bluuebunny/crossref_metadata_2025 huggingface dataset:
Failure‐mode analysis of modular multilevel capacitor‐clamped converter for electric vehicle application
Authors: Vidhya S Devi , M Balaji
Published: June 2019

The bi‐directional buck/boost converter is being widely used as bi‐directional DC/DC converter (BDC) in an electric vehicle (EV) traction system owing to its simple topological configuration. The major drawback of this configuration is in the event of failure of any of the power semiconductor devices and the power supply to the load will be interrupted. To overcome the above drawback, this work proposes a modular multilevel capacitor clamped converter (MMCCC) for EV application employing battery and ultracapacitor (UC) as energy storage sources. The battery‐ultracapacitor (UC) combination provides better acceleration capability during high power demands and efficient energy recovery during regenerative braking. The design, control, and failure‐mode analysis of MMCCC are discussed in detail to showcase the merits in terms of conversion gain, modularity, and reconfiguring capability under fault conditions. The high conversion gain owed to the modularity of the topology ascertains optimal stacking of UC thus reducing the weight and cost. Simulation is performed in MATLAB/SIMULINK environment, and hardware prototype is fabricated to validate the simulation results.
Analytical solution for the inductor current of BOOST converter
Authors: Botao Zhang , Qi Wang , Min Zhao , Huan Huang
Published: June 2019

This study proposes an analytical solution for the inductor current of the BOOST converter using the relative inductance as an independent variable based on the relative variable method. First, the expressions of the actual and relative values of current and energy for BOOST circuits are derived, based on the principle of KCL and conservation of energy. Second, three different cases for calculating the minimum and maximum values of the critical inductance are discussed under a variable input voltage. Then, the analytical solutions for inductor current and duty cycle in CCM and DCM are derived by taking the relative inductance as an independent variable. Furthermore, based on the inductor current equations, the authors deduce the analytical solutions for RMS, derivatives of RMS, delta, the maximum and minimum of the inductor current, and the maximum energy of the inductor. Finally, simulation and experimental results are presented to verify those formulas.
Simple soft‐switched phase‐shifted FB converter for reduced voltage stress and negligible duty cycle loss
Authors: Tah Avisha , Lakshmi Narasamma
Published: June 2019

A simple modified configuration of the conventional phase‐shifted full‐bridge (C‐PSFB) converter, phase‐shifted FB converter without filter inductor (PSFB‐w/o‐L) is proposed in this study in order to reduce the peak voltage stress on the rectifier diodes. As the proposed configuration is devoid of filter inductor, it features lighter weight and low cost. As the proposed configuration is achieved eliminating the filter inductor, the maximum voltage that comes across the rectifier diode is limited to the output voltage, thus eliminating the need for snubber circuit. Additionally, the proposed PSFB‐w/o‐L has the advantage of negligible duty cycle loss. A comprehensive analysis on the mechanism of the peak voltage problem across the rectifier diode in the C‐PSFB is addressed and the way it is eliminated in the proposed PSFB‐w/o‐L is described. The detailed analysis of the operation and design consideration of the proposed PSFB‐w/o‐L is presented. Simulation and experimental results are presented to verify the analysis.
An optimal self‐excited heating method for biogas production under cold climate
Authors: Yang Hanyu , Zhou Bin , Li Canbing , Huang Sheng , Chen Dawei , Long Xijin , Wei Juan
Published: June 2019

Biogas, as the product of anaerobic fermentation, is one of the main routes to utilize bioenergy. The biogas production rate is determined by lots of factors, of which temperature determines most. However, when operating in the cold climate or cold areas, the low digesting temperature often results in a relatively low efficiency or even a suspension in the fermentation process. This paper proposes a self‐excited heating method to increase the digesting temperature in cold weather. It utilizes the self‐produced biogas as fuel to generate heat for heating the biogas digester. The influence of this method on biogas production rate and digesting temperature are verified in this study. The results show that the digesting temperature increases about 3%–9% with a self‐excited heating method for both household‐scaled biogas digester and industry‐scaled digester.
Fast and accurate estimation of multifrequency signals with noise and harmonics in control of photovoltaic systems
Authors: Kania Dariusz , Borkowski Jozef
Published: June 2019

Photovoltaic systems are the important part of the energy market in many countries around the world. Such systems contain several parts and one of them is the inverter to produce the AC signal. In this paper, an estimation method is used to obtain the value of frequency, amplitude and phase of the grid signal used to drive the inverter in a proper way. The method is based on the 3‐point spectrum interpolation and I class Rife‐Vincent time windows. The tested signal contains harmonics and AWGN noise to reflect real and practical measurement conditions. Additionally, simulations were performed for various values of measurement parameters to show broadly properties of the method. The estimation time is only up to two CiR (cycles of the signal in the measurement window). Harmonic components and noise negatively affect the accuracy but the method is so flexible that it can be adjusted to the needs of a current estimation. The estimation error for SNR  = 50–60 dB and for two additional harmonics is in the order of approximately 10−3.
Network studies for a 100% converter‐based power system
Authors: Thakurta Priyanko Guha , Flynn Damian
Published: June 2019

