bluuebunny/crossref_metadata_2025 huggingface dataset:
Scale factor management in the studies of affine models of shockproof garment elements
Authors: Denisov Oleg , Pleshko Mikhail , Ponomareva Irina , Merenyashev Vitaliy
Published: March 2018

New samples of protective garment for performing construction work at height require numerous tests in conditions close to real conditions of extreme vital activity. The article presents some results of shockproof garment element studies and a description of a patented prototype. The tests were carried out on a model which geometric dimensions were convenient for manufacturing it in a limited batch. In addition, the used laboratory equipment (for example, a unique power pendulum), blanks made of a titanium-nickel alloy with a shape memory effect also imposed their limitations. The problem of the adequacy of the obtained experimental results transfer to mass-produced products was solved using tools of the classical similarity theory. Scale factor management influence in the affine modeling of the shockproof element, studied on the basis of the equiatomic titanium-nickel alloy with the shape memory effect, allowed us to assume, with a sufficient degree of reliability, the technical possibility of extrapolating the results of experimental studies to full-scale objects for the formation of the initial data of the mathematical model of shockproof garment dynamics elastoplastic deformation (while observing the similarity of the features of external loading).
Principles for the formation of an effective concept of multifunctional high-rise construction investment projects
Authors: Beliakov Sergei
Published: March 2018

Investment projects of high-rise construction have a number of features that determine specific risks and additional opportunities that require analysis and accounting in the formation of an effective project concept. The most significant features of high-rise construction include long construction time, complexity of technical and technological solutions, complexity of decisions on the organization of construction and operation, high cost of construction and operation, complexity in determining the ratio of areas designed to accommodate different functional areas, when organizing and coordinating the operation of the facility, with internal zoning. Taking into account the specificity of high-rise construction, among the factors determining the effectiveness of projects, it is advisable to consider as key factors: organizational, technological and investment factors. Within the framework of the article, the author singled out key particular functions for each group of factors under consideration, and also developed a system of principles for the formation of an effective concept of multifunctional high-rise construction investment projects, including the principle of logistic efficiency, the principle of optimal functional zoning, the principle of efficiency of equipment use, the principle of optimizing technological processes, the principle maximization of income, the principle of fund management, the principle of risk management . The model of formation of an effective concept of investment projects of multifunctional high-rise construction developed by the author can contribute to the development of methodological tools in the field of managing the implementation of high-rise construction projects, taking into account their specificity in the current economic conditions.
Prompt fissionγ-ray characteristics from neutron-induced fission on 239Pu and the time-dependence of prompt-γray emission
Authors: Gatera Angélique , Göök Alf , Hambsch Franz-Josef , Moens André , Oberstedt Andreas , Oberstedt Stephan , Sibbens Goedele , Vanleeuw David , Vidali Marzio
Published: March 2018

Recent years have seen an increased interest in prompt fission γ-ray (PFG) measurements motivated by a high priority request of the OECD/NEA for high precision data, mainly for the nuclear fuel isotopes 235U and 239Pu. Our group has conducted a PFG measurement campaign using state-of-the-art lanthanum halide detectors for all the main actinides to a precision better than 3%. The experiments were performed in a coincidence setup between a fission trigger and γ-ray detectors. The time-of-flight technique was used to discriminate photons, traveling at the speed of light, and prompt fission neutrons. For a full rejection of all neutrons below 20 MeV, the PFG time window should not be wider than a few nanoseconds. This window includes most PFG, provided that no isomeric states were populated during the de-excitation process. When isomeric states are populated, PFGs can still be emitted up to 1 yus after the instant of fission or later. To study these γ-rays, the detector response to neutrons had to be determined and a correction had to be applied to the γ-ray spectra.

The latest results for PFG characteristics from the reaction 239Pu(nth,f) will be presented, together with an analysis of PFGs emitted up to 200 ns after fission in the spontaneous fission of 252Cf as well as for thermal-neutron induced fission on 235U and 239Pu. The results are compared with calculations in the framework of the Hauser-Feshbach Monte Carlo code CGMF and FIFRELIN.
New measurements on isobaric fission product yields and mean kinetic energy for 241Pu thermal neutron-induced fission
Authors: Julien-Laferrière Sylvain , Kessedjian Grégoire , Serot Olivier , Chebboubi Abdelaziz , Bernard David , Blanc Aurélien , Köster Ulli , Litaize Olivier , Materna Thomas , Meplan Olivier , Rapala Michal , Sage Christophe
Published: March 2018

Nuclear fission yields data measurements for thermal neutron induced fission of 241Pu have been carried out at the Institut Laue Langevin (ILL) in Grenoble, using the Lohengrin mass spectrometer. Mass, isotopic and isomeric yields have been extracted for the last measurements. A focus is given in this document to the mass yield results which are obtained for almost the entire heavy peak and most of the light high yields masses, along with the covariance matrix. The mean kinetic energy as a function of the fission product mass has also been extracted from the measurements. The total mean kinetic energy pre and post neutron emission have been assessed and compared to other works showing a rather good agreement.
Determination of the fast-neutron-induced fission cross-section of 242Pu at nELBE
Authors: Kögler Toni , Beyer Roland , Junghans Arnd R. , Schwengner Ronald , Wagner Andreas
Published: March 2018

The fast-neutron-induced fission cross section of 242Pu was determined in the energy range of 0.5 MeV to 10MeV at the neutron time-of-flight facility nELBE. Using a parallel-plate fission ionization chamber this quantity was measured relative to 235U(n,f). The number of target nuclei was thereby calculated by means of measuring the spontaneous fission rate of 242Pu. An MCNP 6 neutron transport simulation was used to correct the relative cross section for neutron scattering. The determined results are in good agreement with current experimental and evaluated data sets.
Staggering of angular momentum distribution in fission
Authors: Tamagno Pierre , Litaize Olivier
Published: March 2018

