovery Approaches for Rare Neuromuscular Diseases
Authors: Wynne Graham M. , Russell Angela J.
Published: July 2014

Rare neuromuscular diseases encompass many diverse and debilitating musculoskeletal disorders, ranging from ultra-orphan conditions that affect only a few families, to the so-called ‘common’ orphan diseases like Duchenne muscular dystrophy (DMD) and spinal muscular atrophy (SMA), which affect several thousand individuals worldwide. Increasingly, pharmaceutical and biotechnology companies, in an effort to improve productivity and rebuild dwindling pipelines, are shifting their business models away from the formerly popular ‘blockbuster’ strategy, with rare diseases being an area of increased focus in recent years. As a consequence of this paradigm shift, coupled with high-profile campaigns by not-for-profit organisations and patient advocacy groups, rare neuromuscular diseases are attracting considerable attention as new therapeutic areas for improved drug therapy. Much pioneering work has taken place to elucidate the underlying pathological mechanisms of many rare neuromuscular diseases. This, in conjunction with the availability of new screening technologies, has inspired the development of several truly innovative therapeutic strategies aimed at correcting the underlying pathology. A survey of medicinal chemistry approaches and the resulting clinical progress for new therapeutic agents targeting this devastating class of degenerative diseases is presented, using DMD and SMA as examples. Complementary strategies using small-molecule drugs and biological agents are included.
An air-stable cationic iridium hydride as a highly active and general catalyst for the isomerization of terminal epoxides
Authors: Humbert Nicolas , Vyas Devendra J. , Besnard Céline , Mazet Clément
Published: July 2014

We describe the use of an air-stable iridium hydride catalyst for the isomerization of terminal epoxides into aldehydes with perfect regioselectivity.
Low-temperature reduction of brownmillerite CaFeO2.5 in LaAlO3/CaFeO2.5 heterostructures made on SrTiO3
Authors: Murakami Noriaki , Kan Daisuke , Ichikawa Noriya , Shimakawa Yuichi
Published: July 2014

A CaFeO2.5 layer was reduced to CaFeO2 by oxygen-ion migration through the coherently grown LaAlO3 layer of the heterostructure.
3D reconstruction of atomic structures from high angle annular dark field (HAADF) STEM images and its application on zeolite silicalite-1
Authors: Willhammar Tom , Mayoral Alvaro , Zou Xiaodong
Published: July 2014

The 3D atomic structure of silicalite-1 has been reconstructed for the first time by combining three high resolution HAADF-STEM images.
Imaging molecular structure through femtosecond photoelectron diffraction on aligned and oriented gas-phase molecules
Authors: Boll Rebecca , Rouzée Arnaud , Adolph Marcus , Anielski Denis , Aquila Andrew , Bari Sadia , Bomme Cédric , Bostedt Christoph , Bozek John D. , Chapman Henry N. , Christensen Lauge , Coffee Ryan , Coppola Niccola , De Sankar , Decleva Piero , Epp Sascha W. , Erk Benjamin , Filsinger Frank , Foucar Lutz , Gorkhover Tais , Gumprecht Lars , Hömke André , Holmegaard Lotte , Johnsson Per , Kienitz Jens S. , Kierspel Thomas , Krasniqi Faton , Kühnel Kai-Uwe , Maurer Jochen , Messerschmidt Marc , Moshammer Robert , Müller Nele L. M. , Rudek Benedikt , Savelyev Evgeny , Schlichting Ilme , Schmidt Carlo , Scholz Frank , Schorb Sebastian , Schulz Joachim , Seltmann Jörn , Stener Mauro , Stern Stephan , Techert Simone , Thøgersen Jan , Trippel Sebastian , Viefhaus Jens , Vrakking Marc , Stapelfeldt Henrik , Küpper Jochen , Ullrich Joachim , Rudenko Artem , Rolles Daniel
Published: July 2014

This paper gives an account of our progress towards performing femtosecond time-resolved photoelectron diffraction on gas-phase molecules in a pump–probe setup combining optical lasers and an X-ray free-electron laser. We present results of two experiments aimed at measuring photoelectron angular distributions of laser-aligned 1-ethynyl-4-fluorobenzene (C8H5F) and dissociating, laser-aligned 1,4-dibromobenzene (C6H4Br2) molecules and discuss them in the larger context of photoelectron diffraction on gas-phase molecules. We also show how the strong nanosecond laser pulse used for adiabatically laser-aligning the molecules influences the measured electron and ion spectra and angular distributions, and discuss how this may affect the outcome of future time-resolved photoelectron diffraction experiments.
Naphthalene and 2,3-dihydrobenzo[b][1,4]dioxine derivatives with extended side chains as new scaffolds of CB2-selective ligands
Authors: Osman Noha A. , Mahmoud Amr H. , Klein Christian D. , Allarà Marco , Di Marzo Vincenzo , Abouzid Khaled M. , Abadi Ashraf H.
Published: July 2014

