bluuebunny/crossref_metadata_2025 huggingface dataset:
Ion-Exchange Strategy Enabling Direct Reformation of Unreliable Perfluorinated Cationic Polymer for Robust Proton Exchange Membrane towards Hydrogen Fuel Cells
Authors: Xie Xuqiu , Jia Wenjing , Liu Changyuan , Li Yongzhe , Xu Anhou , Liu Xundao
Published: June 2024

Perfluorosulfonated anionic ionomers are known for their robust ion conductivity and chemical and mechanical stability. However, the structure and transport property degradation of perfluorinated cationic polymers (PfCPs) are not well understood. Herein, we propose an ion-exchange strategy to identify the structural degradation, ion transport mechanisms, and architectural reformation of PfCPs. Particularly, we demonstrate that the utility of a –SO2–N+ strategy employing the Menshutkin reaction cannot yield reliable PfCPs and anion-exchange membranes, but can yield an unreliable zwitterionic intermediate (cations–anions molar ratio is approximately 7.6%). Moreover, the degradation products were efficiently reformed as proton exchange membranes (PEMs), and the as-reformed PEMs achieved an ion-exchange capacity (IEC) value (0.89 mmol g−1), meanwhile retaining more than 94.7% of their initial capacity. Furthermore, the fuel cell assembled with reformed PEMs displayed a power density of 0.91 Wcm−2 at 2.32 A cm−2, which was 90.1% of that of the robust perfluorosulfonic acid PEMs. Our combined findings shed some fresh light on the state of understanding of the structure–property relationship in PfCPs.
Metaheuristic Optimization Methods in Energy Community Scheduling: A Benchmark Study
Authors: Gomes Eduardo , Pereira Lucas , Esteves Augusto , Morais Hugo
Published: June 2024

The prospect of the energy transition is exciting and sure to benefit multiple aspects of daily life. However, various challenges, such as planning, business models, and energy access are still being tackled. Energy Communities have been gaining traction in the energy transition, as they promote increased integration of Renewable Energy Sources (RESs) and more active participation from the consumers. However, optimization becomes crucial to support decision making and the quality of service for the effective functioning of Energy Communities. Optimization in the context of Energy Communities has been explored in the literature, with increasing attention to metaheuristic approaches. This paper contributes to the ongoing body of work by presenting the results of a benchmark between three classical metaheuristic methods—Differential Evolution (DE), the Genetic Algorithm (GA), and Particle Swarm Optimization (PSO)—and three more recent approaches—the Mountain Gazelle Optimizer (MGO), the Dandelion Optimizer (DO), and the Hybrid Adaptive Differential Evolution with Decay Function (HyDE-DF). Our results show that newer methods, especially the Dandelion Optimizer (DO) and the Hybrid Adaptive Differential Evolution with Decay Function (HyDE-DF), tend to be more competitive in terms of minimizing the objective function. In particular, the Hybrid Adaptive Differential Evolution with Decay Function (HyDE-DF) demonstrated the capacity to obtain extremely competitive results, being on average 3% better than the second-best method while boasting between around 2× and 10× the speed of other methods. These insights become highly valuable in time-sensitive areas, where obtaining results in a shorter amount of time is crucial for maintaining system operational capabilities.
SMC Algorithms in T-Type Bidirectional Power Grid Converter
Authors: Sawiński Albert , Chudzik Piotr , Tatar Karol
Published: June 2024

In this paper, the implementation of sliding mode control algorithms for the case of power grid current regulation in a T-type bidirectional inverter system connected via an LCL filter to the power grid is proposed and presented. A mathematical model of such a system has been proposed, which was then implemented in a simulation environment. The method of designing sliding controllers using the Lyapunov method to conduct a stability proof is presented. The article includes a comparative analysis of two sliding mode control algorithms: the classic one, which includes equivalent control, discontinuous part, and proportional reaching law, and the hybrid one, in which the discontinuous part and reaching law were modified.
Enzyme Activity Stoichiometry Suggests That Fertilization, Especially Nitrogen Fertilization, Alleviates Nutrient Limitation of Soil Microorganisms in Moso Bamboo Forests
Authors: Chu Haoyu , Su Wenhui , Zhou Yaqi , Wang Ziye , Long Yongmei , Sun Yutong , Fan Shaohui
Published: June 2024

