Search Results (1,220)

Many rhizobia use quorum sensing (QS) systems to detect their population density and modify their symbiotic behavior with the legume host. There are three LuxRI-type QS systems in Rhizobium etli CFN42, and CinR plays a key role in symbiotic performance. However, the details of how CinR regulates the symbiotic process remain unknown. In this study, we employed the RNA-Seq method to screen differentially expressed genes between the wild-type strain and the ΔcinR mutant of R. etli CFN42. We found that most of the genes related to reactive oxygen species (ROS) were expressed at lower levels in the ΔcinR mutant than in CFN42. We also found that the ΔcinR mutant was more sensitive to H₂O₂ than to CFN42. We then showed that CinR positively regulated katG expression and possessed an affinity to bind the katG promoter in the absence of the AHL ligand. The addition of AHLs promoted CinR binding to the katG promoter and enhanced katG expression. Accumulation of H₂O₂ and O₂^•− was observed in root nodules formed by the ΔcinR mutant. Crucially, katG overexpression rescued the H₂O₂-sensitive phenotype in vitro and partially restored defective symbiotic performance in nodules formed by the ΔcinR mutant on the common bean. These results suggest that CinR globally regulates ROS scavenging gene expression in order to balance oxidative stress within root nodules, promoting nitrogenase activity of R. etli CFN42. Full article

As a highly oxidizing and toxic gas, ozone (O₃) poses significant hazards to human health and the environment even at low concentrations. Therefore, the development of ozone gas sensors that can operate stably at low temperatures while simultaneously exhibiting high response, fast response characteristics, excellent selectivity, and long-term stability remains a crucial challenge in the field of gas sensing. In this work, Pure In₂O₃ and Yb-doped urchin-like hierarchical In₂O₃ microspheres were successfully synthesized via a one-step hydrothermal method. The crystal structure, morphological features, elemental composition, and band structure of the as-prepared samples were systematically characterized by XRD, FESEM, TEM, HRTEM, XPS, and UV–vis spectroscopy. Gas-sensing tests demonstrated that Yb doping significantly enhanced the ozone-sensing performance of In₂O₃. Among all the samples, the 3%Yb-doped In₂O₃ sensor exhibited the best response toward 1 ppm ozone at 40 °C, reaching approximately 1015, which was about 11 times higher than that of pristine In₂O₃. Meanwhile, the sensor showed a response time of 172 s. In addition, the 3%Yb-doped In₂O₃ sensor exhibited good repeatability, excellent selectivity, and long-term stability. The excellent gas-sensing performance can be attributed to the electronic structure modulation and increased O_V-related oxygen defect component induced by Yb doping, as well as the enhanced gas diffusion and interfacial reaction capability provided by the urchin-like hierarchical structure. Full article

Background/Objectives: Dental anxiety represents a major challenge in paediatric dentistry and is a frequent cause of non-cooperative behaviour during dental treatment. Nitrous oxide/oxygen inhalation conscious sedation is widely used to reduce anxiety in children, while audiovisual distraction is a non-pharmacological behavioural technique aimed at diverting attention from stressful stimuli. Evidence regarding the combined effect of these two approaches during dental treatment is still limited. Methods: This randomized crossover clinical trial included 25 paediatric patients aged 4–7 years with dental anxiety and previous failed attempts at conventional dental treatment. Each child underwent two dental treatment sessions under nitrous oxide/oxygen conscious sedation, one with and one without audiovisual distraction. Anxiety and behaviour were assessed using the Modified Venham Scale and the Facial Image Scale (FIS). Vital parameters were recorded before, during, and after sedation. Results: A significant reduction in heart rate over time was observed in both groups (p < 0.05). In children aged 4–5 years, the combined audiovisual distraction and conscious sedation approach was associated with significantly lower heart rate values compared to conscious sedation alone (p < 0.05). No significant differences were found between the two approaches for behavioural scores assessed by the Venham and FIS scales. Conclusions: Although behavioural scores did not differ significantly, audiovisual distraction contributed to greater physiological stability, particularly in terms of heart rate control. This no-pharmacological approach may complement the pharmacological effects of nitrous oxide sedation by enhancing the overall sense of relaxation and comfort during dental care. Full article

