bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of Extremes of BMI on Outcomes following Lung Resection
Authors: Ahmed-Issap Amber , Jain Shubham , Habib Akolade , Mantio Kim , Spence Angelica , Raseta Marko , Abah Udo
Published: April 2023

Background Body mass index (BMI) has been shown to be an independent predictor of survival following lung resection surgery. This study aimed to quantify the short- to midterm impact of abnormal BMI on postoperative outcomes.

Methods Lung resections at a single institution were examined between 2012 and 2021. Patients were divided into low BMI (<18.5), normal/high BMI (18.5–29.9), and obese BMI (>30). Postoperative complications, length of stay, and 30- and 90-day mortality were examined.

Results A total of 2,424 patients were identified. Of these patients, 2.6% (n = 62) had a low BMI, 67.4% (n = 1,634) had a normal/high BMI, and 30.0% (n = 728) had an obese BMI. Overall postoperative complications were higher in the low BMI group (43.5%) when compared with normal/high (30.9%) and obese BMI group (24.3%) (p = 0.0002). Median length of stay was significantly higher in the low BMI group (8.3 days) compared with 5.2 days in the normal/high and obese BMI groups (p < 0.0001). Ninety-day mortality was higher in the low (16.1%) compared with the normal/high (4.5%) and obese BMI groups (3.7%) (p = 0.0006). Subgroup analysis of the obese cohort did not elucidate any statistically significant differences in overall complications in the morbidly obese. Multivariate analysis determined that BMI is an independent predictor of reduced postoperative complications (odds ratio [OR], 0.96; 95% confidence interval [CI], 0.94–0.97; p < 0.0001) and 90-day mortality (OR, 0.96; 95% CI, 0.92–0.99; p = 0.02).

Conclusion Low BMI is associated with significantly worse postoperative outcomes and an approximate fourfold increase in mortality. In our cohort, obesity is associated with reduced morbidity and mortality following lung resection surgery, confirming the existence of the obesity paradox.
Neonatal Intensive Care Unit Patients Receiving More Than 25 Platelet Transfusions
Authors: Bahr Timothy M. , Ohls Robin K. , Ilstrup Sarah J. , Christensen Robert D.
Published: April 2023

Objective A few patients in neonatal intensive care units (NICU) receive numerous platelet transfusions. These patients can become refractory, defined as transfusions of ≥10 mL/kg failing to increase the platelet count by at least 5,000/µL. Causes of, and best treatments for, platelet transfusion refractoriness in neonates have not been defined.

Study Design Multi-NICU multiyear retrospective analysis of neonates receiving >25 platelet transfusions.

Results Eight neonates received 29 to 52 platelet transfusions. All eight were blood group O. Five had sepsis, four were very small for gestational age, four had bowel resections, two Noonan syndrome, two had cytomegalovirus infection. All eight had some (19–73%) refractory transfusions. Many (2–69%) of the transfusions were ordered when the platelet count was >50,000/µL. Higher posttransfusion counts occurred after ABO-identical transfusions (p = 0.026). Three of the eight had late NICU deaths related to respiratory failure; all five survivors had severe bronchopulmonary dysplasia requiring tracheostomy for prolonged ventilator management.

Conclusion Neonates who are high users of platelet transfusions appear to be at high risk for poor outcomes, especially respiratory failure. Future studies will examine whether group O neonates are more likely to develop refractoriness and whether certain neonates would have a higher magnitude of posttransfusion rise if they received ABO-identical donor platelets.

Key Points
Design and testing of a high perveance sheet beam electron gun
Authors: Smirnov A. V. , Agustsson R. , Chao D. , Gavryushkin D. , Hoyt K. J. , Shchegolkov D. , Zavadtsev A.
Published: April 2023

This paper presents the design, prototype engineering, and initial testing of a relatively low-voltage, high aspect ratio electron gun for versatile pulsed power applications. The sheet beam, diode electron gun is designed for (23–25) kV voltage and 6 µA/V1.5, as is required for x-band klystron, as a part of a compact Klylac delivering electron beam energy in the MeV range. The gun prototype was engineered, built, and tested using a Scandinova M1-0.5 modulator. Beam loss on the anode aperture is evaluated from transient waveforms and equivalent circuit modeling.
Quantum tomographic Aubry–Mather theory
Authors: Shabani A. , Khellat F.
Published: April 2023

In this paper, we study the quantum analog of the Aubry–Mather theory from a tomographic point of view. In order to have a well-defined real distribution function for the quantum phase space, which can be a solution for variational action minimizing problems, we reconstruct quantum Mather measures by means of inverse Radon transform and prove that the resulting tomograms, which are fair and non-negative distribution functions, are also solutions of the quantum Mather problem and, in the semi-classical sense, converge to the classical Mather measures.
Research on the performance of a valveless piezoelectric pump with a herringbone bluffbody
Authors: Yu Dahai , Hu Renhui , Huang Yongxin , Hu Dianbin , He Lipeng , Cheng Guangming
Published: April 2023

