bluuebunny/crossref_metadata_2025 huggingface dataset:
Does Vaginal Cuff Creation and Avoidance of a Uterine Manipulator Improve the Prognosis of Total Laparoscopic Radical Hysterectomy for Early Cervical Cancer? A Retrospective Multicenter Study
Authors: Kondo Eiji , Yoshida Kenta , Kubo-Kaneda Michiko , Nii Masafumi , Okamoto Kota , Magawa Shoichi , Nimua Ryo , Okumura Asumi , Okugawa Toshiharu , Yamawaki Takaharu , Nagao Kenji , Yoshimura Kouichi , Watashige Naoki , Yanoh Kenji , Ikeda Tomoaki
Published: September 2022

Our goal was to compare the treatment outcomes of open-abdominal radical hysterectomy (O-RH) and total laparoscopic hysterectomy (TLRH) with vaginal cuff creation and without using a uterine manipulator in stage IB1-B2 (tumor size < 4 cm) cervical cancer cases. In this retrospective multicenter analysis, 94 cervical cancer stage IB1-B2 patients who underwent O-RH or TLRH in six hospitals in Japan between September 2016 and July 2020 were included; 36 patients underwent TLRH. Propensity score matching was performed because the tumor diameter was large, and positive cases of lymph node metastases were included in the O-RH group due to selection bias. The primary endpoint was progression-free survival (PFS) and recurrence sites of TLRH and O-RH. PFS and OS (overall survival) were not significant in both the TLRH (n = 27) and O-RH (n = 27) groups; none required conversion to laparotomy. The maximum tumor size was <2 and ≥2 cm in 12 (44.4%) and 15 (55.6%) patients, respectively, in both groups. Reportedly, the TLRH group had lesser bleeding than the O-RH group (p < 0.001). Median follow-up was 33.5 (2–65) and 41.5 (6–75) months in the TLRH and O-RH groups, respectively. PFS and OS were not significantly different between the two groups (TLRH: 92.6%, O-RH: 92.6%; log-rank p = 0.985 and 97.2%, 100%; p = 0.317, respectively). The prognosis of early cervical cancer was not significantly different between TLRH and O-RH. Tumor spillage was prevented by creating a vaginal cuff and avoiding the use of a uterine manipulator. Therefore, TLRH might be considered efficient.
MET Oncogene Controls Invasive Growth by Coupling with NMDA Receptor
Authors: Gallo Simona , Vitacolonna Annapia , Comoglio Paolo , Crepaldi Tiziana
Published: September 2022

The N-methyl-D-aspartate receptor (NMDAR) is a glutamate-gated ion channel involved in excitatory synaptic transmission. Outside the nervous system, the NMDAR is expressed in a variety of tissues and in cancers, notably in the highly invasive and metastatic triple-negative breast carcinoma. MET encodes the tyrosine kinase receptor for HGF and is a master regulator gene for “invasive growth”. In silico analysis shows that high expression of the NMDAR2B subunit is a negative prognostic factor in human invasive breast carcinoma. Here, we show that in triple-negative breast cancer cell lines NMDAR2B and MET proteins are coexpressed. HGF stimulation of these cells is followed by autophosphorylation of the MET kinase and phosphorylation of the NMDAR2B subunit at tyrosines 1252 and 1474. MET and phosphorylated NMDAR2B are physically associated, as demonstrated by co-immunoprecipitation, confocal immunofluorescence, and proximity ligation assays. Notably, pharmacological inhibition of NMDAR by MK801 and ifenprodil blunts the biological response to HGF. These results demonstrate the existence of a MET-NMDAR crosstalk driving the invasive program, paving the way for a new combinatorial therapy.
Safety and Efficacy of the Superior Gluteal Artery Perforator (SGAP) Flap in Autologous Breast Reconstruction: Systematic Review and Meta-Analysis
Authors: Martineau Jérôme , Kalbermatten Daniel F. , Oranges Carlo M.
Published: September 2022

(1) Background: The superior gluteal artery perforator (SGAP) flap is a prominent technique for autologous breast reconstruction. Unlike other commonly used techniques, current literature on the safety and efficacy of the SGAP flap is heterogenous and limited. The aim of this article was to perform a systematic literature review and meta-analysis of postoperative outcomes and complications associated with SGAP flap autologous breast reconstructions. (2) Methods: A systematic literature search of multiple databases was performed using the PRISMA guidelines. We included articles evaluating SGAP flaps in autologous breast reconstruction. Outcomes and complications were recorded and analyzed. Proportions and their 95% confidence intervals (CIs) were calculated in a random-effects meta-analysis. (3) Results: Fourteen studies meeting inclusion criteria, representing a total of 667 SGAP flaps, were included. The total flap loss rate was 1% (95% CI 0–3%), partial flap loss rate was 1% (95% CI 0–3%), hematoma rate was 3% (95% CI 1–6%), emergent surgical re-exploration rate was 5% (95% CI 2–9%), and overall donor-site complications were 12% (95% CI 4–23%). (4) Conclusions: This systematic review and meta-analysis provide comprehensive knowledge on the efficacy and safety of the SGAP flap in autologous breast reconstruction. It demonstrates its overall safety and low complication rate, validating its important role as an effective option in breast reconstruction.
Remodeling of the Neurovascular Unit Following Cerebral Ischemia and Hemorrhage
Authors: Sato Yoshimichi , Falcone-Juengert Jaime , Tominaga Teiji , Su Hua , Liu Jialing
Published: September 2022

