bluuebunny/crossref_metadata_2025 huggingface dataset:
High-Fat Diet-Induced Dysregulation of Immune Cells Correlates with Macrophage Phenotypes and Chronic Inflammation in Adipose Tissue
Authors: Kiran Sonia , Rakib Ahmed , Kodidela Sunitha , Kumar Santosh , Singh Udai P.
Published: April 2022

Obesity is a complex disease associated with various metabolic abnormalities, cardiovascular diseases, and low-grade chronic inflammation. Inflammation associated with T helper 1 (Th1) immune cells is dominant in adipose tissue (AT) and exerts metabolically deleterious impacts. The precise mechanism of alteration in AT immune system and its effect on metabolic homeostasis remains unclear. In this study, we investigated how a high-fat diet (HFD) alters the AT immune response and influences inflammation during obesity. HFD consumption amends the metabolic parameters, including body weight, glucose, and insulin levels. We observed increased infiltration of Th17 cells, a subset of dendritic cells (CD103+), and M1 macrophages in AT of mice fed HFD compared to those fed a normal diet (ND). In mice that were fed HFD, we also observed a reduction in regulatory T cells (Tregs) relative to the numbers of these cells in mice fed ND. Corresponding with this, mice in the HFD group exhibited higher levels of proinflammatory cytokines and chemokines than those in the ND group. We also observed alterations in signaling pathways, including increased protein expression of IRF3, TGFβ1, and mRNA expression of IL-6, KLF4, and STAT3 in the AT of the mice fed HFD as compared to those fed ND. Further, HFD-fed mice exhibited decreased protein expression of peroxisome proliferator-activated receptor-gamma (PPAR-γ) compared to mice fed ND, suggesting that PPAR-γ functions as a negative regulator of Th17 cell differentiation. These results suggest that HFD induces increased levels of inflammatory cytokines and key immune cells, including Th17, M1 macrophages, and CD103+ dendritic cells, and reduces levels of PPAR-γ and Tregs to sustain AT inflammation. This study supports the notion that dysregulation of Th17/Tregs, which polarizes macrophages towards M1 phenotypes in part through TGFβ1-IRF3-STAT3 and negatively regulates PPAR-γ mediated pathways, results in AT inflammation during obesity.
Calreticulin Shortage Results in Disturbance of Calcium Storage, Mitochondrial Disease, and Kidney Injury
Authors: Tayyeb Asima , Dihazi Gry H. , Tampe Björn , Zeisberg Michael , Tampe Desiree , Hakroush Samy , Bührig Charlotte , Frese Jenny , Serin Nazli , Eltoweissy Marwa , Müller Gerhard A. , Dihazi Hassan
Published: April 2022

Renal Ca2+ reabsorption plays a central role in the fine-tuning of whole-body Ca2+ homeostasis. Here, we identified calreticulin (Calr) as a missing link in Ca2+ handling in the kidney and showed that a shortage of Calr results in mitochondrial disease and kidney pathogenesis. We demonstrated that Calr+/− mice displayed a chronic physiological low level of Calr and that this was associated with progressive renal injury manifested in glomerulosclerosis and tubulointerstitial damage. We found that Calr+/− kidney cells suffer from a disturbance in functionally active calcium stores and decrease in Ca2+ storage capacity. Consequently, the kidney cells displayed an abnormal activation of Ca2+ signaling and NF-κB pathways, resulting in inflammation and wide progressive kidney injury. Interestingly, the disturbance in the Ca2+ homeostasis and signaling in Calr+/− kidney mice cells triggered severe mitochondrial disease and aberrant mitophagy, resulting in a high level of oxidative stress and energy shortage. These findings provide novel mechanistic insight into the role of Calr in kidney calcium handling, function, and pathogenesis.
RMR-Related DNAJC6 Expression Suppresses Adipogenesis in 3T3-L1 Cells
Authors: Kim Juhee , Lee Myoungsook
Published: April 2022

Obesity causes various complications such as type 2 diabetes, hypertension, fatty liver, cardiovascular diseases, and cancer. In a pilot GWAS study, we screened the DNAJC6 gene which is significantly related to the resting metabolic rate (RMR) in childhood obesity. With DNAJC6-overexpressed 3T3-L1 cells (TgHsp), we investigated the new obesity mechanism caused by an energy imbalance. After differentiation, lipid droplets (Oil red O staining) were not formed in TgHsp cells compared to the control. TgHsp preadipocyte fibroblast morphology was also not clearly observed in the cell morphology assay (DAPI/BODIPY). In TgHsp cells, the expression of PPARγ, C/EBPα, and aP2 (adipogenesis-related biomarkers) decreased 3-, 39-, and 200-fold, respectively. The expression of the adipokines leptin and adiponectin from adipose tissues also decreased 2.4- and 840-fold, respectively. In addition, the levels of pHSL(Ser563) and free glycerol, which are involved in lipolysis, were significantly lower in TgHsp cells than in the control. The reduction in insulin receptor expression in TgHsp cells suppressed insulin signaling systems such as AKT phosphorylation, and GLUT4 expression. Degradation of IRS-1 in 3T3-L1 adipocytes was caused by chronic exposure to insulin, but not TgHsp. Mitochondrial functions such as oxygen consumption and ATP production, as well as proton leak and UCP1 protein expression, decreased in TgHsp cells compared to the control. Moreover, autophagy was observed by increasing autophagosomal proteins, LC3, on Day 8 of differentiation in TgHsp cells. Through our first report on the DNAJC6 gene related to RMR, we found a new mechanism related to energy metabolism in obesity. DNAJC6 expression positively suppressed adipogenesis, leading to the subsequent resistance of lipolysis, adipokine expression, insulin signaling, and mitochondrial functions.
Electrochemical Oxidation of Sodium Metabisulfite for Sensing Zinc Oxide Nanoparticles Deposited on Graphite Electrode
Authors: Wang Kailai , Lai Edward P. C.
Published: April 2022

