bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of Dl1.72, a Novel Anti-DLL1 Antibody with Anti-Tumor Efficacy against Estrogen Receptor-Positive Breast Cancer
Authors: Silva Gabriela , Sales-Dias Joana , Casal Diogo , Alves Sara , Domenici Giacomo , Barreto Clara , Matos Carolina , Lemos Ana R. , Matias Ana T. , Kucheryava Khrystyna , Ferreira Andreia , Moita Maria Raquel , Braga Sofia , Brito Catarina , Cabral M. Guadalupe , Casalou Cristina , Barral Duarte C. , Sousa Pedro M. F. , Videira Paula A. , Bandeiras Tiago M. , Barbas Ana
Published: August 2021

The Notch-signaling ligand DLL1 has emerged as an important player and promising therapeutic target in breast cancer (BC). DLL1-induced Notch activation promotes tumor cell proliferation, survival, migration, angiogenesis and BC stem cell maintenance. In BC, DLL1 overexpression is associated with poor prognosis, particularly in estrogen receptor-positive (ER+) subtypes. Directed therapy in early and advanced BC has dramatically changed the natural course of ER+ BC; however, relapse is a major clinical issue, and new therapeutic strategies are needed. Here, we report the development and characterization of a novel monoclonal antibody specific to DLL1. Using phage display technology, we selected an anti-DLL1 antibody fragment, which was converted into a full human IgG1 (Dl1.72). The Dl1.72 antibody exhibited DLL1 specificity and affinity in the low nanomolar range and significantly impaired DLL1-Notch signaling and expression of Notch target genes in ER+ BC cells. Functionally, in vitro treatment with Dl1.72 reduced MCF-7 cell proliferation, migration, mammosphere formation and endothelial tube formation. In vivo, Dl1.72 significantly inhibited tumor growth, reducing both tumor cell proliferation and liver metastases in a xenograft mouse model, without apparent toxicity. These findings suggest that anti-DLL1 Dl1.72 could be an attractive agent against ER+ BC, warranting further preclinical investigation.
Deep Learning Analysis of CT Images Reveals High-Grade Pathological Features to Predict Survival in Lung Adenocarcinoma
Authors: Choi Yeonu , Aum Jaehong , Lee Se-Hoon , Kim Hong-Kwan , Kim Jhingook , Shin Seunghwan , Jeong Ji Yun , Ock Chan-Young , Lee Ho Yun
Published: August 2021

We aimed to develop a deep learning (DL) model for predicting high-grade patterns in lung adenocarcinomas (ADC) and to assess the prognostic performance of model in advanced lung cancer patients who underwent neoadjuvant or definitive concurrent chemoradiation therapy (CCRT). We included 275 patients with 290 early lung ADCs from an ongoing prospective clinical trial in the training dataset, which we split into internal–training and internal–validation datasets. We constructed a diagnostic DL model of high-grade patterns of lung ADC considering both morphologic view of the tumor and context view of the area surrounding the tumor (MC3DN; morphologic-view context-view 3D network). Validation was performed on an independent dataset of 417 patients with advanced non-small cell lung cancer who underwent neoadjuvant or definitive CCRT. The area under the curve value of the DL model was 0.8 for the prediction of high-grade histologic patterns such as micropapillary and solid patterns (MPSol). When our model was applied to the validation set, a high probability of MPSol was associated with worse overall survival (probability of MPSol >0.5 vs. <0.5; 5-year OS rate 56.1% vs. 70.7%), indicating that our model could predict the clinical outcomes of advanced lung cancer patients. The subgroup with a high probability of MPSol estimated by the DL model showed a 1.76-fold higher risk of death (HR 1.76, 95% CI 1.16–2.68). Our DL model can be useful in estimating high-grade histologic patterns in lung ADCs and predicting clinical outcomes of patients with advanced lung cancer who underwent neoadjuvant or definitive CCRT.
Useful MRI Findings for Minimally Invasive Surgery for Early Cervical Cancer
Authors: Park Byung Kwan , Kim Tae-Joong
Published: August 2021

According to the recent International Federation of Gynecology and Obstetrics (FIGO) staging system, Stage III cervical cancer indicates pelvic or paraaortic lymph node metastasis. Accordingly, the new FIGO stage accepts imaging modalities, such as MRI, as part of the FIGO 2018 updated staging. Magnetic resonance imaging (MRI) is the best imaging modality to estimate the size or volume of uterine cancer because of its excellent soft tissue contrast. As a result, MRI is being used increasingly to determine treatment options and follow-up for cervical cancer patients. Increasing availability of cancer screening and vaccination have improved early detection of cervical cancer. However, the incidence of early cervical cancers has increased compared to that of advanced cervical cancer. A few studies have investigated if MRI findings are useful in management of early cervical cancer. MRI can precisely predict tumor burden, allowing conization, trachelectomy, and simple hysterectomy to be considered as minimally invasive treatment options for early cervical cancer. This imaging modality also can be used to determine whether there is recurrent cancer following minimally invasive treatments. The purpose of this review is to highlight useful MRI features for managing women with early cervical cancer.
Kidney Dysfunction Is Associated with Thrombosis and Disease Severity in Myeloproliferative Neoplasms: Implications from the German Study Group for MPN Bioregistry
Authors: Gecht Judith , Tsoukakis Ioannis , Kricheldorf Kim , Stegelmann Frank , Klausmann Martine , Griesshammer Martin , Schulz Holger , Hollburg Wiebke , Göthert Joachim R. , Sockel Katja , Heidel Florian H. , Gattermann Norbert , Maintz Christoph , Al-Ali Haifa K. , Platzbecker Uwe , Hansen Richard , Hänel Mathias , Parmentier Stefani , Bommer Martin , Pahl Heike L. , Lang Fabian , Kirschner Martin , Isfort Susanne , Brümmendorf Tim H. , Döhner Konstanze , Koschmieder Steffen
Published: August 2021

