bluuebunny/crossref_metadata_2025 huggingface dataset:
Classification of different post-hyperdoping treatments for enhanced crystallinity of IR-sensitive femtosecond-laser processed silicon
Authors: Paulus Simon , Roser Michael , McKearney Patrick , Will Matthias , Schäfer Sören , Kontermann Stefan
Published: December 2022

Crystalline silicon becomes photosensitive and absorbing in the sub-bandgap spectral region if hyperdoped, i.e. supersaturated to a level above the solubility limit in thermal equilibrium, by deep impurities, such as sulfur. Here we apply femtosecond laserpulses to crystalline silicon in a SF6 atmosphere as hyperdoping method. The ultrashort laser pulses cause crystal damage and amorphous phases that would decrease quantum efficiency in a potential optoelectronic device application. We investigate five different post-hyperdoping methods: three etching techniques (ion beam etching IBE, reactive ion etching RIE, and wet-chemical etching HNA) as well as ns-annealing and minute-long thermal annealing and study their impact on crystallinity by Raman spectroscopy and absorptance in the visible and near infrared wavelength regime. We use femtosecond laser hyperdoped silicon (fs-hSi) with two different levels of surface roughness to study a potential dependence on the impact of post-treatments. In our investigation, ns-annealing leads to the best results, characterized by a high Raman crystallinity and a high remaining absorptance in the sub-bandgap spectral region of silicon. Within the used etching methods IBE outperforms the other etching methods above a certain level of fs-hSi surface roughness. We relate this to the specific anisotropic material removal behavior of the IBE technique and back this up with simulations of the effect of the various etching processes.
High-performance flexible pentacene transistor memory with PTCDI-C13 as N-type buffer layer
Authors: Wu Lei , Yu Tianpeng , Liu Zhenliang , Wang Yiru , Wan ZuTeng , Yin Jiang , Xia Yidong , Liu Zhiguo
Published: December 2022

Flexible organic field-effect transistor nonvolatile memories (OFET-NVMs) with polymer electrets have aroused great attention for its important role in next-generation flexible data storage devices application. However, the OFET-NVMs to date still hardly reach the requirements for practical applications. In air environment, the positively charged defects formed in pentacene near the interface with polymer, result in unsatisfied high programming/erasing (P/E) voltages. Here, we propose an OFET memory structure, in which an n-type semiconductor N, N′-Bis(3-pentyl) perylene-3, 4, 9, 10-bis(dicarboximide) (PTCDI-C13) is inserted between pentacene and poly(4-vinyl phenol. Based on the electrostatic induction effect, electrons are induced on the surface of PTCDI-C13 due to the electrostatic field generated by the positive charges at the interface of pentacene/polymer, and compensate part of the positive charges at the interface, resulting in the reduction of the height of hole-barrier. The flexible memory device with PTCDI-C13 exhibits a memory window of larger than 7 V at P/E voltages (±20 V), fast switching speeds (0.5 ms), good P/E endurance (>400 cycles), large field-effect mobility (0.026 cm2 V−1 s−1), and long retention time (over 104 s).
Energy efficient ternary computation unit using differential spin Hall effect MRAM
Authors: Soni Sandeep , Verma Gaurav , Kaushik Brajesh Kumar
Published: December 2022

Recent advances in quantized neural networks (QNNs) have paved the way for energy efficient hardware architectures for machine learning tasks. Binary and ternary QNNs are suitable for image classification and recognition applications on highly resource constrained hardware. Binary neural networks have low precision thus suffer a significant accuracy loss for dense networks and large datasets. This issue can be resolved through ternary neural networks (TNNs) with higher weight precision and better resource utilization. TNN implementation using conventional complementary metal oxide semiconductor and memristive devices show limited improvement in area and energy efficiency. Spintronics based magnetic random access memory (MRAM) devices are the most prominent choice amongst the various non-volatile memories for neural networks. This work presents the implementation of differential spin Hall effect (DSHE) MRAM-based two and three input ternary computation units (TCUs) for TNN. Furthermore, a multilayer perceptron architecture with synaptic crossbar array using the proposed TCU is implemented for Modified National Institute of Standards and Technology data classification. The results show that DSHE-based TCU is 30% more energy efficient as compared with spin-transfer torque (STT)-MRAM based design. Furthermore, DSHE-MRAM based TNN shows improvement in energy and area by 82% and 9%, respectively, when compared to STT-based TNN.
Recessed-gate AlGaN/GaN MIS-FETs with dual 2DEG channels
Authors: Hsu Hao-Ching , Xie Hong-Gang , Hsin Yue-Ming
Published: December 2022

In this study, a normally-on AlGaN/GaN metal–insulator-semiconductor high electron mobility transistor (MIS-HEMT) and a normally-off AlGaN/GaN metal–insulator-semiconductor field-effect transistor (MIS-FET) with recessed MIS gate are fabricated by dual-channel epitaxy structure. The recessed region is cleaned by dipping it into diluted buffered oxide etch (BOE), HCl, and tetramethylammonium hydroxide (TMAH) solutions. After cleaning, a 20 nm Al2O3 is deposited by atomic layer deposition (ALD). Then, the post-deposition annealing is executed. Non-recessed MIS-HEMT demonstrates a threshold voltage of −9.81 V, a high drain current of 660.76 mA mm−1, and a small on-resistance of 6.47 Ω mm. Recessed gate MIS-FET shows a positive threshold voltage of 1.46 V with a drain current of 144.81 mA mm−1. In addition, the devices present a high gate breakdown voltage of 26.5 V by non-recessed MIS-HEMT and 18.5 V by recessed MIS-FET. Both devices show a low I–V hysteresis under double sweep I
D–V
GS measurement.
A low-cost flexible piezoresistive sensor with high sensitivity and broad detection range based on porous random microstructures for wearable electronics
Authors: Zhang Yangyang , Zhang Xiaopeng , Zhang Xia , Li Liping
Published: December 2022

