bluuebunny/crossref_metadata_2025 huggingface dataset:
Boosting the Immune Response—Combining Local and Immune Therapy for Prostate Cancer Treatment
Authors: Karwacki Jakub , Kiełbik Aleksander , Szlasa Wojciech , Sauer Natalia , Kowalczyk Kamil , Krajewski Wojciech , Saczko Jolanta , Kulbacka Julita , Szydełko Tomasz , Małkiewicz Bartosz
Published: September 2022

Due to its slow progression and susceptibility to radical forms of treatment, low-grade PC is associated with high overall survival (OS). With the clinical progression of PC, the therapy is becoming more complex. The immunosuppressive tumor microenvironment (TME) makes PC a difficult target for most immunotherapeutics. Its general immune resistance is established by e.g., immune evasion through Treg cells, synthesis of immunosuppressive mediators, and the defective expression of surface neoantigens. The success of sipuleucel-T in clinical trials initiated several other clinical studies that specifically target the immune escape of tumors and eliminate the immunosuppressive properties of the TME. In the settings of PC treatment, this can be commonly achieved with radiation therapy (RT). In addition, focal therapies usually applied for localized PC, such as high-intensity focused ultrasound (HIFU) therapy, cryotherapy, photodynamic therapy (PDT), and irreversible electroporation (IRE) were shown to boost the anti-cancer response. Nevertheless, the present guidelines restrict their application to the context of a clinical trial or a prospective cohort study. This review explains how RT and focal therapies enhance the immune response. We also provide data supporting the combination of RT and focal treatments with immune therapies.
Melatonin Attenuates Spinal Cord Injury in Mice by Activating the Nrf2/ARE Signaling Pathway to Inhibit the NLRP3 Inflammasome
Authors: Wang Haoyu , Wang Haifan , Huang Heng , Qu Zhigang , Ma Dong , Dang Xiaoqian , Dong Quanyu
Published: September 2022

Background: Spinal cord injury (SCI) is a central nervous system (CNS) trauma involving inflammation and oxidative stress, which play important roles in this trauma’s pathogenesis. Therefore, controlling inflammation is an effective strategy for SCI treatment. As a hormone, melatonin is capable of producing antioxidation and anti-inflammation effects. In the meantime, it also causes a neuroprotective effect in various neurological diseases. Nrf2/ARE/NLRP3 is a well-known pathway in anti-inflammation and antioxidation, and Nrf2 can be positively regulated by melatonin. However, how melatonin regulates inflammation during SCI is poorly explored. Therefore, it was investigated in this study whether melatonin can inhibit the NLRP3 inflammasome through the Nrf2/ARE signaling pathway in a mouse SCI model. Methods: A model of SCI was established in C57BL/6 mice and PC12 cells. The motor function of mice was detected by performing an open field test, and Nissl staining and terminal deoxynucleotidyl transferase dUTP nick end labeling were carried out to evaluate the survival of neurons. Mitochondrial dysfunction was detected by transmission electron microscopy (TEM) and by assessing the mitochondrial membrane potential. In addition, the expression of NLRP3 inflammasome and oxidative-stress-related proteins were detected through Western blot and immunofluorescence double staining. Results: By inhibiting neuroinflammation and reducing neuronal death, melatonin promotes the recovery of neuromotor function. Besides this, melatonin is able to reduce the damage that causes neuronal mitochondrial dysfunction, reduce the level of reactive oxygen species (ROS) and malondialdehyde, and enhance the activity of superoxide dismutase and the production of glutathione peroxidase. Mechanically, melatonin inhibits the activation of NLRP3 inflammasomes and reduces the secretion of pro-inflammatory factors through the Nrf2/ARE signaling. Conclusions: In conclusion, melatonin inhibits the NLRP3 inflammasome through stimulation of the Nrf2/ARE pathway, thereby suppressing neuroinflammation, reducing mitochondrial dysfunction, and improving the recovery of nerve function after SCI.
Regulating the Expression of HIF-1α or lncRNA: Potential Directions for Cancer Therapy
Authors: Zhang Minghui , Zhang Yu , Ding Yubo , Huang Jialu , Yao Jingwei , Xie Zhuoyi , Lv Yufan , Zuo Jianhong
Published: September 2022

Previous studies have shown that tumors under a hypoxic environment can induce an important hypoxia-responsive element, hypoxia-induced factor-1α (HIF-1α), which can increase tumor migration, invasion, and metastatic ability by promoting epithelial-to-mesenchymal transition (EMT) in tumor cells. Currently, with the deeper knowledge of long noncoding RNAs (lncRNAs), more and more functions of lncRNAs have been discovered. HIF-1α can regulate hypoxia-responsive lncRNAs under hypoxic conditions, and changes in the expression level of lncRNAs can regulate the production of EMT transcription factors and signaling pathway transduction, thus promoting EMT progress. In conclusion, this review summarizes the regulation of the EMT process by HIF-1α and lncRNAs and discusses their relationship with tumorigenesis. Since HIF-1α plays an important role in tumor progression, we also summarize the current drugs that inhibit tumor progression by modulating HIF-1α.
From the Difficult Airway Management to Diagnosis of Retropharyngeal Synovial Cell Carcinoma
Authors: Jassem-Bobowicz Joanna Maria , Sokołowska Ewa Magdalena , Hinca Katarzyna Monika , Drążkowska Izabela , Stefańska Katarzyna
Published: September 2022

