Search Results (528)

Background/Objectives: Numerous studies have demonstrated that dietary plant-derived polyphenols suppress signaling and metabolic pathways in various malignancies, including neuroblastoma. In the present study, we compared the inhibitory activities of selected polyphenols and their combinations on key metabolic and signaling pathways in two human neuroblastoma cell lines and two noncancerous cell lines—mesenchymal stem cells (MSCs). Methods: The influence of polyphenols on neuroblastoma cells and MSCs were studied via an MTT-assay, cell cycle analysis, and an apoptosis assay (flow cytometry). Chou-Talalay algorithms were used to quantify drug interactions. SeaHorse energy profiling was applied to study energy metabolism. The influence of the compounds on metabolic enzymes and signaling pathways was examined using immunoblotting. Total protein biosynthesis was assessed using o-propargyl-puromycin labeling (flow cytometry). Results: While most of the studied polyphenols displayed a more significant inhibitory effect on neuroblastoma cells than on mesenchymal stem cells (MSCs), we found that the combinations of curcumin and quercetin (CQ) and curcumin, quercetin, and resveratrol (CQR) were significantly superior to the individual compounds. These combinations displayed synergistic effects and inhibited the cell cycle while inducing apoptosis. The CQ and CQR combinations effectively suppressed metabolic reprogramming by downregulating key enzymes of glycolysis, respiration, one-carbon metabolism, glutaminolysis, and fatty acid biosynthesis, as well as N-Myc and c-Myc, which are master regulators of metabolic processes. Furthermore, CQ and CQR inhibited AKT/mTOR, MAPK/ERK, and WNT/β-catenin signaling pathways and total protein biosynthesis and sensitized malignant cells to doxorubicin. Conclusions: Polyphenol combinations exert multifaceted inhibitory effects on metabolic rewiring and signaling networks in neuroblastoma cells. Full article

In eutrophic shallow lakes, dissolved oxygen (DO) exhibits significant temporal variations, regulated by the combined effects of photosynthesis and water temperature (WT). High-frequency monitoring enables a detailed capture of DO diel cycles, providing a more comprehensive understanding of the dynamic changes within lake ecosystems. This study involved high-frequency (10 min intervals) in situ monitoring of DO over a three-year period (2020–2022) in the littoral zone of Taihu Lake, China. Random forest regression analysis identified WT, photosynthetically active radiation (PAR), and relative humidity (RH) as the three most influential variables governing DO dynamics. The relative importance of these factors varied seasonally (0.117–0.392), with PAR dominating in summer (0.383), whereas WT had the highest importance in other seasons (0.312–0.392). Cusum analysis further revealed that the DO-WT relationship changed from a dome-shaped pattern in spring, autumn, and winter to a bowl-shaped pattern in summer, indicating that thermal stratification intensified oxygen gradients. In addition, the majority of DO recovery occurred in the late afternoon during summer, suggesting that severe oxygen consumption delayed the daytime accumulation of DO. Our findings emphasize the critical roles of photosynthesis, respiration, and abiotic factors in shaping DO dynamics. This research enhances our understanding of DO fluctuations in eutrophic shallow lakes and provides valuable insights for ecosystem management, supporting the development of effective strategies to prevent and mitigate hypoxia. Full article

