bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on a Novel Variable-Frequency Rolling Pendulum Bearing
Authors: Pang Hui , Xu Wen , Dai Junwu , Jiang Tao
Published: February 2022

Seismic isolation is a technique that has been widely used around the world to decouple the superstructure from the ground motions during earthquakes. However, the attention of seismic isolation is mostly focused on the protection of the building structures. Acceleration-sensitive devices or equipment, which are in desperate need of seismic protection, are still not fully emphasized. Meanwhile, the stiffness and frequencies of the conventional rolling- and sliding-type isolation bearings demonstrate an upward trend as the isolation layer displacement increases, which may bring self-centering and resonance issues. Thus, a novel variable-frequency rolling pendulum bearing is developed for the protection of acceleration-sensitive equipment. The rolling-type isolation bearing is selected to enhance the self-centering capacity, and additional viscous dampers are incorporated to improve the system damping. Moreover, the theoretical formulas of several typical variable-frequency rolling pendulum bearings are derived and presented to figure out the dynamic characterization of the device. The isolation efficiency of the proposed device under different parameters is also validated using shake table tests. Test results demonstrate that the newly proposed devices show excellent isolation performance at reducing both acceleration and displacement responses. Finally, the numerical model of this isolation system is proposed in detail. The simulated results, including relative acceleration responses, relative displacement responses and movement locus of the upper plates, are consistent with test results, which demonstrates this simplified model could be used for further studies.
Applications of Frameless Image-Guided Robotic Stereotactic Radiotherapy and Radiosurgery in Pediatric Neuro-Oncology: A Systematic Review
Authors: Ehret Felix , Kaul David , Budach Volker , Lohkamp Laura-Nanna
Published: February 2022

Background: CyberKnife-based robotic radiosurgery (RRS) is a widely used treatment modality for various benign and malignant tumors of the central nervous system (CNS) in adults due to its high precision, favorable safety profile, and efficacy. Although RRS is emerging in pediatric neuro-oncology, scientific evidence for treatment indications, treatment parameters, and patient outcomes is scarce. This systematic review summarizes the current experience and evidence for RRS and robotic stereotactic radiotherapy (RSRT) in pediatric neuro-oncology. Methods: We performed a systematic review based on the databases Ovid Medline, Embase, Cochrane Library, and PubMed to identify studies and published articles reporting on RRS and RSRT treatments in pediatric neuro-oncology. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were applied herein. Articles were included if they described the application of RRS and RSRT in pediatric neuro-oncological patients. The quality of the articles was assessed based on their evidence level and their risk for bias using the original as well as an adapted version of the Newcastle Ottawa Quality Assessment Scale (NOS). Only articles published until 1 August 2021, were included. Results: A total of 23 articles were included after final review and removal of duplicates. Articles reported on a broad variety of CNS entities with various treatment indications. A majority of publications lacked substantial sample sizes and a prospective study design. Several reports included adult patients, thereby limiting the possibility of data extraction and analysis of pediatric patients. RRS and RSRT were mostly used in the setting of adjuvant, palliative, and salvage treatments with decent local control rates and acceptable short-to-intermediate-term toxicity. However, follow-up durations were limited. The evidence level was IV for all studies; the NOS score ranged between four and six, while the overall risk of bias was moderate to low. Conclusion: Publications on RRS and RSRT and their application in pediatric neuro-oncology are rare and lack high-quality evidence with respect to entity-related treatment standards and long-term outcomes. The limited data suggest that RRS and RSRT could be efficient treatment modalities, especially for children who are unsuitable for surgical interventions, suffer from tumor recurrences, or require palliative treatments. Nevertheless, the potential short-term and long-term adverse events must be kept in mind when choosing such a treatment. Prospective studies are necessary to determine the actual utility of RRS and RSRT in pediatric neuro-oncology.
The Inorganic Perovskite-Catalyzed Transfer Hydrogenation of Cinnamaldehyde Using Glycerol as a Hydrogen Donor
Authors: Mabate Tafadzwa Precious , Meijboom Reinout , Bingwa Ndzondelelo
Published: February 2022

Catalytic transfer hydrogenation reactions (CTHs) produce value-added chemicals in the most economical, safe, green, and sustainable way. However, understanding the reaction mechanism and developing stable, selective, and cheap catalysts has been a significant challenge. Herein, we report on the hydrogenation of cinnamaldehyde utilizing glycerol as a hydrogen donor and metal-oxides (SnO2, LaFeO3, and LaSnO3) as heterogeneous catalysts. The perovskite types were used because they are easy to synthesize, the metal components are readily available, and they are good alternatives to noble metals. The catalysts were synthesized through the nanocasting (hard-template) method with SiO2 (KIT-6) as a template. The template was synthesized using the soft-template (sol-gel) method resulting in a high surface area of 624 m2/g. Furthermore, catalytic evaluations gave high cinnamaldehyde percentage conversions of up to 99%. Interestingly, these catalysts were also found to catalyze the etherification of glycerol in one pot. Therefore, we propose competitive surface catalytic reactions driven by the transition metal cations as the binding sites for the cinnamaldehyde and the sacrificial glycerol.
Hepatitis B Viral Protein HBx and the Molecular Mechanisms Modulating the Hallmarks of Hepatocellular Carcinoma: A Comprehensive Review
Authors: Sivasudhan Enakshi , Blake Neil , Lu Zhiliang , Meng Jia , Rong Rong
Published: February 2022