Formulated as a group effort of the stroke community, the transforming concept of the neurovascular unit (NVU) depicts the structural and functional relationship between brain cells and the vascular structure. Composed of both neural and vascular elements, the NVU forms the blood–brain barrier that regulates cerebral blood flow to meet the oxygen demand of the brain in normal physiology and maintain brain homeostasis. Conversely, the dysregulation and dysfunction of the NVU is an essential pathological feature that underlies neurological disorders spanning from chronic neurodegeneration to acute cerebrovascular events such as ischemic stroke and cerebral hemorrhage, which were the focus of this review. We also discussed how common vascular risk factors of stroke predispose the NVU to pathological changes. We synthesized existing literature and first provided an overview of the basic structure and function of NVU, followed by knowledge of how these components remodel in response to ischemic stroke and brain hemorrhage. A greater understanding of the NVU dysfunction and remodeling will enable the design of targeted therapies and provide a valuable foundation for relevant research in this area.
Age-Related NAFLD: The Use of Probiotics as a Supportive Therapeutic Intervention
Authors: Campagnoli Lucrezia Irene Maria , Marchesi Nicoletta , Vairetti Mariapia , Pascale Alessia , Ferrigno Andrea , Barbieri Annalisa
Published: September 2022

Human aging, a natural process characterized by structural and physiological changes, leads to alterations of homeostatic mechanisms, decline of biological functions, and subsequently, the organism becomes vulnerable to external stress or damage. In fact, the elderly population is prone to develop diseases due to deterioration of physiological and biological systems. With aging, the production of reactive oxygen species (ROS) increases, and this causes lipid, protein, and DNA damage, leading to cellular dysfunction and altered cellular processes. Indeed, oxidative stress plays a key role in the pathogenesis of several chronic disorders, including hepatic diseases, such as non-alcoholic fatty liver disease (NAFLD). NAFLD, the most common liver disorder in the Western world, is characterized by intrahepatic lipid accumulation; is highly prevalent in the aging population; and is closely associated with obesity, insulin resistance, hypertension, and dyslipidemia. Among the risk factors involved in the pathogenesis of NAFLD, the dysbiotic gut microbiota plays an essential role, leading to low-grade chronic inflammation, oxidative stress, and production of various toxic metabolites. The intestinal microbiota is a dynamic ecosystem of microbes involved in the maintenance of physiological homeostasis; the alteration of its composition and function, during aging, is implicated in different liver diseases. Therefore, gut microbiota restoration might be a complementary approach for treating NAFLD. The administration of probiotics, which can relieve oxidative stress and elicit several anti-aging properties, could be a strategy to modify the composition and restore a healthy gut microbiota. Indeed, probiotics could represent a valid supplement to prevent and/or help treating some diseases, such as NAFLD, thus improving the already available pharmacological intervention. Moreover, in aging, intervention of prebiotics and fecal microbiota transplantation, as well as probiotics, will provide novel therapeutic approaches. However, the relevant research is limited, and several scientific research works need to be done in the near future to confirm their efficacy.
Human Amniotic Membrane Mesenchymal Stem Cell-Synthesized PGE2 Exerts an Immunomodulatory Effect on Neutrophil Extracellular Trap in a PAD-4-Dependent Pathway through EP2 and EP4
Authors: Estúa-Acosta Gibrán Alejandro , Buentello-Volante Beatriz , Magaña-Guerrero Fátima Sofía , Flores José Eduardo-Aguayo , Vivanco-Rojas Oscar , Castro-Salas Ilse , Zarco-Ávila Karla , García-Mejía Mariana A. , Garfias Yonathan
Published: September 2022

Human amniotic membrane mesenchymal stem cells (hAM-MSC) secrete a myriad of components with immunosuppressive activities. In the present research, we aimed to describe the effect of prostaglandin E2 (PGE2) secreted by hAM-MSCs on neutrophil extracellular trap (NET) release and to characterize the role of its receptors (EP2/EP4) in PAD-4 and NFκB activity in neutrophils. Human peripheral blood neutrophils were ionomycin-stimulated in the presence of hAM-MSC conditioned medium (CM) treated or not with the selective PGE2 inhibitor MF-63, PGE2, EP2/EP4 agonists, and the selective PAD-4 inhibitor GSK-484. NET release, PAD-4, and NFκB activation were analyzed. Ionomycin induced NET release, which was inhibited in the presence of hAM-MSC-CM, while CM from hAM-MSCs treated with MF-63 prevented NET release inhibition. PGE2 and EP2/EP4 agonists, and GSK-484 inhibited NET release. EP2/EP4 agonists and GSK-484 inhibited H3-citrullination but did not affect PAD-4 protein expression. Finally, PGE2 and EP2/EP4 agonists and GSK-484 increased NFκB phosphorylation. Taken together, these results suggest that hAM-MSC exert their immunomodulatory activities through PGE2, inhibiting NET release in a PAD-4-dependent pathway. This research proposes a new mechanism by which hAM-MSC exert their activities when modulating the innate immune response and inhibiting NET release.
Mitochondrial Genome Variants as a Cause of Mitochondrial Cardiomyopathy
Authors: Campbell Teresa , Slone Jesse , Huang Taosheng
Published: September 2022