A novel concept was successfully evaluated for the electrochemical quantitative analysis of zinc oxide nanoparticles originally in aqueous suspension. An aliquot of the suspension was first placed on the working area of a graphite screen-printed electrode and the water was evaporated to form a dry deposit of ZnO nanoparticles. Deposition of ZnO nanoparticles on the electrode was confirmed by energy-dispersive X-ray spectroscopy. A probe solution containing KCl and sodium metabisulfite was added on top of the deposit for electrochemical analysis by cyclic voltammetry. The anodic peak current (Ipa) for metabisulfite, measured at +1.2 V vs. Ag/AgCl, afforded a lower detection limit of 3 µg and exhibited a linear dependence on the mass of deposited ZnO nanoparticles up to 15 μg. Further, the current increased nonlinearly until it reached a saturation level beyond 60 μg of ZnO nanoparticles. The diffusion coefficient of metabisulfite anions through the electrical double layer was determined to be 4.16 × 10−5 cm2/s. Apparently the surface reactivity of ZnO originated from the oxide anion rather than the superoxide anion or the hydroxyl radical. Enhancement of the metabisulfite oxidation peak current can be developed into a sensitive method for the quantitation of ZnO nanoparticles.
Comparison of the Standard vs. Thoracoscopic Extrapleural Modification of the Nuss Procedure—Two Centers’ Experiences
Authors: Pajić Miloš , Vidovič Damjan , Jokić Radoica , Antić Jelena , Čubrić Nenad , Fratrić Ivana , Bukarica Svetlana , Komarčević Aleksandar , Milenković Marina
Published: April 2022

Pectus excavatum is the most common congenital anterior chest wall deformity, with an incidence of 1:400 to 1:1000. Surgical strategy has evolved with the revolutionary idea of Donald Nuss, who was a pioneer in the operative correction of this deformity using minimally invasive surgery. The aim of this paper is to compare the preliminary results of pectus excavatum repair in two University Centers with a moderate number of patients using the standard Nuss procedure and its modification, the extrapleural thoracoscopic approach. The statistical analysis showed no significant difference for the patient’s age (14.52 ± 3.70 vs. 14.57 ± 1.86; p = 0.95) and the CT Haller index (4.17 ± 1.58 vs. 3.78 ± 0.95; p = 0.32). A statistically significant difference was noted for the duration of a pectus bar implant (2.16 ± 0.24 vs. 2.48 ± 0.68; p = 0.03) between the Maribor and Novi Sad Center. We report 14 complications (28%), including dislocation of the pectus bar (10%), pleural effusion (8%), wound inflammation (6%), pericarditis (2%) and an allergic reaction to the pectus bar (2%). Standard and thoracoscopic extrapleural Nuss procedures are both safe and effective procedures used to correct a pectus excavatum deformity. The choice of surgical procedure should be made according to a surgeon’s reliability in performing a particular procedure. Our study found no advantages of one procedure over the other.
Associations of APOE Gene Variants rs429358 and rs7412 with Parameters of the Blood Lipid Profile and the Risk of Myocardial Infarction and Death in a White Population of Western Siberia
Authors: Semaev Sergey , Shakhtshneider Elena , Shcherbakova Liliya , Ivanoshchuk Dinara , Orlov Pavel , Malyutina Sophia , Gafarov Valery , Ragino Yuliya , Voevoda Mikhail
Published: April 2022

The present study aimed to analyze possible associations of rs7412 and rs429358 of the APOE gene with lipid profile parameters, the risk of myocardial infarction, and death in the mostly white population of Western Siberia (Russia). The study population was selected from a sample surveyed within the framework of the Health, Alcohol and Psychosocial Factors In Eastern Europe (HAPIEE) study (9360 subjects, age 53.8 ± 7.0 years, males/females 50/50). PCR was conducted with fluorescence detection according to the TaqMan principle on a real-time PCR machine. The frequency of a minor allele (C) of rs429358 was 0.13, and the frequency of a minor allele (T) of rs7412 was 0.09. In our study, the woman with the rare ɛ1/ɛ4 genotype had substantial aberrations in blood lipid levels. In Kaplan–Meier curves, statistically significant differences were revealed in the prognosis of survival within the subgroup of females who had a myocardial infarction (p = 0.0006): the prognosis was worse for carriers of the ɛ2/ɛ2 genotype and for ɛ4/ɛ4 carriers. Survival analysis regarding deaths from all causes showed (p = 0.0238) that female carriers of the ɛ2/ɛ4 genotype had a worse prognosis than did carriers of other genotypes. Thus, in the population of Western Siberia (Russia), we confirmed statistically significant associations between rs7412 & rs429358 genotypes and lipid profile parameters.
Selection of Organic Coating Systems for Corrosion Protection of Industrial Equipment
Authors: Drozda Michał , Miszczyk Andrzej
Published: April 2022