We review here the role of angular momentum distributions in the fission process. To do so the algorithm implemented in the FIFRELIN code [?] is detailed with special emphasis on the place of fission fragment angular momenta. The usual Rayleigh distribution used for angular momentum distribution is presented and the related model derivation is recalled. Arguments are given to justify why this distribution should not hold for low excitation energy of the fission fragments. An alternative ad hoc expression taking into account low-lying collectiveness is presented as has been implemented in the FIFRELIN code. Yet on observables currently provided by the code, no dramatic impact has been found. To quantify the magnitude of the impact of the low-lying staggering in the angular momentum distribution, a textbook case is considered for the decay of the 144Ba nucleus with low excitation energy.
Fission observables from 4D Langevin calculations with macroscopic transport coefficients
Authors: Usang Mark D. , Ivanyuk Fedir A. , Ishizuka Chikako , Chiba Satoshi , Maruhn Joachim A.
Published: March 2018

We have extended the Langevin equations to 4 dimensions (4D) by allowing the independent deformation for the left (δ1) and right fragments (δ2) of the fissioning nucleus. At the moment we are only able to use them in conjunction with the macroscopic transport coefficients. Nevertheless, we can see a considerable improvement in the preliminary results for the fission observables, especially those related to the total kinetic energy (TKE) of fission fragments. By plotting the TKE distributions we have revealed the super-long fission modes in236U and super-short fission modes in257Fm. By plotting the distribution ofδagainst the fragment’s TKE we have noted a correlation between the values ofδand Brosa’s fission modes. We have found that the standard fission modes correspond to prolate tips of the light fragments while the complementary heavy fragments have oblate fission tips. On the other hand, if both fragments were prolate at the tips, we get super-long fission modes. If both fragments were oblate at the tips, we get super-short fission modes.
Study of photon emission with the fission event generator FREYA
Authors: Vogt Ramona , Randrup Jørgen
Published: March 2018

The event-by-event fission model FREYA is employed to study photon observables. The model has been expanded beyond the simple statistical photon emission reported previously to include the discrete RIPL-3 lines. We update the earlier results and discuss the sensitivity of the results to the FREYA input parameters.
Angular distribution of scission neutrons studied with time-dependent Schrödinger equation
Authors: Wada Takahiro , Asano Tomomasa , Carjan Nicolae
Published: March 2018

We investigate the angular distribution of scission neutrons taking account of the effects of fission fragments. The time evolution of the wave function of the scission neutron is obtained by integrating the time-dependent Schrodinger equation numerically. The effects of the fission fragments are taken into account by means of the optical potentials. The angular distribution is strongly modified by the presence of the fragments. In the case of asymmetric fission, it is found that the heavy fragment has stronger effects. Dependence on the initial distribution and on the properties of fission fragments is discussed. We also discuss on the treatment of the boundary to avoid artificial reflections
Full Orifice Patching without Annuloplasty for Severe Functional Tricuspid Valve Regurgitation
Authors: De Filippo Carlo , Totaro Antonio , Pelini Piero , Mauro Michele , Calafiore Antonio
Published: March 2018

Surgical treatment of severe functional tricuspid regurgitation associated with dilated right ventricle and increased chordal tethering (>8 mm) is challenging. We designed a technique where the anterior and posterior leaflets are detached from 50% of the annulus and a patch as large as the tricuspid orifice is sewn to augment the leaflets' tissue to force the coaptation with the septal leaflet. Annuloplasty is not performed, as it can only increase the chordal tethering, reducing the benefit of tissue augmentation. Early and midterm results in a subgroup of patients with unfavorable anatomical aspects are encouraging.
Impact of Peanut Ball Device on the Duration of Active Labor: A Randomized Control Trial
Authors: Kwan Mei , Mercier Rebecca
Published: March 2018

Objective To evaluate whether the use of a peanut ball device shortens the duration of active labor in nulliparas.

Study Design Single-site, nonblinded randomized trial in nulliparous women admitted for labor or labor induction. English-speaking women > 18 years of age with singleton pregnancies were enrolled. Participants were randomized to the use of peanut ball or usual care upon reaching the active phase of labor (≥ 6 cm cervical dilation) with an epidural. Primary outcome was rate of cervical dilation. Secondary outcomes were rates of cesarean delivery and fetal presentation at time of full dilation or delivery.

Results Ninety-six patients enrolled; 63 reached full cervical dilation. There was no statistically significant difference in rates of cervical dilation (0.98cm/h vs. 0.79cm/h, p = 0.27) or length of labor (315 minutes vs. 387 minutes, p = 0.14) between the groups. There was no difference in the rates of cesarean delivery (33% vs. 35%, p = 0.8) or occiput posterior presentation. (28% vs. 9%, p = 0.09). Among the subgroup who had labor arrest, fewer patients using the peanut ball experienced arrest of dilation; this approached but did not reach statistical significance (30% vs. 73% p = 0.05).

