bluuebunny/crossref_metadata_2025 huggingface dataset:
The use of methods of structural optimization at the stage of designing high-rise buildings with steel construction
Authors: Vasilkin Andrey
Published: March 2018

The more designing solutions at the search stage for design for high-rise buildings can be synthesized by the engineer, the more likely that the final adopted version will be the most efficient and economical. However, in modern market conditions, taking into account the complexity and responsibility of high-rise buildings the designer does not have the necessary time to develop, analyze and compare any significant number of options. To solve this problem, it is expedient to use the high potential of computer-aided designing. To implement automated search for design solutions, it is proposed to develop the computing facilities, the application of which will significantly increase the productivity of the designer and reduce the complexity of designing. Methods of structural and parametric optimization have been adopted as the basis of the computing facilities. Their efficiency in the synthesis of design solutions is shown, also the schemes, that illustrate and explain the introduction of structural optimization in the traditional design of steel frames, are constructed. To solve the problem of synthesis and comparison of design solutions for steel frames, it is proposed to develop the computing facilities that significantly reduces the complexity of search designing and based on the use of methods of structural and parametric optimization.
Determination of the nuclear level densities and radiative strength function for 43 nuclei in the mass interval 28≤A≤200
Authors: Knezevic David , Jovancevic Nikola , Sukhovoj Anatoly M. , Mitsyna Ludmila V. , Krmar Miodrag , Cong Vu D. , Hambsch Franz-Josef , Oberstedt Stephan , Revay Zsolt , Stieghorst Christian , Dragic Aleksandar
Published: March 2018

The determination of nuclear level densities and radiative strength functions is one of the most important tasks in low-energy nuclear physics. Accurate experimental values of these parameters are critical for the study of the fundamental properties of nuclear structure. The step-like structure in the dependence of the level densities p on the excitation energy of nuclei Eex is observed in the two-step gamma cascade measurements for nuclei in the 28 ≤ A ≤ 200 mass region. This characteristic structure can be explained only if a co-existence of quasi-particles and phonons, as well as their interaction in a nucleus, are taken into account in the process of gamma-decay. Here we present a new improvement to the Dubna practical model for the determination of nuclear level densities and radiative strength functions. The new practical model guarantees a good description of the available intensities of the two step gamma cascades, comparable to the experimental data accuracy.
Measurement of the ROT effect in the neutron induced fission of 235U in the 0.3 eV resonance at a hot source of polarized neutrons
Authors: Kopatch Yuri , Novitsky Vadim , Ahmadov Gadir , Gagarsky Alexei , Berikov Daniyar , Danilyan Gevorg , Hutanu Vladimir , Klenke Jens , Masalovich Sergey
Published: March 2018

The TRI and ROT asymmetries in fission of heavy nuclei have been extensively studied during more than a decade. The effects were first discovered in the ternary fission in a series of experiments performed at the ILL reactor (Grenoble) by a collaboration of Russian and European institutes, and were carefully measured for a number of fissioning nuclei. Later on, the ROT effect has been observed in the emission of prompt gamma rays and neutrons in fission of 235U and 233U, although its value was an order of magnitude smaller than in the α-particle emission from ternary fission. All experiments performed so far are done with cold polarized neutrons, what assumes a mixture of several spin states, the weights of these states being not well known. The present paper describes the first attempt to get “clean” data by performing the measurement of gamma and neutron asymmetries in an isolated resonance of 235U at the POLI instrument of the FRM2 reactor in Garching.
Investigation of the heavy nuclei fission with anomalously high values of the fission fragments total kinetic energy
Authors: Khryachkov Vitaly , Goverdovskii Andrei , Ketlerov Vladimir , Mitrofanov Vecheslav , Sergachev Alexei
Published: March 2018

Binary fission of 232Th and 238U induced by fast neutrons were under intent investigation in the IPPE during recent years. These measurements were performed with a twin ionization chamber with Frisch grids. Signals from the detector were digitized for further processing with a specially developed software. It results in information of kinetic energies, masses, directions and Bragg curves of registered fission fragments. Total statistics of a few million fission events were collected during each experiment. It was discovered that for several combinations of fission fragment masses their total kinetic energy was very close to total free energy of the fissioning system. The probability of such fission events for the fast neutron induced fission was found to be much higher than for spontaneous fission of 252Cf and thermal neutron induced fission of 235U. For experiments with 238U target the energy of incident neutrons were 5 MeV and 6.5 MeV. Close analysis of dependence of fission fragment distribution on compound nucleus excitation energy gave us some explanation of the phenomenon. It could be a process in highly excited compound nucleus which leads the fissioning system from the scission point into the fusion valley with high probability.
Parameterisation of the residual temperature distribution based on the modelling of successive emission of prompt neutrons
Authors: Tudora Anabella , Hambsch Franz-Josef
Published: March 2018

