bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of “Open” Superstructure Tramway Tracks in Budapest
Authors: Jóvér Vivien , Major Zoltán , Németh Attila , Kurhan Dmytro , Sysyn Mykola , Fischer Szabolcs
Published: February 2023

The most important thing nowadays is to use available resources to develop infrastructure as efficiently as possible. In this regard, evaluating the deterioration of tramway tracks is critical from both a technical and an economic viewpoint. In Hungary, seven types of superstructure systems are currently differentiated in the case of tramway transport, but the geometrical deterioration, lifecycle, and lifecycle cost of the tramway tracks are not accurately known. The current study aimed to evaluate and compare the results of track geometry measurements of two different “open” tramway superstructure systems depending on their traffic load and age. The geometry measurements we re executed by TrackScan 4.01 instrument, developed and maintained by a Hungarian developer company called Metalelektro Méréstechnika Ltd. The evaluation of the measurements showed a clear relationship between the traffic load, age, and track deterioration. Based on the results, it can be generally stated, concerning “open” superstructure systems, that regardless of the “open” superstructure system or the level of traffic load, the average value of alignment is decreasing; however, the average value of the longitudinal level is increasing. Furthermore, the deterioration of an older ballasted track with lower traffic is similar to that of a younger ballasted track that has a higher traffic load. Another significant result was that the deterioration of the track gauge parameter in the case of concrete slab tracks is clearly described as the broadening of the track gauge.
A Background to a Methodology for Transport Mobile Applications Designing with a Focus on EU Interoperability
Authors: Šmídová Pavla , Machalík Stanislav
Published: February 2023

European rail transport policy aims to create a single railway area. European Union (EU) issues, for this purpose, sets of regulations and directives. Individual countries are involved in its implementation according to their capabilities. The aim of this article is to examine the current state of interoperability in the EU, especially in the Czech Republic, and to compare selected mobile applications regarding the possibility of unifying their design of mobile applications. A systematic literature research review methodology was used. The sources of information were mainly the scientific database Web of Science and the database of EU documents EUR-Lex. When examining one of the main parameters—the use of mobile networks—it was found that all of the selected applications use public mobile networks, none of them uses the Global System for Mobile Communications–Railway (GSM–R) network. This finding confirmed the theoretical assumption that this network is not currently ready for more or less massive operation of mobile applications. The possibility of using the next generation railway mobile network is open for discussion as one of the next steps to ensure interoperability in telematics applications.
Incorporating the Benefits of Geosynthetic into MEPDG
Authors: Abu-Farsakh Murad , Zadehmohamad Mehdi , Voyiadjis George Z.
Published: February 2023

One of the most effective ways to increase the longevity of pavement structures is through the integration of geosynthetic reinforcement. Geosynthetics are synthetic materials such as geotextiles, geogrids, or geocomposites that are added to the interface between the subgrade and the base layer of a pavement structure. To evaluate the effect of various parameters on the structural benefits of geosynthetic reinforcement on the pavement structure of low-volume traffic flexible pavements, a finite element (FE) study was performed using the ABAQUS program. These parameters included the geosynthetic type, geosynthetic tensile stiffness, subgrade stiffness, and base thickness. The FE rutting curves for the 100 cycles were calibrated using the mechanistic–empirical (M-E) transfer functions, which were then used to calculate the long-term rutting curves. The traffic benefit ratio (TBR) was initially calculated based on the calibrated rutting curves for each pavement layer. The calculated TBRs were then used as an input in AASHTOWare to compute the base effective resilient modulus (MR-eff) and the factor of base course reduction (BCR). The results showed that adding one layer of geosynthetics enhanced the rutting performance of pavement structures significantly (up to 8.9 in TBR, 322% in MR-eff, and 64% in BCR). Geogrids showed higher benefits than geotextiles due to the interlocking between base aggregates and geogrid aperture. The values of TBR, MR-eff, and BCR increase with the increasing tensile stiffness of the geosynthetics and the rutting target and with the decreasing subgrade stiffness. The results also demonstrated peak values of TBR, MR-eff, and BCR for a base thickness of 25.4 cm.
Peripheral Regional Anesthesia Using Local Anesthetics: Old Wine in New Bottles?
Authors: Gasteiger Lukas , Kirchmair Lukas , Hoerner Elisabeth , Stundner Ottokar , Hollmann Markus W.
Published: February 2023

During the past decade, numerous efforts were undertaken aiming at prolonging the analgesic effect of regional anesthesia. With the development of extended-release formulations and enhanced selectivity for nociceptive sensory neurons, a very promising contribution to the development of pain medications has been achieved. At present, liposomal bupivacaine is the most popular, non-opioid, controlled drug delivery system, but its duration of action, which is still controversially discussed, and its expensiveness have decreased initial enthusiasm. Continuous techniques can be seen as an elegant alternative for providing a prolonged duration of analgesia, but for logistic or anatomical reasons, they are not always the best choice. Therefore, focus has been directed towards the perineural and/or intravenous addition of old and established substances. As for perineural application, most of these so-called ‘adjuvants’ are used outside their indication, and their pharmacological efficacy is often not or only poorly understood. This review aims to summarize the recent developments for prolonging the duration of regional anesthesia. It will also discuss the potential harmful interactions and side effects of frequently used analgesic mixtures.
Association between Exposure to Selected Heavy Metals and Blood Eosinophil Counts in Asthmatic Adults: Results from NHANES 2011–2018
Authors: Wen Jun , Giri Mohan , Xu Li , Guo Shuliang
Published: February 2023

