bluuebunny/crossref_metadata_2025 huggingface dataset:
Vibration Analysis of Piezoelectric Cantilever Beams with Bimodular Functionally-Graded Properties
Authors: Jing Hong-Xia , He Xiao-Ting , Du Da-Wei , Peng Dan-Dan , Sun Jun-Yi
Published: August 2020

Piezoelectric materials have been found to have many electromechanical applications in intelligent devices, generally in the form of the flexible cantilever element; thus, the analysis to the corresponding cantilever is of importance, especially when advanced mechanical properties of piezoelectric materials should be taken into account. In this study, the vibration problem of a piezoelectric cantilever beam with bimodular functionally-graded properties is solved via analytical and numerical methods. First, based on the equivalent modulus of elasticity, the analytical solution for vibration of the cantilever beam is easily derived. By the simplified mechanical model based on subarea in tension and compression, as well as on the layer-wise theory, the bimodular functionally-graded materials are numerically simulated; thus, the numerical solution of the problem studied is obtained. The comparison between the theoretical solution and numerical study is carried out, showing that the result is reliable. This study shows that the bimodular functionally-graded properties may change, to some extent, the dynamic response of the piezoelectric cantilever beam; however, the influence could be relatively small and unobvious.
On the Synergy between Elemental Carbon and Inorganic Ions in the Determination of the Electrical Conductance Properties of Deposited Aerosols: Implications for Energy Applications
Authors: Ferrero Luca , Bigogno Alessandra , Cefalì Amedeo M. , Rovelli Grazia , D’Angelo Luca , Casati Marco , Losi Niccolò , Bolzacchini Ezio
Published: August 2020

The role of the elemental carbon (EC), in synergy with hygroscopic ionic species, was investigated to study the formation of electrical bridging phenomena once the aerosol deliquescence is achieved. Ambient aerosol samples were collected on hydrophobic surfaces in urban and rural sites in Northern Italy; their conductance was measured in an Aerosol Exposure Chamber (AEC) while varying the relative humidity. An electric signal was detected on 64% of the collected samples with conductance values (11.20 ± 7.43 μS) above the failure threshold (1 μS) of printed circuit boards. The ionic content was higher for non-electrically conductive samples (43.7 ± 5.6%) than for electrically conductive ones (37.1 ± 5.6%). Conversely, EC was two times higher for electrically conductive samples (26.4 ± 4.1 μg cm−2; 8.4 ± 1.7%) than for non-electrical ones (12.0 ± 4.1 μg cm−2; 5.2 ± 1.9%) suggesting that the synergy between the ionic and carbonaceous fractions is necessary to promote a bridging phenomenon. Synthetic aerosols (EC only, saline only, mixed saline and EC) were generated in laboratory and their conductance was measured in the AEC to verify the ambient results. Only in case of a contemporary presence of both EC and ionic components the bridging phenomenon occurred in keeping with the theoretical deliquescence values of each salt (R2 = 0.996).
Assessment of Fiber Orientation on the Mechanical Properties of PA6/Cellulose Composite
Authors: Sridhara Pruthvi K. , Vilaseca Fabiola
Published: August 2020

Cellulose is being considered as a suitable renewable reinforcement for materials production. In particular, cellulose based composites are attracting global interest for their unique and intrinsic properties such as strength to weight ratio, dimensional stability and low thermal expansion and contraction. This article investigates the preparation of cellulose pulp fibers with polyamide-6 (PA6) polymer and the effect of fiber orientation within the matrix on the final properties of the biocomposite. Cellulose pulp fibers were melt compounded with PA6 using a thermo-kinetic mixer. Different formulations were prepared and the compounds were manufactured into test samples by injection molding. Mechanical characterization revealed that elastic modulus and the flexural properties increased linearly with the fiber composition. The effect of fiber orientation was examined from square samples out of which individual specimens were cut at different directions with respect to the flow direction. The contributions related to fiber content and effect of fiber orientation on the tensile properties assessed lent positively towards parallel oriented samples (0°) with respect to flow direction. Furthermore, the cellulose network within the biocomposite revealed the superior interfacial properties between the cellulose and PA6 matrix when observed under a scanning electron microscope.
Sound Quality Estimation of Electric Vehicles Based on GA-BP Artificial Neural Networks
Authors: Qian Kun , Hou Zhichao , Sun Dengke
Published: August 2020

The sound quality (SQ) and sound perception assessments of electric vehicles (EVs) clearly differ from those of conventional internal combustion engine vehicles (ICEVs). Therefore, it is essential to describe and evaluate the SQ of EVs. To evaluate the SQ in EVs, it is necessary to organize evaluators for conducting subjective jury tests, which are time-consuming and labor-intensive. In addition, the evaluation results are subject to the evaluators themselves and other external interferences. With the advancement of machine learning and artificial neural networks (ANNs), this problem can be well solved. This paper outlines a model for SQ estimation in EVs based on a genetic algorithm-optimized back propagation artificial neural network (GA-BP ANN). Moreover, the correlation between the physical-psychoacoustical parameters and the subjective SQ estimations obtained from the jury tests was investigated in this study. It was found that the GA-BP ANN SQ model has many advantages in comparison with the multiple linear regression (MLR) model in terms of precision and generalization. In addition, this method is ready to be applied for rapidly evaluating the SQ in EVs without jury tests, and it can also be of high significance in dealing with the acoustical designs and improvements of EVs in the future.
Virtual Control Volume Approach to the Study of Climate Causal Flows: Identification of Humidity and Wind Pathways of Influence on Rainfall in Ecuador
Authors: Vázquez-Patiño Angel , Campozano Lenin , Ballari Daniela , Córdova Mario , Samaniego Esteban
Published: August 2020