Mitochondria are small double-membraned organelles responsible for the generation of energy used in the body in the form of ATP. Mitochondria are unique in that they contain their own circular mitochondrial genome termed mtDNA. mtDNA codes for 37 genes, and together with the nuclear genome (nDNA), dictate mitochondrial structure and function. Not surprisingly, pathogenic variants in the mtDNA or nDNA can result in mitochondrial disease. Mitochondrial disease primarily impacts tissues with high energy demands, including the heart. Mitochondrial cardiomyopathy is characterized by the abnormal structure or function of the myocardium secondary to genetic defects in either the nDNA or mtDNA. Mitochondrial cardiomyopathy can be isolated or part of a syndromic mitochondrial disease. Common manifestations of mitochondrial cardiomyopathy are a phenocopy of hypertrophic cardiomyopathy, dilated cardiomyopathy, and cardiac conduction defects. The underlying pathophysiology of mitochondrial cardiomyopathy is complex and likely involves multiple abnormal processes in the cell, stemming from deficient oxidative phosphorylation and ATP depletion. Possible pathophysiology includes the activation of alternative metabolic pathways, the accumulation of reactive oxygen species, dysfunctional mitochondrial dynamics, abnormal calcium homeostasis, and mitochondrial iron overload. Here, we highlight the clinical assessment of mtDNA-related mitochondrial cardiomyopathy and offer a novel hypothesis of a possible integrated, multivariable pathophysiology of disease.
Nitric Oxide Trickle Drives Heme into Hemoglobin and Muscle Myoglobin
Authors: Sumi Mamta P. , Tupta Blair , Ghosh Arnab
Published: September 2022

Ever since the days of NO being proclaimed as the “molecule of the year”, the molecular effects of this miracle gas on the globins have remained elusive. While its vasodilatory role in the cardiopulmonary system and the vasculature is well recognized, the molecular underpinnings of the NO–globin axis are incompletely understood. We show, by transwell co-culture of nitric oxide (NO) generating, HEK eNOS/nNOS cells, and K562 erythroid or C2C12 muscle myoblasts, that low doses of NO can effectively insert heme into hemoglobin (Hb) and myoglobin (Mb), making NO not only a vasodilator, but also a globin heme trigger. We found this process to be dependent on the NO flux, occurring at low NO doses and fading at higher doses. This NO-triggered heme insertion occurred into Hb in just 30 min in K562 cells and into muscle Mb in C2C12 myoblasts between 30 min and 1 h, suggesting that the classical effect of NO on upregulation of globin (Hb or Mb) is just not transcriptional, but may involve sufficient translational events where NO can cause heme-downloading into the apo-globins (Hb/Mb). This effect of NO is unexpected and highlights its significance in maintaining globins in its heme-containing holo-form, where such heme insertions might be required in the circulating blood or in the muscle cells to perform spontaneous functions.
Ferroptosis: The Potential Target in Heart Failure with Preserved Ejection Fraction
Authors: Li Qing , Zhao Zhiqiang , Zhou Xia , Yan Yuting , Shi Lusi , Chen Jiafan , Fu Baohui , Mao Jingyuan
Published: September 2022

Ferroptosis is a recently identified cell death characterized by an excessive accumulation of iron-dependent reactive oxygen species (ROS) and lipid peroxides. Intracellular iron overload can not only cause damage to macrophages, endothelial cells, and cardiomyocytes through responses such as lipid peroxidation, oxidative stress, and inflammation, but can also affect cardiomyocyte Ca2+ handling, impair excitation–contraction coupling, and play an important role in the pathological process of heart failure with preserved ejection fraction (HFpEF). However, the mechanisms through which ferroptosis initiates the development and progression of HFpEF have not been established. This review explains the possible correlations between HFpEF and ferroptosis and provides a reliable theoretical basis for future studies on its mechanism.
Drug-Containing Layered Double Hydroxide/Alginate Dispersions for Tissue Engineering
Authors: Zanin Juan Pablo , Gil German A. , García Mónica C. , Rojas Ricardo
Published: September 2022

Alginate (Alg) is increasingly studied as a constitutive material of scaffolds for tissue engineering because of its easy gelation and biocompatibility, and the incorporation of drugs into its formulation allows for its functionality to be extended. However, Alg presents a low cell adhesion and proliferation capacity, and the incorporation of drugs may further reduce its biocompatibility. Layered double hydroxides (LDH) are promising fillers for Alg-based biomaterials, as they increase cell adhesion and interaction and provide drug storage and controlled release. In this work, LDH containing ibuprofen or naproxen were synthesized by coprecipitation at a constant pH and their properties upon their incorporation in Alg dispersions (LDH-Drug/Alg) were explored. Drug release profiles in simulated body fluid and the proliferation of pre-osteoblastic MC3T3-E1 cells by LDH-Drug/Alg dispersions were then evaluated, leading to results that confirm their potential as biomaterials for tissue engineering. They showed a controlled release with diffusive control, modulated by the in-situ formation of an Alg hydrogel in the presence of Ca2+ ions. Additionally, LDH-Drug/Alg dispersions mitigated the cytotoxic effects of the pure drugs, especially in the case of markedly cytotoxic drugs such as naproxen.
Development of a Novel Electrochemical Biosensor Based on Organized Mesoporous Carbon and Laccase for the Detection of Serotonin in Food Supplements
Authors: Dăscălescu Dorin , Apetrei Constantin
Published: September 2022

