Ectothermic fish exposure to hypothermal stress requires adjusting their metabolic molecular machinery, which was investigated using Indian medaka (Oryzias dancena; 10 weeks old, 2.5 ± 0.5 cm) ...cultured in fresh water (FW) and seawater (SW; 35‰) at room temperature (28 ± 1 °C). The fish were fed twice a day, once in the morning and once in the evening, and the photoperiod was 12 h:12 h light: dark. In this study, we applied two hypothermal treatments to reveal the mechanisms of energy metabolism via pgc-1α regulation in the gills of Indian medaka; cold-stress (18 °C) and cold-tolerance (extreme cold; 15 °C). The branchial ATP content was significantly higher in the cold-stress group, but not in the cold-tolerance group. In FW- and SW-acclimated medaka, the expression of genes related to mitochondrial energy metabolism, including pgc-1α, prc, Nrf2, tfam, and nd5, was analyzed to illustrate differential responses of mitochondrial energy metabolism to cold-stress and cold-tolerance environments. When exposed to cold-stress, the relative mRNA expression of pgc-1α, prc, and Nrf2 increased from 2 h, whereas that of tfam and nd5 increased significantly from 168 h. When exposed to a cold-tolerant environment, prc was significantly upregulated at 2 h post-cooling in the FW and SW groups, and pgc-1α was significantly upregulated at 2 and 12 h post-cooling in the FW group, while tfam and nd5 were downregulated in both FW and SW fish. Hierarchical clustering revealed gene interactions in the cold-stress group, which promoted diverse mitochondrial energy adaptations, causing an increase in ATP production. However, the cold-tolerant group demonstrated limitations in enhancing ATP levels through mitochondrial regulation via the PGC-1α energy metabolism pathway. These findings suggest that ectothermic fish may develop varying degrees of thermal tolerance over time in response to climate change. This study provides insights into the complex ways in which fish adjust their metabolism when exposed to cold stress, contributing to our knowledge of how they adapt.
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•As reaction temperature increased from 100 to 160 °C, the Hg° adsorption efficiencies of 5–30%V2O5/TiO2 greatly decreased.•The adsorption efficiency and capacity were highly enhanced ...by the dopant amount. 20%V2O5/TiO2 has the highest activity.•The results of adsorption kinetic confirm that the diffusion process controlled the overall reaction.•The major resistance was identified by analyzing external mass transfer coefficient and effective diffusion efficiency.•The diffusion resistance may offset the high Hg° adsorption efficiency of V2O5/TiO2.
To investigate the effect of low temperature and catalyst filling pattern on the adsorption of Hg° by DeNOx equipment, the chemisorption and kinetic mechanisms of Hg° adsorption on 5–30%V2O5/TiO2 immobilized on glass beads at 100–160 °C were investigated. The effects of the reaction temperature, influent Hg° concentration, and V2O5 doping amount on the adsorption efficiency and capacity for Hg° were explored. The active sites for Hg° adsorption were further identified. Additionally, the adsorption kinetics were modelled using the linear driving force approximation, Fick’s diffusion model, and pseudo-second-order kinetic model. Finally, the influence of immobilization on the adsorption of Hg° was also investigated. Experimental results showed that the bridged oxygen atom of V-O-V played a key role in the adsorption of Hg°. The Hg° adsorption efficiencies decreased from >90% to 40% as the reaction temperature increased from 120 °C to 160 °C for 20%V2O5/TiO2, while the adsorptive capacities for Hg° were highly influenced by the influent Hg° concentration and V2O5 doping amount. 20%V2O5/TiO2 had the highest adsorptive capacity of 2547 μg Hg°/g V2O5/TiO2 at 160 °C. The kinetic results showed that the linear driving force approximation model fit the Hg° adsorption better than the other models. The diffusion resistance increased significantly for the immobilized catalysts because the external mass transfer coefficient decreased by more than 1200-fold.
The mass planting of mangroves has been proposed as a mitigation strategy to compensate for mangrove loss. However, the effects of mangrove vegetation on the abundance and community composition of ...macrobenthos remain controversial. The macrobenthic communities in four intact mangrove forests with different conditions and the adjacent nonvegetated mudflats of two mangrove species with distinct stand structures on the western coast of Taiwan were examined. Some macrobenthic taxa occurred only in the mangroves, suggesting macrobenthic critical habitats. Seasonal shift in community composition was more pronounced in the mudflats than in the mangroves, possibly due to the rich food supply, low temperature, and shelter function provided by mangrove forests. However, crab density was always lower in the mangroves than in the mudflats. There was a negative relationship between the stem density of Kandelia obovata (S., L.) and infaunal density. The pneumatophore density of Avicennia marina (Forsk.) correlated negatively with epifaunal density. Our results show that the response of macrobenthic abundance and community composition to mangrove vegetation was inconsistent. We reason that mangroves are critical habitats for the macrobenthos in the mudflats. However, if mangrove tree density is high, we predict that the macrobenthic density will decrease. This suggests that at some intermediate level of mangrove tree density, where there are enough mangrove trees to harbor a macrobenthic community but not enough trees to significantly reduce this density, mangroves management can be optimally achieved to promote the presence of a diverse and dense macrobenthic community.