Unraveling the relationship between humidity, wind, and rainfall is vitally important to understand the dynamics of water vapor transport. In recent years, the use of causal networks to identify causal flows has gained much ground in the field of climatology to provide new insights about physical processes and hypothesize previously unknown ones. In this paper, the concept of a virtual control volume is proposed, which resembles the Eulerian description of a vector field, but is based on causal flows instead. A virtual control surface is used to identify the influence of surrounding climatic processes on the control volume (i.e., the study region). Such an influence is characterized by using a causal inference method that gives information about its direction and strength. The proposed approach was evaluated by inferring and spatially delineating areas of influence of humidity and wind on the rainfall of Ecuador. It was possible to confirm known patterns of influence, such as the influence of the Pacific Ocean on the coast and the influence of the Atlantic Ocean on the Amazon. Moreover, the approach was able to identify plausible new hypotheses, such as the influence of humidity on rainfall in the northern part of the boundary between the Andes and the Amazon, as well as the origin (the Amazon or the tropical Atlantic) and the altitude at which surrounding humidity and wind influence rainfall within the control volume. These hypotheses highlight the ability of the approach to exploit a large amount of scalar data and identify pathways of influence between climatic variables.
Quercetin Caused Redox Homeostasis Imbalance and Activated the Kynurenine Pathway
Authors: Adeyemi Oluyomi Stephen , Ebugosi Chinemerem , Akpor Oghenerobor Benjamin , Hetta Helal F. , Al-Rashed Sarah , Otohinoyi David Adeiza , Rotimi Damilare , Owolabi Akinyomade , Evbuomwan Ikponmwosa Owen , Batiha Gaber El-Saber
Published: August 2020

The search for new and better antimicrobial therapy is a continuous effort. Quercetin is a polyphenol with promising antimicrobial properties. However, the understanding of its antimicrobial mechanism is limited. In this study, we investigated the biochemical mechanistic action of quercetin as an antibacterial compound. Isolates of Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia, and Staphylococcus aureus were initially exposed to quercetin for antibacterial evaluation. Subsequently, S. aureus (Gram-positive) and E. coli (Gram-negative) cells were exposed to quercetin with or without ascorbic acid, and cells were harvested for selected biochemical assays. These assays included redox homeostasis (lipid peroxidation, total thiol, total antioxidant capacity), nitric oxide, and kynurenine concentration as well as DNA fragmentation. The results revealed that quercetin caused lipid peroxidation in the bacterial isolates. Lipid peroxidation may indicate ensuing oxidative stress resulting from quercetin treatment. Furthermore, tryptophan degradation to kynurenine was activated by quercetin in S. aureus but not in E. coli, suggesting that local L-tryptophan concentration might become limiting for bacterial growth. These findings, considered together, may indicate that quercetin restricts bacterial growth by promoting oxidative cellular stress, as well as by reducing the local L-tryptophan availability by activating the kynurenine pathway, thus contributing to our understanding of the molecular mechanism of the antimicrobial action of quercetin.
Visuo-Perceptual and Decision-Making Contributions to Visual Hallucinations in Mild Cognitive Impairment in Lewy Body Disease: Insights from a Drift Diffusion Analysis
Authors: Revie Lauren , Hamilton Calum A , Ciafone Joanna , Donaghy Paul C , Thomas Alan , Metzler-Baddeley Claudia
Published: August 2020

Background: Visual hallucinations (VH) are a common symptom in dementia with Lewy bodies (DLB); however, their cognitive underpinnings remain unclear. Hallucinations have been related to cognitive slowing in DLB and may arise due to impaired sensory input, dysregulation in top-down influences over perception, or an imbalance between the two, resulting in false visual inferences. Methods: Here we employed a drift diffusion model yielding estimates of perceptual encoding time, decision threshold, and drift rate of evidence accumulation to (i) investigate the nature of DLB-related slowing of responses and (ii) their relationship to visuospatial performance and visual hallucinations. The EZ drift diffusion model was fitted to mean reaction time (RT), accuracy and RT variance from two-choice reaction time (CRT) tasks and data were compared between groups of mild cognitive impairment (MCI-LB) LB patients (n = 49) and healthy older adults (n = 25). Results: No difference was detected in drift rate between patients and controls, but MCI-LB patients showed slower non-decision times and boundary separation values than control participants. Furthermore, non-decision time was negatively correlated with visuospatial performance in MCI-LB, and score on visual hallucinations inventory. However, only boundary separation was related to clinical incidence of visual hallucinations. Conclusions: These results suggest that a primary impairment in perceptual encoding may contribute to the visuospatial performance, however a more cautious response strategy may be related to visual hallucinations in Lewy body disease. Interestingly, MCI-LB patients showed no impairment in information processing ability, suggesting that, when perceptual encoding was successful, patients were able to normally process information, potentially explaining the variability of hallucination incidence.
Behavioral Deficits in Juvenile Onset Huntington’s Disease
Authors: Langbehn Kathleen E. , Cochran Ashley M. , van der Plas Ellen , Conrad Amy L. , Epping Eric , Martin Erin , Espe-Pfeifer Patricia , Nopoulos Peg
Published: August 2020

