Search Results (2,330)

This study examines the design and implementation of a sensor developed to measure total pressure in supersonic flow conditions using nitrogen as the working fluid. Using a combination of absolute and differential pressure sensors, the total pressure distribution downstream of a nozzle—where normal shock waves are generated—was characterized across a range of low-pressure regimes. The experimental results were employed to validate and calibrate computational fluid dynamics (CFD) models, particularly within pressure ranges approaching the limits of continuum mechanics. The validated analyses enabled a more detailed examination of shock-wave behavior under near-continuum conditions, with direct relevance to the operational environment of differentially pumped chambers in Environmental Scanning Electron Microscopy (ESEM). Furthermore, an entropy increase across the normal shock wave at low pressures was quantified, attributed to the extended molecular mean free path and local deviations from thermodynamic equilibrium. Full article

This study investigated the effects of elevated temperature on the phenology and morphology of the early-maturing peach cultivar ‘Mihong’. The experiment was conducted from 2019 to 2024 in a temperature-gradient chamber at the National Institute of Horticultural and Herbal Science, Wanju, Korea, with four warming treatments (+2.2 °C to +5.0 °C above ambient). Higher temperatures delayed the onset of endodormancy and markedly shortened the period from endodormancy release to full bloom. Elevated temperatures also increased the LD ratio, with the proportion of fruits exceeding an LD ratio of 1.0 rising significantly with temperature. The LD ratio showed strong correlations with November mean temperature (MT11) and March maximum temperature (HT3) (r = 0.81) and was also associated with the average temperature (Temp3, r = 0.51) and duration (P3, r = −0.54) of the endodormancy release to full bloom phase. Stepwise and PLS regression identified temperatures in May, November, and March as key predictors of the LD ratio, while PCA revealed that temperature variables (Temp3, Temp5) and stage durations (P3, P4) were major contributors. These results confirm that climate warming alters the phenology and morphology of ‘Mihong’, reducing fruit quality and marketability, while providing a basis for predictive modeling and highlighting the importance of adaptive strategies such as shading or growth regulator application. Full article

Glaucoma is a leading cause of irreversible blindness, and animal models are essential for studying its pathophysiology and testing therapeutic strategies. In this study, a novel hydrogel-based approach was developed and evaluated to induce experimental glaucoma in mice, using composites of hyaluronic acid (HA) and the self-assembling peptide fluorenylmethoxycarbonyl-diphenylalanine (FmocFF). Two formulations with different HA-to-FmocFF ratios were injected either intracamerally or intravitreally in C57BL/6 mice. Intraocular pressure (IOP) was monitored over 21 days, and retinal tissues were analyzed histologically and immunohistochemically. Significant IOP elevation was observed in one hydrogel formulation (Mixture B), yet without detectable retinal ganglion cell loss. A significant reduction in retinal ganglion cell (RGC) density, independent of IOP changes or injection site, was observed in Mixture A. Histological staining confirmed successful delivery and localization of the hydrogel in the anterior chamber, and no evidence of gliosis, microglial activation, or increased apoptosis was revealed by immunostaining. Collectively, these data position the HA-FmocFF hydrogel as a proof-of-concept that advances glaucoma model development, although it does not yet recapitulate the full disease. This model may facilitate future studies of neuroprotection and disease-modifying therapies in glaucoma without confounding inflammatory responses. 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

Animal models are essential for studying tumor pathophysiology; however, most lack the capacity for repeated in vivo observation of tumor growth and vascularization over extended periods. This study aimed to establish a novel in vivo model using the mouse dorsal skinfold chamber. Tumor induction was performed using different membrane types (two polytetrafluoroethylene meshes and a polydioxanone plate), followed by monitoring of tumor vascularization via intravital fluorescence microscopy (IVM). Tumors developed successfully over six weeks, demonstrating sustained vascular supply and enabling, for the first time, the investigation of vascular networks in advanced tumors. Among the membranes tested, the polydioxanone membrane facilitated easier chamber preparation but may negatively affect angiogenesis and promote inflammation. IVM revealed persistent microcirculation in manifested tumors over six consecutive days, allowing detailed assessment of microvascular parameters, leukocyte–endothelial interactions, and functional capillary density. This model enables repetitive, high-resolution visualization of tumor microcirculation dynamics in vivo. In conclusion, this improved mouse dorsal skinfold chamber combined with IVM provides a powerful tool for investigating tumor angiogenesis and evaluating therapeutic interventions in advanced tumors. Full article