Aiming to improve the output performance of a valveless piezoelectric pump, this article presents a valveless piezoelectric pump with a herringbone bluffbody. The bluffbody is herringbone shaped and distributed in a tapered chamber. The tapered chamber and the bluffbody create a large reverse resistance in the chamber, thus effectively mitigating the backflow problem of the valveless pump. The theoretical analysis determined the relationship between the flow rate and the flow resistance coefficient as well as the variation of the pump chamber volume. It was also concluded that the piezoelectric pump has the best output flow at intrinsic frequencies. Through simulation calculations, the effectiveness of the bluffbody structure in mitigating backflow in piezoelectric pumps is analyzed to provide a reference for experimental prototype design parameters. Finally, a range of prototypes is produced for experimentation. The experimental results show that the designed bluffbody shape can increase the return energy loss to effectively mitigate the return flow issues of the valveless piezoelectric pump, thus improving the output performance. The optimum output flow rate is 158.5 ml/min at 200 V and 52.5 Hz and the tapered chamber angle of 6°, and the bluffbody height, angle, and quantities are 2 mm, 40°, and 2, respectively. The construction of the valveless piezoelectric pump proposed in this research can be used as a reference for subsequent improvements in the performance of valveless piezoelectric pumps, and due to the high output performance, experimental studies can be carried out in applications such as dispensing and heat dissipation in electronic products.
Direct stellarator coil optimization for nested magnetic surfaces with precise quasi-symmetry
Authors: Giuliani Andrew , Wechsung Florian , Cerfon Antoine , Landreman Matt , Stadler Georg
Published: April 2023

We present a robust optimization algorithm for the design of electromagnetic coils that generate vacuum magnetic fields with nested flux surfaces and precise quasi-symmetry. The method is based on a bilevel optimization problem, where the outer coil optimization is constrained by a set of inner least squares optimization problems whose solutions describe magnetic surfaces. The outer optimization objective targets coils that generate a field with nested magnetic surfaces and good quasi-symmetry. The inner optimization problems identify magnetic surfaces when they exist, and approximate surfaces in the presence of magnetic islands or chaos. We show that this formulation can be used to heal islands and chaos, thus producing coils that result in magnetic fields with precise quasi-symmetry. We show that the method can be initialized with coils from the traditional two-stage coil design process, as well as coils from a near-axis expansion optimization. We present a numerical example where island chains are healed and quasi-symmetry is optimized up to surfaces with aspect ratio 6. Another numerical example illustrates that the aspect ratio of nested flux surfaces with optimized quasi-symmetry can be decreased from 6 to approximately 4. The last example shows that our approach is robust and a cold-start using coils from a near-axis expansion optimization.
Deep sub-60 mV/dec subthreshold swing independent of gate bias sweep direction in an in situ SiN/Al0.6Ga0.4N/GaN-on-Si metal-insulator high electron mobility transistor
Authors: Du Hanghai , Liu Zhihong , Hao Lu , Gao Guangjie , Xing Weichuan , Zhang Weihang , Zhang Yachao , Zhou Hong , Zhao Shenglei , Zhang Jincheng , Hao Yue
Published: April 2023

In this Letter, we demonstrated deep sub-60 mV/dec subthreshold swings (SS) independent of gate bias sweep direction in GaN-based metal–insulator–semiconductor high electron mobility transistors (MISHEMTs) with an Al0.6Ga0.4N/GaN heterostructure and in situ SiN as gate dielectric and surface passivation. Average SS values of 22 and 29 mV/dec over 3–4 orders of drain current (ID) swing were measured during forward and reverse sweeps, respectively, in a 75-nm gate length (LG) device. Sub-60 mV/dec SS was also observed in the GaN MISHEMTs with longer LG up to 350 nm. The intrinsic physical mechanisms of deep sub-60 mV/dec SS were comprehensively studied. The observed negative differential resistance in the gate current, the kinks in the output ID-VD curve, and the capacitance spike in the depletion region of the C–V curves suggest that the capture and emission of electrons in the traps are the dominant physical mechanisms responsible for the small SS.
Impact of the radial density profile on the Z-pinch stability at a microsecond rise time of the driving current
Authors: Cherdizov R. K. , Baksht R. B. , Kokshenev V. A. , Rousskikh A. G. , Shishlov A. V. , Shmelev D. L. , Zhigalin A. S. , Oreshkin V. I.
Published: April 2023

This paper considers the instabilities of imploding aluminum metal-puff Z-pinches with an outer plasma shell. An experiment was performed on the GIT-12 generator (3.2–3.6 MA, ∼1 μs implosion times, and ∼15 cm initial Z-pinch radius). It was shown that the density profile of the Z-pinch material had the dominant effect on the growth and suppression of instabilities. Two Z-pinch load configurations were used. The first configuration provided a tailored density profile (TDP) [A. L. Velikovich et al., Phys. Rev. Lett. 77, 853 (1996)], which ensured the suppression of the magneto-Rayleigh–Taylor (MRT) instability in the Z-pinch. For the second configuration, the density profile was changed in such a way that a density notch from 10 to 0.5 μg/cm3 occurred at a radius of about 3 cm from the Z-pinch axis. The notch in the density profile and the nonmonotonic increase in density resulted in a completely unstable compression of the Z-pinch. This gave rise to large-scale instabilities, which were detected by optical diagnostics. The instabilities grew and were not suppressed even in the stagnation phase, despite a sharp increase in the density of the Z-pinch material near the axis. The results were interpreted using the model proposed by Curzon et al. [Proc. R. Soc. London A 257, 386 (1960)]. The total instability amplitude is the sum of the amplitudes of MRT and magneto-hydrodynamic (MHD) instabilities. The growth of the total instability in the density notch region is due to the development of MRT instability. Thus, if the density profile has a notch, the Z-pinch compression in the stagnation phase occurs under strong perturbations at the magnetic field/plasma interface. This results in a dramatic growth of MHD instabilities. Hence, a stable implosion of a Z-pinch with TDP is possible only if the density increases monotonically toward the axis.
Enabling technology for global 3D+3V hybrid-Vlasov simulations of near-Earth space
Authors: Ganse Urs , Koskela Tuomas , Battarbee Markus , Pfau-Kempf Yann , Papadakis Konstantinos , Alho Markku , Bussov Maarja , Cozzani Giulia , Dubart Maxime , George Harriet , Gordeev Evgeny , Grandin Maxime , Horaites Konstantinos , Suni Jonas , Tarvus Vertti , Kebede Fasil Tesema , Turc Lucile , Zhou Hongyang , Palmroth Minna
Published: April 2023

