bluuebunny/crossref_metadata_2025 huggingface dataset:
m6A RNA Methylation Regulator YTHDF1 Correlated With Immune Microenvironment Predicts Clinical Outcomes and Therapeutic Efficacy in Breast Cancer
Authors: Hu Ying , Pan Qinwen , Wang Minghao , Ai Xiang , Yan Yuzhao , Tian Yuan , Jing Yuting , Tang Peng , Jiang Jun
Published: August 2021

Objective: Increasing evidence highlights the roles of N6-methyladenosine (m6A) and its regulators in oncogenesis. Herein, this study observed the associations of m6A regulators with breast cancer.

Methods: RNA-seq profiles of breast cancer were retrieved from the Cancer Genome Atlas (TCGA) database. The expression of m6A regulators was analyzed in tumor and normal tissues. Their expression correlations were analyzed by Spearson test. Overall survival (OS) analysis of these regulators was then presented. Gene set enrichment analysis (GSEA) was performed in high and low YTHDF1 expression groups. The correlations of YTHDF1 expression with immune cells and tumor mutation burden (TMB) were calculated in breast cancer samples. Somatic variation was assessed in high and low YTHDF1 expression groups.

Results: Most of m6A regulators were abnormally expressed in breast cancer compared to normal tissues. At the mRNA levels, there were closely relationships between them. Among them, YTHDF1 up-regulation was significantly related to undesirable prognosis (p = 0.025). GSEA results showed that high YTHDF1 expression was associated with cancer-related pathways. Furthermore, YTHDF1 expression was significantly correlated with T cells CD4 memory activated, NK cells activated, monocytes, and macrophages. There were higher TMB scores in YTHDF1 up-regulation group than its down-regulation group. Missense mutation and non-sense mutation were the most frequent mutation types.

Conclusion: Our findings suggested that dysregulated m6A regulator YTHDF1 was predictive of survival outcomes as well as response to immunotherapy of breast cancer, and were closely related to immune microenvironment.
Role of Carnitine in Non-alcoholic Fatty Liver Disease and Other Related Diseases: An Update
Authors: Li Na , Zhao Hui
Published: August 2021

Carnitine is an amino acid-derived substance that coordinates a wide range of biological processes. Such functions include transport of long-chain fatty acids from the cytoplasm to the mitochondrial matrix, regulation of acetyl-CoA/CoA, control of inter-organellar acyl traffic, and protection against oxidative stress. Recent studies have found that carnitine plays an important role in several diseases, including non-alcoholic fatty liver disease (NAFLD). However, its effect is still controversial, and its mechanism is not clear. Herein, this review provides current knowledge on the biological functions of carnitine, the “multiple hit” impact of carnitine on the NAFLD progression, and the downstream mechanisms. Based on the “multiple hit” hypothesis, carnitine inhibits β-oxidation, improves mitochondrial dysfunction, and reduces insulin resistance to ameliorate NAFLD. L-carnitine may have therapeutic role in liver diseases including non-alcoholic steatohepatitis, cirrhosis, hepatocellular carcinoma, alcoholic fatty liver disease, and viral hepatitis. We also discuss the prospects of L-carnitine supplementation as a therapeutic strategy in NAFLD and related diseases, and the factors limiting its widespread use.
Meta-Analysis of Renal Replacement Therapy for Burn Patients: Incidence Rate, Mortality, and Renal Outcome
Authors: Duan ZhiYu , Cai GuangYan , Li JiJun , Chen FengKun , Chen XiangMei
Published: August 2021

Background: Renal replacement therapy (RRT) was often needed by some severe burn patients with acute kidney injury (AKI). The primary aim of this study was to review incidence rate and mortality of RRT in severe burn patients. Second aims were to review RRT complications and renal outcome.

Methods: We searched multiple databases for studies published between 1 January 1960 and 31 December 2019. Studies about adult populations with burn injury, providing epidemiologic data on prevalence or mortality of RRT, were included.

Results: A total of selected 57 studies, including 27,437 patients were enrolled in our analysis. The prevalence rates of RRT were 8.34% (95% CI 7.18–9.5%) in all burn patients and 37.05% (95% CI 29.85–44.24%) in AKI patients. The mortality of all burn patients with RRT was 65.52% (95% CI 58.41–72.64%). The prevalence rates of RRT in sample size≥100 group were 6.86% (95% CI 5.70–8.03%), which was lower than that of <100 group (17.61%, 95% CI 13.39–21.82%). With the increase of TBSA, the prevalence of RRT may have the increasing trend. The prevalence rates of RRT in Asian group was 12.75% (95% CI 9.50–16.00%), which was higher than that of European (10.45%, 95% CI 7.30–13.61%) and North America group (5.61%, 95% CI 4.27–6.95%). The prevalence rates of RRT in 2010–2019 group was 12.22% (95% CI 10.09–14.35%), which was higher than that of 2009–2000 group (5.17%, 95% CI 2.88–7.46%). The prevalence rates of RRT in 1989 and before group was the lowest, which was 1.56% (95% CI 0–3.68%). However, there was no significant correlation between the year of publication and the mortality of burn patients with RRT. Dialysis-requiring AKI in burn patients could increases the risk of chronic kidney disease progression and end-stage renal disease. About 35% of RRT patients need to maintain haemodialysis temporarily, even if they survive and leave hospital.