Due to their simple structures and high sensitivity, flexible piezoresistive sensors have great potential for physiological monitoring, tactile recognition of prosthetics, and electronic skin. Here, a flexible piezoresistive sensor based on porous random microstructures and having high sensitivity and a wide detection range is proposed. Conductive carbon black was used as an active filler and thermoplastic expandable microspheres and sandpaper were used as templates for the fabrication of the pore structures and random microstructures of the substrates, respectively. Synergistic interactions between these two components in the sensor led to a high sensitivity of 11.02 kPa−1 (0–6 kPa), wide measuring range (0–30 kPa), rapid response time (<200 ms), and long-term durability (>2000 cycles). The sensor was effective for monitoring a variety of hand movements, including bending of the fingers and wrist. In addition, the sensors were effective when attached to a robotic hand to simulate the traditional Chinese medicine pulse diagnosis and to grasp objects. This device thus has broad application prospects in the field of human-machine interactions and robot teleoperation.
Monitoring mechanical behaviors of CLT connections under reciprocating loading based on PZT-enabled active sensing and machine learning algorithms
Authors: Gao Weihang , Zhang Caiyan , Chen Lin
Published: December 2022

Monitoring the mechanical behaviors of cross-laminated timber (CLT) connections is of great importance to the condition assessment of timber structures. To date, numerous research works have demonstrated that Lead Zirconate Titanate (PZT)-enabled active sensing approaches can achieve structural healthy state monitoring under monotonic loads, whereas their effectiveness for reciprocating loads still needs to be further studied. Moreover, traditional PZT-enabled active sensing approaches depend on prior knowledge and human judgment, restricting their field applications. Based on the above background, this research proposes an innovative method to monitor the mechanical behaviors of CLT connections under reciprocating loading by integrating PZT-enabled active sensing and eight machine learning (ML) approaches. Meanwhile, a new damage index based on wavelet packet decomposition and multiple signal path fusion is designed to improve the performance of ML methods. Finally, cyclic loading tests on CLT connections are conducted to demonstrate the outstanding capabilities of the proposed method than conventional PZT-enabled active sensing approaches.
Synergistic composites energy harvester beams based on hybrid ZnO/PZT piezoelectric nanomaterials
Authors: Furnes Simon , Al-Haik Marwan , Philen Michael
Published: December 2022

This study aims at elucidating the synergistic effect of the hybridization of two piezoelectric materials: zinc oxide nanowires (ZnO NWs) and a thin film of lead zirconium titanate (PZT), on the mechanical and energy harvesting performance of carbon fiber reinforced polymer composites beams. Novel synthesis techniques were utilized to develop energy-harvesting composite beams with surface-grown ZnO NWs and sputtered PZT thin films. While not an extraordinarily strong piezoelectric material, ZnO NWs enhanced the strength and damping parameter of the composite due to the increased surface area and mechanical interlocking. The composite comprising two piezoelectric materials showed a substantial gain in stiffness, a 25.8% increase compared to plain composite without piezoelectric materials. The hybrid composite energy harvester based on PZT/ZnO NWs exhibited a significant electric power gain of 733.94% more than that for beams with ZnO NWs compared to 44% improvement for a beam utilizing only PZT. Using PZT thin films with ZnO NWs on carbon fiber could yield a high-performance hybrid composite with excellent mechanical properties and energy harvesting capabilities.
Auxeticity modifications and unit cell doubling in Yukawa fcc crystals with [001]-nanochannels filled by hard spheres
Authors: Tretiakov Konstantin V , Pigłowski Paweł M , Wojciechowski Krzysztof W
Published: December 2022

In recent years, the investigation of auxetic materials is receiving more and more attention due to their wide range of applications which follow enhancing indentation resistance, toughness, shear resistance, and other advantages of such materials. This work reports results of studies of models of auxetic metamaterials with nanoinclusions. Yukawa crystals with nanoinclusions in the form of nanochannels (NCs) in the [001] crystallographic direction, filled by hard spheres, were simulated by Monte Carlo in a wide range of pressures to determine their elastic properties. Particular attention has been devoted to the Poisson’s ratio (PR). It has been found that depending on the NCs’ type and pressure, the value of PR can vary from −0.302(12) to 1.083(14). The microscopic structures of the crystals were also examined in detail. A solid-solid phase transition in a host-guest system (the Yukawa crystal with hard spheres) was observed. Interestingly, this phase transition generates a unit cell doubling along the NCs. To localize this phase transition, apart from studies of the structure, the PR as a sensitive indicator of the phase transition was applied. In addition, it was found that the studied Yukawa systems with nanoinclusions for certain pressure values are completely non-auxetic, despite both the Yukawa and hard sphere crystals without inclusions are partially auxetic at the same conditions. This indicates that the presence of [001] NCs in the system not only can enhance auxeticity in comparison to the system without NCs but also, at some thermodynamic conditions, can lead to a completely non-auxetic behavior of the system which is partially auxetic without the NCs. Hence, one can use NCs to tune auxetic properties of crystals.
Anomalous temperature dependence of multiple Andreev reflections in a topological insulator Josephson junction
Authors: Schmitt Tobias W , Frohn Benedikt , Wittl Wilhelm , Jalil Abdur R , Schleenvoigt Michael , Zimmermann Erik , Schmidt Anne , Schäpers Thomas , Cuevas Juan Carlos , Brinkman Alexander , Grützmacher Detlev , Schüffelgen Peter
Published: December 2022

