bluuebunny/crossref_metadata_2025 huggingface dataset:
Noxa and Mcl-1 expression influence the sensitivity to BH3-mimetics that target Bcl-xL in patient-derived glioma stem cells
Authors: Vera Mariana Belén , Morris-Hanon Olivia , Nogueiras Germán Ignacio , Ripari Luisina Belén , Esquivel Myrian Inés , Perez-Castro Carolina , Romorini Leonardo , Sevlever Gustavo Emilio , Scassa María Elida , Videla-Richardson Guillermo Agustín
Published: October 2022

The recurrence of Glioblastoma is partly attributed to the highly resistant subpopulation of glioma stem cells. A novel therapeutic approach focuses on restoring apoptotic programs in these cancer stem cells, as they are often deregulated. BH3-mimetics, targeting anti-apoptotic Bcl-2 family members, are emerging as promising compounds to sensitize cancer cells to antineoplastic treatments. Herein, we determined that the most abundantly expressed anti-apoptotic Bcl-2 family members, Bcl-xL and Mcl-1, are the most relevant in regulating patient-derived glioma stem cell survival. We exposed these cells to routinely used chemotherapeutic drugs and BH3-mimetics (ABT-263, WEHI-539, and S63845). We observed that the combination of BH3-mimetics targeting Bcl-xL with chemotherapeutic agents caused a marked increase in cell death and that this sensitivity to Bcl-xL inhibition correlated with Noxa expression levels. Interestingly, whereas co-targeting Bcl-xL and Mcl-1 led to massive cell death in all tested cell lines, down-regulation of Noxa promoted cell survival only in cell lines expressing higher levels of this BH3-only. Therefore, in glioma stem cells, the efficacy of Bcl-xL inhibition is closely associated with Mcl-1 activity and Noxa expression. Hence, a potentially effective strategy would consist of combining Bcl-xL inhibitors with chemotherapeutic agents capable of inducing Noxa, taking advantage of this pro-apoptotic factor.
Personalized ctDNA micro-panels can monitor and predict clinical outcomes for patients with triple-negative breast cancer
Authors: Barnell Erica K. , Fisk Bryan , Skidmore Zachary L. , Cotto Kelsy C. , Basu Anamika , Anand Aparna , Richters Megan M. , Luo Jingqin , Fronick Catrina , Anurag Meenakshi , Fulton Robert , Ellis Matthew J. , Griffith Obi L. , Griffith Malachi , Ademuyiwa Foluso O.
Published: October 2022

Circulating tumor DNA (ctDNA) in peripheral blood has been used to predict prognosis and therapeutic response for triple-negative breast cancer (TNBC) patients. However, previous approaches typically use large comprehensive panels of genes commonly mutated across all breast cancers. Given the reduction in sequencing costs and decreased turnaround times associated with panel generation, the objective of this study was to assess the use of custom micro-panels for tracking disease and predicting clinical outcomes for patients with TNBC. Paired tumor-normal samples from patients with TNBC were obtained at diagnosis (T0) and whole exome sequencing (WES) was performed to identify somatic variants associated with individual tumors. Custom micro-panels of 4–6 variants were created for each individual enrolled in the study. Peripheral blood was obtained at baseline, during Cycle 1 Day 3, at time of surgery, and in 3–6 month intervals after surgery to assess variant allele fraction (VAF) at different timepoints during disease course. The VAF was compared to clinical outcomes to evaluate the ability of custom micro-panels to predict pathological response, disease-free intervals, and patient relapse. A cohort of 50 individuals were evaluated for up to 48 months post-diagnosis of TNBC. In total, there were 33 patients who did not achieve pathological complete response (pCR) and seven patients developed clinical relapse. For all patients who developed clinical relapse and had peripheral blood obtained ≤ 6 months prior to relapse (n = 4), the custom ctDNA micro-panels identified molecular relapse at an average of 4.3 months prior to clinical relapse. The custom ctDNA panel results were moderately associated with pCR such that during disease monitoring, only 11% of patients with pCR had a molecular relapse, whereas 47% of patients without pCR had a molecular relapse (Chi-Square; p-value = 0.10). In this study, we show that a custom micro-panel of 4–6 markers can be effectively used to predict outcomes and monitor remission for patients with TNBC. These custom micro-panels show high sensitivity for detecting molecular relapse in advance of clinical relapse. The use of these panels could improve patient outcomes through early detection of relapse with preemptive intervention prior to symptom onset.
Geometric learning of functional brain network on the correlation manifold
Authors: You Kisung , Park Hae-Jeong
Published: October 2022

The correlation matrix is a typical representation of node interactions in functional brain network analysis. The analysis of the correlation matrix to characterize brain networks observed in several neuroimaging modalities has been conducted predominantly in the Euclidean space by assuming that pairwise interactions are mutually independent. One way to take account of all interactions in the network as a whole is to analyze the correlation matrix under some geometric structure. Recent studies have focused on the space of correlation matrices as a strict subset of symmetric positive definite (SPD) matrices, which form a unique mathematical structure known as the Riemannian manifold. However, mathematical operations of the correlation matrix under the SPD geometry may not necessarily be coherent (i.e., the structure of the correlation matrix may not be preserved), necessitating a post-hoc normalization. The contribution of the current paper is twofold: (1) to devise a set of inferential methods on the correlation manifold and (2) to demonstrate its applicability in functional network analysis. We present several algorithms on the correlation manifold, including measures of central tendency, cluster analysis, hypothesis testing, and low-dimensional embedding. Simulation and real data analysis support the application of the proposed framework for brain network analysis.
A data driven approach in less expensive robust transmitting coverage and power optimization
Authors: Parnianifard Amir , Mumtaz Shahid , Chaudhary Sushank , Imran Muhammad Ali , Wuttisittikulkij Lunchakorn
Published: October 2022