The aim of the present study is to evaluate the impact of chromium (Cr) supplementation on glucose and lipid metabolism in breast muscle in broilers under heat stress. A total of 220 day-old broiler chicks were reared in cages. At 29 days old, 180 birds were randomly assigned to three treatments (0, 400, and 800 µg Cr/kg, as chromium picolinate) and transferred to climate chambers (31 ± 1 °C, 60 ± 7% humidity) for 14 days. Growth performance, carcass traits, serum biochemical indices, fasting glucose and insulin, homeostasis model assessment of insulin resistance (HOMA-IR), as well as muscle metabolomic profiles and gene expression related to energy and lipid metabolism were analyzed. The results showed that, compared with the heat stress group, the groups supplemented with 400 and 800 µg Cr/kg showed higher dry matter intake and average daily gain, breast muscle ratio, and lower feed conversion ratio and abdominal fat ratio; chickens supplemented with 400 and 800 µg Cr/kg showed significantly lower serum corticosterone (CORT), free fatty acids, and cholesterol levels compared with the heat stress (HS) group (p < 0.05). Fasting blood glucose and HOMA-IR were also significantly reduced, while fasting insulin was significantly increased in the Cr-supplemented groups (p < 0.05). Metabolomic analysis revealed that Cr supplementation regulated lipid and amino acid metabolism by altering key metabolites such as citric acid, L-glutamine, and L-proline, and modulating pathways including alanine, aspartate, and glutamate metabolism, and glycerophospholipid metabolism. Furthermore, Cr supplementation significantly upregulated the expression of Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1 α (PGC-1α), ATP Binding Cassette Subfamily A Member 1 (ABCA1), Peroxisome Proliferator-Activated Receptor α (PPARα), and ATP Binding Cassette Subfamily G Member 1 (ABCG1) in both the hepatic and muscle tissue. This paper suggested that chromium supplementation may enhance energy metabolism and lipid transport like the findings of our study suggested. Full article

Background/Objectives: Patient education materials (PEMs) in ophthalmology often exceed recommended readability levels, limiting accessibility for many patients. While organizations like the AAO provide relatively easy-to-read resources, topics remain limited, and other associations’ PEMs are too complex. AI chatbots could help clinicians create more comprehensive, accessible PEMs to improve patient understanding. This study aims to compare the readability of patient education materials (PEMs) written by the American Academy of Ophthalmology (AAO) with those generated by large language models (LLMs), including ChatGPT-4o, Microsoft Copilot, and Meta-Llama-3.1-70B-Instruct. Methods: LLMs were prompted to generate PEMs for 15 common diagnoses relating to cornea and anterior chamber, which was followed by a follow-up readability-optimized (FRO) prompt to reword the content at a 6th-grade reading level. The readability of these materials was evaluated using nine different readability analysis python libraries and compared to existing PEMs found on the AAO website. Results: For all 15 topics, ChatGPT, Copilot, and Llama successfully generated PEMs, though all exceeded the recommended 6th-grade reading level. While initially prompted ChatGPT, Copilot, and Llama outputs were 10.8, 12.2, and 13.2, respectively, FRO prompting significantly improved readability to 8.3 for ChatGPT, 11.2 for Copilot, and 9.3 for Llama (p < 0.001). While readability improved, AI-generated PEMs were on average, not statistically easier to read than AAO PEMs, which averaged an 8.0 Flesch–Kincaid Grade Level. Conclusions: Properly prompted AI chatbots can generate PEMs with improved readability, nearing the level of AAO materials. However, most outputs remain above the recommended 6th-grade reading level. A subjective analysis of a representative subtopic showed that compared to AAO, there was less nuance, especially in areas of clinical uncertainty. By creating a blueprint that can be utilized in human–AI hybrid workflows, AI chatbots show promise as tools for ophthalmologists to increase the availability of accessible PEMs in ophthalmology. Future work should include a detailed qualitative review by ophthalmologists using a validated tool (like DISCERN or PEMAT) to score accuracy, bias, and completeness alongside readability. Full article