Electricity generation is largely dominated by conventional generators powered by fossil fuels. However, current trends are shifting towards installing renewable energy generation sources, such as wind and solar. Modern wind generators employ a converter in order to feed the generated power into the grid at the fundamental grid frequency. A converter is also required for solar generation for the same reason, converting DC to AC. In a 100% converter interfaced generation (CIG) based grid the existing operational rules regarding network security and system stability need to be re‐defined, whereby converter controls should be developed which replace the system services traditionally provided by synchronous machines. This paper highlights the challenges associated with operating a 100% CIG‐based system and the associated network locational issues required to maintain a stable system.
Thermal and economic optimisation of windfarm export cable
Authors: Pilgrim James , Kelly Sean
Published: June 2019

A method is proposed for the economic optimisation of offshore wind cable connections through utilising the thermal inertia of the cable system. Taking account of expected wind yields, turbine reliability, and the dynamic thermal environment, the method determines the economically optimal number of turbines for a given export cable system. Analysis has shown that, providing means to actively curtail generation output so as to thermally protect the cable are in place, it is possible to reduce the cost of energy delivered to shore by up to £1/MWhr through the use of ‘over‐planting’, i.e. building a wind farm that is larger than the continuous rating of its export cables.
Reducing voltage fluctuations using DSTATCOMs and reactive power of PV inverters in a medium voltage distribution system
Authors: Hung Duong Quoc , Mishra Yateendra , Walker Geoffrey
Published: June 2019

This paper proposes local reactive power control to mitigate the voltage fluctuation in medium‐voltage systems using DSTATCOMs and photovoltaic (PV) inverters. New expressions are developed to estimate voltage fluctuations and reactive power compensations by transforming line segment power‐flow variables into nodal power injections. Using local measurements of voltages and solar powers, the method can provide a fast estimation of reactive power compensations to maintain the voltage at every bus. DSTATCOMs are also properly allocated to enhance the voltage controllability. Coordinated control of multiple reactive power resources is investigated as well. One‐second solar irradiance along with one‐minute home loads is used to demonstrate the effectiveness of the proposed method.
Enhancing the fault ride through capability of DFIG‐based wind energy system using saturated core fault current limiter
Authors: Tripathi Prashant Mani , Sekhar Sahoo Subhendu , Chatterjee Kalyan
Published: June 2019

Doubly fed induction generator (DFIG) is the most popular machine for the wind power application that consists of the ability for variable speed operation and reactive power control with the help of power electronics converters. It is one of the prominent system that follows grid code requirement as it remains connected with the grid even during the fault occurrence. For making the DFIG continuity in the grid, low‐voltage ride through or fault ride through (FRT) techniques are used. Fault current limiter is one of the major schemes used under the FRT. A saturated core fault current limiter (SCFCL) is used in DFIG system to enhance the FRT capability. The main property of SCFCL is the change in permeability between the saturated and unsaturated conditions of the magnetic core to concurrently provide low steady‐state impedance and high transient fault impedance for limiting the fault current.
Development of low translator mass linear Vernier machine for wave energy power take off
Authors: Raihan Mohammad A.H. , Baker Nick J. , Smith Kris J. , Almoraya Ahmed A.
Published: June 2019

This article proposes a new topology of double‐sided linear Vernier permanent magnet (LVPM) machine with segmented translator structure. A combination of a typical Halbach array consists of two horizontally magnetised permanent magnets (PMs) sandwiched between a salient iron tooth and adjacent vertically magnetised PM pole with the aim of improving its electromagnetic performance. The coreless partitioned translator contributes to a significant reduction in mass and the associated cost. With the aid of finite element analysis (FEA), two LVPM machines with the same PM, and stator volume have been investigated, analysed, and compared. The results imply that the proposed LVPM is capable of producing higher force density, while it exhibits lower cogging force and force ripple compared to its counterpart.
Connecting planet formation and astrochemistry
Authors: Cridland Alexander J. , Eistrup Christian , van Dishoeck Ewine F.
Published: June 2019

Combining a time-dependent astrochemical model with a model of planet formation and migration, we compute the carbon-to-oxygen ratio (C/O) of a range of planetary embryos starting their formation in the inner solar system (1–3 AU). Most of the embryos result in hot Jupiters (M ≥ MJ, orbital radius <0.1 AU) while the others result in super-Earths at wider orbital radii. The volatile and ice abundance of relevant carbon and oxygen bearing molecular species are determined through a complex chemical kinetic code that includes both gas and grain surface chemistry. This is combined with a model for the abundance of the refractory dust grains to compute the total carbon and oxygen abundance in the protoplanetary disk available for incorporation into a planetary atmosphere. We include the effects of the refractory carbon depletion that has been observed in our solar system, and posit two models that would put this missing carbon back into the gas phase. This excess gaseous carbon then becomes important in determining the final planetary C/O because the gas disk now becomes more carbon rich relative to oxygen (high gaseous C/O). One model, where the carbon excess is maintained throughout the lifetime of the disk results in hot Jupiters that have super-stellar C/O. The other model deposits the excess carbon early in the disk life and allows it to advect with the bulk gas. In this model the excess carbon disappears into the host star within 0.8 Myr, returning the gas disk to its original (substellar) C/O, so the hot Jupiters all exclusively have substellar C/O. This shows that while the solids tend to be oxygen rich, hot Jupiters can have super-stellar C/O if a carbon excess can be maintained by some chemical processing of the dust grains. The atmospheric C/O of the super-Earths at larger radii are determined by the chemical interactions between the gas and ice phases of volatile species rather than the refractory carbon model. Whether the carbon and oxygen content of the atmosphere was accreted primarily by gas or solid accretion is heavily dependent on the mass of the atmosphere and where in the disk the growing planet accreted.
Nonthermal emission from the reverse shock of the youngest Galactic supernova remnant G1.9+0.3
Authors: Brose R. , Sushch I. , Pohl M. , Luken K. J. , Filipović M. D. , Lin R.
Published: June 2019

