bluuebunny/crossref_metadata_2025 huggingface dataset:
Infective endocarditis in childhood: a single-centre experience of 26 years
Authors: Demir Fadli , Varan Celal , Erdem Sevcan , Atmış Anıl , Akbaş Tolga , Subaşı Berivan , Güzel Yasin , Özbarlas Nazan
Published: November 2022

The aim of this study was to present the clinical and microbiological characteristics of patients with infective endocarditis.

A retrospective evaluation was made of patients diagnosed with infective endocarditis between 1995 and 2021. The clinical and laboratory characteristics of the patients were recorded together with conditions constituting a risk for the development of endocarditis, treatment, and surgical outcomes.

Evaluation was made of 68 patients with a mean age of 7.3 years (3 months–17 years), diagnosed with infective endocarditis. An underlying cause of CHD was determined in 47 (69%) patients and rheumatic valve disease in 3 (4.4%). There was no structural heart disease in 18 (26%) patients of whom 13 of them had other risk factors. A causative organism was found in 41 (60%) cases, and the microorganism most often determined was viridans group streptococcus. No difference was determined between the patients diagnosed before and after 2007 in respect of the frequency of viridans streptococcus (p > 0.05). Septic emboli were seen in 18 (26%) patients, of which 17 required surgical treatments. In 5 of 11 (16.6%) patients with mortality, the agent was S. aureus. Of the total 28 (41%) patients were evaluated as hospital-acquired endocarditis. The most frequently determined agents in this group were staphylococcus epidermidis and S. aureus.

Although CHDs continue to be the greatest risk factor for endocarditis, there is an increasing frequency of endocarditis in patients with no structural heart disease. Mortality rates are still high in infective endocarditis, especially in S. aureus endocarditis.
Achieving High-Resolution Hard X-ray Microscopy using Monolithic 2D Multilayer Laue Lenses
Authors: Xu Wei , Xu Weihe , Bouet Nathalie , Zhou Juan , Yan Hanfei , Huang Xiaojing , Lu Ming , Zalalutdinov Maxim , Chu Yong S , Nazaretski Evgeny
Published: November 2022

This article introduces the 2D multilayer Laue lens (MLL) nanofocusing optics recently developed for high-resolution hard X-ray microscopy. The new optics utilized a micro-electro-mechanical-system (MEMS)-based template to accommodate two linear MLL optics in a pre-aligned configuration. Angular misalignment between the two lenses was controlled in tens of millidegrees, and the lateral position error was on a micrometer scale. Using the developed 2D MLLs, an astigmatism-free point focus of approximately 14 nm by 13 nm in horizontal and vertical directions, respectively, at 13.6 keV photon energy was obtained. The success of 2D MLL optics with an approaching 10 nm resolution is a significant step forward for the development of high-resolution hard X-ray microscopy and applications of MLL optics in the hard X-ray community.
A Roadmap for Edge Computing Enabled Automated Multidimensional Transmission Electron Microscopy
Authors: Mukherjee Debangshu , Roccapriore Kevin M , Al-Najjar Anees , Ghosh Ayana , Hinkle Jacob D , Lupini Andrew R , Vasudevan Rama K , Kalinin Sergei V , Ovchinnikova Olga S , Ziatdinov Maxim A , Rao Nageswara S
Published: November 2022

The advent of modern, high-speed electron detectors has made the collection of multidimensional hyperspectral transmission electron microscopy datasets, such as 4D-STEM, a routine. However, many microscopists find such experiments daunting since analysis, collection, long-term storage, and networking of such datasets remain challenging. Some common issues are their large and unwieldy size that often are several gigabytes, non-standardized data analysis routines, and a lack of clarity about the computing and network resources needed to utilize the electron microscope. The existing computing and networking bottlenecks introduce significant penalties in each step of these experiments, and thus, real-time analysis-driven automated experimentation for multidimensional TEM is challenging. One solution is to integrate microscopy with edge computing, where moderately powerful computational hardware performs the preliminary analysis before handing off the heavier computation to high-performance computing (HPC) systems. Here we trace the roots of computation in modern electron microscopy, demonstrate deep learning experiments running on an edge system, and discuss the networking requirements for tying together microscopes, edge computers, and HPC systems.
GENERALIZED PARTIAL MEET AND KERNEL CONTRACTIONS
Authors: GARAPA MARCO , REIS MAURÍCIO D. L.
Published: November 2022

Two of the most well-known belief contraction operators are partial meet contractions (PMCs) and kernel contractions (KCs). In this paper we propose two new classes of contraction operators, namely the class of generalized partial meet contractions (GPMC) and the class of generalized kernel contractions (GKC), which strictly contain the classes of PMCs and of KCs, respectively. We identify some extra conditions that can be added to the definitions of GPMCs and of GKCs, which give rise to some interesting subclasses of those classes of functions, namely the classes of extensional and of uniform GPMCs/GKCs. In the context of contractions on belief sets the classes of partial meet contractions, uniform GPMCs and extensional GPMCs are all identical. Nevertheless, when considered as operations on belief bases, the class of uniform GPMCs coincides with the class of partial meet contractions, but the extensional GPMCs constitute a new kind of belief base contraction functions whose characterizing postulate of irrelevance of syntax is extensionality—the same postulate of irrelevance of syntax which occurs in the classical axiomatic characterization of partial meet contractions for belief sets—rather than the postulate of uniformity—which is the irrelevance of syntax postulate used in the axiomatic characterization for partial meet contractions on belief bases. Analogous results are obtained regarding the classes of extensional and of uniform GKCs. We present the interrelations in the sense of inclusion among all the new classes of operators presented in this paper and several well known classes of PMCs and of KCs.
Future Changes in Global Runoff and Runoff Coefficient From CMIP6 Multi‐Model Simulation Under SSP1‐2.6 and SSP5‐8.5 Scenarios
Authors: Wang Aihui , Miao Yue , Kong Xianghui , Wu Huan
Published: November 2022