We present methods and algorithms that allow the Vlasiator code to run global, three-dimensional hybrid-Vlasov simulations of Earth's entire magnetosphere. The key ingredients that make Vlasov simulations at magnetospheric scales possible are the sparse velocity space implementation and spatial adaptive mesh refinement. We outline the algorithmic improvement of the semi-Lagrangian solver for six-dimensional phase space quantities, discuss the coupling of Vlasov and Maxwell equations' solvers in a refined mesh, and provide performance figures from simulation test runs that demonstrate the scalability of this simulation system to full magnetospheric runs.
Influence of the axial oscillations on the electron cyclotron drift instability and electron transport in Hall thrusters
Authors: Quan Lulu , Cao Yong , Li Yang , Liu Hongtao , Tian Bin
Published: April 2023

A 2D-3V finite-element particle-in-cell model, which is applied to simulate the radial-azimuthal plane near the exit of Hall thrusters, has been presented to investigate the influence of axial oscillation on electron cyclotron drift instability (ECDI) and anomalous cross field electron transports. The simplified theoretical analysis about the ECDI and the anomalous electron transport has been introduced. The uniform and harmonic axial electric fields, which are based on the typical axial oscillations in Hall thrusters, have been considered in the simulations. It is concluded that different constant axial electric fields can influence the properties of instability but cannot significantly change the cross field electron mobility. However, the axial oscillation plays a significant role in the instability, and the electron transports provided that appropriate amplitudes and frequencies are achieved. The equilibrium of the instability is destroyed and reformed with the axial oscillation. The cross field electron transports are enhanced in the range of low amplitudes and frequencies and are suppressed when they are in a high value. In addition, it is observed that the variation of the electron mobility and electron–ion friction force show high consistency with the trend of electron temperature. It is further confirmed that the increase in electron temperature takes responsibility for the enhanced cross field electron transport due to the axial oscillation.
Relation between microscopic structure and macroscopic properties in polyacrylonitrile-based lithium-ion polymer gel electrolytes
Authors: Rushing Jeramie C. , Gurung Anit , Kuroda Daniel G.
Published: April 2023

Polymer gel electrolytes (PGE) have seen a renewed interest in their development because they have high ionic conductivities but low electrochemical degradation and flammability. PGEs are formed by mixing a liquid lithium-ion electrolyte with a polymer at a sufficiently large concentration to form a gel. PGEs have been extensively studied, but the direct connection between their microscopic structure and macroscopic properties remains controversial. For example, it is still unknown whether the polymer in the PGE acts as an inert, stabilizing scaffold for the electrolyte or it interacts with the ionic components. Here, a PGE composed of a prototypical lithium-carbonate electrolyte and polyacrylonitrile (PAN) is pursued at both microscopic and macroscopic levels. Specifically, this study focused on describing the microscopic and macroscopic changes in the PGE at different polymer concentrations. The results indicated that the polymer-ion and polymer–polymer interactions are strongly dependent on the concentration of the polymer and the lithium salt. In particular, the polymer interacts with itself at very high PAN concentrations (10% weight) resulting in a viscous gel. However, the conductivity and dynamics of the electrolyte liquid components are significantly less affected by the addition of the polymer. The observations are explained in terms of the PGE structure, which transitions from a polymer solution to a gel, containing a polymer matrix and disperse electrolyte, at low and high PAN concentrations, respectively. The results highlight the critical role that the polymer concentration plays in determining both the macroscopic properties of the system and the molecular structure of the PGE.
Large-capacity AC superimposed DC power supply for the degradation evaluation of DC-link capacitors
Authors: Zhang Guohao , Li Hua , Li Haobo , Lan Jing , Zhang Qin , Lin Fuchang
Published: April 2023

The DC-link capacitor, whose operating voltage is a periodic irregular waveform, is a key device in the converter. A large-capacity DC/AC superimposed experimental power supply above 100 kVA is an important piece of equipment that must be used in the aging research of DC-link capacitors. The irregular periodic operating voltage of the DC support capacitor is equivalent in the form of DC voltage superimposed with multiple harmonics based on the Fast Fourier transform analysis. The power supply is mainly divided into four parts: an AC module, a DC module, a protection module, and an isolation component. The composited harmonics are output by the IGBT (Insulated Gate Bipolar Transistor) inverter of the AC module. The soft start method is applied to the AC module in order to ensure the long-term reliable operation of the power supply. The kV-level high-voltage is output by four inverter units connected in series. The amplitude and phase control of harmonic decomposition is adopted, and the inverter is controlled by Sinusoidal Pulse Width Modulation. The output voltage of the power supply is close to the operating voltage of the capacitor. Based on the designed power supply, the degradation experiment was carried out. The temperature rise and aging characteristics of DC-link capacitors under different AC/DC ratios were studied.
Transition of a 2D crystal to a non-equilibrium two-phase coexistence state
Authors: Singh Swarnima , Bandyopadhyay P. , Kumar Krishan , Hariprasad M. G. , Arumugam S. , Sen A.
Published: April 2023

