bluuebunny/crossref_metadata_2025_split huggingface dataset:
Seismic control performance of a three‐story frame prototype equipped with semi‐active variable stiffness and damping structural joints
Authors: Wang Qinyu , Senatore Gennaro , Jansen Kaspar , Habraken Arjan , Teuffel Patrick 
Published: July 2021

AbstractThis paper presents numerical and experimental studies on semi‐active seismic response control of structures equipped with variable stiffness and damping structural joints. Such adaptive joints, which are comprised of a shape memory polymer (SMP) core reinforced by an SMP‐aramid composite skin, function as load‐transfer components as well as semi‐active control devices. The SMP core material can transition from a glassy to a rubbery state through thermal actuation resulting in a shift of the structural natural frequencies and a parallel increase of damping ratio, which enables a new semi‐active control strategy. Control performance has been evaluated on a three‐story frame equipped with 12 adaptive joints and subjected to seismic excitations. Full‐transient analysis has shown that when the joints are thermally actuated to the transition temperature (65°C), acceleration and base shear are reduced by up to 62% and 65%, respectively. Shake‐table tests have been carried out on a 1/10‐scale prototype, confirming that through thermal actuation of the adaptive joints the structural damping ratio increases from 2.6% to 11.3% and the first natural frequency shifts by up to 37%. As the structure becomes more flexible, an increase of displacements and interstory drift might occur. However, depending on the seismic excitation, top‐story acceleration and base shear are significantly reduced in the range 43%–50% and 35%–51%, respectively. These results confirm that semi‐active control through thermal actuation of variable stiffness and damping structural joints is effective to mitigate the structure response under seismic excitation.
Characteristics of in situ stress and its influence on coal seam permeability in the Liupanshui Coalfield, Western Guizhou
Authors: Fang Xiaojie , Wu Caifang , Jiang Xiuming , Liu Ningning , Zhou Dan , Ju Yiwen 
Published: July 2021

AbstractThe current in situ stress regime is of great significance to the exploration and development of coalbed methane (CBM). In this study, the vertical stress (), maximum horizontal principal stress (), and minimum horizontal principal stress () in the Liupanshui Coalfield were studied. Variations of the maximum and minimum envelopes and trend lines of the lateral pressure coefficient () with depth were obtained, and the non‐monotonic decrease of permeability with burial depth was determined. On this basis, the effect of in situ stress on the coal reservoir permeability was evaluated. The results show that the average vertical stress gradient of the main coal seam in the Liupanshui Coalfield is 0.024 MPa/m. Generally, there are two stress regimes of > > (44.23%) and > > (46.15%); > > accounts for a smaller proportion (9.62%), and only occurs in relatively shallow coal seams (<622.85 m). In the range of the tested burial depths, for <600 m, > > is dominant; > > is dominant between 600 and 800 m; and between 800 and 980 m, the coal reservoir is affected by both > > and > > , representing a transition zone between the two stress states. With the increase of burial depth, the permeability of the coal reservoir shows a complex non‐monotonic decline, and the variation of the permeability of the coal reservoir differs under the influence of different stress regimes. Further analysis shows that under the background of stress regime transformation, permeability is mainly affected by the stress value, horizontal principal stress difference, stress regime, and coal cleat, indicating that in situ stress is the main controlling factor of coal reservoir permeability in the Liupanshui Coalfield.
New shape‐stabilized phase change materials obtained by single‐screw extruder
Authors: Salgado‐Pizarro Rebeca , Ulldemolins Guilllermo , Navarro Maria Elena , Palacios Anabel , Calderón Alejandro , Ding Yulong , Fernández A. Ines , Barreneche Camila 
Published: July 2021