With 296 million cases estimated worldwide, chronic hepatitis B virus (HBV) infection is the most common risk factor for hepatocellular carcinoma (HCC). HBV-encoded oncogene X protein (HBx), a key multifunctional regulatory protein, drives viral replication and interferes with several cellular signalling pathways that drive virus-associated hepatocarcinogenesis. This review article provides a comprehensive overview of the role of HBx in modulating the various hallmarks of HCC by supporting tumour initiation, progression, invasion and metastasis. Understanding HBx-mediated dimensions of complexity in driving liver malignancies could provide the key to unlocking novel and repurposed combinatorial therapies to combat HCC.
Enhanced Autophagic Flux, Suppressed Apoptosis and Reduced Macrophage Infiltration by Dasatinib in Kidneys of Obese Mice
Authors: Elsayed Hassan Reda Hassan , El-Gamal Randa , Rabei Mohammed R. , Elhadidy Mona G. , Hamed Shereen , Othman Basma H. , Elshaer Mohamed Mahmoud Abdelraheem , Sedky Mostafa Khaled , Hassan Ahmed Tarek Abd Elbaset , El-Nablaway Mohammad
Published: February 2022

Obesity causes renal changes (ORC), characterized by defective renal autophagy, lipogenesis, enhanced macrophage infiltration and apoptosis. We hypothesize that Dasatinib, a tyrosine kinase inhibitor, may ameliorate changes associated with obesity. We the mice with either Obesogenic diet (OD) or a standard basal diet. After 12 weeks, the mice received either vehicle or Dasatinib 4 mg/kg/d for an additional four weeks. We examined serum creatinine, urea, lipid profile and renal cortical mRNA expression for lipogenesis marker SREBP1, inflammatory macrophage marker iNOS and fibrosis markers; TGFβ and PDGFA genes; immunohistochemical (IHC) staining for CD68; inflammatory macrophage marker and ASMA; fibrosis marker, LC3 and SQSTM1/P62; autophagy markers and western blotting (WB) for caspase-3; and, as an apoptosis marker, LC3II/I and SQSTM1/P62 in addition to staining for H&E, PAS, Sirius red and histopathological scoring. Dasatinib attenuated renal cortical mRNA expression for SREBP1, iNOS, PDGFA and TGFβ and IHC staining for CD68, ASMA and SQSTM1/P62 and WB for caspase-3 and SQSTM1/P62, while elevating LC3 expression. Moreover, Dasatinib ameliorated ORC; glomerulosclerosis, glomerular expansion, tubular dilatation, vacuolation and casts; inflammatory cellular infiltration; and fibrosis. Dasatinib is a promising therapy for ORC by correcting autophagy impairment, attenuating lipogenesis, apoptosis and macrophage infiltration by inducing antifibrotic activity.
Functional and Genetic Characterization of Porcine Beige Adipocytes
Authors: Zhang Lilan , Hu Silu , Cao Chunwei , Chen Chuanhe , Liu Jiali , Wang Yu , Liu Jianfeng , Zhao Jianguo , Tao Cong , Wang Yanfang
Published: February 2022

Beige adipocytes are a distinct type of fat cells with a thermogenic activity that have gained substantial attention as an alternative cellular anti-obesity target in humans. These cells may provide an alternative strategy for the genetic selection of pigs with reduced fat deposition. Despite the presence of beige adipocytes in piglets, the molecular signatures of porcine beige adipocytes remain unclear. Here, white and beige adipocytes from Tibetan piglets were primarily cultured and differentiated. Compared to the white adipocytes, the beige adipocytes exhibited a stronger thermogenic capacity. RNA-sequencing-based genome-wide comparative analyses revealed distinct gene expression profiles for white and beige adipocytes. In addition, two genes, integrin alpha-2 (ITGA2) and calponin 1 (CNN1), which were specifically differentially expressed in porcine beige adipocytes, were further functionally characterized using a loss-of-function approach. Our data showed that both genes were involved in differentiation and thermogenesis of porcine beige adipocytes. Collectively, these data furthered our understanding of gene expression in porcine white and beige adipocytes. Elucidating the genetic basis of beige adipogenesis in pigs will pave the way for molecular design breeding in both pigs and large animal models of human diseases.
The HIFα-Stabilizing Drug Roxadustat Increases the Number of Renal Epo-Producing Sca-1+ Cells
Authors: Jatho Aline , Zieseniss Anke , Brechtel-Curth Katja , Guo Jia , Böker Kai Oliver , Salinas Gabriela , Wenger Roland H. , Katschinski Dörthe M.
Published: February 2022

Inhibition of the prolyl-4-hydroxylase domain (PHD) enzymes, leading to the stabilization of hypoxia-inducible factor (HIF) α as well as to the stimulation of erythropoietin (Epo) synthesis, is the functional mechanism of the new anti-anemia drug roxadustat. Little is known about the effects of roxadustat on the Epo-producing cell pool. To gain further insights into the function of PHD inhibitors, we characterized the abundance of mesenchymal stem cell (MSC)-like cells after roxadustat treatment of mice. The number of Sca-1+ mesenchymal cells following roxadustat treatment increased exclusively in the kidneys. Isolated Sca-1+ cells demonstrated typical features of MSC-like cells, including adherence to tissue culture plates, trilineage differentiation potential, and expression of MSC markers. Kidney-derived Sca-1+ MSC-like cells were cultured for up to 21 days. Within the first few days in culture, cells stabilized HIF-1α and HIF-2α and temporarily increased Epo production upon incubation in hypoxia. In summary, we have identified a Sca-1+ MSC-like cell population that is involved in renal Epo production and might contribute to the strong anti-anemic effect of the PHD inhibitor roxadustat.
Basal Autophagy Is Necessary for A Pharmacologic PPARα Transactivation
Authors: Kim Eun Young , Lee Jae Man
Published: February 2022

