bluuebunny/crossref_metadata_2025 huggingface dataset:
Selective Fetal Growth Restriction in Dichorionic Twin Pregnancies: Diagnosis, Natural History, and Perinatal Outcome
Authors: Antonakopoulos Nikolaos , Pateisky Petra , Liu Becky , Kalafat Erkan , Thilaganathan Baskaran , Khalil Asma
Published: May 2020

This study aims to evaluate the natural history, disease progression, and outcomes in dichorionic twins with selective fetal growth restriction (sFGR) according to different diagnostic criteria and time of onset. Dichorionic twins seen from the first trimester were included. sFGR was classified according to the Delphi consensus, and was compared to the outcomes of those classified by the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) diagnostic criteria. Early sFGR occurred before 32-weeks, and late sFGR after 32-weeks. Disease progression, neonatal outcomes such as gestation at delivery, birthweight, neonatal unit (NNU) admission, and morbidities were compared. One-hundred twenty-three of 1053 dichorionic twins had sFGR, where 8.4% were classified as early sFGR, and 3.3% were late sFGR. Disease progression was seen in 36%, with a longer progression time (5 vs. 1 week) and higher progression rate (40% vs. 26%) in early sFGR. Perinatal death was significantly higher in the sFGR than the non-sFGR group (24 vs. 16 per 1000 births, p = 0.018), and those with early sFGR had more NNU admissions than late sFGR (p = 0.005). The ISUOG diagnostic criteria yielded a higher number of sFGR than the Delphi criteria, but similar outcomes. sFGR have worse perinatal outcomes, with early onset being more prevalent. Use of the Delphi diagnostic criteria can reduce over-diagnosis of sFGR and avoid unnecessary intervention.
Influence of Overcrowding in the Emergency Department on Return Visit within 72 H
Authors: Kim Dong-uk , Park Yoo Seok , Park Joon Min , Brown Nathan J. , Chu Kevin , Lee Ji Hwan , Kim Ji Hoon , Kim Min Joung
Published: May 2020

This study was conducted to determine whether overcrowding in the emergency department (ED) affects the occurrence of a return visit (RV) within 72 h. The crowding indicator of index visit was the average number of total patients, patients under observation, and boarding patients during the first 1 and 4 h from ED arrival time and the last 1 h before ED departure. Logistic regression analysis was conducted to determine whether each indicator affects the occurrence of RV and post-RV admission. Of the 87,360 discharged patients, 3743 (4.3%) returned to the ED within 72 h. Of the crowding indicators pertaining to total patients, the last 1 h significantly affected decrease in RV (p = 0.0046). Boarding patients were found to increase RV occurrence during the first 1 h (p = 0.0146) and 4 h (p = 0.0326). Crowding indicators that increased the likelihood of admission post-RV were total number of patients during the first 1 h (p = 0.0166) and 4 h (p = 0.0335) and evaluating patients during the first 1 h (p = 0.0059). Overcrowding in the ED increased the incidence of RV and likelihood of post-RV admission. However, overcrowding at the time of ED departure was related to reduced RV.
Combined and Isolated Effects of Acute Exercise and Brain Stimulation on Executive Function in Healthy Young Adults
Authors: Hussey Erika K. , Fontes Eduardo B. , Ward Nathan , Westfall Daniel R. , Kao Shih-Chun , Kramer Arthur F. , Hillman Charles H.
Published: May 2020

Acute cognitive enhancement has been sought by healthy young individuals to improve academic and professional performance. Among several methods, physical exercise interventions and transcranial direct current brain stimulation (tDCS) have shown promise in impacting executive functions. Here, we observed a set of new findings about the causal effect of acute aerobic exercise and tDCS across three facets of executive function: Inhibition (as measured by a flanker task) was selectively impacted by acute aerobic exercise but not tDCS, whereas working memory (as measured by an n-back task) was impacted by both acute aerobic exercise and tDCS, with effects emerging on distinct processing components for each manipulation. Sustained attention (as measured by the Mackworth clock task), on the other hand, was not impacted by acute aerobic exercise or tDCS. Interestingly, no effects of combining acute aerobic exercise and tDCS emerged. We argue that understanding the unique and combined contributions of these cognitive enhancement techniques can not only contribute to a deeper mechanistic explanation in healthy individuals but also inform future research with clinical and aging populations.
Timing of Initiation of Renal Replacement Therapy in Sepsis-Associated Acute Kidney Injury
Authors: Agapito Fonseca José , Gameiro Joana , Marques Filipe , Lopes José António
Published: May 2020

Sepsis-associated acute kidney injury (SA-AKI) is a major issue in medical, surgical and intensive care settings and is an independent risk factor for increased mortality, as well as hospital length of stay and cost. SA-AKI encompasses a proper pathophysiology where renal and systemic inflammation play an essential role, surpassing the classic concept of acute tubular necrosis. No specific treatment has been defined yet, and renal replacement therapy (RRT) remains the cornerstone supportive therapy for the most severe cases. The timing to start RRT, however, remains controversial, with early and late strategies providing conflicting results. This article provides a comprehensive review on the available evidence on the timing to start RRT in patients with SA-AKI.
Racial Disparity in Pregnancy Risks and Complications in the US: Temporal Changes during 2007–2018
Authors: Bornstein Eran , Eliner Yael , Chervenak Frank A. , Grünebaum Amos
Published: May 2020

