bluuebunny/crossref_metadata_2025 huggingface dataset:
Reduced-Scale Models of Variable Speed Hydro-Electric Plants for Power Hardware-in-the-Loop Real-Time Simulations
Authors: Guo Baoling , Mohamed Amgad , Bacha Seddik , Alamir Mazen , Boudinet Cédric , Pouget Julien
Published: November 2020

Variable Speed Hydro-Electric Plant (VS-HEP) equipped with power electronics has been increasingly introduced into the hydraulic context. This paper is targeting a VS-HEP Power Hardware-In-the-Loop (PHIL) real-time simulation system, which is dedicated to different hydraulic operation schemes tests and control laws validation. Then, a proper hydraulic model will be the key factor for building an efficient PHIL real-time simulation system. This work introduces a practical and generalised modelling hydraulic modelling approach, which is based on ‘Hill Charts’ measurements provided by industrial manufacturers. The hydraulic static model is analytically obtained by using mathematical optimization routines. In addition, the nonlinear dynamic model of the guide vane actuator is introduced in order to evaluate the effects of the induced dynamics on the electric control performances. Moreover, the reduced-scale models adapted to different laboratory conditions can be established by applying scaling laws. The suggested modelling approach enables the features of decent accuracy, light computational complexity, high flexibility and wide applications for their implementations on PHIL real-time simulations. Finally, a grid-connected energy conversion chain of bulb hydraulic turbine associated with a permanent magnet synchronous generator is chosen as an example for PHIL design and performance assessment.
SEPIC Converter with an LC Regenerative Snubber for EV Applications
Authors: Kasasbeh Abdalkreem , Kelleci Burak , Ozturk Salih Baris , Aksoz Ahmet , Hegazy Omar
Published: November 2020

A Single-Ended Primary-Inductor Converter (SEPIC) converter with an Inductor-Capacitor (LC) regenerative snubber is proposed to reduce Electromagnetic Interference (EMI) for Electric Vehicle (EV) applications. The switching energy is transferred through a capacitor to an inductor which is coupled to SEPIC inductors. This technique reduces the number of components and also returns some of switching energy to SEPIC converter. The mathematical analysis and optimization of LC snubber with respect to number of turns is also presented. Spice simulations and experimental results are provided to verify its performance. The proposed LC regenerative snubber reduces the peak voltage by 16 V on the switching transistor during the switching transient. It is also indicated that 8 dB reduction is achieved in the EMI measurements at ringing frequency and 10 dB reduction at high frequency band.
Functionalization of Silica SBA-15 with [3-(2-Aminoethylamino)Propyl] Trimethoxysilane in Supercritical CO2 Modified with Methanol or Ethanol for Carbon Capture
Authors: Sánchez-Vicente Yolanda , Stevens Lee , Pando Concepción , Cabañas Albertina
Published: November 2020

The CO2 adsorption process using amine-grafted silica is a promising technology for reducing the CO2 emissions from the power and industry sectors. In this work, silica SBA-15 was functionalized using [3-(2-aminoethylamino)propyl] trimethoxysilane (AEAPTS) in supercritical CO2 (scCO2) modified with 10% mol methanol or ethanol. The functionalization experiments were carried out at 323 K and 12.5 MPa, and with reaction times of 2 and 3 h. The molar fraction of AEAPTS in scCO2 plus 10% mol alcohol ranged from 0.5 × 10−3 to 1.8 × 10−3. It was found that as the molar fraction of AEAPTS increased, the amino-grafting density steadily rose, and the pore volume, surface area and pore size of the functionalized silica SBA-15 also decreased gradually. The scCO2 functionalization method was compared to the traditional toluene method. The diamine-SBA-15 prepared in the scCO2 process shows a slightly lower amine-grafting density but a higher surface area and pore volume than the ones obtained using the traditional method. Finally, the excess CO2 adsorption capacity of the materials at different temperatures and low pressure was measured. The diamine-silica SBA-15 displayed moderate excess CO2 adsorption capacities, 0.7–0.9 mmol∙g−1, but higher amine efficiency, ca. 0.4, at 298 K, due to the chemisorption of CO2. These findings show that diamine-grafted silica for post-combustion capture or direct air capture can be obtained using a media more sustainable than organic solvents.
A Controller for Optimum Electrical Power Extraction from a Small Grid-Interconnected Wind Turbine
Authors: García-Sánchez Tania , Mishra Arbinda Kumar , Hurtado-Pérez Elías , Puché-Panadero Rubén , Fernández-Guillamón Ana
Published: November 2020

Currently, wind power is the fastest-growing means of electricity generation in the world. To obtain the maximum efficiency from the wind energy conversion system, it is important that the control strategy design is carried out in the best possible way. In fact, besides regulating the frequency and output voltage of the electrical signal, these strategies should also extract energy from wind power at the maximum level of efficiency. With advances in micro-controllers and electronic components, the design and implementation of efficient controllers are steadily improving. This paper presents a maximum power point tracking controller scheme for a small wind energy conversion system with a variable speed permanent magnet synchronous generator. With the controller, the system extracts optimum possible power from the wind speed reaching the wind turbine and feeds it to the grid at constant voltage and frequency based on the AC–DC–AC conversion system. A MATLAB/SimPowerSystems environment was used to carry out the simulations of the system. Simulation results were analyzed under variable wind speed and load conditions, exhibiting the performance of the proposed controller. It was observed that the controllers can extract maximum power and regulate the voltage and frequency under such variable conditions. Extensive results are included in the paper.
Development and Application of a Flexible Modeling Approach to Reference Buildings for Energy Analysis
Authors: Kwak Younghoon , Kang Jeonga , Mun Sun-Hye , Jeong Young-Sun , Huh Jung-Ho
Published: November 2020

