bluuebunny/crossref_metadata_2025 huggingface dataset:
Highly Sensitive Electrochemical Aptasensor for Detecting the VEGF165 Tumor Marker with PANI/CNT Nanocomposites
Authors: Park Yunjeong , Hong Min-Sung , Lee Woo-Hyuk , Kim Jung-Gu , Kim Kyunghoon
Published: April 2021

Sensing targeted tumor markers with high sensitivity provides vital information for the fast diagnosis and treatment of cancer patients. A vascular endothelial growth factor (VEGF165) have recently emerged as a promising biomarker of tumor cells. The electrochemical aptasensor is a promising tool for detecting VEGF165 because of its advantages such as a low cost and quantitative analysis. To produce a sensitive and stable sensor electrode, nanocomposites based on polyaniline (PANI) and carbon nanotube (CNT) have potential, as they provide for easy fabrication, simple synthesis, have a large surface area, and are suitable in biological environments. Here, a label-free electrochemical aptasensor based on nanocomposites of CNT and PANI was prepared for detecting VEGF165 as a tumor marker. The nanocomposite was assembled with immobilized VEGF165 aptamer as a highly sensitive VEGF165 sensor. It exhibited stable and wide linear detection ranges from 0.5 pg/mL to 1 μg/mL, with a limit of detection of 0.4 pg/mL because of the complementary effect of PANI/CNT. The fabricated aptasensor also exhibited good stability in biological conditions, selectivity, and reproducibility after several measurement times after the dissociation process. Thus, it could be applied for the non-invasive determination of VEGF, in biological fluid diagnosis kits, or in an aptamer-based biosensor platform in the near future.
Chewing Behavior Attenuates the Tumor Progression-Enhancing Effects of Psychological Stress in a Breast Cancer Model Mouse
Authors: Zhou Qian , Katano Masahisa , Zhang Jia-He , Liu Xiao , Wang Ke-Yong , Iinuma Mitsuo , Kubo Kin-ya , Azuma Kagaku
Published: April 2021

We examined whether chewing behavior affects the tumor progression-enhancing impact of psychological stress. Human breast cancer cell line (MDA-MB-231) cells were inoculated into the mammary fat pads of athymic nude mice. The mice were assigned randomly to control, stress, and stress+chewing groups. Psychological stress was created by keeping mice in a transparent restraint cylinder for 45 min, three times a day, for 35 days after cell inoculation. Animals in the stress+chewing group were provided with a wooden stick for chewing on during the psychological stress period. Chewing behavior remarkably inhibited the tumor growth accelerated by the psychological stress. Immunohistochemical and Western blot findings revealed that chewing behavior during psychological stress markedly suppressed tumor angiogenesis and cell proliferation. In addition, chewing behavior decreased serum glucocorticoid levels and expressions of glucocorticoid and β2-adrenergic receptors in tumors. Chewing behavior decreased expressions of inducible nitric oxide synthase and 4-hydroxynonenal, and increased expression of superoxide dismutase 2 in tumors. Our findings suggest that chewing behavior could ameliorate the enhancing effects of psychological stress on the progression of breast cancer, at least partially, through modulating stress hormones and their receptors, and the subsequent signaling pathways involving reactive oxygen and nitrogen species.
Anxiety and Attentional Processes: The Role of Resting Heart Rate Variability
Authors: Forte Giuseppe , Favieri Francesca , Oliha Esther Osariemen , Marotta Andrea , Casagrande Maria
Published: April 2021

Individuals with high anxiety preferentially focus attention on emotional information. The autonomic nervous system (ANS) plays an important role in modulating both anxiety and attentional processes. Despite many studies having evaluated attentional bias in anxious people, few of them have investigated the change blindness phenomenon associated with the attentional response toward salient stimuli, considering the role of the ANS. This study aimed to examine the role of heart rate variability (HRV) in trait anxiety and top-down and bottom-up attentional processes toward emotional stimuli. Seventy-five healthy university students were divided into high (N = 39) and low (N = 36) trait anxiety groups and completed a change detection flicker task with neutral, positive, and negative stimuli. The results evidenced a different attentional pattern between people with high and low anxiety considering both the two attentional processes and the valence of the stimuli. Specifically, individuals with high anxiety showed a bias in elaborating emotional stimuli related to their salience (i.e., negative stimuli were faster elaborated than neutral and positive stimuli when top-down attentional mechanisms were involved, while slower performances were highlighted considering bottom-up attentional mechanisms in response to emotional stimuli compared to neutral stimuli). Moreover, an association between HRV, trait anxiety levels, and change blindness phenomenon was confirmed. These results underline the role of HRV as a possible predictor of the alteration of attentional mechanism in anxiety.
Magnetically Agitated Nanoparticle-Based Batch Reactors for Biocatalysis with Immobilized Aspartate Ammonia-Lyase
Authors: Imarah Ali Obaid , Csuka Pál , Bataa Naran , Decsi Balázs , Sánta-Bell Evelin , Molnár Zsófia , Balogh-Weiser Diána , Poppe László
Published: April 2021