Maternal race and ethnicity have been associated with differences in pregnancy related morbidity and mortality. We aimed to evaluate the trends of several pregnancy risk factors/complications among different maternal racial/ethnic groups in the US between 2007 and 2018. Specifically, we used the Center for Disease Control and Prevention (CDC) natality files for these years to assess the trends of hypertensive disorders of pregnancy (HDP), chronic hypertension (CH), diabetes mellitus (DM), advanced maternal age (AMA) and grand multiparity (GM) among non-Hispanic Whites, non-Hispanic Blacks and Hispanics. We find that the prevalence of all of these risk factors/complications increased significantly across all racial/ethnic groups from 2007 to 2018. In particular, Hispanic women exhibited the highest increase, followed by non-Hispanic Black women, in the prevalence of HDP, CH, DM and AMA. However, throughout the entire period, the overall prevalence remained highest among non-Hispanic Blacks for HDP, CH and GM, among Hispanics for DM, and among non-Hispanic Whites for AMA. Our results point to significant racial/ethnic differences in the overall prevalence, as well as the temporal changes in the prevalence, of these pregnancy risk factors/complications during the 2007–2018 period. These findings could potentially contribute to our understanding of the observed racial/ethnic differences in maternal morbidity and mortality.
Selected Atherosclerosis-Related Diseases May Differentially Affect the Relationship between Plasma Advanced Glycation End Products, Receptor sRAGE, and Uric Acid
Authors: Gryszczyńska Bogna , Budzyń Magdalena , Formanowicz Dorota , Wanic-Kossowska Maria , Formanowicz Piotr , Majewski Wacław , Iskra Maria , Kasprzak Magdalena P.
Published: May 2020

Our study aimed to identify the relationship between advanced glycation end products (AGEs), soluble receptor for advanced glycation end products (sRAGE), the AGEs/sRAGE, and uric acid (UA) levels in selected atherosclerosis diseases, i.e., abdominal aortic aneurysms (AAA), aortoiliac occlusive disease (AIOD), and chronic kidney disease (CKD), resulting from apparent differences in oxidative stress intensity. Furthermore, we suggest that increased AGEs levels may stimulate an antioxidant defense system reflected by the UA level. The studied group size consisted of 70 AAA patients, 20 AIOD patients, 50 patients in the pre-dialyzed group (PRE), and 35 patients in the hemodialyzed group (HD). The enzyme-linked immunosorbent assay was used to measure AGEs and sRAGE levels. We found a significantly higher concentration of AGEs in CKD patients as compared to AAA and AIOD patients. Furthermore, the sRAGE level was higher in the CKD patients in comparison to AIOD and AAA patients. UA level was significantly higher in the PRE group compared to AAA patients. In conclusion, the diseases included in this study differ in the anti- and prooxidant defense system, which is reflected in the relations between the AGEs, the sRAGE, the AGEs/sRAGE ratio, as well as the UA levels.
Circulating MicroRNAs as Potential Predictors of Anthracycline-Induced Troponin Elevation in Breast Cancer Patients: Diverging Effects of Doxorubicin and Epirubicin
Authors: Gioffré Sonia , Chiesa Mattia , Cardinale Daniela Maria , Ricci Veronica , Vavassori Chiara , Cipolla Carlo Maria , Masson Serge , Sandri Maria Teresa , Salvatici Michela , Ciceri Fabio , Latini Roberto , Staszewsky Lidia Irene , Pompilio Giulio , Colombo Gualtiero I. , D’Alessandra Yuri
Published: May 2020

Anthracyclines are anti-neoplastic drugs presenting cardiotoxicity as a side effect. Cardiac troponins (cTn) and echocardiography are currently used to assess cardiac damage and dysfunction, but early biomarkers identifying patients in need of preventive treatments remain a partially met need. Circulating microRNAs (miRNAs) represent good candidates, so we investigated their possible roles as predictors of troponin elevation upon anthracycline treatment. Eighty-eight female breast cancer patients administered with doxorubicin (DOX) or epirubicin (EPI) were divided into four groups basing on drug type and cTn positive (cTn+) or negative (cTn−) levels: DOX cTn−, DOX cTn+, EPI cTn− and EPI cTn+. Blood was collected at baseline, during treatment, and at follow-up. We identified plasma miRNAs of interest by OpenArray screening and single assay validation. Our results showed miR-122-5p, miR-499a-5p and miR-885-5p dysregulation in DOX patients at T0, identifying a signature separating, with good accuracy, DOX cTn− from DOX cTn+. No miRNAs showed differential expression in EPI subjects. Conversely, an anthracycline-mediated modulation (regardless of cTn) was observed for miR-34a-5p, -122-5p and -885-5p. Our study indicates specific circulating miRNAs as possible prediction markers for cardiac troponin perturbation upon anthracycline treatment. Indeed, our findings hint at the possible future use of plasma miRNAs to predict the cardiac responsiveness of patients to different anticancer agents.
COVID-19, MERS and SARS with Concomitant Liver Injury—Systematic Review of the Existing Literature
Authors: Kukla Michał , Skonieczna-Żydecka Karolina , Kotfis Katarzyna , Maciejewska Dominika , Łoniewski Igor , Lara Luis. F. , Pazgan-Simon Monika , Stachowska Ewa , Kaczmarczyk Mariusz , Koulaouzidis Anastasios , Marlicz Wojciech
Published: May 2020

