bluuebunny/crossref_metadata_2025 huggingface dataset:
Machine learning-based diagnostic prediction of IgA nephropathy: model development and validation study
Authors: Noda Ryunosuke , Ichikawa Daisuke , Shibagaki Yugo
Published: May 2024

IgA nephropathy progresses to kidney failure, making early detection important. However, definitive diagnosis depends on invasive kidney biopsy. This study aimed to develop non-invasive prediction models for IgA nephropathy using machine learning. We collected retrospective data on demographic characteristics, blood tests, and urine tests of the patients who underwent kidney biopsy. The dataset was divided into derivation and validation cohorts, with temporal validation. We employed five machine learning models—eXtreme Gradient Boosting (XGBoost), LightGBM, Random Forest, Artificial Neural Networks, and 1 Dimentional-Convolutional Neural Network (1D-CNN)—and logistic regression, evaluating performance via the area under the receiver operating characteristic curve (AUROC) and explored variable importance through SHapley Additive exPlanations method. The study included 1268 participants, with 353 (28%) diagnosed with IgA nephropathy. In the derivation cohort, LightGBM achieved the highest AUROC of 0.913 (95% CI 0.906–0.919), significantly higher than logistic regression, Artificial Neural Network, and 1D-CNN, not significantly different from XGBoost and Random Forest. In the validation cohort, XGBoost demonstrated the highest AUROC of 0.894 (95% CI 0.850–0.935), maintaining its robust performance. Key predictors identified were age, serum albumin, IgA/C3, and urine red blood cells, aligning with existing clinical insights. Machine learning can be a valuable non-invasive tool for IgA nephropathy.
Identification of genomic regions controlling spikelet degeneration under FRIZZLE PANICLE (FZP) defect genetic background in rice
Authors: Wang Sheng-Shan , Tsai Pei-Hua , Cheng Shu-Fang , Chen Rong-Kuen , Chen Kai-Yi
Published: May 2024

The FZP gene plays a critical role in the formation of lateral branches and spikelets in rice panicle architecture. This study investigates the qSBN7 allele, a hypomorphic variant of FZP, and its influence on panicle architectures in different genetic backgrounds. We evaluated two backcross inbred lines (BILs), BC5_TCS10sbn and BC3_TCS10sbn, each possessing the homozygous qSBN7 allele but demonstrating differing degrees of spikelet degeneration. Our analysis revealed that BC5_TCS10sbn had markedly low FZP expression, which corresponded with an increase in axillary branches and severe spikelet degeneration. Conversely, BC3_TCS10sbn exhibited significantly elevated FZP expression, leading to fewer secondary and tertiary branches, and consequently decreased spikelet degeneration. Compared to BC5_TCS10sbn, BC3_TCS10sbn carries three additional chromosomal substitution segments from its donor parent, IR65598-112-2. All three segments significantly enhance the expression of FZP and reduce the occurrence of tertiary branch and spikelet degeneration. These findings enhance our understanding of the mechanisms regulating FZP and aid rice breeding efforts.
A review of machine learning methods for cancer characterization from microbiome data
Authors: Teixeira Marco , Silva Francisco , Ferreira Rui M. , Pereira Tania , Figueiredo Ceu , Oliveira Hélder P.
Published: May 2024

Recent studies have shown that the microbiome can impact cancer development, progression, and response to therapies suggesting microbiome-based approaches for cancer characterization. As cancer-related signatures are complex and implicate many taxa, their discovery often requires Machine Learning approaches. This review discusses Machine Learning methods for cancer characterization from microbiome data. It focuses on the implications of choices undertaken during sample collection, feature selection and pre-processing. It also discusses ML model selection, guiding how to choose an ML model, and model validation. Finally, it enumerates current limitations and how these may be surpassed. Proposed methods, often based on Random Forests, show promising results, however insufficient for widespread clinical usage. Studies often report conflicting results mainly due to ML models with poor generalizability. We expect that evaluating models with expanded, hold-out datasets, removing technical artifacts, exploring representations of the microbiome other than taxonomical profiles, leveraging advances in deep learning, and developing ML models better adapted to the characteristics of microbiome data will improve the performance and generalizability of models and enable their usage in the clinic.
Mitigating gut microbial degradation of levodopa and enhancing brain dopamine: Implications in Parkinson’s disease
Authors: Cheng Gang , Hardy Micael , Hillard Cecilia J. , Feix Jimmy B. , Kalyanaraman Balaraman
Published: May 2024

Parkinson’s disease is managed using levodopa; however, as Parkinson’s disease progresses, patients require increased doses of levodopa, which can cause undesirable side effects. Additionally, the oral bioavailability of levodopa decreases in Parkinson’s disease patients due to the increased metabolism of levodopa to dopamine by gut bacteria, Enterococcus faecalis, resulting in decreased neuronal uptake and dopamine formation. Parkinson’s disease patients have varying levels of these bacteria. Thus, decreasing bacterial metabolism is a promising therapeutic approach to enhance the bioavailability of levodopa in the brain. In this work, we show that Mito-ortho-HNK, formed by modification of a naturally occurring molecule, honokiol, conjugated to a triphenylphosphonium moiety, mitigates the metabolism of levodopa—alone or combined with carbidopa—to dopamine. Mito-ortho-HNK suppresses the growth of E. faecalis, decreases dopamine levels in the gut, and increases dopamine levels in the brain. Mitigating the gut bacterial metabolism of levodopa as shown here could enhance its efficacy.
SGLT2 inhibition eliminates senescent cells and alleviates pathological aging
Authors: Katsuumi Goro , Shimizu Ippei , Suda Masayoshi , Yoshida Yohko , Furihata Takaaki , Joki Yusuke , Hsiao Chieh-Lun , Jiaqi Liang , Fujiki Shinya , Abe Manabu , Sugimoto Masataka , Soga Tomoyoshi , Minamino Tohru
Published: May 2024