Herein, we report the synthesis of naphthalene, dihydrobenzodioxine and fluorene derivatives with extended side chains and their biological evaluation as ligands of CB1 and CB2 receptors.
CdSe/CdS-quantum rods: fluorescent probes for in vivo two-photon laser scanning microscopy
Authors: Dimitrijevic Jelena , Krapf Lisa , Wolter Christopher , Schmidtke Christian , Merkl Jan-Philip , Jochum Tobias , Kornowski Andreas , Schüth Anna , Gebert Andreas , Hüttmann Gereon , Vossmeyer Tobias , Weller Horst
Published: July 2014

CdSe/CdS-Quantum-dots-quantum-rods are encapsulated by PI-b-PEG shells and transferred into various aqueous media to study their stability and performance as probes for two-photon laser scanning microscopy.
Development and mechanistic studies of an optimized receptor for trimethyllysine using iterative redesign by dynamic combinatorial chemistry
Authors: Pinkin Nicholas K. , Waters Marcey L.
Published: July 2014

Iterative monomer redesign leads to a Kme3-peptide receptor with 10-fold tighter affinity and 5-fold improved selectivity over Kme2than the original receptor. Thermodynamic analysis provides insight into this improvement.
Linear versus branched poly-lysine/arginine as polarity enhancer tags
Authors: Paradís-Bas Marta , Albert-Soriano Maria , Tulla-Puche Judit , Albericio Fernando
Published: July 2014

The design and synthesis of Lys- and Arg-containing peptides as solubilizing tags were studied to evaluate their influence on polarity.
Membraneless hydrogen peroxide micro semi-fuel cell for portable applications
Authors: Mousavi Shaegh Seyed Ali , Mousavi Ehteshami Seyyed Mohsen , Chan Siew Hwa , Nguyen Nam-Trung , Tan Swee Ngin
Published: July 2014

A one-compartment hydrogen peroxide semi-fuel cell was fabricated using a metallic anode (Mg or Al) and Prussian blue as the cathode to improve the power density of the device.
Metal ionic size directed complexation in manganese(ii) coordination chemistry: efficient candidates showing phenoxazinone synthase mimicking activity
Authors: Panja Anangamohan
Published: July 2014

Influence of the ionic size of metal on the diverse coordination chemistry of manganese(ii) has been examined by X-ray diffraction and IR spectral studies, and their relative phenoxazinone synthase activity has also been explored.
A solution spectroscopy study of tea polyphenol and cellulose: effect of surfactants
Authors: Sarkar Deboleena , Das Somnath , Pramanik Amitava
Published: July 2014

Catechin, a bioflavonoid, found in green tea leaves has various applications in the food and pharmaceutical industries.
Fabrication and characterization of PNA–DNA hybrid nanostructures
Authors: Gnapareddy Bramaramba , Kim Jang Ah , Dugasani Sreekantha Reddy , Tandon Anshula , Kim Byeonghoon , Bashar Saima , Choi Ji Ah , Joe Goon Ho , Kim Taesung , Ha Tai Hwan , Park Sung Ha
Published: July 2014

The feasibility of constructing PNA–DNA hybrid nanostructures by conventional free solution annealing and substrate assisted growth methods was studied.
Influence of the grain orientation on the charge transport properties of organic field-effect transistors
Authors: Ribierre J. C. , Yokota Y. , Sato M. , Ishizuka A. , Tanaka T. , Watanabe S. , Matsumoto M. , Muranaka A. , Matsumoto S. , Uchiyama M. , Aoyama T.
Published: July 2014

We report the effects of crystalline grain orientation on the charge transport properties of a J-aggregate bisazomethine dye (DE2) in thin films.
Genetic algorithm spectral feature selection coupled with quadratic discriminant analysis for ATR-FTIR spectrometric diagnosis of basal cell carcinoma via blood sample analysis
Authors: Khanmohammadi Mohammadreza , Ghasemi Keyvan , Garmarudi Amir Bagheri
Published: July 2014

