bluuebunny/crossref_metadata_2025 huggingface dataset:
The Role of Somatic Mutations on the Immune Response of the Tumor Microenvironment in Prostate Cancer
Authors: Melo Camila Morais , Vidotto Thiago , Chaves Luiz Paulo , Lautert-Dutra William , Reis Rodolfo Borges dos , Squire Jeremy Andrew
Published: September 2021

Immunotherapy has improved patient survival in many types of cancer, but for prostate cancer, initial results with immunotherapy have been disappointing. Prostate cancer is considered an immunologically excluded or cold tumor, unable to generate an effective T-cell response against cancer cells. However, a small but significant percentage of patients do respond to immunotherapy, suggesting that some specific molecular subtypes of this tumor may have a better response to checkpoint inhibitors. Recent findings suggest that, in addition to their function as cancer genes, somatic mutations of PTEN, TP53, RB1, CDK12, and DNA repair, or specific activation of regulatory pathways, such as ETS or MYC, may also facilitate immune evasion of the host response against cancer. This review presents an update of recent discoveries about the role that the common somatic mutations can play in changing the tumor microenvironment and immune response against prostate cancer. We describe how detailed molecular genetic analyses of the tumor microenvironment of prostate cancer using mouse models and human tumors are providing new insights into the cell types and pathways mediating immune responses. These analyses are helping researchers to design drug combinations that are more likely to target the molecular and immunological pathways that underlie treatment failure.
Performance of Polymer Cementitious Coatings for High-Voltage Electrical Infrastructure
Authors: Xu Bowen , Li Hui , Bompa Dan V. , Elghazouli Ahmed Y. , Chen Jiangbo
Published: September 2021

This paper investigates the electrical, thermal and mechanical properties as well as the environmental performance of polymer cementitious composites (PCCs) as sustainable coating materials for underground power cables and as high-voltage insulators. Particular focus is placed on the optimised mix design and the effect of the manufacturing method on the performance of PCCs, incorporating liquid styrene and acrylic (SA) monomers, wollastonite and muscovite. Microstructural investigations, together with results from strength tests, indicate that the manufacturing method is a key performance parameter. Experimental results show that PCC mixes containing 25% SA emulsion, 12.5% wollastonite and no muscovite provide the most favourable dielectric properties from the mixes investigated. The PCC material has a dielectric strength up to 16.5 kV/mm and a dielectric loss factor lower than 0.12. Additional experiments also show that PCC has good thermal stability and thermal conductivity. The mechanical strength tests indicate that PCC specimens possess reliable strengths which are applicable in structural design. Environmental assessments also show that PCCs possess significantly lower embodied energy and embodied carbon than conventional plastic insulating materials.
Fascination and Joy: Emotions Predict Urban Gardeners’ Pro-Pollinator Behaviour
Authors: Sturm Ulrike , Straka Tanja M. , Moormann Alexandra , Egerer Monika
Published: September 2021

The conservation of pollinators requires social understanding to catalyse restoration action. Citizen science (CS) is discussed as a way to promote interest and action for pollinating insects. Yet, the drivers behind pro-pollinator behaviour are largely unclear, especially in urban areas. To better understand public engagement in pollinator conservation, we studied urban community gardeners’ identity, nature-relatedness, emotions, and attitudes toward pollinators and their intentions to get involved in pro-pollinator behaviour in their gardening practice. We surveyed community gardeners in Berlin and Munich, Germany, some of which were participating in a citizen science project. In this scientific study, we created four different sets of generalized linear models to analyse how the gardeners’ pro-pollinator behaviour intentions and behaviour were explained by socio-psychological factors. The responses of 111 gardeners revealed that gardeners that were fascinated by pollinators, held positive attitudes and felt joy about seeing pollinators reported intentions to protect or support pollinators, suggesting that fascination and joy can be harnessed for research and conservation on pollinators. Similarly, joy about seeing pollinators predicted participation in the CS project. We believe that CS may represent a pathway through which urban residents may become key actors in conservation projects within their nearby greenspaces.
The Beneficial Effects of Eccentric Exercise in the Management of Lateral Elbow Tendinopathy: A Systematic Review and Meta-Analysis
Authors: Yoon Seo Yeon , Kim Yong Wook , Shin In Soo , Kang Seok , Moon Hyun Im , Lee Sang Chul
Published: September 2021

As a first-line treatment for lateral elbow tendinopathy (LET), eccentric exercise has been suggested as a conservative treatment method. This study aimed to investigate the impact of eccentric exercise on LET with regard to pain reduction, and strength and functional improvement. The PubMed, EMBASE, and Cochrane Central Register of Controlled Trials databases were searched, and studies up to May 2021 were included if (1) randomization was used for patient allocation, (2) the study comprised patients with LET, (3) the intervention was eccentric exercise, and (4) the primary outcomes included improvement in pain intensity, muscle strength, or function. The meta-analysis comprised of six studies, totaling 429 participants. Additional eccentric exercise with underlying adjuvant therapy significantly improved the visual analog scale (VAS) scores (standardized mean difference [SMD], −0.63; 95% confidence interval [CI], −0.90–−0.36) and muscle strength (SMD, 1.05; 95% CI, 0.78–1.33) compared with adjuvant therapy alone. Compared with the concentric or isotonic exercise group, the eccentric exercise group showed significantly improved VAS scores (SMD, −0.30; 95% CI, −0.58–−0.02). However, no differences in muscle strength and function were observed between the two groups. Eccentric exercise can improve pain and muscle strength in patients with LET. The limited number of included studies and heterogeneous exercise parameters are important when interpreting these findings.
Myeloma Bone Disease: The Osteoblast in the Spotlight
Authors: Andrews Rebecca E. , Brown Janet E. , Lawson Michelle A. , Chantry Andrew D.
Published: September 2021

