bluuebunny/crossref_metadata_2025 huggingface dataset:
Design, synthesis, insecticidal activity and 3D-QSR study for novel trifluoromethyl pyridine derivatives containing an 1,3,4-oxadiazole moiety
Authors: Xu F. Z. , Wang Y. Y. , Luo D. X. , Yu G. , Guo S. X. , Fu H. , Zhao Y. H. , Wu J.
Published: February 2018

Novel trifluoromethyl pyridine derivatives bearing 1,3,4-oxadiazole whereas synthesized, their which showed good insecticidal activity; a 3D-QSAR model with good predictability was is proposed.
The CARMENES search for exoplanets around M dwarfs
Authors: Passegger V. M. , Reiners A. , Jeffers S. V. , Wende-von Berg S. , Schöfer P. , Caballero J. A. , Schweitzer A. , Amado P. J. , Béjar V. J. S. , Cortés-Contreras M. , Hatzes A. P. , Kürster M. , Montes D. , Pedraz S. , Quirrenbach A. , Ribas I. , Seifert W.
Published: February 2018

Context. The new CARMENES instrument comprises two high-resolution and high-stability spectrographs that are used to search for habitable planets around M dwarfs in the visible and near-infrared regime via the Doppler technique. Aims. Characterising our target sample is important for constraining the physical properties of any planetary systems that are detected. The aim of this paper is to determine the fundamental stellar parameters of the CARMENES M-dwarf target sample from high-resolution spectra observed with CARMENES. We also include several M-dwarf spectra observed with other high-resolution spectrographs, that is CAFE, FEROS, and HRS, for completeness.

Methods. We used a χ2 method to derive the stellar parameters effective temperature Teff, surface gravity logg, and metallicity [Fe/H] of the target stars by fitting the most recent version of the PHOENIX-ACES models to high-resolution spectroscopic data. These stellar atmosphere models incorporate a new equation of state to describe spectral features of low-temperature stellar atmospheres. Since Teff, logg, and [Fe/H] show degeneracies, the surface gravity is determined independently using stellar evolutionary models.

Results. We derive the stellar parameters for a total of 300 stars. The fits achieve very good agreement between the PHOENIX models and observed spectra. We estimate that our method provides parameters with uncertainties of σTeff = 51 K, σlog g = 0.07, and σ[Fe/H] = 0.16, and show that atmosphere models for low-mass stars have significantly improved in the last years. Our work also provides an independent test of the new PHOENIX-ACES models, and a comparison for other methods using low-resolution spectra. In particular, our effective temperatures agree well with literature values, while metallicities determined with our method exhibit a larger spread when compared to literature results.
Counseling Skill Development in Audiology: Clinical Instruction Considerations
Authors: Muñoz Karen
Published: February 2018

Audiologists play a critical role in supporting patients as they provide diagnostic information about their hearing and in the delivery of treatment services. Graduate training related to counseling, however, varies among programs in the extent students are prepared to engage effectively and intentionally with patients. Instruction is needed to provide students with a framework that supports their ability to learn and implement evidence-based counseling services. This article addresses the impact patients can experience when counseling gaps exist, shares clinical instruction strategies that can support students' acquisition of counseling skills, and discusses considerations for integration of counseling education into graduate training programs.
Study of Relationship between Central Venous Pressure and Peripheral Venous Pressure during Intraoperative Period in Neurosurgical Patients
Authors: Prakash Jay , Rao Natesh S. , Kumar Sanjeev , Raghwendra Kumar H. , Saran Khushboo , Reddy Sandeep D.
Published: February 2018

Background and Objectives Central venous pressure (CVP) and peripheral venous pressure (PVP) are strongly correlated during various surgeries. This study was designed to examine the consistency of CVP–PVP relationships in circumstances of rapidly fluctuating hemodynamics in neurosurgical patients. Prime objective of this study was to determine if PVP can be an effective alternative to invasive CVP for assessing volume status during neurosurgical procedures when expertise, equipment, and patient’s condition contraindicate invasive monitoring.

Subjects and Methods After the approval by the Institutional Ethics Committee, CVP and PVP were measured in 50 neurosurgical patients of the American Society of Anesthesiologists grade I and II operated in supine position. Paired measurements of CVP and PVP were made every 20 minutes, from the starting of anesthesia until the end of surgery; however, in situations of hemodynamic instability, the readings were taken every 5 minutes of interval.

Results The study showed a strong correlation between CVP and PVP (Pearson’s correlation coefficient between CVP and PVP, r = 0.89; 95% CI: 0.81–0.93; p < 0.001). Mean CVP was 5.7 ± 0.8 mm of Hg, mean PVP was 10.4 ± 0.6 mm of Hg, and bias between CVP and PVP was 4.7 ± 0.4 (95% CI: − 4.61 to − 4.83). The Bland–Altman analysis showed that limit of agreement to be 4.0 to 5.5 mm of Hg.