The novel coronavirus SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection has been predominantly linked to respiratory distress syndrome, but gastrointestinal symptoms and hepatic injury have also been reported. The mechanism of liver injury is poorly understood and may result as a consequence of viral hepatitis, systemic inflammatory response, gut barrier and microbiome alterations, intensive care treatment or drug toxicity. The incidence of hepatopathy among patients with coronavirus disease 2019 (COVID-19) is unclear, but studies have reported liver injury in patients with SARS and Middle East respiratory syndrome (MERS). We aimed to systematically review data on the prevalence of hepatic impairments and their clinical course in SARS and MERS Coronaviridae infections. A systematic literature search (PubMed/Embase/Cinahl/Web of Science) according to preferred reporting items for systematic review and meta-analysis protocols (PRISMA) was conducted from database inception until 17/03/2020 for studies that evaluated the incidence of hepatic abnormalities in SARS CoV-1, SARS CoV-2 and MERS infected patients with reported liver-related parameters. A total of forty-three studies were included. Liver anomalies were predominantly mild to moderately elevated transaminases, hypoalbuminemia and prolongation of prothrombin time. Histopathology varied between non-specific inflammation, mild steatosis, congestion and massive necrosis. More studies to elucidate the mechanism and importance of liver injury on the clinical course and prognosis in patients with novel SARS-CoV-2 infection are warranted.
Mechanotransduction in Wound Healing and Fibrosis
Authors: Kuehlmann Britta , Bonham Clark A. , Zucal Isabel , Prantl Lukas , Gurtner Geoffrey C.
Published: May 2020

Skin injury is a common occurrence and mechanical forces are known to significantly impact the biological processes of skin regeneration and wound healing. Immediately following the disruption of the skin, the process of wound healing begins, bringing together numerous cell types to collaborate in several sequential phases. These cells produce a multitude of molecules and initiate multiple signaling pathways that are associated with skin disorders and abnormal wound healing, including hypertrophic scars, keloids, and chronic wounds. Studies have shown that mechanical forces can alter the microenvironment of a healing wound, causing changes in cellular function, motility, and signaling. A better understanding of the mechanobiology of cells in the skin is essential in the development of efficacious therapeutics to reduce skin disorders, normalize abnormal wound healing, and minimize scar formation.
Engagement in Lifestyle Activities is Associated with Increased Alzheimer’s Disease-Associated Cortical Thickness and Cognitive Performance in Older Adults
Authors: Bae Seongryu , Lee Sangyoon , Harada Kenji , Makino Keitaro , Chiba Ippei , Katayama Osamu , Shinkai Yohei , Park Hyuntae , Shimada Hiroyuki
Published: May 2020

The aim of this study was to examine the association between lifestyle activities, including physical, cognitive, and social activities, and Alzheimer’s disease (AD) signature cortical thickness, as well as to examine the mediating role of AD signature cortical thickness in lifestyle activities and cognitive function in community-dwelling healthy older adults. Participants were 1026 older adults who met the study inclusion criteria. The physical, cognitive, and social activities of daily life were assessed using a self-reporting questionnaire. AD signature cortical thickness was determined using FreeSurfer software. Cognitive function was evaluated using the National Center for Geriatrics and Gerontology-Functional Assessment Tool. Path analysis (based on structural equation modeling (SEM)) of cognitive activities indicated that the direct path from cognitive activities to cognitive function was significant (p < 0.001), as was the direct path from AD signature cortical thickness to cognitive function (p < 0.001). Physical (p < 0.05) or social activities (p < 0.05) had a direct effect on cognitive function. However, AD signature cortical thickness did not mediate the relationship between physical or social activities and cognitive function. Our findings suggest that higher levels of cognitive activities later in life have a significant and positive direct effect on cognitive function. Additionally, AD signature cortical thickness significantly mediates the relationship between cognitive activities and cognitive function.
HIP1R Expression and Its Association with PD-1 Pathway Blockade Response in Refractory Advanced NonSmall Cell Lung Cancer: A Gene Set Enrichment Analysis
Authors: Koh Young Wha , Han Jae-Ho , Haam Seokjin , Lee Hyun Woo
Published: May 2020

Huntingtin-interacting protein 1-related protein (HIP1R) plays an important role in the regulation of programmed death-ligand 1 (PD-L1). The aim of this study was to investigate the expression of HIP1R and confirm its predictive or prognostic roles in anti-PD-1 therapy in nonsmall cell lung cancer (NSCLC) patients. HIP1R and PD-L1 immunohistochemical expression was examined in 52 refractory advanced NSCLC patients treated with anti-PD-1 inhibitors. We performed gene set enrichment analysis (GSEA) to detect HIP1R-specific gene sets. Patients in the PD-1 inhibitor responder group had lower HIP1R expression by univariate logistic regression analysis (odds ratio (OR) = 0.235, p = 0.015) and multivariate logistic regression analysis (OR = 0.209, p = 0.014). Patients with high HIP1R expression had poorer progression-free survival (PFS) than patients with low HIP1R expression in univariate analysis (p = 0.037) and multivariate Cox analysis (hazard ratio = 2.098, p = 0.019). The web-based mRNA dataset also showed that high HIP1R expression correlated with inferior overall survival in lung adenocarcinoma (p = 0.026). GSEA revealed that HIP1R levels correlate with a set of genes that reflect PD-L1-related immune pathways. HIP1R expression may be a promising predictor for determination of patient responses to anti-PD-1 treatment.
Contemporary Cardiovascular Risk Assessment for Type 2 Diabetes Including Heart Failure as an Outcome: The Fremantle Diabetes Study Phase II
Authors: Davis Wendy A. , Hellbusch Valentina , Hunter Michael L. , Bruce David G. , Davis Timothy M. E.
Published: May 2020