Context. The youngest Galactic supernova remnant G1.9+0.3 is an interesting target for next-generation gamma-ray observatories. So far, the remnant is only detected in the radio and the X-ray bands, but its young age of ≈100 yr and inferred shock speed of ≈14 000 km s−1 could make it an efficient particle accelerator.

Aims. We aim to model the observed radio and X-ray spectra together with the morphology of the remnant. At the same time, we aim to estimate the gamma-ray flux from the source and evaluate the prospects of its detection with future gamma-ray experiments.

Methods. We performed spherical symmetric 1D simulations with the RATPaC code, in which we simultaneously solved the transport equation for cosmic rays, the transport equation for magnetic turbulence, and the hydro-dynamical equations for the gas flow. Separately computed distributions of the particles accelerated at the forward and the reverse shock were then used to calculate the spectra of synchrotron, inverse Compton, and pion-decay radiation from the source.

Results. The emission from G1.9+0.3 can be self-consistently explained within the test-particle limit. We find that the X-ray flux is dominated by emission from the forward shock while most of the radio emission originates near the reverse shock, which makes G1.9+0.3 the first remnant with nonthermal radiation detected from the reverse shock. The flux of very-high-energy gamma-ray emission from G1.9+0.3 is expected to be close to the sensitivity threshold of the Cherenkov Telescope Array. The limited time available to grow large-scale turbulence limits the maximum energy of particles to values below 100 TeV, hence G1.9+0.3 is not a PeVatron.
Indications of non-conservative mass transfer in AMXPs
Authors: Marino A. , Di Salvo T. , Burderi L. , Sanna A. , Riggio A. , Papitto A. , Del Santo M. , Gambino A. F. , Iaria R. , Mazzola S. M.
Published: June 2019

Context. Since the discovery of the first accreting millisecond X-ray pulsar (AMXP) SAX J1808.4−3658 in 1998, the family of these sources has kept growing. Currently, it has 22 members. All AMXPs are transients with usually very long quiescence periods, implying that the mass accretion rate in these systems is quite low and not constant. Moreover, for at least three sources, a non-conservative evolution was also proposed.

Aims. Our purpose is to study the long term averaged mass-accretion rates in all the AMXPs discovered so far, to investigate a non-conservative mass-transfer scenario.

Methods. We calculated the expected mass-transfer rate under the hypothesis of a conservative evolution based on their orbital periods and on the (minimum) mass of the secondary star (as derived from the mass function), driven by gravitational radiation and/or magnetic braking. Using this theoretical mass transfer, we determined the expected accretion luminosity of the systems. Thus, we achieved the lower limit to the distance of the sources by comparing the computed theoretical luminosity and the observed flux averaged over a time period of 20 years. Then, the lower limit to the distance of the sources was compared to the value of the distance reported in the literature to evaluate how reasonable the hypothesis of a conservative mass transfer is.

Results. Based on a sample of 18 sources, we found strong evidence of a non-conservative mass transfer for five sources, for which the estimated distance lower limits are higher than their known distances. We also report hints of mass outflows in a further six sources. The discrepancy can be fixed under the hypothesis of a non-conservative mass transfer in which a fraction of the mass transferred onto the compact object is swept away from the system, likely due to the (rotating magnetic dipole) radiation pressure of the pulsar.
Massive dust clumps in the envelope of the red supergiant VY Canis Majoris
Authors: Kamiński T.
Published: June 2019

The envelope of the red supergiant VY CMa has long been considered an extreme example of episodic mass loss that is possibly taking place in other cool and massive evolved stars. Recent (sub-)millimeter observations of the envelope revealed the presence of massive dusty clumps within 800 mas of the star and reinforce the picture of drastic mass-loss phenomena in VY CMa. We present new ALMA observations at an angular resolution of 0.1″ and at an unprecedented sensitivity that reveal further details about the dusty clumps. We resolve more discrete features and identify a submillimeter counterpart of a more distant Southwest (SW) Clump known from visual observations. The brightest clump, named C, is marginally resolved in the observations. Gas seen against the resolved continuum emission of clump C produces a molecular spectrum in absorption, in lines of mainly sulfur-bearing species. Except for SW Clump, no molecular emission is found to be associated with the dusty clumps and we propose that the dusty structures have an atypically low gas content. We attempt to reproduce the properties of the dusty clumps through 3D radiative transfer modeling. Although a clump configuration explaining the observations is found, it is not unique. A very high optical depth of all clumps to the stellar radiation makes the modeling very challenging, and requires an unrealistically high dust mass for one of the clumps. We suggest that the dusty features have substructures (e.g., porosity) that allow deeper penetration of stellar photons within the clumps than in a homogeneous configuration. A comparison of the estimated clump ages to variations in the stellar visual flux for over a century suggests that the mechanism responsible for their formation is not uniquely manifested by enhanced or strongly diminished visual light. The study demonstrates that the dusty mass-loss episodes of VY CMa are indeed unparalleled among all known non-explosive stars. The origin of these episodes remains an unsolved problem.
Discovery of the first heavily obscured QSO candidate at z > 6 in a close galaxy pair
Authors: Vito F. , Brandt W. N. , Bauer F. E. , Gilli R. , Luo B. , Zamorani G. , Calura F. , Comastri A. , Mazzucchelli C. , Mignoli M. , Nanni R. , Shemmer O. , Vignali C. , Brusa M. , Cappelluti N. , Civano F. , Volonteri M.
Published: June 2019