As a promising platform for unconventional superconductivity, Josephson junctions (JJs) of tetradymite topological insulators (TIs) and s-wave superconductors have been investigated in recent years. This family of TI materials, however, often suffers from spurious bulk transport, which hampers the observation of the exotic physics of their topological surface states. Thus, disentangling the transport mechanism of bulk and surface contributions in TI JJs is of high importance when investigating proximity induced superconductivity in those crystals. In this work, we add to the insights regarding these contributions by studying the temperature-dependent behaviour of a Bi2Te3-based JJ with transparent interfaces. In electrical transport measurements, we investigate differential conductance spectra of multiple Andreev reflections (MARs) and find a qualitative temperature-dependent change from peak features at low temperatures to dip features at higher ones. The observation of both kind of MAR patterns in a single JJ suggests contributions of diffusive bulk and ballistic surface states and links to a similar finding in the temperature dependence of the critical current. Our work advances the research of induced superconductivity in TIs and offers new avenues to study the induced superconductivity in the topological surface states of these materials.
Effect of carbon doping on magnetic flux pinning and superconducting performance in FeSe0.5Te0.5 single crystals
Authors: Zhang J , Hänisch Jens , Yang X S , Zhao K , Zhao Y
Published: December 2022

A series of carbon-doped single crystals with nominal composition FeSe0.5Te0.5 were synthesized by a self-flux method. X-ray diffraction indicated that the lattice parameter c increases with increasing carbon content, suggesting that carbon atoms enter the lattice. The critical current densities were measured and the flux pinning mechanism and its change with doping were analyzed. These samples showed a higher J
c in high magnetic fields as well as a narrower superconducting transition. We studied the impact of the introduction of carbon into FeSe0.5Te0.5 on the temperature dependence of the irreversibility field H
irr(T) and upper critical field (H
c2). The pinning mechanism for the system was obtained via analysis of J
c.
Shell-model Study of Two-neutrino Double-Beta Decay for Z = 40–50 Nuclei and their SSD Properties
Authors: Jia Juanjuan , Li Hantao , Dong Chengwei
Published: December 2022

In this paper, large-scheme shell-model calculations are carried out for two-neutrino double-beta decay of Z = 40–50 nuclei (94Zr, 96Zr, 98Mo, 104Ru, 108Cd, and 116Cd). Within this region, only the half-lives of nuclei 96Zr and 116Cd are experimentally known. The calculated results agree well with experimental data and we predict the half-lives for the remaining four nuclei. Among them, 94Zr and 104Ru have relatively short half-lives of 4.57 × 1023 and 9.83 × 1023 years, respectively, together with large abundance, and are expected to be detected in the near future. By analyzing the convergence of nuclear matrix elements, special attention is paid to their single-state dominance (SSD) property. Here, a new SSD nucleus, i.e., 94Zr, is found, which is a supplement to the previous SSD nuclei list.
Boron carbon oxynitride coated arc-shaped fiber as an optical modulator for passively mode-locked fiber lasers at 1.5 and 2 μm wavelength
Authors: Ahmad H , Nizamani B , Sekar S , Samion M Z , Yusoff N , Venkataprasad Bhat S
Published: December 2022

Two-dimensional (2D) materials have recently been explored as potential saturable absorbers (SAs) due to their remarkable optoelectronic and nonlinear optical properties. In this work, we have experimentally reported 2D boron carbon oxynitride (BCNO) as a potential mode-locker in erbium-(EDFL) and thulium-doped fiber lasers (TDFL) for the first time. The BCNO-coated arc-shaped fiber was explored as a novel optical loss modulator and exhibited a modulation depth of 8.2% and 5% at 1.5 μm and 2 μm, respectively. Mode-locking was achieved by the BCNO-coated arc-shaped fiber in EDFL having a pulse width, repetition rate, and center wavelength of 1.56 ps, 19.14 MHz, and 1562.2 nm, respectively. Mode-locked pulses of 1.456 ps duration were achieved by incorporating BCNO-coated arc-shaped fiber in TDFL, operated at center wavelength, repetition rate, and signal-to-noise ratio (SNR) of 1944 nm, 13 MHz, and 70.3 dB, respectively. These results prove BCNO to be a promising low-cost 2D material to be further explored for laser-related applications.
Synthesis of silver nanoparticles using pulsed laser ablation in liquid: a review
Authors: Ganash Entesar A
Published: December 2022