AbstractShape‐stabilized phase change materials (SS‐PCM) are promising materials given their potential to control leakage of liquid PCM. However, SS‐PCM still has low thermal conductivity and high flammability, which are important properties for several applications, such as the thermal indoor comfort in buildings. In this study, two new polymeric SS‐PCM were developed and their properties were optimized by the use of different additives. Both high‐density polyethylene (HDPE) and polyoxymethylene (POM) work as matrix materials and MPCM 28 from Microtek acts as PCM. Besides, the graphite was used as an additive material to increase the thermal conductivity, and the magnesium hydroxide to minimize flammability of the composite. Both inorganic fillers also help in the PCM dispersion within the matrix. To evaluate the effect of each component, seven formulations were manufactured by a single screw extruder and a set of characterization (Differential scanning calorimetry, Thermogravimetric analyses, for thermophysical evaluation, and dynamical mechanical analyses, for thermomechanical evaluation over 1000 thermal cycles was performed. The main outputs of the investigation are the proposed formulations that have a good fire reaction performance, whereas their thermal and chemical stability are guaranteed up to 1000 cycles. The HDPE samples present around 12 kJ/kg melting enthalpy when 10 wt% microencapsulated PCM is included in the formulation. In addition, the POM samples present around 7.5 kJ/kg when 10 wt% microencapsulated PCM is included in the formulation. For all formulations, the melting enthalpy obtained is around 27.5°C, in concordance with the reported by the manufacturer.
Physics‐based numerical simulation of heat and moisture transport in red chili subjected to mix‐mode solar drying with phase change energy storage
Authors: Ndukwu Macmanus C. , Horsfall Ibiba T. , Onwude Daniel I. , Simo‐Tagne Merlin , Abam Fidelis I. 
Published: July 2021

AbstractIn this study, a coupled heat and mass transfer model was developed using a finite element (FE) simulation approach to describe solar drying of red chili integrated with Na2SO4∙10H2O as phase change material thermal storage. The coupled heat and mass transfer equation solution was achieved by using COMSOL multiphysics with three‐dimensional (3D) axisymmetric geometry mesh generation. The Lagrange triangular FEs of very fine size were employed in obtaining the geometry of the mesh. This study adopts a time‐dependent study that shows the variation of time within 0, 2, 3, 4, and 5 hours, respectively, for continuous drying of red chili in the solar dryer. The effect of air temperature and thermal storage on temperature and moisture distribution on drying of red chili was investigated. The temperature distribution was not uniform and heat transfer at the base was higher than the tip while there is a clear moisture gradient for different drying times, though this moisture moves from the base to the tip and more uniform distribution was obtained after 4 hours of drying. Drying temperature increased from a side to the core of the sample as the drying progresses. Although thermal storage accelerated the drying process, solar radiation showed a greater influence on the drying process. The developed numerical model with the experimental results showed the same trend with the values of MAE and SE for temperature found to be 0.48132 and 0.000842 for the without thermal storage (NTS) sample, 0.2266 and 30.000551 for thermal storage (TS). Also, the values of MAE and SE are 0.0051 and 0.006048 for NTS, 0.00212 and 0.00538 for TS, respectively for moisture profile. The lower values of these errors specify a better prediction capability of the model code.
Highly active carbon nanotube supported iridium, copper, ruthenium catalysts for glucose electrooxidation
Authors: Er Omer Faruk , Kivrak Hilal 
Published: July 2021

AbstractHerein, carbon nanotube (CNT) supported ruthenium (Ru), iridium (Ir), and copper (Cu) catalysts at 0.1 to 20 wt% metal loading are prepared by the NaBH4 reduction method for glucose electrooxidation reaction (GER). These catalysts are successfully characterized by X‐ray diffraction, scanning electron microscope, and N2 adsorption‐desorption measurements. Voltammetric measurements of these catalysts are taken using cyclic voltammetry and chronoamperometry techniques. The crystallite sizes of these catalysts are calculated as 2.53 nm for Ru/CNT, 2.94 nm for Ir/CNT, and 13.06 nm for Cu/CNT by using Scherrer equation. For GER, 10% Ru/CNT, 0.1% Ir/CNT, and 0.5% Cu/CNT catalysts have high current densities as 1.86 mA cm−2 (160.6 mA mg−1 Ru), 3.03 mA cm−2 (23 857.2 mA mg−1 Ir), and 1.12 mA cm−2 (1768.8 mA mg−1 Cu), respectively. These catalysts have also good stability. Results reveal that 10% Ru/CNT, 0.1% Ir/CNT, and 0.5% Cu/CNT catalysts are promising catalysts as direct glucose fuel cell anode catalysts.
Occurrence and dietary exposure of heavy metals in marketed vegetables and fruits of Shandong Province, China
Authors: Zhang Tianran , Zhang Yuan , Li Wei , Wang Lin , Jiao Yanni , Wang Yuxin , Jiang Dafeng , Gao Xibao 
Published: July 2021