While theoretical arguments predict that most of the early growth of supermassive black holes (SMBHs) happened during heavily obscured phases of accretion, current methods used for selecting z >  6 quasars (QSOs) are strongly biased against obscured QSOs, thus considerably limiting our understanding of accreting SMBHs during the first gigayear of the Universe from an observational point of view. We report the Chandra discovery of the first heavily obscured QSO candidate in the early universe, hosted by a close (≈5 kpc) galaxy pair at z = 6.515. One of the members is an optically classified type-1 QSO, PSO167–13. The companion galaxy was first detected as a [C II] emitter by Atacama large millimeter array (ALMA). An X-ray source is significantly (P = 0.9996) detected by Chandra in the 2–5 keV band, with < 1.14 net counts in the 0.5–2 keV band, although the current positional uncertainty does not allow a conclusive association with either PSO167–13 or its companion galaxy. From X-ray photometry and hardness-ratio arguments, we estimated an obscuring column density of NH >  2 × 1024 cm−2 and NH >  6 × 1023 cm−2 at 68% and 90% confidence levels, respectively. Thus, regardless of which of the two galaxies is associated with the X-ray emission, this source is the first heavily obscured QSO candidate at z >  6.
Umsetzungshilfe zu methodischen Kriterien des CONSORT-Statements zur transparenten Publikation von RCTs in der Augenheilkunde
Authors: Baulig Christine , Knippschild Stephanie , Krummenauer Frank
Published: June 2019

Das CONSORT-Statement (Consolidated Standards of Reporting Trials) stellt eine evidenzbasierte Minimalempfehlung für die standardisierte Berichterstattung randomisierter Studien (RCT) dar. Entlang einer Checkliste aus 25 Kriterien zu redaktionellen, regulatorischen und methodischen Determinanten einer RCT ermöglicht die Anleitung deren strukturierte und standardisierte Berichtung; besonderes Augenmerk gilt dabei der Charakterisierung von Designs und Ergebnissen mit Blick auf deren Generalisierbarkeit. Ziel der Anleitung ist eine vollständige und transparente Berichterstattung, um für Leser eine kritische Bewertung und Interpretation der zugrunde liegenden Studiendaten sicherzustellen. In der Realität zeigt sich jedoch immer wieder, dass vor allem die Umsetzung der methodischen Kriterien dieser Checkliste für publizierende Arbeitsgruppen eine Herausforderung darstellt. Hierzu soll mit der folgenden Übersicht eine illustrierte Anleitung zu Mindestangaben zu methodischen Determinanten von Design und Ergebnisdarstellung sowie deren möglicher Ausführung gegeben werden.
Differenzialdiagnostik entzündlicher Gelenkschmerzen und-schwellungen im Kindesalter
Authors: Klein Ariane , Horneff Gerd
Published: June 2019

Kindliche Gelenkbeschwerden zählen zu den häufigsten Symptomen, die zur Vorstellung beim Kinderarzt führen. Entzündliche Gelenkerkrankungen sind im Kindesalter insgesamt nicht selten. Es werden nach dem zeitlichen Verlauf akute und chronische Arthritiden unterschieden, sowie Arthritiden im Rahmen von Systemerkrankungen. Akute Arthritiden schließen die septische Arthritis, Coxitis fugax und andere postinfektiöse selbstlimitierende Arthritiden ein, ebenso das rheumatische Fieber und die Lyme-Arthritis. Die häufigste chronische Gelenkerkrankung mit einer über zumindest 6 Wochen persistierende Arthritis ist die juvenile idiopathische Arthritis, die in 7 Kategorien eingeteilt wird: Oligoarthritis, rheumafaktorpositive und -negative Polyarthritis, systemische Arthritis/Still-Syndrom, enthesitisassozierte Arthritis, Psoriasisarthritis und unklassifizierte Arthritis. Arthritiden sind auch eine häufige Manifestation bei rheumatischen Systemerkrankungen, bei Vaskulitiden und bei den autoinflammatorischen Erkrankungen vor. Diese Arbeit gibt einen Einblick in die Differenzialdiagose bei Arthritiden im Kindesalter.
Differenzialdiagnostik intermittierender Fieberschübe im Kindesalter
Authors: Horneff Gerd
Published: June 2019