This paper aims the development of a new reduced-cost algorithm for a multi-objective robust transmitter placement under uncertainty. Toward this end, we propose a new hybrid Kriging/Grey Wolf Optimizer (GWO) approach combined with robust design optimization to estimate the set of Pareto frontier by searching robustness as well as accuracy (lower objective function) in a design space. We consider minimization of the energy power consumption for transmitting as well as maximization of signal coverage in a multi-objective robust optimization model. The reliability of the model to control signal overlap for multiple transmitting antennas is also provided. To smooth computational cost, the proposed method instead of evaluating all receiver test points in each optimization iteration approximates signal coverages using Kriging interpolation to obtain optimal transmitter positions. The results demonstrate the utility and the efficiency of the proposed method in rendering the robust optimal design and analyzing the sensitivity of the transmitter placement problem under practically less-expensive computational efforts (350% and 320% less than computational time elapsed using standalone GWO and NSGAII respectively).
Communication skills in children aged 6–8 years, without cerebral palsy cooled for neonatal hypoxic-ischemic encephalopathy
Authors: Robb Thomas J. , Tonks James , Spencer Arthur P. C. , Jary Sally , Whitfield Charlotte K. , Thoresen Marianne , Cowan Frances M. , Chakkarapani Ela
Published: October 2022

We assessed communication skills of 48 children without cerebral palsy (CP) treated with therapeutic hypothermia (TH) for neonatal hypoxic-ischemic encephalopathy (HIE) (cases) compared to 42 controls at early school-age and examined their association with white matter diffusion properties in both groups and 18-month Bayley-III developmental assessments in cases. Parents completed a Children’s Communication Checklist (CCC-2) yielding a General Communication Composite (GCC), structural and pragmatic language scores and autistic-type behavior score. GCC ≤ 54 and thresholds of structural and pragmatic language score differences defined language impairment. Using tract-based spatial statistics (TBSS), fractional anisotropy (FA) was compared between 31 cases and 35 controls. Compared to controls, cases had lower GCC (p = 0.02), structural (p = 0.03) and pragmatic language score (p = 0.04) and higher language impairments (p = 0.03). GCC correlated with FA in the mid-body of the corpus callosum, the cingulum and the superior longitudinal fasciculus (p < 0.05) in cases. Bayley-III Language Composite correlated with GCC (r = 0.34, p = 0.017), structural (r = 0.34, p = 0.02) and pragmatic (r = 0.32, p = 0.03) language scores and autistic-type behaviors (r = 0.36, p = 0.01).
Neural interactions in working memory explain decreased recall precision and similarity-based feature repulsion
Authors: Johnson Jeffrey S. , van Lamsweerde Amanda E. , Dineva Evelina , Spencer John P.
Published: October 2022

Over the last several years, the study of working memory (WM) for simple visual features (e.g., colors, orientations) has been dominated by perspectives that assume items in WM are stored independently of one another. Evidence has revealed, however, systematic biases in WM recall which suggest that items in WM interact during active maintenance. In the present study, we report two experiments that replicate a repulsion bias between metrically similar colors during active storage in WM. We also observed that metrically similar colors were stored with lower resolution than a unique color held actively in mind at the same time. To account for these effects, we report quantitative simulations of two novel neurodynamical models of WM. In both models, the unique behavioral signatures reported here emerge directly from laterally-inhibitory neural interactions that serve to maintain multiple, distinct neural representations throughout the WM delay period. Simulation results show that the full pattern of empirical findings was only obtained with a model that included an elaborated spatial pathway with sequential encoding of memory display items. We discuss implications of our findings for theories of visual working memory more generally.
Effect of aspirin on primary prevention of cardiovascular disease and mortality among patients with chronic kidney disease
Authors: Haim-Pinhas Hadar , Yoskovitz Gil , Lishner Michael , Pereg David , Kitay-Cohen Yona , Topaz Guy , Sela Yaron , Wand Ori , Rozenberg Ilan , Benchetrit Sydney , Cohen-Hagai Keren
Published: October 2022

Chronic kidney disease is associated with an increased risk for cardiovascular and bleeding events. Data regarding the effectiveness and risks of aspirin therapy for primary prevention in the high-risk group of patients with chronic kidney disease are scant and controversial. This retrospective study included patients with chronic kidney disease. Participants were divided according to aspirin use. Outcomes included non-fatal cardiovascular events, major bleeding events and all-cause mortality. Among 10,303 patients, 2169 met the inclusion criteria and 1818 were included after 1:1 propensity-score matching. Our final cohort included patients with mean age of 73.4 ± 11.6 years, estimated glomerular filtration rate of 31.5 ± 10.5 ml/min/1.73m2 with follow up of 4.9 ± 1.5 years. There were no significant differences in all-cause mortality and bleeding events (odds ratio = 1.03, confidence interval [0.62, 1.84], p = .58 and odds ratio = 1.09, confidence interval [0.65, 1.72], p = .87 respectively). The incidence of cardiovascular events was higher in aspirin users versus non-users on univariate analysis (p < 0.01) and was comparable after controlling for possible risk-factors (OR = 1.05, CI [0.61, 3.14], p = .85). Chronic aspirin use for primary prevention of cardiovascular disease was not associated with lower mortality, cardiovascular events or increased bleeding among patients with chronic kidney disease. Those results were unexpected and should prompt further research in this field.
Haplotyping pharmacogenes using TLA combined with Illumina or Nanopore sequencing
Authors: Tilleman Laurentijn , Rubben Kaat , Van Criekinge Wim , Deforce Dieter , Van Nieuwerburgh Filip
Published: October 2022

