bluuebunny/crossref_metadata_2025 huggingface dataset:
The UV Effect on the Chemiresistive Response of ZnO Nanostructures to Isopropanol and Benzene at PPM Concentrations in Mixture with Dry and Wet Air
Authors: Solomatin Maksim A. , Glukhova Olga E. , Fedorov Fedor S. , Sommer Martin , Shunaev Vladislav V. , Varezhnikov Alexey S. , Nasibulin Albert G. , Ushakov Nikolay M. , Sysoev Victor V.
Published: July 2021

Towards the development of low-power miniature gas detectors, there is a high interest in the research of light-activated metal oxide gas sensors capable to operate at room temperature (RT). Herein, we study ZnO nanostructures grown by the electrochemical deposition method over Si/SiO2 substrates equipped by multiple Pt electrodes to serve as on-chip gas monitors and thoroughly estimate its chemiresistive performance upon exposing to two model VOCs, isopropanol and benzene, in a wide operating temperature range, from RT to 350 °C, and LED-powered UV illumination, 380 nm wavelength; the dry air and humid-enriched, 50 rel. %, air are employed as a background. We show that the UV activation allows one to get a distinctive chemiresistive signal of the ZnO sensor to isopropanol at RT regardless of the interfering presence of H2O vapors. On the contrary, the benzene vapors do not react with UV-illuminated ZnO at RT under dry air while the humidity’s appearance gives an opportunity to detect this gas. Still, both VOCs are well detected by the ZnO sensor under heating at a 200–350 °C range independently on additional UV exciting. We employ quantum chemical calculations to explain the differences between these two VOCs’ interactions with ZnO surface by a remarkable distinction of the binding energies characterizing single molecules, which is −0.44 eV in the case of isopropanol and −3.67 eV in the case of benzene. The full covering of a ZnO supercell by H2O molecules taken for the effect’s estimation shifts the binding energies to −0.50 eV and −0.72 eV, respectively. This theory insight supports the experimental observation that benzene could not react with ZnO surface at RT under employed LED UV without humidity’s presence, indifference to isopropanol.
Anethum graveolens Prevents Liver and Kidney Injury, Oxidative Stress and Inflammation in Mice Exposed to Nicotine Perinatally
Authors: Ajarem Jamaan , Maodaa Saleh , El-Serehy Hamed , Altoom Naif , Allam Ahmed , Hernandez-Bautista Rene , Mahmoud Ayman
Published: July 2021

Perinatal exposure to nicotine imbalances the redox status in newborns. This study investigated the effect of Anethum graveolens (dill) extract on oxidative stress and tissue injury in the liver and kidney of mice newborns exposed to nicotine perinatally. Pregnant mice received nicotine (0.25 mg/kg) on gestational day 12 to day 5 after birth and/or A. graveolens extract on gestational day 1 to day 15 after birth. Newborn mice exposed to nicotine showed multiple histopathological alterations in the kidney and liver, including inflammatory cell infiltration and degenerative changes. Nicotine exposure increased hepatic and renal reactive oxygen species (ROS), lipid peroxidation, tumor necrosis factor (TNF-α), interleukin-6 (IL-6) and inducible nitric oxide synthase (iNOS) (p < 0.001), and decreased antioxidant defenses (p < 0.001). A. graveolens supplementation significantly prevented liver and kidney injury, suppressed ROS generation (p < 0.001), lipid peroxidation (p < 0.001) and inflammatory response (p < 0.001), and enhanced antioxidant defenses. In addition, A. graveolens upregulated hepatic and renal Nrf2 and HO-1 mRNA and increased HO-1 activity in normal and nicotine-exposed mice. In conclusion, A. graveolens protects against perinatal nicotine-induced oxidative stress, inflammation and tissue injury in the liver and kidney of newborn mice. A. graveolens upregulated hepatic and renal Nrf2/HO-1 signaling and enhanced antioxidant defenses in mice.
Corrosion Resistance of Epoxy Coatings Modified by Bis-Silane Prepolymer on Aluminum Alloy
Authors: Zeng Diping , Liu Zhiyi , Zou Lihua , Wu Haijiang
Published: July 2021

In this communication, a bis-silane prepolymer was used to modify epoxy resin, aiming to enhance the corrosion resistance of epoxy coatings on aluminum alloy substrates. The bis-silane prepolymer was prepared by tetraethoxysilane (TEOS) and γ-glycidoxypropyl trimethoxysilane (GPTMS). The corrosion behavior of silane-epoxy coatings was studied. Compared with silane monomer-modified epoxy coatings, bis-silane-modified epoxy coatings have lower coating capacitance (Cc), higher charge transfer resistances (Rdl), and lower double layer capacitance (Cdl) during long-time immersion. It indicates that bis-silane-modified epoxy coating has stronger waterproof permeability and substrate corrosion protection ability. In addition, due to the leaching of the silane component and cross-linking reaction between different silanes during the immersion process, the bis-silane-modified epoxy coatings exhibit much stronger “self-healing” ability.
Isothermal Oxidation Performance of Laser Cladding Assisted with Preheat (LCAP) Tribaloy T-800 Composite Coatings Deposited on EN8
Authors: Nyadongo Sipiwe Trinity , Pityana Sisa Lesley , Olakanmi Eyitayo Olatunde
Published: July 2021