Pulsed laser ablation in liquid (PLAL) is an important method for synthesizing metal nanoparticles (NPs). Recently, it has garnered increasing interest as it is simple, rapid, and ecofriendly. Herein, PLAL is proposed as an approach to produce varied sizes of silver nanoparticles (Ag NPs) because NP size plays a vital role in their characteristics and several applications in the physical, chemical, biological, and medical fields. In PLAL, metal NP size could be controlled by either adjusting the laser parameters, such as wavelength, energy, fluence, reptation rate, ablation time, and focusing lens, or by modifying the ablation solvent properties. Herein, PLAL is proved as an effective and simple method for fabricating Ag NPs. This can provide guidance for synthesizing nanomaterials in diverse sizes, types, and shapes for applications in different fields.
Lorentz quantum computer
Authors: He Wenhao , Wang Zhenduo , Wu Biao
Published: December 2022

A theoretical model of computation is proposed based on Lorentz quantum mechanics. Besides the standard qubits, this model has an additional bit, which we call hyperbolic bit (or hybit in short). A set of basic logical gates are constructed and their universality is proved. As an application, a search algorithm is designed for this computer model and is found to be exponentially faster than Grover’s search algorithm.
Narrowed Si0.7Ge0.3 channel FinFET with subthreshold swing of 64 mV/Dec using cyclic self-limited oxidation and removal process
Authors: Liu Hao-Yan , Li Yong-Liang , Wang Wen-Wu
Published: December 2022

A narrowed Si0.7Ge0.3 channel fin field-effect transistor (FinFET) device is demonstrated in detail by using an accurate cyclic wet treatment process. The Si0.7Ge0.3 fin/per side of 0.63 nm in thickness can be accurately removed in each cycle by utilizing a self-limited oxidation with 40% HNO3 solution in 40 s and oxidation removal can be achieved with 1% HF solution in 10 s. As a result, after the dummy gate removal, the fin width of Si0.7Ge0.3 can be narrowed from 20 nm to 8 nm by utilizing 10 cycles of this wet treatment process. Compared with the conventional Si0.7Ge0.3 FinFET under a similar process, the narrowed Si0.7Ge0.3 channel FinFET can realize a strong gate control capability by using this newly developed wet treatment process, because its subthreshold slope can be reduced by 24%, improving from 87 mV/dec to 64 mV/dec.
Internal combustion engine test plan execution order optimization using Travelling Salesman Problem heuristics approach
Authors: Mrdja Predrag , Kitanovic Marko , Miljic Nenad , Popovic Slobodan
Published: December 2022

For a given internal combustion (IC) engine stationary test plan, significant time savings during its realization could be achieved if the sequence of test points execution is adequately determined. The criterion for stabilizing the engine operating point is determined by the magnitude of the change in the most inert parameter, and in the general case, it is the temperature of the engine exhaust gases. A certain level of prior knowledge about the examined object is necessary to conduct such an analysis. If there are no results from previous tests, simulation models, or experiences, the Slow Dynamic Slope (SDS) tests are a great way to quickly gather the necessary information. The task of finding the optimal sequence for a stationary engine testing plan can be set as Travelling Salesman Problem (TSP). This paper will present the application of one of the heuristic methods for solving the TSP on the example of testing the IC engine, which is a very complex dynamic system. Following this model, it is possible to optimize the stationary test plan for any other dynamic system. The basic idea is to find such a sequence of stationary operating points, during the realization of which a minor deviation of the engine exhaust gas temperature is obtained, resulting in the operating point's shortest stabilization time.
Numerical analysis of intake port modification onto fluid flow pattern and flame propagation in particular combustion chamber
Authors: Masoničić Z , Grujić I , Davinić A , Savić S , Pešić R
Published: December 2022

It is known for a long time that inlet port geometry has a great influence onto fluid flow pattern and flame propagation in spark ignition IC engines. In this paper only the initial results of the very complex study on the effects that proposed inlet port modification has onto the in-cylinder flow processes including the combustion stage, in particular. The study mentioned below incorporates state of the art multidimensional numerical modelling of reactive flow in the inlet port and combustion chamber geometry layout with moving boundaries of spark ignition IC engine with two valves. The main objective of this study is to investigate the possibilities for improvement the IC engine output characteristics through the inlet port modifications. Bearing in mind that flame propagation through unburnt mixture of spark ignition IC engine is primarily controlled by dint of turbulence diffusion, it is of prime importance for engine optimization to correctly identify the influence of certain types of organized flows onto the fluid flow pattern and flame propagation. The efforts for improvement have to be aimed on the type of organized flow or eventually their combination that is of prime importance for further development of the in-cylinder processes and combustion stage.
A review of hypereutectic aluminum piston materials
Authors: Miladinovic Slavica , Stojanović Blaža , Gajević Sandra , Ivanović Lozica , Skulić Aleksandar
Published: December 2022

Demands of today’s automotive industry are increasing; there is a constant tendency of weight reduction and higher reliability of constructions. Pistons and piston liners for vehicles are mostly manufactured from aluminum-silicon alloys. With different manufacturing methods and/or the addition of some chemical elements, base alloy properties can be modified. Methods for hypereutectic aluminum alloys and composites manufacturing and their influence on material properties will be given in this paper. The influence of Si percentage in base alloy and how an addition of some chemical elements affects the properties of these materials will be observed as well.
Measurement noise level of E-bus HIGER KLQ6125GEV3 on the polygon
Authors: Misanovic S , Taranovic D , Maljkovic M , Milicic B
Published: December 2022