A diagnostic approach for basal cell carcinoma (BCC) has been developed based on investigation of the infrared spectra of blood samples.
Selective oxidation of glycerol to formic acid in highly concentrated aqueous solutions with molecular oxygen using V-substituted phosphomolybdic acids
Authors: Zhang Jizhe , Sun Miao , Han Yu
Published: July 2014

We report here that glycerol can be selectively oxidized to FA in highly concentrated aqueous solutions with molecular oxygen by using vanadium-substituted phosphomolybdic acids as catalysts, which also offers an alternative route to the direct extraction of H2 from glycerol.
A microfluidic process for on-chip formation of assemblies of oxide nanoparticles
Authors: Parashar V. K. , Wacker J. B. , Necula D. , Gijs M. A. M.
Published: July 2014

A microfluidic process for on-chip formation of assemblies of oxide nanoparticles.
Hollow hierarchical hydroxyapatite/Au/polyelectrolyte hybrid microparticles for multi-responsive drug delivery
Authors: Xu Shuhan , Shi Jun , Feng Desheng , Yang Liu , Cao Shaokui
Published: July 2014

Hollow hierarchical hydroxyapatite/Au/polyelectrolyte hybrid microparticles with a hollow HAP core and polymer multilayer/Au nanoparticle shell for multi-responsive drug delivery have been prepared via an LbL technique.
A Kirkpatrick-Baez microscope for the National Ignition Facility
Authors: Pickworth L. A. , McCarville T. , Decker T. , Pardini T. , Ayers J. , Bell P. , Bradley D. , Brejnholt N. F. , Izumi N. , Mirkarimi P. , Pivovaroff M. , Smalyuk V. , Vogel J. , Walton C. , Kilkenny J.
Published: July 2014

Current pinhole x ray imaging at the National Ignition Facility (NIF) is limited in resolution and signal throughput to the detector for Inertial Confinement Fusion applications, due to the viable range of pinhole sizes (10–25 μm) that can be deployed. A higher resolution and throughput diagnostic is in development using a Kirkpatrick-Baez microscope system (KBM). The system will achieve <9 μm resolution over a 300 μm field of view with a multilayer coating operating at 10.2 keV. Presented here are the first images from the uncoated NIF KBM configuration demonstrating high resolution has been achieved across the full 300 μm field of view.
Probing the plasma near high power wave launchers in fusion devices for static and dynamic electric fields (invited)
Authors: Klepper C. C. , Martin E. H. , Isler R. C. , Colas L. , Goniche M. , Hillairet J. , Panayotis S. , Pegourié B. , Jacquot J. , Lotte Ph. , Colledani G. , Biewer T. M. , Caughman J. B. , Ekedahl A. , Green D. L. , Harris J. H. , Hillis D. L. , Shannon S. C. , Litaudon X.
Published: July 2014

An exploratory study was carried out in the long-pulse tokamak Tore Supra, to determine if electric fields in the plasma around high-power, RF wave launchers could be measured with non-intrusive, passive, optical emission spectroscopy. The focus was in particular on the use of the external electric field Stark effect. The feasibility was found to be strongly dependent on the spatial extent of the electric fields and overlap between regions of strong (>∼1 kV/cm) electric fields and regions of plasma particle recycling and plasma-induced, spectral line emission. Most amenable to the measurement was the RF electric field in edge plasma, in front of a lower hybrid heating and current drive launcher. Electric field strengths and direction, derived from fitting the acquired spectra to a model including time-dependent Stark effect and the tokamak-range magnetic field Zeeman-effect, were found to be in good agreement with full-wave modeling of the observed launcher.
Surface electromagnetic states in the photonic crystal–ferrite–plasma-like medium structure
Authors: Averkov Yu. O. , Tarapov S. I. , Kharchenko A. A. , Yakovenko V. M.
Published: July 2014

Frequencies of the surface electromagnetic states in the photonic crystal–ferrite–plasma-like medium structure were studied both theoretically and experimentally as a function of the ferrite layer thickness, external dc magnetic field and temperature. The photonic crystal was a periodic stack of a finite number of unit cells, each consisting of two different nonmagnetic dielectrics. A nonmagnetic semiconductor played the role of a plasma-like medium. A dc magnetic field was applied parallel to the ferrite layer. The propagation direction of an electromagnetic wave was perpendicular to the dc magnetic field with the electrical component of a microwave field parallel to the magnetic field. An analytical expression relating the frequencies of the surface electromagnetic states to the structural parameters and the magnitude of the dc magnetic field value was derived within the framework of the model of non-conducting and magnetized to saturation ferrite. It was predicted that the states under study are multimodal within a single photonic-crystal band gap.
The Griffiths phase and the metal-insulator transition in substituted manganites (Review Article)
Authors: Krivoruchko V. N.
Published: July 2014

