bluuebunny/crossref_metadata_2025 huggingface dataset:
Kick-Starting Wound Healing: A Review of Pro-Healing Drugs
Authors: Patenall Bethany L. , Carter Kristyn A. , Ramsey Matthew R.
Published: January 2024

Cutaneous wound healing consists of four stages: hemostasis, inflammation, proliferation/repair, and remodeling. While healthy wounds normally heal in four to six weeks, a variety of underlying medical conditions can impair the progression through the stages of wound healing, resulting in the development of chronic, non-healing wounds. Great progress has been made in developing wound dressings and improving surgical techniques, yet challenges remain in finding effective therapeutics that directly promote healing. This review examines the current understanding of the pro-healing effects of targeted pharmaceuticals, re-purposed drugs, natural products, and cell-based therapies on the various cell types present in normal and chronic wounds. Overall, despite several promising studies, there remains only one therapeutic approved by the United States Food and Drug Administration (FDA), Becaplermin, shown to significantly improve wound closure in the clinic. This highlights the need for new approaches aimed at understanding and targeting the underlying mechanisms impeding wound closure and moving the field from the management of chronic wounds towards resolving wounds.
Proteome Analysis of Serum Purified Using Solanum tuberosum and Lycopersicon esculentum Lectins
Authors: Nakajima Daisuke , Konno Ryo , Miyashita Yasuomi , Ishikawa Masaki , Ohara Osamu , Kawashima Yusuke
Published: January 2024

Serum and plasma exhibit a broad dynamic range of protein concentrations, posing challenges for proteome analysis. Various technologies have been developed to reduce this complexity, including high-abundance depletion methods utilizing antibody columns, extracellular vesicle enrichment techniques, and trace protein enrichment using nanobead cocktails. Here, we employed lectins to address this, thereby extending the scope of biomarker discovery in serum or plasma using a novel approach. We enriched serum proteins using 37 different lectins and subjected them to LC–MS/MS analysis with data-independent acquisition. Solanum tuberosum lectin (STL) and Lycopersicon esculentum lectin (LEL) enabled the detection of more serum proteins than the other lectins. STL and LEL bind to N-acetylglucosamine oligomers, emphasizing the significance of capturing these oligomer-binding proteins when analyzing serum trace proteins. Combining STL and LEL proved more effective than using them separately, allowing us to identify over 3000 proteins from serum through single-shot proteome analysis. We applied the STL/LEL trace-protein enrichment method to the sera of systemic lupus erythematosus model mice. This revealed differences in >1300 proteins between the systemic lupus erythematosus model and control mouse sera, underscoring the utility of this method for biomarker discovery.
A Review of Natural Polysaccharides: Sources, Characteristics, Properties, Food, and Pharmaceutical Applications
Authors: Benalaya Ikbel , Alves Gilberto , Lopes João , Silva Luís R.
Published: January 2024

Natural polysaccharides, which are described in this study, are some of the most extensively used biopolymers in food, pharmaceutical, and medical applications, because they are renewable and have a high level of biocompatibility and biodegradability. The fundamental understanding required to properly exploit polysaccharides potential in the biocomposite, nanoconjugate, and pharmaceutical industries depends on detailed research of these molecules. Polysaccharides are preferred over other polymers because of their biocompatibility, bioactivity, homogeneity, and bioadhesive properties. Natural polysaccharides have also been discovered to have excellent rheological and biomucoadhesive properties, which may be used to design and create a variety of useful and cost-effective drug delivery systems. Polysaccharide-based composites derived from natural sources have been widely exploited due to their multifunctional properties, particularly in drug delivery systems and biomedical applications. These materials have achieved global attention and are in great demand because to their biochemical properties, which mimic both human and animal cells. Although synthetic polymers account for a substantial amount of organic chemistry, natural polymers play a vital role in a range of industries, including biomedical, pharmaceutical, and construction. As a consequence, the current study will provide information on natural polymers, their biological uses, and food and pharmaceutical applications.
8-Oxoadenine: A «New» Player of the Oxidative Stress in Mammals?
Authors: Kruchinin Alexander A. , Kamzeeva Polina N. , Zharkov Dmitry O. , Aralov Andrey V. , Makarova Alena V.
Published: January 2024

Numerous studies have shown that oxidative modifications of guanine (7,8-dihydro-8-oxoguanine, 8-oxoG) can affect cellular functions. 7,8-Dihydro-8-oxoadenine (8-oxoA) is another abundant paradigmatic ambiguous nucleobase but findings reported on the mutagenicity of 8-oxoA in bacterial and eukaryotic cells are incomplete and contradictory. Although several genotoxic studies have demonstrated the mutagenic potential of 8-oxoA in eukaryotic cells, very little biochemical and bioinformatics data about the mechanism of 8-oxoA-induced mutagenesis are available. In this review, we discuss dual coding properties of 8-oxoA, summarize historical and recent genotoxicity and biochemical studies, and address the main protective cellular mechanisms of response to 8-oxoA. We also discuss the available structural data for 8-oxoA bypass by different DNA polymerases as well as the mechanisms of 8-oxoA recognition by DNA repair enzymes.
The Effect of S-Allyl L-Cysteine on Retinal Ischemia: The Contributions of MCP-1 and PKM2 in the Underlying Medicinal Properties
Authors: Chao Windsor Wen-Jin , Chao Howard Wen-Haur , Lee Hung-Fu , Chao Hsiao-Ming
Published: January 2024