This paper assesses the performances of runoff (Ro) and runoff coefficient (α, the ratio of runoff to precipitation) simulations from 23 models during the historical period and then projects their future changes under the two emission scenarios (SSP1‐2.6 and SSP5‐8.5) in the Coupled Model Intercomparison Project. Compared with the UNH/GRDC Ro dataset (0.82 mm day−1), the multi‐model median (MME) Ro of 1995–2014 produces a comparable global mean magnitude (0.80 mm day−1), displays a similar spatial distribution of mean Ro, and also well captures the seasonal cycles at both global and basin scales. The global mean Ro of MME is projected to be increased by 0.01–0.02 mm day−1 (SSP1‐2.6) and 0.02–0.10 mm day−1 (SSP5‐8.5) during the twenty‐first century. Regional hotspots for strong increasing Ro appear across most areas of northern high latitudes, Africa, and southeastern Asia, with high inter‐model consistency. The global mean α is projected to be slightly decreased (−0.17 to −0.63%) except for the long‐term under the SSP5‐8.5 (0.26%). Although signs of changes in Ro vary with the river basins, periods, and scenarios, α in more than half (7 out of 12) river basins are projected to decrease. The uneven distributions of projected Ro changes over global land areas are related to the response of multiple hydroclimatic variables to the global warming. Given regions with inconstancy change signs of the projected precipitation, we speculate that changes in Ro are affected by more complicated hydroclimatic processes that warrant further investigations with physical‐based approaches.
Multiphysics Modeling of Volcanic Unrest at Mt. Ruapehu (New Zealand)
Authors: Arens Fee , Coco Armando , Gottsmann Joachim , Hickey James , Kilgour Geoff
Published: November 2022

Pre‐eruptive signals at the crater lake‐bearing Mt. Ruapehu (New Zealand) are either absent or hard to identify. Here, we report on geophysical anomalies arising from hydrothermal unrest (HTU) and magmatic unrest (MU) using multiphysics numerical modeling. Distinct spatio‐temporal anomalies are revealed when jointly solving for ground displacements and changes in gravitational and electrical potential fields for a set of subsurface disturbances including magma recharge and anomalous hydrothermal flow. Protracted hydrothermal injections induce measurable surface displacements (>0.5 cm) at Ruapehu's summit plateau, while magmatic pressurization (5–20 MPa) results in ground displacements below detection limits. Source density changes of 10 kg/m3 (MU simulations) and CO2 fluxes between 2,150 and 3,600 t/d (HTU simulations) induce resolvable residual gravity changes between +8 and −8 μGal at the plateau. Absolute self‐potential (SP) anomalies are predicted to vary between 0.3 and 2.5 mV for all unrest simulations and exceed the detection limit of conventional electric surveying. Parameter space exploration indicates that variations of up to 400% in the Biot‐Willis coefficient produce negligible differences in surface displacement in MU simulations, but strongly impact surface displacement in HTU simulations. Our interpretation of the findings is that monitoring of changes in SP and gravity should permit insights into MU at Ruapehu, while HTU is best characterized using ground displacements, residual gravity changes and SP anomalies. Our findings are useful to inform multiparameter monitoring strategies at Ruapehu and other volcanoes hosting crater lakes.
Survival of compromised adult sensory neurons involves macrovesicular formation
Authors: Krishnan Anand , Areti Aparna , Komirishetty Prashanth , Chandrasekhar Ambika , Cheng Chu , Zochodne Douglas W.
Published: November 2022

Adult neurons are recognized as post-mitotically arrested cells with limited regenerative potential. Given these restraints, it is perplexing how neurons sustain routine physiological and occasional reparative stress without compromising their density and integrity. We observed that specific insults or physiological alterations drive adult sensory neurons to attempt cell cycle entry. In this context, we demonstrate that at least a small population of sensory neurons modify their cytoskeleton as a survival mechanism in settings of growth arrest and associated stress. Most notably, among their apparent survival modifications is included a unique, and uncharacterized form of macrovesicle shedding and a subsequent neuron size adjustment. Using time-lapse imaging, we demonstrate macrovesicle shedding in some neurons subjected to growth restraint, but not associated with apoptosis. In axotomized neurons in vivo, cell cycle entry was rare to absent and macrovesicles were not observed, but we nonetheless identified changes in mRNA associated with autophagy. In vivo, neighbouring macrophages may have a role in modifying the neuron cytoskeleton after axotomy. Overall, the findings identify previously unrecognized structural adaptations in adult sensory neurons that may provide resilience to diverse insults.
Inference of epigenetic subnetworks by Bayesian regression with the incorporation of prior information
Authors: Jing Anqi , Han Jie
Published: November 2022

