bluuebunny/crossref_metadata_2025_split huggingface dataset:
A long term resilient modulus rate dependent model for coarse fine mixtures geomaterials under freezing and thawing cyclic
Authors: Wang Ke , Tang Liang , Tian Shuang , Ling XianZhang , Ye Yangsheng , Cai Degou , Liu Min 
Published: October 2022

AbstractThe cyclic loading frequency (fcyc) effects on the resilient modulus (Mr) of freezing–thawing coarse–fine mixtures geomaterials (FTCFG) have always been a research hotspot. A series of long-term cyclic triaxial tests were conducted on FTCFG having different fines content (FC) under different number of freeze–thaw cycles (NFT) to investigate the effect of fcyc and deviator stress amplitude (qcyc) on the Mr of FTCFG. The freezing–thawing cyclic was found to improve the Mr of FTCFG. Additionally, Mr of FTCFG shown an obviously rate-dependent characteristics. Then three kinetic effects (rate effect, piston effect, and fatigue effect) are discussed in systemically which are related to qcyc, fcyc and moisture holding capacity (wh). Finally, a rate dependent model of long-term resilient modulus was developed to predict FTCFG materials’ resilient moduli as a function of qcyc, fcyc and wh. The comparisons between the calculation and experimental results reveal that the present model describes the Mr of FTCFG well.
Utilization of CO2 in supercritical conditions for the synthesis of cyclic poly (N-isopropylacrylamide) via emulsion and homogeneous reactions
Authors: Daneshyan Sahar , Sodeifian Gholamhossein 
Published: October 2022

AbstractIn this study, cyclic poly (N-isopropylacrylamide) (cPNIPAAM) was synthesized in supercritical carbon dioxide (SC-CO2) using emulsion and homogeneous reactions for the first time. This was accomplished by applying free radical polymerization and nitroxide compounds to produce low molecular weight precursors in the SC-CO2 solvent. The cyclization reaction occurred in a homogeneous phase in the SC-CO2 solvent, with dimethylformamide (DMF) serving as a co-solvent for dissolving the linear precursor. This reaction was also conducted in emulsion of SC-CO2 in water. The effects of pressure and time on the morphology, molecular weight, and yield of a difunctionalized chain were investigated, where a higher pressure led to a higher yield. The maximum yield was 64% at 23 MPa, and the chain molecular weight (Mw) was 4368 (gr/mol). Additionally, a lower pressure reduced the solubility of materials (particularly terminator) in SC-CO2 and resulted in a chain with a higher molecular weight 9326 (gr/mol), leading to a lower conversion. Furthermore, the effect of cyclization reaction types on the properties of cyclic polymers was investigated. In cyclic reactions, the addition of DMF as a co-solvent resulted in the formation of a polymer with a high viscosity average molecular weight (Mv) and a high degree of cyclization (100%), whereas the CO2/water emulsion resulted in the formation of a polymer with a lower Mv and increased porosity. Polymers were characterized by 1HNMR, FTIR, DSC, TLC, GPC, and viscometry tests. The results were presented and thoroughly discussed.
Infrasonic gliding reflects a rising magma column at Mount Etna (Italy)
Authors: Sciotto Mariangela , Watson Leighton M. , Cannata Andrea , Cantarero Massimo , De Beni Emanuela , Johnson Jeffrey B. 
Published: October 2022

