bluuebunny/crossref_metadata_2025 huggingface dataset:
Modular and practical diamination of allenes
Authors: Dai Jian-Jun , Yin Xianglin , Li Lei , Rivera Mario E. , Wang Ye-Cheng , Dai Mingji
Published: March 2023

Vicinal diamines are privileged scaffolds in medicine, agrochemicals, catalysis, and other fields. While significant advancements have been made in diamination of olefins, diamination of allenes is only sporadically explored. Furthermore, direct incorporation of acyclic and cyclic alkyl amines onto unsaturated π systems is highly desirable and important, but problematic for many previously reported amination reactions including the diamination of olefins. Herein, we report a modular and practical diamination of allenes, which offers efficient syntheses of β,γ-diamino carboxylates and sulfones. This reaction features broad substrate scope, excellent functional group tolerability, and scalability. Experimental and computational studies support an ionic reaction pathway initiated with a nucleophilic addition of the in situ formed iodoamine to the electron deficient allene substrate. An iodoamine activation mode via a halogen bond with a chloride ion was revealed to substantially increase the nucleophilicity of the iodoamine and lower the activation energy barrier for the nucleophilic addition step.
Hydrovoltaic effect-enhanced photocatalysis by polyacrylic acid/cobaltous oxide–nitrogen doped carbon system for efficient photocatalytic water splitting
Authors: Xin Xu , Zhang Youzi , Wang Ruiling , Wang Yijin , Guo Peng , Li Xuanhua
Published: March 2023

Severe carrier recombination and the slow kinetics of water splitting for photocatalysts hamper their efficient application. Herein, we propose a hydrovoltaic effect-enhanced photocatalytic system in which polyacrylic acid (PAA) and cobaltous oxide (CoO)–nitrogen doped carbon (NC) achieve an enhanced hydrovoltaic effect and CoO–NC acts as a photocatalyst to generate H2 and H2O2 products simultaneously. In this system, called PAA/CoO–NC, the Schottky barrier height between CoO and the NC interface decreases by 33% due to the hydrovoltaic effect. Moreover, the hydrovoltaic effect induced by H+ carrier diffusion in the system generates a strong interaction between H+ ions and the reaction centers of PAA/CoO–NC, improving the kinetics of water splitting in electron transport and species reaction. PAA/CoO–NC exhibits excellent photocatalytic performance, with H2 and H2O2 production rates of 48.4 and 20.4 mmol g−1 h−1, respectively, paving a new way for efficient photocatalyst system construction.
Virome-wide detection of natural infection events and the associated antibody dynamics using longitudinal highly-multiplexed serology
Authors: Kelley Erin J. , Henson Sierra N. , Rahee Fatima , Boyle Annalee S. , Engelbrektson Anna L. , Nelson Georgia A. , Mead Heather L. , Anderson N. Leigh , Razavi Morteza , Yip Richard , Ladner Jason T. , Scriba Thomas J. , Altin John A.
Published: March 2023

Current methods for detecting infections either require a sample collected from an actively infected site, are limited in the number of agents they can query, and/or yield no information on the immune response. Here we present an approach that uses temporally coordinated changes in highly-multiplexed antibody measurements from longitudinal blood samples to monitor infection events at sub-species resolution across the human virome. In a longitudinally-sampled cohort of South African adolescents representing >100 person-years, we identify >650 events across 48 virus species and observe strong epidemic effects, including high-incidence waves ofAichivirus Aand the D68 subtype ofEnterovirus Dearlier than their widespread circulation was appreciated. In separate cohorts of adults who were sampled at higher frequency using self-collected dried blood spots, we show that such events temporally correlate with symptoms and transient inflammatory biomarker elevations, and observe the responding antibodies to persist for periods ranging from ≤1 week to >5 years. Our approach generates a rich view of viral/host dynamics, supporting novel studies in immunology and epidemiology.
Widespread detection of chlorine oxyacids in the Arctic atmosphere
Authors: Tham Yee Jun , Sarnela Nina , Iyer Siddharth , Li Qinyi , Angot Hélène , Quéléver Lauriane L. J. , Beck Ivo , Laurila Tiia , Beck Lisa J. , Boyer Matthew , Carmona-García Javier , Borrego-Sánchez Ana , Roca-Sanjuán Daniel , Peräkylä Otso , Thakur Roseline C. , He Xu-Cheng , Zha Qiaozhi , Howard Dean , Blomquist Byron , Archer Stephen D. , Bariteau Ludovic , Posman Kevin , Hueber Jacques , Helmig Detlev , Jacobi Hans-Werner , Junninen Heikki , Kulmala Markku , Mahajan Anoop S. , Massling Andreas , Skov Henrik , Sipilä Mikko , Francisco Joseph S. , Schmale Julia , Jokinen Tuija , Saiz-Lopez Alfonso
Published: March 2023

