bluuebunny/crossref_metadata_2025 huggingface dataset:
A rapid feature selection method for catalyst design: Iterative Bayesian additive regression trees (iBART)
Authors: Liu Chun-Yen , Ye Shengbin , Li Meng , Senftle Thomas P.
Published: April 2022

Feature selection (FS) methods often are used to develop data-driven descriptors (i.e., features) for rapidly predicting the functional properties of a physical or chemical system based on its composition and structure. FS algorithms identify descriptors from a candidate pool (i.e., feature space) built by feature engineering (FE) steps that construct complex features from the system’s fundamental physical properties. Recursive FE, which involves repeated FE operations on the feature space, is necessary to build features with sufficient complexity to capture the physical behavior of a system. However, this approach creates a highly correlated feature space that contains millions or billions of candidate features. Such feature spaces are computationally demanding to process using traditional FS approaches that often struggle with strong collinearity. Herein, we address this shortcoming by developing a new method that interleaves the FE and FS steps to progressively build and select powerful descriptors with reduced computational demand. We call this method iterative Bayesian additive regression trees (iBART), as it iterates between FE with unary/binary operators and FS with Bayesian additive regression trees (BART). The capabilities of iBART are illustrated by extracting descriptors for predicting metal–support interactions in catalysis, which we compare to those predicted in our previous work using other state-of-the-art FS methods (i.e., least absolute shrinkage and selection operator + l0, sure independence screening and sparsifying operator, and Bayesian FS). iBART matches the performance of these methods yet uses a fraction of the computational resources because it generates a maximum feature space of size O(102), as opposed to O(106) generated by one-shot FE/FS methods.
Convergent evolution of
Authors: Jirapatrasilp Parin , Huang Chih-Wei , Hwang Chung-Chi , Sutcharit Chirasak , Lee Chi-Tse
Published: April 2022

East Asian terrestrial snails of the family Camaenidae Pilsbry, 1895a are diverse in terms of genus and species numbers, shell morphology and mode of living. This family also includes colourful conical arboreal snails that traditionally have been assigned to the genus Amphidromus Albers, 1850. Yet, the present study shows that, despite their deceiving conchological similarity, some of these East Asian arboreal snails do not belong to the genus Amphidromus or the subfamily Camaeninae Pilsbry, 1895a. The presence of a dart complex comprising a mucous gland, a dart sac, an accessory sac and a proximal accessory sac, along with a pronounced penial caecum and molecular phylogenetic analyses revealed that former ‘Amphidromus’ dautzenbergi, ‘A.’ roemeri and ‘Camaena’ mirifica, and one additional new species belong to Aegistohadra Wu, 2004 (subfamily Bradybaeninae Pilsbry, 1934). Aegistohadra dautzenbergi, comb. nov. and Aegistohadra roemeri, comb. nov. are conical with colourful spiral bands, whereas Aegistohadra mirifica, comb. nov. and Aegistohadra zhangdanae, sp. nov. are heliciform to conical with colourful, variegated spiral and transverse banding patterns. DNA sequence analyses also revealed that each variety of Aegistohadra dautzenbergi could not be differentiated by mitochondrial (cytochrome c oxidase subunit I and 16S rRNA) gene fragments. The phylogenetic position of Aegistohadra within the East Asian camaenids revealed that the similar appearance in shell morphology, microhabitat use and diet to arboreal snails in the genus Amphidromus is homoplastic. Moreover, the presence or absence of a dart complex is also homoplastic and is unsuitable for suprageneric classification. By contrast, the presence of a flagellum and a penial caecum is useful for the suprageneric classification.
Multidimensional political apportionment
Authors: Cembrano Javier , Correa José , Verdugo Victor
Published: April 2022

Significance

A cornerstone in the modern political organization of societies is the existence of a deliberative assembly, reflecting the needs of different population segments. As modern societies become more complex, representation according to dimensions beyond political affiliation and geography is demanded; examples include gender balance and ethnicity. As this dimensionality increases, the task becomes more challenging and requires more sophisticated mathematical tools. In this paper, we initiate the study of multidimensional apportionments and show that, in three and more dimensions, their existence is not guaranteed. However, our main result states that it is possible to elect a house nearly respecting proportionality of representation along several dimensions simultaneously. We finally illustrate the potential of our approach with recent election data.
Pten
heterozygosity restores neuronal morphology in fragile X syndrome mice
Authors: Sathyanarayana Shivaprasad H. , Saunders Jasmine A. , Slaughter Jacob , Tariq Kamran , Chakrabarti Rajarshi , Sadanandappa Madhumala K. , Luikart Bryan W. , Bosco Giovanni
Published: April 2022

Significance

Phosphatase and tensin homolog protein (PTEN) and fragile X mental retardation protein (FMRP) play a vital role in neuronal development and function. This work provides new evidence for the genetic interaction of
Pten
and
Fmr1
in postnatal development of granule neurons and conserved mechanisms across evolution. The observed cellular phenotypic defects in
Pten
and
Fmr1
knockout (KO) could be rectified and restored by heterozygosity of
Pten
in
Fmr1
KO neurons. Additionally, increased expression of PTEN in background
Fmr1
KO animals suggests that FMRP negatively regulates PTEN, and we propose that introducing a combination of genetic mutations may normalize structural aspects of neuronal morphology by balancing each other’s expression.
The CHARGE syndrome ortholog CHD-7 regulates TGF-β pathways in
Caenorhabditis elegans
Authors: Jofré Diego M. , Hoffman Dane K. , Cervino Ailen S. , Hahn Gabriella M. , Grundy McKenzie , Yun Sijung , Amrit Francis R. G. , Stolz Donna B. , Godoy Luciana F. , Salvatore Esteban , Rossi Fabiana A. , Ghazi Arjumand , Cirio M. Cecilia , Yanowitz Judith L. , Hochbaum Daniel
Published: April 2022