Lytic bone disease remains a life-altering complication of multiple myeloma, with up to 90% of sufferers experiencing skeletal events at some point in their cancer journey. This tumour-induced bone disease is driven by an upregulation of bone resorption (via increased osteoclast (OC) activity) and a downregulation of bone formation (via reduced osteoblast (OB) activity), leading to phenotypic osteolysis. Treatments are limited, and currently exclusively target OCs. Despite existing bone targeting therapies, patients successfully achieving remission from their cancer can still be left with chronic pain, poor mobility, and reduced quality of life as a result of bone disease. As such, the field is desperately in need of new and improved bone-modulating therapeutic agents. One such option is the use of bone anabolics, drugs that are gaining traction in the osteoporosis field following successful clinical trials. The prospect of using these therapies in relation to myeloma is an attractive option, as they aim to stimulate OBs, as opposed to existing therapeutics that do little to orchestrate new bone formation. The preclinical application of bone anabolics in myeloma mouse models has demonstrated positive outcomes for bone repair and fracture resistance. Here, we review the role of the OB in the pathophysiology of myeloma-induced bone disease and explore whether novel OB targeted therapies could improve outcomes for patients.
Sex-Related Disparities in the Incidence and Outcomes of Community-Acquired Pneumonia among Type 2 Diabetes Patients: A Propensity Score-Matching Analysis Using the Spanish National Hospital Discharge Database for the Period 2016–2019
Authors: Lopez-de-Andres Ana , Jimenez-Garcia Rodrigo , Hernandez-Barrera Valentin , de Miguel-Diez Javier , de Miguel-Yanes Jose M. , Carabantes-Alarcon David , Zamorano-Leon Jose J. , Sanz-Rojo Sara , Lopez-Herranz Marta
Published: September 2021

(1) Background: To analyze incidence, clinical characteristics, procedures, and in-hospital outcomes among patients hospitalized with community-acquired pneumonia (CAP) according to the presence of T2DM in Spain (2016–2019) and to assess the role of gender among those with T2DM. (2) Methods: Using the Spanish National Hospital Discharge Database, we estimated hospitalized CAP incidence. Propensity score matching was used to compare population subgroups. (3) Results: CAP was coded in 520,723 patients, of whom 140,410 (26.96%) had T2DM. The hospitalized CAP incidence was higher in patients with T2DM (both sexes) (IRR 4.25; 95% CI 4.23–4.28). The hospitalized CAP incidence was higher in men with T2DM than in women with T2DM (IRR 1.46; 95% CI 1.45–1.47). The hospitalized CAP incidence among T2DM patients increased over time; however, the in-hospital mortality (IHM) decreased between 2016 and 2019. IHM was higher among non-T2DM men and women than matched T2DM men and women (14.23% and 14.22% vs. 12.13% and 12.91%; all p < 0.001, respectively), After adjusting for confounders, men with T2DM had a 6% higher mortality risk than women (OR 1.06; 95% CI 1.02–1.1). (4) Conclusions: T2DM is associated with a higher hospitalized CAP incidence and is increasing overtime. Patients hospitalized with CAP and T2DM have lower IHM. Male sex is a significant risk factor for mortality after CAP among T2DM patients.
Validation of the Eating Disorder Examination Questionnaire in Danish Eating Disorder Patients and Athletes
Authors: Lichtenstein Mia Beck , Haastrup Lauge , Johansen Karen Krogh , Bindzus Jacob B. , Larsen Pia Veldt , Støving René Klinkby , Clausen Loa , Linnet Jakob
Published: September 2021

The Eating Disorder Examination Questionnaire (EDE-Q) is a gold standard questionnaire to identify eating disorder symptoms but has not yet been validated in Danish. The scale consists of four theoretical constructs of disordered eating: Restraint eating, Eating concerns, Shape concerns and Weight concerns. However, the four-factor structure has been difficult to replicate across cultures. This study aimed to examine the factor structure and psychometric properties of the EDE-Q in Danish. The study consisted of four samples (aged 15–70): Patients with anorexia, bulimia and unspecified eating disorders (n = 101), patients with symptoms of binge-eating disorder (n = 300), recreational athletes (n = 404), and elite athletes (n = 526). Depending on the analysis performed, participants had to complete the EDE-Q, the SCOFF questionnaire for eating disorders or the Binge Eating Disorders Questionnaire. In accordance with international research, we found no evidence for a four-factor structure in the EDE-Q among patients or among athletes. But our results showed significant, positive associations between EDE-Q and SCOFF, BED-Q and MDI in all samples. We conclude that the internal structure of EDE-Q is low, while construct validity is high, making EDE-Q useful as an instrument to identify individuals with eating disorder symptoms, including recreational, and elite athletes.
Does Attentional Style Moderate the Relationship between Time Perspective and Social Network Addiction? A Cross-Sectional Study on a Sample of Social Networking Sites Users
Authors: Miceli Silvana , Scrima Fabrizio , Cardaci Maurizio , Quatrosi Giuseppe , Vetri Luigi , Roccella Michele , Caci Barbara
Published: September 2021

