bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparing Protection of Remote Limb with Resveratrol Preconditioning following Rodent Subarachnoid Hemorrhage
Authors: Koch Sebastian , De La Rua Giselle , Farquharson Donnae , Saul Isabel , Perez-Pinzon Miguel , Dave Kunjan
Published: April 2022

Background: Preventing delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH) remains an important therapeutic target. Preconditioning stimulates multiple endogenous protective mechanisms and may be a suitable treatment for DCI following SAH. We here compare remote limb conditioning with resveratrol conditioning in a clinically relevant SAH model. Methods: We produced a SAH in 39 male Sprague Dawley rats using a single injection model. Animals were randomized to four groups: repetitive limb conditioning with a blood pressure cuff, sham conditioning, intraperitoneal resveratrol (10 mg/kg) or intraperitoneal vehicle administered at 24, 48 and 72 h after SAH. On day 4 neurological and behavioral scores were obtained, and animals were euthanized. The cross-sectional area of the basilar artery was measured at the vertebrobasilar junction, and at the mid and distal segments. Hippocampal cells were counted in both hemispheres and normalized per mm length. We compared true limb preconditioning with sham conditioning and resveratrol with vehicle preconditioning. Results: The cross-sectional area of the mid-basilar artery in the true limb preconditioning group was significantly larger by 43% (p = 0.03) when compared with the sham preconditioning group. No differences in the cross-sectional area were found in the resveratrol-treated group when compared to the vehicle-treated group. We found no differences in the neuro score, behavioral score, and in mean hippocampal neuron counts between the groups. Conclusion: We found beneficial vascular effects of remote limb preconditioning on SAH-induced basilar artery vasoconstriction. Our findings support further studies of limb preconditioning as a potential treatment after SAH.
Propofol, an Anesthetic Agent, Inhibits HCN Channels through the Allosteric Modulation of the cAMP-Dependent Gating Mechanism
Authors: Shimizu Morihiro , Mi Xinya , Toyoda Futoshi , Kojima Akiko , Ding Wei-Guang , Fukushima Yutaka , Omatsu-Kanbe Mariko , Kitagawa Hirotoshi , Matsuura Hiroshi
Published: April 2022

Propofol is a broadly used intravenous anesthetic agent that can cause cardiovascular effects, including bradycardia and asystole. A possible mechanism for these effects is slowing cardiac pacemaker activity due to inhibition of the hyperpolarization-activated, cyclic nucleotide-gated (HCN) channels. However, it remains unclear how propofol affects the allosteric nature of the voltage- and cAMP-dependent gating mechanism in HCN channels. To address this aim, we investigated the effect of propofol on HCN channels (HCN4 and HCN2) in heterologous expression systems using a whole-cell patch clamp technique. The extracellular application of propofol substantially suppressed the maximum current at clinical concentrations. This was accompanied by a hyperpolarizing shift in the voltage dependence of channel opening. These effects were significantly attenuated by intracellular loading of cAMP, even after considering the current modification by cAMP in opposite directions. The differential degree of propofol effects in the presence and absence of cAMP was rationalized by an allosteric gating model for HCN channels, where we assumed that propofol affects allosteric couplings between the pore, voltage-sensor, and cyclic nucleotide-binding domain (CNBD). The model predicted that propofol enhanced autoinhibition of pore opening by unliganded CNBD, which was relieved by the activation of CNBD by cAMP. Taken together, these findings reveal that propofol acts as an allosteric modulator of cAMP-dependent gating in HCN channels, which may help us to better understand the clinical action of this anesthetic drug.
Gender Influences Virtual Reality-Based Recovery of Cognitive Functions in Patients with Traumatic Brain Injury: A Secondary Analysis of a Randomized Clinical Trial
Authors: Bruschetta Roberta , Maggio Maria Grazia , Naro Antonino , Ciancarelli Irene , Morone Giovanni , Arcuri Francesco , Tonin Paolo , Tartarisco Gennaro , Pioggia Giovanni , Cerasa Antonio , Calabrò Rocco Salvatore
Published: April 2022

The rehabilitation of cognitive deficits in individuals with traumatic brain injury is essential for promoting patients’ recovery and autonomy. Virtual reality (VR) training is a powerful tool for reaching this target, although the effectiveness of this intervention could be interfered with by several factors. In this study, we evaluated if demographical and clinical variables could be related to the recovery of cognitive function in TBI patients after a well-validated VR training. One hundred patients with TBI were enrolled in this study and equally randomized into the Traditional Cognitive Rehabilitation Group (TCRG: n = 50) or Virtual Reality Training Group (VRTG: n = 50). The VRTG underwent a VRT with BTs-N, whereas the TCRG received standard cognitive treatment. All the patients were evaluated by a complete neuropsychological battery before (T0) and after the end of the training (T1). We found that the VR-related improvement in mood, as well as cognitive flexibility, and selective attention were influenced by gender. Indeed, females who underwent VR training were those showing better cognitive recovery. This study highlights the importance of evaluating gender effects in planning cognitive rehabilitation programs. The inclusion of different repetitions and modalities of VR training should be considered for TBI male patients.
Role of Homologous Recombination Repair (HRR) Genes in Uterine Leiomyosarcomas: A Retrospective Analysis
Authors: Ciccarone Francesca , Bruno Matteo , De Paolis Elisa , Piermattei Alessia , De Bonis Maria , Lorusso Domenica , Zannoni Gian Franco , Normanno Nicola , Minucci Angelo , Scambia Giovanni , Ferrandina Gabriella
Published: April 2022