Conclusion This study demonstrated a strong correlation between CVP and PVP. Therefore, PVP monitoring may be a reliable alternative to CVP monitoring during neurosurgery.
Kopfschmerz bei Liquorüberdruck
Authors: Hoffmann J. , Förderreuther S.
Published: February 2018

Die idiopathische intrakranielle Hypertension beruht auf einer intrakraniellen Drucksteigerung unklarer Ätiologie. Das daraus resultierende klinische Bild ist in erster Linie durch einen weitgehend unspezifischen Kopfschmerz und progrediente, potenziell irreversible Sehstörungen charakterisiert wobei nicht selten auch Hirnnervenlähmungen, Riechstörungen und kognitive Defizite beobachtet werden. Die Ursache der intrakraniellen Drucksteigerung ist nicht eindeutig geklärt. Das Vorliegen einer venösen Abflussstörung, die aufgrund des häufig bestehenden Übergewichts oder auch aufgrund eines vaskulären Hindernisses in Form einer bilateralen Stenose des Sinus transversus auftreten kann, erscheint am nahe liegendsten. Auch hormonelle Faktoren könnten von wesentlicher Bedeutung sein und erklären warum überwiegend Frauen von der Erkrankung betroffen sind. Die Behandlung besteht in erster Linie aus einer Gewichtsreduktion und der oralen Gabe von Carboanhydrasehemmern, wobei lediglich für Acetazolamid Daten aus einer placebo-kontrollierten Studie vorliegen. Invasive Behandlungsverfahren sollten nur in therapierefraktären oder besonders fulminanten Fällen mit drohendem Verlust des Sehvermögens erwogen werden.
Update Chronische Obstipation im Kindes- und Jugendalter
Authors: Scholz D. , Gosemann J.-H. , Flemming G.
Published: February 2018

Die chronische Obstipation gehört zu den häufigsten Vorstellungsgründen beim Kinder-arzt. In über 95 % der Fälle liegt eine funktionelle Obstipation (keine organische Erkrankung) vor, die Genese ist meist multikausal. Die Differenzialdiagnostik sollte sich nach den Befunden einer gezielten und strukturierten Anamnese und Untersuchung richten, um ressourcensparend strukturelle, endokrine und metabolische Ursachen auszuschließen. Der Ausschluss organischer Erkrankungen ist unerlässlich, um umgehend eine adäquate Therapie durch entsprechende Spezialisten zu initiieren. Alle Kinder und Jugendlichen mit einer (funktionellen) Obstipation profitieren von einer prompten und sorgfältigen therapeutischen Intervention. Eine verzögerte oder inadäquate Behandlung kann zu einem Stuhlvermeidungsverhalten mit konsekutiver Verschlechterung der Obstipation und ernst-haften psychosozialen Konsequenzen führen. Die besten Ergebnisse hinsichtlich des lang-fristigen Therapieerfolges werden durch eine multimodale Therapie erreicht.
Vertical Impulse as a Determinant of Combination of Step Length and Frequency During Sprinting
Authors: Nagahara Ryu , Takai Yohei , Kanehisa Hiroaki , Fukunaga Tetsuo
Published: February 2018

This study aimed to clarify the influence of vertical impulse on the magnitude of step length (SL) and frequency (SF) and their ratio during the entire acceleration phase of maximal sprinting. Thirty-nine male soccer players performed 60-m sprints, during which step-to-step ground reaction forces were recorded over a 50-m distance. The mean values of spatiotemporal variables and vertical and anteroposterior impulses for each set of four steps during the acceleration phase until the 28th step were computed to examine relationships among variables in seven sections. When controlling for the influence of running speed, stature and corresponding duration of braking or propulsion, vertical impulses during the propulsive phase at the 1st–4th step section and those during the braking phases in the sections from the 5th–8th to the 25th–28th step were positively correlated with SL and SL/SF ratio and negatively correlated with SF, whereas the anteroposterior impulses were not correlated with SL or SF. In conclusion, the current results demonstrate that vertical impulse during the propulsive phase in the initial acceleration stage and that during the braking phase in the middle and later acceleration stages are the most likely determinants of the combination of SL and SF during sprinting.
How to perform Contrast-Enhanced Ultrasound (CEUS)
Authors: Dietrich Christoph , Averkiou Michalakis , Nielsen Michael , Barr Richard , Burns Peter , Calliada Fabrizio , Cantisani Vito , Choi Byung , Chammas Maria , Clevert Dirk-André , Claudon Michel , Correas Jean-Michel , Cui Xin-Wu , Cosgrove David , D'Onofrio Mirko , Dong Yi , Eisenbrey JohnR. , Fontanilla Teresa , Gilja Odd , Ignee Andre , Jenssen Christian , Kono Yuko , Kudo Masatoshi , Lassau Nathalie , Lyshchik Andrej , Franca Meloni Maria , Moriyasu Fuminori , Nolsøe Christian , Piscaglia Fabio , Radzina Maija , Saftoiu Adrian , Sidhu Paul , Sporea Ioan , Schreiber-Dietrich Dagmar , Sirlin Claude , Stanczak Maria , Weskott Hans-Peter , Wilson Stephanie , Willmann Juergen , Kim Tae , Jang Hyun-Jung , Vezeridis Alexandar , Westerway Sue
Published: February 2018

“How to perform contrast-enhanced ultrasound (CEUS)” provides general advice on the use of ultrasound contrast agents (UCAs) for clinical decision-making and reviews technical parameters for optimal CEUS performance. CEUS techniques vary between centers, therefore, experts from EFSUMB, WFUMB and from the CEUS LI-RADS working group created a discussion forum to standardize the CEUS examination technique according to published evidence and best personal experience. The goal is to standardise the use and administration of UCAs to facilitate correct diagnoses and ultimately to improve the management and outcomes of patients.
10-Jahres-Entwicklung operativer Eingriffe an der Wirbelsäule in Deutschland
Authors: Petzold Thomas , Tesch Falko , Adler Jürgen-Bernhard , Günster Christian , Niethard Fritz-Uwe , Schmitt Jochen
Published: February 2018

Hintergrund Analyse der regionalen zeitlichen Entwicklung von Wirbelsäulenoperationen in Deutschland zwischen 2005 und 2014.