Fluorescence resonance energy transfer (FRET) was implemented in a photonic crystal-structured oxygen sensing film by incorporating fluorescein isothiocyanate (FITC) with platinum octaethylporphyrin (PtOEP). The highest Stern-Volmer quenching constant (K_SV = 20.20 ± 0.25) and maximum quenching ratio (21.81 ± 0.21) were achieved at a PtOEP:FITC molar ratio of 1:1. Compared to the control, the K_SV and maximum quenching ratio increased by 56.8% and 48.4%, respectively. Additionally, imidazole was introduced into the oxygen-sensing film via a casting method. The results demonstrated that imidazole effectively modulates the energy transfer efficiency between oxygen molecules and PtOEP. Under 20% O₂ and 100% O₂ atmospheres, the fluorescence intensity of the imidazole-modified film increased by 18.4% and 52.4%, respectively. Furthermore, imidazole provided excellent protection for PtOEP, yielding a fluorescence retention rate of 99.77% ± 0.18%. Full article

Plants are constantly exposed to diverse abiotic stresses, including drought, salinity, and extreme temperatures, which severely limit growth, development, and crop productivity. These stresses disrupt physiological, biochemical, and molecular processes, leading to reduced photosynthesis, altered water and ion homeostasis, and accumulation of reactive oxygen species (ROS). Plants have evolved sophisticated sensing and signaling mechanisms to perceive these stresses, with phytohormones playing central roles in mediating adaptive responses. Key hormones, including abscisic acid (ABA), salicylic acid (SA), jasmonates (JAs), gibberellins (GAs), auxin (IAA), ethylene (ET), melatonin, and strigolactones (SLs), regulate stress tolerance by controlling stomatal behavior, root architecture, antioxidant systems, osmolyte accumulation, and stress-responsive gene expression. Importantly, these hormones operate within an intricate network of crosstalk, integrating multiple signaling pathways to balance growth and stress adaptation. Interactions among ABA, GA, JA, SA, auxin, ET, SLs, and melatonin enable plants to coordinate transcriptional regulation, protein phosphorylation, and ROS signaling, optimizing survival under fluctuating environmental conditions. Understanding the molecular mechanisms underlying hormonal crosstalk and their roles in abiotic stress tolerance provides valuable insights for developing resilient crops in the face of climate change. Full article

In this study, NiO/ZnO heterojunction materials were prepared by calcining metal–organic frameworks (MOFs). The structural and morphological characteristics of the NiO/ZnO composite were investigated using various characterization methods, including X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy. Gas-sensing tests showed that at the operating temperature of 190 °C, the NiO/ZnO heterojunction (with a molar ratio of 1:1) exhibited the highest response value (R_a/R_g = 201.7) and good selectivity toward 100 ppm n-propanol. Compared to pure ZnO and NiO, the response of NiO/ZnO was significantly improved (ZnO: 6, NiO: 14.6), with increases of 33.5-fold and 13.8-fold, respectively. The response and recovery times were 92 and 30 s, respectively. Additionally, to enable rapid identification of n-propanol gas concentrations, this study developed and validated a method by training and predicting response curves using a random forest algorithm, achieving identification of n-propanol gas at different concentrations (2–100 ppm) within 7 s. Finally, the enhanced sensing performance was mainly attributed to the formation of the interfacial p-n heterojunction between NiO and ZnO, together with increased surface active sites, oxygen vacancies, and chemisorbed oxygen species. Full article