Uterine leiomyosarcomas (uLMS) is a very rare disease, and patients experience a dismal prognosis even when treated with chemotherapy. Therefore, a more in-depth molecular characterization of this disease could provide suitable data for the identification of potential target-based drugs. This retrospective, single institutional study aimed to define the frequencies of gene alterations in uLMS, especially regarding the somatic mutations of BRCA and Homologous Recombination Repair (HRR) genes, and the impact of molecular alterations on clinical outcomes. The 16-genes Next-Generation Sequencing (NGS) panel, Homologous Recombination Solution TM (HRS, Sophia Genetics, Saint Sulpice, Switzerland), was used for the molecular evaluation of samples. The majority of patients (66/105, 63%) carried at least one sequence alteration, with a prevalence of TP53 involvement followed by RAD51B, BRCA1/2, and FANCL. Patients with TP53 gene alterations experienced a significantly worse prognosis for progression free survival (PFS) and overall survival (OS) versus wild-type patients. Given the number of patients with the BRCA1/2 mutation (N = 12), we included them in the HRR patient group; there was no difference in clinical outcomes with HRR versus non-HRR. The Cox’s multivariate analysis showed that stage and TP53 gene alterations resulted in a significantly worse OS. The integration of gene networking data, such as tumor mutation burdens and cancer driver gene identification, could show a clearer discrimination of gene distribution patterns, and lead to the implementation of therapeutic targets.
Familial Risks for Liver, Gallbladder and Bile Duct Cancers and for Their Risk Factors in Sweden, a Low-Incidence Country
Authors: Hemminki Kari , Sundquist Kristina , Sundquist Jan , Försti Asta , Liska Vaclav , Hemminki Akseli , Li Xinjun
Published: April 2022

We used the Swedish Cancer Registry data to address familial risks for concordant (same) and discordant (different) hepatobiliary cancers, including their associations with any other cancers and with known risk factors. Risks were also assessed between spouses. The analysis covered Swedish families and their cancers between years 1958 and 2018. Adjusted familial risks were expressed as standardized incidence ratios (SIRs). Familial SIRs for concordant hepatocellular carcinoma (HCC) were 2.60, and for gallbladder cancer they were at the same level (2.76). Familial risk was also found for intrahepatic bile duct cancer and for female extrahepatic bile duct cancer. HCC was associated with lung and cervical cancers; extrahepatic bile duct and ampullary cancers were associated with colon and pancreatic cancers, suggesting Lynch syndrome. Among spouses, hepatobiliary cancer was associated with HCC, stomach, pancreatic, cervical and upper aerodigestive tract cancers. Among risk factors, family members diagnosed with alcohol-related disease showed association with HCC. The observed familial risks for hepatobiliary cancers were relatively high, and considering the poor prognosis of these cancers, prevention is of the utmost importance and should focus on moderation of alcohol consumption, vaccination/treatment of hepatitis viral infections and avoidance of overweight and other risk factors of type 2 diabetes.
B Cells Specific CpG Induces High IL-10 and IL-6 Expression In Vitro in Neuro-Behçet’s Disease
Authors: Maghrebi Olfa , Belghith Meriam , Jeridi Cyrine , Rachdi Amine , Fatnassi Fatma Nabli , Saied Zakaria , Belal Samir , Ben Sassi Samia , Barbouche Mohamed-Ridha
Published: April 2022

Remitting-RelapsingMultiple Sclerosis (RRMS) and Neuro-Behçet Disease (NBD) are two chronic neuroinflammatory disorders leading to neurological damage. Herein, we investigated in these patients the IL-10-producing cells during the early stages of these disorders. Cellular and molecular investigations were carried out on treatment naive patients suffering from RRMS and NBD recruited at the first episode of clinical relapse. Our findings demonstrate that CSF-B cells from NBD patients, but not RRMS, are the major source of intrathecal IL-10 as compared to T-CD4 cells. Moreover, we showed a lower expression of TGF-β and IL35, in the CSF cells of NBD patients as compared to the control group. Specific in vitro CpG stimulation of peripheral blood B cells from NBD patients resulted in a concomitant early mRNA expression of IL6 and IL10 but was limited to IL10 for RRMS patients. Furthermore, mRNA expression of IL-6 and IL-10 receptors was assessed and intriguingly IL6ST receptor subunit was significantly lower in NBD CSF, but not RRMS while IL10RB was increased in both. Deciphering the role of increased IL-10-producing B cells and IL10RB despite relapsing disease as well as the discordant expression of IL6 and IL6ST may pave the way for a better understanding of the pathophysiology of these neuro-inflammatory disorders.
Effects of Robotic Interactive Gait Training Combined with Virtual Reality and Augmented Reality on Balance, Gross Motor Function, Gait Kinetic, and Kinematic Characteristics in Angelman Syndrome: A Case Report
Authors: Han Sangkeun , Park Chanhee , You Joshua (Sung) H.
Published: April 2022