Inflammation-induced thrombosis represents a severe complication in patients with myeloproliferative neoplasms (MPN) and in those with kidney dysfunction. Overlapping disease-specific attributes suggest common mechanisms involved in MPN pathogenesis, kidney dysfunction, and thrombosis. Data from 1420 patients with essential thrombocythemia (ET, 33.7%), polycythemia vera (PV, 38.5%), and myelofibrosis (MF, 27.9%) were extracted from the bioregistry of the German Study Group for MPN. The total cohort was subdivided according to the calculated estimated glomerular filtration rate (eGFR, (mL/min/1.73 m2)) into eGFR1 (≥90, 21%), eGFR2 (60–89, 56%), and eGFR3 (<60, 22%). A total of 29% of the patients had a history of thrombosis. A higher rate of thrombosis and longer MPN duration was observed in eGFR3 than in eGFR2 and eGFR1. Kidney dysfunction occurred earlier in ET than in PV or MF. Multiple logistic regression analysis identified arterial hypertension, MPN treatment, increased uric acid, and lactate dehydrogenase levels as risk factors for kidney dysfunction in MPN patients. Risk factors for thrombosis included arterial hypertension, non-excessive platelet counts, and antithrombotic therapy. The risk factors for kidney dysfunction and thrombosis varied between MPN subtypes. Physicians should be aware of the increased risk for kidney disease in MPN patients, which warrants closer monitoring and, possibly, early thromboprophylaxis.
Spontaneous Coronary Artery Dissection as Presenting Feature of Vascular Ehlers-Danlos Syndrome
Authors: Bos J. , Overwater E. , Dirksen M.T. , Simsek S. , Demirdas S. , Houweling A.C.
Published: August 2021

A spontaneous coronary artery dissection as the sole presenting feature of vascular Ehlers-Danlos syndrome is an uncommon finding. We present a 33-year-old woman with sudden onset chest pain caused by a spontaneous coronary artery dissection. Genetic testing revealed vascular Ehlers-Danlos syndrome as the underlying cause. Specifically, we show the value of genetic testing, which in some patients may be the only way of establishing a diagnosis.
Preliminary Study of Extended Ripening Effects on Peptides Evolution and DPPH Radical Scavenging Activity in Mexican Goat Cheese
Authors: Vázquez-García Rosa , Cardador-Martínez Anaberta , Orihuela-López Miguel Angel , Ramos-Hernández Livia Sofía , Martín-del-Campo Sandra Teresita
Published: August 2021

Cheese ripening causes intense proteolysis, particularly when the cheese contains starter cultures. Several studies have shown the presence of bioactive peptides in goat’s milk cheeses with antioxidant activity. Mexican goat cheeses’ peptide fractions were evaluated at different ripening stages. Additionally, they were correlated with their antioxidant activity. Proteolysis was measured in the acid-soluble nitrogen and non-protein nitrogen fractions using reverse-phase high-performance liquid chromatography. While the antioxidant activity in both nitrogenous fractions was determined using a 2,2-diphenyl-1-picrylhydrazyl solution. Analyzed cheeses showed peptides fraction in the retention time of 2.05, 18.36, and 50.11 min for acid-soluble fraction and non-protein protein nitrogen, and showed antioxidant activity from the first day of ripening to 73% discoloration in the DPPH solution at 55 ripening days. Obtained results suggested that ripened Mexican goat cheese had a DPPH radical scavenging activity related to peptides present originally in the milk or released by starter culture action during cheese ripening.
The Adipose-Derived Stem Cell and Endothelial Cell Coculture System—Role of Growth Factors?
Authors: Steiner Dominik , Mutschall Hilkea , Winkler Sophie , Horch Raymund E. , Arkudas Andreas
Published: August 2021

Adequate vascularization is a fundamental prerequisite for bone regeneration, formation and tissue engineering applications. Endothelialization of scaffold materials is a promising strategy to support neovascularization and bone tissue formation. Besides oxygen and nutrition supply, the endothelial network plays an important role concerning osteogenic differentiation of osteoprogenitor cells and consecutive bone formation. In this study we aimed to enhance the growth stimulating, proangiogenic and osteogenic features of the ADSC and HUVEC coculture system by means of VEGFA165 and BMP2 application. We were able to show that sprouting phenomena and osteogenic differentiation were enhanced in the ADSC/HUVEC coculture. Furthermore, apoptosis was unidirectionally decreased in HUVECs, but these effects were not further enhanced upon VEGFA165 or BMP2 application. In summary, the ADSC/HUVEC coculture system per se is a powerful tool for bone tissue engineering applications.
Arginine Supplementation Promotes Extracellular Matrix and Metabolic Changes in Keratoconus
Authors: McKay Tina B. , Priyadarsini Shrestha , Rowsey Tyler , Karamichos Dimitrios
Published: August 2021