This paper proposes a flexible modeling approach to develop a theoretical reference building (RB) for energy analysis. We designed an RB for five non-residential buildings, using dynamic simulation from statistically analyzed data of building stock in South Korea. For modeling, four subsets of data—form, envelope, system, and operation—were assessed. This study uses the autosizing function within EnergyPlus, to develop the RB. The proposed approach allows for a flexible design where capacities and flow rates of the heating, ventilation, and air-conditioning (HVAC) system match the newly defined RB model. This approach would be ideal for closing the gap between the architectural data and equipment elements. The RB developed in this study allows for performing energy performance analysis by end-use. The analysis results by the end-use can provide support for country-level greenhouse gas (GHG)-mitigation-strategy development.
Modeling of Working Machines Synergy in the Process of the Hybrid Electric Vehicle Acceleration
Authors: Prajwowski Konrad , Golebiewski Wawrzyniec , Lisowski Maciej , Abramek Karol F. , Galdynski Dominik
Published: November 2020

There are many different mathematical models that can be used to describe relations between energy machines in the power-split hybrid drive system. Usually, they are created based on simulations or measurements in bench (laboratory) conditions. In that sense, however, these are the idealized conditions. It is not known how the internal combustion engine and electrical machines work in real road conditions, especially during acceleration. This motivated the authors to set the goal of solving this research problem. The solution was to implement and develop the model predictive control (MPC) method for driving modes (electric, normal) of a hybrid electric vehicle equipped with a power-split drive system. According to the adopted mathematical model, after determining the type of model and its structure, the measurements were performed. There were carried out as road tests in two driving modes of the hybrid electric vehicle: electric and normal. The measurements focused on the internal combustion engine and electrical machines parameters (torque, rotational speed and power), state of charge of electrochemical accumulator system and equivalent fuel consumption (expressed as a cost function). The operating parameters of the internal combustion engine and electric machines during hybrid electric vehicle acceleration assume the maximum values in the entire range (corresponding to the set vehicle speeds). The process of the hybrid electric vehicle acceleration from 0 to 47 km/h in the electric mode lasted for 12 s and was transferred into the equivalent fuel consumption value of 5.03 g. The acceleration of the hybrid electric vehicle from 0 to 47 km/h in the normal mode lasted 4.5 s and was transferred to the value of 4.23 g. The hybrid electric vehicle acceleration from 0 to 90 km/h in the normal mode lasted 11 s and corresponded to the cost function value of 26.43 g. The presented results show how the fundamental importance of the hybrid electric vehicle acceleration process with a fully depressed gas pedal is (in these conditions the selected driving mode is a little importance).
Olive Oil: Processing Characterization, and Health Benefits
Authors: Boskou Dimitrios , Clodoveo Maria Lisa
Published: November 2020

The Mediterranean diet is now well known worldwide and recognized as a nutrition reference model by the World Health Organization. Virgin olive oil, prepared from healthy and intact fruits of the olive tree only by mechanical means, is a basic ingredient, a real pillar of this diet. Its positive role in health has now been a topic of universal concern. The virtues of natural olive oil, and especially of extra virgin olive oil, are related to the quality of the fruits, the employment of advanced technologies, and the availability of sophisticated analytical techniques that are used to control the origin of the fruits and guarantee the grade of the final product. With the aim of enriching the recent multidisciplinary scientific information that orbits around this healthy lipid source, a new special issue of Foods journal has been published.
Global Prevalence of Macroprolactinemia among Patients with Hyperprolactinemia: A Systematic Review and Meta-Analysis
Authors: Che Soh Noor Azlin Azraini , Yaacob Najib Majdi , Omar Julia , Mohammed Jelani Aniza , Shafii Noorazliyana , Tuan Ismail Tuan Salwani , Wan Azman Wan Norlina , Ghazali Anis Kausar
Published: November 2020

Hyperprolactinemia (hPRL) often poses a diagnostic dilemma due to the presence of macroprolactin. Understanding the prevalence of macroprolactinemia (mPRL) has an important implication in managing patients with hPRL. The primary aim of this study was to determine the prevalence of mPRL globally and to explore selected factors influencing the prevalence estimate. Studies with original data related to the prevalence of mPRL among patients with hPRL from inception to March 2020 were identified, and a random effects meta-analysis was performed. Of the 3770 records identified, 67 eligible studies from 27 countries were included. The overall global prevalence estimate was 18.9% (95% CI: 15.8%, 22.1%) with a substantial statistical heterogeneity (I2 = 95.7%). The highest random effects pooled prevalence was observed in the African region (30.3%), followed by Region of the Americas (29.1%), European (17.5%), Eastern Mediterranean (13.9%), South-East Asian (12.7%), and Western Pacific Region (12.6%). Lower prevalence was observed in studies involving both sexes as compared to studies involving only female participants (17.1% vs. 25.4%) and in more recent studies (16.4%, 20.4%, and 26.5% in studies conducted after 2009, between 2000 and 2009, and before 2000, respectively). The prevalence estimate does not vary according to the age group of study participants, sample size, and types of polyethylene glycol (PEG) used for detection of macroprolactin (PEG 6000 or PEG 8000). With macroprolactin causing nearly one-fifth of hPRL cases, screening for mPRL should be made a routine before an investigation of other causes of hPRL.
Physical Activity, Resilience, Sense of Coherence and Coping in People with Multiple Sclerosis in the Situation Derived from COVID-19
Authors: Reguera-García María Mercedes , Liébana-Presa Cristina , Álvarez-Barrio Lorena , Alves Gomes Lisa , Fernández-Martínez Elena
Published: November 2020