Retinal ischemia plays a vital role in vision-threatening retinal ischemic disorders, such as diabetic retinopathy, age-related macular degeneration, glaucoma, etc. The aim of this study was to investigate the effects of S-allyl L-cysteine (SAC) and its associated therapeutic mechanism. Oxidative stress was induced by administration of 500 μM H2O2 for 24 h; SAC demonstrated a dose-dependent neuroprotective effect with significant cell viability effects at 100 μM, and it concurrently downregulated angiogenesis factor PKM2 and inflammatory biomarker MCP-1. In a Wistar rat model of high intraocular pressure (HIOP)-induced retinal ischemia and reperfusion (I/R), post-administration of 100 μM SAC counteracted the ischemic-associated reduction of ERG b-wave amplitude and fluorogold-labeled RGC reduction. This study supports that SAC could protect against retinal ischemia through its anti-oxidative, anti-angiogenic, anti-inflammatory, and neuroprotective properties.
Initial Molecular Mechanisms of the Pathogenesis of Parkinson’s Disease in a Mouse Neurotoxic Model of the Earliest Preclinical Stage of This Disease
Authors: Kolacheva Anna , Pavlova Ekaterina , Bannikova Alyona , Bogdanov Vsevolod , Ugrumov Michael
Published: January 2024

Studying the initial molecular mechanisms of the pathogenesis of Parkinson’s disease (PD), primarily in the nigrostriatal dopaminergic system, is one of the priorities in neurology. Of particular interest is elucidating these mechanisms in the preclinical stage of PD, which lasts decades before diagnosis and is therefore not available for study in patients. Therefore, our main goal was to study the initial molecular mechanisms of the pathogenesis of PD in the striatum, the key center for dopamine regulation in motor function, in a mouse model of the earliest preclinical stage of PD, from 1 to 24 h after the administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). It was shown that the content of tyrosine hydroxylase (TH), the first enzyme in dopamine synthesis, does not change within 6 h after the administration of MPTP, but decreases after 24 h. In turn, TH activity increases after 1 h, decreases after 3 h, remains at the control level after 6 h, and decreases 24 h after the administration of MPTP. The concentration of dopamine in the striatum gradually decreases after MPTP administration, despite a decrease in its degradation. The identified initial molecular mechanisms of PD pathogenesis are considered as potential targets for the development of preventive neuroprotective treatment.
Comprehensive Analysis of 1-Year-Old Female Apolipoprotein E-Deficient Mice Reveals Advanced Atherosclerosis with Vulnerable Plaque Characteristics
Authors: Kotsovilis Sotirios , Salagianni Maria , Varela Aimilia , Davos Constantinos H. , Galani Ioanna E. , Andreakos Evangelos
Published: January 2024

Apolipoprotein E-knockout (Apoe-/-) mice constitute the most widely employed animal model of atherosclerosis. Deletion of Apoe induces profound hypercholesterolemia and promotes the development of atherosclerosis. However, despite its widespread use, the Apoe-/- mouse model remains incompletely characterized, especially at late time points and advanced disease stages. Thus, it is unclear how late atherosclerotic plaques compare to earlier ones in terms of lipid deposition, calcification, macrophage accumulation, smooth muscle cell presence, or plaque necrosis. Additionally, it is unknown how cardiac function and hemodynamic parameters are affected at late disease stages. Here, we used a comprehensive analysis based on histology, fluorescence microscopy, and Doppler ultrasonography to show that in normal chow diet-fed Apoe-/- mice, atherosclerotic lesions at the level of the aortic valve evolve from a more cellular macrophage-rich phenotype at 26 weeks to an acellular, lipid-rich, and more necrotic phenotype at 52 weeks of age, also marked by enhanced lipid deposition and calcification. Coronary artery atherosclerotic lesions are sparse at 26 weeks but ubiquitous and extensive at 52 weeks; yet, left ventricular function was not significantly affected. These findings demonstrate that atherosclerosis in Apoe-/- mice is a highly dynamic process, with atherosclerotic plaques evolving over time. At late disease stages, histopathological characteristics of increased plaque vulnerability predominate in combination with frequent and extensive coronary artery lesions, which nevertheless may not necessarily result in impaired cardiac function.
Systemic Antibiotic Use in Acute Irreversible Pulpitis: Evaluating Clinical Practices and Molecular Insights
Authors: Khijmatgar Shahnawaz , Bellucci Gionata , Creminelli Luca , Tartaglia Giulia Margherita , Tumedei Margherita
Published: January 2024