The present study investigates the role of attentional style as a moderator variable between temporal perspective and social network addiction, since little is known about users’ cognitive variables involved in this kind of addictive behavior. To achieve this goal, a sample of 186 volunteers and anonymous social networking sites users (M = 34%; F = 66%; Mage = 22.54 years; SD = 3.94; range: 18 ÷ 45 years) participated in a cross-sectional study. All participants filled out self-report instruments measuring temporal perspective, internal vs. external attentional style, and social network addiction. The results align with the previous literature and show that present fatalistic and past negative time orientations are associated with social network addiction, whereas the future is a negative precursor. Moreover, a four-step hierarchical regression analysis showed that internal attentional style is a significant moderator of the relationship between high levels of temporal perspective and a high level of social network addiction. This result suggests that social network-addicted users are oriented toward internal stimuli such as their intrusive thoughts or feelings and that social network addiction is similar to obsessive compulsive disorders, depression, or anxiety. Despite its limitations, the present study could contribute to the efforts of clinicians, psychiatrists, psychologists, teachers, and all those who seek to combat social network addiction in developing treatment programs to reduce its harmful effects.
Pain Control Affects the Radiographic Diagnosis of Segmental Instability in Patients with Degenerative Lumbar Spondylolisthesis
Authors: Chou Shih-Hsiang , Lin Sung-Yen , Shen Po-Chih , Tu Hung-Pin , Huang Hsuan-Ti , Shih Chia-Lung , Lu Cheng-Chang
Published: September 2021

Background: Diagnosing intervertebral instability is crucial for the treatment of degenerative lumbar spondylolisthesis (DLS). Disabling back pain will reduce spinal mobility which leads to an underestimate of the incidence of intervertebral instability. We hypothesized that adequate analgesia could alter the flexion/extension exam performance, and thus increase the diagnostic accuracy of segmental instability. Materials and methods: One hundred patients with low-grade DLS were prospectively enrolled in the before–after cohort study. Standing lateral flexion/extension radiographs of lumbar spines were examined and analyzed before and after intramuscular injections of 30 mg ketorolac. Results: Pain score decreased significantly after analgesic injections (p < 0.001). Dynamic slip (DS), dynamic segmental angle (DA), dynamic lumbar lordosis, and slip percentage (SP) were significantly increased after pain reduction (all p < 0.001). According to the diagnostic criteria for segmental instability (DS > 4.5 mm, DA > 15°, or SP > 15%), there were 4%, 4%, and 0.7% of total motion segments fulfilling the criteria which markedly increased to 42%, 32%, and 16.7% after analgesia was administered. The incidence of instability also increased from 6% to 38% after analgesia. Conclusions: The diagnosis rate of intervertebral instability is commonly underestimated in the presence of low back pain. This short-term pain relief facilitates reliable functional imaging adding to the diagnosis of intervertebral instability.
Interstitial Lung Disease at High Resolution CT after SARS-CoV-2-Related Acute Respiratory Distress Syndrome According to Pulmonary Segmental Anatomy
Authors: Baratella Elisa , Ruaro Barbara , Marrocchio Cristina , Starvaggi Natalia , Salton Francesco , Giudici Fabiola , Quaia Emilio , Confalonieri Marco , Cova Maria Assunta
Published: September 2021

Background: The purpose of this study was to evaluate High-Resolution CT (HRCT) findings in SARS-CoV-2-related ARDS survivors treated with prolonged low-dose methylprednisolone after hospital discharge. Methods: A total of 44 consecutive patients (M: 32, F: 12, average age: 64), hospitalised in our department from April to September 2020 for SARS-CoV-2-related ARDS, who had a postdischarge CT scan, were enrolled into this retrospective study. We reviewed the electronic medical charts to collect laboratory, clinical, and demographic data. The CT findings were evaluated and classified according to lung segmental distribution. The imaging findings were correlated with spirometry results and included ground glass opacities (GGOs), consolidations, reticulations, bronchiectasis/bronchiolectasis, linear bands, and loss of pulmonary volume. Results: Alterations in the pulmonary parenchyma were observed in 97.7% of patients at HRCT (median time lapse between ARDS diagnosis and HRCT: 2.8 months, range 0.9 to 6.7). The most common findings were linear bands (84%), followed by GGOs (75%), reticulations (34%), bronchiolectasis (32%), consolidations (30%), bronchiectasis (30%) and volume loss (25%). They had a symmetric distribution, and both lower lobes were the most affected areas. Conclusions: A reticular pattern with a posterior distribution was observed 3 months after discharge from severe COVID-19 pneumonia, and this differs from previously described postCOVID-19 fibrotic-like changes. We hypothesized that the systematic use of prolonged low-dose of corticosteroid could be the main reason of this different CT scan appearance.
Modified Polylactic Acid with Improved Impact Resistance in the Presence of a Thermoplastic Elastomer and the Influence of Fused Filament Fabrication on Its Physical Properties
Authors: Kasmi Samir , Cayuela Julien , Backer Bertrand De , Labbé Eric , Alix Sébastien
Published: September 2021