Conclusion Use of the peanut ball does not significantly increase rates of cervical dilation or decrease time in active labor.
Intra- und Intertester-Reliabilität klinischer Tests zur Untersuchung der Bewegungskontrolle bei Patienten mit Nackenschmerzen
Authors: Allofs Jana , van Baal Katharina , Schwarz Fiona , Ehrenbrusthoff Katja , Hering Thomas
Published: March 2018

Hintergrund Nackenschmerzen sind weltweit eine häufig auftretende Gesundheitseinschränkung. Der große Anteil von Patienten mit unspezifischen Nackenschmerzen kann in Subgruppen eingeteilt werden. Eine dieser Subgruppen sind Patienten mit Bewegungskontrollproblemen. Für eine eindeutige Identifizierung dieser Gruppe sind zuverlässige Messverfahren notwendig. Es gibt eine Vielzahl verschiedener Tests zur Überprüfung der Bewegungskontrolle. Bisher liegt kein Review über den aktuellen Forschungsstand zur Intertester- und Intratester-Reliabilität der vielen Bewegungskontrolltests ohne technische Geräte bei Patienten mit Nackenschmerzen vor.

Ziel Das Ziel der Arbeit ist es, die aktuell vorhandene Evidenz zur Intratester- und Intertester-Reliabilität von Bewegungskontrolltests bei Patienten mit Nackenschmerzen zu untersuchen.

Methode Die Recherche fand im April 2017 bei Medline, Cochrane und PEDro unter anderem mit den Suchbegriffen „neck pain“ [Mesh], „reproducibility of results“ [Mesh], „reliability“ und „movement control impairment“ sowie einer Vielzahl von Synonymen statt. Um das Bias-Risiko der eingeschlossenen Studien zu ermitteln, wurde die QAREL-Checkliste verwendet 17. Eine Autorin extrahierte die Studien- und Patientencharakteristika.

Ergebnisse 4 Studien mit einem geringen (8/11) bis moderaten (7/11) Bias-Risiko wurden eingeschlossen. Die Intertester-Reliabilität der 26 Tests lag zwischen ausreichend und sehr gut (k = 0,32 – 1,0), die Intratester-Reliabilität der 11 Tests war moderat bis sehr gut (k = 0,59 – 0,92). Lediglich 3 Tests wurden von je 2 Studien, alle anderen Tests jeweils nur von 1 Studie überprüft. Der am besten untersuchte und beurteilte Test zur Einschätzung der Bewegungskontrolle der HWS war der Test „Blickstabilität“.

Schlussfolgerung Weitere Studien sollten neben der Untersuchung der Validität einzelner Tests eine Testbatterie zur zuverlässigen Beurteilung der Bewegungskontrolle der HWS entwickeln.
Umfrage bei Physio- und Ergotherapeuten zu Verständnis und Anwendung von Patientenedukation
Authors: Beckmann-Fries Vera , Gubler-Gut Barbara , Niedermann Karin
Published: March 2018

Hintergrund Patientenedukation gilt als Standard im klinischen Management von Patienten und wird wegen der Zunahme von chronisch kranken Menschen immer wichtiger. Auch in der Physio- und Ergotherapie gilt sie als zunehmend zentrale Intervention. Das tatsächliche Verständnis von Patientenedukation und deren Anwendung ist jedoch unklar.

Ziel Das Verständnis von Patientenedukation und die selbst-deklarierte Anwendung im Berufsalltag von Physio- und Ergotherapeuten eines Universitätsspitals zu evaluieren.

Methode Online-Querschnittserhebung unter allen 139 Physio- und Ergotherapeuten des Universitätsspitals.

Ergebnisse Die Rücklaufquote betrug 42 % (n = 59); 55 Fragebögen wurden ausgewertet. Im Verhältnis zur Gesamtgruppe antworteten mehr Ergo- (16; 64 %) als Physiotherapeuten (39; 34 %). Mit zunehmender Berufserfahrung wurden individuelle Definitionen von Patientenedukation differenzierter und umfassender. Es zeigten sich keine Unterschiede im Verständnis und der benannten Anwendung von Patientenedukation zwischen den beiden Berufsgruppen. Alle Therapeuten (mit wenig oder viel Berufserfahrung) nannten die Informationsvermittlung am häufigsten als Teil von Patientenedukation (91 %). Mit zunehmender Berufserfahrung werden öfter Aspekte der Beratung und Verhaltensinterventionen erwähnt. Die Hälfte der Physio- und Ergotherapeuten (n = 28) berichtete, dass Patientenedukation in ihrer Grundausbildung ein wichtiges Thema war, und etwas mehr als ein Drittel (n = 19) besuchte schon eine Weiterbildung zum Thema. Praktisch alle Therapeuten (n = 54) wünschten sich, mehr zu Patientenedukation dazuzulernen.

Schlussfolgerung Patientenedukation ist für Physio- und Ergotherapeuten ein wichtiges Thema. Die Ergebnisse dieser Erhebung bilden die Basis für eine weitere, vertiefte Auseinandersetzung. Aspekte der Beratung oder der Verhaltensinterventionen wurden im Vergleich zur Informationsvermittlung weniger häufig genannt; dem sollte bei der Planung von In-house-Weiterbildungen Rechnung getragen werden.
Langzeitevaluation der Umsetzungstreue des Kraft- und Balancetrainings in vollstationären Pflegeeinrichtungen: Das bayerische Sturz- und Frakturpräventionsprogramm (BF2P2)
Authors: Roigk Patrick , Rupp Karin , Becker Clemens , Schulz Claudia , König Hans-Helmut , Rapp Kilian
Published: March 2018

Hintergrund Stürze treten in Pflegeeinrichtungen häufig auf. Aus diesem Grund wurde in den Jahren 2007 – 2010 ein Sturz- und Frakturpräventionsprogramm in nahezu 1000 bayerischen Pflegeeinrichtungen nach den Vorgaben des „Ulmer Modells“ implementiert. Einen zentralen Bestandteil des Programms bildet ein gruppenbasiertes Kraft- und Balancetraining.