A new deterministic modelling taking into account the successive emission of prompt neutrons from initial fragments of a fragmentation range {A, Z, TKE} constructed as in the Point-by-Point (PbP) treatment is described. The good agreement of different prompt emission quantities obtained from this modelling (e.g. v(A), v(TKE), E-γ(A), E-γ(TKE), etc.) with the experimental data and the results of the PbP model and other Monte-Carlo models validates the present modelling of sequential emission. The distributions of different residual quantities, including the residual temperature distributions P(T) of light and heavy fragments allow to obtain a new parameterisation of P(T) which can be used in the PbP model and the Los Alamos model.
Analysis of a queueing system in random environment with an unreliable server and geometric abandonments
Authors: Jiang Tao , Xin Baogui , Chang Baoxian , Liu Liwei
Published: March 2018

This paper studies a single server queueing model in a multi-phase random environment with server breakdowns and geometric abandonments, where server breakdowns only occur while the server is in operation. At a server breakdown instant (i.e., an abandonment opportunity epoch), all present customers adopt the so-called geometric abandonments, that is, the customers decide sequentially whether they will leave the system or not. In the meantime, the server abandons the service and a repair process starts immediately. After the server is repaired, the server resumes its service, and the system enters into the operative phaseiwith probabilityqi,i= 1, 2, …,d. Using probability generating functions and matrix geometric approach, we obtain the steady state distribution and various performance measures. In addition, some numerical examples are presented to show the impact of parameters on the performance measures.
Évaluation quadriennale des 39 programmes d’éducation thérapeutique de l’hôpital Necker – Enfants malades : propositions d’amélioration pédagogique et organisationnelle
Authors: Godot Cécile , Robert Jean-Jacques , Meux Marie-Claire , Cheurfi Radhia , Benfradj Ayed , Gagnayre Remi
Published: March 2018

Introduction : Trente-neuf programmes d’éducation thérapeutique ont été autorisés par l’Agence régionale de santé d’Île-de-France entre 2010 et 2012 à l’hôpital universitaire Necker – Enfants malades et ont donc dû conduire leur évaluation quadriennale pour demander leur renouvellement en 2014 et 2015.Objectifs : La réalisation d’une synthèse de ces évaluations avait pour objectifs de faire un état des lieux après quatre ans de mise en œuvre des programmes et de définir des pistes d’amélioration.Résultats : Trente-huit programmes sont destinés à des enfants/adolescents et 30 concernent des pathologies rares. L’offre initiale d’éducation est réalisée en hospitalisation (15/39), en ambulatoire (17/39), ou les deux selon le patient (7/39), et a le plus souvent des objectifs de compétences de soins et de sécurité. Trente-quatre programmes proposent une offre éducative de suivi, 24 des offres de reprise de l’éducation. Les équipes sont toutes pluridisciplinaires, 41 % des intervenants sont formés, et des parents-ressources interviennent dans deux programmes. L’évaluation des compétences acquises par le patient est formalisée dans 18 programmes. Six programmes ont des indicateurs clinico-biologiques de suivi, 25 utilisent des questionnaires de satisfaction et 18 font des auto-évaluations annuelles régulièrement. Le principal frein à la mise en œuvre des programmes est le manque de personnel, les leviers sont l’implication de l’équipe, l’amélioration de la coordination, la collaboration avec d’autres structures de soins et la valorisation des activités.Discussion : L’offre éducative proposée est spécifique et complète, même si elle est principalement axée sur les compétences de soins. Des évolutions sont nécessaires pour poursuivre la promotion d’une éducation thérapeutique de qualité, adapter l’offre aux besoins des patients et à leur contexte de vie, lever le principal frein à la mise en œuvre qu’est celui du temps et impliquer les patients.Conclusion : La conduite des évaluations quadriennales a permis de valoriser le travail des équipes, de montrer les spécificités de l’offre éducative, mais aussi de définir des pistes d’amélioration à mettre en œuvre à l’échelle des programmes et de l’établissement.
Non-Small Cell Lung Cancer with Chest Wall Involvement: Integrated Treatment or Surgery Alone?
Authors: Chiappetta Marco , Nachira Dania , Congedo Maria Teresa , Meacci Elisa , Porziella Venanzio , Margaritora Stefano
Published: March 2018

Background The aim of this study was to identify prognostic factors in patients affected by non-small cell lung cancer (NSCLC) with chest wall (CW) involvement, analyzing different strategies of treatment and surgical approaches.

Methods Records of 59 patients affected by NSCLC with CW involvement underwent surgery were retrospectively reviewed, from January 2000 to March 2013.

Results Induction therapy was administered to 18 (30.5%) patients while adjuvant treatment to 36 (61.0%). In 36 (61%) patients, lung resection was associated only with a parietal pleural resection while in 23 (39%) with CW en-bloc resection. Overall 5-year survival was 34%. Prognostic factors were evaluated in the 51 (86.4%) completely resected (R0) patients.

Five-year survival was 60% in patients undergoing induction therapy followed by surgery and 24% in those who underwent surgery as first treatment (p = 0.11). Five-year survival was better in the neoadjuvant group than that in the surgery group in IIB (T3N0) p-stage (100 vs 28%, p = 0.03), while in the IIIA (T3N1–2,T4N0) p-stage it was of 25 vs 0%, respectively (p = 0.53).

No 5-year survival difference was found in case of parietal pleural resection versus CW en-bloc resection (p = 0.27) and in case of only parietal pleural involvement versus soft tissue (p = 0.78).

