Search Results (21,657)

The deep sea is characterized by unique and extreme habitats. The absence of light, high salinity, hydrostatic pressure, low temperature, and high competition led to the evolution of physiological and biochemical adaptations necessary for survival. Marine fungi represent a significant part of deep-sea microbial communities. Studying bathypelagic sediment fungi helps us to understand their little-known communities and ecology, as well as their metabolic potential and ecophysiological properties, which have applications in pharmaceutical biotechnologies and bioremediation protocols. During an oceanographic campaign off the coast of Toulon (France, northwest Mediterranean Sea) in October 2021, as part of the KM3NeT Project, the Hybrid Remotely Operated Vehicle (HROV) Ariane collected a composite sediment sample at a depth of 2417 m. The sediment was physically, geochemically and mycologically characterized. Culturable fungi were isolated, and vital fungal strains were identified morphologically and molecularly. A total of 17 strains were isolated and identified in pure culture. The major taxa belonged to the Penicillium, Aspergillus, and Cladosporium genera, but widespread species such as Wallemia sebi were also found. This study also paves the way for further research into the advantages and disadvantages of using HROV technology for mycological cultural investigations at prohibitive depths. Full article

To investigate the effects of freeze–thaw cycles on the fatigue performance of reinforced concrete beams strengthened with carbon fiber reinforced polymer (CFRP) grid-polymer modified cement mortar (PCM) composites, this study conducted experimental research under combined freeze–thaw and fatigue loading on beams with two reinforcement ratios (0.84% and 1.31%). The evolution of failure modes, variations in fatigue life, accumulation of residual deformation, and the development of strains in various materials were analyzed. Experimental results show that CFRP grid–PCM strengthening can significantly improve the fatigue performance of beams. The fatigue life of beams with a low reinforcement ratio increased by approximately 275% after strengthening; even after undergoing freeze–thaw cycles, beams with a high reinforcement ratio could withstand over 3 million fatigue load cycles, demonstrating excellent long-term fatigue resistance. Under combined freeze–thaw and fatigue loading, the crack development in strengthened beams exhibited a typical three-stage characteristic, and the failure mode transitioned from fatigue fracture of steel reinforcement to a composite form involving fiber pull-out of the CFRP grid or interfacial debonding. Based on experimental data, a cumulative evolution model considering the synergistic damage of concrete, CFRP grid, and interfacial bonding was established, which effectively describes the stiffness degradation and damage accumulation process under combined freeze–thaw and fatigue action. The research findings provide a theoretical basis for the fatigue performance evaluation and life prediction of CFRP grid-strengthened RC structures in cold regions. Full article

In the cold and arid regions of northern China, efficient water and nitrogen (N) management is critical for the sustainable production of leafy vegetables. Simplified models that estimate crop N and water transpiration demands using simple inputs based on climate parameters become an important method for making precise suggestions on N and irrigation application at a regional scale. This study developed and validated a regionally adapted version of the VegSyst model, named VegSyst-CH, based on a multi-year open-field experiment from 2021 to 2023. Model parameters were calibrated using data from the 2021 growing season and validated with independent datasets from 2022 and 2023. A critical N concentration (CNC) curve was established to describe the relationship between biomass accumulation and N content. VegSyst-CH, with a radiation use efficiency of 1.94 g MJ⁻¹, demonstrated high simulation accuracy for crop growth. The model showed a good predictive performance of N uptake under medium (N1) and high (N2) N treatments, with coefficients of determination (R²) above 0.80 across years and normalized root mean square error (NRMSE) values generally below 30%. The VegSyst-CH model also showed high accuracy in simulating crop evapotranspiration (ETc) over three consecutive growing seasons (2021–2023), with the dynamic trends of cumulative ETc closely aligning with measured values and the coefficients of determination (R²) consistently exceeding 0.90. These results validate the model’s robustness and applicability across different years. In conclusion, the VegSyst-CH model has strong spatiotemporal regulation capacity and climatic responsiveness, offering a robust decision support tool for precision fertilization and irrigation in open-field lettuce production in cold and arid regions. Full article