Changes in gene expression have been thought to play a crucial role in various types of cancer. With the advance of high-throughput experimental techniques, many genome-wide studies are underway to analyze underlying mechanisms that may drive the changes in gene expression. It has been observed that the change could arise from altered DNA methylation. However, the knowledge about the degree to which epigenetic changes might cause differences in gene expression in cancer is currently lacking. By considering the change of gene expression as the response of altered DNA methylation, we introduce a novel analytical framework to identify epigenetic subnetworks in which the methylation status of a set of highly correlated genes is predictive of a set of gene expression. By detecting highly correlated modules as representatives of the regulatory scenario underling the gene expression and DNA methylation, the dependency between DNA methylation and gene expression is explored by a Bayesian regression model with the incorporation of g-prior followed by a strategy of an optimal predictor subset selection. The subsequent network analysis indicates that the detected epigenetic subnetworks are highly biologically relevant and contain many verified epigenetic causal mechanisms. Moreover, a survival analysis indicates that they might be effective prognostic factors associated with patient survival time.
Modular automated microfluidic cell culture platform reduces glycolytic stress in cerebral cortex organoids
Authors: Seiler Spencer T. , Mantalas Gary L. , Selberg John , Cordero Sergio , Torres-Montoya Sebastian , Baudin Pierre V. , Ly Victoria T. , Amend Finn , Tran Liam , Hoffman Ryan N. , Rolandi Marco , Green Richard E. , Haussler David , Salama Sofie R. , Teodorescu Mircea
Published: November 2022

Organ-on-a-chip systems combine microfluidics, cell biology, and tissue engineering to culture 3D organ-specific in vitro models that recapitulate the biology and physiology of their in vivo counterparts. Here, we have developed a multiplex platform that automates the culture of individual organoids in isolated microenvironments at user-defined media flow rates. Programmable workflows allow the use of multiple reagent reservoirs that may be applied to direct differentiation, study temporal variables, and grow cultures long term. Novel techniques in polydimethylsiloxane (PDMS) chip fabrication are described here that enable features on the upper and lower planes of a single PDMS substrate. RNA sequencing (RNA-seq) analysis of automated cerebral cortex organoid cultures shows benefits in reducing glycolytic and endoplasmic reticulum stress compared to conventional in vitro cell cultures.
Efficacy of plasma activated saline in a co-culture infection control model
Authors: Tsoukou Evanthia , Bourke Paula , Boehm Daniela
Published: November 2022

Plasma activated liquids have demonstrated antimicrobial effects and receive increasing attention due to the potential to strengthen the armoury of novel approaches against antibiotic resistant bacteria. However, the antibacterial activity and cytotoxic effects of these solutions need to be understood and balanced before exposure to humans. In this study, the antibacterial effects of plasma activated saline (PAS) were tested against Gram negative and positive bacteria, and HaCaT keratinocytes were used for cytotoxicity studies. For the first time, a co-culture model between these bacteria and eukaryotic cells under the influence of PAS has been described. Exposure of saline to plasma resulted in high concentrations of nitrate, hydrogen peroxide and a reduction of pH. PAS caused high antibacterial effects in the co-culture model, accompanied by high cytotoxic effects to the monolayer of mammalian cells. We present evidence and provide a deeper understanding for the hypothesis that upon treatment with PAS, chemical species generated in the liquid mediate high antimicrobial effects in the co-culture setup as well as mitochondrial depolarization and glutathione depletion in HaCaT cells and cell lysis due to acidic pH. In conclusion, PAS retains strong antibacterial effects in a co-culture model, which may have unintended negative biological effects on mammalian cells.
Taphonomic and technological analyses of Lower Palaeolithic bone tools from Clacton-on-Sea, UK
Authors: Parfitt Simon A. , Lewis Mark D. , Bello Silvia M.
Published: November 2022

The exceptional survival of Middle Pleistocene wooden spears at Schöningen (Germany) and Clacton-on-Sea (UK) provides tantalizing evidence for the widespread use of organic raw materials by early humans. At Clacton, less well-known organic artefacts include modified bones that were identified by the Abbé Henri Breuil in the 1920s. Some of these pieces were described and figured by Hazzledine Warren in his classic 1951 paper on the flint industry from the Clacton Channel, but they have been either overlooked in subsequent studies or dismissed as the product of natural damage. We provide the first detailed analysis of two Clactonian bone tools found by Warren and a previously unrecognized example recovered in 1934 during excavations directed by Mary Leakey. Microscopic examination of percussion damage suggests the bones were used as knapping hammers to shape or resharpen flake tools. Early Palaeolithic bone tools are exceedingly rare, and the Clacton examples are the earliest known organic knapping hammers associated with a core-and-flake (Mode 1) lithic technology. The use of soft hammers for knapping challenges the consensus that Clactonian flintknapping was undertaken solely with hard hammerstones, thus removing a major technological and behavioural difference used to distinguish the Clactonian from late Acheulean handaxe (Mode 2) industries.
Gender differences in the prevalence and impact factors of adolescent dissociative symptoms during the coronavirus disease 2019 pandemic
Authors: Cheng Qinglin , Zhao Gang , Chen Junfang , Deng Yuanyuan , Xie Li , Wang Le
Published: November 2022