Keratoconus (KC) is a common corneal ectatic disease that affects 1:500–1:2000 people worldwide and is associated with a progressive thinning of the corneal stroma that may lead to severe astigmatism and visual deficits. Riboflavin-mediated collagen crosslinking currently remains the only approved treatment to halt progressive corneal thinning associated with KC by improving the biomechanical properties of the stroma. Treatments designed to increase collagen deposition by resident corneal stromal keratocytes remain elusive. In this study, we evaluated the effects of arginine supplementation on steady-state levels of arginine and arginine-related metabolites (e.g., ornithine, proline, hydroxyproline, spermidine, and putrescine) and collagen protein expression by primary human corneal fibroblasts isolated from KC and non-KC (healthy) corneas and cultured in an established 3D in vitro model. We identified lower cytoplasmic arginine and spermidine levels in KC-derived constructs compared to healthy controls, which corresponded with overall higher gene expression of arginase. Arginine supplementation led to a robust increase in cytoplasmic arginine, ornithine, and spermidine levels in controls only and a significant increase in collagen type I secretion in KC-derived constructs. Further studies evaluating safety and efficacy of arginine supplementation are required to elucidate the potential therapeutic applications of modulating collagen deposition in the context of KC.
LIM-Kinases in Synaptic Plasticity, Memory, and Brain Diseases
Authors: Ben Zablah Youssif , Zhang Haiwang , Gugustea Radu , Jia Zhengping
Published: August 2021

Learning and memory require structural and functional modifications of synaptic connections, and synaptic deficits are believed to underlie many brain disorders. The LIM-domain-containing protein kinases (LIMK1 and LIMK2) are key regulators of the actin cytoskeleton by affecting the actin-binding protein, cofilin. In addition, LIMK1 is implicated in the regulation of gene expression by interacting with the cAMP-response element-binding protein. Accumulating evidence indicates that LIMKs are critically involved in brain function and dysfunction. In this paper, we will review studies on the roles and underlying mechanisms of LIMKs in the regulation of long-term potentiation (LTP) and depression (LTD), the most extensively studied forms of long-lasting synaptic plasticity widely regarded as cellular mechanisms underlying learning and memory. We will also discuss the involvement of LIMKs in the regulation of the dendritic spine, the structural basis of synaptic plasticity, and memory formation. Finally, we will discuss recent progress on investigations of LIMKs in neurological and mental disorders, including Alzheimer’s, Parkinson’s, Williams–Beuren syndrome, schizophrenia, and autism spectrum disorders.
Isolation and Antimalarial Activity of a New Flavonol from Tithonia diversifolia Leaf Extract
Authors: Ngarivhume Talkmore , Noreljaleel Anwar , Bonnet Susanna L. , Wilhelm Anke
Published: August 2021

An antiplasmodial activity-guided isolation was carried out on the dichloromethane extract of Tithonia diversifolia dried leaves. A total of five germacranolide type sesquiterpene lactones and a new flavonol, 3,6-dihydroxy-2-(4′-hydroxyphenyl)-7-methoxy-4H-chromen-4-one, were isolated. The flavonol reported an IC50 above 6.00 µM against the chloroquine sensitive strain, NF54. The antimalarial activity of the Tithonia diversifolia dichloromethane leaf extract was attributed to orizabin and tagitinin C.
Magnetic Shielding Study of Bonding and Aromaticity in Corannulene and Coronene
Authors: Karadakov Peter B.
Published: August 2021

Bonding and aromaticity in the bowl-shaped C5v and planar D5h geometries of corannulene and the planar D6h geometry of coronene are investigated using 3D isosurfaces and 2D contour plots of the isotropic magnetic shielding σiso(r) and, for planar geometries, of the out-of-plane component of the shielding tensor σzz(r). Corannulene and coronene both feature conjoined shielded “doughnuts” around a peripheral six-membered carbon ring, suggesting strong bonding interactions and aromatic stability; a deshielded region inside the hub ring of corannulene indicates that this ring is antiaromatic, more so in planar corannulene. The switch from the planar to the bowl-shaped geometry of corannulene is shown to enhance both bonding and the local aromaticities of the five- and six-membered rings; these factors, in addition to ring strain reduction, favour the bowl-shaped geometry. The most and least shielded bonds in both corannulene and coronene turn out to be the spoke and hub bonds, respectively. The higher π electron activity over spoke bonds in planar corannulene and coronene is supported by σzz(r) contour plots in planes 1 Å above the respective molecular planes; these findings about spoke bonds are somewhat unexpected, given that ring current studies indicate next to no currents over spoke bonds.
eHealth Literacy, Awareness of Pandemic Infectious Diseases, and Healthy Lifestyle in Middle School Students
Authors: Choi Sinyoung , Bang Kyung-Sook , Shin Da-Ae
Published: August 2021