In this study, we investigated the influence of different modes of magnetic mixing on effective enzyme activity of aspartate ammonia-lyase from Pseudomonas fluorescens immobilized onto epoxy-functionalized magnetic nanoparticles by covalent binding (AAL-MNP). The effective specific enzyme activity of AAL-MNPs in traditional shake vial method was compared to the specific activity of the MNP-based biocatalyst in two devices designed for magnetic agitation. The first device agitated the AAL-MNPs by moving two permanent magnets at two opposite sides of a vial in x-axis direction (being perpendicular to the y-axis of the vial); the second device unsettled the MNP biocatalyst by rotating the two permanent magnets around the y-axis of the vial. In a traditional shake vial, the substrate and biocatalyst move in the same direction with the same pattern. In magnetic agitation modes, the MNPs responded differently to the external magnetic field of two permanent magnets. In the axial agitation mode, MNPs formed a moving cloud inside the vial, whereas in the rotating agitation mode, they formed a ring. Especially, the rotating agitation of the MNPs generated small fluid flow inside the vial enabling the mixing of the reaction mixture, leading to enhanced effective activity of AAL-MNPs compared to shake vial agitation.
Quantitative Methodologies to Dissect Immune Cell Mechanobiology
Authors: Pfannenstill Veronika , Barbotin Aurélien , Colin-York Huw , Fritzsche Marco
Published: April 2021

Mechanobiology seeks to understand how cells integrate their biomechanics into their function and behavior. Unravelling the mechanisms underlying these mechanobiological processes is particularly important for immune cells in the context of the dynamic and complex tissue microenvironment. However, it remains largely unknown how cellular mechanical force generation and mechanical properties are regulated and integrated by immune cells, primarily due to a profound lack of technologies with sufficient sensitivity to quantify immune cell mechanics. In this review, we discuss the biological significance of mechanics for immune cells across length and time scales, and highlight several experimental methodologies for quantifying the mechanics of immune cells. Finally, we discuss the importance of quantifying the appropriate mechanical readout to accelerate insights into the mechanobiology of the immune response.
Simple and Efficient Protocol for Subcellular Fractionation of Normal and Apoptotic Cells
Authors: Senichkin Viacheslav V. , Prokhorova Evgeniia A. , Zhivotovsky Boris , Kopeina Gelina S.
Published: April 2021

Subcellular fractionation approaches remain an indispensable tool among a large number of biochemical methods to facilitate the study of specific intracellular events and characterization of protein functions. During apoptosis, the best-known form of programmed cell death, numerous proteins are translocated into and from the nucleus. Therefore, suitable biochemical techniques for the subcellular fractionation of apoptotic cells are required. However, apoptotic bodies and cell fragments might contaminate the fractions upon using the standard protocols. Here, we compared different nucleus/cytoplasm fractionation methods and selected the best-suited approach for the separation of nuclear and cytoplasmic contents. The described methodology is based on stepwise lysis of cells and washing of the resulting nuclei using non-ionic detergents, such as NP-40. Next, we validated this approach for fractionation of cells treated with various apoptotic stimuli. Finally, we demonstrated that nuclear fraction could be further subdivided into nucleosolic and insoluble subfractions, which is crucial for the isolation and functional studies of various proteins. Altogether, we developed a method for simple and efficient nucleus/cytoplasm fractionation of both normal and apoptotic cells.
Assembly and Entry of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2): Evaluation Using Virus-Like Particles
Authors: Kumar Binod , Hawkins Grant M. , Kicmal Tom , Qing Enya , Timm Emily , Gallagher Tom
Published: April 2021

Research on infectious severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) is currently restricted to BSL-3 laboratories. SARS-CoV2 virus-like particles (VLPs) offer a BSL-1, replication-incompetent system that can be used to evaluate virus assembly and virus-cell entry processes in tractable cell culture conditions. Here, we describe a SARS-CoV2 VLP system that utilizes nanoluciferase (Nluc) fragment complementation to track assembly and entry. We utilized the system in two ways. Firstly, we investigated the requirements for VLP assembly. VLPs were produced by concomitant synthesis of three viral membrane proteins, spike (S), envelope (E), and matrix (M), along with the cytoplasmic nucleocapsid (N). We discovered that VLP production and secretion were highly dependent on N proteins. N proteins from related betacoronaviruses variably substituted for the homologous SARS-CoV2 N, and chimeric betacoronavirus N proteins effectively supported VLP production if they contained SARS-CoV2 N carboxy-terminal domains (CTD). This established the CTDs as critical features of virus particle assembly. Secondly, we utilized the system by investigating virus-cell entry. VLPs were produced with Nluc peptide fragments appended to E, M, or N proteins, with each subsequently inoculated into target cells expressing complementary Nluc fragments. Complementation into functional Nluc was used to assess virus-cell entry. We discovered that each of the VLPs were effective at monitoring virus-cell entry, to various extents, in ways that depended on host cell susceptibility factors. Overall, we have developed and utilized a VLP system that has proven useful in identifying SARS-CoV2 assembly and entry features.
Leukocyte TNFR1 and TNFR2 Expression Contributes to the Peripheral Immune Response in Cases with Ischemic Stroke
Authors: Hansen Rikke B. , Laursen Cathrine C. H. , Nawaz Niala , Madsen Jonna S. , Nielsen Helle H. , Kruuse Christina , Møller Arne , Degn Matilda , Lambertsen Kate L.
Published: April 2021