The most important element of corrosion protection in industrial conditions is the protective coating system. However, selecting the right coating can often be a real problem due to the sheer number of coating manufacturers and their products on the market. A quantitative approach based on the data mining technique used to analyze the obtained multi-site exposure data has been proposed. This was demonstrated by the example of the selection of a coating system to protect an industrial ball mill located in a hall for the enrichment of copper ore at the Polish company KGHM Polska Miedz S.A. A collection of 21 two-layer coating systems from different manufacturers was tested for one year. Multiple areas on the industrial ball mill, subjected to varying degrees of vibrations and abrasion, were painted. In addition, sets of samples that can be detached from the mill housing were mounted, as well as the set exposed in the hall without vibrations. The condition of the coatings after exposure was assessed using impedance spectroscopy. The obtained data from many different exposure areas were analyzed using principal components analysis (PCA). In this way, the most advantageous coating systems for the specific conditions in the hall were indicated. Additionally, on this basis, the contribution of various destructive factors, including vibrations and abrasion, to the protective properties of the tested coatings, was estimated.
Supercritical Fluid-Assisted Fabrication of PDA-Coated Poly (l-lactic Acid)/Curcumin Microparticles for Chemo-Photothermal Therapy of Osteosarcoma
Authors: Zhao Zheng , Chen Shilu , Xiao Yao , Xie Maobin , Yu Wen
Published: April 2022

After traditional osteosarcoma resection, recurrence of tumor is still a major clinical challenge. The combination of chemotherapy and photothermal therapy (PTT) has great potential in improving therapeutic effect. However, the studies using polydopamine (PDA) as photothermal transducing agent to improve the anti-cancer activity of curcumin (CM)-loaded poly (l-lactic acid) (PLLA) microparticles (PLLA/CM) have seldom been investigated. In this study, we reported the synthesis of PDA-coated PLLA/CM microparticles (PDA-PLLA/CM) prepared by PDA coating on the surface of the PLLA/CM microparticles fabricated by solution-enhanced dispersion by supercritical CO2 (SEDS) for chemo-photothermal therapy of osteosarcoma. The average particle sizes of PLLA/CM and PDA-PLLA/CM microparticles with a spherical shape were (802.6 ± 8.0) nm and (942.5 ± 39.5) nm, respectively. PDA-PLLA/CM microparticles exhibited pH- and near-infrared (NIR)-responsive release behavior to promote CM release in the drug delivery system. Moreover, PDA-PLLA/CM microparticles displayed good photothermal conversion ability and photothermal stability attributed to PDA coating. Additionally, the results of in vitro anti-cancer experiment showed that 500 μg/mL PDA-PLLA/CM microparticles had good anti-cancer effect on MG-63 cells and no obvious toxicity to MC3T3-E1 cells. After incubation with PDA-PLLA/CM microparticles for 2 days, NIR irradiation treatment improved the anti-cancer activity of PDA-PLLA/CM microparticles obviously and reduced the cell viability of osteosarcoma from 47.4% to 20.6%. These results indicated that PDA-PLLA/CM microparticles possessed a synergetic chemo-photothermal therapy for osteosarcoma. Therefore, this study demonstrated that PDA-PLLA/CM microparticles may be an excellent drug delivery platform for chemo-photothermal therapy of tumors.
Comparative Study of Cu/ZSM-5 Catalysts Synthesized by Two Ion-Exchange Methods
Authors: Santa Cruz-Navarro Dalia , Torres-Rodríguez Miguel , Gutiérrez-Arzaluz Mirella , Mugica-Álvarez Violeta , Pergher Sibele Berenice
Published: April 2022

As catalysis is one of the pillars of green chemistry, this work aimed at continuing the development of synthesized catalysts under controlled conditions that allow the attainment of materials with the best physicochemical properties for the process for which they were designed. Based on this, the synthesis, characterization, and comparison of copper-based catalysts supported on ammonium and acidic ZSM-5-type zeolite by two ion exchange methods, liquid phase and solid state, are presented. The catalysts obtained were characterized by SEM/EDS, FTIR, XRD, and TPR to study the effect of the synthesis method on the physicochemical properties of each catalyst. The SEM/EDS results showed a homogeneous distribution of copper in the zeolite and the TPR led to determining the temperature ranges for the reduction of Cu2+ → Cu+ → Cu0. Furthermore, the X-ray results showed no modification of the structure of the zeolite after ion exchange, heat treatment, and TPR analysis.
Novel Therapies for the Treatment of HER2-Positive Advanced Breast Cancer: A Canadian Perspective
Authors: Ferrario Cristiano , Christofides Anna , Joy Anil Abraham , Laing Kara , Gelmon Karen , Brezden-Masley Christine
Published: April 2022

The advent of anti-HER2 targeted therapies has dramatically improved the outcome of HER2-positive breast cancer; however, resistance to treatment in the metastatic setting remains a challenge, highlighting the need for novel therapies. The arrival of new treatment options and clinical trials examining the efficacy of novel agents may improve outcomes in the metastatic setting, including in patients with brain metastases. In the first-line setting, we can potentially cure a selected number of patients treated with pertuzumab + trastuzumab + taxane. In the second-line setting, clinical trials show that trastuzumab deruxtecan (T-DXd) is a highly effective option, resulting in a shift from trastuzumab emtansine (T-DM1) as the previous standard of care. Moreover, we now have data for patients with brain metastases to show that tucatinib + trastuzumab + capecitabine can improve survival in this higher-risk group and be an effective regimen for all patients in the third-line setting. Finally, we have a number of effective anti-HER2 therapies that can be used in subsequent lines of therapy to improve patient outcomes. This review paper discusses the current treatment options and presents a practical treatment sequencing algorithm in the context of the Canadian landscape.
Stripes Matter: Integrative Systematics of Coryphellina rubrolineata Species Complex (Gastropoda: Nudibranchia) from Vietnam
Authors: Ekimova Irina , Deart Yury , Antokhina Tatiana , Mikhlina Anna , Schepetov Dimitry
Published: April 2022