Fiebersyndrome und autoinflammatorische Erkrankungen sind eine Gruppe von erblichen und nicht-erblichen Erkrankungen des angeborenen Immunsystems, gekennzeichnet durch wiederkehrende Entzündungen, scheinbar grundlos, in regelmäßigen oder unregelmäßigen Zeitabständen und Manifestationen an Haut, Schleimhäuten, Gelenken, Knochen, Magen-Darm-Trakt aber auch Gefäßen und ZNS. Amyloidose und andere mögliche schwere langfristige Komplikationen sind von Bedeutung. Fortschritte in der Genetik und Molekularbiologie haben das Verständnis der Pathogenese dieser Erkrankungen verbessert. Pathogenetisch sind unterschiedliche Entzündungswege, wie Interleukin-1-, Interferon-, NF-Kappa-B-vermittelte oder andere Wege bedeutsam. Der Zweck dieser Darstellung ist es nicht nur das Bewusstsein für die mittlerweile zahlreichen autoinflammatorischen Syndrome zu stärken, sondern auch differentialdiagnostisch Wege aufzuzeigen. Die finale Diagnose wird im Zeitalter der Genetik sicher häufig genetisch verifiziert, doch gibt die Klinik wichtige Hinweise auf die wahrscheinliche Diagnose. Leitsymptom ist das wiederkehrende Fieber, doch kann dies bei zahlreichen autoinflammatorischen Syndromen fehlen. Haut- und Schleimhautmanifestationen, psoriatiforme und pustulöse, sowie Urtikaria, eine Livedo oder Knoten können wegweisend sein.
Direct Synthesis of 1-Arylprop-1-ynes with Calcium Carbide as an Acetylene Source
Authors: Gao Lei , Li Zheng
Published: June 2019

A simple method is described for the synthesis of 1-arylprop-1-ynes directly from aromatic aldehyde p-tosylhydrazones by using calcium carbide as an acetylene source. The salient features of this protocol are its use of a readily available and easily handled source of acetylene, its operational simplicity, its high yield, and its broad substrate scope.
Repair of Y-T Humeral Condyle Fractures with Locking Compression Plate Fixation
Authors: Moffatt Felicity , Kulendra Elvin , Meeson Richard L.
Published: June 2019

Objectives The aim of this study was to describe the use of locking compression plates (LCP) in Y-T humeral condyle fractures and to evaluate their clinical outcome.

Methods This study involved a retrospective review, including clinical, radiographical and canine brief pain inventory outcome evaluation.

Results Eighteen consecutive dogs met the inclusion criteria, and 15/18 were considered to have humeral intracondylar fissure. Twelve of 18 dogs had simple fractures, and the remaining six had comminuted fractures. Postoperative radiographs revealed accurate intracondylar reconstruction (articular step defect [ASD] < 1 mm) in 17/18 of patients. Short-term outcome was considered fully functional in 9/13 and acceptable in 3/13 patients. Complications were diagnosed in 2/13; infection in one with resolution after antibiotic treatment, and one case of implant failure. Nine of 18 owners provided postoperative questionnaire responses (median 25; range: 14–52 months) and 8/9 clients perceived the treatment to have resulted in an excellent overall outcome.

Clinical significance Repair of Y-T humeral fractures with LCP allowed for hybrid fixation and monocortical screw placement in distal fracture fragments. There was no significant ASD at the intracondylar fracture line in most cases. ASD using combined medial and lateral approaches depends upon the accuracy of supracondylar reduction, particularly on the side that is reduced and stabilized first, and the use of locking screws may have been influential in minimizing primary loss of reduction, potentially maintaining the initial fragment reduction.
Challenges and Opportunities to Improve the Clinician Experience Reviewing Electronic Progress Notes
Authors: Hultman Gretchen M. , Marquard Jenna L. , Lindemann Elizabeth , Arsoniadis Elliot , Pakhomov Serguei , Melton Genevieve B.
Published: June 2019

Background High-quality clinical notes are essential to effective clinical communication. However, electronic clinical notes are often long, difficult to review, and contain information that is potentially extraneous or out of date. Additionally, many clinicians write electronic clinical notes using customized templates, resulting in notes with significant variability in structure. There is a need to understand better how clinicians review electronic notes and how note structure variability may impact clinicians' note-reviewing experiences.

Objective This article aims to understand how physicians review electronic clinical notes and what impact section order has on note-reviewing patterns.

Materials and Methods We conducted an experiment utilizing an electronic health record (EHR) system prototype containing four anonymized patient cases, each composed of nine progress notes that were presented with note sections organized in different orders to different subjects (i.e., Subjective, Objective, Assessment, and Plan, Assessment, Plan, Subjective, and Objective, Subjective, Assessment, Objective, and Plan, and Mixed). Participants, who were mid-level residents and fellows, reviewed the cases and provided a brief summary after reviewing each case. Time-related data were collected and analyzed using descriptive statistics. Surveys were administered and interviews regarding experiences reviewing notes were collected and analyzed qualitatively.

Results Qualitatively, participants reported challenges related to reviewing electronic clinical notes. Experimentally, time spent reviewing notes varied based on the note section organization. Consistency in note section organization improved performance (e.g., less scrolling and searching) compared with Mixed section organization when reviewing progress notes.