In this paper, we present experimental observation of the transition of a 2D dust crystal to a non-equilibrium solid–liquid phase coexistence state. The experiments have been carried out in an L-shaped dusty plasma experimental device in a DC glow discharge argon plasma environment. Initially, a monolayer crystalline structure is formed, which is later transformed to a two-phase coexistence state using the background neutral pressure as a control parameter. Self-excited horizontal oscillations are found in the center of the monolayer prior to the appearance of the coexistence state. It is observed that a molten center coexists with a solid periphery. Various structural, thermodynamic, and dynamical quantities are used to characterize the phase state. The surface tension at the solid–liquid circular interface is also determined. A detailed parametric study is made to delineate the existence region of such a state. It is found that melting caused at the core is due to the onset of a localized Schweigert instability in the presence of a few stray particles beneath the top layer in that region.
Toward developing a comprehensive algorithm for solving kinetic plasma dispersion relations for parallel propagation with a kappa distribution
Authors: Bai Wei , Xie Huasheng
Published: April 2023

In general, it is challenging to numerically solve all the roots of plasma wave dispersion relations. The velocity distributions of multi-component particles in an anisotropic high-energy plasma can be better described by a drift loss-cone bi-Kappa distribution or a mixed drift loss-cone distribution containing bi-Kappa and bi-Maxwellian plasma in space and laboratories. In this work, we have developed a code with a new numerical algorithm to solve all roots of the kinetic dispersion relation for parallel propagation in hot magnetized plasmas with drift loss-cone bi-Kappa distribution. Solving all roots of the rational expansions of the kinetic dispersion relation is equivalent to a matrix eigenvalue problem of a linear system. We have performed detailed numerical solutions for three kinds of plasmas: bi-Maxwellian, bi-Kappa, and cold plasmas. We have also proposed a unified numerical method to solve the mixed dispersion relation based on the bi-Kappa and bi-Maxwellian distributions. The numerical results and benchmark studies demonstrate that the new algorithm is in agreement with the data from previous studies. This is a crucial step toward revealing a full picture of kinetic plasma waves and instabilities.
Transition from ITG to MTM linear instabilities near pedestals of high density plasmas
Authors: McClenaghan J. , Slendebroek T. , Staebler G. M. , Smith S. P. , Meneghini O. M. , Grierson B. A. , Thome K. E. , Avdeeva G. , Lao L. L. , Candy J. , Guttenfelder W.
Published: April 2023

Investigation of linear gyrokinetic ion-scale modes ( k θ ρ s = 0.3) finds that a transition from ion temperature gradient to microtearing mode (MTM) dominance occurs as the density is increased near the pedestal region of a parameterized DIII-D sized tokamak. H-modes profile densities, temperatures, and equilibria are parameterized utilizing the OMFIT PRO_create module. With these profiles, linear gyrokinetic ion-scale instabilities are predicted with CGYRO. This transition (nMTM) has a weak dependence on radial location in the region near the top of the pedestal ( ρ = 0.7 − 0.9), which allows simulating single radii to examine the approximate scaling of nMTM with global parameters. The critical nMTM is found to scale with plasma current. Additionally, increasing the minor radius by decreasing the aspect ratio and increasing the major radius are found to reduce nMTM. However, any relationship between nMTM and density limit physics remains unclear as nMTM increases relative to the Greenwald density with larger minor radius and with larger magnetic field, suggesting that the transport due to MTM may be less important for a reactor. Additionally, nMTM is sensitive to the pedestal temperature, the local electron and ion gradients, the ratio of ion to electron temperature T i / T e, and the current profile. MTMs are predicted to be the dominant instability in the core at similar Greenwald fractions for DIII-D, NSTX, and NSTX-U H-mode experiments, supporting the results of the parameterized study. Additionally, MTMs continue to be the dominant linear instability in a DIII-D L-mode after an H–L transition as the plasma approaches a density limit disruption despite the large change in plasma profiles.
Investigating the effect of surface protrusions on galloping energy harvesting
Authors: Xing Juntong , Rezaei Masoud , Dai Huliang , Liao Wei-Hsin
Published: April 2023

This Letter explores the potential effect of implementing different surface protrusions on galloping energy harvesters. Three types of protruded bluff bodies with rectangular, triangular, and elliptical metasurfaces are proposed, and four kinds of surface treatments are deployed to vary their protruded shape. Wind tunnel experiments reveal that adding the protrusions can obviously change the mode of oscillations, and only the backward protrusions can enhance the galloping response. Both the experiments and simulations show that elliptical surface protrusions have the greatest potential to enhance the galloping energy harvesting performance. Specifically, with a backward protruded length of 15 mm, the maximum output power in the experiments is measured to be 0.757 mW, which occurs at 5.1 m/s, and an optimal load resistance of 300 kΩ. In this case, the energy harvester outperforms its counterpart carrying a simple square prism by 157.48%.
A ring shear device to simulate cryosphere processes
Authors: Zoet L. K. , Sobol P. , Lord N. , Hansen D. D.
Published: April 2023