Material und Methoden Es erfolgte eine Sekundärdatenanalyse stationärer Daten des Wissenschaftlichen Instituts der AOK (WIdO) für den Zeitraum 2005 bis 2014. Für 14 definierte Eingriffsgruppen wurde die Zahl operierter Patienten (Eingriffsfälle) sowie der durchgeführten Wirbelsäulenoperationen (Prozeduren anhand OPS-Code) ermittelt. Die regionale Versorgungshäufigkeit in den 402 Kreisen in Deutschland sowie die alters- und geschlechtsstandardisierte Verteilung wird in Versorgungskarten dargestellt.

Ergebnisse Im Beobachtungszeitraum erfolgten 796 870 stationäre Behandlungsfälle mit Wirbelsäulenoperation bei AOK-Versicherten. Die relative Zunahme im 10-Jahres-Zeitraum betrug 82% von 51 053 Eingriffen 2005 auf 91 971 Eingriffe 2014. Die Fallzahlerhöhung fand insbesondere 2005 bis 2011 statt und betraf alle Eingriffsgruppen außer „Exzision von Bandscheiben und Knochen“. Sie war unterschiedlich stark ausgeprägt mit stärksten Zuwächsen bei der „Knöchernen Dekompression“ (280% Anstieg). Bei allen Eingriffsgruppen fanden sich regionale Unterschiede. 2014 betrug die Schwankung zwischen 109 und 729 Eingriffen je 100 000 AOK-Versicherte zwischen den Kreisen.

Schlussfolgerung Die deutlichen Anstiege um > 80% in 10 Jahren sind soziodemografisch nicht plausibel erklärbar. Die dargestellten, ausgeprägten regionalen Unterschiede allein erlauben keine abschließenden Rückschlüsse zum Vorliegen einer regionalen Unter-, Über- oder Fehlversorgung. Sie unterstreichen jedoch die Notwendigkeit weiterführender versorgungsepidemiologischer Studien zur Indikationsqualität und zu Determinanten der regionalen Variation von Eingriffszahlen.
Krankheitsspezifisches Wissen in der konservativen Therapie der idiopathischen Adoleszentenskoliose
Authors: Wagner Ferdinand , Brendel Julia , Dingeldey Esther , Winkler Sebastian , Grifka Joachim , Matussek Jan
Published: February 2018

Hintergrund Die idiopathische Adoleszentenskoliose (IAS) tritt üblicherweise in der Pubertät und damit in einem sensiblen Lebensabschnitt auf. Die konservative Korsetttherapie der IAS erfordert zudem eine hohe Mitarbeit der Patienten. Wie von anderen Erkrankungen bekannt, fördert ein hohes Maß an krankheitsspezifischem Wissen (KSW) den Behandlungserfolg und kann die Lebensqualität (LQ) erhöhen.

Fragestellung Das Ziel der Studie war, das KSW unserer Patienten mit IAS zu überprüfen und Rückschlüsse auf deren Lebensqualität zu ziehen.

Methoden 67 Patienten mit IAS unter konservativer Korsetttherapie wurden gebeten, einen anonymisierten Fragebogen bez. krankheitsspezifischer Fakten zu beantworten. Zusätzlich wurde der SRS-22r-Score der Scoliosis Research Society als Maß für die LQ erhoben.

Ergebnisse Die Hauptinformationsquelle der Patienten stellten das behandelnde Ärzteteam und das Internet dar. Die Mehrheit gab an, verstanden zu haben was Skoliose sei. Detailliertere Fragen ließen jedoch erhebliche Wissenslücken erkennen. Signifikante Unkenntnisse waren insbesondere in den Feldern Therapieregime und Therapieziele vorhanden. Insbesondere die voraussichtliche Dauer der Therapie erschien den meisten Patienten unklar. Eine höhere LQ korrelierte mit hoher Compliance. Patienten, die sich durch die Therapie eine Verbesserung ihres Rückenprofils erhofften, fielen mit einer niedrigeren LQ im Bereich Selbstwahrnehmung auf.

Diskussion Unsere Studie zeigte signifikante Wissenslücken im KSW der Patienten mit IAS auf. Eine optimierte Informationsweitergabe an die Patienten könnte die LQ und auch das Therapieergebnis beeinflussen. Da wir uns als behandelnde Ärzte in der Position der Hauptinformationsquelle befinden, liegt es an uns, diese Situation zu nutzen und zu verbessern.
Nucleation of the lamellar phase from the disordered phase of the renormalized Landau-Brazovskii model
Authors: Carilli Michael F. , Delaney Kris T. , Fredrickson Glenn H.
Published: February 2018

Using the zero-temperature string method, we investigate nucleation of a stable lamellar phase from a metastable disordered phase of the renormalized Landau-Brazovskii model at parameters explicitly connected to those of an experimentally accessible diblock copolymer melt. We find anisotropic critical nuclei in qualitative agreement with previous experimental and analytic predictions; we also find good quantitative agreement with the predictions of a single-mode analysis. We conduct a thorough search for critical nuclei containing various predicted and experimentally observed defect structures. The predictions of the renormalized model are assessed by simulating the bare Landau-Brazovskii model with fluctuations. We find that the renormalized model makes reasonable predictions for several important quantities, including the order-disorder transition (ODT). However, the critical nucleus size depends sharply on proximity to the ODT, so even small errors in the ODT predicted by the renormalized model lead to large errors in the predicted critical nucleus size. We conclude that the renormalized model is a poor tool to study nucleation in the fluctuating Landau-Brazovskii model, and recommend that future studies work with the fluctuating bare model directly, using well-chosen collective variables to investigate kinetic pathways in the disorder → lamellar transition.
A variable partially polarizing beam splitter
Authors: Flórez Jefferson , Carlson Nathan J. , Nacke Codey H. , Giner Lambert , Lundeen Jeff S.
Published: February 2018

