bluuebunny/crossref_metadata_2025 huggingface dataset:
Matrix Metalloproteinases and Their Inhibitors as Potential Prognostic Biomarkers in Head and Neck Cancer after Radiotherapy
Authors: Fornieles Gabriel , Núñez María Isabel , Expósito José
Published: December 2023

Head and neck cancer (HNC) is among the ten most frequent tumours, with 5-year survival rates varying from 30% to 70% depending on the stage and location of the tumour. HNC is traditionally known as head and neck squamous cell carcinoma (HNSCC), since 90% arises from epithelial cells. Metastasis remains a major cause of mortality in patients with HNSCC. HNSCC patients with metastatic disease have an extremely poor prognosis with a survival rate of less than a year. Matrix metalloproteinases (MMPs) have been described as biomarkers that promote cell migration and invasion. Radiotherapy is widely used to treat HNSCC, being a determining factor in the alteration of the tumour’s biology and microenvironment. This review focuses on analysing the current state of the scientific literature on this topic. Although few studies have focused on the role of these proteinases in HNC, some authors have concluded that radiotherapy alters the behaviour of MMPs and tissue inhibitors of metalloproteinases (TIMPs). Therefore, more research is needed to understand the roles played by MMPs and their inhibitors (TIMPs) as prognostic biomarkers in patients with HNC and their involvement in the response to radiotherapy.
Aluminum Supplementation Mediates the Changes in Tea Plant Growth and Metabolism in Response to Calcium Stress
Authors: Zhang Hua , Song Yakang , Fan Zhenglei , Ruan Jianyun , Hu Jianhui , Zhang Qunfeng
Published: December 2023

Tea plants are more sensitive to variations in calcium concentration compared to other plants, whereas a moderate aluminum concentration facilitates the growth and development of tea plants. Aluminum and calcium show a competitive interaction with respect to the uptake of elements, consequently exerting physiological effects on plants. To further explore these interactions, in this study, we used the solution culture method to treat tea plants with two calcium concentrations (0.8 mM and 5.6 mM) and three aluminum concentrations (0 mM, 0.4 mM, and 1 mM). We then determined the influence of the combined treatments on root growth and quality compound accumulation in the tissues by a combination of phenotype, gene expression, and metabolite analyses. Moderate aluminum supplementation (0.4 mM) alleviated the inhibition of root growth caused by high calcium stress. High calcium stress significantly inhibited the accumulation of most amino acids (e.g., Glutamic acid, Citulline, and Arginine) and organic acids (e.g., a-ketoglutaric acid) in the roots, stems, and leaves, whereas aluminum deficiency significantly increased most amino acids in the roots and leaves (except Serine, Alanine, and Phenylalanine in the roots and Ser in the leaves), with a more than two-fold increase in Arg and Lysine. High calcium stress also induced the accumulation of secondary metabolites such as epigallocatechin gallate and procyanidin in the roots, whereas aluminum supplementation significantly reduced the contents of flavonol glycosides such as quercetin, rutin, myricitrin, and kaempferitrin, as well as caffeine, regardless of calcium concentration. Aluminum supplementation reversed some of the changes in the contents of leaf metabolites induced by calcium stress (e.g., 4-dihydroquercetin, apigenin C-pentoside, phenethylamine, and caffeine). Overall, calcium stress caused severe growth inhibition and metabolic disorders in tea plants, which could be reversed by aluminum supplementation, particularly in maintaining the root tips and the accumulation of secondary metabolites. These results provide a theoretical basis for improving calcium-aluminum nutrient management to promote tea plant growth and quality.
Analysis of the Methylation Level of the DAT1 Dopamine Transporter Gene in Patients Addicted to Stimulants, Taking into Account an Analysis of Personality Traits
Authors: Recław Remigiusz , Lachowicz Milena , Chmielowiec Krzysztof , Chmielowiec Jolanta , Strońska-Pluta Aleksandra , Kowalski Michał Tomasz , Kudliński Bartosz , Grzywacz Anna
Published: December 2023

Drug addiction is a chronic biochemical drug use disorder that affects the human brain and behavior and leads to the uncontrolled use of legal or illicit drugs. It has been shown that three factors are involved in the development of addiction: genetic factors, a diverse environment, and the effect of medication on gene expression. The comprehensive approach and holistic analysis of the problem are due to the multigenic and multifactorial nature of addiction. Dopamine, one of the major neurotransmitters in the brain, is believed to be the “culprit” that leads to a drug abuse-induced “high”. That is why, in our research, we focused mainly on the genes related to dopaminergic reuptake. In the present study, we chose methylation of the DAT1 dopamine transporter gene based on molecular reasons related to the dopaminergic theory of addiction. This study included two groups: 226 stimulant-dependent and 290 non-stimulant-dependent subjects. The analysis consisted of a case–control comparison of people addicted to psychostimulants compared to a control group of healthy and non-addicted people. There were differences in the levels of statistical significance between the groups. Our research shows lower methylation of islands 1, 9, and 14 in addicted people and greater methylation of islands 32 and 33. The difference in individual CpG methylation islands of the gene under study provides valuable information about the DNA methylation process in patients addicted to psychostimulants. Pearson’s linear correlation analysis in stimulant dependence showed a negative correlation between total methylation island levels and the NEO-FFI Neuroticism scale. In subjects with neuroticism, the methylation level was statistically significantly lower. Pearson’s linear correlation analysis of stimulant-dependent subjects showed a positive correlation between total methylation island levels and the NEO-FFI Openness scale and the NEO-FFI Conscientiousness scale.
Red Cabbage Juice-Mediated Gut Microbiota Modulation Improves Intestinal Epithelial Homeostasis and Ameliorates Colitis
Authors: Jean Wilson Emily , Sirpu Natesh Nagabhishek , Ghadermazi Parsa , Pothuraju Ramesh , Prajapati Dipakkumar R. , Pandey Sanjit , Kaifi Jussuf T. , Dodam John R. , Bryan Jeffrey N. , Lorson Christian L. , Watrelot Aude A. , Foster Jason M. , Mansell Thomas J. , Joshua Chan Siu Hung , Batra Surinder K. , Subbiah Jeyamkondan , Rachagani Satyanarayana
Published: December 2023

