bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of a novel SARS-CoV-2 variant with a truncated protein in ORF8 gene by next generation sequencing
Authors: DeRonde Stephanie , Deuling Hannah , Parker Jayme , Chen Jack
Published: March 2022

Using next generation sequencing technology, we identified a novel SARS-CoV-2 variant with a truncated ORF8 protein mutation near the end of the viral genome from nucleotides 27,878 to 27,958. This point mutation from C to T at nucleotide 27,956 changed the amino acid codon CAA (glutamine) to a stop codon, TAA, created a novel stop codon in ORF8 gene, resulting in a much smaller ORF8 protein (26 aa) than the wild type ORF8 protein (121 aa). This variant belongs to Pango lineage B.1.1291, which also contains the D614G mutation in the Spike (S) gene. The B.1.1291 lineage is predominantly circulated in the United States of America (97.18%), although it was also found in other counties (Russia, Canada, Latvia, Chile, India, Japan, Colombia, Germany, Greece, Mexico, and UK). A total of 340 closely related variants to this novel variant were identified in GISAID database with collection dates ranged from 3/6/2020 to 10/21/2020. In addition, a search within NCBI Genbank database found that 108,405 of 873,230 (12.4%) SAR-CoV-2 complete genomes contain this truncated ORF8 protein mutation, indicating this mutation may arise spontaneously in other lineages as well. The wide distribution of this mutation indicates that this truncated ORF8 protein mutation may provide the virus a growth advantage and adaptive evolution.
Scalable total synthesis of (+)-aniduquinolone A and its acid-catalyzed rearrangement to aflaquinolones
Authors: Guo Feng-Wei , Mou Xiao-Feng , Qu Yong , Wei Mei-Yan , Chen Guang-Ying , Wang Chang-Yun , Gu Yu-Cheng , Shao Chang-Lun
Published: March 2022

The strong antibacterial, antiviral and anticancer activities demonstrated by quinolones make them promising lead structures and important synthetic targets for drug discovery. Here, we report, to the best of our knowledge, the first scalable total synthesis of antiviral (+)-aniduquinolone A, possessing a 3,4-dioxygenated 5-hydroxy-4-aryl-quinolin-2(1H)-one skeleton. This synthetic strategy explores E-stereoselective Horner–Wadsworth–Emmons (HWE) olefination as the key step to assemble isopropenyl substituted tetrahydrofuran onto the 3,4-dioxygenated 5-hydroxy-4-aryl-quinolin-2(1H)-one core, which is built by highly diastereoselective intramolecular aldol reaction. Moreover, two sets of stereoisomers of aniduquinolone A with substantially overlapping NMR data were synthesized completely and assigned unambiguously by comprehensive analysis of both their spectroscopic and X-ray diffraction data. Unexpectedly, aflaquinolones A, C, and D that feature different 2,4-dimethyl cyclohexanone moieties were transformed successfully from (+)-aniduquinolone A by treating with TFA. The methodology delineated herein can be applied broadly to the synthesis of natural alkaloids containing the core structure of 3,4-dioxygenated 5-hydroxy-4-aryl-quinolin-2(1H)-one.
Grass species identity shapes communities of root and leaf fungi more than elevation
Authors: Kivlin Stephanie N , Mann Michael A , Lynn Joshua S , Kazenel Melanie R , Taylor D Lee , Rudgers Jennifer A
Published: March 2022

Fungal symbionts can buffer plants from environmental extremes and may affect host capacities to acclimate, adapt, or redistribute under environmental change; however, the distributions of fungal symbionts along abiotic gradients are poorly described. Fungal mutualists should be the most beneficial in abiotically stressful environments, and the structure of networks of plant-fungal interactions likely shift along gradients, even when fungal community composition does not track environmental stress. We sampled 634 unique combinations of fungal endophytes and mycorrhizal fungi, grass species identities, and sampling locations from 66 sites across six replicate altitudinal gradients in the western Colorado Rocky Mountains. The diversity and composition of leaf endophytic, root endophytic, and arbuscular mycorrhizal (AM) fungal guilds and the overall abundance of fungal functional groups (pathogens, saprotrophs, mutualists) tracked grass host identity more closely than elevation. Network structures of root endophytes become more nested and less specialized at higher elevations, but network structures of other fungal guilds did not vary with elevation. Overall, grass species identity had overriding influence on the diversity and composition of above- and belowground fungal endophytes and AM fungi, despite large environmental variation. Therefore, in our system climate change may rarely directly affect fungal symbionts. Instead, fungal symbiont distributions will most likely track the range dynamics of host grasses.
Homo- and heterometallic chiral dynamic architectures from allyl–palladium(ii) building blocks
Authors: Ferrer Montserrat , Gallen Albert , Martínez Manuel , Rocamora Mercè , Puttreddy Rakesh , Rissanen Kari
Published: March 2022

Allyl–palladium chiral metallamacrocycles were prepared by self-assembly reactions. Their dynamic behaviour and catalytic activity in the allylic alkylation reaction were investigated.
Environmentally stable MXene ink for direct writing flexible electronics
Authors: Kong Na , Zhang Jizhen , Hegh Dylan , Usman Ken Aldren S. , Qin Si , Lynch Peter A. , Yang Wenrong , Razal Joselito M.
Published: March 2022