We have developed a new cryogenic ring shear device at the University of Wisconsin–Madison to simulate cryosphere processes, with an emphasis on the physics of glacier slip. The device spins a ring of ice (inner diameter of 20 cm, outer diameter of 60 cm, height of ∼20–30 cm) at the pressure melting point over a rotationally fixed bed. The ice ring is spun at a prescribed velocity (range of ∼0.01–1000 m a−1) while the resistance to slip is measured. A ram at the base of the device applies a vertical load to the sample chamber to simulate the overburden pressure (range ∼5–915 kPa) felt at a glacier’s base. The sample chamber is constructed with transparent acrylic walls, allowing subglacial processes to be observed directly by a series of cameras. The entire device is housed in a large walk-in freezer. In the freezer, the sample chamber is submerged in a tub of temperature-controlled fluid that precisely regulates heat flux into the sample chamber, replicating in situ conditions and allowing for prolonged experiments that last weeks to months. This device can be used to study several of the most unconstrained physical processes that regulate glacier movement and, in doing so, greatly improve predictions of glacier contributions to sea-level rise.
Near infrared photoluminescence of Si1–xGex quantum dots fabricated by double hot Ge+/Si+ implantation into SiO2 layer
Authors: Mizuno Tomohisa , Murakawa Koki , Sameshima Toshiyuki
Published: April 2023

In this study, we developed very simple and ULSI (ultra large scale integration) compatible fabrication processes for group-IV (Si1–xGex and Si) semiconductor quantum dots (QDs) to apply hybrid ULSIs with photonic and electron devices, using double Ge+/Si+ hot-ion implantation into a SiO2 layer with larger bandgap EG and the post-furnace annealing. We successfully demonstrated the near-infrared (IR) photoluminescence (PL) from Si1–xGex-QDs. Transmission electron microscopy observations of single-crystallized Si1–xGex-QDs revealed that the diameter and the QD density were 3.6 ± 0.9 nm and (2.6 ± 0.4) × 1012 cm−2, respectively. In addition, Ge atoms were detected in the Si1–xGex-QDs by the energy dispersive x-ray spectroscopy analysis, and the Ge fraction of Si1–xGex-QDs was varied from 0.06 to 0.26 by changing the Ge ion dose. The increase in the PL intensity by forming gas annealing was attributed to the dangling-bond reduction by the H-atom termination method. The PL spectrum of Si1–xGex-QDs was fitted by PL components of two QD structures containing Si1–xGex and Si materials. The PL intensity and PL-peak photon energy of Si1–xGex-QDs strongly depended on the Ge fraction. The Si1–xGex-QDs achieved the maximum PL intensity at x ≈ 0.13. High PL-peak photon energy (∼1.31 eV) of Si1–xGex-QDs is attributed to the quantum confinement effect of carriers in QDs. Consequently, group-IV semiconductor QDs including Si1–xGex, Si, SiC, and C, through the simple hot-ion implantation into the SiO2 layer, exhibited a wide range of PL emissions from the near-IR to ultraviolet regions.
Entropy driven disorder–order transition of a metal–organic framework with frustrated flexibility
Authors: Pallach Roman , Weiß Jan-Benedikt , Vollmari Katrin , Henke Sebastian
Published: April 2023

Flexible metal–organic frameworks (MOFs), showing a reversible phase change behavior in response to guest adsorption or temperature, provide unique opportunities for molecular separation or energy storage applications. Herein, we investigate the complex guest- and temperature-responsive behavior of a functionalized MOF-5 derivative. The material is characterized by a geometrically rigid network structure that is decorated with dispersion energy donating hexyloxy substituents. Distinguished by the phenomenon of frustrated flexibility, the functionalized MOF-5 derivative switches between a highly crystalline, cubic structure and a semi-crystalline, aperiodically distorted structure depending on guest adsorption and temperature. Via a combination of several variable temperature global and local structure techniques (x-ray diffraction, x-ray total scattering, and Fourier-transform IR spectroscopy), detailed insights into the complementary disorder–order transitions of the framework backbone and the dangling hexyloxy substituents are provided. Our results set the stage for the discovery of new responsive MOFs exhibiting a more complex phase change behavior interfacing periodic and aperiodic structural changes.
Propulsion of a combined heaving and trailing-edge morphing foil for bio-inspired applications
Authors: Neogi Ishan , Niral Shah Vardhan , Dev Singh Pragalbh , Joshi Vaibhav
Published: April 2023

Locomotion of aquatic animals involves flapping of their body to generate lift and thrust. Through evolution, they have mastered their ability to move through complex environments in an energy-efficient manner. A crucial component of this movement is the ability to actively bend their bodies to generate maximum thrust. This motion is widely termed as morphing. A simplification of this motion is implemented for a foil in this study to realize a thrust-generating bio-inspired device. The propulsive performance of the heaving foil undergoing a prescribed trailing-edge morphing is numerically studied by a stabilized finite element moving mesh formulation. The effects of the morph position and amplitude on the flow dynamics and propulsion of the foil are investigated in the present work. The position of trailing-edge morphing varies from the leading edge to half of the foil's chord, whereas the morph amplitude varies from 10 ° to 60 ° at the trailing edge. The instantaneous thrust is analyzed with vorticity plots and surface pressure diagrams. Within the parametric space, it is found that the foil is highly efficient in generating propulsive forces at high morph amplitudes and low morph positions. The interplay between the thrust-generating leading-edge vortex (LEV) and the drag-inducing trailing-edge vortex (TEV), which governs the thrust cycle of a morphing–heaving foil, is elucidated. It is observed that the LEV-induced thrust is higher at low morph positions, while the TEV-induced drag is dominant at high morph amplitudes. An ideal balance of these opposing effects of LEV and TEV occurs at the lowest morph position and intermediate morph amplitudes, emphasizing the optimal flexibility for the maximum propulsive performance of the foil.
Alfvén mode induced particle loss in LHD
Authors: White Roscoe , Ogawa Kunihiro
Published: April 2023