Objective of this study is to develop a barge-type floating offshore wind turbine (FOWT) in order to face extreme environmental conditions in western Taiwan offshore water area. The prototype of FOWT ...considered here consists of (1) NERL 5 MW wind turbine, (2) a single steel column with a hub height of 90 m above sea level, (3) a square barge-type floating platform equipped with a damping pool and heave plate to improve the stability of the floating foundation, (4) catenary mooring system using anchor chain, and installation at a water depth of 70 m in the western Taiwan offshore water area.
In order to verify the feasibility of the concept, a 1/20 scale model of the FOWT prototype was used by conducting hydraulic model tests in the large flume (300m × 5m× 5m) at Tainan Hydraulics Laboratory (THL), National Cheng Kung University (NCKU) and field experiments at the Anping Harbor. Hydraulic model tests include (1) regular wave test, with normal wave period from 5.7sec to 8.9sec, and long wave period from 9 s to 14sec. (2) irregular wave test, including normal sea condition, northeast monsoon sea condition, ten-year return period typhoon wave condition, and 50-year return period typhoon wave condition. Moreover, investigation of wind speed, wind direction, wave height, dynamic motion of FOWT, mooring tension, and rotor speed were conducted in the field experiment.
After examining the motion of the barge-type offshore floating wind turbine, it was found that the pitch and the roll motions could satisfy the DNV standard. The tension of the mooring line did not exceed the minimum breaking load (MBL), which indicating the good stability of the barge-type FOWT proposed by this study.
•A barge-type FOWT was developed to face extreme environmental conditions in western Taiwan offshore water area.•Model test in large flume and field experiment in harbor were conducted to investigate the FOWT stability performance.•The designed mooring system of barge-type FOWT is safety, even in the scenario of one mooring line failure case.•During field experiment in harbor, good stability of the barge-type FOWT was also verified by local wave/wind climate.
Molecular dynamics (MD) simulations were applied to investigate proton transfer in a Nafion polymer. This study focused on Nafion 117 (Dupont) membrane at a hydration level of λ = 4. We investigated ...the transport of proton at 298 K using MD simulations. The mean square displacement, radial distribution function, and movement trajectories of protons as indicated by the MD simulations were analyzed. The calculated conductivity of a single proton was consistent with the experimental value obtained for said conductivity. We further found that protons could easily be coordinated with their neighboring water molecules. In addition, multi-hydrated protons were observed from MD trajectories. This result suggested that the proton transfer that occurs in such a Nafion polymer system is due to Grotthuss and vehicle mechanisms.
•Protons could easily be coordinated with their neighboring water molecules.•Multi-hydrated protons were observed from MD trajectories.•It suggested that the proton transfer that occurs in such a Nafion polymer system is due to Grotthuss and vehicle mechanisms.
Diabetic macular edema (DME) is the most common cause of vision loss among patients with diabetes mellitus (DM), rendering it an important growing challenge in ophthalmology. In the past decades, the ...management strategies for DME had a few paradigm shifts, and the advent of an expanding number of anti-vascular endothelial growth factor (VEGF) agents also calls for an in-depth examination of the currently available evidence. This article was composed with the intention to provide recommendations for practicing clinicians to improve the management and, through it the outcomes of DME. Drawing from current guideline recommendations, clinical trial findings and local clinical experiences, these consensus recommendations for the management of DME were formed by an expert panel through iterations of discussion and voting. First, the treatment goal of DME is to achieve best visual outcome with edema improvement while minimizing treatment burden. Second, anti-VEGF therapy should be considered as the first-line treatment for patients with center-involving DME causing vision loss. Baseline visual acuity (VA) and central subfield thickness (CST) should be taken into consideration when choosing anti-VEGF agents. Third, early intensive anti-VEGF therapy (at least 3 monthly doses) is important for better patients’ VA and anatomical improvement. In non-responders who have already been treated with 3-5 injections of anti-VEGF agents, it is reasonable to switch to other modalities, such as steroids. Finally, for the follow-up phase, fixed or individualized dosing should be considered based on VA and OCT.