Respiratory complications are among the most common problems addressed in neonatology in the first hours after birth, whereas the risk of any cancer in the neonatal period is 28 per million. Sarcomas, malignant mesenchymal neoplasms, account for about 8% of all neoplasms in the neonatal period. We report on a male neonate born at 36 + 4/7 weeks of gestation, diagnosed with retropharyngeal synovial carcinoma. Ineffective respiratory movements and generalized cyanosis were the first symptoms to be noted. On the ultrasound examination of the neck, a tumor of the retropharyngeal space was exposed, then visualized by an MRI of the head and neck. The biopsy analysis revealed the diagnosis of an extremely rare tumor in a neonate. The location of its growth was atypical, contributing to a diagnostic challenge. The neoplasm was treated solely with chemotherapy concordantly with the CWS protocol, individually customized for our patient. Preterm birth, as in our case, 36 + 4/7 weeks of gestation, may imply a possible need for resuscitation or support in the transition period. Aggressive high-grade tumors of the head and neck region are locally invasive and prone to metastasize. However, prognosis in infants is hard to estimate, therefore both individualized treatment and multidisciplinary care should be tailored to the needs of the patient.
The Role of Electroencephalography in the Prognostication of Clinical Outcomes in Critically Ill Children: A Review
Authors: Gilman Carley A. , Wusthoff Courtney J. , Guerriero Réjean M.
Published: September 2022

Electroencephalography (EEG) is a neurologic monitoring modality that allows for the identification of seizures and the understanding of cerebral function. Not only can EEG data provide real-time information about a patient’s clinical status, but providers are increasingly using these results to understand short and long-term prognosis in critical illnesses. Adult studies have explored these associations for many years, and now the focus has turned to applying these concepts to the pediatric literature. The aim of this review is to characterize how EEG can be utilized clinically in pediatric intensive care settings and to highlight the current data available to understand EEG features in association with functional outcomes in children after critical illness. In the evaluation of seizures and seizure burden in children, there is abundant data to suggest that the presence of status epilepticus during illness is associated with poorer outcomes and a higher risk of mortality. There is also emerging evidence indicating that poorly organized EEG backgrounds, lack of normal sleep features and lack of electrographic reactivity to clinical exams portend worse outcomes in this population. Prognostication in pediatric critical illness must be informed by the comprehensive evaluation of a patient’s clinical status but the utilization of EEG may help contribute to this assessment in a meaningful way.
Features of the Formation of Surface Structures under Dry Friction of Al-30Sn Composite against Steel
Authors: Rusin Nikolay , Skorentsev Alexander , Krinitcyn Maksim
Published: September 2022

Features of the frictional interaction of a sintered Al-30Sn composite, which is used as a coating of bearing inserts, with steel counterbody in the absence of liquid lubricant were studied. The tribological tests were carried out according to the pin-on-disk scheme at room temperature. The friction coefficient μ of the friction pair is increased up to approximately 0.6 during the running-in process. Its growth stops when the stage of steady state friction begins, and then μ fluctuates around some relatively high and constant value. The study of the friction surfaces of the friction pair showed that the aforementioned increase in μ is due to the formation of a discrete transferred layer on the friction track surface and strain hardening of the subsurface layer of the Al-30Sn sample under the action of hard particles of the transferred layer. It was established that tin is transferred on the friction track surface mainly in a composition of wear particles, despite the high content of the solid lubricant in the investigated samples. The wear intensity of the samples subjected to processing by equal channel angular pressing with route A is much lower than that of the sintered (unprocessed) ones. The main wear mechanism of Al-30Sn composites under dry friction against steel is a delamination of the highly deformed subsurface aluminum grains along their interphase boundaries.
High-Aligned PVDF Nanofibers with a High Electroactive Phase Prepared by Systematically Optimizing the Solution Property and Process Parameters of Electrospinning
Authors: He Zhongchen , Rault François , Vishwakarma Astha , Mohsenzadeh Elham , Salaün Fabien
Published: September 2022