Maintaining the pro- and antioxidative balance during pregnancy is crucial. Oxidative stress (OS) can complicate pregnancy and disrupt maternal–foetal communication, which is partly mediated by extracellular vesicles (EVs). This study investigated how OS affects EV secretion by bovine caruncular epithelial cells isolated from the established bovine placenta (4th month of gestation). To induce OS, cells were treated for 48 h with 1% cigarette smoke extract (CSE), known to increase reactive oxygen species (ROS) levels, while controls remained untreated. EVs were isolated via ultracentrifugation (UC) and size-exclusion chromatography (SEC) and characterized using Tunable Resistive Pulse Sensing (TRPS) technology, transmission electron microscopy (TEM), and Western blotting (WB). WB confirmed small-EV enrichment in fractions 5–8 of SEC by detecting CD9 and flotillin-1 markers. TRPS analysis demonstrated that OS increased EV concentration. In fractions 5–6, CSE treatment increased EV concentration from 1.79 × 10⁹ (mode diameter 127 nm) to 3.12 × 10⁹ particles/mL (122 nm). In fractions 7–8 of SEC, concentration rose from 4.48 × 10¹⁰ (84 nm) to 7.53 × 10¹⁰ particles/mL (80 nm). These data indicate that OS increases EV secretion by bovine maternal epithelial cells, providing a basis for future studies on the potential role of stress-induced EVs in foetal–maternal communication. Full article

Lake Taihu is a vital source of surface water for the Yangtze River Delta region, so effective monitoring of its water quality is essential for protecting the water source. However, most existing studies on unmanned aerial vehicle (UAV)-based water quality remote sensing have focused on single large rivers or lakes, primarily employing validation methods involving randomly selected samples. This makes it difficult to assess the generalisability of the models to unfamiliar watercourses. This study focuses on 13 inflow rivers on Xishan Island, a central island in Lake Taihu, which are characterized by short flow paths, independent catchment areas, and varying land use influences. Using a UAV multispectral remote sensing platform, we have designed a water quality monitoring and assessment framework tailored to multi-river systems with small sample sizes. First, various water body indices were developed and analysed for correlation with measured water quality parameters. Then, machine learning algorithms such as Backpropagation (BP) neural networks, Random Forest, XGBoost, Convolutional Neural Networks (CNN) and Support Vector Machines (SVM) were selected to construct retrieval models. For accuracy evaluation, a spatial independent validation strategy was employed whereby one sample was forcibly set aside from each river to constitute the validation set. Using this method, we generated spatial distribution maps of water quality parameters for the inflow rivers and evaluated the influencing factors of spatial variation in water quality by area, taking into account water body functional types and ecological characteristics. The experimental results indicate that under the conditions of spatial independent validation strategy, the SVM model achieved the highest retrieval accuracy for dissolved oxygen (R² = 0.892, RMSE = 0.414 mg/L and MRE = 0.057), whereas the XGBoost model achieved the highest retrieval accuracy for turbidity (R² = 0.853, RMSE = 0.632 NTU and MRE = 0.065). The spatial pattern of water quality exhibited a pronounced gradient: dissolved oxygen (DO) concentrations followed the order of aquaculture area rivers > agricultural area rivers > urban area rivers, while turbidity displayed the opposite trend, reflecting that surrounding land use types, phytoplankton density, and human activity intensity are the dominant factors driving the spatial differentiation of river water quality on Xishan Island in spring. The full-chain technical framework of “multi-river synchronous retrieval—spatially independent validation strategy—area mechanistic assessment” proposed in this study provides a replicable evaluation paradigm for rapid water quality monitoring of Lake Taihu islands and similar watersheds, and holds significant implications for the construction of the Lake Taihu Eco-Island and the protection of the water environment. Full article

Chronic and infected wounds remain difficult to treat due to persistent microbial burden, biofilm formation, and dysregulated inflammation. As a multifunctional polyphenol, curcumin exhibits broad-spectrum antimicrobial, anti-inflammatory, and antioxidant activities. Nevertheless, the clinical application of curcumin is constrained by its limited solubility in water, inherent instability, and insufficient bioavailability. Chitosan, a cationic polysaccharide, provides complementary advantages including intrinsic antimicrobial activity, mucoadhesion, and the capacity to form versatile delivery platforms such as nanoparticles, hydrogels, and films. This review reframes chitosan–curcumin systems as dual-function bioactive platforms in which both the carrier and payload actively contribute to therapeutic outcomes. Mechanistically, chitosan disrupts microbial membranes, enhances bioadhesion, and supports tissue regeneration, while curcumin modulates intracellular targets including reactive oxygen species, quorum sensing, and inflammatory signaling pathways. Their integration enables multimodal antimicrobial activity, improved biofilm disruption, and coordinated regulation of the wound-healing cascade. This review critically examines the structure–function relationships governing release kinetics, stability, and cytocompatibility, with particular emphasis on chitosan molecular weight, degree of deacetylation, crosslinking strategies, and curcumin loading. Solubility-enhancement strategies for curcumin, including surfactants, nanoparticles, solid dispersions, and chemical derivatives, are evaluated in the context of antimicrobial efficacy and cytotoxicity. Finally, the review highlights translational challenges and future directions, such as antibiotic synergy, antifungal applications, formulation complexity, and the emerging role of artificial intelligence in predictive material design. Collectively, these insights establish design principles for next-generation multifunctional biomaterials that integrate antimicrobial activity with immune modulation and tissue repair. Full article