The standard polylactic acid (PLA), as a biodegradable thermoplastic polymer, is commonly used in various industrial sectors, food, and medical fields. Unfortunately, it is characterized by a low elongation at break and low impact energy. In this study, a thermoplastic copolyester elastomer (TPCE) was added at different weight ratios to improve the impact resistance of PLA. DSC analysis revealed that the two polymers were immiscible. A good balance of impact resistance and rigidity was reached using the formulation that was composed of 80% PLA and 20% TPCE, with an elongation at break of 155% compared to 4% for neat PLA. This new formulation was selected to be tested in a fused filament fabrication process. The influence of the nozzle and bed temperatures as printing parameters on the mechanical and thermal properties was explored. Better impact resistance was observed with the increase in the two thermal printing parameters. The crystallinity degree was not influenced by the variation in the nozzle temperature. However, it was increased at higher bed temperatures. Tomographic observations showed an anisotropic distribution of the porosity, where it was mostly present between the adjacent printed filaments and it was reduced with the increase in the nozzle and bed temperatures.
Study on Data Partition for Delimitation of Masses in Mammography
Authors: Viegas Luís , Domingues Inês , Mendes Mateus
Published: September 2021

Mammography is the primary medical imaging method used for routine screening and early detection of breast cancer in women. However, the process of manually inspecting, detecting, and delimiting the tumoral massess in 2D images is a very time-consuming task, subject to human errors due to fatigue. Therefore, integrated computer-aided detection systems have been proposed, based on modern computer vision and machine learning methods. In the present work, mammogram images from the publicly available Inbreast dataset are first converted to pseudo-color and then used to train and test a Mask R-CNN deep neural network. The most common approach is to start with a dataset and split the images into train and test set randomly. However, since there are often two or more images of the same case in the dataset, the way the dataset is split may have an impact on the results. Our experiments show that random partition of the data can produce unreliable training, so the dataset must be split using case-wise partition for more stable results. In experimental results, the method achieves an average true positive rate of 0.936 with 0.063 standard deviation using random partition and 0.908 with 0.002 standard deviation using case-wise partition, showing that case-wise partition must be used for more reliable results.
Acidification and Deoxygenation of the Northwestern Japan/East Sea
Authors: Tishchenko Pavel , Lobanov Vyacheslav , Kaplunenko Dmitry , Sagalaev Sergey , Tishchenko Petr
Published: September 2021

Seasonal hypoxia in the bottom waters of the Peter the Great Bay (PGB) of the Japan/East Sea (JES) occurs in summer. Using the empirical relationship between dissolved oxygen (DO) and pH obtained for hypoxic conditions and available historical DO data, acidification rates were estimated. Carefully sampled time-series observations from the northwestern part of the JES, carried out from 1999 to 2014 along the 132°20′ E and 134°00′ E longitudes, were chosen to determine the interannual variability of the sea’s hydrochemical parameters (DO, pH, and TA—the total alkalinity phosphates, nitrate, and silicates). To limit the effects of seasonal and spatial variability, only data obtained in the warm period were used. Additionally, all data from depths shallower than 500 m were discarded because they are affected by high natural variability, mostly due to strong mesoscale dynamic structures. Our results demonstrated that the pH and DO concentrations measured in the Upper Japan Sea Proper Water (750 m), Lower Japan Sea Proper Water (1250, 1750, 2250 m), and Bottom Water (3000 m) have been decreasing in recent years. On the other hand, calculated normalized dissolved inorganic carbon (NDIC), CO2 partial pressure (pCO2), and measured nutrient concentrations have been increasing. Maximum rates of acidification and deoxygenation are occurring at around 750 m. The annual rate of increase of pCO2 in the water exceeds the atmospheric rate more than 2-fold at a depth of 750 m. The observed variability of the hydrochemical properties can be explained by the combination of the slowdown ventilation of the vertical water column and eutrophication. However, the results obtained here are valid for the subpolar region of the JES, not for the whole sea. The synchronization of the deoxygenation of the open part of the JES and PGB has been found.
A Critical Review on Communication Mechanism within Plant-Endophytic Fungi Interactions to Cope with Biotic and Abiotic Stresses
Authors: Lu Hongyun , Wei Tianyu , Lou Hanghang , Shu Xiaoli , Chen Qihe
Published: September 2021

Endophytic fungi infect plant tissues by evading the immune response, potentially stimulating stress-tolerant plant growth. The plant selectively allows microbial colonization to carve endophyte structures through phenotypic genes and metabolic signals. Correspondingly, fungi develop various adaptations through symbiotic signal transduction to thrive in mycorrhiza. Over the past decade, the regulatory mechanism of plant-endophyte interaction has been uncovered. Currently, great progress has been made on plant endosphere, especially in endophytic fungi. Here, we systematically summarize the current understanding of endophytic fungi colonization, molecular recognition signal pathways, and immune evasion mechanisms to clarify the transboundary communication that allows endophytic fungi colonization and homeostatic phytobiome. In this work, we focus on immune signaling and recognition mechanisms, summarizing current research progress in plant-endophyte communication that converge to improve our understanding of endophytic fungi.
Overview on the Prevalence of Fungal Infections, Immune Response, and Microbiome Role in COVID-19 Patients
Authors: Roudbary Maryam , Kumar Sunil , Kumar Awanish , Černáková Lucia , Nikoomanesh Fatemeh , Rodrigues Célia F.
Published: September 2021