Gut microbiota plays a crucial role in inflammatory bowel diseases (IBD) and can potentially prevent IBD through microbial-derived metabolites, making it a promising therapeutic avenue. Recent evidence suggests that despite an unclear underlying mechanism, red cabbage juice (RCJ) alleviates Dextran Sodium Sulfate (DSS)-induced colitis in mice. Thus, the study aims to unravel the molecular mechanism by which RCJ modulates the gut microbiota to alleviate DSS-induced colitis in mice. Using C57BL/6J mice, we evaluated RCJ’s protective role in DSS-induced colitis through two cycles of 3% DSS. Mice were daily gavaged with PBS or RCJ until the endpoint, and gut microbiota composition was analyzed via shotgun metagenomics. RCJ treatment significantly improved body weight (p ≤ 0.001), survival in mice (p < 0.001) and reduced disease activity index (DAI) scores. Further, RCJ improved colonic barrier integrity by enhancing the expression of protective colonic mucins (p < 0.001) and tight junction proteins (p ≤ 0.01) in RCJ + DSS-treated mice compared to the DSS group. Shotgun metagenomic analysis revealed an enrichment of short-chain fatty acids (SCFAs)-producing bacteria (p < 0.05), leading to increased Peroxisome Proliferator-Activated Receptor Gamma (PPAR-γ) activation (p ≤ 0.001). This, in turn, resulted in repression of the nuclear factor κB (NFκB) signaling pathway, causing decreased production of inflammatory cytokines and chemokines. Our study demonstrates colitis remission in a DSS-induced mouse model, showcasing RCJ as a potential modulator for gut microbiota and metabolites, with promising implications for IBD prevention and treatment.
Matrine Targets BTF3 to Inhibit the Growth of Canine Mammary Tumor Cells
Authors: Feng Zijian , Sun Na , Noor Fida , Sun Panpan , Zhang Hua , Zhong Jia , Yin Wei , Fan Kuohai , Yang Huizhen , Zhang Zhenbiao , Sun Yaogui , Li Hongquan
Published: December 2023

The canine mammary tumor model is more suitable for studying human breast cancer, and the safety concentrations of matrine and the biotin-labeled matrine probe were determined in canine primary mammary epithelial cells, and then selected canine mammary tumor cell lines CHMm and CHMp were incubated with matrine, and cell viability was detected by CCK-8. The biotin-labeled matrine probe was used to pull-down the targets of matrine in canine mammary tumor cells, and the targets were screened in combination with activity-based protein profiling (ABPP) and Genecards database, and verified by qPCR and western blot. The results showed that the maximum non-cytotoxic concentrations of matrine and biotin-labeled matrine probe in canine primary mammary epithelial cells were 250 μg/mL and 500 μg/mL, respectively. Matrine and biotin-labeled matrine probe had a proliferation inhibitory effect time-dependently on CHMm and CHMp cells within a safe concentration range, and induced autophagy in cells. Then BTF3 targets were obtained by applying ABPP and Genecards screening. Cellular thermal shift assay (CETSA) findings indicated that matrine could increase the heat stability of BTF3 protein. Pull-down employing biotin-labeled matrine probe with CHMm and CHMp cell lysates revealed that BTF3 protein was detected in the biotin-labeled matrine probe group and that BTF3 protein was significantly decreased by the addition of matrine. The qPCR and western blot findings of CHMm and CHMp cells treated with matrine revealed that matrine decreased the expression of the BTF3 gene and protein with the extension of the action time, and the impact was more substantial at the protein level, respectively.
Enhancing Bone Infection Diagnosis with Raman Handheld Spectroscopy: Pathogen Discrimination and Diagnostic Potential
Authors: Lindtner Richard Andreas , Wurm Alexander , Pirchner Elena , Putzer David , Arora Rohit , Coraça-Huber Débora Cristina , Schirmer Michael , Badzoka Jovan , Kappacher Christoph , Huck Christian Wolfgang , Pallua Johannes Dominikus
Published: December 2023

Osteomyelitis is a bone disease caused by bacteria that can damage bone. Raman handheld spectroscopy has emerged as a promising diagnostic tool for detecting bone infection and can be used intraoperatively during surgical procedures. This study involved 120 bone samples from 40 patients, with 80 samples infected with either Staphylococcus aureus or Staphylococcus epidermidis. Raman handheld spectroscopy demonstrated successful differentiation between healthy and infected bone samples and between the two types of bacterial pathogens. Raman handheld spectroscopy appears to be a promising diagnostic tool in bone infection and holds the potential to overcome many of the shortcomings of traditional diagnostic procedures. Further research, however, is required to confirm its diagnostic capabilities and consider other factors, such as the limit of pathogen detection and optimal calibration standards.
Current and Emerging Therapeutic Targets for the Treatment of Cholangiocarcinoma: An Updated Review
Authors: Hadfield Matthew J. , DeCarli Kathryn , Bash Kinan , Sun Grace , Almhanna Khaldoun
Published: December 2023