Coryphellina rubrolineata (Gastropoda: Nudibranchia: Flabellinidae) was believed to be a widespread tropical species demonstrating high diversity in external and internal morphological traits. In this paper, we perform an integrative analysis of the C. rubrolineata species complex based on samples collected in Vietnam waters, combined with available data from other localities of the Indo-West Pacific. The methods of the study include morphological analysis of external and internal traits using light and scanning electron microscopy and the molecular analysis of four markers (COI, 16S, H3, and 28S). The phylogenetic hypothesis was performed using Bayesian and maximum likelihood approaches, and the species delimitation analyses included ASAP, GMYC, and bPTP. Our results support the validity of the genus Coryphellina as a distinct taxon and confirm that Coryphellina rubrolineata is restricted to the type locality and adjacent waters, while in the Indo-West Pacific, it represents a complex of pseudocryptic species. Based on our integrative analysis, we describe four new species: Coryphellina pseudolotos sp. nov., Coryphellina pannae sp. nov., Coryphellina flamma sp. nov., and Coryphellina aurora sp. nov. For the first time, Coryphellina lotos is reported in Vietnam waters. All five species differ in combination of coloration and other external traits and show minor differences in internal morphology.
Unusual N Gene Dropout and Ct Value Shift in Commercial Multiplex PCR Assays Caused by Mutated SARS-CoV-2 Strain
Authors: Bozidis Petros , Tsaousi Eleni , Kostoulas Charilaos , Sakaloglou Prodromos , Gouni Athanasia , Koumpouli Despoina , Sakkas Hercules , Georgiou Ioannis , Gartzonika Konstantina
Published: April 2022

Several SARS-CoV-2 variants have emerged and early detection for monitoring their prevalence is crucial. Many identification strategies have been implemented in cases where sequencing data for confirmation is pending or not available. The presence of B.1.1.318 among prevalent variants was indicated by an unusual amplification pattern in various RT-qPCR commercial assays. Positive samples for SARS-CoV-2, as determined using the Allplex SARS-CoV-2 Assay, the Viasure SARS-CoV-2 Real Time Detection Kit and the GeneFinder COVID-19 Plus RealAmp Kit, presented a delay or failure in the amplification of the N gene, which was further investigated. Whole-genome sequencing was used for variant characterization. The differences between the mean Ct values for amplification of the N gene vs. other genes were calculated for each detection system and found to be at least 14 cycles. Sequencing by WGS revealed that all the N gene dropout samples contained the B.1.1.318 variant. All the isolates harbored three non-synonymous mutations in the N gene, which resulted in four amino acid changes (R203K, G204R, A208G, Met234I). Although caution should be taken when the identification of SARS-CoV-2 variants is based on viral gene amplification failure, such patterns could serve as a basis for rapid and cost-effective screening, functioning as indicators of community circulation of specific variants, requiring subsequent verification via sequencing.
Predictive Variables for Interventional Angiography among Patients with Knee Hemarthrosis
Authors: Ko Sang-Hun , Jung Kwang-Hwan , Cha Jae-Ryong , Park Ki-Bong
Published: April 2022

Studies regarding the variables that could predict the success of conservative treatment for knee hemarthrosis are lacking. This retrospective study evaluated the laboratory variables of patients who had unsatisfactory results from conservative treatment for knee hemarthrosis. Twenty-nine patients conservatively treated for knee hemarthrosis were included and divided into two groups: group A comprised 14 patients who underwent interventional angiography and selective embolization due to failed conservative treatment, and group B comprised 15 patients with successful results after conservative treatment. The results of the serological and synovial fluid tests were evaluated. The mean number of synovial red blood cells (RBCs) was 1,905,857 cells/µL and 7730 cells/µL in groups A and B, respectively (p = 0.01), while the mean number of RBCs per high-power field (HPF) was 68.9 and 3.2, respectively (p < 0.01). Patients who underwent interventional angiography and selective embolization after failed conservative treatment for knee hemarthrosis had higher synovial RBC counts and RBC counts per HPF than those with successful outcomes after conservative treatment. It is necessary to carefully interpret the results of the synovial fluid analysis in patients with knee hemarthrosis; if the synovial fluid analysis shows a synovial RBC count greater than 81,500 and RBC count per HPF greater than 16.3, we recommend immediate interventional angiography rather than continuing conservative treatment.
Aortic Root Downward Movement as a Novel Method for Identification of an Adequately Performed Valsalva Maneuver to Detect Patent Foramen Ovale during Transesophageal Echocardiography
Authors: Chen Lixin , Sheng Yuanyuan , Huang Yuxiang , Li Jian , Liu Xiaohua , Liu Qian , Shi Bobo , Zhong Xiaofang , Xu Jinfeng , Liu Yingying
Published: April 2022

