bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of a Technical Solution on Stress of Surgical Staff in Operating Theatres
Authors: Lehrke Jan , Boos Margarete , Cordes Andreas , Leitsmann Conrad , Friedrich Martin
Published: February 2022

Background Noise in operating theaters (OT) exceeds safety standards with detrimental effects on the health and performance of OT crews as well as patient safety. One of the reasons for these effects is the stress response to noise, which could be minimized by the Silent Operating Theater Optimisation System (SOTOS), a noise-reductive headset solution.

Methods This study evaluates the effects of the SOTOS on the stress perceived by OT crew members, operationalized through stress level and exhaustion. Twenty-one heart surgeries and 32 robot-assisted prostatectomies at the University Medical Center Goettingen, Germany were examined. Twenty-six surgeries were conducted with and 27 without the SOTOS. The SOTOS-effect is defined as a more beneficial stress course from before to after surgery, when comparing the experimental group with and control group without SOTOS.

Findings Eighty-one OT workers were investigated. The linear multilevel models revealed significant interactions between treatment and time of measurement on stress level (F[1, 406.66] = 3.62, p = 0.029) and exhaustion (F[1, 397.62] = 13.12, p = 0.00017). Nevertheless, there was no a significant main effect of surgery type on stress level (F[1, 82.69] = 1.00, p = 0.32) or on exhaustion (F[1, 80.61] = 0.58, p = 0.45). Additionally, no significant three-way interaction including surgery type, for stress level (F[1, 406.66] = 0.32, p = 0.29) or exhaustion (F[1, 397.62] = 0.03, p = 0.43), was found.

Interpretation An SOTOS-effect was confirmed: the development of stress over the course of an operation was beneficially modified by the SOTOS. Both surgery types are perceived as similarly stressful, and the staff benefits equally strongly from the intervention in both settings.
Platelet Function Test in Coronary Artery Bypass Grafting: Does It Predict Postoperative Bleeding?
Authors: Sharan Sandeep , Kapoor Poonam Malhotra , Choudhury Minati , Prakash Mohit , Chowdhury Ujjwal K. , Hote Milind , Ravi Vajala
Published: February 2022

Background Patients undergoing on-pump coronary artery bypass grafting (CABG) are at increased risk of perioperative bleeding and morbidity associated with transfusion as a result of acquired and pharmacologically induced impaired platelet function.

Settings and Design In this a prospective observational study where 52 patients underwent on-pump CABG were analyzed with ROTEM platelet aggregometry.

Materials and Methods Patients were assigned to the “nonexcessive” and “excessive” postoperative bleeding groups according to the postoperative chest tube drainage over 24 hours. Platelet function was assessed by ROTEM platelet using three different activators (arachidonic acid, adenosine diphosphate, and thrombin receptor-activating peptide), at two perioperative time points (T1, before heparinization and T2, 5–10 minutes after protamine administration).

Results There were no differences regarding demographic, pre–cardiopulmonary bypass (CPB) platelet count and antiplatelet therapy. Platelet function was impaired over the time course in all parameters with three different activators. At T2 point, area under the curve (AUC) of all the three platelet indices, that is, TRAPTEM, ARATEM, and ADPTEM, showed significant difference between excessive and nonexcessive groups. At both T1 and T2 points, the amplitude after 6 minutes (A6) and maximum slope (MS) parameters of TRAPTEM, ARATEM, and ADPTEM tests were not significantly different in excessive and nonexcessive groups. At T1 point, AUC was also not significantly different in all three ROTEM platelet tests. Results after protamine administration showed correlation with postoperative chest tube drainage. Cut-off values, as determined by receiver operating characteristics (ROC) analyses, had a consistently weak positive predictive value for all tests at T2 time point, whereas negative predictive values were higher.

Conclusion Platelet function analysis using ROTEM platelet can help to exclude platelet dysfunction as the reason for bleeding after cardiac surgery. Point-of-care platelet function analysis, particularly in combination with viscoelastic testing can reduce perioperative bleeding and transfusion requirements, as well as improve patient outcomes in cardiac surgery.
DKI Krankenhaus Barometer: Kliniken am Limit
Authors: Kucera Martin
Published: February 2022

Das zum Jahresende erschienene aktuelle Krankenhaus Barometer des Deutschen Krankenhausinstituts (DKI) zeichnet ein düsteres Bild der wirtschaftlichen Lage der deutschen Krankenhäuser. Zugespitzt hat sich demzufolge auch die Personalsituation in der Pflege. Vier von fünf Kliniken haben Probleme, offene Stellen auf Allgemein- und Intensivstationen zu besetzen.
kma Entscheider-Blog: Kommt mit der Ampel endlich Besserung für die Pflegeberufe?
Authors: Bechtel Florian
Published: February 2022

Seit dem 9. Dezember 2021 ist die Ampel-Koalition im Amt. Viele haben mit großer Spannung erwartet, worauf sich SPD, Grüne und FDP insbesondere im Bereich Gesundheitswesen und Pflege im Koalitionsvertrag einigen konnten. Denn eines haben die letzten Jahrzehnte gezeigt: Der Markt wird den Fachkräftemangel nicht regeln.
Gesundheitskongress des Westens: Nachhaltige Strukturen immer wichtiger
Authors: Kleine Diana
Published: February 2022