Chlorine radicals are strong atmospheric oxidants known to play an important role in the depletion of surface ozone and the degradation of methane in the Arctic troposphere. Initial oxidation processes of chlorine produce chlorine oxides, and it has been speculated that the final oxidation steps lead to the formation of chloric (HClO3) and perchloric (HClO4) acids, although these two species have not been detected in the atmosphere. Here, we present atmospheric observations of gas-phase HClO3 and HClO4. Significant levels of HClO3 were observed during springtime at Greenland (Villum Research Station), Ny-Ålesund research station and over the central Arctic Ocean, on-board research vessel Polarstern during the Multidisciplinary drifting Observatory for the Study of the Arctic Climate (MOSAiC) campaign, with estimated concentrations up to 7 × 106 molecule cm−3. The increase in HClO3, concomitantly with that in HClO4, was linked to the increase in bromine levels. These observations indicated that bromine chemistry enhances the formation of OClO, which is subsequently oxidized into HClO3 and HClO4 by hydroxyl radicals. HClO3 and HClO4 are not photoactive and therefore their loss through heterogeneous uptake on aerosol and snow surfaces can function as a previously missing atmospheric sink for reactive chlorine, thereby reducing the chlorine-driven oxidation capacity in the Arctic boundary layer. Our study reveals additional chlorine species in the atmosphere, providing further insights into atmospheric chlorine cycling in the polar environment.
Well-defined double hysteresis loop in NaNbO3 antiferroelectrics
Authors: Luo Nengneng , Ma Li , Luo Gengguang , Xu Chao , Rao Lixiang , Chen Zhengu , Cen Zhenyong , Feng Qin , Chen Xiyong , Toyohisa Fujita , Zhu Ye , Hong Jiawang , Li Jing-Feng , Zhang Shujun
Published: March 2023

Antiferroelectrics (AFEs) are promising candidates in energy-storage capacitors, electrocaloric solid-cooling, and displacement transducers. As an actively studied lead-free antiferroelectric (AFE) material, NaNbO3 has long suffered from its ferroelectric (FE)-like polarization-electric field (P-E) hysteresis loops with high remnant polarization and large hysteresis. Guided by theoretical calculations, a new strategy of reducing the oxygen octahedral tilting angle is proposed to stabilize the AFE P phase (Space group Pbma) of NaNbO3. To validate this, we judiciously introduced CaHfO3 with a low Goldschmidt tolerance factor and AgNbO3 with a low electronegativity difference into NaNbO3, the decreased cation displacements and [BO6] octahedral tilting angles were confirmed by Synchrotron X-ray powder diffraction and aberration-corrected scanning transmission electron microscopy. Of particular importance is that the 0.75NaNbO3−0.20AgNbO3−0.05CaHfO3 ceramic exhibits highly reversible phase transition between the AFE and FE states, showing well-defined double P-E loops and sprout-shaped strain-electric field curves with reduced hysteresis, low remnant polarization, high AFE-FE phase transition field, and zero negative strain. Our work provides a new strategy for designing NaNbO3-based AFE material with well-defined double P-E loops, which can also be extended to discover a variety of new lead-free AFEs.
Anomalous quantized plateaus in two-dimensional electron gas with gate confinement
Authors: Yan Jiaojie , Wu Yijia , Yuan Shuai , Liu Xiao , Pfeiffer L. N. , West K. W. , Liu Yang , Fu Hailong , Xie X. C. , Lin Xi
Published: March 2023

Quantum information can be coded by the topologically protected edges of fractional quantum Hall (FQH) states. Investigation on FQH edges in the hope of searching and utilizing non-Abelian statistics has been a focused challenge for years. Manipulating the edges, e.g. to bring edges close to each other or to separate edges spatially, is a common and essential step for such studies. The FQH edge structures in a confined region are typically presupposed to be the same as that in the open region in analysis of experimental results, but whether they remain unchanged with extra confinement is obscure. In this work, we present a series of unexpected plateaus in a confined single-layer two-dimensional electron gas (2DEG), which are quantized at anomalous fractions such as 9/4, 17/11, 16/13 and the reported 3/2. We explain all the plateaus by assuming surprisingly larger filling factors in the confined region. Our findings enrich the understanding of edge states in the confined region and in the applications of gate manipulation, which is crucial for the experiments with quantum point contact and interferometer.
Strong variation of spin-orbit torques with relative spin relaxation rates in ferrimagnets
Authors: Zhu Lijun , Ralph Daniel C.
Published: March 2023

Spin-orbit torques (SOTs) have been widely understood as an interfacial transfer of spin that is independent of the bulk properties of the magnetic layer. Here, we report that SOTs acting on ferrimagnetic FexTb1-x layers decrease and vanish upon approaching the magnetic compensation point because the rate of spin transfer to the magnetization becomes much slower than the rate of spin relaxation into the crystal lattice due to spin-orbit scattering. These results indicate that the relative rates of competing spin relaxation processes within magnetic layers play a critical role in determining the strength of SOTs, which provides a unified understanding for the diverse and even seemingly puzzling SOT phenomena in ferromagnetic and compensated systems. Our work indicates that spin-orbit scattering within the magnet should be minimized for efficient SOT devices. We also find that the interfacial spin-mixing conductance of interfaces of ferrimagnetic alloys (such as FexTb1-x) is as large as that of 3d ferromagnets and insensitive to the degree of magnetic compensation.
Prime editing with genuine Cas9 nickases minimizes unwanted indels
Authors: Lee Jaesuk , Lim Kayeong , Kim Annie , Mok Young Geun , Chung Eugene , Cho Sung-Ik , Lee Ji Min , Kim Jin-Soo
Published: March 2023