Significance

CHARGE syndrome is a complex developmental disorder caused by mutations in CHD7 (chromodomain helicase DNA-binding protein-7). We identified
Caenorhabditis elegans chd-7
in a screen for suppressors of dauer formation, an alternative larval stage that develops under harsh environmental conditions. We found
chd-7
regulates tumor growth factor-β (TGF-β) signaling pathways both for dauer diapause and for development of the cuticle, a specialized extracellular matrix. In frog embryos, Chd7 promotes Col2a1 expression, which is necessary and sufficient to prevent CHARGE features. These studies establish a conserved role for Chd7 from worms to vertebrates in regulating the TGF-β signaling pathway. Genetic dissection of
chd-7
’s role in
C. elegans
may help to define the molecular and cellular events that contribute to CHARGE syndrome.
FKBP52 and FKBP51 differentially regulate the stability of estrogen receptor in breast cancer
Authors: Habara Makoto , Sato Yuki , Goshima Takahiro , Sakurai Masashi , Imai Hiroyuki , Shimizu Hideyuki , Katayama Yuta , Hanaki Shunsuke , Masaki Takahiro , Morimoto Masahiro , Nishikawa Sayaka , Toyama Tatsuya , Shimada Midori
Published: April 2022

Significance

Estrogen receptor α (ERα) is a transcription factor that induces cell proliferation and exhibits increased expression in a large subset of breast cancers. We comprehensively searched for indicators of poor prognosis in ERα-positive breast cancer through the multiple databases, including interactome, transcriptome, and survival analysis, and identified FKBP52. We found that two immunophilins, FKBP52 and FKBP51, have opposing effects on ERα stability and propose that therapeutic targeting of FKBP52 could be useful for the prevention and treatment of ERα-positive breast cancers, including endocrine therapy–resistant breast cancers.
Monocyte-derived SDF1 supports optic nerve regeneration and alters retinal ganglion cells’ response to Pten deletion
Authors: Xie Lili , Cen Ling-Ping , Li Yiqing , Gilbert Hui-Ya , Strelko Oleksandr , Berlinicke Cynthia , Stavarache Mihaela A. , Ma Madeline , Wang Yongting , Cui Qi , Kaplitt Michael G. , Zack Donald J. , Benowitz Larry I. , Yin Yuqin
Published: April 2022

Significance

The optic nerve conveys information from retinal ganglion cells (RGCs) to visual processing areas of the brain. Although this pathway normally cannot regenerate when injured nor in degenerative diseases such as glaucoma, this failure can be partially reversed by eliciting a controlled immune reaction in the eye. We show here that the chemokine SDF1 (stromal cell–derived factor 1) is an important contributor to this phenomenon. SDF1 is produced by infiltrative monocytes and acts through its cognate receptor to enhance RGC survival, promote optic nerve regeneration, and sensitize subtypes of RGCs that normally fail to respond to a complementary treatment to exhibit robust, long-distance regeneration. These findings establish SDF1 as an important therapeutic candidate for repairing the injured optic nerve.
Workplace inequality is associated with status-signaling expenditure
Authors: Muggleton Naomi , Trendl Anna , Walasek Lukasz , Leake David , Gathergood John , Stewart Neil
Published: April 2022

Significance

Scholars have identified that inequality is a notable detriment to well-being. Status-signaling luxury expenditure is taken as a symptom of the reduced well-being associated with income inequality. Despite evidence that status-signaling luxury expenditure is higher in unequal regions, it remains unclear who is affected by inequality. We use payroll and daily spending data from 683,677 individuals in 32,008 precisely-defined workplace peer groups to show that workers at unequal firms spend significantly more on high-status, luxury goods. This is also seen in those with a high absolute salary, but low salary rank within their workplace. Compared to aggregated, regional data, financial data allow us to identify groups of workplace peers and offer precise measurements of status-signaling expenditure for each individual.
Glycosaminoglycans modulate long-range mechanical communication between cells in collagen networks
Authors: Chen Xingyu , Chen Dongning , Ban Ehsan , Toussaint Kimani C. , Janmey Paul A. , Wells Rebecca G. , Shenoy Vivek B.
Published: April 2022

Significance

Glycosaminoglycans (GAGs) are carbohydrates that are expressed ubiquitously in the human body and are among the key macromolecules that influence the development, homeostasis, and pathology of native tissues. Abnormal accumulation of GAGs has been observed in metabolic disorders, solid tumors, and fibrotic tissues. Here we theoretically and experimentally show that tissue swelling caused by the highly polar nature of GAGs significantly affects the mechanical interactions between resident cells by altering the organization and alignment of the collagenous extracellular matrix. The role of GAGs in modulating cellular force transmission revealed here can guide the design of biomaterial scaffolds in regenerative medicine and provides insights on the role of cell–cell communication in tumor progression and fibrosis.
LPA suppresses T cell function by altering the cytoskeleton and disrupting immune synapse formation
Authors: Kremer Kimberly N. , Buser Alan , Thumkeo Dean , Narumiya Shuh , Jacobelli Jordan , Pelanda Roberta , Torres Raul M.
Published: April 2022