Ziel Das Ziel dieser Studie war, Verfügbarkeit und Umsetzungstreue des Trainingsprogramms nach den Vorgaben des „Ulmer Modells“ nach mehreren Jahren Laufzeit zu untersuchen.

Methode Die Querschnittserhebung fand zwischen Januar und Juni 2016 in 40 zufällig ausgewählten Pflegeeinrichtungen statt. Eine standardisierte Beobachtung des Gruppentrainings wurde durchgeführt. Die Auswertung erfolgte stratifiziert nach Trainerqualifikation.

Ergebnisse Fast alle der kontaktierten Pflegeeinrichtungen boten eine Bewegungsgruppe an (94,3 %), die häufig Komponenten eines Krafttrainings beinhaltete. Das Krafttraining der unteren Extremitäten erfolgte allerdings nur in 30 % der Gruppen mit Gewichtsmanschetten. Übungen zum Training der Balance fanden in vielen Gruppen wenig oder gar nicht statt. Das Balancetraining wurde dann häufiger umgesetzt, wenn ein Trainer mit einer therapeutischen Qualifikation die Gruppen leitete. Nur 10 % der Gruppen erfüllten vollständig die Anforderungen an ein Sturzpräventionstraining nach den Vorgaben des „Ulmer Modells“.

Schlussfolgerung Bewegungsgruppen sind mittlerweile fester Bestandteil in Pflegeeinrichtungen. Allerdings ist die Umsetzungstreue des Programms im Bereich des Balancetrainings häufig gering. Die Qualität des Trainings scheint höher zu sein, wenn ein Trainer mit einer therapeutischen Qualifikation die Gruppen leitete.
Symptomatologie und klinischer Verlauf bei hospitalisierten Erwachsenen mit Virusinfektionen durch Influenza A und Respiratory Syncytial-Virus (RSV)
Authors: Ambrosch Andreas , Klinger Alfons , Luber Doris , Arp Claudia , Lepiorz Marc , Schroll Stefan , Klawonn Frank
Published: March 2018

Einleitung Zum klinischen Profil und Verlauf von komplizierten Infektionen mit RSV bei Erwachsenen im Vergleich zur Influenza A ist wenig bekannt. Die vorliegende Untersuchung hatte deshalb zum Ziel. prädisponierende Grunderkrankungen, klinisches Profil, Verlauf und Prognose bei hospitalisierten Patienten mit RSV- und Influenza-A-Infektionen miteinander zu vergleichen.

Material und Methode Eingeschlossen wurden Patienten mit RSV- und Influenza-A-Infektionen, die zwischen 1.1.2017 und 31.3.2017 hospitalisiert wurden. Die Diagnostik erfolgte mittels molekularbiologischer Verfahren. Zur Charakterisierung wurden klinische Symptome, Laborparameter sowie disponierende chronische Grunderkrankungen erfasst. Darüber hinaus wurde Verlauf und Schwere der Infektion anhand verschiedener klinischer Parameter einschließlich Beatmungspflichtigkeit und Letalität abgeschätzt.

Ergebnisse Insgesamt wurden 190 Patienten mit Influenza-A- und 98 Patienten mit RSV-Infektion ausgewertet. Sowohl das mittlere Alter als auch die klinische Symptomatologie bei Diagnosestellung waren in beiden Patientengruppen vergleichbar. Nur 2/3 der Patienten zeigten Influenza-typische respiratorische Symptome. Zwischen 13 und 16 % der Infektionen waren nosokomialen Ursprungs. Bezüglich des klinischen Verlaufs mussten insbesondere Patienten mit RSV-Infektion und einer chronischen Lungenerkrankung signifikant häufiger invasiv beatmet werden (odds ratio 10,55 [95 % CI 1,18 – 507,1] p = 0,014).

Schlussfolgerung RSV-Infektionen kommen als häufige Ursache von komplizierten Influenza-ähnlichen Erkrankungen bei älteren, hospitalisierten Patienten in Frage. Im Vergleich zur Influenza A verlaufen RSV-Infektionen insbesondere bei einer chronischen Lungenerkrankung schwerer. Bei beiden Entitäten ist ein nicht unerheblicher Teil der Infektionen nosokomialen Ursprungs, was im Hinblick auf ein erfolgreiches Hygienemanagement eine möglichst rasche Diagnosestellung impliziert.
Calcium ions in aqueous solutions: Accurate force field description aided by ab initio molecular dynamics and neutron scattering
Authors: Martinek Tomas , Duboué-Dijon Elise , Timr Štěpán , Mason Philip E. , Baxová Katarina , Fischer Henry E. , Schmidt Burkhard , Pluhařová Eva , Jungwirth Pavel
Published: March 2018

We present a combination of force field and ab initio molecular dynamics simulations together with neutron scattering experiments with isotopic substitution that aim at characterizing ion hydration and pairing in aqueous calcium chloride and formate/acetate solutions. Benchmarking against neutron scattering data on concentrated solutions together with ion pairing free energy profiles from ab initio molecular dynamics allows us to develop an accurate calcium force field which accounts in a mean-field way for electronic polarization effects via charge rescaling. This refined calcium parameterization is directly usable for standard molecular dynamics simulations of processes involving this key biological signaling ion.
Very high S-band microwave absorption of carbon nanotube buckypapers with Mn nanoparticle interlayers
Authors: Lu Shaowei , Bai Yaoyao , Wang Jijie , Zhang Lu , Tian Caijiao , Ma Keming , Wang Xiaoqiang
Published: March 2018

