bluuebunny/crossref_metadata_2025 huggingface dataset:
Beta-Hydroxybutyrate Mitigates Sensorimotor and Cognitive Impairments in a Photothrombosis-Induced Ischemic Stroke in Mice
Authors: Gureev Artem P. , Sadovnikova Irina S. , Chernyshova Ekaterina V. , Tsvetkova Arina D. , Babenkova Polina I. , Nesterova Veronika V. , Krutskikh Ekaterina P. , Volodina Daria E. , Samoylova Natalia A. , Andrianova Nadezda V. , Silachev Denis N. , Plotnikov Egor Y.
Published: May 2024

The consequences of stroke include cognitive deficits and sensorimotor disturbances, which are largely related to mitochondrial impairments in the brain. In this work, we have shown that the mimetic of the ketogenic diet beta-hydroxybutyrate (βHB) can improve neurological brain function in stroke. At 3 weeks after photothrombotic stroke, mice receiving βHB with drinking water before and after surgery recovered faster in terms of sensorimotor functions assessed by the string test and static rods and cognitive functions assessed by the Morris water maze. At the same time, the βHB-treated mice had lower expression of some markers of astrocyte activation and inflammation (Gfap, Il-1b, Tnf). We hypothesize that long-term administration of βHB promotes the activation of the nuclear factor erythroid 2-related factor 2/antioxidant response element (Nrf2/ARE) pathway, which leads to increased expression of antioxidant genes targeting mitochondria and genes involved in signaling pathways necessary for the maintenance of synaptic plasticity. βHB partially maintained mitochondrial DNA (mtDNA) integrity during the first days after photothrombosis. However, in the following three weeks, the number of mtDNA damages increased in all experimental groups, which coincided with a decrease in Ogg1 expression, which plays an important role in mtDNA repair. Thus, we can assume that βHB is not only an important metabolite that provides additional energy to brain tissue during recovery from stroke under conditions of mitochondrial damage but also an important signaling molecule that supports neuronal plasticity and reduces neuroinflammation.
Zirconia Dental Implants Surface Electric Stimulation Impact on Staphylococcus aureus
Authors: Rodrigues Flávio , Pereira Helena F. , Pinto João , Padrão Jorge , Zille Andrea , Silva Filipe S. , Carvalho Óscar , Madeira Sara
Published: May 2024

Tooth loss during the lifetime of an individual is common. A strategy to treat partial or complete edentulous patients is the placement of dental implants. However, dental implants are subject to bacterial colonization and biofilm formation, which cause an infection named peri-implantitis. The existing long-term treatments for peri-implantitis are generally inefficient. Thus, an electrical circuit was produced with zirconia (Zr) samples using a hot-pressing technique to impregnate silver (Ag) through channels and holes to create a path by LASER texturing. The obtained specimens were characterized according to vitro cytotoxicity, to ensure ZrAg non-toxicity. Furthermore, samples were inoculated with Staphylococcus aureus using 6.5 mA of alternating current (AC). The current was delivered using a potentiostat and the influence on the bacterial concentration was assessed. Using AC, the specimens displayed no bacterial adhesion (Log 7 reduction). The in vitro results presented in this study suggest that this kind of treatment can be an alternative and promising strategy to treat and overcome bacterial adhesion around dental implants that can evolve to biofilm.
Genome-Wide Identification and Multi-Stress Response Analysis of the DABB-Type Protein-Encoding Genes in Brassica napus
Authors: Wang Siyi , Wang Kunmei , Xia Qi , Xia Shitou
Published: May 2024

The DABB proteins, which are characterized by stress-responsive dimeric A/B barrel domains, have multiple functions in plant biology. In Arabidopsis thaliana, these proteins play a crucial role in defending against various pathogenic fungi. However, the specific roles of DABB proteins in Brassica napus remain elusive. In this study, 16 DABB encoding genes were identified, distributed across 10 chromosomes of the B. napus genome, which were classified into 5 branches based on phylogenetic analysis. Genes within the same branch exhibited similar structural domains, conserved motifs, and three-dimensional structures, indicative of the conservation of BnaDABB genes (BnaDABBs). Furthermore, the enrichment of numerous cis-acting elements in hormone induction and light response were revealed in the promoters of BnaDABBs. Expression pattern analysis demonstrated the involvement of BnaDABBs, not only in the organ development of B. napus but also in response to abiotic stresses and Sclerotinia sclerotiorum infection. Altogether, these findings imply the significant impacts of BnaDABBs on plant growth and development, as well as stress responses.
Computational Screening for the Dipeptidyl Peptidase-IV Inhibitory Peptides from Putative Hemp Seed Hydrolyzed Peptidome as a Potential Antidiabetic Agent
Authors: Thongtak Arisa , Yutisayanuwat Kulpariya , Harnkit Nathaphat , Noikaew Tipanart , Chumnanpuen Pramote
Published: May 2024