Rational application of N fertilizer is essential for maintaining the long-term productivity of Moso bamboo forests. Microbial activity is a crucial indicator of soil quality. Changes in soil nutrient resources due to N addition can lead to microbial nutrient limitations, thereby impeding the maintenance of soil quality. Currently, there is limited research on the effects of N application on microbial nutrient limitations in Moso bamboo forest soils. To examine the changes in extracellular enzyme activity and microbial nutrient limitations in Moso bamboo forest soils following N application, we conducted an N application experiment in northern Guizhou. The findings revealed that the N3 treatment (726 kg·N·hm−2·yr−1) significantly reduced β-glucosidase (BG) activity by 27.61% compared to the control group (no fertilization). The N1 (242 kg·N·hm−2·yr−1), N2 (484 kg·N·hm−2·yr−1), and N3 treatments notably increased the activities of leucine aminopeptidase (LAP) and N-acetyl-β-D-glucosidase (NAG) by 11.45% to 15.79%. Acid phosphatase (ACP) activity remained unaffected by fertilization. N application treatments significantly decreased the C:Ne and C:Pe ratios, while the N:Pe ratio was less influenced by N fertilizer application. Scatter plots and vector characteristics of enzyme activity stoichiometry suggested that microorganisms in the study area were limited by C and N, and N fertilizer application reduced the vector length and increased the vector angle, indicating that N application alleviated the C and N limitation of microorganisms in Moso bamboo forests. Redundancy Analysis (RDA) demonstrated that microbial biomass phosphorus (MBP) was the most critical factor affecting extracellular enzyme activity and stoichiometry. Furthermore, Random Forest Regression analysis identified MBP and the N:Pm ratio as the most significant factors influencing microbial C and N limitation, respectively. The study demonstrated that N application modulates the microbial nutrient acquisition strategy by altering soil nutrient resources in Moso bamboo forests. Formulating fertilizer application strategies based on microbial nutrient requirements is more beneficial for maintaining soil quality and sustainably managing Moso bamboo forests. Additionally, our study offers a theoretical reference for understanding carbon cycling in bamboo forest ecosystems in the context of substantial N inputs.
A Hybrid Method for Individual Tree Detection in Broadleaf Forests Based on UAV-LiDAR Data and Multistage 3D Structure Analysis
Authors: Deng Susu , Jing Sishuo , Zhao Huanxin
Published: June 2024

Individual tree detection and segmentation in broadleaf forests have always been great challenges due to the overlapping crowns, irregular crown shapes, and multiple peaks in large crowns. Unmanned aerial vehicle (UAV)-borne light detection and ranging (LiDAR) is a powerful tool for acquiring high-density point clouds that can be used for both trunk detection and crown segmentation. A hybrid method that combines trunk detection and crown segmentation is proposed to detect individual trees in broadleaf forests based on UAV-LiDAR data. A trunk point distribution indicator-based approach is first applied to detect potential trunk positions. The treetops extracted from a canopy height model (CHM) and the crown segments obtained by applying a marker-controlled watershed segmentation to the CHM are used to identify potentially false trunk positions. Finally, the three-dimensional structures of trunks and branches are analyzed at each potentially false trunk position to distinguish between true and false trunk positions. The method was evaluated on three plots in subtropical urban broadleaf forests with varying proportions of evergreen trees. The F-score in three plots ranged from 0.723 to 0.829, which are higher values than the F-scores derived by a treetop detection method (0.518–0.588) and a point cloud-based individual tree segmentation method (0.479–0.514). The influences of the CHM resolution (0.25 and 0.1 m) and the data acquisition season (leaf-off and leaf-on) on the final individual tree detection result were also evaluated. The results indicated that using the CHM with a 0.25 m resolution resulted in under-segmentation of crowns and higher F-scores. The data acquisition season had a small influence on the individual tree detection result when using the hybrid method. The proposed hybrid method needs to specify parameters based on prior knowledge of the forest. In addition, the hybrid method was evaluated in small-scale urban broadleaf forests. Further research should evaluate the hybrid method in natural forests over large areas, which differ in forest structures compared to urban forests.
Improved Particle Filter in Machine Learning-Based BLE Fingerprinting Method to Reduce Indoor Location Estimation Errors
Authors: Qian Jingshi , Li Jiahe , Komuro Nobuyoshi , Kim Won-Suk , Yoo Younghwan
Published: June 2024

Indoor position fingerprint-based location estimation methods have been widely used by applications on smartphones. In these localization estimation methods, it is very popular to use the RSSI (Received Signal Strength Indication) of signals to represent the position fingerprint. This paper proposes the design of a particle filter for reducing the estimation error of the machine learning-based indoor BLE location fingerprinting method. Unlike the general particle filter, taking into account the distance, the proposed system designs improved likelihood functions, considering the coordinates based on fingerprint points using mean and variance of RSSI values, combining the particle filter with the k-NN (k-Nearest Neighbor) algorithm to realize the reduction in indoor positioning error. The initial position is estimated by the position fingerprinting method based on the machine learning method. By comparing the fingerprint method based on k-NN with general particle filter processing, and the fingerprint estimation method based on only k-NN or SVM (Support Vector Machine), experiment results showed that the proposed method has a smaller minimum error and a better average error than the conventional method.
IMTIBOT: An Intelligent Mitigation Technique for IoT Botnets
Authors: Garg Umang , Kumar Santosh , Mahanti Aniket
Published: June 2024

The tremendous growth of the Internet of Things (IoT) has gained a lot of attention in the global market. The massive deployment of IoT is also inherent in various security vulnerabilities, which become easy targets for hackers. IoT botnets are one type of critical malware that degrades the performance of the IoT network and is difficult to detect by end-users. Although there are several traditional IoT botnet mitigation techniques such as access control, data encryption, and secured device configuration, these traditional mitigation techniques are difficult to apply due to normal traffic behavior, similar packet transmission, and the repetitive nature of IoT network traffic. Motivated by botnet obfuscation, this article proposes an intelligent mitigation technique for IoT botnets, named IMTIBoT. Using this technique, we harnessed the stacking of ensemble classifiers to build an intelligent system. This stacking classifier technique was tested using an experimental testbed of IoT nodes and sensors. This system achieved an accuracy of 0.984, with low latency.
Learning Modality Consistency and Difference Information with Multitask Learning for Multimodal Sentiment Analysis
Authors: Fang Cheng , Liang Feifei , Li Tianchi , Guan Fangheng
Published: June 2024