It has been reported that accumulation of senescent cells in various tissues contributes to pathological aging and that elimination of senescent cells (senolysis) improves age-associated pathologies. Here, we demonstrate that inhibition of sodium–glucose co-transporter 2 (SGLT2) enhances clearance of senescent cells, thereby ameliorating age-associated phenotypic changes. In a mouse model of dietary obesity, short-term treatment with the SGLT2 inhibitor canagliflozin reduced the senescence load in visceral adipose tissue and improved adipose tissue inflammation and metabolic dysfunction, but normalization of plasma glucose by insulin treatment had no effect on senescent cells. Canagliflozin extended the lifespan of mice with premature aging even when treatment was started in middle age. Metabolomic analyses revealed that short-term treatment with canagliflozin upregulated 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside, enhancing immune-mediated clearance of senescent cells by downregulating expression of programmed cell death-ligand 1. These findings suggest that inhibition of SGLT2 has an indirect senolytic effect by enhancing endogenous immunosurveillance of senescent cells.
High-fidelity detection of picric acid following proton prompted fluorescence quenching by a novel acridine yellow G-based binuclear ZnII-metallacycle
Authors: Chand Prem , Kumar Ashish
Published: May 2024

Highly selective quenching-based fluorescence detection of picric acid in solid and liquid phases by a novel acridine yellow G based binuclear ZnII-metallacycle (1) with a calculated KSV and LOD of 3.44 × 104 M and 7.62 × 10−8 M, respectively.
Photoactivatable substrates show diverse phenotypes of leader cells in collective migration when moving along different extracellular matrix proteins
Authors: Abdellatef Shimaa A. , Bard Francesca , Nakanishi Jun
Published: May 2024

Photoactivatable surface enables the sequential deposition of ECM proteins to produce heterogeneous and homogeneous ECM protein-coated surfaces. Leader cells’ phenotypes vary based on the type of protein they migrate on.
Manganese(ii) promotes prebiotically plausible non-enzymatic RNA ligation reactions
Authors: Liu Ziwei , Jiang Clancy Zhijian , Bond Andrew D. , Tosca Nicholas J. , Sutherland John D.
Published: May 2024

Using different prebiotically plausible activating reagents, the RNA ligation yield was significantly increased in the presence of Mn(II).
An ab initio diabatic study of rovibronic spectra of CN
Authors: Zhang Shuai , Qin Zhi , Liu Linhua
Published: May 2024

This work provides an overall prediction of the rovibronic spectrum of CN considering transitions between 17 electronic states, in which the spin–orbit coupling, electronic angular momentum coupling and diabatic transformations are included.
Gaseous inhibition of the transsulfuration pathway by cystathionine β-synthase
Authors: McFarlane Neil R. , Gui Jiangli , Oláh Julianna , Harvey Jeremy N.
Published: May 2024

This work investigates the signalling mechanism found in human CBS. Quantum chemical calculations give an atomistic insight into gas binding to heme, and molecular dynamics simulations show the allosteric signalling pathway initiated by gas binding.
Carbon-coated silicon/graphite oxide composites as anode materials for highly stable lithium-ion batteries
Authors: Niu Lujie , Zhang Rui , Zhang Qiang , Wang Dong , Bi Yanlei , Wen Guangwu , Qin Lu-Chang
Published: May 2024

The cycling stability of Si materials is greatly enhanced by the introduction of two carbon sources.
Exploring the structure of type V deep eutectic solvents by xenon NMR spectroscopy
Authors: Boventi Matteo , Mauri Michele , Castiglione Franca , Simonutti Roberto
Published: May 2024

Type V deep eutectic solvents thymol : camphor, menthol : thymol and eutectic mixtures based on menthol : carboxylic acids with variable chain length, are investigated to clarify the peculiar nanostructure of these materials..
Intramolecular exciplex featuring a bis-sp3 C-locked acceptor–donor–acceptor sandwich
Authors: Xie Feng-Ming , Wang Han-Yang , Li Hao-Ze , Zhang Kai , Shen Yang , Zou Jianhua , Li Yan-Qing , Tang Jian-Xin
Published: May 2024

A bis-sp3 C-locked A–D–A sandwich intramolecular exciplex is developed, featuring multiple through-space charge-transfer processes. The electroluminescent device with this rigid emitter exhibits an EQE of 28.5% and low efficiency roll-off.
CuO/Mn2O3 heterojunction for efficient electrochemical nitrate reduction to ammonia
Authors: Cheng Xuetao , Zhao Huilin , Fan Chao , Duan Yun , Wang Yan-Qin
Published: May 2024