The coronavirus disease 2019 (COVID-19) pandemic is an unprecedented public health crisis worldwide. This pandemic has led to the spread of online misinformation, closure of schools, postponement of re-opening of schools, and restrictions on healthy outdoor activities. These, in turn, have caused a disruption in the daily life of middle school students. This study aimed to identify the relationships between eHealth literacy, awareness of pandemic infectious diseases, and healthy lifestyle in middle school students. For this purpose, we conducted a descriptive, correlational study in two cities in the capital of South Korea. A total of 138 middle school students completed self-reported questionnaires about eHealth literacy, awareness of pandemic infectious diseases, and healthy lifestyle. Middle school students displayed moderate levels of eHealth literacy (3.72 ± 0.97), awareness of pandemic infectious diseases (3.33 ± 0.92), and healthy lifestyle (2.98 ± 0.72). Positive correlations were found between eHealth literacy and awareness of pandemic infectious diseases (r = 0.44, p < 0.001), between eHealth literacy and healthy lifestyle (r = 0.52, p < 0.001), and between awareness of pandemic infectious diseases and healthy lifestyle (r = 0.38, p < 0.001). These findings suggest that eHealth literacy may be an important aspect of increasing the awareness about pandemic infectious diseases and forming healthy lifestyle habits in Korean middle school students during the COVID-19 pandemic.
An In-Vitro Study to Evaluate the Effect of Denture Cleansing Agents on Color Stability of Denture Bases Fabricated Using CAD/CAM Milling, 3D-Printing and Conventional Techniques
Authors: Jain Saurabh , Sayed Mohammed , Ahmed Walaa Magdy , Halawi Amjad Hussain Asiri , Najmi Naif Mohammed Ahmed , Aggarwal Aparna , Bhandi Shilpa , Patil Shankargouda
Published: August 2021

The current literature lacks substantial information about the effect of denture cleansers on the color stability of denture bases formed using Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) additive and CAD/CAM subtractive manufacturing techniques. This study aimed to assess the effect of two commercially available denture cleansers on the color stability of denture base resins fabricated using four different techniques. Forty-five disc-shaped specimens were fabricated using each technique. Initial color readings were recorded. Specimens were randomly divided into three subgroups (n = 15): a control group (distilled water) and two denture cleanser groups. They were immersed in these solutions, simulating 180 days of use. Final color readings were recorded. The color difference was calculated, and the data were statistically analyzed. For all the specimens, significant color changes were observed after immersion in denture cleanser solutions. The extent of color change varied according to the type of denture cleanser used. When placed in the denture cleanser solutions, the CAD/CAM subtractive group showed the maximum color change (−1.10 and −0.72), while the CAD/CAM additive (3D printing) groups showed the least color change (−0.48 and −0.54). Clinicians should choose appropriate denture cleansers for newly introduced denture base resins to minimize the changes in the color of the dentures.
Environmental Protection with HDPE Geomembranes in Mining Facility Constructions
Authors: Lavoie Fernando Luiz , Kobelnik Marcelo , Valentin Clever Aparecido , da Silva Tirelli Érica Fernanda , de Lurdes Lopes Maria , Lins da Silva Jefferson
Published: August 2021

The present work evaluated two high-density polyethylene (HDPE) geomembranes exhumed from mining facility constructions in Brazil. The MIN sample was exhumed from a pond for water use for the iron ore process after 7.92 years of exposure. The MIN2 sample was exhumed from a spillway channel of a ferronickel tailing dam after 10.08 years of service. The physical evaluations showed high depletion for antioxidants that work in the temperature range of 200 °C. The samples presented brittle tensile behavior and had similar behaviors between stress cracking and tensile. Low tensile elongation values and low-stress crack resistance were noted. The MIN2 sample presented a higher melt flow index (MFI) value and lower stress crack resistance. Thermogravimetric curves (TG) under synthetic air purge gas evaluation showed that both samples presented a similar behavior during the evaluation but had several mass losses. The results showed that exothermic and endothermic events occurred with loss of mass and showed no combustion events in the differential thermal analysis (DTA) curve evaluation. Differential scanning calorimetry (DSC) analysis showed no changes in the samples’ behavior. Thus, the results of tensile, stress cracking, and viscosity properties can demonstrate that changes in polymer structure occurred after field exposures.
Value of Left Atrial Appendage Function Measured by Transesophageal Echocardiography for Prediction of Atrial Fibrillation Recurrence after Radiofrequency Catheter Ablation
Authors: Istratoaie Sabina , Vesa Ștefan C. , Cismaru Gabriel , Pop Dana , Roșu Radu , Puiu Mihai , Pepine Diana , Ciobanu Cristina , Minciuna Ioan A. , Simu Gelu , Zdrenghea Dumitru , Buzoianu Anca D.
Published: August 2021