This scoping review systematically evaluates the use of systemic antibiotics in treating acute irreversible pulpitis, integrating clinical practice patterns with recent molecular insights. We analyzed clinical evidence on antibiotic prescription trends among dental professionals and examined molecular research advancements in relation to pulpitis. This review is intended to bridge the gap between clinical practice and molecular research, guiding more evidence-based approaches to treating acute irreversible pulpitis. Electronic databases were searched for relevant articles published in English based on the objective of the review. A second search using all identified keywords and index terms was undertaken across all the included databases. In addition, a reference list of identified articles was searched. Studies including original research, systematic reviews, meta-analyses, clinical trials, and observational and retrospective studies, all written in English and published from 2010 onwards, were included, and an analysis of the text words contained in the titles and abstracts of the retrieved papers and of the index terms used to describe the articles was performed. A total of N = 53 articles were selected. Altogether, N = 43 (76.79%) articles were cross-sectional studies, N = 4 (11.11%) were systematic reviews, and N = 3 (5.36%) were guidelines. The most frequent level of evidence was level VI (N = 43 (76.79%). The mean percentage of dentists who prescribed antibiotics to treat acute irreversible pulpitis was 23.89 ± 23.74% (range: 0.05–75.7). Similarly, for specialists, it was 22.41 ± 15.64 (range 2.2–50.4), and the percentage for undergraduates was 17.52 ± 20.59 (range 0–62.6). The significant developments in research models for pulpitis research and the characterisation of biomarkers have led to better management strategies. Concurrently, significant advancements in molecular research provide new understandings of pulpitis, suggesting alternative therapeutic approaches. Although there are guidelines available, increased rates of antibiotic prescription are still prevalent around the globe.
Comparative Structure-Based Virtual Screening Utilizing Optimized AlphaFold Model Identifies Selective HDAC11 Inhibitor
Authors: Baselious Fady , Hilscher Sebastian , Robaa Dina , Barinka Cyril , Schutkowski Mike , Sippl Wolfgang
Published: January 2024

HDAC11 is a class IV histone deacylase with no crystal structure reported so far. The catalytic domain of HDAC11 shares low sequence identity with other HDAC isoforms, which makes conventional homology modeling less reliable. AlphaFold is a machine learning approach that can predict the 3D structure of proteins with high accuracy even in absence of similar structures. However, the fact that AlphaFold models are predicted in the absence of small molecules and ions/cofactors complicates their utilization for drug design. Previously, we optimized an HDAC11 AlphaFold model by adding the catalytic zinc ion and minimization in the presence of reported HDAC11 inhibitors. In the current study, we implement a comparative structure-based virtual screening approach utilizing the previously optimized HDAC11 AlphaFold model to identify novel and selective HDAC11 inhibitors. The stepwise virtual screening approach was successful in identifying a hit that was subsequently tested using an in vitro enzymatic assay. The hit compound showed an IC50 value of 3.5 µM for HDAC11 and could selectively inhibit HDAC11 over other HDAC subtypes at 10 µM concentration. In addition, we carried out molecular dynamics simulations to further confirm the binding hypothesis obtained by the docking study. These results reinforce the previously presented AlphaFold optimization approach and confirm the applicability of AlphaFold models in the search for novel inhibitors for drug discovery.
Molecular Advances in Microbial Metabolism 2.0
Authors: Martínez-Espinosa Rosa María
Published: January 2024

The advances in molecular biology techniques and omics approaches have made it possible to take giant steps in applied research in life sciences [...]
Software Platform for the Comprehensive Testing of Transmission Protocols Developed in GNU Radio
Authors: Stef Mihai Petru , Polgar Zsolt Alfred
Published: January 2024

With the constant growth of software-defined radio (SDR) technologies in fields related to wireless communications, the need for efficient ways of testing and evaluating the physical-layer (PHY) protocols developed for these technologies in real-life traffic scenarios has become more critical. This paper proposes a software testbed that enhances the creation of network environments that allow GNU radio applications to be fed with test traffic in a simple way and through an interoperable interface. This makes the use of any traffic generator possible—existing ones or one that is custom-built—to evaluate a GNU radio application. In addition, this paper proposes an efficient way to collect PHY-specific monitoring data to improve the performance of the critical components of the message delivery path by employing the protocol buffers library. This study considers the entire testing and evaluation ecosystem and demonstrates how PHY-specific monitoring information is collected, handled, stored, and processed as time series to allow complex visualization and real-time monitoring.
Benchmarking Automated Machine Learning (AutoML) Frameworks for Object Detection
Authors: Oliveira Samuel de , Topsakal Oguzhan , Toker Onur
Published: January 2024

Automated Machine Learning (AutoML) is a subdomain of machine learning that seeks to expand the usability of traditional machine learning methods to non-expert users by automating various tasks which normally require manual configuration. Prior benchmarking studies on AutoML systems—whose aim is to compare and evaluate their capabilities—have mostly focused on tabular or structured data. In this study, we evaluate AutoML systems on the task of object detection by curating three commonly used object detection datasets (Open Images V7, Microsoft COCO 2017, and Pascal VOC2012) in order to benchmark three different AutoML frameworks—namely, Google’s Vertex AI, NVIDIA’s TAO, and AutoGluon. We reduced the datasets to only include images with a single object instance in order to understand the effect of class imbalance, as well as dataset and object size. We used the metrics of the average precision (AP) and mean average precision (mAP). Solely in terms of accuracy, our results indicate AutoGluon as the best-performing framework, with a mAP of 0.8901, 0.8972, and 0.8644 for the Pascal VOC2012, COCO 2017, and Open Images V7 datasets, respectively. NVIDIA TAO achieved a mAP of 0.8254, 0.8165, and 0.7754 for those same datasets, while Google’s VertexAI scored 0.855, 0.793, and 0.761. We found the dataset size had an inverse relationship to mAP across all the frameworks, and there was no relationship between class size or imbalance and accuracy. Furthermore, we discuss each framework’s relative benefits and drawbacks from the standpoint of ease of use. This study also points out the issues found as we examined the labels of a subset of each dataset. Labeling errors in the datasets appear to have a substantial negative effect on accuracy that is not resolved by larger datasets. Overall, this study provides a platform for future development and research on this nascent field of machine learning.
Diversity, Distribution and Host Blood Meal Analysis of Adult Black Flies (Diptera: Simuliidae) from Thailand
Authors: Gomontean Bhuvadol , Jumpato Waraporn , Wongpakam Komgrit , Tangkawanit Ubon , Wannasingha Wannachai , Thanee Isara , Ya’cob Zubaidah , Pramual Pairot
Published: January 2024