Patients with severe COVID-19, such as individuals in intensive care units (ICU), are exceptionally susceptible to bacterial and fungal infections. The most prevalent fungal infections are aspergillosis and candidemia. Nonetheless, other fungal species (for instance, Histoplasma spp., Rhizopus spp., Mucor spp., Cryptococcus spp.) have recently been increasingly linked to opportunistic fungal diseases in COVID-19 patients. These fungal co-infections are described with rising incidence, severe illness, and death that is associated with host immune response. Awareness of the high risks of the occurrence of fungal co-infections is crucial to downgrade any arrear in diagnosis and treatment to support the prevention of severe illness and death directly related to these infections. This review analyses the fungal infections, treatments, outcome, and immune response, considering the possible role of the microbiome in these patients. The search was performed in Medline (PubMed), using the words “fungal infections COVID-19”, between 2020–2021.
A Balanced Portfolio Can Have a Higher Geometric Return Than the Risky Asset
Authors: Arden Miriam , Woutersen Tiemen
Published: September 2021

In the U.S., the geometric return on stocks has been higher than the geometric return on bonds over long periods. We study whether balanced portfolios have a larger geometric return (and expected log return) than stock portfolios when the risk premium is low. We use a theoretical model and historical data and find that this is the case. This low-risk premium is often observed in other developed countries. Further, in the past two decades, a balanced portfolio with 70% or 90% invested in the U.S. stock market (with the remainder invested in U.S. government bonds) performed better than a 100% stock or bond portfolio. The reason for this is that a pure stock portfolio loses a large fraction of its value in a downturn. We show that this result is not driven by outliers, and that it occurs even when the returns are log normally distributed. This result has broad policy implications for the construction of pension systems and target-date mutual funds.
Impact of Elimination of Dividend Distribution Tax on Indian Corporate Firms Amid COVID Disruptions
Authors: Agrawal Anshu
Published: September 2021

Economic fallouts from COVID-19 have been unprecedented across all industries, with a handful of exceptions. The present study attempts to capture the impact of dividend distribution tax elimination, introduced through the Indian Finance Act 2020, on corporate dividend behavior in India. It explores the determinants of dividend payouts, changing payout decisions, dividend behavior of regular payers, and the prevalence of factors associated with changing payouts. Out of the top 1000 firms, based on their market capitalization at the Bombay Stock Exchange, 509 non-financial firms pursuing consistent dividend payments from 2015 to 2019 are analyzed. The study also examines the dividend behavior of regular payers exhibiting a stable or step-up payout from 2015 to 2019. COVID’s impact on the firm’s financial performance and sentiments seems to dominate, suppressing investors’ expectations of enhanced payouts associated with dividend distribution tax advantages, with considerable reductions in payouts and omissions shown by regular and irregular payers in 2020 and 2021 vis-à-vis the preceding years. The findings signify that the dividend payouts of sample firms are positively associated with the firms’ size, MBV ratio, and past dividends, and negatively allied with free cash flows and the EBITDA margin. Regular payers are observed to be more sensitive to past dividends. The study lends credence to the conservatism and prevalence of signaling and catering theories in the dividend behavior of Indian corporate firms.
Elevation Mechanisms and Diagnostic Consideration of Cardiac Troponins under Conditions Not Associated with Myocardial Infarction. Part 1
Authors: Chaulin Aleksey
Published: September 2021

Although cardiac troponins are considered the most specific biomarkers for the diagnosis of acute myocardial infarction (AMI), their diagnostic consideration goes far beyond the detection of this dangerous disease. The mechanisms of cardiac troponin elevation are extremely numerous and not limited to ischemic necrosis of cardiac myocytes. Practitioners should be well aware of the underlying pathological and physiological conditions that can lead to elevated serum levels of cardiac troponins to avoid differential diagnostic errors, which will be greatly increased if clinicians rely on laboratory data alone. This article presents a classification of the main causes of an elevation in cardiac troponins and discusses in detail the mechanisms of such elevation and the diagnostic consideration of cardiac troponins in some conditions not associated with AMI, such as physical exertion, inflammatory heart diseases (myocarditis and endocarditis), pulmonary embolism (PE), renal failure, and systemic inflammation (sepsis).
The Blow-Off Impulse Equivalence of Typical Missile Homogeneous Al-Alloy under Multienergy Composite Spectrum Electron Beam and Powerful Pulsed X-ray
Authors: Wang Dengwang , Gao Yong , Chen Wei , Yang Shanghui , Zhang Jing , Wang Jie , Wang Sheng
Published: September 2021