Dipeptidyl peptidase-IV (DPPIV) inhibitory peptides are a class of antihyperglycemic drugs used in the treatment of type 2 diabetes mellitus, a metabolic disorder resulting from reduced levels of the incretin hormone GLP-1. Given that DPPIV degrades incretin, a key regulator of blood sugar levels, various antidiabetic medications that inhibit DPPIV, such as vildagliptin, sitagliptin, and linagliptin, are employed. However, the potential side effects of these drugs remain a matter of debate. Therefore, we aimed to investigate food-derived peptides from Cannabis sativa (hemp) seeds. Our developed bioinformatics pipeline was used to identify the putative hydrolyzed peptidome of three highly abundant proteins: albumin, edestin, and vicilin. These proteins were subjected to in silico digestion by different proteases (trypsin, chymotrypsin, and pepsin) and then screened for DPPIV inhibitory peptides using IDPPIV-SCM. To assess potential adverse effects, several prediction tools, namely, TOXINpred, AllerCatPro, and HemoPred, were employed to evaluate toxicity, allergenicity, and hemolytic effects, respectively. COPID was used to determine the amino acid composition. Molecular docking was performed using GalaxyPepDock and HPEPDOCK, 3D visualizations were conducted using the UCSF Chimera program, and MD simulations were carried out with AMBER20 MD software. Based on the predictive outcomes, FNVDTE from edestin and EAQPST from vicilin emerged as promising candidates for DPPIV inhibitors. We anticipate that our findings may pave the way for the development of alternative DPPIV inhibitors.
NGS-Based Identification of Two Novel PCDH19 Mutations in Female Patients with Early-Onset Epilepsy
Authors: Szalai Renata , Hadzsiev Kinga , Till Agnes , Fogarasi Andras , Bodo Timea , Buki Gergely , Banfai Zsolt , Bene Judit
Published: May 2024

Developmental and epileptic encephalopathy-9 (DEE9) is characterized by seizure onset in infancy, mild to severe intellectual impairment, and psychiatric features and is caused by a mutation in the PCDH19 gene on chromosome Xq22. The rare, unusual X-linked type of disorder affects heterozygous females and mosaic males; transmitting males are unaffected. In our study, 165 patients with epilepsy were tested by Next Generation Sequencing (NGS)-based panel and exome sequencing using Illumina technology. PCDH19 screening identified three point mutations, one indel, and one 29 bp-long deletion in five unrelated female probands. Two novel mutations, c.1152_1180del (p.Gln385Serfs*6) and c.830_831delinsAA (p.Phe277*), were identified and found to be de novo pathogenic. Moreover, among the three inherited mutations, two originated from asymptomatic mothers and one from an affected father. The PCDH19 c.1682C>T and c.1711G>T mutations were present in the DNA samples of asymptomatic mothers. After targeted parental testing, X chromosome inactivation tests and Sanger sequencing were carried out for mosaicism examination on maternal saliva samples in the two asymptomatic PCDH19 mutation carrier subjects. Tissue mosaicism and X-inactivation tests were negative. Our results support the opportunity for reduced penetrance in DEE9 and contribute to expanding the genotype–phenotype spectrum of PCDH19-related epilepsy.
Participation of miR165a in the Phytochrome Signal Transduction in Maize (Zea mays L.) Leaves under Changing Light Conditions
Authors: Fedorin Dmitry N. , Eprintsev Alexander T. , Chuykova Victoria O. , Igamberdiev Abir U.
Published: May 2024

The involvement of the microRNA miR165a in the light-dependent mechanisms of regulation of target genes in maize (Zea mays) has been studied. The light-induced change in the content of free miR165a was associated with its binding by the AGO10 protein and not with a change in the rate of its synthesis from the precursor. The use of knockout Arabidopsis plants for the phytochrome A and B genes demonstrated that the presence of an active form of phytochrome B causes an increase in the level of the RNA-induced silencing miR165a complex, which triggers the degradation of target mRNAs. The two fractions of vesicles from maize leaves, P40 and P100 that bind miR165a, were isolated by ultracentrifugation. The P40 fraction consisted of larger vesicles of the size >0.170 µm, while the P100 fraction vesicles were <0.147 µm. Based on the quantitative PCR data, the predominant location of miR165a on the surface of extracellular vesicles of both fractions was established. The formation of the active form of phytochrome upon the irradiation of maize plants with red light led to a redistribution of miR165a, resulting in an increase in its proportion inside P40 vesicles and a decrease in P100 vesicles.
Proof of Concept Study: Comparability of Microbiome Diversity in Self- and Physician-Collected HPV-Positive and HPV-Negative Cervicovaginal Samples
Authors: Asensio-Puig Laura , de Andrés-Pablo Álvaro , Khannous-Lleiffe Olfat , Ibáñez Raquel , Acera Amelia , de Sanjosé Silvia , Gabaldón Toni , Alemany Laia , Bruni Laia , Pavón Miquel Àngel
Published: May 2024