A heterojunction catalyst CuO/Mn2O3 constructed by CuO and Mn2O3 with a unique spindle-like morphology is successfully fabricated, which demonstrates excellent NO3RR performance.
Au- and Pd-catalyzed cyclization processes: synthesis of polyfunctionalized cyclopropanes
Authors: Truchon Alexis , Dupeux Aurélien , Olivero Sandra , Michelet Véronique
Published: May 2024

Reported herein is an efficient 2-step process involving an Au-catalyzed Prins-type cyclization and a Pd-catalyzed cyclopropane C–H activation for the synthesis of polysubstituted cyclopropanes.
A dual-signal optical sensing platform of CDs–MnO2 NS composites for facile detection of ascorbic acid based on a combination of Tyndall effect scattering and fluorescence
Authors: Zhou ShuJing , Wan Jing , Zou Jianmei , Zhang Yulan , He Huijun , Li Wei , Hu Jiale , Nie Jinfang , Yuan Yali , Zhang Yun
Published: May 2024

A Tyndall effect scattering and fluorescence dual-signal optical sensing platform based on CDs–MnO2 NS composites was successfully constructed for the detection of ascorbic acid.
High-throughput parallel testing of ten photoelectrochemical cells for water splitting: case study on the effects of temperature in hematite photoanodes
Authors: Valenza Roberto , Holmes-Gentle Isaac , Bedoya-Lora Franky E. , Haussener Sophia
Published: May 2024

A setup that simultaneously tests ten photoelectrochemical cells whilst controlling temperature was developed. Applied to Sn:α-Fe2O3 photoanodes, increasing temperature penalized energy conversion efficiency due to increased surface recombination.
Harnessing the power of silica aerogels for applications in energy and water sustainability
Authors: Tai Ming Hang , Kumar Palaniswamy Suresh
Published: May 2024

SiO2 aerogel, characterized by its lightweight, highly porous, and thermally insulating properties, has emerged as a versatile material capable of addressing the challenges of providing sustainable energy and clean water.
Minimizing ion/electron pathways through ultrathin conformal holey graphene encapsulation in Li- and Mn-rich layered oxide cathodes for high-performance lithium-ion batteries
Authors: Kim Sungwook , Hwang Jeonguk , Jo Youngseok , Park Changyong , Bansal Neetu , Salunkhe Rahul R. , Ahn Heejoon
Published: May 2024

PEI/holey graphene encapsulation applied thinly and uniformly to LMR cathode surfaces enhances electrical conductivity, facilitates lithium-ion diffusion, and acts as a protective layer, demonstrating excellent electrochemical performance.
Morphology-enhanced piezoelectric performance of SnS nanobelts for acetaminophen degradation
Authors: Liu Shuhui , Zhang Huayang , Wang Yantao , Sun Hongqi , Wang Shaobin , Tian Wenjie
Published: May 2024

This study reveals the enhanced piezoelectric activity of SnS nanobelts with step edges compared to nanobelts/nanoparticles and nanobelts, demonstrating superior catalytic performance for acetaminophen degradation in water.
An equivalent RLC circuit loss mechanism introduced by Fe2O3 nanoneedle arrays towards high-performance electromagnetic wave absorption materials
Authors: Xu Jingshen , Lu Na , Shi Kefan , Zhao Yuelin , Yuan Mengwei , Sun Genban
Published: May 2024

The introduction of an equivalent RLC circuit loss mechanism realizes strong EMW absorption in a low-filling ratio and even lower thicknesses.
A simple, efficient, and environmentally friendly strategy for preparing P(VDF–TrFE) with double bonds
Authors: Hu Bing , Wang Linping , Li Bowen , Gao Liang , Lin Huang , Jin Deng-Ren , Hu Ben-Lin
Published: May 2024

An efficient and environmentally friendly one-step reaction to insert double bonds in P(VDF–TrFE) was developed, which is important to prepare elastic ferroelectrics.
Dopamine synthesis and transport: current and novel therapeutics for parkinsonisms
Authors: Tai Mary Dayne Sia , Gamiz-Arco Gloria , Martinez Aurora
Published: May 2024

Parkinsonism is the primary type of movement disorder in adults, encompassing a set of clinical symptoms, including rigidity, tremors, dystonia, bradykinesia, and postural instability. These symptoms are primarily caused by a deficiency in dopamine (DA), an essential neurotransmitter in the brain. Currently, the DA precursor levodopa (synthetic L-DOPA) is the standard medication to treat DA deficiency, but it only addresses symptoms rather than provides a cure. In this review, we provide an overview of disorders associated with DA dysregulation and deficiency, particularly Parkinson's disease and rare inherited disorders leading predominantly to dystonia and/or parkinsonism, even in childhood. Although levodopa is relatively effective for the management of motor dysfunctions, it is less effective for severe forms of parkinsonism and is also associated with side effects and a loss of efficacy over time. We present ongoing efforts to reinforce the effect of levodopa and to develop innovative therapies that target the underlying pathogenic mechanisms affecting DA synthesis and transport, increasing neurotransmission through disease-modifying approaches, such as cell-based therapies, nucleic acid- and protein-based biologics, and small molecules.
Identification of aileron control derivatives based on measured loads in maneuvering flight
Authors: JIANG Xian , MENG Min , CHEN Zhiming
Published: May 2024