Poly(vinylidene fluoride) (PVDF)-electrosprayed nanofibers have been the subject of much research due to their flexibility and piezoelectric properties compared to other piezoelectrics, for example, ceramics or other polymeric materials. The piezoelectric performance of PVDF is mainly related to the presence of β-phase. This study aims to determine the influence of working and formulation parameters on the generation of β-phase, morphology, and crystal structure of PVDF nanofibers. In addition, this research innovatively analyzes the effect of the dispersion state of PVDF molecular chains in the solvent on the electrospinning results. The morphology and crystal structure of PVDF nanofibers were determined using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR). Beadless nanofibers are obtained when the PVDF concentration reaches the semi-diluted regime entangled in dimethylformamide (DMF) or DMF/acetone solution. The optimization of the process parameters (static collector, tip to collector distance—25 cm, flow rate—1 mL/h, applied voltage—20 kV) allows the increase in the β-phase fraction from 68.3% ± 1.2% to 94.5% ± 0.6% for a PVDF concentration of 25 w/v% in a DMF/acetone mixture (2/3 v/v). With these same parameters applied to a rotating collector, it was observed that the piezoelectric performance is at maximum for a maximum β-phase fraction of 90.6% ± 1.1%, obtained for a rotational speed of 200 rpm. The effect of orientation of PVDF nanofibers on piezoelectric properties was quantitatively discussed for the first time; the piezoelectric properties are independent of the alignment of the nanofibers.
Amphibian Taxonomic and Functional Diversity in a Heterogeneous Landscape of West-Central Mexico
Authors: Rosas-Espinoza Verónica Carolina , Peña-Joya Karen Elizabeth , Álvarez-Grzybowska Eliza , Godoy-González Arquímedes Alfredo , Santiago-Pérez Ana Luisa , Rodríguez-Zaragoza Fabián Alejandro
Published: September 2022

Land use in Mexico has dramatically changed in recent decades since deforested lands have been repurposed for agriculture. We evaluated the amphibian taxonomic and functional diversity of a heterogeneous landscape with ten land cover/use types in west-central Mexico. Taxonomic diversity was evaluated with q-order indices, and functional diversity was calculated with three multivariate functional diversity indices by land cover/use. The relationship between amphibian diversity, habitat structure, and environmental variables was analyzed using multidimensional distance-based analyses. Our results showed that most native land cover types exhibited a similar species richness (low values) among the studied crops, except for the riparian habitat surrounded by tropical dry forest (high richness) and secondary vegetation (intermediate richness). Regarding functional diversity, the riparian habitat surrounded by tropical dry forest, sugar cane field, and secondary vegetation had the highest values. The secondary vegetation had more functional groups than other land cover/use types. Despite the lack of a clear spatial pattern of amphibian taxonomic and functional diversity, we determined that attributes such as herbaceous cover and water availability are essential to maintain both facets with high amphibian diversity in the land cover/use types (e.g., secondary vegetation and sugar cane).
Approach of Heterogeneous Spectrum Involving 3beta-Hydroxysteroid Dehydrogenase 2 Deficiency
Authors: Nicola Andreea Gabriela , Carsote Mara , Gheorghe Ana-Maria , Petrova Eugenia , Popescu Alexandru Dan , Staicu Adela Nicoleta , Țuculină Mihaela Jana , Petcu Cristian , Dascălu Ionela Teodora , Tircă Tiberiu
Published: September 2022

We aim to review data on 3beta-hydroxysteroid dehydrogenase type II (3βHSD2) deficiency. We identified 30 studies within the last decade on PubMed: 1 longitudinal study (N = 14), 2 cross-sectional studies, 1 retrospective study (N = 16), and 26 case reports (total: 98 individuals). Regarding geographic area: Algeria (N = 14), Turkey (N = 31), China (2 case reports), Morocco (2 sisters), Anatolia (6 cases), and Italy (N = 1). Patients’ age varied from first days of life to puberty; the oldest was of 34 y. Majority forms displayed were salt-wasting (SW); some associated disorders of sexual development (DSD) were attendant also—mostly 46,XY males and mild virilisation in some 46,XX females. SW pushed forward an early diagnosis due to severity of SW crisis. The clinical spectrum goes to: premature puberty (80%); 9 with testicular adrenal rest tumours (TARTs); one female with ovarian adrenal rest tumours (OARTs), and some cases with adrenal hyperplasia; cardio-metabolic complications, including iatrogenic Cushing’ syndrome. More incidental (unusual) associations include: 1 subject with Barter syndrome, 1 Addison’s disease, 2 subjects of Klinefelter syndrome (47,XXY/46,XX, respective 47,XXY). Neonatal screening for 21OHD was the scenario of detection in some cases; 17OHP might be elevated due to peripheral production (pitfall for misdiagnosis of 21OHD). An ACTH stimulation test was used in 2 studies. Liquid chromatography tandem–mass spectrometry unequivocally sustains the diagnostic by expressing high baseline 17OH-pregnenolone to cortisol ratio as well as 11-oxyandrogen levels. HSD3B2 gene sequencing was provided in 26 articles; around 20 mutations were described as “novel pathogenic mutation” (frameshift, missense or nonsense); many subjects had a consanguineous background. The current COVID-19 pandemic showed that CAH-associated chronic adrenal insufficiency is at higher risk. Non-adherence to hormonal replacement contributed to TARTs growth, thus making them surgery candidates. To our knowledge, this is the largest study on published cases strictly concerning 3βHSD2 deficiency according to our methodology. Adequate case management underlines the recent shift from evidence-based medicine to individualized (patient-oriented) medicine, this approach being particularly applicable in this exceptional and challenging disorder.
The Influence of Eyelid Position and Environmental Conditions on the Corneal Changes in Early Postmortem Interval: A Prospective, Multicentric OCT Study
Authors: Nioi Matteo , Napoli Pietro Emanuele , Demontis Roberto , Chighine Alberto , De-Giorgio Fabio , Grassi Simone , Scorcia Vincenzo , Fossarello Maurizio , d’Aloja Ernesto
Published: September 2022