Angelman syndrome (AS) is a genetic neurological disorder resulting in cognitive and neuromuscular impairments, such as lack of safety awareness and attention, as well as lack of balance and locomotor control. The robotic interactive gait training (RIGT) system is designed to provide accurate proprioceptive, kinematic, and kinetic feedback, and facilitate virtual reality and augmented reality (VR-AR) interactive exercises during gait training. In the present case report, we examined the effect of an innovative hip-knee-ankle interlimb-coordinated RIGT system. We utilized this therapeutic modality in a participant with Angelman syndrome (AS). Gross motor function measures, risk of fall, and gait-related kinetic (force), and kinematic (joint angle) biomechanical characteristics were assessed before and after 20 sessions of RIGT with VR-AR. We found RIGT with VR-AT improved gait ability, as shown by Performance-Oriented Mobility Assessment score, gross motor function by Gross Motor Function Measure score, balance by Pediatric Balance Scale score, knee and hip joint kinetics, and kinematics during gait. Our clinical and biomechanical evidence provide important clinical insights to improve the effectiveness of current neurorehabilitation approaches for treating patients with AS in balance and locomotor control and reduce the risk of falling.
Understanding the Mechanisms through Which Family Risk Affects Adolescent Mental Health: A Model of Multisystemic Resilience in Context
Authors: Cameranesi Margherita , Theron Linda , Höltge Jan , Jefferies Philip , Ungar Michael
Published: April 2022

There is substantial evidence that exposure to family adversity significantly and negatively impacts positive adolescent development by placing adolescents at increased risk of experiencing developmental difficulties, including conduct problems. Although the mechanisms responsible for these effects are still largely unknown, a novel line of inquiry in the resilience field conceptualizes positive adaptation, following exposure to atypical adversity, as resulting from complex interactions of systems at multiple ecological levels. The purpose of the present analysis was to apply this multisystemic resilience framework to the study of positive adaptation following exposure to family adversity in a sample of Canadian adolescents (n = 230; mean age 16.16, SD = 1.38) and South African adolescents (n = 421; mean age = 15.97, SD = 1.19) living in economically volatile communities dependent on the oil and gas industry. Cross-sectional survey data were used to investigate the mechanisms through which family adversity exercises its impact on adolescent conduct problems by accounting for their caregiving, peer, and community resources. Results of two moderated mediation analyses showed that family adversity impacts adolescent externalizing mental health negatively, via disrupted caregiving, when other resources are also considered. For the Canadian adolescents, these negative impacts were protectively moderated by peer support, but not moderated by appreciation for community traditions. In contrast, peer support showed no significant protective effect for the South African sample, while a strong appreciation for community traditions was positively and significantly associated with conduct difficulties. Contextual dynamics (e.g., social unrest) provide a plausible explanation for the discrepant results and bring attention to the importance of theorizing resilience in context.
Effect of Growth Hormone Therapy on a 4-Year-Old Girl with Pfeiffer Syndrome and Short Stature: A Case Report
Authors: Jang Min Jeong , Ahn Moon Bae
Published: April 2022

Fibroblast growth factor receptors (FGFRs) are expressed in epiphyseal cartilage cells of developing bones and regulate endochondral bone formation with interdependent signaling pathways. Gene mutation in FGFRs disrupts the formation of endochondral bony structure by reducing the number of proliferating chondrocytes. Among the syndromes caused by mutation in the FGFR gene, Pfeiffer syndrome is a rare inherited disease characterized by acrocephalosyndactyly related to hypertelorism, broad pollex, and hallux. We describe the case of a 4-year-old girl with short stature, advanced bone age, wide thumbs and great toes. The patient was diagnosed with partial growth hormone deficiency and an identified mutation in the FGFR2 gene. Standard deviation score of her height increased after starting growth hormone therapy. This report will raise awareness of the growth hormone provocation test regardless of bone age in patients with short stature founded FGFR gene mutation.
New Models for the Properties of Warm Mix Asphalt with Sasobit
Authors: Rezaeizadeh Herozi Morteza , Valenzuela Wilfredo , Rezagholilou Alireza , Rigabadi Ali , Nikraz Hamid
Published: April 2022

Warm Mix Asphalt (WMA) is a set of technologies that uses additives to reduce binder viscosity and increase mixture workability, which provides a complete coating of aggregates at lower temperatures around 100 °C to 130 °C. Organic wax or Sasobit is one of the additives that can be used for this purpose. It reduces the viscosity at the melting point of the wax, which allows the production of asphalt mixes at lower temperatures. This attempt proposes new relationships for elastic modulus, indirect tensile strength (in dry and wet conditions), dynamic modulus, fatigue, and rutting resistance of WMA asphalt samples with various Sasobit percentages. Findings show that Sasobit improves modulus of elasticity, dynamic modulus, and rutting resistance. However, it lessens the tensile strength slightly. Although Sasobit enhances the flexural stiffness, it drops the number of loading cycles, which means lower fatigue resistance. Results also showed that at 20 °C and 10 Hz frequency, the resilient modulus, dynamic modulus, and flexural stiffness of WMA improved 53%, 27%, and 39%, respectively, compared with HMA. Rutting resistance at 60 °C improves 226% in WMA with 6% Sasobit compared to the HMA mix.
Design, Fabrication and Analysis for Al2O3/Ti/Al2O3 Colored Solar Selective Absorbers for Building Applications
Authors: Lai Fu-Der , Li Wen-Yang
Published: April 2022