The primary challenge in Multimodal sentiment analysis (MSA) lies in developing robust joint representations that can effectively learn mutual information from diverse modalities. Previous research in this field tends to rely on feature concatenation to obtain joint representations. However, these approaches fail to fully exploit interactive patterns to ensure consistency and differentiation across different modalities. To address this limitation, we propose a novel framework for multimodal sentiment analysis, named CDML (Consistency and Difference using a Multitask Learning network). Specifically, CDML uses an attention mechanism to assign the attention weights of each modality efficiently. Adversarial training is used to obtain consistent information between modalities. Finally, the difference among the modalities is acquired by the multitask learning framework. Experiments on two benchmark MSA datasets, CMU-MOSI and CMU-MOSEI, showcase that our proposed method outperforms the seven existing approaches by at least 1.3% for Acc-2 and 1.7% for F1.
Wildfire Susceptibility Prediction Based on a CA-Based CCNN with Active Learning Optimization
Authors: Yu Qiuping , Zhao Yaqin , Yin Zixuan , Xu Zhihao
Published: June 2024

Wildfires cause great losses to the ecological environment, economy, and people’s safety and belongings. As a result, it is crucial to establish wildfire susceptibility models and delineate fire risk levels. It has been proven that the use of remote sensing data, such as meteorological and topographical data, can effectively predict and evaluate wildfire susceptibility. Accordingly, this paper converts meteorological and topographical data into fire-influencing factor raster maps for wildfire susceptibility prediction. The continuous convolutional neural network (CCNN for short) based on coordinate attention (CA for short) can aggregate different location information into channels of the network so as to enhance the feature expression ability; moreover, for different patches with different resolutions, the improved CCNN model does not need to change the structural parameters of the network, which improves the flexibility of the network application in different forest areas. In order to reduce the annotation of training samples, we adopt an active learning method to learn positive features by selecting high-confidence samples, which contributes to enhancing the discriminative ability of the network. We use fire probabilities output from the model to evaluate fire risk levels and generate the fire susceptibility map. Taking Chongqing Municipality in China as an example, the experimental results show that the CA-based CCNN model has a better classification performance; the accuracy reaches 91.7%, and AUC reaches 0.9487, which is 5.1% and 2.09% higher than the optimal comparative method, respectively. Furthermore, if an accuracy of about 86% is desired, our method only requires 50% of labeled samples and thus saves about 20% and 40% of the labeling efforts compared to the other two methods, respectively. Ultimately, the proposed model achieves the balance of high prediction accuracy and low annotation cost and is more helpful in classifying fire high warning zones and fire-free zones.
Effects of Dietary Supplementation with Endogenous Probiotics Bacillus subtilis on Growth Performance, Immune Response and Intestinal Histomorphology of Juvenile Rainbow Trout (Oncorhynchus mykiss)
Authors: Wang Jing , Fan Dan , Zhao Ran , Lu Tongyan , Li Shaowu , Wang Di
Published: June 2024

The rainbow trout (Oncorhynchus mykiss) is an important commercial fish. Studies have shown that probiotics can promote the healthy growth of fish. In this study, we assessed the impact of an endogenous Bacillus subtilis strain (RT-BS07) on the growth, survival and immunological response of juvenile rainbow trout. Additionally, the morphology of rainbow trout’s intestinal tissue was measured. Control (CT) and experimental groups (B) were fed with conventional and probiotic-supplemented diets (1.0 × 108 CFU per gram) for 42 days, respectively. Following feeding, a challenge experiment was carried out with Aeromonas hydrophila at 1.0 × 107 CFU/mL to determine the experimental fish’s tolerance to the bacteria. The results showed that the weight gain rate (WGR) in group B was 118.2%, which was significantly higher than that in group CT (54.86%) after 42 days. The height of intestinal villi and the number of goblet cells increased in group B, thus increasing the resistance of rainbow trout to pathogenic bacteria. The alkaline phosphatase (AKP) activity (U/mg prot) in the liver, spleen and intestinal tissues of group B was significantly higher than that in the CT group. The expression of interleukin-1β (IL-1β) in the intestinal tissue of group B was 6-fold higher than that in group CT. Furthermore, the expression of growth hormone-2 (GH-2) in the spleen was 3-fold higher than that in group CT. After 12 days of A. hydrophila injection, the survival rate was 40% and 70% in group CT and group B, respectively. Collectively, the present study demonstrated that the addition of endogenous B. subtilis strain (1.0 × 108 CFU per gram) to the feed can effectively promote the growth of rainbow trout and enhance immunity, which is beneficial to rainbow trout culture.
Unveiling Temporal Cyclicities in Seismic b-Values and Major Earthquake Events in Japan by Local Singularity Analysis and Wavelet Methods
Authors: Li Siyuan , Zhou Yuanzhi , Cheng Qiuming
Published: June 2024

Studying the temporal characteristics of earthquake activity contributes to enhancing earthquake prediction capabilities. The seismic b-value is a key indicator describing the relationship between seismic frequency and magnitude. This study investigates the correlation between the occurrence of major earthquakes and seismic b-values using earthquake activity records in Japan from 1990 to 2023. Local singularity analysis and wavelet analysis of earthquake frequency and b-value time series reveal significant 5-year periodic features in seismic activity in Japan. Furthermore, our research identifies that this periodicity is also prominent in major earthquakes with magnitudes of 7 and above. Additionally, through a detailed analysis of the cross-correlation between seismic b-values and the occurrence time of major earthquakes, we uncover a notable pattern: major earthquakes often occur approximately two years after the peak of seismic b-values. This discovery offers a new perspective on earthquake prediction and may play a crucial role in future earthquake early warning systems.
Effects of Self-Leadership on Nursing Professionalism among Nursing Students: The Mediating Effects of Positive Psychological Capital and Consciousness of Calling
Authors: Seo Jiyoung , Ko Hana
Published: June 2024

