bluuebunny/crossref_metadata_2025 huggingface dataset:
Parvalbumin Interneuron Dysfunction in Neurological Disorders: Focus on Epilepsy and Alzheimer’s Disease
Authors: Leitch Beulah
Published: May 2024

Parvalbumin expressing (PV+) GABAergic interneurons are fast spiking neurons that provide powerful but relatively short-lived inhibition to principal excitatory cells in the brain. They play a vital role in feedforward and feedback synaptic inhibition, preventing run away excitation in neural networks. Hence, their dysfunction can lead to hyperexcitability and increased susceptibility to seizures. PV+ interneurons are also key players in generating gamma oscillations, which are synchronized neural oscillations associated with various cognitive functions. PV+ interneuron are particularly vulnerable to aging and their degeneration has been associated with cognitive decline and memory impairment in dementia and Alzheimer’s disease (AD). Overall, dysfunction of PV+ interneurons disrupts the normal excitatory/inhibitory balance within specific neurocircuits in the brain and thus has been linked to a wide range of neurodevelopmental and neuropsychiatric disorders. This review focuses on the role of dysfunctional PV+ inhibitory interneurons in the generation of epileptic seizures and cognitive impairment and their potential as targets in the design of future therapeutic strategies to treat these disorders. Recent research using cutting-edge optogenetic and chemogenetic technologies has demonstrated that they can be selectively manipulated to control seizures and restore the balance of neural activity in the brains of animal models. This suggests that PV+ interneurons could be important targets in developing future treatments for patients with epilepsy and comorbid disorders, such as AD, where seizures and cognitive decline are directly linked to specific PV+ interneuron deficits.
Inhibition of Amyloid-β (Aβ)-Induced Cognitive Impairment and Neuroinflammation in CHI3L1 Knockout Mice through Downregulation of ERK-PTX3 Pathway
Authors: Ham Hyeon Joo , Lee Yong Sun , Koo Ja Keun , Yun Jaesuk , Son Dong Ju , Han Sang-Bae , Hong Jin Tae
Published: May 2024

Several clinical studies reported that the elevated expression of Chitinase-3-like 1 (CHI3L1) was observed in patients suffering from a wide range of diseases: cancer, metabolic, and neurological diseases. However, the role of CHI3L1 in AD is still unclear. Our previous study demonstrated that 2-({3-[2-(1-Cyclohexen-1-yl)ethyl]-6,7-dimethoxy-4-oxo-3,4-dihydro-2-quinazolinyl}culfanyl)-N-(4-ethylphenyl)butanamide, a CHI3L1 inhibiting compound, alleviates memory and cognitive impairment and inhibits neuroinflammation in AD mouse models. In this study, we studied the detailed correlation of CHI3L1 and AD using serum from AD patients and using CHI3L1 knockout (KO) mice with Aβ infusion (300 pmol/day, 14 days). Serum levels of CHI3L1 were significantly elevated in patients with AD compared to normal subjects, and receiver operating characteristic (ROC) analysis data based on serum analysis suggested that CHI3L1 could be a significant diagnostic reference for AD. To reveal the role of CHI3L1 in AD, we investigated the CHI3L1 deficiency effect on memory impairment in Aβ-infused mice and microglial BV-2 cells. In CHI3L1 KO mice, Aβ infusion resulted in lower levels of memory dysfunction and neuroinflammation compared to that of WT mice. CHI3L1 deficiency selectively inhibited phosphorylation of ERK and IκB as well as inhibition of neuroinflammation-related factors in vivo and in vitro. On the other hand, treatment with recombinant CHI3L1 increased neuroinflammation-related factors and promoted phosphorylation of IκB except for ERK in vitro. Web-based gene network analysis and our results showed that CHI3L1 is closely correlated with PTX3. Moreover, in AD patients, we found that serum levels of PTX3 were correlated with serum levels of CHI3L1 by Spearman correlation analysis. These results suggest that CHI3L1 deficiency could inhibit AD development by blocking the ERK-dependent PTX3 pathway.
Chemiresistors Based on Hybrid Nanostructures Obtained from Graphene and Conducting Polymers with Potential Use in Breath Methane Detection Associated with Irritable Bowel Syndrome
Authors: Trandabat Alexandru F. , Ciobanu Romeo C. , Schreiner Oliver Daniel , Schreiner Thomas Gabriel , Aradoaei Sebastian
Published: May 2024

This paper describes the process of producing chemiresistors based on hybrid nanostructures obtained from graphene and conducting polymers. The technology of graphene presumed the following: dispersion and support stabilization based on the chemical vapor deposition technique; transfer of the graphene to the substrate by spin-coating of polymethyl methacrylate; and thermal treatment and electrochemical delamination. For the process at T = 950 °C, a better settlement of the grains was noticed, with the formation of layers predominantly characterized by peaks and not by depressions. The technology for obtaining hybrid nanostructures from graphene and conducting polymers was drop-casting, with solutions of Poly(3-hexylthiophene (P3HT) and Poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-bithiophene] (F8T2). In the case of F8T2, compared to P3HT, a 10 times larger dimension of grain size and about 7 times larger distances between the peak clusters were noticed. To generate chemiresistors from graphene–polymer structures, an ink-jet printer was used, and the metallization was made with commercial copper ink for printed electronics, leading to a structure of a resistor with an active surface of about 1 cm2. Experimental calibration curves were plotted for both sensing structures, for a domain of CH4 of up to 1000 ppm concentration in air. A linearity of the curve for the low concentration of CH4 was noticed for the graphene structure with F8T2, presenting a sensitivity of about 6 times higher compared with the graphene structure with P3HT, which makes the sensing structure of graphene with F8T2 more feasible and reliable for the medical application of irritable bowel syndrome evaluation.
Identification of Transcripts with Shared Roles in the Pathogenesis of Postmenopausal Osteoporosis and Cardiovascular Disease
Authors: Reppe Sjur , Gundersen Sveinung , Sandve Geir K. , Wang Yunpeng , Andreassen Ole A. , Medina-Gomez Carolina , Rivadeneira Fernando , Utheim Tor P. , Hovig Eivind , Gautvik Kaare M.
Published: May 2024