Tumor necrosis factor receptor 1 and 2 (TNFR1 and TNFR2) have been found in brain parenchyma of stroke patients, and plasma levels are increased in the acute phase of stroke. We evaluated associations between TNFR1 and TNFR2 plasma levels and stroke severity, infarct size, and functional outcome. Furthermore, we examined cellular expression of TNFR1 and TNFR2 on leukocyte subpopulations to explore the origin of the increased receptor levels. Blood samples were taken from 33 acute ischemic stroke patients and 10 healthy controls. TNFR1 and TNFR2 plasma concentrations were measured and correlated against the Scandinavian Stroke Scale at admission, infarct volume, and the modified Rankin Scale score three months after stroke onset. Classical, intermediate, and non-classical monocytes as well as neutrophils were purified, and cellular expression of TNFR1 and TNFR2 was examined using flow cytometry. TNFR1 and TNFR2 plasma levels were both increased after ischemic stroke, but we found no correlation with patient outcome measurements. Compared to healthy controls, ischemic stroke patients had decreased non-classical monocyte and neutrophil populations expressing TNFR1 and increased neutrophils expressing TNFR2, and decreased non-classical populations co-expressing both TNFR1 and TNFR2. This study supports the hypothesis of an acute immunological response orchestrated by the peripheral immune system following an ischemic stroke. However, the origin of the increased TNFR1 and TNFR2 plasma levels could not be clearly linked to peripheral monocytes or neutrophils. Future studies are needed and will help clarify the potential role as treatment target.
Naphthoquinones and Their Derivatives: Emerging Trends in Combating Microbial Pathogens
Authors: Mone Nishigandha , Bhagwat Srushti , Sharma Deepansh , Chaskar Manohar , Patil Rajendra , Zamboni Paolo , Nawani Neelu , Satpute Surekha
Published: April 2021

In the current era, an ever-emerging threat of multidrug-resistant (MDR) pathogens pose serious health challenges to mankind. Researchers are uninterruptedly putting their efforts to design and develop alternative, innovative strategies to tackle the antibiotic resistance displayed by varied pathogens. Among several naturally derived and chemically synthesized compounds, quinones have achieved a distinct position to defeat microbial pathogens. This review unleashes the structural diversity and promising biological activities of naphthoquinones (NQs) and their derivatives documented in the past two decades. Further, realizing their functional potentialities, researchers were encouraged to approach NQs as lead molecules. We have retrieved information that is dedicated on biological applications (antibacterial, antifungal, antiparasitic) of NQs. The multiple roles of NQs offer them a promising armory to combat microbial pathogens including MDR and the ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) group. In bacteria, NQs may exhibit their function in the following ways (1) plasmid curing, (2) inhibiting efflux pumps (EPs), (3) generating reactive oxygen species (ROS), (4) the inhibition of topoisomerase activity. Sparse but meticulous literature suggests the mechanistic roles of NQs. We have highlighted the possible mechanisms of NQs and how the targeted drug synthesis can be achieved via molecular docking analysis. This bioinformatics-oriented approach will explicitly lead to the development of effective and most potent drugs against targeted pathogens. The mechanistic approaches of emerging molecules like NQs might prove a milestone to defeat the battle against microbial pathogens.
Influence of Hydrophilic Surfactants on the W1–W2 Coalescence in Double Emulsion Systems Investigated by Single Droplet Experiments
Authors: Leister Nico , Karbstein Heike P.
Published: April 2021

Double emulsions are a promising formulation for encapsulation and targeted release in pharmaceutics, cosmetics and food. An inner water phase is dispersed in an oil phase, which is again emulsified in a second water phase. The encapsulated inner water phase can be released via diffusion or via coalescence, neither of which is desired during storage but might be intended during application. The two interfaces in a double emulsion are stabilized by a hydrophilic and a lipophilic surfactant, to prevent the coalescence of the outer and the inner emulsion, respectively. This study focuses on the influence of the hydrophilic surfactant on the release of inner water or actives encapsulated therein via coalescence of the inner water droplet with the outer O–W2 interface. Since coalescence and diffusion are difficult to distinguish in double emulsions, single-droplet experiments were used to quantify differences in the stability of inner droplets. Different lipophilic (PGPH and PEG-30 dipolyhydroxylstearate) and hydrophilic surfactants (ethoxylates, SDS and polymeric) were used and resulted in huge differences in stability. A drastic decrease in stability was found for some combinations, while other combinations resulted in inner droplets that could withstand coalescence longer. The destabilization effect of some hydrophilic surfactants depended on their concentration, but was still present at very low concentrations. A huge spread of the coalescence time for multiple determinations was observed for all formulations and the necessary statistical analysis is discussed in this work. The measured stabilities of single droplets are in good accordance with the stability of double emulsions for similar surfactant combinations found in literature. Therefore, single droplet experiments are suggested for a fast evaluation of potentially suitable surfactant combinations for future studies on double-emulsion stability.
Driven Transport of Dilute Polymer Solutions through Porous Media Comprising Interconnected Cavities
Authors: Nagarajan Karthik , Chen Shing Bor
Published: April 2021

