bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of two-terminal perovskite/silicon tandem solar cells with differing texture structure, perovskite carrier lifetime, and tunneling junction quality
Authors: Hsieh Chun-Hao , Huang Jun-Yu , Wu Yuh-Renn
Published: March 2024

Presented here is the optimization of a planar two-terminal perovskite/silicon tandem solar cell with a texture structure. The developed simulation model is fitted to published experimental results, and the importance of current matching in the two-terminal structure is discussed. With the texture structure optimized and considering current matching, the optimal texture structure improves Jsc from 17.9 to 20.87 mA/cm2 compared to the planar structure, as well as improving the power conversion efficiency from 25.8% to 35.9%. Furthermore, if the quality of the perovskite thin film and tunneling junction efficiency with a smaller voltage penalty can be improved, then the efficiency can be further improved to 38.13%. This indicates that this tandem solar cell still has much room for improvement.
Experimental and numerical study on a heat-driven direct-coupled Stirling refrigerator
Authors: Wang Junxiang , Luo Kaiqi , Yang Rui , Zhang Limin , Luo Ercang , Hu Jianying , Wu Zhanghua , Sun Yanlei
Published: March 2024

As an environmentally friendly refrigeration system, the heat-driven Stirling refrigerator, which has demonstrated high efficiency and promising application prospects, is receiving significant attention for utilizing the waste heat to generate the cooling capacity. In this study, a heat-driven direct-coupled Stirling refrigerator, featuring an engine unit and a refrigeration unit directly coupled through a thermal buffer tube rather than utilizing a piston-based mechanism, is designed and tested. In comparison to the conventional heat-driven Stirling refrigeration systems, the proposed system exhibits the potential for significantly increased reliability and simplicity. Simulations and experiments were carried out to investigate the output characteristics of the system under different heating temperatures and mean pressures. The results show that higher heating temperature is beneficial for producing the acoustic power, thereby increasing the cooling capacity, with the mean pressure among 2.7–3.2 MPa. In the experiments, the system can provide a cooling capacity of 363W with a coefficient of performance of 0.17 when the heating, ambient, and cooling temperatures are 250, 35, and 7 °C, respectively. The results have validated the feasibility of the heat-driven direct-coupled Stirling refrigerator, which is a potential alternative for air-conditioning through waste-heat recovery.
Structural and dynamical aspect of DNA motif sequence specific binding of AP-1 transcription factor
Authors: Patra Piya , Gao Yi Qin
Published: March 2024

Activator protein-1 (AP-1) comprises one of the largest and most evolutionary conserved families of ubiquitous eukaryotic transcription factors that act as a pioneer factor. Diversity in DNA binding interaction of AP-1 through a conserved basic-zipper (bZIP) domain directs in-depth understanding of how AP-1 achieves its DNA binding selectivity and consequently gene regulation specificity. Here, we address the structural and dynamical aspects of the DNA target recognition process of AP-1 using microsecond-long atomistic simulations based on the structure of the human AP-1 FosB/JunD bZIP–DNA complex. Our results show the unique role of DNA shape features in selective base specific interactions, characteristic ion population, and solvation properties of DNA grooves to form the motif sequence specific AP-1–DNA complex. The TpG step at the two terminals of the AP-1 site plays an important role in the structural adjustment of DNA by modifying the helical twist in the AP-1 bound state. We addressed the role of intrinsic motion of the bZIP domain in terms of opening and closing gripper motions of DNA binding helices, in target site recognition and binding of AP-1 factors. Our observations suggest that binding to the cognate motif in DNA is mainly accompanied with the precise adjustment of closing gripper motion of DNA binding helices of the bZIP domain.
The large magnetocaloric effect in GdErHoCoM (M = Cr and Mn) high-entropy alloy ingots with orthorhombic structures
Authors: Wang Xuejiao , Zong Shuotong , Zhang Yan , Mo Zhaojun , Qiao Junwei , Liaw Peter K.
Published: March 2024

High-entropy alloys (HEAs) with significant magnetocaloric effects (MCEs) have attracted widespread attention due to their potential magnetic refrigeration applications over a much more comprehensive temperature range with large refrigerant capacity (RC). However, most of them are metallic glasses (MGs) with problems of limited size, resulting in the difficulty of further applications. Therefore, research on HEAs with crystalline structures and giant MCE is urgently needed. In this paper, GdErHoCoM (M = Cr and Mn) rare-earth HEA ingots with orthorhombic structures are developed, and their magnetic behavior and MCE are studied in detail. Phase investigations find that the main phase of GdErHoCoM ingots is probably (GdErHo)Co with an orthorhombic Ho3Co-type structure of a space group of Pnma. The secondary phases in GdErHoCoCr and GdErHoCoMn are body-center-cubic Cr and Mn-rich HoCo2-type phases, respectively. Magnetic investigations reveal that both ingots undergo a first-order magnetic phase transition below their respective Neel temperatures. Above their respective Neel temperatures, a second-order transition is observed. The Neel temperatures are 40 and 56 K for GdErHoCoCr and GdErHoCoMn, respectively. Additionally, the GdErHoCoCr and GdErHoCoMn ingots exhibit maximum magnetic entropy changes and RC values of 12.29 J/kg/K and 746 J/kg and 10.13 J/kg/K and 606 J/kg, respectively, under a magnetic field of 5 T. The ingots GdErHoCoM (M = Cr and Mn) show excellent MEC properties and can be manufactured easily, making them promising for magnetic refrigerant applications.
Radioisotope production using lasers: From basic science to applications
Authors: Rodrigues M. R. D. , Bonasera A. , Scisciò M. , Pérez-Hernández J. A. , Ehret M. , Filippi F. , Andreoli P. L. , Huault M. , Larreur H. , Singappuli D. , Molloy D. , Raffestin D. , Alonzo M. , Rapisarda G. G. , Lattuada D. , Guardo G. L. , Verona C. , Consoli Fe. , Petringa G. , McNamee A. , La Cognata M. , Palmerini S. , Carriere T. , Cipriani M. , Di Giorgio G. , Cristofari G. , De Angelis R. , Cirrone G. A. P. , Margarone D. , Giuffrida L. , Batani D. , Nicolai P. , Batani K. , Lera R. , Volpe L. , Giulietti D. , Agarwal S. , Krupka M. , Singh S. , Consoli Fa.
Published: March 2024