The currently used pharmacogenetic genotyping assays offer limited haplotype information, which can potentially cause specific functional effects to be missed. This study tested if Targeted Locus Amplification (TLA), when using non-patient-specific primers combined with Illumina or Nanopore sequencing, can offer an advantage in terms of accurate phasing. The TLA method selectively amplifies and sequences entire genes based on crosslinking DNA in close physical proximity. This way, DNA fragments that were initially further apart in the genome are ligated into one molecule, making it possible to sequence distant variants within one short read. In this study, four pharmacogenes, CYP2D6, CYP2C19, CYP1A2 and BRCA1, were sequenced after enrichment using different primer pairs. Only 24% or 38% of the nucleotides mapped on target when using Illumina or Nanopore sequencing, respectively. With an average depth of more than 1000X for the regions of interest, none of the genes were entirely covered with either sequencing method. For three of the four genes, less than half of the variants were phased correctly compared to the reference. The Nanopore dataset with the optimized primer pair for CYP2D6 resulted in the correct haplotype, showing that this method can be used for reliable genotyping and phasing of pharmacogenes but does require patient-specific primer design and optimization to be effective.
Effects of different milk feeding levels and frequencies on performance of Holstein heifers during weaning and first lactation
Authors: Ahmadi Fatemeh , Akbarian-Tefaghi Majid , jafari Azam , Ghaffari Morteza Hosseini
Published: October 2022

In the present study, the effects of milk feeding amount and feeding frequency (FF) on performance, blood metabolites, rumen fermentation, and performance of dairy heifers during the first artificial insemination (AI) and first lactation were investigated. The treatment group consisted of 48 female Holstein heifer calves (12/treatment) distributed in a 2 × 2 factorial arrangement with milk feeding [high = 8 L/d, HL or medium = 6 L/d, ML] and feeding frequency [2 × or 3 ×]. All calves were fed on a step-up/step-down method, weaned from milk at 56 d of age, and observed until 70 d of age. Heifer calves were kept uniform from 70 d of age until the first lactation to evaluate the long-term effects of the treatments. We observed no FF effect and no interaction between the level and FF on feed intake, average daily gain (ADG), feed efficiency (FE), body weight (BW), structural growth, blood metabolites, and rumen fermentation parameters. Calves fed HL milk had higher total dry matter intake (DMI), BW, and ADG during the pre- and post-weaning periods. During the preweaning period, HL-fed calves had higher serum insulin (trend) and glucose concentrations compared to ML-fed calves. Lower age at first AI was observed in calves fed HL rather than ML regardless of FF. Weight at first AI, milk yield (305 d), and energy-corrected milk (ECM-305 d) in the first lactation showed a trend toward higher values in HL-fed calves compared to ML-fed calves. Preweaning performance and calf maturity can be positively affected by feeding high amounts of milk at both FF.
Feasibility of the optimal cerebral perfusion pressure value identification without a delay that is too long
Authors: Deimantavicius Mantas , Chaleckas Edvinas , Boere Katherine , Putnynaite Vilma , Tamosuitis Tomas , Tamasauskas Arimantas , Kavaliauskas Mindaugas , Rocka Saulius , Preiksaitis Aidanas , Vosylius Saulius , Krakauskaite Solventa , Berskiene Kristina , Petkus Vytautas , Ragauskas Arminas
Published: October 2022

Optimal cerebral perfusion pressure (CPPopt)-targeted treatment of traumatic brain injury (TBI) patients requires 2–8 h multi-modal monitoring data accumulation to identify CPPopt value for individual patient. Minimizing the time required for monitoring data accumulation is needed to improve the efficacy of CPPopt-targeted therapy. A retrospective analysis of multimodal physiological monitoring data from 87 severe TBI patients was performed by separately representing cerebrovascular autoregulation (CA) indices in relation to CPP, arterial blood pressure (ABP), and intracranial pressure (ICP) to improve the existing CPPopt identification algorithms. Machine learning (ML)-based algorithms were developed for automatic identification of informative data segments that were used for reliable CPPopt, ABPopt, ICPopt and the lower/upper limits of CA (LLCA/ULCA) identification. The reference datasets of the informative data segments and, artifact-distorted segments, and the datasets of different clinical situations were used for training the ML-based algorithms, allowing us to choose the appropriate individualized CPP-, ABP- or ICP-guided management for 79% of the full monitoring time for the studied population. The developed ML-based algorithms allow us to recognize informative physiological ABP/ICP variations within 24 min intervals with an accuracy up to 79% (compared to the initial accuracy of 74%) and use these segments for timely optimal value identification or CA limits determination in CPP, ABP or ICP data. Prospective clinical studies are needed to prove the efficiency of the developed algorithms.
On the relations between letter, word, and sentence-level processing during reading
Authors: Brossette Brice , Grainger Jonathan , Lété Bernard , Dufau Stéphane
Published: October 2022