Cholangiocarcinoma is a malignancy of the bile ducts that is often associated with late diagnosis, poor overall survival, and limited treatment options. The standard of care therapy for cholangiocarcinoma has been cytotoxic chemotherapy with modest improvements in overall survival with the addition of immune checkpoint inhibitors. The discovery of actionable mutations has led to the advent of targeted therapies against FGFR and IDH-1, which has expanded the treatment landscape for this patient population. Significant efforts have been made in the pre-clinical space to explore novel immunotherapeutic approaches, as well as antibody–drug conjugates. This review provides an overview of the current landscape of treatment options, as well as promising future therapeutic targets.
Proof-of-Concept Study on the Use of Tangerine-Derived Nanovesicles as siRNA Delivery Vehicles toward Colorectal Cancer Cell Line SW480
Authors: Rabienezhad Ganji Nima , Urzì Ornella , Tinnirello Vincenza , Costanzo Elisa , Polito Giulia , Palumbo Piccionello Antonio , Manno Mauro , Raccosta Samuele , Gallo Alessia , Lo Pinto Margot , Calligaris Matteo , Scilabra Simone Dario , Di Bella Maria Antonietta , Conigliaro Alice , Fontana Simona , Raimondo Stefania , Alessandro Riccardo
Published: December 2023

In the last years, the field of nanomedicine and drug delivery has grown exponentially, providing new platforms to carry therapeutic agents into the target sites. Extracellular vesicles (EVs) are ready-to-use, biocompatible, and non-toxic nanoparticles that are revolutionizing the field of drug delivery. EVs are involved in cell–cell communication and mediate many physiological and pathological processes by transferring their bioactive cargo to target cells. Recently, nanovesicles from plants (PDNVs) are raising the interest of the scientific community due to their high yield and biocompatibility. This study aims to evaluate whether PDNVs may be used as drug delivery systems. We isolated and characterized nanovesicles from tangerine juice (TNVs) that were comparable to mammalian EVs in size and morphology. TNVs carry the traditional EV marker HSP70 and, as demonstrated by metabolomic analysis, contain flavonoids, organic acids, and limonoids. TNVs were loaded with DDHD1-siRNA through electroporation, obtaining a loading efficiency of 13%. We found that the DDHD1-siRNA complex TNVs were able to deliver DDHD1-siRNA to human colorectal cancer cells, inhibiting the target expression by about 60%. This study represents a proof of concept for the use of PDNVs as vehicles of RNA interference (RNAi) toward mammalian cells.
Optimizing Hexose Utilization Pathways of Cupriavidus necator for Improving Growth and L-Alanine Production under Heterotrophic and Autotrophic Conditions
Authors: Wang Lei , Luo Huiying , Yao Bin , Yao Junhu , Zhang Jie
Published: December 2023

Cupriavidus necator is a versatile microbial chassis to produce high-value products. Blocking the poly-β-hydroxybutyrate synthesis pathway (encoded by the phaC1AB1 operon) can effectively enhance the production of C. necator, but usually decreases cell density in the stationary phase. To address this problem, we modified the hexose utilization pathways of C. necator in this study by implementing strategies such as blocking the Entner–Doudoroff pathway, completing the phosphopentose pathway by expressing the gnd gene (encoding 6-phosphogluconate dehydrogenase), and completing the Embden–Meyerhof–Parnas pathway by expressing the pfkA gene (encoding 6-phosphofructokinase). During heterotrophic fermentation, the OD600 of the phaC1AB1-knockout strain increased by 44.8% with pfkA gene expression alone, and by 93.1% with gnd and pfkA genes expressing simultaneously. During autotrophic fermentation, gnd and pfkA genes raised the OD600 of phaC1AB1-knockout strains by 19.4% and 12.0%, respectively. To explore the effect of the pfkA gene on the production of C. necator, an alanine-producing C. necator was constructed by expressing the NADPH-dependent L-alanine dehydrogenase, alanine exporter, and knocking out the phaC1AB1 operon. The alanine-producing strain had maximum alanine titer and yield of 784 mg/L and 11.0%, respectively. And these values were significantly improved to 998 mg/L and 13.4% by expressing the pfkA gene. The results indicate that completing the Embden–Meyerhof–Parnas pathway by expressing the pfkA gene is an effective method to improve the growth and production of C. necator.
The Involvement of LAG-3positive Plasma Cells in the Development of Multiple Myeloma
Authors: Kreiniz Natalia , Eiza Nasren , Tadmor Tamar , Levy Yurkovski Ilana , Matarasso Greenfeld Sarah , Sabag Adi , Mubariki Raeda , Suriu Celia , Votinov Ekaterina , Toubi Elias , Vadasz Zahava
Published: December 2023