Atrial fibrillation (AF) recurrence after radiofrequency catheter ablation (RFCA) remains a challenging issue. This study aims to explore the left atrial appendage function by transesophageal echocardiography (TEE) and assess its value in predicting AF recurrence following RFCA in paroxysmal AF patients. Eighty-one patients with paroxysmal AF that underwent RFCA were recruited. TEE was performed before ablation with the assessment of left atrial appendage emptying flow velocity (LAAeV). AF recurrence occurred in 24 patients (29.6%) within 12 months after RFCA. The left atrium diameter (LAD) and left atrium volume index (LAVI) were both significantly higher in the recurrence group compared to the non-recurrence group, while the LAAeV was significantly lower in the recurrence group. LAD, LAVi and LAAeV were univariately significant risk factors for AF recurrence after ablation. Based on receiver operating curve (ROC), LAAeV < 40.5 cm/s, LAVi > 40.5 mL and LAD > 41 mm were identified as cut-off values for predicting AF recurrence. In multivariate regression analysis LAAeV < 40.5 cm/s (HR 8.194, 95% CI 2.980–22.530, p < 0.001) was identified as the only statistically significant independent predictor of AF recurrence, as the statistical significance threshold was not achieved for LAVI > 40.5 mL and LAD > 41 mm (p = 0.319; p = 0.507, respectively). A low LAAeV was the only important independent predictor of AF recurrence within 1 year after first RFCA.
Current Developments in Corneal Topography and Tomography
Authors: Kanclerz Piotr , Khoramnia Ramin , Wang Xiaogang
Published: August 2021

Introduction: Accurate assessment of the corneal shape is important in cataract and refractive surgery, both in screening of candidates as well as for analyzing postoperative outcomes. Although corneal topography and tomography are widely used, it is common that these technologies are confused. The aim of this study was to present the current developments of these technologies and particularly distinguish between corneal topography and tomography. Methods: The PubMed, Web of Science and Embase databases were the main resources used to investigate the medical literature. The following keywords were used in various combinations: cornea, corneal, topography, tomography, Scheimpflug, Pentacam, optical coherence tomography. Results: Topography is the study of the shape of the corneal surface, while tomography allows a three-dimensional section of the cornea to be presented. Corneal topographers can be divided into large- and small-cone Placido-based devices, as well as devices with color-LEDs. For corneal tomography, scanning slit or Scheimpflug imaging and optical coherence tomography may be employed. In several devices, corneal topography and tomography have been successfully combined with tear-film analysis, aberrometry, optical biometry and anterior/posterior segment optical coherence tomography. Conclusion: There is a wide variety of imaging techniques to obtain corneal power maps. As different technologies are used, it is imperative that doctors involved in corneal surgery understand the science and clinical application of devices for corneal evaluation in depth.
Detecting Transient Trapping from a Single Trajectory: A Structural Approach
Authors: Lanoiselée Yann , Grimes Jak , Koszegi Zsombor , Calebiro Davide
Published: August 2021

In this article, we introduce a new method to detect transient trapping events within a single particle trajectory, thus allowing the explicit accounting of changes in the particle’s dynamics over time. Our method is based on new measures of a smoothed recurrence matrix. The newly introduced set of measures takes into account both the spatial and temporal structure of the trajectory. Therefore, it is adapted to study short-lived trapping domains that are not visited by multiple trajectories. Contrary to most existing methods, it does not rely on using a window, sliding along the trajectory, but rather investigates the trajectory as a whole. This method provides useful information to study intracellular and plasma membrane compartmentalisation. Additionally, this method is applied to single particle trajectory data of β2-adrenergic receptors, revealing that receptor stimulation results in increased trapping of receptors in defined domains, without changing the diffusion of free receptors.
Revealed Preferences of Fourth Graders When Requesting Face-to-Face Help While Doing Math Exercises Online
Authors: Araya Roberto , Gormaz Raúl
Published: August 2021

When in doubt, asking a peer can be very helpful. Students learn a lot of social strategies from peers. However, stated preference studies have found that for elementary school students with math questions, they prefer to ask their teacher for help. In this paper, we study revealed preferences instead of stated preferences. We analyzed the behavior of fourth-grade students seeking face-to-face assistance while working on an online math platform. Students started by working independently on the platform, before the teacher selected two or three tutors from among those who have answered 10 questions correctly. Each student was then able to choose between the teacher or one of these tutors when requesting assistance. We studied the students’ preferences over 3 years, involving 88 fourth-grade classes, 2700 students, 1209 sessions with classmate tutors, and a total of 16,485 requests for help when there was an option to choose between a teacher or a classmate. We found that students prefer asking classmates for help three times more than asking their teachers when given the choice. Furthermore, this gap increases from the first to the second semester. We also found that students prefer to request help from classmates of the same sex and of higher academic performance. In this context, students from the two highest tertiles sought help from classmates in the same two tertiles, and students from the medium tertile prefer to seek help from students of the highest tertile. However, students in the two lowest tertiles do not prefer asking for help from students from the top tertile more than from their own tertiles.
Real-Time Implementation of Robust Loop-Shaping Controller for a VSC HVDC System
Authors: Faisal Syed F. , Beig Abdul R. , Thomas Sunil
Published: August 2021