In case of incomplete resection (R1), patients undergoing adjuvant radiotherapy had better 2-year survival than patients untreated: 60% vs 0% (p = 0.025).

Conclusions Type of surgical resection and the deep of infiltration of disease do not influence survival in this subset of patients. Integrated treatments seem to be suitable: neoadjuvant therapies ensure a better survival rate than surgery alone in IIB and IIIA patients, instead adjuvant radiotherapy proves a fundamental option in incomplete resections.
Elective Cesarean Delivery at Term and the Long-Term Risk for Neurological Morbidity of the Offspring
Authors: Sheiner Eyal , Wainstock Tamar , Segal Idit , Sergienko Ruslan , Landau Daniella , Walfisch Asnat , Baumfeld Yael
Published: March 2018

Objective The study's objective was to determine whether mode of delivery has an impact on the long-term risk for neurologic morbidity of the offspring.

Materials and Methods This population-based cohort analysis included all term singleton deliveries between 1991 and 2014. The study population was divided into two study group: elective cesarean deliveries (CD) versus vaginal deliveries (VD). Urgent cesarean deliveries, pregnancy, and delivery complications including preeclampsia and gestational diabetes were excluded. The evaluation of cumulative neurological hospitalization rate over time was performed with a Kaplan–Meier survival analysis and Cox proportional hazards models were used to study the independent association between mode of delivery and neurological morbidity while controlling for potential confounders.

Results During the study period 132,054 deliveries met the inclusion criteria, 11,746 CD (8.9%), and 120,308 (91.1%) VD. A total of 3,626 neurological hospitalizations were documented with 2.70% (3,244) in the VD group as compared with 3.25% (382) in the CD group. The survival curves showed higher cumulative hospitalization rates in the CD as compared with the VD group (p ≤ 0.001). The Cox analysis demonstrated CD to be an independent risk factor for pediatric neurological hospitalizations (p < 0.001).

Conclusion Term elective CD is an independent risk factor for neurological morbidity of the offspring.
DEGUM Recommendations on Infection Prevention in Ultrasound and Endoscopic Ultrasound
Authors: Müller Thomas , Martiny Heike , Merz Eberhard , Döffert Jens , Wüstner Matthias , Lessel Wolfgang , Heynemann Hans , Enzmann Thomas , Dudwiesus Heiko , Nuernberg Dieter , Tesch Christian , Weber Marc , Krishnabhakdi Siegfried , Heil Jörg , Wree Alexander , Jenssen Christian
Published: March 2018

Microbial contamination of ultrasound probes for percutaneous or endoscopic use is common. However, infectious diseases caused by transmission of microorganisms by US procedures have rarely been reported. In Germany, legal regulations address hygiene in ultrasound procedures. Based on these regulations and the available literature, an expert panel of the German Society of Ultrasound in Medicine (DEGUM) has formulated sophisticated recommendations on hygienic measures in percutaneous and endoscopic US, including US-guided interventions.
Effect of gas filling pressure and operation energy on ion and neutron emission in a medium energy plasma focus device
Authors: Niranjan Ram , Rout R. K. , Srivastava Rohit , Kaushik T. C.
Published: March 2018

The effects of gas filling pressure and operation energy on deuterium ions and neutrons have been studied in a medium energy plasma focus device, MEPF-12. The deuterium gas filling pressure was varied from 1 to 10 mbar at an operation energy of 9.7 kJ. Also, the operation energy was varied from 3.9 to 9.7 kJ at a deuterium gas filling pressure of 4 mbar. Time resolved emission of deuterium ions was measured using a Faraday cup. Simultaneously, time integrated and time resolved emissions of neutrons were measured using a silver activation detector and plastic scintillator detector, respectively. Various characteristics (fluence, peak density, and most probable energy) of deuterium ions were estimated using the Faraday cup signal. The fluence was found to be nearly independent of the gas filling pressure and operation energy, but the peak density and most probable energy of deuterium ions were found to be varying. The neutron yield was observed to be varying with the gas filling pressure and operation energy. The effect of ions on neutrons emission was observed at each operation condition.
A hydrogen leak-tight, transparent cryogenic sample container for ultracold-neutron transmission measurements
Authors: Döge Stefan , Hingerl Jürgen
Published: March 2018

The improvement of the number of extractable ultracold neutrons (UCNs) from converters based on solid deuterium (sD2) crystals requires a good understanding of the UCN transport and how the crystal’s morphology influences its transparency to the UCNs. Measurements of the UCN transmission through cryogenic liquids and solids of interest, such as hydrogen (H2) and deuterium (D2), require sample containers with thin, highly polished and optically transparent windows and a well defined sample thickness. One of the most difficult sealing problems is that of light gases like hydrogen and helium at low temperatures against high vacuum. Here we report on the design of a sample container with two 1 mm thin amorphous silica windows cold-welded to aluminum clamps using indium wire gaskets, in order to form a simple, reusable, and hydrogen-tight cryogenic seal. The container meets the above-mentioned requirements and withstands up to 2 bar hydrogen gas pressure against isolation vacuum in the range of 10−5 to 10−7 mbar at temperatures down to 4.5 K. Additionally, photographs of the crystallization process are shown and discussed.
Transmission in situ and operando high temperature X-ray powder diffraction in variable gaseous environments
Authors: Schlicker Lukas , Doran Andrew , Schneppmüller Peter , Gili Albert , Czasny Mathias , Penner Simon , Gurlo Aleksander
Published: March 2018