(1) Background: Heavy metals are widely used and dispersed in the environment and people’s daily routines. Many studies have reported an association between heavy metal exposure and asthma. Blood eosinophils play a crucial role in the occurrence, progression, and treatment of asthma. However, there have thus far been few studies that aimed to explore the effects of heavy metal exposure on blood eosinophil counts in adults with asthma. Our study aims to discuss the association between metal exposure and blood eosinophil counts among asthmatic adults. (2) Methods: A total of 2026 asthmatic individuals were involved in our research from NHANES with metal exposure, blood eosinophils, and other covariates among the American population. A regression model, the XGBoost algorithm, and a generalized linear model (GAM) were used to explore the potential correlation. Furthermore, we conducted a stratified analysis to determine high-risk populations. (3) Results: The multivariate regression analysis indicated that concentrations of blood Pb (log per 1 mg/L; coefficient β, 25.39; p = 0.010) were positively associated with blood eosinophil counts. However, the associations between blood cadmium, mercury, selenium, manganese, and blood eosinophil counts were not statistically significant. We used stratified analysis to determine the high-risk group regarding Pb exposure. Pb was identified as the most vital variable influencing blood eosinophils through the XGBoost algorithm. We also used GAM to observe the linear relationship between the blood Pb concentrations and blood eosinophil counts. (4) Conclusions: The study demonstrated that blood Pb was positively correlated with blood eosinophil counts among asthmatic adults. We suggested that long-time Pb exposure as a risk factor might be correlated with the immune system disorder of asthmatic adults and affect the development, exacerbation, and treatment of asthma.
Location of Hyperintense Vessels on FLAIR Associated with the Location of Perfusion Deficits in PWI
Authors: Bunker Lisa D. , Hillis Argye E.
Published: February 2023

Perfusion imaging is preferred for identifying hypoperfusion in the management of acute ischemic stroke, but it is not always feasible/available. An alternative method for quantifying hypoperfusion, using FLAIR-hyperintense vessels (FHVs) in various vascular regions, has been proposed, with evidence of a statistical relationship with perfusion-weighted imaging (PWI) deficits and behavior. However, additional validation is needed to confirm that areas of suspected hypoperfusion (per the location of FHVs) correspond to the location of perfusion deficits in PWI. We examined the association between the location of FHVs and perfusion deficits in PWI in 101 individuals with acute ischemic stroke, prior to the receipt of reperfusion therapies. FHVs and PWI lesions were scored as present/absent in six vascular regions (i.e., the ACA, PCA, and (four sub-regions of) the MCA territories). Chi-square analyses showed a significant relationship between the two imaging techniques for five vascular regions (the relationship in the ACA territory was underpowered). These results suggest that for most areas of the brain, the general location of FHVs corresponds to hypoperfusion in those same vascular territories in PWI. In conjunction with prior work, results support the use of estimating the amount and location of hypoperfusion using FLAIR imaging when perfusion imaging is not available.
Molecular Basis of Surgical Coaptation Techniques in Peripheral Nerve Injuries
Authors: Pereira Clifford T. , Hill Elise E. , Stasyuk Anastasiya , Parikh Neil , Dhillon Jannat , Wang Aijun , Li Andrew
Published: February 2023

Peripheral nerve injuries requiring surgical repair affect over 100,000 individuals in the US annually. Three accepted methods of peripheral repair include end-to-end, end-to-side, and side-to-side neurorrhaphy, each with its own set of indications. While it remains important to understand the specific circumstances in which each method is employed, a deeper understanding of the molecular mechanisms underlying the repair can add to the surgeon’s decision-making algorithm when considering each technique, as well as help decide nuances in technique such as the need for making epineurial versus perineurial windows, length and dept of the nerve window, and distance from target muscle. In addition, a thorough knowledge of individual factors that are active in a particular repair can help guide research into adjunct therapies. This paper serves to summarize the similarities and divergences of the three commonly used nerve repair strategies and the scope of molecular mechanisms and signal transduction pathways in nerve regeneration as well as to identify the gaps in knowledge that should be addressed if we are to improve clinical outcomes in our patients.
Association between Mean Arterial Pressure during the First 24 Hours and Clinical Outcome in Critically Ill Stroke Patients: An Analysis of the MIMIC-III Database
Authors: Zhang Sheng , Cui Yun-Liang , Yu Sheng , Shang Wei-Feng , Li Jie , Pan Xiao-Jun , Wen Zhen-Liang , Huang Si-Si , Chen Li-Min , Shen Xuan , Yu Yue-Tian , Liu Jiao , Chen De-Chang
Published: February 2023