It is anticipated that laser cladding assisted with preheat (LCAP)-deposited Tribaloy (T-800) composite coatings enhances resistance to structural degradation upon exposure to elevated-temperature oxidation service environments. The oxidation kinetics of LCAP T-800 composite coatings deposited on EN8 substrate and its mechanisms have not been explored in severe conditions that are similar to operational parameters. The isothermal oxidation behaviour of the T-800 composite coating deposited on EN8 via LCAP was studied at 800 °C in air for up to 120 h (5 × 24 h cycles) and contrasted to that of uncoated samples. The mass gain per unit area of the coating was eight times less than that of the uncoated EN8 substrate. The parabolic rate constant (Kp) for EN8 was 6.72 × 10−12 g2·cm−4·s−1, whilst that for the T-800 composite coating was 8.1 × 10−13 g2·cm−4·s−1. This was attributed to a stable chromium oxide (Cr2O3) layer that formed on the coating surface, thereby preventing further oxidation, whilst the iron oxide film that formed on the EN8 substrate allowed the permeation of the oxygen ions into the oxide. The iron oxide (Fe2O3) film that developed on EN8 spalled, as evidenced by the cracking of oxide when the oxidation time was greater than 72 h, whilst the Cr2O3 film maintained its integrity up to 120 h. A parabolic law was observed by the T-800 composite coating, whilst a paralinear law was reported for EN8 at 800 °C up to 120 h. This coating can be used in turbine parts where temperatures are <800 °C.
Application of Machine Learning to Solid Particle Erosion of APS-TBC and EB-PVD TBC at Elevated Temperatures
Authors: Liu Yuan , Ravichandran Ravi , Chen Kuiying , Patnaik Prakash
Published: July 2021

Machine learning (ML) and deep learning (DL) for big data (BD) management are currently viable approaches that can significantly help in high-temperature materials design and development. ML-DL can accumulate knowledge by learning from existing data generated through multi-physics modelling (MPM) and experimental tests (ETs). DL mainly involves analyzing nonlinear correlations and high-dimensional datasets implemented through specifically designed numerical algorithms. DL also makes it possible to learn from new data and modify predictive models over time, identifying anomalies, signatures, and trends in machine performance, develop an understanding of patterns of behaviour, and estimate efficiencies in a machine. Machine learning was implemented to investigate the solid particle erosion of both APS (air plasma spray) and EB-PVD (electron beam physical vapour deposition) TBCs of hot section components. Several ML models and algorithms were used such as neural networks (NNs), gradient boosting regression (GBR), decision tree regression (DTR), and random forest regression (RFR). It was found that the test data are strongly associated with five key factors as identifiers. Following test data collection, the dataset is subjected to sorting, filtering, extracting, and exploratory analysis. The training and testing, and prediction results are analysed. The results suggest that neural networks using the BR model and GBR have better prediction capability.
Fibre Individualisation and Mechanical Properties of a Flax-PLA Non-Woven Composite Following Physical Pre-Treatments
Authors: Gautreau Maxime , Kervoelen Antoine , Barteau Guillaume , Delattre François , Colinart Thibaut , Pierre Floran , Hauguel Maxime , Le Moigne Nicolas , Guillon Fabienne , Bourmaud Alain , Beaugrand Johnny
Published: July 2021

Pre-treatments for plant fibres are very popular for increasing the fineness of bundles, promoting individualisation of fibres, modifying the fibre-matrix interface or reducing water uptake. Most pre-treatments are based on the use of chemicals and raise concerns about possible harmful effects on the environment. In this study, we used physical pre-treatments without the addition of chemical products. Flax tows were subjected to ultrasound and gamma irradiation to increase the number of elementary fibres. For gamma pre-treatments, a 20% increase in the number of elementary fibres was quantified. The biochemical composition of pre-treated flax tows exhibited a partial elimination of sugars related to pectin and hemicelluloses depending on the pre-treatment. The hygroscopic behaviour showed a comparable decreasing trend for water sorption-desorption hysteresis for both types of pre-treatment. Then, non-woven composites were produced from the pre-treated tows using poly-(lactid) (PLA) as a bio-based matrix. A moderate difference between the composite mechanical properties was generally demonstrated, with a significant increase in the stress at break observed for the case of ultrasound pre-treatment. Finally, an environmental analysis was carried out and discussed to quantitatively compare the different environmental impacts of the pre-treatments for composite applications; the environmental benefit of using gamma irradiation compared to ultrasound pre-treatment was demonstrated.
Ultrasonic Technique for Production of Nanoemulsions for Food Packaging Purposes: A Review Study
Authors: Ahari Hamed , Nasiri Mina
Published: July 2021

According to the loss of food due to expired shelf life, there is a global concern on food safety among food science researchers, and food microbiologists. So, any approaches contributing to improved food packaging is most welcome. It has been demonstrated that administration of essential oils, fades away the unsolved obstacles of conventional food packaging, reducing environmental concerns compared with conventional food packaging. Along with substantial progresses in nanoscience, there is a great interest toward usage of nanoemulsions-based delivery systems. They have potentials to simplify targeted delivery of compounds in a high surfaced area, aimed at increasing stability, biodegradability, anti-oxidation, and anti-microbial properties. There are a wide range of methods for fabrication of nanoemulsions. Among them, ultrasonic-based approaches have gained an acceptable efficiency for industrial fabrication of essential oils-based nanoemulsions due to refraining from loss of nutrients through non-thermal approaches. In summary, essential-oils based nanoemulsions are significant due to ability for reduction in microbial load of food-borne pathogens, and prolonged shelf life.
Numerical Simulation of the Effect of Wall-Equiaxed Crystal Density on the Number of Columnar Crystals and the Thickness of an Equiaxed Crystal Layer for Al-4.7%Cu Alloy Ingot Based on 3D LBM-CA Method
Authors: Wang Qi , Wang Yingming , Li Yan , Zhang Shijie , Li Ri
Published: July 2021