This article presents the development of a new pneumatic device for the precise application of mineral fertilizers, designed for use in precision agriculture systems involving farming robots. The proposed device is mounted on an autonomous agricultural platform and utilizes a machine vision system to determine plant coordinates. Its operating principle is based on accumulating a single dose of fertilizer in a chamber and delivering it precisely to the plant’s root zone using a directed airflow. The study includes a theoretical investigation of fertilizer movement inside the applicator tube under the influence of airflow and rotational motion of the tube. A mathematical model has been developed to describe both the relative and translational motion of the fertilizer. The equations, which account for frictional forces, inertia, and air pressure, enable the determination of optimal structural and kinematic parameters of the device depending on operating conditions and the properties of the applied material. The use of numerical methods to solve the developed mathematical model allows for synchronization of the device’s operating time parameters with the movement of the agricultural robot along the crop rows. The obtained results and the developed device improve the accuracy and speed of fertilizer application, minimize fertilizer consumption, and reduce soil impact, making the proposed device a promising solution for precision agriculture. Full article

Saline–alkali soils in arid regions are increasingly recognized as critical yet underrepresented components of the global carbon cycle. However, their CO₂ flux dynamics under warming remain poorly understood. In this study, we conducted controlled growth-chamber experiments using typical saline–alkali soils from the Taklamakan Desert, where temperature, soil moisture, and atmospheric CO₂ concentrations were systematically manipulated. We quantified how warming reshaped moisture–temperature interactions regulating soil CO₂ fluxes. The results revealed a pronounced diurnal variation pattern, characterized by daytime CO₂ release and nighttime uptake. Temperature was identified as the dominant driver (R² > 0.93, p < 0.001), whereas soil moisture primarily modulated flux intensity; at 0.8 cm³ cm⁻³, fluxes declined by up to 61% compared with the baseline. Warming enhanced the temperature–moisture synergy (−43%, p < 0.01) and simultaneously reduced baseline fluxes (−56%, p < 0.01). These shifts fundamentally altered the regulation of CO₂ flux dynamics. Our findings highlight the necessity of integrating salt dynamics and carbonate equilibria into multiphase reactive transport models to improve regional carbon sink assessments. Ultimately, this study refines estimates of the contribution of saline–alkali soils to the global “missing carbon sink” (~1.7 Pg C a⁻¹) and emphasizes their overlooked role in the Earth’s carbon budget under a warming climate. Full article

The unsteady and discontinuous liquid flow in the microchannel affects the efficiency of sample mixing, molecular detection, target acquisition, and biochemical reaction. In this work, an active method of reducing the flow pulsation in the microchannel of a pneumatic microfluidic chip is proposed by using an on-chip membrane microvalve as a valve chamber damping hole or a valve chamber accumulator. The structure, working principle, and multi-physical model of the reducing element of reducing the flow pulsation in a microchannel are presented. When the flow pulsation in the microchannel is sinusoidal, square wave, or pulse, the simulation effect of flow pulsation reduction is given when the membrane valve has different permutations and combinations. The experimental results show that the inlet flow of the reducing element is a square wave pulsation with an amplitude of 0.1 mL/s and a period of 2 s, the outlet flow of the reducing element is assisted by 0.017 and the fluctuation frequency is accompanied by a decrease. The test data and simulation results verify the rationality of the flow reduction element in the membrane valve microchannel, the correctness of the theoretical model, and the practicability of the specific application, which provides a higher precision automatic control technology for the microfluidic chip with high integration and complex reaction function. Full article

In deep-sea oil and gas development scenarios, deep-sea dual-channel connectors often face the risk of seal failure due to internal and external temperature difference loads. To address this issue, this paper systematically establishes equivalent heat transfer models for the key parts of the connector based on the third-type boundary condition. On this basis, the quantitative correlation between the equivalent thermal conductivity, composite heat transfer coefficient and temperature of each part is explored. Using the finite element numerical simulation method, the transient temperature field of the connector under three working conditions (heating, cooling and temperature shock) is simulated and analyzed, revealing the temperature distribution characteristics and temperature change trends of the maximum temperature difference of each key component of the connector; combined with thermal–structural coupling simulation, the temperature field is converted into static load, to determine the behavior of the contact stress on the sealing surface under different temperature–pressure coupling working conditions; in addition, by placing the test prototype in a high-low temperature cycle chamber, the seal performance tests under pressurized and non-pressurized working conditions are carried out to verify the reliable sealing performance of the connector under variable temperature conditions. The results of this paper provide comprehensive theoretical support and an experimental basis for the thermodynamic optimization design of deep-sea connectors and the improvement of the reliability of the sealing system. Full article