Buses for public city transport in cities represent a significant source of noise, especially in the central city zones, on the traffic corridors with the highest hourly frequencies of public transport vehicles. The introduction of electric buses is one of the possible ways to reduce noise. The paper will present the results of the experimental measurement of noise levels of e-bus Higer KLQ6125GEV3 on the polygon, using the Lutron SL-4001 measuring instrument, following UN ECE 51.02 regulations and a comparison with the results of noise levels measurement with buses on diesel and CNG driveline.
Examining the surface roughness and kerf quality of micro-slots cut on the surfaces of Ti-B4C nanocomposites by WEDM: a desirability approach
Authors: Ragavan G Vijaya Raja , Lakshmanan Poovazhagan , Mahalingam Mariyappan
Published: December 2022

Micro slots and textures are created on Titanium (Ti) composites to improve its surface characteristics. Micro-textured Ti composites are generally recommended for bio implants, automobile, and aerospace components. In the current research, Ti-B4C nanocomposites were prepared by powder metallurgical route. Micro slots were cut on the Ti-B4C surfaces by Wire Electrical Discharge Machining (WEDM) Technology by varying the current, pulse-ON time, and pulse-OFF time. Scanning electron microscopy and XRD analysis validates the uniform distribution and inclusion of B4C nanoparticles in Ti matrix. Response surface methodology was used to plan the experimental runs. Analysis of variance and desirability analysis were employed to identify the most suitable machining factors for obtaining the minimum surface roughness, lower kerf width and higher material removal rate (MRR). Increase in applied current and pulse-ON time, increases the MRR. Increase of pulse-OFF time from 50 μs to 60 μs gradually reduces the MRR and reduce the surface roughness of the cut slots. Contrastingly an increase in pulse-ON time increases the roughness due to an extensive melting and resolidification of Ti nanocomposites. The morphology of the WEDMed surface reveals the recast layer and localized melting zones on the cut surfaces.
Development of WS2/MXene (Ti3C2T
x
) nanohybrid based multi-functional textronic sensor for non-invasive personal healthcare monitoring
Authors: Adepu Vivek , Tathacharya Manav , Mattela Venkat , Sahatiya Parikshit
Published: December 2022

This report demonstrates the development of a WS2/Ti3C2T
X
nanohybrid-based multifunctional physical sensor (pressure, strain, and humidity) on a textile cloth. The fabricated sensor demonstrates excellent sensitivity and gauge factor of 3.66198 kPa−1, 3.17119, and 1.61787 towards pressure, strain, and humidity stimuli, respectively, with exceptional long-term stability showing an insignificant change in performance over ∼4000 and ∼4200 cycles. The underlying transduction mechanism for the fabricated piezoresistive multifunctional physical sensor is explained utilizing the intrinsic piezoresistive effect as well as the modulation of the Schottky barrier height exhibited by the WS2/Ti3C2T
x
at the local heterojunctions with the help of detailed band structures that are realized by ultraviolet photoelectron spectroscopy. A smartphone-based application was established to authenticate wireless incorporation of the fabricated multifunctional physical sensors to demonstrate applications such as tetraplegic call detection, mood detection, and dry/wet skin monitoring system. The successful demonstration of connected healthcare applications using the WS2/Ti3C2T
x
multifunctional sensor opens up new possibilities and applications in the fields of smart healthcare, e-textiles, and flexible electronics.
Biomaterials of human source for 3D printing strategies
Authors: Maia João Rocha , Sobreiro-Almeida Rita , Cleymand Franck , Mano João F
Published: December 2022

Three-dimensional printing has risen in recent years as a promising approach that fast-tracked the biofabrication of tissue engineering constructs that most resemble utopian tissue/organ replacements for precision medicine. Additionally, by using human-sourced biomaterials engineered towards optimal rheological proprieties of extrudable inks, the best possible scaffolds can be created. These can encompass native structure and function with a low risk of rejection, enhancing overall clinical outcomes; and even be further optimized by engaging in information- and computer-driven design workflows. This paper provides an overview of the current efforts in achieving ink’s necessary rheological and print performance proprieties towards biofabrication from human-derived biomaterials. The most notable step for arranging such characteristics to make biomaterials inks are the employed crosslinking strategies, for which examples are discussed. Lastly, this paper illuminates the state-of-the-art of the most recent literature on already used human-sourced inks; with a final emphasis on future perspectives on the field.
Device engineering of organic solar cells based on a boron subphthalocyanine electron donor molecule
Authors: Ahmadpour Mehrad , Prete Michela , Aryal Um Kanta , Petersen Anne Ugleholdt , Ahmad Mariam , Rubahn Horst-Günter , Jespersen Malte F , Mikkelsen Kurt V , Turkovic Vida , Nielsen Mogens Brøndsted , Madsen Morten
Published: December 2022

A boron subphthalocyanine molecule has been employed as a novel electron donor in organic solar cells (OPVs), and optimized in terms of composition and device structure in small molecule solar cells. It is demonstrated that the power conversion efficiency (PCE) of the devices obtained by solution-processing in bulk heterojunction solar cells could be improved by one order of magnitude by changing the fabrication method to vacuum deposition, which promotes a better morphology in the OPV active layers. Importantly, upon insertion of an additional pristine C70 thin interlayer between the active layer and the hole transport layer the PCE was further improved, highlighting the importance of interfacial layer engineering in such subphthalocyanine small molecule OPVs.
On the eigenvalue problem of Schrödinger-Poisson system
Authors: Liu Zhisu
Published: December 2022