Abnormal blood pressure is common in critically ill stroke patients. However, the association between mean arterial pressure (MAP) and mortality of critically ill stroke patients remains unclear. We extracted eligible acute stroke patients from the MIMIC-III database. The patients were divided into three groups: a low MAP group (MAP ≤ 70 mmHg), a normal MAP group (70 mmHg < MAP ≤ 90 mmHg), and a high MAP group (MAP > 90 mmHg). The Cox proportional hazards model and restricted cubic splines were used to assess the association between MAP and mortality. Sensitivity analyses were conducted to investigate whether MAP had different effects on mortality in different subpopulations. A total of 2885 stroke patients were included in this study. The crude 7-day and 28-day mortality was significantly higher in the low MAP group than that in the normal MAP group. By contrast, patients in the high MAP group did not have higher crude 7-day and 28-day mortality than those in the normal MAP group. After multiple adjustments using the Cox regression model, patients with low MAP were consistently associated with higher 7-day and 28-day mortality than those with normal MAP in the following subgroups: age > 60 years, male, those with or without hypertension, those without diabetes, and those without CHD (p < 0.05), but patients with high MAP were not necessarily associated with higher 7-day and 28-day mortality after adjustments (most p > 0.05). Using the restricted cubic splines, an approximately L-shaped relationship was established between MAP and the 7-day and 28-day mortality in acute stroke patients. The findings were robust to multiple sensitivity analyses in stroke patients. In critically ill stroke patients, a low MAP significantly increased the 7-day and 28-day mortality, while a high MAP did not, suggesting that a low MAP is more harmful than a high MAP in critically ill stroke patients.
Disparate Clinical Characteristics and Prognosis of HFpEF versus HFrEF Phenotype of Diabetic Cardiomyopathy
Authors: Li Zheng , Shi Yi , Xia Yiyuan , Wu Lida , Li Hui , Zhou Rong , Gao Xiaofei , Zhang Hongsong , Jin Xiaoping , Zhang Junxia
Published: February 2023

Aims: Diabetic cardiomyopathy (DCM) is an ill-defined entity. This study aims to explore the clinical characteristics and prognosis of diabetic patients that disparately develop heart failure (HF) with preserved ejection fraction (HFpEF) other than HF with reduced ejection fraction (HFrEF). Patients and Methods: A total of 911 patients diagnosed with diabetes mellitus were identified in the ChiHFpEF cohort (NCT05278026). DCM was defined as diabetic patients diagnosed with HF, absent from flow obstructive coronary artery disease (CAD), uncontrolled refractory hypertension and hemodynamics significant heart valvular diseases, arrhythmia and congenital heart diseases. The primary endpoint was a composite of all-cause death and rehospitalization due to HF. Results: As compared to DCM-HFrEF patients, DCM-HFpEF patients had a longer duration of diabetes, were older and more noticeable in hypertension and non-obstructive CAD. After a median follow-up of 45.5 months, survival analysis showed that DCM-HFpEF patients had a better composite endpoint. Cox regression implicated that non-obstructive CAD was a negative (HR 0.101, 95% CI 0.028–0.373, p = 0.001) predictor for the composite endpoint of DCM-HFrEF patients. Age was a positive predictor for the composite endpoint of DCM-HFpEF patients (HR 1.044, 95% CI 1.007–1.082, p = 0.018). Conclusion: DCM-HFpEF is a disparate entity from DCM-HFrEF. Additional phenomic studies are needed to explore the molecular mechanisms and develop targeted therapies.
Effect of Cadmium on Oxidative Stress Indices and Vitamin D Concentrations in Children
Authors: Chwalba Artur , Orłowska Joanna , Słota Michał , Jeziorska Marta , Filipecka Kinga , Bellanti Francesco , Dobrakowski Michał , Kasperczyk Aleksandra , Zalejska-Fiolka Jolanta , Kasperczyk Sławomir
Published: February 2023

Heavy metal poisoning can have serious health consequences, including damage to the brain, kidneys, and other organs. Cadmium is a toxic heavy metal that can accumulate in the body over time and the exposure to this element has been linked to a variety of adverse health effects. Cadmium toxicity can lead to an imbalance in the cellular redox state and be a source of oxidative stress. On the molecular level, cadmium ions negatively affect cellular metabolism, including the disruption of energy production, protein synthesis, and DNA damage. The study has been carried out on a group of 140 school-age children (8 to 14 years old) inhabiting the industrialized areas of Upper Silesia. The study population was divided into two sub-groups based on the median concentration of cadmium in blood (0.27 µg/L): Low-CdB and High-CdB. Measured traits comprised blood cadmium levels (CdB) as well as a blood count and selected oxidative stress markers. This research study aimed to demonstrate a correlation between the impact of exposure to elevated cadmium concentrations in a population of children and certain markers of oxidative stress, and 25-OH vitamin D3 concentration. A negative correlation has been found between cadmium concentration and 25-OH vitamin D3 level, protein sulfhydryl groups content in blood serum, glutathione reductase activity, and lipofuscin and malondialdehyde levels in erythrocytes. The concentration of 25-OH vitamin D3 in the High-CdB group was decreased by 23%. The oxidative stress indices can be considered a valuable indicator of early Cd-toxicity effects to be included in the routinely-applied cadmium exposure monitoring parameters, allowing the evaluation of stress intensity to the cell metabolism.
Association of GLIM Defined Malnutrition According to Preoperative Chronic Inflammation with Long-Term Prognosis after Gastrectomy in Patients with Advanced Gastric Cancer
Authors: Matsui Ryota , Inaki Noriyuki , Tsuji Toshikatsu , Fukunaga Tetsu
Published: February 2023