Much prior research on reading has focused on a specific level of processing, with this often being letters, words, or sentences. Here, for the first time in adult readers, we provide a combined investigation of these three key component processes of reading comprehension. We did so by testing the same group of participants in three tasks thought to reflect processing at each of these levels: alphabetic decision, lexical decision, and grammatical decision. Participants also performed a non-reading classification task, with an aim to partial-out common binary decision processes from the correlations across the three main tasks. We examined the pairwise partial correlations for response times (RTs) in the three reading tasks. The results revealed strong significant correlations across adjacent levels of processing (i.e., letter-word; word-sentence) and a non-significant correlation between non-adjacent levels (letter-sentence). The results provide an important new benchmark for evaluating computational models that describe how letters, words, and sentences contribute to reading comprehension.
Realizing high stretch ratio of flexible wavy circuit via laser carving
Authors: Yun Jung-Hoon , Victoria Adebisi Oluwabukola , Cho Maenghyo
Published: October 2022

Stretchable wavy circuit is an essential component in flexible devices, which have wide applications in various fields. In the industrial field, the stretching ability of the circuit is a crucial factor for flexible devices. Therefore, this study proposes laser carving method to increase both stretch ratio and device resolution of the flexible device. The results obtained from the experiment and finite element analysis verifies that laser carving on the wavy circuit increases the maximum stretch ratio of wavy circuit. The obtained analytic model confirms that laser carving generates tilted section on the wavy circuit, and reduces the bending rigidity of the curvy point of the wavy circuit. The study also verified that laser carved groove induces crack propagation into vertical to the circuit direction, so that the laser carved wavy circuit is less likely to disconnect than uncarved wavy circuit. Due to the reduced bending rigidity and crack induce, the wavy circuit stretches more than the conventional uncarved wavy circuit.
Presence of entry receptors and viral markers suggest a low level of placental replication of hepatitis B virus in a proportion of pregnant women infected with chronic hepatitis B
Authors: Garg Garima , Meenu M. N. , Patel Kajal , Singh Ravinder , Gupta Priyal , Purwar Shashank , Mukhopadhyay Sramana , Mishra Nitu , Gupta Sudheer , Rawat Sumit Kumar , Goel Harsh , Kumar Rahul , Tanwar Pranay , Singh Jitendra , Nema Shashwati , Biswas Debasis , Trehanpati Nirupma , Singh Anirudh K. , Vyas Ashish Kumar
Published: October 2022

The transplacental route of vertical transmission of Hepatitis B Virus (HBV) has been known for over a decade. Here we present evidence which suggest HBV can replicate in placenta. Forty-one HBsAg positive and 10 control pregnant women were enrolled in the study after obtaining informed consent. HBV positives were further divided in the High Viral Load (HVL) Group and Low Viral Load (LVL) Group according to INASL guidelines 2018. The Presence of the HBV DNA and expression of NTCP in the placenta was analyzed by qPCR/RT-qPCR and/or immunohistochemistry (IHC). The presence of cccDNA was assessed using Digital Droplet PCR while the presence of pre-genomic (pg) RNA was assessed through qRT-PCR and sequencing. The presence of HBeAg and HBcAg in the placenta was assessed by IHC. Immunostaining of NTCP, HBeAg and HBcAg on trophoblasts along with the presence of total HBV DNA, cccDNA and pgRNA indicated, that these cells are not only susceptible to HBV infection but may also support viral replication. This is further supported by the finding that trophoblasts of the several HBeAg seronegative samples harbored the HBeAg. Although, we did not find any correlation in NTCP expression and viral markers with viral load indicates placental replication may not aping hepatocytes. The presence of the HBV receptor, NTCP along with the presence of cccDNA, pgRNA, and HBeAg in placenta of HBV infected females without circulating HBeAg suggest that placenta act as a replication host.
Using bioelectrohydrogenesis left-over residues as a future potential fertilizer for soil amendment
Authors: Ndayisenga Fabrice , Yu Zhisheng , Wang Bobo , Yang Jie , Wu Gang , Zhang Hongxun
Published: October 2022

In this current research, the left-over residues collected from the dark fermentation-microbial electrolysis cells (DF-MEC) integrated system solely biocatalyzed by activated sludge during the bioconversion of the agricultural straw wastes into hydrogen energy, was investigated for its feasibility to be used as a potential alternative biofertilizer to the commonly costly inorganic ones. The results revealed that the electrohydrogenesis left-over residues enriched various plant growth-promoting microbial communities including Enterobacter (8.57%), Paenibacillus (1.18%), Mycobacterium (0.77%), Pseudomonas (0.65%), Bradyrhizobium (0.12%), Azospirillum (0.11%), and Mesorhizobium (0.1%) that are generally known for their ability to produce different essential phytohormones such as indole-3-acetic acid/indole acetic acid (IAA) and Gibberellins for plant growth. Moreover, they also contain both phosphate-solubilizing and nitrogen-fixing microbial communities that remarkably provide an adequate amount of assimilable phosphorus and nitrogen required for enhanced plants or crop growth. Furthermore, macro-, and micronutrients (including N, P, K, etc.) were all analyzed from the residues and detected adequate appreciate concentrations required for plant growth promotions. The direct application of MEC-effluent as fertilizer in this current study conspicuously promoted plant growth (Solanum lycopersicum L. (tomato), Capsicum annuum L. (chilli), and Solanum melongena L. (brinjal)) and speeded up flowering and fruit-generating processes. Based on these findings, electrohydrogenesis residues could undoubtedly be considered as a potential biofertilizer. Thus, this technology provides a new approach to agricultural residue control and concomitantly provides a sustainable, cheap, and eco-friendly biofertilizer that could replace the chemical costly fertilizers.
Optimization, purification, and characterization of xylanase production by a newly isolated Trichoderma harzianum strain by a two-step statistical experimental design strategy
Authors: Dhaver Priyashini , Pletschke Brett , Sithole Bruce , Govinden Roshini
Published: October 2022