Significance

Cancers and chronic infectious pathogens often evade immune-mediated elimination by suppressing T cell function via engaging inhibitory receptors expressed on T cells. The phospholipid lysophosphatidic acid (LPA) is often increased systemically from basal concentrations upon development of cancer and chronic infections. We previously showed that, at these elevated concentrations, LPA suppresses the ability of CD8 T cells to kill malignant cells and to control tumor growth. Here, we demonstrate that LPA signaling suppresses T cell function via disrupting T cell receptor–induced cytoskeletal dynamics, immune synapse formation, signal transduction, and the tubulin code. This report identifies a targetable mechanism of receptor-mediated inhibition of T cell function that could be used in combination therapies to enhance antitumor and antiviral immunity.
Signaling from the RNA sensor RIG-I is regulated by ufmylation
Authors: Snider Daltry L. , Park Moonhee , Murphy Kristen A. , Beachboard Dia C. , Horner Stacy M.
Published: April 2022

Significance

The viral RNA sensor RIG-I initiates the antiviral innate immune response by activating a signaling cascade that induces interferon. Activation of the RIG-I signaling pathway is highly regulated to quickly mount a protective immune response while preventing dysregulation that can lead to excessive inflammation or autoimmune disorders. Here, we characterize one such mechanism of regulation. We describe that UFL1, an E3 ligase for the ubiquitin-like modifier conjugation system called ufmylation, is important to promote RIG-I signaling. Using molecular approaches, we show that ufmylation promotes RIG-I interaction with the membrane-targeting protein 14-3-3ε. As such, ufmylation positively regulates RIG-I recruitment to its signaling adaptor protein MAVS for induction of interferon in response to RNA virus infection.
TCR-mimic bispecific antibodies to target the HIV-1 reservoir
Authors: Sengupta Srona , Board Nathan L. , Wu Fengting , Moskovljevic Milica , Douglass Jacqueline , Zhang Josephine , Reinhold Bruce R. , Duke-Cohan Jonathan , Yu Jeanna , Reed Madison C. , Tabdili Yasmine , Azurmendi Aitana , Fray Emily J. , Zhang Hao , Hsiue Emily Han-Chung , Jenike Katharine , Ho Ya-Chi , Gabelli Sandra B. , Kinzler Kenneth W. , Vogelstein Bert , Zhou Shibin , Siliciano Janet D. , Sadegh-Nasseri Scheherazade , Reinherz Ellis L. , Siliciano Robert F.
Published: April 2022

Significance

Novel approaches to promote killing of HIV-1–infected cells are necessary for elimination of the latent reservoir, the main barrier to a cure. Here, we utilized a diverse phage-display library to construct T cell receptor (TCR)-mimic antibodies to HIV-1 peptide-major histocompatibility complexes (pMHC). We show that single-chain diabody forms of these antibodies recognize distinct epitopes in Gag and reverse transcriptase in a specific manner and induce T cell-mediated killing of HIV-1–infected CD4
+
T cells. This study lays the groundwork for future exploration of pMHC-based immunotherapeutic approaches toward elimination of the latent reservoir once effective latency-reversing strategies are developed.
Aster proteins mediate carotenoid transport in mammalian cells
Authors: Bandara Sepalika , Ramkumar Srinivasagan , Imanishi Sanae , Thomas Linda D. , Sawant Onkar B. , Imanishi Yoshikazu , von Lintig Johannes
Published: April 2022

Significance

Carotenoid pigments accumulate in specific patterns in vertebrate tissues and play important roles as colorants, chromophores, and hormone precursors. However, proteins that facilitate transportation of these lipophilic pigments within cells have not been identified. We provide evidence that Aster proteins are key components for this process and show that they bind the pigments with high affinity. We observed in mice that carotenoids accumulate in tissues that express Aster-B and this accumulation can be prevented by enzymatic turnover by the BCO2 protein. Accordingly, we found opposing expression patterns of the Aster-B protein and BCO2 in the human retina that seemingly contribute to the unique carotenoid concentration in the macula lutea.
A multimodal approach to the technological representations in CFL textbooks
Authors: Zhang Qi , Leahy Angela
Published: April 2022

The study scrutinizes the intermodal relations and interactive meaning-making of the textual and visual semiotics involved in modern technology representation, which indicates the engagement of authentic communication in language learning. The findings show that both textbooks show attempts to capture the up-to-date technology of modern life. Learners tend to be involved with the interpretation of the indexical relations between the visual and textual resources in one textbook, while the other textbook consists of a few texts and images that are not indexically related and are less likely to be interpreted interactively. Findings indicate the importance of being aware of the different emphases of these two textbooks through multimodal research, for the purpose of effective adaptations in CFL teaching and learning.
Drastic demographic events triggered the Uralic spread
Authors: Grünthal Riho , Heyd Volker , Holopainen Sampsa , Janhunen Juha A. , Khanina Olesya , Miestamo Matti , Nichols Johanna , Saarikivi Janne , Sinnemäki Kaius
Published: April 2022