Reports of behavioral disturbance in Juvenile-Onset Huntington’s Disease (JOHD) have been based primarily on qualitative caregiver reports or retrospective medical record reviews. This study aims to quantify differences in behavior in patients with JOHD using informant- and self-report questionnaires. Informants of 21 children/young adults (12 female) with JOHD and 115 children/young adults (64 female) with a family history of Huntington’s Disease, but who did not inherit the disease themselves (Gene-Non-Expanded; GNE) completed the Behavior Rating Inventory of Executive Function (BRIEF) and the Pediatric Behavior Scale (PBS). Mixed linear regression models (age/sex adjusted) were conducted to assess group differences on these measures. The JOHD group had significantly higher scores, indicating more problems, than the GNE group on all BRIEF subscales, and measures of Aggression/Opposition and Hyperactivity/Inattention of the PBS (all p < 0.05). There were no group differences in Depression/Anxiety. Inhibit, Plan/Organize, Initiate, and Aggression/Opposition had significant negative correlations with Cytosine-Adenine-Guanine (CAG) repeat length (all p < 0.05) meaning that individuals with higher CAG repeats scored lower on these measures. There was greater discrepancy between higher informant-vs. lower self-reported scores in the JOHD group, supporting the notion of lack of insight for the JOHD-affected group. These results provide quantitative evidence of behavioral characteristics of JOHD.
Cytoreductive Surgery for Heavily Pre-Treated, Platinum-Resistant Epithelial Ovarian Carcinoma: A Two-Center Retrospective Experience
Authors: Tuninetti Valentina , Di Napoli Marilena , Ghisoni Eleonora , Maggiorotto Furio , Robella Manuela , Scotto Giulia , Giannone Gaia , Turinetto Margherita , Siatis Dimitris , Ponzone Riccardo , Vaira Marco , De Simone Michele , Scaffa Cono , Pignata Sandro , Greggi Stefano , Di Maio Massimo , Valabrega Giorgio
Published: August 2020

Few retrospective studies have shown a benefit in selected patients affected by heavily pre-treated, platinum-resistant ovarian carcinomas (PROCs) who have undergone cytoreduction at relapse. However, the role of tertiary and quaternary cytoreductive surgery is not fully defined. Our aim was to evaluate survival and surgical morbidity and mortality after maximal cytoreduction in this setting. We evaluated all consecutive patients undergoing cytoreduction for platinum-resistance over an 8-year period (2010–2018) in two different centers. Fifty patients (median age 52.5 years, range 34–75) were included; the median number of previous chemotherapy lines was three (range 1–7) and the median number of previous surgeries was one (range 1–4). Completeness of cytoreduction (CC = 0) was achieved in 22 patients (44%). Rates of major operative morbidity and 30-day mortality were 38% and 8%, respectively. Median follow-up was 35 months. The absence of tumor residual (CC = 0) was associated with a significantly better overall survival (OS) compared to the CC > 0 subgroup (median OS 32.9 months (95% CI 21.6–44.2) vs. 4.8 months (95% CI n.a.–9.8), hazard ratio (HR) 4.21 (95% CI 2.07–8.60), p < 0.001). Optimal cytoreduction is feasible and associated with promising OS in selected, heavily pre-treated PROCs. Further prospective studies are required to better define the role of surgery in platinum-resistant disease.
Genomic Mapping Identifies Mutations in RYR2 and AHNAK as Associated with Favorable Outcome in Basal-Like Breast Tumors Expressing PD1/PD-L1
Authors: Cimas Francisco J. , Manzano Arancha , Baliu-Piqué Mariona , García-Gil Elena , Pérez-Segura Pedro , Nagy Ádám , Pandiella Atanasio , Győrffy Balázs , Ocana Alberto
Published: August 2020

Treatment with anti-PD-L1 antibodies has shown efficacy in basal-like breast cancer. In this context, identification of pre-activated immune tumors is a main goal. Here we explore mutations in PD1 and PD-L1 high-expressing tumors to identify genomic correlates associated with outcome. To do so, RNA-seq and mutation data from 971 breast cancer patients from the TCGA dataset were used to identify most prevalent mutations in patients with high levels of PD1 and PD-L1. Transcriptomic signatures associated with the selected mutations were identified and analyzed in terms of outcome and immune cell infiltration. We identified co-occurrent mutations in RYR2 and AHNAK in 8% and 5% of basal-like tumors respectively, which conferred good prognosis in patients with high expression of PD1 and PD-L1 genes. The transcriptomic signature associated with these mutations, composed of CXCL9, GBP5, C1QA, IL2RG, CSF2RB, IDO1 and LAG3 genes, also conferred good prognosis and correlated with immune infiltrations within the tumors. The joint signature classified patients with favorable relapse-free survival (HR: 0.28; CI: 0.2–0.38; p = 1.7 × 10−16) and overall survival (HR: 0.18; CI: 0.09–0.34; p = 6.8 × 10−9), showing a stronger prediction capacity than previous reported signatures. In conclusion, we describe two novel mutations and their transcriptomic signature, both associated with a favorable outcome and immune infiltrates in PD1 and PD-L1 high-expressing basal-like tumors.
Association of a Palliative Surgical Approach to Stage IV Pancreatic Neuroendocrine Neoplasms with Survival: A Systematic Review and Meta-Analysis
Authors: Tsoli Marina , Spei Maria-Eleni , Wallin Göran , Kaltsas Gregory , Daskalakis Kosmas
Published: August 2020