Xylanases are hydrolytic enzymes with a wide range of applications in several industries such as biofuels, paper and pulp, food, and feed. The objective of this study was to optimize the culture conditions and medium components for maximal xylanase production from a newly isolated Trichoderma harzianum strain using the Plackett–Burman Design (PBD) and Box Behnken Design (BBD) experimental strategies. Xylanase production was enhanced 4.16-fold to 153.80 U/ml by BBD compared to a preliminary one-factor-at-a-time (OFAT) activity of 37.01 U/ml and 2.24-fold compared to the PBD (68.70 U/ml). The optimal conditions for xylanase production were: 6 days of fermentation, incubation temperature of 70 °C, pH 5.0, agitation of 160 rpm, and 1.2% wheat bran and ammonium sulphate. The experimental design effectively provided conditions for the production of an acidic-thermostable enzyme with exciting potential for application in animal feed improvement. The acidic-thermostable xylanase was purified from the submerged culture and SDS-PAGE analysis revealed a molecular weight of 72 kDa. This protein had maximum xylanolytic activity at pH 6.0 and 65 °C and was stable for 4 h retaining > 70% activity and exhibited substrate specificity for beechwood xylan with a Km of 5.56 mg/ml and Vmax of 1052.63 µmol/min/mg. Enzyme activity was enhanced by Fe2+, Mg2+, and Zn2+. There was an absence of strong inhibitors of xylanase activity. Overall, these characteristics indicate the potential for at least two industrial applications.
Cortical midfrontal theta dynamics following foot strike may index response adaptation during reactive stepping
Authors: Stokkermans Mitchel , Staring Wouter , Cohen Michael X. , Solis-Escalante Teodoro , Weerdesteyn Vivian
Published: October 2022

Reactive balance recovery often requires stepping responses to regain postural stability following a sudden change in posture. The monitoring of postural stability has been linked to neuroelectrical markers such as the N1 potential and midfrontal theta frequency dynamics. Here, we investigated the role of cortical midfrontal theta dynamics during balance monitoring following foot landing of a reactive stepping response to recover from whole-body balance perturbations. We hypothesized that midfrontal theta dynamics reflect the engagement of a behavioral monitoring system, and therefore that theta would increase time-locked to the moment of foot strike after a stepping response, coinciding with a re-assessment of postural balance to determine if an additional step is necessary. We recorded high-density EEG and kinematic data of 15 healthy young participants while they stood on a platform that delivered multi-directional balance perturbations. Participants were instructed to recover balance with a single step utilizing either their left or right leg (in separate blocks). We used targeted spatial filtering (generalized eigen decomposition) in combination with time–frequency analysis of the EEG data to investigate whether theta dynamics increase following foot strike event. In line with our hypothesis, the results indicate that the foot strike event elicits a midfrontal theta power increase, though only for backward stepping. Counter to our expectations, however, this theta power increase was positively correlated with the margin of stability at foot strike, suggesting a different role of foot strike related theta from monitoring stability. Post-hoc analysis suggests that midfrontal theta dynamics following foot landing may instead facilitate adaptation of stability margins at subsequent stepping responses. We speculate that increase of theta power following foot strikes was not related to stability monitoring but instead may indicate cortical dynamics related to performance monitoring of the balance response.
Natural convection in a porous cavity filled (35%MWCNT-65% Fe3O4)/water hybrid nanofluid with a solid wavy wall via Galerkin finite-element process
Authors: Gumir Fatima Jasim , Al-Farhany Khaled , Jamshed Wasim , Tag El Din El Sayed M. , Abd-Elmonem Assmaa
Published: October 2022

A numerical analysis of natural convective heat transfer in a square porous cavity with a solid wavy finite wall filled with (35% MWCNT-65% Fe3O4)/water hybrid nanofluid. The left wavy wall is heated to a constant temperature, the right wall is held at a low temperature, and the top and bottom walls are thermally insulated. Darcy-Brinkman-Forchheimer model is used to model porous medium with hybrid nanofluid. COMSOL Multiphasic Modeling Software via Galerkin finite element method has been used to solve the governing equations. The dimensionless parameters used in this investigation are; modified Rayleigh number (Ra* = 102, 103, 104, and 106), Darcy number (Da = 10–2, 10–4 and 10–6), Solid volume fraction (ϕ = 0.01, 0.03, and 0.05),undulation number (N = 1, 3, 5, and 7), amplitude of the wavy wall (A = 0.1, 0.2, and 0.3), and Prandtl number = 7.2 at constant high porosity. At a high Darcy number (Da = 10–2), the isotherm lines parallel to the vertical cavity walls, which means that conduction is the primary method of heat transport. At the same time, the convection mode is increasingly necessary at a lower Darcy number. The convection flow and the maximum amounts of stream function are reduced when both A = 0.1 and N = 1 increase. The average Nusselt number increases with increasing Ra*, while it decreases with increasing Darcy number and amplitude wave numbers. It has been determined that the largest improvement in heat transfer is at Ra* = 104, Da = 10–6, ϕ = 0.05, A = 0.1, and N = 1.
Single-cell sequencing deconvolutes cellular responses to exercise in human skeletal muscle
Authors: Lovrić Alen , Rassolie Ali , Alam Seher , Mandić Mirko , Saini Amarjit , Altun Mikael , Fernandez-Gonzalo Rodrigo , Gustafsson Thomas , Rullman Eric
Published: October 2022