Epidemiological evidence suggests existing comorbidity between postmenopausal osteoporosis (OP) and cardiovascular disease (CVD), but identification of possible shared genes is lacking. The skeletal global transcriptomes were analyzed in trans-iliac bone biopsies (n = 84) from clinically well-characterized postmenopausal women (50 to 86 years) without clinical CVD using microchips and RNA sequencing. One thousand transcripts highly correlated with areal bone mineral density (aBMD) were further analyzed using bioinformatics, and common genes overlapping with CVD and associated biological mechanisms, pathways and functions were identified. Fifty genes (45 mRNAs, 5 miRNAs) were discovered with established roles in oxidative stress, inflammatory response, endothelial function, fibrosis, dyslipidemia and osteoblastogenesis/calcification. These pleiotropic genes with possible CVD comorbidity functions were also present in transcriptomes of microvascular endothelial cells and cardiomyocytes and were differentially expressed between healthy and osteoporotic women with fragility fractures. The results were supported by a genetic pleiotropy-informed conditional False Discovery Rate approach identifying any overlap in single nucleotide polymorphisms (SNPs) within several genes encoding aBMD- and CVD-associated transcripts. The study provides transcriptional and genomic evidence for genes of importance for both BMD regulation and CVD risk in a large collection of postmenopausal bone biopsies. Most of the transcripts identified in the CVD risk categories have no previously recognized roles in OP pathogenesis and provide novel avenues for exploring the mechanistic basis for the biological association between CVD and OP.
Molecular Pathways of Genistein Activity in Breast Cancer Cells
Authors: Konstantinou Evangelia K. , Gioxari Aristea , Dimitriou Maria , Panoutsopoulos George I. , Panagiotopoulos Athanasios A.
Published: May 2024

The most common malignancy in women is breast cancer. During the development of cancer, oncogenic transcription factors facilitate the overproduction of inflammatory cytokines and cell adhesion molecules. Antiapoptotic proteins are markedly upregulated in cancer cells, which promotes tumor development, metastasis, and cell survival. Promising findings have been found in studies on the cell cycle-mediated apoptosis pathway for medication development and treatment. Dietary phytoconstituents have been studied in great detail for their potential to prevent cancer by triggering the body’s defense mechanisms. The underlying mechanisms of action may be clarified by considering the role of polyphenols in important cancer signaling pathways. Phenolic acids, flavonoids, tannins, coumarins, lignans, lignins, naphthoquinones, anthraquinones, xanthones, and stilbenes are examples of natural chemicals that are being studied for potential anticancer drugs. These substances are also vital for signaling pathways. This review focuses on innovations in the study of polyphenol genistein’s effects on breast cancer cells and presents integrated chemical biology methods to harness mechanisms of action for important therapeutic advances.
Unveiling the Role of RNA Recognition Motif Proteins in Orchestrating Nucleotide-Binding Site and Leucine-Rich Repeat Protein Gene Pairs and Chloroplast Immunity Pathways: Insights into Plant Defense Mechanisms
Authors: Gu Fengwei , Han Zhikai , Zou Xiaodi , Xie Huabin , Chen Chun , Huang Cuihong , Guo Tao , Wang Jiafeng , Wang Hui
Published: May 2024

In plants, nucleotide-binding site and leucine-rich repeat proteins (NLRs) play pivotal roles in effector-triggered immunity (ETI). However, the precise mechanisms underlying NLR-mediated disease resistance remain elusive. Previous studies have demonstrated that the NLR gene pair Pik-H4 confers resistance to rice blast disease by interacting with the transcription factor OsBIHD1, consequently leading to the upregulation of hormone pathways. In the present study, we identified an RNA recognition motif (RRM) protein, OsRRM2, which interacted with Pik1-H4 and Pik2-H4 in vesicles and chloroplasts. OsRRM2 exhibited a modest influence on Pik-H4-mediated rice blast resistance by upregulating resistance genes and genes associated with chloroplast immunity. Moreover, the RNA-binding sequence of OsRRM2 was elucidated using systematic evolution of ligands by exponential enrichment. Transcriptome analysis further indicated that OsRRM2 promoted RNA editing of the chloroplastic gene ndhB. Collectively, our findings uncovered a chloroplastic RRM protein that facilitated the translocation of the NLR gene pair and modulated chloroplast immunity, thereby bridging the gap between ETI and chloroplast immunity.
Unraveling the Microbiome–Human Body Axis: A Comprehensive Examination of Therapeutic Strategies, Interactions and Implications
Authors: Olteanu Gabriel , Ciucă-Pană Maria-Alexandra , Busnatu Ștefan Sebastian , Lupuliasa Dumitru , Neacșu Sorinel Marius , Mititelu Magdalena , Musuc Adina Magdalena , Ioniță-Mîndrican Corina-Bianca , Boroghină Steluța Constanța
Published: May 2024