Serotonin is a biogenic amine that has multiple roles in the human body and is mainly known as the happiness hormone. A new laccase (Lac)-based biosensor has been developed for the qualitative and quantitative determination of serotonin in three dietary supplements from three different manufacturers. The enzyme was immobilized on an organized mesoporous carbon-modified carbon screen-printed electrode (OMC-SPE) by the drop-and-dry method, the active surface being pretreated with glutaraldehyde. With the new biosensor, serotonin was selectively detected from different solutions. Square-wave voltammetry was the technique used for the quantitative determination of serotonin, obtaining a detection limit value of 316 nM and a quantification limit value of 948 nM in the linearity range of 0.1–1.2 µM. The pH for the determinations was 5.2; at this value, the biocatalytic activity of the laccase was optimal. At the same time, the electrochemical performance of the OMC-SPE/Lac biosensor was compared with that of the unmodified sensor, a performance that highlighted the superiority of the biosensor and the very important role of the enzyme in electrodetection. The results obtained from the quantitative determination of serotonin by square-wave voltammetry were compared with those from the FTIR method, revealing a very good correlation between the results obtained by the two quantitative determination methods.
Processing and Advancements in the Development of Thermal Barrier Coatings: A Review
Authors: Mehta Amrinder , Vasudev Hitesh , Singh Sharanjit , Prakash Chander , Saxena Kuldeep K. , Linul Emanoil , Buddhi Dharam , Xu Jinyang
Published: September 2022

Thermal barrier coating is critical for thermal insulation technology, making the underlying base metal capable of operating at a melting temperature of 1150 °C. By increasing the temperature of incoming gases, engineers can improve the thermal and mechanical performance of gas turbine blades and the piston cylinder arrangement. Recent developments in the field of thermal barrier coatings (TBCs) have made this material suitable for use in a variety of fields, including the aerospace and diesel engine industries. Changes in the turbine blade microstructure brought on by its operating environment determine how long and reliable it will be. In addition, the effectiveness of multi-layer, composite and functionally graded coatings depends heavily on the deposition procedures used to create them. This research aims to clarify the connection between workplace conditions, coating morphology and application methods. This article presents a high-level overview of the many coating processes and design procedures employed for TBCs to enhance the coating’s surface quality. To that end, this review is primarily concerned with the cultivation, processing and characteristics of engineered TBCs that have aided in the creation of specialized coatings for use in industrial settings.
What Does It Take to Further Our Knowledge of Plant Diversity in the Megadiverse South Africa?
Authors: Mamathaba Mashudu Patience , Yessoufou Kowiyou , Moteetee Annah
Published: September 2022

In the context of biodiversity crisis, targeted efforts are required to accelerate the discovery and description of the still-unknown species. In the present study, we collected data on current knowledge of plant richness in South Africa and used a statistical modeling technique to predict what might still be missing in the country. We found that we might be missing 1400–1575 plant species, and it might take 40–45 years to identify and describe these species aided by 64–315 taxonomists. Surveyed taxonomists spent USD 95,559, on average, to describe one species. At this rate, USD 150,506,142 would be required to describe the 1575 species (modeling) or USD 133,783,237 for the 1400 remaining species (expert opinion). However, these estimates do not correspond to what is specifically required for only species description but does integrate connected activities, e.g., running cost, bursary, salaries, grants, etc. Furthermore, these estimates do not account for the possibility of taxonomic revision, which, on its own, needs to be funded, nor do they account for molecular laboratory requirement. Nevertheless, if we consider that 15% of the predicted funds are solely spent on taxonomic activities, we would need ~USD 14,334 on one species. Overall, our study provides figures that can inform attempts to fuel efforts toward a comprehensive assessment of the unique South Africa’s biodiversity.
Mediterranean Diet, a Posteriori Dietary Patterns, Time-Related Meal Patterns and Adiposity: Results from a Cross-Sectional Study in University Students
Authors: Detopoulou Paraskevi , Dedes Vassilis , Syka Dimitra , Tzirogiannis Konstantinos , Panoutsopoulos Georgios I.
Published: September 2022

The transition to university is connected to potentially obesogenic dietary changes. Our aim was to assess the relation of Mediterranean diet adherence, and a posteriori dietary and meal patterns with adiposity in Greek students at the University of the Peloponnese. A total of 346 students (269 women) participated. Anthropometry was performed, and a food frequency questionnaire was administered. The MedDietScore was higher in women and was not linearly related to adiposity. Principal component analysis revealed six patterns: (1) legumes/vegetables/fruits/tea/dairy/whole grains, (2) juice/sodas/liquid calories, (3) olive oil/fats, (4) meat/poultry/fish, (5) alcohol/eggs/dairy and (6) fast foods/sweets. Patterns 4 and 6 were related to overweight/obesity probability (OR = 1.5, 95% CI: 0.995–2.538 and OR = 2.5, 95% CI: 1.07–6.06, respectively) and higher waist circumference (men). Men “early eaters” (breakfast/morning/afternoon snack) had a higher MedDietScore and lower overweight probability (OR = 0.47, 95% CI: 0.220–1.020). Poor meal and dietary patterns relate to overweight and central obesity, which is important for targeted health promotion programs.
Employing the London Atlas in the Age Estimation of a Select South African Population
Authors: Ishwarkumar Sundika , Pillay Pamela , Chetty Manogari , Satyapal Kapil Sewsaran
Published: September 2022