Experimental and theoretical studies of the physics of the metal-insulator (MI) transition in manganites with colossal magnetoresistance are reviewed. The emphasis is on the properties of these systems caused by inhomogeneities in the electronic and magnetic states of the manganites near the Curie temperature. Experimental data supporting the existence of the Griffiths phase and theoretical treatments of the MI transition as a specific realization of a ferromagnetic-Griffiths phase transition in substituted manganites are discussed.
IR-spectroscopic study of the allyl + NO reaction in helium nanodroplets
Authors: Habig Daniel , Leicht Daniel , Kaufmann Matin , Schwaab Gerhard , Havenith Martina
Published: July 2014

The IR-spectrum of the allyl-NO adduct (CH2–CH–CH2–NO) in helium nanodroplets has been recorded in the frequency region 2850–3120 cm−1. CH2–CH–CH2–NO has been investigated as a prototype of the product of radical-radical reactions at 0.37 K. The product of the reaction, 3-nitroso-1-propene, was formed via the reaction of allyl and NO within the helium droplets. For an assignment we have predicted the conformers of the CH2–CH-CH2–NO using density functional theory (DFT) with a BLYP functional and a TZVPP basis set. By comparison with the experimental spectrum we can show that all three conformers are stabilized in superfluid helium nanodroplets.
A method for eliminating Faraday rotation in cryostat windows in longitudinal magneto-optical Kerr effect measurements
Authors: Polewko-Klim A. , Uba S. , Uba L.
Published: July 2014

A solution to the problem of disturbing effect of the background Faraday rotation in the cryostat windows on longitudinal magneto-optical Kerr effect (LMOKE) measured under vacuum conditions and/or at low temperatures is proposed. The method for eliminating the influence of Faraday rotation in cryostat windows is based on special arrangement of additional mirrors placed on sample holder. In this arrangement, the orientation of the cryostat window is perpendicular to the light beam direction and parallel to an external magnetic field generated by the H-frame electromagnet. The operation of the LMOKE magnetometer with the special sample holder based on polarization modulation technique with a photo-elastic modulator is theoretically analyzed with the use of Jones matrices, and formulas for evaluating of the actual Kerr rotation and ellipticity of the sample are derived. The feasibility of the method and good performance of the magnetometer is experimentally demonstrated for the LMOKE effect measured in Fe/Au multilayer structures. The influence of imperfect alignment of the magnetometer setup on the Kerr angles, as derived theoretically through the analytic model and verified experimentally, is examined and discussed.
Theory of standing spin-wave damping
Authors: Baryakhtar V. G.
Published: July 2014

The exchange damping of standing spin waves is calculated for ultrathin magnetic films with thicknesses on the order of the exchange length. Because of the boundary conditions, the wave vectors of spin waves in these films are very large and are proportional to the reciprocal of the film thickness. Exchange damping of these waves becomes dominant and can cause spreading of the standing spin-wave spectrum.
Plastic fiber scintillator response to fast neutrons
Authors: Danly C. R. , Sjue S. , Wilde C. H. , Merrill F. E. , Haight R. C.
Published: July 2014

The Neutron Imaging System at NIF uses an array of plastic scintillator fibers in conjunction with a time-gated imaging system to form an image of the neutron emission from the imploded capsule. By gating on neutrons that have scattered from the 14.1 MeV DT energy to lower energy ranges, an image of the dense, cold fuel around the hotspot is also obtained. An unmoderated spallation neutron beamline at the Weapons Neutron Research facility at Los Alamos was used in conjunction with a time-gated imaging system to measure the yield of a scintillating fiber array over several energy bands ranging from 1 to 15 MeV. The results and comparison to simulation are presented.
Flow around a corner in the water impact problem
Authors: Krechetnikov R.
Published: July 2014