The electron beam, one of the most effective approaches to simulate the irradiation effects of powerful pulsed X-ray in the laboratory, plays an important role in simulating the thermodynamic effects of powerful pulsed X-ray. This paper studies the thermodynamics equivalence between multienergy composite spectrum electron beam and blackbody spectrum X-ray, which is helpful to quickly determine the experimental parameters in the simulation experiment. The experimental data of electron beam are extrapolated by numerical calculation, to increase the range of energy flux. Through calculating the blow-off impulse of blackbody spectrum X-ray irradiation, we obtained the curve of X-ray blow-off impulse varying with energy flux, and then found two categories of equivalent relations—equal-energy flux and equal-impulse—by analyzing the calculation results of electron beam and X-ray blow-off impulse. Based on such relations, we could directly or indirectly obtain the results of blackbody spectrum X-ray irradiation blow-off impulse via electron beam experiment.
Novel Polymer Sorbents with Imprinted Task-Specific Ionic Liquids for Metal Removal
Authors: Filipowiak Kinga , Dudzińska Patrycja , Wieszczycka Karolina , Buchwald Tomasz , Nowicki Marek , Lewandowska Aneta , Marcinkowska Agnieszka
Published: September 2021

In this paper, the potential of novel polymer sorbents with the imprinted IL-functional group for the removal of Cu(II), Cd(II), and Zn(II) from aqueous solutions was investigated by batch mode. The sorbents were fabricated by direct reaction of the prepared polymer matrix (poly(vinylbenzyl chloride-divinylbenzene), VBC, and poly(vinylbenzyl bromide-divinylbenzene), VBBr) with 1-(3- or 4-pyridyl)undecan-1-one and oxime of 1-(3- or 4-pyridyl)undecan-1-one. The Fourier Transform Infrared Spectroscopy (FT-IR), Raman Spectroscopy (Raman), Thermogravimetric Analysis (TG), Differential Scanning Calorimetry (DSC), and Scanning Electron Microscopy (SEM) techniques were used to show functionality and stability of the sorbents. The materials were also characterized by contact-angle goniometry, X-rayphotoelectron spectroscopy (XPS), and Zeta potential analysis. The removal of Cd(II), Cu(II), and Zn(II) was monitored and optimized under the influence of several operational controlling conditions and factors such as pH, shaking time, temperature, initial metal ions concentration, and counter-ions at the functional group. The results obtained confirmed the very high potential of the sorbents; however, the properties depend on the structure of the functional group. The tested sorbents showed fast kinetics, significant capacity at 25 °C (84 mg/g for the Zn(II) sorption with VBC-Ox4.10, 63 mg/g for the Cd(II) sorption with VBBr-Ox3.10, and 69 mg/g for the Cu(II) sorption with VBC-K3.10), and temperature dependence (even 100% increase in capacity values at 45 °C). The selected sorbent can be regenerated without a significant decrease in the metal removal efficiency.
Mechanical Performance of Chairside Ceramic CAD/CAM Restorations and Zirconia Abutments with Different Internal Implant Connections: In Vitro Study and Finite Element Analysis
Authors: Giner Sergio , Bartolomé José F. , Gomez-Cogolludo Pablo , Castellote Carlos , Pradíes Guillermo
Published: September 2021

(computer-aided design-computer-aided manufacturing) CAD/CAM monolithic restorations connected to zirconia abutments manufactured with a chairside workflow are becoming a more common restorative option. However, their mechanical performance is still uncertain. The aim of this study was to evaluate the mechanical behavior of a combination of a zirconia abutment and monolithic all-ceramic zirconia and lithium disilicate crown manufactured with a chairside workflow, connected to titanium implants with two types of internal connection—tube in tube connection and conical connection with platform switching. They were thermally cycled from 5 °C to 55 °C and were subjected to a static and fatigue test following ISO 14801. The fractured specimens from the fatigue test were examined by SEM (scanning electron microscopy). Simulations of the stress distribution over the different parts of the restorative complex during the mechanical tests were evaluated by means of (finite element analysis) FEA. The mechanical performance of the zirconia abutment with an internal conical connection was higher than that of the tube in tube connection. Additionally, the use of disilicate or zirconia all-ceramic chairside CAD/CAM monolithic restorations has similar results in terms of mechanical fracture and fatigue resistance. Stress distribution affects the implant/restoration complex depending on the connection design. Zirconia abutments and monolithic restorations seem to be highly reliable in terms of mechanical resistance.
Microstructure Evolution and Properties of an In-Situ Nano-Gd2O3/Cu Composite by Powder Metallurgy
Authors: Cao Haiyao , Zhan Zaiji , Lv Xiangzhe
Published: September 2021

Gadolinia (Gd2O3) is potentially attractive as a dispersive phase for copper matrix composites due to its excellent thermodynamic stability. In this paper, a series of 1.5 vol% nano-Gd2O3/Cu composites were prepared via an internal oxidation method followed by powder metallurgy in the temperature range of 1123–1223 K with a holding time of 5–60 min. The effects of processing parameters on the microstructure and properties of the composites were analyzed. The results showed that the tensile strength and conductivity of the nano-Gd2O3/Cu composite have a strong link with the microporosity and grain size, while the microstructure of the composite was determined by the sintering temperature and holding time. The optimal sintering temperature and holding time for the composite were 1173 K and 30 min, respectively, under which a maximum ultimate tensile strength of 317 MPa was obtained, and the conductivity was 96.8% IACS. Transmission electron microscopy observations indicated that nano-Gd2O3 particles with a mean size of 76 nm formed a semi-coherent interface with the copper matrix. In the nano-Gd2O3/Cu composite, grain-boundary strengthening, Orowan strengthening, thermal mismatch strengthening, and load transfer strengthening mechanisms occurred simultaneously.
Influence of Polypropylene Fibre Factor on Flowability and Mechanical Properties of Self-Compacting Geopolymer
Authors: Pu Bei-chen , Liu Bin , Li Li , Pang Wei , Wan Zhangrun
Published: September 2021