In this paper, the lattice Boltzmann–cellular automata (LBM-CA) model with dynamic and static grids was used to study the growth of three-dimensional (3D) multidendrites under directional solidification with random preferred angles. In the static grid, the temperature field, flow field, and solute field during solidification were calculated by the LBM method, and in the dynamic grid, each dendrite evolution was calculated based on the CA method at its preferential crystallographic orientation. The coupling of LBM and CA was made by interpolation of the correlation quantities between the two sets of grids. The effects of wall-equiaxed crystal density on the number of columnar crystals and the thickness of the equiaxed crystal layer were studied by this model. The results showed that the density of the wall-equiaxed crystal has little effect on the number of columnar crystals and the thickness of the equiaxed crystal layer. When other conditions were the same, the lower the undercooling, the fewer the columnar crystals, and the thicker the equiaxed layer. In addition, the smaller the heat transfer coefficient, the lower the number of columnar grains, and the smaller the thickness of equiaxed grains.
Effects of Expansive Additives on the Shrinkage Behavior of Coal Gangue Based Alkali Activated Materials
Authors: Gao Xu , Liu Chao , Shui Zhonghe , Yu Rui
Published: July 2021

The suitability of applying shrinkage reducing additives in alkali activated coal gangue-slag composites is discussed in this study. The effect of sulphoaluminate cement (SAC), high performance concrete expansion agent (HCSA) and U-type expansion agent (UEA) on the reaction process, shrinkage behavior, phase composition, microstructure and mechanical properties are evaluated. The results show that the addition of SAC slightly mitigates the early stage reaction process, while HCSA and UEA can either accelerate or inhibit the reaction depending on their dosage. The addition of SAC presents an ideal balance between drying shrinkage reduction and strength increment. As for HCSA and UEA, the shrinkage and mechanical properties are sensitive to their replacement level; excessive dosage would result in remarkable strength reduction and expansion. The specific surface area and average pore size of the hardened matrix are found to be closely related with shrinkage behavior. SAC addition introduces additional hydrotalcite phases within the reaction products, while HCSA and UEA mainly result in the formation of CaCO3 and Ca(OH)2. It is concluded that applying expansive additives can be an effective approach in reducing the drying shrinkage of alkali activated coal gangue-slag mixtures, while their type and dosage must be carefully handled.
How Do Young Community and Citizen Science Volunteers Support Scientific Research on Biodiversity? The Case of iNaturalist
Authors: Aristeidou Maria , Herodotou Christothea , Ballard Heidi L. , Higgins Lila , Johnson Rebecca F. , Miller Annie E. , Young Alison N. , Robinson Lucy D.
Published: July 2021

Online community and citizen science (CCS) projects have broadened access to scientific research and enabled different forms of participation in biodiversity research; however, little is known about whether and how such opportunities are taken up by young people (aged 5–19). Furthermore, when they do participate, there is little research on whether their online activity makes a tangible contribution to scientific research. We addressed these knowledge gaps using quantitative analytical approaches and visualisations to investigate 249 youths’ contributions to CCS on the iNaturalist platform, and the potential for the scientific use of their contributions. We found that nearly all the young volunteers’ observations were ‘verifiable’ (included a photo, location, and date/time) and therefore potentially useful to biodiversity research. Furthermore, more than half were designated as ‘Research Grade’, with a community agreed-upon identification, making them more valuable and accessible to biodiversity science researchers. Our findings show that young volunteers with lasting participation on the platform and those aged 16–19 years are more likely to have a higher proportion of Research Grade observations than younger, or more ephemeral participants. This study enhances our understanding of young volunteers’ contributions to biodiversity research, as well as the important role professional scientists and data users can play in helping verify youths’ contributions to make them more accessible for biodiversity research.
Seasonal Climate Impacts on Vocal Activity in Two Neotropical Nonpasserines
Authors: Pérez-Granados Cristian , Schuchmann Karl-L.
Published: July 2021

Climatic conditions represent one of the main constraints that influence avian calling behavior. Here, we monitored the daily calling activity of the Undulated Tinamou (Crypturellus undulatus) and the Chaco Chachalaca (Ortalis canicollis) during the dry and wet seasons in the Brazilian Pantanal. We aimed to assess the effects of climate predictors on the vocal activity of these focal species and evaluate whether these effects may vary among seasons. Air temperature was positively associated with the daily calling activity of both species during the dry season. However, the vocal activity of both species was unrelated to air temperature during the wet season, when higher temperatures occur. Daily rainfall was positively related to the daily calling activity of both species during the dry season, when rainfall events are scarce and seem to act as a trigger for breeding phenology of the focal species. Nonetheless, daily rainfall was negatively associated with the daily calling activity of the Undulated Tinamou during the wet season, when rainfall was abundant. This study improves our understanding of the vocal behavior of tropical birds and their relationships with climate, but further research is needed to elucidate the mechanisms behind the associations found in our study.
Low-Level Expression of MTUS1 Is Associated with Poor Survival in Patients with Lung Adenocarcinoma
Authors: Jee Seungyun , Kim Hyunsung , Bang Seongsik , Kim Yeseul , Park Ha Young , Paik Seung Sam , Sim Jongmin , Jang Kiseok
Published: July 2021