A good solar selective absorber (SSA) used in building applications must have good color brightness rendering, an excellent photo–thermal conversion efficiency (PTCE) and a long life. The optical thin film design plays an important role before the coating of the optical thin films. In this study, for fabricating a good colored SSA (CSSA), the optical properties and color distribution of Al2O3/Ti/Al2O3 SSA were calculated to obtain the best design. It was found that the color distribution of Al2O3/Ti/Al2O3 SSA with a PTCE in excess of 90% was wide and included all colors, such as red, orange, yellow, green, blue, purple and white. Five colored Al2O3/Ti/Al2O3 solar selective absorbers were designed and fabricated and their performances were analyzed. The best PTCE of a fabricated sample and its thermal emittance efficiency were 93.2% and 7.1%, respectively. The peak values of the measured optical reflectance in the visible region for the five fabricated CSSAs were all greater than 10%. Their lifetime could be very long because the temperature difference between thermal stability of more than 450 °C and the working temperature of less than 150 °C was up to 300 °C. After annealing at 550 °C, the Al2O3–Ti system formed a compound structure of AlTiO5. The Al2O3/Ti/Al2O3 film performances, including the optical properties in the wavelength range of 0.25 to 25 μm, structure, morphology, adhesion, cross-sectional images, AFM image, PTCE, thermal emittance efficiency and thermal stability, were measured and analyzed in detail, and met the characteristic requirements of colored solar absorber films.
Long-Term Performance of Recycled Asphalt Pavement with Recycled Engine Oil Bottom Based on Accelerated Loading Test
Authors: Li Jin , Zhu Li , Yu Miaozhang , Zuo Shen , Cui Xinzhuang , Liu Peng
Published: April 2022

The practical performance of recycled asphalt obtained from recycled engine oil bottom (REOB) was evaluated by paving a test road of base asphalt and REOB-recycled asphalt mixture in a laboratory, where accelerated loading tests with 700,000 cycles were conducted. During accelerated loading, pavement temperature, layer bottom strain, pavement skid resistance, and rutting were monitored. The performance of pavement core material was tested after loading to analyze the index change of binder and the compaction degree of the mixture. The results show that the long-term anti-rutting ability of REOB-recycled asphalt pavement is approximately 10% higher than that of the base asphalt pavement, although the long-term anti-sliding force and anti-fatigue performance are poor. A developed model of rut with loading time can better predict the development trends of these parameters with loading cycles. The performance test of the pavement material after loading shows that 700,000 cycles can only degrade the performance of the test pavement, not damage it. The recycled asphalt pavement with 7% REOB has basically the same performance as the base asphalt under 700,000 cycles, indicating that REOB-recycled asphalt pavement can ensure basic road performance, while providing economic and environmental advantages. These results provide a reference for the application and form optimization of REOB-recycled asphalt pavement.
Automated 3D Segmentation of the Aorta and Pulmonary Artery on Non-Contrast-Enhanced Chest Computed Tomography Images in Lung Cancer Patients
Authors: Wang Hao-Jen , Chen Li-Wei , Lee Hsin-Ying , Chung Yu-Jung , Lin Yan-Ting , Lee Yi-Chieh , Chen Yi-Chang , Chen Chung-Ming , Lin Mong-Wei
Published: April 2022

Pulmonary hypertension should be preoperatively evaluated for optimal surgical planning to reduce surgical risk in lung cancer patients. Preoperative measurement of vascular diameter in computed tomography (CT) images is a noninvasive prediction method for pulmonary hypertension. However, the current estimation method, 2D manual arterial diameter measurement, may yield inaccurate results owing to low tissue contrast in non-contrast-enhanced CT (NECT). Furthermore, it provides an incomplete evaluation by measuring only the diameter of the arteries rather than the volume. To provide a more complete and accurate estimation, this study proposed a novel two-stage deep learning (DL) model for 3D aortic and pulmonary artery segmentation in NECT. In the first stage, a DL model was constructed to enhance the contrast of NECT; in the second stage, two DL models then applied the enhanced images for aorta and pulmonary artery segmentation. Overall, 179 patients were divided into contrast enhancement model (n = 59), segmentation model (n = 120), and testing (n = 20) groups. The performance of the proposed model was evaluated using Dice similarity coefficient (DSC). The proposed model could achieve 0.97 ± 0.007 and 0.93 ± 0.002 DSC for aortic and pulmonary artery segmentation, respectively. The proposed model may provide 3D diameter information of the arteries before surgery, facilitating the estimation of pulmonary hypertension and supporting preoperative surgical method selection based on the predicted surgical risks.
Computer-Aided Image Enhanced Endoscopy Automated System to Boost Polyp and Adenoma Detection Accuracy
Authors: Tang Chia-Pei , Hsieh Chen-Hung , Lin Tu-Liang
Published: April 2022

