bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Methylprednisolone in the Treatment of Spinal Cord Injuries by Evaluation of microRNA-21: An Experimental Study
Authors: Abdallah Anas , Tekin Abdurrahim , Oztanir Mustafa Namik , Süsgün Seda , Yabacı Ayşegül , Çınar İrfan , Can Engin , Tokar Sadık , Akbaş Fahri , Seyithanoğlu Mehmet Hakan
Published: April 2022

Background and Study Aims Spinal cord injury (SCI) is one of the most complicated pathologies that affect active young males. miR-21 primarily regulates several cellular processes. We aimed to elucidate the regulatory role of miR-21 and test methylprednisolone as a disease-modifying agent on experimental SCI tissues.

Methods A total of 36 8- to 10-week-old adult female Sprague-Dawley rats weighing 250 to 300 g were used. Animals were randomly divided into six groups. Except for groups 1 and 4, the spinal trauma model was applied to all animal groups using the clipping method. In groups 3 and 6, methylprednisolone was given. For real-time polymerase chain reaction (PCR) investigations, rats in groups 1, 2, and 3 were reoperated on after the first postoperative day, whereas those in groups 4, 5, and 6 were reoperated on after postoperative day 7 and spinal cord samples from the laminectomy area were removed for gene expression analysis. Relative gene expression of miR-21, Gfap, Vim, Stat3, Faslg, Pten, Bax, Bcl2, Cox2, and Il6 were determined with quantitative reverse transcription (qRT) PCR.

Results In group 3, the miR-21 expression significantly increased compared with groups 1 and 2. When compared with group 3, a decrease in miR-21 expression was observed in group 6 (p < 0.05). When compared with group 4, group 6 had lower levels of Gfap, Pten, Stat3, and Bax (p < 0.05).

Conclusions miR-21 supports the beneficial aspects of the body's healing mechanisms following SCI. In the acute phase, the use of methylprednisolone increases miR-21 expression in the early period of trauma. Methylprednisolone increases some astrogliosis and inflammation biomarkers' levels; however, it did not affect the apoptotic biomarkers.
Recognizing Kounis Syndrome, the Unusual Possible Culprit of Acute Coronary Syndrome: A Rare Case Report
Authors: Kamarullah William , Firmansyah Dena Karina
Published: April 2022

Kounis syndrome encompasses acute coronary syndrome features associated with severe vasospasm of the coronary artery. It is related to allergic anaphylactic reaction triggered by the release of inflammatory cells and mediators. This entity, however, is often not properly diagnosed. In this report, we aimed to discuss a case of Kounis syndrome mimicking acute coronary syndrome. We presented a 58-year-old man with dyspnea, chest pain, dizziness, and itchiness 30 minutes following sodium diclofenac ingestion. His physical examination was remarkable for shock with hypoxia and features of anaphylactic reaction. An urgent electrocardiogram was obtained, manifesting deep ST-segment depression in anterolateral leads with ST elevation of aVR, which hinted a severe three-vessel disease or left main disease. Allergic acute coronary syndrome was suspected. Thus, the patient was managed with fluid resuscitation, epinephrine, and corticosteroid injection along with acute coronary syndrome treatment algorithm with a favorable clinical response. One-hour serial ECG showed complete resolution of ST depression with aVR normalization. This pointed to possible acute coronary spasm. No further coronary intervention was performed, the patient was discharged after 2 days in good condition and planned for further cardiac evaluation during follow-up. Kounis syndrome is an intriguing process caused by the presence of two disease entities that must be treated simultaneously. The difficulty in treating this condition stems from the fact that treating one of both entities may aggravate the other. Thus, a comprehensive approach and health education are strongly advised to ensure that this condition does not reoccur in the future.
Randomized Double-Blind Comparative Study of First Global Denosumab Biosimilar in Oncology
Authors: Apsangikar Prasad , Shirsath Prashant , Naik Manoj , Vasudeva Sonya
Published: April 2022

Purpose The aim of this study was to compare first global biosimilar denosumab for the prevention of skeletal-related events (SREs) in patients with bone metastases from solid tumors.

Methods It was a randomized, double-blind, comparative clinical study. Total of 136 patients of solid tumor were dosed (i.e., 102 subjects in study arm and 34 subjects in the reference arm) with initial double-blind period of 24 weeks (primary efficacy) followed by open-label phase till week 36. Primary endpoint was the incidence of first on-study SRE including hypercalcemia of malignancy with co-primary endpoint of median time to first on-study SRE. Secondary endpoints included mean number and time to first and subsequent on-study SREs (week 12, 24, 36), incidence/proportion of patients with first and subsequent on-study SREs (week 24, 36), change from baseline in nuclear bone scan, quality of life assessment, pharmacokinetics, pharmacodynamic, and safety.

Results In biosimilar study arm, 06 (5.83%) patients suffered SRE from baseline to week 24 compared with 02 (5.71%) patients in reference arm with one (0.97%) patient showing pathological fracture in study arm and one (2.86%) patient having spinal cord compression in reference arm. There was no statistically significant difference in median time to first SRE, mean number of SRE/patient in both arms and improvement in bone repair on nuclear scan at 12, 24 and 36 weeks. Though the study arm showed better health-related quality of life (HRQoL), mean change in HRQoL was statistically not different in both the arms. Pharmacodynamics, serum bone-specific alkaline phosphatase, pharmacokinetic and safety evaluation did not show any statistical difference between arms.