Background: Brain temperature is an important determinant of neurological outcomes in ill infants, yet contributions of environmental temperature and cerebral blood flow remain uncovered because of the lack of non-invasive probes. Methods: Using non-invasive cot-side probes, we examined how cerebral blood flow influences brain temperature during mild cold stress induced by incubator-to-cot transfer. We studied 43 clinically stable infants in a tertiary neonatal intensive care unit. After cot transfer, infants were routinely fitted with knit caps and wrapped in cotton blankets. Scalp and superficial and deep brain temperatures were measured using infrared and zero-heat-flux thermometers, and superior vena cava (SVC) flow—a proxy for cerebral blood flow—was assessed using Doppler velocimetry before, immediately after, and 2 h after transfer, adjusting for rectal temperature. Results: Ambient temperature decreased from 29.7 (SD 0.8) °C to 26.8 (SD 0.9) °C, while rectal temperature remained stable. Scalp and brain temperatures declined after transfer but superficial and deep brain temperatures returned to baseline after 2 h of cap use. The regression coefficient between SVC flow and superficial brain temperature shifted from −0.176 (95% CI, −0.386 to 0.035) to 0.239 (−0.280 to 0.759) after transfer (difference: 0.415 [0.106 to 0.724]; p = 0.009), and then returned to baseline after 2 h (−0.079 [−0.528 to 0.372]). Conclusions: Relationships between brain temperature and perfusion were successfully monitored using non-invasive cot-side biosensors; cerebral blood flow appears to shift from facilitating heat dissipation in warm conditions to supporting heat delivery during cold stress. These findings underscore the physiological role of cerebral blood flow in maintaining brain temperature. Full article

In forest ecosystems, rhizodeposition can lead to significant differences in the availability of soil carbon (C), nitrogen (N), and phosphorus (P) between rhizosphere and bulk soils. Soil stoichiometry affects microbial and enzyme nutrient content and determines the abundance and composition of microbes and thus regulates microbial carbon use efficiency (CUE). However, how soil stoichiometry—particularly its variation between the rhizosphere and bulk soil—regulates microbial CUE by shaping microbial biomass, extracellular enzyme stoichiometry, and community composition remains insufficiently quantified. Here, through the C:N, C:P, and N:P ratios for available soil nutrients, microbial biomass, and extracellular enzyme activities—(β-1,4-glucosidase (BG), β-1,4-N-acetylglucosaminodase (NAG), leucine aminopeptidase (LAP), and acid phosphatase (ACP))—and the composition and activity of microbial communities (based on sequencing of bacterial 16S rRNA and fungal ITS genes) in the rhizosphere and bulk soils of five temperate forest ecosystems in northeastern China, we aimed to unravel their integrated effects on microbial CUE. Results indicated that soil C, N, and P and their stoichiometry, microbial community composition, and microbial CUE were significantly different between rhizosphere and bulk soils among all tree species. The disproportionate variation in soil nutrient pools between the rhizosphere and non-rhizosphere regions has led to a stoichiometric imbalance. There was higher microbial CUE in the rhizosphere soil than that in the bulk soil among all tree species. However, the effect pathways of tree species on microbial CUE in the rhizosphere and bulk soils differed. The structural equation model (SEM) further suggested that tree species affected microbial CUE through distinct pathways in different soil compartments. In the rhizosphere, the effect was directly driven by available nutrient stoichiometry. In bulk soil, it was jointly mediated by both available nutrients and microbial biomass stoichiometry. These findings demonstrate that root rhizodeposition shapes microbial carbon cycling by altering soil stoichiometric imbalances, which can strengthen the current understanding of plant–microbe–soil interactions in temperate forests. Full article

Clarifying migration pathways and the source area–destination relationships of the domestic and foreign beet webworm Loxostege sticticalis (Linnaeus) populations, as well as understanding the meteorological mechanisms shaping these processes, is pivotal for remote, accurate, and location-specific pest early warning and forecasting. Based on light trap data from northern China and field survey data from Mongolia in 2022, we simulated the migration trajectories, source regions, and primary landing areas of L. sticticalis by using the HYSPLIT model and analyzed the synoptic systems, processes and conditions during its migration. The results indicate the frequent exchange of L. sticticalis populations between China and Mongolia in 2022. The L. sticticalis migrants initiating their flights from Mongolia primarily undertook a southeastward migration pathway, supplemented by eastward ‘cyclonic’ and southwestward paths. The main landing areas were located in North China and Northeast China, with migration events potentially extending to the Shandong, Heilongjiang, and Xinjiang provinces. Populations originating from North China exhibited a capacity for migrating into Northeast China and Mongolia through 1–5 consecutive nights of flight. During this period, the Northeast China Cold Vortex (NCCV) and the Mongolian Cyclone alternately regulated the synoptic circulation pattern governing the migration of L. sticticalis. The spatiotemporal distributions and intensities of these systems were key determinants of the transboundary migration routes and distances of L. sticticalis. The NCCV dominated, and the precipitation and downdrafts it induced were crucial for the massive landing of L. sticticalis in northern China. Full article