In this paper, we are concerned with the following Schrödinger-Poisson system with nonhomogeneous boundary conditions
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\begin{equation*} \begin {cases} -\frac {1}{2}\triangle {u}+\phi u =\omega u, & \text {in }\Omega , \\ -\triangle {\phi }=4\pi u^2, & \text {in } \Omega ,\\ \phi =h,u=0, & \text {on } \partial \Omega , \end{cases} \end{equation*}

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Dependent censoring based on parametric copulas
Authors: Czado C , Van Keilegom I
Published: December 2022

Consider a survival time $T$ that is subject to random right censoring, and suppose that $T$ is stochastically dependent on the censoring time $C$. We are interested in the marginal distribution of $T$. This situation is often encountered in practice. Consider, for example, the case where $T$ is a patient’s time to death from a certain disease. Then the censoring time $C$ could be the time until the patient leaves the study or the time until death from another cause. If the reason for leaving the study is related to the health condition of the patient, or if the patient dies from a disease that has similar risk factors to the disease of interest, then $T$ and $C$ are likely to be dependent. In this paper we propose a new model that takes such dependence into account. The model is based on a parametric copula for the relationship between $T$ and $C$, and on parametric marginal distributions for $T$ and $C$. Unlike most other authors, we do not assume that the parameter defining the copula is known. We give sufficient conditions on these parametric copulas and marginals under which the bivariate distribution of $(T,C)$ is identified. These sufficient conditions are then checked for a wide range of common copulas and marginals. We also study the estimation of the model, and carry out extensive simulations and analysis on a pancreatic cancer dataset to illustrate the proposed model and estimation procedure.
Acetylcholine and noradrenaline differentially regulate hippocampus-dependent spatial learning and memory
Authors: de Leo Gioacchino , Gulino Rosario , Coradazzi Marino , Leanza Giampiero
Published: December 2022

Severe loss of cholinergic neurons in the basal forebrain nuclei and of noradrenergic neurons in the locus coeruleus are almost invariant histopathological hallmarks of Alzheimer’s disease. However, the role of these transmitter systems in the spectrum of cognitive dysfunctions typical of the disease is still unclear, nor is it yet fully known whether do these systems interact and how. Selective ablation of either neuronal population, or both of them combined, were produced in developing animals to investigate their respective and/or concurrent contribution to spatial learning and memory, known to be severely affected in Alzheimer’s disease. Single or double lesions were created in 4–8 days old rats by bilateral intraventricular infusion of two selective immunotoxins. At about 16 weeks of age, the animals underwent behavioural tests specifically designed to evaluate reference and working memory abilities, and their brains were later processed for quantitative morphological analyses. Animals with lesion to either system alone showed no significant reference memory deficits which, by contrast, were evident in the double-lesioned subjects. These animals could not adopt an efficient search strategy on a given testing day and were unable to transfer all relevant information to the next day, suggesting deficits in acquisition, storage and/or recall. Only animals with single noradrenergic or double lesions exhibited impaired working memory. Interestingly, ablation of cholinergic afferents to the hippocampus stimulated a robust ingrowth of thick fibres from the superior cervical ganglion which, however, did not appear to have contributed to the observed cognitive performance. Ascending cholinergic and noradrenergic afferents to the hippocampus and neocortex appear to be primarily involved in the regulation of different cognitive domains, but they may functionally interact, mainly at hippocampal level, for sustaining normal learning and memory. Moreover, these transmitter systems are likely to compensate for each other, but apparently not via ingrowing sympathetic fibres.
Morphology dynamics in intestinal crypt during postnatal development affect age-dependent susceptibility to radiation-induced intestinal tumorigenesis in Apc
Min/+ mice: possible mechanisms of radiation tumorigenesis
Authors: Sasatani Megumi , Shimura Tsutomu , Doi Kazutaka , Zaharieva Elena Karamfilova , Li Jianxiang , Iizuka Daisuke , Etoh Shinpei , Sotomaru Yusuke , Kamiya Kenji
Published: December 2022

Age at exposure is a major modifier of radiation-induced carcinogenesis. We used mouse models to elucidate the mechanism underlying age-related susceptibility to radiation-induced tumorigenesis. Radiation exposure in infants was effective at inducing tumors in B6/B6-Chr18MSM-F1 ApcMin/+ mice. Loss of heterozygosity analysis revealed that interstitial deletion may be considered a radiation signature in this model and tumor number containing a deletion correlated with the susceptibility to radiation-induced tumorigenesis as a function of age. Furthermore, in Lgr5-eGFP-ires-CreERT2; Apcflox/flox mice, deletions of both floxed Apc alleles in Lgr5-positive stem cells in infants resulted in the formation of more tumors than in adults. These results suggest that tumorigenicity of Apc-deficient stem cells varies with age and is higher in infant mice. Three-dimensional immunostaining analyses indicated that the crypt architecture in the intestine of infants was immature and different from that in adults concerning crypt size and the number of stem cells and Paneth cells per crypt. Interestingly, the frequency of crypt fission correlated with the susceptibility to radiation-induced tumorigenesis as a function of age. During crypt fission, the percentage of crypts with lysozyme-positive mature Paneth cells was lower in infants than that in adults, whereas no difference in the behavior of stem cells or Paneth cells was observed regardless of age. These data suggest that morphological dynamics in intestinal crypts affect age-dependent susceptibility to radiation-induced tumorigenesis; oncogenic mutations in infant stem cells resulting from radiation exposure may acquire an increased proliferative potential for tumor induction compared with that in adults.
Ethical challenges for a community-based researcher: a case study from Bihar, India
Authors: Khatoon Shakila , Kumar Neerajha Krishna
Published: December 2022