Microtubule-associated tumor suppressor 1 (MTUS1) is thought to be downregulated in arious human cancers, which suggests its role as a tumor suppressor. This study investigated the clinicopathological significance of MTUS1 expression in lung adenocarcinoma. Tissue microarray blocks consisting of 161 cases were constructed, and immunohistochemical staining was used to assess MTUS1 expression. Correlations of MTUS1 expression and clinicopathological parameters were analyzed. In addition, we used public databases and performed bioinformatics analysis. Low level of MTUS1 was significantly associated with higher clinical stage (p = 0.006), higher tumor stage (p = 0.044), lymph node metastasis (p = 0.01), worse histologic grade (p = 0.007), lymphovascular invasion (p = 0.014), and higher Ki-67 proliferation index (p < 0.001). Patients with low MTUS1 expression also showed shorter disease-free survival (p = 0.002) and cancer-specific survival (p = 0.006). Analysis of data from the Cancer Genome Atlas confirmed that the mRNA expression of MTUS1 in lung adenocarcinoma was significantly lower than that of normal lung tissue (p = 0.02), and patients with decreased MTUS1 expression showed significantly shorter overall survival (p = 0.008). These results suggest that MTUS1 may be a potential biomarker for predicting clinical outcomes in lung adenocarcinoma patients.
Diagnostic Performance of a Contrast-Enhanced Ultra-Low-Dose High-Pitch CT Protocol with Reduced Scan Range for Detection of Pulmonary Embolisms
Authors: Brendlin Andreas S. , Winkelmann Moritz T. , Peisen Felix , Artzner Christoph P. , Nikolaou Konstantin , Othman Ahmed E. , Afat Saif
Published: July 2021

(1) Background: To evaluate the diagnostic performance of a simulated ultra-low-dose (ULD), high-pitch computed tomography pulmonary angiography (CTPA) protocol with low tube current (mAs) and reduced scan range for detection of pulmonary embolisms (PE). (2) Methods: We retrospectively included 130 consecutive patients (64 ± 16 years, 69 female) who underwent clinically indicated high-pitch CTPA examination for suspected acute PE on a 3rd generation dual-source CT scanner (SOMATOM FORCE, Siemens Healthineers, Forchheim, Germany). ULD datasets with a realistic simulation of 25% mAs, reduced scan range (aortic arch—basal pericardium), and Advanced Modeled Iterative Reconstruction (ADMIRE®, Siemens Healthineers, Forchheim, Germany) strength 5 were created. The effective radiation dose (ED) of both datasets (standard and ULD) was estimated using a dedicated dosimetry software solution. Subjective image quality and diagnostic confidence were evaluated independently by three reviewers using a 5-point Likert scale. Objective image quality was compared using noise measurements. For assessment of diagnostic accuracy, patients and pulmonary vessels were reviewed binarily for affection by PE, using standard CTPA protocol datasets as the reference standard. Percentual affection of pulmonary vessels by PE was computed for disease severity (modified Qanadli score). (3) Results: Mean ED in ULD protocol was 0.7 ± 0.3 mSv (16% of standard protocol: 4.3 ± 1.7 mSv, p < 0.001, r > 0.5). Comparing ULD to standard protocol, subjective image quality and diagnostic confidence were comparably good (p = 0.486, r > 0.5) and image noise was significantly lower in ULD (p < 0.001, r > 0.5). A total of 42 patients (32.2%) were affected by PE. ULD protocol had a segment-based false-negative rate of only 0.1%. Sensitivity for detection of any PE was 98.9% (95% CI, 97.2–99.7%), specificity was 100% (95% CI, 99.8–100%), and overall accuracy was 99.9% (95% CI, 98.6–100%). Diagnoses correlated strongly between ULD and standard protocol (Chi-square (1) = 42, p < 0.001) with a decrease in disease severity of only 0.48% (T = 1.667, p = 0.103). (4) Conclusions: Compared to a standard CTPA protocol, the proposed ULD protocol proved reliable in detecting and ruling out acute PE with good levels of image quality and diagnostic confidence, as well as significantly lower image noise, at 0.7 ± 0.3 mSv (84% dose reduction).
Pancreatic Fibrosis (Early Chronic Pancreatitis) as Emerging Diagnosis in Structural Causes of Dyspepsia: Evidence from Endoscopic Ultrasonography and Shear Wave Elastography
Authors: Huang Chung-Tsui , Lee Tzong-Hsi , Lin Cheng-Kuan , Chen Chao-Yi , Yang Yi-Feng , Liang Yao-Jen
Published: July 2021