Conclusion There was no clinically meaningful difference in the biosimilar denosumab and reference product after detailed efficacy and safety evaluation.
Continuous motion estimation of lower limbs based on deep belief networks and random forest
Authors: Wang Fei , Lu Jian , Fan Zhibo , Ren Chuanjian , Geng Xin
Published: April 2022

Due to the lag problem of traditional sensor acquisition data, the following movement of exoskeleton robots can affect the comfort of the wearer and even the normal movement pattern of the wearer. In order to solve the problem of lag in exoskeleton motion control, this paper designs a continuous motion estimation method for lower limbs based on the human surface electromyographic (sEMG) signal and achieves the recognition of the motion intention of the wearer through a combination of the deep belief network (DBN) and random forest (RF) algorithm. First, the motion characteristics of human lower limbs are analyzed, and the hip–knee angle and sEMG signal related to lower limb motion are collected and extracted; then, the DBN is used in the dimensionality reduction of the sEMG signal feature values; finally, the motion intention of the wearer is predicted using the RF model optimized by the genetic algorithm. The experimental results show that the root mean square error of knee and hip prediction results of the combined algorithm proposed in this article improved by 0.2573° and 0.3375°, respectively, compared to the algorithm with dimensionality reduction by principal component analysis, and the single prediction time is 0.28 ms less than that before dimensionality reduction, provided that other conditions are exactly the same.
Soft quantum waveguides in three dimensions
Authors: Exner Pavel
Published: April 2022

We discuss a three-dimensional soft quantum waveguide, in other words, Schrödinger operator in R3 with an attractive potential supported by an infinite tube and by keeping its transverse profile fixed. We show that if the tube is asymptotically straight, the distance between its ends is unbounded, and its twist satisfies the so-called Tang condition, the essential spectrum is not affected by smooth bends. Furthermore, we derive a sufficient condition, expressed in terms of the tube geometry, for the discrete spectrum of such an operator to be nonempty.
Hermitian and non-Hermitian perturbations of chiral Gaussian β-ensembles
Authors: Alpan Gökalp , Kozhan Rostyslav
Published: April 2022

We compute the joint eigenvalue distribution for the rank one Hermitian and non-Hermitian perturbations of chiral Gaussian β-ensembles (β > 0) of random matrices.
Alloyed β-(AlxGa1−x)2O3 bulk Czochralski single β-(Al0.1Ga0.9)2O3 and polycrystals β-(Al0.33Ga0.66)2O3, β-(Al0.5Ga0.5)2O3), and property trends
Authors: Jesenovec Jani , Dutton Benjamin , Stone-Weiss Nicholas , Chmielewski Adrian , Saleh Muad , Peterson Carl , Alem Nasim , Krishnamoorthy Sriram , McCloy John S.
Published: April 2022

In this work, bulk Czochralski-grown single crystals of 10 mol. % Al2O3 alloyed β-Ga2O3—monoclinic 10% AGO or β-(Al0.1Ga0.9)2O3—are obtained, which show +0.20 eV increase in the bandgap compared with unintentionally doped β-Ga2O3. Further, growths of 33% AGO—β-(Al0.33Ga0.67)2O3—and 50% AGO—β-(Al0.5Ga0.5)2O3 or β-AlGaO3—produce polycrystalline single-phase monoclinic material (β-AGO). All three compositions are investigated by x-ray diffraction, Raman spectroscopy, optical absorption, and 27Al nuclear magnetic resonance (NMR). By investigating single phase β-AGO over a large range of Al2O3 concentrations (10–50 mol. %), broad trends in the lattice parameter, vibrational modes, optical bandgap, and crystallographic site preference are determined. All lattice parameters show a linear trend with Al incorporation. According to NMR, aluminum incorporates on both crystallographic sites of β-Ga2O3, with a slight preference for the octahedral (GaII) site, which becomes more disordered with increasing Al. Single crystals of 10% AGO were also characterized by x-ray rocking curve, transmission electron microscopy, purity (glow discharge mass spectroscopy and x-ray fluorescence), optical transmission (200 nm–20 μm wavelengths), and resistivity. These measurements suggest that electrical compensation by impurity acceptor doping is not the likely explanation for high resistivity, but rather the shift of a hydrogen level from a shallow donor to a deep acceptor due to Al alloying. Bulk crystals of β-(Al0.1Ga0.9)2O3 have the potential to be ultra-wide bandgap substrates for thin film growth, with a lattice parameter that may even allow higher Al concentration β-Ga2O3 single crystal thin films to be grown.
Excitation of tunable plasmons in silicon using microwave transmission through a metallic aperture
Authors: Ghalgaoui Ahmed , Reimann Klaus
Published: April 2022