To provide high-quality nursing care, nursing education requires the basic quality of self-leadership from professional nurses so that they can make self-directed and responsible judgments and decisions. Therefore, this study aimed to investigate relationships among self-leadership, positive psychological capital, consciousness of calling, and nursing professionalism in nursing students. A cross-sectional online survey of 202 students from two universities in South Korea was conducted between August and September 2022, using a convenience sampling method. A structured questionnaire was used to collect data. Data were analyzed using descriptive statistics, Pearson’s correlation coefficient analysis, and bootstrapping using Hayes’ PROCESS macro for mediation. A significant positive correlation was found between self-leadership, positive psychological capital, consciousness of calling, and nursing professionalism. Positive psychological capital and consciousness of calling showed an indirect mediating effect on the relationship between self-leadership and nursing professionalism. To improve nursing professionalism, programs should be developed to educate nursing students, strengthen their self-leadership skills, and increase the influence of positive psychological capital and consciousness of calling for nursing. This will ultimately contribute to improving the quality of patient care by fostering competent nursing experts.
Mindfulness, Gut–Brain Axis, and Health-Related Quality of Life: The Paradigm of IBD Patients
Authors: Christodoulou Efstratios , Mpali Tsambika , Dimitriadou Maroula-Eleni , Koutelidakis Antonios E.
Published: June 2024

Health-related quality of life (HRQoL) is a comprehensive measure that evaluates an individual’s well-being across physical, mental, and social dimensions. Enhancing HRQoL, particularly in individuals with chronic conditions like inflammatory bowel diseases (IBD), necessitates a holistic approach. Mindfulness, a scientifically supported strategy for managing anxiety, has shown promise in improving both physical and mental health. Its benefits may be partly explained through its effects on the gut–brain axis (GBA), a bidirectional communication link between the gastrointestinal system and the central nervous system. By exploring the interplay between mindfulness and the GBA, this study aims to uncover how these elements collectively influence HRQoL in both healthy individuals and those with IBD, offering insights into potential therapeutic pathways. A cross-sectional investigation involved 338 adults, including 50 IBD patients, utilizing validated Greek scales for Mindfulness (MAAS-15), Mediterranean Diet (14-MEDAS), and HRQoL (EQ-5D-5L). The questionnaire gathered demographic, anthropometric, and lifestyle data. Among healthy participants, EQ-5D-5L showed a moderate correlation with the MAAS-15 scale (r = 0.389, p < 0.05) and a low correlation with 14-MEDAS (r = 0.131, p < 0.05). IBD patients exhibited significantly lower mean EQ-5D-5L scores than healthy individuals (0.75 vs. 0.85, p < 0.05). MAAS-15 demonstrated a robust correlation (r = 0.414, p < 0.001) with EQ-5D-5L in IBD patients. Elevated mindfulness levels emerged as predictive factors for higher HRQoL in IBD patients (OR: 1.101, 95% CI: 1.008, 1.202, p < 0.05, compared to low mindfulness). In summary, factors influencing the GBA, including mindfulness and the Mediterranean diet, exhibit positive associations with HRQoL. Increased mindfulness levels predict better HRQoL in IBD patients, emphasizing the potential for clinical trials to validate these cross-sectional study findings.
Perinatal Outcomes of Immigrant Mothers and Their Infants Born Very Preterm across Germany
Authors: Hüning Britta M. , Jaekel Julia , Jaekel Nils , Göpel Wolfgang , Herting Egbert , Felderhoff-Müser Ursula , Spiegler Juliane , Härtel Christoph
Published: June 2024

Background: In Germany, more than 40% of infants are born to immigrant parents. Increased survival rates of very preterm (below 32 weeks gestation at birth; VP) infants have not resulted in equally improved life chances and quality of life. More information on perinatal variations in outcomes according to social inequalities, migration background, and language barriers is needed. We tested whether mothers’ immigrant status and language barriers are associated with perinatal health and short-term neonatal outcomes. Methods: The data are from the national multi-centre German Neonatal Network (GNN) cohort, including VP births from 2009 onwards. In total, 3606 (n = 1738 female) children were assessed, and 919 (n = 449 female) of these children had immigrant backgrounds. Immigrant status was operationalised as a binary variable based on the children’s mothers’ countries of birth (born in Germany vs. foreign-born). Self-reported home language (L1) was used to calculate the average linguistic distance to German as one continuous variable. Results: Mixed-effects models showed that two out of fourteen effects of interest survived the adjustment for known confounders and accounting for the nestedness of data within birth hospitals. Linguistic distance from mothers’ L1s to German was independently associated with diagnoses of preeclampsia (OR = 1.01, 95% CI = [1.00, 1.01]). Infants of foreign-born mothers had higher odds for amniotic infection syndrome (AIS; OR = 1.45 [1.13, 1.86]) than infants of German mothers. Conclusions: Our findings from this large multi-centre longitudinal cohort of VP-born children indicate that maternal immigrant status and language barriers have limited impact on perinatal health and severe neonatal outcomes. This suggests that, regardless of background or language skills, there may be few inequalities in the perinatal health of pregnant women and their newborn preterm infants.
Knowledge, Attitudes, and Practices Regarding Air Pollution among Medical Students
Authors: Rendon-Marin Santiago , Higuita-Gutiérrez Luis Felipe , Gomez-Gallego Diana Maryory
Published: June 2024