Driven transport of dilute polymer solutions through porous media has been simulated using a recently proposed novel dissipative particle dynamics method satisfying the no-penetration and no-slip boundary conditions. The porous media is an array of overlapping spherical cavities arranged in a simple cubic lattice. Simulations were performed for linear, ring, and star polymers with 12 arms for two cases with the external force acting on (I) both polymer and solvent beads to model a pressure-driven flow; (II) polymer beads only, similar to electrophoresis. When the external force is in the direction of a principal axis, the extent of change in the polymers’ conformation and their alignment with the driving force is more significant for case I. These effects are most pronounced for linear chains, followed by rings and stars at the same molecular weight. Moreover, the polymer mean velocity is affected by its molecular weight and architecture as well as the direction and strength of the imposed force.
Correlation of Electrical Properties and Acoustic Loss in Single Crystalline Lithium Niobate-Tantalate Solid Solutions at Elevated Temperatures
Authors: Suhak Yuriy , Roshchupkin Dmitry , Redkin Boris , Kabir Ahsanul , Jerliu Bujar , Ganschow Steffen , Fritze Holger
Published: April 2021

Electrical conductivity and acoustic loss Q−1 of single crystalline Li(Nb,Ta)O3 solid solutions (LNT) are studied as a function of temperature by means of impedance spectroscopy and resonant piezoelectric spectroscopy, respectively. For this purpose, bulk acoustic wave resonators with two different Nb/Ta ratios are investigated. The obtained results are compared to those previously reported for congruent LiNbO3. The temperature dependent electrical conductivity of LNT and LiNbO3 show similar behavior in air at high temperatures from 400 to 700 °C. Therefore, it is concluded that the dominant transport mechanism in LNT is the same as in LN, which is the Li transport via Li vacancies. Further, it is shown that losses in LNT strongly increase above about 500 °C, which is interpreted to originate from conductivity-related relaxation mechanism. Finally, it is shown that LNT bulk acoustic resonators exhibit significantly lower loss, comparing to that of LiNbO3.
Increase the Performances of Lime Finishing Mixes Due to Modification with Calcium Silicate Hydrates
Authors: Loganina Valentina , Sergeeva Kristina , Fediuk Roman , Uvarov Valery , Vatin Nikolai , Vasilev Yuriy , Amran Mugahed , Szelag Maciej
Published: April 2021

Lime plaster mixes are becoming more and more popular in the world’s building materials market every year. Therefore, the issue of increasing the efficiency of lime finishing coatings is relevant. The paper aim is the modification of lime binders with specially synthesized calcium silicate hydrates (CSHs). To obtain the CSH filler, liquid sodium glass was used with a silicate module of 1.53–2.9 and a density of 1130–1663 kg/m3. Using differential thermal analysis (DTA), X-ray diffraction (XRD) patterns, synthesized calcium silicate hydrates, as well as dry plaster mixes, and finishing coatings based on using them were studied. The regularities of the filler synthesis were established depending on the temperature, density, and silicate modulus of liquid glass, the amount of the precipitant additive, the rate of its introduction, and the drying mode. As a result of processing the obtained experimental data, a mathematical model was obtained for the composition “lime + CSH”. The phase composition of the filler was revealed, which is characterized by the presence of calcium silicate hydrates of the tobermorite group, a solid solution CSH (B) in the form of a weakly crystallized gel, a solid solution of C–S–H (II), hydrohalites, and calcites. It was found that the use of the fillers into the lime compositions, obtained with the rapid introduction of CaCl2 additive into water glass during the synthesis of the filler, promotes the acceleration of the plastic strength gain of lime compositions. It was revealed that the lime composites with the CSH filler are characterized by reduced shrinkage deformations up to 45%. The introduction of the CSH filler into the lime compositions increases the water resistance of the lime finishing layer by 36%. A technological scheme for the production of the lime dry plaster mixes has been developed; it can be introduced at existing factories of building materials without significant re-equipment of production.
Comparison and Fusion of Machine Learning Algorithms for Prospective Validation of PET/CT Radiomic Features Prognostic Value in Stage II-III Non-Small Cell Lung Cancer
Authors: Sepehri Shima , Tankyevych Olena , Upadhaya Taman , Visvikis Dimitris , Hatt Mathieu , Cheze Le Rest Catherine
Published: April 2021