Losses of beam ions due to Alfvén modes are simulated for discharges in the Large Helical Device at Toki, Japan, using a guiding center code. High frequency beam particle resonances are found for the equilibria for passing particles, providing locations for the destablization of Alfvén modes observed in the device. Losses due to even small modes due to these resonances are significant.
Excited-state dynamics of o-nitrophenol studied with UV pump–VUV probe time-resolved photoelectron and photoion spectroscopy
Authors: McClung Samuel , Abeygunewardane Dakshitha , Matsika Spiridoula , Weinacht Thomas
Published: April 2023

Time-resolved photoionization measurements were performed on o-nitrophenol pumped with UV laser pulses at a central wavelength of 255 nm (4.9 eV) and probed with vacuum ultraviolet (VUV) pulses at 153 nm (8.1 eV). The photoelectron spectrum and time of flight mass spectrum for ions were recorded at each pump–probe delay. The measurements are interpreted with the aid of electronic structure calculations for both the neutral and ionic states. Evidence is found for the formation of a bicyclic intermediate followed by NO dissociation through a process of internal conversion and intersystem crossing. The combination of photoelectron and photoion spectroscopy, together with computational results, provides strong evidence of intersystem crossing that is difficult to establish with only a single technique.
Photofabrication of chiral plasmonic nanospiroids
Authors: Shimomura Koki , Nakane Yuma , Ishida Takuya , Tatsuma Tetsu
Published: April 2023

Nanofabrication of three-dimensional chiral plasmonic structures has been a challenging research topic. In the present study, we shaped dielectric caps on plasmonic gold nanocubes (AuNCs) into three-dimensional nanospiroids by circularly polarized light (CPL) as the chirality source, without using lithographic methods or chiral molecules. AuNCs adsorbed on a TiO2 substrate were irradiated with right or left CPL in the presence of Pb2+ for the deposition of PbO2 on AuNCs. The Au–PbO2 nanocomposites, thus, obtained are the first spiral plasmonic nanostructures prepared by CPL. They exhibit strong and sharp signals of circular dichroism, and the signs of the signals are reversed by changing the rotation direction of the CPL used. Their g-factor values are highest among the chiral plasmonic nanostructures fabricated by CPL.
Helimagnet-based nonvolatile multi-bit memory units
Authors: Islam Rabiul , Li Peng , Beg Marijan , Sachdev Manoj , Miao Guo-Xing
Published: April 2023

In this Letter, we present a design of a helimagnet-based emerging memory device that is capable of storing multiple bits of information per device. The device consists of a helimagnet layer placed between two ferromagnetic layers, which allows us to lock-in specific spin configurations. The bottom pinned layer has high anisotropy energy or stays exchange biased, which keeps its spin configuration fixed on a specific direction, while the top layer is free to rotate under the influence of in-plane magnetic fields. We begin by finding the relaxed spin structure, which is the result of the competition between the Dzyaloshinskii–Moriya interaction (DMI) and exchange energy and is referred to as the equilibrium state (“0”). The writing of a memory state is simulated by applying an in-plane field that rotates and transforms the spin configurations of the memory device. Our results indicate that stable configurations can be achieved at rotations of an integer multiple of 180° (corresponding to states “−2,” “−1,” “1,” “2,” etc.), where the anisotropy stabilizes the free layer and, thus, the exchange coupled helimagnet. These states are separated by magnetic energy barriers and intermediate, unstable spin configurations tend to revert to their adjacent states. By simply changing the direction of the field, we can achieve multi-bit data storage per unit memory cell. The maximum number of bits is reached when the anisotropy energy barriers cannot withstand the strong DMI energy. Reading can be done by evaluating the different resistance states due to the twisted spin texture.
Deterrence through punishment can resolve collective risk dilemmas in carbon emission games
Authors: Jiang Luo-Luo , Chen Zhi , Perc Matjaž , Wang Zhen , Kurths Jürgen , Moreno Yamir
Published: April 2023

Collective risk social dilemmas are at the heart of the most pressing global challenges we are facing today, including climate change mitigation and the overuse of natural resources. Previous research has framed this problem as a public goods game (PGG), where a dilemma arises between short-term interests and long-term sustainability. In the PGG, subjects are placed in groups and asked to choose between cooperation and defection, while keeping in mind their personal interests as well as the commons. Here, we explore how and to what extent the costly punishment of defectors is successful in enforcing cooperation by means of human experiments. We show that an apparent irrational underestimation of the risk of being punished plays an important role, and that for sufficiently high punishment fines, this vanishes and the threat of deterrence suffices to preserve the commons. Interestingly, however, we find that high fines not only avert freeriders, but they also demotivate some of the most generous altruists. As a consequence, the tragedy of the commons is predominantly averted due to cooperators that contribute only their “fair share” to the common pool. We also find that larger groups require larger fines for the deterrence of punishment to have the desired prosocial effect.
Agronomic, phytochemical and drought tolerance evaluation of Iranian cannabis (Cannabis sativa L.) ecotypes under different soil moisture levels: a step towards identifying pharmaceutical and industrial populations
Authors: Asadi Sadegh , Moghaddam Hosein , Naghdi Badi Hassanali , Naghavi Mohammad Reza , Salami Seyed Alireza
Published: April 2023