Background: Type 2 diabetes (T2D) cardiovascular disease (CVD) risk assessment has limitations. The aim of this study was to develop a risk equation adding heart failure (HF) to conventional major adverse cardiovascular events (MACE, myocardial infarction, stroke, and CVD death) and allowing for non-CVD death. Methods: 1551 community-based people with T2D (mean age 66 years, 52% males) were followed from baseline in 2008–2011 for five years to the first CVD event/death. Cox and competing risk regression identified predictors of three-point MACE and four-point MACE (including HF). Discrimination was assessed by the area under the receiver-operating characteristic curve (AUC) and calibration by the Hosmer-Lemeshow test. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were determined for a 10% five-year CVD risk cut-off. Results: 143 participants (9.2%) experienced a three-point MACE during 7,111 person-years of follow-up and 245 (15.8%) a four-point MACE during 6,896 person-years. The best model was the competing risk four-point MACE (221 predicted events (14.3%), AUC 0.82 (95% CI: 0.79–0.85), Hosmer-Lemeshow test, p = 0.17, sensitivity 79.2%, specificity 68.1%, PPV 31.8%, NPV 94.6%) with validation in 177 adults with T2D from an independent population (AUC 0.81 (0.74–0.89). Conclusions: A validated four-point MACE competing risk model reliably predicts key T2D CVD outcomes.
Non-Isothermal Crystallization Kinetics of Injection Grade PHBV and PHBV/Carbon Nanotubes Nanocomposites Using Isoconversional Method
Authors: Montanheiro Thaís Larissa do Amaral , de Menezes Beatriz Rossi Canuto , Montagna Larissa Stieven , Beatrice Cesar Augusto Gonçalves , Marini Juliano , Lemes Ana Paula , Thim Gilmar Patrocínio
Published: May 2020

Carbon nanotubes (CNT)-reinforced polymeric composites are being studied as promising materials due to their enhanced properties. However, understanding the behavior of polymers during non-isothermal crystallization is important once the degree of crystallinity and crystallization processes are affected when nanoparticles are added to matrices. Usually, crystallization kinetics studies are performed using a model-fitting method, though the isoconversional method allows to obtain the kinetics parameter without assuming a crystallization model. Therefore, in this work, CNTs were oxidized (CNT-Ox) and functionalized with gamma-aminobutyric acid (GABA) (CNT-GB) and incorporated into a poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) matrix. The influence of the addition and functionalization of CNT in the crystallization kinetics of PHBV was evaluated using the isoconversional method with differential scanning calorimetry (DSC), and by polarized light optical microscopy (PLOM) and Shore D hardness. The incorporation and functionalization of CNT into PHBV matrix did not change the Šesták and Berggren crystallization model; however, the lowest activation energy was obtained for the composite produced with CNT-GB, suggesting a better dispersion into the PHBV matrix. PLOM and Shore D hardness confirmed the results obtained in the kinetics study, showing the smallest crystallite size for CNT-containing nanocomposites and the highest hardness value for the composite produced with CNT-GB.
Influence of Image TIFF Format and JPEG Compression Level in the Accuracy of the 3D Model and Quality of the Orthophoto in UAV Photogrammetry
Authors: Alfio Vincenzo Saverio , Costantino Domenica , Pepe Massimiliano
Published: May 2020

The aim of this study is to evaluate the degradation of the accuracy and quality of the images in relation to the TIFF format and the different compression level of the JPEG format compared to the raw images acquired by UAV platform. Experiments were carried out using DJI Mavic 2 Pro and Hasselblad L1D-20c camera on three test sites. Post-processing of images was performed using software based on structure from motion and multi-view stereo approaches. The results show a slight influence of image format and compression levels in flat or slightly flat surfaces; in the case of a complex 3D model, instead, the choice of a format became important. Across all tests, processing times were found to also play a key role, especially in point cloud generation. The qualitative and quantitative analysis, carried out on the different orthophotos, allowed to highlight a modest impact in the use of the TIFF format and a strong influence as the JPEG compression level increases.
Numerical Study on Regular Wave Shoaling, De-Shoaling and Decomposition of Free/Bound Waves on Gentle and Steep Foreshores
Authors: Eldrup Mads Røge , Lykke Andersen Thomas
Published: May 2020

Numerical tests are performed to investigate wave transformations of nonlinear nonbreaking regular waves with normal incidence to the shore in decreasing and increasing water depth. The wave height transformation (shoaling) of nonlinear waves can, just as for linear waves, be described by conservation of the mechanical energy flux. The numerical tests show that the mechanical energy flux for nonlinear waves on sloping foreshores is well described by stream function wave theory for horizontal foreshore. Thus, this theory can be used to estimate the shoaled wave height. Furthermore, the amplitude and the celerity of the wave components of nonlinear waves on mildly sloping foreshores can also be predicted with the stream function wave theory. The tests also show that waves propagating to deeper water (de-shoaling) on a very gentle foreshore with a slope of cot(β) = 1200 can be described in the same way as shoaling waves. For de-shoaling on steeper foreshores, free waves are released leading to waves that are not of constant form and thus cannot be modelled by the proposed approach.
Finding Nemo: Predicting Movie Performances by Machine Learning Methods
Authors: Kim Jong-Min , Xia Leixin , Kim Iksuk , Lee Seungjoo , Lee Keon-Hyung
Published: May 2020