The widespread Uralic family offers several advantages for tracing prehistory: a firm absolute chronological anchor point in an ancient contact episode with well-dated Indo-Iranian; other points of intersection or diagnostic non-intersection with early Indo-European (the Late Proto-Indo-European-speaking Yamnaya culture of the western steppe, the Afanasievo culture of the upper Yenisei, and the Fatyanovo culture of the middle Volga); lexical and morphological reconstruction sufficient to establish critical absences of sharings and contacts. We add information on climate, linguistic geography, typology, and cognate frequency distributions to reconstruct the Uralic origin and spread. We argue that the Uralic homeland was east of the Urals and initially out of contact with Indo-European. The spread was rapid and without widespread shared substratal effects. We reconstruct its cause as the interconnected reactions of early Uralic and Indo-European populations to a catastrophic climate change episode and interregionalization opportunities which advantaged riverine hunter-fishers over herders.
A new nonlocal low-rank regularization method with applications to magnetic resonance image denoising
Authors: Lu Jian , Xu Chen , Hu Zhenwei , Liu Xiaoxia , Jiang Qingtang , Meng Deyu , Lin Zhouchen
Published: April 2022

Magnetic resonance (MR) images are frequently corrupted by Rician noise during image acquisition and transmission. And it is very challenging to restore MR data because Rician noise is signal-dependent. By exploring the nonlocal self-similarity of natural images and further using the low-rank prior of the matrices formed by nonlocal similar patches for 2D data or cubes for 3D data, we propose in this paper a new nonlocal low-rank regularization (NLRR) method including an optimization model and an efficient iterative algorithm to remove Rician noise. The proposed mathematical model consists of a data fidelity term derived from a maximum a posteriori estimation and a NLRR term using the log-det function. The resulting model in terms of approximated patch/cube matrices is non-convex and non-smooth. To solve this model, we propose an alternating reweighted minimization (ARM) algorithm using the Lipschitz-continuity of the gradient of the fidelity term and the concavity of the logarithmic function in the log-det function. The subproblems of the ARM algorithm have closed-form solutions and its limit points are first-order critical points of the problem. The ARM algorithm is further integrated with a two-stage scheme to enhance the denoising performance of the proposed NLRR method. Experimental results tested on 2D and 3D MR data, including simulated and real data, show that the NLRR method outperforms existing state-of-the-art methods for removing Rician noise.
Microlocal properties of seven-dimensional lemon and apple Radon transforms with applications in Compton scattering tomography
Authors: Webber James W , Quinto Eric Todd
Published: April 2022

We present a microlocal analysis of two novel Radon transforms of interest in Compton scattering tomography, which map compactly supported L
2 functions to their integrals over seven-dimensional sets of apple and lemon surfaces. Specifically, we show that the apple and lemon transforms are elliptic Fourier integral operators, which satisfy the Bolker condition. After an analysis of the full seven-dimensional case, we focus our attention on nD subsets of apple and lemon surfaces with fixed central axis, where n < 7. Such subsets of surface integrals have applications in airport baggage and security screening. When the data dimensionality is restricted, the apple transform is shown to violate the Bolker condition, and there are artifacts which occur on apple–cylinder intersections. The lemon transform is shown to satisfy the Bolker condition, when the support of the function is restricted to the strip

0
<
z
<
1

.
Ehrenfest theorem in relativistic quantum theory*
Authors: Bialynicki-Birula Iwo , Bialynicka-Birula Zofia
Published: April 2022

Ehrenfest theorem is extended to the relativistic quantum theory of charged particles, moving under the influence of a classical electromagnetic field. In order to extend the original Ehrenfest result to the relativistic domain we bypassed the problems with the relativistic position operator by deriving directly Newton’s second law. Our approach is characterized by its universality. The detailed form of the wave equation is not needed. All that is required is the existence of the conserved electric four-current built from the particle wave function. The derivation is based on the conservation laws for the energy and momentum.
Thermal dilepton production in collisional hot QCD medium in the presence of chromo-turbulent fields
Authors: Naik Lakshmi J , Sreekanth V , Kurian Manu , Chandra Vinod
Published: April 2022

The effects of collisional processes in the hot QCD medium to thermal dilepton production from

q

q

¯

annihilation in relativistic heavy-ion collisions have been investigated. The non-equilibrium corrections to the momentum distribution function have been estimated within the framework of ensemble-averaged diffusive Vlasov–Boltzmann equation, encoding the effects of collisional processes and turbulent chromo-fields in the medium. The contributions from the 2 → 2 elastic scattering processes have been quantified for the thermal dilepton production rate. It is seen that the collisional corrections enhance the equilibrium dilepton spectra at high p
T and suppress at lower p
T. A comparative study between collisional and anomalous contributions to the dilepton production rates has also been explored. The collisional contributions are seen to be marginal compared to those due to collisionless anomalous transport.
A first-principles study on crystal structures and metallization of sodium-rich sulfides under high pressure
Authors: Song Liying , Jin Xilian , Li Ying , Zhuang Quan , Yang Shuhan , Zhang Li , An Lin , Liu Yang , Huo Zihao , Li Jisheng , Cui Tian , Liu Bingbing
Published: April 2022