The discovery of chirped pulse amplification has led to great improvements in laser technology, enabling energetic laser beams to be compressed to pulse durations of tens of femtoseconds and focused to a few micrometers. Protons with energies of tens of MeV can be accelerated using, for instance, target normal sheath acceleration and focused on secondary targets. Under such conditions, nuclear reactions can occur, with the production of radioisotopes suitable for medical application. The use of high-repetition lasers to produce such isotopes is competitive with conventional methods mostly based on accelerators. In this paper, we study the production of 67Cu, 63Zn, 18F, and 11C, which are currently used in positron emission tomography and other applications. At the same time, we study the reactions 10B(p,α)7Be and 70Zn(p,4n)67Ga to put further constraints on the proton distributions at different angles, as well as the reaction 11B(p,α)8Be relevant for energy production. The experiment was performed at the 1 PW laser facility at Vega III in Salamanca, Spain. Angular distributions of radioisotopes in the forward (with respect to the laser direction) and backward directions were measured using a high purity germanium detector. Our results are in reasonable agreement with numerical estimates obtained following the approach of Kimura and Bonasera [Nucl. Instrum. Methods Phys. Res., Sect. A 637, 164–170 (2011)].
Equilibrium contact angles and dewetting in capillaries
Authors: Pekker Leonid , Pekker David , Myrick James
Published: March 2024

In this work, we extend the model of contact angles that we have previously developed for sessile drops on a wetted surface to the case of a meniscus in a capillary. The underlying physics of our model describe the intermolecular forces between the fluid and the surface of the capillary that result in the formation of a thin, non-removable fluid layer that coats the capillary wall. We describe the shape of the meniscus using a Young–Laplace equation and an incompressible, two-phase, computational fluid dynamics (CFD) calculation, both modified to take into account intermolecular forces using the disjoining pressure model. We find that our numerical solutions of the Young–Laplace equation and equilibrium meniscus shapes obtained by CFD agree well with each other. Furthermore, for capillaries that are sufficiently larger than the thickness of the non-removable film, our numerical solutions agree well with the effective contact angle model that we previously developed for sessile drops. Finally, we observe that it is possible to tune the disjoining pressure model parameters so that the intermolecular forces between the liquid and solid molecules become so strong compared to the surface tension that our formula for effective contact angle gives an imaginary solution. We analyze this situation using CFD and find that it corresponds to dewetting, where the bulk liquid detaches from the walls of the capillary leaving behind the non-removable thin liquid film.
High performance low power multilevel oxide based RRAM devices based on TiOxNy/Ga2O3 hybrid structure
Authors: Cui Dongsheng , Lin Zhenhua , Kang Mengyang , Wang Yifei , Gao Xiangxiang , Su Jie , Miao Jinshui , Zhang Jincheng , Hao Yue , Chang Jingjing
Published: March 2024

In this study, the resistive memory devices with Ag/TiOxNy/Pt structure and Ag/TiOxNy/Ga2O3/Pt structure are fabricated. The results showed that they exhibit typical resistive behaviors as well as excellent cycling and retention characteristics (>104 s). Especially, the double-layer device with Ga2O3 layer exhibits superior resistive behavior, which has a larger storage window (ON/OFF ratio >105), a smaller set voltage (0.17 V) and a reset voltage (−0.057 V), and lower power consumption (21.7, 0.17 μW) compared with the single-layer device. Furthermore, the Ag/TiOxNy/Ga2O3/Pt device demonstrates ultraviolet light (UV-365 nm)-dependent resistance state (RS), which is advantageous for multilevel memory cells. As the intensity of UV light increases, eight high resistance state (HRS) levels are produced. Finally, the conductive mechanism for both device structures is discussed, and it is found that the conductive filaments mechanism dominates in the low resistance state. However, for the HRS, the single-layer TiOxNy device is dominated by the space charge-limited conduction mechanism, and the double-layer TiOxNy/Ga2O3 device is dominated by the Schottky emission mechanism.
Anomalous thermal conductivity in 2D silica nanocages of immobilizing noble gas atom
Authors: Wang Yang , Gao Zhibin , Wang Xiaoying , Sun Jinping , Feng Minxuan , Hao Yuzhou , Li Xuejie , Zhao Yinchang , Ding Xiangdong
Published: March 2024