Seit Pandemiebeginn wird deutlich, wie knapp die Ressourcen im Gesundheitswesen sind. Die Frage, wie Finanzen, Rohstoffe, Medikamente, aber auch Fachkräfte nachhaltig eingesetzt werden könnten, rückt zunehmend in den Fokus. Nötig seien strukturelle Veränderungen, sagt Prof. Dr. Wolfgang Greiner.
Mit Kleeblatt gegen Triage: Ein Ventil gegen den Sturm
Authors: König Romy
Published: February 2022

Die Lage ist kritisch im ausgehenden Jahr 2021: Die Covid-19-Fallzahlen steigen, die Intensivabteilungen steuern auf ihre Belastungsgrenze zu, das Wort Triage macht die Runde. Da öffnen Kliniken das letzte Überlaufventil: Sie aktivieren das Kleeblattsystem.
Uniklinik Giessen und Marburg: „Maximalversorgung und Gewinnerwartung passen nicht zusammen“
Authors: März Sigrid
Published: February 2022

Deutschlandweit herrscht in Kliniken Fachkräftemangel, vor allem in der Pflege. Das spürt auch das Universitätsklinikum Gießen und Marburg. Doch was hat, neben der Pandemie, die Privatisierung vor 15 Jahren damit zu tun?
EU-Medizinprodukte-Verordnung (MDR): Über das Ziel hinausgeschossen
Authors: Möll Marc-Pierre
Published: February 2022

Der Start der EU-Medizinprodukte-Verordnung (MDR) im vergangenen Jahr hat zu den im Vorfeld befürchteten Schwierigkeiten geführt. MedTech-Unternehmen und Kliniken brauchen jetzt pragmatische Lösungen für Spezial- und Bestandsprodukte.
Conceptualising attitudes towards brand genuinuity: scale development and validation
Authors: ‘t Hart Brian , Phau Ian
Published: February 2022

This paper aims to conceptualise attitudes towards brand genuinuity by developing and validating a psychometric scale through four studies. Study 1 generates a pool of potential scale items through a review of the literature, thesaurus search, focus groups, and expert surveys. Study 2 confirms the unidimensionality of the scale items using confirmatory factor analysis. Study 3 establishes convergent, discriminant, predictive, and nomological validity. Finally, Study 4 confirms the generalisability of the scale by applying it in a different context. The process resulted in a 5-item unidimensional scale measuring attitudes towards the brand’s genuinuity. The results demonstrated that brand genuinuity is a unique construct, and distinct from related concepts, brand sincerity, and brand heritage. The development and validation of the current scale fill an important gap in the advertising literature. It provides a better understanding of and mechanism to measure attitudes towards brand genuinuity, which could not be measured with previous scales. Likewise, the scale provides important insights for brand managers and will be an important tool for managers to test and confirm the degree to which new advertising material exhibits brand genuinuity.
Experiences of food poverty among undocumented parents with children in three European countries: a multi-level research strategy
Authors: Brannen Julia , O’Connell Rebecca
Published: February 2022

A growing literature addresses undocumented migrants in different countries, with governmental exclusion from welfare and health services a common theme. However, little is known comparatively about the difference social context makes to the resources available to these migrants in different circumstances or how they manage and experience material deprivation and social exclusion. Adopting a realist approach, this paper draws on a comparative study that examined food poverty in low-income families with children aged 11–15 years in the UK, Portugal and Norway following the 2008 financial crisis. It shows the ways in which the study’s multi-tiered research design enabled the analysis of the complex conditions in which parents sought to sustain and feed their families. Undocumented migrants living in extreme conditions constitute ‘test cases’ for examining the specific resources available (or not) to households in different layers of context and the consequences for the ways in which food and food poverty were experienced by children and parents in these contexts. The paper thus contributes to the methodological literature on comparative research, in particular to research design in the field of migration and to knowledge about an under-researched group in an increasingly hostile Europe.
Large-volume magnetic trap for studying ultracold atomic hydrogen
Authors: Thompson Avery
Published: February 2022

Ioffe-Pritchard trap design enables study of large volumes of atomic hydrogen at millikelvin temperatures.
Global model study of plasma parameter variation in helicon plasma source in oxygen discharge
Authors: Sharma N. , Dutta D. , Chakraborty M. , Mukherjee A. , Neog N. K. , Bandyopadhyay M.
Published: February 2022

In this work, different plasma parameters, such as electron density, temperature, and negative ion density are measured in both the source and expansion chamber of the Helicon Plasma Source (HeliPS) in a radio frequency (RF) oxygen discharge of 13.56 MHz and are compared with the values obtained numerically using the volume-averaged global model. For this purpose, the global model of RF oxygen discharge suitable for the HeliPS having two chambers (source and expansion) together with the electromagnet in the source chamber and the magnetic cage in the expansion chamber to reduce the radial loss of plasma is developed using the particle and power balance equations. In this model, the radial confinement by the axial field of the electromagnet in the source chamber and the confinement in the expansion chamber by the cusped field of the magnetic cage is incorporated. Studies on the charged particle dynamics by both the model and the experiment show comparable values of the variation of species density and electron temperature with RF power and working pressure as well as with the applied magnetic field of the electromagnet in the source chamber.
Proton deflectometry with in situ x-ray reference for absolute measurement of electromagnetic fields in high-energy-density plasmas
Authors: Johnson C. L. , Malko S. , Fox W. , Schaeffer D. B. , Fiksel G. , Adrian P. J. , Sutcliffe G. D. , Birkel A.
Published: February 2022