Unlike CRISPR-Cas9 nucleases, which yield DNA double-strand breaks (DSBs), Cas9 nickases (nCas9s), which are created by replacing key catalytic amino-acid residues in one of the two nuclease domains of S. pyogenesis Cas9 (SpCas9), produce nicks or single-strand breaks. Two SpCas9 variants, namely, nCas9 (D10A) and nCas9 (H840A), which cleave target (guide RNA-pairing) and non-target DNA strands, respectively, are widely used for various purposes, including paired nicking, homology-directed repair, base editing, and prime editing. In an effort to define the off-target nicks caused by these nickases, we perform Digenome-seq, a method based on whole genome sequencing of genomic DNA treated with a nuclease or nickase of interest, and find that nCas9 (H840A) but not nCas9 (D10A) can cleave both strands, producing unwanted DSBs, albeit less efficiently than wild-type Cas9. To inactivate the HNH nuclease domain further, we incorporate additional mutations into nCas9 (H840A). Double-mutant nCas9 (H840A + N863A) does not exhibit the DSB-inducing behavior in vitro and, either alone or in fusion with the M-MLV reverse transcriptase (prime editor, PE2 or PE3), induces a lower frequency of unwanted indels, compared to nCas9 (H840A), caused by error-prone repair of DSBs. When incorporated into prime editor and used with engineered pegRNAs (ePE3), we find that the nCas9 variant (H840A + N854A) dramatically increases the frequency of correct edits, but not unwanted indels, yielding the highest purity of editing outcomes compared to nCas9 (H840A).
Widespread natural methane and oil leakage from sub-marine Arctic reservoirs
Authors: Serov Pavel , Mattingsdal Rune , Winsborrow Monica , Patton Henry , Andreassen Karin
Published: March 2023

Parceling the anthropogenic and natural (geological) sources of fossil methane in the atmosphere remains problematic due to a lack of distinctive chemical markers for their discrimination. In this light, understanding the distribution and contribution of potential geological methane sources is important. Here we present empirical observations of hitherto undocumented, widespread and extensive methane and oil release from geological reservoirs to the Arctic Ocean. Methane fluxes from >7000 seeps significantly deplete in seawater, but nevertheless reach the sea surface and may transfer to the air. Oil slick emission spots and gas ebullition are persistent across multi-year observations and correlate to formerly glaciated geological structures, which have experienced km-scale glacial erosion that has left hydrocarbon reservoirs partially uncapped since the last deglaciation ~15,000 years ago. Such persistent, geologically controlled, natural hydrocarbon release may be characteristic of formerly glaciated hydrocarbon-bearing basins which are common across polar continental shelves, and could represent an underestimated source of natural fossil methane within the global carbon cycle.
Long-range skin Josephson supercurrent across a van der Waals ferromagnet
Authors: Hu Guojing , Wang Changlong , Wang Shasha , Zhang Ying , Feng Yan , Wang Zhi , Niu Qian , Zhang Zhenyu , Xiang Bin
Published: March 2023

The emerging field of superconducting spintronics promises new quantum device architectures without energy dissipation. When entering a ferromagnet, a supercurrent commonly behaves as a spin singlet that decays rapidly; in contrast, a spin-triplet supercurrent can transport over much longer distances, and is therefore more desirable, but so far has been observed much less frequently. Here, by using the van der Waals ferromagnet Fe3GeTe2 (F) and spin-singlet superconductor NbSe2 (S), we construct lateral Josephson junctions of S/F/S with accurate interface control to realize long-range skin supercurrent. The observed supercurrent across the ferromagnet can extend over 300 nm, and exhibits distinct quantum interference patterns in an external magnetic field. Strikingly, the supercurrent displays pronounced skin characteristics, with its density peaked at the surfaces or edges of the ferromagnet. Our central findings shed new light on the convergence of superconductivity and spintronics based on two-dimensional materials.
Unravelling the clinicopathological and functional significance of replication protein A (RPA) heterotrimeric complex in breast cancers
Authors: Algethami Mashael , Toss Michael S. , Woodcock Corinne L. , Jaipal Chandar , Brownlie Juliette , Shoqafi Ahmed , Alblihy Adel , Mesquita Katia A. , Green Andrew R. , Mongan Nigel P. , Jeyapalan Jennie N. , Rakha Emad A. , Madhusudan Srinivasan
Published: March 2023

Replication Protein A (RPA), a heterotrimeric complex consisting of RPA1, 2, and 3 subunits, is a single-stranded DNA (ssDNA)-binding protein that is critically involved in replication, checkpoint regulation and DNA repair. Here we have evaluated RPA in 776 pure ductal carcinomas in situ (DCIS), 239 DCIS that co-exist with invasive breast cancer (IBC), 50 normal breast tissue and 4221 IBC. Transcriptomic [METABRIC cohort (n = 1980)] and genomic [TCGA cohort (n = 1090)] evaluations were completed. Preclinically, RPA deficient cells were tested for cisplatin sensitivity and Olaparib induced synthetic lethality. Low RPA linked to aggressive DCIS, aggressive IBC, and shorter survival outcomes. At the transcriptomic level, low RPA tumours overexpress pseudogene/lncRNA as well as genes involved in chemical carcinogenesis, and drug metabolism. Low RPA remains linked with poor outcome. RPA deficient cells are sensitive to cisplatin and Olaparib induced synthetic lethality. We conclude that RPA directed precision oncology strategy is feasible in breast cancers.
High performance flexible Sn-Pb mixed perovskite solar cells enabled by a crosslinking additive
Authors: Li Ya , Yan Suhao , Cao Jiupeng , Chen Haoyu , Liu Bingxu , Xie Jiankai , Shu Yuting , Wang Fangfang , Wang Aifei , Dong Jingjin , Qin Tianshi
Published: March 2023