AbstractThe contamination of heavy metals in vegetables and fruits is a serious threat to food safety and human health. The present study was designed to investigate the occurrence and dietary exposure of lead (Pb), arsenic (As), cadmium (Cd), and mercury (Hg) in vegetables and fruits in Shandong Province, China. Results demonstrated that the mean level of total heavy metals was 30.25 µg/kg. The most frequently found heavy metal was Cd (69.2%) with a mean value of 11.54 µg/kg. The mean exposure values of Pb, As, Cd, and Hg in vegetables were 0.052, 0.045, 0.038, and 2.40 × 10–3 µg/kg bw/day, respectively. Moreover, the calculated hazard quotient (HQ) values of mean levels for these four heavy metals were all less than 1, indicating the health risk of heavy metal exposure caused by vegetable consumption was low. This study has displayed baseline information on heavy metal contamination in vegetables and fruits, which can provide useful data support for the formulation of relevant standards and government management.
A systematic review of risk stratification tools internationally used in primary care settings
Authors: Girwar Shelley‐Ann M. , Jabroer Robert , Fiocco Marta , Sutch Stephen P. , Numans Mattijs E. , Bruijnzeels Marc A. 
Published: July 2021

AbstractBackground and AimsIn our current healthcare situation, burden on healthcare services is increasing, with higher costs and increased utilization. Structured population health management has been developed as an approach to balance quality with increasing costs. This approach identifies sub‐populations with comparable health risks, to tailor interventions for those that will benefit the most. Worldwide, the use of routine healthcare data extracted from electronic health registries for risk stratification approaches is increasing. Different risk stratification tools are used on different levels of the healthcare continuum. In this systematic literature review, we aimed to explore which tools are used in primary healthcare settings and assess their performance.MethodsWe performed a systematic literature review of studies applying risk stratification tools with health outcomes in primary care populations. Studies in Organisation for Economic Co‐operation and Development countries published in English‐language journals were included. Search engines were utilized with keywords, for example, “primary care,” “risk stratification,” and “model.” Risk stratification tools were compared based on different measures: area under the curve (AUC) and C‐statistics for dichotomous outcomes and R2 for continuous outcomes.ResultsThe search provided 4718 articles. Specific election criteria such as primary care populations, generic health utilization outcomes, and routinely collected data sources identified 61 articles, reporting on 31 different models. The three most frequently applied models were the Adjusted Clinical Groups (ACG, n = 23), the Charlson Comorbidity Index (CCI, n = 19), and the Hierarchical Condition Categories (HCC, n = 7). Most AUC and C‐statistic values were above 0.7, with ACG showing slightly improved scores compared with the CCI and HCC (typically between 0.6 and 0.7).ConclusionBased on statistical performance, the validity of the ACG was the highest, followed by the CCI and the HCC. The ACG also appeared to be the most flexible, with the use of different international coding systems and measuring a wider variety of health outcomes.
Pathophysiological mechanisms of bradycardia in patients with anorexia nervosa
Authors: Buchhorn Reiner , Baumann Christoph , Willaschek Christian 
Published: July 2021

AbstractBackgroundThe purpose of this investigation was to examine heart rate variability (HRV), interbeat interval (IBI), and their interrelationship in healthy controls, bradycardic hyperpolarization‐activated cyclic nucleotide‐gated channel 4 (HCN4) mutation carriers, and patients with anorexia nervosa (AN). We tested the hypothesis that neural mechanisms cause bradycardia in patients with AN. Therefore, we assumed that saturation of the HRV/IBI relationship as a consequence of sustained parasympathetic control of the sinus node is exclusively detectable in patients with AN.MethodsPatients with AN between the ages of 12 and 16 years admitted to our hospital due to malnutrition were grouped and included in the present investigation (N = 20). A matched‐pair group with healthy children and adolescents was created. Groups were matched for age and sex. A 24‐hour Holter electrocardiography (ECG) was performed in controls and patients. More specifically, all patients underwent two 24‐hour Holter ECG examinations (admission; refeeding treatment). Additionally, the IBI was recorded during the night in HCN4 mutation carriers (N = 4). HRV parameters were analyzed in 5‐minute sequences during the night and plotted against mean corresponding IBI length. HRV, IBI, and their interrelationship were examined using Spearman's rank correlation analyses, Mann‐Whitney U tests, and Wilcoxon signed‐rank tests.ResultsThe relationship between IBI and HRV showed signs of saturation in patients with AN. Furthermore, signs of HRV saturation were present in two HCN4 mutation carriers. In contrast, signs of HRV saturation were not present in controls.ConclusionsThe existence of HRV saturation does not support the existence of parasympathetically mediated bradycardia. Nonneural mechanisms, such as HCN4 downregulation, may be responsible for bradycardia and HRV saturation in patients with AN.
The role of Bag3 in cell signaling
Authors: Sherman Michael Y. , Gabai Vladimir 
Published: July 2021