This work describes a device for time-resolved synchrotron-based in situ and operando X-ray powder diffraction measurements at elevated temperatures under controllable gaseous environments. The respective gaseous sample environment is realized via a gas-tight capillary-in-capillary design, where the gas flow is achieved through an open-end 0.5 mm capillary located inside a 0.7 mm capillary filled with a sample powder. Thermal mass flow controllers provide appropriate gas flows and computer-controlled on-the-fly gas mixing capabilities. The capillary system is centered inside an infrared heated, proportional integral differential-controlled capillary furnace allowing access to temperatures up to 1000 °C.
HEKATE—A novel grazing incidence neutron scattering concept for the European Spallation Source
Authors: Glavic Artur , Stahn Jochen
Published: March 2018

Structure and magnetism at surfaces and buried interfaces on the nanoscale can only be accessed by few techniques, one of which is grazing incidence neutron scattering. While the technique has its strongest limitation in a low signal and large background, due to the low scattering probability and need for high resolution, it can be expected that the high intensity of the European Spallation Source in Lund, Sweden, will make many more such studies possible, warranting a dedicated beamline for this technique. We present an instrument concept, Highly Extended K range And Tunable Experiment (HEKATE), for surface scattering that combines the advantages of two Selene neutron guides with unique capabilities of spatially separated distinct wavelength frames. With this combination, it is not only possible to measure large specular reflectometry ranges, even on free liquid surfaces, but also to use two independent incident beams with tunable sizes and resolutions that can be optimized for the specifics of the investigated samples. Further the instrument guide geometry is tuned for reduction of high energy particle background and only uses low to moderate supermirror coatings for high reliability and affordable cost.
Non-intrusive investigation of flow and heat transfer characteristics of a channel with a built-in circular cylinder
Authors: Vyas Apoorv , Mishra Biswajit , Agrawal Atul , Srivastava Atul
Published: March 2018

Interferometry-based experimental investigation of heat transfer phenomena associated with a channel fitted with a circular cylinder has been reported. Experiments have been performed with water as the working fluid, and the range of Reynolds number considered is 75 ≤ Re ≤ 165. The circular cylinder, placed at the inlet section of the channel, provides a blockage ratio of 0.5. The experimental methodology has been benchmarked against the results of transient numerical simulations. In order to assess the performance of the channel fitted with a circular cylinder for possible heat transfer enhancement from the channel wall(s), experiments have also been performed on a plane channel (without a cylinder). The interferometry-based experiments clearly highlighted the influence of the built-in cylinder in generating the flow instabilities and alterations in the thermal boundary layer profile along the heated wall of the channel. The phenomenon of vortex shedding behind the cylinder was successfully captured. A gradual increase in the vortex shedding frequency was observed with increasing Reynolds number. Quantitative data in the form of two-dimensional temperature distributions revealed an increase in the strength of wall thermal gradients in the wake region of the cylinder due to the periodic shedding of the vortices. In turn, a clear enhancement in the wall heat transfer rates was observed for the case of the channel fitted with a cylinder vis-à-vis the plane channel. To the best of the knowledge of the authors, the work reported is one of the first attempts to provide the planar field experimental data for a channel configuration with a built-in circular cylinder using non-intrusive imaging techniques and has the potential to serve as one of the benchmark studies for validating the existing as well as future numerical studies in the related area.
Rayleigh-Plesset equation of the bubble stable cavitation in water: A nonequilibrium all-atom molecular dynamics simulation study
Authors: Man Viet Hoang , Li Mai Suan , Derreumaux Philippe , Nguyen Phuong H.
Published: March 2018

The Rayleigh-Plesset (RP) equation was derived from the first principles to describe the bubble cavitation in liquids in terms of macroscopic hydrodynamics. A number of nonequilibrium molecular dynamics studies have been carried out to validate this equation in describing the bubble inertial cavitation, but their results are contradictory and the applicability of the RP equation still remains to be examined, especially for the stable cavitation. In this work, we carry out nonequilibrium all-atom simulation to validate the applicability of the RP equation in the description of the stable cavitation of nano-sized bubbles in water. We show that although microscopic effects are not explicitly included, this equation still describes the dynamics of subnano-bubbles quite well as long as the contributions of various terms including inertial, surface tension, and viscosity are correctly taken into account. These terms are directly and inversely proportional to the amplitude and period of the cavitation, respectively. Thus, their contributions to the RP equation depend on these two parameters. This may explain the discrepancy between the current results obtained using different parameters. Finally, the accuracy of the RP equation in the current mathematical modeling studies of the ultrasound-induced blood-brain-barrier experiments is discussed in some detail.
Determination of angle of light deflection in higher-derivative gravity theories
Authors: Xu Chenmei , Yang Yisong
Published: March 2018