The Lymphocyte-Activation Protein 3 (LAG-3) inhibitory receptor is expressed on regulatory plasma cells (PCs). Micro-environmental cells that express LAG-3 were found to be increased during the progression of smoldering multiple myeloma (SMM). To assess the possible role of LAG-3 expression on regulatory PCs in patients with plasma cell dyscrasia. Purified Cluster of Differentiation 138 (CD138+) PCs from patients with premalignant conditions, active multiple myeloma (MM), and controls were analyzed for the expression of LAG-3 by flow cytometry. Autologous CD8+T cells were incubated with sorted LAG-3pos or LAG-3neg PCs for 24 h. The expression of granzyme (Grz) in CD8+T cells was assessed by flow cytometry. LAG-3 expression on PCs in active MM (newly diagnosed and relapse refractory MM) was significantly increased compared to monoclonal gammopathy of undetermined significance (MGUS)/ SMM. Grz expression was significantly decreased in CD8+T cells incubated with CD138+LAG-3pos PCs, compared to CD138+LAG-3neg PCs in patients with plasma cell dyscrasia, n = 31, p = 0.0041. LAG-3 expression on malignant PCs can be involved in the development of MM from MGUS by decreasing the expression of Grz in CD8+T cells.
Zearalenone Induces Blood-Testis Barrier Damage through Endoplasmic Reticulum Stress-Mediated Paraptosis of Sertoli Cells in Goats
Authors: Liu Tengfei , Liu Gengchen , Xu Yinghuan , Huang Yuqi , Zhang Yunxuan , Wu Yongjie , Xu Yongping
Published: December 2023

Zearalenone (ZEA) is present worldwide as a serious contaminant of food and feed and causes male reproductive toxicity. The implication of paraptosis, which is a nonclassical paradigm of cell death, is unclear in ZEA-induced male reproductive disorders. In this study, the toxic effects of ZEA on the blood-testis barrier (BTB) and the related mechanisms of paraptosis were detected in goats. ZEA exposure, in vivo, caused a significant decrease in spermatozoon quality, the destruction of seminiferous tubules, and damage to the BTB integrity. Furthermore, ZEA exposure to Sertoli cells (SCs) in vitro showed similar dysfunction in structure and barrier function. Importantly, the formation of massive cytoplasmic vacuoles in ZEA-treated SCs corresponded to the highly swollen and dilative endoplasmic reticulum (ER), and paraptosis inhibition significantly alleviated ZEA-induced SC death and vacuolization, which indicated the important contribution of paraptosis in ZEA-induced BTB damage. Meanwhile, the expression of ER stress marker proteins was increased after ZEA treatment but decreased under the inhibition of paraptosis. The vacuole formation and SC death, induced by ZEA, were remarkably blocked by ER stress inhibition. In conclusion, these results facilitate the exploration of the mechanisms of the SC paraptosis involved in ZEA-induced BTB damage in goats.
Environmental Toxicology and Human Health
Authors: Demir Esref , Kacew Sam
Published: December 2023

Humans and animals may be exposed on a continuous daily basis to a mixture of environmental contaminants that may act on several organ systems through differing mechanisms [...]
Editorial for the IJMS Special Issue on Molecular Pathogenesis and Molecular Therapy of Lymphoid Malignancies
Authors: Eiken Alexandria P. , El-Gamal Dalia
Published: December 2023

In the era of targeted therapies, researchers have aimed to uncover the molecular drivers of malignant pathogenesis in lymphoid malignancies in an endeavor to develop effective therapeutic strategies [...]
Variations in Postmenopausal Body Composition: A Cross-Sectional Comparison between Physical Activity Practitioners and Sedentary Individuals
Authors: Dias Damasceno Camila Mahara , de Sá Pereira Guimarães Fernando José , Costa Keyla Brandão , Morais Godoy Figueiredo Ana Claudia , Araújo Rodrigo Cappato de , da Cunha Costa Manoel
Published: December 2023

Physical activity is broadly recognized for promoting weight reduction and bestowing numerous health benefits. Nonetheless, robust evidence concerning the impact of physical activity on postmenopausal women, undergoing physiological shifts, remains scant. This study aimed to elucidate the relationship between physical activity and body composition among postmenopausal women. Employing a cross-sectional and retrospective design, 702 women were examined. Data on physical activity and body composition were amassed through anthropometric assessments and Dual-Energy X-ray Absorptiometry (DEXA). A significant proportion of women exhibited anthropometric alterations indicative of overweight/obesity, alongside elevated values in Waist Circumference (WC), Waist-to-Hip Ratio, Waist-to-Height, and bone mass, signifying a heightened risk for disease onset. While a majority engaged in some form of physical activity, this did not yield notable reductions in the assessed metrics. Noteworthy changes were only discerned in BMI and bone mass among pre-menopausal women; whereas among postmenopausal women, in addition to disparities in bone mass, those inactive were 1.18 times more prone to a very high disease risk, as gauged by WC.
Multispectral Deep Neural Network Fusion Method for Low-Light Object Detection
Authors: Thaker Keval , Chennupati Sumanth , Rawashdeh Nathir , Rawashdeh Samir A.
Published: December 2023

Despite significant strides in achieving vehicle autonomy, robust perception under low-light conditions still remains a persistent challenge. In this study, we investigate the potential of multispectral imaging, thereby leveraging deep learning models to enhance object detection performance in the context of nighttime driving. Features encoded from the red, green, and blue (RGB) visual spectrum and thermal infrared images are combined to implement a multispectral object detection model. This has proven to be more effective compared to using visual channels only, as thermal images provide complementary information when discriminating objects in low-illumination conditions. Additionally, there is a lack of studies on effectively fusing these two modalities for optimal object detection performance. In this work, we present a framework based on the Faster R-CNN architecture with a feature pyramid network. Moreover, we design various fusion approaches using concatenation and addition operators at varying stages of the network to analyze their impact on object detection performance. Our experimental results on the KAIST and FLIR datasets show that our framework outperforms the baseline experiments of the unimodal input source and the existing multispectral object detectors.
Activation of Ustilaginoidin Biosynthesis Gene uvpks1 in Villosiclava virens Albino Strain LN02 Influences Development, Stress Responses, and Inhibition of Rice Seed Germination
Authors: Xue Mengyao , Hou Xuwen , Gu Gan , Dong Jie , Yang Yonglin , Pan Xiaoqian , Zhang Xuan , Xu Dan , Lai Daowan , Zhou Ligang
Published: December 2023