The confinement forced by COVID-19 can have repercussions on the health of people diagnosed with multiple sclerosis. The objective of this study is to analyze the relationships between physical activity, a sense of coherence, resilience and coping among people diagnosed with Multiple Sclerosis during the health emergency situation. To achieve this goal, this transversal descriptive study included 84 patients that belonged to multiple sclerosis associations during the period of confinement. Participants filled out the Physical Activity (IPAQ-SF), Sense of Coherence (SOC-13), Resilience Scale (ER-14) and coping (COPE-28) questionnaires. The results showed that the average age was 46.9 and that 67.9% had Relapsing Remittent Multiple Sclerosis diagnosed on average 13.9 years ago. They had a high degree (33.3%) and moderate degree (34.5%) of physical activity, high levels of resilience, while the level of a sense of coherence was average and the most commonly used strategies for coping were active confrontation and religion. Physical activity was not related to the rest of the studied variables, but there were correlations between the other variables. The people with multiple sclerosis who belong to patient associations have remained physically active during the obligatory confinement period and have elevated degrees of resilience and an average sense of coherence, as well as using suitable coping strategies, which is why the social-health resource of belonging to a patient association could be boosting these variables that are beneficial to their health.
Consumers’ Implicit and Explicit Recall, Understanding and Perceptions of Products with Nutrition-Related Messages: An Online Survey
Authors: Franco-Arellano Beatriz , Vanderlee Lana , Ahmed Mavra , Oh Angela , L’Abbé Mary R.
Published: November 2020

This study aimed to assess consumers’ implicit and explicit recall, understanding and perceptions of products with a nutrition claim and a symbol depicting ‘health,’ and to determine whether these perceptions differed among Nutrition Facts table (NFt) users vs. nonusers. In an online survey, participants (n = 1997) were randomized to one of eight conditions in a 2 × 2 × 2 factorial design, consisting of a label with a claim (present/absent) a heart-shaped symbol depicting ‘health’ (present/absent) for a healthier or less healthy soup. Participants were shown a label for 10 s and asked whether they recalled seeing a claim. If participants answered yes, they were then asked to describe their response using open-ended questions. Participants also rated the product’s perceived nutritional quality and purchase intentions using seven-point Likert scales. In the claim condition, most participants (75%) were able to recall the presence of a claim, while 12% incorrectly mentioned the presence of a claim when there was none. Claims likely attracted consumers’ attention and increased perceived nutritional quality, although with limited influence among NFt users (23%). The symbol depicting ‘health’ did not enhance perceived nutritional quality or purchase intentions. Although most participants (77%) made their decisions implicitly using the front of labels, those who used the NFt had a better understanding of the nutritional quality of products.
Effects of a 12-Week Change-of-Direction Sprints Training Program on Selected Physical and Physiological Parameters in Professional Basketball Male Players
Authors: Brini Seifeddine , Ben Abderrahman Abderraouf , Boullosa Daniel , Hackney Anthony C. , Zagatto Alessandro Moura , Castagna Carlo , Bouassida Anissa , Granacher Urs , Zouhal Hassane
Published: November 2020

Multidirectional repeated sprints with quick changes-of-direction (CoD) are considered a key performance determinant in basketball. The objective of this study was to investigate the effects of a 12-week CoD sprint training program compared to regular basketball training on selected measures of physical fitness and physiological adaptations in male basketball players. Sixteen professional basketball players were randomly assigned to an intervention group (INT = 8) or an active control group (CON = 8). INT completed a 12-week CoD sprint training program with two sessions per week while CON continued their regular training. Training volume was similar between groups. Before and after the intervention, the two groups were evaluated for the repeated sprint ability test with CoD (IRSA5COD), the squat jump (SJ) and countermovement jump (CMJ) test, the five time-jump test (FJT) and change of direction t-test. Blood samples were taken before the beginning of the experimental protocol, after 4, 8 and 12 weeks to monitor the testosterone/cortisol ratio (T/C). For t-test, post-hoc tests revealed significant pre-to-post improvements for INT (3.4%; p = 0.001, ES = 0.91). For CMJ, post-hoc tests revealed a significant pre-to-post decrease for INT (−11.6%; p = 0.001, ES = 0.94), and a significant improvement for CON (4.96%; p = 0.014, ES = 0.60). For T/C ratio, post-hoc tests revealed a significant decrease after 12 weeks of training for INT (52.3%; p < 0.001; ES = 0.63). In conclusion, twelve weeks of CoD sprint training enhanced CoD performance but negatively affected vertical jump capacity in male basketball players. T/C ratio indicated that the physiological demands associated with INT were well-balanced.
Characteristics of Early Mother–Infant and Father–Infant Interactions: A Comparison between Assisted Reproductive Technology and Spontaneous Conceiving Parents
Authors: Agostini Francesca , Andrei Federica , Neri Erica , Trombini Elena , Nuccini Francesca , Villani Maria Teresa , Aguzzoli Lorenzo , Paterlini Marcella
Published: November 2020