Background: Air pollution has emerged as a global public health concern. Specifically, in Medellín, Colombia, episodes of elevated air pollution have been documented. Medical students’ knowledge of air pollution is paramount for implementing future interventions directed toward patients. The aim of this research was to delineate the knowledge, attitudes, and practices regarding air pollution among medical students at a private university in Medellín. Methods: A cross-sectional study involving 352 medical students was conducted. A questionnaire was administered, generating scores ranging from 0 to 100, where a higher score signified better knowledge, attitudes, and practices. Data were analyzed using frequencies, summary measures, non-parametric tests, and linear regression. Results: In total, 31% rated the education received at the university on the relationship between health and air quality as fair to poor, and 81% perceived the air quality in the city as poor. The knowledge score was 77.8 (IQR 71.1–85.6), with 90% acknowledging that exposure to air pollution increases the risk of various diseases. The attitudes score was 82.1 (IQR 71.8–87.2), and 25.9% believed that air pollution is a multifactorial problem, rendering their actions ineffective. In terms of practices, the score was 50 (IQR 42.9–57.1), indicating that students either did not employ protective measures against pollution or used inappropriate practices such as masks or air purifiers. Regression analysis revealed no association between knowledge and practices. Conclusion: The findings of this study underscore that medical students possess commendable knowledge regarding the health effects of air pollution. However, their adoption of inappropriate practices for self-protection is evident. The lack of correlation between knowledge and practices highlights the necessity of educational initiatives to be complemented by regulatory and cultural interventions.
Antibacterial Effect of Spanish Honeys of Different Botanical Origins against Staphylococcus epidermidis
Authors: Núñez-Gómez Vanesa , San Mateo Marta , Sánchez-Martínez Lorena , Periago María Jesús
Published: June 2024

Honey is traditionally used for its medicinal properties attributed to its antibacterial and antioxidant effects. It is considered a natural alternative to conventional antibiotics. This effect has been attributed to their physico-chemical properties, as various chemical parameters can synergistically influence this effect. The aim of this study is to assess Spanish honeys of diverse botanical origins for their antibacterial efficacy against Staphylococcus epidermidis, correlating their physico-chemical attributes, (poly)phenol content, and antioxidant activity. The methods included colour determination via two methodologies, acidity, pH, moisture content, and sugar concentration. (Poly)phenol content was quantified using the Folin-Ciocalteau method, while antioxidant activity was evaluated via the FRAP method. Subsequently, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against S. epidermidis were investigated with different concentrations of honeys. The results revealed a direct relationship between honey darkness, (poly)phenol concentration, antioxidant activity, and antibacterial efficacy. Darker honeys exhibited higher (poly)phenol levels, greater antioxidant activity, and consequently, lower MIC and MBC values, showing enhanced antibacterial properties. These findings underscore the potential of honey as a therapeutic agent against S. epidermidis, particularly in wound healing applications to avoid infection. Further research into honey’s multifaceted properties is warranted to unveil novel therapeutic avenues in healthcare.
Calcium Regulation of Connexin Hemichannels
Authors: Bayraktar Erva , Lopez-Pigozzi Diego , Bortolozzi Mario
Published: June 2024

Connexin hemichannels (HCs) expressed at the plasma membrane of mammalian cells are of paramount importance for intercellular communication. In physiological conditions, HCs can form gap junction (GJ) channels, providing a direct diffusive path between neighbouring cells. In addition, unpaired HCs provide conduits for the exchange of solutes between the cytoplasm and the extracellular milieu, including messenger molecules involved in paracrine signalling. The synergistic action of membrane potential and Ca2+ ions controls the gating of the large and relatively unselective pore of connexin HCs. The four orders of magnitude difference in gating sensitivity to the extracellular ([Ca2+]e) and the cytosolic ([Ca2+]c) Ca2+ concentrations suggests that at least two different Ca2+ sensors may exist. While [Ca2+]e acts as a spatial modulator of the HC opening, which is most likely dependent on the cell layer, compartment, and organ, [Ca2+]c triggers HC opening and the release of extracellular bursts of messenger molecules. Such molecules include ATP, cAMP, glutamate, NAD+, glutathione, D-serine, and prostaglandins. Lost or abnormal HC regulation by Ca2+ has been associated with several diseases, including deafness, keratitis ichthyosis, palmoplantar keratoderma, Charcot–Marie–Tooth neuropathy, oculodentodigital dysplasia, and congenital cataracts. The fact that both an increased and a decreased Ca2+ sensitivity has been linked to pathological conditions suggests that Ca2+ in healthy cells finely tunes the normal HC function. Overall, further investigation is needed to clarify the structural and chemical modifications of connexin HCs during [Ca2+]e and [Ca2+]c variations. A molecular model that accounts for changes in both Ca2+ and the transmembrane voltage will undoubtedly enhance our interpretation of the experimental results and pave the way for developing therapeutic compounds targeting specific HC dysfunctions.
A Novel Strategy for the Treatment of Aneurysms: Inhibition of MMP-9 Activity through the Delivery of TIMP-1 Encoding Synthetic mRNA into Arteries
Authors: Golombek Sonia , Doll Isabelle , Kaufmann Louisa , Lescan Mario , Schlensak Christian , Avci-Adali Meltem
Published: June 2024