This review scrutinizes the intricate interplay between the microbiome and the human body, exploring its multifaceted dimensions and far-reaching implications. The human microbiome, comprising diverse microbial communities inhabiting various anatomical niches, is increasingly recognized as a critical determinant of human health and disease. Through an extensive examination of current research, this review elucidates the dynamic interactions between the microbiome and host physiology across multiple organ systems. Key topics include the establishment and maintenance of microbiota diversity, the influence of host factors on microbial composition, and the bidirectional communication pathways between microbiota and host cells. Furthermore, we delve into the functional implications of microbiome dysbiosis in disease states, emphasizing its role in shaping immune responses, metabolic processes, and neurological functions. Additionally, this review discusses emerging therapeutic strategies aimed at modulating the microbiome to restore host–microbe homeostasis and promote health. Microbiota fecal transplantation represents a groundbreaking therapeutic approach in the management of dysbiosis-related diseases, offering a promising avenue for restoring microbial balance within the gut ecosystem. This innovative therapy involves the transfer of fecal microbiota from a healthy donor to an individual suffering from dysbiosis, aiming to replenish beneficial microbial populations and mitigate pathological imbalances. By synthesizing findings from diverse fields, this review offers valuable insights into the complex relationship between the microbiome and the human body, highlighting avenues for future research and clinical interventions.
Systematic-Narrative Hybrid Literature Review: Crosstalk between Gastrointestinal Renin–Angiotensin and Dopaminergic Systems in the Regulation of Intestinal Permeability by Tight Junctions
Authors: Khan Nadia , Kurnik-Łucka Magdalena , Latacz Gniewomir , Gil Krzysztof
Published: May 2024

In the first part of this article, the role of intestinal epithelial tight junctions (TJs), together with gastrointestinal dopaminergic and renin–angiotensin systems, are narratively reviewed to provide sufficient background. In the second part, the current experimental data on the interplay between gastrointestinal (GI) dopaminergic and renin–angiotensin systems in the regulation of intestinal epithelial permeability are reviewed in a systematic manner using the PRISMA methodology. Experimental data confirmed the copresence of DOPA decarboxylase (DDC) and angiotensin converting enzyme 2 (ACE2) in human and rodent enterocytes. The intestinal barrier structure and integrity can be altered by angiotensin (1-7) and dopamine (DA). Both renin–angiotensin and dopaminergic systems influence intestinal Na+/K+-ATPase activity, thus maintaining electrolyte and nutritional homeostasis. The colocalization of B0AT1 and ACE2 indicates the direct role of the renin–angiotensin system in amino acid absorption. Yet, more studies are needed to thoroughly define the structural and functional interaction between TJ-associated proteins and GI renin–angiotensin and dopaminergic systems.
Cocatalytic Activity of the Furfuryl and Oxanorbornane-Substituted Guanidines in the Aldol Reaction Catalyzed by (S)-Proline
Authors: Barešić Luka , Marijanović Monika , Dokli Irena , Margetić Davor , Glasovac Zoran
Published: May 2024

This work investigated the cocatalytic activity of recently prepared guanidinium salts containing an oxanorbornane subunit in an (S)-proline-catalyzed aldol reaction. The activity was interpreted by the diastereoselectivity of the reaction (anti/syn ratio) and for the most interesting polycyclic guanidinium salt, the enantioselectivity of the reaction was determined. The results indicated a negative impact on the oxanorbornane unit if present as the flexible substituent. For most of the tested aldehydes, the best cocatalysts provided enantioselectivities above 90% and above 95% at room temperature and 0 °C, respectively, culminating in >99.5% for 4–chloro– and 2–nitrobenzaldehyde as the substrate. The barriers for forming four possible enantiomers were calculated and the results for two anti–enantiomers are qualitatively consistent with the experiment. Obtained results suggest that the representatives of furfurylguanidinium and rigid polycyclic oxanorbornane-substituted guanidinium salts are good lead structures for developing new cocatalysts by tuning the chemical space around the guanidine moiety.
Technoeconomic Analysis for Deployment of Gait-Oriented Wearable Medical Internet-of-Things Platform in Catalonia
Authors: Codina Marc , Castells-Rufas David , Torrelles Maria-Jesus , Carrabina Jordi
Published: May 2024

The Internet of Medical Things (IoMT) extends the concept of eHealth and mHealth for patients with continuous monitoring requirements. This research concentrates on the use of wearable devices based on the use of inertial measurement units (IMUs) that account for a gait analysis for its use in three health cases, equilibrium evaluation, fall prevention and surgery recovery, that impact a large elderly population. We also analyze two different scenarios for data capture: supervised by clinicians and unsupervised during activities of daily life (ADLs). The continuous monitoring of patients produces large amounts of data that are analyzed in specific IoMT platforms that must be connected to the health system platforms containing the health records of the patients. The aim of this study is to evaluate the factors that impact the cost of the deployment of such an IoMT solution. We use population data from Catalonia together with an IoMT deployment model for costs from the current deployment of connected devices for monitoring diabetic patients. Our study reveals the critical dependencies of the proposed IoMT platforms: from the devices and cloud cost, the size of the population using these services and the savings from the current model under key parameters such as fall reduction or rehabilitation duration. Future research should investigate the benefit of continuous monitoring in improving the quality of life of patients.
Autophagy in Osteoarthritis: A Double-Edged Sword in Cartilage Aging and Mechanical Stress Response: A Systematic Review
Authors: Lee Dong-Yeong , Bahar Md Entaz , Kim Chang-Won , Seo Min-Seok , Song Myung-Geun , Song Sang-Youn , Kim Soung-Yon , Kim Deok-Ryong , Kim Dong-Hee
Published: May 2024