The case study is based on a first-person account of the experiences of a community researcher in India involved in community-based participatory development. It highlights the ethical stances taken by the community researcher during primary research that was carried out in remote villages in the state of Bihar among members of a denotified tribal community. It highlights her journey of reflecting on the research engagement, from an ethical perspective, after her engagement in an ethical review committee constituted by the Praxis Institute of Participatory Practices (herein, referred to as Praxis). The case study maps the journey of the researcher and the intrinsic and extrinsic motivations that led her to reflect on her ethical practices while carrying out community research. It also highlights the reflexivity of the researcher during her journey of the research process.
Phenotyping the late- and younger-onset neuronal surface antibody-mediated autoimmune encephalitis: a multicenter study
Authors: Cai Meng-Ting , Zheng Yang , Lai Qi-Lun , Fang Gao-Li , Shen Chun-Hong , Ding Mei-Ping , Zhang Yin-Xi
Published: December 2022

Neuronal surface antibody-mediated autoimmune encephalitis (NSAE) occurs across a wide age range. However, few studies focused on the onset age and their related characteristics. We aimed to explore the age-dependent profile of NSAE. A total of 134 patients with a definite diagnosis of NSAE were retrospectively enrolled from 3 tertiary hospitals between July 2014 and August 2020. Demographic, clinical, therapeutic, and prognostic data were collected and compared between the late- (≥45) and younger-onset (<45) groups. The results showed that 56 (41.8%) patients were classified as late-onset NSAE, and 78 (58.2%) as younger-onset NSAE. There were more males, especially in the late-onset group (P = 0.036). Prodromal symptoms were more common in the younger-onset group (P = 0.004). Among the onset symptoms, more late-onset patients presented as seizures, while more younger-onset patients presented as psychiatric symptoms. Throughout the disease course, the late-onset patients were more likely to have memory dysfunction (P < 0.001), but less likely to have central hypoventilation (P = 0.045). The late-onset patients also had a significantly lower modified Rankin Scale score on admission (P = 0.042), required intensive care unit (ICU) admission less frequently during hospitalization (P = 0.042) and had a shorter hospital stay (P = 0.014). Our study revealed that the late- and younger-onset NSAE had a distinct spectrum of demographic features, presentations, and prognoses. More attention is needed for the younger-onset patients, given a higher disease severity on admission, more frequent requirement for ICU admission and longer length of stay.
Endothelial progenitor cell mobilization based on exercise volume in patients with cardiovascular disease and healthy individuals: a systematic review and meta-analysis
Authors: Mitsiou Georgios , Tokmakidis Savvas P , Dinas Petros C , Smilios Ilias , Nanas Serafeim
Published: December 2022

Endothelial progenitor cells (EPCs) play a vital role in protecting endothelial dysfunction and cardiovascular disease (CVD). Physical exercise stimulates the mobilization of EPCs, and along with vascular endothelial growth factor (VEGF), promotes EPC differentiation, and contributes to vasculogenesis. The present meta-analysis examines the exercise-induced EPC mobilization and has an impact on VEGF in patients with CVD and healthy individuals. Database research was conducted (PubMed, EMBASE, Cochrane Library of Controlled Trials) by using an appropriate algorithm to indicate the exercise-induced EPC mobilization studies. Eligibility criteria included EPC measurements following exercise in patients with CVD and healthy individuals. A continuous random effect model meta-analysis (PROSPERO-CRD42019128122) was used to calculate mean differences in EPCs (between baseline and post-exercise values or between an experimental and control group). A total of 1460 participants (36 studies) were identified. Data are presented as standard mean difference (Std.MD) and 95% confidence interval (95% CI). Aerobic training stimulates the mobilization of EPCs and increases VEGF in patients with CVD (EPCs: Std.MD: 1.23, 95% CI: 0.70–1.76; VEGF: Std.MD: 0.76, 95% CI:0.16–1.35) and healthy individuals (EPCs: Std.MD: 1.11, 95% CI:0.53–1.69; VEGF: Std.MD: 0.75, 95% CI: 0.01-1.48). Acute aerobic exercise (Std.MD: 1.40, 95% CI: 1.00–1.80) and resistance exercise (Std.MD: 0.46, 95%CI: 0.10–0.82) enhance EPC numbers in healthy individuals. Combined aerobic and resistance training increases EPC mobilization (Std.MD:1.84, 95% CI: 1.03–2.64) in patients with CVD. Adequate exercise volume (>60%VO2max >30 min; P = 0.00001) yields desirable results. Our meta-analysis supports the findings of the literature. Exercise volume is required to obtain clinically significant results. Continuous exercise training of high-to-moderate intensity with adequate duration as well as combined training with aerobic and resistance exercise stimulates EPC mobilization and increases VEGF in patients with CVD and healthy individuals.
High-intensity interval training induces beneficial effects on coronary atheromatous plaques: a randomized trial
Authors: Vesterbekkmo Elisabeth Kleivhaug , Aksetøy Inger-Lise Aamot , Follestad Turid , Nilsen Hans Olav , Hegbom Knut , Wisløff Ulrik , Wiseth Rune , Madssen Erik
Published: December 2022