In the current study, using portable optical coherence tomography, we evaluated 46 corneas of 23 individuals in a multicenter setting during the first 17 h after death. Twenty-three eyes were kept open, and twenty three were kept closed. Furthermore, the experiment was carried out for 12 samples in summer and 11 in winter. Our data show that postmortem corneal alterations largely depend on the phenomena of dehydration (in particular in open eyes) and swelling of the stroma in closed eyes, probably due in the first phase to hypoxia/anoxia and subsequently to the passage by osmosis of the aqueous humor from the anterior chamber to the corneal tissue. Our findings could have significant repercussions in forensic pathology for estimating the postmortem interval and transplantation to optimize the conservation of the tissue before the explant.
Modeling Overdispersed Dengue Data via Poisson Inverse Gaussian Regression Model: A Case Study in the City of Campo Grande, MS, Brazil
Authors: Saraiva Erlandson Ferreira , Vigas Valdemiro Piedade , Flesch Mariana Villela , Gannon Mark , de Bragança Pereira Carlos Alberto
Published: September 2022

Dengue fever is a tropical disease transmitted mainly by the female Aedes aegypti mosquito that affects millions of people every year. As there is still no safe and effective vaccine, currently the best way to prevent the disease is to control the proliferation of the transmitting mosquito. Since the proliferation and life cycle of the mosquito depend on environmental variables such as temperature and water availability, among others, statistical models are needed to understand the existing relationships between environmental variables and the recorded number of dengue cases and predict the number of cases for some future time interval. This prediction is of paramount importance for the establishment of control policies. In general, dengue-fever datasets contain the number of cases recorded periodically (in days, weeks, months or years). Since many dengue-fever datasets tend to be of the overdispersed, long-tail type, some common models like the Poisson regression model or negative binomial regression model are not adequate to model it. For this reason, in this paper we propose modeling a dengue-fever dataset by using a Poisson-inverse-Gaussian regression model. The main advantage of this model is that it adequately models overdispersed long-tailed data because it has a wider skewness range than the negative binomial distribution. We illustrate the application of this model in a real dataset and compare its performance to that of a negative binomial regression model.
Cox Proportional Hazards Regression for Interval-Censored Data with an Application to College Entrance and Parental Job Loss
Authors: Kim HeeJin , Kim Sunghun , Lee Eunjee
Published: September 2022

This study involved conducting a survival analysis by fitting a Cox proportional hazards model to Korea Labor Panel data to analyze the impact of parental job loss on children’s delayed admission to colleges and universities in South Korea, using 376 subjects whose parental education levels were college-level or higher. Since Korea Labor Panel data are interval- and right-censored, we compared three imputation methods: simple omission, imputation as the average of the left and right values of the interval, and multiple imputation. Their integrated areas under the ROC curve (AUC) and mean square errors (MSE) were compared to assess their predictive and estimation performances. It was found that, within the simulation, the multiple imputation method exhibited a lower MSE than the other two methods. However, no difference was observed in the iAUC values. In the group where each householder had at least a college degree, parental job loss was significantly related to the delayed college or university admission of the first-born child regardless of the use of the interval censoring imputation method. In particular, when the first-born children experienced their parents’ unemployment at the age of 18, the probability of college admission was reduced nearly by 53% compared to cases where they did not. This analysis implies that the government should develop a policy in the education system offering psychosocial support for adolescents who cannot expect parental help.
Efficient Health Data Transmission Method in a Wireless Body Area Network for Rural Elderly
Authors: Wu Huarui , Zhu Huaji , Gu Jingqiu , Peng Cheng , Han Xiao
Published: September 2022

The wireless body area network (WBAN) can monitor human physiological information for a long time and alleviate problems such as the imbalance of medical resources distribution and population aging. The complex human media may make data transmission unstable in wireless body area networks. A delay-tolerant WBAN opportunity transmission method based on human data priority was studied. In this method, the historical states between links are recorded by a sliding window. Then, the link stability is measured by a prediction function. At the same time, considering the heterogeneity of the data in the body area network, transmission priority is assigned to different health data. Combined with residual energy, link stability, and distance, the transmission cost of the candidate set is calculated, and the node with the lowest expected transmission cost is selected as the next hop to improve the reliability of data transmission. The experimental results showed that this method includes the characteristics of opportunity routing and WBAN to transmit health data with lower delay and higher efficiency than previous methods.
Intelligent Identification and Order-Sensitive Correction Method of Outliers from Multi-Data Source Based on Historical Data Mining
Authors: Chen Guangyu , Zhu Zhengyang , Yang Li , Huang Wenhao , Zhang Yuzhuo , Lin Gang , Zhang Shengjie
Published: September 2022