Background: Although osteoarthritis (OA) development is epidemiologically multifactorial, a primary underlying mechanism is still under debate. Understanding the pathophysiology of OA remains challenging. Recently, experts have focused on autophagy as a contributor to OA development. Method: To better understand the pathogenesis of OA, we survey the literature on the role of autophagy and the molecular mechanisms of OA development. To identify relevant studies, we used controlled vocabulary and free text keywords to search the MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, Web of Science, and SCOPUS database. Thirty-one studies were included for data extraction and systematic review. Among these studies, twenty-five studies investigated the effects of autophagy in aging and OA chondrocytes, six studies examined the effects of autophagy in normal human chondrocytes, and only one study investigated the effects of mechanical stress-induced autophagy on the development of OA in normal chondrocytes. Results: The studies suggest that autophagy activation prevents OA by exerting cell-protective effects in normal human chondrocytes. However, in aging and osteoarthritis (OA) chondrocytes, the role of autophagy is intricate, as certain studies indicate that stimulating autophagy in these cells can have a cytotoxic effect, while others propose that it may have a protective (cytoprotective) effect against damage or degeneration. Conclusions: Mechanical stress-induced autophagy is also thought to be involved in the development of OA, but further research is required to identify the precise mechanism. Thus, autophagy contributions should be interpreted with caution in aging and the types of OA cartilage.
Ability-Related Emotional Intelligence: An Introduction
Authors: Robinson Michael D.
Published: May 2024

Emotionally intelligent people are thought to be more skilled in recognizing, thinking about, using, and regulating emotions. This construct has garnered considerable interest, but initial enthusiasm has faded and it is time to take stock. There is consensus that ability-related measures of emotional intelligence (EI) can be favored to self-report tests, in part because the resulting scores cannot be equated with personality traits. However, there are questions surrounding measurement as well as predictive value. Experts in the field were encouraged to chart new directions, with the idea that these new directions could reinvigorate EI scholarship. Special Issue papers speak to theory, mechanism, measurement, and training. In addition, these papers seek to forge links with research traditions focused on interpersonal perception, emotional awareness, and emotion regulation. As a result of these efforts, new insights into what EI is and how it works can be anticipated in upcoming years.
A Mini-Review of In Vitro Data for Candida Species, Including C. auris, Isolated during Clinical Trials of Three New Antifungals: Fosmanogepix, Ibrexafungerp, and Rezafungin
Authors: Espinel-Ingroff Ana , Wiederhold Nathan P.
Published: May 2024

This mini-review summarizes the clinical outcomes and antifungal susceptibility results, where available, for three new antifungals, including fosmanogepix, ibrexafungerp, and rezafungin, against Candida isolates cultured from patients in clinical trials. When reported, most of the data were generated by the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method or by both the CLSI and European Committee on Antimicrobial Susceptibility Testing (EUCAST) methodologies. For fosmanogepix, we summarize the in vitro data for C. auris isolates from 9 patients and for Candida spp. cultured from 20 patients in two clinical trials. Ibrexafungerp has also been evaluated in several clinical trials. From conference proceedings, a total of 176 Candida isolates were evaluated in the FURI and CARES studies, including 18 C. auris isolates (CARES study). However, MIC data are not available for all clinical isolates. Results from the ReSTORE rezafungin phase 3 clinical study also included in vitro results against Candida spp., but no patients with C. auris infections were included. In conclusion, this mini-review summarizes insights regarding clinical outcomes and the in vitro activity of three new antifungals against Candida spp. cultured from patients in clinical trials.
Coniocybe Ach. Revisited
Authors: Temu Stella G. , Tibell Sanja , Tibuhwa Donatha D. , Tibell Leif
Published: May 2024

Calicioids form a research field that has encompassed ascomycetous fungi with stalked ascomata similar to those of the lichen genus Calicium. Early generic circumscriptions of calicioid lichens and fungi were mainly based on morphological and secondary chemistry information. After the introduction of molecular data, taxonomy in the group has been reconsidered. Here, based on a broad geographical sampling, Coniocybe Ach. was revised using molecular and morphological features. Three loci (ITS, LSU and rpb1) were compared to infer its phylogenetic position, and a total of 52 new sequences (14 ITS, 24 LSU and 14 rpb1) were produced. Apart from its type C. furfuracea, Coniocybe was revised and emended to also include C. brachypoda and C. confusa. In addition, a new species, Coniocybe eufuracea, was described, and a key to the species of Coniocybe was provided.
Ellipsoid Zone Integrity and Visual Function in Dry Age-Related Macular Degeneration
Authors: Yordi Sari , Cakir Yavuz , Kalra Gagan , Cetin Hasan , Hu Ming , Abraham Joseph , Reese Jamie , Srivastava Sunil K. , Ehlers Justis P.
Published: May 2024