Gravitational light deflection is known as one of three classical tests of general relativity and the angle of deflection may be computed explicitly using approximate or exact solutions describing the gravitational force generated from a point mass. In various generalized gravity theories, however, such explicit determination is often impossible due to the difficulty in obtaining an exact expression for the deflection angle. In this work, we present some highly effective globally convergent iterative methods to determine the angle of semiclassical gravitational deflection in higher- and infinite-derivative formalisms of quantum gravity theories. We also establish the universal properties that the deflection angle always stays below the classical Einstein angle and is a strictly decreasing function of the incident photon energy, in these formalisms.
Towards terahertz detection and calibration through spontaneous parametric down-conversion in the terahertz idler-frequency range generated by a 795 nm diode laser system
Authors: Kornienko Vladimir V. , Kitaeva Galiya Kh. , Sedlmeir Florian , Leuchs Gerd , Schwefel Harald G. L.
Published: March 2018

We study a calibration scheme for terahertz wave nonlinear-optical detectors based on spontaneous parametric down-conversion. Contrary to the usual low wavelength pump in the green, we report here on the observation of spontaneous parametric down-conversion originating from an in-growth poled lithium niobate crystal pumped with a continuous wave 50 mW, 795 nm diode laser system, phase-matched to a terahertz frequency idler wave. Such a system is more compact and allows for longer poling periods as well as lower losses in the crystal. Filtering the pump radiation by a rubidium-87 vapor cell allowed the frequency-angular spectra to be obtained down to ∼0.5 THz or ∼1 nm shift from the pump radiation line. The presence of an amplified spontaneous emission “pedestal” in the diode laser radiation spectrum significantly hampers the observation of spontaneous parametric down-conversion spectra, in contrast to conventional narrowband gas lasers. Benefits of switching to longer pump wavelengths are pointed out, such as collinear optical-terahertz phase-matching in bulk crystals.
Weight of fitness deviation governs strict physical chaos in replicator dynamics
Authors: Pandit Varun , Mukhopadhyay Archan , Chakraborty Sagar
Published: March 2018

Replicator equation—a paradigm equation in evolutionary game dynamics—mathematizes the frequency dependent selection of competing strategies vying to enhance their fitness (quantified by the average payoffs) with respect to the average fitnesses of the evolving population under consideration. In this paper, we deal with two discrete versions of the replicator equation employed to study evolution in a population where any two players' interaction is modelled by a two-strategy symmetric normal-form game. There are twelve distinct classes of such games, each typified by a particular ordinal relationship among the elements of the corresponding payoff matrix. Here, we find the sufficient conditions for the existence of asymptotic solutions of the replicator equations such that the solutions—fixed points, periodic orbits, and chaotic trajectories—are all strictly physical, meaning that the frequency of any strategy lies inside the closed interval zero to one at all times. Thus, we elaborate on which of the twelve types of games are capable of showing meaningful physical solutions and for which of the two types of replicator equation. Subsequently, we introduce the concept of the weight of fitness deviation that is the scaling factor in a positive affine transformation connecting two payoff matrices such that the corresponding one-shot games have exactly same Nash equilibria and evolutionary stable states. The weight also quantifies how much the excess of fitness of a strategy over the average fitness of the population affects the per capita change in the frequency of the strategy. Intriguingly, the weight's variation is capable of making the Nash equilibria and the evolutionary stable states, useless by introducing strict physical chaos in the replicator dynamics based on the normal-form game.
Reduced linear noise approximation for biochemical reaction networks with time-scale separation: The stochastic tQSSA+
Authors: Herath Narmada , Del Vecchio Domitilla
Published: March 2018

Biochemical reaction networks often involve reactions that take place on different time scales, giving rise to “slow” and “fast” system variables. This property is widely used in the analysis of systems to obtain dynamical models with reduced dimensions. In this paper, we consider stochastic dynamics of biochemical reaction networks modeled using the Linear Noise Approximation (LNA). Under time-scale separation conditions, we obtain a reduced-order LNA that approximates both the slow and fast variables in the system. We mathematically prove that the first and second moments of this reduced-order model converge to those of the full system as the time-scale separation becomes large. These mathematical results, in particular, provide a rigorous justification to the accuracy of LNA models derived using the stochastic total quasi-steady state approximation (tQSSA). Since, in contrast to the stochastic tQSSA, our reduced-order model also provides approximations for the fast variable stochastic properties, we term our method the “stochastic tQSSA+”. Finally, we demonstrate the application of our approach on two biochemical network motifs found in gene-regulatory and signal transduction networks.
Vanadium substitution: A simple and economic way to improve UV sensing in ZnO
Authors: Srivastava Tulika , Bajpai Gaurav , Rathore Gyanendra , Liu Shun Wei , Biring Sajal , Sen Somaditya
Published: March 2018

The UV sensing in pure ZnO is due to oxygen adsorption/desorption process from the ZnO surface. Vanadium doping improves the UV sensitivity of ZnO. The enhancement in UV sensitivity in vanadium-substituted ZnO is attributed to trapping and de-trapping of electrons at V4+ and V5+-related defect states. The V4+ state has an extra electron than the V5+ state. A V4+ to V5+ transformation happens with excitation of this electron to the conduction band, while a reverse trapping process liberates a visible light. An analytic study of response phenomenon reveals this trapping and de-trapping process.
Evolution of ferroelectric HfO2 in ultrathin region down to 3 nm
Authors: Tian Xuan , Shibayama Shigehisa , Nishimura Tomonori , Yajima Takeaki , Migita Shinji , Toriumi Akira
Published: March 2018