Recent studies have revealed the impact of human papillomavirus (HPV) infections on the cervicovaginal microbiome; however, few have explored the utility of self-collected specimens (SCS) for microbiome detection, obtained using standardised methods for HPV testing. Here, we present a proof-of-concept analysis utilising Oxford Nanopore sequencing of the 16S rRNA gene in paired samples collected either by the patient using an Evalyn Brush or collected by a physician using liquid-based cytology (LBC). We found no significant differences in the α-diversity estimates between the SCS and LBC samples. Similarly, when analysing β-diversity, we observed a close grouping of paired samples, indicating that both collection methods detected the same microbiome features. The identification of genera and Lactobacillus species in each sample allowed for their classification into community state types (CSTs). Notably, paired samples had the same CST, while HPV-positive and -negative samples belonged to distinct CSTs. As previously described in other studies, HPV-positive samples exhibited heightened bacterial diversity, reduced Lactobacillus abundance, and an increase in genera like Sneathia or Dialister. Altogether, this study showed comparable results between the SCS and LBC samples, underscoring the potential of self-sampling for analysing the microbiome composition in cervicovaginal samples initially collected for HPV testing in the context of cervical cancer screening.
An Efficient EEG Signal Analysis for Emotion Recognition Using FPGA
Authors: Ezilarasan M. R. , Leung Man-Fai
Published: May 2024

Electroencephalography (EEG), electromyography (EMG), galvanic skin response (GSR), and electrocardiogram (ECG) are among the techniques developed for collecting psychophysiological data from humans. This study presents a feature extraction technique for identifying emotions in EEG-based data from the human brain. Independent component analysis (ICA) was employed to eliminate artifacts from the raw brain signals before applying signal extraction to a convolutional neural network (CNN) for emotion identification. These features were then learned by the proposed CNN-LSTM (long short-term memory) algorithm, which includes a ResNet-152 classifier. The CNN-LSTM with ResNet-152 algorithm was used for the accurate detection and analysis of human emotional data. The SEED V dataset was employed for data collection in this study, and the implementation was carried out using an Altera DE2 FPGA development board, demonstrating improved performance in terms of FPGA speed and area optimization.
A Framework Model of Mining Potential Public Opinion Events Pertaining to Suspected Research Integrity Issues with the Text Convolutional Neural Network model and a Mixed Event Extractor
Authors: Zou Zongfeng , Ji Xiaochen , Li Yingying
Published: May 2024

With the development of the Internet, the oversight of research integrity issues has extended beyond the scientific community to encompass the whole of society. If these issues are not addressed promptly, they can significantly impact the research credibility of both institutions and scholars. This article proposes a text convolutional neural network based on SMOTE to identify short texts of potential public opinion events related to suspected scientific integrity issues from common short texts. The SMOTE comprehensive sampling technique is employed to handle imbalanced datasets. To mitigate the impact of short text length on text representation quality, the Doc2vec embedding model is utilized to represent short text, yielding a one-dimensional dense vector. Additionally, the dimensions of the input layer and convolution kernel of TextCNN are adjusted. Subsequently, a short text event extraction model based on TF-IDF and TextRank is proposed to extract crucial information, for instance, names and research-related institutions, from events and facilitate the identification of potential public opinion events related to suspected scientific integrity issues. Results of experiments have demonstrated that utilizing SMOTE to balance the dataset is able to improve the classification results of TextCNN classifiers. Compared to traditional classifiers, TextCNN exhibits greater robustness in addressing the problems of imbalanced datasets. However, challenges such as low information content, non-standard writing, and polysemy in short texts may impact the accuracy of event extraction. The framework can be further optimized to address these issues in the future.
Standardized Solutions of Catecholamines in Intensive Care Medicine: Application, Safety and Economic Aspects
Authors: Flinspach Armin Niklas , Mohr André , Wehrle Jahn , Zacharowski Kai , Neef Vanessa , Raimann Florian Jürgen
Published: May 2024

Background/Objectives: Catecholamines are among those agents that are indispensable in modern intensive care medicine. The rapid availability of hygienically impeccable and correctly concentrated injectable solutions, e.g., for syringe pumps, is becoming more and more important. However, little research has been conducted regarding how the use of catecholamines is distributed in different wards and what options can be used to achieve optimal availability. Methods: In a retrospective monocentric study from 2019 to 2022, all continuously applied catecholamines in intensive care units (ICU) and intermediate care units (IMC) were investigated. The focus was on potential optimization by utilizing manufactured ready-to-administer solutions in the context of the economization of patient care. Results: Norepinephrine syringes represented 81% of all syringes administered, appearing to be the most frequently used on all wards. Production by the in-house pharmacy showed both financial advantages and an increase in patient safety compared to syringes produced at the bedside. Discussion: Increasing numbers of critically ill patients coupled with growing staff shortages and an increased awareness of safety requirements are driving the move towards ready-to-use and ready-to-administer solutions in critical care medicine. In-house manufacturing by hospital pharmacies can be a promising option to optimize processes and improve the economics of patient care. Conclusions: Individual calculations of the required catecholamine preparations with regard to possible economic advantages should be carried out in hospitals. In particular, in-house production of ready-to-use and ready-to-administer preparations could significantly increase patient safety and seems to be economically viable.
A Comprehensive Approach to PROMs in Elective Orthopedic Surgery: Comparing Effect Sizes across Patient Subgroups
Authors: Äärimaa Ville , Kohtala Karita , Rantalaiho Ida , Ekman Elina , Mäkelä Keijo , Taskinen Hanna-Stiina , Ryösä Anssi , Kostensalo Joel , Meronen Saara , Laaksonen Inari
Published: May 2024