Conclusions: The prevalence rate of RRT is about 6–8%; approximately, one-third of burn patients with AKI need RRT. The prevalence rate of RRT increased over time, but the mortality did not change. The prevalence rates of RRT in Asian group was higher than that of European and North America group.
Risk Factors for Development and Severity of COVID-19 in COPD Patients
Authors: Bonato Matteo , Semenzato Umberto , Tinè Mariaenrica , Bazzan Erica , Damin Marco , Biondini Davide , Casara Alvise , Romagnoli Micaela , Turato Graziella , Cosio Manuel G. , Saetta Marina , Baraldo Simonetta
Published: August 2021

The impact that COVID-19 could have on patients with COPD is a real concern. In this study we evaluated, in a cohort of longitudinally followed COPD subjects, the incidence of COVID-19, seeking for possible risk factors and prognostic factors predicting the clinical outcome. In our cohort of 370 patients (followed for 5.3 ± 2.7 years), 22 developed COVID-19 (COPD/COVID-19+) between February/November 2020 (5.9%). Cardio-metabolic conditions (hypertension, dyslipidemia, obesity, diabetes) but not respiratory abnormalities (FEV1, DLCO, emphysema and exacerbation history), were risk factors for development of COVID-19 in COPD patients. Out of the 22 COPD/COVID-19+ patients, 10 needed intensive care. Low DLCO and emphysema, but also metabolic comorbidities, were related to the need for intensive care.
Effect of Dietary Protein Levels on Dynamic Changes and Interactions of Ruminal Microbiota and Metabolites in Yaks on the Qinghai-Tibetan Plateau
Authors: Zhang XiaoLing , Xu TianWei , Wang XunGang , Geng YuanYue , Zhao Na , Hu LinYong , Liu HongJin , Kang ShengPing , Xu ShiXiao
Published: August 2021

To improve performance and optimize rumen function in yaks (Bos grunniens), further knowledge on the appropriate dietary protein levels for ruminal microbiota and the metabolite profiles of yaks in feedlot feeding is necessary. Current understanding of dietary protein requirements, ruminal microbiota, and metabolites is limited. In this study, yaks were fed a low-protein diet (L; 9.64%), middle low-protein diet (ML; 11.25%), middle high-protein diet (MH; 12.48%), or a high-protein diet (H; 13.87%), and the effects of those diets on changes and interactions in ruminal microbiota and metabolites were investigated. Twenty-four female yaks were selected, and the effects on ruminal microbiota and metabolites were investigated using 16s rRNA gene sequencing and gas chromatography time-of-flight/mass spectrometry (GC-TOF/MS). Diets containing different protein levels changed the composition of the rumen bacterial community, the H group significantly reduced the diversity of ruminal microbiota (p< 0.05), and the number of shared amplicon sequence variants (ASVs) between the H group and the other three groups was lower, suggesting that the ruminal microbiota community fluctuated more with a high-protein diet. In rumen,Bacteroidetes,Firmicutes, andProteobacteriawere the most abundant bacteria at the phylum level, andBacteroideteswas significantly less abundant in the MH group than in the L and ML groups (p< 0.05).Prevotella_1,Rikenellaceae_RC9_gut_group, andChristensenellaceae_R-7_grouphad the highest abundance at the genus level.Prevotellaceaewas enriched in the low-protein groups, whereasBacteroidales_BS11_gut_groupwas enriched in the high-protein groups. Rumen metabolite concentrations and metabolic patterns were altered by dietary protein levels: organic acid metabolites, antioxidant-related metabolites, and some plant-derived metabolites showed variation between the groups. Enrichment analysis revealed that significant changes were concentrated in six pathways, including the citrate cycle (TCA cycle), glyoxylate and dicarboxylate metabolism, and butanoate metabolism. Network analysis showed promotion or restraint relationships between different rumen microbiota and metabolites. Overall, the rumen function was higher in the MH group. This study provides a reference for appropriate dietary protein levels and improves understanding of rumen microbes and metabolites.
P3-MSDA: Multi-Source Domain Adaptation Network for Dynamic Visual Target Detection
Authors: Song Xiyu , Zeng Ying , Tong Li , Shu Jun , Bao Guangcheng , Yan Bin
Published: August 2021

Single-trial electroencephalogram detection has been widely applied in brain-computer interface (BCI) systems. Moreover, an individual generalized model is significant for applying the dynamic visual target detection BCI system in real life because of the time jitter of the detection latency, the dynamics and complexity of visual background. Hence, we developed an unsupervised multi-source domain adaptation network (P3-MSDA) for dynamic visual target detection. In this network, a P3 map-clustering method was proposed for source domain selection. The adversarial domain adaptation was conducted for domain alignment to eliminate individual differences, and prediction probabilities were ranked and returned to guide the input of target samples for imbalanced data classification. The results showed that individuals with a strong P3 map selected by the proposed P3 map-clustering method perform best on the source domain. Compared with existing schemes, the proposed P3-MSDA network achieved the highest classification accuracy and F1 score using five labeled individuals with a strong P3 map as the source domain. These findings can have a significant meaning in building an individual generalized model for dynamic visual target detection.
Measuring Mind Wandering During Online Lectures Assessed With EEG
Authors: Conrad Colin , Newman Aaron
Published: August 2021