The ferroelectric properties of ultrathin Y-doped HfO2 films were investigated. Ferroelectricity was demonstrated experimentally in 3 nm-thick Y-doped HfO2 via direct detection of displacement currents during polarization switching. The dependence on the HfO2 thickness within the 30 to 3 nm range revealed that the ferroelectric properties decrease rapidly below a critical thickness. In the ultrathin HfO2 region, methods such as higher Y doping or metal capping annealing were required to further stabilize the ferroelectric phase. These methods could be used to enhance the switchable polarization (Psw) to 35 μC/cm2 in 5 nm- and 10 μC/cm2 in 3 nm-thick Y-doped HfO2. This paper indicates that HfO2 ferroelectricity is scalable even in the ultrathin region.
Ultrahigh thermal conductivity of isotopically enriched silicon
Authors: Inyushkin Alexander V. , Taldenkov Alexander N. , Ager Joel W. , Haller Eugene E. , Riemann Helge , Abrosimov Nikolay V. , Pohl Hans-Joachim , Becker Peter
Published: March 2018

Most of the stable elements have two and more stable isotopes. The physical properties of materials composed of such elements depend on the isotopic abundance to some extent. A remarkably strong isotope effect is observed in the phonon thermal conductivity, the principal mechanism of heat conduction in nonmetallic crystals. An isotopic disorder due to random distribution of the isotopes in the crystal lattice sites results in a rather strong phonon scattering and, consequently, in a reduction of thermal conductivity. In this paper, we present new results of accurate and precise measurements of thermal conductivity κ(T) for silicon single crystals having three different isotopic compositions at temperatures T from 2.4 to 420 K. The highly enriched crystal containing 99.995% of 28Si, which is one of the most perfect crystals ever synthesized, demonstrates a thermal conductivity of about 450 ± 10 W cm−1 K–1 at 24 K, the highest measured value among bulk dielectrics, which is ten times greater than the one for its counterpart natSi with the natural isotopic constitution. For highly enriched crystal 28Si and crystal natSi, the measurements were performed for two orientations [001] and [011], a magnitude of the phonon focusing effect on thermal conductivity was determined accurately at low temperatures. The anisotropy of thermal conductivity disappears above 31 K. The influence of the boundary scattering on thermal conductivity persists sizable up to much higher temperatures (∼80 K). The κ(T) measured in this work gives the most accurate approximation of the intrinsic thermal conductivity of single crystal silicon which is determined solely by the anharmonic phonon processes and diffusive boundary scattering over a wide temperature range.
Singular vectors for the WN algebras
Authors: Ridout David , Siu Steve , Wood Simon
Published: March 2018

In this paper, we use free field realisations of the A-type principal, or Casimir, WN algebras to derive explicit formulae for singular vectors in Fock modules. These singular vectors are constructed by applying screening operators to Fock module highest weight vectors. The action of the screening operators is then explicitly evaluated in terms of Jack symmetric functions and their skew analogues. The resulting formulae depend on sequences of pairs of integers that completely determine the Fock module as well as the Jack symmetric functions.
Stress distribution and pressure-bearing capacity of a high-pressure split-cylinder die with prism cavity
Authors: Zhao Liang , Li Mingzhe , Wang Liyan , Qu Erhu , Yi Zhuo
Published: March 2018

A novel high-pressure belt-type die with a split-type cylinder is investigated with respect to extending its lifetime and improving its pressure bearing capacity. Specifically, a tungsten carbide cylinder is split into several parts along the radial direction with a prism-type cavity. In this paper, the cylinders with different split numbers are chosen to study the stress distribution and compare them with the traditional belt-type die. The simulation results indicate that the split cylinder has much smaller stress than those in the belt-type cylinder, and the statistical analysis reveals that the split-pressure cylinder is able to bear higher pressure. Experimental tests also show that the high-pressure die with a split cylinder and prism cavity has a stronger pressure-bearing capacity than a belt-type die. The split cylinder has advantages of easy manufacturing, high pressure bearing capacity, and replaceable performance.
Towards an unconscious neural reinforcement intervention for common fears
Authors: Taschereau-Dumouchel Vincent , Cortese Aurelio , Chiba Toshinori , Knotts J. D. , Kawato Mitsuo , Lau Hakwan
Published: March 2018

Significance

Conventional therapies for the treatment of anxiety disorders are aversive, and as a result, many patients terminate treatment prematurely. We have developed an unconscious method to bypass the unpleasantness in conscious exposure using functional magnetic resonance imaging neural reinforcement. Using this method, participants learn to generate brain patterns similar to the multivariate brain pattern of a feared animal. We demonstrate in a double-blind placebo-controlled experiment that neural reinforcement can lead to reliable reductions in physiological fear responses. Crucially, this intervention can be achieved completely unconsciously and without any aversive reaction. Extending our approach to other forms of psychopathologies, such as posttraumatic stress disorders, might eventually provide another means of intervention for patients currently receiving insufficient exposure treatments.
Intermediate filament accumulation can stabilize microtubules inCaenorhabditis elegansmotor neurons
Authors: Kurup Naina , Li Yunbo , Goncharov Alexandr , Jin Yishi
Published: March 2018