We performed systematical theoretical simulations on phase diagrams, crystal structures, electron properties, and phonon features of Na–S system under high pressures. NaS, Na2S, and Na4S, were found to be stable under pressures. The superconducting transition critical temperature was estimated to nearly 0 K at 100 GPa in Na3S due to the weak electron–phonon coupling. Furthermore, by the comparison on the structures, the electron features, and alkali metal ions of stoichiometric proportion, we found that not only the pressure but also the number of sodium atoms in the formula unit of alkali metal atoms can promote the insulator–metal transformation in the alkali metal sulfides, such as Li–S, Na–S, and K–S systems.
A quantitative estimation method of ball bearing localized defect size based on vibration instantaneous energy analysis
Authors: He Zhiyuan , Chen Guo , Zhang Kaiyong , Gryllias Konstantinos
Published: April 2022

The quantitative evaluation of bearing damage size is of great significance for accurately predicting the remaining useful life of bearing. Existing studies have shown that rolling elements will produce corresponding vibration features when they enter and leave localized defects, and these features are the premise of accurately estimating the defect size. This paper presents an accurate quantitative estimation method of bearing localized defect size based on vibration instantaneous energy analysis. The time interval of rolling element entry and exit the damaged area is determined by analysing the instantaneous energy of fault impulse. The effectiveness of the proposed method is verified by the experiments of different defect sizes of the outer race and inner race at various speeds. Besides, the proposed method has higher accuracy compared with the conventional methods, which provides a new idea for fast and convenient estimation of the ball bearing localized defect size.
Uncertainty estimation for ensemble particle image velocimetry
Authors: Ahmadzadegan Adib , Bhattacharya Sayantan , Ardekani Arezoo M , Vlachos Pavlos P
Published: April 2022

We present a novel approach to estimate the uncertainty in ensemble particle image velocimetry (PIV) measurements. The ensemble PIV technique is widely used when the cross-correlation signal-to-noise ratio is insufficient to perform a reliable instantaneous velocity measurement. Despite the utility of ensemble PIV, uncertainty quantification for this type of measurement has not been studied. Here, we propose a method for estimating the uncertainty directly from the probability density function of displacements found by deconvolving the ensemble cross-correlation from the ensemble autocorrelation. We then find the second moment of the probability density function and apply a scaling factor to report the uncertainty in the velocity measurement. We call this method the moment of probability of displacement (MPD). We assess MPD’s performance with synthetic and experimental images. We show that predicted uncertainties agree well with the expected root mean square (RMS) of the error in the velocity measurements over a wide range of image and flow conditions. MPD shows good sensitivity to various PIV error sources with around 86% accuracy in matching the RMS of the error in the baseline data sets. So, MPD establishes itself as a reliable uncertainty quantification algorithm for ensemble PIV. We compared the results of MPD against one of the existing instantaneous PIV uncertainty approaches, moment of correlation (MC). We adapted the MC approach for ensemble PIV, however, its primary limitations remain the assumption of the Gaussian probability density function of displacements and the Gaussian particles’ intensity profile. In addition, our analysis shows that ensemble MC consistently underestimates the uncertainty, while MPD outperforms that and removes the limiting Gaussian assumption for the particle and probability density function, thus overcoming the limitations of MC.
Investigation of vibration and rotation multifunctional sensors based on the triboelectric effect
Authors: Wang Zhihua , Wang Dong , Li Na , Yao Tao
Published: April 2022

Studies show that to monitor the status of a rotating device accurately, vibration and rotation should be monitored simultaneously. In this regard and based on the effects of triboelectricity and electrostatic induction, a multifunctional sensor (MS) with a rotating-sleeve structure and two independent sensitive units is proposed in the present study. Nylon fabric and polytetrafluoroethylene film are used in the sensitive units, and the bounce of the copper ball on the sandwich elastic sensitive layer is used to determine the vibration level. Then theoretical analysis and finite element simulations are carried out to study the charge transfer characteristics of the sensor. It is found that the MS can truly reflect the vibration and rotation characteristics of the rotating device. Moreover, experiments are carried out and the obtained results show that the detection range of the sensor and its sensitivity are 0–36 m s−2, and 40.38 mV s2 m−1, respectively. It is concluded that the proposed MS can accurately identify the vibration frequency. The obtained results demonstrate that at rotation speeds of up to 2000 rpm, this MS can be used to measure the direction of rotation, speed, and angular acceleration with a relative error of less than 0.95%. Considering the superior characteristics of the proposed MS, it can be used to monitor the motion state of objects in real-time and has potential application prospects in the field of internet of things.
Green syntheses of graphene and its applications in internet of things (IoT)—a status review
Authors: Banerjee Arghya Narayan
Published: April 2022

Internet of Things (IoT) is a trending technological field that converts any physical object into a communicable smarter one by converging the physical world with the digital world. This innovative technology connects the device to the internet and provides a platform to collect real-time data, cloud storage, and analyze the collected data to trigger smart actions from a remote location via remote notifications, etc. Because of its wide-ranging applications, this technology can be integrated into almost all the industries. Another trending field with tremendous opportunities is Nanotechnology, which provides many benefits in several areas of life, and helps to improve many technological and industrial sectors. So, integration of IoT and Nanotechnology can bring about the very important field of Internet of Nanothings (IoNT), which can re-shape the communication industry. For that, data (collected from trillions of nanosensors, connected to billions of devices) would be the ‘ultimate truth’, which could be generated from highly efficient nanosensors, fabricated from various novel nanomaterials, one of which is graphene, the so-called ‘wonder material’ of the 21st century. Therefore, graphene-assisted IoT/IoNT platforms may revolutionize the communication technologies around the globe. In this article, a status review of the smart applications of graphene in the IoT sector is presented. Firstly, various green synthesis of graphene for sustainable development is elucidated, followed by its applications in various nanosensors, detectors, actuators, memory, and nano-communication devices. Also, the future market prospects are discussed to converge various emerging concepts like machine learning, fog/edge computing, artificial intelligence, big data, and blockchain, with the graphene-assisted IoT field to bring about the concept of ‘all-round connectivity in every sphere possible’.
InP nanowire light-emitting diodes with different pn-junction structures
Authors: Kimura S , Gamo H , Katsumi Y , Motohisa J , Tomioka K
Published: April 2022