Analyzing the success of movies has always been a popular research topic in the film industry. Artificial intelligence and machine learning methods in the movie industry have been applied to modeling the financial success of the movie industry. The new contribution of this research combined Bayesian variable selection and machine learning methods for forecasting the return on investment (ROI). We also attempt to compare machine learning methods including the quantile regression model with movie performance data in terms of in-sample and out of sample forecasting.
4’-Methyl-2’-(quinolin-8-ylcarbamoyl)-biphenyl-4-carboxylic Acid Ethyl Ester
Authors: Mamari Hamad H. Al , Hasani Anfal Al
Published: May 2020

In this short note communication, we report the synthesis of a novel amide 4’-methyl-2’-(quinolin-8-ylcarbamoyl)-biphenyl-4-carboxylic acid ethyl ester by the Ru-catalyzed C(sp2)-H bond arylation reaction. The catalytic C-H bond functionalization reaction was employed, amongst other reaction reagents and conditions, [RuCl2(p-cymene)]2 as a precatalyst and (p-tol)3P as a ligand. The arylation product was characterized by various spectroscopic methods (1H NMR, 13C NMR, IR, GC-MS, and IR spectroscopy), and its composition was confirmed by elemental analysis.
Soft, Wirelessly Powered Humidity Sensor Based on SnO2 Nanowires for Wireless/Wearable Sensor Application
Authors: Shin Gunchul
Published: May 2020

Humidity, along with temperature, is one of the most important environmental variables in people’s lives. The control of humidity is an important matter that is related to material properties and stability in various industries, as well as basic living. In order to detect humidity, changes in the physical, chemical, and electrical properties of materials related to humidity are used, and studies using various methods are conducted. In this study, a field-effect transistor (FET) device was fabricated on a soft polymer substrate with SnO2 nanowires (NWs), whose electrical properties change in response to water molecules. The SnO2 NWs, synthesized by chemical vapor deposition (CVD), were transferred onto a polymer substrate, using a sliding transfer method. The NW FET device, which was connected to an aluminum (Al)-based radio frequency (RF) receiving antenna, was wirelessly operated as a humidity sensor, based on the change in electrical properties of SnO2 NWs according to the relative humidity (RH). It was configured with a wireless antenna and light emitting diode (LED) indicator to implement a soft wirelessly powered humidity sensor that senses high RH and is expected to be used as a wearable electronic/sensor in the future.
Utilization of Composts for Adsorption of Methylene Blue from Aqueous Solutions: Kinetics and Equilibrium Studies
Authors: Paradelo Remigio , Al-Zawahreh Khaled , Barral María Teresa
Published: May 2020

Utilization of composts as low-cost adsorbents is an important application in the field of environmental remediation, but these materials have not yet been extensively used for dye removal. In this work, we have studied the characteristics of adsorption of methylene blue onto two composts (a municipal solid waste compost and a pine bark compost). Kinetics and equilibrium batch experiments testing the influence of adsorbent particle size, solution pH and ionic strength were performed. Both composts have a high adsorption capacity for methylene blue, similar to other low-cost adsorbents. Kinetics of adsorption followed a pseudo-first-order model, with maximum adsorption reached after a contact time of two hours. Equilibrium adsorption followed a Langmuir model in general. Reduction of particle size only increased adsorption slightly for composted pine bark. Increase in ionic strength had no effect on adsorption by municipal solid waste compost, but increased adsorption by composted pine bark. Modification of pH between 5 and 7 did not influence adsorption in any case. Overall, the results suggest that electrostatic interaction between the cationic dye and the anionic functional groups in the composts is not the only mechanism involved in adsorption. In conclusion, the use of composts for dye removal is a likely application, in particular for those composts presenting limitations for agricultural use.
In Situ Characterization of Damage Development in Cottonid Due to Quasi-Static Tensile Loading
Authors: Scholz Ronja , Delp Alexander , Walther Frank
Published: May 2020

Cottonid is a layered material based 100% on cellulose that holds excellent material properties by being completely sustainable. The finite nature of petroleum-based resources nowadays makes these properties significant for technical applications again. To understand how Cottonid reacts to application-oriented mechanical loads and how it fails, development of microstructural damage on the surface and in the volume of Cottonid was studied using innovative in situ testing techniques for the first time. Quasi-static tensile tests were comparatively performed in a scanning electron microscope as well as a microfocus computer tomograph, and the development of defects present in the initial condition of the material was investigated. In the elastic region, no visible damage initiation on the surface and a decrease of overall void volume within the gauge length could be detected. When reaching the yield strength, crack initiation on the surface starts at critical areas, like pores and microcracks, which propagation and assembly could be visualized via scanning electron micrographs. In the plastic region, an increase in void volume could be shown in the gauge length until final failure of the specimen. Innovative material testing techniques presented in this study support lifetime estimation in technical applications and understanding of process–structure–property relations. Particularly, characterization of microstructural damage development due to a mechanical load, which leads to final failure of the specimen, is essential to be able to create material models for lifetime prediction in respect to variable manufacturing or application parameters.
Fatigue Reliability Analysis of a Compressor Disk Based on Probability Cumulative Damage Criterion
Authors: Ren Jungang , Zhao Bingfeng , Xie Liyang , Hu Zhiyong
Published: May 2020

