bluuebunny/crossref_metadata_2025 huggingface dataset:
Revelation of microcracks as tooth structural element by X-ray tomography and machine learning
Authors: Dumbryte Irma , Narbutis Donatas , Vailionis Arturas , Juodkazis Saulius , Malinauskas Mangirdas
Published: December 2022

Although teeth microcracks (MCs) have long been considered more of an aesthetic problem, their exact role in the structure of a tooth and impact on its functionality is still unknown. The aim of this study was to reveal the possibilities of an X-ray micro-computed tomography ($$\mu$$
μ
CT) in combination with convolutional neural network (CNN) assisted voxel classification and volume segmentation for three-dimensional (3D) qualitative analysis of tooth microstructure and verify this approach with four extracted human premolars. Samples were scanned using a $$\mu$$
μ
CT instrument (Xradia 520 Versa; ZEISS) and segmented with CNN to identify enamel, dentin, and cracks. A new CNN image segmentation model was trained based on “Multiclass semantic segmentation using DeepLabV3+” example and was implemented with “TensorFlow”. The technique which was used allowed 3D characterization of all MCs of a tooth, regardless of the volume of the tooth in which they begin and extend, and the evaluation of the arrangement of cracks and their structural features. The proposed method revealed an intricate star-shaped network of MCs covering most of the inner tooth, and the main crack planes in all samples were arranged radially in two almost perpendicular directions, suggesting that the cracks could be considered as a planar structure.
Photo-oscillations in MgZnO/ZnO heterostructures
Authors: Iñarrea Jesús
Published: December 2022

We theoretically examine the characteristics of microwave-induced magnetoresistance (MIRO) and photovoltage oscillations in MgZno/ZnO heterostructures. We demonstrate that both kind of oscillations, although described with different physical properties, are intimately related sharing the same physical origin. We use the radiation driven electron orbit model showing that the interplay of radiation driven swinging Landau orbits and the scattering processes are at the heart of the oscillations in both scenarios. Thus, our simulations show that all photo-oscillations present the main features of MIRO: they are periodic with the inverse of the magnetic field and the oscillations minima are 1/4 cycle shifted.
Multi-objective steel plate cutting optimization problem based on real number coding genetic algorithm
Authors: Xu Jianqiao , Yang Wenguo
Published: December 2022

The rectangular packing problem is an NP-complete combinatorial optimization problem. This problem occurs widely in social production scenarios, with steel plate cutting being one example. The cutting scheme for the rectangular packing problem needs to be improved because, without the globally optimal solution, there are many unnecessary edges in the steel cutting process. Based on a practical roll-fed disc shearing steel plate optimization problem, this paper explores a generalized packing method for rectangles of special dimensions and abstractly condenses complex quantitative relationships to establish a multi-objective mixed-integer nonlinear programming model. An innovative algorithm design based on a genetic algorithm is established to plan the cutting scheme in a high-speed and efficient way. The outcome is a utilization rate of up to 92.73% for raw materials and a significant reduction in labor, providing a guide for practical production and processing tasks. The advantages and disadvantages of the model and algorithm are discussed, and it is concluded that this rectangular packing method has strong universality and generalization ability, allowing rectangular packing tasks with large data volumes to be completed within a short time.
AI in the hands of imperfect users
Authors: Kostick-Quenet Kristin M. , Gerke Sara
Published: December 2022

As the use of artificial intelligence and machine learning (AI/ML) continues to expand in healthcare, much attention has been given to mitigating bias in algorithms to ensure they are employed fairly and transparently. Less attention has fallen to addressing potential bias among AI/ML’s human users or factors that influence user reliance. We argue for a systematic approach to identifying the existence and impacts of user biases while using AI/ML tools and call for the development of embedded interface design features, drawing on insights from decision science and behavioral economics, to nudge users towards more critical and reflective decision making using AI/ML.
RNaseH2A downregulation drives inflammatory gene expression via genomic DNA fragmentation in senescent and cancer cells
Authors: Sugawara Sho , Okada Ryo , Loo Tze Mun , Tanaka Hisamichi , Miyata Kenichi , Chiba Masatomo , Kawasaki Hiroko , Katoh Kaoru , Kaji Shizuo , Maezawa Yoshiro , Yokote Koutaro , Nakayama Mizuho , Oshima Masanobu , Nagao Koji , Obuse Chikashi , Nagayama Satoshi , Takubo Keiyo , Nakanishi Akira , Kanemaki Masato T. , Hara Eiji , Takahashi Akiko
Published: December 2022

Cellular senescence caused by oncogenic stimuli is associated with the development of various age-related pathologies through the senescence-associated secretory phenotype (SASP). SASP is mediated by the activation of cytoplasmic nucleic acid sensors. However, the molecular mechanism underlying the accumulation of nucleotide ligands in senescent cells is unclear. In this study, we revealed that the expression of RNaseH2A, which removes ribonucleoside monophosphates (rNMPs) from the genome, is regulated by E2F transcription factors, and it decreases during cellular senescence. Residual rNMPs cause genomic DNA fragmentation and aberrant activation of cytoplasmic nucleic acid sensors, thereby provoking subsequent SASP factor gene expression in senescent cells. In addition, RNaseH2A expression was significantly decreased in aged mouse tissues and cells from individuals with Werner syndrome. Furthermore, RNaseH2A degradation using the auxin-inducible degron system induced the accumulation of nucleotide ligands and induction of certain tumourigenic SASP-like factors, promoting the metastatic properties of colorectal cancer cells. Our results indicate that RNaseH2A downregulation provokes SASP through nucleotide ligand accumulation, which likely contributes to the pathological features of senescent, progeroid, and cancer cells.
Geodesy of irregular small bodies via neural density fields
Authors: Izzo Dario , Gómez Pablo
Published: December 2022