This study aimed to investigate the association of malnutrition, defined by the Global Leadership Initiative on Malnutrition (GLIM) according to preoperative chronic inflammation with long-term prognosis after gastrectomy in patients with advanced gastric cancer. We included patients with primary stage I-III gastric cancer who underwent gastrectomy between April 2008 and June 2018. Patients were categorized as normal, moderate malnutrition, and severe malnutrition. Preoperative chronic inflammation was defined as a C-reactive protein level of >0.5 mg/dL. The primary endpoint was overall survival (OS), compared between the inflammation and non-inflammation groups. Among the 457 patients, 74 (16.2%) and 383 (83.8%) were included in the inflammation and non-inflammation groups, respectively. The prevalence of malnutrition was similar in both groups (p = 0.208). Multivariate analyses for OS showed that moderate malnutrition (hazard ratios: 1.749, 95% concordance interval: 1.037–2.949, p = 0.036) and severe malnutrition (hazard ratios: 1.971, 95% CI: 1.130–3.439, p = 0.017) were poor prognostic factors in the non-inflammation group, but malnutrition was not a prognostic factor in the inflammation group. In conclusion, preoperative malnutrition was a poor prognostic factor in patients without inflammation, but it was not a prognostic factor in patients with inflammation.
CFD Simulations of the Effects of Wave and Current on Power Performance of a Horizontal Axis Tidal Stream Turbine
Authors: Liu Bohan , Park Sunho
Published: February 2023

To ensure the long-term reliability of tidal stream turbines, waves and currents must be considered during the design phase. In this paper, a three-bladed horizontal axis turbine with a diameter of 0.9 m was used as the baseline model. OpenFOAM, an open-source computational fluid dynamics (CFD) library platform, was used to predict the performance of a horizontal axis tidal stream turbine (HATST) under waves and currents. A mesh dependency test was carried out to select the optimal mesh to capture the flow’s features. As a validation study, the power of the turbine under only the current was predicted and was found to be consistent with the experimental results. The generated wave profile under a current was compared with the results obtained using the third-order Stokes wave theory. The performance of the HATST was predicted for various wave frequencies and heights and compared with experimental data. The effect of the wave height on the power performance was greater than the wave frequency. Vortical flow structures behind the turbine were investigated for various wave conditions. The generated tip vortices propagated upward and downward at wave crest and trough conditions, respectively.
Multi-Domain Modeling and Analysis of Marine Steam Power System Based on Digital Twin
Authors: Zeng Guoqing , Wang Jintao , Zhang Lei , Xie Xuyang , Wang Xuefeng , Chen Guobing
Published: February 2023

The marine steam power system includes a large amount of thermal equipment; meanwhile, the marine environment is harsh and the working conditions change frequently. Operation management involves many disciplines, such as heat, machinery, control, electricity, etc. It is a complex multi-discipline physical system with typical nonlinear, multi-parameter, strong coupling characteristics. In order to realize the health management of a marine steam power system, based on digital twin technology combined with the Modelica language, modular modeling, etc., this paper conducts in-depth research on the multi-domain modeling of the marine steam power system, characteristic analysis of variable working conditions, fault simulation, etc. The analysis results show that the dynamic response trend of the model is consistent with the actual operation, the error of the main steam flow at 1800 s is the largest and is −4.9%, and the error of the main steam flow, steam turbine output power, cooling water outlet temperature and other key parameters is within ±5%. Virtual reality mapping between the digital model and the physical equipment is realized, which lays a foundation for mastering the dynamic characteristics of the marine steam power system.
Assessing the Spatio-Temporal Features and Mechanisms of Symmetric Instability Activity Probability in the Central Part of the South China Sea Based on a Regional Ocean Model
Authors: Jiang Yifei , Zhang Weimin , Wang Huizan , Zhang Xiaojiang
Published: February 2023