Colonoscopy is the gold standard to detect colon polyps prematurely. Early detection, characterization and resection of polyps decrease colon cancer incidence. Colon polyp missing rate remains high despite novel methods development. Narrowed-band imaging (NBI) is one of the image enhance techniques used to boost polyp detection and characterization, which uses special filters to enhance the contrast of the mucosa surface and vascular pattern of the polyp. However, the single-button-activated system is not convenient for a full-time colonoscopy operation. We selected three methods to simulate the NBI system: Color Transfer with Mean Shift (CTMS), Multi-scale Retinex with Color Restoration (MSRCR), and Gamma and Sigmoid Conversions (GSC). The results show that the classification accuracy using the original images is the lowest. All color transfer methods outperform the original images approach. Our results verified that the color transfer has a positive impact on the polyp identification and classification task. Combined analysis results of the mAP and the accuracy show an excellent performance of the MSRCR method.
Signing and Verifying Encrypted Medical Images Using Double Random Phase Encryption
Authors: Abdallah Hanaa A. , ElKamchouchi Dalia H.
Published: April 2022

Digital Signature using Self-Image signing is introduced in this paper. This technique is used to verify the integrity and originality of images transmitted over insecure channels. In order to protect the user’s medical images from changing or modifying, the images must be signed. The proposed approach uses the Discrete Wavelet Transform to subdivide a picture into four bands and the Discrete Cosine Transform DCT is used to embed a mark from each sub-band to another sub-band of DWT according to a determined algorithm. To increase the security, the marked image is then encrypted using Double Random Phase Encryption before transmission over the communication channel. By verifying the presence of the mark, the authority of the sender is verified at the receiver. Authorized users’ scores should, in theory, always be higher than illegal users’ scores. If this is the case, a single threshold might be used to distinguish between authorized and unauthorized users by separating the two sets of scores. The results are compared to those obtained using an approach that does not employ DWT.
Structural Analysis of Loosely Coupled Transformers with FEA-Aided Visualization for Wireless Power Transfer Systems against Misalignment Tolerance
Authors: Zhang Yao , Li Jiayang , Zhang Fan , Chen Zhangping , Kong Yaguang , Huang Na
Published: April 2022

The main problems of automotive wireless power transmission (WPT) systems include a weak misalignment tolerance are urgently required to be solved through the design of the loosely coupled transformer. In this paper, an analysis methodology based on finite element analysis (FEA) visualization is proposed, it is easy-implemented and straightforwardly explains this complex electromagnetic phenomenon. Firstly, the transformer structures with different winding and magnetic core arrangement were modeled by FEA in both 3-D and 2-D visualizations. The distribution of space coupling magnetic fields and leakage fields was analyzed by ANSYS Electronics. The key parameters that have a great influence on the coupling performance were delicately chosen. Then, the quantitative analysis of these key parameters and coupling performance against misalignment tolerance is presented. The numerical statistical result shows that the maximum coupling coefficient of the three structures that have been optimized consistently appears when the two key parameters, the inner and outer diameter, account for about 20% and 60% of the whole dimension of the transformers. A new transformer with a solenoid-shaped structure and strong misalignment tolerance was proposed based on the analysis methodology and the FEA results of the three structures. The delivered power and transfer efficiency under different misalignments of the new structure were analyzed via an FEA-aided joint method as well. The relationships among misalignment tolerance, key structural dimensions and coupling coefficients for all these structures were comprehensively investigated, which provide guidance for the subsequent multi-objective optimization strategies.
Lightweight Path Recovery in IPv6 Internet-of-Things Systems
Authors: Liu Zhuoliu , Fu Luwei , Pan Maojun , Zhao Zhiwei
Published: April 2022

In an Internet-of-Things system supported by Internet Protocol version 6 (IPv6), the Routing Protocol for Low-Power and Lossy Networks (RPL) presents extensive applications in various network scenarios. In these novel scenarios characterized by the access of massive devices, path recovery, which reconstructs the complete path of the packet transmission, plays a vital role in network measurement, topology inference, and information security. This paper proposes a Lightweight Path recovery algorithm (LiPa) for multi-hop point-to-point communication. The core idea of LiPa is to make full use of the spatial and temporal information of the network topology to recover the unknown paths iteratively. Specifically, spatial and temporal information refer to the potential correlations between different paths within a time slot and path status during different time slots, respectively. To verify the effect of our proposal, we separately analyze the performance of leveraging temporal information, spatial information, and their composition by extensive simulations. We also compare LiPa with two state-of-the-art methods in terms of the recovery accuracy and the gain–loss ratio. The experiment results show that LiPa significantly outperforms all its counterpart algorithms in different network settings. Thus, LiPa can be considered as a promising approach for packet-level path recovery with minor loss and great adaptability.
Performance Comparison of Silicon- and Gallium-Nitride-Based MOSFETs for a Power-Efficient, DC-to-DC Flyback Converter
Authors: Ahmed Osama , Khan Yousuf , Butt Muhammad A. , Kazanskiy Nikolay L. , Khonina Svetlana N.
Published: April 2022