Flexible and high-performance electromagnetic absorbing materials of multi-walled carbon nanotube (MWCNT) buckypapers with Mn nanoparticles (NPSs) interlayer were fabricated via monodisperse solutions through layer by layer vacuum filtration method. The morphology and element composition of buckypapers were characterized by scanning electron microscopy, energy dispersive spectrometer, and X-ray diffraction. The formation of flexible MWCNT buckypapers with Mn NPS (0–30 wt. %) interlayer was attributed to nanostructure and morphology of the samples. When the blended Mn NPS content in buckypapers is 20 wt. %, there are evidently two larger absorption peaks (−13.2 dB at 3.41 GHz, −15.6 dB at 3.52 GHz) of the buckypaper with an absorbing thickness of 0.1 mm. The fundamental microwave absorption mechanism of the buckypapers is discussed. This work opens a new pathway towards tuning microwave absorbers performance and this method can be extended to exploit other excellent microwave absorbers with interlayer.
Adsorption of 3d, 4d, and 5d transition-metal atoms on single-layer boron nitride
Authors: Li Shujing , Zhou Mei , Li Menglei , Lu Guo , Wang Xiaohui , Zheng Fawei , Zhang Ping
Published: March 2018

The adsorption of 3d, 4d, and 5d transition-metal (TM) atoms on single-layer boron nitride (SLBN) sheets was systematically studied through comparison of structural and magnetic properties determined using first-principles calculations. We found that the majority of TM atoms were chemically adsorbed on SLBN with adsorption energies larger than 0.5 eV, whereas some TM atoms in d5 or d10 configuration were physically adsorbed on SLBN with adsorption energies lower than 0.5 eV. The charge density difference indicated that the main contribution to the adsorption energy was the interaction between the TM and the nearest B atoms rather than N atoms. Moreover, TM adatoms from Sc (Y, La) to Co (Rh, Ir) and Cu (Ag, Au) displayed nonzero magnetic moments arising from the d-orbital occupation of TM atoms. Our results provide fundamental knowledge of TM atom adsorption on SLBN, which will be useful for not only spintronics applications but also the development of magnetic nanostructures.
Improvement in current density of nano- and micro-structured Si solar cells by cost-effective elastomeric stamp process
Authors: Jeon Kiseok , Jee Hongsub , Lim Sangwoo , Park Min Joon , Jeong Chaehwan
Published: March 2018

Effective incident light should be controlled for improving the current density of solar cells by employing nano- and micro-structures on silicon surface. The elastomeric stamp process, which is more cost effective and simpler than conventional photolithography, was proposed for the fabrication of nano- and micro-structures. Polydimethylsiloxane (PDMS) was poured on a mother pattern with a diameter of 6 μm and a spacing of 2 μm; then, curing was performed to create a PDMS mold. The regular micropattern was stamped on a low-viscosity resin-coated silicon surface, followed by the simple reactive ion etching process. Nano-structures were formed using the Ag-based electroless etching process. As etching time was increased to 6 min, reflectance decreased to 4.53% and current density improved from 22.35 to 34.72 mA/cm2.
Structure and atomic correlations in molecular systems probed by XAS reverse Monte Carlo refinement
Authors: Di Cicco Andrea , Iesari Fabio , Trapananti Angela , D’Angelo Paola , Filipponi Adriano
Published: March 2018

The Reverse Monte Carlo (RMC) algorithm for structure refinement has been applied to x-ray absorption spectroscopy (XAS) multiple-edge data sets for six gas phase molecular systems (SnI2, CdI2, BBr3, GaI3, GeBr4, GeI4). Sets of thousands of molecular replicas were involved in the refinement process, driven by the XAS data and constrained by available electron diffraction results. The equilibrated configurations were analysed to determine the average tridimensional structure and obtain reliable bond and bond-angle distributions. Detectable deviations from Gaussian models were found in some cases. This work shows that a RMC refinement of XAS data is able to provide geometrical models for molecular structures compatible with present experimental evidence. The validation of this approach on simple molecular systems is particularly important in view of its possible simple extension to more complex and extended systems including metal-organic complexes, biomolecules, or nanocrystalline systems.
Rhodium doped InGaAs: A superior ultrafast photoconductor
Authors: Kohlhaas R. B. , Globisch B. , Nellen S. , Liebermeister L. , Schell M. , Richter P. , Koch M. , Semtsiv M. P. , Masselink W. T.
Published: March 2018

The properties of rhodium (Rh) as a deep-level dopant in InGaAs lattice matched to InP grown by molecular beam epitaxy are investigated. When InGaAs:Rh is used as an ultrafast photoconductor, carrier lifetimes as short as 100 fs for optically excited electrons are measured. Rh doping compensates free carriers so that a near intrinsic carrier concentration can be achieved. At the same time, InGaAs:Rh exhibits a large electron mobility of 1000 cm2/V s. Therefore, this material is a very promising candidate for application as a semi-insulating layer, THz antenna, or semiconductor saturable absorber mirror.
Synthesis of the zeolitic imidazolate framework ZIF-4 from the ionic liquid 1-butyl-3-methylimidazolium imidazolate
Authors: Hovestadt Maximilian , Schwegler Johannes , Schulz Peter S. , Hartmann Martin
Published: March 2018

A new synthesis route for the zeolitic imidazolate framework ZIF-4 using imidazolium imidazolate is reported. Additionally, the ionic liquid-derived material is compared to conventional ZIF-4 with respect to the powder X-ray diffraction pattern pattern, nitrogen uptake, particle size, and separation potential for olefin/paraffin gas mixtures. Higher synthesis yields were obtained, and the different particle size affected the performance in the separation of ethane and ethylene.
Integrating micro-ignitors with Al/Bi2O3/graphene oxide composite energetic films to realize tunable ignition performance
Authors: Ma Xiaoxia , Cheng Shengxian , Hu Yan , Ye Yinghua , Shen Ruiqi
Published: March 2018

