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The parallel steel wires used in arch bridge suspenders experience random corrosion damage on their surfaces during service. Corrosion damage, including micro-cracks, pitting, and a combination of both, leads to significant stress concentration under axial loading, which affects the performance of the steel wires. The change in the stress field caused by surface damage alters the stress intensity factor at the crack tip, and the presence of adjacent crack tips significantly amplifies the stress intensity factor, thereby accelerating crack propagation. The development of small surface damages in the steel wires is difficult to control and observe through experiments. By utilizing finite element methods for simulation, it is possible to intuitively analyze the crack propagation process, the trend of stress changes at the crack tip, and the interaction between damages. Numerical simulation results based on Paris’ law indicate that corrosion pits have a certain impact on the stress intensity factor at the crack tip. The propagation process of coplanar double cracks is highly sensitive to the initial crack size and the distance between adjacent crack tips. When the crack spacing is less than the crack depth, the stress intensity factor at the adjacent crack tips exhibits significant amplification. Based on this phenomenon, the coplanar double-crack system can be simplified to a complete single crack for analysis. By comparing the fatigue life of the double-crack system with that of the equivalent single crack, the effectiveness of the simplification rule has been validated.

B-phycoerythrin (B-PE), a pigment protein, has found extensive applications in the food, pharmaceutical, and cosmetic industries. However, the effects and potential mechanisms of B-PE on colitis and colitis-associated bone loss remain unclear. Thus, the aim of this study was to investigate the pharmacological mechanisms of B-PE against colitis and colitis-associated bone loss using network pharmacology analysis, molecular docking, and experimental validation. Based on public databases, 99 common targets of B-PE against inflammatory bowel disease and osteoporosis were predicted. The protein-protein interaction network identified 16 core targets, including TNF, AKT1, EGFR, etc., as hub targets. Additionally, functional enrichment analyses and molecular docking results revealed that the PI3K/AKT signaling pathway may serve as a potential signaling pathway for B-PE in the treatment of colitis and colitis-associated bone loss. Furthermore, pharmacological experiments indicated that B-PE not only reversed the elevated expression of TNF-α, IL-1β, MMP9, and CXCL8a, and the reduced expression of ZO-1, E-cadherin, COL1A1, and RUNX2 in the DSS-induced colitis zebrafish model, but also enhanced the phosphorylation of PI3K and AKT, thereby mitigating inflammatory response and promoting osteogenesis. In conclusion, this study provides a theoretical basis for considering B-PE as a promising candidate for the treatment of colitis and colitis-associated bone loss.

The suspenders on the sides of an arch bridge are highly vulnerable to damage caused by traffic load and environmental corrosion. To accurately estimate the cable force of suspenders, herein, we analyse the influencing factors through a suspender tension test based on the principle of suspender vibration. The frequency of each suspender of the bridge is evaluated using the frequency method. By combining the cable force data measured directly and the measured suspender frequency, the formulas for calculating the cable forces of long and short suspenders are fitted, and a reasonable estimation method for the calculated length of short suspenders is provided. The formulas are verified through application to a CFST arch bridge. Results indicate that the proposed formula effectively considers the influence of the sleeve on the overall calculated length of the suspender. The formula calculates the suspender cable force with higher accuracy, proving its suitability for engineering use.

Highway traffic load, speed, and volume have been increasing continuously over the years. Because of its special structural form, the fatigue problem of a long-span concrete-filled steel tube arch bridge becomes more and more serious. To research the vehicle load spectrum and fatigue vehicle model of a long-span concrete-filled steel tubular arch bridge, the traffic data of the arch bridge were collected using the weight-in-motion system. The vehicle type and vehicle load in the actual traffic flow have strong stochastic characteristics, which cannot be directly applied. Therefore, according to the measured data, 10 representative models are proposed to facilitate the classification and screening of vehicle data. The wheelbase, mass, axle load, and overload data of the representative vehicle types were analysed, and the axle load distribution characteristics of vehicles in different lanes were studied. It is found that the vehicle load is not uniformly distributed in different lanes but concentrated in one lane. Moreover, a vehicle load spectrum for the fatigue assessment of the long-span concrete-filled steel tubular arch bridge is proposed. Based on the fatigue damage equivalence principle, a fatigue vehicle model and a simplified fatigue vehicle model of bridge heavy-duty vehicles are proposed. Compared with the model in the AASHTO specification, it is found that the weight of the local fatigue vehicle load model is 15.1 t heavier than the vehicle model given in the specification. This study could be further referenced in bridge-fatigue life prediction, management and maintenance, etc.