AbstractInfrasound is increasing applied as a tool to investigate magma dynamics at active volcanoes, especially at open-vent volcanoes, such as Mt. Etna (Italy), which are prodigious sources of infrasound. Harmonic infrasound signals have been used to constrain crater dimensions and track the movement of magma within the shallow plumbing system. This study interprets the remarkable systematic change in monotonic infrasound signals preceding a lava fountaining episode at Mt. Etna on 20 February 2021. We model the changing tones (0.7 to 3 Hz fundamental frequency) as a rise in the magma column from 172 ± 25 m below the crater rim to 78 ± 8 m over the course of 24 h. The infrasonic gliding disappears approximately 4 h before the onset of lava fountaining as the magma column approaches the flare of the crater and acoustic resonance is no longer supported. The featured 20 February event was just one of 52 lava fountain episodes that occurred at Mt. Etna over the course of 9 months in 2021 and was the only lava fountain episode where dramatic gliding was observed as a subsequent partial collapse of the crater prevented future resonance. The results presented here demonstrate that analysis of infrasonic gliding can be used to track the position of the magma free surface and hence may provide information on the processes taking place within the plumbing system before eruptive activity.
Thermal enhancement and numerical solution of blood nanofluid flow through stenotic artery
Authors: Sarwar Lubna , Hussain Azad , Fernandez-Gamiz Unai , Akbar Sobia , Rehman Aysha , Sherif El-Sayed M. 
Published: October 2022

AbstractThe blood flow through stenotic artery is one of the important research area in computational fluid mechanics due to its application in biomedicine. Aim of this research work is to investigate the impact of nanoparticles on the characteristics of human blood flow in a stenosed blood artery. In under consideration problem Newtonian fluid is assumed as human blood. Newtonian fluid flows through large blood vessels (more than 300 μm). The constitutive equations together with the boundary conditions are diminished to non-dimensional form by using boundary layer approximation and similarity transfiguration to attain the solution of velocity and temperature distribution of blood flow through arterial stenosis numerically with the help of Matlab bvp4c. The results for physical quantities at cylindrical surface are calculated and their effects are also presented through tables. The heat transfer rate increases throughout the stenosed artery with the concentration of copper nanoparticle. Velocity curve decreases by increasing the values of flow parameter and nanoparticle volume fraction. Temperature curve increases due to increase in the values of nanoparticle volume fraction and decrease in Prandtl number.
Evaluating the detectability of methane point sources from satellite observing systems using microscale modeling
Authors: Bhardwaj Piyush , Kumar Rajesh , Mitchell Douglas A. , Randles Cynthia A. , Downey Nicole , Blewitt Doug , Kosovic Branko 
Published: October 2022

AbstractThis study evaluates the efficacy of current satellite observing systems to detect methane point sources from typical oil and gas production (O&G) facilities using a novel very high-resolution methane concentration dataset generated using a microscale model. Transport and dispersion of typical methane emissions from seven well pads were simulated and the column enhancements for pseudo satellite pixel sizes of 3, 1, and 0.05 km were examined every second of the 2-h simulations (7200 realizations). The detectability of plumes increased with a pixel resolution, but two orders of magnitude change in emission rates at the surface results only in about 0.4%, 1.6%, and 47.8% enhancement in the pseudo-satellite retrieved methane column at 3, 1, and 0.05 km, respectively. Average methane emission rates estimated by employing the integrated mass enhancement (IME) method to column enhancements at 0.05 km showed an underestimation of the mean emissions by 0.2–6.4%. We show that IME derived satellite-based inversions of methane emissions work well for large persistent emission sources (e.g., super emitters), however, the method is ill-suited to resolve short-term emission fluctuations (< 20 min) in typical well site emissions due to the limitations in satellite detection limits, precision, overpass timing, and pixel resolution.
Gut microbiome diversity of porcine peritonitis model of sepsis
Authors: Chalupova Miroslava , Horak Jan , Kramna Lenka , Nalos Lukas , Stengl Milan , Chudejova Katerina , Kraftova Lucie , Cinek Ondrej , Klein Pavel , Matejovic Martin , Hrabak Jaroslav 
Published: October 2022