Mind wandering can inhibit learning in multimedia classrooms, such as when watching online lectures. One explanation for this effect is that periods of mind wandering cause learners’ attention to be redirected from the learning material toward task-unrelated thoughts. The present study explored the relationship between mind wandering and online education using electroencephalography (EEG). Participants were asked to attend to a 75 minute educational video lecture, while task-irrelevant auditory tones played at random intervals. The tones were of two distinct pitches, with one occurring frequently (80%) and the other infrequently (20%). Participants were prompted at pseudo-random intervals during the lecture to report their degree of experienced mind wandering. EEG spectral power and event-related potentials (ERP) were compared between states of high and low degrees of self-reported mind wandering. Participants also performed pre/post quizzes based on the lecture material. Results revealed significantly higher delta, theta and alpha band activity during mind wandering, as well as a decreased P2 ERP amplitude. Further, learning scores (improvement on quizzes pre to post) were lower among participants who reported higher degrees of mind wandering throughout the video. The results are consistent with a view that mind wandering during e-learning is characterized by a shift in attention away from the external world and toward internal thoughts, which may be a cause of reduced learning.
Altered Cerebrospinal Fluid Clearance and Increased Intracranial Pressure in Rats 18 h After Experimental Cortical Ischaemia
Authors: Bothwell Steven W. , Omileke Daniel , Hood Rebecca J. , Pepperall Debbie-Gai , Azarpeykan Sara , Patabendige Adjanie , Spratt Neil J.
Published: August 2021

Oedema-independent intracranial pressure (ICP) rise peaks 20–22-h post-stroke in rats and may explain early neurological deterioration. Cerebrospinal fluid (CSF) volume changes may be involved. Cranial CSF clearance primarily occurs via the cervical lymphatics and movement into the spinal portion of the cranio-spinal compartment. We explored whether impaired CSF clearance at these sites could explain ICP rise after stroke. We recorded ICP at baseline and 18-h post-stroke, when we expect changes contributing to peak ICP to be present. CSF clearance was assessed in rats receiving photothrombotic stroke or sham surgery by intraventricular tracer infusion. Tracer concentration was quantified in the deep cervical lymph nodes ex vivo and tracer transit to the spinal subarachnoid space was imaged in vivo. ICP rose significantly from baseline to 18-h post-stroke in stroke vs. sham rats [median = 5 mmHg, interquartile range (IQR) = 0.1–9.43, n = 12, vs. −0.3 mmHg, IQR = −1.9–1.7, n = 10], p = 0.03. There was a bimodal distribution of rats with and without ICP rise. Tracer in the deep cervical lymph nodes was significantly lower in stroke with ICP rise (0 μg/mL, IQR = 0–0.11) and without ICP rise (0 μg/mL, IQR = 0–4.47) compared with sham rats (4.17 μg/mL, IQR = 0.74–8.51), p = 0.02. ICP rise was inversely correlated with faster CSF transit to the spinal subarachnoid space (R = −0.59, p = 0.006, Spearman’s correlation). These data suggest that reduced cranial clearance of CSF via cervical lymphatics may contribute to post-stroke ICP rise, partially compensated via increased spinal CSF outflow.
Identification of Key Genes Mutations Associated With the Radiosensitivity by Whole Exome Sequencing in Pancreatic Cancer
Authors: Hu Bin , Ma Xiumei , Huang Renhua , Wu Zheng , Lu Jun , Guo Yuntao , Tang Jianmin , Ma Chunhui , Ma Jun , Zhang Lei , Bai Yongrui
Published: August 2021

Background

Pancreatic cancer (PC) is one of the most lethal human cancers, and radiation therapy (RT) is an important treating option. Many patients diagnosed with PC do not achieve objective responses because of the existence of intrinsic and acquired radioresistance. Therefore, biomarkers, which predict radiotherapy benefit in PC, are eagerly needed to be identified.

Methods

Whole-exome sequencing of six pancreatic ductal adenocarcinoma patients (PDAC) (three with a good response and three with a poor response) who had received radical surgery and then radiotherapy has been performed as standard of care treatment. Somatic and germline variants and the mutational signatures were analyzed with bioinformatics tools and public databases. Functional enrichment and pathway-based protein-protein interaction analyses were utilized to address the possibly mechanism in radioresistance. MTT, LDH, and colony formation assay were applied to evaluate cell growth and colony formation ability.

Results

In the present study, somatic mutations located in 441 genes were detected to be radiosensitivity-related loci. Seventeen genes, including the Smad protein family members (SMAD3 and SMAD4), were identified to influence the radiosensitivity in PDAC. The SMAD3 and SMAD4 genes mutate differently between radiosensitive and radioresistant PDAC patients. Mutation of SMAD3 potentiates the effects of ionizing radiation (IR) on cell growth and colony formation in PDAC cells, whereas mutation of SMAD4 had the opposite effects. SMAD3 and SMAD4 regulate the radiosensitivity of PDAC, at least in part, by P21 and FOXO3a, respectively.