Machine learning (ML) algorithms for selecting and combining radiomic features into multiparametric prediction models have become popular; however, it has been shown that large variations in performance can be obtained by relying on different approaches. The purpose of this study was to evaluate the potential benefit of combining different algorithms into an improved consensus for the final prediction, as it has been shown in other fields. Methods: The evaluation was carried out in the context of the use of radiomics from 18F-FDG PET/CT images for predicting outcome in stage II-III Non-Small Cell Lung Cancer. A cohort of 138 patients was exploited for the present analysis. Eighty-seven patients had been previously recruited retrospectively for another study and were used here for training and internal validation. We also used data from prospectively recruited patients (n = 51) for testing. Three different machine learning pipelines relying on embedded feature selection were trained to predict overall survival (OS) as a binary classification: Support Vector machines (SVMs), Random Forests (RFs), and Logistic Regression (LR). Two different clinical endpoints were investigated: median OS or OS shorter than 6 months. The fusion of the three approaches was implemented using two different strategies: majority voting on the binary outputs or averaging of the output probabilities. Results: Our results confirm previous findings, highlighting that different ML pipelines select different sets of features and reach different classification performances (accuracy in the testing set ranging between 63% and 67% for median OS, and between 75% and 80% for OS < 6 months). Generating a consensus improved the performance for both endpoints; with the probabilities averaging strategy outperforming the majority voting (accuracy of 78% vs. 71% for median OS and 89 vs. 84% for OS < 6 months). Overall, the performance of these radiomic-based models outperformed the standard clinical staging in both endpoints (accuracy of 58% and 53% accuracy in the testing set for each endpoint). Conclusion: Although obtained in a small cohort of patients, our results suggest that a consensus of machine learning algorithms can improve performance in the context of radiomics. The resulting prognostic stratification in the prospective testing cohort is higher than when relying on the clinical stage. This could be of interest for clinical practice as it could help to identify patients with higher risk amongst stage II and III patients, who could benefit from intensified treatment and/or more frequent follow-up after treatment.
Immune Response Visualized In Vivo by [18F]-FDG PET/CT after COVID-19 Vaccine
Authors: Seban Romain-David , Champion Laurence , Deleval Nicolas , Richard Capucine , Provost Claire
Published: April 2021

Worldwide deployment of COVID-19 vaccines is in progress. Recent immune activation following vaccination can sometimes be seen in fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography ([18F]-FDG PET/CT). As previously evidenced, FDG-avid axillary lymph node(s) are common in patients receiving vaccines against SARS-CoV-2, influenza virus, or human papillomavirus, and reflect a regional immune response. In addition, these findings may also be accompanied by an increased spleen glucose metabolism after the COVID-19 vaccine, which captures a systemic immune response. Hence, we provide here a clinical example demonstrating that immune response could be associated with increased glucose metabolism in lymphoid organs such as lymph nodes and the spleen, which are critical modulators of T cell immunity. We believe that it is of paramount importance that nuclear physicians should be able to recognize clinical and imaging features of such immune responses upon vaccination for COVID-19 and beyond.
Serological Tests in the Detection of SARS-CoV-2 Antibodies
Authors: Guevara-Hoyer Kissy , Fuentes-Antrás Jesús , De la Fuente-Muñoz Eduardo , Rodríguez de la Peña Antonia , Viñuela Marcos , Cabello-Clotet Noemí , Estrada Vicente , Culebras Esther , Delgado-Iribarren Alberto , Martínez-Novillo Mercedes , Torrejón Maria José , Pérez de Diego Rebeca , Fernández-Arquero Miguel , Ocaña Alberto , Pérez-Segura Pedro , Sánchez-Ramón Silvia
Published: April 2021

Early detection of SARS-CoV-2 is essential for a timely update of health policies and allocation of resources. Particularly, serological testing may allow individuals with low-risk of being contagious of SARS-CoV-2 to return to daily activities. Both private and academic initiatives have sought to develop serological assays to detect anti-SARS-CoV-2 antibodies. Herein, we compared five different assays in active healthcare personnel exposed to SARS-CoV-2 in a large center in Madrid, Spain, in a retrospective study. Median time lapse between polymerase chain-reaction (PCR) and serological testing was 11 days (7–21). All tests assessed IgM/IgG titers except for Euroimmun (IgA/IgG) and The Binding-Site (IgA/IgM/IgG). The highest concordance rate was observed between Dia.Pro and Euroimmun (75.76%), while it was lowest between The Binding-Site and Euroimmun (44.55%). The Binding-Site assay showed the highest concordance (85.52%) with PCR results. Considering PCR results as reference, Dia.Pro was the most sensitive test, although The Binding-Site assay exhibited the highest area under the curve (AUC; 0.85). OrientGene and MAGLUMI tests were performed in a smaller cohort with confirmed infection and thus were not adequate to estimate sensitivity and specificity. The Binding-Site assay presented the best joint sensitivity and specificity among all the tests analyzed in our cohort. Likewise, this serological assay presents a greater repertoire of antibodies and antigen-regions tested, which is why each individual’s humoral immunity is more accurately reflected. The better the immunity test, the most adequate the health strategy to take in terms of organization of consultations, surgery, and treatments in vulnerable patients. The three antibody classes (IgG/IgM/IgA) were determined jointly, which translates to an economic impact on healthcare. While their role in the protection status remains elusive, serological tests add a valuable tool in the early management of SARS-CoV-2 after known exposition.
Pulmonary Hypertension in Association with Lung Disease: Quantitative CT and Artificial Intelligence to the Rescue? State-of-the-Art Review
Authors: Dwivedi Krit , Sharkey Michael , Condliffe Robin , Uthoff Johanna M. , Alabed Samer , Metherall Peter , Lu Haiping , Wild Jim M. , Hoffman Eric A. , Swift Andrew J. , Kiely David G.
Published: April 2021