Skeletal muscle adaptations to exercise have been associated with a range of health-related benefits, but cell type-specific adaptations within the muscle are incompletely understood. Here we use single-cell sequencing to determine the effects of exercise on cellular composition and cell type-specific processes in human skeletal muscle before and after intense exercise. Fifteen clusters originating from six different cell populations were identified. Most cell populations remained quantitatively stable after exercise, but a large transcriptional response was observed in mesenchymal, endothelial, and myogenic cells, suggesting that these cells are specifically involved in skeletal muscle remodeling. We found three subpopulations of myogenic cells characterized by different maturation stages based on the expression of markers such asPAX7,MYOD1,TNNI1, andTNNI2. Exercise accelerated the trajectory of myogenic progenitor cells towards maturation by increasing the transcriptional features of fast- and slow-twitch muscle fibers. The transcriptional regulation of these contractile elements upon differentiation was validated in vitro on primary myoblast cells. The cell type-specific adaptive mechanisms induced by exercise presented here contribute to the understanding of the skeletal muscle adaptations triggered by physical activity and may ultimately have implications for physiological and pathological processes affecting skeletal muscle, such as sarcopenia, cachexia, and glucose homeostasis.
Silylium ion migration dominated hydroamidation of siloxy-alkynes
Authors: Wang Heng-Ding , Jiang Ling , Fan Hong-Jun
Published: October 2022

The mechanism of silver-catalyzed hydroamidation of siloxy-alkynes reaction remains controversial. Using density functional theory (DFT), we revealed that the reaction takes place through a silylium ion migration mediated hydroamination (SMH) pathway. The SMH pathway goes through two steps, the first step is Ag+ promoted proton and silylium ion exchange between siloxy-alkynes and amide, leading to ketene and silyl-imines, the second step is Ag+ catalyzed nucleophilic addition between ketene and silyl-imines, following with a silylium ion migration afford the final product. In this reaction, Ag+ activates the siloxy-alkyne into silylium ion (TIPS+) and silver-ketene through thep–πconjugate effect, the silylium ion then catalyzes the reaction. According to our calculation, the scopes of alkynes in this reaction may be extended to silyl-substituted ynamines or silyl-substituted ynamides. The scopes of amide may be extended into thep–πconjugate system such as diazoles, diazepines, etc. Our calculations also reveal a concise way to construct enamides through Ag+ catalyzed nucleophilic addition between substituted-ketenes and silyl-substitutedp–πconjugate system.
Perturbations in stratospheric aerosol evolution due to the water-rich plume of the 2022 Hunga-Tonga eruption
Authors: Zhu Yunqian , Bardeen Charles G. , Tilmes Simone , Mills Michael J. , Wang Xinyue , Harvey V. Lynn , Taha Ghassan , Kinnison Douglas , Portmann Robert W. , Yu Pengfei , Rosenlof Karen H. , Avery Melody , Kloss Corinna , Li Can , Glanville Anne S. , Millán Luis , Deshler Terry , Krotkov Nickolay , Toon Owen B.
Published: October 2022

The January 2022 Hunga Tonga-Hunga Ha’apai volcanic eruption injected a relatively small amount of sulfur dioxide, but significantly more water into the stratosphere than previously seen in the modern satellite record. Here we show that the large amount of water resulted in large perturbations to stratospheric aerosol evolution. Our climate model simulation reproduces the observed enhanced water vapor at pressure levels ~30 hPa for three months. Compared with a simulation without a water injection, this additional source of water vapor increases hydroxide, which halves the sulfur dioxide lifetime. Subsequent coagulation creates larger sulfate particles that double the stratospheric aerosol optical depth. A seasonal forecast of volcanic plume transport in the southern hemisphere indicates this eruption will greatly enhance the aerosol surface area and water vapor near the polar vortex until at least October 2022, suggesting that there will continue to be an impact of this eruption on the climate system.
Study on the formation mechanism of asymmetric growth hillocks on pyramidal faces of KDP crystals
Authors: Xu Longyun , Wang Shenglai , Yu Guangwei , Liu Hui , Zhang Liyuan , Li Xianglin
Published: October 2022

Growth hillocks on the pyramidal faces of KDP crystals were investigated using an atomic force microscope (AFM) and first-principles analysis techniques.
Five 3D Co(ii)-MOFs constructed from 5-(2-methylimidazol-1-yl) isophthalic acid and different bis(imidazole) ligands and one of their derivatives as an efficient electrocatalyst for ORR
Authors: Yang Ming-Xing , Yan Rong-Zhi , Chen Li-Juan , Lin Shen
Published: October 2022