Discussion Clinicians face significant challenges reviewing electronic clinical notes. Our findings support minimizing extraneous information in notes, removing information that can be found in other parts of the EHR, and standardizing the display and order of note sections to improve clinicians' note review experience.

Conclusion Our findings support the need to improve EHR note design and presentation to support optimal note review patterns for clinicians.
Current and Emerging Direct Oral Anticoagulants: State-of-the-Art
Authors: Lippi Giuseppe , Gosselin Robert , Favaloro Emmanuel J.
Published: June 2019

Anticoagulant drugs comprise a specific subcategory of antithrombotic agents that act to inhibit blood coagulation at various stages, reducing clot development and ultimately lowering the risk of developing new-onset or recurrent thrombosis. Although the long history of anticoagulant drugs has been characteristically shaped by coumarin and heparin derivatives, a new generation of direct oral anticoagulants (DOACs), which specifically inhibit thrombin or activated factor X, combine many advantages of their progenitor drugs, and hence are prepotently revolutionizing the landscape of antithrombotic therapy. Several drugs (apixaban [BMS-562247], dabigatran [BIBR953], edoxaban [DU-1766], rivaroxaban [BAY 59–7939]) have already received widespread approval by national or supranational medicinal agencies. This narrative article provides a state-of-the-art for these and for several other DOACs at different stages of clinical evaluation (betrixaban, darexaban, eribaxaban, letaxaban, nokxaban), and certain others whose development has been discontinued (AZD-0837, fidexaban, LY517717, odiparcil, otamixaban, TTP889, and ximelagatran). What clearly emerges from our analysis is that DOACs sharing very similar mechanisms of action are still characterized by different efficacy and safety profiles. This not only depends on biochemical, biological, and pharmacokinetic characteristics, but also on lack of standardization between different clinical trials in terms of targeted disease, patient recruitment, sample size, duration and endpoints, as well as lack of harmonization around procedures used for drug licensing. These factors contribute to challenging the minds of physicians, who may find difficulty navigating their way through multiple indications, different pharmacological profiles, various side effects, and specific drug-to-drug interactions. Such considerations also burden laboratory professionals, who may face organizational and economic challenges in developing and/or implementing multiple assays to assess the pharmacodynamics (effect on coagulation) or pharmacokinetics (drug levels) of DOACs.
Prediction models of bit errors for NAND flash memory using 200 days of measured data
Authors: Wei Debao , Qiao Liyan , Chen Xiaoyu , Feng Hua , Peng Xiyuan
Published: June 2019

NAND flash memory, with its excellent storage performance, has become a leader in storage media for scientific instruments. With improvements in the manufacturing technique, its reliability is decreasing. Thus, methods for improving the storage reliability of scientific instruments has become a major topic. If a method to effectively evaluate NAND flash error distribution is found, it will provide significant guidance for error correction codes and the wear equalization algorithm to improve the performance of NAND flash memory. It will also be a good method to predict the flash memory life. Based on data measured over 200 days from an experimental platform for the NAND flash, in this study, the polynomial fitting method, an artificial neural network, and a support vector regression were adopted to build a NAND flash bit errors prediction model, and efficacies of the methods are compared. The simulation results show that the different evaluation models have their own advantages in different situations.
Shear-rate dependence of thermodynamic properties of the Lennard-Jones truncated and shifted fluid by molecular dynamics simulations
Authors: Lautenschlaeger Martin P. , Hasse Hans
Published: June 2019

It was shown recently that using the two-gradient method, thermal, caloric, and transport properties of fluids under quasi-equilibrium conditions can be determined simultaneously from nonequilibrium molecular dynamics simulations. It is shown here that the influence of shear stresses on these properties can also be studied using the same method. The studied fluid is described by the Lennard-Jones truncated and shifted potential with the cut-off radius rc* = 2.5σ. For a given temperature T and density ρ, the influence of the shear rate on the following fluid properties is determined: pressure p, internal energy u, enthalpy h, isobaric heat capacity cp, thermal expansion coefficient αp, shear viscosity η, and self-diffusion coefficient D. Data for 27 state points in the range of T ∈ [0.7, 8.0] and ρ ∈ [0.3, 1.0] are reported for five different shear rates (γ̇ ∈ [0.1,1.0]). Correlations for all properties are provided and compared with literature data. An influence of the shear stress on the fluid properties was found only for states with low temperature and high density. The shear-rate dependence is caused by changes in the local structure of the fluid which were also investigated in the present work. A criterion for identifying the regions in which a given shear stress has an influence on the fluid properties was developed. It is based on information on the local structure of the fluid. For the self-diffusivity, shear-induced anisotropic effects were observed and are discussed.
On the drag reconfiguration of plates near the free surface
Authors: Satheesh Sukruth , Huera-Huarte Francisco J.
Published: June 2019