Previous research indicated that black and yellow leaf spots on Cymbidium, Ondontioda, Dendrobium and Cattleya could be caused by Fusarium proliferatum worldwide. However, the agent causing leaf spot ...on Cymbidium spp. plants is still obscure in Taiwan. Thirty‐five F. fujikuroi species complex (FFSC)‐like isolates were collected from Cymbidium leaf spot from different greenhouses in Taiwan. All isolates were identified as F. proliferatum based on morphological characteristics and molecular analysis. Sequence of translation elongation factor 1‐alpha gene showed 99%–100% homology with F. proliferatum. In addition, two assay techniques using either detached leaves or seedlings were used to evaluate the pathogenicity and host range of the isolates and consequently their effects on Cymbidium and other orchid plants. Pathogenicity assays revealed that all isolates induced black and necrotic spots on detached leaves of Cymbidium, showing 9.4%–29.5% severity on seedlings of Cymbidium. Results of host specificity tests on detached leaves of different plants indicated that the F. proliferatum isolates collected from Cymbidium plants caused severe black spots on Oncidium, Cymbidium, Dendrobium and Cattleya plants. The symptoms on Phalaenopsis plants were relatively mild. Results of host specificity tests on plant seedlings indicated that the F. proliferatum isolates of Cymbidium origin were also pathogenic to Oncidium, Cymbidium and Dendrobium, but not to Cattleya and Phalaenopsis. Phylogenetic analysis of the translation elongation factor (TEF) gene among all fungal isolates using maximum parsimony (MP) and Bayesian inference (BI) methods revealed that the isolates of F. proliferatum from Cymbidium spp. could be separated from other FFSC‐like species with high phylogenetic support.
Abstract
Railway tracks exhibit a complex, sudden alteration in their cross-sectional configuration. Generating guided waves within thick rail tracks using conventional guided wave transducers is ...challenging. This research employs directional decomposition to comprehend how guided waves form within the rail. These waves arise from constructive interference between multiple reflected bulk waves, which are induced by point forces on the top surface of the railhead or diffracted from cracks in the rail structure. This study simulates finite-range detection of rail defects using finite element analysis to demonstrate a potential application to the guided wave rail inspection car. The transmitter and a series of monitoring points are located on the same side of the rail defect in the pitch-catch configuration. The transmitting guided waves often hide the small backscatter waves induced by defects. A directional filter extracts the small backscatter signals from the entire received data. A 100 kHz tone burst actuates on the top surface of the rail in three orthogonal directions. Numerical findings demonstrate that vertical and tangential excitations are suitable for detecting defects in the railhead and lower region, while transverse excitation and detection are appropriate for identifying defects in the rail web. The application of directional decomposition provides valuable insights into the complex process of backscatter waves arising from rail track defects.
Abstract
Joint structures made from plates or shells are frequently used in large constructions, such as oil storage tanks in petrochemical industries. The corrosion-induced metal loss often appears ...on the back side of the bottom plate supported by ground or sand. The welding residual stress and weight of shell walls accelerate the corrosion. Determining the severity of metal loss under the joint is challenging. This work uses the mode pair technique for nondestructive inspection of inaccessible regions in joint structures. A finite element analysis model simulates the transient responses of the incident and mode-converted fundamental and second harmonic plate waves. The second harmonic s0 plate wave satisfying the phase velocity matching condition accompanies the transmitted fundamental SH0 plate wave. A directional filter identifies every mode-converted plate wave by comparing the frequency spectra with the dispersion curves. Linear ultrasonic guided waves can detect inaccessible regions using mode-converted reflections. The symmetry of the linear mode-converted fundamental plate waves depends on the defect position and geometry, not the size. The mode-converted second harmonic guided wave can achieve better spatial resolution for defect sizing. The nonlinear parameter shows a proportional trend with an increasing thickness reduction. Experimental and numerical evidence reveals nonlinear ultrasonic guided wave technique has the potential for defect detection in joint structures.
Photocrosslinked nanogels with a hydrophobic core and hydrophilic shell are successfully fabricated with the goal of obtaining a biocompatible and biodegradable drug carrier for hydrophobic ...anticancer drugs. These nanogels are composed of amphiphilic triblock copolymers, poly(D,L‐lactic acid)/poly(ethylene glycol)/poly(D,L‐lactic acid) (PLA‐PEG‐PLA), with acrylated groups at the end of the PLA segments. The copolymers are synthesized by ring‐opening polymerization and possess a low CMC (49.6 mg · L−1), which easily helps to form micelles by self‐assembly. The acrylated end groups allow the micelles to be photocrosslinked by ultraviolet irradiation, which turn the micelles into nanogels. These nanogels exhibit excellent stability as a suspension in aqueous media at ambient temperature as compared to the micelles. Moreover, the size of the nanogels is easily manipulated in a range of 150 to 250 nm by changing the concentration of crosslinkers, e.g., ethylene glycol dimethacrylate, and ultraviolet light irradiation time. The nanogels achieve a high encapsulation efficiency and offer a steady and long‐term release mechanism for the hydrophobic anticancer drug, CPT. It shows that these nanogels are useful for a hydrophobic anticancer drug‐carrier system.
Formation of the PLA‐PEG‐PLA nanogels.
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