Dental age estimation in the living and deceased is a fundamental aspect of forensic sciences, civil cases, medico-legal proceedings and clinical dentistry. Accordingly, this study aimed to validate the accuracy and reproducibility of the London Atlas in a select South African sample of KwaZulu-Natal. In this cross-sectional study, 760 digital panoramic radiographs (n = 760) aged between 5.00 and 23.99 years were retrospectively reviewed through consecutive sampling. Each radiograph was assessed and assigned a dental age in accordance with the London Atlas of Human Tooth Development and Eruption by AlQahtani et al. (2010). The London Atlas overestimated age with a mean difference of −0.85 to −1.26 years in the selected South African sample of KwaZulu-Natal. A statistically significant difference between the chronological and estimated dental ages was recorded. Furthermore, the South African Black and Indian males had a higher overestimation of age than their female counterparts, with a mean difference of 0.13 and 0.07 years, respectively. This overestimation was less in the South African Indian population in comparison to the SA Black population. This outcome resulted in the creation of the KZN population- and sex-specific charts and atlases for the two selected cohorts of KwaZulu-Natal. The KZN Atlases were found to be more accurate in the selected sample, with a mean absolute error of 0.57 years and no statistically significant differences between the chronological and estimated dental ages.
Constrained Predictive Tracking Control for Unmanned Hexapod Robot with Tripod Gait
Authors: Gao Yong , Wang Dongliang , Wei Wu , Yu Qiuda , Liu Xiongding , Wei Yuhai
Published: September 2022

Since it is difficult to accurately track reference trajectories under the condition of stride constraints for an unmanned hexapod robot moving with rhythmic gait, an omnidirectional tracking strategy based on model predictive control and real-time replanning is proposed in this paper. Firstly, according to the characteristic that the stride dominates the rhythmic motion of an unmanned multi-legged robot, a body-level omnidirectional tracking model is established. Secondly, a quantification method of limb’s stretch and yaw constraints described by motion stride relying on a tripod gait is proposed, and then, a body-level accurate tracking controller based on constrained predictive control is designed. Then, in view of the low tracking efficiency of the robot under the guidance of common reference stride, a solution strategy of variable stride period and a real-time replanning scheme of reference stride are proposed based on the limb constraints and the integral mean, which effectively avoid the tracking deviation caused by the guidance of constant reference strides. Finally, the effectiveness and practicability of the proposed control strategy are demonstrated through the comparative analysis and simulation test of a hexapod robot WelCH with omnidirectional movement ability to continuously track the directed curve and the undirected polyline trajectory.
A Novel Color Image Encryption Algorithm Based on 5-D Hyperchaotic System and DNA Sequence
Authors: Li Xinyu , Zeng Jian , Ding Qun , Fan Chunlei
Published: September 2022

Nowadays, it is increasingly necessary to improve the encryption and secure transmission performance of images. Therefore, in this paper, a bit-level permutation algorithm based on hyper chaos is proposed, with a newly constructed 5-D hyperchaotic system combined with DNA sequence encryption to achieve bit-wide permutation of plaintexts. The proposed 5-D hyperchaotic system has good chaotic dynamics, combining hyperchaotic sequence with bit-level permutation to enhance the pseudo-randomness of the plaintext image. We adopt a scheme of decomposing the plaintext color image into three matrices of R, G, and B, and performing block operations on them. The block matrix was DNA encoded, operated, and decoded. The DNA operation was also determined by the hyperchaotic sequence, and finally generated a ciphertext image. The result of the various security analyses prove that the ciphertext images generated by the algorithm have good distribution characteristics, which can not only resist differential attacks, but also have the advantages of large cryptographic space.
Supervised Contrastive Learning and Intra-Dataset Adversarial Adaptation for Iris Segmentation
Authors: Zhou Zhiyong , Liu Yuanning , Zhu Xiaodong , Liu Shuai , Zhang Shaoqiang , Li Yuanfeng
Published: September 2022

Precise iris segmentation is a very important part of accurate iris recognition. Traditional iris segmentation methods require complex prior knowledge and pre- and post-processing and have limited accuracy under non-ideal conditions. Deep learning approaches outperform traditional methods. However, the limitation of a small number of labeled datasets degrades their performance drastically because of the difficulty in collecting and labeling irises. Furthermore, previous approaches ignore the large distribution gap within the non-ideal iris dataset due to illumination, motion blur, squinting eyes, etc. To address these issues, we propose a three-stage training strategy. Firstly, supervised contrastive pretraining is proposed to increase intra-class compactness and inter-class separability to obtain a good pixel classifier under a limited amount of data. Secondly, the entire network is fine-tuned using cross-entropy loss. Thirdly, an intra-dataset adversarial adaptation is proposed, which reduces the intra-dataset gap in the non-ideal situation by aligning the distribution of the hard and easy samples at the pixel class level. Our experiments show that our method improved the segmentation performance and achieved the following encouraging results: 0.44%, 1.03%, 0.66%, 0.41%, and 0.37% in the Nice1 and 96.66%, 98.72%, 93.21%, 94.28%, and 97.41% in the F1 for UBIRIS.V2, IITD, MICHE-I, CASIA-D, and CASIA-T.
Research on the Rapid Diagnostic Method of Rolling Bearing Fault Based on Cloud–Edge Collaboration
Authors: Tang Xianghong , Xu Lei , Chen Gongsheng
Published: September 2022