Voltage source converter (VSC) based HVDC systems are one of the most promising technologies for high voltage bulk power transmission. The reliability and stability of a VSC-based HVDC system greatly depends on the design of a proper controller for the inner decoupled d-q current loop. One of the major causes of instability in a properly tuned controller is due to system parameter variation. This paper presents the design of a fixed parameter robust controller for the inner decoupled d-q current loop for a VSC-based HVDC system to deal with the uncertainties due to system parameter variations. The method of multiplicative uncertainty is employed in the robust design to model the variations in the system parameters. The robust control design was realized through a graphical procedure known as the loop-shaping technique. The graphical loop shaping technique is a much simpler and more straightforward method compared to the traditional H∞-based algorithms for robust controller design. The designed robust controller was experimentally verified using a real-time hardware in loop (HIL) system and was tested on a VSC HVDC system. The performance of the designed robust controller is compared to that of a traditional PI controller. It has been observed that a classical PI controller is effective for a given operating point, and its performance deteriorates when the operating point changes or when the system parameters change. The studies conducted using real-time hardware in the loop (HIL) system prove that the designed loop-shaping-based robust controller provides very good performance and stability for a wide range of system parameter variations, such as changes in resistance and the inductance of the VSC HVDC system compared to the PI controller tuned using conventional methods.
Modeling and Control of Dynamic Stall Loads on a Smart Airfoil at Low Reynolds Number
Authors: Mohamed Ayman , Wood David , Pieper Jeffery
Published: August 2021

This article describes the development and testing of a modified, semi-empirical ONERA dynamic stall model for an airfoil with a trailing edge flap—a “smart airfoil”—pitching at reduced frequencies up to 0.1. The Reynolds number is 105. The model reconstructs the load fluctuations associated with the shedding of multiple dynamic stall vortices (DSVs) in a time-marching solution, which makes it suitable for real-time control of a trailing edge flap (TEF). No other model captures the effect of the DSVs on the aerodynamic loads on smart airfoils. The model was refined and tuned for force measurements on a smart NACA 643-618 airfoil model that was pitching with an inactive TEF and was validated against the measurements when the TEF was activated. A substantial laminar separation bubble can develop on this airfoil, which is challenging for modelers of the unsteady response. A closed-loop controller was designed offline in SIMULINK, and the output of the controller was applied to the TEF in a wind tunnel. The results indicated that the model has a comparable accuracy for predicting loads with the active TEF compared to inactive TEF loads. In the fully separated flow regime, the controller performed worse when dealing with the development of the laminar separation bubble and DSVs.
An Open-Hardware and Low-Cost Maintenance Tool for Light-Electric-Vehicle Batteries
Authors: Carloni Andrea , Baronti Federico , Di Rienzo Roberto , Roncella Roberto , Saletti Roberto
Published: August 2021

The large increment expected in the diffusion of light-electric-vehicles will raise several issues that must be addressed to cope with this trend, including battery diagnostic and maintenance services. The battery system is the most expensive part in the majority of the e-mobility devices. Therefore, battery manufacturers tend to reduce the battery cost by using simple battery management systems that provide only basic safety features. Possible advanced functionalities are not implemented and the battery may lose performanceduring its use. Widely spread maintenance centers are thus required to support the mobility electrification process, but their diffusion is limited by the high cost ofprofessional battery characterization instruments. This work proposes an open-hardware low-cost battery maintenance tool architecture that can be used with common laboratory instruments. The tool is based on a relay-matrix and a battery monitor integrated circuit. It is able to completely characterize and optimize the state of a battery independently of the battery management system and also gives a figure of the individual aging of the battery cells. The work shows the architecture and the experimental validation of a 16-cells battery maintenance tool prototype. The results demonstrate that utilizing the tool brings the battery in the best possible state and identifies the degradation of the cells in terms of capacity and resistance.
Influence of Selected Working Conditions on Electricity Generation in Bifacial Photovoltaic Modules in Polish Climatic Conditions
Authors: Dobrzycki Arkadiusz , Kurz Dariusz , Maćkowiak Ewa
Published: August 2021

This paper discusses the conversion of solar irradiance energy into electricity. Double-sided (bifacial) panels are gaining increasing popularity in commercial applications due to the increased energy yield with a constant occupied mounting surface. However, the value of the additional energy yield produced by the back of the panel depends on several important factors. This paper presents the influence of working conditions on electricity generation in bifacial modules. This paper also investigates the influence of weather conditions, the module inclination angle, and the substrate beneath the panel surface on electricity generation. Fill factor and efficiency were calculated for each case included in the study scope. Based on the current voltage, power characteristics, and calculations, the module operation for different conditions was compared. It was observed that the optimal inclination angle to the surface is higher for the bifacial modules compared to the unilateral modules. The type of surface under the module has also been indicated to impact the amount of electricity generated. The additional energy yield associated with the panels’ rear side accounts for 2% to more than 35% of the total power generated by a photovoltaic (PV) module. The unit cost of electricity generation in the analyzed cases was also determined.
Multi-Objective Optimization and Fluid Selection of Different Cogeneration of Heat and Power Systems Based on Organic Rankine Cycle
Authors: Teng Shiyang , Feng Yong-Qiang , Hung Tzu-Chen , Xi Huan
Published: August 2021