Diabetic chronic wounds, characterized by persistent inflammation and a complex microenvironment, pose a major challenge to global healthcare. Traditional dressings act merely as passive physical barriers, lacking the ability to sense biochemical fluctuations or respond to dynamic pathological changes. Therefore, developing smart platforms for in situ, continuous, and non-invasive monitoring is crucial for early warning and precision intervention. This review systematically explores recent advances in high-fidelity wound monitoring, focusing on the deep integration of “front-end interface engineering” and “back-end data analysis”. We first analyze the specific physicochemical and biochemical abnormalities of the diabetic wound microenvironment. Next, we discuss how advanced material designs, such as active fluid management, anti-biofouling zwitterionic networks, and nanozyme-based reactive oxygen species (ROS) scavenging, ensure the long-term stability of sensing interfaces against complex microenvironmental interference. Building on this hardware foundation, we summarize in situ sensing strategies and multiparameter decoupling techniques tailored for key biomarkers, including pH, temperature, glucose, ROS, and MMP-9. Furthermore, we highlight cutting-edge developments in signal digitization, emphasizing the pivotal role of portable devices and machine learning algorithms in extracting high-dimensional features and translating complex multimodal signals into objective clinical metrics. By outlining this comprehensive technological closed-loop, this review aims to provide a systematic theoretical framework for the development and clinical translation of next-generation smart wound monitoring platforms. Full article

In this work, we propose a bamboo-shaped Mach-Zehnder interferometer coated with chitosan for relative humidity (RH) and temperature measurement. The sensor is fabricated by fusing no-core fiber and multimode fiber segments through arc discharge, followed by tapering with a hydrogen–oxygen flame to form a unique bamboo-shaped configuration. To functionalize the structure for humidity sensing, chitosan is coated onto the fiber surface. The refractive index of chitosan varies with water molecule adsorption, which enhances the spectral response of the sensor to RH. Therefore, the sensitivity response is enhanced after the film coating is applied. Experimental results demonstrate that the proposed sensor achieves the maximum sensitivities to RH and temperature determined at −0.9261 nm/%RH and 0.0952 nm/°C, respectively. The sensor features a compact structure, high sensitivity and the ability to achieve dual-parameter sensing, which supports applications in biomedical, agricultural and electronic manufacturing fields. Full article

The widespread accumulation of ampicillin (AMP) poses significant ecological and health risks, demanding rapid and portable monitoring tools. Herein, a Fe-Ni bimetallic-doped polydopamine (FeNi@PDA) nanozyme with exceptional peroxidase-like activity was synthesized for the visual and on-site monitoring of AMP. Optimized through bimetallic electronic coupling, FeNi@PDA exhibited enhanced catalytic efficiency (K_M = 0.051 mmol/L for H₂O₂ and 0.049 mmol/L for 3,3′,5,5′-tetramethylbenzidine) and generated ¹O₂ and ·O₂⁻ via H₂O₂ activation. Leveraging the competitive consumption of reactive oxygen species (ROS) by electron-rich AMP, a colorimetry detection mode was developed where AMP concentration inversely correlated with oxidized 3,3′,5,5′-tetramethylbenzidine (oxTMB) formation. This strategy achieved a good linear relationship of between 0.05 to 100 μg/mL, with a limit of detection (LOD) of 10.38 ng/mL. Furthermore, a smartphone-integrated paper-based detection mode was fabricated by immobilizing FeNi@PDA on filter paper. The color gradient of test papers, analyzed via smartphone imaging, enabled on-site AMP quantification with a LOD of 340 ng/mL. This work not only developed a novel Fe-Ni bimetallic nanozyme with enhanced peroxidase-like activity and established a competitive ROS-consumption sensing mechanism but also pioneered a dual-mode detection platform for low-cost, user-friendly ampicillin monitoring in environmental samples. Full article