Background: There is limited knowledge regarding the comparative patient-reported outcomes (PROMs) and effect sizes (ESs) across orthopedic elective surgery. Methods: All patient data between January 2020 and December 2022 were collected, and treatment outcomes assessed as a PROM difference between baseline and one-year follow-up. The cohort was divided into subgroups (hand, elbow, shoulder, spine, hip, knee, and foot/ankle). The PROM ESs were calculated for each patient separately, and patients with ES > 0.5 were considered responders. Results: In total, 7695 patients were operated on. The mean ES across all patient groups was 1.81 (SD 1.41), and the largest ES was observed in shoulder patients and the smallest in hand patients. Overall, shoulder, hip, and knee patients had a larger ES compared to hand, spine, and foot/ankle patients (p < 0.0001). The proportion of positive responders ranged between 91–94% in the knee, shoulder, and hip, and 69–70% in the hand, spine, and foot/ankle subgroups. Conclusions: The ESs are generally high throughout elective orthopedic surgery. However, based on our institutional observations, shoulder, hip, and knee patients experience larger treatment effects compared to hand, spine, and foot/ankle patients, among whom there are also more non-responders. The expected treatment outcomes should be clearly communicated to patients when considering elective surgery. Because of the study limitations, the results should be approached with some caution.
Intranasal Immunotherapy with M2 Macrophage Secretome Ameliorates Language Impairments and Autistic-like Behavior in Children
Authors: Shevela Ekaterina Ya. , Loginova Tatiana A. , Munkuev Alexandr S. , Volskaya Tatiana E. , Sergeeva Svetlana A. , Rashchupkin Ivan M. , Kafanova Marina Yu. , Degtyareva Valentina G. , Sosnovskaya Anastasia V. , Ostanin Alexandr A. , Chernykh Elena R.
Published: May 2024

Background/Objectives: The intranasal delivery of various neurotropic substances is considered a new attractive therapeutic approach for treating neuropathologies associated with neuroinflammation and altered regeneration. Specific language impairment (SLI) that arises as a result of damage to the cortical speech zones during the developmental period is one of the most common problems in preschool children, and it is characterized by persistent difficulties in the acquisition, understanding, and use of language. This study’s objective is to evaluate the efficacy and safety of intranasal immunotherapy using the M2 macrophage secretome as a rich source of immunoregulatory and neurotrophic factors for the treatment of severe language impairment in children. Methods: Seventy-one children (54 boys and 17 girls, aged 3 to 13 years) were recruited to participate in a clinical trial (NCT04689282) in two medical centers. The children were examined before, 1 month after, and 6 months after the start of therapy. In the vast majority of children (55/71), language impairment was associated with autistic-like symptoms and attention deficit hyperactivity disorder (ADHD). Results: Daily intranasal inhalations of M2 macrophage-conditioned medium (for 30 days) were well tolerated and led to a decrease in the severity of language impairments, autistic-like behavior, and ADHD symptoms. The clinical effect appeared within a month after the first procedure and persisted or intensified during a 6-month follow-up. Two-thirds of the children showed a clear clinical improvement, while the rest had less pronounced improvement. Conclusions: Thus, the use of the M2 macrophage secretome and its intranasal delivery is safe, well tolerated, and clinically effective in children with severe language impairments.
Perspectives on Optimized Transcranial Electrical Stimulation Based on Spatial Electric Field Modeling in Humans
Authors: Gomez-Tames Jose , Fernández-Corazza Mariano
Published: May 2024

Background: Transcranial electrical stimulation (tES) generates an electric field (or current density) in the brain through surface electrodes attached to the scalp. Clinical significance has been demonstrated, although with moderate and heterogeneous results partly due to a lack of control of the delivered electric currents. In the last decade, computational electric field analysis has allowed the estimation and optimization of the electric field using accurate anatomical head models. This review examines recent tES computational studies, providing a comprehensive background on the technical aspects of adopting computational electric field analysis as a standardized procedure in medical applications. Methods: Specific search strategies were designed to retrieve papers from the Web of Science database. The papers were initially screened based on the soundness of the title and abstract and then on their full contents, resulting in a total of 57 studies. Results: Recent trends were identified in individual- and population-level analysis of the electric field, including head models from non-neurotypical individuals. Advanced optimization techniques that allow a high degree of control with the required focality and direction of the electric field were also summarized. There is also growing evidence of a correlation between the computationally estimated electric field and the observed responses in real experiments. Conclusions: Computational pipelines and optimization algorithms have reached a degree of maturity that provides a rationale to improve tES experimental design and a posteriori analysis of the responses for supporting clinical studies.
Management of Arrhythmias and Conduction Disorders in Amyloid Cardiomyopathy
Authors: Holcman Katarzyna , Ząbek Andrzej , Boczar Krzysztof , Podolec Piotr , Kostkiewicz Magdalena
Published: May 2024