Understanding the factors associated with the species diversity and distribution of insect vectors is critically important for disease epidemiology. Black flies (Diptera: Simuliidae) are significant hematophagous insects, as many species are pests and vectors that transmit pathogens to humans and other animals. Ecological factors associated with black fly species distribution have been extensively examined for the immature stages but are far less well explored for the adult stage. In this study, we collected a total of 7706 adult black fly specimens from various locations in forests, villages and animal shelters in Thailand. The integration of morphology and DNA barcoding revealed 16 black fly taxa, including Simulium yvonneae, a species first found in Vietnam, which is a new record for Thailand. The most abundant species was the Simulium asakoae complex (n = 5739, 74%), followed by S. chumpornense Takaoka and Kuvangkadilok (n = 1232, 16%). The Simulium asakoae complex was dominant in forest (3786 of 4456; 85%) and village (1774 of 2077; 85%) habitats, while S. chumpornense predominated (857 of 1175; 73%) in animal shelter areas. The Simulium asakoae complex and S. nigrogilvum Summers, which are significant pests and vectors in Thailand, occurred at a wide range of elevations, although the latter species was found mainly in high (>1000 m) mountain areas. Simulium chumpornense, S. nodosum Puri and the S. siamense Takaoka and Suzuki complex occurred predominately in low (<800 m)-elevation areas. Simulium furvum Takaoka and Srisuka; S. phurueaense Tangkawanit, Wongpakam and Pramual; and S. nr. phurueaense were only found in high (>1000 m) mountain areas. A host blood meal analysis revealed that the S. asakoae; S. chamlongi Takaoka and Suzuki; S. nigrogilvum; S. chumpornense; and the S. striatum species group were biting humans. This is the first report of the latter two species biting humans. We also found that S. chumpornense was biting turkeys, and S. chamlongi was biting chickens, which are new host blood sources recorded for these species. In addition, we found that the S. feuerborni Edwards complex was biting water buffalo, which is the first report on the biting habits of this species.
Deceptive Seduction by Femme Fatale Fireflies and Its Avoidance by Males of a Synchronous Firefly Species (Coleoptera: Lampyridae)
Authors: Maquitico Yara , Coronado Jazmín , Luna Andrea , Vergara Aldair , Cordero Carlos
Published: January 2024

Photuris female fireflies attract males of different firefly species by responding to their flashing signals; then, they try to capture and feed on them. This aggressive mimicry is considered a major selective pressure on the communication systems of the fireflies of the American continent. The intensity of this selective pressure is a function of its efficiency in prey capture. In this study, the rates of attraction and capture of males of the synchronous firefly Photinus palaciosi by the predatory females of Photuris lugubris are reported. Although the females attract numerous males, their hunting success is low. This result is consistent with the few previous measurements published. In agreement with the predicted coevolutionary race between predator and prey, behaviors consistent with predation avoidance in P. palaciosi and increasing prey encounters and prey deception by P. lugubris were observed.
Integrated Identification and Genetic Diversity of Potentially Invasive Clearwing Moths (Lepidoptera: Cossoidea: Sesiidae) in Korea
Authors: Kim Sora , Jung Jong-Kook , Park Ikju , Lee Bong-Woo , Kim Yong-Hun
Published: January 2024

The populations of clearwing moth borers in Korea have recently caused extensive and severe damage to pin oaks (Quercus palustris Munchh.). We conducted field monitoring and molecular analyses to identify them in an integrated manner. Morphological examination and molecular analyses of the COI gene, based on intra- and interspecific genetic divergences (GDs), revealed that the borers were identified as two invasive species, Sphecodoptera sheni and Paranthrenella pinoakula sp. nov. The maximum intraspecific GD was found to be 1.9%, whereas the minimum interspecific GD was confirmed as 8.1%, indicating a distinct barcoding gap. Both the MJ network and NJ tree also showed that 18 haplotypes (Hs) were detected from the 52 COI sequences. The borers revealed a total of 17 Hs: (i) H1–H7 were detected in all seven regions with S. sheni; (ii) Wonju and Goyang populations of S. sheni revealed more than three Hs; (iii) H7 was closely connected with H8 of the Chinese population of S. sheni; (iv) H9–H10 were detected in other samples from the Wonju population with P. pinoakula sp. n. and were closely located with congeneric species. A maximum likelihood tree also revealed that P. pinoacula sp. n. nested within the congeneric species, genetically separating from S. sheni.
Universal Bond Models of FRP Reinforcements Externally Bonded and Near-Surface Mounted to RC Elements in Bending
Authors: Slaitas Justas
Published: January 2024