Flexible perovskite solar cells (PSCs) have drawn increasing attention due to their promising applications for wearable electronics and aerospace applications. However, the efficiency and stability of flexible PSCs still lag behind their rigid counterparts. Here, we use N,N-dimethyl acrylamide (DMAA) to in situ synthesize cross-linking polymer for flexible Sn–Pb mixed PSCs. DMAA can gather at grain boundary as a scaffold to regulate the crystallization of perovskite and reduce defects. The rigid and flexible Sn–Pb mixed PSCs showed efficiencies of 16.44% and 15.44%, respectively. In addition, the flexible Sn–Pb mixed PSCs demonstrated excellent bending durability, which retained over 80% of the original efficiency after 5000 bending cycles at a radius of 5 mm.
A dataset of asymptomatic human gait and movements obtained from markers, IMUs, insoles and force plates
Authors: Grouvel Gautier , Carcreff Lena , Moissenet Florent , Armand Stéphane
Published: March 2023

Human motion capture and analysis could be made easier through the use of wearable devices such as inertial sensors and/or pressure insoles. However, many steps are still needed to reach the performance of optoelectronic systems to compute kinematic parameters. The proposed dataset has been established on 10 asymptomatic adults. Participants were asked to walk at different speeds on a 10-meters walkway in a laboratory and to perform different movements such as squats or knee flexion/extension tasks. Three-dimensional trajectories of 69 reflective markers placed according to a conventional full body markerset, acceleration and angular velocity signals of 8 inertial sensors, pressure signals of 2 insoles, 3D ground reaction forces and moments obtained from 3 force plates were simultaneously recorded. Eight calculated virtual markers related to joint centers were also added to the dataset. This dataset contains a total of 337 trials including static and dynamic tasks for each participant. Its purpose is to enable comparisons between various motion capture systems and stimulate the development of new methods for gait analysis.
Age and market capitalization drive large price variations of cryptocurrencies
Authors: Pessa Arthur A. B. , Perc Matjaž , Ribeiro Haroldo V.
Published: March 2023

Cryptocurrencies are considered the latest innovation in finance with considerable impact across social, technological, and economic dimensions. This new class of financial assets has also motivated a myriad of scientific investigations focused on understanding their statistical properties, such as the distribution of price returns. However, research so far has only considered Bitcoin or at most a few cryptocurrencies, whilst ignoring that price returns might depend on cryptocurrency age or be influenced by market capitalization. Here, we therefore present a comprehensive investigation of large price variations for more than seven thousand digital currencies and explore whether price returns change with the coming-of-age and growth of the cryptocurrency market. We find that tail distributions of price returns follow power-law functions over the entire history of the considered cryptocurrency portfolio, with typical exponents implying the absence of characteristic scales for price variations in about half of them. Moreover, these tail distributions are asymmetric as positive returns more often display smaller exponents, indicating that large positive price variations are more likely than negative ones. Our results further reveal that changes in the tail exponents are very often simultaneously related to cryptocurrency age and market capitalization or only to age, with only a minority of cryptoassets being affected just by market capitalization or neither of the two quantities. Lastly, we find that the trends in power-law exponents usually point to mixed directions, and that large price variations are likely to become less frequent only in about 28% of the cryptocurrencies as they age and grow in market capitalization.
Effect of hetero-atom doping on the electrocatalytic properties of graphene quantum dots for oxygen reduction reaction
Authors: Goswami Mrigaraj , Mandal Sneha , Pillai Vijayamohanan K.
Published: March 2023

Oxygen reduction is an important reaction involved in a diverse variety of energy storage devices and also in many chemical and biological processes. However, the high cost of suitable catalysts like platinum, rhodium, and iridium proves to be a major obstacle for its commercialization. Consequently, many new materials have emerged in recent years such as various forms of carbon, carbides, nitrides, core–shell particles, Mxenes, and transition metal complexes as alternatives to platinum and other noble metals for oxygen reduction reaction (ORR). Among these, Graphene Quantum Dots (GQDs) as metal-free alternatives have captured universal attention, since electrocatalytic properties can be tuned not only by size and functionalization but by heteroatom doping also. We discuss electrocatalytic properties of GQDs (approximate size 3–5 nm) with specific dopants such as N and S focusing on their synergistic effects of co-doping, prepared by solvothermal routes. Cyclic Voltammetry shows benefits of doping as lowering of the onset potentials while steady-state Galvanostatic Tafel polarization measurements show a clear difference in the apparent Tafel slope, along with enhanced exchange current densities, suggesting higher rate constants.
An evaluation framework for operational interventions on urban mass public transport during a pandemic
Authors: Singh Ramandeep , Hörcher Daniel , Graham Daniel J.
Published: March 2023

Decision making in a rapidly changing context, such as the development and progression of a pandemic, requires a dynamic assessment of multiple variable and competing factors. Seemingly beneficial courses of action can rapidly fail to deliver a positive outcome as the context changes. In this paper, we present a flexible data-driven agent-based simulation framework that considers multiple outcome criteria to increase opportunities for safe mobility and economic interactions on urban transit networks while reducing the potential for Covid-19 contagion in a dynamic setting. Using a case study of the Victoria line on the London Underground, we model a number of operational interventions with varied demand levels and social distancing constraints including: alterations to train headways, dwell times, signalling schemes, and train paths. Our model demonstrates that substantial performance gains ranging from 12.3–195.7% can be achieved in metro service provision when comparing the best performing operational scheme and headway with those realised on the Victoria line during the pandemic.
Phylogenetic and functional characterization of water bears (Tardigrada) tubulins
Authors: Novotná Floriančičová Kamila , Baltzis Athanasios , Smejkal Jiří , Czerneková Michaela , Kaczmarek Łukasz , Malý Jan , Notredame Cedric , Vinopal Stanislav
Published: March 2023