The Valsalva maneuver (VM) is the most sensitive auxiliary method for the detection of patent foramen ovale (PFO), but it is difficult to assess whether the maneuver is adequately performed during transesophageal echocardiography (TEE). In this study, we tried to use aortic root downward movement as a novel method for judging whether VM was adequate or not, and to evaluate whether this novel method can increase the sensitivity of detecting PFO. A total of 224 patients with clinically suspected PFO were enrolled in this study. These patients were injected with activated normal saline to detect the right-to-left shunt (RLS), in the following three conditions: contrast-enhanced transthoracic echocardiography under adequate VM (AVM cTTE), contrast-enhanced TEE under non-adequate VM (non-AVM cTEE), and cTEE under adequate VM (AVM cTEE). A novel method in which the aorta root moves downward (movement range ≥16 mm) in the cTEE judged whether AVM was performed. The PFO detection rate and sensitivity of AVM cTEE were better than that of non-AVM cTEE (detection rate: 108 PFOs [48.2%] vs. 86 PFOs [38.4%], p = 0.036; sensitivity: 100% vs. 79.6%). Among AVM cTTE, non-AVM cTEE, and AVM cTEE, the RLS grade evaluation results were inconsistent, with significant differences (p < 0.05). Non-AVM cTEE had RLS underestimation or false negatives. Compared with non-AVM cTEE, AVM cTEE and AVM cTTE had better consistency in evaluating PFO RLS (kappa value = 0.675). Aortic root downward movement could be used as a novel method for judging the effectiveness of VM, which is critical for the detection of PFO in cTEE. Concerning effectiveness and convenience, this method should be promoted during the clinical detection of PFO.
The Added Value of Atrial Strain Assessment in Clinical Practice
Authors: Molnár Andrea Ágnes , Merkely Béla
Published: April 2022

Speckle tracking echocardiography has emerged as a sensitive tool to analyze myocardial function with improved diagnostic accuracy and prognostic value. Left atrial strain assessment has become a novel imaging method in cardiology with superior prognostic value compared to conventional left atrial volume indices. Left atrial function is divided into three phases, reservoir function being the most important. This review summarizes the added value of speckle tracking echocardiography derived left atrial strain assessment in clinical practice. Recently published data suggest the prognostic value of left atrial reservoir function in heart failure, atrial fibrillation, stroke and valvular heart disease. Furthermore, left atrial reservoir strain proved to be a predictor of cardiovascular morbidity and mortality in the general population. Thus, routine assessment of left atrial function can be an optimal strategy to improve cardiovascular risk prediction and supplement the current risk prediction models.
Simplification of the Gram Matrix Eigenvalue Problem for Quadrature Amplitude Modulation Signals
Authors: Miyazaki Ryusuke , Wang Tiancheng , Usuda Tsuyoshi Sasaki
Published: April 2022

In quantum information science, it is very important to solve the eigenvalue problem of the Gram matrix for quantum signals. This allows various quantities to be calculated, such as the error probability, mutual information, channel capacity, and the upper and lower bounds of the reliability function. Solving the eigenvalue problem also provides a matrix representation of quantum signals, which is useful for simulating quantum systems. In the case of symmetric signals, analytic solutions to the eigenvalue problem of the Gram matrix have been obtained, and efficient computations are possible. However, for asymmetric signals, there is no analytic solution and universal numerical algorithms that must be used, rendering the computations inefficient. Recently, we have shown that, for asymmetric signals such as amplitude-shift keying coherent-state signals, the Gram matrix eigenvalue problem can be simplified by exploiting its partial symmetry. In this paper, we clarify a method for simplifying the eigenvalue problem of the Gram matrix for quadrature amplitude modulation (QAM) signals, which are extremely important for applications in quantum communication and quantum ciphers. The results presented in this paper are applicable to ordinary QAM signals as well as modified QAM signals, which enhance the security of quantum cryptography.
Measurement Uncertainty, Purity, and Entanglement Dynamics of Maximally Entangled Two Qubits Interacting Spatially with Isolated Cavities: Intrinsic Decoherence Effect
Authors: Mohamed Abdel-Baset A. , Rahman Atta Ur , Eleuch Hichem
Published: April 2022

In a system of two charge-qubits that are initially prepared in a maximally entangled Bell’s state, the dynamics of quantum memory-assisted entropic uncertainty, purity, and negative entanglement are investigated. Isolated external cavity fields are considered in two different configurations: coherent-even coherent and even coherent cavity fields. For different initial cavity configurations, the temporal evolution of the final state of qubits and cavities is solved analytically. The effects of intrinsic decoherence and detuning strength on the dynamics of bipartite entropic uncertainty, purity and entanglement are explored. Depending on the field parameters, nonclassical correlations can be preserved. Nonclassical correlations and revival aspects appear to be significantly inhibited when intrinsic decoherence increases. Nonclassical correlations stay longer and have greater revivals due to the high detuning of the two qubits and the coherence strength of the initial cavity fields. Quantum memory-assisted entropic uncertainty and entropy have similar dynamics while the negativity presents fewer revivals in contrast.
A Conversation with Katarina Juselius
Authors: Mosconi Rocco , Paruolo Paolo
Published: April 2022

This article was prepared for the Special Issue ‘Celebrated Econometricians: Katarina Juselius and Søren Johansen’ of Econometrics. It is based on material recorded on 30–31 October 2018 in Copenhagen. It explores Katarina Juselius’ research, and discusses inter alia the following issues: equilibrium; short and long-run behaviour; common trends; adjustment; integral and proportional control mechanisms; model building and model comparison; breaks, crisis, learning; univariate versus multivariate modelling; mentoring and the gender gap in Econometrics.
An Analysis of Student Anxiety Affecting on Online Learning on Conceptual Applications in Physics: Synchronous vs. Asynchronous Learning
Authors: Phanphech Parinda , Tanitteerapan Tanes , Mungkung Narong , Arunrungrusmi Somchai , Chunkul Charathip , Songruk Apidat , Yuji Toshifumi , Kinoshita Hiroyuki
Published: April 2022