Aneurysms pose life-threatening risks due to the dilatation of the arteries and carry a high risk of rupture. Despite continuous research efforts, there are still no satisfactory or clinically effective pharmaceutical treatments for this condition. Accelerated inflammatory processes during aneurysm development lead to increased levels of matrix metalloproteinases (MMPs) and destabilization of the vessel wall through the degradation of the structural components of the extracellular matrix (ECM), mainly collagen and elastin. Tissue inhibitors of metalloproteinases (TIMPs) directly regulate MMP activity and consequently inhibit ECM proteolysis. In this work, the synthesis of TIMP-1 protein was increased by the exogenous delivery of synthetic TIMP-1 encoding mRNA into aortic vessel tissue in an attempt to inhibit MMP-9. In vitro, TIMP-1 mRNA transfection resulted in significantly increased TIMP-1 protein expression in various cells. The functionality of the expressed protein was evaluated in an appropriate ex vivo aortic vessel model. Decreased MMP-9 activity was detected using in situ zymography 24 h and 48 h post microinjection of 5 µg TIMP-1 mRNA into the aortic vessel wall. These results suggest that TIMP-1 mRNA administration is a promising approach for the treatment of aneurysms.
The Immune Checkpoint BTLA in Oral Cancer: Expression Analysis and Its Correlation to Other Immune Modulators
Authors: Ries Jutta , Trumet Leah , Hahn Alina , Kunater Lina , Lutz Rainer , Geppert Carol , Kesting Marco , Weber Manuel
Published: June 2024

In oral squamous cell carcinoma (OSCC) tissues, an immunotolerant situation triggered by immune checkpoints (ICPs) can be observed. Immune checkpoint inhibitors (ICIs) against the PD1/PD-L axis are used with impressive success. However, the response rate is low and the development of acquired resistance to ICI treatment can be observed. Therefore, new treatment strategies especially involving immunological combination therapies need to be developed. The novel negative immune checkpoint BTLA has been suggested as a potential biomarker and target for antibody-based immunotherapy. Moreover, improved response rates could be displayed for tumor patients when antibodies directed against BTLA were used in combination with anti-PD1/PD-L1 therapies. The aim of the study was to check whether the immune checkpoint BTLA is overexpressed in OSCC tissues compared to healthy oral mucosa (NOM) and could be a potential diagnostic biomarker and immunological target in OSCC. In addition, correlation analyses with the expression of other checkpoints should clarify more precisely whether combination therapies are potentially useful for the treatment of OSCC. A total of 207 tissue samples divided into 2 groups were included in the study. The test group comprised 102 tissue samples of OSCC. Oral mucosal tissue from 105 healthy volunteers (NOM) served as the control group. The expression of two isoforms of BTLA (BTLA-1/2), as well as PD1, PD-L1/2 and CD96 was analyzed by RT-qPCR. Additionally, BTLA and CD96 proteins were detected by IHC. Expression levels were compared between the two groups, the relative differences were calculated, and statistical relevance was determined. Furthermore, the expression rates of the immune checkpoints were correlated to each other. BTLA expression was significantly increased in OSCC compared to NOM (pBTLA_1 = 0.003; pBTLA_2 = 0.0001, pIHC = 0.003). The expression of PD1, its ligands PD-L1 and PD-L2, as well as CD96, were also significantly increased in OSCC (p ≤ 0.001). There was a strong positive correlation between BTLA expression and that of the other checkpoints (p < 0.001; ρ ≥ 0.5). BTLA is overexpressed in OSCC and appears to be a relevant local immune checkpoint in OSCC. Thus, antibodies directed against BTLA could be potential candidates for immunotherapies, especially in combination with ICI against the PD1/PD-L axis and CD96.
Exosomes Derived from Adipose Mesenchymal Stem Cells Promote Regeneration of Injured Liver in Minipigs
Authors: Wang Yue , Piao Chenxi , Liu Tao , Lu Xiangyu , Ma Yajun , Zhang Jiantao , Ma Haiyang , Wang Hongbin
Published: June 2024

Hepatic ischemia/reperfusion injury (IRI) is an important factor affecting liver regeneration and functional recovery postoperatively. Many studies have suggested that mesenchymal stem cells (MSCs) contribute to hepatic tissue repair and functional recovery through paracrine mechanisms mediated by exosomes. Minipigs exhibit much more similar characteristics of the liver to those of humans than rodents. This study aimed to explore whether exosomes from adipose-derived MSCs (ADSCs-exo) could actively promote liver regeneration after hepatectomy combined with HIRI in minipigs and the role they play in the cell proliferation process. This study also compared the effects and differences in the role of ADSCs and ADSCs-exo in the inflammatory response and liver regeneration. The results showed that ADSCs-exo suppressed histopathological changes and reduced inflammatory infiltration in the liver; significantly decreased levels of ALT, TBIL, HA, and the pro-inflammatory cytokines TNF-α, IL-6, and CRP; increased levels of the anti-inflammatory cytokine IL-10 and the pro-regeneration factors Ki67, PCNA, CyclinD1, HGF, STAT3, VEGF, ANG1, ANG2; and decreased levels of the anti-regeneration factors SOCS3 and TGF-β. These indicators above showed similar changes with the ADSCs intervention group. Indicating that ADSCs-exo can exert the same role as ADSCs in regulating inflammatory responses and promoting liver regeneration. Our findings provide experimental evidence for the possibility that ADSCs-exo could be considered a safe and effective cell-free therapy to promote regeneration of injured livers.
Reactive Oxygen Species Induction by Hepatitis B Virus: Implications for Viral Replication in p53-Positive Human Hepatoma Cells
Authors: Jeong Yuna , Han Jiwoo , Jang Kyung Lib
Published: June 2024