Asteroids’ and comets’ geodesy is a challenging yet important task for planetary science and spacecraft operations, such as ESA’s Hera mission tasked to look at the aftermath of the recent NASA DART spacecraft’s impact on Dimorphos. Here we present a machine learning approach based on so-called geodesyNets which learns accurate density models of irregular bodies using minimal prior information. geodesyNets are a three-dimensional, differentiable function representing the density of a target irregular body. We investigate six different bodies, including the asteroids Bennu, Eros, and Itokawa and the comet Churyumov-Gerasimenko, and validate on heterogeneous and homogeneous ground-truth density distributions. Induced gravitational accelerations and inferred body shape are accurate, resulting in a relative acceleration error of less than 1%, also close to the surface. With a shape model, geodesyNets can even learn heterogeneous density fields and thus provide insight into the body’s internal structure. This adds a powerful tool to consolidated approaches like spherical harmonics, mascon models, and polyhedral gravity.
Modulation of hypoxia and redox in the solid tumor microenvironment with a catalytic nanoplatform to enhance combinational chemodynamic/sonodynamic therapy
Authors: Liu Yeping , Wang Likai , Wei Fengyuan , Tian Ya , Mou Juan , Yang Shiping , Wu Huixia
Published: December 2022

A catalytic nanoplatform (Mn3O4/OCN-PpIX@BSA) was developed for MRI-guided combinational chemodynamic–sonodynamic therapy through tumor microenvironment modulation.
Phase transition of individual anatase TiO2 microcrystals with large percentage of (001) facets: a Raman mapping and SEM study
Authors: Lu Weigang , Zhu Hao , Birmingham Blake , Craft Nolan , Hu Jonathan , Park Kenneth , Zhang Zhenrong
Published: December 2022

The anatase–rutile phase transition of anatase microcrystals is dominated by surface nucleation and growth. The anatase/rutile co-existing particle will be a perfect platform to study the anatase/rutile synergistic effect in catalysis.
Nanoparticle-based surface enhanced Raman spectroscopic imaging of biological arrays
Authors: Nsiah Francis , McDermott Mark T.
Published: December 2022

Surfaces serve as the communication link between the adsorbate and the substrate.
Influence of microbial weathering on the partitioning of per- and polyfluoroalkyl substances (PFAS) in biosolids
Authors: Lewis Asa J. , Ebrahimi Farshad , McKenzie Erica R. , Suri Rominder , Sales Christopher M.
Published: December 2022

Per- and polyfluoroalkyl substances (PFAS) are a large group of man-made fluorinated organic chemicals that can accumulate in the environment.
Machine-learning based prediction of small molecule–surface interaction potentials
Authors: Rouse Ian , Lobaskin Vladimir
Published: December 2022

We present a flexible artificial neural network model for the prediction of small molecule–surface interaction potentials including medium effects.
Zero-strain strategy incorporating TaC with Ta2O5 to enhance its rate capacity for long-term lithium storage
Authors: Gao Yinhong , Nan Xu , Sun Bing , Xu Wenli , Huang Qiang , Cong Ye , Li Yanjun , Li Xuanke , Zhang Qin
Published: December 2022

A zero-strain strategy has been used to construct Ta2O5/TaC heterostructure. This anode displayed enhanced kinetics, a high-rate capacity, and a long lifetime due to the synergistic effect between Ta2O5 and zero-strain TaC.
Effect of connectivity variation in azulene-BODIPY triads and their optoelectronic properties
Authors: Kumar Neha Rani , Agrawal Abhijeet R. , Debnath Sashi , Choudhury Aditya , Zade Sanjio S.
Published: December 2022

A series of azulene-BODIPY triads with an acetylene spacer have been synthesized to study the influence of connectivity variation.
Block copolymer self-assembly to pattern gold nanodots for site-specific placement of DNA origami and attachment of nanomaterials
Authors: Ranasinghe Dulashani R. , Doerk Gregory , Aryal Basu R. , Pang Chao , Davis Robert C. , Harb John N. , Woolley Adam T.
Published: December 2022

A self-assembled block copolymer is used to create nanoscale arrays of gold dots for selective self-assembly of DNA origami and directed placement of gold nanorods for nanoelectronics applications.
XFCT-MRI hybrid multimodal contrast agents for complementary imaging
Authors: Saladino Giovanni Marco , Vogt Carmen , Brodin Bertha , Shaker Kian , Kilic Nuzhet Inci , Andersson Kenth , Arsenian-Henriksson Marie , Toprak Muhammet Sadaka , Hertz Hans Martin
Published: December 2022

Hybrid nanoparticles (Ru-SPIONs) designed for dual-mode complementary X-ray fluorescence computed tomography (XFCT) and magnetic resonance imaging (MRI).
Practical synthesis of unsymmetrical disulfides promoted by bromodimethylsulfonium bromide
Authors: Dong Bo , Chen Yifeng , Xie Shubing , Zhang Jieying , Shen Jian , Xie Lan-Gui
Published: December 2022

We present the synthesis of unsymmetrical disulfides where the homo-coupling of the thiols is inhibited by adding the thiols sequentially via rapid oxidation using bromodimethylsulfonium bromide.
Easy access to α-carbonyl sulfones using cross-coupling of α-aryl-α-diazoesters with sulfonyl hydrazides
Authors: Sharma Anup Kumar , Chand Shiv , Kumar Pandey Anand , Singh Krishna Nand
Published: December 2022