A new concept for the diagnosis and management of non-functional dyspepsia in guidelines was lacking in the past decade. Medical advancement has proven pancreatic fibrosis (essential image evidence of early chronic pancreatitis) to be a cause of dyspepsia and related to pancreatic exocrine dysfunction. This study aimed to analyze the clinical picture, biomarker, and percentage of pancreatic fibrosis in the dyspeptic population. A total of 141 consecutive patients were retrospectively enrolled. They were diagnosed with peptic ulcer disease, 9.2% (n = 13); pancreatic fibrosis, 17% (n = 24); pure Helicobacter pylori infection, 19.9% (n = 28); functional dyspepsia, 53.2% (n = 75); and chronic pancreatitis, 0.7% (n = 1). Among those with pancreatic fibrosis, (n = 24), 11 were diagnosed on the basis of a pancreatic acoustic radiation force impulse exceeding 1.4 m/s, and the remaining 13 were diagnosed with early chronic pancreatitis with at least three of the Japanese endoscopic ultrasonography criteria. The anatomic distribution of parenchymal criteria of early chronic pancreatitis was head, 53%; body, 38%; and tail, 9%. There were 17 cases (71%, 17/24) without Helicobacter pylori and whose dyspepsia improved after pancreatic enzyme replacement with a ratio of 82.3% (14/17). Of the 141 cases, 19 received gastric emptying scintigraphy and Western blot analysis of chromogranin-A in duodenal mucosa. Delayed gastric emptying was more common in functional dyspepsia and chromogranin-A was expressed more in pancreatic fibrosis. In conclusion, pancreatic fibrosis (including early chronic pancreatitis) outnumbered peptic ulcer disease in the dyspeptic population and pancreatic enzyme therapy was effective for 82% of cases. In early chronic pancreatitis, pancreatic fibrosis is dominant in the head location, and duodenum mucosa chromogranin-A is a potential biomarker with increased expression in an age-matched manner.
Hepatitis C Diagnosis: Simplified Solutions, Predictive Barriers, and Future Promises
Authors: Shahid Imran , Alzahrani Abdullah R. , Al-Ghamdi Saeed S. , Alanazi Ibrahim M. , Rehman Sidra , Hassan Sajida
Published: July 2021

The simplification of current hepatitis C diagnostic algorithms and the emergence of digital diagnostic devices will be very crucial to achieving the WHO’s set goals of hepatitis C diagnosis (i.e., 90%) by 2030. From the last decade, hepatitis C diagnosis has been revolutionized by the advent and approval of state-of-the-art HCV diagnostic platforms which have been efficiently implemented in high-risk HCV populations in developed nations as well as in some low-to-middle income countries (LMICs) to identify millions of undiagnosed hepatitis C-infected individuals. Point-of-care (POC) rapid diagnostic tests (RDTs; POC-RDTs), RNA reflex testing, hepatitis C self-test assays, and dried blood spot (DBS) sample analysis have been proven their diagnostic worth in real-world clinical experiences both at centralized and decentralized diagnostic settings, in mass hepatitis C screening campaigns, and hard-to-reach aboriginal hepatitis C populations in remote areas. The present review article overviews the significance of current and emerging hepatitis C diagnostic packages to subvert the public health care burden of this ‘silent epidemic’ worldwide. We also highlight the challenges that remain to be met about the affordability, accessibility, and health system-related barriers to overcome while modulating the hepatitis C care cascade to adopt a ‘test and treat’ strategy for every hepatitis C-affected individual. We also elaborate some key measures and strategies in terms of policy and progress to be part of hepatitis C care plans to effectively link diagnosis to care cascade for rapid treatment uptake and, consequently, hepatitis C cure.
Fat-Bone Relationship in Chronic Kidney Disease—Mineral Bone Disorders: Adiponectin Is Associated with Skeletal Events among Hemodialysis Patients
Authors: Chen Po-Cheng , Chang Shu-Wei , Hsieh Chih-Yu , Liou Jian-Chiun , Chang Jia-Feng , Wang Ting-Ming
Published: July 2021

Background: The risk of skeletal events is rising in parallel with the burden of chronic kidney disease and mineral bone disorder (CKD-MBD), whilst the role of the fat-bone axis in CKD-MBD remains elusive. Adiponectin derived from adipocytes has emerged as a valid biomarker of low bone mineral density and increased marrow adiposity. We aimed to explore the association between adiponectin and bone fracture (BF) risks in patients with maintenance hemodialysis (MHD). Methods: Serum concentrations of adiponectin and bio-clinical data were determined at study entry. The Cox proportional hazard regression analyses were used to assess unadjusted and adjusted hazard ratios (aHRs) of adiponectin and various clinical predictors for BF risks. The predictive accuracy of adiponectin for BF events was evaluated by receiver operating characteristic (ROC) curve analysis. Results: Age and serum concentrations of adiponectin, phosphate, and intact parathyroid hormone were significantly associated with higher risks of BF. With respect to the risk of BF events, the cumulative event-free survival curves differed significantly between the high and low concentration groups of adiponectin (p = 0.02). In multivariable analysis, higher adiponectin levels were associated with an incremental risk of BF (adjusted hazard ratios (aHRs): 1.08 (95% confidence interval (CI): 1.01–1.15, p < 0.05). The ROC analysis of adiponectin cutoff point concentration (18.15 ug/mL) for prediction of BF showed 0.66 (95% CI = 0.49 to 0.84). Conclusion: Adiponectin was associated with an incremental risk of BF that could serve as a potential predictor of BF in MHD patients. In the high-risk population with hyperphosphatemia, an elevated adiponectin level could alert clinicians to the urgent need to correct mineral dysregulation and undertake further bone survey.
Host-Pathogen Adhesion as the Basis of Innovative Diagnostics for Emerging Pathogens
Authors: van Belkum Alex , Almeida Carina , Bardiaux Benjamin , Barrass Sarah V. , Butcher Sarah J. , Çaykara Tuğçe , Chowdhury Sounak , Datar Rucha , Eastwood Ian , Goldman Adrian , Goyal Manisha , Happonen Lotta , Izadi-Pruneyre Nadia , Jacobsen Theis , Johnson Pirjo H. , Kempf Volkhard A. J. , Kiessling Andreas , Bueno Juan Leva , Malik Anchal , Malmström Johan , Meuskens Ina , Milner Paul A. , Nilges Michael , Pamme Nicole , Peyman Sally A. , Rodrigues Ligia R. , Rodriguez-Mateos Pablo , Sande Maria G. , Silva Carla Joana , Stasiak Aleksandra Cecylia , Stehle Thilo , Thibau Arno , Vaca Diana J. , Linke Dirk
Published: July 2021