This study examines the impact of students’ anxiety, due to online learning, in different learning environments: a synchronous (Zoom) and asynchronous learning environment (YouTube) to compare students’ conceptual understanding of electric circuits. Multiple linear regression and factor analyses were conducted to examine the factor of students’ anxiety and conceptual understanding. A sample of 99 vocational students participated in the study, including YouTube (n = 49) and Zoom (n = 50) groups. The DIRECT was used to diagnose test for conceptual understanding in the electric circuits, and OTAI was used to assess anxiety in online learning test. The OTAI consists of three factors: psychological, physiological, and online. The results showed that students’ anxiety, in some factors, affected their conceptual understanding of the electric circuits in both groups. However, there was a significant increase in conceptual understanding in both treatment groups. Although the students’ conceptual understanding had a slight increase, online learning has to improve to reduce the anxiety of learners.
Teachers’ Global Perceptions and Views, Practices and Needs in Multicultural Settings
Authors: Karanikola Zoe , Katsiouli Glykeria , Palaiologou Nektaria
Published: April 2022

Multiculturalism and globalization are common traits of western societies, and affect the way people interact and communicate. In such a context, this study comes to investigate teachers’ perceptions, practices and needs towards global and intercultural competences. This study was designed and implemented in order to shed light on major issues which are associated with the context of global competences as an umbrella term, which arose during the researchers’ participation at an Erasmus plus European project. The research took place at the region of Attica and thirteen teachers (N = 13) of reception classes—Zones of Educational Priority (ZEP)—participated in the interview. A qualitative case study followed, focusing on a specific geographic region, and the semi-structured interview tool was used. The findings of the research indicate that educators do not feel certain about the differences between global and intercultural competences. However, they consider that these competences are of great importance and they recognize the contribution of schools to their development. Regarding their practices, they mostly refer to the dialogue and discussion techniques, the role playing, and the project-based teaching. Finally, participants consider that they are not sufficiently prepared to teach global and intercultural competences. Thus, participation in relevant training programs is important.
Machine-Learning-Based Uplink Throughput Prediction from Physical Layer Measurements
Authors: Eyceyurt Engin , Egi Yunus , Zec Josko
Published: April 2022

The uplink (UL) throughput prediction is indispensable for a sustainable and reliable cellular network due to the enormous amounts of mobile data used by interconnecting devices, cloud services, and social media. Therefore, network service providers implement highly complex mobile network systems with a large number of parameters and feature add-ons. In addition to the increased complexity, old-fashioned methods have become insufficient for network management, requiring an autonomous calibration to minimize utilization of the system parameter and the processing time. Many machine learning algorithms utilize the Long-Term Evolution (LTE) parameters for channel throughput prediction, mainly in favor of downlink (DL). However, these algorithms have not achieved the desired results because UL traffic prediction has become more critical due to the channel asymmetry in favor of DL throughput closing rapidly. The environment (urban, suburban, rural areas) affect should also be taken into account to improve the accuracy of the machine learning algorithm. Thus, in this research, we propose a machine learning-based UL data rate prediction solution by comparing several machine learning algorithms for three locations (Houston, Texas, Melbourne, Florida, and Batman, Turkey) and determine the best accuracy among all. We first performed an extensive LTE data collection in proposed locations and determined the LTE lower layer parameters correlated with UL throughput. The selected LTE parameters, which are highly correlated with UL throughput (RSRP, RSRQ, and SNR), are trained in five different learning algorithms for estimating UL data rates. The results show that decision tree and k-nearest neighbor algorithms outperform the other algorithms at throughput estimation. The prediction accuracy with the R2 determination coefficient of 92%, 85%, and 69% is obtained from Melbourne, Florida, Batman, Turkey, and Houston, Texas, respectively.
A Carbon-Nanotube Cold-Cathode Reflex Klystron Oscillator: Fabrication @ X-Band and Returning Electron Beam Realization
Authors: Li Jiupeng , Zhang Yu , Ke Yanlin , Hong Tianzeng , Deng Shaozhi
Published: April 2022

This paper presents the design and fabrication of a reflex klystron oscillator based on a carbon nanotube (CNT) cold-cathode. An X-band klystron oscillator structure is assembled with a CNT cold-cathode electron gun with an electrostatic focusing, a re-entrant cavity as anode, and a repeller. The electron gun adopts a convex CNT film emitter as the cathode. A re-entrant cavity resonating at 8.376 GHz is fabricated. The study mainly focuses on the returning electron beam in the klystron oscillator structure. The experimental results of variations of the anode current and returning electron beam amplitude with repeller voltage are presented. It is demonstrated that a higher extracting voltage of the cold-cathode has an important influence on the returning electron beam. To decelerate electron velocity from the extracting voltage, increasing negative focusing voltage and focusing electrode height in the electron gun can improve the returning electron beam characteristics.
Research on Inter-Turn Short Circuit Fault Diagnosis of Electromechanical Actuator Based on Transfer Learning and VGG16
Authors: Huangfu Haibin , Zhou Yong , Zhang Jianxin , Ma Shangjun , Fang Qian , Wang Ye
Published: April 2022