Noble gas atoms such as Kr and Xe are byproducts of nuclear fission in nuclear plants. How to trap and confine these volatile even radioactive gases is particularly challenging. Recent studies have shown that they can be trapped in nanocages of ultrathin silica. Here, we exhibit with self-consistent phonon theory and four-phonon (4ph) scattering where the adsorption of noble gases results in an anomalous increase in lattice thermal conductivity (κL), while the presence of Cu atoms doping leads to a reduction in κL. We trace this behavior in host–guest 2D silica to an interplay of tensile strain, rattling phonon modes, and redistribution of electrons. We also find that 4ph scatterings play indispensable roles in κL of 2D silica. Our work illustrates the microscopic heat transfer mechanism in 2D silica nanocages with the immobilization of noble gas atoms and inspires further exploring materials with the kagome and glasslike κL.
Manipulation of rotation for triangular plasma photonic crystals in dielectric barrier discharge
Authors: Fan Wei-li , Wang Qi-han , Li Rui , Deng Teng-kun , Wang Shuo , Li Yao-hua , He Ya-feng , Chu Li-zhi , Liu Fu-cheng
Published: March 2024

Rotation manipulation in the fields of metamaterials and metasurfaces has led to a variety of striking properties. Here, we propose an efficient scheme for realizing rotation-controllable plasma metamaterials in dielectric barrier discharge. Rotating triangular plasma photonic crystals (RTPPCs) are obtained by self-organization of filaments in simply ambient air. Independent control of the angular velocity and the lattice constant of RTPPCs is realized. A phenomenological reaction–diffusion model with two coupled layers is established to reveal the underlying mechanism of RTPPCs. Moreover, the changes in the bandgaps with angular reorientation of RTPPCs are demonstrated by using microwave diagnosis. Experimental observations and numerical simulations are in good agreement. Our method provides an additional degree of freedom to tailor plasma metamaterials, which may find potential applications, such as integrated optical components, wireless communications, precision radiolocation, time-resolved imaging, and sensing.
Ammonium iodide-incorporated SnO2 obtains perovskite solar cells with over 24% efficiency
Authors: Li Hui , Xu Jianyu , Han Junhui , Lan Qimin , Wu Zhe , Xie Meiqiu , Shao Cong , Li Xing'ao , Wang Jizheng
Published: March 2024

Tin dioxide (SnO2) as the most promising electron transport layer (ETL) has been widely used in high-efficiency perovskite solar cells (PSCs) due to its excellent optical/electronic properties, chemical stability, and low-temperature processing. However, the surface of SnO2 ETL contains defect sites, which result in energy losses in PSCs. In order to passivate the defects of SnO2 surface and together tune the electronic properties of SnO2 ETL for getting high-performance PSCs, we herein incorporate the low-cost material ammonium iodide (NH4I) into the SnO2. After the NH4I doping, the optimized photovoltaic power conversation efficiency is significantly enhanced (the highest efficiency can reach 24.4%), the hysteresis of device is largely suppressed to a negligible level, and the stability of device is also obviously improved. The origin of these enhancements is further disclosed by the positive effects of NH4I doping on both ETL and perovskite film: the surface morphology of ETL is effectively flatten, the energy level of ETL is suitably adjusted, the electron mobility of ETL and the perovskite grain size are clearly increased, the surface defects of ETL and the trap states in the perovskite film are greatly reduced, and the PbI2 residue in the perovskite layer is obviously diminished. The study here of incorporating cheap inorganic small molecule in the ETL provides an ingenious way to enhance the performance of the planar PSCs.
Core-shell designed high entropy alloy CoNiFeCuV-C nanoparticles for enhanced microwave absorption
Authors: Hassan Sibt ul , Yang Yang , Qamar Tauqeer Haider , Shah Mohsin , Khan Imran , Hou Lizhen , Wang Shiliang
Published: March 2024

The widespread interest in high entropy alloy nanostructures stems from their potential utilization in a variety of technological and scientific fields. This study presents an innovative approach employing a one-step metal organic chemical vapor deposition to synthesize quinary high entropy alloy (CoNiFeCuV-C) core-shell nanoparticles designed for microwave absorption applications. Superior microwave absorption performance is attained through the optimization of conduction loss via thermal treatment, coupled with the interfacial polarization across the interfaces between CoNiFeCuV cores and C shell. The paraffin composite filled with an optimal 20% content of CoNiFeCuV-C core-shell nanoparticles demonstrates a minimal reflection loss (RLmin) of −51.8 dB at 13.76 GHz, achieving this performance with a thickness of 2.2 mm. Moreover, the absorbing bandwidth spans 7.44 GHz at a thickness of 2.4 mm. The outstanding accomplishments underscore the potential of utilizing CoNiFeCuV-C core-shell nanoparticles as a promising choice for lightweight, effective microwave absorber material.
Terahertz plasmonic resonances in coplanar graphene nanoribbon structures
Authors: Ryzhii V. , Tang C. , Otsuji T. , Ryzhii M. , Shur M. S.
Published: March 2024