Cogeneration of heat and power systems based on the organic Rankine cycle (ORC-CHP) has been proven to be an effective way to utilize waste heat at medium and low temperatures. In this work, three ORC-CHP (combined heat and power based on organic Rankine cycle) systems are simulated and compared, including the SS (serial system), the CS (the condensation system), and the SS/CS. The multi-objective genetic algorithm (MOGA) is used to optimize the three systems respectively to achieve higher exergy efficiency and profit ratio of investment (PRI). The optimal thermal-economic performance is obtained. Twelve organic fluids are adopted to evaluate their performance as working fluids. The calculation results show that SS has the highest exergy efficiency, while SS/CS has the best economic performance. Compared with the highest exergy efficiency of SS and the best economic performance of SS/CS, CS will be the optimal solution considering these two objective functions. Under the optimal working conditions, SS has the highest thermal efficiency because it has the highest net power output. The components with the largest proportion of exergy destruction are the heat exchangers, which also has the highest cost.
Development and Application of a Big Data Analysis-Based Procedure to Identify Concerns about Renewable Energy
Authors: Jeong So-Yun , Kim Jae-Wook , Joo Han-Young , Kim Young-Seo , Moon Joo-Hyun
Published: August 2021

To achieve carbon neutrality by 2050, Korea has been expanding its investment in renewal energy distribution and technology development. However, with this rapid expansion of renewable energy, public concern about it has grown. This study developed and used a big data analysis-based procedure to analyze the questions registered on Naver, the largest portal site in Korea, from 2008 to 2020 to identify public concern over renewable energy. The big data analysis-based procedure consisted of two steps. The first was a frequency analysis to identify the most frequently registered words. The second was to classify questions using term frequency-inverse document frequency (TF-IDF) weight and cosine similarity based on word2vec. The analysis revealed the most frequently registered words related to renewable energy, such as “solar power,” “power generation,” “energy,” and “wind power.” It also revealed the most frequently registered questions, such as those related to solar panel installation, renewable energy generation methods, and certificates. To continue expanding renewable energy, it is becoming increasingly important to understand the public’s concerns and create a method to resolve their objections to renewable energy. It is expected that the procedure in this study may provide relevant insight for the method.
Biofuels for Maritime Transportation: A Spatial, Techno-Economic, and Logistic Analysis in Brazil, Europe, South Africa, and the USA
Authors: Carvalho Francielle , Portugal-Pereira Joana , Junginger Martin , Szklo Alexandre
Published: August 2021

Low or zero carbon fuels are crucial for maritime transportation decarbonization goals. This paper assesses potential localities for maritime biofuels (biobunkers) production in Brazil, Europe, South Africa, and United States considering geographical, logistic, and economic aspects. This assessment combines georeferenced and techno-economic analyses to identify suitable fuel production hotspots based on not only plant performance and costs but also on logistic integration and biomass seasonality. Five technology pathways were considered: Straight vegetable Oils (SVO), Hydrotreated Vegetable Oils (HVO), Fischer–Tropsch Biomass-to-liquids (FT-BTL), Alcohol oligomerization to middle distillates (ATD), and Hydrotreated Pyrolysis Oil (HDPO). Findings reveal that biomass concentration in Brazil makes it the region with highest biobunker potential, which are mostly close to coastal areas and surpasses regional demand. Although other regions registered more limited potentials, hotspots proximity to ports would enable fossil fuel replacements in these areas. For all cases, biobunker costs (USD 21–104/GJ) are higher than conventional marine fuels prices (USD 11–17/GJ). Only 15% of the hotspots’ carbon prices that would allow its competitiveness are lower than USD 100/tCO2. Alternatives to incentivize biobunker production would be, first, to establish mandatory fuel blends and second, to join forces with other sectors that would be benefited from the co-production of advanced biofuels.
The Transposition of Energy Communities into Swedish Regulations: Overview and Critique of Emerging Regulations
Authors: Palm Jenny
Published: August 2021

One organizational innovation introduced by the clean energy for all Europeans package (CEP) is that of the energy community (EC), including the renewable energy community (REC) and citizen energy community (CEC). The translation of related directives into national legislation is underway in Sweden, and the Swedish Energy Market Inspectorate (Ei) has proposed a new law on ECs, which has been sent for consultation. This article analyzes the Ei proposal and the responses from the 27 referral bodies commenting on the new EC regulations. Positive aspects of the proposal were that it would be a law on ECs and that it would be easy to start and run an EC. Critics were concerned that the law was too vague, the relationship between existing cooperatives and the new ECs was not clear, both CEC and REC are used instead of only using one term, there is a lack of suggestions on supportive measures for ECs, ECs will have less favorable conditions than other micro-producers of electricity, there is a lack of barrier analysis and visions of a future of ECs, and finally, that the situation for marginalized households was not dealt with in the proposal.
Ginkgo biloba L. Responds to Red and Blue Light: Via Phenylpropanoid and Flavonoid Biosynthesis Pathway
Authors: Zhang Lei , Wang Gaiping , Wang Guibin , Cao Fuliang
Published: August 2021