The use of fibre-reinforced polymer materials (FRPs) for the retrofitting of reinforced concrete (RC) structures has become very popular. However, the main concern for the exploitation of FRPs is their premature debonding failure modes. This paper presents two different universal models for calculating flexed RC elements strengthened with externally bonded and near-surface mounted FRP reinforcements, which were derived by coupling principles of the fracture mechanics of solids and generally accepted assumptions. The first model allows a complete analysis of the behaviour, development, and propagation of rupture of the joint. The main advantages of the proposed model, compared to existing ones, are that it does not require additional bond shear tests to identify missing factors, and it is versatile and suitable for both externally bonded reinforcements (EBR) and near surface mounted (NSM) strengthening techniques. In addition, the concrete–FRP connection is divided into zones and the current phase and length of each zone are determined, allowing for more detailed analysis of the connection at different load stages. The proposed computational model and its derivation focus on the performance of the joint between the two cracks and the distribution of the shear stresses in that joint. The second one requires fewer computations and can be fully exploited when the joint is treated as a unit, without division. The results of the calculations have been validated using the experimental database of 77 RC beams and strengthened with externally bonded and near-surface mounted carbon fibre reinforced polymer (CFRP) and glass fibre reinforced polymer (GFRP) sheets, plates, strips, and bars taken from 13 different studies. Both the prestress force and the initial stress state before strengthening were evaluated.
Applications of Thermochemical Modeling in Molten Salt Reactors
Authors: Besmann Theodore M. , Schorne-Pinto Juliano , Aziziha Mina , Mofrad Amir M. , Booth Ronald E. , Yingling Jacob A. , Paz Soldan Palma Jorge , Dixon Clara M. , Wilson Jack A. , Hartanto Donny
Published: January 2024

The extensively evaluated and consistent thermodynamic database, the Molten Salt Thermal Properties Database—Thermochemical (MSTDB-TC), was used along with additional thermodynamic values from other sources as examples of ways to examine molten salt reactor (MSR) fuel behavior. Relative stability with respect to halide potential and temperature for likely fuel and fission product components were mapped in Ellingham diagrams for the chloride and fluoride systems. The Ellingham diagrams provide a rich, visual means for identifying halide-forming components in proposed fuel/solvent salt systems. Thermochemical models and values from MSTDB-TC and ancillary sources were used in global equilibrium calculations to provide compositions for a close analysis of the behavior of a possible Molten Chloride Salt Fast Reactor and a Molten Salt Reactor Experiment-type system at high burnup (100 GWd/t). The results illustrated the oxidative nature of burnup in MSRs and provided information about redox behavior and possible control.
The Dependence on Hue, Value and Opacity of Real-Time- and Post-Curing Light Transmission in a Nano-Hybrid Ormocer
Authors: Ilie Nicoleta
Published: January 2024

This study aims to quantify the influence of hue, value and opacity on the variation in light transmittance of a full color palette of an ormocer-based dental composite. Samples with a thickness of 2 mm were cured in real time while the incident irradiance and light transmittance were recorded with a spectrophotometer, either in real time during the polymerization or through the polymerized composite at different exposure distances. Across the entire shade range, light attenuation was high, varying between 70.3% and 92.1%. The light transmittance during polymerization increased exponentially with exposure time in all shades. The differences between the cured and uncured composites decrease with increasing value and with increasing opacity within a value. The pattern of variation in light transmittance with increasing value is non-linear and depends on the hue, but not on the opacity within a hue. Small variations in value in lighter shades of hue B reduce the transmitted light more than in hue A, while the opposite is true for darker shades. The results strongly suggest an adequate curing of the lower increments in larger restorations, as the additional light expected from curing the upper increments is very small, regardless of hue, value or opacity. An additional unfavorable condition by increasing the exposure distance consistently contributes to a reduction in light transmission and thus further supports the above statement.
Confined Layer Slip Process in Nanolaminated Ag and Two Ag/Cu Nanolaminates
Authors: Fani Mahshad , Jian Wu-Rong , Su Yanqing , Xu Shuozhi
Published: January 2024

The exceptional strength of nanolaminates is attributed to the influence of their fine stratification on the movement of dislocations. Through atomistic simulations, the impact of interfacial structure on the dynamics of an edge dislocation, which is compelled to move within a nanoscale layer of a nanolaminate, is examined for three different nanolaminates. In this study, we model confined layer slip in three structures: nanolaminated Ag and two types of Ag/Cu nanolaminates. We find that the glide motion is jerky in the presence of incoherent interfaces characterized by distinct arrays of misfit dislocations. In addition, the glide planes exhibit varying levels of resistance to dislocation motion, where planes with intersection lines that coincide with misfit dislocation lines experience greater resistance than planes without such intersection lines.
Specific Heat Capacity of Solar Salt-Based Nanofluids: Molecular Dynamics Simulation and Experiment
Authors: Abir Fahim Mahtab , Shin Donghyun
Published: January 2024