AbstractAnimal models are essential in understanding of the mechanisms of sepsis moreover the development and the assessment of emerging therapies. In clinically relevant porcine model, however, a significant variability in the host response has been observed among animals. Thus, there is a strong demand to better understand the potential sources of this heterogeneity. In this study, we compared faecal microbiome composition of 12 animals. Three samples were collected at different time points from each animal. Bacteriome was subjected to 16S rDNA profiling. A significant difference in bacterial composition was associated with the season (p < 0.001) but not with the sex of the pig (p = 0.28), the timing of sample collection (p = 0.59), or interactions thereof (all p > 0.3). The season batch explained 55% of the total variance in the bacteriome diversity. The season term was highly significant from the high-resolution level of the bacterial amplicon sequencing variants up to the level of phylum. The diversity of the microbiome composition could significantly influence experimental model of sepsis, and studies are warranted to demonstrate the effects of gut microbiome diversity on the host-response. If confirmed, control of the gut microbiome should become a standard part of the pre-clinical sepsis experiments.
Investigating attentional scope as a novel indicator of emotional state in animals
Authors: Hamlaoui Anne , Keeling Linda , Burman Oliver , Verbeek Else 
Published: October 2022

AbstractIn humans, contrasting emotional states can lead to a broadening or narrowing of attentional scope. Whether this is also the case in animals has yet to be investigated. If confirmed, measurement of attentional scope has potential as a novel cognitive method of welfare assessment. In this study, we therefore aimed to investigate a test of attentional scope as a measure of emotional state in animals. We did this by inducing four putatively different emotional states in dogs (N = 10), varying in valence (positive, negative) and arousal (high, low), in two different reward contexts (food rewards in Experiment 1, social rewards in Experiment 2) and then assessing dogs’ behavioural responses in a test of attentional scope. We also recorded heart rate variability (HRV) parameters as additional confirmatory affective indicators. In Experiment 1, the dogs showed a narrowing of attentional scope after the induction of both positively valenced emotional states. That dogs were in a positive state was supported by the reduced Standard Deviation of normal-to-normal R-R intervals (SDNN) and the reduced Low Frequency (LF) and Very Low Frequency (VLF) HRV. In Experiment 2, when responses to social rewards were examined, we did not detect any statistically significant differences in attentional scope between the emotional states, but dogs had a slightly narrow attentional scope in the negatively valenced emotional states. The LF tended to be reduced in the high arousal positive treatment. In conclusion, our study provides the first indication that emotional states can also alter attentional scope in animals. The results justify further investigation of this approach for use in animal welfare assessment, although additional studies are needed to refine predictions.
Low-voltage driving high-resistance liquid crystal micro-lens with electrically tunable depth of field for the light field imaging system
Authors: Wang Wenwen , Chen Wandi , Peng Yuyan , Zhang Yongai , Yan Qun , Guo Tailiang , Zhou Xiongtu , Wu Chaoxing 
Published: October 2022

AbstractLight field imaging (LFI) based on Liquid crystal microlens array (LC MLAs) are emerging as a significant area for 3D imaging technology in the field of upcoming Internet of things and artificial intelligence era. However, in scenes of LFI through conventional MLAs, such as biological imaging and medicine imaging, the quality of imaging reconstruction will be severely reduced due to the limited depth of field. Here, we are proposed a low-voltage driving LC MLAs with electrically tunable depth of field (DOF) for the LFI system. An aluminum-doped zinc oxide (AZO) film was deposited on the top of the hole-patterned driven-electrode arrays and used as a high resistance (Hi-R) layer, a uniform gradient electric field was obtained across the sandwiched LC cell. Experimental results confirm that the proposed LC MLAs possess high-quality interference rings and tunable focal length at a lower working voltage. In addition, the focal lengths are tunable from 3.93 to 2.62 mm and the DOF are adjustable from 15.60 to 1.23 mm. The experiments demonstrated that the LFI system based on the proposed structure can clearly capture 3D information of the insets with enlarged depths by changing the working voltage and driving frequency, which indicates that the tunable DOF LC MLAs have a potential application prospects for the biological and medical imaging.
Clinician preference instrumental variable analysis of the effectiveness of magnesium supplementation for atrial fibrillation prophylaxis in critical care
Authors: Wilson Matthew G. , Rashan Aasiyah , Klapaukh Roman , Asselbergs Folkert W. , Harris Steve K. 
Published: October 2022