We present designs for variably polarizing beam splitters. These are beam splitters allowing the complete and independent control of the horizontal and vertical polarization splitting ratios. They have quantum optics and quantum information applications, such as quantum logic gates for quantum computing and non-local measurements for quantum state estimation. At the heart of each design is an interferometer. We experimentally demonstrate one particular implementation, a displaced Sagnac interferometer configuration, that provides an inherent instability to air currents and vibrations. Furthermore, this design does not require any custom-made optics but only common components which can be easily found in an optics laboratory.
On the enhancement of p-11B fusion reaction rate in laser-driven plasma by α → p collisional energy transfer
Authors: Belloni Fabio , Margarone Daniele , Picciotto Antonino , Schillaci Francesco , Giuffrida Lorenzo
Published: February 2018

The possibility of triggering an avalanche reaction in laser-driven p-11B fusion by the effect of collisional energy transfer from α particles to protons has recently been debated, especially in connection to the high yield of α particles (4 × 108 per laser shot) achieved on engineered targets at the Prague Asterix Laser System (PALS), with a pulse of 500 J, 0.3 ns FWHM. We elucidate this controversial subject within the framework of a simple two-population model for protons, based on the binary collision theory in a plasma. We find an avalanche characteristic time of almost 1 μs for the 675 keV fusion cross section resonance in typical PALS plasma, upon idealized confinement conditions. This avalanche time is one order of magnitude higher than previously reported, meaning that no such process can substantially develop in plasma at the PALS on the 675 keV resonance, not even in the most optimistic confinement scenarios. Nevertheless, we put forward for further investigation that more realistic conditions for setting up the avalanche regime could rather be attained by suitably targeting the narrow 163 keV resonance in the fusion cross section, also in connection to recently proposed laser-driven magnetic trapping techniques.
Extension of local front reconstruction method with controlled coalescence model
Authors: Rajkotwala A. H. , Mirsandi H. , Peters E. A. J. F. , Baltussen M. W. , van der Geld C. W. M. , Kuerten J. G. M. , Kuipers J. A. M.
Published: February 2018

The physics of droplet collisions involves a wide range of length scales. This poses a challenge to accurately simulate such flows with standard fixed grid methods due to their inability to resolve all relevant scales with an affordable number of computational grid cells. A solution is to couple a fixed grid method with subgrid models that account for microscale effects. In this paper, we improved and extended the Local Front Reconstruction Method (LFRM) with a film drainage model of Zang and Law [Phys. Fluids 23, 042102 (2011)]. The new framework is first validated by (near) head-on collision of two equal tetradecane droplets using experimental film drainage times. When the experimental film drainage times are used, the LFRM method is better in predicting the droplet collisions, especially at high velocity in comparison with other fixed grid methods (i.e., the front tracking method and the coupled level set and volume of fluid method). When the film drainage model is invoked, the method shows a good qualitative match with experiments, but a quantitative correspondence of the predicted film drainage time with the experimental drainage time is not obtained indicating that further development of film drainage model is required. However, it can be safely concluded that the LFRM coupled with film drainage models is much better in predicting the collision dynamics than the traditional methods.
Huge domain-wall speed variation with respect to ferromagnetic layer thickness in ferromagnetic Pt/Co/TiO2/Pt films
Authors: Kim Dae-Yun , Park Min-Ho , Park Yong-Keun , Yu Ji-Sung , Kim Joo-Sung , Kim Duck-Ho , Min Byoung-Chul , Choe Sug-Bong
Published: February 2018

In this study, we investigate the influence of the ferromagnetic layer thickness on the magnetization process. A series of ultrathin Pt/Co/TiO2/Pt films exhibits domain-wall (DW) speed variation of over 100,000 times even under the same magnetic field, depending on the ferromagnetic layer thickness. From the creep-scaling analysis, such significant variation is found to be mainly attributable to the thickness-dependence of the creep-scaling constant in accordance with the creep-scaling theory of the linear proportionality between the creep-scaling constant and the ferromagnetic layer thickness. Therefore, a thinner film shows a faster DW speed. The DW roughness also exhibits sensitive dependence on the ferromagnetic layer thickness: a thinner film shows smoother DW. The present observation provided a guide for an optimal design rule of the ferromagnetic layer thickness for better performance of DW-based devices.
Experimental validation of calculated atomic charges in ionic liquids
Authors: Fogarty Richard M. , Matthews Richard P. , Ashworth Claire R. , Brandt-Talbot Agnieszka , Palgrave Robert G. , Bourne Richard A. , Vander Hoogerstraete Tom , Hunt Patricia A. , Lovelock Kevin R. J.
Published: February 2018

A combination of X-ray photoelectron spectroscopy and near edge X-ray absorption fine structure spectroscopy has been used to provide an experimental measure of nitrogen atomic charges in nine ionic liquids (ILs). These experimental results are used to validate charges calculated with three computational methods: charges from electrostatic potentials using a grid-based method (ChelpG), natural bond orbital population analysis, and the atoms in molecules approach. By combining these results with those from a previous study on sulfur, we find that ChelpG charges provide the best description of the charge distribution in ILs. However, we find that ChelpG charges can lead to significant conformational dependence and therefore advise that small differences in ChelpG charges (<0.3 e) should be interpreted with care. We use these validated charges to provide physical insight into nitrogen atomic charges for the ILs probed.
Structure formation and surface chemistry of ionic liquids on model electrode surfaces—Model studies for the electrode | electrolyte interface in Li-ion batteries
Authors: Buchner Florian , Uhl Benedikt , Forster-Tonigold Katrin , Bansmann Joachim , Groß Axel , Behm R. Jürgen
Published: February 2018