Conclusions

These results indicate that mutations of SMAD3 and SMAD4 likely cause the difference of response to radiotherapy in PDAC, which might be considered as the biomarkers and potential targets for the radiotherapy of pancreatic cancer.
The Olfactory Chemosensation of Hematophagous Hemipteran Insects
Authors: Liu Feng , Chen Zhou , Ye Zi , Liu Nannan
Published: August 2021

As one of the most abundant insect orders on earth, most Hemipteran insects are phytophagous, with the few hematophagous exceptions falling into two families: Cimicidae, such as bed bugs, and Reduviidae, such as kissing bugs. Many of these blood-feeding hemipteran insects are known to be realistic or potential disease vectors, presenting both physical and psychological risks for public health. Considerable researches into the interactions between hemipteran insects such as kissing bugs and bed bugs and their human hosts have revealed important information that deepens our understanding of their chemical ecology and olfactory physiology. Sensory mechanisms in the peripheral olfactory system of both insects have now been characterized, with a particular emphasis on their olfactory sensory neurons and odorant receptors. This review summarizes the findings of recent studies of both kissing bugs (including Rhodnius prolixus and Triatoma infestans) and bed bugs (Cimex lectularius), focusing on their chemical ecology and peripheral olfactory systems. Potential chemosensation-based applications for the management of these Hemipteran insect vectors are also discussed.
Gaze Behavior During Navigation and Visual Search of an Open-World Virtual Environment
Authors: Enders Leah R. , Smith Robert J. , Gordon Stephen M. , Ries Anthony J. , Touryan Jonathan
Published: August 2021

Eye tracking has been an essential tool within the vision science community for many years. However, the majority of studies involving eye-tracking technology employ a relatively passive approach through the use of static imagery, prescribed motion, or video stimuli. This is in contrast to our everyday interaction with the natural world where we navigate our environment while actively seeking and using task-relevant visual information. For this reason, an increasing number of vision researchers are employing virtual environment platforms, which offer interactive, realistic visual environments while maintaining a substantial level of experimental control. Here, we recorded eye movement behavior while subjects freely navigated through a rich, open-world virtual environment. Within this environment, subjects completed a visual search task where they were asked to find and count occurrence of specific targets among numerous distractor items. We assigned each participant into one of four target conditions: Humvees, motorcycles, aircraft, or furniture. Our results show a statistically significant relationship between gaze behavior and target objects across Target Conditions with increased visual attention toward assigned targets. Specifically, we see an increase in the number of fixations and an increase in dwell time on target relative to distractor objects. In addition, we included a divided attention task to investigate how search changed with the addition of a secondary task. With increased cognitive load, subjects slowed their speed, decreased gaze on objects, and increased the number of objects scanned in the environment. Overall, our results confirm previous findings and support that complex virtual environments can be used for active visual search experimentation, maintaining a high level of precision in the quantification of gaze information and visual attention. This study contributes to our understanding of how individuals search for information in a naturalistic (open-world) virtual environment. Likewise, our paradigm provides an intriguing look into the heterogeneity of individual behaviors when completing an un-timed visual search task while actively navigating.
Altruistic Giving Toward Refugees: Identifying Factors That Increase Citizens' Willingness to Help
Authors: Hellmann Dshamilja Marie , Fiedler Susann , Glöckner Andreas
Published: August 2021

Over the past decade, the world has faced an unprecedented refugee crisis. The large number of incoming refugees represents a challenge for host societies and its citizens triggering reactions from a supportive welcome to brusque rejection and hostile behavior toward refugees. In a pre-registered study, we investigated factors that could promote altruistic behavior in fully incentivized one-shot Dictator Game toward various receiver groups including refugees. We find that host citizens behave more altruistically toward refugees and other receiver groups if they (a) share a local identity with them (i.e., live in the same city), and (b) perceive them to be close (to the self) and warm-hearted. Moreover, citizens that are (c) generally more prosocial and hold a more left-wing political orientation are more willing to give. Unexpectedly, from a theoretical point of view, altruistic giving toward refugees was not influenced in the predicted direction by a shared student identity, competition and perceived income differences (although the latter effect was significant when considering all receiver groups). For shared student identity we even observe a reduction of altruistic behavior, while the opposite effect was predicted. We discuss implications for public policies for successful refugee helping and integration.
“Infeliz” or “Triste”: A Paradigm for Mixed Methods Exploration of Outcome Measures Adaptation Across Language Variants
Authors: Evans Chris , Paz Clara , Mascialino Guido
Published: August 2021

The literature on measure translation tends to hold, overtly or covertly, a questionable assumption about the possibility of exact translation and almost completely ignores issues of within language variation. Equally, psychometric methods used to assess cross-cultural validity after translation focus on large sample tests of cross-sectional measurement invariance. Such invariance is often not found and is of dubious pertinence to change/outcome measures usually used in psychotherapy research. We present a sequential process of three substudies using quantitative and qualitative procedures to explore whether an outcome measure needs to be changed when used across language variation. Qualitative data confirmed that an item was not ideal in the new context. However, quantitative exploration showed that, although statistically significant and affected by gender and item order, the impact of changing the item in the overall score was small, allowing retention of the existing Spanish translation. We argue that the myth of perfect translation and over-reliance on large-sample psychometric testing pursuing measurement invariance limit exploration of language effects. We recommend that these be used in the companion of user-based, sequential, mixed-method exploration to support the development of a richer field of understanding of outcomes and change self-report measures across languages and cultures and both across and within languages.
Connections Between Perceived Social Support and the Body Image in the Group of Women With Diastasis Recti Abdominis
Authors: Izydorczyk Bernadetta , Walenista Wiktoria , Kamionka Agata , Lizińczyk Sebastian , Ptak Magdalena
Published: August 2021