The purpose of this study was to explore the differences between the prevalence and impact factors of adolescent dissociative symptoms (ADSs) by using sex-stratification during the coronavirus disease 2019 (COVID-19) pandemic. A school-based, two-center cross-sectional study was conducted in Hangzhou City, China, between January 1, 2021 and April 30, 2022. The sample included 1,916 adolescents aged 13–18 years that were randomly selected using a multiphase, stratified, cluster sampling technique. A two-stage assessment procedure was used to find out the ADSs. We used a multivariate logistic regression analysis to assess the impact factors of ADSs during the COVID-19 pandemic. The adolescent dissociative scores (t = 4.88, P < 0.001) and positive ADSs rate (Chi-square = 15.76, P < 0.001) in males were higher than in females. Gender-stratified, stepwise multiple logistic regression analysis revealed that the conflict relationship of teacher-student [adjusted odds ratio (AOR) 1.06, 95% confidence interval (CI) 1.01–1.10], family expressiveness (AOR 0.87, 95% CI 0.78–0.98), family conflict (AOR 1.15, 95% CI 1.05–1.27), family organization (AOR 0.88, 95% CI 0.78–0.99), and family cohesion (AOR 0.87, 95% CI 0.77–0.99) were linked to ADSs only in males, while individual psychological states of somatic complaint (AOR 1.04, 95% CI 1.00–1.08) and paranoid ideation (AOR 1.09, 95% CI 1.01–1.19) were associated with female ADSs only. The ADSs seemed to be prevalent in Hangzhou City, studied during the COVID-19 pandemic. Gender differences in the prevalence and impact factors of dissociative symptoms seem to be significant among adolescents. Thus, gender-specific intervention programs against ADSs should be considered as reducing this risk.
Reduction of hexavalent chromium using bacterial isolates and a microbial community enriched from tannery effluent
Authors: Plestenjak Eva , Kraigher Barbara , Leskovec Simona , Mandic Mulec Ines , Marković Stefan , Ščančar Janez , Milačič Radmila
Published: November 2022

We investigated microbial growth in increasing concentrations of hexavalent chromium (Cr(VI)) and its reduction by a microbial community enriched from tannery effluent and by the bacterial strains isolated from the enriched community. The bacterial growth was monitored by measuring the optical cell density (OD650), while the Cr(VI) concentration in the samples was determined using spectrophotometry and liquid chromatography hyphenated to inductively coupled plasma mass spectrometry (HPLC–ICP–MS). At a Cr(VI) concentration of 100 mg/L, the isolates affiliated with Pseudomonas aeruginosa (P. aeruginosa) reached higher optical cell densities, but were in general less effective for Cr(VI) reduction than the isolates affiliated with Mammaliicoccus sciuri (M. sciuri). All three M. sciuri isolates and only one of the seven P. aeruginosa isolates were able to reduce 50% of the Cr(VI) with an initial concentration of 100 mg/L within 24 h (pH 7.1), while the six isolates affiliated with P. aeruginosa were less effective. Compared to the isolated, individual bacterial strains, the enriched microbial community was better adapted to the elevated Cr(VI) concentrations, but needed a longer time (48 h) to reduce the Cr(VI) with the same efficacy as the most efficient individual isolates. The ability of the enriched microbial community and the isolated bacterial strains to reduce the Cr(VI) highlights their potential for use in the rapid bioremediation of wastewaters contaminated with Cr(VI).
Structure-property relationships of photofunctional diiridium(II) complexes with tetracationic charge and an unsupported Ir–Ir bond
Authors: Zheng Fangrui , Yang Yuhong , Wu Siye , Zhao Shunan , Zhu Yifan , Su Huimin , Dai Jun-Feng , Yan Zeyin , Chung Lung Wa , Wong Keith Man-Chung
Published: November 2022

In contrast to the extensively studied dirhodium(II) complexes and iridium(III) complexes, neutral or dicationic dinuclear iridium(II) complexes with an unsupported ligand are underdeveloped. Here, a series of tetracationic dinuclear iridium(II) complexes, featuring the unsupported Ir(II)–Ir(II) single bond with long bond distances (2.8942(4)–2.9731(4) Å), are synthesized and structurally characterized. Interestingly, compared to the previous unsupported neutral or dicationic diiridium(II) complexes, our DFT and high-level DLPNO-CCSD(T) results found the largest binding energy in these tetracationic complexes even with the long Ir(II)–Ir(II) bond. Our study further reveals that London dispersion interactions enhance the stability cooperatively and significantly to overcome the strong electrostatic repulsion between two half dicationic metal fragments. This class of complexes also exhibit photoluminescence in solution and solid states, which, to our knowledge, represents the first example of this unsupported dinuclear iridium(II) system. In addition, their photoreactivity involving the generation of iridium(II) radical monomer from homolytic cleavage was also explored. The experimental results of photophysical and photochemical behaviours were also correlated with computational studies.
Enhanced mitigation in nutrient surplus driven by multilateral crop trade patterns
Authors: Lu Hongwei , Feng Wei , Yan Pengdong , Kang Jiajie , Jiang Chunfang , Yu Qing , Yao Tianci , Xue Yuxuan , Liang Dongzhe , Yan Yiming
Published: November 2022

Multilateral crop trade is likely to drive enhancement or mitigation of nutrient surpluses of the trading countries; however, the driving mechanisms are unclear. Here we explore the effects of multilateral crop trade on nitrogen and phosphorus surpluses based on two optimal multilateral crop trade models, a regional nutrient surplus model and crop trade data. Focusing on China and Central Asia, we find that optimal multilateral crop trades are effective to mitigate both nutrient surplus and footprint. Compared to the base year (2018), a single-objective-based crop trade would drive an obvious transition from nitrogen surplus enhancement (1170.5 kt) to mitigation (−705.8 kt over 2030–2034); the phosphorus surplus enhancement would be transferred from 1741.5 to mitigation of −2934 kt. Driven by the bilevel-objective-based crop trade, great mitigations in both nitrogen and phosphorus surpluses are detected, with the projected levels reaching −571 and −2809 kt, respectively. This implies that strengthening optimal multilateral crop trades across the world would facilitate global nutrient management.
CeO2/Cr2O3 direct Z-scheme heterojunction for photo-thermal synergistic catalytic isopropanol degradation and nitrogen fixation
Authors: Zhou Kun , Sun Hao , Liu Yajing , Wang Qian , Liu Bin , Li Dongke , Zhao Hongming , Tao Ran , Fan Xiaoxing
Published: November 2022