Light quality is a key environmental factor affecting plant growth and development. In this study, RNA-seq technology was used to explore the molecular mechanisms of ginkgo metabolism under different monochromatic lights. Leaves were used for transcriptome sequencing analysis after being irradiated by red, blue, and white LED lights. After treatment, 2040 differentially expressed genes (DEGs) were identified. Gene Ontology (GO) analysis showed that the DEGs were annotated into 49 terms. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that 736 DEGs were enriched in 100 metabolic pathways, and 13 metabolic pathways were significantly enriched, especially ‘phenylpropanoid biosynthesis’ and ‘flavonoid biosynthesis’. Further analysis of DEGs expression in the two pathways showed that Ginkgo biloba adapts to blue light mainly by promoting the expression of GbFLS to synthesize quercetin, kaempferol, and myncetin, and adapts to red light by promoting the expression of GbDFR to synthesize leucocyanidin. Nine DEGs were randomly selected for qRT-PCR verification, and the gene expression results were consistent with that of transcriptome sequencing. In conclusion, this study is the first to explore the molecular mechanism of ginkgo in response to different monochromatic lights, and it will lay a foundation for the research and application of light quality in the cultivation of leaf-use G. biloba.
Mechanisms of Adaptation of Trees and Shrubs to Dry and Hot Environments
Authors: de Dato Giovanbattista , Gil-Pelegrín Eustaquio
Published: August 2021

This Special Issue, focused on the study of different “Mechanisms of Adaptation of Trees and Shrubs to Dry and Hot Environments”, would be a humble tribute to A [...]
Benchmarking Procurement Cost Saving Strategies for Wood Supply Chains
Authors: Kogler Christoph , Schimpfhuber Sophie , Eichberger Clemens , Rauch Peter
Published: August 2021

Intense international competition pushes the actors of wood supply chains to implement efficient wood supply chain management incorporating coordinated cost-saving strategies to remain competitive. In order to observe the effects of individual and coordinated decision making, mixed-integer programming models for forestry, round-wood transport, and the wood-based industry were developed and integrated. The models deal with operational planning issues regarding production, harvest, and transport and are solved sequentially for individual cost optimization of each wood supply chain actor as well as simultaneously by a combined model representing joint cost optimization in an integrated wood supply chain. This allows for the first time, benchmarking relative cost-saving potential of the wood procurement strategies coordinated transports, integrated supply chains, satellite stockyards, and higher truck payloads within a single case study setting. Based on case study data from southern Austria, results show the advantages of an integrated supply chain with a cost-saving potential of up to 24%. Higher truck payloads reinforce this potential and enable up to 40% savings compared to the predominant wood procurement situation in Central Europe. Wood supply chain integration for Central European circumstances seems to be feasible only for a limited consortium of a few companies, for example when restricted to a wood-buying syndicate supplying several industry plants or a few large forest enterprises, especially as both groups are commonly steering wood transport on their own. Consequently, further research on the challenging task of implementing integrated supply chains using the opportunities of digitalization to realize existing cost savings potential by deepening cooperation and intensifying information exchange is needed.
Patterns and Their Large-Scale Distortions in Marangoni Convection with Insoluble Surfactant
Authors: Mikishev Alexander B. , Nepomnyashchy Alexander A.
Published: August 2021

Nonlinear dynamics of patterns near the threshold of long-wave monotonic Marangoni instability of conductive state in a heated thin layer of liquid covered by insoluble surfactant is considered. Pattern selection between roll and square planforms is analyzed. The dependence of pattern stability on the heat transfer from the free surface of the liquid characterized by Biot number and the gravity described by Galileo number at different surfactant concentrations is studied. Using weakly nonlinear analysis, we derive a set of amplitude equations governing the large-scale roll distortions in the presence of the surface deformation and the surfactant redistribution. These equations are used for the linear analysis of modulational instability of stationary rolls.
FAO/WHO Joint Expert Meeting on Microbiological Risk Assessment (JEMRA): Twenty Years of International Microbiological Risk Assessment
Authors: LeJeune Jeffrey T. , Zhou Kang , Kopko Christine , Igarashi Haruka
Published: August 2021

Since the late 1990s, the Food and Agriculture Organization (FAO) of the United Nations and the World Health Organization (WHO) has convened expert meetings and consultations to address the microbiological risk assessment (MRA). These meetings are held to provide scientific advice in response to requests for from Codex Alimentarius, the international food standard-setting body. Individuals participate in the FAO/WHO joint expert meetings on the microbiological risk assessment (JEMRA) in their personal capacity, as technical experts, yet bring diverse regional and national perspectives that contribute to practical applications, particularly for low- and middle-income countries (LMICs). Over 370 experts from around the globe have contributed to the meeting outcomes that have been published in nearly 40 monographs in the FAO/WHO microbial risk assessment (MRA) series, addressing particular food commodities with microbial hazard(s) combinations or a methodological aspect of microbial risk assessment. FAO/WHO MRA series inform Codex decision-making for the development of international standards for safe food and faire trade in food products; are consulted by risk managers such as food safety authorities and food business operators to make science-based decisions; and are used by academics to advance food safety research and educate the next generation of food safety professionals.
Qualitative Behavior of Unbounded Solutions of Neutral Differential Equations of Third-Order
Authors: Kumar M. Sathish , Elayaraja R. , Ganesan V. , Bazighifan Omar , Al-Shaqsi Khalifa , Nonlaopon Kamsing
Published: August 2021

New oscillatory properties for the oscillation of unbounded solutions to a class of third-order neutral differential equations with several deviating arguments are established. Several oscillation results are established by using generalized Riccati transformation and a integral average technique under the case of unbounded neutral coefficients. Examples are given to prove the significance of new theorems.