In this work, we study the local flow in the vicinity of a flat sector of arbitrary angle α in the water impact problem as motivated by recent experimental observations in the author's laboratory. The key question is as to why the ejecta formed during the impact at zero deadrise angle is considerably higher along a straight edge of the sector compared to that near a sharp corner α < π, e.g., if the impacting body is a rectangular plate. Resolving this question is made possible by the discovered here mathematical equivalence of the problem to electromagnetic diffraction phenomena. The main result of the present study is the revealed and quantified influence of the geometry of a flat plate corner on the fluid flow around it, which also contributes to the understanding of certain three-dimensional effects in the water impact problem and provides a generalization of the classical two-dimensional results on the impact at zero deadrise angle. The offered theoretical solution is also qualitatively supported with the help of particle image velocimetry measurements.
Thermal transitions in nano-patterned XY-magnets
Authors: Arnalds Unnar B. , Ahlberg Martina , Brewer Matthew S. , Kapaklis Vassilios , Papaioannou Evangelos Th. , Karimipour Masoud , Korelis Panagiotis , Stein Aaron , Ólafsson Sveinn , Hase Thomas P. A. , Hjörvarsson Björgvin
Published: July 2014

We have fabricated ultra-thin disc shaped islands wherein shape anisotropy confines the moment to the island plane, creating XY-like superspins. At low temperatures, the superspins are blocked, and, as the temperature is increased, they undergo a transition into a superparamagnetic state. The onset of this dynamic superspin state scales with the diameter of the islands, and it persists up to a temperature governed by the intrinsic ordering temperature of the island material defining a range in temperature in which dynamic behavior of the magnetic islands can be obtained.
Modulation of rotation-induced lift force for cell filtration in a low aspect ratio microchannel
Authors: Zhou Jian , Giridhar Premkumar Vummidi , Kasper Susan , Papautsky Ian
Published: July 2014

Cell filtration is a critical step in sample preparation in many bioapplications. Herein, we report on a simple, filter-free, microfluidic platform based on hydrodynamic inertial migration. Our approach builds on the concept of two-stage inertial migration which permits precise prediction of microparticle position within the microchannel. Our design manipulates equilibrium positions of larger microparticles by modulating rotation-induced lift force in a low aspect ratio microchannel. Here, we demonstrate filtration of microparticles with extreme efficiency (>99%). Using multiple prostate cell lines (LNCaP and human prostate epithelial tumor cells), we show filtration from spiked blood, with 3-fold concentration and >83% viability. Results of a proliferation assay show normal cell division and suggest no negative effects on intrinsic properties. Considering the planar low-aspect-ratio structure and predictable focusing, we envision promising applications and easy integration with existing lab-on-a-chip systems.
Temperature dependence of dielectric and electromechanical properties of (K,Na)(Nb,Ta)O3 single crystal and corresponding domain structure evolution
Authors: Zheng Limei , Wang Junjun , Huo Xiaoqing , Wang Rui , Sang Shijing , Li Shiyang , Zheng Peng , Cao Wenwu
Published: July 2014

Domain structures and their evolution with temperature in the [001]C oriented (K,Na)(Nb,Ta)O3 (KNNT) single crystal have been studied before and after poling by polarizing light microscopy. The results indicate that the KNNT crystal is difficult to be completely poled by the room temperature poling process. The domain structure is rather stable in the orthorhombic phase, but exhibits substantial changes near the phase transition temperatures TO-T and TC. Narrower stripe domains are formed during both the orthorhombic-tetragonal and tetragonal-cubic phase transition processes, no intermediate phases were found during the phase transitions. The temperature dependence of the dielectric and piezoelectric properties were measured, and the influence of domain structures on the dielectric and electromechanical properties were quantified.
Asymmetric transmission of terahertz waves through a graphene-loaded metal grating
Authors: Zhou Yu , Dong Ye-Qing , Fan Ren-Hao , Hu Qing , Peng Ru-Wen , Wang Mu
Published: July 2014

In this work, we theoretically investigate the propagation of terahertz (THz) waves through a graphene-loaded metal grating under external magnetic field. It is found that resonant modes in the system can be converted between transverse-electric and transverse-magnetic polarizations due to Hall conductivity of graphene. As a consequence, asymmetric transmission of THz waves through this graphene-loaded metal grating is achieved. Furthermore, by adjusting either the external magnetic field or the Fermi level of graphene, such asymmetric wave propagation can be significantly tuned. The investigations may provide a unique way to achieve the graphene-loaded optodevices for THz waves.
Internal resonances in a periodic magneto-electro-elastic structure
Authors: Piliposyan D. G. , Ghazaryan K. B , Piliposian G. T.
Published: July 2014