Cu-catalyzed cross-coupling of α-aryl-α-diazoesters with sulfonyl hydrazides is explored to access α-carbonyl sulfones via migratory insertion of Cu-carbene species.
Cooperatively enhanced photothermal-chemotherapyviasimultaneously downregulating HSPs and promoting DNA alkylation in cancer cells
Authors: Zou Yang , Huang Daipeng , He Shan , Song Xuefang , Liu Weijian , Sun Wen , Du Jianjun , Fan Jiangli , Peng Xiaojun
Published: December 2022

Cooperatively enhanced photothermal-chemotherapyviasimultaneously downregulating heat shock proteins and promoting DNA alkylation to achieve efficient cancer therapy.
Uniform dispersion of ultrafine ruthenium nanoparticles on nano-cube ceria as efficient catalysts for hydrogen production from ammonia-borane hydrolysis
Authors: Peng Zhiwei , Wang Yuhuan , Yin Chengwang , Qiu Shujun , Xia Yongpeng , Zou Yongjin , Xu Fen , Sun Lixian , Chu Hailiang
Published: December 2022

Ultrafine Ru nanoparticles supported on nano-cube ceria with Ce3+ and oxygen vacancies can provide a strong metal–support interaction, thereby exhibiting superior catalytic performance toward AB hydrolysis.
Chemiosomotic flow in a soft conical nanopore: harvesting enhanced blue energy
Authors: Pandey Doyel , Mondal Pranab Kumar , Wongwises Somchai
Published: December 2022

Harvesting blue energy in a soft conical nanopore. Results reveal a great enhancement in power generation.
A multifunctional structural coloured electronic skin monitoring body motion and temperature
Authors: Froyen Arne A. F. , Schenning Albert P. H. J.
Published: December 2022

A structural coloured e-skin is reported, which is prepared via scalable methods that can simultaneously monitor the skin temperature and body motion when patched onto the human skin.
A new honeycomb MOF for C2H4purification and C3H6enrichment by separating methanol to olefin products
Authors: Zhang Lin , Ma Li-Na , Wang Gang-Ding , Hou Lei , Zhu Zhonghua , Wang Yao-Yu
Published: December 2022

A new C3H6-selective MOF based on infinite helix SBUs was constructed, realizing the effective separation of C2H4–C3H6to not only yield ≥99.9% purity of C2H4by a one-step method but also greatly increase the purity of C3H6in the adsorbed mixtures.
Nanomedicine-mediated ferroptosis targeting strategies for synergistic cancer therapy
Authors: Yin Weimin , Chang Jiao , Sun Jiuyuan , Zhang Tingting , Zhao Yuge , Li Yongyong , Dong Haiqing
Published: December 2022

The mechanisms of ferroptosis induction and synergistic strategies for cancer therapy.
The influence of terminal alkyl groups on the structure, and electrical and sensing properties of thin films of self-assembling organosilicon derivatives of benzothieno[3,2-b][1]benzothiophene
Authors: Polinskaya Marina S. , Trul Askold A. , Borshchev Oleg V. , Skorotetcky Maxim S. , Gaidarzhi Victoria P. , Toirov Siyovush K. , Anisimov Daniil S. , Bakirov Artem V. , Chvalun Sergey N. , Agina Elena V. , Ponomarenko Sergey A.
Published: December 2022

A correlation between the sensing and electrical properties of monolayer OFETs based on novel organosilicon derivatives of BTBT with different lengths of terminal alkyl groups was revealed.
A facile scalable hydrophobic biocomposite for oil spill cleanup
Authors: Kandanelli Ramesh , Siva Kesava Raju Chinthalapati
Published: December 2022

A hydrophobic biocomposite (HBC) has been developed using a waste wood residue for circumventing oil spill issues. The ease of oil removal, biocomposite regeneration and recyclability is demonstrated.
Recent trends towards privacy‐preservation in Internet of Things, its challenges and future directions
Authors: Safaei Yaraziz Mahdi , Jalili Ahmad , Gheisari Mehdi , Liu Yang
Published: December 2022

The Internet of Things (IoT) is a self‐configuring, intelligent system in which autonomous things connect to the Internet and communicate with each other. As ‘things’ are autonomous, it may raise privacy concerns. In this study, the authors describe the background of IoT systems and privacy and security measures, including (a) approaches to preserving privacy in IoT‐based systems, (b) existing privacy solutions, and (c) recommending privacy models for different layers of IoT applications. Based on the results of our study, it is clear that new methods such as Blockchain, Machine Learning, Data Minimisation, and Data Encryption can greatly impact privacy issues to ensure security and privacy. Moreover, it makes sense that users can protect their personal information easier if there is fewer data to collect, store, and share by smart devices. Thus, this study proposes a machine learning‐based data minimisation method that, in these networks, can be very beneficial for privacy‐preserving.
Satisfacción personal y percepción de éxito en mujeres en Traumatología: Factores determinantes en la elección de la especialidad y desarrollo profesional
Authors: Ramírez Constanza , Iñiguez Magaly , Reginato Rafaella , Ibáñez Angélica , Ahumada Ximena
Published: December 2022

Históricamente, las médicas han sido asociadas a especialidades determinadas. En los últimos años, estos estereotipos han sido lentamente revertidos con mayor participación de la mujer en especialidades quirúrgicas. En el proceso de aprendizaje se sabe la importancia que tienen los modelos y mentores. Buscamos evaluar el grado de satisfacción y el éxito profesional de las mujeres en Traumatología, y qué factores cumplieron un rol positivo en la decisión de optar por ella.