Gallium Nitride (GaN)-based devices offer many advantages over conventional electronic devices, such as lower input/output capacitances, a higher switching speed, and a compact size, resulting in higher-density power outputs and reduced switching losses. This research investigates the power and switching efficiency of GaN-based FET in an active-clamp, DC-to-DC flyback converter for step-down application (24 V to 7 V) and compares it with silicon (Si)- based devices in the same circuit topology. The operation is analyzed under various input conditions and output loads such as R, RC, RL, and RLC. The proposed topology can achieve a maximum power-conversion efficiency of 99.6% and can operate at higher frequency values above 1 MHz. The presented GaN-based flyback model can replace conventional Si-based switches in power applications which require high power-efficiency and switching speed in a compact device.
Metallic Particle Motion and Breakdown at AC Voltages in CO2/O2 and SF6
Authors: Donzel Lise , Seeger Martin , Over Daniel , Carstensen Jan
Published: April 2022

This study deals with gaseous insulation contaminated by free moving particles. Two gases were investigated: SF6 (0.45 MPa) and a CO2/O2 gas mixture (0.75 MPa). Video recordings were used to track a free particle moving between a plate and a Rogowski electrode for validation of a 1D particle motion model. The effect of fixed and free particles (4 or 8 mm, Ø 0.9 mm) on the breakdown voltage and the mean time between breakdowns was determined in a concentric set of electrodes. The value of the breakdown voltage for a free particle was between those of a particle fixed to the enclosure and the central electrode. The particle motion in the concentric case could not be observed in the experimental set-up and was therefore simulated using a 1D model. For the 4 mm free particle, the breakdown seemed to be initiated in the inter-electrode gap in CO2 and at the crossing in SF6, while for the 8 mm particle, breakdown occurred at lift-off in both gases. A parameter k describing the width of the time to breakdown distribution was introduced. A low value of k was associated with the breakdown from the particles at the electrodes, while k was larger than 10 when the breakdown was decided during particle flight.
Determining the Composition of Carbonate Solvent Systems Used in Lithium-Ion Batteries without Salt Removal
Authors: Parhizi Mohammad , Caceres-Martinez Louis Edwards , Modereger Brent A. , Kenttämaa Hilkka I. , Kilaz Gozdem , Ostanek Jason K.
Published: April 2022

In this work, two methods were investigated for determining the composition of carbonate solvent systems used in lithium-ion (Li-ion) battery electrolytes. One method was based on comprehensive two-dimensional gas chromatography with electron ionization time-of-flight mass spectrometry (GC×GC/EI TOF MS), which often enables unknown compound identification by their electron ionization (EI) mass spectra. The other method was based on comprehensive two-dimensional gas chromatography with flame ionization detection (GC×GC/FID). Both methods were used to determine the concentrations of six different commonly used carbonates in Li-ion battery electrolytes (i.e., ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), and vinylene carbonate (VC) in model compound mixtures (MCMs), single-blind samples (SBS), and a commercially obtained electrolyte solution (COES). Both methods were found to be precise (uncertainty < 5%), accurate (error < 5%), and sensitive (limit of detection <0.12 ppm for FID and <2.7 ppm for MS). Furthermore, unlike the previously reported methods, these methods do not require removing lithium hexafluorophosphate salt (LiPF6) from the sample prior to analysis. Removal of the lithium salt was avoided by diluting the electrolyte solutions prior to analysis (1000-fold dilution) and using minimal sample volumes (0.1 µL) for analysis.
A Multi-Turbine Approach for Improving Performance of Wind Turbine Power-Based Fault Detection Methods
Authors: Aziz Usama , Charbonnier Sylvie , Berenguer Christophe , Lebranchu Alexis , Prevost Frederic
Published: April 2022

The relationship between wind speed and the power produced by a wind turbine is expressed by its power curve. Power curves are commonly used to monitor the production performance of a wind turbine by asset managers to ensure optimal production. They can also be used as a tool to detect faults occurring on a wind turbine when the fault causes a decrease in performance. However, the wide dispersion of data generally observed around the reference power curve limits the detection performance of power curve-based techniques. Fault indicators, such as residuals, which measure the difference between the actual power produced and the expected power, are largely affected by this dispersion. To increase the detection performance of power-based fault detection methods, a hybrid solution of mono-multi-turbine residual generation is proposed in this paper to reduce the influence of the power curve dispersion. A new simulation framework, modeling the effect of wind nature (turbulent/laminar) on the wind turbine performance, is also proposed. This allows us to evaluate and compare the performances of two fault detection methods in their multi-turbine implementation. The results show that the application of a multi-turbine approach to a basic residual generation method significantly improves its detection performance and makes it as efficient as a more complex method.
Pollution from Transport: Detection of Tyre Particles in Environmental Samples
Authors: Worek Jagoda , Badura Xymena , Białas Anna , Chwiej Joanna , Kawoń Kamil , Styszko Katarzyna
Published: April 2022