In this study, a nanofluid composed of molten solar salt (MSS) and 1.0% SiO2 nanoparticles by mass was created and analyzed using differential scanning calorimetry (DSC) to determine its specific heat capacity (SHC). The SHC of the nanofluid was found to be significantly higher than that of pure MSS. The average increase in SHC of the nanofluid with 1.0% SiO2 nanoparticles (NPs) loading was found to be 15.65% compared with pure MSS. The formation of nanostructures after doping with NPs may increase the SHC of molten salt (MS) nanofluids, according to certain published research that included experimental confirmation. Nevertheless, no thorough theoretical or computational studies have been conducted to verify the experimental findings related to MSS nanofluid. Molecular dynamics (MD) simulations were conducted in various simulation boxes for different cases to verify the experimental findings and investigate the mechanism behind the enhancement of SHC caused by the addition of SiO2 NPs in eutectic MSS. The simulations used pure MSS and mixtures containing NaNO3 nanostructures bonded with SiO2 NPs. The highest SHC increase of 25.03% was observed when the simulation box contained 13.71% NaNO3 nanostructures by weight. The incorporation of NaNO3 nanostructures increased the surface area and total surface energy, leading to a positive effect on the SHC of the MSS nanofluid. However, the decrease in the base molten salt’s SHC had a slight negative impact on the overall SHC of the MS nanofluid.
Study on Magnetic and Plasmonic Properties of Fe3O4-PEI-Au and Fe3O4-PEI-Ag Nanoparticles
Authors: Ning Shuya , Wang Shuo , Liu Zhihui , Zhang Naming , Yang Bin , Zhang Fanghui
Published: January 2024

Magnetic–plasmonic nanoparticles (NPs) have attracted great interest in many fields because they can exhibit more physical and chemical properties than individual magnetic or plasmonic NPs. In this work, we synthesized Au- or Ag-decorated Fe3O4 nanoparticles coated with PEI (Fe3O4-PEI-M (M = Au or Ag) NPs) using a simple method. The influences of the plasmonic metal NPs’ (Au or Ag) coating density on the magnetic and plasmonic properties of the Fe3O4-PEI-M (M = Au or Ag) NPs were investigated, and the density of the plasmonic metal NPs coated on the Fe3O4 NPs surfaces could be adjusted by controlling the polyethyleneimine (PEI) concentration. It showed that the Fe3O4-PEI-M (M = Au or Ag) NPs exhibited both magnetic and plasmonic properties. When the PEI concentration increased from 5 to 35 mg/mL, the coating density of the Au or Ag NPs on the Fe3O4 NPs surfaces increased, the corresponding magnetic intensity became weaker, and the plasmonic intensity was stronger. At the same time, the plasmonic resonance peak of the Fe3O4-PEI-M (M = Au or Ag) NPs was red shifted. Therefore, there was an optimal coverage of the plasmonic metal NPs on the Fe3O4 NPs surfaces to balance the magnetic and plasmonic properties when the PEI concentration was between 15 and 25 mg/mL. This result can guide the application of the Fe3O4-M (M = Au or Ag) NPs in the biomedical field.
Deep-Learning-Based Segmentation of Keyhole in In-Situ X-ray Imaging of Laser Powder Bed Fusion
Authors: Dong William , Lian Jason , Yan Chengpo , Zhong Yiran , Karnati Sumanth , Guo Qilin , Chen Lianyi , Morgan Dane
Published: January 2024

In laser powder bed fusion processes, keyholes are the gaseous cavities formed where laser interacts with metal, and their morphologies play an important role in defect formation and the final product quality. The in-situ X-ray imaging technique can monitor the keyhole dynamics from the side and capture keyhole shapes in the X-ray image stream. Keyhole shapes in X-ray images are then often labeled by humans for analysis, which increasingly involves attempting to correlate keyhole shapes with defects using machine learning. However, such labeling is tedious, time-consuming, error-prone, and cannot be scaled to large data sets. To use keyhole shapes more readily as the input to machine learning methods, an automatic tool to identify keyhole regions is desirable. In this paper, a deep-learning-based computer vision tool that can automatically segment keyhole shapes out of X-ray images is presented. The pipeline contains a filtering method and an implementation of the BASNet deep learning model to semantically segment the keyhole morphologies out of X-ray images. The presented tool shows promising average accuracy of 91.24% for keyhole area, and 92.81% for boundary shape, for a range of test dataset conditions in Al6061 (and one AliSi10Mg) alloys, with 300 training images/labels and 100 testing images for each trial. Prospective users may apply the presently trained tool or a retrained version following the approach used here to automatically label keyhole shapes in large image sets.
Mechanism Analysis for the Enhancement of Low-Temperature Impact Toughness of Nodular Cast Iron by Heat Treatment
Authors: Zhuang Huanyu , Shen Jiahui , Yu Minhua , An Xulong , Hu Jing
Published: January 2024

The low-temperature impact toughness of nodular cast iron can be significantly enhanced by heat treatment, and thus meet the severe service requirements in the fields of high-speed rail and power generation, etc. In order to explore the enhancement mechanism, microstructure, hardness, composition and other characteristics of as-cast and heat-treated nodular cast iron is systematically tested and compared by optical microscopy, microhardness tester, EBSD, SEM, electron probe, and impact toughness testing machine in this study. The results show that heat treatment has little effect on the morphology and size of graphite in nodular cast iron, ignores the effect on the grain size, morphology, and distribution of ferritic matrix, and has little effect on the hardness and exchange of elements, while it is meaningful to find that heat treatment brings about significant decrease in high-angle grain boundaries (HAGB) between 59° and 60°, decreasing from 10% to 3%. Therefore, the significant enhancement of low-temperature impact toughness of nodular cast iron by heat treatment may result from the obvious decrease in HAGB between 59° and 60°, instead of other reasons. From this perspective, the study can provide novel ideas for optimizing the heat treatment process of nodular cast iron.
Influence of Chemical Composition on Structure and Mechanical Properties of Vacuum-Carburized Low-Alloy Steels
Authors: Kochmański Paweł , Chylińska Renata , Figiel Paweł , Fryska Sebastian , Kochmańska Agnieszka E. , Kwiatkowska Magdalena , Kwiatkowski Konrad , Niemczyk Agata , Słowik Justyna , Maziarz Wojciech , Rogal Łukasz , Dybowski Konrad , Baranowska Jolanta
Published: January 2024