Symmetric instability (SI) is credited with one of the important submesoscale instabilities. However, due to its small scales, it is challenging to capture using current observational measurements and ocean models. Estimates of SI activity are useful for assessing whether SI should be parameterized. Based on a high-resolution ocean model, we use a criterion to assess the spatio-temporal features of SI activity without directly solving SI in the Xisha–Zhongsha waters. An Ertel potential vorticity (PV) analysis is performed, and the negative PV injection and frontal tendency are calculated to analyze the generation mechanisms. The results show that the activity of SI is strongly seasonal. In comparison, SI is active in winter, but it is inactive in summer. In addition, it is mainly found within the ocean surface mixed layer (SML), and it almost disappears in the base of the surface mixed layer (BML). Moreover, the vertical component of the Ertel PV leads to the vertical spatial difference of SI activity, and both the vertical component of the Ertel PV and the sea surface buoyancy flux play an important role in the seasonality of SI activity. The stronger frontogenesis around the Xisha Islands partially accounts for the horizontal distribution difference of SI. This work implies that the parameterization of SI may have potential value in practical application in this region in winter due to the high probability of SI activity.
Introducing the “SIMline”—A Simulation Course in the Management of Severe Burns as a Tool in Undergraduate Medical Education
Authors: Sawetz Isabel , Hasiba-Pappas Sophie , Kamolz Lars-Peter , Holzer-Geissler Judith C. J. , Tuca Alexandru Cristian , Lumenta David Benjamin , Wegscheider Thomas , Luze Hanna , Nischwitz Sebastian P. , Winter Raimund
Published: February 2023

Background: Management of burn injuries presents a complex and challenging situation for medical staff, especially for inexperienced young doctors. However, training on how to treat burn victims in the clinical setting is rarely taught in undergraduate medical classes. We have created the “SIMline”, a simulation training program explicitly designed for coaching medical students in burn management. Methods: A total of 43 students participated in the “SIMline” course, which took place at the training facility at the Medical University of Graz, between 2018 and 2019. The course provided theoretical classes, practical exercises, and a full-scale care process simulation training. The learning progress of the students was monitored via a formative integrated test. Results: Students showed great progress throughout the course of the “SIMline” program, as their test scores improved by an average of 88%. The passing rate was 0% at the first exam (prior to course) as compared to 87% at the final exam, taken after the training. Conclusions: Comprehensive practical training programs in burn care are underrepresented in medical education. The “SIMline” course presents a novel and effective approach in training medical students in burn management. However, follow-up evaluation is necessary to confirm long-term educational benefits.
Board Gender Diversity and Carbon Proactivity: The Influence of Cultural Factors
Authors: Wang Haifei , Tang Qingliang , Guo Ting
Published: February 2023

Due to inadequate studies, our knowledge of the effect of female directors and national culture on the corporate response to climate change is still limited. To address this gap, the purpose of this paper is to investigate the dynamic relationship between gender diversity on the board of directors and corporate carbon proactivity and how two dimensions of national culture (individualism and indulgence) moderate this relationship. This study focuses on large companies that disclosed carbon-related information via the CDP survey in 2011–2017. Our findings show that gender diversity promotes corporate carbon proactivity. Furthermore, the positive effect of gender diversity on carbon proactivity is weaker when firms are in countries marked by a higher level of individualism and indulgence. As far as we know, this study is the first to explore and document the empirical evidence on the dynamic impact of gender diversity in the corporate governance body and national culture on managers’ climate change behaviors in terms of green proactivity.
Sex Differences in Behavior and Learning Abilities in Adult Rats
Authors: Pupikina Maria , Sitnikova Evgenia
Published: February 2023

Laboratory rats have excellent learning abilities and are often used in cognitive neuroscience research. The majority of rat studies are conducted on males, whereas females are usually overlooked. Here, we examined sex differences in behavior and tactile sensitivity in littermates during adulthood (5.8–7.6 months of age). We used a battery of behavioral tests, including the 2% sucrose preference test (positive motivation), a free-choice paradigm (T-maze, neutral situation), and associative fear-avoidance learning (negative motivation, aversive situation). Tactile perception was examined using the von Frey test (aversive situation). In two aversive situations (von Frey test and avoidance learning), females were examined during the diestrus stage of the estrous cycle, and ultrasonic vocalization was recorded in both sexes. It was found that (1) females, but not males, lost their body weight on the first day of the sucrose preference test, suggesting sex differences in their reaction to environmental novelty or in metabolic homeostasis; (2) the tactile threshold in females was lower than in males, and females less frequently emitted aversive ultrasonic calls; (3) in the avoidance learning task, around 26% of males (but no females) were not able to learn and experienced frizzing. Overall, the performance of associative fear-avoidance in males was worse than in females. In general, females demonstrated higher abilities of associative learning and less persistently emitted aversive ultrasonic calls.
Molecular Identification of Bacteria Isolated from Marketed Sparus aurata and Penaeus indicus Sea Products: Antibiotic Resistance Profiling and Evaluation of Biofilm Formation
Authors: Abdulhakeem Mohammad A. , Alreshidi Mousa , Bardakci Fevzi , Hamadou Walid Sabri , De Feo Vincenzo , Noumi Emira , Snoussi Mejdi
Published: February 2023