Background: Non-invasive respiratory supports (High-Flow Nasal Oxygen, HFNO; Continuous Positive Airway Pressure, CPAP; Non-Invasive Ventilation, NIV) are frequently used in Acute Hypoxemic Respiratory Failure (AHRF). However, the experience of assisted breathing may profoundly affect patients’ psychological balance, particularly during acute critical illness and subsequent rehabilitation. Aims and objectives: This longitudinal study investigated the psychological burden associated with non-invasive respiratory support use in patients with COVID-19-related AHRF, exploring changes in psychological functioning from acute hospitalization (RICU/ICU) (T0) to follow-up, conducted at a mean of 6.0 ± 3.1 months after respiratory rehabilitation (T1). Methods: Fifty-two patients (mean age = 66.9 ± 9.17 years) were assessed at T0 and T1. Standardized measures evaluated anxiety, psychological distress, post-traumatic stress symptoms, depression, and resilience, in relation to perceived illness severity and subjective experience of non-invasive respiratory support. Results: During acute care, patients reported high levels of fear and anxiety related to illness severity and uncertainty. The experience of non-invasive respiratory support, often perceived as a marker of critical condition, was associated with increased fear and anxiety (t(14) = 2.79, p = 0.014) compared to the recovery phase, leading to feelings of loss of control and diminished psychological well-being (t(17) = 2.35, p = 0.031). However, resilience significantly improved over time (t(16) = −4.78, p < 0.001). Conclusions: Non-invasive respiratory support may represent a psychologically demanding experience, often perceived as challenging to patients’ sense of safety and control. Encouragingly, psychological adaptation and resilience can improve during rehabilitation. Integrating structured psychological support within respiratory rehabilitation pathways may promote recovery and restore psychological balance in patients requiring assisted ventilation. Full article

Reducing energy consumption while maintaining stable water quality remains a major challenge in ornamental aquaculture. This study proposes an integrated predictive and energy-aware aquaculture management framework combining Internet of Things (IoT) sensing, Long Short-Term Memory (LSTM)-based prediction, Digital Twin (DT) simulation, and Cyber-Physical System (CPS) control. Real-time sensor networks monitored dissolved oxygen (DO), ammonia (NH₃), temperature, pH, turbidity, and energy consumption in a koi pond over a 45-day deployment period. Forecasted environmental states generated by the LSTM model were validated through a physics-informed Digital Twin prior to actuator execution to improve operational reliability and control safety. Experimental results demonstrated strong agreement between the Digital Twin and observed pond dynamics, achieving R² values of 0.97 for dissolved oxygen and 0.94 for ammonia. Compared with conventional manual operation, the proposed smart predictive control mode reduced total energy consumption by 26.86%. Statistical analysis confirmed that the reduction was highly significant (p < 0.001), with average daily energy consumption decreasing from 212 ± 6.06 Wh/day under manual operation to 154.71 ± 4.52 Wh/day under smart predictive control. Full article

This study develops high-performance ammonia sensors based on composites of metal-organic frameworks (MOF-808 and MOF-818) with reduced graphene oxide (rGO). Two sensor architectures were fabricated: interdigital electrodes and silicon micropillar arrays. The MOF-808/rGO composite demonstrated superior sensing performance for 40 ppm NH₃ at room temperature, with faster response kinetics and higher sensitivity compared to pristine rGO and MOF-818/rGO. Silicon micropillar array sensors showed enhanced performance through optimized periodic arrangements, while oxygen plasma surface modification improved both sensor types. Comprehensive testing confirmed that the MOF-808/rGO sensor maintains reliable NH₃ detection at concentrations as low as 5 ppm under high humidity conditions, exhibiting excellent stability and selectivity. These findings provide valuable insights for developing advanced gas sensors for environmental monitoring applications. Full article