Benthic bacterial communities play a critical role in nutrient cycling and are highly sensitive to environmental pollution. This study aimed to investigate the physiological, compositional and functional responses of bacterial communities across a range of carbon (C), nitrogen (N), phosphorus (P), and sulfur (S) gradients in sediments from Lake Villarrica, Chile. Sediment samples were collected from 5 sites representing a gradient of nutrient pressure from the lake basin (NL < PuB < PoP < SL < VB). Nutrient forms (TC, TN, TP, TS, and OM) were chemically quantified. Community function was assessed via community-level physiological profiles (CLPPs) using Biolog^® EcoPlates (C substrates), PM3B (N substrates), and PM4A (P and S substrates). Function and composition were assessed based on total bacterial and functional nutrient-cycling gene abundances (16Sr RNA, chiA, mcrA, nifH, amoA, nosZ, phoD, pqqC, soxB, dsrA) using qPCR and 16S rRNA metabarcoding, respectively. In general, the CLPPs were higher for C substrates, followed by P, S, and N substrates, with metabolism of organic forms of these nutrients preferential, and P-cycling genes were the most abundant in the lake. Spatially, the most nutrient-enriched site (VB) showed a significantly (p ≤ 0.05) higher nutrient content (e.g., 5.4% TC, 0.54% TN, 1302.8 mg kg⁻¹ TP and 854.1 mg kg⁻¹ TS) and total bacterial abundance (2.9 × 10¹¹ gene copy g⁻¹ dw sediment) but displayed lower CLPPs (from 0.63 to 1.02 AWCD) and nutrient-cycling gene abundances (e.g., 9.1 × 10¹, 2.7 × 10³, 3.6 × 10³ and 4.7 × 10³ gene copy g⁻¹ dw sediment for chiaA, nifH, phoD and dsrA, respectively) compared to the less nutrient-enriched sites (e.g., NL). The bacterial community composition shifted accordingly, with Bacillota enriched in VB and Planctomycetota occurring more frequently in less nutrient-exposed sites. Functional prediction analysis revealed enhanced methanotrophy and sulfate respiration in nutrient-rich sediments, whereas nitrification and organic P (P_o) mineralization dominated in less impacted areas. The results demonstrate that nutrient enrichment constrains bacterial functional diversity in Lake Villarrica and, so, may be useful indicators of environmental stress to be considered in pollution monitoring programmes. Full article

Maintaining an effective facial seal is critical for the performance of tight-fitting industrial respirators used in high-risk sectors such as mining, manufacturing, and construction. Traditional fit verification methods—Qualitative Fit Testing (QLFT) and Quantitative Fit Testing (QNFT)—are limited to periodic assessments and cannot detect fit degradation during active use. This study presents a real-time fit detection system based on embedded breath sensors and machine learning algorithms. A compact sensor module inside the respirator continuously measures pressure, temperature, and humidity, transmitting data via Bluetooth Low Energy (BLE) to a smartphone for on-device inference. This system functions as a multimodal biosensor: intra-mask pressure tracks flow-driven mechanical dynamics, while temperature and humidity capture the thermal–hygrometric signature of exhaled breath. Their cycle-synchronous patterns provide an indirect yet reliable readout of respirator–face sealing in real time. Data were collected from 20 healthy volunteers under fit and misfit conditions using OSHA-standardized procedures, generating over 10,000 labeled breathing cycles. Statistical features extracted from segmented signals were used to train Random Forest, Support Vector Machine (SVM), and XGBoost classifiers. Model development and validation were conducted using variable-size sliding windows depending on the person’s breathing cycles, k-fold cross-validation, and leave-one-subject-out (LOSO) evaluation. The best-performing models achieved F1 scores approaching or exceeding 95%. This approach enables continuous, non-invasive fit monitoring and real-time alerts during work shifts. Unlike conventional techniques, the system relies on internal physiological signals rather than external particle measurements, providing a scalable, cost-effective, and field-deployable solution to enhance occupational safety and regulatory compliance. Full article

Monitoring electrocardiogram (ECG) and respiration continuously and non-invasively is essential for managing cardiopulmonary health. An effective wearable device can be used to regularly monitor key vitals, reducing the need for clinical visits. In this work, we propose a custom device for real-time continuous ECG by inkjet printed (IJP) dry electrodes and respiration monitoring by using a novel single 6-axis inertial measurement unit (IMU). The proposed system can extract the heart rate (HR) and respiration rate (RR) during static and dynamic postures. The respiration process implements a quaternion-based update and multiple filtering stages to estimate the signal. The custom device uses Bluetooth protocol to send the raw and processed data to a mobile application. The RR is investigated in stationary, i.e., sitting and standing, and dynamic, i.e., walking, running, and cycling, postures. The proposed device is evaluated with commercial Go Direct^® respiration belt from Vernier^® for RR and offers an overall accuracy of 99.3% and 98.6% for static and dynamic conditions, respectively. The wearable also offers 98.9% and 97.9% accuracy for HR measurements, respectively, in static and active postures when compared with the Kardia^® device. Furthermore, the device is assessed in an ambulatory monitoring setup in both indoor and outdoor environments. The low-power wearable consumes an average of only 7.4 mA of current during data processing. The device performs effectively and efficiently in both stationary and active states, offering a low complexity, portable solution for real-time monitoring. The proposed system can benefit from the continuous monitoring and early detection of pulmonary and cardio-respiratory health issues. Full article