Propagation of electro-magneto-acoustic waves in a three phase magneto-electro-elastic periodic structure has been investigated with full coupling between mechanical, electric, and magnetic fields. Due to simultaneous piezoelectric and piezomagnetic effects, an orthogonally polarised electromagnetic wave couples with the similarly polarised lattice vibration, resulting in a both dielectric and magnetic phonon-polaritons. The closed form of dispersion relation has been used to demonstrate the phonon-polariton coupling not only in the long wave region at high acoustic microwave frequencies but also for shorter waves at optical infrared frequencies. The results also show that neither at acoustic nor at optical frequencies the magneto-electro-elastic effect affects the band structure due to the Bragg scattering.
Design of a terahertz parametric oscillator based on a resonant cavity in a terahertz waveguide
Authors: Saito K. , Tanabe T. , Oyama Y.
Published: July 2014

We demonstrate ns-pulsed pumping of terahertz (THz) parametric oscillations in a quasi-triply resonant cavity in a THz waveguide. The THz waves, down converted through parametric interactions between the pump and signal waves at telecom frequencies, are confined to a GaP single mode ridge waveguide. By combining the THz waveguide with a quasi-triply resonant cavity, the nonlinear interactions can be enhanced. A low threshold pump intensity for parametric oscillations can be achieved in the cavity waveguide. The THz output power can be maximized by optimizing the quality factors of the cavity so that an optical to THz photon conversion efficiency, ηp, of 0.35, which is near the quantum-limit level, can be attained. The proposed THz optical parametric oscillator can be utilized as an efficient and monochromatic THz source.
Shaping the composition profiles in heteroepitaxial quantum dots: Interplay of thermodynamic and kinetic effects
Authors: Georgiou C. , Leontiou T. , Kelires P. C.
Published: July 2014

Atomistic Monte Carlo simulations, coupling thermodynamic and kinetic effects, resolve a longstanding controversy regarding the origin of composition profiles in heteroepitaxial SiGe quantum dots. It is shown that profiles with cores rich in the unstrained (Si) component derive from near-equilibrium processes and intraisland diffusion. Profiles with cores rich in the strained (Ge) component are of nonequilibrium nature, i.e., they are strain driven but kinetically limited. They are shaped by the distribution of kinetic barriers of atomic diffusion in the islands. The diffusion pathways are clearly revealed for the first time. Geometrical kinetics play a minor role.
Hot-stage transmission electron microscopy study of (Na, K)NbO3 based lead-free piezoceramics
Authors: Lu Shengbo , Xu Zhengkui , Kwok K. W. , Chan Helen L. W.
Published: July 2014

Hierarchical nanodomains assembled into micron-sized stripe domains, which is believed to be associated with outstanding piezoelectric properties, were observed at room temperature in a typical lead free piezoceramics, (Na0.52K0.48−x)(Nb0.95−xTa0.05)-xLiSbO3, with finely tuned polymorphic phase boundaries (x = 0.0465) by transmission electron microscopy. The evolution of domain morphology and crystal structure under heating and cooling cycles in the ceramic was investigated by in-situ hot stage study. It is found that the nanodomains are irreversibly transformed into micron-sized rectangular domains during heating and cooling cycles, which lead to the thermal instability of piezoelectric properties of the materials.
A spin-filter made of quantum anomalous Hall insulator nanowires
Authors: Wu Jiansheng
Published: July 2014

Topological end states (TES) in quantum anomalous Hall insulator nanowires can induce tunneling within the gap. Such TES are spin polarized, thus the induced current is spin polarized as well, which can be used to construct a spin-filter applied in spintronics. An interferometry device is designed to control the polarized current as well. The advantage and finite size effect on this system are discussed.
Model test and simulation of modified spar type floating offshore wind turbine with three catenary mooring lines
Authors: Shin Hyunkyoung , Lee Wooseob , Jung Kwangjin , Kim Jungtae
Published: July 2014

Korea is a peninsula which is surrounded by the Yellow Sea (shallow sea), the southern sea and the East Sea (deep sea). These circumstances always make us consider that a platform could have good motion performances in both shallow and deep seas. In this paper, the typical spar type platform of the Offshore Code Comparison Collaboration Hywind Floating Offshore Wind Turbine (FOWT) has been modified and a new concept FOWT platform is suggested for both seas. Its motion performances are evaluated by both 1:80 scale model tests and full scale numerical simulations.
Revisiting the percolation phenomena in dielectric composites with conducting fillers
Authors: Zhang Lin , Bass Patrick , Cheng Z.-Y.
Published: July 2014