In this paper, an inter-turn short-circuit fault of a permanent magnet synchronous motor in an electromechanical actuator is analyzed, and a fault diagnosis method based on transfer learning with a VGG16 convolution network is proposed. First, a 2D finite element model of an inter-turn short circuit fault of a permanent magnet synchronous motor was established in ANSOFT Maxwell, and then a simulation experiment analysis was completed. A three-phase current was chosen as a fault characteristic signal. Second, a fault diagnosis method with a VGG16 deep convolutional neural network and based on transfer learning was designed, and the fine tuning of the hyperparameters of the fault diagnosis model was completed by using grid search and cross verification methods. Finally, based on the transfer learning VGG16 model established in this paper, the inter-turn short circuit fault of a permanent magnetic synchronous machine (PMSM) was diagnosed and verified. The experimental results showed that the proposed convolutional network model based on transfer learning can identify faults effectively and accurately, and has a good engineering guidance significance.
Mechanistic Model of an Air Cushion Surge Tank for Hydro Power Plants
Authors: Pandey Madhusudhan , Winkler Dietmar , Vereide Kaspar , Sharma Roshan , Lie Bernt
Published: April 2022

Due to the increasing use of renewable energy sources, and to counter the effects of fossil fuels, renewable dispatchable hydro power can be used for balancing load and generation from intermittent sources (solar and wind). During higher percentage change in load acceptance or rejection in the intermittent grid, the operations of surge tanks are crucial in terms of water mass oscillation and water hammer pressure, and to avoid wear and tear in actuators and other equipment, such as hydro turbines. Surge tanks are broadly classified as open types, with access to open air, and closed types, with a closed volume of pressurized air. Closed surge tanks are considered to have a more flexible operation in terms of suppressing water mass oscillation and water hammer pressure. In this paper, a mechanistic model of an air cushion surge tank (ACST) for hydro power plants is developed based on the ordinary differential equations (ODEs) for mass and momentum balances. The developed mechanistic model of the ACST is a feature extension to an existing open-source hydro power library—OpenHPL. The developed model is validated with experimental data from the Torpa hydro power plant (HPP) in Norway. Results show that the air friction inside the ACST is negligible as compared to the water friction. The results also indicate that a hydro power plant with an ACST is a potential candidate as a flexible hydro power in an interconnected power system grid supplied with intermittent energy sources. Conclusions are drawn based on the simulation results from hydraulic performance of the ACST.
Peukert Generalized Equations Applicability with Due Consideration of Internal Resistance of Automotive-Grade Lithium-Ion Batteries for Their Capacity Evaluation
Authors: Yazvinskaya Nataliya , Lipkin Mikhail , Galushkin Nikolay , Galushkin Dmitriy
Published: April 2022

In this paper, the applicability of the Peukert equation and its generalizations were investigated for capacity evaluation of automotive-grade lithium-ion batteries. It is proved that the classical Peukert equation is applicable within the range of the discharge currents from 0.2Cn to 2Cn (Cn is the nominal battery capacity). As a rule, the operating currents of many automotive-grade lithium-ion batteries are exactly within this range of the discharge currents. That is why, successfully, the classical Peukert equation is used in many analytical models developed for these batteries. The generalized Peukert equation C = Cm/(1 + (i/i0)n) is applicable within the discharge currents range from zero to approximately 10Cn. All kinds of operating discharge currents (including both very small ones and powerful short-term bursts) fall into this discharge currents range. The modified Peukert equation C = Cm(1 − i/i1)/((1 − i/i1) + (i/i0)n) is applicable at any discharge currents. This equation takes into account the battery’s internal resistance and has the smallest error of experimental data approximation. That is why the discussed modified Peukert equation is most preferable for use in analytical models of automotive-grade lithium-ion batteries. The paper shows that all the parameters of the generalized Peukert equations have a clear electrochemical meaning in contrast to the classical Peukert equation, where all the parameters are just empirical constants.
A Graphical Method for Combined Heat Pump and Indirect Heat Recovery Integration
Authors: Agner Raphael , Ong Benjamin H. Y. , Stampfli Jan A. , Krummenacher Pierre , Wellig Beat
Published: April 2022

Industrial sectors are improving their energy efficiency and increasing their share of renewables for heating and cooling demands by using lower emission technologies. One specific approach to help achieve these targets is the integration of heat pumps (HPs) in industrial processes. However, due to the temporal variation of the heating and cooling requirements in non-continuous processes, the integration of HP is challenging. In this paper, a structured method for the design of HP integration is proposed. The method implements an engineer-centred workflow that extends the concept of the Indirect Source Sink Profile (ISSP) to HP integration. For this purpose, an adapted Grand Composite Curve is derived from the ISSP. This ensures correct HP integration across the pinch while maintaining the temperature lift of the HP small. The proposed workflow is applied to a demonstration case study and a case study from industry. In both cases, the resulting system with integrated HP enables the elimination of hot utility demand and significantly reduces cold utility demands. The static paybacks of the proposed solutions are in the range of 4.5 to 5 year.
Numerical Improvement Using Flow and Heat Transfer Calculations of the Zigzag Geometry for Carbon Dioxide PCHEs
Authors: Wang Bo , Shen Jiafei , Cheng Jindong , Wang Yaliang
Published: April 2022