Cucumis sativus L. is a globally important vegetable crop that occupies a significant position in protected agriculture due to its high nutritional value, short cultivation cycle, and considerable economic benefits. As a cold-sensitive plant, however, cucumber is highly susceptible to low-temperature stress. which can severely inhibit growth and development, hinder seed germination, and reduce photosynthetic efficiency. Under low-temperature stress, cucumber plants typically incur damage to cellular membrane structures, experience an accumulation of reactive oxygen species (ROS), exhibit a disruption in hormonal homeostasis, and suffer from the inhibition of pivotal metabolic pathways. In response, cucumber plants activate an array of resistance mechanisms, encompassing osmotic adjustment, reinforcement of the antioxidant system, and modulation of cold-responsive gene expression. This review summarizes the physiological and molecular mechanisms underlying cucumber’s response to low-temperature stress, aiming to provide effective strategies for improving abiotic stress resistance. The main findings are as follows: (1) Low-temperature stress damages cucumber cell membranes, suppresses photosynthesis and respiration, suppresses water and nutrient uptake/transport, and suppresses growth retardation. (2) Cucumber counters these adverse effects by orchestrating the accumulation of osmoregulators (e.g., soluble sugars, proline), activating activation defenses (e.g., SOD, CAT), and rebalancing its phytohormone network (e.g., ABA, GA, SA, ethylene). (3) At the molecular level, cucumber activates low-temperature-responsive genes (e.g., COR, GoIS) through transcription factors such as CBF, MYB, and WRKY, thereby enhancing cold tolerance. (4) Application of exogenous protectants (e.g., hydrogen sulfide, melatonin, oligosaccharides) significantly improves cucumber’s low-temperature tolerance by modulating the antioxidant system, promoting osmoregulatory substances accumulation, and regulating hormone signaling pathways. Future research should focus on elucidating the molecular regulatory network in cucumber under low-temperature stress and developing gene editing with multi-omics techniques to advance the development of cold-resistant cultivars and cultivation practices. This study offers a scientific foundation for research on cucumber cold tolerance and proposes potential solutions to agricultural challenges in the context of global climate change. Full article

Background: Polycystic ovary syndrome (PCOS) is the leading cause of anovulatory infertility. The apoptosis of granulosa cells (GCs) is strongly associated with the impaired follicular development in PCOS. The underlying mechanisms, however, remain incompletely elucidated. A significant increase in circulating lactic acid, an anaerobic respiration product, has been detected in PCOS patients. Yet, alterations in local ovarian lactic acid levels and their impact on GCs remain unknown. Methods: PCOS mouse models were established via 20-day daily subcutaneous dehydroepiandrosterone (DHEA) injections. In vitro experiments utilized DHEA-treated KGN cells to mimic hyperandrogenic conditions. Circulating, ovarian, and cellular lactic acid concentrations were quantified. Intracellular and extracellular pH values were measured using BCECF-AM fluorescent probe and a blood gas analyzer, respectively. Apoptosis was assessed through both flow cytometry and TUNEL assay. The antioxidant N-acetylcysteine (NAC) was used to investigate its effects on lactic acid levels and the subsequent GC apoptosis. Results: High androgen levels caused mitochondrial damage, promoted anaerobic glycolysis and led to lactic acid accumulation, inducing decreased intracellular pH and thus apoptosis of GCs. The antioxidant NAC effectively alleviated oxidative stress, mitigated mitochondrial damage, and decreased lactic acid levels and apoptosis in KGN cells. In PCOS mice, NAC improved ovarian morphology, but it did not affect the estrous cycle of the mice. Conclusions: Hyperandrogenemia-induced mitochondrial dysfunction caused the accumulation of lactic acid and thus apoptosis of ovarian GCs in PCOS mice. NAC enhanced mitochondrial function, consequently decreasing lactic acid concentrations. These findings suggest novel therapeutic targets for PCOS. Full article