In this longitudinal retrospective image analysis, conducted on patients diagnosed with dry age-related macular degeneration (AMD) and 5 years of follow-up imaging data, the study aimed to investigate the relationship between ellipsoid zone (EZ) integrity on spectral domain optical coherence tomography (SD-OCT) and visual acuity (VA). Using a machine learning-enabled feature extraction tool, quantitative EZ parameters were derived from SD-OCT images. The analysis revealed significant correlations between EZ integrity metrics and VA. Eyes with excellent VA (≥20/25 Snellen) exhibited higher EZ integrity, including less EZ attenuation, thicker ellipsoid zone-retinal pigment epithelium (EZ-RPE) thickness, and higher EZ intensity, in contrast to eyes with worse VA (≤20/40 Snellen). Additionally, eyes with geographic atrophy (GA) in the foveal region displayed compromised EZ integrity compared to those without GA. Notably, baseline EZ integrity metrics were predictive of future VA loss. These findings suggest that quantitative SD-OCT measurements of EZ integrity could potentially detect early changes in dry AMD and serve as valuable indicators for predicting future functional outcomes. Furthermore, these measurements hold promise for use in clinical trial screenings, offering insights into the progression of the disease and its impact on visual acuity. This study underscores the importance of EZ integrity assessment in understanding and managing dry AMD.
Risk Characterization of Firms with ESG Attributes Using a Supervised Machine Learning Method
Authors: Simlai Prodosh Eugene
Published: May 2024

We examine the risk–return tradeoff of a portfolio of firms that have tangible environmental, social, and governance (ESG) attributes. We introduce a new type of penalized regression using the Mahalanobis distance-based method and show its usefulness using our sample of ESG firms. Our results show that ESG companies are exposed to financial state variables that capture the changes in investment opportunities. However, we find that there is no economically significant difference between the risk-adjusted returns of various ESG-rating-based portfolios and that the risk associated with a poor ESG rating portfolio is not significantly different than that of a good ESG rating portfolio. Although investors require return compensation for holding ESG stocks, the fact that the risk of a poor ESG rating portfolio is comparable to that of a good ESG rating portfolio suggests risk dimensions that go beyond ESG attributes. We further show that the new covariance-adjusted penalized regression improves the out-of-sample cross-sectional predictions of the ESG portfolio’s expected returns. Overall, our approach is pragmatic and based on the ease of an empirical appeal.
The Collective Domains in the Ecological Transition: A Preliminary Analysis in an Inner Area in the Campania Region, Italy
Authors: Forte Fabiana , Cupo Paolo
Published: May 2024

The growing attention to the sustainable management of territories leads to a reconsideration of common properties, those institutions which concern property rights belonging to all members of a well-defined community. Spread throughout the world in a variety of forms, they can play a crucial role in addressing the challenges posed by the ecological transition promoted by the European Green Deal. In Italy, common properties represent a historical phenomenon, specifically involving rural and mountain areas. Despite the fact that national law regarding collective domains fully recognizes their economic, social, and environmental functions, there is still much to be done in terms of their recognition. As the status of knowledge is lacking, especially in some areas of southern Italy, this article represents a preliminary analysis of the current consistency of collective domains. The introductory section places the topic in the broadest context of ecological transition, tracing its regulatory evolution. Next, collective domains are framed from an economic perspective, highlighting their multidimensional values and emerging assessment issues. The subsequent sections, based on the most recent available data, critically analyze the current supply of collective domains in Italy and in the Campania region. The in-depth analysis of an inner area, characterized by socio-economic marginality, represents the starting point from which it will be possible to identify the demand and to support policy makers and local communities in the valorization of common properties.
First-Principles Study of Discharge Products and Their Stability for Lithium-Nitrogen Batteries
Authors: Qu Guoxiong , Zhao Xudong , Wei Chengdong , Zhang Hongyi , Yang Yutong , Xue Hongtao , Tang Fuling
Published: May 2024

Li-N2 batteries present a relatively novel approach to N2 immobilization, and an advanced N2/Li3N cycling method is introduced in this study. The low operating overpotential of metal–air batteries is quite favorable to their stable cycling performance, providing a prospect for the development of a new type of battery with extreme voltage. The battery system of Li-N2 uses N2 as the positive electrode, lithium metal as the negative electrode, and a conductive medium containing soluble lithium salts as the electrolyte. In accordance with its voltage-distribution trend, a variety of lithium-nitrogen molecule intermediates are produced during the discharge process. There is a lack of theoretical description of material changes at the microscopic level during the discharge process. In this paper, the first-principles approach is used to simulate and analyze possible material changes during the discharge process of Li-N2 batteries. The discharge process is simulated on a 4N-graphene anode substrate model, and simulations of its electrostatic potential, Density of States (DOS), HOMO (Highest Occupied Molecular Orbital) and LUMO (Lowest Unoccupied Molecular Orbital) aspects confirm that the experimentally found Li3N becomes the final stabilized product of the Li-N2 battery. It can also be seen in the density of states that graphene with adsorption of 4N transforms from semiconducting to metallic properties. In addition, the differential charge also indicates that the Li-N2 material has a strong adsorption effect on the substrate, which can play the dual role of electricity storage and nitrogen fixation.
Study of the Long-Term High-Temperature Structural Stability of RuAl Electrodes for Microelectronic Devices
Authors: Seifert Marietta , Leszczynska Barbara , Gemming Thomas
Published: May 2024