Autophagy is a conserved cellular process of catabolism leading to nutrient recycling upon starvation and maintaining tissue and energy homeostasis. Tissue-specific loss of core-autophagy-related genes often triggers diverse diseases, including cancer, neurodegeneration, inflammatory disease, metabolic disorder, and muscle disease. The nutrient-sensing nuclear receptors peroxisome proliferator-activated receptor α (PPARα) plays a key role in fasting-associated metabolisms such as autophagy, fatty acid oxidation, and ketogenesis. Here we show that autophagy defects impede the transactivation of PPARα. Liver-specific ablation of the Atg7 gene in mice showed reduced expression levels of PPARα target genes in response to its synthetic agonist ligands. Since NRF2, an antioxidant transcription factor, is activated in autophagy-deficient mice due to p62/SQSTM1 accumulation and its subsequent interaction with KEAP1, an E3 ubiquitin ligase. We hypothesize that the nuclear accumulation of NRF2 by autophagy defects blunts the transactivation of PPARα. Consistent with this idea, we find that NRF2 activation is sufficient to inhibit the pharmacologic transactivation of PPARα, which is dependent on the Nrf2 gene. These results reveal an unrecognized requirement of basal autophagy for the transactivation of PPARα by preventing NRF2 from a nuclear translocation and suggest a clinical significance of basal autophagy to expect a pharmacologic efficacy of synthetic PPARα ligands.
The Influence of Diamond Nanoparticles on Fibroblast Cell Line L929, Cytotoxicity and Bacteriostaticity of Selected Pathogens
Authors: Mitura Katarzyna , Kornacka Joanna , Niemiec-Cyganek Aleksandra , Pawlus-Łachecka Lucyna , Mydłowska Katarzyna , Sobczyk-Guzenda Anna , Kaczorowski Witold , Ossowska Paulina , Bałasz Błażej , Wilczek Piotr
Published: February 2022

The main problem with using modified allotrophic forms of carbon with nanodiamond particles in the production of food packaging is establishing the boundary between safety, as it affects the human body, and the adequate and effective action of the substances. One vital area of concern is the transmission of pathogens in food into the body. The aim of this study was to evaluate the cytotoxicity and bacteriostatic biological activity of two different modifications of diamond nanoparticles: pure detonation nanodiamond particles (DND) obtained by Danienko and plasma-chemically modified detonation nanodiamond particles obtained by the microwave plasma activated chemical vapor deposition method in a rotary chamber (MDP1) An indirect method was used to evaluate the cytotoxicity effect in accordance with ISO 10993–5. The viability of the L929 fibroblast cell line used as a control was 98.5%, for DND 95.14%, and the lowest level of viability for MDP1 was 88.63%. Escherichia coli and Staphylococcus aureus bacteria were used in bacteriostatic tests and the degree of cytotoxicity of the tested materials was classified as low. The in vitro cytotoxicity results indicate no toxic effect on L929 cells nor any effect on any of the samples tested against the bacterial strains us
Chemical Bath Deposited Orthorhombic SnS Films for Solar Cell Applications
Authors: Ocampo-Ortega Carlos , Riech Ines , Abelenda Arturo , Mis-Fernández Ricardo , Rodríguez-Fragoso Patricia , Mendoza-Alvarez Julio
Published: February 2022

Tin sulfide (SnS) thin films were deposited by the chemical bath deposition technique. The used procedure allows us to obtain orthorhombic SnS in 3.5 h and achieve thicknesses of 390 nm. We study the influence of deposition times, percentage of Sn precursor, and post-annealing on the structural and optical properties. The X-ray diffraction measurements of SnS films prepared at a deposition time of 3 h showed orthorhombic structure with characteristic peaks of SnS2. However, increasing the deposition time and the Sn precursor, the orthorhombic SnS phase in these samples becomes predominant. Thin-film morphologies and thicknesses were identified by scanning electron microscopy (SEM). An increase in bandgap from 1.41 eV to 1.56 eV was observed by increasing Sn precursor. The optical properties remain constant after air annealing of 285 °C. Low-temperature photoluminescence spectra show emission bands at 2.5 eV attributed to the presence of SO2. Other deep level transitions were observed at about 0.9 eV, probably due to oxygen.
Formation Mechanism and Weights Analysis of Residual Stress Holes in E690 High-Strength Steel by Laser Shock Peening
Authors: Cao Yupeng , Wang Zhimin , Shi Weidong , Hua Guoran , Qiu Ming
Published: February 2022