When a certain type of aircraft is maneuvered laterally, the aileron and the spoiler will be coupled and deflected to realize the rolling motion of the aircraft. The existing aerodynamic parameter identification methods cannot separately identify the control derivatives of the aileron and the spoiler. Based on the design logic of the aircraft control law and the loading characteristics of the structure during the roll motion, a new method for identifying the aileron control derivative based on the flight measured load is proposed. Firstly, the measurement method of wing aerodynamic load in maneuvering flight is proposed by measuring the structural loads of each load-testing section of the wing in maneuvering flight and combining the structural mass and acceleration distribution outside the section. Secondly, combining the instantaneous rolling moment balance of aircraft lateral control based on the equation and control surface deflection logic, the identification process of aileron control derivatives during roll recovery is deduced, and the identification method of aileron control derivatives based on the measured load of the wing is proposed. Finally, based on the aforementioned method, the identification of aileron control derivatives is carried out, and the influence of different Mach numbers on the derivative of aileron control is analyzed. The results show that the aileron control derivative can be identified based on the flight measured load, and the concentration of the aileron control derivative results is better at the same Mach number. As the Mach number increases, the aileron control effectiveness will decrease. The measured results of flight loads have the potential to be applied to the identification of aerodynamic parameters.
Analysis of aerodynamic characteristics of helicopter biplane tailplane
Authors: SUN Huixun , SUN Pengpeng , YANG Yongfei , YUAN Mingchuan , FAN Feng , LIN Yongfeng
Published: May 2024

To analyze the aerodynamic characteristics of helicopter biplane tailplane, computational models for helicopter biplane tailplane and monoplane tailplane were established via CFD. The aerodynamic characteristics of different configurations of tailplanes at low speed forward flight and high angle of attack was obtained. The aerodynamic characteristics and flow characteristics of biplane/monoplane tailplane were analyzed. The mechanism of biplane tailplane to improve the longitudinal static stability at low speed forward flight and high angle of attack was investigated. The results show that the biplane tailplane can improve the helicopter pitch moment surge at low speed forward flight by restraining the rotor/tailplane interference, comparing with the monplane tailplane, the pitch moment of the biplane tailplane was reduced by about 56.8% at an advance ratio of 0.05. The stall angle of attack and maximum pitch moment of the biplane tailplane were larger, which can enhance the helicopter longitudinal static stability at high angle of attack, comparing with the monplane tailplane, the pitch moment of the biplane tailplane increased by about 60.1% at an attack angle of 20°.
Study on real-time prediction and warning technology for negative acceleration flight test of civil airplanes
Authors: MI Yi , LI Aijun , WEN Yajun , FAN Zhipeng , HU Xuesong
Published: May 2024

The flight test of modern civil aircraft verifies the limits of aircraft design performance through a series of rigorous flight tests. Flight test mission is characterized by high risk and complex technology. The negative acceleration flight test is to verify that the aircraft power unit, auxiliary power unit, or any component or system related to it shall not have dangerous faults during negative acceleration. The risk level of negative acceleration flight test is high-risk. This paper presents a real-time prediction and alarm technology for negative acceleration flight test of civil airliners. Firstly, a fusion simulation system for the flight test scene of negative acceleration was developed. The accuracy verification results indicate that the system can meet the requirements of engineering applications. Secondly, the main factors that affect the negative acceleration flight test are given through theoretical analysis, which provides a guidance for simulation. Finally, the negative acceleration prediction model based on compensation factor is established by using BP neural network algorithm and XGBoost algorithm. And the real-time prediction and alarm program of negative acceleration flight test is developed, which is used in negative acceleration flight test of a certain civil aircraft. The prediction results indicate that the accuracy of real-time prediction and alarm program can meet the requirements of flight test monitoring.
Retention Rate of Free Pericardial Fat Grafts after Bronchial Stump Coverage
Authors: Karasaki Takahiro , Fujimori Sakashi , Suzuki Souichiro , Kikunaga Shinichiro
Published: May 2024

The postoperative course of the graft tissue after bronchial stump coverage remains unclear. We retrospectively analyzed 44 patients who underwent anatomical lung resection followed by bronchial stump coverage using free pericardial fat grafts. All patients underwent minimally invasive video-assisted thoracoscopic surgery. Computed tomography scans showed a graft retention rate of 100% on 60 days after surgery, 61% on 180 days, and plateauing at around 20% after 1 year. Free pericardial fat grafts, harvested minimally invasively, demonstrated a promising retention rate after surgery, making them a suitable option for patients with a high risk of bronchopleural fistula.
Oncological Safety and Feasibility of Posterior Marginal Mandibulectomy vis-à-vis Anterior Marginal Mandibulectomy in Oral Cancers
Authors: Nair Sudhir , Singhavi Hitesh R. , Joshi Kamal Deep , Shetty Rathan , Joshi Poonam , Lashkar Sarbani Ghosh , Chaturvedi Pankaj
Published: May 2024

The surgical management of retromolar trigone cancer (RTC) is an area of contention regarding the extent of bony resection. We aim to evaluate the oncological safety and feasibility of posterior marginal mandibulectomy (PMM) for RTC. We analyzed the clinical records of 98 patients with squamous cell carcinoma managed surgically using marginal mandibulectomy during 2014 to 2017, in which anterior segment mandibulectomy (AMM) and PMM were done in 56 and 42 patients, respectively. The median follow-up time was 44.4 months (95% confidence interval [CI] 42.3, 49.5) and the overall survival rate was 93.9% (95% CI 89.4–98.8%). The local recurrence rate was 19.6 and 18.3 % in PMM and AMM (p = 0.854). In the PMM group, osteoradionecrosis (ORN) was detected in two patients (4.3%) and fractures in one (2.1%) patient, while the AMM group neither had fracture nor ORN till the latest follow-up. The study results suggest that PMM is an oncological safe and adequate procedure for RTC.
Long-Term Outcomes of Endovascular Repair of Thoracic Aortic Aneurysms
Authors: Gorton Andrew J. , Keshavamurthy Suresh , Saha Sibu P.
Published: May 2024