Hepatitis B virus (HBV) infects approximately 300 million people worldwide, causing chronic infections. The HBV X protein (HBx) is crucial for viral replication and induces reactive oxygen species (ROS), leading to cellular damage. This study explores the relationship between HBx-induced ROS, p53 activation, and HBV replication. Using HepG2 and Hep3B cell lines that express the HBV receptor NTCP, we compared ROS generation and HBV replication relative to p53 status. Results indicated that HBV infection significantly increased ROS levels in p53-positive HepG2-NTCP cells compared to p53-deficient Hep3B-NTCP cells. Knockdown of p53 reduced ROS levels and enhanced HBV replication in HepG2-NTCP cells, whereas p53 overexpression increased ROS and inhibited HBV replication in Hep3B-NTCP cells. The ROS scavenger N-acetyl-L-cysteine (NAC) reversed these effects. The study also found that ROS-induced degradation of the HBx is mediated by the E3 ligase Siah-1, which is activated by p53. Mutations in p53 or inhibition of its transcriptional activity prevented ROS-mediated HBx degradation and HBV inhibition. These findings reveal a p53-dependent negative feedback loop where HBx-induced ROS increases p53 levels, leading to Siah-1-mediated HBx degradation and HBV replication inhibition. This study offers insights into the molecular mechanisms of HBV replication and identifies potential therapeutic targets involving ROS and p53 pathways.
Hydrogel Wound Dressings Accelerating Healing Process of Wounds in Movable Parts
Authors: Yu Pengcheng , Wei Liqi , Yang Zhiqi , Liu Xin , Ma Hongxia , Zhao Jian , Liu Lulu , Wang Lili , Chen Rui , Cheng Yan
Published: June 2024

Skin is the largest organ in the human body and requires proper dressing to facilitate healing after an injury. Wounds on movable parts, such as the elbow, knee, wrist, and neck, usually undergo delayed and inefficient healing due to frequent movements. To better accommodate movable wounds, a variety of functional hydrogels have been successfully developed and used as flexible wound dressings. On the one hand, the mechanical properties, such as adhesion, stretchability, and self-healing, make these hydrogels suitable for mobile wounds and promote the healing process; on the other hand, the bioactivities, such as antibacterial and antioxidant performance, could further accelerate the wound healing process. In this review, we focus on the recent advances in hydrogel-based movable wound dressings and propose the challenges and perspectives of such dressings.
Diagnostic and Prognostic Markers for Pancreatitis and Pancreatic Ductal Adenocarcinoma
Authors: Kantheti Havish S. , Hale Michael A. , Pal Choudhuri Shreoshi , Huang Huocong , Wang Xu-dong , Zolghadri Yalda , Innamorati Giulio , Manikonda Sai Prasada Rao , Reddy Naviya , Reddy Sarthak , Kollipara Rahul K. , Lumani Valbona , Girard Luc , Bezrukov Yakov , Demenkov Pavel , MacDonald Raymond J. , Brekken Rolf A. , Yu Yonghao , Wilkie Thomas M.
Published: June 2024

Diagnostic markers are desperately needed for the early detection of pancreatic ductal adenocarcinoma (PDA). We describe sets of markers expressed in temporal order in mouse models during pancreatitis, PDA initiation and progression. Cell type specificity and the differential expression of PDA markers were identified by screening single cell (sc) RNAseq from tumor samples of a mouse model for PDA (KIC) at early and late stages of PDA progression compared to that of a normal pancreas. Candidate genes were identified from three sources: (1) an unsupervised screening of the genes preferentially expressed in mouse PDA tumors; (2) signaling pathways that drive PDA, including the Ras pathway, calcium signaling, and known cancer genes, or genes encoding proteins that were identified by differential mass spectrometry (MS) of mouse tumors and conditioned media from human cancer cell lines; and (3) genes whose expression is associated with poor or better prognoses (PAAD, oncolnc.org). The developmental progression of PDA was detected in the temporal order of gene expression in the cancer cells of the KIC mice. The earliest diagnostic markers were expressed in epithelial cancer cells in early-stage, but not late-stage, PDA tumors. Other early markers were expressed in the epithelium of both early- and late-state PDA tumors. Markers that were expressed somewhat later were first elevated in the epithelial cancer cells of the late-stage tumors, then in both epithelial and mesenchymal cells, or only in mesenchymal cells. Stromal markers were differentially expressed in early- and/or late-stage PDA neoplasia in fibroblast and hematopoietic cells (lymphocytes and/or macrophages) or broadly expressed in cancer and many stromal cell types. Pancreatitis is a risk factor for PDA in humans. Mouse models of pancreatitis, including caerulein treatment and the acinar-specific homozygous deletion of differentiation transcription factors (dTFs), were screened for the early expression of all PDA markers identified in the KIC neoplasia. Prognostic markers associated with a more rapid decline were identified and showed differential and cell-type-specific expression in PDA, predominately in late-stage epithelial and/or mesenchymal cancer cells. Select markers were validated by immunohistochemistry in mouse and human samples of a normal pancreas and those with early- and late-stage PDA. In total, we present 2165 individual diagnostic and prognostic markers for disease progression to be tested in humans from pancreatitis to late-stage PDA.
The Effect of Neuronal CoQ10 Deficiency and Mitochondrial Dysfunction on a Rotenone-Induced Neuronal Cell Model of Parkinson’s Disease
Authors: Millichap Lauren , Turton Nadia , Damiani Elisabetta , Marcheggiani Fabio , Orlando Patrick , Silvestri Sonia , Tiano Luca , Hargreaves Iain P.
Published: June 2024