To investigate the surface residual stress hole formation mechanism induced by laser shock peening (LSP) in an E690 high-strength steel sheet and to assign weights to the relevant causes; E690 steel samples were loaded using four laser beams with different power densities. The dynamic strain in thin plate samples was measured using a polyvinylidene fluoride piezoelectric sensor during LSP and the residual stress distributions on thin- and thick-plate samples were studied using an X-ray stress analyzer. The residual stress distribution of the simulated laser shock E690 high-strength steel sheet was consistent with that of the measured residual stress field, and the propagation pattern induced by a pulsed laser shock wave obtained via simulation shows good consistency with the surface dynamic strain test results. A shock wave propagation model was established for E690 high-strength steel sheets. At laser power densities of 1.98 and 2.77 GW/cm2, the residual stress fields obtained through simulations and experiments show the residual stress hole phenomenon. The combined effect of the shock wave, which is reflected back and forth, and the rarefaction waves that converge toward the center produced the residual stress hole phenomenon, and shock wave reflection has a slightly greater impact than surface rarefaction wave convergence on the residual stress holes on the material’s surface. When the laser power density is 4.07 GW/cm2, the maximum residual principal stress is distributed uniformly.
Low-Temperature Performance of Asphalt Mixtures Modified by Microencapsulated Phase Change Materials with Various Graphene Contents
Authors: Ren Yong-Xiang , Hao Pei-Wen
Published: February 2022

Microencapsulated phase change materials (PCMs) added to conventional ones can store excessive heat energy and reduce thermal stresses. In this study, melamine–formaldehyde resin phase change microencapsulated PCMs, with different contents of graphene (CG), were added to asphalt mixtures, in order to reduce their low-temperature cracking, induced by thermal stresses. Low-temperature and heat-conducting/storing performance of the obtained mixtures was examined via beam bending tests, semi-circular bending low-temperature performance tests, thermal conductivity tests and volume-specific heat capacity tests. Besides, the prepared asphalt mixtures’ water stability and high-temperature stability values were obtained via freeze-thaw splitting and wheel tracking tests. The low-temperature performance of PCM-modified asphalt mixtures was evaluated via their bending strain energy densities, with one of the PCM-modified asphalt mixtures, namely CGMFPCM3, synthesized by the authors, was 1.7 times higher than that of the common asphalt mixture. Although the dynamic stability of all three PCM-modified mixtures was deteriorated by 68, 50, and 20% compared to the common one, that of CGMFPCM3 still complied with the standard requirement. Thermal conductivity and volume-specific heat capacity of the asphalt mixture at 278.15 K was enhanced by 5 and 43%, respectively, after adding CGMFPCM3. It is recommended for reducing the temperature variation-induced cracking in the asphalt pavement. Thermal conductivity and volume-specific heat capacity can be used for evaluating the temperature-regulating performance of asphalt mixtures.
Simultaneous Precipitation and Electrodeposition of Hydroxyapatite Coatings at Different Temperatures on Various Metal Substrates
Authors: Taranu Bogdan-Ovidiu , Ianasi Paula , Rus Stefania Florina , Bucur Alexandra Ioana
Published: February 2022

The coating of orthopedic and dental implants with hydroxyapatite (HA) is recognized as a method to increase their integration ability. A new metal coating method, comprising simultaneous precipitation and electrodeposition, is presented. Two studies are described: the first is related to the influence of time/temperature increase on the morpho-structural characteristics of the deposited layer on the Ti substrate, while the second study presents the characteristics of the layers deposited on different metal substrates. For comparison, specimens were obtained using the classical electrochemical deposition under the same experimental conditions. The addition of Ca to the electrolyte creates more compact and more uniform coatings, while the addition of P creates more porous layers. Only a very small quantity of crystalline HA deposited on the C55, Cu, and Ni substrates when the classic electrodeposition method was employed, while using the new approach has clearly led to a larger crystalline HA amount electrodeposited on the same types of metals. With some exceptions, the advantages of using the new method are: better crystallinity, more uniform and continuous surface, higher roughness, and potentially higher anti-corrosion capabilities.
A Solid-Solid Phase Transformation of Triclabendazole at High Pressures
Authors: Ali Imran , Tang Jiequn , Han Yanqiang , Wei Zhiyun , Zhang Yongli , Li Jinjin
Published: February 2022

Triclabendazole is an effective medication to treat fascioliasis and paragonimiasis parasitic infections. We implemented a reliable quantum mechanical method which is density functional theory at the level of ωB97XD/6-31G* along with embedded fragments to elucidate stability and phase transition between two forms of triclabendazole. We calculated crystal structure parameters, volumes, Gibbs free energies, and vibrational spectra of two polymorphic forms of triclabendazole under different pressures and temperatures. We confirmed form I was more stable than form II at atmospheric pressure and room temperature. From high-pressure Gibbs free energy computations, we found a pressure-induced phase transformation between form I (triclinic unit cell) and form II (monoclinic unit cell). The phase transition between forms I and II was found at a pressure and temperature of 5.5 GPa and ≈350 K, respectively. In addition, we also studied the high-pressure polymorphic behavior of two forms of triclabendazole. At the pressure of 5.5 GPa and temperature from ≈350 K to 500 K, form II was more stable than form I. However, at temperatures lower than ≈350 K, form I was more stable than form II. We also studied the effects of pressures on volumes and Raman spectra. To the best of our knowledge, no such research has been conducted to determine the presence of phase transformation between two forms of triclabendazole. This is a case study that can be applied to various polymorphic crystals to study their structures, stabilities, spectra, and phase transformations. This research can assist scientists, chemists, and pharmacologists in selecting the desired polymorph and better drug design.
Effect of Fineness and Heat Treatment on the Pozzolanic Activity of Natural Volcanic Ash for Its Utilization as Supplementary Cementitious Materials
Authors: Khan Kaffayatullah , Amin Muhammad Nasir , Usman Muhammad , Imran Muhammad , Al-Faiad Majdi Adel , Shalabi Faisal I.
Published: February 2022