We report a technique of proton deflectometry that uses a grid and an in situ reference x-ray grid image for precise measurements of magnetic fields in high-energy-density plasmas. A D3He fusion implosion provides a bright point source of both protons and x-rays, which is split into beamlets by a grid. The protons undergo deflections as they propagate through the plasma region of interest, whereas the x-rays travel along straight lines. The x-ray image, therefore, provides a zero-deflection reference image. The line-integrated magnetic fields are inferred from the shifts of beamlets between the deflected (proton) and reference (x-ray) images. We developed a system for analysis of these data, including automatic algorithms to find beamlet locations and to calculate their deflections from the reference image. The technique is verified in an experiment performed at OMEGA to measure a nonuniform magnetic field in vacuum and then applied to observe the interaction of an expanding plasma plume with the magnetic field.
Detection of sub-micrometer thermomechanical and thermochemical failure mechanisms in titanium with a laser-based thermoreflectance technique
Authors: Quiambao-Tomko Kathleen , White Richard R. , Tomko John A. , Rost Christina M. , Backman Lavina , Opila Elizabeth J. , Hopkins Patrick E.
Published: February 2022

This work reports on a pump–probe laser-based heating and sensing metrology to study the failure mechanisms of materials during extreme heat fluxes localized near surfaces, the localization of which is controlled by the focus of the laser beam and sensed by the reflection of a secondary probe laser. We focus the demonstration of these power density at failure tests on the damage mechanisms of commercially pure titanium metal during and after high heat fluxes induced from the absorbed laser energy. Using this steady-state thermoreflectance pump–probe metrology, a localized region of the material was irradiated at a low modulated frequency, while the average change in the thermoreflectance signal was monitored. We observe surface and cross-sectional oxidation of the titanium, revealing correlations between microstructural evolution events and shifts in thermoreflectance trends as a function of absorbed power density. Furthermore, the damage morphology was shown to be heavily influenced by the size of the heater (dictated by the radius of the pump laser beam), which controlled the relative degree of thermomechanical, melting, and oxidative decohesion failure mechanisms in the samples. The analysis of the temperature distribution coupled with the observed microstructural damage gives rise to a high-throughput experimental technique to induce desired deformation modes through cyclic thermal testing.
Wind turbine power prediction based on wind energy utilization coefficient and multivariate polynomial regression
Authors: Niu Wangqiang , Huang Jiaying , Yang Huajian , Wang Xiaotong
Published: February 2022

The power curve can reflect the overall generation performance of wind turbines. To avoid the difficulty in input feature selection in power curve modeling, based on power extraction of air streams, the blade tip speed ratio and pitch angle are taken as the input variables of wind energy utilization coefficient modeling. First, by analyzing the characteristic curve of a wind turbine, its working state is divided into three phases: constant power, constant speed, and maximum power point tracking phases. Then, aiming at the limitations of neural network in training time, hyperparameter selection, and model interpretation, a multivariate polynomial segmented power prediction method is proposed. Based on the supervisory control and data acquisition (SCADA) data of a 2 MW wind turbine, the expressions of the wind energy utilization coefficient in three phases are given. In the constant power phase and constant speed phase, the wind energy utilization coefficient is quadratic and quintic polynomial about the blade tip speed ratio and pitch angle, respectively. In the maximum power point tracking phase, the wind energy utilization coefficient is a cubic polynomial of the blade tip speed ratio. The results show that, in the four methods (multivariate polynomial regression and neural network power curve modeling with and without segmentation), the segmented polynomial regression method can not only improve the interpretation ability of the model, but also has high accuracy, and the mean absolute percentage error is 6.29%.
Preparation and characterization of multifunctional piezoenergetic polyvinylidene fluoride/aluminum nanocomposite films
Authors: Örnek Metin , Uhlenhake Kyle E. , Zhou Yao , Zhang Bruce , Kalaswad Matias , Collard Diane N. , Wang Haiyan , Wang Qing , Son Steven F.
Published: February 2022

We prepared poly(vinylidene fluoride) (PVDF) and aluminum composite dense films using a tape caster and investigated the microstructural, thermal, and electrical properties and the combustion behavior of the films as a function of nano-aluminum (nAl) solids loading (5–30 wt. %). We found that the addition of nAl facilitates the formation of piezoelectric β and γ phases of PVDF as determined by x-ray diffraction and Fourier transform infrared spectroscopy. At higher nAl solid loadings, the lower onset temperature of the pre-ignition and decomposition reactions have been observed. Moreover, the intentionally incorporated porosity into the films slightly affected the thermal decomposition behavior. While the dielectric constant of the films increases with higher nAl content, the dielectric breakdown strength of the films decreases significantly. The critical active nAl content for the films to exhibit self-propagated reaction was determined to be between 10 and 15 wt. %. Thermochemical calculations using the NASA CEA code showed the maximum flame temperature of 1750 °C near the stoichiometric ratio (∼20 wt. %). The burning rate of the films is enhanced drastically at ambient conditions with further addition of nAl. However, the films with active nAl content over 20 wt. % showed lower flame temperatures, which is due to the reduction of hydrofluoric acid gas generation and the incomplete combustion of Al to form aluminum monofluoride (AlF), instead of aluminum fluoride (AlF3) gas. The fabrication of energetic thin films with tunable properties could enable their use in multifunctional energetic material systems.
In situ radiographic and ex situ tomographic investigation of pore collapse in laser shock-loaded polyurethane foam
Authors: Pradel P. , de Rességuier T. , Malaise F. , Olbinado M. P. , Rack A. , Grenzer J. , Loison D. , Berthe L.
Published: February 2022