The role of primary tumor resection in patients with pancreatic neuroendocrine neoplasms (PanNENs) and unresectable distant metastases remains controversial. We aimed to evaluate the effect of palliative primary tumor resection (PPTR) on overall survival (OS) in this setting. We searched the MEDLINE, Embase, Cochrane Library, Web of Science and SCOPUS databases up to January 2020 and used the Newcastle–Ottawa scale (NOS) criteria to assess quality/risk of bias. A total of 5661 articles were screened. In 10 studies, 5551 unique patients with stage IV PanNEN and unresectable metastases were included. The five-year OS for PanNEN patients undergoing PPTR in stage IV was 56.6% vs. 23.9% in the non-surgically treated patients (random effects relative risk (RR): 1.70; 95% CI: 1.53–1.89). Adjusted analysis of pooled hazard ratios (HR) confirmed longer OS in PanNEN patients undergoing PPTR (random effects HR: 2.67; 95% CI: 2.24–3.18). Cumulative OS analysis confirmed an attenuated survival benefit over time. The complication rate of PPTR was as high as 27%. In conclusion, PPTR may exert a survival benefit in stage IV PanNEN. However, the included studies were subject to selection bias, and special consideration should be given to PPTR anchored to a multimodal treatment strategy. Further longitudinal studies are warranted, with long-term follow-up addressing the survival outcomes associated with surgery in stage IV disease.
Intrinsic Balance between ZEB Family Members Is Important for Melanocyte Homeostasis and Melanoma Progression
Authors: Bruneel Kenneth , Verstappe Jeroen , Vandamme Niels , Berx Geert
Published: August 2020

It has become clear that cellular plasticity is a main driver of cancer therapy resistance. Consequently, there is a need to mechanistically identify the factors driving this process. The transcription factors of the zinc-finger E-box-binding homeobox family, consisting of ZEB1 and ZEB2, are notorious for their roles in epithelial-to-mesenchymal transition (EMT). However, in melanoma, an intrinsic balance between ZEB1 and ZEB2 seems to determine the cellular state by modulating the expression of the master regulator of melanocyte homeostasis, microphthalmia-associated transcription factor (MITF). ZEB2 drives MITF expression and is associated with a differentiated/proliferative melanoma cell state. On the other hand, ZEB1 is correlated with low MITF expression and a more invasive, stem cell-like and therapy-resistant cell state. This intrinsic balance between ZEB1 and ZEB2 could prove to be a promising therapeutic target for melanoma patients. In this review, we will summarise what is known on the functional mechanisms of these transcription factors. Moreover, we will look specifically at their roles during melanocyte-lineage development and homeostasis. Finally, we will overview the current literature on ZEB1 and ZEB2 in the melanoma context and link this to the ‘phenotype-switching’ model of melanoma cellular plasticity.
Uptake Transporters of the SLC21, SLC22A, and SLC15A Families in Anticancer Therapy—Modulators of Cellular Entry or Pharmacokinetics?
Authors: Brecht Karin , Schäfer Anima Magdalena , Meyer zu Schwabedissen Henriette E.
Published: August 2020

Solute carrier transporters comprise a large family of uptake transporters involved in the transmembrane transport of a wide array of endogenous substrates such as hormones, nutrients, and metabolites as well as of clinically important drugs. Several cancer therapeutics, ranging from chemotherapeutics such as topoisomerase inhibitors, DNA-intercalating drugs, and microtubule binders to targeted therapeutics such as tyrosine kinase inhibitors are substrates of solute carrier (SLC) transporters. Given that SLC transporters are expressed both in organs pivotal to drug absorption, distribution, metabolism, and elimination and in tumors, these transporters constitute determinants of cellular drug accumulation influencing intracellular drug concentration required for efficacy of the cancer treatment in tumor cells. In this review, we explore the current understanding of members of three SLC families, namely SLC21 (organic anion transporting polypeptides, OATPs), SLC22A (organic cation transporters, OCTs; organic cation/carnitine transporters, OCTNs; and organic anion transporters OATs), and SLC15A (peptide transporters, PEPTs) in the etiology of cancer, in transport of chemotherapeutic drugs, and their influence on efficacy or toxicity of pharmacotherapy. We further explore the idea to exploit the function of SLC transporters to enhance cancer cell accumulation of chemotherapeutics, which would be expected to reduce toxic side effects in healthy tissue and to improve efficacy.
Efficient One-Step Immobilization of CaLB Lipase over MOF Support NH2-MIL-53(Al)
Authors: Gascón-Pérez Victoria , Jiménez Mayra Belen , Molina Asunción , Blanco Rosa María , Sánchez-Sánchez Manuel
Published: August 2020