We report on the characterization of wurtzite (WZ) InP nanowire (NW) light-emitting diodes (LEDs) with different pn junctions (axial and radial). The series resistance tended to be smaller in the NW-LED using core–shell InP NWs with a radial pn junction than in the NW-LED using InP NWs with an axial pn junction, indicating that radial pn junctions are more suitable for current injection. The electroluminescence (EL) properties of both NW LEDs revealed that the EL had three peaks originating from the zinc-blende (ZB) phase, WZ phase, and ZB/WZ heterojunction. Transmission electron microscopy showed that the dominant EL in the radial pn junction originated from the ZB/WZ interface across the stacking faults.
LptD-antigen system on gold nanoparticles: an innovative strategy in the nanovaccine development
Authors: Aguilera-Juárez Ana , Hernández-Adame Luis , Ruíz-Gómez Miguel Ángel , Monreal-Escalante Elizabeth , Reyes-Becerril Martha , Rosales-Mendoza Sergio , Pereyra Héctor Gabriel Silva , Angulo Carlos
Published: April 2022

Nanovaccine development is a growing research field in which the development of new carriers and bioconjugation approaches is a priority. In this sense, this report describes for the first time, the development of a novel conjugate that consists of gold nanoparticles (AuNPs) obtained by a one-step synthesis using an immunogenic peptide of the Lipopolysaccharide-assembly protein LptD from Vibrio parahaemolyticus bacteria as a reducing and capping agent. The resulting LptD@AuNPs compounds were fully characterized and the results showed the high capacity of the peptide to form complexes and reduce gold ions. The reaction yield estimated was higher than 83% and the chemical integrity of the peptide on the NP surface revealed a tyrosine amino acid bonding on the AuNP surface. Furthermore, the LptD@AuNP system showed high colloidal stability in a wide pH range (3–11 pH values), where the hydrodynamic diameter and Zeta potential behavior were strongly influenced by the functional groups of the antigenic peptide. The cytotoxicity assays showed that the obtained system is safe for mouse leukocytes, while immunized mice with LptD@AuNPs produced specific IgG antibodies. These encouraging results revealed the efficacy of some antigenic peptides as reducers and capping agents, in addition, opening the path to determine immunogenicity and immunoprotective efficacy of the LptD@AuNP system against the disease induced by Vibrio parahaemolyticus.
In situ investigation on melting characteristics of 1D SnCu alloy nanosolder
Authors: Zhang Xuan , Zhang Wei , Peng Yong
Published: April 2022

Nanosoldering can bond various nanomaterials together or connect them with electrodes to form electrical contacts, thus assembling these nanomaterials into functional nanodevices; it is believed to be a promising interconnection technique due to its flexibility, controllability and crucial advantage of avoiding detrimental effects on the nano-objects. In this technique, molten solder as a filler material is introduced between the objects to be joined to form a reliable bond, in which the nanosolder reflow melting is a crucial prerequisite for successful nanosoldering. This work focuses on studying the melting characteristics of one-dimensional 97Sn3Cu nanosolder with low-cost, prominent electrical property and high mechanical reliability, aiming to promote its applications in nanosoldering. The reflow melting of an individual nanosolder has been dynamically observed by in situ heating holder in transmission electron microscopy, where the obtained reflow temperature (530 °C) is much higher than its melting temperature (220.4 °C) because of the external oxide layer confinement. Furthermore, the size-dependent melting temperature of nanosolders with various diameters (20–300 nm) has been investigated by both differential scanning calorimetry and theoretical calculation, revealing that the melting temperature decreases as the diameter goes down, especially for the nanosolders in the sub 80 nm range, where the value decreases significantly. The experimental results are in good agreement with the theoretical predictions. These results pointed out here can be readily extended to other nanosolders.
Study of Size, Shape, and Etch pit formation in InAs/InP Droplet Epitaxy Quantum Dots
Authors: Gajjela Raja S R , van Venrooij Niels R S , da Cruz Adonai R , Skiba-Szymanska Joanna , Stevenson R Mark , Shields Andrew J , Pryor Craig E , Koenraad Paul M
Published: April 2022