Cardiac amyloidosis, a condition characterized by abnormal protein deposition in the heart, leads to restrictive cardiomyopathy and is notably associated with an increased risk of arrhythmias and conduction disorders. This article reviews the current understanding and management strategies for these cardiac complications, with a focus on recent advancements and clinical challenges. The prevalence and impact of atrial arrhythmias, particularly atrial fibrillation, are examined, along with considerations for stroke risk and anticoagulation therapy. The article also addresses the complexities of managing rate and rhythm control, outlining the utility and limitations of pharmacological agents and interventions such as catheter ablation. Furthermore, it reviews the challenges in the treatment of ventricular arrhythmias, including the contentious use of implantable cardioverter-defibrillators for primary and secondary prevention. Individualized approaches, considering the unique characteristics of cardiac amyloidosis, are paramount. Continuous research and clinical exploration are essential to refine treatment strategies and improve outcomes in this challenging patient population.
Milling Stability Modeling by Sample Partitioning with Chatter Frequency-Based Test Point Selection
Authors: Schmitz Tony
Published: May 2024

This paper describes a sample partitioning approach to retain or reject samples from an initial distribution of stability maps using milling test results. The stability maps are calculated using distributions of uncertain modal parameters that represent the tool tip frequency response functions and cutting force model coefficients. Test points for sample partitioning are selected using either (1) the combination of spindle speed and mean axial depth from the available samples that provides the high material removal rate, or (2) a spindle speed based on the chatter frequency and mean axial depth at that spindle speed. The latter is selected when an unstable (chatter) result is obtained from a test. Because the stability model input parameters are also partitioned using the test results, their uncertainty is reduced using a limited number of tests and the milling stability model accuracy is increased. A case study is provided to evaluate the algorithm.
Angle of Arrival Estimator Utilizing the Minimum Number of Omnidirectional Microphones
Authors: Kim Jonghoek
Published: May 2024

In sound signal processing, angle of arrival indicates the direction from which a propagating sound signal arrives at a point where multiple omnidirectional microphones are positioned. Considering a small underwater platform (e.g., underwater unmanned vehicle), this article addresses how to estimate a non-cooperative target’s signal direction utilizing the minimum number of omnidirectional microphones. It is desirable to use the minimum number of microphones, since one can reduce the cost and size of the platform by using small number of omnidirectional microphones. Suppose that each microphone measures a real-valued sound signal whose speed and frequency information are not known in advance. Since two microphones cannot determine a unique AOA solution, this study presents how to estimate the angle of arrival using a general configuration composed of three omnidirectional microphones. The effectiveness of the proposed angle of arrival estimator utilizing only three microphones is demonstrated by comparing it with the state-of-the-art estimation algorithm through computer simulations.
NGO-Led Community-Based Conservation: A New Frontier of Territorialization with Implications for Pastoralists’ Land Tenure and Climate Change Adaptation
Authors: Wachira Jackson , Atela Joanes , Stacey Paul , Outa George
Published: May 2024

In recent years, many community-based conservancies (CBCs) led by non-governmental organizations (NGOs) have been established on land inhabited by pastoralists in Northern Kenya. Despite a growing body of research, little attention has been paid to the impacts on pastoralists’ climate change adaptation. We provide a deeper understanding by considering NGO-led community-based conservation (NGO-led CBC) as a new frontier of territorialization and adaptation to climate change and variability as a social-natural process. Based on an analysis of primary data collected in Samburu County, Kenya, we show that NGO-led CBC involves resource enclosures that aggravate conflicts over land rights and pastoralists’ vulnerability to climate change and variability by constraining their mobility. In relation, the legal and institutional environment promoted by NGO-led CBC leads to increased control over ecologically vibrant lands, which erodes pastoralists’ land tenure security and climate change adaptation. Although NGO-led CBC plays an important role in enhancing access to external finance and incentivizing diversification, governance mechanisms remain opaque and overshadow local institutions. Overall, we highlight the need for actors to carefully consider the implications of this conservation/development model for already hard-pressed land-dependent communities.
Full-Term and Preterm Newborns Differ More Significantly in Photoplethysmographic Waveform Variability than Heart Rate Variability
Authors: Kiselev Anton R. , Mureeva Elena N. , Skazkina Viktoria V. , Panina Olga S. , Karavaev Anatoly S. , Chernenkov Yuri V.
Published: May 2024