The composition (φ) dependence of the effective dielectric constant (εeff) on conductor-dielectric composites is widely described as εeff∝(φc−φ)−s. This relationship has been extensively used to fit experimental results for determining the percolation behavior (percolation threshold φc and power constant s). The equation was checked using experimental results from two 0–3 nanocomposite systems with uniform microstructures. It is found that the equation can be used to fit the experimental results, but the fitting constants (φc and s) do not reflect the percolation behavior: the values of both fitting constants are dependent on the frequency (f) and temperature selected. It is also found that the fitting constant φc increases with increasing frequency selected and it is believed that this arises from the critical phenomenon, εeff∝fγ−1, for composites close to the φc.
Enhanced field emission properties of doped graphene nanosheets with layered SnS2
Authors: Rout Chandra Sekhar , Joshi Padmashree D. , Kashid Ranjit V. , Joag Dilip S. , More Mahendra A. , Simbeck Adam J. , Washington Morris , Nayak Saroj K. , Late Dattatray J.
Published: July 2014

We report here our experimental investigations on p-doped graphene using tin sulfide (SnS2), which shows enhanced field emission properties. The turn on field required to draw an emission current density of 1 μA/cm2 is significantly low (almost half the value) for the SnS2/reduced graphene oxide (RGO) nanocomposite (2.65 V/μm) compared to pristine SnS2 (4.8 V/μm) nanosheets. The field enhancement factor β (∼3200 for the SnS2 and ∼3700 for SnS2/RGO composite) was calculated from Fowler-Nordheim (F-N) plots, which indicates that the emission is from the nanometric geometry of the emitter. The field emission current versus time plot shows overall good emission stability for the SnS2/RGO emitter. The magnitude of work function of SnS2 and a SnS2/graphene composite has been calculated from first principles density functional theory (DFT) and is found to be 6.89 eV and 5.42 eV, respectively. The DFT calculations clearly reveal that the enhanced field emission properties of SnS2/RGO are due to a substantial lowering of the work function of SnS2 when supported by graphene, which is in response to p-type doping of graphene.
Detection of saliva-range glucose concentrations using organic thin-film transistors
Authors: Elkington D. , Belcher W. J. , Dastoor P. C. , Zhou X. J.
Published: July 2014

We describe the development of a glucose sensor through direct incorporation of an enzyme (glucose oxidase) into the gate of an organic thin film transistor (OTFT). We show that glucose diffusion is the key determinant of the device response time and present a mechanism of glucose sensing in these devices that involves protonic doping of the transistor channel via enzymatic oxidation of glucose. The integrated OTFT sensor is sensitive across 4 decades of glucose concentration; a range that encompasses both the blood and salivary glucose concentration levels. As such, this work acts as a proof-of-concept for low-cost printed biosensors for salivary glucose.
The Relevance of Structural Biology in Studying Molecules Involved in Parasite–Host Interactions: Potential for Designing New Interventions
Authors: Mason Lyndel , Amani Parisa , Cross Megan , Baker Joshua , Bailey Ulla-Maja , Jones Malcolm K. , Gasser Robin B. , Hofmann Andreas
Published: July 2014

New interventions against infectious diseases require a detailed knowledge and understanding of pathogen–host interactions and pathogeneses at the molecular level. The combination of the considerable advances in systems biology research with methods to explore the structural biology of molecules is poised to provide new insights into these areas. Importantly, exploring three-dimensional structures of proteins is central to understanding disease processes, and establishing structure–function relationships assists in identification and assessment of new drug and vaccine targets. Frequently, the molecular arsenal deployed by invading pathogens, and in particular parasites, reveals a common theme whereby families of proteins with conserved three-dimensional folds play crucial roles in infectious processes, but individual members of such families show high levels of specialisation, which is often achieved through grafting particular structural features onto the shared overall fold. Accordingly, the applicability of predictive methodologies based on the primary structure of proteins or genome annotations is limited, particularly when thorough knowledge of molecular-level mechanisms is required. Such instances exemplify the need for experimental three-dimensional structures provided by protein crystallography, which remain an essential component of this area of research. In the present article, we review two examples of key protein families recently investigated in our laboratories, which could represent intervention targets in the metabolome or secretome of parasites.
Biomechanics of the Right Ventricle in Health and Disease (2013 Grover Conference Series)
Authors: Naeije Robert , Brimioulle Serge , Dewachter Laurence
Published: July 2014