We analyze plasmonic oscillations in the coplanar graphene nanoribbon (GNR) structures induced by the applied terahertz (THz) signals and calculate the GNR impedance. The plasmonic oscillations in the GNR structures are associated with the electron and hole inductances and the lateral inter-GNR capacitance. A relatively low inter-GNR capacitance enables the resonant excitation of the THz plasmonic oscillations in the GNR structures with long GNRs. The GNR structures under consideration can be used in different THz devices as the resonant structures incorporated in THz detectors, THz sources using resonant-tunneling diodes, photomixers, and surface acoustic wave sensors.
Signatures of nearly compensated magnetism and spin glass behavior in highly frustrated β-Mn-type Mn50Fe25+xAl25−x Heusler alloys
Authors: Khorwal Abhinav Kumar , Saha Sujoy , Lukoyanov Alexey V. , Patra Ajit K.
Published: March 2024

The present study examines the effect of Fe/Al concentration on the structural and magnetic properties of Mn-rich Mn50Fe25+xAl25−x (x = 5, 10, 15) Heusler alloys through x-ray diffraction, temperature- and field-dependent DC magnetization, thermoremanent magnetization, magnetic memory effect, AC susceptibility measurements, and DFT calculations. The samples crystallize in a cubic β-Mn structure. The trend shows a reduction in lattice parameters (unit cell volume) with the increasing Fe proportion. These alloys exhibit strong antiferromagnetic interactions with large frustration parameters, indicating the presence of competing magnetic interactions. The DC magnetization data reveal spin glass-like features with a peak at spin glass freezing temperature (Tf). The observation of bifurcation in temperature-dependent zero-field-cooled and field-cooled magnetization curves, exponential dependence of the temperature variation of remanence and coercivity, magnetic relaxation, and magnetic memory effect below Tf support the spin-glass character of these alloys. The frequency dependence of Tf is also examined in the context of dynamic scaling laws, such as the Vogel–Fulcher law and critical slowing down model, which further supports the presence of spin glass behavior. In the theoretical DFT calculations, the electronic structure is found to be metallic and similar for both spin projections. Moreover, the antiferromagnetic arrangement of the magnetic moments, in line with the experimental observations, is stabilized by exchange interactions, resulting in an almost compensated total magnetic moment of 0.02–0.38 µB/f.u. This is probably caused by the frustrated structure and non-stoichiometric compositions of Mn50Fe25+xAl25−x.
Highlighting efficiency and redundancy in the Royal Australian College of General Practice standards for accreditation
Authors: McNaughton David , Mara Paul , Jones Michael
Published: March 2024

Objectives Accreditation to standards developed by the Royal Australian College of General Practice provides assurance to the community of the quality and safety of general practices in Australia. The objective of this study was to conduct an empirical evaluation of the 5th edition standards. Minimal empirically driven evaluation of the standards has been conducted since their publication in 2020. Methods Data encompass consecutive Australian general practice accreditation assessments between December 2020 and July 2022 recorded from a single accrediting agency. Met and not met compliance (binary) scores for 124 indicators evaluated at the site visit were recorded. A subset of indicators derived from a selection of existing and consistently non-conformant indicators within each criterion was generated. Concordance between the indicator subset and the criterion was assessed to determine the predictive ability of the indicator subset in distinguishing practices who are conformant to the entire criterion. Results A total of 757 general practices were included in the analysis. On average, 113.69 (s.d. = 8.16) of 124 indicators were evaluated as conformant at the site visit. In total, 52 (42%) indicators were required to obtain a true positive conformity rate above 95% for all criterions of the standards. For criterion 1 (General Practice 1) conformity to the entire criterion (nine indicators; >95% true positive rate) could be obtained by including 2/9 indicators (C1-1a and C1-2a). Conclusion Our results identified that indicator non-conformity was driven by a small proportion of indicators and identifying a subset of these consistently non-conformant indicators predicted a true positive rate above 95% at the criterion level.
Acceptance and use of condoms among school-aged young people in Australia
Authors: Power Jennifer , Kauer Sylvia , Fisher Christopher , Bourne Adam
Published: March 2024

Background Despite availability of vaccines or medical prophylaxis for some sexually transmissible infections (STIs), promoting condom use remains an important public health strategy for the prevention of STIs. Recent research shows that regular condom use among young people in Australia has declined over the past decade, while the rate of common STIs has increased. Method In this paper, we report findings from a large survey of school-aged young people in Australia (14–18 years old) in which we looked at the association between condom use and positive feelings about sex, beliefs about social acceptability of condoms and confidence talking with partners about sex and condoms. Results Communication and relational factors supported more consistent condom use. Participants were more likely to regularly use condoms if they discussed condom use with a sexual partner, perceived condom use to be easy (a measure that included perceived ease of discussing condoms with a partner) and perceived condom use to offer social or relational benefits, including perceiving condom use as a demonstration of care for a partner. Young men were more likely to report positive feelings about sex and regular condom use than young women. Young women were less likely than young men or trans and non-binary young people to report regular condom use. Conclusions The study shows the importance of supporting young people to build confidence expressing sexual needs and wants with partners. Public health approaches to STI prevention need to consider condom promotion in the context of young people’s contemporary sexual, gendered and relationships cultures.
‘Every strategy needs to be contributing to erasing the stigma’: Māori and Pacific young people talk about overcoming barriers to testing for sexually transmitted infections
Authors: Rose Sally B. , Dunlop Abby , Gardiner Tracey , Cole Marama , Garrett Susan M. , McKinlay Eileen M.
Published: March 2024