Background: Features of cardiovascular autonomic regulation in infants are poorly studied compared with adults. However, the clinical significance of autonomic dysfunction in infants is very high. The goal of our research was to study the temporal and frequency-dependent features, as well as low-frequency synchronization in cardiovascular autonomic regulation in full-term vs. preterm newborns, based on the analysis of their heart rate variability (HRV) and photoplethysmographic waveform variability (PPGV). Methods: The study included three groups of newborns: 64 full-term newborns (with a gestational age at birth of 37–40 weeks) with a physiological course of the neonatal adaptation; 23 full-term newborns (with a gestational age at birth of 37–40 weeks) with a pathological course of the neonatal adaptation; and 17 preterm newborns (with a postconceptional age of 34 weeks or more). We conducted spectral analysis of HRV and PPGV, along with an assessment of the synchronization strength between low-frequency oscillations in HRV and in PPGV (synchronization index). We employed several options for the boundaries of the high-frequency (HF) band: 0.15–0.40 Hz, 0.2–2 Hz, 0.15–0.8 Hz, and 0.24–1.04 Hz. Results: Preterm newborns had higher heart rate, RMSSD, and PNN50 values relative to both groups of full-term newborns. Values of SDNN index and synchronization index (S index) were similar in all groups of newborns. Differences in frequency domain indices of HRV between groups of newborns depended on the considered options of HF band boundaries. Values of frequency domain indices of PPGV demonstrated similar differences between groups, regardless of the boundaries of considered options of HF bands and the location of PPG signal recording (forehead or leg). An increase in sympathetic influences on peripheral blood flow and a decrease in respiratory influences were observed along the following gradient: healthy full-term newborns → preterm newborns → full-term newborns with pathology. Conclusions: Differences in frequency domain indices of autonomic regulation between the studied groups of newborns depended on the boundaries of the considered options of the HF band. Frequency domain indices of PPGV revealed significantly more pronounced differences between groups of newborns than analogous HRV indicators. An increase in sympathetic influences on peripheral blood flow and a decrease in respiratory influences were observed along the following gradient: healthy full-term newborns → preterm newborns → full-term newborns with pathology.
Low Bacterial Diversity and Nitrate Levels in Cores from Deep Boreholes in Pristine Karst
Authors: Mulec Janez , Skok Sara , Pašić Lejla
Published: May 2024

This study investigates the nitrate gradients within the deep biosphere of karst carbonate rocks and their resident microbiota. Samples were taken from borehole cores at depths down to 350 m below the surface, collected during geological site investigations for proposed railway tunnels and analysed using 16S rRNA amplicon sequencing. 16S rRNA amplicon sequencing analysis revealed relatively low microbial diversity, which can serve as a reliable indicator of the pristine nature of deep karst. However, some local hotspots of diversity are independent of depth. Pseudomonadota dominated the samples, with Gammaproteobacteria dominating at the class level. The low nitrate content in deep karst, in contrast to higher values closer to the surface, serves as an additional marker of its undisturbed and unpolluted status. Based on the prediction of functional profiles from 16S rRNA sequencing data, nitrates remain low due to indigenous microbial denitrification and assimilatory nitrate reduction. Pathways related to nitrogen fixation, ammonia assimilation, and nitrification were not confirmed. When elevated nitrate levels are observed in karst, they are most probably related to anthropogenic activities. Environmental factors other than depth and nitrate content play an important role in shaping bacterial communities.
Hydrogels for Lubrication: Synthesis, Properties, Mechanism, and Challenges
Authors: Hu Lulin , Yang Yi , Yu Weiyan , Xu Lu
Published: May 2024

Hydrogels have received extensive attention as functional lubricants because of their excellent anti-friction and anti-wear properties, tunable tribological performances, and effectiveness in alleviating lubrication failures caused by the creeping or leakage of conventional liquid lubricants owing to their semi-solid nature. This review summarizes the current research advances in hydrogel lubricants fabricated with various organic and/or inorganic gelators, including organic polymeric or supramolecular hydrogels, inorganic particles-based hydrogels, and organic polymer-inorganic particle hybrid hydrogels. We illustrate not only the design strategies for constructing high-performance hydrogel lubricants but also the tribological behavior and mechanism of different types of hydrogel lubricants and their potential applications in industrial and biomimetic fields. Corresponding outlooks and suggestions for future studies have also been proposed.
Effect of Rotary Swaging on Mechanical Behaviors of Axle Steel Rod
Authors: Tian Tiantai , Xu Hongtu , Zheng Huaibei , Zhan Wenbin , Zhang Yu , Zhu Haosong , Zhang Qi
Published: May 2024

The short-chain forming process using rotary swaging (RS) is an important method of achieving the manufacturing of lightweight axles. Axle steel, like 42CrMo, is widely used in many types of axles and shafts; however, there is no existing research on rotary-swaged axle steel’s mechanical properties. It makes sense to carry out a comprehensive study on the effect of RS on the mechanical behaviors of axle steel rods. In this study, a 42CrMo steel rod was processed by RS through ten passes. The tensile properties, torsion properties, compression properties, and fatigue properties were tested. There was an overall improvement in the torsional and fatigue performance after RS. Combined with a finite element analysis (FEM), the uneven distribution of the dislocations and existence of the elongation material were inferred to have caused the different modes of the mechanical behaviors. Fracture surfaces were analyzed and the results showed that the fracture pattern had changed. There existed a competitive relation between the internal fatigue cracks and external cracks, which could be attributed to uneven strain hardening. This research proved the advantages of RS in the processing of axle parts, which mainly benefitted the torsional working conditions, and provided evidence for a new processing route for lightweight axles with RS.
A Macroscopic Interpretation of the Correlation between Electrical Percolation and Mechanical Properties of Poly-(Ethylene Vinyl Acetate)/Zn Composites
Authors: Agrisuelas Jerónimo , Balart Rafael , García-Jareño José J. , López-Martínez Juan , Vicente Francisco
Published: May 2024