Background: The psychological features of the body image and the role of perceived social support for women with diastasis recti abdominis (DRAM) is significant for the treatment of this group of patients, but it is difficult to identify research on this topic. We aimed to search for similarities and differences between postpartum women with DRAM in terms of their psychological features of the body image and perceived social support from the partner, family and friends.

Methods: Three hundred forty-five Polish women with DRAM were asked to fill the The Multidimensional Body-Self Relations Questionnaire (MBSRQ), The Multidimensional Scale of Perceived Social Support (MSPSS) and The Drawing Self-Assessment Sheet. Data analysis included the stepwise regression analysis and k-cluster analysis.

Results: We identified several predictors in the group of women with DRAM. Social support of partner, family, and friends are the predictors of self-assessment of general body appearance. Social support of family is a predictor of self-assessment of the health of the body. Social support of friends is a predictor of self-esteem of weight and fear of gaining weight. Moreover, three clusters of women with DRAM were found. Type 1—women with DRAM with one child and low self-esteem of the general appearance of the body, low self-esteem of health condition of the body, high self-esteem of weight, and fear of weight gain, and low level of social support; Type 2—women with DRAM with three or more children and low self-esteem of the general appearance of the body, low self-esteem of health condition of the body, high self-esteem of weight and fear of weight gain, and high level of social support; and Type 3—women with DRAM with two children and high self-esteem for the general appearance of the body, high level of self-esteem for health of the body, low self-esteem of weight and fear of weight gain, and high levels of social support.

Conclusions: Social support is a predictor of body image in women with DRAM, but there are other factors that influence body acceptance more in this group of women. Furthermore the three clusters featured in the study may help in treating women with DRAM.
Adverse Childhood Experiences and Psychological Well-Being in Chinese College Students: Moderated Mediation by Gender and Resilience
Authors: Chen Yafan , Hua Kai , Huang Chienchung , Zhou Gaosheng , Wang Jianfeng
Published: August 2021

Adverse childhood experiences (ACEs), including child abuse/neglect and household challenges, are a prevalent social issue that impacts individuals' well-being worldwide. Relatively few ACEs studies orient to the presence of psychological wellness, especially in ethnically Chinese populations. Furthermore, less is known about resilience as a mechanism between ACEs and psychological well-being, in addition to the moderating effect of gender. This study examined the relationship between ACEs and psychological well-being among Chinese college students and the potential mediating and moderating effects of resilience and gender, respectively. A total of 1,871 college students studying social science from 12 Chinese colleges completed an anonymous online survey between late September and early October 2020. Multiple-group path analyses were conducted to examine whether the relationships among ACEs, resilience, and psychological well-being differed as a function of gender. Results suggested that gender moderated the relationships studied. For female students, resilience mediated the association between abuse/neglect and psychological well-being, where abuse/neglect was negatively associated with resilience, which in turn had a negative relationship with psychological well-being. For male students, household challenges were negatively related to psychological well-being through reduced resilience. Based on the findings, various ACE-informed initiatives may be essential to prevent and protect individuals from ACEs. We also call for resilience-based interventions to enhance individuals' resilience and thus strengthen their psychological well-being.
Acquisition of Swept Aerodynamic Data by the Consecutive Changing of Wing Model Configuration in a Wind Tunnel Test Using Remote Feedback Control
Authors: Wakimoto Ken , Chiba Kazuhisa , Kato Hiroyuki , Nakakita Kazuyuki
Published: August 2021

This study conducted wind tunnel tests with consecutive deflection angle changes on a three-dimensional (3D) wing with a control surface to procure aerodynamic data by sweeping the deflection angle. Configuration changes of a wind tunnel test model, such as changing the deflection angle of control surfaces, are usually performed manually with the ventilation suspended. Hence, the number of configurations that can be implemented within a confined test period is restricted; the aerodynamic data gained are discrete values. To accomplish continuous angular modulation would dramatically improve the ability by sweeping through the aerodynamic data in wind tunnel tests, enhancing the test system as a tool for discussing complex physical phenomena. Thus, this study created a compact remote feedback control system using optical measurement to continuously obtain high-precision aerodynamic data without stopping the wind tunnel, eliminating human operation. In particular, this study targets a 3D wing wind tunnel model with a control surface, which is more challenging to fabricate, miniaturizing the system in a model. The system consequently attained consecutive aerodynamic data multiple times under numerous configurations, which had been impracticable to reach in the past, within a wind tunnel test period of several days, thereby dramatically increasing the testing capability. The reproducibility was quantitatively verified by comparing the multiple data for the identical configurations. Furthermore, the reliability was demonstrated using discrete data obtained by conventional stepwise deflection angle adjustments. Eventually, the system was able to grasp physical phenomena involving hysteresis.
Design, Production and Evaluation of 3D-Printed Mold Geometries for a Hybrid Rocket Engine
Authors: Grefen Benedict , Becker Johannes , Linke Stefan , Stoll Enrico
Published: August 2021