Ionic liquids (ILs) are considered as attractive electrolyte solvents in modern battery concepts such as Li-ion batteries. Here we present a comprehensive review of the results of previous model studies on the interaction of the battery relevant IL 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([BMP]+[TFSI]−) with a series of structurally and chemically well-defined model electrode surfaces, which are increasingly complex and relevant for battery applications [Ag(111), Au(111), Cu(111), pristine and lithiated highly oriented pyrolytic graphite (HOPG), and rutile TiO2(110)]. Combining surface science techniques such as high resolution scanning tunneling microscopy and X-ray photoelectron spectroscopy for characterizing surface structure and chemical composition in deposited (sub-)monolayer adlayers with dispersion corrected density functional theory based calculations, this work aims at a molecular scale understanding of the fundamental processes at the electrode | electrolyte interface, which are crucial for the development of the so-called solid electrolyte interphase (SEI) layer in batteries. Performed under idealized conditions, in an ultrahigh vacuum environment, these model studies provide detailed insights on the structure formation in the adlayer, the substrate–adsorbate and adsorbate–adsorbate interactions responsible for this, and the tendency for chemically induced decomposition of the IL. To mimic the situation in an electrolyte, we also investigated the interaction of adsorbed IL (sub-)monolayers with coadsorbed lithium. Even at 80 K, postdeposited Li is found to react with the IL, leading to decomposition products such as LiF, Li3N, Li2S, LixSOy, and Li2O. In the absence of a [BMP]+[TFSI]− adlayer, it tends to adsorb, dissolve, or intercalate into the substrate (metals, HOPG) or to react with the substrate (TiO2) above a critical temperature, forming LiOx and Ti3+ species in the latter case. Finally, the formation of stable decomposition products was found to sensitively change the equilibrium between surface Li and Li+ intercalated in the bulk, leading to a deintercalation from lithiated HOPG in the presence of an adsorbed IL adlayer at >230 K. Overall, these results provide detailed insights into the surface chemistry at the solid | electrolyte interface and the initial stages of SEI formation at electrode surfaces in the absence of an applied potential, which is essential for the further improvement of future Li-ion batteries.
Two-dimensional ZnO nanosheets grown on flexible ITO-PET substrate for self-powered energy-harvesting nanodevices
Authors: Wang Qingyi , Yang Dechao , Qiu Yu , Zhang Xiaotong , Song Wenbin , Hu Lizhong
Published: February 2018

Here, we report the two-step growth method of two-dimensional (2-D) ZnO nanosheets (NSs) and explore their formation mechanism. Additionally, we illustrate their application for high-performance piezoelectric nanogenerators (NGs) by using grown products from various reaction times. The result shows that NGs based on 2-D NSs demonstrated better output performance than those based on 1-D NWs, which surprisingly increased from ∼40 nA to ∼0.15 μA under the same compressive force of ∼1 kgf. It can also be observed that the output current is slightly elevated as the 2-D nanostructures become thinner. Our results offer a unique way to improve the output performance of NGs by means of controlling the synthesis period of ZnO nanostructures, which have important applications in flexible electronics and wearable devices.
Millimeter-scale liquid metal droplet thermal switch
Authors: Yang Tianyu , Kwon Beomjin , Weisensee Patricia B. , Kang Jin Gu , Li Xuejiao , Braun Paul , Miljkovic Nenad , King William P.
Published: February 2018

Devices capable of actively controlling heat flow have been desired by the thermal management community for decades. The need for thermal control has become particularly urgent with power densification resulting in devices with localized heat fluxes as high as 1 kW/cm2. Thermal switches, capable of modulating between high and low thermal conductances, enable the partitioning and active control of heat flow pathways. This paper reports a millimeter-scale thermal switch with a switching ratio >70, at heat fluxes near 10 W/cm2. The device consists of a silicone channel filled with a reducing liquid or vapor and an immersed liquid metal Galinstan slug. Galinstan has a relatively high thermal conductivity (≈16.5 W/mK at room temperature), and its position can be manipulated within the fluid channel, using either hydrostatic pressure or electric fields. When Galinstan bridges the hot and cold reservoirs (the “ON” state), heat flows across the channel. When the hot and cold reservoirs are instead filled with the encapsulating liquid or vapor (the “OFF” state), the cross-channel heat flow significantly reduces due to the lower thermal conductivity of the solution (≈0.03–0.6 W/mK). We demonstrate switching ratios as high as 15.6 for liquid filled channels and 71.3 for vapor filled channels. This work provides a framework for the development of millimeter-scale thermal switches and diodes capable of spatial and temporal control of heat flows.
Exploring optimal topology of thermal cloaks by CMA-ES
Authors: Fujii Garuda , Akimoto Youhei , Takahashi Masayuki
Published: February 2018

This paper presents topology optimization for thermal cloaks expressed by level-set functions and explored using the covariance matrix adaptation evolution strategy (CMA-ES). Designed optimal configurations provide superior performances in thermal cloaks for the steady-state thermal conduction and succeed in realizing thermal invisibility, despite the structures being simply composed of iron and aluminum and without inhomogeneities caused by employing metamaterials. To design thermal cloaks, a prescribed objective function is used to evaluate the difference between the temperature field controlled by a thermal cloak and when no thermal insulator is present. The CMA-ES involves searches for optimal sets of level-set functions as design variables that minimize a regularized fitness involving a perimeter constraint. Through topology optimization subject to structural symmetries about four axes, we obtain a concept design of a thermal cloak that functions in an isotropic heat flux.
Ion energy distributions in highly transient EUV induced plasma in hydrogen
Authors: van de Ven T. H. M. , Reefman P. , de Meijere C. A. , van der Horst R. M. , van Kampen M. , Banine V. Y. , Beckers J.
Published: February 2018