Tardigrades are microscopic ecdysozoans that can withstand extreme environmental conditions. Several tardigrade species undergo reversible morphological transformations and enter into cryptobiosis, which helps them to survive periods of unfavorable environmental conditions. However, the underlying molecular mechanisms of cryptobiosis are mostly unknown. Tubulins are evolutionarily conserved components of the microtubule cytoskeleton that are crucial in many cellular processes. We hypothesize that microtubules are necessary for the morphological changes associated with successful cryptobiosis. The molecular composition of the microtubule cytoskeleton in tardigrades is unknown. Therefore, we analyzed and characterized tardigrade tubulins and identified 79 tardigrade tubulin sequences in eight taxa. We found three α-, seven β-, one γ-, and one ε-tubulin isoform. To verify in silico identified tardigrade tubulins, we also isolated and sequenced nine out of ten predictedHypsibius exemplaristubulins. All tardigrade tubulins were localized as expected when overexpressed in mammalian cultured cells: to the microtubules or to the centrosomes. The presence of a functional ε-tubulin, clearly localized to centrioles, is attractive from a phylogenetic point of view. Although the phylogenetically close Nematoda lost their δ- and ε-tubulins, some groups of Arthropoda still possess them. Thus, our data support the current placement of tardigrades into the Panarthropoda clade.
Process development for an effective COVID-19 vaccine candidate harboring recombinant SARS-CoV-2 delta plus receptor binding domain produced by Pichia pastoris
Authors: Kalyoncu Sibel , Yilmaz Semiramis , Kuyucu Ayca Zeybek , Sayili Dogu , Mert Olcay , Soyturk Hakan , Gullu Seyda , Akinturk Huseyin , Citak Erhan , Arslan Merve , Taskinarda Melda Guray , Tarman Ibrahim Oguzhan , Altun Gizem Yilmazer , Ozer Ceren , Orkut Ridvan , Demirtas Aysegul , Tilmensagir Idil , Keles Umur , Ulker Ceren , Aralan Gizem , Mercan Yavuz , Ozkan Muge , Caglar Hasan Onur , Arik Gizem , Ucar Mehmet Can , Yildirim Muzaffer , Yildirim Tugce Canavar , Karadag Dilara , Bal Erhan , Erdogan Aybike , Senturk Serif , Uzar Serdar , Enul Hakan , Adiay Cumhur , Sarac Fahriye , Ekiz Arzu Tas , Abaci Irem , Aksoy Ozge , Polat Hivda Ulbegi , Tekin Saban , Dimitrov Stefan , Ozkul Aykut , Wingender Gerhard , Gursel Ihsan , Ozturk Mehmet , Inan Mehmet
Published: March 2023

Recombinant protein-based SARS-CoV-2 vaccines are needed to fill the vaccine equity gap. Because protein-subunit based vaccines are easier and cheaper to produce and do not require special storage/transportation conditions, they are suitable for low-/middle-income countries. Here, we report our vaccine development studies with the receptor binding domain of the SARS-CoV-2 Delta Plus strain (RBD-DP) which caused increased hospitalizations compared to other variants. First, we expressed RBD-DP in thePichia pastorisyeast system and upscaled it to a 5-L fermenter for production. After three-step purification, we obtained RBD-DP with > 95% purity from a protein yield of > 1 g/L of supernatant. Several biophysical and biochemical characterizations were performed to confirm its identity, stability, and functionality. Then, it was formulated in different contents with Alum and CpG for mice immunization. After three doses of immunization, IgG titers from sera reached to > 106and most importantly it showed high T-cell responses which are required for an effective vaccine to prevent severe COVID-19 disease. A live neutralization test was performed with both the Wuhan strain (B.1.1.7) and Delta strain (B.1.617.2) and it showed high neutralization antibody content for both strains. A challenge study with SARS-CoV-2 infected K18-hACE2 transgenic mice showed good immunoprotective activity with no viruses in the lungs and no lung inflammation for all immunized mice.
Hybrid high-concentration photovoltaic system designed for different weather conditions
Authors: Sun Chi , Wu Chi-Shou , Lin Yong-Sheng , Kao Tsung Sheng , Fang Shuo-Ting , Chiu Yao-Hsuan , Sun Ching-Cherng
Published: March 2023

In this study, we propose a novel high-concentration photovoltaic (HCPV) cell by considering both the light leakage characteristics of the Fresnel-lens-based solar cell modules and the performance issues arising from cloud shading in practical use. We use our self-constructed systems to conduct field measurements for up to half a year under various environmental conditions. According to the acquired results, it was surprising to know that in the area other than the focusing area, the so-called light leakage region, there always bears illuminance of about 20,000–40,000 lx whether it is a sunny day or a cloudy day with different cloud conditions. Such an interesting result is caused by the light scattering of the clouds and the inherent leakage characteristic of a Fresnel lens. To prove this important finding, we simulated the illuminance of the Fresnel lens structure used in the measurement with apertures of different sizes to determine the detected area. In the laboratory, the diffuse plates were used to mimic the situation of varying cloud layer thicknesses. The trend of calculated and measured results fitted well with the field measurements. Also, the experimental and simulation results show that the round angle and draft facet of the Fresnel lens were responsible for light leakage. This finding prompted us to propose a hybrid high-concentration solar module in which more cost-effective polycrystalline silicon solar cells are placed around the high-efficiency wafer of HCPV to capture the dissipated light leakage and convert it into usable electricity.
Label-free macrophage phenotype classification using machine learning methods
Authors: Hourani Tetiana , Perez-Gonzalez Alexis , Khoshmanesh Khashayar , Luwor Rodney , Achuthan Adrian A. , Baratchi Sara , O’Brien-Simpson Neil M. , Al-Hourani Akram
Published: March 2023