Recent deep-learning methods for fault diagnosis of rolling bearings need a significant amount of computing time and resources. Most of them cannot meet the requirements of real-time fault diagnosis of rolling bearings under the cloud computing framework. This paper proposes a quick cloud–edge collaborative bearing fault diagnostic method based on the tradeoff between the advantages and disadvantages of cloud and edge computing. First, a collaborative cloud-based framework and an improved DSCNN–GAP algorithm are suggested to build a general model using the public bearing fault dataset. Second, the general model is distributed to each edge node, and a limited number of unique fault samples acquired by each edge node are used to quickly adjust the parameters of the model before running diagnostic tests. Finally, a fusion result is made from the diagnostic results of each edge node by DS evidence theory. Experiment results show that the proposed method not only improves diagnostic accuracy by DSCNN–GAP and fusion of multi-sensors, but also decreases diagnosis time by migration learning with the cloud–edge collaborative framework. Additionally, the method can effectively enhance data security and privacy protection.
Local-Forest Method for Superspreaders Identification in Online Social Networks
Authors: Hao Yajing , Tang Shaoting , Liu Longzhao , Zheng Hongwei , Wang Xin , Zheng Zhiming
Published: September 2022

Identifying the most influential spreaders in online social networks plays a prominent role in affecting information dissemination and public opinions. Researchers propose many effective identification methods, such as k-shell. However, these methods are usually validated by simulating propagation models, such as epidemic-like models, which rarely consider the Push-Republish mechanism with attenuation characteristic, the unique and widely-existing spreading mechanism in online social media. To address this issue, we first adopt the Push-Republish (PR) model as the underlying spreading process to check the performance of identification methods. Then, we find that the performance of classical identification methods significantly decreases in the PR model compared to epidemic-like models, especially when identifying the top 10% of superspreaders. Furthermore, inspired by the local tree-like structure caused by the PR model, we propose a new identification method, namely the Local-Forest (LF) method, and conduct extensive experiments in four real large networks to evaluate it. Results highlight that the Local-Forest method has the best performance in accurately identifying superspreaders compared with the classical methods.
DC Motor Drive Powered by Solar Photovoltaic Energy: An FPGA-Based Active Disturbance Rejection Control Approach
Authors: Guerrero-Ramirez Esteban , Martinez-Barbosa Alberto , Contreras-Ordaz Marco Antonio , Guerrero-Ramirez Gerardo , Guzman-Ramirez Enrique , Barahona-Avalos Jorge Luis , Adam-Medina Manuel
Published: September 2022

This paper presents an experimental platform for regulating the DC motor angular speed powered by photovoltaic cells. The experimental platform comprises an Eco Green Energy EGE-260P-60 solar panel, DC/DC SEPIC converter, DC bus, DC/DC buck converter, DC motor and Nexys 4 board with an Artix-7 100T FPGA. The DC/DC SEPIC converter is used for harvesting the maximum amount of energy from the PV cells using the perturb and observe algorithm to track the maximum power point. The DC/DC buck converter is used as the motor drive using the active disturbance rejection control to regulate the angular speed of the DC motor. In addition, the FPGA architecture design is presented using a hierarchical top-down methodology with the VHDL hardware description language and Xilinx System Generator tool. The software takes advantage of the FPGA’s concurrency to simultaneously evaluate the different processes, which is the main reason for choosing this digital device. Several tests were performed on the platform such as irradiance changes, DC bus variations, DC motor connection and load torque variations applied in the motor shaft. The results indicate that the maximum power is obtained from the photovoltaic cells, establishing the minimum operating conditions. In addition, the control approach estimates and cancels the effects of disturbances caused by variations in the environmental conditions, photovoltaic system, DC bus, and load changes in order to regulate DC motor speed.
Validation through Experiment and Simulation of Internal Charging–Discharging Characteristics of Polyimide under High-Energy Electron Radiation
Authors: Wu Jiang , Zhang Bo , Zhi Yibo , He Minheng , Shang Penghui , Qian Yufeng
Published: September 2022

Due to the injection of energetic particles, such as electrons in space environment, the internal charging–discharging characteristics of spacecraft dielectrics need to be evaluated for the safety of spacecraft, and the evaluation results from experiments and simulations should be comparatively validated. An in-site pulsed electroacoustic (PEA) measurement system under high-energy electron radiation was established for evaluating the charging characteristics of thick plate samples about 3 mm, while a joint simulation method based on Geant4 and COMSOL was also proposed. The deposited charge distributions were compared through experiment and joint simulation method under 0.7, 1.0 and 1.3 MeV for 30 min and 1.0 MeV for 10, 60 and 120 min, respectively. Meanwhile, the electrostatic discharging characteristics were also comparative evaluated by both methods under 0.3 MeV for 20 min under 5, 10 and 15 µA beam current, and the total discharging times and initial discharging time were compared and analyzed. Overall, a good consistency existed between experimental and simulation results of charging–discharging characteristics under electron radiation while the difference was also analyzed in the perspective of dielectric properties, such as charge leakage by conduction. Through the comparative study, both evaluation methods are validated, which offers effective reference for the safety evaluation of spacecraft dielectrics in future.
Distributed Optimization of District Heating Networks Using Optimality Condition Decomposition
Authors: Maurer Jona , Illerhaus Jochen , Soneira Pol Jané , Hohmann Sören
Published: September 2022