Direct Z-scheme CeO2/Cr2O3 with oxygen vacancies is successfully prepared. The photothermal synergy in direct Z-scheme CeO2/Cr2O3 could improve the nitrogen fixation and isopropanol degradation activities.
Simple one-pot, high-yield synthesis of 2D graphitic carbon nitride nanosheets for photocatalytic hydrogen production
Authors: Ye Ziwei , Yue Wenhui , Tayyab Muhammad , Zhang Jungang , Zhang Jinlong
Published: November 2022

Two-dimensional (2D) g-C3N4 nanosheets with high photocatalytic activity were synthesized at a high yield using urea and dicyandiamide as precursors.
Probing B–X to B–H conversions and applications in C–F bond activation catalysis
Authors: Yeganeh-Salman Amir , Elser Iris , Bamford Karlee L. , Ebanks Daniel , Stephan Douglas W.
Published: November 2022

The conversion of B–X to B–H bonds in the presence of silane is probed. 9-X-9-borabicyclo[3.3.1]nonane (B–F-9-BBN, = F) is shown to react directly with silane. Thus 9-BBN in the presence of silane catalyzes benzylation of arenes with benzyl fluorides.
Direct synthesis of fluorene-based spirolactones through a BF3-promoted spiroannulation of α-keto acids and o-alkynylbiaryls
Authors: Song Qingting , Zhang Zhen , Xie Xiaoyu , Ding Guang-Zhu , Li Pinhua , Wang Lei , Miao Tao
Published: November 2022

A novel and practical approach to fluorene-based spirolactones has been described via BF3-promoted spiroannulation of α-keto acids and o-alkynyl biaryls. This metal-free cascade reaction provides a wide range of products in good to excellent yields.
C–N bond metathesis: mechanistic insight into palladium-catalyzed ring-closing using aminal species
Authors: Liu Song , Zhang Dianmin , Xiao Min , Pu Chengling , Zhang Xiaoqing , Yang Xiuwen , Zhang Tao , Bai Ruopeng
Published: November 2022

A computational study was conducted to investigate the mechanism of a new type of C–N bond metathesis reaction, in which a reversible reductive elimination/oxidative addition mode is involved.
Nitrogen-doped cyan-emissive carbon quantum dots for fluorescence tetracycline detection and lysosome imaging
Authors: Zhu Tongtong , Cao Lei , Kou Xinyue , Liu Yulu , Dong Wen-Fei , Ge Mingfeng , Li Li
Published: November 2022

Schematic diagram of the synthesis of C-CQDs and experimental results in vitro and in cell.
Surface protection against corrosion of Ni turbine blades by electrophoretic deposition of MnO2, TiO2 and TiO2–C nanocoating
Authors: Yousif Qahtan. A. , Majeed Mohammad N. , Bedair Mahmoud A.
Published: November 2022

MnO2, TiO2 and TiO2–C nanomaterials have been coated on the nickel alloy, which is the composition of turbine blades, by the electrophoretic deposition technique for protection against the corrosion process.
Upgrading furanic platforms to α-enaminones: tunable continuous flow hydrogenation of bio-based cyclopentenones
Authors: Cavaca Lídia A. S. , Coelho Jaime A. S. , Lucas Susana D. , Loureiro Rui M. S. , Gomes Rafael F. A. , Afonso Carlos A. M.
Published: November 2022

Continuous flow hydrogenation of trans-4,5-diamino cyclopentenones to diamino cyclopentanones and base-promoted elimination originates α-enaminones. The strategy is applied to the short synthesis of reported ATP-sensitive potassium channel agonist.
Stellar signal components seen in HARPS and HARPS-N solar radial velocities
Authors: Al Moulla K. , Dumusque X. , Figueira P. , Lo Curto G. , Santos N. C. , Wildi F.
Published: November 2022

Context. Radial velocity (RV) measurements induced by the presence of planets around late-type stars are contaminated by stellar signals that are on the order of a few meters per second in amplitude, even for the quietest stars. Those signals are induced by acoustic oscillations, convective granulation patterns, active regions corotating with the stellar surface, and magnetic activity cycles.

Aims. This study investigates the properties of all coherent stellar signals seen on the Sun on timescales up to its sidereal rotational period. By combining HARPS and HARPS-N solar data spanning several years, we are able to clearly resolve signals on timescales from minutes to several months.

Methods. We used a Markov chain Monte Carlo (MCMC) mixture model to determine the quality of the solar data based on the expected airmass–magnitude extinction law. We then fit the velocity power spectrum of the cleaned and heliocentric RVs with all known variability sources, to recreate the RV contribution of each component.

Results. After rejecting variations caused by poor weather conditions, we were able to improve the average intra-day root mean square (rms) value by a factor of ∼1.8. On sub-rotational timescales, we were able to fully recreate the observed rms of the RV variations. In order to also include rotational components and their strong alias peaks introduced by nightly sampling gaps, the alias powers were accounted for by being redistributed to the central frequencies of the rotational harmonics.