Se encuestó a 108 mujeres dedicadas a la Traumatología, y se evaluaron las influencias positivas y los mentores como modelo en la toma de decisión por la especialidad y los grados de satisfacción personal y profesional.

Pese a una mayor percepción de dificultades en lograr el objetivo, destacan los altos grados de satisfacción profesional y personal de las mujeres en Traumatología: 95% refirió haber elegido la especialidad correcta, 100% afirmó que las dificultades se compensan con los resultados obtenidos, y 96% volvería a elegir la misma especialidad. En relación con la percepción de éxito, 73% se considera exitosa en su vida profesional, y en la vida personal, 85%.

Muy relevante en la toma de decisión por la especialidad es el rol que cumplen docentes, mentores, y el gusto por la cirugía y los deportes. Un 84% recibió alguna influencia positiva, 61% tuvo como modelo en su formación una traumatóloga, y un 98% recomendaría a otras mujeres en período de formación que se dedicaran a la Traumatología.

Las estrategias de incremento de la participación femenina en la especialidad pudiesen orientarse a fomentar modelos femeninos durante el aprendizaje.
Lesión de Bony Bankart: Conceptos fundamentales para su comprensión y tratamiento
Authors: Morán Nicolás
Published: December 2022

Las lesiones óseas en el borde anterior del anillo glenoideo secundarias a un episodio de inestabilidad anterior del hombro cada vez son más reportadas. Conocidas como lesión de Bony Bankart, su presencia genera una pérdida de la estabilidad estática glenohumeral que provoca un aumento del riesgo de un nuevo evento de luxación. Por ende, resulta fundamental que los cirujanos ortopédicos comprendan y diagnostiquen estas lesiones de forma correcta y oportuna para evaluar la necesidad de restaurar la superficie articular glenoidea. El objetivo de esta revisión narrativa es otorgar los conceptos más importantes de la lesión ósea de Bankart para comprender y enfrentar de forma adecuada esta lesión.

Nivel de Evidencia V
Comparison of Trauma in Dogs due to Direct Motor Vehicle Collision or Fall from Open Pick-up Truck Bed during Transportation (2002-2020)
Authors: Salmelin Bettina R.M. , Ueda Yu , Gilbert Peter J. , Martinez Steven A.
Published: December 2022

Objective The aim of this study was to report injuries sustained by dogs following motor vehicle trauma: direct motor vehicle collision (MVC), and fall from an open pickup truck bed during transportation (PTB).

Study Design Medical records of dogs involved in motor vehicle trauma between 2002 and 2020 were reviewed. Signalment, mode of injury, injuries sustained, and treatments performed were recorded. An owner questionnaire investigated effects of the trauma on the dog and owner.

Results Six hundred and ninety-eight dogs met the inclusion criteria (569 MVC, 102 PTB). Orthopaedic trauma was significantly more common after PTB (90.2%) (MVC, 75.6%; p = 0.011). There were not any differences in the prevalence of soft tissue injuries between groups (76.4% MVC, 67.6% PTB; p = 0.058), however, MVC dogs had significantly more thoracic (26.9% MVC, 4.4% PTB) and abdominal (12.9% MVC, 0% PTB) trauma (p <0.001). Surgical treatments were performed significantly more often after PTB (71.6%) (MVC, 47.6%) (p <0.001). Discharge rate after PTB (95.0%) was significantly higher (MVC, 84.0%) (p <0.001). Aftercare was reported to be significantly more difficult after PTB (76.2%) (MVC, 34.0%; p = 0.002).

Conclusion MVC and PTB result in significantly different trauma. PTB causes predominantly orthopaedic and integument injuries, whereas MVC results in thoracic and abdominal trauma. Survival to discharge is greater following PTB than MVC.
Do handgrip strength and dexterity predict respiratory function in neuromuscular disease?
Authors: Safran Ertugrul , Ozer Aysel Yildiz , Gurses Hulya Nilgun
Published: December 2022

Background Neuromuscular diseases are acquired or inherited diseases that affect the function of the muscles in our body, including respiratory muscles.

Objective We aimed to discover more cost-effective and practical tools to predict respiratory function status, which causes serious problems with patients with neuromuscular disease.

Methods The Vignos and Brooke Upper Extremity Functional Scales were used to evaluate functional status for patient recruitment. The handgrip strength and dexterity of patients were measured using a dynamometer and nine-hole peg test. Respiratory function parameters: forced vital capacity, forced expiratory volume in one second, and peak expiratory flow were evaluated using spirometry.

Results The mean age of the 30 patients was 11.5 ± 3.79 years old. Significant relationships were found between nine-hole-peg-test scores and respiratory function parameters on both sides. Significant correlations were found between both handgrip strength and respiratory function parameters (p < 0.05). In the linear regression analysis, it was seen that the forced expiratory volume in 1 second, and peak expiratory flow values could be explained in different percentages (p < 0.05).