The thoracic aorta is a dynamic structure composed of the aortic root, ascending aorta, aortic arch, and descending aorta. It is subject to the pressure and volume of the cardiac cycle and susceptible to atherosclerotic and aneurysmal changes. With these changes, the risk for acute aortic syndromes increases, thus creating the impetus for earlier interventions. The previous standard of open surgical repair has undergone a transition in recent years toward endovascular repair being favored in the descending and abdominal aortas with ongoing investigation into approaches for the ascending and aortic arch. These therapies have been shown to improve early mortality and morbidity outcomes with the caveat of more interventions compared with open surgery. We undertook this review to analyze the current data available regarding long-term outcomes in patients undergoing endovascular repair for thoracic aortic disease. The data support long-term benefit of endovascular repair for thoracic aortic disease. The primary indications identified for reintervention are endoleak and further aneurysmal degeneration. As the devices available for endovascular repair evolve, ongoing review of these outcomes will be necessary. It will also be important to trend the results as further techniques become available for endovascular repair of the ascending aorta and aortic arch.
The impact of self-determination theory: the moderating functions of social media (SM) use in education and affective learning engagement
Authors: Alturki Uthman , Aldraiweesh Ahmed
Published: May 2024

This study attempts to explore the relationship between the two mediator variables effective learning engagement and educational social media (SM) usage and the study’s outcome measures, which include student satisfaction and learning performance. The distribution of a self-determination theory questionnaire with external factors to 293 university students served as the primary data collection method. King Saud University used a poll to personally collect data. Partial least squares structural equation modeling was then used to examine the data and assess the model in Smart-PLS. Students’ academic success and contentment at colleges and universities seem to be positively correlated, and their active involvement in learning activities and educational use of SM. It was shown that important factors influencing affective learning participation and the instructional use of SM for teaching and learning include perceived competence, perceived autonomy, perceived relatedness, information sharing, and collaborative learning environments. It was discovered that these connections were important. The self-determination theory provided confirmation that this model is appropriate for fostering students’ feelings of competence, autonomy, and relatedness in order to increase their affective learning involvement. This, in turn, improves students’ satisfaction and achievement in higher education.
Charged particle transport coefficient challenges in high energy density plasmas
Authors: Haines Brian M.
Published: May 2024

High energy density physics (HEDP) and inertial confinement fusion (ICF) research typically relies on computational modeling using radiation-hydrodynamics codes in order to design experiments and understand their results. These tools, in turn, rely on numerous charged particle transport and relaxation coefficients to account for laser energy absorption, viscous dissipation, mass transport, thermal conduction, electrical conduction, non-local ion (including charged fusion product) transport, non-local electron transport, magnetohydrodynamics, multi-ion-species thermalization, and electron-ion equilibration. In many situations, these coefficients couple to other physics, such as imposed or self-generated magnetic fields. Furthermore, how these coefficients combine are sensitive to plasma conditions as well as how materials are distributed within a computational cell. Uncertainties in these coefficients and how they couple to other physics could explain many of the discrepancies between simulation predictions and experimental results that persist in even the most detailed calculations. This paper reviews the challenges faced by radiation-hydrodynamics in predicting the results of HEDP and ICF experiments with regard to these and other physics models typically included in simulation codes.
Evaluating aliphatic CF, CF2, and CF3 groups as vibrational Stark effect reporters
Authors: Cruz R. , Ataka K. , Heberle J. , Kozuch J.
Published: May 2024

Given the extensive use of fluorination in molecular design, it is imperative to understand the solvation properties of fluorinated compounds and the impact of the C–F bond on electrostatic interactions. Vibrational spectroscopy can provide direct insights into these interactions by using the C–F bond stretching [v(C–F)] as an electric field probe through the vibrational Stark effect (VSE). In this work, we explore the VSE of the three basic patterns of aliphatic fluorination, i.e., mono-, di-, and trifluorination in CF, CF2, and CF3 groups, respectively, and compare their response to the well-studied aromatic v(C–F). Magnitudes (i.e., Stark tuning rates) and orientations of the difference dipole vectors of the v(C–F)-containing normal modes were determined using density functional theory and a molecular dynamics (MD)-assisted solvatochromic analysis of model compounds in solvents of varying polarity. We obtain Stark tuning rates of 0.2–0.8 cm−1/(MV/cm), with smallest and largest electric field sensitivities for CFaliphatic and CF3,aliphatic, respectively. While average electric fields of solvation were oriented along the main symmetry axis of the CFn, and thus along its static dipole, the Stark tuning rate vectors were tilted by up to 87° potentially enabling to map electrostatics in multiple dimensions. We discuss the influence of conformational heterogeneity on spectral shifts and point out the importance of multipolar and/or polarizable MD force fields to describe the electrostatics of fluorinated molecules. The implications of this work are of direct relevance for studies of fluorinated molecules as found in pharmaceuticals, fluorinated peptides, and proteins.
A new method for solving the linearized 1D Vlasov–Poisson system yielding a new class of solutions
Authors: Lee Frank M. , Shadwick B. A.
Published: May 2024