Conclusions. In order to enable a better understanding and mitigation of stellar activity sources, their respective impact on the total RV must be well measured and characterized. We were able to recreate RV components up to rotational timescales, which can be further used to analyze the impact of each individual source of stellar signals on the detectability of exoplanets orbiting very quiet solar-type stars and test the observational strategies of RV surveys.
The Possible Protective Effects of Ondansetron and Tropisetron on
Optic Nerve Crush Injury in Rats
Authors: Shayan Maryam , Eslami Faezeh , Khosravi Ayda , Rashidian Amir , Jafari Razie Mohammad , Maroufi Seyed Farzad , Golroudbari Hasti Tashak , Dehpour Ahmad Reza
Published: November 2022

Background This study aimed to evaluate the potential neuroprotective
effect of cyclosporine – a calcineurin inhibitor–, ondansetron,
and tropisetron-5-hydroxytryptamine (serotonin) 3 receptor (5-HT3R)
antagonists–, on optic nerve crush (ONC) injury in rats. Moreover,
underlying signaling activities of their beneficial neuroprotective effects were
studied.

Methods Adult male rats were treated with the intravitreal administration
of cyclosporine (1.6 mM), ondansetron (100 nM), and tropisetron
(100 nM) immediately after the induction of ONC. Subsequently, on 7th
day after surgery, the rats’ retinas were extracted, and the expression
of apoptotic regulators (Bax and Bcl-2) and calcineurin were studied by western
blot analysis.

Results The induction of ONC injury was associated to higher expression of
Bax and calcineurin, while Bcl-2 expression was considerably decreased in these
animals. Intravitreal treatment with cyclosporine (1.6 mM), ondansetron
(100 nM), and tropisetron (100 nM) significantly attenuated the
increased expression of Bax and calcineurin. Moreover, the treatment with these
agents resulted in an elevated expression of Bcl-2 in the retina.

Conclusion Our findings indicate that cyclosporine, ondansetron, and
tropisetron protect against ONC injury in rats, possibly via the suppression of
apoptosis and modulation of calcineurin activity directly and via 5-HT3
receptors. Moreover, immunoblotting showed that tropisetron was more effective
as opposed to ondansetron. Further studies are needed to evaluate the precise
mechanism behind cyclosporine, ondansetron, and tropisetron activities.
Stereoselective Synthesis of Euscapholide and Tetraketide via Prins Cyclisation and Ring-Closing Metathesis
Authors: Biradar Dhanraj O. , Subba Reddy Basi V. , Mane Yogesh D.
Published: November 2022

A concise and diastereoselective total synthesis of tetraketide and euscapholide is described in ten steps in 10.6% overall yield from acetaldehyde and (S)-pent-4-ene-1,2-diol. Jacobsen hydrolytic kinetic­ resolution, Prins cyclization, ring-closing metathesis and oxa-Michael­ addition reactions are the key steps involved in the synthesis.
A Rare Case of Encephalopathy in Children—Known but Unknown
Authors: Jain Mukesh Kumar , Behera Chinmaya Kumar , Panda Sangram , Patnaik Sibabratta , Sahoo Bandya , Mishra Reshmi , Behera Jyoti Ranjan
Published: November 2022

Metronidazole-induced encephalopathy is a rare cause of toxic encephalopathy in children. Although many cases have been reported in adults, it is rarely reported in the pediatric population. Here, we report a case of an 11-year-old boy who presented with acute-onset encephalopathy with slurring of speech after receiving metronidazole for treatment of acute gastroenteritis. Neuroimaging is the cornerstone in the diagnosis of this entity with typical involvement of cerebellum, brain stem, and splenium of the corpus callosum. In our case, magnetic resonance imaging of the brain revealed hyperintensity of the splenium of the corpus callosum on the fluid-attenuated inversion recovery sequence along with diffusion restriction in the diffusion-weighted imaging and apparent diffusion coefficient images. Rapid complete neurological and radiological recovery with supportive treatment is key in making the diagnosis. Although a safer and commonly used drug, new-onset encephalopathy after the use of metronidazole must be considered.
Knowledge, Awareness, and Practices among Pakistani Population regarding COVID-19: An Online Survey-Based Study
Authors: Uzair Mohammad , Farooq Ahmad , Arshad Muhammad , Waheed Usman , Ullah Rana Hissan , Bashir Shahid
Published: November 2022

Aim The study aims to analyze the knowledge, awareness, and practices among the Pakistani population.

Study Method This is an online survey-based study conducted in July 2020 among the general public of Pakistan. Pretested and structured self-administered questionnaire, designed on Google Forms Inc., was used to collect data. The questionnaire included sociodemographic and measurable coronavirus disease 2019 (COVID-19) knowledge data. Assessments on participants' attitudes and practices toward COVID-19 included questions on transmission, symptoms knowledge, and preventive measures.

Results Among the survey completers (n = 962) 61% (n = 590) were male and 39% (n = 372) were female. The majority of participants is aged 18 to 25 and belonged to Punjab. The participants had moderate knowledge regarding disease origin, clinical features, symptoms, and prevention. A vast majority of participants had good knowledge of symptoms and prevention measurements. A good number of participants were also practicing precautionary measures. The majority of participants utilize media and government authorities as authoritative sources of information. The population was also satisfied with the information given by the government.