Metal-organic framework (MOF) materials possess the widest versatility in structure, composition, and synthesis procedures amongst the known families of materials. On the other hand, the extraordinary affinity between MOFs and enzymes has led to widely investigating these materials as platforms to support these catalytic proteins in recent years. In this work, the MOF material NH2-MIL-53(Al) has been tested as a support to immobilize by one-step methodology (in situ) the enzyme lipase CaLB from Candida antarctica by employing conditions that are compatible with its enzymatic activity (room temperature, aqueous solution, and moderate pH values). Once the nature of the linker deprotonating agent or the synthesis time were optimized, the MOF material resulted in quite efficient entrapping of the lipase CaLB through this in situ approach (>85% of the present enzyme in the synthesis media) while the supported enzyme retained acceptable activity (29% compared to the free enzyme) and had scarce enzyme leaching. The equivalent post-synthetic method led to biocatalysts with lower enzyme loading values. These results make clear that the formation of MOF support in the presence of the enzyme to be immobilized substantially improves the efficiency of the biocatalysts support for retaining the enzyme and limits their leaching.
Biology and Physics of Heterochromatin-Like Domains/Complexes
Authors: Singh Prim B. , Belyakin Stepan N. , Laktionov Petr P.
Published: August 2020

The hallmarks of constitutive heterochromatin, HP1 and H3K9me2/3, assemble heterochromatin-like domains/complexes outside canonical constitutively heterochromatic territories where they regulate chromatin template-dependent processes. Domains are more than 100 kb in size; complexes less than 100 kb. They are present in the genomes of organisms ranging from fission yeast to human, with an expansion in size and number in mammals. Some of the likely functions of domains/complexes include silencing of the donor mating type region in fission yeast, preservation of DNA methylation at imprinted germline differentially methylated regions (gDMRs) and regulation of the phylotypic progression during vertebrate development. Far cis- and trans-contacts between micro-phase separated domains/complexes in mammalian nuclei contribute to the emergence of epigenetic compartmental domains (ECDs) detected in Hi-C maps. A thermodynamic description of micro-phase separation of heterochromatin-like domains/complexes may require a gestalt shift away from the monomer as the “unit of incompatibility” that determines the sign and magnitude of the Flory–Huggins parameter, χ. Instead, a more dynamic structure, the oligo-nucleosomal “clutch”, consisting of between 2 and 10 nucleosomes is both the long sought-after secondary structure of chromatin and its unit of incompatibility. Based on this assumption we present a simple theoretical framework that enables an estimation of χ for domains/complexes flanked by euchromatin and thereby an indication of their tendency to phase separate. The degree of phase separation is specified by χN, where N is the number of “clutches” in a domain/complex. Our approach could provide an additional tool for understanding the biophysics of the 3D genome.
Increased Resilience Weakens the Relationship between Perceived Stress and Anxiety on Sleep Quality: A Moderated Mediation Analysis of Higher Education Students from 7 Countries
Authors: Du Chen , Zan Megan Chong Hueh , Cho Min Jung , Fenton Jenifer I. , Hsiao Pao Ying , Hsiao Richard , Keaver Laura , Lai Chang-Chi , Lee HeeSoon , Ludy Mary-Jon , Shen Wan , Swee Winnie Chee Siew , Thrivikraman Jyothi , Tseng Kuo-Wei , Tseng Wei-Chin , Tucker Robin M.
Published: August 2020

High levels of perceived stress and anxiety among university students are a global concern and are known to negatively influence sleep. However, few studies have explored how stress response styles, like psychological resilience and rumination, might alter these relationships. Using validated tools, perceived stress, anxiety, stress response styles, and sleep behaviors of undergraduate and graduate students from seven countries during the height of the COVID-19 pandemic were characterized in order to examine the relationships between these factors using mediation and moderation analyses. Students enrolled in universities in China, Ireland, Malaysia, Taiwan, South Korea, the Netherlands, and the United States were recruited in May 2020. A total of 2254 students completed this cross-sectional study. Perceived stress and anxiety were negatively associated with sleep quality through the mediation of rumination. Increased psychological resilience weakened the relationships between perceived stress and anxiety on sleep quality. The majority of students reported that COVID-19 negatively influenced their mental health and sleep quality but not sleep duration. Based on these results, university students would likely benefit from sleep education and mental health promotion programs that include trainings to increase psychological resilience and reduce rumination, particularly during times of increased stress.
Modelling the Anti-Methicillin-Resistant Staphylococcus Aureus (MRSA) Activity of Cannabinoids: A QSAR and Docking Study
Authors: Cortes Eliceo , Mora José , Márquez Edgar
Published: August 2020

Twenty-four cannabinoids active against MRSA SA1199B and XU212 were optimized at WB97XD/6-31G(d,p), and several molecular descriptors were obtained. Using a multiple linear regression method, several mathematical models with statistical significance were obtained. The robustness of the models was validated, employing the leave-one-out cross-validation and Y-scrambling methods. The entire data set was docked against penicillin-binding protein, iso-tyrosyl tRNA synthetase, and DNA gyrase. The most active cannabinoids had high affinity to penicillin-binding protein (PBP), whereas the least active compounds had low affinities for all of the targets. Among the cannabinoid compounds, Cannabinoid 2 was highlighted due to its suitable combination of both antimicrobial activity and higher scoring values against the selected target; therefore, its docking performance was compared to that of oxacillin, a commercial PBP inhibitor. The 2D figures reveal that both compounds hit the protein in the active site with a similar type of molecular interaction, where the hydroxyl groups in the aromatic ring of cannabinoids play a pivotal role in the biological activity. These results provide some evidence that the anti-Staphylococcus aureus activity of these cannabinoids may be related to the inhibition of the PBP protein; besides, the robustness of the models along with the docking and Quantitative Structure–Activity Relationship (QSAR) results allow the proposal of three new compounds; the predicted activity combined with the scoring values against PBP should encourage future synthesis and experimental testing.
Effects of the Target on the Performance of an Ultra-Low Power Eddy Current Displacement Sensor for Industrial Applications
Authors: Bertacchini Alessandro , Lasagni Marco , Sereni Gabriele
Published: August 2020