Five 3D Co(II)-MOFs constructed from 5-(2-methylimidazol-1-yl) isophthalic acid and different bis(imidazole) ligands and one of their derivatives as an efficient electrocatalyst for ORR.
Monitoring nanoparticle dissolution via fluorescence-colour shift
Authors: Ritschel Christian , Napp Joanna , Alves Frauke , Feldmann Claus
Published: October 2022

Nanoparticle dissolution is monitored via a fluorescence-colour shift. Intact solid nanoparticles show red emission, whereas green emission indicates nanoparticle dissolution. As a proof-of-concept, this is also shown in vitro.
Backbone flexibility/amphiphilicity modulation of AIE active polyelectrolytes for mitochondria- and nucleus-targeted synergistic photodynamic therapy of cancer cells
Authors: He Zhiguo , Han Xuejiao , Yan Zifeng , Guo Bing , Cai Qiang , Yao Youwei
Published: October 2022

Mitochondria- and nucleus-targeted photodynamic therapy (PDT) to locally destruct organelles that play vital roles in physiologic processes holds great promise.
DFT study on ruthenium-catalyzedN-methylbenzamide-directed 1,4-addition of theorthoC–H bond to maleimideviaC–H/C–C activation
Authors: Wu Zi-Hao , Fang De-Cai
Published: October 2022

B3LYP-D3a+IDSCRF/tzp-dkh(-dfg) calculations indicate that CO as a directing group is much more favourable than the N–H group, and the real active catalyst is an ionic type with one [SbF6]−group.
Diamond nitrogen‐vacancy centres spin‐state‐based quantum sensor using a compact broadband antenna
Authors: Cui Mingming , Shen Fazhong , Qiao Yingying , Du Guanxiang , Zhuo Xiang , Zang Jiawei , Zhang Zhenyuan , Wang Yi , Li Lei , Gao Yang
Published: October 2022

This paper presents a compact broadband antenna that is used in the spin‐state‐based magnetic field quantum sensor. In the diamond nitrogen‐vacancy (NV) centre system, the qubit resonance is excited by the microwave signal, and the frequency shift is proportional to the external magnetic field strength. Conventional narrow‐band antennas or single resonators are not able to match the resonance frequency of the NV centre over a wide bandwidth, resulting in degraded sensitivity and dynamic range of the sensor. Here, the authors designed a compact broadband antenna, which achieves a fractional bandwidth of 71.43% at the Zeeman splitting frequency of 2.87 GHz. With the introduced slot structure on the antenna, a higher microwave near field strength can also be achieved, which improves the magnetic field sensitivity and dynamic range. By applying our design antenna, the experimental results indicate that the NV‐based quantum sensor achieves a sensitivity of 3.07 μT/Hz1/2 and a dynamic range up to 44.9 dB, which are both greatly improved compared to sensor that uses a conventional antenna.
Generation of turbulent inflow data from realistic approximations of the covariance tensor
Authors: Hao Muting , Hope-Collins Joshua , di Mare Luca
Published: October 2022

This study presents a novel synthetic inflow generator capable of producing a random field matching a realistic set of two-point statistics with minimal input. The method is based on two main elements. The first element is a procedure to infer realistic two-point covariance tensors from readily available data (e.g., freestream velocity, boundary layer thickness, and turbulence intensity) by a preliminary Reynolds-averaged Navier–Stokes simulation with an explicit algebraic Reynolds stress model closure. The second element is an efficient eigen-decomposition step of the two-point correlation tensor, which determines a set of modes. The modal decomposition guarantees the spatial correlation in transversal directions, while the temporal correlation/streamwise spatial correlation is obtained by digital filters based on longitudinal and transversal spectra of a realistic shape and Taylor's hypothesis. The instantaneous inlet flow field is obtained by a linear combination of the modes via uncorrelated random weights with unit variance. The modes are generated in a computationally inexpensive pre-processing step. Compared to existing inflow generation methods that try to match given two-point statistics, the proposed method relieves the burden of obtaining data from direct numerical simulation (DNS) or experiments, while the complexity of the eigenvalue problem that needs to be solved is reduced. The proposed method is shown to produce a realistic turbulent channel flow and a realistic turbulent boundary layer by the large-eddy simulation, which contains statistics that are in good agreement with results from DNS. The proposed inflow generator features, cost-effectiveness, robustness, and potential for generalization to complex geometries.
Learning ocean circulation models with reservoir computing
Authors: Yao Kevin , Forgoston Eric , Yecko Philip
Published: October 2022

Two elementary models of ocean circulation, the well-known double-gyre stream function model and a single-layer quasi-geostrophic (QG) basin model, are used to generate flow data that sample a range of possible dynamical behavior for particular flow parameters. A reservoir computing (RC) machine learning algorithm then learns these models from the stream function time series. In the case of the QG model, a system of partial differential equations with three physically relevant dimensionless parameters is solved, including Munk- and Stommel-type solutions. The effectiveness of a RC approach to learning these ocean circulation models is evident from its ability to capture the characteristics of these ocean circulation models with limited data including predictive forecasts. Further assessment of the accuracy and usefulness of the RC approach is conducted by evaluating the role of both physical and numerical parameters and by comparison with particle trajectories and with well-established quantitative assessments, including finite-time Lyapunov exponents and proper orthogonal decomposition. The results show the capability of the methods outlined in this article to be applied to key research problems on ocean transport, such as predictive modeling or control.
Study of the streamwise location of a micro vortex generator for a separation-control mechanism in supersonic flow
Authors: Wu Han , Huang Wei , Zhong Xiang-Yu , Du Zhao-Bo
Published: October 2022