A long shelf time MXene ink was prepared using a mixture of water and ethylene glycol and is a promising candidate for fabricating conductive circuits and paper-based flexible devices.
Application of patterned sapphire substrate for III-nitride light-emitting diodes
Authors: Zhou Shengjun , Zhao Xiaoyu , Du Peng , Zhang Ziqi , Liu Xu , Liu Sheng , Guo L. Jay
Published: March 2022

This review summarizes the applications of patterned sapphire substrates for III-nitride light-emitting diodes and provides an outlook of future LED development based on patterned sapphire substrates.
Design and testing of an ozonolysis reactor module with on-the-fly ozone degassing under flow conditions
Authors: Neyt Nicole C. , van der Westhuizen C. Johan , Panayides Jenny-Lee , Riley Darren L.
Published: March 2022

Ozonolysis is an attractive, efficient, and green means of introducing oxygen containing functionalities using only oxygen and electricity.
A biosensor material with robust mechanical properties, fatigue-resistance, biocompatibility, biodegradability, and anti-freezing capabilities
Authors: Wei Yanqiang , Jiang Shuaicheng , Li Jiongjiong , Li Xiaona , Li Kuang , Li Jianzhang , Fang Zhen
Published: March 2022

A mechanically durable, biocompatible, and frost-resistant protein-based biosensor with biomimetic nanoparticles has been fabricated, and it can be used to monitor physiological signals and movement states.
Pressure -induced changes in the persistent luminescence of Gd2.994Ce0.006Ga3Al2O12 and Gd2.964Ce0.006Dy0.03Ga3Al2O12 nanoceramics
Authors: Głuchowski P.
Published: March 2022

Pressure applied during sintering of the nanoceramics may enhance persistent luminescence.
Frustrated Lewis pair chemistry of hydride sponges
Authors: Becker Christian , Schwabedissen Jan , Neumann Beate , Stammler Hans-Georg , Mitzel Norbert W.
Published: March 2022

Hydride and proton sponges together form a Frustrated Lewis pair that cleaves NH3, H2O, PH3, H2S, H2Se and HCN but not dihydrogen, although the formal dihydrogen adduct, obtained in a synthetic detour, is stable to air and moisture and up to 100 °C.
ROESY and 13C NMR to distinguish between d- and l-rhamnose in the α-d-Manp-(1 → 4)-β-Rhap-(1 → 3) repeating motif
Authors: Davidson Jeffrey , Gauthier-Signore Charles , Bishop Kevin P. , Wicks Christopher , Monteiro Mario A. , Roy Pierre-Nicholas , Auzanneau France-Isabelle
Published: March 2022

CH3-6 of l-Rha and H-2 of d-Man give ROE correlation in the α-d-Manp-(1 → 4)-l-Rhap motif. C-2 in d-Man is shifted upfield in the 13C NMR spectrum of the β-d-Rhap-(1 → 3)-d-Manp motif.
Photocatalyzed alkylative cyclization of 2-isocyanobiphenyls with unactivated alkyl iodides
Authors: Tripathy Alisha Rani , A Rizwana Rahmathulla , Kumar Amit , Yatham Veera Reddy
Published: March 2022

Photocatalyzed radical cascade cyclization of 2-isocyanobiaryls with unactivated alkyl iodides was developed. This protocol operates under mild conditions and tolerates a variety of functional groups affording 6-alkyl phenanthridines in good yields.
Turn-on green fluorescence imaging for latent fingerprint applications
Authors: Tian Rui , Wang Ya-Long , Li Chong , Zhu Ming-Qiang
Published: March 2022

Binding of a synthesized fluorescent probe to latent fingerprints results in the aggregation-induced emission of green light, which is better perceived by the human eye than other colors and provides up to three levels of minutiae characteristics of latent fingerprints.
Microwave modification of iron supported on beta silicon carbide catalysts for Fischer–Tropsch synthesis
Authors: Mbuya Christel Olivier Lenge , Okoye-Chine Chike George , Ramutsindela Katu , Jewell Linda L. , Scurrell Mike
Published: March 2022

Beta silicon carbide is a good microwave absorber support. Microwave irradiation can improve the surface properties of Fe/β-SiC catalysts. Microwave irradiation can be used to improve the catalytic performance of Fe/β-SiC catalysts.
A new aggregation induced emission enhancement (AIEE) dye which self-assembles to panchromatic fluorescent flowers and has application in sensing dichromate ions
Authors: Kshtriya Vivekshinh , Koshti Bharti , Mehmood Tahir , Singh Ramesh , Joshi Khashti Ballabh , Bandyopadhyay Sujoy , Boukhvalov Danil W. , Reddy J. Prakasha , Gour Nidhi
Published: March 2022

We report for the very first time the crystal structure and self-assembly of a new aggregation-induced emission enhancement (AIEE) dye 4-(5-methoxythiazolo[4,5-b]pyridin-2-yl)-N,N-dimethylaniline (TPA) to well defined panchromatic fluorescent flower-like morphologies and its application in sensing dichromate ions.
A small-molecule-templated nanostructure back electrode for enhanced light absorption and photocurrent in perovskite quantum dot photovoltaics
Authors: Han Sanghun , Kim Jigeon , Kim Dong Eon , Ko Min Jae , Choi Jongmin , Baek Se-Woong , Kim Younghoon
Published: March 2022

A nanostructured spiro-OMeTAD can be fabricated via nanoimprint soft lithography and realizes back-side nanostructured perovskite quantum dot solar cells showing improved photovoltaic performance due to the enhanced light absorption and photocurrent.
Materials for thermally activated delayed fluorescence and/or triplet fusion upconversion
Authors: Jeffries-EL Malika , Yanai Nobuhiro , Zysman-Colman Eli
Published: March 2022