Conclusions Handgrip strength and dexterity measurements can be used as indicators for estimating respiratory function parameters in terms of cost and accessibility, although it is known that they will not replace respiratory function tests.
Complex numbers simplify solar forecasting
Authors: Piccone Ashley
Published: December 2022

Accurately predicting global solar irradiance is indispensable for smart management of electric grids.
A non-collinear autocorrelator for single-shot characterization of ultrabroadband terahertz pulses
Authors: Sun Fang-Zheng , Liao Guo-Qian , Lei Hong-Yi , Wang Tian-Ze , Wei Yan-Yu , Wang Dan , Chen Hao , Liu Feng , Li Yu-Tong , Zhang Jie
Published: December 2022

Conventional terahertz (THz) waveform or spectral diagnostics mainly employ the electro-optic-based techniques or the multi-shot Michelson interferometer. Simultaneously, single-shot, ultrabroadband THz spectral measurements remain challenging. In this paper, a novel probe-free scheme based on the non-collinear autocorrelation technique is proposed to characterize the ultrabroadband THz spectrum at a single-shot mode. The non-collinear autocorrelator is a modified beam-division interferometer, in which the two beams are recombined non-collinearly onto a camera. The temporal or spectral resolution and range depend on the noncollinear configuration and camera parameters. This simple approach has been applied experimentally to characterize the ultrashort THz pulse generated from ultraintense laser–solid interactions, demonstrating the capability of single-shot ultrabroadband measurements without an auxiliary ultrafast laser probe. The proposed non-collinear autocorrelator here would be much useful for characterization and applications of low-repetition-rate intense THz sources and could also be extended to other frequency bands.
Anomalous stability of non-van der Waals bonded B4C nanosheets through surface reconstruction
Authors: Gupta A. , Biswas T. , Singh A. K.
Published: December 2022

Boron carbide (B4C) has been well studied both theoretically and experimentally in its bulk form due to its exceptional hardness and use as a high-temperature thermoelectric. However, the properties of its two-dimensional nanosheets are not well established. In this paper, using van der Waals-corrected density-functional theory simulations, we show that bulk B4C can be cleaved along different directions to form B4C nanosheets with low formation energies. We find that there is minimal dependence of formation energies on cleavage planes and surface terminations, even though the bulk is not van der Waals layered. This anomalous stability of B4C nanosheets is found to be a result of surface reconstructions that are unique to B-rich systems. While the density of states of the bulk B4C indicate that it is a semiconductor, the B4C nanosheets are found to be predominantly metallic. We attribute this metallic behavior to a redistribution of charges on the surface bonds of the films. The Seebeck coefficients of the B4C films remain comparable to those of the bulk and are nearly constant as a function of temperature. Our results provide guidance for experimental synthesis efforts and future application of B4C nanosheets in nanoelectronic and thermoelectric applications.
Root cause for the difference in photovoltaic parameters of perovskite solar cells prepared by one- and two-step processes
Authors: Liu Jing , Wang Minhuan , Cai Wanxian , Cai Rui , Shi Yantao , Bian Jiming
Published: December 2022

Benefiting from good solubility of metal halide perovskites, low-temperature solution processes (including one- and two-step spin-coating) have become the most common approach for perovskite solar cells (PSCs). However, one confusing issue is that what are specifically effective strategies for the one-step process may not be applicable for the two-step process, and vice versa. Herein, the PSCs with the same perovskite composition and device configuration were prepared by one- and two-step processes, respectively. The results indicated that high performance PSCs with comparable power conversion efficiency over 22% were achieved by both methods, while the detailed photovoltaic parameters varied greatly depending on the one- or two-step process. Compared to the one-step counterpart, the two-step processed PSCs exhibit lower open-circuit voltage and fill factor, but superior short-circuit current, which was in-depth interpreted in terms of the crystalline growth mode, optical properties, defect types, and carrier transport mechanisms related to a perovskite film surface (including a top and a bottom surface). Understanding the root cause for such differences would be central toward identifying what is really crucial for further producing high performance PSCs.
Doublet structure in the optical spectrum of a semiconductor laser with optoelectronic feedback in a square-wave regime
Authors: Islam Md Shariful , Kovalev A. V. , Iachkula V. N. , Viktorov E. A. , Citrin D. S. , Locquet A.
Published: December 2022

We observe an optical spectrum consisting of a doublet in the output of a semiconductor laser diode with optoelectronic feedback in a dynamical regime in which a self-sustained square-wave modulation is observed, depending on injection current and feedback strength. The doublet frequency splitting is strongly correlated with the duty cycle of the square wave; both parameters as well as the relative magnitude of the peaks are observed to vary with the feedback level. A rate equation model reproduces the spectral doublets. The appearance of the doublet is attributed to active medium gain saturation and refractive index dependence on the carrier density.
Effects of surface wettability on the aerodynamics of wind-driven droplets at the verge of shedding
Authors: Zhang Zichen , Emami Reza Yaghoubi , Amirfazli Alidad
Published: December 2022

An experimental study was conducted to investigate the time-averaged aerodynamics of sessile droplets at the verge of shedding on hydrophilic and hydrophobic surfaces. A high-resolution particle image velocimetry system was used to measure/reconstruct the velocity and pressure fields in the droplet symmetry plane and obtain the time-averaged aerodynamic loading. It was found that the stagnation angle (the angle bounded by the substrate and the ray emanating from the droplet center connecting to the stagnation point) decreases with decreasing contact angle due to the shrinking size of the horseshoe vortex. The air pressure reaches the maximum near the stagnation point and its minimum near the droplet apex where flow separation occurs. In the near wake of droplets, a recirculation region, where the velocity reduces to nearly zero and the pressure is low, is generated due to the flow separation. The normalized length of the recirculation region decreases with increasing contact angle since droplets with higher contact angles need flows with lower Reynolds number to reach the point of shedding. In addition, the aerodynamic drag over droplets was evaluated by the wake integral method, analyzing the contribution of momentum deficit, Reynolds stress, and pressure deficit. The drag coefficient of the droplets, at the verge of shedding, was independent of the contact angle. This work shows that the drag coefficient of droplets with different contact angles at the verge of shedding can be similar even though the droplet shape, Reynolds number, and flow structures are different.
High-frequency and functional mitochondrial DNA mutations at the single-cell level
Authors: Guo Xiaoxian , Xu Weilin , Zhang Weiping , Pan Cuiping , Thalacker-Mercer Anna E. , Zheng Hongxiang , Gu Zhenglong
Published: December 2022