Infectious diseases are an existential health threat, potentiated by emerging and re-emerging viruses and increasing bacterial antibiotic resistance. Targeted treatment of infectious diseases requires precision diagnostics, especially in cases where broad-range therapeutics such as antibiotics fail. There is thus an increasing need for new approaches to develop sensitive and specific in vitro diagnostic (IVD) tests. Basic science and translational research are needed to identify key microbial molecules as diagnostic targets, to identify relevant host counterparts, and to use this knowledge in developing or improving IVD. In this regard, an overlooked feature is the capacity of pathogens to adhere specifically to host cells and tissues. The molecular entities relevant for pathogen–surface interaction are the so-called adhesins. Adhesins vary from protein compounds to (poly-)saccharides or lipid structures that interact with eukaryotic host cell matrix molecules and receptors. Such interactions co-define the specificity and sensitivity of a diagnostic test. Currently, adhesin-receptor binding is typically used in the pre-analytical phase of IVD tests, focusing on pathogen enrichment. Further exploration of adhesin–ligand interaction, supported by present high-throughput “omics” technologies, might stimulate a new generation of broadly applicable pathogen detection and characterization tools. This review describes recent results of novel structure-defining technologies allowing for detailed molecular analysis of adhesins, their receptors and complexes. Since the host ligands evolve slowly, the corresponding adhesin interaction is under selective pressure to maintain a constant receptor binding domain. IVD should exploit such conserved binding sites and, in particular, use the human ligand to enrich the pathogen. We provide an inventory of methods based on adhesion factors and pathogen attachment mechanisms, which can also be of relevance to currently emerging pathogens, including SARS-CoV-2, the causative agent of COVID-19.
Machine-Learning-Based Radiomics MRI Model for Survival Prediction of Recurrent Glioblastomas Treated with Bevacizumab
Authors: Ammari Samy , Sallé de Chou Raoul , Assi Tarek , Touat Mehdi , Chouzenoux Emilie , Quillent Arnaud , Limkin Elaine , Dercle Laurent , Hadchiti Joya , Elhaik Mickael , Moalla Salma , Khettab Mohamed , Balleyguier Corinne , Lassau Nathalie , Dumont Sarah , Smolenschi Cristina
Published: July 2021

Anti-angiogenic therapy with bevacizumab is a widely used therapeutic option for recurrent glioblastoma (GBM). Nevertheless, the therapeutic response remains highly heterogeneous among GBM patients with discordant outcomes. Recent data have shown that radiomics, an advanced recent imaging analysis method, can help to predict both prognosis and therapy in a multitude of solid tumours. The objective of this study was to identify novel biomarkers, extracted from MRI and clinical data, which could predict overall survival (OS) and progression-free survival (PFS) in GBM patients treated with bevacizumab using machine-learning algorithms. In a cohort of 194 recurrent GBM patients (age range 18–80), radiomics data from pre-treatment T2 FLAIR and gadolinium-injected MRI images along with clinical features were analysed. Binary classification models for OS at 9, 12, and 15 months were evaluated. Our classification models successfully stratified the OS. The AUCs were equal to 0.78, 0.85, and 0.76 on the test sets (0.79, 0.82, and 0.87 on the training sets) for the 9-, 12-, and 15-month endpoints, respectively. Regressions yielded a C-index of 0.64 (0.74) for OS and 0.57 (0.69) for PFS. These results suggest that radiomics could assist in the elaboration of a predictive model for treatment selection in recurrent GBM patients.
The Stock Market Model with Delayed Information Impact from a Socioeconomic View
Authors: Wang Zhiting , Shi Guiyuan , Shang Mingsheng , Zhang Yuxia
Published: July 2021

Finding the critical factor and possible “Newton’s laws” in financial markets has been an important issue. However, with the development of information and communication technologies, financial models are becoming more realistic but complex, contradicting the objective law “Greatest truths are the simplest.” Therefore, this paper presents an evolutionary model independent of micro features and attempts to discover the most critical factor. In the model, information is the only critical factor, and stock price is the emergence of collective behavior. The statistical properties of the model are significantly similar to the real market. It also explains the correlations of stocks within an industry, which provides a new idea for studying critical factors and core structures in the financial markets.
Topology-Optimization-Based Learning: A Powerful Teaching and Learning Framework under the Prism of the CDIO Approach
Authors: Tyflopoulos Evangelos , Haskins Cecilia , Steinert Martin
Published: July 2021