This study aims to describe parents’ and infant’s interactive styles after assisted reproduction treatments (ART), to compare them with parent–infant interactions after spontaneous conception (SC), and to assess the effect of specific ART variables (cause of infertility, treatment type, and previous ART attempts) on interaction quality. The sample included 25 ART conceiving couples and 31 SC couples with their 3-months-old babies. Free parent–infant interactions (3–5 min) were coded using the CARE-Index, a video-based assessment scale that gives both dimensional (e.g., sensitivity, control, passivity) and categorical scores (sensitive, inept, at-risk) for parents and infants. Results showed a global similarity between groups in CARE-Index dimensions. Nevertheless, differences emerged in categorical scores, as the interactive patterns of ART parents were more frequently classified as “inept” and “at-risk” compared to SC parents. With regards to ART dyads only, infants conceived through intracytoplasmic sperm injection scored significantly lower to the dimension compulsivity and higher to passivity, compared to infants conceived through in vitro fertilization. Yet, infants conceived at the first ART cycle had significantly lower levels of difficulty than infants conceived after one ART attempt. These results speak about the existence of important parent–infant interactive differences related to conception modality and ART technique and suggest the need to implement support programs to promote more sensitive parenting styles.
Trajectories of Depressive Symptoms among Multicultural Adolescents in Korea: Longitudinal Analysis Using Latent Class Growth Model
Authors: Song Min Kyung , Yoon Ju Young , Kim Eunjoo
Published: November 2020

The purpose of this study was to investigate the trajectory of depressive symptoms in multicultural adolescents using longitudinal data, and to identify predictive factors related to depressive symptoms of multicultural adolescents using latent class analysis. We used six time-point data derived from the 2012 to 2017 Multicultural Adolescents Panel Study (MAPS). Latent growth curve modeling was used to assess the overall features of depressive symptom trajectories in multicultural adolescents, and latent class growth modeling was used to determine the number and shape of trajectories. We applied multinomial logistic regression analysis to each class to explore predictive factors. We found that the overall slope of depressive symptoms in multicultural adolescents increased. Latent class analysis demonstrated three classes: (1) high-increasing class (i.e., high intercept, significantly increasing slope), (2) moderate-increasing class (i.e., moderate intercept, significantly increasing slope), and (3) low-stable class (i.e., low intercept, no significant slope). In particular, we found that the difference in the initial intercept of depressive symptoms determined the subsequent trajectory. There is a need for early screening for depressive symptoms in multicultural adolescents and preparing individual mental health care plans.
A Novel Indoor Structure Extraction Based on Dense Point Cloud
Authors: Shi Pengcheng , Ye Qin , Zeng Lingwen
Published: November 2020

Herein, we propose a novel indoor structure extraction (ISE) method that can reconstruct an indoor planar structure with a feature structure map (FSM) and enable indoor robot navigation using a navigation structure map (NSM). To construct the FSM, we first propose a two-staged region growing algorithm to segment the planar feature and to obtain the original planar point cloud. Subsequently, we simplify the planar feature using quadtree segmentation based on cluster fusion. Finally, we perform simple triangulation in the interior and vertex-assignment triangulation in the boundary to accomplish feature reconstruction for the planar structure. The FSM is organized in the form of a mesh model. To construct the NSM, we first propose a novel ground extraction method based on indoor structure analysis under the Manhattan world assumption. It can accurately capture the ground plane in an indoor scene. Subsequently, we establish a passable area map (PAM) within different heights. Finally, a novel-form NSM is established using the original planar point cloud and the PAM. Experiments are performed using three public datasets and one self-collected dataset. The proposed plane segmentation approach is evaluated on two simulation datasets and achieves a recall of approximately 99%, which is 5% higher than that of the traditional plane segmentation method. Furthermore, the triangulation performance of our method compared with the traditional greedy projection triangulation show that our method performs better in terms of feature representation. The experimental results reveal that our ISE method is robust and effective for extracting indoor structures.
Visitor Flows at a Large-Scale Cultural Event: GPS Tracking at Dutch Design Week
Authors: Dane Gamze , Borgers Aloys , Kaya Deniz Ikiz , Feng Tao
Published: November 2020

Large-scale cultural events bring many economic, social, and cultural benefits to the hosting cities. Although event producers aim to satisfy the visitors’ needs, they do not usually receive feedback on visitors’ experiences. Moreover, lack of spatial dispersal of visitors might result in less visibility for some activities and locations. An understanding of visitors’ spatial and temporal behavior and the factors influencing visitors’ intra-event destination choices is key to efficient and successful event management and future planning. In this article, we examine the relationship between visitors’ spatial and temporal behavior, the spatial structure of the host city, and visitor characteristics. In order to do this, data are collected from 281 event visitors by means of GPS tracking and paper surveys at the Dutch Design Week (DDW) 2017 event in Eindhoven, the Netherlands. Data are used to understand the area of interest locations, visitor flows, visitor clusters and area of interest choices by applying data processing, network analysis, cluster analysis and bivariate analysis. The results show that one of the three dedicated event areas was considerably less popular by the DDW visitors. Moreover, the choice of intra-event destination locations and areas depended mainly on temporal constraints of the visitors. The findings of this study can inform future event planning and management policies in hosting cities.
Rescue Potential of Supportive Embryo Culture Conditions on Bovine Embryos Derived from Metabolically Compromised Oocytes
Authors: Smits Anouk , Leroy Jo L. M. R. , Bols Peter E. J. , De Bie Jessie , Marei Waleed F. A.
Published: November 2020