Accurate phenotyping of patients with pulmonary hypertension (PH) is an integral part of informing disease classification, treatment, and prognosis. The impact of lung disease on PH outcomes and response to treatment remains a challenging area with limited progress. Imaging with computed tomography (CT) plays an important role in patients with suspected PH when assessing for parenchymal lung disease, however, current assessments are limited by their semi-qualitative nature. Quantitative chest-CT (QCT) allows numerical quantification of lung parenchymal disease beyond subjective visual assessment. This has facilitated advances in radiological assessment and clinical correlation of a range of lung diseases including emphysema, interstitial lung disease, and coronavirus disease 2019 (COVID-19). Artificial Intelligence approaches have the potential to facilitate rapid quantitative assessments. Benefits of cross-sectional imaging include ease and speed of scan acquisition, repeatability and the potential for novel insights beyond visual assessment alone. Potential clinical benefits include improved phenotyping and prediction of treatment response and survival. Artificial intelligence approaches also have the potential to aid more focused study of pulmonary arterial hypertension (PAH) therapies by identifying more homogeneous subgroups of patients with lung disease. This state-of-the-art review summarizes recent QCT developments and potential applications in patients with PH with a focus on lung disease.
EcoQBNs: First Application of Ecological Modeling with Quantum Bayesian Networks
Authors: Marcot Bruce G.
Published: April 2021

A recent advancement in modeling was the development of quantum Bayesian networks (QBNs). QBNs generally differ from BNs by substituting traditional Bayes calculus in probability tables with the quantum amplification wave functions. QBNs can solve a variety of problems which are unsolvable by, or are too complex for, traditional BNs. These include problems with feedback loops and temporal expansions; problems with non-commutative dependencies in which the order of the specification of priors affects the posterior outcomes; problems with intransitive dependencies constituting the circular dominance of the outcomes; problems in which the input variables can affect each other, even if they are not causally linked (entanglement); problems in which there may be >1 dominant probability outcome dependent on small variations in inputs (superpositioning); and problems in which the outcomes are nonintuitive and defy traditional probability calculus (Parrondo’s paradox and the violation of the Sure Thing Principle). I present simple examples of these situations illustrating problems in prediction and diagnosis, and I demonstrate how BN solutions are infeasible, or at best require overly-complex latent variable structures. I then argue that many problems in ecology and evolution can be better depicted with ecological QBN (EcoQBN) modeling. The situations that fit these kinds of problems include noncommutative and intransitive ecosystems responding to suites of disturbance regimes with no specific or single climax condition, or that respond differently depending on the specific sequence of the disturbances (priors). Case examples are presented on the evaluation of habitat conditions for a bat species, representing state-transition models of a boreal forest under disturbance, and the entrainment of auditory signals among organisms. I argue that many current ecological analysis structures—such as state-and-transition models, predator–prey dynamics, the evolution of symbiotic relationships, ecological disturbance models, and much more—could greatly benefit from a QBN approach. I conclude by presenting EcoQBNs as a nascent field needing the further development of the quantum mathematical structures and, eventually, adjuncts to existing BN modeling shells or entirely new software programs to facilitate model development and application.
Multifractality through Non-Markovian Stochastic Processes in the Scale Relativity Theory. Acute Arterial Occlusions as Scale Transitions
Authors: Tesloianu Nicolae Dan , Dobreci Lucian , Ghizdovat Vlad , Zala Andrei , Cotirlet Adrian Valentin , Gavrilut Alina , Agop Maricel , Vasincu Decebal , Nedelciuc Igor , Rusu Cristina Marcela , Costache Irina Iuliana
Published: April 2021

By assimilating biological systems, both structural and functional, into multifractal objects, their behavior can be described in the framework of the scale relativity theory, in any of its forms (standard form in Nottale’s sense and/or the form of the multifractal theory of motion). By operating in the context of the multifractal theory of motion, based on multifractalization through non-Markovian stochastic processes, the main results of Nottale’s theory can be generalized (specific momentum conservation laws, both at differentiable and non-differentiable resolution scales, specific momentum conservation law associated with the differentiable–non-differentiable scale transition, etc.). In such a context, all results are explicated through analyzing biological processes, such as acute arterial occlusions as scale transitions. Thus, we show through a biophysical multifractal model that the blocking of the lumen of a healthy artery can happen as a result of the “stopping effect” associated with the differentiable-non-differentiable scale transition. We consider that blood entities move on continuous but non-differentiable (multifractal) curves. We determine the biophysical parameters that characterize the blood flow as a Bingham-type rheological fluid through a normal arterial structure assimilated with a horizontal “pipe” with circular symmetry. Our model has been validated based on experimental clinical data.
CIRO: The Effects of Visually Diminished Real Objects on Human Perception in Handheld Augmented Reality
Authors: Kim Hanseob , Kim Taehyung , Lee Myungho , Kim Gerard Jounghyun , Hwang Jae-In
Published: April 2021