Laser-driven shock experiments were conducted at a synchrotron facility to investigate the dynamic response of polyurethane foam. These experiments were coupled to in situ x-ray imaging to radiograph foam deformations and to determine the propagation velocity of stress waves. To increase the amplitude and the duration of the pressure load generated by the laser–matter interaction, the front surface of the target was covered with a confining layer (water and BK7 glass). Preliminary calibration tests involving time-resolved velocity measurements were performed to calculate the ablation pressure on the front surface of foam samples. The calculated pressure loads were used as input data for hydrodynamic simulations, in which the foam is modeled using a homogeneous porous macroscopic model, and model predictions were compared with experimental results. A fair consistency was found for most experiments, while for the others, an overestimation of the applied pressure is suspected, likely due to a laser breakdown within the confining medium. Finally, post-shot x-ray tomography of the recovered samples showed permanent deformation of the foam, unlike what was observed under quasi-static compression, and revealed heavy damage in the vicinity of the loaded zone.
Enhanced second-order sideband via surface plasmon polaritons in a low-Q microcavity
Authors: Wu Zhen , Yang Wen-Xing , Li Ling , Li Xiyun , Wang Xin
Published: February 2022

We investigate the creation of the optical second-order sideband (OSS) from a hybrid system consisting of a single quantum dot (QD), a spherical metallic nanoparticle, and a low-Q microcavity driven with a weak probe and a strong control field. Beyond the conventional linearized description, we solve the nonlinear Heisenberg–Langevin equations for achieving the nonlinear coefficient of the OSS by employing the perturbation technique. It is shown that the hybrid of plasmon and cavity modes induces the formation of the surface plasmon polaritons, resulting in a controllable interaction that can be enhanced into a strong coupling regime even if the cavity–QD interaction is initially in the weak-coupling regime. As a result, enhanced OSS generation and the splitting of the transmission spectra can be observed. In addition, it is also shown that the size of the metal nanoparticle (MNP) has a profound effect on the output OSS spectrum, which might form a precision self-referenced detection scheme for extracting size information of the MNP.
Isotope effects on the structural transformation and relaxation of deeply supercooled water
Authors: Kringle Loni , Thornley Wyatt A. , Kay Bruce D. , Kimmel Greg A.
Published: February 2022

We have examined the structure of supercooled liquid D2O as a function of temperature between 185 and 255 K using pulsed laser heating to rapidly heat and cool the sample on a nanosecond timescale. The liquid structure can be represented as a linear combination of two structural motifs, with a transition between them described by a logistic function centered at 218 K with a width of 10 K. The relaxation to a metastable state, which occurred prior to crystallization, exhibited nonexponential kinetics with a rate that was dependent on the initial structural configuration. When the temperature is scaled by the temperature of maximum density, which is an isostructural point of the isotopologues, the structural transition and the non-equilibrium relaxation kinetics of D2O agree remarkably well with those for H2O.
A molecular dynamics study on the cyclic plastic deformation mechanism of Al–Mg alloys
Authors: Xue Hao , Cui Tianlun , Guo Haoshan , Chu Ruihua , Zhang Chunxiang , Luo Junting
Published: February 2022

The deformation mechanism and hardening law of single-crystal and polycrystalline Al–Mg alloy materials during the cyclic loading deformation process of different paths are studied herein according to the principle of molecular dynamics. An analysis of the single-crystal simulation results indicates that the Bauschinger effect decreases with the increase of strain. The cyclic loading leads to dislocation locking and other obstacles, which, in turn, lead to hardening of the material. After that, the force generated by the accumulated strain moves the dislocation obstacle and causes the material to soften. Based on the Voronoi polygon method, polycrystalline models with different grain sizes are established, and the plastic deformation mechanism of these models under cyclic loading is analyzed. The results show that the critical grain size of the direct and inverse Hall–Petch relationship exists in the Al–Mg alloy. When the grain size is below this value, grain rotation and grain boundary sliding become the main deformation mechanisms of the small polycrystalline grains. Dislocation blockage remains an important factor in the hardening of polycrystalline materials, while the aggregation of solute atoms at the grain boundaries is another contributing factor.
Phylogenetic evidence for an independent origin of extreme sexual size dimorphism in a genus of araneid spiders (Araneae: Araneidae)
Authors: Yu Kuang-Ping , Kuntner Matjaž , Cheng Ren-Chung
Published: February 2022