Context Cannabis is a herbaceous annual plant that belongs to the Cannabaceae family, which is used in the production of fibre, paper, oil and pharmaceutical products. Aims The aim of this study was to identify drought-tolerant ecotypes and medicinal and industrial populations. Methods Due to the medicinal and industrial importance of cannabis, 12 cannabis ecotypes were collected from different regions of Iran. Then, their agronomic and phytochemical characteristics were evaluated under different soil moisture conditions. Key results The soil moisture levels had significant effects (P < 0.01) on the studied traits except for the 1000 seed weight. Based on duration of the growth period, the Tabas and Dasht-e-Moghan ecotypes were identified as early and late maturing ecotypes, respectively. Also, the highest stem dry weight and stem height/diameter ratio and the lowest seed yield were related to the Dasht-e-Moghan ecotype, which is valuable for fibre production. Based on seed yield (relative reduction) and some tolerance indexes, the Tabas and Tabrize ecotypes were shown to be the most tolerant and sensitive ecotypes, respectively. As soil moisture decreased, tetrahydrocannabinol levels increased and cannabidiol levels decreased. The highest amount of tetrahydrocannabinol was related to the Qom ecotype at 50% soil moisture and the highest amount of cannabidiol was related to the Rasht ecotype at 100% soil moisture. Conclusions Generally, these ecotypes had different responses to soil moisture. Some ecotypes were valuable in terms of the production of pharmaceutical metabolites and some in terms of fibre production. Implications Tolerant and sensitive ecotypes might be considered in production and also breeding programs.
Historical imprints on Chinese ideological given names
Authors: Su Heng , Sabet Peyman G. P. , Zhang Grace Q.
Published: April 2023

This diachronic study investigates Chinese ideological given names (personal names which represent the name-givers’ shared ideas and beliefs) by focusing on historical changes over five time periods between 1935 and 2012. Based on an analysis of 21,687 given names, 2,687 (12.4%) of which are ideological names, the study finds that naming practices bear historical imprints in terms of content and syllabic form. The more intensely a society is politicized, the higher the rate of occurrence of ideological given names. The data also illustrate the dynamic that exists in naming practices between conformity and individuality. In this article, we argue that names are like social cards: people play them to serve their ideological needs, as shown by the evolution of naming strategies through different historical periods. The implication is that historical changes can influence the way in which a name can communicate ideological views.
Quambalaria eucalypti (Wingfield, Crous & Swart) Simpson
Authors: CABI  , EPPO
Published: April 2023

A new distribution map is provided for Quambalaria eucalypti (Wingfield, Crous & Swart) Simpson. Ustilaginomycotina: Microstromatales: Quambalariaceae. Hosts: Spotted gum (
Corymbia spp.
);
Eucalyptus spp.
; Myrceugenia glaucescens.
Autolysosomal exocytosis of lipids protect neurons from ferroptosis
Authors: Ralhan Isha , Chang Jinlan , Moulton Matthew J. , Goodman Lindsey D. , Lee Nathanael Y.J. , Plummer Greg , Pasolli H. Amalia , Matthies Doreen , Bellen Hugo J. , Ioannou Maria S.
Published: April 2023

During oxidative stress neurons release lipids that are internalized by glia. Defects in this coordinated process play an important role in several neurodegenerative diseases. Yet, the mechanisms of lipid release and its consequences on neuronal health are unclear. Here, we demonstrate that lipid-protein particle release by autolysosome exocytosis protects neurons from ferroptosis, a form of cell death driven by lipid peroxidation. We show that during oxidative stress, peroxidated lipids and iron are released from neurons by autolysosomal exocytosis which requires the exocytic machinery VAMP7 and syntaxin 4. We observe membrane-bound lipid-protein particles by TEM and demonstrate that these particles are released from neurons using cryoEM. Failure to release these lipid-protein particles causes lipid hydroperoxide and iron accumulation and sensitizes neurons to ferroptosis. Our results reveal how neurons protect themselves from peroxidated lipids. Given the number of brain pathologies that involve ferroptosis, defects in this pathway likely play a key role in the pathophysiology of neurodegenerative disease.
Quantum cosmology of pure connection general relativity
Authors: Gielen Steffen , Nash Elliot
Published: April 2023

We study homogeneous cosmological models in formulations of general relativity with cosmological constant based on a (complexified) connection rather than a spacetime metric, in particular in a first order theory obtained by integrating out the self-dual two-forms in the chiral Plebański formulation. Classical dynamics for the Bianchi IX model are studied in the Lagrangian and Hamiltonian formalism, where we emphasise the reality conditions needed to obtain real Lorentzian solutions. The solutions to these reality conditions fall into different branches, which in turn lead to different real Hamiltonian theories, only one of which is the usual Lorentzian Bianchi IX model. We also show the simpler case of the flat Bianchi I model, for which both the reality conditions and dynamical equations simplify considerably. We discuss the relation of a real Euclidean version of the same theory to this complex theory. Finally, we study the quantum theory of homogeneous and isotropic models, for which the pure connection action for general relativity reduces to a pure boundary term and the path integral is evaluated immediately, reproducing known results in quantum cosmology. An intriguing aspect of these theories is that the signature of the effective spacetime metric, and hence the interpretation of the cosmological constant, are intrinsically ambiguous.
A micro packed preconcentrator using ionic liquid coated graphitized carbons for detection of low concentration isoprene
Authors: Wu Xinyu , Wang Dazuo , Zhang Kangning , Hua Xinyuan , Wang Hairong , Sun Jianhai
Published: April 2023