This study aims to generate foundational metabolomic data of aqueous humor (AH) in healthy horses and donkeys, and to investigate potential changes or trends in the metabolomic profile associated with age, sex or ocular pathology in horses. The AH metabolomic fingerprint from 5 donkeys and 35 equine eyes (17 controls, 8 with cataracts, 6 with retinal disease and 4 with anterior chamber disease (ACD)) were analyzed using nuclear magnetic resonance (NMR) spectroscopy. A linear mixed-effects model, with individual horse as a random effect and group as a fixed effect, with multiple testing correction using the Benjamini–Hochberg false discovery rate (FDR) method was used to compare groups. The metabolomic profile of the donkeys and horse’s AH is very similar to that of other mammals. Threonine was higher in young horses (p = 0.04), and creatinine was elevated in males (p = 0.04). Compared with control groups, dimethyl sulfone was higher in the retina (p < 0.00) and cataract (p = 0.05) groups. Arginine (p = 0.05) and valine (p = 0.03) were lower in the retina group compared to controls. This study successfully characterized the AH metabolomic profile in healthy horses and donkeys and identified several metabolites that could be associated with ocular pathology, warranting further investigation to determine their potential as biomarkers of ocular disease. Full article

Particulate matter (PM) exposure is linked to chronic kidney disease; however, its effect on immunoglobulin A (IgA) nephropathy (IgAN) remains unclear. We investigated whether PM exposure exacerbates IgAN in a mouse model. HIGA mice (IgAN model) and BALB/c controls were exposed to PM in a sealed chamber for 13 weeks. Lung Toll-like receptor 9 (TLR9) expression, serum aberrantly glycosylated IgA, A proliferation-inducing ligand (APRIL) levels, mesangial IgA deposition, and kidney pathology were assessed. RNA sequencing of splenic B cells was performed to evaluate immune-related gene expression. PM exposure increased lung TLR9 expression in both strains, particularly around pigment-laden macrophages. HIGA mice showed elevated aberrant IgA and APRIL levels, with aggravated mesangial expansion and IgA deposition. Transcriptomic analysis revealed immune dysregulation in splenic B cells of PM-exposed HIGA mice. Our findings provide experimental evidence that PM exposure aggravates IgAN via TLR9-mediated mucosal immune activation, leading to aberrant IgA glycosylation and mesangial deposition. These findings emphasize that reducing PM exposure may benefit patients with IgAN. Full article

Unbalance in rotating machinery causes significant vibrations, reducing lifespan and efficiency. This study overcomes the limitations of conventional offline balancing by introducing an online rotor balancing system utilizing Magnetorheological Fluid (MRF). The system employs three chambers containing MRF and balancing spheres. A hybrid magnetic system is designed, combining permanent magnets for fixing in the balanced state and a stationary electromagnet for contactless control of the sphere position during balancing. A control algorithm was developed based on multiphysics modeling and experimental parameterization. Experimental validation demonstrated the high effectiveness of reducing initial rotor unbalance, thereby confirming the feasibility of the proposed concept. The hybrid magnetic design provides inherent multistability and energy efficiency, making it a promising and effective solution for active vibration reduction in rotating machinery. Full article

This paper presents an intelligent design framework for a high-performance 26 GHz MIMO antenna array tailored to 5G applications, built upon a compact single-element patch. The 11.5 mm × 11.5 mm × 1.6 mm microstrip patch on FR4 exhibits near-unity electrical length, an ultra-deep return loss (S11 < −40 dB at 26 GHz), and a wide operational bandwidth from 24.4 to 31.2 GHz (6.8 GHz, ~26.2%). A two-element array, spaced at λ/2, is first augmented with a inspired metamaterial (MTM) unit cell whose dimensions are optimized via a Multi-Layer Perceptron (MLP) model to maximize gain (+2 dB) while preserving S11. In the second phase, a closed-square parasitic ring is introduced between the elements; its side length, thickness, and position are predicted by a Random Forest (RF) model with Bayesian optimization to minimize mutual coupling (S12) from −25 dB to −58 dB at 26 GHz without significantly degrading S11 (remains below −25 dB). Full-wave simulations and anechoic chamber measurements confirm the ML predictions. The close agreement among predicted, simulated, and measured S-parameters validates the efficacy of the proposed AI-assisted optimization methodology, offering a rapid and reliable route to next-generation millimeter-wave MIMO antenna systems. Full article