The reliability of aero engine has a direct impact on the flight safety of the whole plane. With the continuous improvement of performance requirements of aero engines, the related fatigue and reliability problems also appear. For the fatigue failure characteristics of the typical component (compressor disk) in an aero engine, the fatigue reliability of its multi-site damage structure in service is analyzed by using probability cumulative damage criterion in this paper. The probability distribution definitions of life, damage and damage threshold are discussed and the relationship among them is also introduced by the new proposed criterion. Meanwhile, a method to determine the probability distribution of cumulative damage threshold and probability life prediction is carried out, based on which a hierarchical index system of statistical analysis and reliability modeling principle on the system level is further constructed for compressor disk. At the end of the paper, a certain cruise of fighter plane is analyzed to verify the validity of the new model. Emphasizing the difference between the compressor disk and traditional component, the new reliability analysis model developed in this study is basically reasonable for most of the load histories for the compressor disk, other than the traditional one, especially for the changeable and complex cruise missions.
Bond Strength Tests under Pure Shear and Tension between Masonry and Sprayed Mortar
Authors: Huang Dawei , Pons Oriol , Albareda Albert
Published: May 2020

Sprayed mortar or shotcrete is a construction technology that could enhance existing masonry buildings’ resilience by reinforcing low-safety load-bearing walls. Many factors affect the resistance of shotcrete-reinforced structures. One of the most important is the bond strength at the interface between the shotcrete and the reinforced wall. According to previous technical literature, bond strength usually has two evaluation criteria: shear and tensile strength. The experimental campaign described in this article focused on the bond strength between sprayed mortar and three masonry materials without the influence of normal force or constraint, as well as the roughness of these materials. The analysis of these tests focused on determining the relation between bond strength, roughness, and material strength. The analyses revealed that material strength has a more significant effect on bond strength than roughness, and bond strength is related to shrinkage of the materials. On the basis of previous theories, these researchers found that when there is no obvious influence due to normal force and constraint, the shear strength and tensile strength are different, and the shear strength is likely to be the cohesion force of the two materials. Finally, this article concludes with a novel logarithmic relationship between these strengths.
DNA Origami as Emerging Technology for the Engineering of Fluorescent and Plasmonic-Based Biosensors
Authors: Loretan Morgane , Domljanovic Ivana , Lakatos Mathias , Rüegg Curzio , Acuna Guillermo P.
Published: May 2020

DNA nanotechnology is a powerful and promising tool for the development of nanoscale devices for numerous and diverse applications. One of the greatest potential fields of application for DNA nanotechnology is in biomedicine, in particular biosensing. Thanks to the control over their size, shape, and fabrication, DNA origami represents a unique opportunity to assemble dynamic and complex devices with precise and predictable structural characteristics. Combined with the addressability and flexibility of the chemistry for DNA functionalization, DNA origami allows the precise design of sensors capable of detecting a large range of different targets, encompassing RNA, DNA, proteins, small molecules, or changes in physico-chemical parameters, that could serve as diagnostic tools. Here, we review some recent, salient developments in DNA origami-based sensors centered on optical detection methods (readout) with a special emphasis on the sensitivity, the selectivity, and response time. We also discuss challenges that still need to be addressed before this approach can be translated into robust diagnostic devices for bio-medical applications.
Comparative Surface Morphology, Chemical Composition, and Cytocompatibility of Bio-C Repair, Biodentine, and ProRoot MTA on hDPCs
Authors: Ghilotti James , Sanz José Luis , López-García Sergio , Guerrero-Gironés Julia , Pecci-Lloret María P. , Lozano Adrián , Llena Carmen , Rodríguez-Lozano Francisco Javier , Forner Leopoldo , Spagnuolo Gianrico
Published: May 2020

Biocompatibility is an essential property for any vital pulp material that may interact with the dental pulp tissues. Accordingly, this study aimed to compare the chemical composition and ultrastructural morphology of Biodentine (Septodont, Saint Maur-des-Fosses, France), ProRoot MTA (Dentsply Tulsa Dental Specialties, Johnson City, TN, USA), and Bio-C Repair (Angelus, Londrina, PR, Brazil), as well as their biological effects on human dental pulp cells. Chemical element characterization of the materials was undertaken using scanning electron microscopy and energy dispersive X-ray analysis (SEM-EDX). The cytotoxicity was assessed by analyzing the cell viability (MTT assay), cell morphology (immunofluorescence assay), and cell attachment (flow cytometry assay). The results were statistically analyzed using ANOVA and Tukey’s test (p < 0.05). EDX revealed that ProRoot MTA and Biodentine were mostly composed of calcium, carbon, and oxygen (among others), whereas Bio-C Repair evidenced a low concentration of calcium and the highest concentration of zirconium. SEM showed adequate attachment of human dental pulp cells (hDPCS) to vital pulp materials and cytoskeletal alterations were not observed in the presence of material eluates. Remarkably, the undiluted Biodentine group showed higher viability than the control group cells (without eluates) at 24 h, 48 h, and 72 h (p < 0.001). Based on the evidence derived from an in vitro cellular study, it was concluded that Bio-C Repair showed excellent cytocompatibility that was similar to Biodentine and ProRoot MTA.
In Situ and Ex Situ Characterization of the Microstructure Formation in Ni-Cr-Si Alloys during Rapid Solidification—Toward Alloy Design for Laser Additive Manufacturing
Authors: Li Xiaoshuang , Zweiacker Kai , Grolimund Daniel , Ferreira Sanchez Dario , Spierings Adriaan B. , Leinenbach Christian , Wegener Konrad
Published: May 2020