The feasibility of 3D-printed molds for complex solid fuel block geometries of hybrid rocket engines is investigated. Additively produced molds offer more degrees of freedom in designing an optimized but easy to manufacture mold. The solid fuel used for this demonstration was hydroxyl-terminated polybutadiene (HTPB). Polyvinyl alcohol (PVA) was chosen as the mold material due to its good dissolving characteristics. It is shown that conventional and complex geometries can be produced reliably with the presented methods. In addition to the manufacturing process, this article presents several engine tests with different fuel grain geometries, including a short overview of the test bed, the engine and first tests.
The Relationship between Motor Coordination and Imitation: An fNIRS Study
Authors: Zhao Wenrui , Hui Minqiang , Zhang Xiaoyou , Li Lin
Published: August 2021

Although motor coordination and imitation are important factors affecting motor skill learning, few studies have examined the relationship between them in healthy adults. In order to address this in the present study, we used fNIRS to analyze the relationship between motor coordination and imitation in college students. Our results showed that: (1) motor coordination in female students was positively correlated with the average time taken to perform an imitation; (2) the mean imitation time was negatively correlated with the activation level of the supplementary motor cortex, primary somatosensory cortex, and angular gyrus of the mirror neuron system; (3) motor coordination in female students moderated mirror neuron system (MNS) activation and imitation. For women with low rather than high motor coordination, higher MNS activation was associated with a stronger imitation ability. These results demonstrate that motor coordination in female students is closely related to action imitation, and that it moderates the activation of the MNS, as measured via fNIRS.
Applicability and Limitations of Simplified Elastic Shell Theories for Vibration Modelling of Double-Walled Carbon Nanotubes
Authors: Strozzi Matteo , Gendelman Oleg V. , Elishakoff Isaac E. , Pellicano Francesco
Published: August 2021

The applicability and limitations of simplified models of thin elastic circular cylindrical shells for linear vibrations of double-walled carbon nanotubes (DWCNTs) are considered. The simplified models, which are based on the assumptions of membrane and moment approximate thin-shell theories, are compared with the extended Sanders–Koiter shell theory. Actual discrete DWCNTs are modelled by means of couples of concentric equivalent continuous thin, circular cylindrical shells. Van der Waals interaction forces between the layers are taken into account by adopting He’s model. Simply supported and free–free boundary conditions are applied. The Rayleigh–Ritz method is considered to obtain approximate natural frequencies and mode shapes. Different aspect and thickness ratios, and numbers of waves along longitudinal and circumferential directions, are analysed. In the cases of axisymmetric and beam-like modes, it is proven that membrane shell theory, differently from moment shell theory, provides results with excellent agreement with the extended Sanders–Koiter shell theory. On the other hand, in the case of shell-like modes, it is found that both membrane and moment shell theories provide results reporting acceptable agreement with the extended Sanders–Koiter shell theory only for very limited ranges of geometries and wavenumbers. Conversely, for shell-like modes it is found that a newly developed, simplified shell model, based on the combination of membrane and semi-moment theories, provides results in satisfactory agreement with the extended Sanders–Koiter shell theory in all ranges.
Water Purification of Classical and Emerging Organic Pollutants: An Extensive Review
Authors: Somma Simona , Reverchon Ernesto , Baldino Lucia
Published: August 2021

The main techniques used for organic pollutant removal from water are adsorption, reductive and oxidative processes, phytoremediation, bioremediation, separation by membranes and liquid–liquid extraction. In this review, strengths and weaknesses of the different purification techniques are discussed, with particular attention to the newest results published in the scientific literature. This study highlighted that adsorption is the most frequently used method for water purification, since it can balance high organic pollutants removal efficiency, it has the possibility to treat a large quantity of water in semi-continuous way and has acceptable costs.
Urinary Biomarkers of Renal Injury KIM-1 and NGAL: Reference Intervals for Healthy Pediatric Population in Sri Lanka
Authors: De Silva P. , Gunasekara T. , Gunarathna S. , Sandamini P. , Pinipa R. , Ekanayake E. , Thakshila W. , Jayasinghe S. , Chandana E. , Jayasundara Nishad
Published: August 2021