In recent years, outliers caused by manual operation errors and equipment acquisition failures often occur, bringing challenges to big data analysis. In view of the difficulties in identifying and correcting outliers of multi-source data, an intelligent identification and order-sensitive correction method of outliers from multi-data sources based on historical data mining was proposed. First, an intelligent identification method of outliers of single-source data is proposed based on neural tangent kernel K-means (NTKKM) clustering. The original data is mapped to high-dimensional feature space using Neural Tangent Kernel, where the features of outliers are acquired by K-means clustering to realize the accurate identification of outliers. Second, an order-sensitive missing value imputation framework for multi-source data (OMSMVI) was proposed. The similarity graph of sources with missing data was constructed based on multidimensional similarity analysis, and the filling order decision was transformed into an optimization problem to realize the optimal filling order decision of missing values in multi-source data. Finally, a neighborhood-based imputation (NI) algorithm is proposed. Based on the traditional KNN filling algorithm, neighboring nodes of sources with missing data are flexibly selected to the achieve accurate correction of outliers. The case experiment was operated on actual power grid data, and the results show that the proposed clustering method can identify outliers more accurately, and the determined optimal imputation sequence has higher accuracy, which provide a feasible new idea for the identification and correction of outliers in the process of data preprocessing.
Content-Aware Proactive VR Video Caching for Cache-Enabled AP over Edge Networks
Authors: Ruan Jinjia , Xie Dongliang
Published: September 2022

With the rapid development of virtual reality (VR) video networked applications, the use of network caching mechanisms to guarantee the quality of VR services has been proven to be a very effective method. Most of the existing methods on cache placement prediction only consider the one-sided information of user viewpoints and do not consider the video characteristic information of virtual reality, because the asymmetry of the two types of information causes the accuracy of current predictions to gradually decrease, which affects the cache hit rate and leads to VR performance metrics that cannot be guaranteed. In this paper, we analyze the demanding requirements of VR for low latency and high bandwidth in a multi-access point (multi-AP) scenario environment, and further improve the cache hit rate of user requests by increasing network throughput. First, the throughput of VR users after associating APs is analyzed using a Markov model. Second, a nonlinear mixed integer programming problem is constructed with the goal of maximizing the overall throughput of the network system. Finally, combining the characteristics of the VR video content itself and the popularity of the requested video content, the symmetry of the information is guaranteed by considering the ratio between the video characteristic information and the user feature information to determine the weights. The experimental results demonstrate that the proposed algorithm achieves the improvement of cache hit rate and the improvement of network throughput while ensuring the quality of service.
Comparison and Optimization of a Magnetic Lead Screw Applied in Wave Energy Conversions
Authors: Xia Tao , Li Junhui , Zhang Yangfei , Yu Haitao , Lu Kaiyuan
Published: September 2022

In order to improve the power density of the wave power generation system, a magnetic lead screw (MLS) is introduced in this paper as a speed-increasing device in a wave energy converter (WEC), which converts low-speed linear wave motion to high-speed rotational motion. Then, several types of MLSs with different topologies, which were optimized, are described. Finite element analysis (FEA) was used to investigate and evaluate their electromagnetic performances, such as the thrust force, torque, air gap magnetic density, etc. The optimized MLS prototype was manufactured, and the measurements verify the FEA results. Finally, a magnetic lead screw hybrid generator (MLSHG) for application to the WEC is proposed. This MLS significantly improved the power density under different wave conditions. When the moving speed v = 0.15 m/s, the output power of the MLSHG and outer-PM linear tubular generator were 923 W and 87 W, respectively, when the load resistance was 5 Ω. The output power of the MLSHG was more than 10 times compared to that of the outer-PM linear tubular generator in a fair comparison. Here, it is shown that the power density and output power of were MLSHG increased greatly.
Determinants Influencing the Continuous Intention to Use Digital Technologies in Higher Education
Authors: Almaiah Mohammed , Alfaisal Raghad , Salloum Said , Al-Otaibi Shaha , Al Sawafi Omar , Al-Maroof Rana , Lutfi Abdalwali , Alrawad Mahmaod , Mulhem Ahmed , Awad Ali
Published: September 2022

There is increasing evidence that the lack of access to digital information and technologies is not widely considered in the educational sectors when focusing on the perceived experience, tutor quality and students’ satisfaction. In this paper, we report on an evaluation of a project aiming to bridge the use of digital information in the educational sector by proposing an integrated model that measures teachers’ quality, uncertainty avoidance effects and students’ satisfaction concerning TAM constructs and the perceived experience of digital information in education (DIE). The model and hypotheses were validated using data collected from a survey of 553 students at a college level. The results revealed that users may perceive the importance of DIE based on several external factors that enhance their learning and teaching experiences. The personal characteristics of the user including his/her readiness to use technology are crucial in correlation with the perceived ease of use. In addition, the high quality of the tutor in some cultures may enhance the perceived usefulness of the technology. Other factors such as flow of information, uncertain avoidance and satisfaction may strongly assess the continuous intention to use the technology.
A 5 V-to-32 V Input PVT-Robust Charge-Pump Circuit with Adjustable Output in a 0.18 μm BCD Process
Authors: Ma Xinyi , Wang Liangkun , Yu Jiaqing
Published: September 2022