This work reports on the measurements of ion flux composition and ion energy distribution functions (IEDFs) at surfaces in contact with hydrogen plasmas induced by extreme ultraviolet (EUV) radiation. This special type of plasma is gaining interest from industries because of its appearance in extreme ultraviolet lithography tools, where it affects exposed surfaces. The studied plasma is induced in 5 Pa hydrogen gas by irradiating the gas with short (30 ns) pulses of EUV radiation (λ= 10–20 nm). Due to the low duty cycle (10–4), the plasma is highly transient. The composition and IEDF are measured using an energy resolved ion mass spectrometer. The total ion flux consists of H+, H2+, and H3+. H3+ is the dominant ion as a result of the efficient conversion of H2+ to H3+ upon collision with background hydrogen molecules. The IEDFs of H2+ and H3+ appear similar, showing a broad distribution with a cut-off energy at approximately 8 eV. In contrast, the IEDF of H+ shows an energetic tail up to 18 eV. Most probably, the ions in this tail gain their energy during their creation process by photoionization and dissociative electron impact ionization.
Improvement of inverted organic solar cells using acetic acid as an additive for ZnO layer processing
Authors: Li Yang , Liu Yawen , Liu Zhihai , Xie Xiaoyin , Lee Eun-Cheol
Published: February 2018

In this work, we used acetic acid as an additive for the preparation of ZnO layers and improved the performance of poly{4,8-bis[(2-ethylhexyl)-oxy]benzo[1,2-b:4,5-b’] dithiophene-2,6-diyl-alt-3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophene- 4,6-diyl} (PTB7)-based inverted organic solar cells. The addition of acetic acid to the ZnO precursor solution improved the transparency and conductivity of the sol-gel-synthesized ZnO film, by increasing the grain size of the film. Accordingly, the power conversion efficiency (PCE) of the organic solar cells was improved from 6.42% to 7.55%, which was mainly caused by the enhanced current density and fill factor. The best sample demonstrated a high PCE of 7.85% with negligible hysteresis and good stability. Our results indicate that using acetic acid as an additive for the preparation of ZnO is a simple and effective way of fabricating high-performance inverted organic solar cells.
Watt-level widely tunable single-mode emission by injection-locking of a multimode Fabry-Perot quantum cascade laser
Authors: Chevalier Paul , Piccardo Marco , Anand Sajant , Mejia Enrique A. , Wang Yongrui , Mansuripur Tobias S. , Xie Feng , Lascola Kevin , Belyanin Alexey , Capasso Federico
Published: February 2018

Free-running Fabry-Perot lasers normally operate in a single-mode regime until the pumping current is increased beyond the single-mode instability threshold, above which they evolve into a multimode state. As a result of this instability, the single-mode operation of these lasers is typically constrained to few percents of their output power range, this being an undesired limitation in spectroscopy applications. In order to expand the span of single-mode operation, we use an optical injection seed generated by an external-cavity single-mode laser source to force the Fabry-Perot quantum cascade laser into a single-mode state in the high current range, where it would otherwise operate in a multimode regime. Utilizing this approach, we achieve single-mode emission at room temperature with a tuning range of 36 cm−1 and stable continuous-wave output power exceeding 1 W at 4.5 μm. Far-field measurements show that a single transverse mode is emitted up to the highest optical power, indicating that the beam properties of the seeded Fabry-Perot laser remain unchanged as compared to free-running operation.
Study on the luminous characteristics of a natural ball lightning
Authors: Wang Hao , Yuan Ping , Cen Jianyong , Liu Guorong
Published: February 2018

According to the optical images of the whole process of a natural ball lightning recorded by two slit-less spectrographs in the Qinghai plateau of China, the simulated observation experiment on the luminous intensity of the spherical light source was carried out. The luminous intensity and the optical power of the natural ball lightning in the wavelength range of 400–690 nm were estimated based on the experimental data and the Lambert-Beer Law. The results show that the maximum luminous intensity was about 1.24 × 105 cd in the initial stage of the natural ball lightning, and the maximum luminous intensity and the maximum optical power in most time of its life were about 5.9 × 104 cd and 4.2 × 103 W, respectively.
Collective dynamics of large aspect ratio dusty plasma in an inhomogeneous plasma background: Formation of the co-rotating vortex series
Authors: Choudhary Mangilal , Mukherjee S. , Bandyopadhyay P.
Published: February 2018

In this paper, the collective dynamics of large aspect ratio dusty plasma is studied over a wide range of discharge parameters. An inductively coupled diffused plasma, which creates an electrostatic trap to confine the negatively charged grains, is used to form a large volume (or large aspect ratio) dusty plasma at low pressure. For introducing the dust grains into the potential well, a unique technique using secondary DC glow discharge plasma is employed. The dust dynamics is recorded in a two-dimension (2D) plane at a given axial location. The dust fluid exhibits wave-like behavior at low pressure (p < 0.06 mbar) and high rf power (P > 3 W). The mixed motion, waves and vortices, is observed at an intermediate gas pressure (p ∼ 0.08 mbar) and low power (P < 3 W). Above the threshold value of gas pressure (p > 0.1 mbar), the clockwise and anti-clockwise co-rotating vortex series are observed on edges of the dust cloud, whereas the particles in the central region show random motion. These vortices are only observed above the threshold width of the dust cloud. The occurrence of the co-rotating vortices is understood on the basis of the charge gradient of dust particles, which is orthogonal to the gravity. The charge gradient is a consequence of the plasma inhomogeneity from the central region to the outer edge of the dust fluid. Since a vortex has the characteristic size in the dissipative medium; therefore, a series of the co-rotating vortex on both sides of dusty plasma is observed. The experimental results on the vortex formation and its multiplicity are compared to an available theoretical model and are found to be in close agreement.
Arbitrary amplitude nucleus-acoustic solitons in multi-ion quantum plasmas with relativistically degenerate electrons
Authors: Sultana S. , Schlickeiser R.
Published: February 2018