We describe a new method for solving the linearized 1D Vlasov–Poisson system by using properties of Cauchy-type integrals. Our method remedies critical flaws of the two standard methods, reveals a previously unrecognized Gaussian-in-time-like decay, and can also account for an externally applied electric field. The Landau approximation involves deforming the Bromwich contour around the poles closest to the real axis due to the analytically continued dielectric function, finding the long-time behavior for a stable system: Landau damping. Jackson's generalization encircles all poles while sending the contour to infinity, assuming its contribution vanishes, which is not true in general. This gives incorrect solutions for physically reasonable configurations and can exhibit pathological behavior, of which we show examples. The van Kampen method expresses the solution for a stable equilibrium as a continuous superposition of waves, resulting in an opaque integral. Case's generalization includes unstable systems and predicts a decaying discrete mode for each growing discrete mode, an apparent contradiction to both the Jackson solution and ours. We show, without imposing additional constraints, that the decaying modes are never present in the time evolution due to an exact cancellation with part of the continuum. Our solution is free of integral expressions, is obtained using algebra and Laurent series expansions, does not rely on analytic continuations, and results in a correct asymptotically convergent form in the case of infinite sums. The analysis used can be readily applied in higher-dimensional, electromagnetic systems and also provides a new technique for evaluating certain inverse Laplace transforms.
Exploration of intrinsic magnetic topological insulators in multiple-MnTe-intercalated topological insulator Bi2Te3
Authors: Yang Wenjia , Zhang Yaling , Wang Fei , Peng Jiahui , Zhang Huisheng , Xu Xiaohong
Published: May 2024

The fabrication of MnBi2Te4 family of materials has been demonstrated that intercalating magnetic MnTe layer into topological insulator Bi2Te3 is an efficient way to explore magnetic topological insulator. A natural question is that if multiple MnTe layers can be intercalated into Bi2Te3, meanwhile if the topological properties are well preserved. Based on first-principles calculations, we first confirm that multiple MnTe layers can be inserted into Bi2Te3 by forming antiferromagnetic MnnBi2Te3+n (n = 1–5) crystals, where each system is energetically stable and can be readily exfoliated down to a monolayer. Specifically, the structural phase transition from ABC to ABAC stacking happens when n ≥ 2. Further electronic band structure calculations and topological identification reveal that the magnetic MnnBi2Te3+n undergoes a topologically nontrivial to trivial phase transition when n > 2, which is attributed to that multiple MnTe layers destroy the topological property of Bi2Te3. In addition to applying compressed strain, the topological states can be restored by intercalating Bi2Te3 layers by forming (MnTe)n(Bi2Te3)m heterostructures. Most strikingly, it is found that the topological properties of (MnTe)n(Bi2Te3)m are universally determined by the ratio of n/m, once n/m ≤ 2.8, the desired topological states are recovered. Our notable findings enrich the family of magnetic topological insulator, providing opportunities to explore more intriguing topological phenomena.
Silicon nitride stoichiometry tuning for visible photonic integrated components
Authors: Blasco M. , Dacunha S. , Dominguez C. , Faneca J.
Published: May 2024

In integrated photonics, silicon nitride-based devices operating in the visible range of light may experience auto-fluorescence, an undesired effect that can interfere with the propagating signal. In this article, a reduction in auto-fluorescence has been obtained by studying stoichiometric and silicon-rich silicon nitride, subjected to different post-thermal annealings in different atmospheres. Stoichiometric silicon nitride treated with rapid thermal annealing at 1100 °C in an argon atmosphere reduces the photoluminescence intensity of the material by 95%. Silicon-rich nitride shows a more stable photoluminescence response to different annealings and atmospheres than the stoichiometric. Compared to the stoichiometric material, the emission peaks experienced by the silicon-rich silicon nitride are red shifted between 140 and 190 nm, and the refractive index value is increased by 7% at 633 nm. Also, the interface effects have been studied, showing a remarkable contribution when the annealing is performed in an argon atmosphere, while no contribution from these effects is observed in a nitrogen atmosphere. Finally, taking advantage of the refractive index variation between nitrides, a vertical directional coupler using two asymmetric waveguides, one of each type of silicon nitride, has been designed and simulated, obtaining a coupling length of 9.8 μm with a coupling power of 95.8%, demonstrating the 3D integration capabilities of combining silicon nitride layers of variable composition.
Thinking Bayesian for plasma physicists
Authors: Kruger S. E. , Leddy J. , Howell E. C. , Madireddy S. , Akcay C. , Bechtel Amara T. , McClenaghan J. , Lao L. L. , Orozco D. , Smith S. P. , Sun X. , Samaddar A. , Pankin A.-Y.
Published: May 2024