Analysis of volatile organic compounds in the human exhaled mixture is a promising disease screening approach, and isoprene is a typical biomarker for nonalcoholic fatty liver disease in breath diagnosis. However, accurate detection of trace isoprene (ppb) is difficult due to the interfering effect of various gas sensors. In this study, we developed an integrated silicon-based micro preconcentrator (micro-PC) as a pretreatment component of the portable gas chromatography (GC) system. The device was the structure of parallel micro channels with flat dimensions of 20 mm × 10 mm on the silicon substrate, and the total internal empty volume is about 18 μl. The micro electro mechanical system processes were used to fabricate the micro channels and the heating and temperature measuring resistances. The preconcentrator was filled with graphitized carbons with ionic liquids coating as an adsorbent. In the experiments, a GC equipped with a flame ionization detector was used to characterize the preconcentration performance. The micro-PC has a preconcentration factor (PF) value up to 49.8 for 100 ppb isoprene in 5 min adsorption time. Under the same conditions, the PF value of micro-PC using the modified adsorbent was 3.3 times higher than that using the commercial functional material. Besides, the fabricated preconcentrator had excellent desorption efficiency and good humidity resistance. These results indicated that the micro-PC we developed had a potential application in the micro GC system for non-invasive screening of chronic liver related diseases by detecting the trace isoprene.
Modeling and simulation of erbium-ytterbium co-doped optical waveguide amplifiers with dual-wavelength pumping at 980 nm and 1480 nm
Authors: Tao Siliang , Yan Jinming , Song Hangyu , Wei Jiashuo , Fu Yuewu , Zhao Dan , Wang Fei , Zhang Daming
Published: April 2023

With the rapid development of silicon photonic chips and integrated photonic circuits, erbium-doped optical waveguide amplifiers have received more and more attention in order to compensate for the transmission and coupling losses caused by the integration of optical devices on a chip. Pumping wavelength and pumping efficiency directly affect the gain and noise figure of the amplifier. In this paper, we propose an innovative dual-wavelength pumping method based on an erbium-ytterbium co-doped optical waveguide amplifier with simultaneous pumping at 980 nm and 1480 nm. A relaxation method based on the fourth-order Range-Kutta method is used to solve the rate and propagation equations and simulate the gain characteristics of the dual-wavelength pumping method for different ytterbium-erbium ion concentration ratios, erbium ion concentrations and ratio K between the 980 nm and total pump power. From the simulation results, it can be seen that the gain of the dual-wavelength pumping method is higher than that of the single-wavelength pumping methods when the erbium ion concentration exceeds 3 × 1026 m−3. At higher erbium ion concentrations, the dual-wavelength pumping method can provide higher gain for optical waveguide amplifiers, and may be able to become a new choice of pumping method for optical waveguide amplifiers.
The effects of electric field and strain on the BP/GeTe van der Waals heterojunction
Authors: Wang Xinxin , Chen Jiale , Shi Lijie , Ma Jie
Published: April 2023

Recently, van der Waals heterojunctions (vdWHs) constructed from two two-dimensional materials have attracted considerable attention. In particular, vdWHs based on black phosphorus (BP) have shown excellent photoelectric properties. In this work, we construct a BP/GeTe vdWH and investigate its electronic and optical properties. We find that the BP/GeTe vdWH has a type-II band alignment. Its optical absorption exhibits a red shift compared to the freestanding BP and GeTe monolayers. The electric field and strain effects on the BP/GeTe vdWH are also investigated. The band offsets can be modulated by the electric field and the strain. The BP/GeTe vdWH will convert from type-II to type-I when applying an electric field and to type-III under strain, which will expand the application of BP/GeTe vdWHs in transistor devices. Furthermore, the strain can significantly enhance the optical absorption and induce the red shift of the absorption edge, which indicates the broad applications of the BP/GeTe vdWH in photodetector devices.
Magnetic transitions of hydrogenated H
x
CrO2 (x = 0–2) monolayer from a ferromagnetic half-metal to antiferromagnetic insulator
Authors: Ouyang Wenbin , Shi Bowen , Su Tianhao , Cheng Xuli , Gao Heng , Jia Fanhao , Whangbo Myung-Hwan , Ren Wei
Published: April 2023

Two-dimensional (2D) transition metal oxide monolayers are currently attracting great interest in materials research due to their versatility and tunable electronic and magnetic properties. In this study, we report the prediction of magnetic phase changes in H
x
CrO2 (0 ⩽ x ⩽ 2) monolayer on the basis of first-principles calculations. As the H adsorption concentration x increases from 0 to 0.75, H
x
CrO2 monolayer transforms from a ferromagnetic (FM) half-metal to a small-gap FM insulator. When x = 1.00 and 1.25, it behaves as a bipolar antiferromagnetic (AFM) insulator, and eventually becomes an AFM insulator as x increases further up to 2.00. The results suggest that the magnetic properties of CrO2 monolayer can be effectively controlled by hydrogenation, and that H
x
CrO2 monolayers have the potential for realizing tunable 2D magnetic materials. Our results provide a comprehensive understanding of the hydrogenated 2D transition metal CrO2 and provide a research method that can be used as a reference for the hydrogenation of other similar 2D materials.