AbstractAtrial fibrillation is a frequently encountered condition in critical illness and causes adverse effects including haemodynamic decompensation, stroke and prolonged hospital stay. It is a common practice in critical care to supplement serum magnesium for the purpose of preventing episodes of atrial fibrillation. However, no randomised studies support this practice in the non-cardiac surgery critical care population, and the effectiveness of magnesium supplementation is unclear. We sought to investigate the effectiveness of magnesium supplementation in preventing the onset of atrial fibrillation in a mixed critical care population. We conducted a single centre retrospective observational study of adult critical care patients. We utilised a natural experiment design, using the supplementation preference of the bedside critical care nurse as an instrumental variable. Using routinely collected electronic patient data, magnesium supplementation opportunities were defined and linked to the bedside nurse. Nurse preference for administering magnesium was obtained using multilevel modelling. The results were used to define "liberal" and "restrictive" supplementation groups, which were inputted into an instrumental variable regression to obtain an estimate of the effect of magnesium supplementation. 9114 magnesium supplementation opportunities were analysed, representing 2137 critical care admissions for 1914 patients. There was significant variation in magnesium supplementation practices attributable to the individual nurse, after accounting for covariates. The instrumental variable analysis showed magnesium supplementation was associated with a 3% decreased relative risk of experiencing an atrial fibrillation event (95% CI − 0.06 to − 0.004, p = 0.03). This study supports the strategy of routine supplementation, but further work is required to identify optimal serum magnesium targets for atrial fibrillation prophylaxis.
Predicting mortality in the very old: a machine learning analysis on claims data
Authors: Krasowski Aleksander , Krois Joachim , Kuhlmey Adelheid , Meyer-Lueckel Hendrik , Schwendicke Falk 
Published: October 2022

AbstractMachine learning (ML) may be used to predict mortality. We used claims data from one large German insurer to develop and test differently complex ML prediction models, comparing them for their (balanced) accuracy, but also the importance of different predictors, the relevance of the follow-up period before death (i.e. the amount of accumulated data) and the time distance of the data used for prediction and death. A sample of 373,077 insured very old, aged 75 years or above, living in the Northeast of Germany in 2012 was drawn and followed over 6 years. Our outcome was whether an individual died in one of the years of interest (2013–2017) or not; the primary metric was (balanced) accuracy in a hold-out test dataset. From the 86,326 potential variables, we used the 30 most important ones for modeling. We trained a total of 45 model combinations: (1) Three different ML models were used; logistic regression (LR), random forest (RF), extreme gradient boosting (XGB); (2) Different periods of follow-up were employed for training; 1–5 years; (3) Different time distances between data used for prediction and the time of the event (death/survival) were set; 0–4 years. The mortality rate was 9.15% in mean per year. The models showed (balanced) accuracy between 65 and 93%. A longer follow-up period showed limited to no advantage, but models with short time distance from the event were more accurate than models trained on more distant data. RF and XGB were more accurate than LR. For RF and XGB sensitivity and specificity were similar, while for LR sensitivity was significantly lower than specificity. For all three models, the positive-predictive-value was below 62% (and even dropped to below 20% for longer time distances from death), while the negative-predictive-value significantly exceeded 90% for all analyses. The utilization of and costs for emergency transport as well as emergency and any hospital visits as well as the utilization of conventional outpatient care and laboratory services were consistently found most relevant for predicting mortality. All models showed useful accuracies, and more complex models showed advantages. The variables employed for prediction were consistent across models and with medical reasoning. Identifying individuals at risk could assist tailored decision-making and interventions.
Design, structural, spectral, DFT and analytical studies of novel nano-palladium schiff base complex
Authors: Akl Magda A. , El-Mahdy Nora A. , El-Gharkawy El-Sayed R. H. 
Published: October 2022