Atmospheric nitrogen input has been a severe challenge worldwide. The influences of N deposition on carbon cycling, loss, and storage have been recognized as a critical issue. This study aimed to assess the immediate responses of soil respiration to different N deposition treatments in radiata pine (Pinus radiata D. Don) and chestnut-leaved oak (Quercus castaneifolia C. A. Mey) plantations within 12 months. N treatments were performed monthly at levels of 0, 50, 100, and 150 kg N ha⁻¹ year⁻¹ from October 2017 to September 2018. Litterfall was collected and analyzed seasonally for its mass and C content. Within the 0–10 cm depth of mineral soil in both plantations, parameters such as total nitrogen, pH, microbial biomass carbon (MBC), organic carbon (OC), and fine root biomass were measured seasonally. Soil respiration (Rs) was determined through monthly measurements of CO₂ concentration in the field using a portable, closed chamber technique. The control plots exhibited the highest Rs during spring (2.96, 2.85 μmol CO₂ m⁻² s⁻¹) and summer (2.92, 3.1 μmol CO₂ m⁻² s⁻¹) seasons in oak and pine plantations, respectively. However, the introduction of nitrogen significantly diminished Rs in both plantations. Moreover, N treatments caused a notable reduction of soil MBC and fine root biomass. Soil microbial entropy and the C/N ratio were also significantly decreased by nitrogen treatments in both plantations, with the most prominent effects observed in summer. The observed decline in Rs in N-treated plots can be attributed to the decrease in MBC and fine root biomass, potentially with distinct contributions of these components in the pine and oak plantations. Our findings suggested that N-induced alteration in soil carbon dynamics was more pronounced in the oak plantation, which resulted in more SOC accumulation with increasing N inputs, while the pine plantation showed no significant changes in SOC. Full article

Soil respiration (Rs), the second largest carbon flux in terrestrial ecosystems, critically regulates the turnover of soil carbon pools. However, its seasonal and annual responses to extreme events in monsoon forests remain unclear. This study used a continuous multichannel automated chamber system to monitor Rs over three years of drought (2019–2021) in an Asian monsoon forest in Taiwan. We assessed seasonal and annual Rs patterns and examined how drought influenced autotrophic (Rr) and heterotrophic (Rh) respiration through changes in soil temperature and moisture. Results showed Rs declined from 5.20 ± 2.08 to 3.86 ± 1.20 μmol CO₂ m⁻² s⁻¹, and Rh from 3.36 ± 1.21 to 3.15 ± 0.98 μmol CO₂ m⁻² s⁻¹ over the study period. Spring Rr values dropped significantly—by 29.3% in 2020 and 62.2% in 2021 compared to 2019 (p < 0.05), while Rh remained unchanged (p > 0.05). These results suggest that spring drought strongly suppresses autotrophic respiration but has minimal effect on Rh. Incorporating these dynamics into carbon models could improve predictions of carbon cycling under climate change. Our findings demonstrate that spring drought exerts a strong influence on soil carbon fluxes in Asian monsoon forests. Full article

Pistachio (Pistacia vera L.) holds significant importance due to its diverse applications and nutritional benefits. The nuts are rich in essential amino acids, antioxidants, fiber, healthy fats, and minerals, making them highly valuable for human nutrition. However, pistachios are significantly challenged by salinity stress, which negatively affects their growth and metabolism. Understanding the impact of salinity stress on pistachios is crucial for developing effective strategies to enhance their tolerance, improve growth, and ensure sustainable production in saline environments. To investigate the effects of salinity on energy metabolism and amino acid composition, we monitored key metabolites and free amino acid levels in UCB-1 pistachio leaves at 7- and 21-day salt stress treatments using Liquid Chromatography–Mass Spectrometry (LC-MS) and Ultra Performance Liquid Chromatography (UPLC). Our findings revealed that salinity affected nearly all analyzed metabolites, with varied patterns observed at different time points. Notably, all free amino acids except threonine accumulated significantly in response to salt stress. Meanwhile, reductions in 3PGA, Fru1,6bP, and Glu6P+Fru6P (glycolysis and Calvin cycle intermediates) suggest a decrease in photosynthetic activity, which may ultimately impact respiration rates. These results demonstrate that salinity stress affects both amino acid metabolism and central carbon metabolism, with the magnitude and pattern of these changes depending on the duration of exposure. The observed metabolic adjustments likely represent an adaptive response, enabling the plant to partially mitigate the detrimental effects of salt stress. Full article