In this paper, a new closed-loop charge-pump circuit with adjustable output voltage and an on-chip compensation technique is proposed. The environmental temperature and process corner can be detected with an on-chip detection circuit and automatically feedback an adjusted reference voltage. With this, the magnitude of the charge-pump output voltage with Pulse-Width Modulation (PWM) can be compensated. The charge-pump circuit is designed and verified with a 180 nm Bipolar-CMOS-DMOS (BCD) process, and its output voltage at different process, voltage, and temperature (PVT) is controllable with low ripple. There are three selections for adjusting the output voltage: +5 V/+7 V/+10 V shifts, with the supply voltage ranging from 5 V to 32 V. It can remain tunable and stable at any shifts. The maximum deviation is ±0.265%, and the maximum load current can reach 30 mA. The ripple voltage is less than 0.3% (Δ Vripple/Vout) underthe maximum load. The Monte Carlo simulation results show that the worst case of the process sensitivity (σ/μ) is 0.1%. The charge-pump core area is 0.308 mm2, and the power consumption is 4.753 mW. The circuit can produce high-precision output and is suitable for high-side driving IC applications.
Fat-Corrected Pancreatic R2* Relaxometry from Multi-Echo Gradient-Recalled Echo Sequence Using Convolutional Neural Network
Authors: Santarelli Maria Filomena , Joubbi Sara , Meloni Antonella , Pistoia Laura , Casini Tommaso , Massei Francesco , Bitti Pier Paolo , Allò Massimo , Cademartiri Filippo , Positano Vincenzo
Published: September 2022

Fat-corrected R2* relaxometry from multi-echo gradient-recalled echo sequences (mGRE) could represent an efficient approach for iron overload evaluation, but its use is limited by computational constraints. A new method for the fast generation of R2* and fat fractions (FF) maps from mGRE using a convolutional neural network (U-Net) and deep learning (DL) is presented. A U-Net for the calculation of pancreatic R2* and FF maps was trained with 576 mGRE abdominal images and compared to conventional fat-corrected relaxometry. The U-Net was effectively trained and provided R2* and FF maps visually comparable to conventional methods. Predicted pancreatic R2* and FF values were well correlated with the conventional model. Estimated and ground truth mean R2* values were not significantly different (43.65 ± 21.89 vs. 43.77 ± 19.81 ms, p = 0.692, intraclass correlation coefficient-ICC = 0.9938, coefficient of variation-CoV = 5.3%), while estimated FF values were slightly higher in respect to ground truth values (27.8 ± 16.87 vs. 25.67 ± 15.43 %, p < 0.0001, ICC = 0.986, CoV = 10.1%). Deep learning utilizing the U-Net is a feasible method for pancreatic MR fat-corrected relaxometry. A trained U-Net can be efficiently used for MR fat-corrected relaxometry, providing results comparable to conventional model-based methods.
Bridging the Gap between Physical and Circuit Analysis for Variability-Aware Microwave Design: Power Amplifier Design
Authors: Donati Guerrieri Simona , Ramella Chiara , Catoggio Eva , Bonani Fabrizio
Published: September 2022

Process Induced Variability (PIV) stemming from fabrication tolerance can impact the performance of integrated circuits. This issue is particularly significant at high frequencies, since Monolithic Microwave Integrated Circuits (MMICs) rely on advanced semiconductor technologies exploiting device sizes at the nanoscale in conjunction with complex passive structures, featuring both distributed elements (transmission lines) and lumped components. Black-box (behavioral) models extracted from accurate physical simulations can be profitably exploited to incorporate PIV into circuit-level MMIC analysis. In this paper, these models are applied to the statistical analysis of a single and of a combined MMIC power amplifier designed in GaAs technology for X-band applications. The relative impact of the active device variability towards the passive matching networks one is evaluated, demonstrating the relevance of PIV. The significant spread found, with only two variable parameters, confirms the importance of a PIV-aware PA design approach, with suitable margins and careful network optimization.
Power Line Scene Recognition Based on Convolutional Capsule Network with Image Enhancement
Authors: Zou Kuansheng , Zhao Shuaiqiang , Jiang Zhenbang
Published: September 2022

With the popularization of unmanned aerial vehicle (UAV) applications and the continuous development of the power grid network, identifying power line scenarios in advance is very important for the safety of low-altitude flight. The power line scene recognition (PLSR) under complex background environments is particularly important. The complex background environment of power lines is usually mixed by forests, rivers, mountains, buildings, and so on. In these environments, the detection of slender power lines is particularly difficult. In this paper, a PLSR method of complex backgrounds based on the convolutional capsule network with image enhancement is proposed. The enhancement edge features of power line scenes based on the guided filter are fused with the convolutional capsule network framework. First, the guided filter is used to enhance the power line features in order to improve the recognition of the power line in the complex background. Second, the convolutional capsule network is used to extract the depth hierarchical features of the scene image of power lines. Finally, the output layer of the convolutional capsule network identifies the power line and non-power line scenes, and through the decoding layer, the power lines are reconstructed in the power line scene. Experimental results show that the accuracy of the proposed method obtains 97.43% on the public dataset. Robustness and generalization test results show that it has a good application prospect. Furthermore, the power lines can be accurately extracted from the complex backgrounds based on the reconstructed module.
Computational Simulation of Microflaw Detection in Carbon-Fiber-Reinforced Polymers
Authors: Santos Mário , Santos Jaime , Petrella Lorena
Published: September 2022