Background: Marketed fish and shellfish are a source of multidrug-resistant and biofilm-forming foodborne pathogenic microorganisms. Methods: Bacteria isolated from Sparus aurata and Penaeus indicus collected from a local market in Hail region (Saudi Arabia) were isolated on selective and chromogenic media and identified by using 16S RNA sequencing technique. The exoenzyme production and the antibiotic susceptibility patterns of all identified bacteria were also tested. All identified bacteria were tested for their ability to form biofilm by using both qualitative and quantitative assays. Results: Using 16S RNA sequencing method, eight genera were identified dominated by Vibrio (42.85%), Aeromonas (23.80%), and Photobacterium (9.52%). The dominant species were V. natrigens (23.8%) and A. veronii (23.80%). All the identified strains were able to produce several exoenzymes (amylases, gelatinase, haemolysins, lecithinase, DNase, lipase, and caseinase). All tested bacteria were multidrug-resistant with a high value of the multiple antibiotic index (MARI). The antibiotic resistance index (ARI) was about 0.542 for Vibrio spp. and 0.553 for Aeromonas spp. On Congo red agar, six morphotypes were obtained, and 33.33% were slime-positive bacteria. Almost all tested microorganisms were able to form a biofilm on glass tube. Using the crystal violet technique, the tested bacteria were able to form a biofilm on glass, plastic, and polystyrene abiotic surfaces with different magnitude. Conclusions: Our findings suggest that marketed S. aurata and P. indicus harbor various bacteria with human interest that are able to produce several related-virulence factors.
Cytotoxic Effect of Phenylethanoid Glycosides Isolated from Plantago lanceolata L.
Authors: Budzianowska Anna , Totoń Ewa , Romaniuk-Drapała Aleksandra , Kikowska Małgorzata , Budzianowski Jaromir
Published: February 2023

The aim of the study is to investigate whether the bioactive compounds isolated from P. lanceolata inflorescences, namely, phenylethanoid glucosides, acteoside, plantamajoside, and a flavonoid, isorhamnetin-3-O-rutinoside-4′-O-glucoside, possessed cytotoxic activity against the selected cancer cell lines. The potential antitumor effects of two phenylethanoid glycosides and one flavonoid were evaluated via MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay on seven human carcinoma cell lines (MCF-7, MDA-MB-231, Caco-2, HepG2, OVCAR-3, U138-MG, U251-MG) and one nontumorigenic mammary epithelial cell line (MCF-12A). For the first time, acteoside was studied in ovarian cancer cell line OVCAR-3, and plantamajoside in all cell lines except breast adenocarcinoma MDA-MB-281 and hepatocarcinoma HepG2. The phenylethanoid glycosides showed stronger cytotoxic activity than that of the glycoside flavonoid. Acteoside and plantamajoside, at concentrations of 200 and 300 μM, respectively, had a highly toxic effect on the selected two cancer cell lines of breast adenocarcinoma MDA-MB-231 and MCF-7, ovarian cancer cell line OVCAR-3, glioblastoma cell line U138-MG, and hepatocarcinoma cell line HepG2. Both glycosides were significantly less cytotoxic towards nontumorigenic cell line MCF-12A; the effect appeared at a concentration of 400 μM. For the first time, the activity of acteoside and plantamajoside was compared in one parallel investigation. The results are discussed against a broad background of existing knowledge on biological effects, their mechanisms, and structure–activity relationships. Phenylethanoids may be potential compounds with cytotoxic activity against the selected cancer types.
Experimental Verification of the Boundary Element Method for Adhesive Contacts of a Coated Elastic Half-Space
Authors: Lyashenko Iakov A. , Popov Valentin L. , Borysiuk Vadym
Published: February 2023

We consider analytical, numerical, and experimental approaches developed to describe the mechanical contact between a rigid indenter and an elastic half-space coated with an elastic layer. Numerical simulations of the indentation process were performed using the recently generalized boundary element method (BEM). Analytical approximation of the dependence of contact stiffness on the indenter diameter was used to verify the results of BEM simulations. Adhesive contacts of hard indenters of different shapes with soft rubber layers have been experimentally studied using specially designed laboratory equipment. The comparison of the results from all three implemented methods shows good agreement of the obtained data, thus supporting the generalized BEM simulation technique developed for the JKR limit of very small range of action of adhesive forces. It was shown that the half-space approximation is asymptotical at high ratios of layer thickness h to cylindrical indenter diameter D; however, it is very slowly. Thus, at the ratio h/D = 3.22, the half-space approximation leads to 20% lower contact stiffness compared with that obtained for finite thickness using both an experiment and simulation.
Microstructure and Properties of Nickel-Based Gradient Coatings Prepared Using Cold Spraying Combined with Laser Cladding Methods
Authors: Liu Sainan , Sun Yangyang , Zhai Pengyuan , Fan Pengyu , Zhang Yongtong , Li Muyang , Fang Jianxiao , Wu Ruilin , Cai Zhenyang
Published: February 2023