The integration of composite energetic films (CEFs) with various types of initiators can effectively adjust their performance and represents potential applications in microscale energy-demanding systems. In this study, the Al/Bi2O3/graphene oxide (GO) CEFs were successfully integrated into copper micro-ignitors by electrophoretic deposition, a low-cost and time-saving method. The effects of the Al/Bi2O3/GO CEFs with different GO contents on exothermic performance and ignition properties of micro-ignitors were then systematically investigated in terms of heat release, activation energy, ignition duration, the maximum height of the ignition product, and ignition delay time. The results showed that the addition of GO promoted more heat releases and higher activation energies of Al/Bi2O3/GO CEFs. The addition of ≤3.5 wt. % GO prolonged the ignition duration from 450 μs to 950 μs and increased the maximum height of the ignition product from about 40 mm to 60 mm. However, the micro-ignitors with more than 3.5 wt. % GO cannot be ignited, which suggested that GO played a contradictory role in the ignition properties of micro-ignitors and the controlled GO content was a prerequisite for improved ignition performance. The ignition delay time gradually extended from 10.7 μs to 27.6 μs with increases in the GO contents of Al/Bi2O3 CEFs, revealing that an increase in the weight ratio of GO leads to lower ignition sensitivity of micro-ignitors.
Broadband terahertz modulator based on graphene metamaterials
Authors: Huang Zehua , Han Qi , Ji Chunhui , Wang Jun , Jiang Yadong
Published: March 2018

Tunable complementary split ring resonators (CSRRs) based on monolayer graphene are presented in terahertz regime. By applying different gate voltage, the Fermi level and optical conductivity of monolayer graphene pattern can be changed. Here, we employ a numerical simulation to study the interaction of light with graphene CSRRs. The results indicate that the extinction in transmission becomes stronger, and the resonance frequency presents blue shift with higher Fermi level of the graphene pattern. Three pronounced resonant peaks appear which can be modulated dynamically in the range of 1-2THz and 3-7THz, and realizing dynamic broadband terahertz modulation, the modulation depth exceeds 85% at all three resonant peaks, the highest modulation depth reaches 98.8% at 7.47THz.
Formation of porous silicon oxide from substrate-bound silicon rich silicon oxide layers by continuous-wave laser irradiation
Authors: Wang Nan , Fricke-Begemann Th. , Peretzki P. , Ihlemann J. , Seibt M.
Published: March 2018

Silicon nanocrystals embedded in silicon oxide that show room temperature photoluminescence (PL) have great potential in silicon light emission applications. Nanocrystalline silicon particle formation by laser irradiation has the unique advantage of spatially controlled heating, which is compatible with modern silicon micro-fabrication technology. In this paper, we employ continuous wave laser irradiation to decompose substrate-bound silicon-rich silicon oxide films into crystalline silicon particles and silicon dioxide. The resulting microstructure is studied using transmission electron microscopy techniques with considerable emphasis on the formation and properties of laser damaged regions which typically quench room temperature PL from the nanoparticles. It is shown that such regions consist of an amorphous matrix with a composition similar to silicon dioxide which contains some nanometric silicon particles in addition to pores. A mechanism referred to as “selective silicon ablation” is proposed which consistently explains the experimental observations. Implications for the damage-free laser decomposition of silicon-rich silicon oxides and also for controlled production of porous silicon dioxide films are discussed.
First-principle approach based bandgap engineering for cubic boron nitride doped with group IIA elements
Authors: Li Yubo , Wang Pengtao , Hua Fei , Zhan Shijie , Wang Xiaozhi , Luo Jikui , Yang Hangsheng
Published: March 2018

Electronic properties of cubic boron nitride (c-BN) doped with group IIA elements were systematically investigated using the first principle calculation based on density functional theory. The electronic bandgap of c-BN was found to be narrowed when the impurity atom substituted either the B (IIA→B) or the N (IIA→N) atom. For IIA→B, a shallow accept level degenerated into valence band (VB); while for IIA→N, a shallow donor level degenerated conduction band (CB). In the cases of IIBe→N and IIMg→N, deep donor levels were also induced. Moreover, a zigzag bandgap narrowing pattern was found, which is in consistent with the variation pattern of dopants’ radius of electron occupied outer s-orbital. From the view of formation energy, the substitution of B atom under N-rich conditions and the substitution of N atom under B-rich conditions were energetically favored. Our simulation results suggested that Mg and Ca are good candidates for p-type dopants, and Ca is the best candidate for n-type dopant.
Initial water adsorption on hematite (α-Fe2O3) (0001): A DFT + U study
Authors: Wang Richard B. , Hellman Anders
Published: March 2018

Interaction between water and oxide surfaces plays an important role in many applications. In the present study, we use a density functional theory + U method to study the initial adsorption behavior of water on various α-Fe2O3 (0001) terminations. In particular, adsorption and dissociation of water at 1 monolayer and 0.5 monolayer coverage on the Fe-terminated, O-terminated, and ferryl-terminated (0001) surfaces are studied. The results show that the dissociated state is preferred, which is in agreement with theoretical and experimental observations. However, experiments show the co-existence of molecular water in the initial adsorption on hematite, which, so far, has no theoretical support. To explain this, we investigate OH-covered Fe-terminated surfaces and find that on R–Fe–(OH)x terminations, molecular water is actually energetically favorable. Thus, we propose that the existence of R–Fe–(OH)x terminations is a requirement for molecular water in the initial adsorption process. This proposal is further supported by comparing the calculated core level shift of R–Fe–(OH)x structures with experimental data.
Magneto-optical absorption and cyclotron–phonon resonance in graphene monolayer
Authors: Hoi Bui Dinh , Phuong Le Thi Thu , Phong Tran Cong
Published: March 2018