The demand for smart, low-power, and low-cost sensors is rapidly increasing with the proliferation of industry automation. In this context, an Ultra-Low Power Eddy Current Displacement Sensor (ULP-ECDS) targeting common industrial applications and designed to be embedded in wireless Industrial Internet of Things (IIoT) devices is presented. A complete characterization of the realized ULP-ECDS operating with different metallic targets was carried out. The choice of the considered targets in terms of material and thickness was inspired by typical industrial scenarios. The experimental results show that the realized prototype works properly with extremely low supply voltages, allowing for obtaining an ultra-low power consumption, significantly lower than other state-of-the-art solutions. In particular, the proposed sensor reached the best resolution of 2 µm in case of a carbon steel target when operated with a supply voltage of 200 mV and with a power consumption of 150 µW. By accepting a resolution of 12 µm, it is possible to further reduce the power consumption of the sensor to less than 10 µW. The obtained results also demonstrate how the performances of the sensor are strongly dependent on both the target and the demodulation technique used to extract the displacement information. This allowed for defining some practical guidelines that can help the design of effective solutions considering application-specific constraints.
Electromagnetic Disturbed Mechanism of Electronic Current Transformer Acquisition Card under High Frequency Electromagnetic Interference
Authors: Liu Guanchen , Zhao Peng , Zhao Mingmin , Yang Zhichao , Chen Henglin
Published: August 2020

The electronic current transformer (ECT) acquisition card is widely used in smart grids with many advantages. However, with the continuous improvement of the power grid and localized intelligent electronic devices, the electromagnetic environment under the operating conditions of gas insulated switchgear (GIS) substations is becoming more complicated. The reliability and safety of the ECT acquisition card will be endangered due to the complicated electromagnetic environment. In order to solve these problems, this paper investigates the electromagnetic disturbed mechanism of the ECT acquisition card. The effects of different grounding methods on the electromagnetic interference of the ECT acquisition card were studied. A platform based on IEC 61000-4-4 was built, and the electromagnetic interference (EMI) of the ECT acquisition card with different grounding methods was measured. The results show that the lower grounding impedance of the ECT acquisition system increased the internal EMI. Further, the high frequency electrical fast transient/burst coupling mechanism was analyzed. The parasitic parameters of the acquisition card were extracted based on the critical circuit by using the finite element method. Then, the high-frequency EMI coupling model of the ECT acquisition card was established.
Power Optimization for Wind Turbines Based on Stacking Model and Pitch Angle Adjustment
Authors: Luo Zhikun , Sun Zhifeng , Ma Fengli , Qin Yihan , Ma Shihao
Published: August 2020

As we know, power optimization for wind turbines has great significance in the area of wind power generation, which means to make use of wind resources more efficiently. Especially nowadays, wind power generation has become more and more important. Generally speaking, many parameters could be optimized to enhance power output, including blade pitch angle, which is usually ignored. In this article, a stacking model composed of Random Forest (RF), Gradient Boosting Decision Tree (GBDT), Extreme Gradient Boosting (XGBOOST) and Light Gradient Boosting Machine (LGBM) is trained based on historical data exported from the Supervisory Control and Data Acquisition (SCADA) system for output power prediction. Then, we carry out power optimization through pitch angle adjustment based on the obtained prediction model. Our research results indicate that power output could be enhanced by adjusting pitch angle appropriately.
On the Performance of Night Ventilation in a Historic Office Building in Nordic Climate
Authors: Bakhtiari Hossein , Akander Jan , Cehlin Mathias , Hayati Abolfazl
Published: August 2020

The effect of mechanical night ventilation on thermal comfort and electricity use for cooling of a typical historic office building in north-central Sweden was assessed. IDA-ICE simulation program was used to model the potential for improving thermal comfort and electricity savings by applying night ventilation cooling. Parametric study comprised different outdoor climates, flow rates, cooling machine’s coefficient of performance and ventilation units’ specific fan power values. Additionally, the effect of different door schemes (open or closed) on thermal comfort in offices was investigated. It was shown that night ventilation cannot meet the building’s total cooling demand and auxiliary active cooling is required, although the building is located in a cold climate. Night ventilation had the potential in decreasing the percentage of exceedance hours in offices by up to 33% and decreasing the total electricity use for cooling by up to 40%. More electricity is saved with higher night ventilation rates. There is, however, a maximum beneficial ventilation rate above which the increase in electricity use in fans outweighs the decrease in electricity use in cooling machine. It depends on thermal mass capacity of the building, cooling machine´s coefficient of performance, design ventilation rate, and available night ventilation cooling potential (ambient air temperature).
Combustion Characteristics of Hydrochar and Pyrochar Derived from Digested Sewage Sludge
Authors: Arauzo Pablo J. , Atienza-Martínez María , Ábrego Javier , Olszewski Maciej P. , Cao Zebin , Kruse Andrea
Published: August 2020