Elastic composites were prepared using a procedure involving hot plates and zinc powder that was directly dispersed into an EVA matrix. The correlation between the zinc content and the conductive properties of the material was studied via impedance spectroscopy, the thermal properties of the material were studied via differential calorimetry and the mechanical properties of the composites were studied via tensile strength curves, representing an important advancement in the characterization of this type of composite material. The composites’ tensile strength and elongation at break decrease with the addition of filler since zinc particles act as stress-concentrating centres, while the composites’ hardness and Young’s modulus increase because of an increase in the stiffness of the material. The AC perturbation across the EVA/Zn composites was characterized using an RC parallel equivalent circuit that allowed us to easily measure their resistivity (ρp) and permittivity (εp). The dependence of these electrical magnitudes on the zinc content is correlated with their mechanical properties across the characteristic time constant τp =  ρp·εp of this equivalent circuit. The dependence of the mechanical and electrical magnitudes on the zinc content is consistent with the formation of percolation clusters. The addition of graphite particles increases their potential performance. Three possible mechanisms for the electrical transport of the ac-perturbation across the EVA/Zn composites have been identified. Chemical corrosion in acid media causes the loss of zinc surface particles, but their bulk physical properties practically remain constant.
Studies on the Evolution of Fatigue Strength of Aluminium Wires for Overhead Line Conductors
Authors: Jurkiewicz Bartosz , Smyrak Beata
Published: May 2024

Traditional ACSR overhead wires, which consist of a high-strength steel core and several layers of aluminium wires, are currently the most popular overhead line conductor (OHL) design globally. Operating conditions, particularly operating under varying stresses from Karman vortices, lead to the fatigue cracking of wires of the outer layer, followed by wires of the inner layers. Karman vortices are formed by the detachment of a laminar wind stream flowing around the conductor, which causes vibrations in the conductor called wind or aeolian oscillations. Aluminium wires are manufactured using standard batch material drawing technology. Although the fatigue strength of such wires is not standardised, there are various criteria for evaluating this characteristic, as well as established limits on the number of cycles needed to break the first wires of the outer layer. Fatigue strength also strongly depends on the geometric structure of the wire and its operating conditions. The article analyses the influence of the mechanical condition of aluminium wires used in ACSR cables on their fatigue strength. We then present results from aluminium wire fatigue tests conducted on a specially constructed test rig. In addition, fatigue cracks were interpreted using scanning microscopy.
Durability and Mechanical Properties of Nano-SiO2 and Polyvinyl Alcohol Fiber-Reinforced Cementitious Composites Subjected to Saline Freeze–Thaw Cycles
Authors: Wan Lijun , Zhao Yongqi , Yu Maopei , Tian Ye , Wang Yipeng
Published: May 2024

To investigate the effects of nano-SiO2 (NS) and polyvinyl alcohol (PVA) fibers on the durability and mechanical properties of cementitious composites subjected to saline freeze–thaw cycling, a series of PVA fiber-reinforced cementitious composite (PFRCC) specimens were prepared using various fiber contents, and a series of NS and PVA fiber-reinforced cementitious composite (NPFRCC) specimens were prepared using various combinations of NS and fiber contents. Durability and fracture toughness tests were subsequently conducted on the specimens after different numbers of saline freeze–thaw cycles. The results indicate that the degradation of material properties can be divided into slow and accelerated damage stages before/after 50 freeze–thaw cycles. The durability and fracture toughness of the specimen series tended to increase, then decrease with increasing NS and PVA contents, suggesting optimum levels. When the PVA fiber content was 0.5%, PFRCC specimens had the best durability after saline freeze–thaw cycles; when the NS and PVA fiber contents were 1.0% and 0.5%, respectively, NPFRCC specimens had the best durability and fracture properties, and the initiation toughness, destabilization toughness, and fracture energy after 100 saline freeze–thaw cycles were 120.69%, 160.02%, and 451.31%, respectively. The results of this study may guide future exploration of the durability and mechanical properties of concrete subjected to freeze–thaw action.
Mechanical Modeling of Viscous Fluid Damper with Temperature and Pressure Coupling Effects
Authors: Zhang Yunlong , Xu Weizhi , Wang Shuguang , Du Dongsheng , Geng Yan
Published: May 2024

During long-duration dynamic loads, such as wind loads or seismic effects, the internal temperature and pressure of a damping cylinder escalate rapidly, which induce shifts in the mechanical attributes of viscous fluid dampers (VFDs). This study investigated the mechanical performance of VFD considering the coupling effects of temperature and pressure under long-duration loads. First, we analyzed the mechanical and energy-dissipation performances of the dampers based on the dynamic mechanical tests considering different loading frequencies, displacement amplitude, and loading cycles. The experimental results indicated that both temperature and pressure influenced the output of the dampers, and in the sealed environment of the damper pip, temperature and pressure exerted mutual influence. Furthermore, the relationship between the damping coefficient and temperature–pressure coupling effects was obtained. Subsequently, an improved mathematical model for the mechanical performance of a gap-type VFD was proposed by considering the macroscopic energy balance of the entire fluid within the damper. Finally, the accuracy of the mathematical model for VFD under long-duration dynamic loads was validated by comparing the computational results with the experimental data.
Autoclaving Achieves pH-Neutralization, Hydrogelation, and Sterilization of Chitosan Hydrogels in One Step
Authors: Yamashita Yusuke , Ohzuno Yoshihiro , Yoshida Masahiro , Takei Takayuki
Published: May 2024