The optical absorption power by Dirac fermions in a graphene monolayer subjected to a perpendicular magnetic field is calculated using a projection operator technique. The electron–optical phonon interaction with optical deformation potential is taken into account. By varying the photon frequency (energy), we observe in the absorption power a series of cyclotron–phonon resonance (CPR) peaks (i.e., the phonon-assisted cyclotron resonance). It is seen that the resonant photon energy is linearly proportional to the square root of the magnetic field. Also, the half width at half maximum (HWHM) of CPR peaks depends on the magnetic field by the law HWHM = 7.42B but does not depend on the temperature. In particular, the magnetic field and temperature dependences of the position and HWHM of CPR peaks are in good agreement with those obtained recently by the perturbation theory and an experiment in graphene.
Lock-in thermography using a cellphone attachment infrared camera
Authors: Razani Marjan , Parkhimchyk Artur , Tabatabaei Nima
Published: March 2018

Lock-in thermography (LIT) is a thermal-wave-based, non-destructive testing, technique which has been widely utilized in research settings for characterization and evaluation of biological and industrial materials. However, despite promising research outcomes, the wide spread adaptation of LIT in industry, and its commercialization, is hindered by the high cost of the infrared cameras used in the LIT setups. In this paper, we report on the feasibility of using inexpensive cellphone attachment infrared cameras for performing LIT. While the cost of such cameras is over two orders of magnitude less than their research-grade counterparts, our experimental results on block sample with subsurface defects and tooth with early dental caries suggest that acceptable performance can be achieved through careful instrumentation and implementation of proper data acquisition and image processing steps. We anticipate this study to pave the way for development of low-cost thermography systems and their commercialization as inexpensive tools for non-destructive testing of industrial samples as well as affordable clinical devices for diagnostic imaging of biological tissues.
Interactive effects of hypoxia and dissolved nutrients on the physiology and biochemistry of the freshwater crayfish Paranephrops zealandicus
Authors: Broughton Rebecca J. , Marsden Islay D. , Hill Jonathan V. , Glover Chris N.
Published: March 2018

A key contributing factor to the decline of the at-risk freshwater crayfish Paranephrops zealandicus is the presence of hypoxia associated with eutrophication. However, there is little information regarding the effects that dissolved nutrients have on the physiological and biochemical mechanisms that this and other freshwater crayfish use to cope with lowered dissolved oxygen. In the present study, P. zealandicus were exposed to an abrupt hypoxia (1.3kPa) in the absence or presence of either ammonia (30mgL–1 total ammonia; 0.04mgL–1 as un-ionised ammonia) or nitrite (20mgL–1) over a 6-h exposure using semi-closed box respirometry. Respiratory (oxygen consumption, haemolymph oxygen partial pressure), cardiac (heart rate) and biochemical (haemolymph acid–base status, glucose and lactate; tissue glucose and lactate) end points were measured. In hypoxia alone, haemolymph oxygen partial pressure, glucose and pH fell, whereas haemolymph lactate increased. The only significant effects of nutrients on hypoxic responses were a further decline in haemolymph oxygen partial pressure and an enhanced hypoglycaemia in the presence of nitrite. These effects may be linked to a nitrite-mediated improvement in tissue perfusion. Overall, these data indicate little additional effect of the presence of nutrients on the responses of P. zealandicus to hypoxia.
Anabolic effects of chrysin on the ventral male prostate and female prostate of adult gerbils (Meriones unguiculatus)
Authors: Campos Mônica S. , Ribeiro Naiara C. S. , de Lima Rodrigo F. , Santos Mariana B. , Vilamaior Patrícia S. L. , Regasini Luis O. , Biancardi Manoel F. , Taboga Sebastião R. , Santos Fernanda C. A.
Published: March 2018

Chrysin is a bioflavonoid found in fruits, flowers, tea, honey and wine, which has antioxidant, anti-inflammatory, antiallergic and anticarcinogenic properties. This flavone has also been considered as beneficial for reproduction due its testosterone-boosting potential. Thus, the aim of this study was to evaluate the effects of chrysin on the prostate and gonads of male and female adult gerbils. In addition, a comparative analysis of the effects of testosterone on these same organs was conducted. Ninety-day-old male and female gerbils were treated with chrysin (50 mg kg−1 day−1) or testosterone cypionate (1 mg kg−1 week−1) for 21 days. The ventral male prostate and female prostate were dissected out for morphological, morphometric–stereological and ultrastructural assays. Testes and ovaries were submitted to morphological and morphometric­­–stereological analyses. Chrysin treatment caused epithelial hyperplasia and stromal remodelling of the ventral male and female prostate. Ultrastructurally, male and female prostatic epithelial cells in the chrysin group presented marked development of the organelles involved in the biosynthetic–secretory pathway, whereas cellular toxicity was observed only in female glands. Chrysin preserved normal testicular morphology and increased the number of growing ovarian follicles. Comparatively, testosterone treatment was detrimental to the prostate and gonads, since foci of prostatic intraepithelial neoplasia and gonadal degeneration were observed in both sexes. Thus, under the experimental conditions of this study, chrysin was better tolerated than testosterone in the prostate and gonads.
4-1BB costimulation induces T cell mitochondrial function and biogenesis enabling cancer immunotherapeutic responses
Authors: Menk Ashley V. , Scharping Nicole E. , Rivadeneira Dayana B. , Calderon Michael J. , Watson McLane J. , Dunstane Deanna , Watkins Simon C. , Delgoffe Greg M.
Published: March 2018