The aim of this study was to investigate the influence of fineness and heat-treatment on the pozzolanic and engineering properties of volcanic ash. To this end, two different fineness levels of volcanic ash, ultra-fine (VAF) and fine (VA), without and after heat treatment at different temperatures (VA550, VA650, and VA750), were partially substituted for cement. In addition to the control (100% cement), five binary mortar mixes, each containing 20% of the different types of volcanic ash (VAF and VA; heat-treated and not), were prepared. First, X-ray fluorescence (XRF), X-ray powder diffraction (XRD), particle size analysis, and modified Chappelle tests were used to characterize the material. All mortar mixes were then tested for compressive strength development, water absorption, and apparent porosity. Finally, the microstructure of each of the mixes was evaluated by performing XRD, thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR) analyses on paste samples at 91 days post-formation. The XRD and Chappelle reactivity results revealed increased pozzolanic reactivity with increasing volcanic ash fineness. In contrast, heat treatment adversely affected the pozzolanic reactivity of the volcanic ash due to the formation of crystalline phases at high temperatures. The mortars containing VAF20 (VAF, no heat, at 20%) showed slightly improved compressive strength (69.6 MPa) than the control (68.1 MPa) and all other binary mixes (66.7, 63.5, 64.2, and 63.9 MPa for VA20, VA20-550, VA20-650, and VA20-750, respectively) at 91 days. The mortar containing VAF20 demonstrated the lowest level of water absorption (9.3%) and apparent porosity (19.1%) of all mixes, including the control. The XRD results for the paste samples show that both VA and VAF showed the least intensity of portlandite phase, as compared to the control and other binary mixes. TGA results also show that binary mixes of VA and VAF have a reduced amount of portlandite, resulting in the densification of the mixes’ microstructures. With the addition of VAF, there is a significant shift in the FTIR band from 980 to 992 cm−1, which causes the formation of additional C–S–H gels that lead to the densification of the paste matrix. These results demonstrate that VAF exhibits high pozzolanic reactivity, making it suitable for use as a natural pozzolan that can partially substitute cement in the production of strong, durable, and environmentally friendly concrete.
A Case Series of Metastatic Malignant Gastrointestinal Neuroectodermal Tumors and Comprehensive Genomic Profiling Analysis of 20 Cases
Authors: Kandler Taylor , Cortez Eliane , Clinton Lani , Hemmerich Amanda , Ahmed Osama , Wong Ralph , Forns Taylor , MacNeill Andrea J. , Hamilton Trevor D. , Khorasani Mohammadali , Feng Xiaolan
Published: February 2022

Malignant gastrointestinal neuroectodermal tumor (GNET) is an ultra-rare soft tissue sarcoma, therefore often misdiagnosed and has no available standard treatment. Here, we report 3 cases of metastatic GNET with variable clinical courses. Our small case series as well as extensive literature review, further support that GNET is a spectrum of diseases with variable inherent biology and prognosis. Surgical management in the setting of recurrent/metastatic disease may be appropriate for GNET with indolent nature. Response to systemic treatments including chemotherapy and targeted treatments is variable, likely related to heterogenous biology as well. Furthermore, we retrospectively identified 20 additional GNET cases from Foundation Medicine’s genomic database and expanded on their clinicopathological and genomic features. Comprehensive genomic profiling (CGP) with DNA and RNA sequencing of this cohort, in the course of clinical care, demonstrated recurrent EWSR1 chromosomal rearrangements and a sparsity of additional recurrent or driver genomic alterations. All cases had low tumor mutational burden (TMB) and were microsatellite stable.
Interexaminer Reliability and Validity of Quantity of Cervical Mobility during Online Dynamic Inspection
Authors: Leonet-Tijero Leire , Corral-de-Toro Jaime , Rodríguez-Sanz Jacobo , Hernández-Secorún Mar , Abenia-Benedí Hugo , Lucha-López María Orosia , Monti-Ballano Sofía , Müller-Thyssen-Uriarte Julián , Tricás-Vidal Héctor , Hidalgo-García César , Tricás-Moreno José Miguel
Published: February 2022

Background: Physical therapists routinely measure range of motion (ROM) of cervical spine. The reliability of the cervical range of motion (CROM) device has been demonstrated in several studies, but current evidence on the validity and reliability of the visual inspection is contradictory. The aim is to assess the validity and interexaminer reliability of the online visual inspection of active cervical ROM in physiotherapy students. Methods: Flexion, extension, both lateral flexions and rotations of a single participant were measured using CROM. Online visual inspection of 18 physiotherapy students against CROM was registered. Results: The validity, against CROM, of the online visual inspection of the active ROM ranged from good to excellent (Intraclass Correlation Coefficient (ICC) 0.83–0.97). Interexaminer reliability of the online visual inspection had favorable outcomes in all cervical movements in the three physiotherapy courses (ICC 0.70–0.96), with the visual inspection of the rotations being the most reliable (ICC 0.93–0.97). Interexaminer reliability of the classification of mobility was poor to good (Kappa 0.03–0.90). Conclusions: The interexaminer reliability and validity of the quantification of active cervical movement during online visual inspection was shown to be good to excellent for flexion-extension and lateral flexions and excellent for rotations.
Combining Hepatic and Splenic CT Radiomic Features Improves Radiomic Analysis Performance for Liver Fibrosis Staging
Authors: Yin Yunchao , Yakar Derya , Dierckx Rudi A. J. O. , Mouridsen Kim B. , Kwee Thomas C. , de Haas Robbert J.
Published: February 2022