Computerized adaptive testing (CAT) systems face major challenges at the beginning of test administration, when limited response data produces unstable ability estimates and poor item selection. This cold-start problem reduces measurement precision and testing efficiency, especially for students whose abilities diverge from population norms. This study introduces a hybrid ability-estimation model that dynamically integrates neural network predictions with classical item response theory (IRT) estimation throughout the adaptive testing process. The neural component uses auxiliary student information-including demographics, prior performance, and early response patterns-to generate accurate initial ability estimates, while the IRT component preserves psychometric validity as response data accumulate. A dynamic fusion mechanism gradually shifts estimation weight from the neural model to the IRT model as more items are administered. Experimental validation on 2847 students across four subject domains shows that the hybrid approach reduces RMSE in ability estimation by 34.2% during the first five items compared with traditional CAT methods, while maintaining equivalent precision in later stages. The system also decreases the number of items required to reach target precision (SE < 0.3) by 28.7% on average, with the largest gains observed for students at ability extremes. Full article

This study focused on slightly to moderately PAH-contaminated farmland soils in freeze–thaw regions of Northeast China, aiming to fill the research gap in the in situ remediation mechanisms of PAHs under natural freeze–thaw conditions. A 12-month in situ experiment was conducted with four treatments—blank control (CK), biochar (BC), microbial agent (MA), and immobilized microorganisms (IM)—to verify that biochar-loaded IM alleviates temperature stress and sustains efficient PAH removal by regulating soil and microbial properties. PAH removal efficiency and soil chemical properties were monitored during both normal-temperature and freeze–thaw periods, and the soil bacterial community structure was analyzed at the end of the experiment. Results showed that IM achieved the optimal remediation performance with a total PAH removal rate of 72.53%, was least affected by temperature fluctuations, and maintained stable remediation during the freeze–thaw period. IM increased soil nutrient contents, with available potassium and nitrogen exerted positive effects on PAH degradation; it also enriched the functional genes K00626 and K00457 and comprehensively optimized the bacterial community. This study clarified the core remediation mechanism and provided scientific, technical, and theoretical support for related in situ remediation practices. Full article

Background/Objectives: Rapid diagnostic tests (RDTs) for human immunodeficiency virus (HIV) are widely used, but most kits lack standardized internal quality control (IQC) materials. In this study, we aimed to develop and evaluate a plasma-based IQC compatible with five HIV RDT brands and with proven long-term stability. Methods: Control samples at three reactivity levels were tested with five HIV RDT kits in lyophilized and liquid forms. Lyophilized samples were produced with and without trehalose, whereas liquid samples were prepared with and without StabilZyme™ SELECT Stabilizer (Stabilizer). Accelerated stability testing was performed at 37 °C and 45 °C for 28 days, and the most stable formulation was selected for long-term storage at 4 ± 2 °C and 25 ± 5 °C. Stability was assessed based on test-line visibility and signal intensity. Signal-intensity trends were analyzed using simple linear regression with a t-test on the slope; samples were considered stable when no significant trend was detected (p > 0.05). Results: Reactivity measured using the Elecsys HIV combi PT assay yielded cutoff index (COI) values of 772.65 (1:8) for the strong-positive control and 269.95 (1:25) for the weak-positive control. Trehalose-containing lyophilized samples maintained reactivity under accelerated testing at 37 and 45 °C and for 6 months at 4 ± 2 °C and 25 ± 5 °C, with no significant change in signal intensity (p > 0.05). Conclusions: The plasma-based IQC materials were compatible with all five HIV RDTs, and trehalose-stabilized lyophilized plasma showed high stability, supporting transport and storage without strict cold-chain requirements. Full article