This study presents research results concerning the vacuum carburizing of four steel grades, specifically conforming to European standards 1.7243, 1.6587, 1.5920, and 1.3532. The experimental specimens exhibited variations primarily in nickel content, ranging from 0 to approximately 3.8 wt. %. As a comparative reference, gas carburizing was also conducted on the 1.3532 grade, which had the highest nickel content. Comprehensive structural analysis was carried out on the resultant carburized layers using a variety of techniques, such as optical and electron scanning, transmission microscopy, and X-ray diffraction. Additionally, mechanical properties such as hardness and fatigue strength were assessed. Fatigue strength evaluation was performed on un-notched samples having a circular cross-section with a diameter of 12 mm. Testing was executed via a three-point bending setup subjected to sinusoidally varying stresses ranging from 0 to maximum stress levels. The carburized layers produced had effective thicknesses from approximately 0.8 to 1.4 mm, surface hardness levels in the range of 600 to 700 HV, and estimated retained austenite contents from 10 to 20 vol%. The observed fatigue strength values for the layers varied within the range from 1000 to 1350 MPa. It was found that changing the processing method from gas carburizing, which induced internal oxidation phenomena, to vacuum carburizing improved the fatigue properties to a greater extent than increasing the nickel content of the steel.
Preparation, Characterization, and Lubrication Performances of Water-Based Nanolubricant for Micro Rolling Strips
Authors: Zhu Yuchuan , Zhang Hongmei , Li Na , Jiang Zhengyi
Published: January 2024

Water-based nanolubricants are widely used in rolling processes due to their unique characteristics. As a common additive, nanoparticles could significantly improve the tribological properties of the lubricant. However, the effect of the physical properties of the particles on the anti-friction behavior is unclear. In this study, the effect of Fe3O4 nanoparticles as an additive for the prepared lubricant is studied. The tribological properties of Fe3O4 water-based nanolubricant are examined using a tribometer and a scratch meter. The absorption energy is calculated using the molecular dynamic simulation method, and the best parameters for the preparation of the nanolubricant are obtained. The developed nanolubricant is used in the rolling process. The results show that the processing quality of samples is promoted and the tribological properties of water-based lubricant can be significantly promoted by an Fe3O4 nanoparticle additive. An economical and environmentally friendly method is presented through which the water-based Fe3O4 nanolubricant can be prepared for the replacement of oil-based lubricant in cold rolling strips.
The Effect of Multi-Step Tempering and Partition Heat Treatment on 25Cr2Ni3MoV Steel’s Cryogenic Strength Properties
Authors: Chen Ye , Chen Ran , Yao Yanchen , Min Na , Li Wei , Diao Anna
Published: January 2024

In this study, the refinement of two microstructures was controlled in medium carbon 25Cr2Ni3MoV steel via multi-step tempering and partition (MTP) to achieve high cryogenic strength–ductility combinations. Microstructure evolution, the distribution of stress concentration, and microcrack formation and propagation during cryogenic Charpy impact testing were investigated. Compared with their performance in the quenching and tempering states (QT), the MTP steels showed a significant improvement in yield strength (1300 MPa), total elongation (25%), and impact toughness (>25 J) at liquid nitrogen temperature (LNT). The strengthening contributions mainly originated from the high dislocation density and refinement cementite (size: 70 nm) in the martensite lath (width: 1.5 μm) introduced by refined reversed austenite and its latter decomposition. The instrumented Charpy impact results indicated that cracks nucleated in the primary austenite grain (PAG) boundary for two steels due to the strain concentration band preferring to appear near PAGs, while cracks in the QT and MTP samples propagated along the PAGs and high-angle grain boundary (HAGB), respectively. The crystallized plasticity finite element simulation revealed that the PAG boundary with cementite precipitates of large size (>200 nm) was less able to dissipate crack propagation energy than the HAGBs by continuously forming a high strain concentration area, thus leading to the low-impact toughness of the QT steel.
Structural and Photoelectronic Properties of κ-Ga2O3 Thin Films Grown on Polycrystalline Diamond Substrates
Authors: Girolami Marco , Bosi Matteo , Pettinato Sara , Ferrari Claudio , Lolli Riccardo , Seravalli Luca , Serpente Valerio , Mastellone Matteo , Trucchi Daniele M. , Fornari Roberto
Published: January 2024

Orthorhombic κ-Ga2O3 thin films were grown for the first time on polycrystalline diamond free-standing substrates by metal-organic vapor phase epitaxy at a temperature of 650 °C. Structural, morphological, electrical, and photoelectronic properties of the obtained heterostructures were evaluated by optical microscopy, X-ray diffraction, current-voltage measurements, and spectral photoconductivity, respectively. Results show that a very slow cooling, performed at low pressure (100 mbar) under a controlled He flow soon after the growth process, is mandatory to improve the quality of the κ-Ga2O3 epitaxial thin film, ensuring a good adhesion to the diamond substrate, an optimal morphology, and a lower density of electrically active defects. This paves the way for the future development of novel hybrid architectures for UV and ionizing radiation detection, exploiting the unique features of gallium oxide and diamond as wide-bandgap semiconductors.
Effect of Multidirectional Forging and Aging Treatment on Wear Properties of ZK61 Alloy
Authors: Zhang Xuhui , Xu Jian , He Wenyu , Jia Jingjing
Published: January 2024