Cyphalonotus is a poorly studied Old World araneid spider genus of which the phylogenetic proximity remains unknown due to the paucity of morphological and molecular data. We test the phylogenetic placement and the taxonomic composition of Cyphalonotus and place the male and female size variation of Cyphalonotus and related genera in an evolutionary context. Our collection and field observations from Taiwan and China facilitate description of a new and a known species, and original sequence data enable species delimitation and phylogenetic analyses. The phylogenetic results reject all four classification hypotheses from the literature and instead recover a well-supported clade comprising Cyphalonotus + Poltys. We review the male and female size variation in Cyphalonotus, Poltys and related genera. These data reveal that all known species of Poltys are extremely sexually size dimorphic (eSSD = females over twice the size of males) reaching values exceeding 10-fold differences, whereas Cyphalonotus and other genera in phylogenetic proximity are relatively sexually monomorphic (SSD < 2.0). This confirms an independent origin of eSSD in Poltys, one of multiple convergent evolutionary outcomes in orbweb spiders.
Loss of TET reprograms Wnt signaling through impaired demethylation to promote lung cancer development
Authors: Xu Qin , Wang Chao , Zhou Jia-Xin , Xu Zhi-Mei , Gao Juan , Sui Pengfei , Walsh Colum P. , Ji Hongbin , Xu Guo-Liang
Published: February 2022

Significance

Previous studies have identified the tumor-suppressive function of TET enzymes in hematological cancers. Given the differential mutational incidence and lacking functional validation, how TET contributes to carcinogenesis in solid tumors remains largely undefined. Here, we report that
TET
mutations co-occur with
KRAS
mutations, and such co-occurrence predicts poor survival in human LUAD. Using genetically engineered mouse models (GEMMs), we show that inactivation of
TET
cooperates with oncogenic
KRAS
to potentiate LUAD development, and that this effect is preferentially induced by augmented Wnt signaling as a consequence of impaired expression of Wnt-associated antagonists due to DNA hypermethylation. Our work reveals the tissue-specific and context-dependent roles of TET during carcinogenesis and implicates Wnt signaling as a therapeutic modality for
TET
-mutant lung tumors.
DNA-encoded library versus RNA-encoded library selection enables design of an oncogenic noncoding RNA inhibitor
Authors: Benhamou Raphael I. , Suresh Blessy M. , Tong Yuquan , Cochrane Wesley G. , Cavett Valerie , Vezina-Dawod Simon , Abegg Daniel , Childs-Disney Jessica L. , Adibekian Alexander , Paegel Brian M. , Disney Matthew D.
Published: February 2022

Significance

Drug discovery generally investigates one target at a time, in sharp contrast to living organisms, which mold ligands and targets by evolution of highly complex molecular interaction networks. We recapitulate this modality of discovery by encoding drug structures in DNA, allowing the entire DNA-encoded library to interact with thousands of RNA fold targets, and then decoding both drug and target by sequencing. This information serves as a filter to identify human RNAs aberrantly produced in cancer that are also binding partners of the discovered ligand, leading to a precision medicine candidate that selectively ablates an oncogenic noncoding RNA, reversing a disease-associated phenotype in cells.
Shape multistability in flexible tubular crystals through interactions of mobile dislocations
Authors: Zakharov Andrei , Beller Daniel A.
Published: February 2022

Significance

Crystalline sheets rolled up into cylinders occur in diverse biological and synthetic systems, including carbon nanotubes, biofilaments of the cellular cytoskeleton, and packings of colloidal particles. In this work, we show, computationally, that such tubular crystals can be programmed with reconfigurable shapes, due to motions of defects that interrupt the periodicity of the crystalline lattice. By identifying and exploiting stable patterns of these defects, we cause tubular crystals to relax into desired target geometries, a design principle that could guide the creation of versatile colloidal analogues to nanotubes. Our results suggest routes to tunable and switchable material properties in ordered, soft materials on deformable surfaces.
Immunogenicity of rVSVΔG-ZEBOV-GP Ebola vaccination in exposed and potentially exposed persons in the Democratic Republic of the Congo
Authors: Hoff Nicole A. , Bratcher Anna , Kelly J. Daniel , Musene Kamy , Kompany Jean Paul , Kabamba Michel , Mbala-Kingebeni Placide , Dighero-Kemp Bonnie , Kocher Gregory , Elliott Elizabeth , Reilly Cavan , Halbrook Megan , Ilunga Kebela Benoit , Gadoth Adva , Ngoie Mwamba Guillaume , Tambu Merly , McIlwain David R. , Mukadi Patrick , Hensley Lisa E. , Ahuka-Mundeke Steve , Rutherford George W. , Muyembe-Tamfum Jean Jacques , Rimoin Anne W.
Published: February 2022

Significance

This paper describes findings from a seroepidemiologic study involving a cohort of Ebola-vaccinated individuals from North Kivu, Democratic Republic of the Congo (DRC), who were studied as part of a collaborative effort between American and Congolese scientists and epidemiologists. Our study examines antibody response at 21 d and 6 mo postvaccination after single-dose rVSVΔG-ZEBOV-GP vaccination among Ebola virus disease–exposed and potentially exposed populations in the DRC. At 21 d of follow-up, 87.2% had an antibody response. Additionally, 95.6% demonstrated antibody persistence at 6 mo of follow-up. These findings give crucial evidence that antibody response and persistence after Ebola vaccination is robust in outbreak settings in the DRC, knowledge that significantly informs the use of vaccination for outbreak control.
Carleman contraction mapping for a 1D inverse scattering problem with experimental time-dependent data
Authors: Le Thuy T , Klibanov Michael V , Nguyen Loc H , Sullivan Anders , Nguyen Lam
Published: February 2022