Guest editors Malika Jeffries-EL, Nobuhiro Yanai and Eli Zysman-Colman introduce this themed issue on thermally activated delayed fluorescence, and triplet–triplet annihilation-based photon upconversion, materials.
Editorial introducing Environmental Science: Advances
Authors: Cai Zongwei , Jones Kevin C. , Manaia Celia M.
Published: March 2022

Editors-in-Chief Zongwei Cai, Kevin Jones and Celia M. Manaia introduce the purpose, aims and scope of Environmental Science: Advances.
Mechanical Methods for the Induction of Labour After Previous Caesarean Section – An Updated, Evidence-based Review
Authors: Rath Werner , Hellmeyer Lars , Tsikouras Panagiotis , Stelzl Patrick
Published: March 2022

There are currently no up-to-date evidence-based recommendations on the preferred method to induce labour after previous Caesarean section, especially for patients with unripe cervix, as
randomised controlled studies are lacking. Intravenous oxytocin and misoprostol are contraindicated in these women because of the high risk of uterine rupture. In women with ripe cervix
(Bishop Score > 6), intravenous administration of oxytocin is an effective procedure with comparable rates of uterine rupture to those with spontaneous onset of labour. Vaginal
prostaglandin E2 (PGE2) and mechanical methods (balloon catheters, hygroscopic cervical dilators) are effective methods to induce labour in pregnant women with unripe
cervix and previous Caesarean section. According to current guidelines, the administration of PGE2 is associated with a higher rate of uterine rupture compared to balloon
catheters. Balloon catheters are therefore a suitable alternative to PGE2 to induce labour after previous Caesarean section, even though this is an off-label use. In addition to
two meta-analyses published in 2016, 12 mostly retrospective cohort/observational studies with low to moderate levels of evidence have been published on mechanical methods of cervical
ripening after previous Caesarean section. But because of the significant heterogeneity of the studies, substantial differences in study design, and insufficient numbers of pregnant women
included in the studies, it is not possible to make any evidence-based recommendations based on these studies. According to a recent meta-analysis, the average rate using balloon catheters
is approximately 53% and the average rate after spontaneous onset of labour is 72%. The uterine rupture rate was 0.2–0.9% for vaginal PGE2 and 0.56–0.94% for balloon catheters and
is therefore comparable to the uterine rupture rate associated with spontaneous onset of labour. According to the product informations, hygroscopic cervical dilators (Dilapan-S) are
currently the only method which is not contraindicated for cervical ripening/induction of labour in women with previous Caesarean section, although data are insufficient. Well-designed,
randomised, controlled studies with sufficient case numbers comparing balloon catheters and hygroscopic cervical dilators with mechanical methods and vaginal prostaglandin E2/oral
misoprostol are therefore necessary to allow proper decision-making.
Individualized treatment of differentiated thyroid cancer: The value of surgery in combination with radioiodine imaging and therapy – A German position paper from Surgery and Nuclear Medicine
Authors: Schmidt Matthias , Bartenstein Peter , Bucerius Jan , Dietlein Markus , Drzezga Alexander , Herrmann Ken , Lapa Constantin , Lorenz Kerstin , Musholt Thomas J. , Nagarajah James , Reiners Christoph , Sahlmann Carsten O. , Kreissl Michael C.
Published: March 2022

A consensus statement about indications for post-surgical radioiodine therapy (RIT) in differentiated thyroid cancer patients (DTC) was recently published by the European Thyroid Association (ETA) 1. This publication discusses indications for RIT on the basis of an individual risk assessment. Many of the conclusions of this consensus statement are well founded and accepted across the disciplines involved. However, especially from the perspective of nuclear medicine, as the discipline responsible for indicating and executing RIT, some of the recommendations may require further clarification with regard to their compatibility with established best practice and national standards of care. Assessment of the indications for RIT is strongly dependent on the weighing up of benefits and risks. On the basis of longstanding clinical experience in nuclear medicine, RIT represents a highly specific precision medicine procedure of proven efficacy with a favorable side-effect profile. This distinguishes RIT significantly from other adjuvant oncological therapies and has resulted in the establishment of this procedure as a usually well-tolerated, standard safety measure. With regard to its favorable risk/benefit ratio, this procedure should not be unnecessarily restricted, in the interest of offering reassurance to the patients. Both patients’ interests and regional/national differences need to be taken into account. We would therefore like to comment on the recent consensus from the perspective of authors and to provide recommendations based on the respective published data.
Trans-Arterial Embolization of High-Flow Renal Arteriovenous Fistula (AVF) with Concomitant Renal Artery Aneurysm
Authors: Basri Niemah , Yusoff Bazli Md , Samsudin Ahmad Hadif Zaidin , Mohamad Nasibah , Nadarajan Chandran , Abdullah Mohd Shafie
Published: March 2022

Arteriovenous fistula (AVF) is an abnormal direct communication between an artery and the venous drainage without a capillary component. Although renal AVF is rare, detecting the disease is important to assist in management and, thus, help reverse the sequelae of the disease such as hypertension and heart failure. The clinical presentation and radiological features are important parameters that can help in the diagnosis and decision of treatment. We would like to share our successful approach to a 52-year-old female with idiopathic high-flow left renal AVF with concomitant renal artery aneurysm using a single Amplatzer vascular plug in the limit of our setting.
Machine learning catches elusive magnetic phenomenon
Authors: Lim Alane
Published: March 2022