Significance

A principal component of the nerve cell is its cytoskeleton—a network of actin, tubulin, and intermediate filament polymers that maintains cell structure, directs cell growth, and transport of cargo. Here, we show that intermediate filaments can alter the dynamics of microtubules to affect developmental synapse remodeling inCaenorhabditis elegans. Accumulation of intermediate filaments is concurrent with hyperstablization of microtubules, which in turn prevents synaptic vesicle transport during rewiring. Our results identify a regulatory role for intermediate filaments in neurons in vivo, providing insight into the mechanisms behind neurological disorders such as ALS, where patients often present with accumulations of intermediate filaments in dying nerve cells.
Mental imagery and fiction
Authors: Stokes Dustin
Published: March 2018

Fictions evoke imagery, and their value consists partly in that achievement. This paper offers analysis of this neglected topic. Section 2 identifies relevant philosophical background. Section 3 offers a working definition of imagery. Section 4 identifies empirical work on visual imagery. Sections 5 and 6 criticize imagery essentialism, through the lens of genuine fictional narratives. This outcome, though, is not wholly critical. The expressed spirit of imagery essentialism is to encourage philosophers to ‘put the image back into the imagination’. The weakened conclusion is that while an image is not essential to imagining, it should be returned to our theories of imagination.
Membrane protein recycling from the vacuole/lysosome membrane
Authors: Suzuki Sho W. , Emr Scott D.
Published: March 2018

The lysosome (or vacuole in yeast) is the central organelle responsible for cellular degradation and nutrient storage. Lysosomes receive cargo from the secretory, endocytic, and autophagy pathways. Many of these proteins and lipids are delivered to the lysosome membrane, and some are degraded in the lysosome lumen, whereas others appear to be recycled through unknown pathways. In this study, we identify the transmembrane autophagy protein Atg27 as a physiological cargo recycled from the vacuole. We reveal that Atg27 is delivered to the vacuole membrane and then recycled using a two-step recycling process. First, Atg27 is recycled from the vacuole to the endosome via the Snx4 complex and then from the endosome to the Golgi via the retromer complex. During the process of vacuole-to-endosome retrograde trafficking, Snx4 complexes assemble on the vacuolar surface and recognize specific residues in the cytoplasmic tail of Atg27. This novel pathway maintains the normal composition and function of the vacuole membrane.
Potassium: an ion with dangerous airs and graces
Authors: Speer Thimoteus , Schunk Stefan J , Zewinger Stephen
Published: March 2018

Take home figure Factors promoting hypokalaemia and hyperkalaemia. CHF, chronic heart failure; CKD, chronic kidney disease.
Trial Readiness in Cavernous Angiomas With Symptomatic Hemorrhage (CASH)
Authors: Polster Sean P , Cao Ying , Carroll Timothy , Flemming Kelly , Girard Romuald , Hanley Daniel , Hobson Nicholas , Kim Helen , Koenig James , Koskimäki Janne , Lane Karen , Majersik Jennifer J , McBee Nichol , Morrison Leslie , Shenkar Robert , Stadnik Agnieszka , Thompson Richard E , Zabramski Joseph , Zeineddine Hussein A , Awad Issam A
Published: March 2018

BACKGROUND

Brain cavernous angiomas with symptomatic hemorrhage (CASH) are uncommon but exact a heavy burden of neurological disability from recurrent bleeding, for which there is no proven therapy. Candidate drugs to stabilize the CASH lesion and prevent rebleeding will ultimately require testing of safety and efficacy in multisite clinical trials. Much progress has been made in understanding the epidemiology of CASH, and novel biomarkers have been linked to the biological mechanisms and clinical activity in lesions. Yet, the ability to enroll and risk-stratify CASH subjects has never been assessed prospectively at multiple sites. Biomarkers and other outcomes have not been evaluated for their sensitivity and reliability, nor have they been harmonized across sites.

OBJECTIVE

To address knowledge gaps and establish a research network as infrastructure for future clinical trials, through the Trial Readiness grant mechanism, funded by National Institute of Neurological Disorders and Stroke/National Institutes of Health.

METHODS

This project includes an observational cohort study to assess (1) the feasibility of screening, enrollment rates, baseline disease categorization, and follow-up of CASH using common data elements at multiple sites, (2) the reliability of imaging biomarkers including quantitative susceptibility mapping and permeability measures that have been shown to correlate with lesion activity, and (3) the rates of recurrent hemorrhage and change in functional status and biomarker measurements during prospective follow-up.

EXPECTED OUTCOMES

We propose a harmonized multisite assessment of enrollment rates of CASH, baseline features relevant to stratification in clinical trials, and follow-up assessments of functional outcomes in relation to clinical bleeds. We introduce novel biomarkers of vascular leak and hemorrhage, with firm mechanistic foundations, which have been linked to clinical disease activity. We shall test their reliability and validity at multiple sites, and assess their changes over time, with and without clinical rebleeds, hence their fitness as outcome instruments in clinical trials.