Despite remarkable responses to cancer immunotherapy in a subset of patients, many patients remain resistant to these therapies. The tumor microenvironment can impose metabolic restrictions on T cell function, creating a resistance mechanism to immunotherapy. We have previously shown tumor-infiltrating T cells succumb to progressive loss of metabolic sufficiency, characterized by repression of mitochondrial activity that cannot be rescued by PD-1 blockade. 4-1BB, a costimulatory molecule highly expressed on exhausted T cells, has been shown to influence metabolic function. We hypothesized that 4-1BB signaling might provide metabolic support to tumor-infiltrating T cells. 4-1BB costimulation of CD8+ T cells results in enhanced mitochondrial capacity (suggestive of fusion) and engages PGC1α-mediated pathways via activation of p38-MAPK. 4-1BB treatment of mice improves metabolic sufficiency in endogenous and adoptive therapeutic CD8+ T cells. 4-1BB stimulation combined with PD-1 blockade results in robust antitumor immunity. Sequenced studies revealed the metabolic support afforded by 4-1BB agonism need not be continuous and that a short course of anti–4-1BB pretreatment was sufficient to provide a synergistic response. Our studies highlight metabolic reprogramming as the dominant effect of 4-1BB therapy and suggest that combinatorial strategies using 4-1BB agonism may help overcome the immunosuppressive metabolic landscape of the tumor microenvironment.
Mass cytometry reveals innate lymphoid cell differentiation pathways in the human fetal intestine
Authors: Li Na , van Unen Vincent , Höllt Thomas , Thompson Allan , van Bergen Jeroen , Pezzotti Nicola , Eisemann Elmar , Vilanova Anna , Chuva de Sousa Lopes Susana M. , Lelieveldt Boudewijn P.F. , Koning Frits
Published: March 2018

Innate lymphoid cells (ILCs) are abundant in mucosal tissues and involved in tissue homeostasis and barrier function. Although several ILC subsets have been identified, it is unknown if additional heterogeneity exists, and their differentiation pathways remain largely unclear. We applied mass cytometry to analyze ILCs in the human fetal intestine and distinguished 34 distinct clusters through a t-SNE–based analysis. A lineage (Lin)−CD7+CD127−CD45RO+CD56+ population clustered between the CD127+ ILC and natural killer (NK) cell subsets, and expressed diverse levels of Eomes, T-bet, GATA3, and RORγt. By visualizing the dynamics of the t-SNE computation, we identified smooth phenotypic transitions from cells within the Lin−CD7+CD127−CD45RO+CD56+ cluster to both the NK cells and CD127+ ILCs, revealing potential differentiation trajectories. In functional differentiation assays, the Lin−CD7+CD127−CD45RO+CD56+CD8a− cells could develop into CD45RA+ NK cells and CD127+RORγt+ ILC3-like cells. Thus, we identified a previously unknown intermediate innate subset that can differentiate into ILC3 and NK cells.
Irg1 expression in myeloid cells prevents immunopathology during M. tuberculosis infection
Authors: Nair Sharmila , Huynh Jeremy P. , Lampropoulou Vicky , Loginicheva Ekaterina , Esaulova Ekaterina , Gounder Anshu P. , Boon Adrianus C.M. , Schwarzkopf Elizabeth A. , Bradstreet Tara R. , Edelson Brian T. , Artyomov Maxim N. , Stallings Christina L. , Diamond Michael S.
Published: March 2018

Immune-Responsive Gene 1 (Irg1) is a mitochondrial enzyme that produces itaconate under inflammatory conditions, principally in cells of myeloid lineage. Cell culture studies suggest that itaconate regulates inflammation through its inhibitory effects on cytokine and reactive oxygen species production. To evaluate the functions of Irg1 in vivo, we challenged wild-type (WT) and Irg1−/− mice with Mycobacterium tuberculosis (Mtb) and monitored disease progression. Irg1−/−, but not WT, mice succumbed rapidly to Mtb, and mortality was associated with increased infection, inflammation, and pathology. Infection of LysM-Cre Irg1fl/fl, Mrp8-Cre Irg1fl/fl, and CD11c-Cre Irg1fl/fl conditional knockout mice along with neutrophil depletion experiments revealed a role for Irg1 in LysM+ myeloid cells in preventing neutrophil-mediated immunopathology and disease. RNA sequencing analyses suggest that Irg1 and its production of itaconate temper Mtb-induced inflammatory responses in myeloid cells at the transcriptional level. Thus, an Irg1 regulatory axis modulates inflammation to curtail Mtb-induced lung disease.
BPRMeth: a flexible Bioconductor package for modelling methylation profiles
Authors: Kapourani Chantriolnt-Andreas , Sanguinetti Guido
Published: March 2018

Motivation

High-throughput measurements of DNA methylation are increasingly becoming a mainstay of biomedical investigations. While the methylation status of individual cytosines can sometimes be informative, several recent papers have shown that the functional role of DNA methylation is better captured by a quantitative analysis of the spatial variation of methylation across a genomic region.

Results

Here, we present BPRMeth, a Bioconductor package that quantifies methylation profiles by generalized linear model regression. The original implementation has been enhanced in two important ways: we introduced a fast, variational inference approach that enables the quantification of Bayesian posterior confidence measures on the model, and we adapted the method to use several observation models, making it suitable for a diverse range of platforms including single-cell analyses and methylation arrays.

Availability and implementation

http://bioconductor.org/packages/BPRMeth

Supplementary information

Supplementary data are available at Bioinformatics online.