The high-temperature stability of RuAl-based electrodes for application in microelectronic devices is analyzed for long-term duration. The electrodes are prepared on Ca3TaGa3Si2O14 (CTGS) substrates using SiO2 and Al-N-O cover and barrier layers as oxidation protection. The samples are annealed at 600, 700, or 800 °C in air for 192 h. Minor degradation is observed after thermal loading at 700 °C. The annealing at 800 °C for 192 h leads to a partial oxidation of the Al in the extended contact pad and to a complete oxidation of the Al within the structured interconnect electrodes. The different degradation of the interconnect electrodes and the contact pads is caused by their different lateral dimensions. In summary, long-term high-temperature stability is demonstrated up to at least 700 °C in air. Less oxidizing atmospheres should allow the application at higher temperatures and for a significantly longer duration.
Investigation of Fiber–Matrix Interface Strength via Single-Fiber Pull-Out Test in 3D-Printed Thermoset Composites: A Simplified Methodology
Authors: Nuhoglu Kaan , Baltodano Neyton M. , Celik Emrah
Published: May 2024

The emergence of additive manufacturing technologies for fiber-reinforced thermoset composites has greatly bolstered their utilization, particularly within the aerospace industry. However, the ability to precisely measure the interface strength between the fiber and thermoset matrix in additively manufactured composites has been constrained by the cumbersome nature of single-fiber pull-out experiments and the need for costly instrumentation. This study aims to introduce a novel methodology for conducting single-fiber pull-out tests aimed at quantifying interface shear strength in additively manufactured thermoset composites. Our findings substantiate the viability of this approach, showcasing successful fiber embedding within composite test specimens and precise characterization of fiber pull-out strength using a conventional mechanical testing system. The test outcome revealed an average interfacial strength value of 2.4 MPa between carbon fiber and the thermoset epoxy matrix, aligning with similar studies in the existing literature. The outcome of this study offers an affordable and versatile test methodology to revolutionize composite material fabrication for superior mechanical performance.
Effect of the Axial Profile of a Ceramic Grinding Wheel on Selected Roughness Parameters of Shaped Surfaces Obtained in the Grinding Process with a Dual-Tool Grinding Head
Authors: Jaskólski Piotr , Sutowska Marzena , Zawadka Wojciech , Malorny Winfried , Rokosz Krzysztof , Nadolny Krzysztof
Published: May 2024

The use of CNC equipment that integrates several machining operations eliminates downtime due to changes in setup and clamping of workpieces in more than one machining device. A review of CNC equipment and tools known from the literature and from manufacturers’ offerings indicates that new technical solutions are being developed to integrate two or more technological operations. However, these examples have numerous limitations and are mostly not suitable for machining surfaces with complex shapes. An example of such solutions is the use of a dual-tool grinding head, which integrates the process of rough grinding with a ceramic grinding wheel and finish grinding with a flexible grinding wheel. Unfortunately, it has the disadvantage of being limited by the angular shape of the ceramic grinding wheel, making it unable to adapt to the complex geometries of the shaped surfaces being ground. The need to overcome this limitation became the motivation for the research work described in this article. By means of experimental research, it was verified what effect the radial outline on the periphery of a ceramic grinding wheel realized by rough grinding would have on the surface roughness parameters obtained in the process of grinding shaped surfaces. For this purpose, grinding processes using a ceramic wheel with a conical and radial outline were compared. The result of the study was a summary of the surface roughness parameters Sa, St, Sq, Spk, Str, and Sds obtained after two-stage machining (rough and finish grinding). The obtained analysis results showed that changing the axial outline of the ceramic grinding wheel makes it possible to significantly expand the range of applications of the dual-tool head without negatively affecting the quality of the machined surface. Thus, such an improvement will make it possible to increase the applicability of the head by grinding shaped surfaces with a radial profile of curvature.
Reversible Multi-Mode Optical Modification in Inverse-Opal-Structured WO3: Yb3+, Er3+ Photonic Crystal
Authors: Zhu Bokun , Ruan Keliang , Tatiana Cherkasova , Cun Yangke
Published: May 2024

Reversible optical regulation has potential applications in optical anti-counterfeiting, storage, and catalysis. Compared to common power materials, the reverse opal structure has a larger specific surface area and an increased contact area for optical regulation, which is expected to achieve higher regulation rates. However, it is difficult to achieve reversible and repeatable regulation of the luminescent properties of photonic crystals, especially with the current research on the structural collapse of photonic crystals. In this work, WO3: Yb3+, Er3+ inverse photonic crystals were prepared by the template approach, and reversible multi-mode optical modification was investigated. Upon heat treatment in a reducing atmosphere or air, the color of the photonic crystals can reversibly change from light yellow to dark green, accompanied by changes in absorption and upconversion of luminescence intensity. The stability and fatigue resistance of this reversible optical modification ability were explored through cyclic experiments, providing potential practical applications for photocatalysis, optical information storage, and electrochromism.
Development of Low-Weight and High-Strength AA6005A Extrudates Intended for Modern Architecture and Design of Innovative Die for Extrusion Process
Authors: Madura Jacek , Puchlerska Sandra , Balcerzak Maciej , Noga Piotr , Bogusz Marek , Zasadziński Józef , Leśniak Dariusz , Żaba Krzysztof , Jurczak Henryk
Published: May 2024