Elevated non-esterified fatty acid (NEFA), predominantly palmitic acid (PA), concentrations in blood and follicular fluid are a common feature in maternal metabolic disorders such as obesity. This has a direct negative impact on oocyte developmental competence and the resulting blastocyst quality. We use NEFA-exposure during bovine oocyte in vitro maturation (IVM) as a model to mimic oocyte maturation under maternal metabolic stress conditions. However, the impact of supportive embryo culture conditions on these metabolically compromised zygotes are not known yet. We investigated if the addition of anti-apoptotic, antioxidative and mitogenic factors (namely, Insulin-Transferrin-Selenium (ITS) or serum) to embryo culture media would rescue development and important embryo quality parameters (cell proliferation, apoptosis, cellular metabolism and gene expression patterns) of bovine embryos derived from high PA- or high NEFA-exposed oocytes when compared to controls (exposed to basal NEFA concentrations). ITS supplementation during in vitro culture of PA-exposed oocytes supported the development of lower quality embryos during earlier development. However, surviving blastocysts were of inferior quality. In contrast, addition of serum to the culture medium did not improve developmental competence of PA-exposed oocytes. Furthermore, surviving embryos displayed higher apoptotic cell indices and an aberrant cellular metabolism. We conclude that some supportive embryo culture supplements like ITS and serum may increase IVF success rates of metabolically compromised oocytes but this may increase the risk of reduced embryo quality and may thus have other long-term consequences.
Molecular Interaction of Protein-Pigment C-Phycocyanin with Bovine Serum Albumin in a Gomphosis Structure Inhibiting Amyloid Formation
Authors: Luo Yi-Cong , Jing Pu
Published: November 2020

Accumulation of amyloid fibrils in organisms accompanies many diseases. Natural extracts offer an alternative strategy to control the process with potentially fewer side effects. In this study, the inhibition of C-phycocyanin from Spirulina sp. on amyloid formation of bovine serum albumin (BSA) during a 21-day incubation was investigated using fluorescence and circular dichroism (CD), and mechanisms were explored via kinetic fitting and molecular docking. C-phycocyanin (0–50 µg/mL) hindered the amyloid formation process of BSA with increased half-lives (12.43–17.73 days) based on fluorescence intensity. A kinetic model was built and showed that the k1 decreased from 1.820 × 10−2 d−1 to 2.62 × 10−3 d−1 with the increase of C-phycocyanin, while k2 showed no changes, indicating that the inhibition of BSA fibrillation by C-phycocyanin occurred in a spontaneous process instead of self-catalyzed one. CD results show that C-phycocyanin inhibited conformational conversion (α-helices and β-sheets) of BSA from day 6 to day 18. Molecular docking suggested that C-phycocyanin may hinder BSA fibrillation by hydrogen-bonding > 6 of 27 α-helices of BSA in a gomphosis-like structure, but the unblocked BSA α-helices might follow the self-catalytic process subsequently.
Aβ-Induced Damage Memory in hCMEC/D3 Cells Mediated by Sirtuin-1
Authors: Liu Haochen , Zhang Yixuan , Zhang Hong , Xu Sheng , Zhao Huimin , Liu Xiaoquan
Published: November 2020

It is well accepted by the scientific community that the accumulation of beta-amyloid (Aβ) may be involved in endothelial dysfunction during Alzheimer’s disease (AD) progression; however, anti-Aβ anti-bodies, which remove Aβ plaques, do not improve cerebrovascular function in AD animal models. The reasons for these paradoxical results require investigation. We hypothesized that Aβ exposure may cause persistent damage to cerebral endothelial cells even after Aβ is removed (referred to as cerebrovascular endothelial damage memory). In this study, we aimed to investigate whether cerebrovascular endothelial damage memory exists in endothelial cells. hCMEC/D3 cells were treated with Aβ1–42 for 12 h and then Aβ1–42 was withdrawn for another 12 h incubation to investigate whether cerebrovascular endothelial damage memory exists in endothelial cells. A mechanism-based kinetics progression model was developed to investigate the dynamic characters of the cerebrovascular endothelial damage. After Aβ1–42 was removed, the sirt-1 levels returned to normal but the cell vitality did not improve, which suggests that cerebrovascular endothelial damage memory may exist in endothelial cells. Sirt-1 activator SRT2104 and NAD+ (Nicotinamide Adenine Dinucleotide) supplement may dose-dependently relieve the cerebrovascular endothelial damage memory. sirt-1 inhibitor EX527 may exacerbate the cerebrovascular endothelial damage memory. Kinetics analysis suggested that sirt-1 is involved in initiating the cerebrovascular endothelial damage memory; otherwise, NAD+ exhaustion plays a vital role in maintaining the cerebrovascular endothelial damage memory. This study provides a novel feature of cerebrovascular endothelial damage induced by Aβ.
Circulating Tumour Cell Expression of Immune Markers as Prognostic and Therapeutic Biomarkers in Head and Neck Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis
Authors: Payne Karl , Pugh Matthew , Brooks Jill , Batis Nikolaos , Taylor Graham , Nankivell Paul , Mehanna Hisham
Published: November 2020