Bayesian statistics offers a powerful technique for plasma physicists to infer knowledge from the heterogeneous data types encountered. To explain this power, a simple example, Gaussian Process Regression, and the application of Bayesian statistics to inverse problems are explained. The likelihood is the key distribution because it contains the data model, or theoretic predictions, of the desired quantities. By using prior knowledge, the distribution of the inferred quantities of interest based on the data given can be inferred. Because it is a distribution of inferred quantities given the data and not a single prediction, uncertainty quantification is a natural consequence of Bayesian statistics. The benefits of machine learning in developing surrogate models for solving inverse problems are discussed, as well as progress in quantitatively understanding the errors that such a model introduces.
Composition-dependent spin exchange interaction for multiferroicity in perovskite Pb(Fe1/2Nb1/2)O3
Authors: Park Ji-Hun , Cho Jae-Hyeon , Marlton Frederick P. , Jang Haeseong , Lee Ju-Hyeon , Jang Jongmoon , Hwang Geon-Tae , Pramanick Abhijit , Jørgensen Mads Ry Vogel , Kim Min Gyu , Jo Wook
Published: May 2024

The composition-dependent spin exchange interaction in a perovskite-structured Pb(Fe0.5−xNix)Nb1/2O3 system has been studied to understand its multiferroicity at room-temperature. Special emphasis was paid to the magnetic behavior in terms of magnetic moment, interatomic distance, and atomic ordering because they play a key role in the modulation of magnetic multiferroic behavior. We observed that 10 mol. % Ni incorporation led to multiferroic behavior with considerable ferrimagnetic properties (saturation magnetization of 0.6 emu/g and a coercive field of 20 Oe) coupled with the inherent properties of displacive ferroelectricity (spontaneous polarization of 20 μC/cm2). A subsequent increase in the Ni substitution degree degraded the ferroelectricity due to a phase transition from a non-centrosymmetric rhombohedral to a centrosymmetric cubic system. We have shown that magnetic spins with a pronounced magnetic moment along the [001] direction are ferrimagnetically arranged when the interatomic distance between the magnetic transition metals at the octahedral site is less than 4 Å, resulting in significant magnetic properties The objective of this study is to provide a general methodology for modulating magnetic orders in ferroelectric perovskite oxides.
Enhanced self-powered metal–semiconductor–metal WSe2 photodetectors with asymmetric Schottky contacts through tailored electrode thickness and positioning
Authors: Zhang Xianjun , Qiu Dan , Hou Pengfei
Published: May 2024

Self-powered metal–semiconductor–metal (M–S–M) photodetectors based on Schottky barrier difference have received extensive attention for their excellent photodetection performance. The Schottky barrier difference generally arises from the utilization of different metal electrodes or from variations in thickness across the ends of the two-dimensional materials, both of which represent extremely complex processes and precise control techniques. In this study, we fabricated self-powered photodetectors with a M–S–M structure using two-dimensional WSe2 nanoflakes and Au electrodes. By adjusting the thickness and positioning of the Au electrodes, a substantial difference between the two Schottky contacts of WSe2/Au and Au/WSe2 interfaces is formed due to the large Fermi-level difference between the two electrodes, which makes the M–S–M WSe2 photodetector to be used for self-powered photodetection. When irradiated with a 405 nm wavelength laser, the specific detectivity (D*) can achieve 6.35 × 1012 Jones, and the on/off ratio can reach 8 × 104. Under 808 and 1064 nm irradiation, D* reaches 5.9 × 1011 and 1.4 × 109 Jones, respectively. Furthermore, the M–S–M WSe2 photodetector, prepared on a transparent polyethylene terephthalate substrate, still achieves a D* of 5.1 × 1011 Jones under 808 nm irradiation. The results are expected to introduce an approach for self-powered photodetectors offering low cost, wide detection range, high detection performance, and broad application possibilities.
A modified viscous flow law for natural glacier ice: Scaling from laboratories to ice sheets
Authors: Ranganathan Meghana , Minchew Brent
Published: May 2024

Glacier flow modulates sea level and is governed largely by the viscous deformation of ice. Multiple molecular-scale mechanisms facilitate viscous deformation, but it remains unclear how each contributes to glacier-scale deformation. Here, we present a model of ice deformation that bridges laboratory and glacier scales, unifies existing estimates of the viscous parameters, and provides a framework for estimating the parameters from observations and incorporating flow laws derived from laboratory observations into glacier-flow models. Our results yield a map of the dominant deformation mechanisms in the Antarctic Ice Sheet, showing that, contrary to long-standing assumptions, dislocation creep, characterized by a value of the stress exponent

n
=
4

, likely dominates in all fast-flowing areas. This increase from the canonical value of

n
=
3

dramatically alters the climate conditions under which marine ice sheets may become unstable and drive rapid rates of sea-level rise.
The function and consequences of fluorescence in tetrapods
Authors: Nicolaï Michaël P. J. , Bok Michael J. , Abalos Javier , D'Alba Liliana , Shawkey Matthew D. , Goldenberg Jonathan
Published: May 2024