Background: The exact focus of computed tomography (CT)-based artificial intelligence techniques when staging liver fibrosis is still not exactly known. This study aimed to determine both the added value of splenic information to hepatic information, and the correlation between important radiomic features and information exploited by deep learning models for liver fibrosis staging by CT-based radiomics. Methods: The study design is retrospective. Radiomic features were extracted from both liver and spleen on portal venous phase CT images of 252 consecutive patients with histologically proven liver fibrosis stages between 2006 and 2018. The radiomics analyses for liver fibrosis staging were done by hepatic and hepatic–splenic features, respectively. The most predictive radiomic features were automatically selected by machine learning models. Results: When using splenic–hepatic features in the CT-based radiomics analysis, the average accuracy rates for significant fibrosis, advanced fibrosis, and cirrhosis were 88%, 82%, and 86%, and area under the receiver operating characteristic curves (AUCs) were 0.92, 0.81, and 0.85. The AUC of hepatic–splenic-based radiomics analysis with the ensemble classifier was 7% larger than that of hepatic-based analysis (p < 0.05). The most important features selected by machine learning models included both hepatic and splenic features, and they were consistent with the location maps indicating the focus of deep learning when predicting liver fibrosis stage. Conclusions: Adding CT-based splenic radiomic features to hepatic radiomic features increases radiomics analysis performance for liver fibrosis staging. The most important features of the radiomics analysis were consistent with the information exploited by deep learning.
Generalizations of Talagrand Inequality for Sinkhorn Distance Using Entropy Power Inequality
Authors: Wang Shuchan , Stavrou Photios A. , Skoglund Mikael
Published: February 2022

The distance that compares the difference between two probability distributions plays a fundamental role in statistics and machine learning. Optimal transport (OT) theory provides a theoretical framework to study such distances. Recent advances in OT theory include a generalization of classical OT with an extra entropic constraint or regularization, called entropic OT. Despite its convenience in computation, entropic OT still lacks sufficient theoretical support. In this paper, we show that the quadratic cost in entropic OT can be upper-bounded using entropy power inequality (EPI)-type bounds. First, we prove an HWI-type inequality by making use of the infinitesimal displacement convexity of the OT map. Second, we derive two Talagrand-type inequalities using the saturation of EPI that corresponds to a numerical term in our expressions. These two new inequalities are shown to generalize two previous results obtained by Bolley et al. and Bai et al. Using the new Talagrand-type inequalities, we also show that the geometry observed by Sinkhorn distance is smoothed in the sense of measure concentration. Finally, we corroborate our results with various simulation studies.
Research of the Oscillation Start-Up Time in an Extended Interaction Oscillator Driven by a Pseudospark-Sourced Sheet Electron Beam
Authors: Peng Ruibin , Li Hailong , Yin Yong , Xu Xiaotao , Chen Qingyun , Bi Liangjie , Xu Che , Wang Bin , Yuan Xuesong , Zhang Ping , Meng Lin
Published: February 2022

High current density and high brightness are critical factors for high-power and compact extended interaction oscillators (EIOs) which are operated in the terahertz (THz) waveband. The pseudospark-sourced (PS) sheet electron beam, which combines merits including high current density, a relatively big beam cross-section and no requirement for the external focusing magnetic field, is a good choice for application to high-frequency EIO. The pulse generated by the PS electron beam can last around tens of nanoseconds or even less, thus the EIO’s oscillation start-up time (OST) should be short enough. This paper researched how to reduce OST in an EIO driven by the PS sheet electron beam. The authors realized that the OST of EIO was very sensitive to the gap length under the equal period. The distribution of the electric field is optimized by adjusting the length of the gap. The strong electric field strength is conducive to the beam-wave interaction, and the OST is affected by the beam-wave interaction. When the gap length reaches a suitable value, the OST becomes the shortest. The simulation results showed the EIO’s shortest OST was 8 ns and the corresponding peak output power was 2 kW at 0.19 THz, while the current density was 500 A/cm2. When current density reached 10,000 A/cm2, the shortest OST could even be 1.9 ns.
Recovery Algorithm of Power Metering Data Based on Collaborative Fitting
Authors: Xu Yukun , Kong Xiangyong , Zhu Zheng , Jiang Chao , Xiao Shuang
Published: February 2022