Developing a method to automatically detect magnetic proximity effect
Finding order within intrinsically disordered proteins
Authors: Thompson Avery
Published: March 2022

Intrinsically disordered proteins have a complex structure and play a key role in intracellular communication.
Perspectives in translating microfluidic devices from laboratory prototyping into scale-up production
Authors: Cong Hengji , Zhang Nan
Published: March 2022

Transforming lab research into a sustainable business is becoming a trend in the microfluidic field. However, there are various challenges during the translation process due to the gaps between academia and industry, especially from laboratory prototyping to industrial scale-up production, which is critical for potential commercialization. In this Perspective, based on our experience in collaboration with stakeholders, e.g., biologists, microfluidic engineers, diagnostic specialists, and manufacturers, we aim to share our understanding of the manufacturing process chain of microfluidic cartridge from concept development and laboratory prototyping to scale-up production, where the scale-up production of commercial microfluidic cartridges is highlighted. Four suggestions from the aspect of cartridge design for manufacturing, professional involvement, material selection, and standardization are provided in order to help scientists from the laboratory to bring their innovations into pre-clinical, clinical, and mass production and improve the manufacturability of laboratory prototypes toward commercialization.
RapidQ: A reader-free microfluidic platform for the quantitation of antibodies against the SARS-CoV-2 spike protein
Authors: Mattila Juha-Pekka , Amaro Arlene , Longo Monica , Antaki James , Koirala Sanam , Gandini Alberto
Published: March 2022

We describe RapidQ, a fast, disposable, easy-to-use microfluidic assay for the quantitation of the anti-SARS-CoV-2 spike (S) protein IgG in plasma samples. The assay utilizes antigen-coated paramagnetic microbeads, which are induced to aggregate inside the RapidQ microfluidic device in the presence of the target antibody. Aggregation occurs via interaction between the biotinylated detection antibody and polymeric streptavidin. The mobility of the beads inside the two microchannels of the device depends on their aggregation state, with larger clusters moving at higher velocities under a given liquid flow rate. One of the microchannels incorporates a permanent magnet that captures arriving beads and forms a localized constriction that retards liquid flow. Since the constriction grows faster when the beads are more aggregated, the length of the liquid column accumulated downstream from the constriction relative to that of the unconstricted control channel is proportional to the sample antibody concentration. The assay demonstrates a detection limit of 4 μg/ml of monoclonal anti-S protein antibody diluted in plasma with CV ≤ 13%, as well as negative and positive percent agreements of 100% (95% CI: 92.75%–100%) and 100% (95% CI: 80.5%–100%), respectively, when compared to a nucleic acid amplification test used to identify COVID-19 positive individuals, whose samples were collected ≥17 d from a positive PCR test. Finally, the RapidQ assay was used to monitor the kinetics of antibody responses to COVID-19 vaccination in a small study cohort.
A universal chemical-induced tensile strain tuning strategy to boost oxygen-evolving electrocatalysis on perovskite oxides
Authors: Guan Daqin , Zhong Jian , Xu Hengyue , Huang Yu-Cheng , Hu Zhiwei , Chen Bin , Zhang Yuan , Ni Meng , Xu Xiaomin , Zhou Wei , Shao Zongping
Published: March 2022

Exploring effective, facile, and universal tuning strategies to optimize material physicochemical properties and catalysis processes is critical for many sustainable energy systems, but still challenging. Herein, we succeed to introduce tensile strain into various perovskites via a facile thermochemical reduction method, which can greatly improve material performance for the bottleneck oxygen-evolving reaction in water electrolysis. As an ideal proof-of-concept, such a chemical-induced tensile strain turns hydrophobic Ba5Co4.17Fe0.83O14-δ perovskite into the hydrophilic one by modulating its solid–liquid tension, contributing to its beneficial adsorption of important hydroxyl reactants as evidenced by fast operando spectroscopy. Both surface-sensitive and bulk-sensitive absorption spectra show that this strategy introduces oxygen vacancies into the saturated face-sharing Co-O motifs of Ba5Co4.17Fe0.83O14-δ and transforms such local structures into the unsaturated edge-sharing units with positive charges and enlarged electrochemical active areas, creating a molecular-level hydroxyl pool. Theoretical computations reveal that this strategy well reduces the thermodynamic energy barrier for hydroxyl adsorption, lowers the electronic work function, and optimizes the charge/electrostatic potential distribution to facilitate the electron transport between active sites and hydroxyl reactants. Also, this strategy is reliable for other single, double, and Ruddlesden–Popper perovskites. We believe that this finding will enlighten rational material design and in-depth understanding for many potential applications.
Passive Silicon Photonic Devices
Authors: Su Yikai , Zhang Yong
Published: March 2022

This important book is a practical guide to the design, fabrication, and testing of passive silicon photonic devices. It outlines the progress of the last decades and is organized into three parts: design principles of silicon waveguides and devices, nano-fabrication processes for passive devices, and testing of waveguide devices including vertical coupling and edge coupling setup for interfacing with fibers.