Right ventricular (RV) function is a major determinant of the symptomatology and outcome in pulmonary hypertension. The normal RV is a thin‐walled flow generator able to accommodate large changes in venous return but unable to maintain flow output in the presence of a brisk increase in pulmonary artery pressure. The RV chronically exposed to pulmonary hypertension undergoes hypertrophic changes and an increase in contractility, allowing for preserved flow output in response to peripheral demand. Failure of systolic function adaptation (homeometric adaptation, described by Anrep's law of the heart) results in increased dimensions (heterometric adaptation; Starling's law of the heart), with a negative effect on diastolic ventricular interactions, limitation of exercise capacity, and vascular congestion. Ventricular function is described by pressure‐volume relationships. The gold standard of systolic function is maximum elastance (Emax), or the maximal value of the ratio of pressure to volume. This value is not immediately sensitive to changes in loading conditions. The gold standard of afterload is arterial elastance (Ea), defined by the ratio of pressure at Emax to stroke volume. The optimal coupling of ventricular function to the arterial circulation occurs at an Emax/Ea ratio between 1.5 and 2. Patients with severe pulmonary hypertension present with an increased Emax, a trend toward decreased Emax/Ea, and increased RV dimensions, along with progression of the pulmonary vascular disease, systemic factors, and left ventricular function. The molecular mechanisms of RV systolic failure are currently being investigated. It is important to refer biological findings to sound measurements of function. Surrogates for Emax and Ea are being developed through bedside imaging techniques.
Acute Effects of Levosimendan in Experimental Models of Right Ventricular Hypertrophy and Failure
Authors: Vildbrad Mads D. , Andersen Asger , Holmboe Sarah , Ringgaard Steffen , Nielsen Jan M. , Nielsen‐Kudsk Jens Erik
Published: July 2014

Pulmonary arterial hypertension (PAH) is a fatal disease, and the ultimate cause of death is right ventricular (RV) failure. In this study, we investigated the acute hemodynamic effects of levosimendan in two rat models of RV hypertrophy and failure. Wistar rats were randomized to receive sham surgery (n = 8), pulmonary trunk banding (PTB; n = 8), or monocrotaline injection (MCT; n = 7). RV function was evaluated at baseline and after injection of placebo and two concentrations of levosimendan (12 and 60 μg/kg) using magnetic resonance imaging, echocardiography, and invasive pressure recordings. PTB and MCT injection caused hypertrophy, dilatation, and failure of the RV compared with sham surgery. Levosimendan increased RV end systolic pressure (sham surgery: 16.0% ± 3.8% [P = 0.0038]; MCT: 9.9% ± 3.1% [P = 0.018]; PTB: 24.5% ± 3.3% [P = 0.0001]; mean ± SEM) compared with placebo. Levosimendan markedly increased RV stroke volume (SV) in the MCT group (29.1% ± 8.3%; P = 0.012), did not change RV SV in the PTB group (0.4% ± 4.5%; P = 0.93), and decreased RV SV in the sham surgery group (−10.9% ± 3.7%; P = 0.020). Nitroprusside, which was used to mimic the systemic arterial vasodilator action of levosimendan, did not influence RV function. These data demonstrate that levosimendan acutely improves the failing right heart in a MCT model of PAH and that the mechanism involves a direct acute positive inotropic effect on the hypertrophic and failing RV of the rat.
OGLE-SMC-LPV-00861 (LIN 9): the first proven Z And outburst in a Magellanic symbiotic star
Authors: Miszalski Brent , Mikołajewska Joanna , Udalski Andrzej
Published: July 2014

We report on the discovery of a new Small Magellanic Cloud symbiotic star, OGLE-SMC-LPV-00861, previously catalogued as Hα emission line source LIN 9. The OGLE light curve shows multiple-maxima outburst behaviour over ∼1200 d with a maximum outburst of ΔV = 1.5 mag. An optical spectrum of LIN 9 taken with the Southern African Large Telescope at quiescence reveals a K5 red giant with emission lines confirming its symbiotic star nature, demonstrating the potential use of ongoing large time-domain surveys to identify strong symbiotic star candidates. It is the first Magellanic symbiotic star proven to show poorly understood Z And outbursts. At outburst the estimated hot component luminosity is L ∼ 3165 L⊙, compared to L ∼ 225 L⊙ at quiescence. Further observations are needed, especially at outburst, to better understand this unique Z And-like system at a known distance, and to provide essential input to physical models of the Z And phenomenon.