Background Māori and Pacific young people are disproportionately impacted by sexually transmitted infections (STIs). Access to STI screening is important to reduce transmission and reproductive health complications. Methods Between November 2022 and May 2023, we held four wānanga (workshops) with Māori and Pacific participants (15–24 years old) to find out what barriers they encounter to STI testing, and hear their ideas about how to overcome these. Participants were recruited via youth-focused community organisations in the Wellington region of Aotearoa New Zealand. Inductive thematic analysis was used to understand data generated from discussions, drawing on Māori and Pacific models of wellbeing to frame themes. Results Thirty-eight participants were involved in the wānanga. Barriers to STI testing related to five themes: (1) differences in cultural values and expression; (2) family/friends; (3) educational gaps; (4) psychological factors; and (5) structural obstacles. Suggested strategies to improve access to sexual health care included the need for free, flexible services, education and health promotion activities to reach young people in their spaces (e.g. church, marae, social media). Participants stressed the need for approaches to be community-based, delivered by trusted individuals using culturally appropriate messages, and saw participation in STI testing as beneficial for whānau/family and communities. Conclusions To improve access to STI testing, participants described the need for free services, together with education and health promotion to improve inter-generational sexual health knowledge. Reframing messages around STIs to align with Māori and Pacific models of wellbeing was identified as a way to normalise conversations, in turn reducing the stigma surrounding STI testing.
The evolutionary genomics of adaptation to stress in wild rhizobium bacteria
Authors: Kehlet-Delgado Hanna , Montoya Angeliqua P. , Jensen Kyson T. , Wendlandt Camille E. , Dexheimer Christopher , Roberts Miles , Torres Martínez Lorena , Friesen Maren L. , Griffitts Joel S. , Porter Stephanie S.
Published: March 2024

Microbiota comprise the bulk of life’s diversity, yet we know little about how populations of microbes accumulate adaptive diversity across natural landscapes. Adaptation to stressful soil conditions in plants provides seminal examples of adaptation in response to natural selection via allelic substitution. For microbes symbiotic with plants however, horizontal gene transfer allows for adaptation via gene gain and loss, which could generate fundamentally different evolutionary dynamics. We use comparative genomics and genetics to elucidate the evolutionary mechanisms of adaptation to physiologically stressful serpentine soils in rhizobial bacteria in western North American grasslands. In vitro experiments demonstrate that the presence of a locus of major effect, the
nre
operon, is necessary and sufficient to confer adaptation to nickel, a heavy metal enriched to toxic levels in serpentine soil, and a major axis of environmental soil chemistry variation. We find discordance between inferred evolutionary histories of the core genome and
nreAXY
genes, which often reside in putative genomic islands. This suggests that the evolutionary history of this adaptive variant is marked by frequent losses, and/or gains via horizontal acquisition across divergent rhizobium clades. However, different
nre
alleles confer distinct levels of nickel resistance, suggesting allelic substitution could also play a role in rhizobium adaptation to serpentine soil. These results illustrate that the interplay between evolution via gene gain and loss and evolution via allelic substitution may underlie adaptation in wild soil microbiota. Both processes are important to consider for understanding adaptive diversity in microbes and improving stress-adapted microbial inocula for human use.
Mesoscale structure of the atmospheric boundary layer across a natural roughness transition
Authors: Cooke Justin , Jerolmack Douglas , Park George Ilhwan
Published: March 2024

The structure and intensity of turbulence in the atmospheric boundary layer (ABL) drive fluxes of sediment, contaminants, heat, moisture, and CO

2

at the Earth’s surface. Where ABL flows encounter changes in roughness—such as cities, wind farms, forest canopies, and landforms—a new mesoscopic flow scale is introduced: the internal boundary layer (IBL), which represents a near-bed region of transient flow adjustment that develops over kilometers. Measurement of this new mesoscopic scale lies outside present observational capabilities of ABL flows, and simplified models fail to capture the sensitive dependence of turbulence on roughness geometry. Here, we use large-eddy simulations, run over high-resolution topographic data and validated against field observations, to examine the structure of the ABL across a natural roughness transition: the emergent sand dunes at White Sands National Park. We observe that development of the IBL is triggered by the abrupt transition from smooth playa surface to dunes; however, continuous changes in the size and spacing of dunes over several kilometers influence the downwind patterns of boundary stress and near-bed turbulence. Coherent flow structures grow and merge over the entire

∼

10 km distance of the dune field and modulate the influence of large-scale atmospheric turbulence on the bed. Simulated boundary stresses in the developing IBL counter existing expectations and explain the observed downwind decrease in dune migration, demonstrating a mesoscale coupling between flow and form that governs landscape dynamics. More broadly, our findings demonstrate the importance of resolving both turbulence and realistic roughness for understanding fluid-boundary interactions in environmental flows.
Crosstalk within and beyond the Polycomb repressive system
Authors: Shi Tianyi Hideyuki , Sugishita Hiroki , Gotoh Yukiko
Published: March 2024

The development of multicellular organisms depends on spatiotemporally controlled differentiation of numerous cell types and their maintenance. To generate such diversity based on the invariant genetic information stored in DNA, epigenetic mechanisms, which are heritable changes in gene function that do not involve alterations to the underlying DNA sequence, are required to establish and maintain unique gene expression programs. Polycomb repressive complexes represent a paradigm of epigenetic regulation of developmentally regulated genes, and the roles of these complexes as well as the epigenetic marks they deposit, namely H3K27me3 and H2AK119ub, have been extensively studied. However, an emerging theme from recent studies is that not only the autonomous functions of the Polycomb repressive system, but also crosstalks of Polycomb with other epigenetic modifications, are important for gene regulation. In this review, we summarize how these crosstalk mechanisms have improved our understanding of Polycomb biology and how such knowledge could help with the design of cancer treatments that target the dysregulated epigenome.
Crosstalk between TGF-β and EGF receptors via direct phosphorylation
Authors: Moustakas Aristidis
Published: March 2024