Rectangular foils of different flexural rigidities were towed normal to the flow at a fixed speed in a quiescent fluid in order to study the effect of the proximity of the upper edge of the models to free surface. It was found that flexibility ensured drag reduction due to the reconfiguration process at all submergence depths, with certain foils exhibiting depth-independent behavior. The study of Vogel exponents also showed that a sublinear or even a depth independent relationship between drag and velocity can be attained at specific flexural rigidity values. A modified classical beam theory model using a power-law based load distribution was utilized to obtain an empirical relationship between the loading exponent and Cauchy numbers and to identify the foil tip location. Particle image velocimetry was also undertaken to interpret and further understand the force results. The experiments showed the existence of 2 ranges of Cauchy numbers with a small degree of overlap in ranges wherein the drag coefficient and Vogel exponents are independent of submergence depth.
Message-passing neural networks for high-throughput polymer screening
Authors: St. John Peter C. , Phillips Caleb , Kemper Travis W. , Wilson A. Nolan , Guan Yanfei , Crowley Michael F. , Nimlos Mark R. , Larsen Ross E.
Published: June 2019

Machine learning methods have shown promise in predicting molecular properties, and given sufficient training data, machine learning approaches can enable rapid high-throughput virtual screening of large libraries of compounds. Graph-based neural network architectures have emerged in recent years as the most successful approach for predictions based on molecular structure and have consistently achieved the best performance on benchmark quantum chemical datasets. However, these models have typically required optimized 3D structural information for the molecule to achieve the highest accuracy. These 3D geometries are costly to compute for high levels of theory, limiting the applicability and practicality of machine learning methods in high-throughput screening applications. In this study, we present a new database of candidate molecules for organic photovoltaic applications, comprising approximately 91 000 unique chemical structures. Compared to existing datasets, this dataset contains substantially larger molecules (up to 200 atoms) as well as extrapolated properties for long polymer chains. We show that message-passing neural networks trained with and without 3D structural information for these molecules achieve similar accuracy, comparable to state-of-the-art methods on existing benchmark datasets. These results therefore emphasize that for larger molecules with practical applications, near-optimal prediction results can be obtained without using optimized 3D geometry as an input. We further show that learned molecular representations can be leveraged to reduce the training data required to transfer predictions to a new density functional theory functional.
Correcting long-range electrostatics in DFTB
Authors: Podeszwa Rafał , Jankiewicz Wojciech , Krzuś Magdalena , Witek Henryk A.
Published: June 2019

We demonstrate that the atom-based charge model implemented in the current versions of the density functional tight binding (DFTB) method fails to reproduce the correct charge distribution of a range of systems, including homonuclear molecules, graphene, and nanotubes, resulting in serious distortions in the electrostatic interactions for such systems caused by the missing quadrupole moments. In particular, this failure seriously impacts the long- and medium-range interaction energies of the DFTB plus dispersion (DFTB-D) model, leading to incorrect predictions of translational or rotational barriers in such systems. We show explicitly on examples of H2 and N2 that correct quadrupole moments—and consequently correct electrostatic interactions—can be restored in such systems by adding additional bond (ghost) sites to the homonuclear molecules. Attempts to determine the point charges associated with the additional sites using the usual Mulliken population analysis lead to unphysical results. Instead, these charges can be determined using the actual DFTB densities used in the parameterization process. For homonuclear molecules, we propose an extension to the DFTB-D model by adding charges that reproduce the physically correct quadrupolar charge distribution. The resulting DFTB-D-Q model greatly improves the rotational barriers for interactions of molecular hydrogen and nitrogen with benzene.
High frequency realization of non-autonomous nonlinear transistor circuit
Authors: Rhea Benjamin K. , Perkins Edmon , Dean Robert N.
Published: June 2019

In this paper, an electronic implementation of a non-autonomous nonlinear transistor circuit is presented. This nonlinear circuit topology requires a minimal number of components, which consists of two resistors, two capacitors, and a single NPN bipolar junction transistor (BJT). This topology is of interest because it is relatively simple to construct and could be used for potential applications such as random number generators (RNGs) or noise signal generators (NSGs). The transistor portion of the circuit was analyzed using the Ebers-Moll model for a BJT. Using this model, time domain and phase space plots that qualitatively match the original systems dynamics were created. This model was also used to create bifurcation diagrams of the base voltage versus both frequency and amplitude, where periodic and chaotic solutions exist. The hardware realization was built using commercial-off-the-shelf (COTS) components with two different printed circuit board (PCB) designs. This PCB included the forcing function on the board with the transistor circuit. This circuit topology functioned over a wide range of frequencies, with an upper limit of approximately 5.1 MHz. Many potential applications could benefit from this high operation frequency.
Nanoparticle-based local translation reveals mRNA as a translation-coupled scaffold with anchoring function
Authors: Kashida Shunnichi , Wang Dan Ohtan , Saito Hirohide , Gueroui Zoher
Published: June 2019