It is demonstrated that the contraction mapping principle with the involvement of a Carleman weight function works for a coefficient inverse problem for a 1D hyperbolic equation. Using a Carleman estimate, the global convergence of the corresponding numerical method is established. Numerical studies for both computationally simulated and experimentally collected data are presented. The experimental part is concerned with the problem of computing dielectric constants of explosive-like targets in the standoff mode using severely underdetermined data.
A generalized quasi-boundary value method for recovering a source in a fractional diffusion-wave equation
Authors: Wei Ting , Luo Yuhua
Published: February 2022

This paper is devoted to identifying a space-dependent source in a time-fractional diffusion-wave equation by using the final time data. By the series expression of the solution of the direct problem, the inverse source problem can be formulated by a first kind of Fredholm integral equation. The existence and uniqueness, ill-posedness and a conditional stability in Hilbert scale for the considered inverse problem are provided. We propose a generalized quasi-boundary value regularization method to solve the inverse source problem and also prove that the regularized problem is well-posed. Further, two kinds of convergence rates in Hilbert scale for the regularized solution can be obtained by using an a priori and an a posteriori regularization parameter choice rule, respectively. The numerical examples in one-dimensional case and two-dimensional case are given to confirm our theoretical results for the constant coefficients problem. We also propose a finite difference method based on a variant of L1 scheme to solve the regularized problem for the variable coefficients problem and give its convergence rate. One finite difference method based on a convolution quadrature is provided to solve the regularized problem for comparison. The numerical results for three examples by two algorithms are provided to show the effectiveness and stability of the proposed algorithms.
Direct observation of the temperature dependence of the Dzyaloshinskii–Moriya interaction
Authors: Zhang Yabing , Kong Xiangjie , Xu Guofu , Jin Ying , Jiang Changjun , Chai Guozhi
Published: February 2022

In this work, we investigate the temperature dependence of the Dzyaloshinskii–Moriya interaction (DMI) in Co/Pt thin film by observing the asymmetric spin-wave dispersion using Brillouin light scattering. The DMI constant D reduce monotonously with the temperature increasing from room temperature to 393 K. By extracting the saturation magnetization M
s and the uniaxial anisotropy K
u, we find that D(T) ∝ K
u (T)2.08±0.13 and D(T) ∝ M
s (T)5.25±0.33. These observations indicate that temperature is a possible way to control the DMI. On the other hand, the temperature dependence of DMI in thin films may have significant influence for potential applications.
Transmission and backscattering characteristics of electromagnetic waves in single layer combined plasma array
Authors: Deng Xuesong , Cheng Li , Shi Jiaming , Fang Ming , Chen Zongsheng , Li Zhigang , Wang Yahui , Lv Xiangyin
Published: February 2022

Manipulation of electromagnetic (EM) waves is essential for various microwave applications. This research studies the modulation of EM waves by using single-layer plasma arrays consisting of discharge tubes. We experimentally investigate the transmission spectra and backscattering attenuation characteristics of the plasma arrays, and numerical simulations further reveal the modulation mechanism and influences of the plasma arrays. The experimental and numerical results show that broadband tunable photonic bandgaps can be achieved in frequency ranges of 4–7.5 GHz and 7–9.5 GHz for the transmission spectrum and the backscattering spectrum, respectively. In addition, the proposed plasma array can achieve different modulation effects to satisfy the corresponding scenario requirements by adjusting the configuration and parameters such as the plasma frequency, spacing of the plasma tubes, and the discharge tube’s excitation or extinction of the plasma array. The wave manipulation of the combined plasma array creates opportunities for developing numerous applications, including large-area spatial filtering, radar stealth, and reconfigurable antennas.
Two-dimensional graphyne–graphene heterostructure for all-carbon transistors
Authors: Huang Jing , Kang Jun
Published: February 2022

Semiconducting graphyne is a two-dimensional (2D) carbon allotrope with high mobility, which is promising for next generation all-carbon field effect transistors (FETs). In this work, the electronic properties of van der Waals heterostructure consists of 2D graphyne and graphene (GY/G) were studied from first-principles calculations. It is found that the band dispersion of isolated graphene and graphyne remain intact after they were stacked together. Due to the charge transfer from graphene to graphyne, the Fermi level of the GY/G heterostructure crosses the VB of graphene and the CB of graphyne. As a result, n-type Ohmic contact with zero Schottky barrier height (SBH) is obtained in GY/G based FETs. Moreover, the electron tunneling from graphene to graphyne is found to be efficient. Therefore, excellent electron transport properties can be expected in GY/G based FETs. Lastly, it is demonstrated that the SBH in the GY/G heterostructure can be tune by applying a vertical external electric field or doping, and the transition from n-type to p-type contact can be realized. These results show that GY/G is potentially suitable for 2D FETs, and provide insights into the development of all-carbon electronic devices.
CAD-based x-ray CT calibration and error compensation
Authors: Fragnaud Cédric , Remacha Clément , Betancur Julián , Roux Stéphane
Published: February 2022