Aristidis Moustakas discusses work from Ye-Guang Chen and colleagues (https://doi.org/10.1083/jcb.202307138) on a new mechanism by which TGF-β modulates HER2 signaling in mammary epithelia.
A DFT approach to explore the structural, optoelectronic, mechanical, and thermoelectric attributes of lead-free RbInX3 (X = I, Br, Cl) halide perovskites for renewable energy applications
Authors: Murtaza Hudabia , Ain Quratul , Munir Junaid , Ghaithan Hamid M , Ahmed Abdullah Ahmed Ali , Aldwayyan Abdullah S , H Qaid Saif M
Published: March 2024

Halide perovskites are significant due to their versatility and high performance in optoelectronics and green technologies. This paper thoroughly investigates the structural, elastic, optoelectronic and transport characteristics of RbInX3 (X = I, Br, Cl) perovskites using density functional theory (DFT) embedded in Wein2K. Modified Becke Johnson as an exchange correlation potential is used to evaluate the physical characteristics. Structural stability is achieved with the tolerance factor and octahedral tilting along with the optimization curves. A metallic character is detected in RbInI3. However, the replacement of I with Br and Cl atoms results in an indirect band gap of 0.9 eV and 1.95 eV at (L-X) symmetry points, respectively. The elastic constants are utilized to determine the elastic parameters that ensure the structural stability of perovskites. Cauchy pressure and Poisson’s ratio indicate the ductile nature of all studied phases. The thermal behavior is evaluated through the computation of Debye temperature. Furthermore, an insight into the material’s interaction with electromagnetic radiation is accessed through the optical parameters. A high absorption at 1.49 eV for RbInI3, 1.65 for RbInBr3 and 2.57 for RbInCl3 show their potential for light emitting devices. The semi-classical Boltzmann theory is employed to compute thermoelectric properties, which show RbInI3, RbInBr3 and RbInCl3 possess high electrical conductivities of 3.068

×

10

19

S m–1, 1.88

×

10

19

S m–1 and 1.76

×

10

19

S m–1 at 1200 K, respectively. The ZT value for RbInBr3 is 0.74 and RbInCl3 is 0.73, while RbInI3 exhibit the lowest ZT of 0.04 at 1200 K. The examined characteristics indicate that RbInBr3 and RbInCl3 possess promising potential for renewable energy applications.
Bound states of relativistic spinless particles in a mix of circularly symmetric vector and scalar harmonic oscillators
Authors: Mendrot V B , de Castro A S , Alberto P
Published: March 2024

We study the dynamics of relativistic spinless particles moving in a plane when there is circular symmetry. The general formalism for solving the Klein–Gordon equation in cylindrical coordinates for such systems is presented, as well as the conserved observables and the corresponding quantum numbers. We look for bound solutions of the corresponding Klein–Gordon equation when one has vector and scalar circularly symmetric harmonic oscillator potentials. Both positive and negative bound solutions are considered when there is either equal vector and scalar potentials or symmetric vector and scalar potentials, and it is shown how both cases are related through charge conjugation. We compute the non-relativistic limit for those cases, and show that for symmetric scalar and vector potentials the limit does not exist in the first order of an harmonic oscillator frequency, recovering a known result from the Dirac equation with the same kind of potentials.
Voltage-tunable graphene-InP schottky photodetector with enhanced responsivity using plasmonic waveguide integration
Authors: Vaghef-Koodehi Arash , Nikoufard Mahmoud , Rostami-Khomami Ali
Published: March 2024

In this work, we propose and theoretically investigate a novel side-illuminated graphene Schottky photodetector (SIGS-PD) integrated on an InP waveguide platform suitable for the telecommunication wavelength of 1.55 μm. Bilayer graphene is positioned to absorb the transverse magnetic (TM) mode, with an InP substrate forming a Schottky junction to enable electrical connectivity and carrier separation. Through electrostatic gating, the graphene Fermi level is actively tuned to reach an epsilon-near-zero condition of 0.51 eV, transitioning the optical properties from dielectric to metallic. This supports reconfigurable plasmonic modes confined within the subwavelength graphene layer, interacting strongly with the TM optical mode. Responsivity of TM mode is enhanced 10 × TE mode reaching 1.24 A W−1 at the epsilon-near-zero point for the wavelength of 1.55 μm due to discontinuity and localization of the perpendicular electric field. The maximum responsivity is achieved at reverse bias of 4.5 V for device lengths under 4 μm. Dark current is suppressed to 10−15 A by the rectifying Schottky junction. An internal specific detectivity of 9.6 × 1012 Jones is predicted along with >25 GHz bandwidth, exploiting combined benefits of plasmonic enhancement and electrical transport control in the hybrid graphene-InP platform. The voltage-tunability of the graphene optical properties provides a pathway to dynamically optimize device performance. This work demonstrates a route towards high-responsivity and high-speed graphene photodetectors seamlessly integrated with photonic integrated circuits.
Molecular docking studies, structural analysis, biological studies, and synthesis of certain novel Schiff base from benzohydrazide derivate
Authors: Gosu Nageswara Reddy , C Hazarathaiah Yadav , K Ramakrishna Reddy , Losetty Venkatramana , Sampath Sridhar
Published: March 2024