Rates of loco-regional recurrence and distant metastasis remain high among head and neck squamous cell carcinoma (HNSCC) patients, despite advancing cancer treatment modalities and therapeutic agents. One area that has generated considerable interest is the immune landscape of the tumour, heralding a wave of immune checkpoint inhibitors with notable efficacy in recurrent/metastatic HNSCC patients. However, HNSCC remains poorly served by biomarkers that can direct treatment in a personalised fashion to target the tumour heterogeneity seen between patients. Detection and analysis of circulating tumour cells (CTCs) in HNSCC has provided a previously unseen view of the metastasis forming cells that are potentially contributing to poor clinical outcomes. In particular, identifying CTC expression of phenotypic and druggable protein markers has allowed CTC sub-populations to be defined that hold prognostic value or are potential therapeutic targets themselves. The aim of this systematic review was to examine the role of CTC immune-marker expression as prognostic/therapeutic biomarkers in HNSCC by evaluating progress to date and discussing areas for future research. Our results highlight how few studies have been able to demonstrate prognostic significance of immune-marker expression in CTCs. As expected, the immune checkpoint PD-L1 was the most widely investigated marker. However, no studies evaluated CTC target immune marker expression in immunotherapy cohorts. Despite these findings, the data presented demonstrate promise that CTCs may be a source of future biomarkers for immunotherapy and will provide valuable information regarding the potential immune evasion of these metastasis forming cells.
Molecular Modeling Study of c-KIT/PDGFRα Dual Inhibitors for the Treatment of Gastrointestinal Stromal Tumors
Authors: Keretsu Seketoulie , Ghosh Suparna , Cho Seung Joo
Published: November 2020

Gastrointestinal stromal tumors (GISTs) are the most common Mesenchymal Neoplasm of the gastrointestinal tract. The tumorigenesis of GISTs has been associated with the gain-of-function mutation and abnormal activation of the stem cell factor receptor (c-KIT) and platelet-derived growth factor receptor alpha (PDGFRα) kinases. Hence, inhibitors that target c-KIT and PDGFRα could be a therapeutic option for the treatment of GISTs. The available approved c-KIT/PDGFRα inhibitors possessed low efficacy with off-target effects, which necessitated the development of potent inhibitors. We performed computational studies of 48 pyrazolopyridine derivatives that showed inhibitory activity against c-KIT and PDGFRα to study the structural properties important for inhibition of both the kinases. The derivative of phenylurea, which has high activities for both c-KIT (pIC50 = 8.6) and PDGFRα (pIC50 = 8.1), was used as the representative compound for the dataset. Molecular docking and molecular dynamics simulation (100 ns) of compound 14 was performed. Compound 14 showed the formation of hydrogen bonding with Cys673, Glu640, and Asp810 in c-KIT, and Cys677, Glu644, and Asp836 in PDGFRα. The results also suggested that Thr670/T674 substitution in c-KIT/PDGFRα induced conformational changes at the binding site of the receptors. Three-dimensional quantitative structure–activity relationship (3D-QSAR) models were developed based on the inhibitors. Contour map analysis showed that electropositive and bulky substituents at the para-position and the meta-position of the benzyl ring of compound 14 was favorable and may increase the inhibitory activity against both c-KIT and PDGFRα. Analysis of the results suggested that having bulky and hydrophobic substituents that extend into the hydrophobic pocket of the binding site increases the activity for both c-KIT and PDGFRα. Based on the contour map analysis, 50 compounds were designed, and the activities were predicted. An evaluation of binding free energy showed that eight of the designed compounds have potential binding affinity with c-KIT/PDGFRα. Absorption, distribution, metabolism, excretion and toxicity (ADMET) and synthetic feasibility tests showed that the designed compounds have reasonable pharmaceutical properties and synthetic feasibility. Further experimental study of the designed compounds is recommended. The structural information from this study could provide useful insight into the future development of c-KIT and PDGFRα inhibitors.
Erythrocyte, Platelet, Serum Ferritin, and P-Selectin Pathophysiology Implicated in Severe Hypercoagulation and Vascular Complications in COVID-19
Authors: Venter Chantelle , Bezuidenhout Johannes Andries , Laubscher Gert Jacobus , Lourens Petrus Johannes , Steenkamp Janami , Kell Douglas B. , Pretorius Etheresia
Published: November 2020

Progressive respiratory failure is seen as a major cause of death in severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2)-induced infection. Relatively little is known about the associated morphologic and molecular changes in the circulation of these patients. In particular, platelet and erythrocyte pathology might result in severe vascular issues, and the manifestations may include thrombotic complications. These thrombotic pathologies may be both extrapulmonary and intrapulmonary and may be central to respiratory failure. Previously, we reported the presence of amyloid microclots in the circulation of patients with coronavirus disease 2019 (COVID-19). Here, we investigate the presence of related circulating biomarkers, including C-reactive protein (CRP), serum ferritin, and P-selectin. These biomarkers are well-known to interact with, and cause pathology to, platelets and erythrocytes. We also study the structure of platelets and erythrocytes using fluorescence microscopy (using the markers PAC-1 and CD62PE) and scanning electron microscopy. Thromboelastography and viscometry were also used to study coagulation parameters and plasma viscosity. We conclude that structural pathologies found in platelets and erythrocytes, together with spontaneously formed amyloid microclots, may be central to vascular changes observed during COVID-19 progression, including thrombotic microangiopathy, diffuse intravascular coagulation, and large-vessel thrombosis, as well as ground-glass opacities in the lungs. Consequently, this clinical snapshot of COVID-19 strongly suggests that it is also a true vascular disease and considering it as such should form an essential part of a clinical treatment regime.
Transcriptional Effects of Psychoactive Drugs on Genes Involved in Neurogenesis
Authors: Bortolasci Chiara C. , Spolding Briana , Kidnapillai Srisaiyini , Connor Timothy , Truong Trang T.T. , Liu Zoe S.J. , Panizzutti Bruna , Richardson Mark F. , Gray Laura , Berk Michael , Dean Olivia M. , Walder Ken
Published: November 2020