Plasmon resonances in semiconductors at microwave frequencies offer the possibility for many functionalities and integration schemes. Semiconductor materials, such as germanium, gallium arsenide, and silicon, have the further advantage of being able to be integrated with standard electronics technology. Here, we probe the bulk plasmon modes in silicon in the vicinity of a copper plate perforated by a single aperture at frequencies between 10 and 60 GHz. Sharp transmission minima are observed at discrete frequencies. The observed frequencies depend on the size of the aperture and the carrier concentration in the silicon; they are well reproduced by the dispersion relation for bulk plasmons. Our results show that one can excite plasmons in silicon in the millimeter-wave region, opening a route to microwave plasmonics for large-scale applications, using low-cost technology.
The bipolar charge plasma spectrometer (BCPS) based on the 2π-field-of-view double-channel electrostatic analyzer
Authors: Su B. , Kong L. G. , Zhang A. B. , Tian Z. , Wang W. J. , Lv Y. L. , Ma L. Y.
Published: April 2022

In this paper, we propose a bipolar charge plasma spectrometer based on the double-channel electrostatic analyzer for simultaneously measuring thermal ions and electrons with a 2π hemispherical field-of-view. Both ions and electrons within the wide field-of-view enter the spectrometer, pass through the variable geometric factor channel, and are then separated by the double-channel electric fields. Two microchannel plates are accommodated at the exit of the analyzer for ion and electron detection. The main performance of the spectrometer has been obtained from on-ground calibration. With the electrostatic deflectors and the cylindrically symmetric structure, the spectrometer provides simultaneous measurements of thermal ion and electron velocity distributions with a shared field-of-view of 360° (azimuth angle) by 90° (elevation angle) and a broad energy range for both ions and electrons. The ion analyzer constant and the electron analyzer constant are 11.1 and 9.7, respectively. The detecting energy range of 33.3–44.4 keV for ions and 29.1–38.8 keV for electrons can be obtained by using the sweeping electrostatic analyzer voltage range of 3–4000 V. The ion and electron energy resolutions are 9.6% and 6.1%, respectively. The variable geometric factor function provides a large geometric factor adjusting range for both ion and electron measurements by two orders of magnitude, which fulfills the requirements of a large dynamic flux range for simultaneous measurements of space thermal plasma in the solar wind and magnetosphere.
Straintronic effect on electronic transport and metal–insulator transition in correlated metal films by electric field
Authors: Zheng Ming , Guan Pengfei , Qi Yaping , Guo Litong
Published: April 2022

Tuning the electronic and magnetic properties of strongly correlated oxides by exerting an electric field is of great significance for understanding the mechanisms of striking quantum phenomena and delivering low-dissipation electronic devices. Here, we demonstrate a linear suppression of electrical resistivity for correlated metallic SrVO3 epitaxial films in a continuous and reversible fashion through the converse piezoelectric response-generated linear lateral compressive strain of ferroelectric Pb(Mg1/3Nb2/3)O3-PbTiO3 substrates. By precisely tailoring the polarization domain configuration of the substrate, a lateral tensile strain can also be dynamically induced into films and, thus, can robustly increase the resistivity due to reduced effective electronic bandwidth and enhanced electron–electron interaction. Particularly, the electrically triggered nonvolatile opening and closing of a metal–insulator transition is driven by the ferroelastic strain-controlled Mott gap. Our findings illustrate the vital role of an electric field in controlling the lattice degree of freedom and electron correlation and provide a framework for exploring the essential physics of the straintronic effect in correlated metallic oxides.
Non-existence of classical solutions with finite energy to the Cauchy problem of the Navier–Stokes–Korteweg equations
Authors: Tang Tong
Published: April 2022

This paper concerns the compressible Navier–Stokes–Korteweg equations. Based on previous work [Li et al., Arch. Ration. Mech. Anal. 232, 557–590 (2019)], we prove that the classical solution with finite energy does not exist in the inhomogeneous Sobolev space for any short time under some natural assumptions on initial data near the vacuum.
Large eddy simulations and modal decomposition analysis of flow past a cylinder subject to flow-induced vibration
Authors: Janocha Marek Jan , Ong Muk Chen , Yin Guang
Published: April 2022

Large eddy simulations (LES) are carried out to investigate the flow around a vibrating cylinder in the subcritical Reynolds number regime at Re = 3900. Three reduced velocities, Ur = 3, 5, and 7, are chosen to investigate the wake structures in different branches of a vortex-induced vibration (VIV) lock-in. The instantaneous vortical structures are identified to show different coherent flow structures in the wake behind the vibrating cylinder for various branches of VIV lock-in. The combined effects of the frequency and amplitude of the oscillation on the flow pattern in the wake region, the hydrodynamic quantities of the cylinder, and the spanwise length scale of the energetic wake flow structures are discussed in detail. It is found that the typical spanwise lengths of the flow structures are 0.22D at Ur = 5 and 0.3D at Ur=[3,7] in the near-wake region and level out at 0.5D further downstream. Furthermore, multiscale proper orthogonal decomposition (mPOD) is used to analyze the dominant flow features in the wake region. With the increasing Ur, the total kinetic energy contribution of superharmonic modes increases and the contribution of subharmonic modes decreases. The dominant flow characteristics associated with the vortex shedding and their super harmonics, and the low-frequency modulation of the wake flow can be captured by the mPOD modes.
Period finding and prime factorization using classical wave superposition
Authors: Balinskiy Michael , Khitun Alexander
Published: April 2022