Topology optimization (TO) has been a useful engineering tool over the last decades. The benefits of this optimization method are several, such as the material and cost savings, the design inspiration, and the robustness of the final products. In addition, there are educational benefits. TO is a combination of mathematics, design, statics, and the finite element method (FEM); thus, it can provide an integrative multi-disciplinary knowledge foundation to undergraduate students in engineering. This paper is focused on the educational contributions from TO and identifies effective teaching methods, tools, and exercises that can be used for teaching. The result of this research is the development of an educational framework about TO based on the CDIO (Conceive, Design, Implement, and Operate) Syllabus for CAD engineering studies at universities. TO could be easily adapted for CAD designers in every academic year as an individual course or a module of related engineering courses. Lecturers interested in the introduction of TO to their courses, as well as engineers and students interested in TO in general, could use the findings of this paper.
Basic Geometric Concepts in the Thinking of In-Service and Pre-Service Mathematics Teachers
Authors: Gambini Alessandro , Lénárt István
Published: July 2021

This paper discusses a model of a mathematics teacher professional development implemented in Italy and Hungary with in-service and pre-service mathematics teachers. The model focuses on comparative geometry, and it develops with the use of an artifact: the Lénárt spheres. The teacher training model is the result of several years of experience of the two authors both as regards the activities in the classroom with the Lénárt spheres and as regards the training of teachers in this field. The proposed teachers’ professional development, in addition to providing ideas for activities to be implemented in the classroom, has the objective of proposing reflective activities from a community of inquiry perspective; during the activities, mediated by the artifact, both the Pedagogical Content Knowledge and the Mathematical Content Knowledge are taken into consideration (Ball et al., 2008). The model has been implemented in Italy in more than 15 training courses taught in the last 5 years, both with primary school teachers and with secondary school teachers. In Hungary, the model is at the basis of elective courses under the title ‘Ball Geometry’ at ELTE University, Budapest, for decades. These courses have been aimed at prospective preschool and elementary school teachers at the Faculty of Primary and Preschool Education, as well as future secondary teachers at the Faculty of Natural Sciences. The subject of the teachers’ professional development paths corresponds to the comparative geometry between the plane and the sphere. After the presentation of the model, some examples of activities implemented in Hungary during the pandemic period will be illustrated and commented from a didactic point of view, which will serve to exemplify the path described. The described path was carried out remotely in online mode through synchronous and asynchronous activities. The distance obviously changed the way we interacted with the artifact, but it did not prevent the achievement of the courses’ objectives.
Two Decades of STEM Education Research in Middle School: A Bibliometrics Analysis in Scopus Database (2000–2020)
Authors: Le Thi Thu Huong , Tran Trung , Trinh Thi Phuong Thao , Le Thi Tuyet Trinh , Le Huy Hoang , Vu Thi Thuy
Published: July 2021

STEM education has become important in many countries around the world. STEM education can begin while students are very young. However, earlier research has shown that one of the most important factors influencing the decision on scientific research selection is the middle school science classes. In this research, we extract database from Scopus to evaluate the scientific results of publications in the field of STEM education in middle school in the period 2000–2020. A data set of 272 academic papers was indexed to monitor the development of this field by Scopus. The results of the quantitative analysis showed that researches on STEM education in middle schools have boomed in the last 5 years, mainly in the USA. The trend of research collaboration in the field of STEM education in middle schools is not strong. The research topics are quite diverse, focusing on a number of issues: gender, engineering education, curriculum, etc. This study has some limitations, including that only data from the Scopus database were selected and manually filtered, so our analyses totally depended on the quality of the input information imported from the Scopus database.
A Predictive Control Strategy for Energy Management in Micro-Grid Systems
Authors: Elmouatamid Abdellatif , Ouladsine Radouane , Bakhouya Mohamed , El kamoun Najib , Zine-Dine Khalid
Published: July 2021

The integration of renewable energy sources (RES) was amplified, during the past decades, in order to tackle the challenges related to energy demands and CO2 increases. Recently, many initiatives have been taken by promoting the deployment and the usage of micro-grids (MG) in buildings, as decentralized systems, for energy production. However, the variable nature of RESs and the limited size of energy storage systems require the deployment of adaptive control strategies for efficient energy balance. In this paper, a generalized predictive control (GPC) strategy is introduced for energy management (EM) in MG systems. Its main objective is to efficiently connect the electricity generators and consumers in order to predict the most suitable actions for energy flow management. In fact, based on energy production and consumption profiles as well as the availability of energy storage systems, the proposed EM will be able to select the best suitable energy source for supplying the building’s loads. It will efficiently manage the usage of energy storage and the utility grid while maximizing RESs power generation. Simulations have been conducted, using real-sitting scenarios, and results are presented to validate the proposed predictive control approach by showing its effectiveness for MG systems control.
Massive MIMO Techniques for 5G and Beyond—Opportunities and Challenges
Authors: Borges David , Montezuma Paulo , Dinis Rui , Beko Marko
Published: July 2021