Aims

Coronary atheroma volume is associated with risk of coronary events in coronary artery disease (CAD). Exercise training is a cornerstone in primary and secondary prevention of CAD, but the effect of exercise on coronary atheromatous plaques is largely unknown. We assessed the effect of 6 months supervised high-intensity interval training (HIIT) on coronary plaque geometry using intravascular ultrasound in patients with stable CAD following percutaneous coronary intervention (PCI).

Methods and results

Sixty patients were randomized to two sessions of weekly supervised HIIT at 85–95% of peak heart rate (n = 30) or to follow contemporary preventive guidelines (control group, n = 30). The study endpoints were change in percent atheroma volume (PAV) and total atheroma volume (TAV) normalized for segment length (TAVnorm) at 6-month follow-up. The change in average PAV for matched coronary segments from baseline to follow-up showed a significant between-group difference (−1.4, 95% CI: −2.7 to −0.1, P = 0.036). There was a significant reduction in the HIIT group (−1.2, 95% CI: −2.1 to −0.2, P = 0.017) while not in the control group (0.2, 95% CI: −0.7 to 1.1, P = 0.616). TAVnorm was reduced (−9 mm3, 95% CI: −14.7 to −3.4, P = 0.002) after HIIT, with a significant between-group difference (−12.0 mm3, 95% CI: −19.9 to −4.2, P = 0.003).

Conclusion

In patients with established CAD, a regression of atheroma volume was observed in those undergoing 6 months of supervised HIIT compared with patients following contemporary preventive guidelines. Our study indicates that HIIT counteracts atherosclerotic coronary disease progression and reduces atheroma volume in residual coronary atheromatous plaques following PCI.
The roles of nucleoid-associated proteins and topoisomerases in chromosome structure, strand segregation, and the generation of phenotypic heterogeneity in bacteria
Authors: Norris Vic , Kayser Clara , Muskhelishvili Georgi , Konto-Ghiorghi Yoan
Published: December 2022

How to adapt to a changing environment is a fundamental, recurrent problem confronting cells. One solution is for cells to organize their constituents into a limited number of spatially extended, functionally relevant, macromolecular assemblies or hyperstructures, and then to segregate these hyperstructures asymmetrically into daughter cells. This asymmetric segregation becomes a particularly powerful way of generating a coherent phenotypic diversity when the segregation of certain hyperstructures is with only one of the parental DNA strands and when this pattern of segregation continues over successive generations. Candidate hyperstructures for such asymmetric segregation in prokaryotes include those containing the nucleoid-associated proteins (NAPs) and the topoisomerases. Another solution to the problem of creating a coherent phenotypic diversity is by creating a growth-environment-dependent gradient of supercoiling generated along the replication origin-to-terminus axis of the bacterial chromosome. This gradient is modulated by transcription, NAPs, and topoisomerases. Here, we focus primarily on two topoisomerases, TopoIV and DNA gyrase in Escherichia coli, on three of its NAPs (H-NS, HU, and IHF), and on the single-stranded binding protein, SSB. We propose that the combination of supercoiling-gradient-dependent and strand-segregation-dependent topoisomerase activities result in significant differences in the supercoiling of daughter chromosomes, and hence in the phenotypes of daughter cells.
Genome assembly of the acoel flatworm Symsagittifera roscoffensis, a model for research on body plan evolution and photosymbiosis
Authors: Martinez Pedro , Ustyantsev Kirill , Biryukov Mikhail , Mouton Stijn , Glasenburg Liza , Sprecher Simon G , Bailly Xavier , Berezikov Eugene
Published: December 2022

Symsagittifera roscoffensis is a well-known member of the order Acoela that lives in symbiosis with the algae Tetraselmis convolutae during its adult stage. Its natural habitat is the eastern coast of the Atlantic, where at specific locations thousands of individuals can be found, mostly, lying in large pools on the surface of sand at low tide. As a member of the Acoela it has been thought as a proxy for ancestral bilaterian animals; however, its phylogenetic position remains still debated. In order to understand the basic structural characteristics of the acoel genome, we sequenced and assembled the genome of aposymbiotic species S. roscoffensis. The size of this genome was measured to be in the range of 910–940 Mb. Sequencing of the genome was performed using PacBio Hi-Fi technology. Hi-C and RNA-seq data were also generated to scaffold and annotate it. The resulting assembly is 1.1 Gb large (covering 118% of the estimated genome size) and highly continuous, with N50 scaffold size of 1.04 Mb. The repetitive fraction of the genome is 61%, of which 85% (half of the genome) are LTR retrotransposons. Genome-guided transcriptome assembly identified 34,493 genes, of which 29,351 are protein coding (BUSCO score 97.6%), and 30.2% of genes are spliced leader trans-spliced. The completeness of this genome suggests that it can be used extensively to characterize gene families and conduct accurate phylogenomic reconstructions.