Prime factorization is a procedure of determining the prime factors of a given number N that requires super-polynomial time for conventional digital computers. Peter Shor developed a polynomial-time algorithm for quantum computers. Period finding is the key part of the algorithm, which is accomplished with the help of quantum superposition of states and quantum entanglement. The period finding can be also accomplished using classical wave superposition. In this study, we present experimental data obtained on a multi-port spin wave interferometer made of Y3Fe2(FeO4)3. Number 817 was factorized by a sequence of phase measurements. We also present the results of numerical modeling on the prime factorization of larger numbers 334597,1172693,3377663,and9363239. The results of numerical modeling reveal significant shortcomings of the period-based approach. The major problems are associated with an inability to predict the period of the modular function, significant overhead over classical digital computers in some cases, and phase accuracy requirements. We argue that the same problems are inherent in classical analog and quantum computers.
Theoretical calculation and particle-in-cell simulation of a multi-mode relativistic backward wave oscillator operating at low magnetic field
Authors: Xiao Renzhen , Chen Kun , Wang Huida , Wang Dongyang , Shi Yanchao , Gao Lei
Published: April 2022

Increasing the dimensions of high power microwave devices is an efficient method to improve the power capacity. However, an overmoded structure usually results in mode competition and a low beam-wave conversion efficiency. In this paper, a multi-mode operation mechanism is used to avoid mode competition and increase the efficiency. The calculation results of nonlinear theory of beam-multimode interaction show that the optimized conversion efficiency is up to 48% when TM01 mode, TM02 mode, and TM03 mode are all considered. As only the TM01 mode, TM02 mode, or TM03 mode is taken into account independently, the corresponding efficiency is 38%, 22%, or 20%. Based on this, a multi-mode relativistic backward wave oscillator is proposed with the ratio of the mean diameter of the slow wave structure (SWS) to the wavelength of the output microwave to be 3.5. The non-uniform SWS is used to increase the beam-wave conversion efficiency, and a combined reflector is adopted to reflect partial of the mixed microwave modes and make the device compact. The particle-in-cell simulations show that as the diode voltage is 1.1 MV, the beam current is 22.8 kA, and the external magnetic field is 0.76 T, the conversion efficiency is 45%, and the output microwave of 11.3 GW is the mixed modes of TM01 mode, TM02 mode, and TM03 modes with the corresponding power ratio of 74%, 7%, and 19%, respectively.
Numerical modeling on the bit error rate of EHF communication in time-varying hypersonic plasma sheath
Authors: Yang Xiaocui , Yuan Kai , Wang Yuhao , Mao Mingyang
Published: April 2022

Plasma sheaths enveloping hypersonic vehicles could yield a communication blackout. Many previous studies have shown that the electromagnetic wave in an extremely high frequency (EHF) band could penetrate a hypersonic plasma sheath effectively. In other words, the EHF communication could be a potential solution to the communication blackout problem. Nevertheless, most of those works used to concern only the EHF signal attenuation. In addition, those works normally treated plasma sheaths as a static plasma layer. However, plasma sheaths always keep evolving. In the present study, the modulated EHF signal propagation in a time-varying plasma sheath was investigated numerically. The plasma sheath was obtained with a hypersonic hydrodynamical model that has been utilized in previous studies. The EHF signal propagation was modeled based on theories of geometrical optics. The frequencies studied are 94, 140, and 225 GHz. The investigation revealed that not only signal attenuation but also the phase shifts for carrier waves vary with time. Their impact on the bit error rate (BER) of the EHF communication system was studied numerically. The modulation modes concerned in the present study are 2ASK, 2PSK, 4QAM, and Non-Coherent demodulation 2FSK (NC-2FSK). According to the study, the BER keeps varying with time. This study also showed that the BER is impacted by the carrier frequency, modulation mode, and the demodulation method. According to the comparison and the analysis, the suggested modulation modes are 2PSK and 4QAM at the carrier frequency of 140 GHz, which could lead to smaller and more stable BER for the EHF communication system utilized by hypersonic vehicles.
Flux ramp modulation based hybrid microwave SQUID multiplexer
Authors: Schuster Constantin , Wegner Mathias , Enss Christian , Kempf Sebastian
Published: April 2022

We present a hybrid microwave superconducting quantum interference device (SQUID) multiplexer that combines two frequency-division multiplexing techniques to allow multiplexing a given number of cryogenic detectors with only a fraction of frequency encoding resonators. Similar to conventional microwave SQUID multiplexing, our multiplexer relies on inductively coupling non-hysteretic, unshunted rf-SQUIDs to superconducting microwave resonators as well as applying flux ramp modulation for output signal linearization. However, instead of utilizing one resonator per SQUID, we couple multiple SQUIDs to a common readout resonator and encode the SQUID input signals in sidebands of the microwave carrier by varying the flux ramp modulation frequency for each SQUID. We prove the suitability of our approach using a prototype device and argue by means of fundamental information theory that our approach is particularly suited for reading out large cryogenic bolometer arrays.
Non-destructive inspection of water or high-pressure hydrogen gas in metal pipes by the flash of neutrons and x rays generated by laser
Authors: Wei Tianyun , Yogo Akifumi , Hayakawa Takehito , Arikawa Yasunobu , Abe Yuki , Nakanishi Maiko , Mirfayzi Seyed Reza , Lan Zechen , Mori Takato , Mima Kunioki , Fujioka Shinsuke , Murakami Masakatsu , Nakai Mitsuo , Nishimura Hiroaki , Kar Satyabrata , Kodama Ryosuke
Published: April 2022