We investigated metal-organic vapor phase epitaxy grown droplet epitaxy (DE) and Stranski–Krastanov (SK) InAs/InP quantum dots (QDs) by cross-sectional scanning tunneling microscopy (X-STM). We present an atomic-scale comparison of structural characteristics of QDs grown by both growth methods proving that the DE yields more uniform and shape-symmetric QDs. Both DE and SKQDs are found to be truncated pyramid-shaped with a large and sharp top facet. We report the formation of localized etch pits for the first time in InAs/InP DEQDs with atomic resolution. We discuss the droplet etching mechanism in detail to understand the formation of etch pits underneath the DEQDs. A summary of the effect of etch pit size and position on fine structure splitting (FSS) is provided via the k · p theory. Finite element (FE) simulations are performed to fit the experimental outward relaxation and lattice constant profiles of the cleaved QDs. The composition of QDs is estimated to be pure InAs obtained by combining both FE simulations and X-STM results. The preferential formation of {136} and {122} side facets was observed for the DEQDs. The formation of a DE wetting layer from As-P surface exchange is compared with the standard SKQDs wetting layer. The detailed structural characterization performed in this work provides valuable feedback for further growth optimization to obtain QDs with even lower FSS for applications in quantum technology.
Carbon nanotube-tungsten nanowire hierarchical structure for augmented field emission performance
Authors: Pulagara Narasimha Vinod , Lahiri Indranil
Published: April 2022

An increasing number of emitting sites and higher aspect ratios are constantly being added to field emission systems to further improve their properties. Such an ever-growing demand has thrown light on the development of hierarchical field emitters. Tungsten (W) and carbon nanotubes (CNT) have been commonly reported as potential field emitter materials. The present work focused on constructing a hierarchical field emitter structure of CNTs/W nanowires. The structural characterization has been studied using field emission scanning electron microscopy, high-resolution transmission electron microscopy, and x-ray diffraction to confirm the hierarchical structure formation. The carbon nanotube-tungsten nanowire hierarchical structural emitters have demonstrated high current density (31.5 mA cm−2), exceptionally low turn-on field (0.068 V μm−1), and emission stability for more than 152 h. This excellent performance could be related to the formation of a strong as well as the electrically favourable interface between tungsten nanowires and CNTs.
Tiny changes in tomographic system matrices can cause large changes in reconstruction quality
Authors: Khellaf F , Clackdoyle R , Rit S , Desbat L
Published: April 2022

This paper studies the impact of tiny changes in region-of-interest (ROI) tomography system matrices on the variance of the reconstructed ROI. In small-scale and medium-scale examples, the variance in the reconstructed ROI was estimated for different system matrices. The results revealed a striking and counterintuitive phenomenon: a tiny change in the system matrix can dramatically affect the variance of the ROI estimate. In one of our examples, a decrease of 0.1% in one element out of hundreds of thousands of the system matrix resulted in a systematic reduction of the variance inside the ROI, and by a factor of 5 to 10 for some pixels. Our results agree with a recently proven theorem about the ability of additional measurements to reduce the variance in ROI tomography.
Improved 3D tumour definition and quantification of uptake in simulated lung tumours using deep learning
Authors: Dal Toso Laura , Chalampalakis Zacharias , Buvat Irène , Comtat Claude , Cook Gary , Goh Vicky , Schnabel Julia A , Marsden Paul K
Published: April 2022

Objective. In clinical positron emission tomography (PET) imaging, quantification of radiotracer uptake in tumours is often performed using semi-quantitative measurements such as the standardised uptake value (SUV). For small objects, the accuracy of SUV estimates is limited by the noise properties of PET images and the partial volume effect. There is need for methods that provide more accurate and reproducible quantification of radiotracer uptake. Approach. In this work, we present a deep learning approach with the aim of improving quantification of lung tumour radiotracer uptake and tumour shape definition. A set of simulated tumours, assigned with ‘ground truth’ radiotracer distributions, are used to generate realistic PET raw data which are then reconstructed into PET images. In this work, the ground truth images are generated by placing simulated tumours characterised by different sizes and activity distributions in the left lung of an anthropomorphic phantom. These images are then used as input to an analytical simulator to simulate realistic raw PET data. The PET images reconstructed from the simulated raw data and the corresponding ground truth images are used to train a 3D convolutional neural network. Results. When tested on an unseen set of reconstructed PET phantom images, the network yields improved estimates of the corresponding ground truth. The same network is then applied to reconstructed PET data generated with different point spread functions. Overall the network is able to recover better defined tumour shapes and improved estimates of tumour maximum and median activities. Significance. Our results suggest that the proposed approach, trained on data simulated with one scanner geometry, has the potential to restore PET data acquired with different scanners.
Variability analysis of the epitaxial layer TFET due to gate work function variation, random dopant fluctuation, and oxide thickness fluctuation using the statistical impedance field method
Authors: Debnath Radhe Gobinda , Baishya Srimanta
Published: April 2022

In this paper, a comparative study on process variability considering work function variation (WFV), random dopant fluctuation (RDF), and oxide thickness fluctuation (OTF) in epitaxial layer tunnel field effect transistor (TFET) with SiGe source (SiGe-ETLTFET) is statistically analyzed using impedance field method (IFM) in Santaurus TCAD tool. Effect of different grain sizes of the gate metal and other device parameter scaling on the variability source are investigated by evaluating the standard deviation of threshold voltage (V
th), on current (I
ON), and off current (I
OFF). At smaller AverageGrainSize, the dispersions in electrical parameters are close to normal, whereas for large AverageGrainSize dispersion increases and deviates from the normal distribution. Compared to RDF and WFV, OTF is not a significant cause of variability in SiGe-ETLTFET. It is found that RDF is the most sensitive variability source while device scaling is concerned. Moreover, L
ov scaling causes the most acute fluctuation of electrical parameters for all considered variability sources. The slope of the Pelgrom plot, A
VT, of SiGe-ETLTFET considering all variability sources, is smaller than the already reported values for the FinFET and MOSFET.
Active flutter control of a bridge-flap system considering aerodynamic interferences in practical considerations
Authors: Li Ke , Zhao Lin , Hui Yi , Yang Qingshan , Chen Zengshun , Qian Guowei
Published: April 2022