A cold spray–laser cladding composite gradient coating (CLGC) was successfully formed on a Cu substrate. In comparison with traditional laser cladding gradient coatings (LGC), cold spraying the pre-set Ni-Cu alloy’s intermediate transition layer not only mitigates the negative impacts due to the high reflectivity of the copper substrate but also helps to minimize the difference in the coefficients of thermal expansion (CTE) between the substrate and coating. This reduces the overall crack sensitivity and improves the cladding quality of the coating. Besides this, the uniform distribution of hard phases in CLGC, such as Ni11Si12 and Mo5Si3, greatly increases its microhardness compared to the Cu substrate, thus resulting in the value of 478.8 HV0.5 being approximately 8 times that of the Cu substrate. The friction coefficient of CLGC is lowered compared to both the Cu substrate and LGC with respective values of 0.28, 0.54, and 0.43, and its wear rate is only one-third of the Cu substrate’s. These results suggest CLGC has excellent anti-wear properties. In addition, the wear mechanism was determined from the microscopic morphology and element distribution and was found to be oxidative and abrasive. This approach combines cold spraying and laser cladding to form a nickel-based gradient coating on a Cu substrate without cracks, holes, or other faults, thus improving the wear resistance of the Cu substrate and improving its usability.
Investigation and Calculation Method for the Mechanical Properties of Filament Wound Profiles for Deformed Shield Tunnel Reinforcement
Authors: Zhang Lei , Liu Xian
Published: February 2023

A new type of structural material has begun to be used in the reinforcement of deformed shield tunnels, known as filament wound profiles (FWPs). The FWPs are formed by wrapping carbon-fiber-reinforced polymer (CFRP) around steel tubes that are grouted with concrete inside. However, for practical engineering applications, the design of FWPs requires further insight into their mechanical behavior, since there is no standard method for this at present. In this study, compression and bending tests were carried out to investigate the mechanical behavior of FWPs. A reliable numerical model was established based on the test results, and the effects of the design parameters on the mechanical properties of the FWPs were analyzed qualitatively. The key design parameters of bearing capacity and stiffness were determined through numerical experiments. Based on the experimental results, a method for the calculation of bearing capacities and stiffness was proposed. It was verified that the results of the calculation formulae and the experimental results showed good agreement. Moreover, the results of the formulae were relatively conservative, and most of the errors were within 15%. Thus, this calculation method can be used to calculate the load-bearing capacity and stiffness of FWPs in practical projects.
Understanding of Excellent Mechanical Performance of 304L Manufactured by Optimal Selective Laser Melting (SLM) Conditions
Authors: Ma Yaxin , Gao Yifei , Zhao Lei , Zhang Hong , Li Dongling , Yang Lixia , Yu Chuntang
Published: February 2023

The optimal SLM conditions of 304L stainless steel were obtained by single factor and orthogonal tests. Results indicated that the optimal hardness (75 HRB) and Relative Density (RD 99.24%) could be obtained when the laser output power was 190 W, the scanning distance was 0.09 mm and the scanning speed was 800 mm/s. The microstructure of fish scales was uniform and compact with a few pores in the optimal sample. The fine particles were randomly distributed near the edge of the molten pool, and some preferred granular columnar crystal structures were formed. Abundant entanglement dislocations were observed between cell structures, forming dislocation clusters. Spherical nano-precipitates, rich in Si, Mn, and O, were also observed near cell structures. The mechanical properties of the specimens were highly anisotropic, and there were obvious necking and ductility at the tensile fracture.
Potential Field Control of a Redundant Nonholonomic Mobile Manipulator with Corridor-Constrained Base Motion
Authors: Baumgartner Jakob , Petrič Tadej , Klančar Gregor
Published: February 2023

This work proposes a solution for redundant nonholonomic mobile manipulator control with corridor constraints on base motion. The proposed control strategy applies an artificial potential field for base navigation to achieve joint control with desired trajectory tracking of the end effector. The overall kinematic model is created by describing the nonholonomic mobile platform and the kinematics of the manipulator. The objective function used consists of a primary control task that optimizes the joint variables to achieve the desired pose or trajectory of the end effector and a secondary control task that optimizes the joint variables for the base to support the arm and stay within the corridor. As a last priority, an additional optimization is introduced to optimize the maneuverability index. The proposed baseline navigation has global convergence without local minima and is computationally efficient. This is achieved by an optimal grid-based search on a coarse discrete grid and a bilinear interpolation to obtain a continuous potential function and its gradient. The performance of the proposed control algorithm is illustrated by several simulations of a mobile manipulator model derived for a Pal Tiago mobile base and an Emiko Franka Panda robotic manipulator.
Energy Absorption of Square Tubes Filled by Modularized Honeycombs with Multiple Gradients
Authors: Li Zhen , Kang Zhengyang , Su Xiaoping
Published: February 2023

The Uniform Honeycomb-filled Tube (UHT) is one of the composite structures that has shown huge potential in absorbing energy. In this paper, Uniform Honeycomb (UH) filler is replaced by an enhanced Modularized Honeycomb (MH). The biggest advantage of MH is that it can significantly enhance energy absorption without adding weight compared with its uniform counterpart. Finite element models are created, and then validated by theoretical models. The energy absorption of the Modularized Honeycomb-filled Tube (MHT) is compared with that of the empty tube and UHT. The results show that the MHT is superior to them in Specific Energy Absorption (SEA). It is also found that the tube can help the MH improve its deformation stability, which is the key of the MHT’s excellent energy absorption capacity. Then, effects of design parameters on the SEA of the MHT are investigated and discussed. The results show that the MH with a large graded coefficient is good for enhancing the SEA of the MHT. However, the SEA also relies on the match between the honeycomb filler and tube walls. The work could inspire designs of modularized filler with various types of cells and benefit the development of advanced energy absorbers with lighter weight and more excellent energy absorption capacity.
Improved Hardy Inequalities with a Class of Weights
Authors: Canale Anna
Published: February 2023