Villosiclava virens (anamorph: Ustilaginoidea virens) is the pathogen of rice false smut (RFS), which is a destructive rice fungal disease. The albino strain LN02 is a natural white-phenotype mutant of V. virens due to its incapability to produce toxic ustilaginoidins. In this study, three strains including the normal strain P1, albino strain LN02, and complemented strain uvpks1C-1 of the LN02 strain were employed to investigate the activation of the ustilaginoidin biosynthesis gene uvpks1 in the albino strain LN02 to influence sporulation, conidia germination, pigment production, stress responses, and the inhibition of rice seed germination. The activation of the ustilaginoidin biosynthesis gene uvpks1 increased fungal tolerances to NaCl-induced osmotic stress, Congo-red-induced cell wall stress, SDS-induced cell membrane stress, and H2O2-induced oxidative stress. The activation of uvpks1 also increased sporulation, conidia germination, pigment production, and the inhibition of rice seed germination. In addition, the activation of uvpks1 was able to increase the mycelial growth of the V. virens albino strain LN02 at 23 °C and a pH from 5.5 to 7.5. The findings help in understanding the effects of the activation of uvpks1 in albino strain LN02 on development, pigment production, stress responses, and the inhibition of rice seed germination by controlling ustilaginoidin biosynthesis.
Additive Manufacturing of Earth-Based Materials: A Literature Review on Mortar Composition, Extrusion, and Processing Earth
Authors: Rocha Douglas , Faria Paulina , Lucas Sandra S.
Published: December 2023

Increasing concerns about global warming and its impact on the environment reinforce the need for new materials and technologies. Additive manufacturing has become more relevant due to its potential to build sustainable and more energy-efficient constructions. However, the materials employed within the technology are not yet fully sustainable. Researchers employing clay as the main binder have found that, besides protecting the environment, it benefits passive control of indoor temperature and relative humidity and contributes to comfort. The mortar design as well as the necessary technological adaptations for the 3D printing of earth mortars are addressed. From a material perspective, this paper reviewed and analyzed the recent developments in additive manufacturing of clay-based mortars, highlighting the main gaps and providing recommendations for future developments in this field.
Research on Damage Evolution Law of Glazed Hollow Beads-Cement/Sodium Silicate Grouting Materials under Different Cycles of Loading and Unloading
Authors: Liu Tao , Yao Weijing , Han Jinxiu , Liu Yu , Wang Heng
Published: December 2023

With the depletion of shallow resources, deep resource mining has become a trend. However, the high temperature and complex stress environment in deep mines make resource extraction extremely challenging. This paper developed a thermal insulation grouting material made of glazed hollow beads, sodium silicate, and cement and tested the compressive strength, gelation time, and stone rate under various curing days in light of the issue of high temperature heat damage in high ground temperature mines and the impact of mining on roadway grouting bolt support. Fatigue strength, fatigue deformation, load-residual strain, energy evolution and microscopic features were studied and analyzed in relation to the damage law of graded cyclic loading and unloading under the number of varying cycles. The findings demonstrate that cyclic loading and unloading strength is lower than uniaxial compressive strength. The fatigue strength is significantly decreased when the number of cycles reaches its limit. Residual strain is less sensitive to changes in stress than load strain. The fitting correlation coefficients of total output energy and elastic energy are higher than 0.71.
Regulation Law of Tempering Cooling Rate on Toughness of Medium-Carbon Medium-Alloy Steel
Authors: Yang Chao , Xu Tingting , Zhao Hongshan , Hu Chundong , Dong Han
Published: December 2023

Temper embrittlement is a major challenge encountered during the heat treatment of high-performance steels for large forgings. This study investigates the microstructural evolution and mechanical properties of Cr-Ni-Mo-V thick-walled steel, designed for large forgings with a tensile strength of 1500 MPa, under different tempering cooling rates. Optical microscopy (OM), scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD) were employed to analyze the microstructural features. The results demonstrate that the embrittlement occurring during air cooling after tempering is attributed to the concentration of impurities near Fe3C at the grain boundaries. The low-temperature impact toughness at −40 °C after water quenching reaches 29 J due to the accelerated cooling rate during tempering, which slows down the diffusion of impurity elements towards the grain boundaries, resulting in a reduced concentration and dislocation density and an increased stability of the grain boundaries, thereby enhancing toughness. The bainite content decreases and the interface between martensite and bainite undergoes changes after water quenching during tempering. These alterations influence the crack propagation direction within the two-phase microstructure, further modifying the toughness. These findings contribute to the understanding of temper embrittlement and provide valuable guidance for optimizing heat treatment processes to enhance the performance of high-performance steels in large forgings.
Predicting Stress Intensity Factor for Aluminum 6062 T6 Material in L-Shaped Lower Control Arm (LCA) Design Using Extended Finite Element Analysis
Authors: El Fakkoussi Said , Vlase Sorin , Marin Marin , Koubaiti Ouadie , Elkhalfi Ahmed , Moustabchir Hassane
Published: December 2023