A printed circuit heat exchanger (PCHE) is an efficient and compact heat exchanger that can work under high temperature and high pressure. For Z-shaped channel PCHEs, the corner structure could enhance heat transfer at the expense of increasing the flow resistance. In order to optimize the structural design and control the pressure loss caused by the corner, a three-dimensional numerical simulation using ICEM and Fluent is conducted to study the flow and heat transfer characteristics of carbon dioxide in a PCHE by inserting straight sections (offset distance 0.5–4 mm) or arc segments (radius of curvature 0.5–4 mm) at the zigzag corners of conventional Z-shaped channels. The overall performance of the PCHEs with different structures was compared based on the comprehensive evaluation factor. The results show that the pressure loss of the PCHE can be significantly reduced by inserting straight sections and arc segments at the zigzag corners, with the mass flow rate varying from 100 to 400 kg/(m2 s). The greater the offset distance of the straight sections or curvature radius of the arc segments are, the more significant the effect is, but the heat transfer performance will be weakened at the same time. The comprehensive performance of the PCHE was the best when the curvature radius of the arc segment inserted at the zigzag corner was 4 mm.
Perspectives and Challenges Related Offshore Wind Turbines in Deep Water
Authors: Nielsen Finn Gunnar
Published: April 2022

In the coming decades, energy from offshore wind turbines is expected to be an important energy source in electric power systems [...]
The Structure of Permafrost in Northern West Siberia: Geophysical Evidence
Authors: Misyurkeeva Natalya , Buddo Igor , Shelokhov Ivan , Smirnov Alexander , Nezhdanov Alexey , Agafonov Yury
Published: April 2022

The permafrost of Arctic West Siberia stores extremely rich resources of hydrocarbon fuels that remain a key energy source and an important element of the global economy. A large amount of natural gas in permafrost is bound in gas hydrates which may become an alternative fuel of the future. Shallow subsurface in the permafrost area of northern West Siberia has been studied by transient electromagnetic (TEM) soundings to estimate the permafrost thickness and to detect faults as channels for fluids and heaving features as possible indicators of gas hydrate accumulations. The shallow transient electromagnetic (sTEM) surveys were conducted in discontinuous and continuous permafrost at two sites in northern West Siberia (the northeastern Yamal Peninsula and the southern Gydan Peninsula), with a focus on the vicinities of lakes and cryogenic landforms (frost mounds). The sTEM method resolves well the heterogeneous permafrost structure, with faults, numerous unfrozen zones (taliks), and frost mounds marked by resistivity and seismic anomalies. Some lakes are located above faults, and their origin may be related to deformation, whereas the frost mounds may mark deep-seated fluid dynamic processes. Local thickening of permafrost may be associated with the presence of gas hydrates. The detected features may trace gas migration pathways and reveal possible sites of gas emission.
Feasibility Investigation of Hydrogen Refuelling Infrastructure for Heavy-Duty Vehicles in Canada
Authors: Yaïci Wahiba , Longo Michela
Published: April 2022

A potentially viable solution to the problem of greenhouse gas emissions by vehicles in the transportation sector is the deployment of hydrogen as alternative fuel. A limitation to the diffusion of the hydrogen-fuelled vehicles option is the intricate refuelling stations that vehicles will require. This study examines the practical use of hydrogen fuel within the internal combustion engine (ICE)-powered long-haul, heavy-duty trucking vehicles. Specifically, it appraises the techno-economic feasibility of constructing a network of long-haul truck refuelling stations using hydrogen fuel, across Canada. Hydrogen fuel is chosen as an option for this study due to its low carbon emissions rate compared to diesel. This study also explores various operational methods, including variable technology integration levels and truck traffic flows, truck and pipeline delivery of hydrogen to stations, and the possibility of producing hydrogen onsite. The proposed models created for this work suggest important parameters for economic development, such as capital costs for station construction, the selling price of fuel, and the total investment cost for the infrastructure of a nation-wide refuelling station. Results showed that the selling price of hydrogen gas pipeline delivery option is more economically stable. Specifically, it was found that at 100% technology integration, the range in selling prices was between 8.3 and 25.1 CAD$/kg. Alternatively, at 10% technology integration, the range was from 12.7 to 34.1 CAD$/kg. Moreover, liquid hydrogen, which is delivered by trucks, generally had the highest selling price due to its very prohibitive storage costs. However, truck-delivered hydrogen stations provided the lowest total investment cost; the highest is shown by pipe-delivered hydrogen and onsite hydrogen production processes using high technology integration methods. It is worth mentioning that once hydrogen technology is more developed and deployed, the refuelling infrastructure cost is likely to decrease considerably. It is expected that the techno-economic model developed in this work will be useful to design and optimize new and more efficient hydrogen refuelling stations for any ICE vehicles or fuel cell vehicles.
A Novel Step Current Excitation Control Method to Reduce the Torque Ripple of Outer-Rotor Switched Reluctance Motors
Authors: Wang Jieyun , Jiang Wei , Wang Shuren , Lu Jingying , Williams Barry W. , Wang Qianlong
Published: April 2022

Featured in low-speed and high-torque operation, outer-rotor switched reluctance motors (OSRMs) have the potential to be widely deployed in low-speed commuter and logistics vehicle applications. In this paper, a five-phase OSRM and the control method featuring torque ripple reduction has been proposed, which can be applied as the wheel hub motor in the electric vehicles. The simulation was carried out to analyze the OSRM operation. The electromagnetic characteristics of single-phase and two-phase hybrid excitation mode, as well as step current excitation mode, were compared and analyzed. To solve the problem of the large torque ripple of OSRMs under traditional excitation modes, the torque ripple suppression method based on step current excitation was also studied. The experiment design, including motor start-up control, speed control, and torque ripple reduction, are presented to verify the system torque ripple mitigation method.