The research described involves the synthesis and characterization of a new benzohydrazide based Schiff base compound namely 4-methyl-N′-(2,4,5-trimethoxybenzylidene) benzohydrazide (HL). The compound was synthesized by condensing a primary amine and an aldehyde functional group. The characterization of the compound was carried out using various spectroscopic techniques, including elemental analysis, Ultraviolet spectroscopy, nuclear magnetic resonance spectroscopy, and infrared spectroscopy. These techniques helped confirm the excellent quality of the synthesized molecules. In addition to the characterization, the Schiff base compound was subjected to docking studies and biological studies. The antibacterial activity of the compound was tested against three strains of bacteria, namely E. faecalis, B. subtills, and E. coli. The results of these tests provided information on the compound effectiveness against these bacterial strains. Furthermore, docking studies was performed to assess the interaction between the synthesized compound and three target enzymes like GlcN-6-p synthase, DNA polymerase, and EGFR tyrosine kinase. Docking studies are computational simulations that provide insights into the binding interactions between Schiff base ligand and target proteins. In this case, the docking studies helped understand the potential mechanisms of action of the synthesized compound by calculating binding constants and the number of binding modes. The biological activity studies revealed interesting fragmentation patterns, which could be further investigated to understand the compound modes of action. Moreover, the docking studies evaluated the compound’s potential as a drug candidate by assessing its binding interactions with the target enzymes. The present study suggests that the synthesized benzohydrazide based Schiff base compound exhibits potential antibacterial activity and shows promising binding interactions with the target protein/enzymes. This information is valuable for designing and developing more potent compounds in the future.
Bionic blink improves real-time eye closure in unilateral facial paralysis
Authors: Cervera-Negueruela Mar , Chee Lauren , Cimolato Andrea , Valle Giacomo , Tschopp Markus , Menke Marcel , Papazoglou Anthia , Raspopovic Stanisa
Published: March 2024

Facial paralysis is the inability to move facial muscles thereby impairing the ability to blink and make facial expressions. Depending on the localization of the nerve malfunction it is subcategorised into central or peripheral and is usually unilateral. This leads to health deficits stemming from corneal dryness and social ostracization. Objective: Electrical stimulation shows promise as a method through which to restore the blink function and as a result improve eye health. However, it is unknown whether a real-time, myoelectrically controlled, neurostimulating device can be used as assistance to this pathological condition. Approach: We developed NEURO-BLINK, a wearable robotic system, that can detect the volitional healthy contralateral blink through electromyography and electrically stimulate the impaired subcutaneous facial nerve and orbicularis oculi muscle to compensate for lost blink function. Alongside the system, we developed a method to evaluate optimal electrode placement through the relationship between blink amplitude and injected charge. Main results: Ten patients with unilateral facial palsy were enrolled in the NEURO-BLINK study, with eight completing testing under two conditions. (1) where the stimulation was cued with an auditory signal (i.e. paced controlled) and (2) synchronized with the natural blink (i.e. myoelectrically controlled). In both scenarios, overall eye closure (distance between eyelids) and cornea coverage measured with high FPS video were found to significantly improve when measured in real-time, while no significant clinical changes were found immediately after use. Significance: This work takes steps towards the development of a portable medical device for blink restoration and facial stimulation which has the potential to improve long-term ocular health.
3D bioprinting of stromal cells-laden artificial cornea based on visible light-crosslinkable bioinks forming multilength networks
Authors: Lee Gyeong Won , Chandrasekharan Ajeesh , Roy Subhadeep , Thamarappalli Akash , Mahaling Binapani , Lee Hyeseon , Seong Keum-Yong , Ghosh Sourabh , Yang Seung Yun
Published: March 2024

3D bioprinting has the potential for the rapid and precise engineering of hydrogel constructs that can mimic the structural and optical complexity of a healthy cornea. However, the use of existing light-activated bioinks for corneal printing is limited by their poor cytocompatibility, use of cytotoxic photoinitiators (PIs), low photo-crosslinking efficiency, and opaque/colored surface of the printed material. Herein, we report a fast-curable, non-cytotoxic, optically transparent bioprinting system using a new water-soluble benzoyl phosphinate-based PI and photocrosslinkable methacrylated hyaluronic acid (HAMA). Compared with commercially available PIs, the newly developed PI, lithium benzoyl (phenyl) phosphinate (BP), demonstrated increased photoinitiation efficiency under visible light and low cytotoxicity. Using a catalytic amount of BP, the HA-based bioinks quickly formed 3D hydrogel constructs under low-energy visible-light irradiation (405 nm, <1 J cm−2). The mechanical properties and printability of photocurable bioinks were further improved by blending low (10 kDa) and high (100 kDa) molecular weight (MW) HAMA by forming multilength networks. For potential applications as corneal scaffolds, stromal cell-laden dome-shaped constructs were fabricated using MW-blended HAMA/BP bioink and a digital light processing printer. The HA-based photocurable bioinks exhibited good cytocompatibility (80%–95%), fast curing kinetics (<5 s), and excellent optical transparency (>90% in the visible range), potentially making them suitable for corneal tissue engineering.
Modification of extended Oxley’s predictive machining theory and determination of Johnson-Cook material model constants by inverse approach
Authors: Dubey Aakash A , Lalwani D I
Published: March 2024