Quantifying deep soil (10–100 cm) and non-growing-season soil respiration (SR) is crucial for refining carbon (C) cycle models, yet the regulatory mechanisms governing these processes remain unclear. The novelty of this study lies in its focus on deep soils and non-growing seasons to elucidate how soil properties regulate SR under these special conditions. We conducted an on-site field experiment in the Caragana korshinskii plantation, measuring SR at soil depths of 0–10 cm, 10–50 cm, and 50–100 cm during the non-growing season and growing. The results suggested that the annual cumulative soil CO₂ fluxes reached 510.1 (0–10 cm), 131.5 (10–50 cm), and 45.3 g CO₂·m⁻² (50–100 cm). These emissions during the non-growing season accounted for 33%, 31%, and 32%, respectively. The soil physical properties (temperature, moisture, bulk density) explained the greatest variation in SR during growing and non-growing periods, followed by the biological properties (α-diversity, root biomass) and chemical properties (soil organic C, ammonium nitrogen, total C/nitrogen ratio). Depth-specific analysis demonstrated that soil physical properties explained the most SR variance at three depths with independent contributions of 78.9% (0–10 cm), 89.7% (10–50 cm), and 76.9% (50–100 cm). These values exceeded the independent contributions of chemical properties (70.3%, 70.9%, 60.0%) and biological properties (54.9%, 45.1%, 41.6%) at the corresponding depths. Overall, deep soil and non-growing season SR represent important C emission sources; excluding them may therefore substantially overestimate net C sequestration potential. Full article

Ammonia-oxidizing bacteria (AOB) are key to the nitrogen cycle, but their resistance to nitrite (NO₂⁻-N) accumulation is unclear. This study examined N.eA1, an AOB from the completely autotrophic nitrogen removal over nitrite (CANON) process, assessing its adaptive responses to NO₂⁻-N. The ammonia oxidation and N₂O emission were evaluated at varying NO₂⁻-N levels, and 3D fluorescence, extracellular polymeric substances (EPS), and soluble microbial products (SMP) analysis were used to probe stress responses. Cellular respiration and key enzyme activities were measured, and proteomics was applied to study protein expression changes. Results showed that higher NO₂⁻-N levels boosted N₂O production, inhibited nitrification, and stimulated denitrification in N.eA1. At 100 mg·L⁻¹ NO₂⁻-N, EPS rose and SMP fell, with ammonia monooxygenase (AMO) suppressed and nitrite reductase (NIR) as well as nitric oxide reductase (NOR) enhanced. Gene expression analysis revealed decreased AMO, hydroxylamine oxidoreductase (HAO), and energy transport-related enzymes, but increased NIR and NOR genes. The downregulation of electron transport complex genes offered insights into molecular adaptation to nitrite stress of N.eA1, highlighting the interplay between metabolic and genetic responses, which is essential for developing sustainable and efficient nitrogen management strategies. Full article

Understanding belowground carbon dynamics is essential for predicting the carbon balance of forest ecosystems. This study aimed to investigate links between soil CO₂ efflux (R_S), soil physicochemical properties, and fine-root morphology across four middle-aged plantations of different species (Robinia pseudoacacia, Quercus mongolica, Pinus koraiensis, and Metasequoia glyptostroboides) in Mt. Ansan, Seoul, Republic of Korea. Seasonal measurements of R_S, soil temperature (T_S), and soil water content (SWC) were conducted, and soils and fine roots (≤2.0 mm) were analyzed for physicochemical properties and morphological traits, with a focus on very-fine roots (≤0.5 mm). The results showed that R_S was positively correlated with T_S (r = 0.77) and negatively with SWC (r = −0.33). R_S normalized at 25 °C (R₂₅), differed significantly among plantations, and exhibited strong positive correlations with electrical conductivity (r = 0.81), as well as with total nitrogen and carbon concentrations and clay content. Among fine root traits, the length, surface area, and volume of very-fine roots exhibited the strongest associations with R₂₅, underscoring their pivotal role in regulating belowground respiration. These findings suggest that species-specific fine root strategies and soil conditions jointly control R_S dynamics, particularly under warmer conditions, and highlight very-fine root traits as key indicators of soil carbon flux in forest ecosystems. Full article