The evaluation of microflaws in carbon-fiber-reinforced composite laminate (CFRP) via ultrasound requires the knowledge of some important factors in addition to its structural composition. Since the laminates are heterogeneous, the high-frequency requirements to acquire high-resolution signals have limitations due to the great scattering that prevents good signal-to-noise ratios. Additionally, the ultrasonic probe’s spatial and lateral resolution characteristics are important parameters for determining the detectability level of microflaws. Modelling appears as a good approach to evaluating the abovementioned factors and the probability of detection of defects in the micron range because it makes it possible to reduce the time and cost associated with developments based on experimental tests. Concerning the subject of this work, simulation is the best way to evaluate the detectability level of the proposed defects since experimental samples are not available. In this work, the simulation was implemented using the Matlab k-Wave toolbox. A 2D matrix for mimicking a CFRP was constructed with 1 μm of resolution. Four different defect types in the micron range were created in the matrix. The simulated and experimental results presented good agreement. It was concluded that the highest frequency probe that could be used to detect the simulated defects without ambiguity was 25 MHz.
Overview of Virtual Synchronous Generators: Existing Projects, Challenges, and Future Trends
Authors: Abuagreb Mohamed , Allehyani Mohammed F. , Johnson Brian K.
Published: September 2022

The rapid growth in renewable energy-based distributed generation has raised serious concerns about the grid’s stability. Due to the intrinsic rotor inertia and damping feature and the voltage (reactive power) control ability, traditional bulk power plants, which are dominated by synchronous generators (SG), can readily sustain system instability. However, converter-based renewable energy sources possess unique properties, such as stochastic real and reactive power output response, low output impedance, and little or no inertia and damping properties, leading to frequency and voltage disturbance in the grid. To overcome these issues, the concept of virtual synchronous generators (VSG) is introduced, which aims to replicate some of the characteristics of the traditional synchronous generators using a converter control technique to supply more inertia virtually. This paper reviews the fundamentals, different topologies, and a detailed VSG structure. Moreover, a VSG-based frequency control scheme is emphasized, and the paper focuses on the different topologies of VSGs in the microgrid frequency regulation task. Then, the characteristics of the control systems and applications of the virtual synchronous generators are described. Finally, the relevant critical issues and technical research challenges are presented, and future trends related to this subject are highlighted.
Sarcasm Detection over Social Media Platforms Using Hybrid Auto-Encoder-Based Model
Authors: Sharma Dilip Kumar , Singh Bhuvanesh , Agarwal Saurabh , Kim Hyunsung , Sharma Raj
Published: September 2022

Sarcasm is a language phrase that conveys the polar opposite of what is being said, generally something highly unpleasant to offend or mock somebody. Sarcasm is widely used on social media platforms every day. Because sarcasm may change the meaning of a statement, the opinion analysis procedure is prone to errors. Concerns about the integrity of analytics have grown as the usage of automated social media analysis tools has expanded. According to preliminary research, sarcastic statements alone have significantly reduced the accuracy of automatic sentiment analysis. Sarcastic phrases also impact automatic fake news detection leading to false positives. Various individual natural language processing techniques have been proposed earlier, but each has textual context and proximity limitations. They cannot handle diverse content types. In this research paper, we propose a novel hybrid sentence embedding-based technique using an autoencoder. The framework proposes using sentence embedding from long short term memory-autoencoder, bidirectional encoder representation transformer, and universal sentence encoder. The text over images is also considered to handle multimedia content such as images and videos. The final framework is designed after the ablation study of various hybrid fusions of models. The proposed model is verified on three diverse real-world social media datasets—Self-Annotated Reddit Corpus (SARC), headlines dataset, and Twitter dataset. The accuracy of 83.92%, 90.8%, and 92.80% is achieved. The accuracy metric values are better than previous state-of-art frameworks.
Lignin Modifications, Applications, and Possible Market Prices
Authors: Nadányi Richard , Ház Aleš , Lisý Anton , Jablonský Michal , Šurina Igor , Majová Veronika , Baco Andrej
Published: September 2022

Lignin is the second most abundant biopolymer in the world. Due to its complex structure, lignin can be considered a valuable source of energy and different chemicals. In addition, using different reactive sites on lignin, it is possible to prepare different value-added products, such as resins, polyurethanes, and many more. Different functional groups are presented on the lignin macromolecule and can be modified via different pathways. Hydroxyl groups are the most promising reactive sites for lignin modifications. Both modified and unmodified lignins could be used for preparing different biomaterials. This paper shows several possible applications of lignin. The main goal of this publication is to show the possible valorization of lignin in different value-added products throughout the actual market prices of non-biobased materials. This review proves that lignin has unquestionable advantages in material technology and can replace different substances which will lead to a higher potential market value of lignins and could create new bio-based materials compared with the actual prices of commercially available materials. Nowadays, it is easier to use lignin as an energy source even though a lot of lignin modifications and conversion processes are still under development and need more time to become more relevant for industrial applications. Information in the presented paper should reveal to the reader the importance and economic benefits of using lignin as a value-added compound in different applications.
Numerical Simulation of Well Type Optimization in Tridimensional Development of Multi-Layer Shale Gas Reservoir
Authors: Huang Tao , Liao Xin , Huang Zhaoqin , Song Fuquan , Wang Renyi
Published: September 2022