Conclusion Participants have moderate knowledge regarding the COVID-19 pandemic, reflected by a positive attitude and safe practices. There are gaps in knowledge of the virus, its origin, and transmission. Rumors affect the psychology of people, which may lead to the worst situation of panic conditions.
Septic Pulmonary Embolism: A Contemporary Profile
Authors: Valerio Luca , Baddour Larry M.
Published: November 2022

Septic pulmonary embolism (SPE) is a rare clinical entity that is distinct from the classic and more common non-septic thrombotic pulmonary embolism. SPE should be suspected in patients with a systemic acute inflammatory reaction or sepsis who develop signs and symptoms of pulmonary involvement. The diagnosis of SPE depends on the specific radiologic finding of multiple, peripheral, nodular, possibly cavitated lesions. SPE should prompt an immediate search for the primary source of infection; typically, right-sided infective endocarditis, cardiac implantable electronic devices, and septic thrombophlebitis as a complication of bone, skin, and soft tissue infection including Lemierre's syndrome, indwelling catheters, or direct inoculation via injection drug use. Invasive treatment of the infection source may be necessary; in thrombophlebitis, the efficacy and safety of anticoagulation remain undefined. Blood cultures may be negative, particularly among patients with recent antibiotic exposure, and broad-spectrum antimicrobial therapy should be considered. The in-hospital mortality of SPE ranges up to 20% in published case series. While trends in the incidence of SPE are unknown, the opioid epidemic, the growing use of cardiac implantable electronic devices worldwide, and the reported increase in cases of septic thrombophlebitis may be leading to an escalation in SPE cases. We provide a contemporary profile of SPE and propose a clinical management algorithm in patients with suspected or confirmed SPE.
Physical and numerical modelling of infiltration and runoff in unsaturated exposed soil using a rainfall simulator
Authors: Mendes Thiago Augusto , Pereira Sávio Aparecido dos Santos , Souza Weber Anselmo dos Ramos , Rebolledo Juan Félix Rodríguez , Gitirana Junior Gilson de Farias Neves , Sales Maurício Martines , da Luz Marta Pereira
Published: November 2022

Context Tropical soils have complex hydromechanical behaviour compared to ordinary soils and are often found in regions with well-defined wet and dry seasons. The analysis of the interaction between the soil and the atmosphere comprises understanding of multiple phenomena, such as infiltration and runoff. Unfortunately, the dynamics of soil–atmosphere interaction are commonly modelled at the watershed scale, using average parameters that do not allow an in depth understanding of the soil–water phenomena involved. Aims This paper presents an investigation of the soil–atmosphere interaction at the local scale, using numerical and physical modelling of the infiltration and runoff of an exposed tropical soil in a laboratory rainfall simulator. Methods The effect of rainfall with two different intensities of 86.0 and 200.0 mm h−1 was used to physically and numerically evaluate infiltration parameters, runoff, volumetric water content, and degree of saturation at five locations in the soil specimen. Key results Calibration of the numerical model showed a maximum root-mean-square error of 0.17. In addition, the modelling exercises indicated the need for an equilibrium time of 48 h for the sample studied under the imposed conditions. Conclusions Results of numerical simulation showed that the representation of the physical model by the numerical model was satisfactory and promising. Thus, the numerical model showed applicability for validating the boundary conditions of physical tests using rainfall simulators.
Non-parallel currents and the Newton’s third law of motion
Authors: Epp V , Veselkova A V
Published: November 2022

We provide an explicit calculation to check that Newtown’s third law holds for non-parallel currents if the field momentum is accounted for. In textbooks of electrodynamics, it is usually noted that in the interaction of non-parallel current elements, the action force is not balanced by the reaction force, though these forces are balanced in the interaction of two closed current-carrying loops. In the case of non-closed current segments the change in the momentum stored in the field should be taken into account. Using a simple model of two non-parallel straight current segments we show how it works. As such a model, two straight orthogonal to each other conductors are considered, with equal charges of opposite signs at the ends of each conductor. For some interval of time, a direct current is supported in the conductors. We show that the total momentum of the system is conserved.
Uniqueness for inverse source problems for fractional diffusion-wave equations by data during not acting time
Authors: Yamamoto M
Published: November 2022

We consider fractional diffusion-wave equations with source term which is represented in a form of a product of a temporal function and a spatial function. We prove the uniqueness for inverse source problem of determining spatially varying factor by decay of data as the time tends to

∞

, provided that the source does not work during the observation. Our main result asserts the uniqueness if data decay more rapidly than

1

t
p

with any

p
∈

N

as

t
→
∞

. Data taken not from the initial time are realistic but the uniqueness is not known in general. The proof is based on the analyticity and the asymptotic behavior of a function generated by the solution.
Numerical and experimental investigation of the aerodynamic performance of anomalous energy harvester geometries
Authors: Özkan Musa , Erkan Onur , Basaran Sinan , Bolat Fevzi Cakmak
Published: November 2022

In this study, anomalous geometries were examined computationally and experimentally in terms of their aerodynamic performance as energy harvesters. The main motivation of this study is that most of these geometries, discussed in the present study, have not yet been previously considered as energy harvesters in literature. Some well-known geometries alongside these anomalous models were also investigated for comparison in this current study. The examination was conducted by means of the computational and experimental fluid dynamics approaches where the flow around these different models was analyzed in detail to shed light on the crucial aspects encountered during the flow separation over these various geometries. By this means, the lift coefficients of the investigated harvester geometries were considered as the essential parameter for time-dependent analyses in the numerical simulations since this parameter is the main reason for the flow-induced vibrations. Moreover, experimentally obtained voltages and power curves were compared for different geometries. Based on the root mean square values of the numerical lift coefficients, it was found that the best aerodynamically beneficial model is Model-7 (equal-length 3-tines fork shape) and the worst model is Model-5 (perpendicular plane). Velocity vectors and pressure distributions around these best and worst models were also provided to reveal the main differences in flow structures that may lead to a better design of energy harvester geometry for further studies.
Skyrmion–skyrmion interaction induced by itinerant electrons in a ferromagnetic strip
Authors: Iroulart E , Rosales H D
Published: November 2022