Decline in mitochondrial function underlies aging and age-related diseases, but the role of mitochondrial DNA (mtDNA) mutations in these processes remains elusive. To investigate patterns of mtDNA mutations, it is particularly important to quantify mtDNA mutations and their associated pathogenic effects at the single-cell level. However, existing single-cell mtDNA sequencing approaches remain inefficient due to high cost and low mtDNA on-target rates. In this study, we developed a cost-effective mtDNA targeted-sequencing protocol called single-cell sequencing by targeted amplification of multiplex probes (scSTAMP) and experimentally validated its reliability. We then applied our method to assess single-cell mtDNA mutations in 768 B lymphocytes and 768 monocytes from a 76-y-old female. Across 632 B lymphocyte and 617 monocytes with medium mtDNA coverage over >100×, our results indicated that over 50% of cells carried at least one mtDNA mutation with variant allele frequencies (VAFs) over 20%, and that cells carried an average of 0.658 and 0.712 such mutation for B lymphocytes and monocytes, respectively. Surprisingly, more than 20% of the observed mutations had VAFs of over 90% in either cell population. In addition, over 60% of the mutations were in protein-coding genes, of which over 70% were nonsynonymous, and more than 50% of the nonsynonymous mutations were predicted to be highly pathogenic. Interestingly, about 80% of the observed mutations were singletons in the respective cell populations. Our results revealed mtDNA mutations with functional significance might be prevalent at advanced age, calling further investigation on age-related mtDNA mutation dynamics at the single-cell level.
Highly stable preferential carbon monoxide oxidation by dinuclear heterogeneous catalysts
Authors: Zhao Yanyan , Dai Sheng , Yang Ke R. , Cao Sufeng , Materna Kelly L. , Lant Hannah M. C. , Kao Li Cheng , Feng Xuefei , Guo Jinghua , Brudvig Gary W. , Flytzani-Stephanopoulos Maria , Batista Victor S. , Pan Xiaoqing , Wang Dunwei
Published: December 2022

Atomically dispersed catalysts have been shown highly active for preferential oxidation of carbon monoxide in the presence of excess hydrogen (PROX). However, their stability has been less than ideal. We show here that the introduction of a structural component to minimize diffusion of the active metal center can greatly improve the stability without compromising the activity. Using an Ir dinuclear heterogeneous catalyst (DHC) as a study platform, we identify two types of oxygen species, interfacial and bridge, that work in concert to enable both activity and stability. The work sheds important light on the synergistic effect between the active metal center and the supporting substrate and may find broad applications for the use of atomically dispersed catalysts.
Structural basis of transition from initiation to elongation in de novo viral RNA-dependent RNA polymerases
Authors: Wu Jiqin , Wang Xinyu , Liu Qiaojie , Lu Guoliang , Gong Peng
Published: December 2022

De novo viral RNA-dependent RNA polymerases (RdRPs) utilize their priming element (PE) to facilitate accurate initiation. Upon transition to elongation, the PE has to retreat from the active site to give room to the template–product RNA duplex. However, PE conformational change upon this transition and the role of PE at elongation both remain elusive. Here, we report crystal structures of RdRP elongation complex (EC) from dengue virus serotype 2 (DENV2), demonstrating a dramatic refolding of PE that allows establishment of interactions with the RNA duplex backbone approved to be essential for EC stability. Enzymology data from both DENV2 and hepatitis C virus (HCV) RdRPs suggest that critical transition of the refolding likely occurs after synthesis of a 4- to 5-nucleotide (nt) product together providing a key basis in understanding viral RdRP transition from initiation to elongation.
Follistatin regulates the specification of the apical cochlea responsible for low-frequency hearing in mammals
Authors: Koo Hei Yeun , Kim Min-A , Min Hyehyun , Hwang Jae Yeon , Prajapati-DiNubila Meenakshi , Kim Kwan Soo , Matzuk Martin M. , Park Juw Won , Doetzlhofer Angelika , Kim Un-Kyung , Bok Jinwoong
Published: December 2022

The cochlea’s ability to discriminate sound frequencies is facilitated by a special topography along its longitudinal axis known as tonotopy. Auditory hair cells located at the base of the cochlea respond to high-frequency sounds, whereas hair cells at the apex respond to lower frequencies. Gradual changes in morphological and physiological features along the length of the cochlea determine each region’s frequency selectivity, but it remains unclear how tonotopy is established during cochlear development. Recently, sonic hedgehog (SHH) was proposed to initiate the establishment of tonotopy by conferring regional identity to the primordial cochlea. Here, using mouse genetics, we provide in vivo evidence that regional identity in the embryonic cochlea acts as a framework upon which tonotopy-specific properties essential for frequency selectivity in the mature cochlea develop. We found that follistatin (FST) is required for the maintenance of apical cochlear identity, but dispensable for its initial induction. In a fate-mapping analysis, we found that FST promotes expansion of apical cochlear cells, contributing to the formation of the apical cochlear domain. SHH, in contrast, is required both for the induction and maintenance of apical identity. In the absence of FST or SHH, mice produce a short cochlea lacking its apical domain. This results in the loss of apex-specific anatomical and molecular properties and low-frequency-specific hearing loss.
The direct binding of
Plasmodium vivax
AMA1 to erythrocytes defines a RON2-independent invasion pathway
Authors: Lee Seong-Kyun , Low Leanne M. , Andersen John F. , Yeoh Lee M. , Valenzuela Leon Paola Carolina , Drew Damien R. , Doehl Johannes S. P. , Calvo Eric , Miller Louis H. , Beeson James G. , Gunalan Karthigayan
Published: December 2022