Macrophages are heterogeneous innate immune cells that are functionally shaped by their surrounding microenvironment. Diverse macrophage populations have multifaceted differences related to their morphology, metabolism, expressed markers, and functions, where the identification of the different phenotypes is of an utmost importance in modelling immune response. While expressed markers are the most used signature to classify phenotypes, multiple reports indicate that macrophage morphology and autofluorescence are also valuable clues that can be used in the identification process. In this work, we investigated macrophage autofluorescence as a distinct feature for classifying six different macrophage phenotypes, namely: M0, M1, M2a, M2b, M2c, and M2d. The identification was based on extracted signals from multi-channel/multi-wavelength flow cytometer. To achieve the identification, we constructed a dataset containing 152,438 cell events each having a response vector of 45 optical signals fingerprint. Based on this dataset, we applied different supervised machine learning methods to detect phenotype specific fingerprint from the response vector, where the fully connected neural network architecture provided the highest classification accuracy of 75.8% for the six phenotypes compared simultaneously. Furthermore, by restricting the number of phenotypes in the experiment, the proposed framework produces higher classification accuracies, averaging 92.0%, 91.9%, 84.2%, and 80.4% for a pool of two, three, four, five phenotypes, respectively. These results indicate the potential of the intrinsic autofluorescence for classifying macrophage phenotypes, with the proposed method being quick, simple, and cost-effective way to accelerate the discovery of macrophage phenotypical diversity.
Diagnostic ability of macular microvasculature with swept-source OCT angiography for highly myopic glaucoma using deep learning
Authors: Lee Yun Jeong , Sun Sukkyu , Kim Young Kook , Jeoung Jin Wook , Park Ki Ho
Published: March 2023

Macular OCT angiography (OCTA) measurements have been reported to be useful for glaucoma diagnostics. However, research on highly myopic glaucoma is lacking, and the diagnostic value of macular OCTA measurements versus OCT parameters remains inconclusive. We aimed to evaluate the diagnostic ability of the macular microvasculature assessed with OCTA for highly myopic glaucoma and to compare it with that of macular thickness parameters, using deep learning (DL). A DL model was trained, validated and tested using 260 pairs of macular OCTA and OCT images from 260 eyes (203 eyes with highly myopic glaucoma, 57 eyes with healthy high myopia). The DL model achieved an AUC of 0.946 with the OCTA superficial capillary plexus (SCP) images, which was comparable to that with the OCT GCL+ (ganglion cell layer + inner plexiform layer; AUC, 0.982; P = 0.268) or OCT GCL++ (retinal nerve fiber layer + ganglion cell layer + inner plexiform layer) images (AUC, 0.997; P = 0.101), and significantly superior to that with the OCTA deep capillary plexus images (AUC, 0.779; P = 0.028). The DL model with macular OCTA SCP images demonstrated excellent and comparable diagnostic ability to that with macular OCT images in highly myopic glaucoma, which suggests macular OCTA microvasculature could serve as a potential biomarker for glaucoma diagnosis in high myopia.
A data-driven investigation of human action representations
Authors: Dima Diana C. , Hebart Martin N. , Isik Leyla
Published: March 2023

Understanding actions performed by others requires us to integrate different types of information about people, scenes, objects, and their interactions. What organizing dimensions does the mind use to make sense of this complex action space? To address this question, we collected intuitive similarity judgments across two large-scale sets of naturalistic videos depicting everyday actions. We used cross-validated sparse non-negative matrix factorization to identify the structure underlying action similarity judgments. A low-dimensional representation, consisting of nine to ten dimensions, was sufficient to accurately reconstruct human similarity judgments. The dimensions were robust to stimulus set perturbations and reproducible in a separate odd-one-out experiment. Human labels mapped these dimensions onto semantic axes relating to food, work, and home life; social axes relating to people and emotions; and one visual axis related to scene setting. While highly interpretable, these dimensions did not share a clear one-to-one correspondence with prior hypotheses of action-relevant dimensions. Together, our results reveal a low-dimensional set of robust and interpretable dimensions that organize intuitive action similarity judgments and highlight the importance of data-driven investigations of behavioral representations.
The role of emotional awareness in evaluative judgment: evidence from alexithymia
Authors: Díaz Rodrigo , Prinz Jesse
Published: March 2023

Evaluative judgments imply positive or negative regard. But there are different ways in which something can be positive or negative. How do we tell them apart? According to Evaluative Sentimentalism, different evaluations (e.g., dangerousness vs. offensiveness) are grounded on different emotions (e.g., fear vs. anger). If this is the case, evaluation differentiation requires emotional awareness. Here, we test this hypothesis by looking at alexithymia, a deficit in emotional awareness consisting of problems identifying, describing, and thinking about emotions. The results of Study 1 suggest that high alexithymia is not only related to problems distinguishing emotions, but also to problems distinguishing evaluations. Study 2 replicated this latter effect after controlling for individual differences in attentional impulsiveness and reflective reasoning, and found that reasoning makes an independent contribution to evaluation differentiation. These results suggest that emotional sensibilities play an irreducible role in evaluative judgment while affording a role for reasoning.
Methods for controlled preparation and dosing of microplastic fragments in bioassays
Authors: Boettcher Hayden , Kukulka Tobias , Cohen Jonathan H.
Published: March 2023