DISCUSSION

The timing cannot be more opportune, with therapeutic targets identified, exceptional collaboration among researchers and the patient community, along with several drugs ready to benefit from development of a path to clinical testing using this network in the next 5 years.
Hepatitis C Treatment Outcomes for People Who Inject Drugs Treated in an Accessible Care Program Located at a Syringe Service Program
Authors: Eckhardt Benjamin J , Scherer Matthew , Winkelstein Emily , Marks Kristen , Edlin Brian R
Published: March 2018

Hepatitis C virus (HCV) is a significant public health problem that disproportionately afflicts people who inject drugs. We describe outcomes of HCV treatment co-located within a syringe services program (SSP). Fifty-three participants started therapy, and 91% achieved sustained virologic response. SSPs provide an effective venue for HCV treatment.
Stereovision Co-Registration in Image-Guided Spinal Surgery: Accuracy Assessment Using Explanted Porcine Spines
Authors: Evans Linton , Olson Jonathan D , Cai Yunliang , Fan Xiaoyao , Paulsen Keith D , Roberts David W , Ji Songbai , Lollis S Scott
Published: March 2018

BACKGROUND

Current methods of spine registration for image guidance have a variety of limitations related to accuracy, efficiency, and cost.

OBJECTIVE

To define the accuracy of stereovision-mediated co-registration of a spinal surgical field.

METHODS

A total of 10 explanted porcine spines were used. Dorsal soft tissue was removed to a variable degree. Bone screw fiducials were placed in each spine and high-resolution computed tomography (CT) scanning performed. Stereoscopic images were then obtained using a tracked, calibrated stereoscopic camera system; images were processed, reconstructed, and segmented in a semi-automated manner. A multistart registration of the reconstructed spinal surface with preoperative CT was performed. Target registration error (TRE) in the region of the laminae and facets was then determined, using bone screw fiducials not included in the original registration process. Each spine also underwent multilevel laminectomy, and TRE was then recalculated for varying amounts of bone removal.

RESULTS

The mean TRE of stereovision registration was 2.19 ± 0.69 mm when all soft tissue was removed and 2.49 ± 0.74 mm when limited soft tissue removal was performed. Accuracy of the registration process was not adversely affected by laminectomy.

CONCLUSION

Stereovision offers a promising means of registering an open, dorsal spinal surgical field. In this study, overall mean accuracy of the registration was 2.21 mm, even when bony anatomy was partially obscured by soft tissue or when partial midline laminectomy had been performed.
Beyond skin deep
Authors: Podd Daniel
Published: March 2018

Pressure injuries (previously called pressure ulcers) are a common finding among patients in acute, long-term, or home settings. Numerous pathophysiologic and risk mechanisms factor into the development of pressure injuries. The timely recognition of these injuries is imperative. Many treatments exist for pressure injuries but the focus of patient management should be on preventing injury-related complications.
Effect of Methamphetamine Hydrochloride on Pregnancy Outcome: A Systematic Review and Meta-analysis
Authors: Kalaitzopoulos Dimitrios-Rafail , Chatzistergiou Konstantinos , Amylidi Anna-Lea , Kokkinidis Damianos G. , Goulis Dimitrios G.
Published: March 2018

Background:

Methamphetamine hydrochloride is 1 of the most widespread psycho-stimulants in the world. Nevertheless, its effect on pregnant women and their neonates has not been investigated extensively.

Objective:

To systematically review the literature for the effect of methamphetamine exposure during pregnancy to neonatal and pregnancy outcomes.

Materials and methods:

A meta-analysis of retrospective, case-control studies was conducted. Inclusion criteria were women who have used methamphetamine during pregnancy, determined by self-report, maternal or neonatal urine test, and/or meconium toxicology, compared with control women not taking methamphetamine. Main study outcomes were gestational age at birth, neonatal characteristics (birth weight, head circumference, body length), and prevalence of gestational hypertensive disorders.

Results:

Eight studies involving 626 women taking methamphetamine during pregnancy and 2626 controls were included in the meta-analysis. Pregnancies complicated by the use of methamphetamine resulted in younger gestational age at birth (mean difference [MD] −0.90 weeks, 95% confidence interval [CI] −0.11, −1.69), lower birth weight (MD −245 g, 95% CI −137, −353), head circumference (MD −0.88 cm, 95% CI −0.48, −1.28), body length (MD −0.94 cm, 95% CI −0.55, −1.32), and Apgar score (MD −0.94, 95% CI −0.33, −1.54) compared with control pregnancies. On the contrary, there was no statistical difference on the incidence of pre-eclampsia (risk ratio [RR] 1.77, 95% CI 0.75, 4.14) and hypertensive complications (RR 1.62, 95% CI 0.37, 7.06).

Conclusions:

Use of methamphetamine during pregnancy results in a deterioration of neonatal somatometric characteristics (birth weight, head circumference, body length), but not in excessive pregnancy complications (hypertension).