We used a transgenic parasite in which
Plasmodium falciparum
parasites were genetically modified to express
Plasmodium vivax
apical membrane antigen 1 (PvAMA1) protein in place of PfAMA1 to study PvAMA1-mediated invasion. In
P. falciparum
, AMA1 interaction with rhoptry neck protein 2 (RON2) is known to be crucial for invasion, and PfRON2 peptides (PfRON2p) blocked the invasion of PfAMA1 wild-type parasites. However, PfRON2p has no effect on the invasion of transgenic parasites expressing PvAMA1 indicating that PfRON2 had no role in the invasion of PvAMA1 transgenic parasites. Interestingly, PvRON2p blocked the invasion of PvAMA1 transgenic parasites in a dose-dependent manner. We found that recombinant PvAMA1 domains 1 and 2 (rPvAMA1) bound to reticulocytes and normocytes indicating that PvAMA1 directly interacts with erythrocytes during the invasion, and invasion blocking of PvRON2p may result from it interfering with PvAMA1 binding to erythrocytes. It was previously shown that the peptide containing Loop1a of PvAMA1 (PvAMA1 Loop1a) is also bound to reticulocytes. We found that the Loop1a peptide blocked the binding of PvAMA1 to erythrocytes. PvAMA1 Loop1a has no polymorphisms in contrast to other PvAMA1 loops and may be an attractive vaccine target. We thus present the evidence that PvAMA1 binds to erythrocytes in addition to interacting with PvRON2 suggesting that the
P. vivax
merozoites may exploit complex pathways during the invasion process.
Efficiently exploring the causal role of contextual moderators in behavioral science
Authors: Hecht Cameron A. , Dweck Carol S. , Murphy Mary C. , Kroeper Kathryn M. , Yeager David S.
Published: December 2022

Behavioral science interventions have the potential to address longstanding policy problems, but their effects are typically heterogeneous across contexts (e.g., teachers, schools, and geographic regions). This contextual heterogeneity is poorly understood, however, which reduces the field’s impact and its understanding of mechanisms. Here, we present an efficient way to interrogate heterogeneity and address these gaps in knowledge. This method a) presents scenarios that vividly represent different moderating contexts, b) measures a short-term behavioral outcome (e.g., an academic choice) that is known to relate to typical intervention outcomes (e.g., academic achievement), and c) assesses the causal effect of the moderating context on the link between the psychological variable typically targeted by interventions and this short-term outcome. We illustrated the utility of this approach across four experiments (total
n
= 3,235) that directly tested contextual moderators of the links between growth mindset, which is the belief that ability can be developed, and students’ academic choices. The present results showed that teachers’ growth mindset-supportive messages and the structural opportunities they provide moderated the link between students’ mindsets and their choices (studies 1 to 3). This pattern was replicated in a nationally representative sample of adolescents and did not vary across demographic subgroups (study 2), nor was this pattern the result of several possible confounds (studies 3 to 4). Discussion centers on how this method of interrogating contextual heterogeneity can be applied to other behavioral science interventions and broaden their impact in other policy domains.
Bandgap evolution of metamaterials with continuous solid–liquid phase change
Authors: Yuan Wenhan , Chai Yijun , Yang Xiongwei , Li Yueming
Published: December 2022

Owing to the instinct difference in atomic buildings between solid and liquid, the phase change of material can fundamentally change wave energy propagation. In the present work, a novel elastic metamaterial system called solid–liquid phase change metamaterial (SPCM) is proposed, which allows continuous variation of the vibration isolation bandgap in thermal environments. The metamaterial is carefully designed by inserting phase change material (PCM) into an external framework. To reveal how wave propagation is affected by phase change, we develop a theoretical model based on Lagrange’s equation, which can describe the kinematic relations within the metamaterial during the entire phase change process. The model is verified through numerical calculations after the dynamic effective parameters are obtained, and good agreement can be found in the band structure and vibration transmission calculation at different phase change states. Due to the continuous phase change of PCM, the frequency range of the negative effective parameter shifts to lower frequencies, leading to a thermally tunable bandgap. Nevertheless, the constantly changing bandgap covers a certain range during the entire phase change process, indicating that the SPCM designed in this work can offer stable vibration attenuation in a wide range of thermal environments. The design and theory would be critically useful in the design of adaptive metamaterial bandgap in thermal environments.
Simulation-to-real generalization for deep-learning-based refraction-corrected ultrasound tomography image reconstruction
Authors: Zhao Wenzhao , Fan Yuling , Wang Hongjian , Gemmeke Hartmut , van Dongen Koen W A , Hopp Torsten , Hesser Jürgen
Published: December 2022