Electric energy metering plays a crucial role in ensuring fair and equitable transactions between grid companies and power users. With the implementation of the State Grid Corporation’s energy Internet strategy, higher requirements have been put forward for power grid companies to reduce costs and increase efficiency and user service capabilities. Meanwhile, the accuracy and real-time requirements for electric energy measurements have also increased. Electricity information collection systems are mainly used to collect the user-side energy metering data for the power users. Attributed to communication errors, communication delays, equipment failures and other reasons, some of the collected data is missed or confused, which seriously affects the refined management and service quality of power grid companies. How to deal with such data has been one of the important issues in the fields of machine learning and data mining. This paper proposes a collaborative fitting algorithm to solve the problem of missing collected data based on latent semantics. Firstly, a tree structure of user history data is established, and then the user groups adjacent to the user with missing data are obtained from this. Finally, the missing data are recovered using the alternating least-squares matrix factorization algorithm. Through numerical verification, this method has high reliability and accuracy in recoverying the missing data.
Low-Carbon Transformation of Electric System against Power Shortage in China: Policy Optimization
Authors: Wang Bo , Wang Limao , Zhong Shuai , Xiang Ning , Qu Qiushi
Published: February 2022

The low-carbon transition of the power system is essential for China to achieve peak carbon and carbon neutrality. However, China could suffer power shortages due to radical policies in some extreme cases. The gap between power demand and supply from March 2021 to November 2021 ranged between 5.2 billion kW·h and 24.6 billion kW·h. The main reason for the power shortage was over-reliance on renewable energy and insufficient coal power supply for the power system. The low-carbon transformation path of the electric system needs to be explored with more flexibility for power security. This study applied a modified LEAP model and carried out a forecast analysis of thermal power generation and installed capacity in 2025 and 2030 under normal and extreme weather scenarios. The results suggested that: the installed capacity of thermal power will need to account for about 44.6–46.1% of power generation in 2025 and 37.4–39.3% in 2030, with the assumption of power shortages caused by the instability and uncertainty of renewable power. In the future, China needs to pursue the development of diversified energy sources and enhance the power supply security capability while strengthening the development and utilization of renewable energy.
Loss Estimation and Thermal Analysis of a Magnetic Levitation Reaction Flywheel with PMB and AMB for Satellite Application
Authors: He Zan , Wen Tong , Liu Xu , Suo Yuchen
Published: February 2022

The magnetic levitation reaction flywheel (MLRW) is a novel actuator of spacecraft attitude control because of its significant advantages, including lack of friction and active suppression of vibration. However, in a vacuum environment, the poor heat dissipation conditions make it more sensitive to various losses and rises in temperature. Therefore, increasing temperature is the key issue for components used in space. In this study, the losses of the three kinds of heat-generating areas in the MLRW, namely, the passive magnetic bearing (PMB), the active magnetic bearing (AMB) and brushless DC motor (BLDCM), were analyzed and calculated. Based on the electromagnetic field theory, the loss model of PMB was proposed. Based on the finite element method (FEM) and Bertotti model, the loss power of the AMB and the BLDCM was obtained. The calculated loss values were brought into the FEM to calculate the temperature field distribution of the MLRW system. Then, the key factors affecting the heat dissipation of the flywheel were obtained by combining thermal network analysis with the temperature field distribution. Finally, a prototype was fabricated. The maximum estimated and experimental temperatures were 34.8 °C and 36.8 °C, respectively, both at the BLDCM stator. The maximum error was 5.4%, which validates the calculated model.
Reliability Assessment under High Penetration of EVs including V2G Strategy
Authors: Mokhtar Mohamed , Shaaban Mostafa F. , Ismail Mahmoud H. , Sindi Hatem F. , Rawa Muhyaddin
Published: February 2022

With the increase in the penetration of battery electric vehicles (BEVs) all over the world, utilities should start considering their increased demand as part of their electric demand. Generally, the literature lacks works that consider the impact of transportation electrification on the reliability of the power system. Thus, this paper proposes a new mechanism for reliability assessment including BEVs, with both grid-to-vehicle (G2V) and vehicle-to-grid (V2G) modes. Three charging strategies: uncontrolled, controlled unidirectional, and controlled bidirectional are considered in this paper to model the interactions between the transportation and electric power systems. A dynamic stochastic consumption model for a fleet of BEVs is developed to be used in the reliability assessment for the distribution networks. This dynamic model takes into consideration the variability and uncertainty of different trip purposes, starting and ending trip times, as well as the corresponding battery consumption in weather conditions. Furthermore, it is composed of two sequential submodels: travel behavior and battery depletion. The first submodel considers trip-related information while the second considers battery-depleted energy. Simulation results on a benchmark test system show the negative impacts of uncontrolled charging on the power system’s reliability. However, they also show that controlled charging can significantly reduce or mitigate these impacts.
Optimal Design of C-Type Filter in Harmonics Polluted Distribution Systems
Authors: Tamaskani Rohollah , Khodsuz Masume , Yazdani-Asrami Mohammad
Published: February 2022

This paper aims to find the optimal size of parameters of a C-type filter in a non-sinusoidal system using a new optimization method called the Archimedes optimization algorithm (AOA). The inductance and capacitance values of the filter are acquired in which the power loss in the Thevenin resistor and the power loss characteristics of the load bus are minimized based on a new proposed objective function. Subject to technical and practical limitations of the IEEE 519 standard, an optimization problem is defined to achieve an optimal filter design that can increase the system power quality. The effectiveness of the proposed method is proved by comparison with the recent previously published methods. The results show the effectiveness of the proposed approach using the AOA in finding the minimum power losses and the harmonic content of frequency-dependent components. Eventually, the current study confirmed that the suggested objective function minimizes power losses of fundamental and harmonic order harmonics in non-sinusoidal systems.
Personalizing Environmental Awareness through Smartphones Using AHP and PROMETHEE II
Authors: Krouska Akrivi , Kabassi Katerina , Troussas Christos , Sgouropoulou Cleo
Published: February 2022