This timely book:Provides detailed materials on the operation of equipment and methods for fabrication and testingTeaches researchers and technical staff the skills to implement silicon photonic circuits quickly and successfullyIs authored by an eminent team from Shanghai Jiao Tong University, School of Electronic Information and Electrical Engineering, Shanghai, China

Researchers, specialists, and students working in photonics and silicon photonics devices will find Passive Silicon Photonic Devices: Design, Fabrication, and Testing an invaluable resource.
Testing of Passive Devices
Authors: Su Yikai , Zhang Yong
Published: March 2022

Passive silicon photonic devices are generally characterized by certain metrics, such as insertion loss and crosstalk. Thermally tunable devices are measured by thermal tuning efficiency. This chapter introduces the setup and methodologies for testing the on-chip passive silicon photonic devices. We first discuss the general measurement schematic and the coupling setup between the devices and optical fibers. Then, we introduce the testing methodologies to measure the insertion loss, crosstalk, and thermal tuning efficiency in detail. Finally, we take some examples to describe the device testing processes, including grating coupler, edge coupler, multimode interferometers, optical 90° hybrid, polarization beam splitter and rotator, and thermo-optic photonic crystal nanobeam.
Learning a new balance task: The influence of prior motor practice on training adaptations
Authors: Keller Martin , Roth Ralf , Achermann Samuel , Faude Oliver
Published: March 2022

Prior motor experience is thought to aid in the acquisition of new skills. However, studies have shown that balance training does not promote learning of a subsequent balance task. These results stand in contrast to the learning‐to‐learn paradigm, which is well described for other tasks. We therefore tested if a coordinative affinity between tasks is needed to achieve a learning‐to‐learn for balance control. Three groups trained different motor tasks during training phase1 (coordination ladder (COOR); bipedal wobble board (2WB); single‐leg wobble board (1WB)). During training phase2, all groups trained a tiltboard balance task. Task‐specific and transfer effects were evaluated for phase1. A potential learning‐to‐learn effect was evaluated by comparing the acquisition rates from phase2 for the tiltboard task that was used for training and testing. The results indicate task‐specific adaptations after phase1 for 1WB. In contrast, 2WB showed similar improvements than 1WB and COOR (effect sizes: −0.31 to −0.38) when tested on the wobble board with bipedal stance indicating no task‐specific improvement for 2WB. For phase2, the linear regression analysis showed larger adaptations for 1WB and 2WB when compared to COOR. This effect implies some uncertainty due to overlapping confidence intervals. Task‐specific adaptations after phase1 were found for 1WB but not 2WB. It is discussed that the difficulty of the training task could explain these contrasting results. During phase2, larger adaptations were found for both groups that trained balance tasks during phase1. Thus, despite some uncertainty, prior balance training appears to promote adaptations of a subsequently learned balance task.

Highlights

Prior balance training augments the learning of a new balance task if the two tasks share certain coordinative features.

The concept of “learning to learn” can probably be applied to postural control, although further studies are needed.

Balance training results (partly) in task‐specific adaptations with no immediate transfer to other (but unrelated) balance tasks.
Memristor hyperchaos in a generalized Kolmogorov-type system with extreme multistability
Authors: Jiao Xiaodong , Yuan Mingfeng , Tao Jin , Sun Hao , Sun Qinglin , Chen Zengqiang
Published: March 2022

Memristor chaotic systems have aroused great attention in recent years with their potentials expected in engineering applications. In this paper, a five-dimension (5D) double-memristor hyperchaotic system (DMHS) is modeled by introducing two active magnetron memristor models into the Kolmogorov-type formula. The boundness condition of the proposed hyperchaotic system is proved. Coexisting bifurcation diagram and numerical verification explain the bistability. The rich dynamics of the system are demonstrated by the dynamic evolution map and the basin. The simulation results reveal the existence of transient hyperchaos and hidden extreme multistability in the presented DMHS. The NIST tests show that the generated signal sequence is highly random, which is feasible for encryption purposes. Furthermore, the system is implemented based on a FPGA experimental platform, which benefits the further applications of the proposed hyperchaos.
Spatially modulated scene illumination for intensity-compensated two-dimensional array photon-counting LiDAR imaging
Authors: Xie Jiaheng , Zhang Zijing , Huang Mingwei , Li Jiahuan , Jia Fan , Zhao Yuan
Published: March 2022

Photon-counting LiDAR using a two-dimensional (2D) array detector has the advantages of high lateral resolution and fast acquisition speed. The non-uniform intensity profile of the illumination beam and non-uniform quantum efficiency of the detectors in the 2D array deteriorate the imaging quality. Herein, we propose a photon-counting LiDAR system that uses a spatial light modulator to control the spatial intensity to compensate for both the non-uniform intensity profile of the illumination beam, and the variation in the quantum efficiency of the detectors in the 2D array. By using a 635 nm peak wavelength and 4 mW average power semiconductor laser, lab-based experiments at a 4.27 m stand-off distance are performed to verify the effectiveness of the proposed method. Compared with the unmodulated method, the standard deviation of the intensity image of the proposed method is reduced from 0.109 to 0.089 for a whiteboard target, with an average signal photon number of 0.006 per pixel.
Orthogonal-triangular decomposition ghost imaging
Authors: Liu Jin-Fen , Wang Le , Zhao Sheng-Mei
Published: March 2022