AbstractBag3 has been implicated in a wide variety of physiological processes from autophagy to aggresome formation and from cell transformation to survival. We argue that involvement of Bag3 in many of these processes is due to its distinct function in cell signaling. The structure of Bag3 suggests that it can serve as a scaffold that links molecular chaperones Hsp70 and small Hsps with components of a variety of signaling pathways. Major protein‐protein interaction motifs of Bag3 that recruit components of signaling pathways are WW domain and PXXP motif that interacts with SH3‐domain proteins. Furthermore, Hsp70‐Bag3 appears to be a sensor of abnormal polypeptides during the proteotoxic stress. It also serves as a sensor of a mechanical force during mechanotransduction. Common feature of these and probably certain other sensory mechanisms is that they represent responses to specific kinds of abnormal proteins, i.e. unfolded filamin A in case of mechanotransduction or stalled translating polypeptides in case of sensing proteasome inhibition. Overall Hsp70‐Bag3 module represents a novel signaling node that responds to multiple stimuli and controls multiple physiological processes.
Construction of Z‐scheme heterojunction g‐C3N4/CQDs/InVO4 with broad‐spectrum response for efficient rhodamine B degradation and H2 evolution under visible light
Authors: Chen Fang‐Yan , Cheng Lei , Tang Yu‐Bin , Shu Ke‐Ke , Shi Wei‐Long 
Published: July 2021

AbstractBACKGROUNDA Z‐scheme structured photocatalyst is a highly efficient photocatalyst for hydrogen evolution and degradation of pollutants.RESULTSAn indirect Z‐scheme heterojunction g‐C3N4/CQDs/InVO4 with carbon quantum dots (CQDs) as electron mediator was constructed and was successfully synthesized using a facile hydrothermal method. The photocatalytic activity of the as‐prepared composite was evaluated in terms of hydrogen generation and degradation of rhodamine B (RhB) dye. The as‐prepared sample CV20/CQDs2 (g‐C3N4/2 wt% CQDs/20 wt% InVO4) exhibits the best photocatalytic activity towards hydrogen production and RhB degradation. Within 90 min, 99.6% of RhB is removed, and the degradation rate constant of RhB over CV20/CQDs2 is 0.06491 min−1, which is 43.9, 6.64 and 3.3 times as high as that of InVO4, g‐C3N4 and binary composite g‐C3N4/InVO4. CV20/CQDs2 exhibits H2 evolution rate of 2.169 mmol g−1 h−1, which is 26.07, 2.65 and 1.6 times as high as that of InVO4, g‐C3N4 and g‐C3N4/InVO4.CONCLUSIONSThe enhanced photocatalytic activity is attributed to two aspects. First, CQDs, as electron mediator, promote the effective separation of photogenerated electrons and holes through Z‐scheme charge transfer pathway, preserving the high redox ability of electrons and holes. Second, g‐C3N4/CQDs/InVO4 shows strong optical absorption in the full visible‐light region. © 2021 Society of Chemical Industry (SCI).
Structurally controlled synthesis of synthetic gypsum derived from industrial wastes: sustainable approach
Authors: Kamarou Maksim , Korob Natalia , Romanovski Valentin 
Published: July 2021

AbstractBACKGROUNDThe article demonstrates the possibility of processing spent sulfuric acid and limestone waste into high‐quality synthetic calcium sulfate dihydrate.RESULTSA comprehensive technological scheme for the production of synthetic gypsum from industrial waste was proposed. Mathematical models of the main technological stages were obtained. In the process of acid processing, at the stage of separating gypsum from the mother liquor, a filtrate was formed containing ions such as Na+, K+, Mg2+ and SO42−, which are some of the main ions necessary for plant growth. A positive effect was found when using the filtrate as fertilizer.CONCLUSIONSOptimal values of synthesis parameters that allow one to obtain crystals of the maximum size were determined. A positive effect when using the filtrate as fertilizer was found. These results mean that it is possible to obtain a technology for gypsum with a closed production cycle (waste‐free technology) derived from waste limestone and spent sulfuric acid. © 2021 Society of Chemical Industry (SCI).
Synovial mesenchymal stem cell‐derived extracellular vesicles containing microRN555A‐26a‐5p ameliorate cartilage damage of osteoarthritis
Authors: Lu Laiya , Wang Jingyi , Fan Aoyuan , Wang Pei , Chen Runzhi , Lu Laibing , Yin Feng 
Published: July 2021