Emerging renal biomarkers (e.g., kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL)) are thought to be highly sensitive in diagnosing renal injury. However, global data on reference intervals for emerging biomarkers in younger populations are lacking. Here, we aimed to determine reference intervals for KIM-1 and NGAL across a pediatric population in Sri Lanka; a country significantly impacted by the emergence of chronic kidney disease of unexplained etiology (CKDu). Urine samples were collected from children (10–18 years) with no prior record of renal diseases from the dry climatic zone of Sri Lanka (N = 909). Urinary KIM-1 and NGAL concentrations were determined using the enzyme-linked immunosorbent assay (ELISA) and adjusted to urinary creatinine. Biomarker levels were stratified by age and gender, and reference intervals derived with quantile regression (2.5th, 50th, and 97.5th quantiles) were expressed at 95% CI. The range of median reference intervals for urinary KIM-1 and NGAL in children were 0.081–0.426 ng/mg Cr, 2.966–4.850 ng/mg Cr for males, and 0.0780–0.5076 ng/mg Cr, 2.0850–3.4960 ng/mg Cr for females, respectively. Renal biomarkers showed weak correlations with age, gender, ACR, and BMI. Our findings provide reference intervals to facilitate screening to detect early renal damage, especially in rural communities that are impacted by CKDu.
Short-Range Berezinskii-Kosterlitz-Thouless Phase Characterization for the q-State Clock Model
Authors: Negrete Oscar A. , Vargas Patricio , Peña Francisco J. , Saravia Gonzalo , Vogel Eugenio E.
Published: August 2021

Beyond the usual ferromagnetic and paramagnetic phases present in spin systems, the usual q-state clock model presents an intermediate vortex state when the number of possible orientations q for the system is greater than or equal to 5. Such vortex states give rise to the Berezinskii-Kosterlitz-Thouless (BKT) phase present up to the XY model in the limit q→∞. Based on information theory, we present here an analysis of the classical order parameters plus new short-range parameters defined here. Thus, we show that even using the first nearest neighbors spin-spin correlations only, it is possible to distinguish the two transitions presented by this system for q greater than or equal to 5. Moreover, the appearance at relatively low temperature and disappearance of the BKT phase at a rather fix higher temperature is univocally determined by the short-range interactions recognized by the information content of classical and new parameters.
Propositional Kernels
Authors: Polato Mirko , Aiolli Fabio
Published: August 2021

The pervasive presence of artificial intelligence (AI) in our everyday life has nourished the pursuit of explainable AI. Since the dawn of AI, logic has been widely used to express, in a human-friendly fashion, the internal process that led an (intelligent) system to deliver a specific output. In this paper, we take a step forward in this direction by introducing a novel family of kernels, called Propositional kernels, that construct feature spaces that are easy to interpret. Specifically, Propositional Kernel functions compute the similarity between two binary vectors in a feature space composed of logical propositions of a fixed form. The Propositional kernel framework improves upon the recent Boolean kernel framework by providing more expressive kernels. In addition to the theoretical definitions, we also provide an algorithm (and the source code) to efficiently construct any propositional kernel. An extensive empirical evaluation shows the effectiveness of Propositional kernels on several artificial and benchmark categorical data sets.
Learning Two-View Correspondences and Geometry via Local Neighborhood Correlation
Authors: Dai Luanyuan , Liu Xin , Wang Jingtao , Yang Changcai , Chen Riqing
Published: August 2021

Seeking quality feature correspondences (also known as matches) is a foundational step in computer vision. In our work, a novel and effective network with a stable local constraint, named the Local Neighborhood Correlation Network (LNCNet), is proposed to capture abundant contextual information of each correspondence in the local region, followed by calculating the essential matrix and camera pose estimation. Firstly, the k-Nearest Neighbor (KNN) algorithm is used to divide the local neighborhood roughly. Then, we calculate the local neighborhood correlation matrix (LNC) between the selected correspondence and other correspondences in the local region, which is used to filter outliers to obtain more accurate local neighborhood information. We cluster the filtered information into feature vectors containing richer neighborhood contextual information so that they can be used to more accurately determine the probability of correspondences as inliers. Extensive experiments have demonstrated that our proposed LNCNet performs better than some state-of-the-art networks to accomplish outlier rejection and camera pose estimation tasks in complex outdoor and indoor scenes.
An Examination of COVID-19-Related Stressors among Parents
Authors: Alonzi Sarah , Park Jae eun , Pagán Angélica , Saulsman Courtney , Silverstein Madison W.
Published: August 2021

The circumstances of the COVID-19 pandemic have taken a psychological toll on parents. Thus, understanding the impact of these contextual stressors on parents is important to help inform the development of family-based health promotion interventions. The present study examined parents’ perception of various sources of stress resulting from the COVID-19 pandemic. Participants (N = 294) completed an open-ended question about their primary source of stress during the pandemic, which we coded into one or more of the following categories: family, work, health, and finance. We used chi-square tests to determine whether gender, marital status, financial strain, and education level were significantly related to each of the four primary sources of stress. We found that female, married, and financially strained participants were more likely to report family-related stressors. Further, we found that participants who expressed concern over health-related stressors were more likely to have pre-existing health conditions. Finally, we found that single participants were more likely to express concerns over financial stressors. Our findings shed light on parental concerns following the pandemic and inform new research directions, clinical approaches, and policy issues at the individual, community, and societal levels.
An Adaptive Early Fault Detection Model of Induced Draft Fans Based on Multivariate State Estimation Technique
Authors: Guo Ruijun , Zhang Guobin , Zhang Qian , Zhou Lei , Yu Haicun , Lei Meng , Lv You
Published: August 2021