Transport is one of the most important sources of environmental pollution. More and more information has shown that one of the greatest sources of emissions from transport are emissions related to the release of microplastics from tyres. This is one of the most underestimated sources of emissions into the environment. In this study, environmental samples are analysed for the presence of these particles. For this purpose, optical methods and spectroscopic methods are used. Fourier transform infrared (FTIR) spectroscopy is used to identify synthetic rubber, most likely derived from car tyres. A complementary confocal microscopy method is used to confirm the FTIR results. The soil samples and road dust from the areas with heavy traffic are tested. An average of 372 ± 50 fragments per kilogram dry weight are detected in the soil samples. In the case of samples from the road, this number is 515 ± 20 fragments per kilogram of dry matter. In the samples, most of the microplastics come from tyres, which confirms the scientists’ assumptions about the amount of emissions in the environment. More than 90% of the black fragments later identified as tyre-derived synthetic rubber are found in the samples. A greater number of microplastics are found in road dust samples than in the soil. This may be due to the direct influence of braking, which causes greater accumulation of samples at the emission source than at a short distance into the soil. There is also a noticeable difference in the size of the fraction. In the case of soils, a fraction below 50 µm accounts for the majority of cases. When one analyses road dust samples, one may observe that most of the fractions are between 50 and 200 µm. This may be due to the possibility of smaller emission particles over longer distances and the greater degradation process that occurs in soils. The microplastics from the road dust are less degraded than the microplastics from the soil.
Rapidly Quantifying Interior Greenery Using 360° Panoramic Images
Authors: Jiang Junzhiwei , Brack Cris , Coe Robert , Gibbons Philip
Published: April 2022

Many people spend the majority of their time indoors and there is emerging evidence that interior greenery contributes to human wellbeing. Accurately capturing the amount of interior greenery is an important first step in studying its contribution to human well-being. In this study, we evaluated the accuracy of interior greenery captured using 360° panoramic images taken within a range of different interior spaces. We developed an Interior Green View Index (iGVI) based on a K-means clustering algorithm to estimate interior greenery from 360° panoramic images taken within 66 interior spaces and compared these estimates with interior greenery measured manually from the same panoramic images. Interior greenery estimated using the automated method ranged from 0% to 34.19% of image pixels within the sampled interior spaces. Interior greenery estimated using the automated method was highly correlated (r = 0.99) with interior greenery measured manually, although we found the accuracy of the automated method compared with the manual method declined with the volume and illuminance of interior spaces. The results suggested that our automated method for extracting interior greenery from 360° panoramic images is a useful tool for rapidly estimating interior greenery in all but very large and highly illuminated interior spaces.
Bio-Based Phase Change Materials for Wooden Building Applications
Authors: Palanti Sabrina , Temiz Ali , Köse Demirel Gaye , Hekimoğlu Gökhan , Sarı Ahmet , Nazari Meysam , Jebrane Mohamed , Schnabel Thomas , Terziev Nasko
Published: April 2022

Solid wood can serve multifunctionality for energy savings in buildings. The study reveals the results of biodeterioration and degradation of solid Scots pine wood used to incorporate single or multicomponent fatty acid mixtures as bio-based phase change materials (BPCMs). The sapwood samples were impregnated with capric acid (CA), methyl palmitate (MP), lauryl alcohol (LA) and a mixture of coconut oil fatty acids and linoleic acid (CoFA-LA). The samples were tested against subterranean termites by an Italian species (Reticulitermes lucifugus), the wood boring beetle Hylotrupes bajulus and mold through a discoloration test. Tested against termites, the impregnated samples were significantly less susceptible to the attack than the controls, i.e., the tested BPCMs were resistant to R. lucifugus. The only test with MP terminated at the moment against H. bajulus showed positive results with no larvae surviving. The mold discoloration test revealed that the wood impregnated with CoFA-LA was identically susceptible to mold discoloration when compared to the control, nonimpregnated samples. This pioneer study verifies that solid wood employed for the encapsulation of BPCMs for building purposes can serve identically or somewhat better than similar wooden building elements regarding attacks of the above microorganisms and insects. Such multifunctional building elements will be tested further in a pilot scale building to characterize better the durability aspects of the new materials.
Developing Tree Mortality Models Using Bayesian Modeling Approach
Authors: Xie Lu , Chen Xingjing , Zhou Xiao , Sharma Ram P. , Li Jianjun
Published: April 2022