Augmented reality (AR) scenes often inadvertently contain real world objects that are not relevant to the main AR content, such as arbitrary passersby on the street. We refer to these real-world objects as content-irrelevant real objects (CIROs). CIROs may distract users from focusing on the AR content and bring about perceptual issues (e.g., depth distortion or physicality conflict). In a prior work, we carried out a comparative experiment investigating the effects on user perception of the AR content by the degree of the visual diminishment of such a CIRO. Our findings revealed that the diminished representation had positive impacts on human perception, such as reducing the distraction and increasing the presence of the AR objects in the real environment. However, in that work, the ground truth test was staged with perfect and artifact-free diminishment. In this work, we applied an actual real-time object diminishment algorithm on the handheld AR platform, which cannot be completely artifact-free in practice, and evaluated its performance both objectively and subjectively. We found that the imperfect diminishment and visual artifacts can negatively affect the subjective user experience.
Impact of Attrition Ball-Mill on Characteristics and Biochemical Methane Potential of Food Waste
Authors: Gu Yang Mo , Park Seon Young , Park Ji Yeon , Sang Byoung-In , Jeon Byoung Seong , Kim Hyunook , Lee Jin Hyung
Published: April 2021

The impact of attrition ball-mill pretreatment on food waste particle size, soluble chemical oxygen demand (SCOD), biochemical methane potential, and microbial community during anaerobic digestion was investigated based on milling speed and time. The uniformity of particle size improved with increasing milling speed and time. The SCOD of the pretreated samples increased to 4%, 7%, and 17% at the speeds of 150, 225, and 300 rpm, respectively, compared to the control. Milling time did not significantly change the SCOD. The cumulative methane productions of 430, 440, and 490 mL/g-VS were observed at the speeds of 150, 225, and 300 rpm, respectively, while the untreated sample exhibited the cumulative methane production of 390 mL/g-VS. Extended milling time did not improve methane production much. When the milling times of 10, 20, and 30 min were applied with the milling speed fixed at 300 rpm, the methane productions of 490, 510, and 500 mL/g-VS were observed respectively. Ball-mill pretreatment also increased the total volatile fatty acids. During the anaerobic digestion (AD) of ball-mill treated food waste, acetoclastic methanogens predominated, with a relative abundance of 48–49%. Interestingly, hydrogenotrophic methanogens were 1.6 times higher in the pretreated samples than those in the control. These results showed the potential of attrition ball milling as a food waste pretreatment for improving methane production.
Health Risks Associated with Occupational Exposure to Biological Air Pollutants Occurring during the Processing of Biomass for Energy Purposes: A Case Study
Authors: Brągoszewska Ewa , Pawlak Maja
Published: April 2021

The main goal of this study was to assess the levels of concentration of biological air pollutants in biomass processing power plants, based on the measurements taken in a plant located in Southern Poland. This work shows problems related to the co-combustion of biomass and indicates the health risks to which employees of positions closely related to the processing and combustion of biomass are exposed. Bacterial and fungal aerosol samples were collected using a six-stage Andersen cascade impactor with aerodynamic cut-off diameters of 7.0, 4.7, 3.3, 2.1, 1.1 and 0.65 µm (Tisch Environmental, USA). The highest average concentration level of micro-organisms was recorded in the air in the biomass analysis laboratory, where there was no constant airflow. It was found that the concentration levels of biological agents were below the Polish proposals for threshold limit values in the work environment polluted with organic dust. However, it was observed that the share of the respirable fraction (RF) of bacterial aerosol (particles less than 3.3 µm) in workplaces was equal to or higher than 50% of the total concentration, which may cause increased potentially adverse health effects and problems with concentration among power plant employees. Therefore, to ensure adequate air quality in the tested object, it is necessary to properly ventilate. This preliminary research could be the important starting point for a complete and precise assessment of bioaerosol exposures in biomass processing power plants in order to protect workers’ health.
On the Retrial-Queuing Model for Strategic Access and Equilibrium-Joining Strategies of Cognitive Users in Cognitive-Radio Networks with Energy Harvesting
Authors: Devarajan Kalpana , Senthilkumar Muthukrishnan
Published: April 2021

This article studies the strategic access of single-server retrial queue with two types of customers, where priority is given according to their category. On the basis of this concept, a cognitive-radio network was developed as retrial queue with energy harvesting. Cognitive radio allows for a secondary user to opportunistically access the idle spectrum of a primary user (PU). Upon arrival of a primary user, the service given to the secondary user by the cognitive radio is interrupted, and the PU band is available for the primary user. After completion of service for the primary user, the PU band is again available to secondary users. Performance metrics are derived to study the equilibrium strategies of secondary users. A Stackelberg game was formulated and Nash equilibrium was derived for the noncooperative strategy of the secondary user. Game-theory concepts are incorporated with queuing theory ideas to obtain the net benefit for the noncooperative strategy and social benefit for cooperative strategy. Lastly, analytical results are verified with numerical examples, and the effects of energy-harvesting rate are discussed.
Barriers to BIM Implementation in Architecture, Construction, and Engineering Projects—The Polish Study
Authors: Leśniak Agnieszka , Górka Monika , Skrzypczak Izabela
Published: April 2021