Designing bridges with spans larger than 2000 m is challenging. One critical problem is that the flutter stability of such bridges is extremely weak. In past studies, actively controlled flaps were found to improve the flutter stability performance. However, in those studies, the deck was always assumed to be an ideal streamlined plate to simplify the aerodynamic interference effect in the deck-flap system. This simplification limits the application of this technique on real projects. To improve the applicability, we adopt a typical bluff body deck to investigate the effect of the active flaps under different wind attack angles. The novelty of this work is the analysis of the aerodynamic interference and resulting control impact considering the application scenario. The tests are conducted through the computational fluid dynamic method. To give intuitive explanations of the aerodynamic interference, the distributed aerodynamic characteristics method is innovatively introduced to quantify the contribution of flap on the flutter stability during the control process. Our results show that the leading flap has a dominant contribution to the flutter stability by inducing the beneficial aerodynamic damping on the deck’s leading surfaces. Its optimal phase should be about π/2 lagging from the deck’s torsional motion. In comparison, the effect of the trailing flap is unstable under different wind attack angles. To guarantee a robust control effect, it is suggested that it remains stationary.
Segregation dynamics driven by network leaders
Authors: Wang Wenxuan , Feng Yuhao , Chen Siru , Xu Wenzhe , Zhuo Xinjian , Li Hui-Jia , Perc Matjaž
Published: April 2022

Network segregation—a critical problem in real-life networks—can reveal the emergence of conflicts or signal an impending collapse of the whole system. However, the strong heterogeneity of such networks and the various definitions for key nodes continue to pose challenges that limit our ability to foresee segregation and to determine the main drivers behind it. In this paper, we show that a multi-agent leader–follower consensus system can be utilized to define a new index, named leadership, to identify key leaders in real-life networks. And then, this paper explores the emergence of network segregation that is driven by these leaders based on the removal or the rewiring of the relations between different nodes in agreement with their contribution distance. We finally show that the observed leaders-driven segregation dynamics reveals the dynamics of heterogeneous attributes that critically influence network structure and its segregation. Thus, this paper provides a theoretical method to study complex social interactions and their roles in network segregation, which ultimately leads to a closed-form explanation for the emergence of imbalanced network structure from an evolutionary perspective.
Effect of divertor plasma-facing materials and drift on the power decay width in the scrape-off layer and divertor on EAST
Authors: Zhang Chen , Sang Chaofeng , Wang Liang , Zhang Yanjie , Li Nami , Wang Dezhen
Published: April 2022

The narrow power decay width λ

q
may lead to high heat flux density to the divertor target, which is one of the most severe challenges for future fusion devices. EAST has upgraded its lower graphite (C) divertor to a tungsten (W) one, and it is important to reveal the dependence of λ

q
on the divertor condition. In the present work, SOLPS-ITER is applied to estimate the effect of various conditions [C/W plasma facing material (PFM), with/without drift] on λ

q
of EAST in attached divertor regime. The simulation results confirm that the power decay width of the upstream λ

q,SOL, divertor λ

q,OT, and private-flux region (PFR) S
OT all depend on the PFMs and drifts. However, the effect of PFM on λ

q,SOL is slight, while it has a significant influence on λ

q,OT and S
OT. In the upstream, positive correlation between λ

q,SOL and

υ

S
O
L

*

is obtained, and the simulation is in qualitative agreement with the two-point model. Both λ

q,SOL and λ

q,OT in without drift case are larger than that of with drift case. The regression of simulation results is obtained, showing a strong positive correlation between SOL collisionality

υ

S
O
L

*

, power radiation friction in divertor region f
rad,OD and λ

q,OT. Thus, the C PFM with intrinsic impurity has the largest λ

q,OT. In the PFR, S
OT with drift is smaller than that of without drift. Moreover, the combination of more D atoms accumulation and stronger E
p × B drift lead to larger S
OT in W PFM case than that of C PFM case.
Modal analysis of arbitrary-oriented ridge waveguides in x-cut lithium niobate thin film
Authors: Liu Wei-chong , Li Ye , Chen Bao-Qin , Li Zhi-Yuan
Published: April 2022

We theoretically and numerically investigate the mode properties of ridge waveguides made on lithium niobate (LN) subwavelength thin film by taking into complete account the anisotropic feature of LN crystal. We analyze the effective refractive index of the quasi-transverse-electrical (q-TE) and quasi-transverse-magnetic (q-TM) modes and their difference in arbitrary-oriented waveguides on x-cut lithium niobate on insulator. Waveguide simulations based on full-vectorial finite element method are performed. The geometrical parameters and directions of the optical axis of the LN material for the ridge waveguides are varied to investigate the single-mode condition, optical power distribution and mode hybridization effect in the straight waveguides. The different trends in optical power distribution in LNOI waveguide between q-TE and q-TM at different crystal optical axis angles will be explained in detail.