The thermal and epithermal neutrons are powerful probes to inspect water or high-pressure hydrogen gas because of their large scattering cross-sections with protons. Laser-driven neutron source, which is able to simultaneously emit different types of radiations such as x rays, can be used for neutron and x-ray radiography in the same laser shot. In this paper, we report the demonstration of non-destructive inspection for H2O contained within a stainless steel pipe using a laser-driven thermal neutron source, where water and stainless containers are detected by neutrons and x rays, respectively. The simulation result indicates that this method can also provide the capability to measure the hydrogen density in high-pressure hydrogen gas in metal containers.
Anisotropic colloidal particles near boundaries
Authors: Yan Jiarui , Wirth Christopher L.
Published: April 2022

Anisotropic colloidal particles are regularly found in applications ranging from health to energy. These particles, typically with non-uniform shape or surface chemistry, interact with boundaries in unique ways, offering pathways to complex assemblies and active systems. Work in this field over the past two decades rapidly advanced, with the last five years seeing significant innovation. One common thread joining many studies and applications is that of the presence of boundaries in the form of a nearby wall or neighboring particle. Asymmetry introduced by a neighboring boundary often leads to unique and surprising particle dynamics from the resulting anisotropic surface interactions. Herein, we provide background for the area, some recent distinctive examples, and describe recent work from our group developing a technique to measure surface interactions of anisotropic particles. Note that we focused on anisotropic “colloidal” particles with the size ranging from 0.1 to 10 μm in the presence of externally or internally generated fields. Within this context, we then motivate and describe recent work from our group developing an ultra-microscopy technique called Scattering Morphology Resolved Total Internal Reflection Microscopy. Finally, we finish the perspective article by identifying challenges and providing an outlook for the field.
Chemical reaction of Ni/Al interface associated with perturbation growth under shock compression
Authors: Xie Yifan , Shao Jian-Li , Liu Rui , Chen Pengwan
Published: April 2022

The exothermic reaction of Ni/Al laminates always starts from the interface, and the role of interfacial instability in the shock-induced chemical reaction has not been clarified. This work reports the Richtmyer–Meshkov (RM) instability growth, atomic diffusion, and chemical reaction of Ni/Al interface under shock compression based on atomistic simulations. For shocking from Al to Ni, the interface experiences finite collapse and exhibits weak localized reaction. The diffusion of solid Ni to molten Al will be inhibited due to the formation of NiAl phase, and continuous inter-diffusion occurs with the melting of Ni. For shocking from Ni to Al, a small amount of NiAl structure is formed due to the atomic residue during defect collapse. RM instability growth is observed at higher shock intensity, which significantly promotes the atomic mixing and results in a power-law increase in the number of diffusing atoms. Meanwhile, the chemical reaction propagates rapidly from the vortex to the head of the spike accompanied by the decomposition of many clusters, with the nonlinear development of RM instability. The number and the size of Ni clusters no more satisfy the simple power-law relationship for which we propose an improved power-law distribution. Interestingly, the growth of nanoscale perturbation approximately satisfies the logarithmic law with time, but the linear growth stage is inhibited due to significant inter-diffusion, especially for the small wavelength. Thus, the mixing width and the reaction degree are positively correlated with the initial wavelength in our simulation scale, which is contrary to the RM growth law of the free surface.
Blood coagulation monitoring under static and flow conditions with optical coherence tomography autocorrelation analysis
Authors: Tang Yun , Zhu Jiang , Zhu Lianqing , Fan Fan , Ma Zongqing , Zhang Fan
Published: April 2022

Detection of blood coagulation functions is essential for diagnosing blood diseases and treating vascular diseases. The viscoelasticity changes of the blood from a liquid to a clot can provide critical information for assessing blood coagulation. Here, we reported on noncontact monitoring of blood coagulation under static and flow conditions with optical coherence tomography (OCT) autocorrelation analysis. After OCT imaging, blood tissue dynamics were assessed by the OCT autocorrelation analysis during coagulation of the whole porcine blood. The properties of blood coagulation were quantitatively evaluated by three metrics, including the coagulation reaction time, the clot formation duration, and the maximum clot strength. The results show that the OCT autocorrelation method can quantify the coagulation properties under static and flow conditions and provides a unique opportunity for in situ coagulation detection and point-of-care testing.
Conformation-related excited-state charge transfer/separation of donor-π-acceptor chromophores
Authors: Kong Jie , Zhang Wei , Zhang Xiaomin , Liu Bo , Li Yang , Xia Andong
Published: April 2022