The aim of this study is to solve a practical problem encountered in the automotive industry, especially the failure of a cracked lower control arm made of al 6062 T6 material during static and crash physical tests, and to characterize the behavior of cracked parts made of aluminum materials using the fracture mechanics parameters. As a first step, we carried out a numerical study and simulation using Abaqus/CAE 2020 software and the finite element method to determine the stress concentration and load limit capacity for different car weight cases. The von Mises stress variation shows crack initiation and propagation to be in the area of the lower control arm’s attachment to the vehicle platform, where stress is concentrated. These numerical results are consistent with the experimental test results found by automotive manufacturers. Also, we find that the mechanical load that can support this part is below 4900 N for good performance. In the second step, we use the results of the first section to simulate the failure of a lower control arm with a crack defect. This paper investigates the stress intensity factor KI in mode I for different lengths (L) and depths (a) of the crack in the lower control arm using the extended finite element method (XFEM) under Abaqus/CAE. For crack failure initiation and progression, we relied on the traction separation law, specifically the maximum principal stress (MAXPS) criterion. The KI factor was evaluated for the materials steel and Al 6062 T6. The results obtained from the variation of the KI coefficient as a function of crack depth (a) and the thickness (t) show that the crack remains stable even when a depth ratio (a/t = 0.8) is reached for the steel material. However, the crack in the Aluminum 6062 T6 material becomes unstable at depth (a/t = 0.6), with a high risk of total failure of the lower control arm.
Flow Front Monitoring in High-Pressure Resin Transfer Molding Using Phased Array Ultrasonic Testing to Optimize Mold Filling Simulations
Authors: Littner Linus , Protz Richard , Kunze Eckart , Bernhardt Yannick , Kreutzbruck Marc , Gude Maik
Published: December 2023

During the production of fiber-reinforced plastics using resin transfer molding (RTM), various characteristic defects and flaws can occur, such as fiber displacement and fiber waviness. Particularly in high-pressure RTM (HP-RTM), fiber misalignments are generated during infiltration by local peaks in the flow rate, leading to a significant reduction in the mechanical properties. To minimize or avoid this effect, the manufacturing process must be well controlled. Simulative approaches allow for a basic design of the mold filling process; however, due to the high number of influencing variables, the real behavior cannot be exactly reproduced. The focus of this work is on flow front monitoring in an HP-RTM mold using phased array ultrasonic testing. By using an established non-destructive testing instrument, the effort required for integration into the manufacturing process can be significantly reduced. For this purpose, investigations were carried out during the production of test specimens composed of glass fiber-reinforced polyurethane resin. Specifically, a phased array ultrasonic probe was used to record individual line scans over the form filling time. Taking into account the specifications of the probe used in these experiments, an area of 48.45 mm was inspected with a spatial resolution of 0.85 mm derived from the pitch. Due to the aperture that had to be applied to improve the signal-to-noise ratio, an averaging of the measured values similar to a moving average over a window of 6.8 mm had to be considered. By varying the orientation of the phased array probe and therefore the orientation of the line scans, it is possible to determine the local flow velocities of the matrix system during mold filling. Furthermore, process simulation studies with locally varying fiber volume contents were carried out. Despite the locally limited measuring range of the monitoring method presented, conclusions about the global flow behavior in a large mold can be drawn by comparing the experimentally determined results with the process simulation studies. The agreement between the measurement and simulation was thus improved by around 70%.
Investigation of In Vitro Cytocompatibility of Zinc-Containing Coatings Developed on Medical Magnesium Alloys
Authors: Wang Yun , Liu Yuzhi , Zhu Yuanyuan , Yu Fanglei , Zhao Rongfang , Lai Xinying , Jiang Haijun , Xu Tianhong , Zhao Ying , Zhang Rongfa
Published: December 2023

In a neutral solution, we investigated the effects of Na2[ZnEDTA] concentrations at 0, 6, 12, 18, and 24 g/L on surface morphology, chemical composition, degradation resistance, and in vitro cytocompatibility of micro-arc oxidation (MAO) coatings developed on WE43 (Mg-Y-Nd-Zr) magnesium alloys. The results show that the enhanced Na2[ZnEDTA] concentration increased the Zn amount but slightly decreased the degradation resistance of MAO-treated coatings. Among the zinc-containing MAO samples, the fabricated sample in the base solution added 6 g/L Na2[ZnEDTA] exhibits the smallest corrosion current density (6.84 × 10−7 A·cm−2), while the sample developed in the solution added 24 g/L Na2[ZnEDTA] and contains the highest Zn content (3.64 wt.%) but exhibits the largest corrosion current density (1.39 × 10−6 A·cm−2). Compared to untreated WE43 magnesium alloys, zinc-containing MAO samples promote initial cell adhesion and spreading and reveal enhanced cell viability. Coating degradation resistance plays a more important role in osseogenic ability than Zn content. Among the untreated WE43 magnesium alloys and the treated MAO samples, the sample developed in the base solution with 6 g/L Na2[ZnEDTA] reveals the highest ALP expression at 14 d. Our results indicate that the MAO samples formed in the solution with Na2[ZnEDTA] promoted degradation resistance and osseogenesis differentiation of the WE43 magnesium alloys, suggesting potential clinic applications.
Possibilities of Measuring and Detecting Defects of Forged Parts in Die Hot-Forging Processes
Authors: Hawryluk Marek , Polak Sławomir , Rychlik Marcin , Dudkiewicz Łukasz , Borowski Jacek , Suliga Maciej
Published: December 2023