Artifacts due to imperfect determination of the scanner geometry, beam hardening (BH), and diffuse Compton scattering, limit the quantitative exploitation of radiographs or tomographies for non-destructive evaluation. Exploiting the computer-aided design (CAD) model of an industrial part, a methodology is proposed to refine the estimation of the computed tomography (CT)-scanner geometry up to a scale factor, to correct or account for artifacts, and to assess the metrology of the part. A projective model describing the formation of x-ray images in CT-scanners is first introduced. The optimal parameters of the projective model are identified using a novel CAD-based calibration method that relies on the registration of simulated projections onto experimental ones. A metrological analysis based on the comparison between acquired and simulated x-ray images is proposed. A turbine blade, for which an automatic inspection procedure from few views is under development, is used as an example to illustrate the proposed methodology. The parametrization accounts for the refinement of the projection geometry, the calibration of BH, and the estimation of scattering. It is shown that, using the proposed procedure, the differences between acquired and simulated radiographic images are significantly reduced, indicating that the optimal parameters are properly identified. These differences are then exploited to detect flaws in the part.
Resolution enhanced statistically optimal cylindrical near-field acoustic holography based on equivalent source method
Authors: Cheng Wei , Zhang Peng , Song Chao , Chen Xuefeng , Ou Kai , Ahsan Muhammad Mubashir
Published: February 2022

For the sound field reconstruction of large cylindrical surfaces, statistically optimal cylindrical near-field acoustic holography (SOCNAH) has high reconstruction accuracy but low resolution. To solve this problem, resolution enhanced SOCNAH (RE-SOCNAH) based on equivalent source method (ESM) is proposed. Firstly, near-field measurements are used to acquire the complex sound pressures on the holographic surface. Secondly, with the sound field on all measurement points as boundary conditions, single-layer potential ESM is used to reconstruct the sound pressure on corresponding interpolation points. Finally, with the sound pressure on all holographic points after interpolation, SOCNAH is used to reconstruct the sound pressure on the large cylindrical surface. Furthermore, arrangement of equivalent sources and performance of RE-SOCNAH are studied according to typical numerical and experimental studies on a cylindrical test bed. Generally, this paper provides an accurate and RE-NAH method for large cylindrical surfaces, which can provide significant evidences for noise monitoring and control.
Nanostructure of the laser-modified transition metal nanocomposites for water splitting
Authors: Wawrzyniak Jakub , Karczewski Jakub , Coy Emerson , Ryl Jacek , Grochowska Katarzyna , Siuzdak Katarzyna
Published: February 2022

Although hydrogen is considered by many to be the green fuel of the future, nowadays it is primarily produced through steam reforming, which is a process far from ecological. Therefore, emphasis is being put on the development of electrodes capable of the efficient production of hydrogen and oxygen from water. To make the green alternative possible, the solution should be cost-efficient and well processable, generating less waste which is a huge challenge. In this work, the laser-based modification technique of the titania nanotubes containing sputtered transition metal species (Fe, Co, Ni, and Cu) was employed. The characteristics of the electrodes are provided both for the hydrogen and oxygen evolution reactions, where the influence of the laser treatment has been found to have the opposite effect. The structural and chemical analysis of the substrate material provides insight into pathways towards more efficient, low-temperature water splitting. Laser-assisted integration of transition metal with the tubular nanostructure results in the match-like structure where the metal species are accumulated at the head. The electrochemical data indicates a significant decrease in material resistance that leads to an overpotential of only +0.69 V at 10 mA cm−2 for nickel-modified material.
Multi-view learning for lymph node metastasis prediction using tumor and nodal radiomics in gastric cancer
Authors: Yang Jing , Wang Li , Qin Jiale , Du Jichen , Ding Mingchao , Niu Tianye , Li Rencang
Published: February 2022

Purpose.This study aims to develop and validate a multi-view learning method by the combination of primary tumor radiomics and lymph node (LN) radiomics for the preoperative prediction of LN status in gastric cancer (GC).Methods.A total of 170 contrast-enhanced abdominal CT images from GC patients were enrolled in this retrospective study. After data preprocessing, two-step feature selection approach including Pearson correlation analysis and supervised feature selection method based on test-time budget (FSBudget) was performed to remove redundance of tumor and LN radiomics features respectively. Two types of discriminative features were then learned by an unsupervised multi-view partial least squares (UMvPLS) for a latent common space on which a logistic regression classifier is trained. Five repeated random hold-out experiments were employed.Results.On 20-dimensional latent common space, area under receiver operating characteristic curve (AUC), precision, accuracy, recall and F1-score are 0.9531 ± 0.0183, 0.9260 ± 0.0184, 0.9136 ± 0.0174, 0.9468 ± 0.0106 and 0.9362 ± 0.0125 for the training cohort respectively, and 0.8984 ± 0.0536, 0.8671 ± 0.0489, 0.8500 ± 0.0599, 0.9118 ± 0.0550 and 0.8882 ± 0.0440 for the validation cohort respectively (reported as mean ± standard deviation). It shows a better discrimination capability than single-view methods, our previous method, and eight baseline methods. When the dimension was reduced to 2, the model not only has effective prediction performance, but also is convenient for data visualization.Conclusions.Our proposed method by integrating radiomics features of primary tumor and LN can be helpful in predicting lymph node metastasis in patients of GC. It shows multi-view learning has great potential for guiding the prognosis and treatment decision-making in GC.
Fast gas heating and kinetics of electronically excited states in a nanosecond capillary discharge in CO2
Authors: Pokrovskiy G V , Popov N A , Starikovskaia S M
Published: February 2022