Understanding the excited-state charge transfer/separation (CT/CS) of donor-π-acceptor chromophores can provide guidance for designing and synthesizing advanced dyes to improve the performance of dye-sensitized solar cells (DSSCs) in practical applications. Herein, two newly synthesized electronic push–pull molecules, CS-14 and CS-15, that consist of carbazole donor and benzothiadiazole acceptor segments are chosen to explore the ultrafast dynamics of intramolecular CT/CS processes. The theoretical calculation results depict an excited-state intramolecular CT character for both dyes, while the dihedral angle between donor and acceptor of CS-14 is larger than that of CS-15, suggesting a more significant CT character of CS-14. Furthermore, compared to CS-14, the bond rotation of CS-15 between donor and π-bridge is restricted by employing the hexatomic ring, indicating the stronger molecular planarization of CS-15. Ultrafast spectroscopy clearly shows a solvent polarity-dependent excited-state species evolution from CT to CS—the CT character is observed in low-polar toluene solvent, while the feature of the CS state in polar tetrahydrofuran and acetone solvents is captured, which successfully proved a solvent polarity modulated excited-state CT/CS characters. We also found that though the generation of the CS state within CS-14 is slightly faster than that of CS-15, the charge recombination process of CS-15 with excellent planar conformation is much slower, providing enough time for a higher charge migration efficiency in DSSCs.
Nitrogen accumulation and remobilisation in wheat and barley plants exposed to waterlogging at different developmental stages
Authors: de San Celedonio Romina P. , Abeledo L. Gabriela , Striker Gustavo G. , Miralles Daniel J.
Published: April 2022

Context Although waterlogging is known to decrease grain yield in wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.), its effect on plant N traits is still unknow. Aims This study evaluated biomass N dynamics and partitioning to grains, in wheat and barley plants subjected to waterlogging. Methods Under contrasting environmental conditions, two pot experiments exposing wheat and barley plants to waterlogging events for 15–20 days at five different developmental stages, from emergence to maturity were performed. Grain N concentration, grain N content, biomass N concentration, N utilisation efficiency (NUE) and N remobilisation were recorded. Key results Both species responded similarly to waterlogging for most N traits. Reductions in grain N content differed according to the moment waterlogging occurred. The greatest reductions (46–77% compared to the control) being for waterlogging from the beginning of stem elongation to anthesis, which also showed the highest reductions in N remobilisation, N uptake at maturity, and N partitioning to the grains, but only a slight decrease in NUE. Grain N concentration raised drastically (up to 45 mg N g DW−1) with minimal grain yields. N concentration of aboveground biomass decreased during waterlogging, recovering control values at maturity. N content at maturity was related to the total biomass. Conclusions Waterlogging differentially reduced N uptake and remobilisation to grains of wheat and barley depending on the developmental stage when water excess occurred. Implications The impact of waterlogging on N economy of wheat and barley appears indirect and predominantly related to carrying effects of the stress on carbon economy due to growth reductions.
Identification and characterisation of blue light photoreceptor gene family and their expression in tomato (
Authors: Batcho Agossa Anicet , Nwogwugwu Joy Oluchi , Ali Mohsin , Jabbar Basit , Javaid Ayesha , Fellner Martin
Published: April 2022

The Arabidopsis thaliana L. photoreceptor genes homologues in tomato (Solanum lycopersicum L.) genome were analysed using bioinformatic tools. The expression pattern of these genes under cold stress was also evaluated. Transcriptome analysis of the tomato sequence revealed that the photoreceptor gene family is involved in abiotic stress tolerance. They participate in various pathways and controlling multiple metabolic processes. They are structurally related to PAS, LIGHT-OXYGEN-VOLTAGE-SENSING (LOV), DNA photolyase, 5,10-methenyl tetrahydrofolate (MTHF), flavin-binding kelch F-box, GAF, PHY, Seven-bladed β-propeller and C27 domains. They also interact with flavin adenine dinucleotide (FAD), (5S)-5-methyl-2-(methylsulfanyl)-5-phenyl-3-(phenylamino)-3,5-dihydro-4H-imidazol-4-one (FNM) and Phytochromobilin (PϕB) ligands. These interactions help to create a cascade of protein phosphorylation involving in cell defence transcription or stress-regulated genes. They localisation of these gene families on tomato chromosomes appeared to be uneven. Phylogenetic tree of tomato and Arabidopsis photoreceptor gene family were classified into eight subgroups, indicating gene expression diversity. Morphological and physiological assessment revealed no dead plant after 4 h of cold treatment. All the plants were found to be alive, but there were some variations in the data across different parameters. Cold stress significantly reduced the rate of photosynthesis from 10.06 to 3.16 μmol m−2 s−1, transpiration from 4.6 to 1.3 mmol m−2 s−1, and stomatal conductance from 94.6 to 25.6 mmol m−2 s−1. The cold stressed plants also had reduced height, root/shoot length, and fresh/dry biomass weight than the control plants. Relative expression analysis under cold stress revealed that after 4 h, light stimulates the transcript level of Cry2 from 1.9 to 5.7 and PhyB from 0.98 to 6.9 compared to other photoreceptor genes.
Feedback loops between mathematics and microbiology
Authors: Brumley Douglas R.
Published: April 2022

The combination of mathematical modelling and quantitative video-microscopy provides exciting opportunities for elucidating the mechanisms behind key processes in microbial ecology, ranging from cell navigation and nutrient cycling to biofilm establishment and symbioses. Central to this approach is the iterative process, whereby experiments and modelling inform one another in a virtuous cycle: vast quantities of experimental data help to test and refine mathematical models, the predictions from which feed back to the experimental design itself. This paper discusses recent technologies, emerging applications, and examples where calibrated mathematical models enable calculation of quantities that are otherwise extremely difficult to measure.
18 months on: an interrupted time series analysis investigating the effect of COVID-19 on chlamydia and gonorrhoea testing and test positivity at the Gold Coast, Australia
Authors: Thng C. , Hughes I. , Poulton G. , O’Sullivan M.
Published: April 2022