Ghost imaging (GI) offers great potential with respect to conventional imaging techniques. However, there are still some obstacles for reconstructing images with high quality, especially in the case that the orthogonal measurement matrix is impossible to construct. In this paper, we propose a new scheme based on the orthogonal-triangular (QR) decomposition, named QR decomposition ghost imaging (QRGI) to reconstruct a better image with good quality. In the scheme, we can change the randomly non-orthogonal measurement matrix into orthonormal matrix by performing QR decomposition in two cases. (1) When the random measurement matrix is square, it can be firstly decomposed into an orthogonal matrix
Q
and an upper triangular matrix
R
. Then let the off-diagonal values of
R
equal to 0.0, the diagonal elements of
R
equal to a constant k, where k is the average of all values of the main diagonal, so the resulting measurement matrix can be obtained. (2) When the random measurement matrix is with full rank, we firstly compute its transpose, and followed with above QR operation. Finally, the image of the object can be reconstructed by correlating the new measurement matrix and corresponding bucket values. Both experimental and simulation results verify the feasibility of the proposed QRGI scheme. Moreover, the results also show that the proposed QRGI scheme could improve the imaging quality comparing to traditional GI (TGI) and differential GI (DGI). Besides, in comparison with the singular value decomposition ghost imaging (SVDGI), the imaging quality and the reconstruction time by using QRGI are similar to those by using SVDGI, while the computing time (the time consuming on the light patterns computation) is substantially shortened.
Single crystal growth and de Haas-van Alphen effect in strong coupling s-wave superconductor SrPt3P
Authors: Horie M , Matsuoka E , Sugawara H , Kotegawa H , Tou H , Terashima T , Uji S
Published: March 2022

We have succeeded in growing a single crystal of SrPt3P, which was reported as a strong coupling s-wave superconductor with the critical temperature of T
c=8.4 K, and have measured the de Haas-van Alphen (dHvA) effect and the electrical resistivity under magnetic fields. Several dHvA frequency branches with the frequencies up to ~ 1 kT with the cyclotron effective masses of mc
* = 0.27 – 0.61 m
0 were observed. It was clarified that the superconducting upper critical fields
μ0Hc2
for fields along H // [001] and H // [100] in the tetragonal structure are almost the same in values of μ
0
H
c2 ~4.8 T.
Unconventional singlet-triplet superconductivity
Authors: Möckli David
Published: March 2022

Have you been lying awake wondering what symmetries determine whether a superconductor is spin-singlet, triplet, or both? We show that if one supplies additional degrees of freedom to BCS theory, spin-singlet can coexist with spin-triplet superconductivity. We guide the reader to the most general superconducting state using symmetry arguments. If both singlet and triplet pairing channels act, a magnetic field can convert between spin-singlet and triplet states. Two possible singlet-triplet superconductors candidates are: CeRh2As2 and bilayer-NbSe2.
Suppression of superconductivity by spin fluctuations
Authors: Yamase Hiroyuki
Published: March 2022

We revisit the superconducting instability mediated by spin fluctuations in generic electron systems on a square lattice. We employ the standard Eliashberg theory, include the electron self-energy, keep a fine momentum resolution, and achieve numerical calculations down to very low temperatures so that the onset temperature of superconductivity (SC) can be determined. We find that spin fluctuations necessarily contain a contribution to suppress SC even though the superconducting instability can eventually occur at lower temperatures. This self-restraint effect stems from the repulsive pairing interaction induced by spin fluctuations, which leads to phase frustration of the pairing gap and consequently the suppression of SC. The self-restraint effect is a special feature of spin fluctuations and does not occur when SC is driven by the attractive pairing interaction from, for example, nematic fluctuations, orbital fluctuations, and electron-phonon coupling.
Possible pairing symmetries in the ordered honeycomb network superconductor BaPtSb
Authors: Kudo Masafumi , Shingu Shohei O. , Imazu Tsuyoshi , Goryo Jun , Imai Yoshiki
Published: March 2022

We investigate the pairing symmetry of the ordered honeycomb network superconductor BaPtSb, which has a crystal structure without inversion center. There is a preliminary μSR report which implies the broken time-reversal symmetry in the superconducting state. In this paper, we classify the pairing symmetry and examine the pairing instability. Among the unconventional states with time-reversal symmetry breaking, we find that the state with a gap structure compatible with Fermi surfaces is the spin-triplet chiral p-wave state.
Effect of the strong electron correlations on the formation of Wigner crystal in n-GaAs/AlGaAs structure: Surface Acoustic Waves studies
Authors: Smirnov I Yu , Drichko I L , Suslov A V , Pfeiffer L N , West K W , Galperin Y M
Published: March 2022

The complex high-frequency conductance of high-mobility n-GaAs/AlGaAs heterostructures was determined in magnetic fields 12–18 T using the Surface Acoustic Waves technique. Analysis of frequency and temperature dependences of conductance showed that in the investigated magnetic field range and at low temperatures, T<200 mK, the electron system forms a Wigner crystal deformed due to pinning by disorder. We have also defined an effective melting temperature of the Wigner crystal.
Magnetic properties of rare-earth zigzag chain systems RAgSe2 (R = Ho, Er, Tm, and Yb)
Authors: Mizutami S. , Ohmagari Y. , Onimaru T. , Shimura Y. , Yamamoto R. , Umeo K. , Takabatake T.
Published: March 2022