Objective. The image reconstruction of ultrasound computed tomography is computationally expensive with conventional iterative methods. The fully learned direct deep learning reconstruction is promising to speed up image reconstruction significantly. However, for direct reconstruction from measurement data, due to the lack of real labeled data, the neural network is usually trained on a simulation dataset and shows poor performance on real data because of the simulation-to-real gap. Approach. To improve the simulation-to-real generalization of neural networks, a series of strategies are developed including a Fourier-transform-integrated neural network, measurement-domain data augmentation methods, and a self-supervised-learning-based patch-wise preprocessing neural network. Our strategies are evaluated on both the simulation dataset and real measurement datasets from two different prototype machines. Main results. The experimental results show that our deep learning methods help to improve the neural networks’ robustness against noise and the generalizability to real measurement data. Significance. Our methods prove that it is possible for neural networks to achieve superior performance to traditional iterative reconstruction algorithms in imaging quality and allow for real-time 2D-image reconstruction. This study helps pave the path for the application of deep learning methods to practical ultrasound tomography image reconstruction based on simulation datasets.
Weakly supervised semantic segmentation of histological tissue via attention accumulation and pixel-level contrast learning
Authors: Han Yongqi , Cheng Lianglun , Huang Guoheng , Zhong Guo , Li Jiahua , Yuan Xiaochen , Liu Hongrui , Li Jiao , Zhou Jian , Cai Muyan
Published: December 2022

Objective. Histopathology image segmentation can assist medical professionals in identifying and diagnosing diseased tissue more efficiently. Although fully supervised segmentation models have excellent performance, the annotation cost is extremely expensive. Weakly supervised models are widely used in medical image segmentation due to their low annotation cost. Nevertheless, these weakly supervised models have difficulty in accurately locating the boundaries between different classes of regions in pathological images, resulting in a high rate of false alarms Our objective is to design a weakly supervised segmentation model to resolve the above problems. Approach. The segmentation model is divided into two main stages, the generation of pseudo labels based on class residual attention accumulation network (CRAANet) and the semantic segmentation based on pixel feature space construction network (PFSCNet). CRAANet provides attention scores for each class through the class residual attention module, while the Attention Accumulation (AA) module overlays the attention feature maps generated in each training epoch. PFSCNet employs a network model containing an inflated convolutional residual neural network and a multi-scale feature-aware module as the segmentation backbone, and proposes dense energy loss and pixel clustering modules are based on contrast learning to solve the pseudo-labeling-inaccuracy problem. Main results. We validate our method using the lung adenocarcinoma (LUAD-HistoSeg) dataset and the breast cancer (BCSS) dataset. The results of the experiments show that our proposed method outperforms other state-of-the-art methods on both datasets in several metrics. This suggests that it is capable of performing well in a wide variety of histopathological image segmentation tasks. Significance. We propose a weakly supervised semantic segmentation network that achieves approximate fully supervised segmentation performance even in the case of incomplete labels. The proposed AA and pixel-level contrast learning also make the edges more accurate and can well assist pathologists in their research.
Hierarchies of resources for measurement-based quantum computation
Authors: Frembs Markus , Roberts Sam , Campbell Earl T , Bartlett Stephen D
Published: December 2022

For certain restricted computational tasks, quantum mechanics provides a provable advantage over any possible classical implementation. Several of these results have been proven using the framework of measurement-based quantum computation (MBQC), where nonlocality and more generally contextuality have been identified as necessary resources for certain quantum computations. Here, we consider the computational power of MBQC in more detail by refining its resource requirements, both on the allowed operations and the number of accessible qubits. More precisely, we identify which Boolean functions can be computed in non-adaptive MBQC, with local operations contained within a finite level in the Clifford hierarchy. Moreover, for non-adaptive MBQC restricted to certain subtheories such as stabiliser MBQC, we compute the minimal number of qubits required to compute a given Boolean function. Our results point towards hierarchies of resources that more sharply characterise the power of MBQC beyond the binary of contextuality vs non-contextuality.
The cross-over from Townes solitons to droplets in a 2D Bose mixture
Authors: Bakkali-Hassani B , Maury C , Stringari S , Nascimbene S , Dalibard J , Beugnon J
Published: December 2022

When two Bose–Einstein condensates—labelled 1 and 2—overlap spatially, the equilibrium state of the system depends on the miscibility criterion for the two fluids. Here, we theoretically focus on the non-miscible regime in two spatial dimensions and explore the properties of the localized wave packet formed by the minority component 2 when immersed in an infinite bath formed by component 1. We address the zero-temperature regime and describe the two-fluid system by coupled classical field equations. We show that such a wave packet exists only for an atom number N
2 above a threshold value corresponding to the Townes soliton state. We identify the regimes where this localized state can be described by an effective single-field equation up to the droplet case, where component 2 behaves like an incompressible fluid. We study the near-equilibrium dynamics of the coupled fluids, which reveals specific parameter ranges for the existence of localized excitation modes.
Magnetic properties of two dimensional V
2
O
3 monolayer
Authors: Demir Vatansever Zeynep
Published: December 2022

Two dimensional (2D) magnetic materials with unique properties offer an ideal platform to study magnetic phase transitions in the low-dimensional systems. In this study, we implement extensive Monte Carlo simulations to investigate the magnetic properties of the 2D V
2
O
3 monolayer. By using finite-size scaling tools, we obtain the critical temperature and critical exponents of the monolayer precisely. Our numerical results demonstrate that 2D V
2
O
3 monolayer belongs to the two-dimensional Ising universality class. Besides, we examine the hysteresis characteristics of the structure and show that V
2
O
3 monolayer is a hard ferromagnetic material with a high coercive field at room temperature.