The Johnson-Cook (J-C) flow stress model, renowned for its consideration of the combined effect of strain, strain-rate, and temperature on material property, forms the cornerstone of this research. Its simplicity and applicability in numerical simulation render it widely popular. The study addresses two primary objectives: first, to modify extended Oxley’s predictive machining theory by eliminating the iterative loop for calculating the tool-chip interface temperature, and second, to utilize an inverse approach for determining J-C material model constants specific to medium carbon steel. The modified approach successfully eliminates the iterative loop, thereby streamlining the determination process and effectively reducing calculation time by 25%–40%, thereby enhancing overall efficiency. Concurrently, the study employs an inverse approach to accurately determine the J-C constants (A, B, n, C, and m). Notably, the research avoids the need for expensive and time-consuming Split Hopkinson Pressure Bar (SHPB) tests, instead opting for low-cost axial tensile tests and numerical optimization techniques to obtain the J-C constants. Thus, this study provides a practical method for determining J-C constants, pivotal for accurate material representation in numerical simulations and metal cutting applications. Standard materials and machines are employed, ensuring ease of understanding for a wider audience. The predicted values for the J-C constants are in proximity to the experimental values obtained by using SHPB test. Validated findings, achieved with precision under specified metal cutting conditions, highlight the effectiveness and applicability of the proposed approach, providing valuable insights for optimizing machining processes and improving efficiency.
Six-dimensional sphere packing and linear programming
Authors: de Courcy-Ireland Matthew , Dostert Maria , Viazovska Maryna
Published: March 2024

We prove that the Cohn–Elkies linear programming bound for sphere packing is not sharp in dimension 6. The proof uses duality and optimization over a space of modular forms, generalizing a construction of Cohn–Triantafillou [Math. Comp. 91 (2021), pp. 491–508] to the case of odd weight and non-trivial character.
α-catenin middle- and actin-binding domain unfolding mutants differentially impact epithelial strength and sheet migration
Authors: Quinn Jeanne M. , Wang Yuou , Wood Megan , Flozak Annette S. , Le Phuong M. , Yemelyanov Alex , Oakes Patrick W. , Gottardi Cara J.
Published: March 2024

α-catenin (α-cat) displays force-dependent unfolding and binding to actin filaments through direct and indirect means, but features of adherens junction structure and function most vulnerable to loss of these allosteric mechanisms have not been directly compared. By reconstituting an α-cat F-actin-binding domain unfolding mutant known to exhibit enhanced binding to actin (α-cat-H0-FABD+) into α-cat knockout Madin Darby Canine Kidney (MDCK) cells, we show that partial loss of the α-cat catch bond mechanism (via an altered H0 α-helix) leads to stronger epithelial sheet integrity with greater colocalization between the α-cat-H0-FABD+ mutant and actin. α-cat-H0-FABD+ -expressing cells are less efficient at closing scratch-wounds, suggesting reduced capacity for more dynamic cell–cell coordination. Evidence that α-cat-H0-FABD+ is equally accessible to the conformationally sensitive α18 antibody epitope as WT α-cat and shows similar vinculin recruitment suggests this mutant engages lower tension cortical actin networks, as its M-domain is not persistently open. Conversely, α-cat-M-domain salt-bridge mutants with persistent recruitment of vinculin and phosphorylated myosin light chain show only intermediate monolayer adhesive strengths, but display less directionally coordinated and thereby slower migration speeds during wound-repair. These data show α-cat M- and FABD-unfolding mutants differentially impact cell–cell cohesion and migration properties, and suggest signals favoring α-cat-cortical actin interaction without persistent M-domain opening may improve epithelial monolayer strength through enhanced coupling to lower tension actin networks.
The E3 ubiquitin ligase TRIM9 regulates synaptic function and actin dynamics in response to netrin-1
Authors: McCormick Laura E. , Evans Elliot B. , Barker Natalie K. , Herring Laura E. , Diering Graham H. , Gupton Stephanie L.
Published: March 2024

During neuronal development, dynamic filopodia emerge from dendrites and mature into functional dendritic spines during synaptogenesis. Dendritic filopodia and spines respond to extracellular cues, influencing dendritic spine shape and size as well as synaptic function. Previously, the E3 ubiquitin ligase TRIM9 was shown to regulate filopodia in early stages of neuronal development, including netrin-1-dependent axon guidance and branching. Here, we demonstrate that TRIM9 also localizes to dendritic filopodia and spines of murine cortical and hippocampal neurons during synaptogenesis and is required for synaptic responses to netrin. In particular, TRIM9 is enriched in the postsynaptic density (PSD) within dendritic spines and loss of Trim9 alters the PSD proteome, including the actin cytoskeleton landscape. While netrin exposure induces accumulation of the Arp2/3 complex and filamentous actin in dendritic spine heads, this response is disrupted by genetic deletion of Trim9. In addition, we document changes in the synaptic receptors associated with loss of Trim9. These defects converge on a loss of netrin-dependent increases in neuronal firing rates, indicating TRIM9 is required downstream of synaptic netrin-1 signaling. We propose that TRIM9 regulates cytoskeletal dynamics in dendritic spines and is required for the proper response to synaptic stimuli.