Environmental awareness refers to the understanding of the importance of protecting the natural environment. Digital technologies can play an important role in raising awareness of environmental issues. In view of this compelling need, this paper presents a novel way to promote environmental awareness with the use of smartphones. To achieve this, it employs personalization techniques, and specifically the Analytic Hierarchy Process (AHP) and PROMETHEE II. In more detail, the mobile application incorporates a user model that holds information, such as location (city, mountain, sea, etc.), age, interests, needs and indicators of waste management, economy of natural resources, general environmental protection, and biodiversity. At the first interaction of the user with the application, the user model is initialized; then, the system uses AHP and PROMETHEE II to provide personalized advice to users in order to help them raise their environmental awareness. The criteria, used to evaluate environmental advice, include the current location, living environment, habits, interests, needs, age, and seasonal suitability of the user. The novelty of this paper is the combination of AHP and PROMETHEE II for personalizing the environmental awareness using mobile technologies, taking into consideration the user profile as well as the surrounding area where the user is at the time that the advice is provided. The presented application has been evaluated regarding the system usefulness and environmental awareness. The findings indicate the high acceptance of this approach and its positive impact on users’ attitude and behavior with regard to reducing their environmental footprint.
Consequences of the Last Glacial Period on the Genetic Diversity of Southeast Asians
Authors: Branco Catarina , Kanellou Marina , González-Martín Antonio , Arenas Miguel
Published: February 2022

The last glacial period (LGP) promoted a loss of genetic diversity in Paleolithic populations of modern humans from diverse regions of the world by range contractions and habitat fragmentation. However, this period also provided some currently submersed lands, such as the Sunda shelf in Southeast Asia (SEA), that could have favored the expansion of our species. Concerning the latter, still little is known about the influence of the lowering sea level on the genetic diversity of current SEA populations. Here, we applied approximate Bayesian computation, based on extensive spatially explicit computer simulations, to evaluate the fitting of mtDNA data from diverse SEA populations with alternative evolutionary scenarios that consider and ignore the LGP and migration through long-distance dispersal (LDD). We found that both the LGP and migration through LDD should be taken into consideration to explain the currently observed genetic diversity in these populations and supported a rapid expansion of first populations throughout SEA. We also found that temporarily available lands caused by the low sea level of the LGP provided additional resources and migration corridors that favored genetic diversity. We conclude that migration through LDD and temporarily available lands during the LGP should be considered to properly understand and model the first expansions of modern humans.
Salinity Gradient Controls Microbial Community Structure and Assembly in Coastal Solar Salterns
Authors: Song Tianran , Liang Qiyun , Du Zhaozhong , Wang Xiaoqun , Chen Guanjun , Du Zongjun , Mu Dashuai
Published: February 2022

Salinity acts as a critical environmental filter on microbial communities in natural systems, negatively affecting microbial diversity. However, how salinity affects microbial community assembly remains unclear. This study used Wendeng multi-pond saltern as a model to evaluate the prokaryotic community composition and diversity and quantify the relative importance of ecological processes across salinity gradients. The results showed that low-saline salterns (45–80 g/L) exhibited higher bacterial diversity than high-saline salterns (175–265 g/L). The relative abundance of taxa assigned to Halomicrobiaceae, Rhodobacteraceae, Saprospiraceae, and Thiotrichaceae exhibited a hump-shaped dependence on increasing salinity. Salinity and pH were the primary environmental factors that directly or indirectly determined the composition and diversity of prokaryotic communities. Microbial co-occurrence network dynamics were more complex in the sediment than in the water of salterns. An infer Community Assembly Mechanisms by Phylogenetic-bin-based null model analysis (iCAMP) showed that microbial community assembly in sediment and water differed. Our findings provide more information about microbial community structure and the importance of various ecological processes in controlling microbial community diversity and succession along salinity gradients in water and sediment.
Cluster-Based Analysis of Retinitis Pigmentosa Modifiers Using Drosophila Eye Size and Gene Expression Data
Authors: Amstutz James , Khalifa Amal , Palu Rebecca , Jahan Kaushara
Published: February 2022

The goal of this research is to computationally identify candidate modifiers for retinitis pigmentosa (RP), a group of rare genetic disorders that trigger the cellular degeneration of retinal tissue. RP being subject to phenotypic variation complicates diagnosis and treatment of the disease. In a previous study, modifiers of RP were identified by an association between genetic variation in the DNA sequence and variation in eye size in a well-characterized Drosophila model of RP. This study will instead focus on RNA expression data to identify candidate modifier genes whose expression is correlated with phenotypic variation in eye size. The proposed approach uses the K-Means algorithm to cluster 171 Drosophila strains based on their expression profiles for 18,140 genes in adult females. This algorithm is designed to investigate the correlation between Drosophila eye size and genetic expression and gather suspect genes from clusters with abnormally large or small eyes. The clustering algorithm was implemented using the R scripting language and successfully identified 10 suspected candidate modifiers for RP. This analysis was followed by a validation study that tested seven candidate modifiers and found that the loss of five of them significantly altered the degeneration phenotype and thus can be labeled as a bona fide modifier of disease.