High pressure processing (HPP) and ultrasound-assisted extraction (UAE) can effectively shorten extraction time and increase extraction efficiency of the cold brew (CB) process. However, their application in CB citri reticulatae pericarpium (CRP) and the underlying mechanisms of flavor modulation remain poorly understood. In this study, CB-CRP beverage was prepared with HPP-assisted, UAE-assisted, and HPP+UAE-assisted extraction from 1, 3, 5, and 10 years CRP. Results revealed that the total soluble solids (TSS), total sugars, flavonoids, polyphenols, and volatile organic compounds (VOCs) and antioxidant activity of CB-CRP increased after assisted extraction. The combined application of HPP and HPP+UAE-assisted extraction exhibited the most pronounced effects. The kinds and total content of VOCs of CB beverages prepared from 10-year-aged CRP increased from 45 to 81, and from 2.44 to 5.98 μg/mL, respectively. Moreover, the combined HPP+UAE extraction promoted the enrichment of fatty and woody aroma-related compounds, which drove a shift in the flavor profile from fresh to a richer woody type. And this endowed the CB-CRP water with a more complex and multidimensional aroma profile. Full article

Offshore wind turbine blades operating in cold climates are frequently affected by surface icing, which compromises aerodynamic performance and reduces power output. To address this challenge, the present study conducted controlled icing wind tunnel experiments to investigate how salinity and liquid water content (LWC) influence ice formation on the S809 airfoil surface. Results indicate that increased salinity substantially inhibits ice accretion: as salinity rises from 0‰ to 35‰, the total icing area rate drops by approximately 20.5% within 6 min, and the maximum ice thickness declines from 17.21 mm to 6.03 mm. Conversely, LWC emerges as a dominant factor intensifying icing severity: raising LWC from 0.5 g/m³ to 1.5 g/m³ leads to a 135% increase in icing area and an increase in maximum ice thickness from 7.69 mm to 18.17 mm. A notable synergistic interaction is observed—higher LWC enhances the inhibitory effect of salinity on ice formation. These findings offer valuable insights into the icing dynamics under marine atmospheric conditions and provide a theoretical foundation for the development of anti-icing strategies for offshore wind turbine blades. Full article

Background/Objectives: Bladder cancer remains a therapeutically challenging malignancy due to high recurrence rates, progression to muscle-invasive disease, and frequent resistance to cisplatin-based chemotherapy. Cold physical plasma (hereafter referred to as plasma) has emerged as a locally applicable modality that generates reactive oxygen species (ROS) and shows preclinical antitumor activity, offering a potential strategy to enhance cisplatin efficacy while enabling dose reduction. Here, we investigated combination treatment with cisplatin and argon plasma generated by the clinically approved kINPen jet in human bladder cancer models. Methods: Three bladder cancer cell lines representing distinct entities were used, namely the urothelial carcinoma lines RT-112 and T24, and the squamous cell carcinoma line SCaBER. IC₂₅ values for plasma and cisplatin monotherapy were established by resazurin assay and used to design combination regimens. Treatment interactions were quantified by coefficient of drug interaction (CDI) analysis and monitored kinetically by long-term live-cell imaging. Plasma-derived ROS were measured in PBS and DMEM, and their functional relevance was assessed in SCaBER cells using catalase and N-acetylcysteine. In ovo validation was performed in the tumor chorioallantoic membrane (TUM-CAM) model, where tumor mass, vascularization, cellular marker expression, and cytokine secretion were analyzed. Results: Plasma and cisplatin exhibited opposing monotherapy sensitivity profiles across cell lines, creating a favorable basis for combination treatment. CDI analysis revealed clear synergy in SCaBER at intermediate cisplatin concentrations, additive effects in RT-112, and additive to mildly synergistic effects in T24. ROS profiling and scavenger experiments identified hydrogen peroxide as a key mediator of plasma and plasma–cisplatin cytotoxicity in SCaBER. In the TUM-CAM model, plasma and cisplatin monotherapies showed notable antitumoral potential. At the same time, plasma–cisplatin combination therapy elicited only modest effects on tumor growth and vascularization compared to monotreatments but induced distinct, cell line-specific alterations in cytokine and marker expression. Conclusions: These findings demonstrate that plasma can potentiate cisplatin cytotoxicity in bladder cancer cells and reshape tumor-associated molecular signatures, supporting further optimization and preclinical evaluation of plasma–cisplatin combination therapy. Full article