The optimal operation of District Heating Networks (DHNs) is a challenging task. Current or future optimal dispatch energy management systems attempt to optimize objectives, such as monetary cost minimization, emission reduction, or social welfare maximization. Typically, this requires highly nonlinear models and has a substantial computational cost, especially for large DHNs. Consequently, it is difficult to solve the resulting nonlinear programming problem in real time. In particular, as typical applications allow for no more than several minutes of computation time. However, a distributed optimization approach may provide real time performance. Thereby, the solution of the central optimization problem is obtained by solving a set of small-scale, coupled optimization problems in parallel. At runtime, information is exchanged between the small-scale problems during the iterative solution procedure. A well-known approach of this class of distributed optimization algorithms is Optimality Condition Decomposition (OCD). Important advantages of this approach are the low amount of information exchange needed between the small-scale problems and that it does not require the tuning of parameters, which can be challenging. However, the DHNs model equation structure brings along many difficulties that hamper the application of the OCD approach. Simulation results demonstrate the applicability range of the presented method.
Do High Fuel Prices Pose an Obstacle to Economic Growth? A Study for Poland
Authors: Przekota Grzegorz
Published: September 2022

Great attention has been paid in recent months to high energy prices, including fuel prices. Numerous studies present the threat this poses to economic growth, but history already knows such situations. Therefore, the elementary question was posed: How do fuel prices affect trade and economic growth? The research was based on the Polish economy between 2000 and 2020. Poland is an importer of energy commodities, so it should exhibit strong sensitivity to fuel price changes. A VAR model was created for the Polish economy, including fuel prices, seaborne trade, gross domestic product, and inflation. The results demonstrate that the Polish economy is quite resilient to fuel market turbulence. Obviously enough, it is easier to function in the conditions of lower fuel prices, but high prices are not a reason to panic. Moreover, ongoing technological progress allows economies to weather fuel market crises more easily than was the case back in the 20th century. Therefore, one may unequivocally state that low fuel prices are not a prerequisite for a country’s development. An economy may develop under conditions of higher fuel prices, and panic over high fuel prices only further fuels the inflationary spiral.
Comparative Analysis of Dynamic Behavior of Liquid Droplet Impacting Flat and Circular Wires
Authors: Meng Yu , Quan Shenglin , Guo Yali , Shen Shengqiang
Published: September 2022

The performance of droplets captured by the wire mesh demister in a seawater desalination system seriously affects the quality of water desalination. Therefore, it is of great significance to study the droplet impact in the wire mesh demister to improve the demister’s efficiency. In this paper, a two-dimensional model of the droplet impacting the wire is established. The processes of the droplet impacting a flat wire and a circular wire are simulated by using the VOF model in Fluent, and a comparative analysis is conducted. The results demonstrate that both wires experience spreading and splashing stages, but when the wire is circular, the length of the lifted lamella is longer, the peak force on the wall is larger, the splash’s start time is earlier, and the number of secondary droplets is greater; the variation rule of the force on the wall caused by the change of initial velocity is similar, and the increase in initial velocity will promote the occurrence of splash phenomenon, but the role of the initial velocity on the splash effect is more obvious for the circular wire; and when the droplet impacts the flat wire, the influence of incident angle on the critical splash velocity is non-monotonic, but the critical splash velocity increases with an increase in incident angle when the wire is circular.
An Improved PLL-Based Speed Estimation Method for Induction Motors through Harmonic Separation
Authors: Yu Jie , Zhang Youjun , Zheng Xiaoqin
Published: September 2022

The real-time speed estimation of induction motors (IMs) is important for the motors’ state monitoring and control. The utilization of rotor slot harmonics (RSHs) due to the inherent cogging effect is regarded as a promising way to realize the speed estimation of IMs. The key to the RSH-based speed estimation method is how to accurately and quickly identify the frequency of an RSH signal. However, as the RSH signal always consists of two side-frequency components that are adjacent to each other, it is actually improper to directly use the conventional phase-locked loop (PLL) method designed for single-frequency tracking. Furthermore, the form of the two side components in the frequency domain also leads to a significant amplitude fluctuation in the time-domain waveform of RSHs, thus resulting in the obvious frequency tracking errors of the conventional PLL method. In this paper, we proposed an improved PLL through harmonic separation to further improve the performance of the RSH-based speed estimation method of multiphase IMs, so that the dynamic tracking errors of PLL due to the reasons mentioned above can be significantly reduced. Simulations and experiments in a wide speed range were also performed, with their results presented as verifications of the proposed method.
Numerical Prediction of Turbulent Drag Reduction with Different Solid Fractions and Distribution Shapes over Superhydrophobic Surfaces
Authors: Nguyen Hoai Thanh , Chang Kyoungsik , Lee Sang-Wook , Ryu Jaiyoung , Kim Minjae
Published: September 2022