Parkinson’s disease (PD) is the second most prevalent neurodegenerative disorder currently affecting the ageing population. Although the aetiology of PD has yet to be fully elucidated, environmental factors such as exposure to the naturally occurring neurotoxin rotenone has been associated with an increased risk of developing PD. Rotenone inhibits mitochondrial respiratory chain (MRC) complex I activity as well as induces dopaminergic neuronal death. The aim of the present study was to investigate the underlying mechanisms of rotenone-induced mitochondrial dysfunction and oxidative stress in an in vitro SH-SY5Y neuronal cell model of PD and to assess the ability of pre-treatment with Coenzyme Q10 (CoQ10) to ameliorate oxidative stress in this model. Spectrophotometric determination of the mitochondrial enzyme activities and fluorescence probe studies of reactive oxygen species (ROS) production was assessed. Significant inhibition of MRC complex I and II–III activities was observed, together with a significant loss of neuronal viability, CoQ10 status, and ATP synthesis. Additionally, significant increases were observed in intracellular and mitochondrial ROS production. Remarkably, CoQ10 supplementation was found to reduce ROS formation. These results have indicated mitochondrial dysfunction and increased oxidative stress in a rotenone-induced neuronal cell model of PD that was ameliorated by CoQ10 supplementation.
Urtica dioica Extract Abrogates Chlorpyrifos-Induced Toxicity in Zebrafish Larvae
Authors: Mhalhel Kamel , Kadmi Yassine , Ben Chira Ahlem , Levanti Maria , Pansera Lidia , Cometa Marzio , Sicari Mirea , Germanà Antonino , Aragona Marialuisa , Montalbano Giuseppe
Published: June 2024

Chlorpyrifos (CPF) is a widely used organophosphate insecticide, though its excessive use causes environmental contamination, raising concerns about its adverse effects on human health. In this regard, Urtica dioica stands out as a promising candidate for counteracting chemical ‘contaminant’ toxicity thanks to its therapeutic properties. Therefore, our study aimed to investigate the potential of an Urtica dioica ethanolic extract (UDE) to mitigate chlorpyrifos-induced toxicity. Eight compounds in the Urtica dioica ethanolic extract have been identified, most of which present significant potential as antioxidant, anti-inflammatory, and neuroprotective agents. Chlorpyrifos exposure altered hatching rates, increased the incidence of teratogenic effects, and upregulated the expression of brain-derived neurotrophic factor (Bdnf) in zebrafish larvae telencephalon. On the other hand, UDE demonstrated a preventive effect against CPF-induced teratogenicity, which is expressed by a lower morphological deformity rate. Moreover, the UDE showed a rather protective effect, maintaining the physiological condition of the telencephalon. Additionally, CPF altered the locomotor behavior of larvae, which was characterized by irregular swimming and increased activity. This defective behavioral pattern was slightly attenuated by the UDE. Our findings suggest that the UDE possesses significant protective properties against CPF-induced toxicity, probably conferred by its natural antioxidant and anti-inflammatory contents. Still, further research is needed to elucidate the recruited mechanisms and implicated pathways on UDE’s protective effects.
Integrated Metabolomic–Transcriptomic Analyses of Flavonoid Accumulation in Citrus Fruit under Exogenous Melatonin Treatment
Authors: Zhao Chenning , Wang Zhendong , Liao Zhenkun , Liu Xiaojuan , Li Yujia , Zhou Chenwen , Sun Cui , Wang Yue , Cao Jinping , Sun Chongde
Published: June 2024

The flavonoids in citrus fruits are crucial physiological regulators and natural bioactive products of high pharmaceutical value. Melatonin is a pleiotropic hormone that can regulate plant morphogenesis and stress resistance and alter the accumulation of flavonoids in these processes. However, the direct effect of melatonin on citrus flavonoids remains unclear. In this study, nontargeted metabolomics and transcriptomics were utilized to reveal how exogenous melatonin affects flavonoid biosynthesis in “Bingtangcheng” citrus fruits. The melatonin treatment at 0.1 mmol L−1 significantly increased the contents of seven polymethoxylated flavones (PMFs) and up-regulated a series of flavonoid pathway genes, including 4CL (4-coumaroyl CoA ligase), FNS (flavone synthase), and FHs (flavonoid hydroxylases). Meanwhile, CHS (chalcone synthase) was down-regulated, causing a decrease in the content of most flavonoid glycosides. Pearson correlation analysis obtained 21 transcription factors co-expressed with differentially accumulated flavonoids, among which the AP2/EREBP members were the most numerous. Additionally, circadian rhythm and photosynthesis pathways were enriched in the DEG (differentially expressed gene) analysis, suggesting that melatonin might also mediate changes in the flavonoid biosynthesis pathway by affecting the fruit’s circadian rhythm. These results provide valuable information for further exploration of the molecular mechanisms through which melatonin regulates citrus fruit metabolism.