Background STI rates have been reported as reduced during the height of the COVID-19 pandemic. Our study evaluates the number of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections recorded relative to the number of tests performed in 2017–2021, thus accurately depicting trends over time and evaluate the effect of COVID-19 restrictions since these were implemented in March 2020. Methods Data was extracted from an electronic database of pathology and clinical records used at Gold Coast Sexual Health Service (GCSHS) in Queensland, Australia from January 2017 to October 2021. Poisson regression-based interrupted time series analyses were performed for number of tests performed and test positivity over the study period. The COVID-19 period was defined as starting from March 2020 when public health directives were implemented. Results CT and NG testing dropped significantly in the month after COVID-19 restrictions were brought in, by 30% and 23% respectively. Over the 5 year study period, the proportion of positive CT tests has consistently decreased by approximately 0.33% points per year (P ≤ 0.001). The instigation of COVID-19 restrictions had no effect on this trend. The proportion of NG positive tests remained steady prior to COVID-19 (P = 0.96) at approximately 3.5%, decreased immediately at the onset of COVID-19 restrictions to approximately 2.5% (P < 0.001) and has remained at this level post-COVID restrictions (P = 0.54). Testing at GCSHS continued to target gay and bisexual men, accounting for ≥50% of all tests performed. Conclusion Our study suggests that there has been a sustained reduction in test positivity of NG infections in the 18 months since COVID-19 restrictions were implemented, and that this is not an artifact of reduced testing. It highlights the importance of maintaining health messaging including screening for sexually transmissible infections and maintaining access to services, which may include alternative models of care such as Telehealth, self-testing and collaboration between all sexual health service providers.
Extracellular vesicles from triple negative breast cancer promote pro-inflammatory macrophages associated with better clinical outcome
Authors: Tkach Mercedes , Thalmensi Jessie , Timperi Eleonora , Gueguen Paul , Névo Nathalie , Grisard Eleonora , Sirven Philemon , Cocozza Federico , Gouronnec Alizée , Martin-Jaular Lorena , Jouve Mabel , Delisle Fabien , Manel Nicolas , Rookhuizen Derek C. , Guerin Coralie L. , Soumelis Vassili , Romano Emanuela , Segura Elodie , Théry Clotilde
Published: April 2022

Significance

Our work uncovers mechanisms by which tumor cells impact tumor-associated macrophages in human triple-negative breast cancer. Via extracellular vesicles (EVs), these tumors promote macrophages with proinflammatory features, correlated with better clinical outcome. Our results suggest exploration of these EVs as tools, alone, or in combination with other therapies, to promote a favorable environment for the generation of anti-tumor immune responses.
Nuclear lamin isoforms differentially contribute to LINC complex-dependent nucleocytoskeletal coupling and whole-cell mechanics
Authors: Vahabikashi Amir , Sivagurunathan Suganya , Nicdao Fiona Ann Sadsad , Han Yu Long , Park Chan Young , Kittisopikul Mark , Wong Xianrong , Tran Joseph R. , Gundersen Gregg G. , Reddy Karen L. , Luxton G. W. Gant , Guo Ming , Fredberg Jeffrey J. , Zheng Yixian , Adam Stephen A. , Goldman Robert D.
Published: April 2022

Significance

Interactions between the cell nucleus and cytoskeleton regulate cell mechanics and are facilitated by the interplay between the nuclear lamina and linker of nucleoskeleton and cytoskeleton (LINC) complexes. To date, the specific contribution of the four lamin isoforms to nucleocytoskeletal connectivity and whole-cell mechanics remains unknown. We discover that A- and B-type lamins distinctively interact with LINC complexes that bind F-actin and vimentin filaments to differentially modulate cortical stiffness, cytoplasmic stiffness, and contractility of mouse embryonic fibroblasts (MEFs). We propose and experimentally verify an integrated lamin–LINC complex–cytoskeleton model that explains cellular mechanical phenotypes in lamin-deficient MEFs. Our findings uncover potential mechanisms for cellular defects in human laminopathies and many cancers associated with mutations or modifications in lamin isoforms.
The impact of predeparture instruction on pragmatic development during study abroad
Authors: Matsumura Shoichi
Published: April 2022

This study investigates the impact of a predeparture intervention on developing pragmatic knowledge in a study abroad context. The study included 66 university-level Japanese learners of English who participated in a four-month study abroad program in Canada. The intervention consisted of the implicit-inductive, explicit-deductive, and explicit-inductive methods of instruction on speech acts. Pragmatic development was measured by gain scores on a written a discourse completion test requiring realization of apologies. Results of the analysis of covariance, controlling for levels of English proficiency, revealed that the explicitly taught groups had significantly larger gains in pragmatic knowledge than the implicitly taught group, and that when comparing the deductive and inductive approaches in the explicit instruction, the two groups did not differ significantly. Follow-up interviews using extreme-case sampling revealed that the metacognitive strategies they had acquired at the predeparture stage contributed to the gains. Implications for maximizing pragmatic development during study abroad are discussed.
Second language pragmatic development in study abroad contexts
Authors: Sánchez Hernández Ariadna
Published: April 2022