Fluorescence, the optical phenomenon whereby short-wavelength light is absorbed and emitted at longer wavelengths, has been widely described in aquatic habitats, in both invertebrates and fish. Recent years have seen a stream of articles reporting fluorescence, ranging from frogs, platypus, to even fully terrestrial organisms such as flying squirrels, often explicitly or implicitly linking the presence of fluorescence with sexual selection and communication. However, many of these studies fail to consider the physiological requirements of evolutionary stable signaling systems, the environmental dependence of perception, or the possible adaptive role of fluorescent coloration in a noncommunicative context. More importantly, the idea that fluorescence may simply constitute an indirect by-product of selection on other traits is often not explored. This is especially true for terrestrial systems where environmental light conditions are often not amenable for fluorescent signaling in contrast to, for example, aquatic habitats in which spectral properties of water promote functional roles for fluorescence. Despite the appeal of previously unknown ways in which coloration may drive evolution, the investigation of a putative role of fluorescence in communication must be tempered by a realistic understanding of its limitations. Here, we not only highlight and discuss the key body of literature but also address the potential pitfalls when reporting fluorescence and how to solve them. In addition, we propose exciting different research avenues to advance the field of tetrapod fluorescence.
Growth couples temporal and spatial fluctuations of tissue properties during morphogenesis
Authors: Fruleux Antoine , Hong Lilan , Roeder Adrienne H. K. , Li Chun-Biu , Boudaoud Arezki
Published: May 2024

Living tissues display fluctuations—random spatial and temporal variations of tissue properties around their reference values—at multiple scales. It is believed that such fluctuations may enable tissues to sense their state or their size. Recent theoretical studies developed specific models of fluctuations in growing tissues and predicted that fluctuations of growth show long-range correlations. Here, we elaborated upon these predictions and we tested them using experimental data. We first introduced a minimal model for the fluctuations of any quantity that has some level of temporal persistence or memory, such as concentration of a molecule, local growth rate, or mechanical property. We found that long-range correlations are generic, applying to any such quantity, and that growth couples temporal and spatial fluctuations, through a mechanism that we call “fluctuation stretching”—growth enlarges the length scale of variation of this quantity. We then analyzed growth data from sepals of the model plant Arabidopsis and we quantified spatial and temporal fluctuations of cell growth using the previously developed cellular Fourier transform. Growth appears to have long-range correlations. We compared different genotypes and growth conditions: mutants with lower or higher response to mechanical stress have lower temporal correlations and longer-range spatial correlations than wild-type plants. Finally, we used theoretical predictions to merge experimental data from all conditions and developmental stages into a unifying curve, validating the notion that temporal and spatial fluctuations are coupled by growth. Altogether, our work reveals kinematic constraints on spatiotemporal fluctuations that have an impact on the robustness of morphogenesis.
The semantic extension of Korean ideophones in newspapers headlines
Authors: Park Ji-Yeon
Published: May 2024

This paper explores the semantic features of Korean ideophones in newspaper headlines. This paper argues that (i)
there is a strong relationship between the language-specific sound symbolic meanings – dark and light vowel polarity and the
meanings of ideophones in newspaper headlines and event descriptions; (ii) ideophones are much more common in articles about the
financial issues; (iii) ideophones which exhibit vowel alternation go through different semantic extension routes to those of
other ideophones. The findings of the paper suggest that Korean ideophones have been lexically highly conventionalized and
integrated into the language system.
Manufacturing and measurement of CMOS-MEMS-based micro thermoelectric generators with long-length thermocouples
Authors: Dai Zhi-Xuan , Chen Chun-Yu , Chiu Bo-Chun , Lee Chi-Yuan
Published: May 2024

The study explores the fabrication and evaluation of a micro thermoelectric generator (MTG) with long-length thermocouples (TCs) through the utilization of a commercial complementary metal oxide semiconductor process. The MTG consists of 23 TCs, and its performance is intricately linked to the temperature difference (T
diff) between the cold and hot sides of these TCs. An increase in T
diff leads to higher output voltage and power for the MTG. To enhance T
diff, the TCs are designed to be 700 µm in length, and an innovative design has been implemented on the cold side of the TCs, creating a suspended structure to improve heat dissipation A post-process is essential for achieving this suspended TC structure. The results demonstrate that the TC structure is fully suspended and remains undamaged. The measured outcomes reveal an output voltage of 13.8 mV when the T
diff reaches 3.5 K. Under these conditions, the MTG exhibits a voltage factor of 2.76 mV mm−2K−1. Furthermore, at a T
diff of 3.5 K, the maximum output power reaches 2.1 nW. The MTG demonstrates a power factor of 0.12 nW mm−2 K−2.
First principles prediction of novel quantum topological insulator state in two-dimensional XMg2Bi2 (X=Eu/Yb)
Authors: Choudhury Amarjyoti , Maitra T
Published: May 2024

Topological insulator (TIs), a novel quantum state of materials, has a lot of significance in the development of low-power electronic equipments as the conducting edge states display exceptional endurance against back-scattering. The absence of suitable materials with high fabrication feasibility and significant nontrivial bandgap, is now the biggest hurdle in their potential applications in devices. Here, we illustrate using first principles density functional calculations that the quintuplet layers of EuMg2Bi2 and YbMg2Bi2 crystals are potential two-dimensional TIs with a sizeable nontrivial gaps of 72 meV and 147 meV respectively. Dynamical stability of these quintuplet layers of EuMg2Bi2 and YbMg2Bi2 is confirmed by our phonon calculations. The weakly coupled layered structure of parent compounds makes it possible for simple exfoliation from a three-dimensional structure. We observed gapless edge states inside the bulk band gap in both the systems which indicate their TI nature. Further, we observed the anomalous and spin Hall conductivities to be quantized in two dimensional EuMg2Bi2 and YbMg2Bi2 respectively. Our findings predict two viable candidate materials as two dimensional quantum TIs which can be explored by future experimental investigations and possible applications of quantized spin and anomalous Hall conductance in spintronics.