Aimed at the development of shale gas reservoirs with large reservoir thickness and multiple layers, this paper carried out a numerical simulation study on the optimization of three different well types: horizontal well, deviated well, and vertical well. To make the model more in line with the characteristics of shale gas reservoirs, a two-phase gas–water seepage mathematical model of shale gas reservoirs was established, considering the adsorption and desorption of shale gas, Knudsen diffusion effect, and stress sensitivity effect. The embedded discrete fracture model was used to describe hydraulic fracture and natural fracture. Based on Fortran language, a numerical simulator for multi-layer development of shale gas reservoirs was compiled, and the calculation results were compared with the actual production data of Barnett shale gas reservoirs to verify the reliability of the numerical simulator. The spread range of hydraulic fractures in the reservoir with different natural fracture densities is calculated by the simulation to determine well spacing and fracture spacing. The orthogonal experimental design method is then used to optimize the best combination of well spacing and fracture spacing for different well types. The results show that the well productivity of the high-density (0.012 m/m2) natural fractures reservoir > the well productivity of the medium-density (0.006 m/m2) natural fractures reservoir > the well productivity of the low-density (0.001 m/m2) natural fractures reservoir. According to the design of the orthogonal test, it can be seen that the most significant factor affecting the productivity of horizontal wells is the fracture spacing in the Y direction. For deviated wells and vertical wells, the X-direction well spacing has the greatest impact on its productivity.
Experimental Study on the Effect of SDS and Micron Copper Particles Mixture on Carbon Dioxide Hydrates Formation
Authors: Li Yan , Gambelli Alberto Maria , Rossi Federico
Published: September 2022

CO2 hydrate formation and dissociation are the fundamental processes for investigating hydrate-based carbon storage. To better understand CO2 hydrate phase behaviors in the presence of surfactant and solid additives, this study reports the effects of Sodium Dodecyl Sulfate (SDS) and micron Cu particles on the formation of CO2 hydrates in the presence of porous quartz sands in a lab-scale reactor. This research is part of a wider study focused on defining the properties of solid additives, produced via gas-atomization, on the formation and dissociation of gas hydrates. The morphology of CO2 hydrate formed in SDS solution shows dispersed crystal particles due to the increase of surface tension. SDS works as the kinetic promoter on CO2 hydrates formation whereas the addition of Cu particles inhibits CO2 gas consumption. The mixture additives show a faint kinetic inhibit effect, in which the Brownian motion restrictions may be responsible for the inhibition of CO2 hydrate production. The solid additives also showed a weak thermodynamic effect on CO2 hydrate phase equilibrium.
Speed Range Extension of Dual-Stator PM Machine Using Multi-Mode Winding Switching Strategy
Authors: Lyu Shukang , Yang Hui , Lin Heyun , Zhan Hanlin , Liu Chaohui
Published: September 2022

In this paper, a novel winding switching (WS) strategy is proposed for the speed range extension of a dual-stator permanent magnet machine (DS-PMM), which can achieve simple and effective dynamic mode conversion over an entire operating region. Two types of WS circuits with an inverter and two switch groups were first designed to enable the winding reconfiguration of the machine, which could operate in three modes. The WS principle was then elucidated by introducing simplified equivalent circuits. Besides, the torque–speed curves of the machine under different operating modes were analyzed, based on the mathematical model. A speed-based WS controller was, subsequently, designed to generate the WS control signal and realize the multi-mode operation according to real-time operating conditions. The feasibility of the proposed WS strategy for extending the speed range of the DS-PMM was, finally, verified by experiments.
Cleaner Potential for Natural Rubber Drying Process Using Microwave Technology Powered by Solar Energy
Authors: Korkua Suratsavadee Koonlaboon , Khongtong Sureurg , Ray Pravat Kumar , Thinsurat Kamon
Published: September 2022

To reduce carbon dioxide emissions from traditional drying methods, this research investigated the use of microwave technology for drying Standard Thai Rubber (STR) in Thailand. Commercial microwave ovens were modified and integrated with the microwave emitting power control system to maintain the appropriate temperature levels to evaporate the moisture from rubber. Throughout the drying process, the temperature of the rubber was measured both internally and outside. The results revealed that STR5L and STR20 could be dried satisfactorily and met the requirements for standard Thai rubber properties by utilizing 500 W for 140 and 120 min, respectively. By keeping the temperatures less than 150 °C, rubbers’ molecular structure is not destroyed from internal heat stress. Although utilizing less power for a longer period of time is possible, more energy was used, which is unfavorable. Compared to traditional hot air drying technologies, which take approximately 4–6 h for the drying process, microwave technology potentially reduces the drying time by half or more. If solar energy is used to supply electrical energy, 300,000 tons of Carbon dioxide can potentially be eliminated annually in the STR drying industry in Thailand by promoting approximately 1115 MW of Photovoltaic technology installations with the solar resources in southern Thailand.