The exploration of superhydrophobic drag reduction has been and continues to be of significant interest to various industries. In the present work, direct numerical simulation (DNS) is utilized to investigate the effect of the parameters on the drag-reducing performance of superhydrophobic surfaces (SHS). Simulations with a friction Reynolds number of 180 were carried out at solid fraction values of ϕs=116,111, and 14, and three distribution shapes: aligned, staggered, and random. The top wall is the smooth one, and the bottom wall is a superhydrophobic surface (SHS). Drag reduction and Reynolds stress profiles are compared for all cases. The turbulent kinetic energy budget, including production, dissipation, and diffusion, is presented with respect to the solid fraction and type of distribution to investigate the drag reduction mechanism. The sizes of the longitudinal vortices and formation of hairpin vortices are investigated through the observation of coherent structures. The simulation of a post model is a useful method to study the drag reduction for different solid fraction values and distribution geometries. Our study demonstrates that the drag reduction could acquire 42% with the solid fraction value ϕs=116 and an aligned distribution shape for post superhydrophobic surface geometry. Our study also showed the relationship of the Reynolds stress component (R11, R22, and R33) to the drag reduction with the differences in the solid fraction values and distribution geometry. In which, the R11 component has the most change between an aligned distribution and a random one. The peak value of R11 tends to shift away from the SHS wall. In addition, the analysis of the TKE budget over the superhydrophobic surface was performed, which can be adopted as a useful resource in turbulence modeling based on RANS methodology.
Aspects Regarding the Optimization of Cross Geometry in Traction Asynchronous Motors Using the Theory of Nonlinear Circuits
Authors: Enache Sorin , Vlad Ion , Enache Monica Adela
Published: September 2022

Modern electrical traction uses asynchronous motors for driving railway vehicles because these motors have a lot of advantages in comparison with the classical, direct current motors. Reducing active and reactive electrical energy consumption is a concern in the case of these motors, meaning a decrease in exploitation costs. The research carried out shows, by results and simulations, the effects of the geometry optimization for the stator and rotor lamination and emphasizes how much the total and exploitation costs. Cross geometry optimization means preserving constant electromagnetic stresses, using the same gauge dimensions, preserving the constant ampere-turn for a pole pair, having a maximum torque exceeding the imposed limit, and increasing the air-gap magnetic induction. The results obtained indicatea decrease in the total cost, by 42,600 € (12.31%), for a asynchronous tractionmotor in comparison with the existing variant.
Energy and Exergy Analyses of a Novel Combined Heat and Power System Operated by a Recuperative Organic Rankine Cycle Integrated with a Water Heating System
Authors: Khan Babras , Kim Man-Hoe
Published: September 2022

This study reports the thermodynamic analysis of a high-temperature recuperative organic Rankine cycle comprising a water heating system that can provide a net power of 585.7 kW and hot water for domestic use at 35 °C. The performance was analysed using seasonal ambient temperature and water temperature data from Seoul, South Korea. The working fluid was separated into two different mass fractions after emerging from the turbine 1 outlet; one fraction provided heat to recuperate the organic Rankine cycle, and the other fraction was transferred to the water heating system for heating water. Mass fractions were balanced based on the projected seasonal need for hot water. Four working fluids with high critical temperatures and five working fluids with low critical temperatures were examined for top and bottom cycles, respectively. Chlorobenzene was selected for the top cycle and R601 was selected for the bottom cycle. The system achievement in individual months was analysed using thermal efficiency and exergy efficiency. Moreover, the performances of the hottest (low hot water demand) and coldest (high hot water demand) months were analysed.
SENERGY: A Novel Deep Learning-Based Auto-Selective Approach and Tool for Solar Energy Forecasting
Authors: Alkhayat Ghadah , Hasan Syed Hamid , Mehmood Rashid
Published: September 2022

Researchers have made great progress in developing cutting-edge solar energy forecasting methods. However, these methods are far from optimal in terms of their accuracy, generalizability, benchmarking, and other requirements. Particularly, no single method performs well across all climates and weather due to the large variations in meteorological data. This paper proposes SENERGY (an acronym for sustainable energy), a novel deep learning-based auto-selective approach and tool that, instead of generalizing a specific model for all climates, predicts the best performing deep learning model for global horizontal irradiance (GHI) forecasting in terms of forecasting error. The approach is based on carefully devised deep learning methods and feature sets created through an extensive analysis of deep learning forecasting and classification methods using ten meteorological datasets from three continents. We analyze the tool in great detail through a variety of metrics and means for performance analysis, visualization, and comparison of solar forecasting methods. SENERGY outperforms existing methods in all performance metrics including mean absolute error (MAE), root mean square error (RMSE), mean absolute percentage error (MAPE), the normalized versions of these three metrics (nMAE, nRMSE, nMAPE), forecast skill (FS), and relative forecasting error. The long short-term memory-autoencoder model (LSTM-AE) outperformed the other four forecasting models and achieved the best results (nMAE = nRMSE = nMAPE = 0.02). The LSTM-AE model is the most accurate in all weather conditions. Predictions for sunny days are more accurate than for cloudy days as well as for summer compared to winter. SENERGY can predict the best forecasting model with 81% accuracy. The proposed auto-selective approach can be extended to other research problems, such as wind energy forecasting, and to predict forecasting models based on different criteria such as the energy required or speed of model execution, different input features, different optimizations of the same models, or other user preferences.