Telecommunications have grown to be a pillar to a functional society and the urge for reliable and high throughput systems has become the main objective of researchers and engineers. State-of-the-art work considers massive Multiple-Input Multiple-Output (massive MIMO) as the key technology for 5G and beyond. Large spatial multiplexing and diversity gains are some of the major benefits together with an improved energy efficiency. Current works mostly assume the application of well-established techniques in a massive MIMO scenario, although there are still open challenges regarding hardware and computational complexities and energy efficiency. Fully digital, analog, and hybrid structures are analyzed and a multi-layer massive MIMO transmission technique is detailed. The purpose of this article is to describe the most acknowledged transmission techniques for massive MIMO systems and to analyze some of the most promising ones and identify existing problems and limitations.
A 0.18-ns Response Time Digital LDO Regulator with Adaptive PI Controller in 180-nm CMOS
Authors: Lv Shengping , Wan Peiyuan , Zhang Hongda , Geng Jiarong , Wen Jiabao , Yao Yiming , Chen Zhijie
Published: July 2021

Digital low drop-out regulator (D-LDO) with fast settling time and superior transient response is gaining increasing attention to make up for the deficiency of analog LDO. However, as the traditional digital LDOs regulate the output voltage code at a rate of 1 bit per clock cycle, the transient response speed is limited. In this paper, a multi-bit conversion technique is proposed to improve the transient response speed. The multi-bit conversion technique is achieved by an error detector with adaptive regulation of proportion and integration parameters in the digital controller before pass devices. Besides, a voltage sensor and a time-to-digital converter are employed to convert the output voltage to digital codes. Implemented in a 180-nm CMOS process, the proposed D-LDO features under 36/33 mV of undershoot/overshoot at VOUT = 0.95 V as the load current steps up with 40 mA/1 ns on a 0.5 nF load capacitor. The simulated response time is 0.18-ns, the figure-of-merit of speed FOM1 is 0.65 ps and FOM2 achieves 0.068 pF.
Automatic Generation of Meta-Path Graph for Concept Recommendation in MOOCs
Authors: Gong Jibing , Wang Cheng , Zhao Zhiyong , Zhang Xinghao
Published: July 2021

In MOOCs, generally speaking, curriculum designing, course selection, and knowledge concept recommendation are the three major steps that systematically instruct users to learn. This paper focuses on the knowledge concept recommendation in MOOCs, which recommends related topics to users to facilitate their online study. The existing approaches only consider the historical behaviors of users, but ignore various kinds of auxiliary information, which are also critical for user embedding. In addition, traditional recommendation models only consider the immediate user response to the recommended items, and do not explicitly consider the long-term interests of users. To deal with the above issues, this paper proposes AGMKRec, a novel reinforced concept recommendation model with a heterogeneous information network. We first clarify the concept recommendation in MOOCs as a reinforcement learning problem to offer a personalized and dynamic knowledge concept label list to users. To consider more auxiliary information of users, we construct a heterogeneous information network among users, courses, and concepts, and use a meta-path-based method which can automatically identify useful meta-paths and multi-hop connections to learn a new graph structure for learning effective node representations on a graph. Comprehensive experiments and analyses on a real-world dataset collected from XuetangX show that our proposed model outperforms some state-of-the-art methods.
Numerical Analysis on the Effects of Saline Injection and Deformation for Radiofrequency Catheter Ablation
Authors: Ahn Jin Woo , Kim Young-Jin
Published: July 2021

Radiofrequency catheter ablation is an interventional procedure used to treat arrhythmia. An electrode catheter that could inject saline has been developed to prevent steam pop on heart tissue during radiofrequency catheter ablation. Thus, we investigated to numerical model on the effect of saline injection and heart tissue’s deformation. In this study, the hyperelastic model was implemented to analyze heart tissue deformation due to the catheter’s contact force. Besides, the advection–diffusion equation was used to analyze the mixture between saline and blood. We developed the multiphysics model that predicts thermal lesions based on the deformation of the heart and mixing between saline and blood flow. The thermal lesion and the maximum temperature in the numerical model that considered mixing saline and blood were smaller than that of other numerical models that did not consider mixing. Therefore, we observed that the saline injection was affected by thermal lesion due to higher electrical conductivity than blood flow and injection at a lower temperature than the human body. The numerical model was researched that considering the deformation of the heart tissue and saline injection in radiofrequency catheter ablation affects the heart tissue’s thermal lesion and maximum temperature.
Power Balance and Power Factors of Distorted Electrical Systems and Variable Speed Asynchronous Electric Drives
Authors: Petrushyn Viktor , Horoshko Vasiliy , Plotkin Juriy , Almuratova Nurgul , Toigozhinova Zhanar
Published: July 2021

In this study, power quality coefficients that determine the distortion of electrical systems are established. The power factor is chosen as a universal criterion for electromagnetic and electro-energetic compatibility of distorted sources and distorting loads. Mathematical expressions are obtained for its calculation in various cases of electrical systems distortion. As an application example, power balances and power factors of a variable frequency asynchronous drive system are considered. The criterion: the power factor not only determines the energy and electromagnetic compatibility of the drive with power supply, but it also evaluates drive efficiency. Experimental studies were carried out under usage of inexpensive, commonly used measuring devices both on the grid side of the frequency converter and on the asynchronous motor side. The studied coefficients were determined in two ways: measuring instruments and analysis of oscillograms. The second method for determining the above coefficients from oscillograms of currents and voltages also requires finding the total harmonic distortion (THD) of currents and voltages for the corresponding load adjusting points. The similarity of the obtained results shows that both of these methods can be applied. According to the operating mode of the load, the criterion is calculated as an average range in a certain range of speed control, or it is determined by considering a given tachogram of speed changes. The results of experimental studies confirm the correctness of the theoretical provisions.