Significance

The spatial regulation of messenger RNA (mRNA) translation is central to cellular functions, yet no current approach has achieved the spatial control of mRNAs to reveal the direct causality between local translation and cellular processes. Here, we develop a biomimetic control system that bypasses endogenous complex processes to analyze this relationship. We demonstrate the magnetic manipulation of mRNA conjugated to nanoparticles to spatially control translation-based protein synthesis. We examined how physical constraints can shape mRNA translation and identify a mechanism of spatial control. We found the general principles underlying the spatial regulation of actin cytoskeleton patterns by local translation. From a biological perspective, this phenomenon may represent a general mechanism of spatial control that cells use to produce functional diversity.
The purine biosynthesis regulator PurR moonlights as a virulence regulator in
Staphylococcus aureus
Authors: Sause William E. , Balasubramanian Divya , Irnov Irnov , Copin Richard , Sullivan Mitchell J. , Sommerfield Alexis , Chan Rita , Dhabaria Avantika , Askenazi Manor , Ueberheide Beatrix , Shopsin Bo , van Bakel Harm , Torres Victor J.
Published: June 2019

The pathogen
Staphylococcus aureus
colonizes and infects a variety of different sites within the human body. To adapt to these different environments,
S. aureus
relies on a complex and finely tuned regulatory network. While some of these networks have been well-elucidated, the functions of more than 50% of the transcriptional regulators in
S. aureus
remain unexplored. Here, we assess the contribution of the LacI family of metabolic regulators to staphylococcal virulence. We found that inactivating the purine biosynthesis regulator
purR
resulted in a strain that was acutely virulent in bloodstream infection models in mice and in ex vivo models using primary human neutrophils. Remarkably, these enhanced pathogenic traits are independent of purine biosynthesis, as the
purR
mutant was still highly virulent in the presence of mutations that disrupt PurR’s canonical role. Through the use of transcriptomics coupled with proteomics, we revealed that a number of virulence factors are differentially regulated in the absence of
purR
. Indeed, we demonstrate that PurR directly binds to the promoters of genes encoding virulence factors and to master regulators of virulence. These results guided us into further ex vivo and in vivo studies, where we discovered that
S. aureus
toxins drive the death of human phagocytes and mice, whereas the surface adhesin FnbA contributes to the increased bacterial burden observed in the
purR
mutant. Thus,
S. aureus
repurposes a metabolic regulator to directly control the expression of virulence factors, and by doing so, tempers its pathogenesis.
Strain rate-dependent hardening with dislocation-twin interaction of Fe–Mn–Al–C steel using crystal plasticity
Authors: Su Z.X. , Li N. , Sun C.Y. , Zhao J.Q. , Wang C.H. , Qian L.Y.
Published: June 2019

A crystal plasticity finite element model with dislocation-twin interaction was developed to study the strain rate-dependent hardening of Fe–Mn–Al–C twinning-induced plasticity steel. Microstructural state variables including twinning space and dislocation density were incorporated to describe the mechanical twins hindering gliding dislocations. In situ scanning electron microscope tension and electron backscatter diffraction tests were conducted as validation and supplement. Predicted stress and strain hardening rate at various strain rates agree well with the experimental results. The increasing strain hardening stage is attributed to the dynamic competition between deformation twinning and dynamic recovery of dislocations. The intergranular deformation heterogeneity associated with the competitive activities of deformation mechanisms was also studied. The results indicate a larger contribution of slip to overall hardening than twinning.

GRAPHICAL ABSTRACT
Laser pulse-length effects in trident pair production
Authors: Hernandez Acosta U , Kämpfer B
Published: June 2019

Laser pulses facilitate multiphoton contributions to the trident pair production

e

L

−

→

e

L

−

+

e

L

+

+

e

L

−

, where the label L indicates a laser field dressed electron (e
−) or positron (e
+ ). We isolate the impact of the pulse envelope in the trident S matrix element, formulated within the Furry picture, in leading order of a series expansion in the classical nonlinearity parameter a
0. Generally, the Fourier transform of the envelope carries the information on the pulse length, which becomes an easily tractable function in the case of a

cos

2

pulse envelope. The transition to a monochromatic laser wave can be handled in a transparent manner, as also the onset of bandwidth effects for short pulses can be factorized out and studied separately.
Dicke time crystals in driven-dissipative quantum many-body systems
Authors: Zhu Bihui , Marino Jamir , Yao Norman Y , Lukin Mikhail D , Demler Eugene A
Published: June 2019

The Dicke model—a paradigmatic example of superradiance in quantum optics—describes an ensemble of atoms which are collectively coupled to a leaky cavity mode. As a result of the cooperative nature of these interactions, the system’s dynamics is captured by the behavior of a single mean-field, collective spin. In this mean-field limit, it has recently been shown that the interplay between photon losses and periodic driving of light–matter coupling can lead to time-crystalline-like behavior of the collective spin (Gong et al 2018 Phys. Rev. Lett.
120 040404). In this work, we investigate whether such a Dicke time crystal (TC) is stable to perturbations that explicitly break the mean-field solvability of the conventional Dicke model. In particular, we consider the addition of short-range interactions between the atoms which breaks the collective coupling and leads to complex many-body dynamics. In this context, the interplay between periodic driving, dissipation and interactions yields a rich set of dynamical responses, including long-lived and metastable Dicke-TCs, where losses can cool down the many-body heating resulting from the continuous pump of energy from the periodic drive. Specifically, when the additional short-range interactions are ferromagnetic, we observe time crystalline behavior at non-perturbative values of the coupling strength, suggesting the possible existence of stable dynamical order in a driven-dissipative quantum many-body system. These findings illustrate the rich nature of novel dynamical responses with many-body character in quantum optics platforms.