In this paper, hydrochars and pyrochars were produced at 260 °C under different residence times (2 and 4 h) using anaerobic digested sewage sludge (SSL) as initial feedstock. The effect of reaction time on the fuel properties of hydrochars and pyrochars was evaluated. Moreover, the combustion kinetics of raw SSL and the derived pyrochars and hydrochars without coal blending were determined at two different air flows (20 and 90 mL/min) and compared. In the same conditions, the yield of hydrochar was significantly lower than that of pyrochar, confirming the different reaction pathways followed in each process. The results showed hydrochars have lower carbon recovery and energy yield than pyrochars, making the latter more suitable for energy purposes. The thermogravimetric combustion study showed that both thermochemical treatments increased the ignition temperature but decreased the burnout temperature, which results in higher stability during handling and storage. However, raw SSL is better for combustion than hydrochar according to the combustibility index. In addition, the kinetic study showed that the activation energy of the combustion of biochars, especially pyrochar, is lower than that of raw SSL, which is advantageous for their combustion.
Changing the Vision in Smart Food Design Utilizing the Next Generation of Nanometric Delivery Systems for Bioactive Compounds
Authors: Donsì Francesco , Ferrari Giovanna
Published: August 2020

In modern foods, the delivery systems for bioactive compounds play a fundamental role in health promotion, wellbeing, and disease prevention through diet. Nanotechnology has secured a fundamental role in the fabrication of delivery systems with the capability of modulating the in-product and in-body behavior for augmenting bioavailability and activity of bioactive compounds. Structured nanoemulsions and nanoparticles, liposomes, and niosomes can be designed to improve bioactives preservation after ingestion, mucoadhesion, as well as of their release and pathophysiological relevance. In the future, it is expected that the delivery systems will also contribute to augment the efficacy of the bioactive compounds, for example by improving the intestinal absorption and delivery in the bloodstream, as well as promoting the formation of additional bioactive metabolites by regulating the transformations taking place during digestion and the interaction with the intestinal microbiota.
Air-Jet Spun Corn Zein Nanofibers and Thin Films with Topical Drug for Medical Applications
Authors: Gough Christopher R. , Bessette Kristen , Xue Ye , Mou Xiaoyang , Hu Xiao
Published: August 2020

Diabetic patients are especially susceptible to chronic wounds of the skin, which can lead to serious complications. Sodium citrate is one potential therapeutic molecule for the topical treatment of diabetic ulcers, but its viability requires the assistance of a biomaterial matrix. In this study, nanofibers and thin films fabricated from natural corn zein protein are explored as a drug delivery vehicle for the topical drug delivery of sodium citrate. Corn zein is cheap and abundant in nature, and easily extracted with high purity, while nanofibers are frequently cited as ideal drug carriers due to their high surface area and high porosity. To further reduce costs, the 1-D nanofibers in this study were fabricated through an air jet-spinning method rather than the conventional electrospinning method. Thin films were also created as a comparative 2-D material. Corn zein composite nanofibers and thin films with different concentration of sodium citrate (1–30%) were analyzed through FTIR, DSC, TGA, and SEM. Results reveal that nanofibers are a much more effective vehicle than films, with the ability to interact with sodium citrate. Thermal analysis results show a stable material with low degradation, while FTIR reveals strong control over the protein secondary structures and hold of citrate. These tunable properties and morphologies allow the fibers to provide a sustained release of citrate and then revert to their structure prior to citrate loading. A statistical analysis via t-test confirmed a significant difference between fiber and film drug release. A biocompatibility study also confirms that cells are much more tolerant of the porous nanofiber structure than the nonporous protein films, and lower percentages of sodium citrate (1–5%) were outperformed to higher percentages (15–30%). This study demonstrated that protein-based nanofiber materials have high potential as vehicles for the delivery of topical diabetic drugs.
A Novel Anion Exchange Membrane for Bisulfite Anion Separation by Grafting a Quaternized Moiety through BPPO via Thermal-Induced Phase Separation
Authors: Alam Md Mofasserul , Wang Yaoming , Jiang Chenxiao , Xu Tingting , Liu Yahua , Xu Tongwen
Published: August 2020

Ion-exchange membranes are the core elements for an electrodialysis (ED) separation process. Phase inversion is an effective method, particularly for commercial membrane production. It introduces two different mechanisms, i.e., thermal induced phase separation (TIPS) and diffusion induced phase separation (DIPS). In this study, anion exchange membranes (AEMs) were prepared by grafting a quaternized moiety (QM,2-[dimethylaminomethyl]naphthalen-1-ol) through brominated poly (2,6-dimethyl-1,4-phenylene oxide) (BPPO) via the TIPS method. Those membranes were applied for selective bisulfite (HSO3−) anion separation using ED. The membrane surface morphology was characterized by SEM, and the compositions were magnified using a high-resolution transmission electron microscope (HRTEM). Notably, the membranes showed excellent substance stability in an alkali medium and in grafting tests performed in a QM-soluble solvent. The ED experiment indicated that the as-prepared membrane exhibited better HSO3− separation performance than the state-of-the-art commercial Neosepta AMX (ASTOM, Japan) membrane.
CD117 Is a Specific Marker of Intraductal Papillary Mucinous Neoplasms (IPMN) of the Pancreas, Oncocytic Subtype
Authors: Mattiolo Paola , Hong Seung-Mo , Paolino Gaetano , Rusev Borislav C. , Marchegiani Giovanni , Salvia Roberto , Andrianello Stefano , Capelli Paola , Piccoli Paola , Parolini Claudia , Scarpa Aldo , Lawlor Rita T. , Luchini Claudio
Published: August 2020