Although neurogenesis is affected in several psychiatric diseases, the effects and mechanisms of action of psychoactive drugs on neurogenesis remain unknown and/or controversial. This study aims to evaluate the effects of psychoactive drugs on the expression of genes involved in neurogenesis. Neuronal-like cells (NT2-N) were treated with amisulpride (10 µM), aripiprazole (0.1 µM), clozapine (10 µM), lamotrigine (50 µM), lithium (2.5 mM), quetiapine (50 µM), risperidone (0.1 µM), or valproate (0.5 mM) for 24 h. Genome wide mRNA expression was quantified and analysed using gene set enrichment analysis, with the neurogenesis gene set retrieved from the Gene Ontology database and the Mammalian Adult Neurogenesis Gene Ontology (MANGO) database. Transcription factors that are more likely to regulate these genes were investigated to better understand the biological processes driving neurogenesis. Targeted metabolomics were performed using gas chromatography-mass spectrometry. Six of the eight drugs decreased the expression of genes involved in neurogenesis in both databases. This suggests that acute treatment with these psychoactive drugs negatively regulates the expression of genes involved in neurogenesis in vitro. SOX2 and three of its target genes (CCND1, BMP4, and DKK1) were also decreased after treatment with quetiapine. This can, at least in part, explain the mechanisms by which these drugs decrease neurogenesis at a transcriptional level in vitro. These results were supported by the finding of increased metabolite markers of mature neurons following treatment with most of the drugs tested, suggesting increased proportions of mature relative to immature neurons consistent with reduced neurogenesis.
Neurogranin and VILIP-1 as Molecular Indicators of Neurodegeneration in Alzheimer’s Disease: A Systematic Review and Meta-Analysis
Authors: Dulewicz Maciej , Kulczyńska-Przybik Agnieszka , Mroczko Barbara
Published: November 2020

Neurogranin (Ng) and visinin-like protein 1 (VILIP-1) are promising candidates for Alzheimer’s Disease (AD) biomarkers closely related to synaptic and neuronal degeneration. Both proteins are involved in calcium-mediated pathways. The meta-analysis was performed in random effects based on the ratio of means (RoM) with calculated pooled effect size. The diagnostic utility of these proteins was examined in cerebrospinal fluid (CSF) of patients in different stages of AD compared to control (CTRL). Ng concentration was also checked in various groups with positive (+) and negative (-) amyloid beta (Aβ). Ng highest levels of RoM were observed in the AD (n = 1894) compared to CTRL (n = 2051) group (RoM: 1.62). Similarly, the VILIP-1 highest values of RoM were detected in the AD (n = 706) compared to CTRL (n = 862) group (RoM: 1.34). Concentrations of both proteins increased in more advanced stages of AD. However, Ng seems to be an earlier biomarker for the assessment of cognitive impairment. Ng appears to be related with amyloid beta, and the highest levels of Ng in CSF was observed in the group with pathological Aβ+ status. Our meta-analysis confirms that Ng and VILIP-1 can be useful CSF biomarkers in differential diagnosis and monitoring progression of cognitive decline. Although, an additional advantage of the protein concentration Ng is the possibility of using it to predict the risk of developing cognitive impairment in normal controls with pathological levels of Aβ1-42. Analyses in larger cohorts are needed, particularly concerning Aβ status.
New Coordination Polymers of Zinc(II), Copper(II) and Cadmium(II) with 1,3-Bis(1,2,4-triazol-4-yl)adamantane
Authors: Xhaferaj Nertil , Tăbăcaru Aurel , Moroni Marco , Senchyk Ganna A. , Domasevitch Kostiantyn V. , Pettinari Claudio , Galli Simona
Published: November 2020

The new coordination polymers (CPs) [Zn(tr2ad)Cl2]n, {[Cu(tr2ad)Cl]Cl∙4H2O}n, [Cd2(tr2ad)Cl4]n, {[Cu(tr2ad)(NO3)](NO3)}n and {[Cd(tr2ad)(NO3)](NO3)∙H2O}n were obtained in the form of air- and moisture-stable microcrystalline powders by the solvothermal reactions of zinc(II), copper(II) and cadmium(II) chlorides or nitrates with the ligand 1,3-bis(1,2,4-triazol-4-yl)adamantane (tr2ad). Investigation of the thermal behaviour assessed the thermal stability of these CPs, with [Cd2(tr2ad)Cl4]n starting to decompose only around 365 °C. As retrieved by powder X-ray diffraction, while [Zn(tr2ad)Cl2]n features 1-D chains along which the metal centre shows a tetrahedral geometry and the spacer is exo-bidentate, the other CPs contain 2-D double-layers in which the metal ions possess an octahedral stereochemistry and the linker is exo-tetradentate. A comparative structural analysis involving known coordination compounds containing the tr2ad ligand enabled us to disclose (i) the versatility of the ligand, as far as the coordination modes are concerned; (ii) the variability in crystal structure dimensionality, ranging from 1-D to 3-D; (iii) the fact that, to the best of our knowledge, [Zn(tr2ad)Cl2]n is the first ZnII-based CP containing the tr2ad spacer.
Application of Tagged Neutron Method for Detecting Diamonds in Kimberlite
Authors: Rogov Yury , Kremenets Vladislav , Sapozhnikov Mikhail , Sebele Motswakae
Published: November 2020