In an antiferromagnetic zigzag chain, competition between the nearest and next-nearest neighbor interactions could give rise to magnetic frustration. Magnetic semiconductors RAgSe2 (R = Ho, Er, Tm, and Yb) crystallize in the ErAgSe2-type orthorhombic structure, where the R ions form a zigzag chain along the orthorhombic a-axis. The magnetic susceptibility data for all the samples follow the Curie-Weiss law between 40 and 300 K. The values of the effective magnetic moment μ
βα are close to those expected for the free R
3+ ions. Negative values of the paramagnetic Curie temperature θρ
indicate antiferromagnetic interactions. For R = Ho and Tm, the specific heat C(T) data exhibit no anomaly down to 0.4 K, which is ascribed to the nonmagnetic singlet ground states under the crystalline electric fields. On the other hand, for R = Er, C(T) shows peaks at T
1 = 1.3 K and T2
= 0.9 K, indicating successive antiferromagnetic transitions. For R = Yb, C(T) shows a lambda-type anomaly at T
m = 1.8 K. The magnetic entropy at T
m is only 30% of Rln2 expected for the ground state doublet, suggesting magnetic fluctuations above T
m.
Low-temperature physical properties of new orthorhombic compounds R4Pt9Al13 (R = Ce, Pr)
Authors: Nakamura Y , Matsuoka E , Sugawara H , Sakurai T , Ohta H
Published: March 2022

Magnetic, transport, and thermal properties of new orthorhombic compounds Ce4Pt9Al13 and Ce4Pt9Al13 have been investigated by the magnetization, the electrical resistivity, and the specific-heat measurements. Ce4Pt9Al13 is a Kondo-lattice compound and shows a ferromagnetic or ferrimagnetic transition at T
C = 0.88 K. Pr4Pt9Al13 is an antiferromagnetic compound with the transition temperature at T
N = 2.6 K.
Memory and rejuvenation effect on the cluster-glass phase of 1-D spin-chain compound Ca3Co2–xBixO6
Authors: Bisht Gajendra Singh , Pal D.
Published: March 2022

We studied the structural, static, and dynamic properties of Ca3Co2–xBixO6 (x = 0 and 0.2) by means of powder X-ray diffraction and magnetization measurements. We reveal the rejuvenation phenomena in magnetic relaxation under cyclic temperature change and quenching below T

c2. The reproduced step in the memory curve confirms the striking feature of rejuvenation effect in these samples. The observed memory and rejuvenation effects are discussed in the framework of hierarchical model of glassy phase.
Quasi-Flat-Band in s1/s2 Pyrochlore Oxides and the Effect of Spin-Orbit Interaction
Authors: Hase I , Higashi Y , Yanagisawa T
Published: March 2022

An isotropic tight-binding model with the nearest-neighbour hopping on a pyrochlore lattice gives a rich variety of physical properties due to the emergence of the flat-band. Moreover, by introducing spin-orbit coupling into this model, the topological properties of the system changes significantly. This model is well applicable to some pyrochlore oxides called s1/s2 pyrochlores. In this paper we apply this model to an s2 pyrochlore oxide Pb2Ta2O7 and found a characteristic quadratic touching of the quasi-flat band and dispersive band. Furthermore, when a ferromagnetic order appears due to this quasi-flat band, a pair of Weyl points appears in that direction.
Anomalous transport properties of the antiferromagnetic Weyl semimetals Mn3
X (X = Sn, Ge)
Authors: Tomita Takahiro , Minami Susumu , Ikhlas Muhammad , Nakamura Hiroto , Arita Ryotaro , Nakatsuji Satoru
Published: March 2022

Noncollinear antiferromagnets Mn3
X (X = Sn, Ge) are characterized by a large anomalous Hall effect originating from a large Berry curvature despite a vanishingly small magnetization. From recent first-principle theories, the large Berry curvature is predicted to be induced by a existence of Weyl nodes broken time-reversal symmetry. The large anomalous Nernst effect is also contributed by the magnetic Weyl state around the Fermi level EF, and likely shares its origin with the anomalous Hall effect. The thermoelectric transport S(T) and thermomagnetic transport Sji(T) are thus investigated in single crystals of Mn3
X. Here, Mn3
X exhibits a large anomalous Nernst effect; in particular, the signal magnitude of Mn3Ge exceeds 1μV/K, which is 1.5 times that of Mn3Sn. The Weyl properties are discussed by analyzing the thermal conductivity, specific heat, and Seebeck and Nernst effects. We also evaluate the zero-field Nernst-driven thermoelectric figure of merit for device applications in the antiferromagnets Mn3
X.
Numerical simulation of the start-up process of a miniature ion thruster
Authors: YANG Xinyong , WEI Liqiu , JIANG Wenjia , JI Tianyuan , ZHOU Liwei , LI Hong , DING Yongjie , TANG Jingfeng , GUO Ning , YU Daren
Published: March 2022

A particle-in-cell Monte Carlo collision model of a discharge chamber is established to investigate the start-up process of a miniature ion thruster. We present the discharge characteristics at different stages (the initial stage, development stage, and stable stage) according to the trend of the discharge current with time. The discharge current is the sum of the sidewall current and the backplate current. During the start-up process, the sidewall current lags behind the backplate current. The variation and distribution characteristics of the discharge current over time are determined by the electron density distribution and electric potential distribution.
A rapid bead-based assay for screening of SARS-CoV-2 neutralizing antibodies
Authors: Lupitha Santhik Subhasingh , Darvin Pramod , Chandrasekharan Aneesh , Varadarajan Shankara Narayanan , Divakaran Soumya Jaya , Easwaran Sreekumar , Nelson-Sathi Shijulal , Umasankar Perunthottathu K , Jones Sara , Joseph Iype , Pillai Madhavan Radhakrishna , Santhoshkumar Thankayyan Retnabai
Published: March 2022