Fast gas heating in a pulsed nanosecond capillary discharge in pure CO2 under the conditions of high specific deposited energy (around 1.2 eV/molecule) and high reduced electric fields (150–250 Td) has been studied experimentally and numerically. Specific deposited energy, reduced electric field and gas temperature have been measured as functions of time. The radial distribution of the electron density has been analyzed experimentally. The role of quenching of O(1D), O(1S) and CO(a3Π) excited atoms and molecules leading to heat release at sub-microsecond time scale have been analyzed by numerical modeling in the framework of 1D axial approximation.
I–V Characteristics of E-mode GaN-based transistors under gate floating
Authors: Qin Zhen-Wei , Tsai Wen-Hsuan , Chen Wei-Chia , Lo Hao-Hsuan , Hsin Yue-Ming
Published: February 2022

This study investigates the I–V behaviors of various E-mode GaN-based transistors under gate floating and zero gate bias. The p-GaN gate high electron mobility transistor (HEMTs), gate injection transistors, and Cascode GaN FETs have been adopted and compared. The high off-state drain current is observed under gate floating except for Cascode GaN FETs based on the measured I–V characteristics. The off-state drain current of p-GaN gate HEMT is up to 0.8 mA under gate floating at a drain bias of 6 V, which is about 107 times larger than zero gate bias. The devices will induce false-turn-on and reverse conduction loss during switching under gate floating due to the capacitance charging effect between the drain and the gate electrodes. The mechanism of the capacitance charging effect is discussed using the equivalent circuit of p-GaN gate HEMTs and confirmed by Silvaco TCAD simulation.
Enhanced electromechanical resilience and mechanism of the composites-coated fabric sensors with crack-induced conductive network for wearable applications
Authors: Wang Xi , Li Qiao , Tao Xiaoming
Published: February 2022

Conductive composites-coated fabric sensors are favorable sensing elements for wearable applications. However, rheology of composites ingredients has been causing inaccuracy due to high hysteresis and low instantaneity in real-time measurements. To address this problem, a composites-coated fabric-based strain sensor was fabricated and studied. A physical pretreatment scheme was designed to produce cracked surface morphology on the conductive composites film, yielding a stable conductive network. Results showed that this scheme can significantly lower the electrical hysteresis of the sensors by about 35% and effectively reduce electrical and mechanical relaxation, hence notably improved electromechanical resilience of the sensors. It is also found that the linear strain-resistance property of the sensors was largely retained after pretreatment. Sensing mechanism of the cracked sensors was further derived to understand the results. Through all the observations and application prospect demonstrated by two sensing belts, it is suggested that cracking can be considered to improve sensing performance for other coated fabric flexible sensors.
Development of modular multi-degree-of-freedom hybrid joints and robotic flexible legs via fluidic elastomer actuators
Authors: Dong Xuguang , Wang Yixin , Liu Xin-Jun , Zhao Huichan
Published: February 2022

Soft actuators with high safety, adaptivity, and energy-to-weight ratio have the potential to be used in developing more adaptive legged robots. In this work, we incorporate soft actuators into rigid parallel mechanisms and develop multi-degree-of-freedom (multi-DOF) soft-rigid hybrid joints that can actively achieve 1, 2, and 3 DOFs actuated by 2, 4, and 8 bellows-type fluidic elastomer actuators (FEAs), respectively. The FEAs exhibit large axial strain (ϵ
e max = 176%, ϵ
c max = 25%), small radial expansion (ϵ
r max = 12%) at 70 kPa, and are light weight, and the rigid parallel mechanisms constrain motions of the joints to the desired DOFs. We characterize the proposed joints’ kinematic and static performances by measuring their range of motion and blocked torque upon actuation. Results show that these joints successfully achieve all desired DOFs and are of high torque to weight ratio (4.07 N·m·kg−1). A bucking prediction model is established to evaluate the critical buckling pressure. As a demonstration for legged robots, we use the proposed joints and develop two types of multi-DOF legs based on inspirations from the DOF configuration of legged mammals’ musculoskeletal systems. Preliminary results demonstrate that FEAs-based multi-DOF legs can perform fundamental biomimetic movements (e.g. leg swing) through pressure adjustment, and high-speed tasks (e.g. ball kicking and jumping) through high-pressure and short-pulse actuation.
Optical properties of 87Rb atomic vapor near the 1D photonic crystal bandgap and all-optical switching of transmitted light
Authors: Shiri J , Khalilzadeh J , Asadpour SH
Published: February 2022

We investigate the steady-state and dynamic behavior of the optical properties of the laser pulse in a GaAs/AlAs 1D photonic crystal (1DPC) with an atomic vapor defect layer. We chose the atomic vapor of the 87Rb as a defect layer by driving the probe field on the D2 transition between 52P3/2 - 52S1/2 levels through the 1DPC. The effect of the photonic bandgap (PBG) on the absorption and dispersion properties of the probe field is discussed. Moreover, the transmission and reflection coefficient of the 1DPC is controlled by applying the various value of the intensity of the coupling field. By comparing these results in the vacuum and near the PBG, we find that the absorption/dispersion and transmission/reflection properties are strongly affected by the PBG. We find that all-optical properties of atomic vapor in the surrounding of 1DPC are improved due to PBG. Furthermore, the effect of the intensity of the coupling field on the all-optical switching is studded. The proposed model may provide some new possibilities for technological applications as an all-optical device based on the photonic crystal in quantum information science, quantum computing, signal processing, and quantum communications.