This special issue illustrates current research on the development of second language (L2) pragmatic competence in study abroad (SA) contexts. In doing so, it accounts for the complexity entailed in learning the linguistic and sociocultural norms of interaction with people of diverse backgrounds while facing the multiple challenges involved in adapting to a new and unknown setting. This introduction to the special issue presents key topics and previous findings that frame such processes of L2 pragmatic development. These include (1) a description ofstudy abroadas a context for L2 pragmatic development, (2) pragmatic targets that students learn during SA, (3) internal and external factors that are likely to play a role in the learning process, and (4) the role of instruction in helping students maximize their stays abroad in terms of pragmatic learning. Finally, an overview of the articles included in this special issue is provided, highlighting how they contribute to the key themes illustrated throughout this introductory section.
Realising carbide ultrafast homogenisation under pulsed electric current
Authors: Hao Jianqiao , Qin Shuyang , Yan Longge , Zhang Xinfang
Published: April 2022

Network carbides, as a deleterious precipitate to the mechanical properties of bearing steel, are difficult to eliminate by traditional heat treatment. Here, an innovative strategy to rapidly dissolve network carbides using electric current pulses to improve the uniformity of the microstructure is proposed. The results show that the diffusion driven by electromigration is significantly enhanced compared to traditional heat treatment due to the high-density current on the network carbide surface. Furthermore, grain boundaries as fast diffusion paths play a key role in accelerating the dissolution of network carbides.
Ultrasonic soldering silica glass and 2024 alloy in low temperature
Authors: Yi Ruixiang , Chen Chao , Li Haijun , Ma Yibo
Published: April 2022

Sn–9Zn–2Al solder alloy was used to weld silica glass and 2024 aluminium alloy with the assistance of ultrasonic wave. It can be concluded from the results that a good metallurgical bond can be formed between silica glass and 2024 aluminium alloy. The effects of different experimental parameters on the properties and morphology of soldering joints were discussed. In the use of ultrasound assisted conditions, the Al–Zn–Sn solution layer was generated on the side of the Sn–Zn–Al solder alloy and 2024 aluminium alloy due to atomic diffusion. In addition, there was an oxide layer between the solid solution layer and the solder alloy. The reason is that Al atoms can combine with O atoms under the action of ultrasonic wave, and the deposition reaction occurs to form an alumina layer. Finally, the interface structure of the soldering joint is silica glass/Sn–Zn eutectic phase, α-Al phase, β-Zn phase/Al2O3 oxide layer/Al–Zn–Sn solution layer/2024 aluminium alloy.
Disappearance of squeezing in superposition states and its manifestation in the energy density
Authors: Kannan S , Sudheesh C
Published: April 2022

We have classified the superposition of squeezed wavepackets into two kinds and studied their quadrature squeezing. We have shown that the squeezing and higher-order squeezing in the quadrature disappear for the states of the first kind. However, for the second kind, it is possible to achieve the maximum amount of squeezing by adjusting the parameters in the superposition. The absence of squeezing for the superposition states is explained based on the expectation value of the energy density. We find that the expectation value of energy density in quantum wavepackets that shows no squeezing is positive. We have also studied the relationship between energy density and the squeezing in the decoherence dynamics of single and two-mode squeezed states. Our further analysis shows that different types of squeezed states, including states which are not wavepackets, exhibit negative energy density.
Random anisotropy magnet at finite temperature
Authors: Garanin Dmitry A , Chudnovsky Eugene M
Published: April 2022

We present finite-temperature Monte Carlo studies of a 2D random-anisotropy (RA) magnet on lattices containing one million spins. The correlated spin-glass state predicted by analytical theories is reproduced in simulations, as are the field-cooled and zero-field-cooled magnetization curves observed in experiments. The orientations of lattice spins begin to freeze when the temperature is lowered. The freezing transition is due to the energy barriers generated by the RA rather than due to random interactions in conventional spin-glasses. We describe freezing by introducing the time-dependent spin-glass order parameter q and the spin-melting time τ
M defined via q = τ
M/t above freezing, where t is the time of the experiment represented by the number of Monte Carlo steps.
Kinetic Monte Carlo simulations of Ge–Sb–Te thin film crystallization
Authors: Portavoce A , Roland G , Remondina J , Descoins M , Bertoglio M , Amalraj M , Eyméoud P , Dutartre D , Lorut F , Putero M
Published: April 2022

Simulation of atomic redistribution in Ge–Sb–Te (GST)-based memory cells during SET/RESET cycling is needed in order to understand GST memory cell failure and to design improved non-volatile memories. However, this type of atomic scale simulations is extremely challenging. In this work, we propose to use a simplified GST system in order to catch the basics of atomic redistribution in Ge-rich GST (GrGST) films using atomistic kinetic Monte Carlo simulations. Comparison between experiments and simulations shows good agreements regarding the influence of Ge excess on GrGST crystallization, as well as concerning the GST growth kinetic in GrGST films, suggesting the crystallized GST ternary compound to be off-stoichiometric. According to the simulation of atomic redistribution in GrGST films during SET/RESET cycling, the film microstructure stabilized during cycling is significantly dependent of the GST ternary phase stoichiometry. The use of amorphous layers exhibiting the GST ternary phase stoichiometry placed at the bottom or at the top of the GrGST layer is shown to be a way of controlling the microstructure evolution of the film during cycling. The significant evolution of the local composition in the amorphous solution during cycling suggests a non-negligible variation of the crystallization temperature with operation time.