We study the properties of a plasma sheath containing cold positive ions, secondary electrons, and primary electrons with a Cairns distribution (a non-thermal velocity distribution). We derive the generalized Bohm criterion and Bohm speed, the new floating potential at the wall, and the new critical secondary electron emission coefficient. We show that these properties of the plasma sheath depend significantly on the α-parameter in the non-thermal α-distribution, and so they are generally different from those of the plasma sheath if the primary electrons were assumed to be a Maxwellian distribution. Full article

Advances in multimodal therapy for high-risk neuroblastomas (NBs) have plateaued, prompting therapeutic initiatives to harness the immune system. NBs, however, are immunologically “cold” and a significant challenge to immunotherapy. Here, in a Jurkat lymphocyte cytotoxicity model, we describe an antigen-independent, cell-mediated mechanism for eliminating NB cells, first detected in PMA-activated low pcDNA-SH-SY5Y and high TrkAIII-SH-SY5Y TrkAIII-expressing cells, which are resistant to Jurkat elimination under normal conditions. Characterization of this mechanism through live cell imaging, adhesion assays, RT-PCR, Western blotting and indirect IF, employing a variety of inhibitors, indicates that it initiates with PMA-induced NB cell CCL2 expression. This results in CCL2 promotion of Jurkat CCR2b expression, CCL2/CCR2b-mediated Jurkat LFA-1 activation and the formation of cytotoxic lipid-raft LFA1/ICAM-1 immune synapses, through which Jurkat m-TRAIL combines with PMA-enhanced NB cell DR5/TRAIL-R2 expression to induce NB cell apoptosis. This mechanism is enhanced by the NB-associated oncoprotein TrkAIII through Shp/Src-regulated c-FLIP sequester and is PD-L1/PD-1-independent and resistant to osteoprotegerin. It eliminates both non-MYCN-amplified (SH-SY5Y and SK-N-SH) and MYCN-amplified (SMS-KCNR) NB cells that exhibit PMA-inducible CCL2 expression but not MYCN-amplified NB cells (IMR-32 and NB-1) that exhibit CCL2 repression, and is offset by reciprocal NB cell-induced Fas-mediated Jurkat cell apoptosis. These findings form a solid foundation for further pre-clinical development aimed at identifying clinically relevant physiological immune cell equivalents and alternative PKC activators, with the ultimate goal of translating this mechanism into an effective immune-therapeutic approach for the treatment of high-risk non-immunogenic NBs, especially NBs that exhibit CCL2 and TrkAIII expression. Full article

The occurrence of contact lens complications caused by inadequate cleaning of the lenses using “All-in-One” contact lens cleaning solutions (CLCSs) represents a medically relevant problem worldwide. This study explores the potential of cold atmospheric plasma (CAP) to enhance the efficacy of CLCSs and address complications from inadequate lens hygiene. It was examined whether exposure to CAP for 1–24 h could boost the antibacterial effects of CLCSs and other solutions, including Milli-Q water (M-QW), physiological saline (NaCl), and Dulbecco’s Phosphate Buffered Saline (DPBS). Additionally, the stability of reactive oxygen and nitrogen species (RONS) and their impact on pH immediately after treatment and over 1–4 weeks was assessed. Furthermore, the cleaning efficacy of plasma-activated solutions (PASs) was tested on lipid-coated silicone hydrogel lenses. Results showed that CAP increased RONS concentrations immediately, with elevated levels persisting over time. While no significant improved antibacterial effect was observed against Escherichia coli in CLCSs, CAP treatment generated disinfectant properties in M-QW and NaCl solutions. Importantly, CAP-treated CLCSs significantly improved the cleaning performance on lipid-coated lenses, though M-QW’s cleaning ability worsened post-treatment. pH measurements indicated notable decreases in M-QW and NaCl after CAP, whereas buffered solutions like CLCSs and DPBS remained stable. Overall, CAP demonstrates promise for contact lens disinfection and surface modification; however, further research and pre-clinical trials are necessary before clinical application in ophthalmology. Full article