Laser beam-based deposition methods such as laser cladding or additive manufacturing of metals promises improved properties, performance, and reliability of the materials and therefore rely heavily on understanding the relationship between chemical composition, rapid solidification processing conditions, and resulting microstructural features. In this work, the phase formation of four Ni-Cr-Si alloys was studied as a function of cooling rate and chemical composition using a liquid droplet rapid solidification technique. Post mortem x-ray diffraction, scanning electron microscopy, and in situ synchrotron microbeam X-ray diffraction shows the present and evolution of the rapidly solidified microstructures. Furthermore, the obtained results were compared to standard laser deposition tests. In situ microbeam diffraction revealed that due to rapid cooling and an increasing amount of Cr and Si, metastable high-temperature silicides remain in the final microstructure. Due to more sluggish interface kinetics of intermetallic compounds than that of disorder solid solution, an anomalous eutectic structure becomes dominant over the regular lamellar microstructure at high cooling rates. The rapid solidification experiments produced a microstructure similar to the one generated in laser coating thus confirming that this rapid solidification test allows a rapid pre-screening of alloys suitable for laser beam-based processing techniques.
The Multidirectional Auxeticity and Negative Linear Compressibility of a 3D Mechanical Metamaterial
Authors: Dudek Krzysztof K. , Attard Daphne , Gatt Ruben , Grima-Cornish James N. , Grima Joseph N.
Published: May 2020

In this work, through the use of a theoretical model, we analyse the potential of a specific three-dimensional mechanical metamaterial composed of arrowhead-like structural units to exhibit a negative Poisson’s ratio for an arbitrary loading direction. Said analysis allows us to assess its suitability for use in applications where materials must be able to respond in a desired manner to a stimulus applied in multiple directions. As a result of our studies, we show that the analysed system is capable of exhibiting auxetic behaviour for a broad range of loading directions, with isotropic behaviour being shown in some planes. In addition to that, we show that there are also certain loading directions in which the system manifests negative linear compressibility. This enhances its versatility and suitability for a number of applications where materials exhibiting auxetic behaviour or negative linear compressibility are normally implemented.
Impact of an Antiresonant Oxide Island on the Lasing of Lateral Modes in VCSELs
Authors: Więckowska Marta , Sarzała Robert P. , Ledzion Rafał , Dems Maciej
Published: May 2020

Use of antiresonant structures is a proven, efficient method of improving lateral mode selectivity in VCSELs. In this paper, we analyze the impact of a low-refractive antiresonant oxide island buried in a top VCSEL mirror on the lasing conditions of lateral modes of different orders. By performing comprehensive thermal, electrical, and optical numerical analysis of the VCSEL device, we show the impact of the size and location of the oxide island on the current-crowding effect and compute threshold currents for various lateral modes. If the island is placed close to the cavity, the threshold shows strong oscillations, which for moderate island distances can be tuned to increase the side mode discrimination. We are therefore able to pinpoint the most important factors influencing mode discrimination and to identify oxide island parameters capable of providing single-lateral-mode emission.
Manufacturing of Large Size and Highly Transparent Nd:YAG Ceramics by Pressure Slip-Casting and Post-Sintering by HIP: An Experimental and Simulation Study
Authors: Boulesteix Rémy , Chevarin Cyril , Belon Rémy , Maître Alexandre , Cochain Léo , Sallé Christian
Published: May 2020

This study reports the fabrication of Nd:YAG (i.e., Neodymium-doped Yttrium Aluminum Garnet: Y3-xNdxAl5O12) transparent ceramics of a large size by the pressure slip-casting forming technique. Colloidal suspensions of primary oxides (i.e., Y2O3, Al2O3, Nd2O3, and SiO2 used as sintering aid) were cast under pressure through a porous membrane. Cakes with a good microstructural homogeneity and mean pore diameter of 90 nm were obtained. Modeling of the pressure slip-casting process at the millimetric to centimetric scale based on a computational fluid dynamics simulation showed good agreement with experimental results in terms of the casting kinetics (i.e., cake thickness and fluid flow as a function of time) and cake permeability. As a result, it was possible to better manage pressure casting parameters in order to obtain large size and homogeneous green parts. Finally, transparent Nd:YAG ceramics sintered by vacuum sintering, followed by post-sintering treatment by Hot Isostatic Pressing (HIP), demonstrated laser slope efficiency (51.7%) and optical-to-optical efficiency (44%) with 130 mJ of output laser energy at 1064 nm equivalent to commercial single crystals.
Investigations on Mechanical Properties of Lattice Structures with Different Values of Relative Density Made from 316L by Selective Laser Melting (SLM)
Authors: Płatek Paweł , Sienkiewicz Judyta , Janiszewski Jacek , Jiang Fengchun
Published: May 2020