To evaluate the nutritional value and development potential of Pterocladiella capillacea in the marine environment of Naozhou Island, Zhanjiang, this study conducted species classification and identification, followed by an analysis of key nutritional components. The combination of morphological and molecular results confirmed the identification of the collected samples as P. capillacea. Further analysis showed that P. capillacea in Zhanjiang had a moisture content of 74.9% and a protein content of 24%. In comparison, the fat (0.4%) and carbohydrate (15.4%) contents were relatively low, with moderate ash (14.3%) and crude fiber (9.1%) content. It contains a diverse range of fatty acids, with saturated fatty acids accounting for 51.82% and unsaturated fatty acids accounting for 48.18% of the total. The amino acid composition was also diverse, with essential amino acids comprising 31.58% and flavor-enhancing amino acids constituting 54.85%. The minerals contained four major elements and four trace elements, while heavy metal levels were within safety limits, ensuring their edibility. In conclusion, P. capillacea is a high-protein, low-fat economic seaweed with a favorable amino acid and fatty acid composition, rich in minerals, and with significant nutritional and developmental potential. This study provides important data to support future research and utilization of this seaweed.

Increasing the yield and purity of B-phycoerythrin (B-PE) can improve the economic state of microalgae industrial processing. One method of cost reduction involves the recovery of remaining B-PE from wastewater. In this study, we developed a chitosan (CS)-based flocculation technique for the efficient recovery of B-PE from a low concentration of phycobilin in wastewater. We investigated the effects of the molecular weight of chitosan, B-PE/CS mass ratio, and solution pH on the flocculation efficiency of CS and the effects of phosphate buffer concentration and pH on the recovery rate of B-PE. The maximum flocculation efficiency of CS, recovery rate, and purity index of B-PE were 97.19% ± 0.59%, 72.07% ± 1.37%, and 3.20 ± 0.025 (drug grade), respectively. The structural stability and activity of B-PE were maintained during the recovery process. Economic evaluation revealed that our CS-based flocculation method is more economical than the ammonium sulfate precipitation method is. Furthermore, the bridging effect and electrostatic interaction play important roles in B-PE/CS complex flocculation process. Hence, our study provides an efficient and economical method to recover high-purity B-PE from a low concentration of phycobilin in wastewater, which promoted the application of B-PE as a natural pigment protein in food and chemical applications.

The corrosion and degradation behavior of high-strength steel wires during service directly affect the safety and usability of suspenders in steel pipe concrete arch bridges. In this study, three different types of specimens were fabricated using steel wires extracted from the suspenders of an 11-year-old in-service arch bridge and subjected to accelerated corrosion tests with acetic acid. Considering the differential diffusion processes of corrosion factors caused by varying degrees of damage to the suspender sheath, the spatial corrosion variability of steel wires at different positions within the suspender cross-section was investigated. Experimental results indicated a two-stage characteristic in the corrosion process of individual galvanized steel wire samples. In the first corrosion stage, the microstructure on the corroded steel wire surface evolved from a dense crystalline structure to a porous one. In the second corrosion stage, corrosion products accumulate on the steel wire substrate, subsequently further aggregating into sheet-like structures. The maximum pitting factor of individual steel wire samples from a specific area could be described by a Type I extreme value distribution. In the time-dependent model that was established, the location parameter and scale parameter exhibited an exponential decrease during the first corrosion stage and a linear decrease during the second corrosion stage. In the absence of sheath protection, the coefficient of variation in corrosion among adjacent steel wires in the suspender followed a normal distribution. The spatial corrosion variability of the wires inside the suspender is significantly influenced by the shape of the suspender sheath damage. As the corrosion time increased, the overall discrepancy in corrosion levels among different layers of wires diminished.