AbstractBackgroundOsteoarthritis (OA) is a degenerative disease characterized by cartilage damage. We aimed to improve the understanding of the protective mechanism of synovial mesenchymal stem cell (SMSC)‐derived extracellular vesicles (EVs) in cartilage damage of OA.MethodsSMSCs and SMSC‐EVs were isolated from synovial biopsies of patients without OA and then identified. The pathological microenvironment of chondrocytes in OA was simulated by inducing SW1353 cells with interleukin (IL)‐1β, followed by SMSC‐EV treatment to assess SW1353 cell proliferation, apoptosis and inflammation. Endocytosis of Dil‐labeled EVs by SW1353 cells was observed. microRNA (miR)‐26a‐5p expression in EVs and EV‐treated SW1353 cells was assessed. The effect of miR‐26a‐5p was evaluated after it was down‐regulated in SMSCs, followed by extraction of EVs, which acted on SW1353 cells. The target relationship of miR‐26a‐5p and phosphatase and tensin homologue (PTEN) was predicted and confirmed. The role of PTEN in OA was evaluated after it was overexpressed. Functional assays were implemented in vivo to certify the role of SMSC‐EVs in OA.ResultsSMSC‐EVs enhanced IL‐1β‐induced SW1353 cell proliferation, whereas they inhibited apoptosis and inflammation. EVs were endocytosed by SW1353 cells and delivered miR‐26a‐5p into SW1353 cells to overexpress miR‐26a‐5p. Down‐regulation of miR‐26a‐5p in EVs attenuated the protection of EVs against IL‐1β‐induced cell damage. miR‐26a‐5p targeted PTEN, for which overexpression spoiled the protection of EVs against IL‐1β‐induced cell damage. SMSC‐EVs carrying miR‐26a‐5p repaired cartilage damage of OA.ConclusionsSMSC‐EVs carried miR‐26a‐5p into chondrocytes to up‐regulate miR‐26a‐5p and inhibit PTEN, thereby inhibiting apoptosis and inflammation and ameliorating cartilage damage of OA.
Surgeon Positioning During Awake Laryngeal Surgery: An Ergonomic Analysis
Authors: Baird Brandon J. , Tynan Monica A. , Tracy Lauren F. , Heaton James T. , Burns James A. 
Published: July 2021

ObjectivesWhile it is acknowledged that otolaryngologists performing microlaryngeal surgery can develop musculoskeletal symptoms due to suboptimal body positioning relative to the patient, flexible laryngoscopy and awake laryngeal surgeries (ALSs) can also pose ergonomic risk. This prospective study measured the effects of posture during ergonomically good and bad positions during laryngoscopy using ergonomic analysis, skin‐surface electromyography (EMG), and self‐reported pain ratings.Study DesignProspective cohort study.MethodsEight participants trained in laryngoscopy assumed four ergonomically distinct standing positions (side/near, side/far, front/near, front/far) at three different heights (neutral—top of patient's head in line with examiner's shoulder, high—6 inches above neutral, and low—6 inches below neutral) in relation to a simulated patient. Participants' postures were analyzed using the validated Rapid Upper Limb Assessment (RULA, 1 [best] to 7 [worst]) tool for the 12 positions. Participants then simulated ALS for 10 minutes in a bad position (low‐side‐far) and a good position (neutral‐front‐near) with 12 EMG sensors positioned on the limbs and torso.ResultsThe position with the worst RULA score was the side/near/high (7.0), and the best was the front/near/neutral (4.5). EMG measurements revealed significant differences between simulated surgery in the bad and good positions, with bad position eliciting an average of 206% greater EMG root‐mean‐squared magnitude across all sampled muscles compared to the good posture (paired t‐test, df = 7, P < .01), consistent with self‐reported fatigue/pain when positioned poorly.ConclusionQuantitative and qualitative measurements demonstrate the impact of surgeon posture during simulated laryngoscopy and suggest ergonomically beneficial posture that should facilitate ALSs.Level of Evidence3 Laryngoscope, 131:2752–2758, 2021