The possibility of using geopolymer instead of Portland cement could effectively reduce carbon dioxide emissions from cement manufacturing. Fibre-reinforced self-compacting geopolymers have great potential in civil engineering applications, such as chord member grouting for concrete-filled steel tubular truss beams. However, to the best of the authors’ knowledge, the quantitative relationship between FF and the properties of the fibre-reinforced geopolymer has been rarely reported. In this research, 26 groups of mixtures were used to study the influence of the polypropylene fibre factor (FF) on the flowability and mechanical properties and also the compactness of the fibre-reinforced self-compacting geopolymer. At the same volume fraction, geopolymers with long fibres present worse flowability than those having short fibres due to the easier contacting of long fibres. By growing the FF the influence of fibre addition on the V-funnel flow rate is more significant than the slump spread. This can be ascribed to the consequence of fibre addition and friction by the V-funnel which estimates the restrained deformability. For FF lesser than critical factor Fc = 100, influence of fibres is negligible and fibres are far apart from each other and, thus, they cannot restrict cracking under load and transfer the load to improve the mechanical properties. For FF between the Fc = 100 and density factor Fd = 350, a noteworthy enhancement of mechanical properties was obtained and the geopolymer was still adequately workable to flow by weight of self, without any symbols of instability and fibre clumping. Under this condition, better fibre dispersal and reinforcing productivity can lead to better hardened properties. For FF higher than Fd = 350, fibres tend to come to be entwined together and form clumping resulting from the fibre balling, resulting in worse hardened properties. This research offers a sensible basis for the application of the workability regulator of the fresh properties of fibre-reinforced geopolymer as an operative way to basically obtain ideal mechanical properties.
A Mandible with the Temporomandibular Joint—A New FEM Model Dedicated to Strength and Fatigue Calculations of Bonding Elements Used in Fracture and Defect Surgery
Authors: Mańkowski Jarosław , Piękoś Jakub , Dominiak Karol , Klukowski Piotr , Fotek Michał , Zawisza Maciej , Żach Piotr
Published: September 2021

The aim of the study was to develop a new FEM (finite element method) model of a mandible with the temporal joint, which can be used in the numerical verification of the work of bonding elements used in surgical operations of patients with mandibular fractures or defects. Most of such types of numerical models are dedicated to a specific case. The authors engaged themselves in building a model that can be relatively easily adapted to various types of tasks, allowing to assess stiffness, strength and durability of the bonded fragments, taking into account operational loads and fatigue limit that vary in time. The source of data constituting the basis for the construction of the model were DICOM (digital imaging and communications in medicine) files from medical imaging using computed tomography. On their basis, using the 3D Slicer program and algorithms based on the Hounsfield scale, a 3D model was created in the STL (standard triangle language) format. A CAD (computer-aided design) model was created using VRMesh and SolidWorks. An FEM model was built using HyperWorks and Abaqus/CAE. Abaqus solver was used for FEM analyses. A model meeting the adopted assumptions was built. The verification was conducted by analyzing the influence of the simplifications of the temporomandibular joint in the assessment of mandibular strain. The work of an undamaged mandible and the work of the bonded fracture of the mandible were simulated.
A New High-Order Jacobian-Free Iterative Method with Memory for Solving Nonlinear Systems
Authors: Behl Ramandeep , Cordero Alicia , Torregrosa Juan R. , Bhalla Sonia
Published: September 2021

We used a Kurchatov-type accelerator to construct an iterative method with memory for solving nonlinear systems, with sixth-order convergence. It was developed from an initial scheme without memory, with order of convergence four. There exist few multidimensional schemes using more than one previous iterate in the very recent literature, mostly with low orders of convergence. The proposed scheme showed its efficiency and robustness in several numerical tests, where it was also compared with the existing procedures with high orders of convergence. These numerical tests included large nonlinear systems. In addition, we show that the proposed scheme has very stable qualitative behavior, by means of the analysis of an associated multidimensional, real rational function and also by means of a comparison of its basin of attraction with those of comparison methods.
A University Teachers’ Teaching Performance Evaluation Method Based on Type-II Fuzzy Sets
Authors: Sun Xixia , Cai Chao , Pan Su , Bao Nan , Liu Ning
Published: September 2021