A three component degenerate relativistic quantum plasma (consisting of relativistically degenerate electrons, nondegenerate inertial light nuclei, and stationary heavy nuclei) is considered to model the linear wave and also the electrostatic solitary waves in the light nuclei-scale length. A well-known normal mode analysis is employed to investigate the linear wave properties. A mechanical-motion analog (Sagdeev-type) pseudo-potential approach, which reveals the existence of large amplitude solitary excitations, is adopted to study the nonlinear wave properties. Only the positive potential solitary excitations are found to exist in the plasma medium under consideration. The basic properties of the arbitrary amplitude electrostatic acoustic modes in the light nuclei-scale length and their existence domain in terms of soliton speed (Mach number) are examined. The modifications of solitary wave characteristics and their existence domain with the variation of different key plasma configuration parameters (e.g., electrons degeneracy parameter, inertial light nuclei number density, and degenerate electron number density) are also analyzed. Our results, which may be helpful to explain the basic features of the nonlinear wave propagation in multi-component degenerate quantum plasmas, in connection with astrophysical compact objects (e.g., white dwarfs) are briefly discussed.
Water vapor pressure affects nanocatalyst shape
Authors: Patrick Chris
Published: February 2018

A study of water adsorbate phases on zinc oxide reveals the importance of commonly overlooked contributions to its stability.
Role of the gut, melanocortin system and malonyl-CoA in control of feed intake in non-ruminant animals
Authors: Dunshea Frank R. , Bittner Evan P. , Pluske John R. , Black John L.
Published: February 2018

Regulation of feed intake is under complex control, involving physical, chemical, hormonal and neuronal responses. Understanding the regulation of feed intake in farm animals is key to optimisation of intake to meet production and profitability goals. Fundamental mechanisms regulating feed intake include constraints imposed by the gut, systems monitoring current and long-term energy status to increase or decrease intake, and hedonic, reward-related drives. Feed intake is closely related to the rate of passage of digesta and the capacity of the gastrointestinal tract. Indigestible fibre increases the rate of digesta passage and feed intake until excess distension sends signals of satiety to the brain. The presence of partially digested nutrients and products of microbial fermentation in the distal intestines releases peptides (PYY, OXM, GPL-1, Apo A-IV, amylin) from gut and pancreas to activate the intestinal brake, which slows the rate of passage and reduces feed intake. These peptides also act on orexigenic (NPY, AgRP) and anorexigenic (POMC, CART) peptides of the melanocortin system of the hypothalamus to reduce intake over the long term. Immediate energy status of the animal is monitored through the ratio of AMP : ATP via adenosine monophosphate-activated kinase and mammalian target of rapamycin, whereas the overall animal energy status is monitored by insulin, leptin and ghrelin. These energy-monitoring systems control short- and long-term intakes through the melanocortin system of the hypothalamus, primarily via malonyl-CoA, to alter the relative expression of orexigenic and anorexigenic peptides. Gut and hypothalamic control of feed intake can be over-ridden by hedonic, reward-related centres of the brain, predominantly through the release of dopamine. These hedonic responses can lead to over-consumption and obesity under some circumstances or reduced feed intake under stressful or other negative environmental situations. Knowledge of these mechanisms can be used to identify practical strategies for either increasing or decreasing voluntary intake in pigs.
Anion Photoelectron Spectroscopy and High Level Ab Initio Calculations of the Halide–Nitric Oxide Dimer Complexes
Authors: Lapere Kim M. L. , McKinley Allan J. , Wild Duncan
Published: February 2018

Anion photoelectron spectra are presented for gas phase complexes formed between halide anions and nitric oxide, X−⋯NO where X− = Cl−, Br−, and I−. Electron binding energies are experimentally determined to be 3.82, 3.51, and 3.17 eV. Results from CCSD(T)/aug-cc-pVTZ calculations are presented for the anion species, whereby a single minimum of Cs symmetry is predicted. Binding energies (D0) of 15.3, 13.3, and 11.7 kJ mol−1 are predicted from complete basis set limit extrapolation, and are found to be in line with previous experimental studies.
Assessment of water quality from the Normanby River catchment to coastal flood plumes on the northern Great Barrier Reef, Australia
Authors: Howley C. , Devlin M. , Burford M.
Published: February 2018

Understanding the flux and fate of nutrients and sediments from rivers is of global importance because of the effects of these materials on coastal ecosystems. The present study followed three flood events from upper tributaries of the Normanby River to Princess Charlotte Bay in the northern Great Barrier Reef (GBR) lagoon, Australia. During each event, nutrients and suspended sediment concentrations were measured along a freshwater to marine transect. The upper catchment provided the majority of suspended sediments and nutrients supplied to the river system, although concentrations of most materials decreased by 52–85% between the upper catchment and estuary. As an exception, ammonium concentrations doubled within the estuary, indicating that undisturbed coastal ecosystems can provide a significant source of dissolved inorganic nitrogen to tropical river flood plumes. The dissolved nutrients in floodwaters stimulated phytoplankton blooms that inundated seagrass meadows and coral reefs. Northern GBR marine ecosystems are increasingly threatened by climate change and catchment development. The results of this study show that increased anthropogenic loads of nutrients and sediments from the upper Normanby catchment have the potential to affect the condition of marine ecosystems at Princess Charlotte Bay.
Field study of charitable giving reveals that reciprocity decays over time
Authors: Chuan Amanda , Kessler Judd B. , Milkman Katherine L.
Published: February 2018