The intraductal oncocytic papillary neoplasm (IOPN) of the pancreas has been recognized by WHO classification as a unique intraductal papillary mucinous neoplasm (IPMN) category. IOPN is composed of oxyphil cells, usually expressing MUC5AC, MUC6, and Hep Par-1, and harboring PRKACA/B fusion genes as their genetic hallmark. Although IOPNs are associated with an infiltrative adenocarcinoma in up to 30% of cases, the survival rate after surgical resection approaches 100%. This highlights the importance of the correct IOPN diagnosis, above all in cases with an associated invasive component. In this study, the immunohistochemical expression of CD117 was investigated in 111 IPMNs, including 17 oncocytic, 45 gastric, 20 pancreatico-biliary, and 29 intestinal IPMNs. We also tested the expression of MUC5AC, MUC6, and Hep Par-1 in the IOPN cohort. CD117 positivity was significantly more frequent in IOPNs compared to the other IPMN subtypes (p < 0.0001). Furthermore, within IOPN, a lower or absent CD117, MUC5AC, MUC6, and Hep Par-1 expression tended to be associated with the presence of an infiltrative component. Our findings shed light into the biology of these complex lesions, which are confirmed to be a distinctive IPMN subtype; notably, CD117 emerged as a potential, additional tool in the differential diagnosis of IPMNs.
The Rare Richardsitas Betsch (Collembola, Symphypleona, Sminthuridae): A New Species from Australia with Comments on the Genus and on the Sminthurinae
Authors: Medeiros Gleyce da S. , Greenslade Penelope , Bellini Bruno C.
Published: August 2020

Richardsitas Betsch is a small genus of Sminthurinae with only two species described so far, both from Madagascar. It resembles other Sminthurinae with long antennae, especially Temeritas Richards. Here we provide the first record of Richardsitas from Australia, Richardsitas subferoleum sp. nov., which is similar to R. najtae Betsch and R. griveaudi Betsch in males’ large abdomen chaetotaxy and presence of tenent-hairs on tibiotarsi II–III, but lacks mucronal chaeta and has 28 segments on the fourth antennal segment plus a unique pair of sensilla on the second. We also provide an updated genus diagnosis to Richardsitas, a key to its species, a discussion of the affinities of Temeritas and Richardsitas to other Sminthurinae, and an updated key to this subfamily.
Resilin Distribution and Sexual Dimorphism in the Midge Antenna and Their Influence on Frequency Sensitivity
Authors: Saltin Brian D. , Matsumura Yoko , Reid Andrew , Windmill James F. , Gorb Stanislav N. , Jackson Joseph C.
Published: August 2020

Small-scale bioacoustic sensors, such as antennae in insects, are often considered, biomechanically, to be not much more than the sum of their basic geometric features. Therefore, little is known about the fine structure and material properties of these sensors—even less so about the degree to which the well-known sexual dimorphism of the insect antenna structure affects those properties. By using confocal laser scanning microscopy (CLSM), we determined material composition patterns and estimated distribution of stiffer and softer materials in the antennae of males and females of the non-biting midge Chironomus riparius. Using finite element modelling (FEM), we also have evidence that the differences in composition of these antennae can influence their mechanical responses. This study points to the possibility that modulating the elastic and viscoelastic properties along the length of the antennae can affect resonant characteristics beyond those expected of simple mass-on-a-spring systems—in this case, a simple banded structure can change the antennal frequency sensitivity. This constitutes a simple principle that, now demonstrated in another Dipteran group, could be widespread in insects to improve various passive and active sensory performances.
The Biomechanical Behavior of Distal Foot Joints in Patients with Isolated, End-Stage Tibiotalar Osteoarthritis Is Not Altered Following Tibiotalar Fusion
Authors: Eerdekens Maarten , Deschamps Kevin , Wuite Sander , Matricali Giovanni
Published: August 2020

Ankle arthrodesis is considered to be an optimal treatment strategy to relieve pain during walking in patients with isolated, end-stage tibiotalar osteoarthritis. The aim of this study was to investigate the post-operative effect of an arthrodesis on the ankle and foot joint biomechanics. We included both patients (n = 10) and healthy reference data (n = 17). A multi-segment foot model was used to measure the kinematics and kinetics of the ankle, Chopart, Lisfranc, and first metatarsophalangeal joints during a three-dimensional (3D) gait analysis. These data, together with patient reported outcome measures, were collected at baseline (pre-operative) and one year post-operatively. Patients experienced a decrease in pain and an increase in general well-being after surgery. Compared to the baseline measurements, patients only demonstrated a significant average post-operative increase of 0.22 W/kg of power absorption in the ankle joint. No other significant differences were observed between baseline and post-operative measurements. Current findings suggest that the biomechanical behavior of distal foot joints is not altered one year after fusion. The pain relief achieved by the arthrodesis improved the loading patterns during walking. Clinical significance of this study dictates that patients do not have to fear a loss in biomechanical functionality after an ankle arthrodesis.