In the framework of Hardy type inequalities and their applications to evolution problems, the paper deals with local and nonlocal weighted improved Hardy inequalities related to the study of Kolmogorov operators perturbed by singular potentials. The class of weights is wide enough. We focus our attention on weighted Hardy inequalities with potentials obtained by inverse square potentials adding a nonnegative correction term. The method used to get the results is based on the introduction of a suitable vector-valued function and on a generalized vector field method. The local estimates show some examples of this type of potentials and extend some known results to the weighted case.
Broad Embedded Logistic Regression Classifier for Prediction of Air Pressure Systems Failure
Authors: Muideen Adegoke A. , Lee Carman Ka Man , Chan Jeffery , Pang Brandon , Alaka Hafiz
Published: February 2023

In recent years, the latest maintenance modelling techniques that adopt the data-based method, such as machine learning (ML), have brought about a broad range of useful applications. One of the major challenges in the automotive industry is the early detection of component failure for quick response, proper action, and minimizing maintenance costs. A vital component of an automobile system is an air pressure system (APS). Failure of APS without adequate and quick responses may lead to high maintenance costs, loss of lives, and component damages. This paper addresses classification problem where we detect whether a fault does or does not belong to APS. If a failure occurs in APS, it is classified as positive class; otherwise, it is classified as negative class. Hence, in this paper, we propose broad embedded logistic regression (BELR). The proposed BELR is applied to predict APS failure. It combines a broad learning system (BLS) and logistic regression (LogR) classifier as a fusion model. The proposed approach capitalizes on the strength of BLS and LogR for a better APS failure prediction. Additionally, we employ the BLS’s feature-mapped nodes for extracting features from the input data. Additionally, we use the enhancement nodes of the BLS to enhance the features from feature-mapped nodes. Hence, we have features that can assist LogR for better classification performances, even when the data is skewed to the positive class or negative class. Furthermore, to prevent the curse of dimensionality, a common problem with high-dimensional data sets, we utilize principal component analysis (PCA) to reduce the data dimension. We validate the proposed BELR using the APS data set and compare the results with the other robust machine learning classifiers. The commonly used evaluation metrics, namely Recall, Precision, an F1-score, to evaluate the model performance. From the results, we validate that performance of the proposed BELR.
Effects of Enamel Matrix Derivative on Cell Spheroids Made of Stem Cells Obtained from the Gingiva on Osteogenic Differentiation
Authors: Hwa Somyeong , Lee Hyun-Jin , Ko Youngkyung , Park Jun-Beom
Published: February 2023

Background and Objectives: A derivative of the enamel matrix was used to speed up periodontal regeneration, including the formation of new cementum, alveolar bone, and periodontal ligament. In this study, human gingiva-derived stem cell–derived cell spheroids were used to assess the effects of an enamel matrix derivative on cell viability, osteogenic differentiation, and mineralization. Materials and Methods: Human gingiva-derived stem cells were used to create spheroids, which were then coupled with unloaded control groups and an enamel matrix derivative at a final concentration of 2.7, 27, 270, and 2700 μg/mL. The morphological examination of the created stem cell spheroids took place on days 1, 3, 5, and 7. The Live/Dead Kit assay was used to determine the qualitative viability of cells on days 3 and 7. Using the Cell Counting Kit-8, the quantitative vitality of the cell spheroids was assessed on days 1, 3, and 5. On days 7 and 14, alkaline phosphatase activity assays and Alizarin Red S staining were carried out to examine the osteogenic differentiation of the cell spheroids. RUNX2 and COL1A1 expression levels on days 7 and 14 were determined using real-time polymerase chain reaction. Results: The added enamel matrix derivative at the tested concentrations did not significantly alter the morphology of the applied stem cells’ well-formed spheroids on day 1. On days 3 and 7, the majority of the spheroids’ cells fluoresced green while they were being cultivated. Alkaline phosphatase activity data revealed a substantial rise in the 2700 μg/mL group on day 7 when compared to the unloaded control (p < 0.05). On days 7 and 14, calcium deposits were distinctly seen in each group. In the 27 and 2700 μg/mL groups, the treatment with the enamel matrix derivative resulted in noticeably higher values for the Alizarin Red S staining (p < 0.05). qPCR results showed that adding an enamel matrix derivative to the culture of the 27 μg/mL group raised the level of RUNX2 mRNA expression. Conclusions: These results lead us to the conclusion that a derivative of the enamel matrix may be used to promote osteogenic differentiation in stem cell spheroids.