In the realm of modern architecture, the demand for materials that combine strength, durability, and aesthetic flexibility is ever-growing. Addressing this need, this paper presents a study on the innovative use of aluminum extrudates in construction. Focusing on the AA6005 alloy, which is known for its excellent balance of strength, corrosion resistance, and weldability, this research delves into the development of an extrusion process that yields thin-walled, lightweight, yet high-strength structural components. Using FEM simulations, a new extrudate of the AA6005A was developed. It is compatible with standard façade systems, with high-strength properties and a weight reduced by 20% compared to that of conventional extrudates made of the AA6063 alloy. Using CAD engineering and FEM simulations of aluminum extrusion process, an innovative die was designed for the extrusion process, ensuring uniform flow of metal from the bearing and minimizing the elastic deflection of the die. This resulted in an increase in the extrusion velocity of thin-walled extrudate from AA6005A by 24% compared to conventional profiles extruded from AA6063. As part of the research, a trial test was carried out in production conditions and the quality of the extrudates was tested by 3D optical scanning, mechanical and structural properties tests, and microstructure observation.
Influence of Fibre Orientation on the Slotting Quality of CFRP Composites Using the Multi-Tooth Mill
Authors: Zhai Ying , Lv Shuwei , Yan Defeng , Wang Shuaishuai , Lin Junyi , Mao Chunyu , Xu Qihao , Liu Jiyu
Published: May 2024

Carbon fibre-reinforced plastic (CFRP) composites, prized for their exceptional properties, often encounter surface quality issues during slotting due to their inherent heterogeneity. This paper tackles CFRP slotting challenges by employing multi-tooth mills in experiments with various fibre orientations and tool feed rates. In-plane scratching tests are performed under linearly varying loads; then, slotting experiments are conducted at different parameters. The scratching test results indicate that the fibre orientation and cutting angles have significant influences on forces and fracture process. The slotting experiments demonstrate that cutting forces and surface roughness Sa of the bottom slotting surface are notably affected by the fibre orientation, with disparities between up-milling and down-milling sides. Reorganising Sa data by local fibre cutting angle θ highlights consistent Sa variations between up-milling and down-milling sides for 0° ≤ θ ≤ 90°, with lower Sa on the up-milling side. However, for 90° < θ ≤ 150°, Sa variations diverge, with lower Sa on the down-milling side. Unexpectedly, Sa on the down-milling side decreases with increasing θ in this range. Additionally, the tool feed rate exerts a more pronounced influence on Sa on the up-milling side.
On the Determination of Elastic Properties of Single-Walled Nitride Nanotubes Using Numerical Simulation
Authors: Sakharova Nataliya A. , Pereira André F. G. , Antunes Jorge M. , Chaparro Bruno M. , Parreira Tomás G. , Fernandes José V.
Published: May 2024

In recent years, tubular nanostructures have been related to immense advances in various fields of science and technology. Considerable research efforts have been centred on the theoretical prediction and manufacturing of non-carbon nanotubes (NTs), which meet modern requirements for the development of novel devices and systems. In this context, diatomic inorganic nanotubes formed by atoms of elements from the 13th group of the periodic table (B, Al, Ga, In, Tl) and nitrogen (N) have received much research attention. In this study, the elastic properties of single-walled boron nitride, aluminium nitride, gallium nitride, indium nitride, and thallium nitride nanotubes were assessed numerically using the nanoscale continuum modelling approach (also called molecular structural mechanics). The elastic properties (rigidities, surface Young’s and shear moduli, and Poisson’s ratio) of nitride nanotubes are discussed with respect to the bond length of the corresponding diatomic hexagonal lattice. The results obtained contribute to a better understanding of the mechanical response of nitride compound-based nanotubes, covering a broad range, from the well-studied boron nitride NTs to the hypothetical thallium nitride NTs.
Characteristics of Si (C,N) Silicon Carbonitride Layers on the Surface of Ni–Cr Alloys Used in Dental Prosthetics
Authors: Klimek Leszek , Makówka Marcin , Sobczyk-Guzenda Anna , Kula Zofia
Published: May 2024

Chromium- and cobalt-based alloys, as well as chrome–nickel steels, are most used in dental prosthetics. Unfortunately, these alloys, especially nickel-based alloys, can cause allergic reactions. A disadvantage of these alloys is also insufficient corrosion resistance. To improve the properties of these alloys, amorphous Si (C,N) coatings were deposited on the surfaces of metal specimens. This paper characterizes coatings of silicon carbide nitrides, deposited by the magnetron sputtering method on the surface of nickel–chromium alloys used in dental prosthetics. Depending on the deposition parameters, coatings with varying carbon to nitrogen ratios were obtained. The study analyzed their structure and chemical and phase composition. In addition, a study of surface wettability and surface roughness was performed. Based on the results obtained, it was found that amorphous coatings of Si (C,N) type with thicknesses of 2 to 4.5 µm were obtained. All obtained coatings increase the value of surface free energy. The study showed that Si (C,N)-type films can be used in dental prosthetics as protective coatings.
Experimental Study on the Microfabrication and Mechanical Properties of Freeze–Thaw Fractured Sandstone under Cyclic Loading and Unloading Effects
Authors: Liu Taoying , Cai Wenbin , Sheng Yeshan , Huang Jun
Published: May 2024