Nine variants of regular lattice structures with different relative densities have been designed and successfully manufactured. The produced structures have been subjected to geometrical quality control, and the manufacturability of the implemented selective laser melting (SLM) technique has been assessed. It was found that the dimensions of the produced lattice struts differ from those of the designed struts. These deviations depend on the strut orientation in relation to the specimen-building direction. Additionally, the microstructures and phase compositions of the obtained structures were characterized and compared with those of conventionally produced 316L stainless steel. The microstructure analysis and X-ray diffraction (XRD) patterns revealed a single austenite phase in the SLM samples. Both a certain broadening and a displacement of the austenite peaks were observed due to residual stresses and a crystallographic texture induced by the SLM process. Furthermore, the mechanical behavior of the lattice structure material has been defined. It was demonstrated that under both quasi-static and dynamic testing, lattice structures with high relative densities are stretch-dominated, whereas those with low relative densities are bending-dominated. Moreover, the linear dependency between the value of energy absorption and relative density under dynamic loading conditions has been established.
Influence of a Coaxial Electrospraying System on the n-Hexadecane/Polycaprolactone Phase Change Microcapsules Properties
Authors: Zhang Shengchang , Chen Yuan , Campagne Christine , Salaün Fabien
Published: May 2020

Electrospraying is considered to be a green, high-efficiency method for synthesizing phase change microcapsules (mPCMs) for possible applications in the fields of energy storage and thermal regulation. In this study, a coaxial nozzle was used to prepare n-hexadecane/polycaprolactone (PCL) microparticles. The objectives of this study were to investigate the influence of working parameters and solutions on morphology, particle size, thermal properties and encapsulation efficiency. Thus, three theoretical loading contents in n-hexadecane (30%, 50% and 70% w/w) and two concentrations of PCL (5 and 10% w/v) were used. The structures, morphologies and thermal properties of mPCMs were characterized by optical microscopy (OM), scanning electron microscopy (SEM), differential scanning calorimeter (DSC), and thermogravimetric analysis (TGA). Spherical microcapsules with a mean diameter of 10–20 µm were prepared. The increased concentration of n-hexadecane and PCL resulted in a change in the particle size distribution from a poly-disperse to monodisperse size distribution and in a change in the surface state from porous to non-porous. In addition, higher encapsulation efficiency (96%) and loading content (67%) were achieved by the coaxial nozzle using the high core-shell ratio (70/30) and 10% w/v of PCL. The latent heat of the mPCMs reached about 134 J.g−1. In addition, it was also observed that the thermal stability was improved by using a coaxial system rather than a single nozzle.
Design of a Motorcycle Steering Damper for a Safer Ride
Authors: Piantini Simone , Giorgetti Alessandro , Baldanzini Niccolò , Monti Cosimo , Pierini Marco
Published: May 2020

Powered-two-wheelers (PTWs) are increasingly popular because of their lower cost compared to cars, and therefore the riders’ exposure risk is increasing. Due to their complex dynamics characterized by high non-linearity and inherent instability, PTWs are more difficult to control compared to four-wheeled vehicles. Wobble is a high-frequency instability mode affecting the steering assembly of the PTW, and which often causes the rider to lose control and crash when it occurs. In this paper, we present the design of a new motorcycle semi-active steering damper integrated into the steering column and utilizing a magnetorheological fluid (MRF) for variable damping torque. An analytical model of the concept was first used to perform the preliminary sizing, followed by concept validation using a 3D FE multiphysics magnetic-fluid analysis. The final innovative design offers several advantages compared to traditional steering dampers: (i) a wide range of adjustable damping torque values, with a multiplication factor up to 10 with a maximum electrical current of 2 A; (ii) total integration into the motorcycle steering column enabled by its axial design and limited radius; (iii) a simple chamber geometry that allows for easy manufacture; (iv) longer seal life due to the absence of direct contact between seals and the MRF.
On Sequential Fractional q-Hahn Integrodifference Equations
Authors: Dumrongpokaphan Thongchai , Patanarapeelert Nichaphat , Sitthiwirattham Thanin
Published: May 2020

In this paper, we prove existence and uniqueness results for a fractional sequential fractional q-Hahn integrodifference equation with nonlocal mixed fractional q and fractional Hahn integral boundary condition, which is a new idea that studies q and Hahn calculus simultaneously.
Geometric Inequalities of Warped Product Submanifolds and Their Applications
Authors: Alluhaibi Nadia , Mofarreh Fatemah , Ali Akram , Mior Othman Wan Ainun
Published: May 2020

In the present paper, we prove that if Laplacian for the warping function of complete warped product submanifold M m = B p × h F q in a unit sphere S m + k satisfies some extrinsic inequalities depending on the dimensions of the base B p and fiber F q such that the base B p is minimal, then M m must be diffeomorphic to a unit sphere S m . Moreover, we give some geometrical classification in terms of Euler–Lagrange equation and Hamiltonian of the warped function. We also discuss some related results.
A Note on Superspirals of Confluent Type
Authors: Inoguchi Jun-ichi , Ziatdinov Rushan , Miura Kenjiro T.
Published: May 2020

Superspirals include a very broad family of monotonic curvature curves, whose radius of curvature is defined by a completely monotonic Gauss hypergeometric function. They are generalizations of log-aesthetic curves, and other curves whose radius of curvature is a particular case of a completely monotonic Gauss hypergeometric function. In this work, we study superspirals of confluent type via similarity geometry. Through a detailed investigation of the similarity curvatures of superspirals of confluent type, we find a new class of planar curves with monotone curvature in terms of Tricomi confluent hypergeometric function. Moreover, the proposed ideas will be our guide to expanding superspirals.