This paper presents research results in the field of industrial die forging, mostly related to the use of advanced measuring techniques and tools, numerical simulations, and other IT tools and methods for a geometrical analysis of the forged items as well as detection of forging flaws and their prevention, and optimization of the hot-forging processes. The results of the conducted investigations were divided into three main areas. The first area refers to the application of, e.g., optical scanners and programs related to their operation, data analysis, including the construction of virtual gauges, measurements of selected geometrical features of both the manufactured forgings and their physical and virtual models, as well as an analysis of the durability of the forging tools based on the proprietary reverse scanning method. The second area presents the results of measurements and analyses performed with the use of finite element modeling and by means of some special functions in the calculation packages, such as contact, flow lines, trap, or fold, for the detection of forging defects and an analysis of the force parameters. In turn, the third area presents a combination of different methods of measurement and analysis, both FEM and scanning, as well as other IT methods (physical modeling, image analysis, etc.) for the analysis of the geometry and defects of the forgings. The presented results point to the great potential of these types of tools and techniques in forging industry applications as they significantly shorten the time and increase the accuracy of the measurement, as well as providing a lot of valuable information, physical variables, and technological parameters that are difficult or impossible to determine either analytically or through experimental means. The use and development of these techniques and methods are fully justified, both in the aspect of science and the increased effectiveness and efficiency of production.
The Evaluation of the Effectiveness of Biomineralization Technology in Improving the Strength of Damaged Fiber-Reinforced LWAC
Authors: Chen How-Ji , Chen Tsung-Kai , Tang Chao-Wei , Chang Han-Wen
Published: December 2023

Concrete cracks and local damage can affect the bond performance between concrete and steel bars, thereby reducing the durability of reinforced concrete structures. Compared with general concrete crack repair methods, biomineralization repair not only has effective bonding capabilities but is also particularly environmentally friendly. Therefore, this study aimed to apply biomineralization technology to repair damaged fiber-reinforced lightweight aggregate concrete (LWAC). Two groups of LWAC specimens were prepared. The experimental group used lightweight aggregates (LWAs) containing bacterial spores and nutrient sources, while the control group used LWAs without bacterial spores and nutrient sources. These specimens were first subjected to compression tests and pull-out tests, respectively, and thus were damaged. After the damaged specimen healed itself in different ways for 28 days, secondary compression and pull-out tests were conducted. The self-healing method of the control group involved placing the specimens in an incubator. The experimental group was divided into experimental group I and experimental group II according to the self-healing method. The self-healing method of experimental group I was the same as that of the control group. The self-healing method of experimental group II involved soaking the specimen in a mixed solution of urea and calcium acetate for two days, and then taking it out and placing it in an incubator for two days, with a cycle of four days. The test results show that in terms of the relative bond strength ratio, the experimental group II increased by 17.9% compared with the control group. Moreover, the precipitate formed at the cracks in the sample was confirmed to be calcium carbonate with the EDS and XRD analysis results, which improved the compressive strength and bond strength after self-healing. This indicates that the biomineralization self-healing method used in experimental group II is more effective.
Synthesis of Long Alkyl and Fluoroalkyl Substituted Siloxane Copolymers for the Water Repellency of Rammed Earth Walls
Authors: Yoon Keun-Byoung , Kim Mu-Jin , Lee Dong-Eun , Kim Hee-Seon
Published: December 2023

Rammed earth in a built environment has vapor diffusion characteristics and humidity control abilities, each of which is respectively attributed to the porous structures and the hydrophilic properties. Indeed, these structures and properties allow for the easy absorbance of water particles, hence affecting the durability of a rammed earth wall. This paper presents the water-repellency method for rammed earth walls, which utilizes siloxane copolymers containing fluorine. The water-repellent properties are investigated by measuring the contact angle, water absorption rate, and compressive strength after spray-coating with the synthesized siloxane copolymers on the surface of the rammed earth specimens under study. The water contact angle of the specimen, coated with a siloxane copolymer containing 10 mol.% of a silane monomer with a fluorine group, is about 140°. The water absorption of the specimen obtained after immersing in water for 24 h is low, at about 3.5 wt.%. In addition, the compressive strength remains more than 80% of the corresponding strength of the specimen which is not immersed in water. It is confirmed that the use of a 10% by volume of the siloxane copolymer containing the fluorine group may enhance the water-repellent performance and economic competitiveness.
Study of Anticorrosion and Antifouling Properties of a Cu-Doped TiO2 Coating Fabricated via Micro-Arc Oxidation
Authors: Hu Pengfei , Zhu Liyang , Tian Chenghuan , Xu Gege , Zhang Xinxin , Cai Guangyi
Published: December 2023