Microplastic fragments (microfragments) are among the most abundant microplastic shapes found in marine ecosystems throughout the world. Due to their limited commercial availability, microfragments are rarely used in laboratory experiments. Here a novel method of microfragment production has been developed and validated. Polyethylene and polypropylene plastic stock (2 and 3 mm thick respectively) was ground using a cryomill, washed, and rinsed through a stack of sieves. Microfragments were prepared at three distinct size classes (53–150, 150–300, 300–1000 μm) and were confirmed to be accurate and consistent in size. Employing a novel ice cap dosing technique, microfragments were accurately dosed into experimental vials while excluding headspace, facilitating particle suspension without the aid of chemical surfactants. A proof of principle ingestion experiment confirmed the bioavailability of 53–150 μm polyethylene microfragments to brine shrimp Artemia sp. Together, these methods provide a controlled way to produce and dose microplastic fragments for experimental and analytical research.
Weakly supervised label propagation algorithm classifies lung cancer imaging subtypes
Authors: Ren Xueting , Jia Liye , Zhao Zijuan , Qiang Yan , Wu Wei , Han Peng , Zhao Juanjuan , Sun Jingyu
Published: March 2023

Aiming at the problems of long time, high cost, invasive sampling damage, and easy emergence of drug resistance in lung cancer gene detection, a reliable and non-invasive prognostic method is proposed. Under the guidance of weakly supervised learning, deep metric learning and graph clustering methods are used to learn higher-level abstract features in CT imaging features. The unlabeled data is dynamically updated through the k-nearest label update strategy, and the unlabeled data is transformed into weak label data and continue to update the process of strong label data to optimize the clustering results and establish a classification model for predicting new subtypes of lung cancer imaging. Five imaging subtypes are confirmed on the lung cancer dataset containing CT, clinical and genetic information downloaded from the TCIA lung cancer database. The successful establishment of the new model has a significant accuracy rate for subtype classification (ACC = 0.9793), and the use of CT sequence images, gene expression, DNA methylation and gene mutation data from the cooperative hospital in Shanxi Province proves the biomedical value of this method. The proposed method also can comprehensively evaluate intratumoral heterogeneity based on the correlation between the final lung CT imaging features and specific molecular subtypes.
Unusual nonlinear switching in branched carbon nanotube nanocomposites
Authors: Lacarbonara Walter , Guruva Sawan Kumar , Carboni Biagio , Krause Beate , Janke Andreas , Formica Giovanni , Lanzara Giulia
Published: March 2023

In this experimental study, we investigate the nonlinear dynamic response of nanocomposite beams composed of polybutylene terephthalate (PBT) and branched carbon nanotubes (bCNTs). By varying the weight fraction of bCNTs, we obtain frequency response curves for cantilever specimens under harmonic base excitations, measuring the tip displacement via 3D scanning laser vibrometry. Our findings reveal a surprising nonlinear softening trend in the steady-state response of the cantilevers, which gets switched into hardening for higher bCNT weight fractions and increasing oscillation amplitudes. The interaction of bCNTs with the thermoplastic hosting matrix results in stick-slip hysteresis, causing a softening nonlinearity that counteracts the geometric hardening associated with the nonlinear curvature of the first mode of the cantilever. However, when the weight fraction of bCNTs is greater than 1%, the bridging of the branched CNTs leads to the formation of a strong network that contributes to the hardening response at higher oscillation amplitudes. This mechanical behavior is detected by the trend of the nonlinear harmonic spectra and the equivalent damping ratio estimated using the half-power bandwidth method. To predict the observed unusual experimental behavior, we use a nonlinear mathematical model of the nanocomposite cantilever samples derived from a 3D mesoscale hysteretic model of the PBT/bCNT material. Our results suggest that the presence of bCNTs in a thermoplastic matrix is the main driver of the highly tunable nonlinear stiffness and damping capacity of the material. The reported experimental and modeling results provide valuable insights into the nonlinear dynamic behavior of PBT/bCNT nanocomposites and have potential applications in the design of advanced materials with tailored mechanical properties.
Effects of histone methylation modification on low temperature seed germination and growth of maize
Authors: Qi Xin , Wan Chang , Zhang Xing , Sun Weifeng , Liu Rui , Wang Zhennan , Wang Zhenhui , Ling Fenglou
Published: March 2023

Low temperature is a limiting factor of seed germination and plant growth. Although there is a lot information on the response of maize to low temperatures, there is still poorly description of how histone methylation affects maize germination and growth development at low temperatures. In this study, the germination rate and physiological indexes of wild-type maize inbred lines B73 (WT), SDG102 silencing lines (AS), SDG102 overexpressed lines (OE) at germination stage and seedling stage were measured under low temperature stress (4 ℃), and transcriptome sequencing was applied to analyze the differences of gene expression in panicle leaves among different materials. The results showed that the germination rate of WT and OE maize seeds at 4 ℃ was significantly lower than 25 ℃. The content of MDA, SOD and POD of 4 ℃ seeding leaves higher than contrast. Transcriptome sequencing results showed that there were 409 different expression genes (DEGs) between WT and AS, and the DEGs were mainly up-regulated expression in starch and sucrose metabolism and phenylpropanoid biosynthesis. There were 887 DEGs between WT and OE, which were mainly up-regulated in the pathways of plant hormone signal transduction, porphyrin and chlorophyll metabolism. This result could provide a theoretical basis for analyzing the growth and development of maize from the perspective of histone methylation modification.
Assessing the utility of a sliding-windows deep neural network approach for risk prediction of trauma patients
Authors: Bonde Alexander , Bonde Mikkel , Troelsen Anders , Sillesen Martin
Published: March 2023