This paper proposes a university teachers’ teaching performance evaluation method based on type-II fuzzy sets (T2 FSs), which solves the problems of fuzziness, complexity and uncertainty in teaching performance evaluation. Firstly, the evaluation indicator system is constructed from the aspects of teaching attitude, teaching contents, teaching professionalism, teaching methods and teaching effects. Then, T2 FSs theory and the perceptual computing method are introduced to model subjective judgments and capture uncertainties, effectively handling higher levels of uncertainty in the evaluation process. Furthermore, the linguistic weighted average operator is applied as the computing with words engine to aggregate scores and weights of indicators, which effectively integrates the uncertain information in the input data into the final evaluation conclusion and guarantees the accuracy of the evaluation results. Finally, the effectiveness of the method of this study is evaluated by simulation experiments. The computational results demonstrate that it can capture more uncertain and complex information, and is more accurate and reliable than the type-I fuzzy sets method.
Measurement in Primary School Mathematics and Science Textbooks
Authors: Montoro Ana B. , Aguayo-Arriagada Carmen Gloria , Flores Pablo
Published: September 2021

The STEM (science, technology, engineering and mathematics) approach to education has acquired considerable prominence among teachers in recent years. Putting forward integrated proposals is nonetheless complex and many educators opt to implement the ones set out in textbooks. We consequently deemed it worthwhile to analyse how content common to mathematics and science is addressed in primary school textbooks with a view to determining whether the approaches adopted complement one another and are compatible with STEM education. More specifically, in light of the importance of measurement in both areas of learning and in everyday life, we describe the meaning of mass and volume found, in two publishers’ textbooks. Based on the components of the meaning of measurement and deploying content analysis techniques, we analysed the explanations and tasks set out in these mathematics and science books to identify the similarities and differences in the handling of those magnitudes in the two subjects. Our findings showed the proposals for teaching mass to pursue similar objectives in the earliest grades, addressing matters that could be included in STEM proposals. On the contrary, inconsistencies were detected in the distribution of volume measurement-related content, as well as in the strategies, units and tools used in the two areas.
Nonlocal PT-Symmetric Integrable Equations of Fourth-Order Associated with so(3, ℝ)
Authors: Zhang Li-Qin , Ma Wen-Xiu
Published: September 2021

The paper aims to construct nonlocal PT-symmetric integrable equations of fourth-order, from nonlocal integrable reductions of a fourth-order integrable system associated with the Lie algebra so(3,R). The nonlocalities involved are reverse-space, reverse-time, and reverse-spacetime. All of the resulting nonlocal integrable equations possess infinitely many symmetries and conservation laws.
COVID-19 and Changes in Social Habits. Restaurant Terraces, a Booming Space in Cities. The Case of Madrid
Authors: Pérez Virgilio , Aybar Cristina , Pavía Jose M.
Published: September 2021

The COVID-19 pandemic and the fear experienced by some of the population, along with the lack of mobility due to the restrictions imposed, has modified the social behaviour of Spaniards. This has had a significant effect on the hospitality sector, viewed as being an economic and social driver in Spain. From the analysis of data collected in two of our own non-probabilistic surveys (N ~ 8400 and N ~ 2000), we show how, during the first six months of the pandemic, Spaniards notably reduced their consumption in bars and restaurants, also preferring outdoor spaces to spaces inside. The restaurant sector has needed to adapt to this situation and, with the support of the authorities (regional and local governments), new terraces have been allowed on pavements and public parking spaces, modifying the appearance of the streets of main towns and cities. This study, focused on the city of Madrid, analyses the singular causes that have prompted this significant impact on this particular city, albeit with an uneven spatial distribution. It seems likely that the new measures will leave their mark and some of the changes will remain. The positive response to these changes from the residents of Madrid has ensured the issue is being widely debated in the public arena.
Differential Evolution with Estimation of Distribution for Worst-Case Scenario Optimization
Authors: Antoniou Margarita , Papa Gregor
Published: September 2021

Worst-case scenario optimization deals with the minimization of the maximum output in all scenarios of a problem, and it is usually formulated as a min-max problem. Employing nested evolutionary algorithms to solve the problem requires numerous function evaluations. This work proposes a differential evolution with an estimation of distribution algorithm. The algorithm has a nested form, where a differential evolution is applied for both the design and scenario space optimization. To reduce the computational cost, we estimate the distribution of the best worst solution for the best solutions found so far. The probabilistic model is used to sample part of the initial population of the scenario space differential evolution, using a priori knowledge of the previous generations. The method is compared with a state-of-the-art algorithm on both benchmark problems and an engineering application, and the related results are reported.
Dynamic Model of Contingency Flight Crew Planning Extending to Crew Formation
Authors: Graf Vojtech , Teichmann Dusan , Dorda Michal , Kontrikova Lenka
Published: September 2021

The creation of a flight schedule and the associated crew planning are clearly among the most complicated tasks in terms of traffic preparation. Even with a relatively small number of pilots and aircraft, numerous specific constraints arising from real operations must be included in the calculation, thus increasing the complexity of the planning process. However, even in a precision-planned operation, non-standard situations often occur, which must be addressed flexibly. It is at this point that an operational solution must be applied, the aims of which are to stabilize the flight schedule as soon as possible and minimize the financial impacts resulting from the non-standard situation. These problems are resolved by the airline’s Operational Control Center, which also uses various software approaches to solve the problem. The problem is approached differently by large air carriers, which use software products to address it, and small and medium-sized air carriers, which resolve the issue of operational rescheduling intuitively, based on the experience of dispatchers. However, this intuitive approach can lead to inaccuracies that can lead to unnecessary financial losses. In this paper, we present an optimization model that can serve as a tool to support the decision-making of employees of the operations centers of smaller and medium-sized air carriers.