Copper is a vital micronutrient for animals and plants acting as a crucial cofactor in the synthesis of numerous metabolic enzymes and contributing to mitochondrial respiration, metabolism, oxido-reductive reactions, signal transmission, and oxidative and nitrosative damage. In the cells, copper may exist in the Cu⁺ and Cu⁺⁺ oxidation states and the interconversion between these two states may occur via various redox reactions regulating cellular respiration, energy metabolism, and cell growth. The human body maintains a low level of copper, and copper deficiency or copper excess may adversely affect cellular functions; therefore, regulation of copper levels within a narrow range is important for maintaining metabolic homeostasis. Recent studies identified a new copper-dependent form of cell death called cuproptosis. Cuproptosis occurs due to copper binding to lipoylated enzymes (for instance, pyruvate dehydrogenase and α-ketoglutarate dehydrogenase) in the tricarboxylic acid Krebs cycle. In recent years, extensive studies on copper homeostasis and copper-induced cell death in degenerative disorders, like Menkes, Wilson, Alzheimer, Parkinson’s, Huntington’s diseases, and Amyotrophic Lateral Sclerosis, have discussed the therapeutic potential of targeting cuproptosis. Copper contamination in the environment, which has increased in recent years due to the expansion of agricultural and industrial activities, is associated with a wide range of human health risks. Soil used for the cultivation of grapes has a long history of copper-based fungicide application (the Bordeaux mixture is rich in copper) resulting in copper accumulation at levels capable of causing toxicity in plants that co-inhabit the vineyards. Phytoremediation, which uses plants and biological solutions to remove toxic heavy metals and pesticides and other contaminants from soil and water, is an environmentally friendly and cost-effective technology used for the removal of copper. It requires plants to be tolerant of high levels of copper and capable of accumulating metal copper in plants’ aerial organs and roots. This review aims at highlighting the importance of copper as an essential metal, as well as its involvement in cuproptosis and neurodegenerative diseases. Full article

Typhoon disturbances significantly influence forest carbon cycling by altering both physical structures and biogeochemical processes. Typhoon-induced fluctuations in soil respiration can substantially affect the carbon balance in forest ecosystems. In this study, we conducted a comparative investigation of soil respiration in plantations of Casuarina equisetifolia L. that were either affected or unaffected by the severe Typhoon Yagi, which ravaged Hainan Island, China, in 2024. The soil respiration and its components in Casuarina equisetifolia L. plantations in the coastal areas of Hainan, China, as well as their responses to environmental factors before and after typhoon disturbance, were investigated based on total soil respiration rate (R_s), heterotrophic respiration rate (R_h), 5 cm soil temperature (T₅), and 10 cm soil moisture (W₁₀) to support the carbon emission estimation in coastal sandy land plantations. The mean R_s and R_h in the typhoon-disturbed plots were (1.82 ± 0.16) and (1.19 ± 0.26) μmol·m⁻²·s⁻¹, respectively, while those in the control plots were (2.62 ± 1.08) and (1.41 ± 0.23) μmol·m⁻²·s⁻¹, respectively, with statistically significant differences (p < 0.05). In both plots, R_s exhibited a significant positive correlation with T₅ (p < 0.01). The T₅ correlation and Q₁₀ values for soil respiration were significantly higher in the typhoon-disturbed plots than in the control plots (p < 0.05). W₁₀ of the soil exhibited significant negative correlations with R_s and R_h in typhoon disturbance plots (p < 0.05). Consequently, typhoon disturbance markedly inhibited soil respiration and its components in the Casuarina equisetifolia L. plantations, indicating substantial impacts of typhoons on soil respiration processes and carbon cycling within the forest ecosystem. This study provides key parameters and empirical evidence to improve the accuracy of soil carbon emission estimates in Casuarina equisetifolia L. plantations on coastal sandy soils affected by typhoon events. Full article