The induced draft (ID) fan is an important piece of auxiliary equipment in coal-fired power plants. Early fault detection of the ID fan can provide predictive maintenance and reduce unscheduled shutdowns, thus improving the reliability of the power generation. In this study, an adaptive model was developed to achieve the early fault detection of ID fans. First, a non-parametric monitoring model was constructed to describe the normal operating characteristics with the multivariate state estimation technique (MSET). A similarity index representing operation status was defined according to the prediction deviations to produce warnings of early faults. To deal with the model accuracy degradation because of variant condition operation of the ID fan, an adaptive strategy was proposed by using the samples with a high data quality index (DQI) to manage the memory matrix and update the MSET model, thereby improving the fault detection results. The proposed method was applied to a 300 MW coal-fired power plant to achieve the early fault detection of an ID fan. In addition, fault detection by using the model without an update was also compared. Results show that the update strategy can greatly improve the MSET model accuracy when predicting normal operations of the ID fan; accordingly, the fault can be detected more than 4 h earlier by using the strategy with the adaptive update when compared to the model without an update.
Liquid Hydrogen Spills on Water—Risk and Consequences of Rapid Phase Transition
Authors: Odsæter Lars H. , Skarsvåg Hans L. , Aursand Eskil , Ustolin Federico , Reigstad Gunhild A. , Paltrinieri Nicola
Published: August 2021

Liquid hydrogen (LH2) spills share many of the characteristics of liquefied natural gas (LNG) spills. LNG spills on water sometimes result in localized vapor explosions known as rapid phase transitions (RPTs), and are a concern in the LNG industry. LH2 RPT is not well understood, and its relevance to hydrogen safety is to be determined. Based on established theory from LNG research, we present a theoretical assessment of an accidental spill of a cryogen on water, including models for pool spreading, RPT triggering, and consequence quantification. The triggering model is built upon film-boiling theory, and predicts that the mechanism for RPT is a collapse of the gas film separating the two liquids (cryogen and water). The consequence model is based on thermodynamical analysis of the physical processes following a film-boiling collapse, and is able to predict peak pressure and energy yield. The models are applied both to LNG and LH2, and the results reveal that (i) an LNG pool will be larger than an LH2 pool given similar sized constant rate spills, (ii) triggering of an LH2 RPT event as a consequence of a spill on water is very unlikely or even impossible, and (iii) the consequences of a hypothetical LH2 RPT are small compared to LNG RPT. Hence, we conclude that LH2 RPT seems to be an issue of only minor concern.
System-Level Modeling and Thermal Simulations of Large Battery Packs for Electric Trucks
Authors: Ramesh Babu Anandh , Andric Jelena , Minovski Blago , Sebben Simone
Published: August 2021

Electromobility has gained significance over recent years and the requirements on the performance and efficiency of electric vehicles are growing. Lithium-ion batteries are the primary source of energy in electric vehicles and their performance is highly dependent on the operating temperature. There is a compelling need to create a robust modeling framework to drive the design of vehicle batteries in the ever-competitive market. This paper presents a system-level modeling methodology for thermal simulations of large battery packs for electric trucks under real-world operating conditions. The battery pack was developed in GT-SUITE, where module-to-module discretization was performed to study the thermal behavior and temperature distribution within the pack. The heat generated from each module was estimated using Bernardi’s expression and the pack model was calibrated for thermal interface material properties under a heat-up test. The model evaluation was performed for four charging/discharging and cooling scenarios typical for truck operations. The results show that the model accurately predicts the average pack temperature, the outlet coolant temperature and the state of charge of the battery pack. The methodology developed can be integrated with the powertrain and passenger cabin cooling systems to study complete vehicle thermal management and/or analyze different battery design choices.
Analysis of Energy Use and Energy Savings: A Case Study of a Condiment Industry in India
Authors: Ullah Khan Rahmat , Thirugnanasambandam Marudhappan , Saidur Rahman , Rahman Kazi Akikur , Kayser Md. Riaz
Published: August 2021

Electric motors and boilers lead the industrial components which consume the largest portion of energy in an industry. This study explores the energy audit data of the condiment industry in India. The study mainly focuses on the estimation of the load factor, energy use, energy savings and annual bill savings with payback period of the electric motors of the plant. During the audit, it was found that there were several motors running under loaded conditions despite non-availability of variable speed drives installed in the plant. Therefore, variable speed drives are recommended to be installed to save energy by reducing the motors speed by up to 60%. According to the estimation, about 276 MWh, 551 MWh and 827 MWh electrical energy can be saved for 20%, 40% and 60% speed reduction of the motors using variable speed drives, respectively, where in most of the cases the payback period remains below 1 year. Furthermore, some suggestions are made to improve the poor power factor of running motors by using capacitor banks to save the reactive power. Besides, an estimation of energy saving is performed with a 2-ton capacity boiler. Since, there was no heat recovery system in the boiler; an air-preheater is suggested to be installed at the end of flue gas exhausting path of the boiler with the purpose of saving 68 tons of fuel per annum and having a payback period of 12 months. Moreover, a digital monitoring system, namely, “The Smart Joules” has been proposed to be installed in the plant aiming at saving about 3–5% of total energy per annum and having a payback period of 19 months. Finally, a summarization is made concluding in the fact that about 90 MWh energy and 95 tons of fuel can be saved (excluding motor energy savings) per annum by implementing proposed measures with a payback period of 15 months.