In this study, based on an actual project, the steel wire in the suspender of a concrete-filled steel tube arch bridge was selected from appropriate samples to perform acetic acid-accelerated salt spray tests, and steel wire samples with different corrosion degrees were obtained. A laser microscope was used to measure the roughness of the samples, and three corrosion samples were randomly selected from each group for grinding. Fatigue tests were performed on steel wire samples with different degrees of corrosion and polished steel wire samples, and the fatigue fracture was observed and analyzed. The results showed that few cracks on the steel wire surface could be eliminated by grinding, and the fatigue life of the specimens could be increased. Finally, the stress-life-mass loss rate (S-N-η) probability model based on the Weibull distribution was obtained using the measured fatigue data, which can be further referenced in the planning of the inspection of suspender service status, steel wire corrosion protection, and fatigue life prediction, etc.

Metformin, the most prescribed antidiabetic medicine, has shown other benefits such as anti-ageing and anticancer effects 1 – 4 . For clinical doses of metformin, AMP-activated protein kinase (AMPK) has a major role in its mechanism of action 4 , 5 ; however, the direct molecular target of metformin remains unknown. Here we show that clinically relevant concentrations of metformin inhibit the lysosomal proton pump v-ATPase, which is a central node for AMPK activation following glucose starvation 6 . We synthesize a photoactive metformin probe and identify PEN2, a subunit of γ-secretase 7 , as a binding partner of metformin with a dissociation constant at micromolar levels. Metformin-bound PEN2 forms a complex with ATP6AP1, a subunit of the v-ATPase 8 , which leads to the inhibition of v-ATPase and the activation of AMPK without effects on cellular AMP levels. Knockout of PEN2 or re-introduction of a PEN2 mutant that does not bind ATP6AP1 blunts AMPK activation. In vivo, liver-specific knockout of Pen2 abolishes metformin-mediated reduction of hepatic fat content, whereas intestine-specific knockout of Pen2 impairs its glucose-lowering effects. Furthermore, knockdown of pen-2 in Caenorhabditis elegans abrogates metformin-induced extension of lifespan. Together, these findings reveal that metformin binds PEN2 and initiates a signalling route that intersects, through ATP6AP1, the lysosomal glucose-sensing pathway for AMPK activation. This ensures that metformin exerts its therapeutic benefits in patients without substantial adverse effects. The molecular target of the antidiabetic medicine metformin is identified as PEN2, a subunit of γ-secretases, and the PEN2–ATP6AP1 axis offers potential targets for screening for metformin substitutes.

There is an urgent need for cost‐effective strategies to produce hydrogen from renewable net‐zero carbon sources using renewable energies. In this context, the electrochemical hydrogen evolution reaction can be boosted by replacing the oxygen evolution reaction with the oxidation of small organic molecules, such as ethylene glycol (EG). EG is a particularly interesting organic liquid with two hydroxyl groups that can be transformed into a variety of C1 and C2 chemicals, depending on the catalyst and reaction conditions. Here, a catalyst is demonstrated for the selective EG oxidation reaction (EGOR) to formate on nickel selenide. The catalyst nanoparticle (NP) morphology and crystallographic phase are tuned to maximize its performance. The optimized NiS electrocatalyst requires just 1.395 V to drive a current density of 50 mA cm−2 in 1 m potassium hydroxide (KOH) and 1 m EG. A combination of in situ electrochemical infrared absorption spectroscopy (IRAS) to monitor the electrocatalytic process and ex situ analysis of the electrolyte composition shows the main EGOR product is formate, with a Faradaic efficiency above 80%. Additionally, C2 chemicals such as glycolate and oxalate are detected and quantified as minor products. Density functional theory (DFT) calculations of the reaction process show the glycol‐to‐oxalate pathway to be favored via the glycolate formation, where the CC bond is broken and further electro‐oxidized to formate. A combination of in situ and ex situ analysis shows the main product of the ethylene glycol (EG) oxidation reaction (EGOR) is formate with a Faradaic efficiency above 80%, and glycolate and oxalate as minor chemicals on nickel selenide nanoparticles (NPs). Further density functional theory (DFT) calculation reveals the electrooxidation mechanism to these products.