This study investigated the effects of multidirectional forging (MDF) and aging treatments on the wear properties of ZK61 magnesium alloy. Dry sliding wear tests were performed on homogenized, MDF, and aged samples using a friction wear machine to analyze the surface morphology by scanning electron microscopy (SEM) and white light interferometry, as well as the hardness and tensile mechanical properties. The ZK61 magnesium alloy has higher sliding wear properties after MDF due to higher strength, hardness, and work hardening. Grain refinement affects the wear resistance of the material, but aging increases the hardness and tensile strength and decreases the wear resistance.
Synthesis and Characterization of Cellulose Microfibril-Reinforced Polyvinyl Alcohol Biodegradable Composites
Authors: Boroujeni Fatemeh Mahdiyeh , Fioravanti Gabriella , Kander Ronald
Published: January 2024

The pursuit of an environmentally sustainable manufacturing process requires the substitution of less damaging and recyclable solutions for harmful reagents. This study aims to assess the effectiveness of using cellulose microfibrils synthesized via different hydrolysis reactions as reinforcing agents in polyvinyl alcohol (PVA) at varying concentrations. The investigation explores the morphology, thermal properties, and chemical behavior of the cellulose particles. The cellulose microfibrils (CMFs) produced using citric acid exhibited the highest yield and aspect ratio. Notably, particles from organic acids demonstrated greater thermal stability, with oxalic acid-derived particles displaying the maximum thermal degradation temperature. Subsequently, cast films of PVA reinforced with the cellulose microfibrils underwent comprehensive analyses, including Fourier transfer infrared (FTIR) spectroscopy, thermal degradation temperature (Td), differential scanning calorimetry (DSC), and tensile strength tests. The thermal behavior of cast films experienced notable changes with the addition of cellulose particles, evidenced by increased melting and crystallinity temperatures, along with a rise in the degree of crystallinity. The incorporation of cellulose particles led to a substantial improvement in mechanical properties. Films containing CMF displayed higher Young’s modulus, and the sample incorporating 5% CMF derived from citric acid exhibited the most significant increase in modulus.
Secondary Ion Mass Spectral Imaging of Metals and Alloys
Authors: Shen Yanjie , Howard Logan , Yu Xiao-Ying
Published: January 2024

Secondary Ion Mass Spectrometry (SIMS) is an outstanding technique for Mass Spectral Imaging (MSI) due to its notable advantages, including high sensitivity, selectivity, and high dynamic range. As a result, SIMS has been employed across many domains of science. In this review, we provide an in-depth overview of the fundamental principles underlying SIMS, followed by an account of the recent development of SIMS instruments. The review encompasses various applications of specific SIMS instruments, notably static SIMS with time-of-flight SIMS (ToF-SIMS) as a widely used platform and dynamic SIMS with Nano SIMS and large geometry SIMS as successful instruments. We particularly focus on SIMS utility in microanalysis and imaging of metals and alloys as materials of interest. Additionally, we discuss the challenges in big SIMS data analysis and give examples of machine leaning (ML) and Artificial Intelligence (AI) for effective MSI data analysis. Finally, we recommend the outlook of SIMS development. It is anticipated that in situ and operando SIMS has the potential to significantly enhance the investigation of metals and alloys by enabling real-time examinations of material surfaces and interfaces during dynamic transformations.
Improving Mechanical Properties of Co-Cr-Fe-Ni High Entropy Alloy via C and Mo Microalloying
Authors: Lv Yukun , Guo Yangyang , Zhang Jie , Lei Yutian , Song Pingtao , Chen Jian
Published: January 2024

The as-cast [Co40Cr25(FeNi)35−yMoy]100−xCx (x = 0, 0.5, y = 3, 4, 5 at.%) HEAs (high-entropy alloys) were prepared by a vacuum arc melting furnace and were then hot rolled. The effect of C and Mo elements on the microstructure evolution and mechanical properties of HEAs was systematically analyzed. The results showed that when no C atoms were added, the HEAs consisted of FCC + HCP dual-phase structure. In addition, as the Mo content increased, the grain size of the alloy increased from 17 μm to 47 μm. However, only the FCC phase appeared after adding 0.5 at.% carbon in Mo microalloyed HEAs, and the grain size of the Mo4C0.5 HEA decreased significantly. Due to the Mo atom content exceeding the solid solution limit, the carbides of Mo combined with the C element appeared in the Mo5C0.5 HEA. The strength of C and Mo microalloyed HEAs significantly increased compared to HEAs with no C added. However, the Mo4C0.5 HEA exhibited excellent comprehensive mechanical properties, which was superior to a majority of reported HEAs and conventional metal alloys. Its yield strength, tensile strength, and elongation were 757 MPa, 1186 MPa, and 69%, respectively. The strengthening mechanism was a combination of fine grain strengthening, TWIP effect, and solid solution strengthening.