The risks of post trauma complications are regulated by the injury, comorbidities, and the clinical trajectories, yet prediction models are often limited to single time-point data. We hypothesize that deep learning prediction models can be used for risk prediction using additive data after trauma using a sliding windows approach. Using the American College of Surgeons Trauma Quality Improvement Program (ACS TQIP) database, we developed three deep neural network models, for sliding-windows risk prediction. Output variables included early- and late mortality and any of 17 complications. As patients moved through the treatment trajectories, performance metrics increased. Models predicted early- and late mortality with ROC AUCs ranging from 0.980 to 0.994 and 0.910 to 0.972, respectively. For the remaining 17 complications, the mean performance ranged from 0.829 to 0.912. In summary, the deep neural networks achieved excellent performance in the sliding windows risk stratification of trauma patients.
Materials swelling revealed through automated semantic segmentation of cavities in electron microscopy images
Authors: Jacobs Ryan , Patki Priyam , Lynch Matthew J. , Chen Steven , Morgan Dane , Field Kevin G.
Published: March 2023

Accurately quantifying swelling of alloys that have undergone irradiation is essential for understanding alloy performance in a nuclear reactor and critical for the safe and reliable operation of reactor facilities. However, typical practice is for radiation-induced defects in electron microscopy images of alloys to be manually quantified by domain-expert researchers. Here, we employ an end-to-end deep learning approach using the Mask Regional Convolutional Neural Network (Mask R-CNN) model to detect and quantify nanoscale cavities in irradiated alloys. We have assembled a database of labeled cavity images which includes 400 images, > 34 k discrete cavities, and numerous alloy compositions and irradiation conditions. We have evaluated both statistical (precision, recall, and F1 scores) and materials property-centric (cavity size, density, and swelling) metrics of model performance, and performed targeted analysis of materials swelling assessments. We find our model gives assessments of material swelling with an average (standard deviation) swelling mean absolute error based on random leave-out cross-validation of 0.30 (0.03) percent swelling. This result demonstrates our approach can accurately provide swelling metrics on a per-image and per-condition basis, which can provide helpful insight into material design (e.g., alloy refinement) and impact of service conditions (e.g., temperature, irradiation dose) on swelling. Finally, we find there are cases of test images with poor statistical metrics, but small errors in swelling, pointing to the need for moving beyond traditional classification-based metrics to evaluate object detection models in the context of materials domain applications.
Hyperpolarized δ-[1- 13C]gluconolactone imaging visualizes response to TERT or GABPB1 targeting therapy for glioblastoma
Authors: Minami Noriaki , Hong Donghyun , Taglang Celine , Batsios Georgios , Gillespie Anne Marie , Viswanath Pavithra , Stevers Nicholas , Barger Carter J. , Costello Joseph F. , Ronen Sabrina M.
Published: March 2023

TERT promoter mutations are a hallmark of glioblastoma (GBM). Accordingly, TERT and GABPB1, a subunit of the upstream mutant TERT promoter transcription factor GABP, are being considered as promising therapeutic targets in GBM. We recently reported that the expression of TERT or GABP1 modulates flux via the pentose phosphate pathway (PPP). Here, we investigated whether 13C magnetic resonance spectroscopy (MRS) of hyperpolarized (HP) δ- [1-13C]gluconolactone can serve to image the reduction in PPP flux following TERT or GABPB1 silencing. We investigated two different human GBM cell lines stably expressing shRNAs targeting TERT or GABPB1, as well as doxycycline-inducible shTERT or shGABPB1cells. MRS studies were performed on live cells and in vivo tumors, and dynamic sets of 13C MR spectra were acquired following injection of HP δ-[1-13C]gluconolactone. HP 6-phosphogluconolactone (6PG), the product of δ-[1-13C]gluconolactone via the PPP, was significantly reduced in TERT or GABPB1-silenced cells or tumors compared to controls in all our models. Furthermore, a positive correlation between TERT expression and 6PG levels was observed. Our data indicate that HP δ-[1-13C]gluconolactone, an imaging tool with translational potential, could serve to monitor TERT expression and its silencing with therapies that target either TERT or GABPB1 in mutant TERT promoter GBM patients.
Stability selection for LASSO with weights based on AUC
Authors: Kwon Yonghan , Han Kyunghwa , Suh Young Joo , Jung Inkyung
Published: March 2023

Stability selection is a variable selection algorithm based on resampling a dataset. Based on stability selection, we propose weighted stability selection to select variables by weighing them using the area under the receiver operating characteristic curve (AUC) from additional modelling. Through an extensive simulation study, we evaluated the performance of the proposed method in terms of the true positive rate (TPR), positive predictive value (PPV), and stability of variable selection. We also assessed the predictive ability of the method using a validation set. The proposed method performed similarly to stability selection in terms of the TPR, PPV, and stability. The AUC of the model fitted on the validation set with the selected variables of the proposed method was consistently higher in specific scenarios. Moreover, when applied to radiomics and speech signal datasets, the proposed method had a higher AUC with fewer variables selected. A major advantage of the proposed method is that it enables researchers to select variables intuitively using relatively simple parameter settings.