The forest mortality models developed so far have ignored the effects of spatial correlations and climate, which lead to the substantial bias in the mortality prediction. This study thus developed the tree mortality models for Prince Rupprecht larch (Larix gmelinii subsp. principis-rupprechtii), one of the most important tree species in northern China, by taking those effects into account. In addition to these factors, our models include both the tree—and stand—level variables, the information of which was collated from the temporary sample plots laid out across the larch forests. We applied the Bayesian modeling, which is the novel approach to build the multi-level tree mortality models. We compared the performance of the models constructed through the combination of selected predictor variables and explored their corresponding effects on the individual tree mortality. The models precisely predicted mortality at the three ecological scales (individual, stand, and region). The model at the levels of both the sample plot and stand with different site condition (block) outperformed the other model forms (model at block level alone and fixed effects model), describing significantly larger mortality variations, and accounted for multiple sources of the unobserved heterogeneities. Results showed that the sum of the squared diameter was larger than the estimated diameter, and the mean annual precipitation significantly positively correlated with tree mortality, while the ratio of the diameter to the average of the squared diameter, the stand arithmetic mean diameter, and the mean of the difference of temperature was significantly negatively correlated. Our results will have significant implications in identifying various factors, including climate, that could have large influence on tree mortality and precisely predict tree mortality at different scales.
Analysis of Alternative Shelf Life-Extending Protocols and Their Effect on the Preservation of Seafood Products
Authors: Pinto de Rezende Lourenço , Barbosa Joana , Teixeira Paula
Published: April 2022

Seafood is essential to a healthy and varied diet due to its highly nutritious characteristics. However, seafood products are highly perishable, which results in financial losses and quality concerns for consumers and the industry. Due to changes in consumer concerns, demand for healthy products has increased. New trends focusing on reducing synthetic preservatives require innovation and the application of additional or alternative strategies to extend the shelf life of this type of product. Currently, refrigeration and freezing storage are the most common methods for fish preservation. However, refrigeration alone cannot provide long shelf-life periods for fish, and freezing worsens sensorial characteristics and consumer interest. Therefore, the need to preserve seafood for long periods without exposing it to freezing temperatures exists. This review focuses on the application of other approaches to seafood products, such as biodegradable films and coating technology; superchilling; irradiation; high-pressure processing; hyperbaric storage; and biopreservation with lactic acid bacteria, bacteriocins, or bacteriophages. The efficiency of these techniques is discussed based on their impact on microbiological quality, sensorial degradation, and overall preservation of the product’s nutritional properties. Although these techniques are already known, their use in the industrial processing of seafood is not widespread. Thus, the novelty of this review is the aggregation of recent studies on shelf life extension approaches, which provide useful information for the selection of the most appropriate technology and procedures and industrial innovation. Despite the fact that all techniques inhibit or delay bacterial proliferation and product decay, an undesirable sensory impact may occur depending on the treatment conditions. Although no technique appears to replace refrigeration, the implementation of additional treatments in the seafood processing operation could reduce the need for freezing, extending the shelf life of fresh unfrozen products.
The Influence of Aerobic Type Exercise on Active Crohn’s Disease Patients: The Incidence of an Elite Athlete
Authors: Papadimitriou Konstantinos
Published: April 2022

A lifestyle factor which contributes to the remission of Crohn’s disease (CD) is physical activity. The effect seems to positively impact the disease’s symptoms, improving the quality of life, especially on patients in remission. Due to the lack of clinical studies about the effects of physical activity on active CD patients, the purpose of the present case study was to record the influence of swimming training (aerobic type of exercise) on an athlete with active CD. In this study participated a 22-year-old male, who is an elite swimmer and who was diagnosed in 2019 with CD. The research was conducted over the last three years (2019–2022). Both the athlete and doctor consented to the clinical examinations by the author. According to the present study, immediate medical examination and the prescription of anti-TNF-α therapy is probably the most appropriate solution for someone who is diagnosed with CD symptoms. Moreover, patient participation in any sport activity is discouraged because of the potential danger of exacerbation of the symptoms. Therefore, for the sake of patient safety, physical activity should only be encouraged when the disease is in remission.
Connexin Mutations and Hereditary Diseases
Authors: Qiu Yue , Zheng Jianglin , Chen Sen , Sun Yu
Published: April 2022

Inherited diseases caused by connexin mutations are found in multiple organs and include hereditary deafness, congenital cataract, congenital heart diseases, hereditary skin diseases, and X-linked Charcot–Marie–Tooth disease (CMT1X). A large number of knockout and knock-in animal models have been used to study the pathology and pathogenesis of diseases of different organs. Because the structures of different connexins are highly homologous and the functions of gap junctions formed by these connexins are similar, connexin-related hereditary diseases may share the same pathogenic mechanism. Here, we analyze the similarities and differences of the pathology and pathogenesis in animal models and find that connexin mutations in gap junction genes expressed in the ear, eye, heart, skin, and peripheral nerves can affect cellular proliferation and differentiation of corresponding organs. Additionally, some dominant mutations (e.g., Cx43 p.Gly60Ser, Cx32 p.Arg75Trp, Cx32 p.Asn175Asp, and Cx32 p.Arg142Trp) are identified as gain-of-function variants in vivo, which may play a vital role in the onset of dominant inherited diseases. Specifically, patients with these dominant mutations receive no benefits from gene therapy. Finally, the complete loss of gap junctional function or altered channel function including permeability (ions, adenosine triphosphate (ATP), Inositol 1,4,5-trisphosphate (IP3), Ca2+, glucose, miRNA) and electric activity are also identified in vivo or in vitro.