A shock wave/boundary layer interaction is a common phenomenon in supersonic (hypersonic) flows, and it usually occurs in an airbreathing propulsion system. It induces a large separation bubble and a local peak heat flux, and means of controlling it have attracted much attention. In this paper, three-dimensional Reynolds-averaged Navier–Stokes equations and the shear stress transfer k–ω model are employed to study the flow control mechanism of a micro vortex generator in a supersonic flow with a freestream at a Mach number of 2.9; the influence of the streamwise location is taken into consideration. At the same time, due to the size of the separation bubble induced by the shock wave/boundary layer interaction, the total pressure recovery coefficient and the wall heat flux density are used to evaluate the control performance. The results show that the size of the separation bubble is greatly reduced, the area of the separation bubble is reduced by 29.63%, and its volume is reduced by 63.27%. However, this entails a total pressure loss and a large peak heat flux, and this should be dealt with through multi-objective design optimization approaches.
Contact angle ageing and anomalous capillary flow of a molten metal
Authors: Lazaridis Konstantinos , Wu Yangyang , Krishna Santhosh K. Muniyal , Yu Cheng-Nien , Krivilyov Mikhail D. , Sekulic Dusan P. , Mesarovic Sinisa Dj.
Published: October 2022

Recent capillary flow experiments, conducted on a combined wetting/non-wetting assemble, consistently feature an anomalous flow over the non-wetting substrate: (i) apparent abrupt or gradual recession stages in the motion of the contact line, (ii) non-monotonic abrupt changes in the receding contact angle, and (iii) contact angle overshoot above the nominal equilibrium contact angle. We find that such behavior of a liquid metal alloy cannot be explained by the standard capillary flow models. However, a model that includes the ageing of the equilibrium contact angle predicts all the observed features qualitatively. We use the phase field formulation for capillary flows with a diffusive motion of the triple line to accommodate the novel diffusive boundary condition with the time-evolving quasi-equilibrium contact angle. We discover that the observed anomalies in capillary flow are qualitatively explained by two factors: (1) time evolution (ageing) of the quasi-equilibrium contact angle and (2) high viscosity of the partially molten braze. We also discover that for the given flow geometry, the transition from the initial to the final configuration may follow two distinct topological paths: one is characterized by a coalescence of liquid–solid contact domains, the other by a contact separation. The selection of the two paths in the configurational space is dependent on both contact ageing parameters and viscosity.
The roles of rigid splitter plates in flow-induced vibration of a circular cylinder
Authors: Sun Yuankun , Wang Jiasong , Fan Dixia , Zheng Hanxu , Hu Zhongming
Published: October 2022

While it is known that rigid splitter plates play significant roles in flow control, the exact roles of them in flow-induced vibration (FIV) have not been systematically investigated. This has motivated the present work to experimentally investigate the FIV of a cylinder equipped with an upstream rigid splitter plate (USP), a downstream plate (DSP), and symmetrically arranged splitter plates in a water tunnel with Reynolds number of 1100–7700. The length of the plate is in a range of L* = 0–3.6 (L*=L/D, L is the plate length, D is the cylinder diameter). The response characteristics, vortex evolution, fluid force, and pressure fields are thoroughly analyzed. Both USP and DSP can succeed in oscillation mitigation and drag reduction. However, dramatic galloping is observed for DSP with L* = 0.4–3.2. The low-pressure region forms near the downstream plate is beneficial to trigger galloping. For USP, only vortex-induced vibration is found, and the transition of response branches corresponds to the variation in oscillation frequency and phase jumps in total transverse force and vortex force. However, the vortex mode transition from 2S to 2P disappears with long plate length. Flow visualization reveals that the upstream vortex induced by USP alters the downstream vortex shedding. Furthermore, a high-pressure region forms near the tip of USP, yielding an obstructive force that suppresses the growth of oscillation. With the combination of USP and DSP, weak galloping is excited in a narrow range of L* = 1.0–1.8, and the linear increase is also broken due to the existence of USP.
Magnus induced diode effect for skyrmions in channels with periodic potentials
Authors: Bellizotti Souza J C , Vizarim N P , Reichhardt C J O , Reichhardt C , Venegas P A
Published: October 2022

Using a particle based model, we investigate the skyrmion dynamical behavior in a channel where the upper wall contains divots of one depth and the lower wall contains divots of a different depth. Under an applied driving force, skyrmions in the channels move with a finite skyrmion Hall angle that deflects them toward the upper wall for −x direction driving and the lower wall for +x direction driving. When the upper divots have zero height, the skyrmions are deflected against the flat upper wall for −x direction driving and the skyrmion velocity depends linearly on the drive. For +x direction driving, the skyrmions are pushed against the lower divots and become trapped, giving reduced velocities and a nonlinear velocity-force response. When there are shallow divots on the upper wall and deep divots on the lower wall, skyrmions get trapped for both driving directions; however, due to the divot depth difference, skyrmions move more easily under −x direction driving, and become strongly trapped for +x direction driving. The preferred −x direction motion produces what we call a Magnus diode effect since it vanishes in the limit of zero Magnus force, unlike the diode effects observed for asymmetric sawtooth potentials. We show that the transport curves can exhibit a series of jumps or dips, negative differential conductivity, and reentrant pinning due to collective trapping events. We also discuss how our results relate to recent continuum modeling on a similar skyrmion diode system.