As a promising material for petroleum industrial applications, titanium (Ti) and its alloys receive wide attention due to their outstanding physicochemical properties. However, the harsh industrial environment requires an antifouling surface with a desired corrosion resistance for Ti and its alloys. In order to achieve the desired antifouling properties, micro-arc oxidation (MAO) was used to prepare a Cu-doped TiO2 coating. The microstructure of the Cu-doped TiO2 coating was investigated by TF-XRD, SEM, and other characterization techniques, and its antifouling and anticorrosion properties were also tested. The results show the effects of the incorporation of Cu (~1.73 wt.%) into TiO2 to form a Cu-doped TiO2, namely, a Ti–Cu coating. The porosity (~4.8%) and average pore size (~0.42 μm) of the Ti–Cu coating are smaller than the porosity (~5.6%) and average pore size (~0.66 μm) of Ti–blank coating. In addition, there is a significant reduction in the amount of SRB adhesion on the Ti–Cu coating compared to the Ti–blank coating under the same conditions, while there is little difference in corrosion resistance between the two coatings. There, the addition of copper helps to improve the fouling resistance of TiO2 coatings without compromising their corrosion resistance. Our work provides a practical method to improve the antifouling function of metallic Ti substrates, which could promote the application of Ti in the petroleum industry.
Two-Dimensional Damage Localization Using a Piezoelectric Smart Aggregate Approach—Implementation on Arbitrary Shaped Concrete Plates
Authors: Marković Nemanja , Grdić Dušan , Stojković Nenad , Topličić-Ćurčić Gordana , Živković Darko
Published: December 2023

This paper presents the application of a hybrid approach for damage localization in concrete plates of arbitrary geometric shapes and a constant thickness. The hybrid algorithm utilizes fast discrete wavelet transformation, energy approach and time of flight criteria for the purpose of the localization of single- and multi-damage problems inside or on the periphery of concrete plates. A brief theoretical background of the hybrid method as well as numerical procedures for modeling the piezoelectric smart aggregate and ultrasonic wave propagation are presented. Experimental and numerical verification of the damage localization were performed on square samples/models with one or two damages and with 16 positions of piezoelectric smart actuator/sensor aggregates. After the verification of the hybrid method, a numerical simulation was performed on models with one or two damages for plates of arbitrary geometric shapes. Based on the obtained results, it was concluded that the proposed method can be applied to damage localization in concrete plates of arbitrary geometric shapes. The presented method and numerical procedure can be further used in research through varying the geometry, number and position of damages as well as the number and position of piezoelectric smart aggregates.
Two-Stage Leaching of PCBs Using Sulfuric and Nitric Acid with the Addition of Hydrogen Peroxide and Ozone
Authors: Lisińska Magdalena , Wojtal Tomasz , Saternus Mariola , Willner Joanna , Rzelewska-Piekut Martyna , Nowacki Krzysztof
Published: December 2023

The paper presents the possibility of recovering metals from printed circuit boards (PCBs) of spent mobile phones using the hydrometallurgical method. Two-stage leaching of Cu(II), Fe(III), Sn(IV), Zn(II), Ni(II) and Pb(II) with H2SO4 (2 and 5 M) and HNO3 (2 M) with the addition of H2O2 (10 and 30%) and O3 (9 or 15 g/h) was conducted at various process conditions (temperature—313, 333 and 353 K, time—60, 120, 240, 300 min, type and concentration of leaching agent, type and concentration of oxidant, solid–liquid ratio (S/L)), allowing for a high or total metals leaching rate. The use of two leaching stages allows for the preservation of selectivity, separation and recovery of metals: in the first stage of Fe(III), Sn(IV) and in the second stage of the remaining tested metal ions, i.e., Cu(II), Zn(II), Ni(II) and Pb(II). Removing Fe from the tested PCBs’ material at the beginning of the process eliminates the need to use magnetic methods, the purpose of which is to separate magnetic metal particles (ferrous) from non-magnetic (non-ferrous) particles; these procedures involve high operating costs. Since the leaching of Cu(II) ions with sulfuric(VI) acid practically does not occur (less than 1%), this allows for almost complete transfer of these ions into the solution in the second stage of leaching. Moreover, to speed up the process and not generate too many waste solutions, oxidants in the form of hydrogen peroxide and ozone were used. The best degree of leaching of all tested metal ions was obtained when 2 M sulfuric(VI) acid at 353 K was used in the 1st research stage, and 2 M nitric(V) acid and 9 g/h O3 at 298 K in the 2nd stage of leaching, which allowed it to be totally leached 100% of Fe(III), Cu(II), Sn(IV), Zn(II), Ni(II) and 90% Pb(II).
High Emissivity MoSi2-SiC-Al2O3 Coating on Rigid Insulation Tiles with Enhanced Thermal Protection Performance
Authors: Yang Xukun , Wan Yange , Li Jiancun , Liu Jiachen , Wang Mingchao , Tao Xin
Published: December 2023

High emissivity coatings with sol as the binder have the advantages of room temperature curing, good thermal shock resistance, and high emissivity; however, only silica sol has been used in the current systems. In this study, aluminum sol was used as the binder for the first time, and MoSi2 and SiC were used as emittance agents to prepare a high emissivity MoSi2-SiC-Al2O3 coating on mullite insulation tiles. The evolution of structure and composition at 1000–1400 °C, the spectral emissivity from 200 nm to 25 μm, and the insulation performance were studied. Compared with the coating with silica sol as a binder, the MoSi2-SiC-Al2O3 coating has better structural uniformity and greater surface roughness and can generate mullite whiskers at lower temperatures. The total emissivity is 0.922 and 0.897, respectively, at the wavelength range of 200–2500 nm and 2.5–25 μm, and the superior emissivity at a low wavelength (<10 μm) is related to a higher surface roughness and reduced feature absorption. The emissivity reduction related to the oxidation of emittance agents at a high temperature (−10.2%) is smaller than that of the silica-sol-bonded coating (−18.6%). The cold surface temperature of the coated substrate is 215 °C lower than the bare substrate, suggesting excellent thermal insulation performance of the coating.