Quantitative determination of neutralizing antibodies against Severe Acute Respiratory Syndrome Corona Virus-2 (SARS-CoV-2) is paramount in immunodiagnostics, vaccine efficacy testing, and immune response profiling among the vaccinated population. Cost-effective, rapid, easy-to-perform assays are essential to support the vaccine development process and immunosurveillance studies. We describe a bead-based screening assay for S1-neutralization using recombinant fluorescent proteins of hACE2 and SARS-CoV2-S1, immobilized on solid beads employing nanobodies/metal-affinity tags. Nanobody-mediated capture of SARS-CoV-2-Spike (S1) on agarose beads served as the trap for soluble recombinant ACE2-GFPSpark, inhibited by neutralizing antibody. The first approach demonstrates single-color fluorescent imaging of ACE2-GFPSpark binding to His-tagged S1-Receptor Binding Domain (RBD-His) immobilized beads. The second approach is dual-color imaging of soluble ACE2-GFPSpark to S1-Orange Fluorescent Protein (S1-OFPSpark) beads. Both methods showed a good correlation with the gold standard pseudovirion assay and can be adapted to any fluorescent platforms for screening.
Group Belief for a Reason
Authors: Brown Jessica
Published: March 2022

In this paper I investigate what it is for a group to believe something for a reason. I defend a non-summative account on which a group can believe that p for a reason even though none of its members believe that p for that reason. By contrast, a summative account would hold that the reason for which a group believes that p is a function of the reason(s) for which its members believe that p. I argue that the proposed non-summative account deals better with cases in which members of a group believe that p for different reasons. I also defend it against a range of objections, including that it conflicts with epistemic norms for assertion and action.
Privacy preserving validation for multiomic prediction models
Authors: Ahmed Talal , Carty Mark A , Wenric Stephane , Dry Jonathan R , Salahudeen Ameen A , Khan Aly A , Lefkofsky Eric , Stumpe Martin C , Pelossof Raphael
Published: March 2022

Reproducibility of results obtained using ribonucleic acid (RNA) data across labs remains a major hurdle in cancer research. Often, molecular predictors trained on one dataset cannot be applied to another due to differences in RNA library preparation and quantification, which inhibits the validation of predictors across labs. While current RNA correction algorithms reduce these differences, they require simultaneous access to patient-level data from all datasets, which necessitates the sharing of training data for predictors when sharing predictors. Here, we describe SpinAdapt, an unsupervised RNA correction algorithm that enables the transfer of molecular models without requiring access to patient-level data. It computes data corrections only via aggregate statistics of each dataset, thereby maintaining patient data privacy. Despite an inherent trade-off between privacy and performance, SpinAdapt outperforms current correction methods, like Seurat and ComBat, on publicly available cancer studies, including TCGA and ICGC. Furthermore, SpinAdapt can correct new samples, thereby enabling unbiased evaluation on validation cohorts. We expect this novel correction paradigm to enhance research reproducibility and to preserve patient privacy.
Identification of patients with branch-duct intraductal papillary mucinous neoplasm and very low risk of cancer: multicentre study
Authors: Tamburrino Domenico , de Pretis Nicolò , Pérez-Cuadrado-Robles Enrique , Uribarri-Gonzalez Laura , Ateeb Zeeshan , Belfiori Giulio , Maisonneuve Patrick , Capurso Gabriele , Vanella Giuseppe , Petrone Maria Chiara , Arcidiacono Paolo Giorgio , Vaalavuo Yrjo , Frulloni Luca , Dominguez-Muñoz J. Enrique , Deprez Pierre H. , Falconi Massimo , del Chiaro Marco , Crippa Stefano , Laukkarinen Johanna
Published: March 2022

Background

Different surveillance strategies for patients with low-risk branch-duct (BD) intraductal papillary neoplasm (IPMN) have been described. The aim of this study was to describe the natural history of low-risk BD-IPMN, and to identify risk factors for the development of worrisome features (WF)/high-risk stigmata (HRS) and of pancreatic malignancies.

Methods

This was a multicentre retrospective study of patients with BD-IPMN who were under active surveillance between January 2006 and December 2015. Patients were eligible if they had a low-risk lesion and had a minimum follow-up of 24 months. Outcomes were development of WF/HRS or cytologically/histologically confirmed malignant IPMN.

Results

Of 837 patients included, 168 (20 per cent) developed WF/HRS. At the end of the observation time, 132 patients (79 per cent) with WF/HRS were still under surveillance without progression to pancreatic cancer. Factors associated with the development of WF or HRS in multivariable analysis included localized nodules (versus diffuse: hazard ratio (HR) 0.43, 95 per cent c.i. 0.26 to 0.68), cyst size 15–19 mm (versus less than 15 mm: HR 1.88, 1.23 to 2.87) or at least 20 mm (versus less than 15 mm: HR 3.25, 2.30 to 4.60), main pancreatic duct size over 3 mm (versus 3 mm or less: HR 2.17, 1.41 to 3.34), and symptoms at diagnosis (versus no symptoms: HR 2.29, 1.52 to 3.45). Surveillance in an endoscopy-oriented centre was also associated with increased detection of WF or HRS (versus radiology-oriented: HR 2.46, 1.74 to 3.47).

Conclusion

Conservative management of patients with low-risk BD-IPMN is safe and feasible.