The results of testing a prototype of a separator for detecting diamonds in kimberlite ore using tagged neutron method are discussed. Kimberlite ore was irradiated with fast tagged neutrons with an energy of 14.1 MeV. The elemental content of the tray with kimberlite ore was determined. The criterion for detecting diamond was the presence of excess carbon concentration in a certain region of a kimberlite sample.
Factors Associated with Ineffectiveness of Sildenafil Treatment in Patients with End-Stage Heart Failure and Elevated Pulmonary Vascular Resistance
Authors: Szczurek Wioletta , Gąsior Mariusz , Skrzypek Michał , Romuk Ewa , Szyguła-Jurkiewicz Bożena
Published: November 2020

Introduction: Elevated pulmonary vascular resistance (PVR) unresponsive to vasodilator treatment is a marker of heart failure (HF) severity, and an important predictor of poor results of heart transplantation (HT). Objective: We sought to analyze factors associated with ineffectiveness of sildenafil treatment in end-stage HF patients with elevated PVR with particular emphasis placed on tenascin-C (TNC) serum concentrations. Patients and Methods: The study is an analysis of 132 end-stage HF patients referred for HT evaluation in the Cardiology Department between 2015 and 2018. TNC was measured by sandwich enzyme-linked immunosorbent assay (Human TNC, SunRedBio Technology, Shanghai, China). The endpoint was PVR > 3 Wood units after the six-month sildenafil therapy. Results: The median age was 58 years, and 90.2% were men. PVR >3 Wood units after 6 months of sildenafil treatment were found in 36.6% patients. The multivariable logistic regression analysis confirmed that TNC (OR = 1.004 (1.002–1.006), p = 0.0003), fibrinogen (OR= 1.019 (1.005–1.033), p = 0.085), creatinine (OR =1.025 (1.004–1.047), p = 0.0223) and right ventricular end-diastolic dimension (RVEDd) (OR = 1.279 (1.074–1.525), p = 0.0059) were independently associated with resistance to sildenafil treatment. Area under the ROC curves indicated an acceptable power of TNC (0.9680 (0.9444–0.9916)), fibrinogen (0.8187 (0.7456–0.8917)) and RVEDd (0.7577 (0.6723–0.8431)), as well as poor strength of creatinine (0.6025 (0.4981–0.7070)) for ineffectiveness of sildenafil treatment. Conclusions: Higher concentrations of TNC, fibrinogen and creatinine, as well as a larger RVEDd are independently associated with the ineffectiveness of sildenafil treatment. TNC has the strongest predictive power, sensitivity and specificity for evaluation of resistance to sildenafil treatment.
Estimation Method of Interpass Time for the Control of Temperature during a Directed Energy Deposition Process of a Ti–6Al–4V Planar Layer
Authors: Chua Bih-Lii , Ahn Dong-Gyu
Published: November 2020

Directed energy deposition (DED) provides a promising additive manufacturing method to fabricate and repair large metallic parts. However, it may suffer from excessive heat accumulation due to a high build rate, particularly during a wire feeding-type DED process. The implementation of interpass time in between two depositions of beads plays an important process role to passively control the interpass temperature. In this study, a method to estimate the proper interpass time using regression analysis from heat transfer finite element analysis is proposed for maintaining the interpass temperature during a wire feeding-type DED deposition of a planar layer. The overlapping beads of a planar layer are estimated using a polygonal-shaped bead profile in the finite element model. From the estimated proper interpass time, a selected proper interpass time scheme (PITS) is suggested for practical implementation. The selected PITS is applied in a thermo-mechanical finite element model to evaluate the temperature distribution and its effects on the depth of the melt pool, the depth of the heat-affected zone (HAZ), displacement, and residual stresses. By comparing the predicted results with those using a constant interpass time scheme (CITS), the selected PITS shows better control in reducing the depths of the melt pool and HAZ without severely inducing large displacement and residual stresses.
Coupled Preparation of Ferronickel and Cementitious Material from Laterite Nickel Ores
Authors: Shi Ruimeng , Li Xiaoming , Cui Yaru , Zhao Junxue , Zou Chong , Qiu Guibao
Published: November 2020

Nickel slags can be produced through ferronickel preparation by the pyrometallurgical processing of laterite nickel ores; however, such techniques are underutilized at present, and serious environmental problems arise from the stockpiling of such nickel ores. In this study, a modification to the process of ferronickel preparation by the direct reduction of carbon bases in laterite nickel ores is proposed. The gangue from the ore is used as a raw material to prepare a cementitious material, with the main components of tricalcium silicate and tricalcium aluminate. By using FactSage software, thermodynamic calculations are performed to analyze the reduction of nickel and iron and the effect of reduction on the formation of tricalcium silicate and tricalcium aluminate. The feasibility of a coupled process to prepare ferronickel and cementitious materials by the direct reduction of laterite nickel ore and gangue calcination, respectively, is discussed under varying thermodynamic conditions. Different warming strategies are applied to experimentally verify the coupled reactions. The coupled preparation of ferronickel and cementitious materials with calcium silicate and calcium aluminate as the main phases in the same experimental process is realized.