AbstractA novel nano-palladium (II) Schiff base complex (C1) is synthesized by the reaction between palladium chloride and the Schiff base N, N’-1, 2-phenylene) bis (3 -aminobenzamide (A1). The prepared compounds were characterized by elemental analysis, Ultraviolet–Visible spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Thermogravimetric Analysis (TGA). A combined solvent sublation-ICP OES methodology has been studied for the preconcentration, separation and determination of trace palladium (II) in media of diverse origin using the Schiff base ligand (A1). The different experimental variables that affect the sublation efficiency (S, %) were thoroughly investigated viz.: pH of sample solution; amounts of A1, Pd (II) and TBAB; type and amounts of surfactants, types of organic solvent, temperature and stirring time. The method involves the determination of trace palladium (II) after selective separation by solvent sublation, thus eliminating the effect of foreign ions and increasing the sensitivity. Also, palladium is determined directly in the organic phase, which decreases the determination time and its loss during determination. At optimum conditions, the linear range of Pd (II) was 10.0–100.0 ngmL−1. The coefficient of determination, the limit of detection (LOD) and limit of quantification (LOQ) were 0.9943, 21.29 ngL−1 and 64.5 ngL−1, respectively. This sublation method was applied to real samples and recoveries of more than 95% were obtained in the spiked samples with a preconcentration factor of 100. The mechanism of solvent sublatation of the TBA.[PdII-(A1)2] ion pairs is discussed. The computational studying was estimated to approve the geometry of the isolated solid compounds.
Prevalence of acute neurological complications and pathological neuroimaging findings in critically ill COVID-19 patients with and without VV-ECMO treatment
Authors: Ippolito Angelo , Urban Hans , Ghoroghi Kimia , Rosbach Nicolas , Lingwal Neelam , Adam Elisabeth H. , Friedrichson Benjamin , Steinbicker Andrea U. , Hattingen Elke , Wenger Katharina J. 
Published: October 2022

AbstractAcute brain injuries such as intracerebral hemorrhage (ICH) and ischemic stroke have been reported in critically ill COVID-19 patients as well as in patients treated with veno-venous (VV)-ECMO independently of their COVID-19 status. The purpose of this study was to compare critically ill COVID-19 patients with and without VV-ECMO treatment with regard to acute neurological symptoms, pathological neuroimaging findings (PNIF) and long-term deficits. The single center study was conducted in critically ill COVID-19 patients between February 1, 2020 and June 30, 2021. Demographic, clinical and laboratory parameters were extracted from the hospital’s databases. Retrospective imaging modalities included head computed tomography (CT) and magnetic resonance imaging (MRI). Follow-up MRI and neurological examinations were performed on survivors > 6 months after the primary occurrence. Of the 440 patients, 67 patients received VV-ECMO treatment (15%). Sixty-four patients (24 with VV-ECMO) developed acute neurological symptoms (pathological levels of arousal/brain stem function/motor responses) during their ICU stay and underwent neuroimaging with brain CT as the primary modality. Critically ill COVID-19 patients who received VV-ECMO treatment had a significantly lower survival during their hospital stay compared to those without (p < 0.001). Among patients treated with VV-ECMO, 10% showed acute PNIF in one of the imaging modalities during their ICU stay (vs. 4% of patients in the overall COVID-19 ICU cohort). Furthermore, 9% showed primary or secondary ICH of any severity (vs. 3% overall), 6% exhibited severe ICH (vs. 1% overall) and 1.5% were found to have non-hemorrhagic cerebral infarctions (vs. < 1% overall). There was a weak, positive correlation between patients treated with VV-ECMO and the development of acute neurological symptoms. However, the association between the VV-ECMO treatment and acute PNIF was negligible. Two survivors (one with VV-ECMO-treatment/one without) showed innumerable microhemorrhages, predominantly involving the juxtacortical white matter. None of the survivors exhibited diffuse leukoencephalopathy. Every seventh COVID-19 patient developed acute neurological symptoms during their ICU stay, but only every twenty-fifth patient had PNIF which were mostly ICH. VV-ECMO was found to be a weak risk factor for neurological complications (resulting in a higher imaging rate), but not for PNIF. Although logistically complex, repeated neuroimaging should, thus, be considered in all critically ill COVID-19 patients since ICH may have an impact on the treatment decisions and outcomes.