A series of freeze–thaw cycling tests, as well as cyclic loading and unloading tests, have been conducted on nodular sandstones to investigate the effect of fatigue loading and freeze–thaw cycling on the damage evolution of fractured sandstones based on damage mechanics theory, the microstructure and sandstone pore fractal theory. The results show that the number of freeze–thaw cycles, the cyclic loading level, the pore distribution and the complex program are important factors affecting the damage evolution of rocks. As the number of freeze–thaw cycles rises, the peak strength, modulus of elasticity, modulus of deformation and damping ratio of the sandstone all declined. Additionally, the modulus of elasticity and deformation increase nonlinearly as the cyclic load level rises. With the rate of increase decreasing, while the dissipation energy due to hysteresis increases gradually and at an increasing rate, and the damping ratio as a whole shows a gradual decrease, with a tendency to increase at a later stage. The NRM (Nuclear Magnetic Resonance) demonstrated that the total porosity and micro-pores of the sandstone increased linearly with the number of freeze–thaw cycles and that the micro-porosity was more sensitive to freeze–thaw, gradually shifting towards meso-pores and macro-pores; simultaneously, the SEM (Scanning Electron Microscope) indicated that the more freeze–thaw cycles there are, the more micro-fractures and holes grow and penetrate each other and the more loose the structure is, with an overall nest-like appearance. To explore the mechanical behavior and mechanism of cracked rock in high-altitude and alpine areas, a damage model under the coupling of freeze–thaw-fatigue loading was established based on the loading and unloading response ratio theory and strain equivalence principle.
Effects of a Complex Environment on Fatigue and Self-Healing Characterization of Asphalt Composites Containing Rock Asphalt
Authors: Li Ruixia , Yu Shangjun , Chen Hailong , Wu Jiahui , Chen Yijun , Yue Jinchao
Published: May 2024

In recent years, asphalt pavement has been subjected to varied environmental conditions during its service life, conditions that predispose it to deformation and cracking. To enhance the performance of asphalt pavement, rock asphalt has been selected as a modifier due to its good compatibility with virgin asphalt binder and its ability to improve the fatigue cracking resistance of asphalt mixtures. Although scholars have conducted some studies on rock asphalt mixtures, research on the fatigue and self-healing performance of these mixtures under conditions such as ultraviolet (UV) aging and freeze–thaw remains limited. This paper presents findings from a study that employs a combined fatigue-healing test to assess the impact of such complex environmental factors on the fatigue and self-healing properties of fine aggregate matrix (FAM) mixtures containing three types of rock asphalts, i.e., Buton, Qingchuan (QC), and Uintaite Modifier (UM). The analysis of fatigue-healing test results, grounded in viscoelastic continuum damage (VECD) theory, indicates that rock asphalt can extend the fatigue life of FAM mixtures, albeit with a concomitant decrease in their self-healing capabilities. The study further reveals that UV aging, freeze–thaw, and UV aging–freeze–thaw conditions all led to a diminution in the fatigue and self-healing properties of FAM mixtures. However, FAM mixtures containing rock asphalt demonstrated greater resilience against these reductions. Atomic force microscope (AFM) results indicate that UV aging reduced the number of bee-structures and enlarged their area, whereas the incorporation of rock asphalt enhanced the uniformity of these structures’ distribution, thereby improving the fatigue cracking resistance of FAM mixtures. Fourier transform infrared spectroscopy (FTIR) analysis reveals that while UV aging increased the carbonyl and sulfoxide indices within the asphalt binder, rock asphalt is effective in mitigating this effect to a certain degree, thereby enhancing the aging resistance of FAM mixtures.
The Microstructure and Mechanical Properties of Si3N4f/BN/SiBCN Microcomposites Fabricated by the PIP Process
Authors: Gong Zhiyou , Xu Zhongkai , Zhang Jian , Guo Ruisong , Han Yao , Sun Xiaohong , Yuan Zhuang , Zhao Xinqi , Zhang Bingqing , Zheng Chunming
Published: May 2024

SiBCN ceramics based on SiC, BN and Si3N4 structures have good comprehensive properties such as high-temperature resistance, oxidation resistance, creep resistance and long life, which makes it one of the very promising ceramic material systems in military and aerospace fields, etc. In this study, SiBCN ceramics, as well as Si3N4f/BN/SiBCN microcomposites, were prepared by a polymer infiltration pyrolysis method using PBSZ as the polymer precursor. The PBSZ was completely ceramized by pyrolysis at 900 °C. The weight loss and elemental bonding forms of the products after the pyrolysis of the precursors hardly changed from 600 °C to 900 °C. After pyrolysis at 600 °C for 4 h and using the BN coating obtained from twice deposition as the interfacial phase, a more desirable weak interface of fiber/matrix with a binding strength of 21.96 ± 2.01 MPa can be obtained. Si3N4f/BN/SiBCN ceramic matrix microcomposites prepared under the same pyrolysis conditions have a relatively good tensile strength of 111.10 MPa while retaining a weak interface between the fibers and the matrix. The results of the study provide more theoretical and methodological support for the application of new composite structural ceramic material systems.