Magnetic skyrmions are promising spin textures for building next-generation magnetic memories and spintronic devices. Nevertheless, one of the major challenges in realizing skyrmion-based devices is the stabilization of ordered arrays of these spin textures in different geometries. Here we numerically study the skyrmion–skyrmion interaction potential that arises due to the dynamics of itinerant electrons coupled to the magnetic texture in a ferromagnetic background with racetrack geometry. We consider different topological textures (ferromagnetic (FM) and antiferromagnetic (AFM)), namely: skyrmions, antiskyrmions and biskyrmions. We show that at low electron filling, for sufficiently short separation, the skyrmions strongly couple each other yielding a bound-state bound by electronic dynamics. However, when the filling is increased, the interaction potential energy presents local minima at specific values of the skyrmion–skyrmion distance. Each of these local minima corresponds to energetically stable positions of skyrmions which are ‘protected’ by well-defined energy barriers. By inspecting the local charge density, we find that in the case of AFM skyrmions, the local antiferromagnetic nature prevents electronic penetration into the core, allowing the AFM skyrmions to be seen as infinite potential barriers for electrons.
Josephson voltage standards as toolkit for precision metrological applications at PTB
Authors: Bauer Stephan , Behr Ralf , Herick Jonas , Kieler Oliver , Kraus Marco , Tian Hao , Pimsut Yoawaret , Palafox Luis
Published: November 2022

About 60 years after the discovery of the Josephson effect, electrical DC voltage calibrations are routinely performed worldwide—mostly using automated Josephson voltage standards (JVSs). Nevertheless, the field of electrical quantum voltage metrology is still propagating towards AC applications. In the past 10 years the fabrication of highly integrated arrays containing more than 50 000 or even 300 000 junctions has achieved a very robust level providing highly functional devices. Such reliable Josephson arrays are the basis for many novel applications mainly focussing on precision AC measurements for signal frequencies up to 500 kHz. Two versions of quantum AC standards are being employed. Programmable JVS, based on series arrays divided into subarrays, reach amplitudes up to 20 V and usually are used as quantum voltage reference in measurement systems. Pulse driven arrays reach amplitudes up to 1 V or even 4 V and are typically used as Josephson arbitrary waveform synthesizers. This paper summarizes the principal contributions from Physikalisch-Technische Bundesanstalt to the present state of JVS with particular focus on developments for precision metrological applications and our proof-of-concept demonstrations.
A sound source localization method based on improved second correlation time delay estimation
Authors: Liu Mengran , Zeng Qiang , Jian Zeming , Peng Yang , Nie Lei
Published: November 2022

The sound source localization (SSL) system based on the microphone array has important applications in audio and video conference, security monitoring and intelligent cockpit. However, the SSL method based on time difference of arrival is susceptible to ambient noise. Therefore, an improved second correlation delay estimation algorithm is proposed in this paper. The pure source signal is obtained by wavelet denoising, and then the time delay is calculated by the second correlation time delay estimation algorithm with the weighting functions of the smoothed coherence transform and the Roth processor. The position of the sound target is calculated from the time delay. Aiming at the moving target, an extended Kalman filter is introduced to track the moving trajectory of the sound source. The static and moving SSL simulations are conducted and the results of the proposed algorithm are compared with those of the single-weighted quadratic correlation (SQC) algorithm and the high-power quadratic correlation algorithm. The static sound source positioning errors of the proposed algorithm under −10 dB SNR are respectively 3.97 m and 5.86 m smaller than those of the HQC algorithm and the SQC algorithm. The moving SSL trajectory based on the proposed algorithm is still closest to the real track under −10 dB SNR. This indicates that the proposed algorithm has high precision and strong robustness for sound source location in the low signal-to-noise ratio (SNR) environment. In the experiment, the proposed algorithm can accurately calculate the direction of arrival (DOA) of static sound source and stably track DOA of moving sound source. This is consistent with the simulation results, which further verifies the effectiveness and practicability of the algorithm. This novel algorithm with high time delay estimation accuracy is of great significance for SSL in low SNR environment.
Torsion pendulum measurement method for time varying moment of inertia
Authors: Wang Jun , Zheng Liu , Zhang Xiaoling , Li Zhenhua , Zhou Qichao
Published: November 2022

A time-varying moment of inertia (MOI) measurement model based on the torsion pendulum method is studied. According to the principle of dynamics, the motion equation of torsion pendulum with single degree of freedom is established by using the second Lagrange equation modeling, which indicates the time-varying MOI can be obtained by the instantaneous undamped natural frequency of torsional pendulum motion and the torsion bar coefficient. Among them, the instantaneous frequency is calculated by the instantaneous angular frequency and envelope signal of angular displacement using Hilbert transform. The torsion bar coefficient is calibrated by the standard weight with known MOI, and has been compensated by temperature. Based on air floating turntable, the torsion pendulum system is built to measure the MOI of fine sand in the funnel, which can minimize the effects of mechanical friction. The relative error of MOI between calculating the result and measuring the value is less than 0.65%, which verifies the effectiveness of the proposed time varying temperature compensation method.