We examine how reciprocity changes over time by studying a large quasiexperiment in the field. Specifically, we analyze administrative data from a university hospital system. The data include information about over 18,000 donation requests made by the hospital system via mail to a set of its former patients in the 4 months after their first hospital visit. We exploit quasiexperimental variation in the timing of solicitation mailings relative to patient hospital visits and find that an extra 30-day delay between the provision of medical care and a donation solicitation decreases the likelihood of a donation by 30%. Our findings have important implications for models of economic behavior, which currently fail to incorporate reciprocity’s sensitivity to time. The fact that reciprocal behavior decays rapidly as time passes also suggests the importance of capitalizing quickly on opportunities to benefit from a quid pro quo.
Comparative transcriptome analysis reveals distinct genetic modules associated with Helios expression in intratumoral regulatory T cells
Authors: Yates Kathleen , Bi Kevin , Haining W. Nicholas , Cantor Harvey , Kim Hye-Jung
Published: February 2018

Significance

Regulatory T cells (Tregs) play a critical role in inflammatory, autoimmune, and antitumor immune responses. Increased expression of transcription factor Helios by tumor-infiltrating Tregs can enhance immune-suppressive activity, while deletion of Helios promotes an effector T helper (Th) cell phenotype that can contribute to the host antitumor immune response. We report that chronic inflammatory conditions of tumors induce Helios-deficient Tregs to express increased levels of genes associated with T cell activation and Th cell differentiation. Helios-dependent changes in gene expression are restricted to tumor sites and not observed in peripheral lymphoid tissues. We suggest that Helios-deficient Tregs that recognize tumor-associated self-antigens may become unstable in the tumor microenvironment and undergo reprogramming into effector T cells that can inhibit tumor growth.
Therapeutically targeting tumor microenvironment–mediated drug resistance in estrogen receptor–positive breast cancer
Authors: Shee Kevin , Yang Wei , Hinds John W. , Hampsch Riley A. , Varn Frederick S. , Traphagen Nicole A. , Patel Kishan , Cheng Chao , Jenkins Nicole P. , Kettenbach Arminja N. , Demidenko Eugene , Owens Philip , Faber Anthony C. , Golub Todd R. , Straussman Ravid , Miller Todd W.
Published: February 2018

Drug resistance to approved systemic therapies in estrogen receptor–positive (ER+) breast cancer remains common. We hypothesized that factors present in the human tumor microenvironment (TME) drive drug resistance. Screening of a library of recombinant secreted microenvironmental proteins revealed fibroblast growth factor 2 (FGF2) as a potent mediator of resistance to anti-estrogens, mTORC1 inhibition, and phosphatidylinositol 3-kinase inhibition in ER+ breast cancer. Phosphoproteomic analyses identified ERK1/2 as a major output of FGF2 signaling via FGF receptors (FGFRs), with consequent up-regulation of Cyclin D1 and down-regulation of Bim as mediators of drug resistance. FGF2-driven drug resistance in anti-estrogen–sensitive and –resistant models, including patient-derived xenografts, was reverted by neutralizing FGF2 or FGFRs. A transcriptomic signature of FGF2 signaling in primary tumors predicted shorter recurrence-free survival independently of age, grade, stage, and FGFR amplification status. These findings delineate FGF2 signaling as a ligand-based drug resistance mechanism and highlights an underdeveloped aspect of precision oncology: characterizing and treating patients according to their TME constitution.
Cancer-Specific Stress and Trajectories of Psychological and Physical Functioning in Patients With Relapsed/Refractory Chronic Lymphocytic Leukemia
Authors: Goyal Neha G , Maddocks Kami J , Johnson Amy J , Byrd John C , Westbrook Travis D , Andersen Barbara L
Published: February 2018

Background

Chronic lymphocytic leukemia is the most prevalent adult leukemia. The disease is incurable with a cycling of treatment and relapse common. Little is known about the psychological and physical functioning of patients with relapsed/refractory chronic lymphocytic leukemia. Cancer-specific stress is an important individual difference variable that predicts psychological and physical outcomes.

Purpose

To examine cancer-specific stress at treatment initiation as a predictor of psychological and physical functioning trajectories in patients with relapsed/refractory chronic lymphocytic leukemia during the first 5 months of treatment.

Methods

Patients with relapsed/refractory chronic lymphocytic leukemia (N = 152) enrolled in a phase II clinical trial completed self-report measures at treatment initiation (baseline), 1, 2, and 5 months of treatment. Cancer-specific stress at baseline was examined as a predictor of psychological (cognitive-affective depressive symptoms, negative mood, mental health quality of life) and physical functioning (fatigue interference, sleep problems, physical health quality of life), controlling for demographic and treatment variables.

Results

Using multilevel modeling, higher baseline cancer-specific stress was related to worse psychological (cognitive-affective depressive symptoms, negative mood, mental health quality of life) and physical functioning (fatigue interference, sleep problems) at baseline and more rapid improvements during the next 5 months. Despite these improvements, higher baseline cancer-specific stress remained associated with poorer 5-month psychological, though not physical, functioning.

Conclusions

Findings suggest cancer-specific stress at treatment initiation may be a risk factor for poorer psychological functioning during treatment for patients with relapsed/refractory chronic lymphocytic leukemia.