Conventionally, chitosan hydrogels are acidic and contain toxic chemicals because chitosan is soluble only in acidic solvents and requires toxic additives such as chemical crosslinkers and polymerization agents to fabricate chitosan hydrogels. These properties prevent chitosan hydrogels from being used for medical applications. In this study, chitosan hydrogels were prepared by a simple and versatile process using urea hydrolysis by autoclaving (steam sterilization, 121 °C, 20 min). When autoclaved, urea hydrolyzes in an acidic chitosan aqueous solution, and ammonia is produced, which increases the pH of the solution, and chitosan becomes insoluble, leading to the formation of a chitosan hydrogel. The pH and osmotic concentration of chitosan hydrogels could be adjusted to be suitable for physiological conditions (pH: 7.0–7.5, and osmotic concentration: 276–329 mOsm/L) by changing the amount of urea added to chitosan solutions (chitosan: 2.5% (w/v), urea: 0.75–1.0% (w/v), pH: 5.5). The hydrogels had extremely low cytotoxicity without the washing process. In addition, not only pure chitosan hydrogels, but also chitosan derivative hydrogels were prepared using this method. The autoclaving technique for preparing low-toxic and wash-free sterilized chitosan hydrogels in a single step is practical for medical applications.
Abnormal Traffic Detection System Based on Feature Fusion and Sparse Transformer
Authors: Zhao Xinjian , Miao Weiwei , Yuan Guoquan , Jiang Yu , Zhang Song , Li Qianmu
Published: May 2024

This paper presents a feature fusion and sparse transformer-based anomalous traffic detection system (FSTDS). FSTDS utilizes a feature fusion network to encode the traffic data sequences and extracting features, fusing them into coding vectors through shallow and deep convolutional networks, followed by deep coding using a sparse transformer to capture the complex relationships between network flows; finally, a multilayer perceptron is used to classify the traffic and achieve anomaly traffic detection. The feature fusion network of FSTDS improves feature extraction from small sample data, the deep encoder enhances the understanding of complex traffic patterns, and the sparse transformer reduces the computational and storage overhead and improves the scalability of the model. Experiments demonstrate that the number of FSTDS parameters is reduced by up to nearly half compared to the baseline, and the success rate of anomalous flow detection is close to 100%.
Multi-View and Multimodal Graph Convolutional Neural Network for Autism Spectrum Disorder Diagnosis
Authors: Song Tianming , Ren Zhe , Zhang Jian , Wang Mingzhi
Published: May 2024

Autism Spectrum Disorder (ASD) presents significant diagnostic challenges due to its complex, heterogeneous nature. This study explores a novel approach to enhance the accuracy and reliability of ASD diagnosis by integrating resting-state functional magnetic resonance imaging with demographic data (age, gender, and IQ). This study is based on improving the spectral graph convolutional neural network (GCN). It introduces a multi-view attention fusion module to extract useful information from different views. The graph’s edges are informed by demographic data, wherein an edge-building network computes weights grounded in demographic information, thereby bolstering inter-subject correlation. To tackle the challenges of oversmoothing and neighborhood explosion inherent in deep GCNs, this study introduces DropEdge regularization and residual connections, thus augmenting feature diversity and model generalization. The proposed method is trained and evaluated on the ABIDE-I and ABIDE-II datasets. The experimental results underscore the potential of integrating multi-view and multimodal data to advance the diagnostic capabilities of GCNs for ASD.
A Modified Three-Term Conjugate Descent Derivative-Free Method for Constrained Nonlinear Monotone Equations and Signal Reconstruction Problems
Authors: Yusuf Aliyu , Manjak Nibron Haggai , Aphane Maggie
Published: May 2024

Iterative methods for solving constraint nonlinear monotone equations have been developed and improved by many researchers. The aim of this research is to present a modified three-term conjugate descent (TTCD) derivative-free method for constrained nonlinear monotone equations. The proposed algorithm requires low storage memory; therefore, it has the capability to solve large-scale nonlinear equations. The algorithm generates a descent and bounded search direction dk at every iteration independent of the line search. The method is shown to be globally convergent under monotonicity and Lipschitz continuity conditions. Numerical results show that the suggested method can serve as an alternative to find the approximate solutions of nonlinear monotone equations. Furthermore, the method is promising for the reconstruction of sparse signal problems.
A Study of Some Generalized Results of Neutral Stochastic Differential Equations in the Framework of Caputo–Katugampola Fractional Derivatives
Authors: Mohammed Djaouti Abdelhamid , Khan Zareen A. , Imran Liaqat Muhammad , Al-Quran Ashraf
Published: May 2024

Inequalities serve as fundamental tools for analyzing various important concepts in stochastic differential problems. In this study, we present results on the existence, uniqueness, and averaging principle for fractional neutral stochastic differential equations. We utilize Jensen, Burkholder–Davis–Gundy, Grönwall–Bellman, Hölder, and Chebyshev–Markov inequalities. We generalize results in two ways: first, by extending the existing result for p=2 to results in the Lp space; second, by incorporating the Caputo–Katugampola fractional derivatives, we extend the results established with Caputo fractional derivatives. Additionally, we provide examples to enhance the understanding of the theoretical results we establish.