BIM (building information modeling) is a kind of technology that has great potential to enhance the level of automation in architecture, engineering, and construction (AEC) projects. The created virtual model of the facility allows coordinating all industries during the entire life cycle of the building. The possibility to save the data related to the given facility in one place, namely in the BIM model, enables control and management of the AEC projects at every stage. During the design and implementation phase, BIM models facilitate the optimization of time, costs, and quality, and in the operational phase, they support effective management of the facility. The use of BIM for building energy modeling (BEM) is the next step of evolution in architecture and engineering design practice. The benefits of using the BIM approach are widely discussed in the literature; however, they may be hard to achieve if appropriate attention is not directed to minimizing the barriers to the implementation of this technology. Observing Europe, one can notice that western and northern countries successfully use BIM for their needs, while the countries of the Eastern Bloc, including Poland, introduce it at a slower pace. In the present paper, the authors conducted a cause-and-effect analysis of the identified barriers to the implementation of BIM technology in the construction process. For this purpose, the authors applied the Ishikawa diagram, which is a tool that helps to recognize the actual or potential causes of failure. The analysis conducted showed that one of the weakest links in the successful BIM implementation is people and, in particular, their lack of knowledge and reluctance to change. The authors indicated the need to introduce and strengthen preventive actions, mainly through education: training, courses, and studies focused on BIM technology.
Self-Sustaining Bioelectrochemical Cell from Fungal Degradation of Lignin-Rich Agrowaste
Authors: Sukri Asiah , Othman Raihan , Abd-Wahab Firdaus , M. Noor Noraini
Published: April 2021

The present work describes a self-sustaining bioelectrochemical system that adopts simple cell configurations and operates in uncontrolled ambient surroundings. The microbial fuel cell (MFC) was comprised of white-rot fungus of Phanaerochaete chrysosporium fed with oil palm empty fruit bunch (EFB) as the substrate. This fungal strain degrades lignin by producing ligninolytic enzymes such as laccase, which demonstrates a specific affinity for oxygen as its electron acceptor. By simply pairing zinc and the air electrode in a membraneless, single-chamber, 250-mL enclosure, electricity could be harvested. The microbial zinc/air cell is capable of sustaining a 1 mA discharge current continuously for 44 days (i.e., discharge capacity of 1056 mAh). The role of the metabolic activities of P. chrysosporium on EFB towards the MFC’s performance is supported by linear sweep voltammetry measurement and scanning electron microscopy observations. The ability of the MFC to sustain its discharge for a prolonged duration despite the fungal microbes not being attached to the air electrode is attributed to the formation of a network of filamentous hyphae under the submerged culture. Further, gradual lignin decomposition by fungal inocula ensures a continuous supply of laccase enzyme and radical oxidants to the MFC. These factors promote a self-sustaining MFC devoid of any control features.
Experimental Investigation of Combustion Characteristics on Opposed Piston Two-Stroke Gasoline Direct Injection Engine
Authors: Ma Fukang , Yang Wei , Xu Junfeng , Li Yufeng , Zhao Zhenfeng , Zhang Zhenyu , Wang Yifang
Published: April 2021

The combustion characteristics of an opposed-piston two-stroke gasoline engine are investigated with experiment. The energy conversion and exergy destruction are analyzed and the organization method of the combustion process is summarized. The effects of phase difference, scavenging pressure, injection timing, ignition timing, and dual spark plug ignition scheme on the combustion process and engine performance are discussed, respectively. The heat release rate of the opposed-piston two-stroke gasoline engine is consistent with the conventional gasoline engine. With the increase of opposed-piston motion phase difference, the scavenging efficiency decreases and overmuch residual exhaust gas is not beneficial to the combustion process. Meanwhile, the faster relative velocity of the opposed-piston near the inner dead center enhances the cylinder working volume change rate, which leads to the rapid decline of in-cylinder pressure and temperature. The 15 °CA of opposed-piston motion phase difference improves the scavenging and combustion process effectively. When scavenging pressure is 0.12 MPa, the scavenging efficiency and heat release rate are improved at medium-high speed conditions. With the delay of injection timing, the flame developing period decreases gradually, and the rapid burning period decreases and then increases. The rapid burning period may reach the minimum value when the injection advance angle is 100 °CA. With the delay of ignition timing, the flame developing period increases gradually, and the rapid combustion period decreases and then increases. The rapid combustion period may reach the minimum value when the ignition advance angle is 20 °CA. Notably, the flat-top piston structure should be matched with the dual spark plug, which the ignition advance angle is 20 °CA at medium-high load conditions.