Corrosion Fatigue Behavior and Damage Mechanism of the Bridge Cable Structures

The long-term performance and corrosion fatigue damage status were investigated and analyzed under the service environment for the cable structures in cable-stayed bridges, suspension bridges, and suspender arch bridges. The artificial accelerated corrosion fatigue tests were carried out on galvanized parallel steel wire under coupled loading and environments. The damage mechanisms of galvanized parallel steel wire in corrosion, stress corrosion, and corrosion fatigue were investigated. The change laws of the mechanical properties of the cable were studied. Based on the image gray analysis, the evaluation method was proposed for the technical status of the damaged cable. Furthermore, combined with the cable damage evolution model, the service life prediction method and assessment technology of cables based on damage safety are established

Test Study of the Bridge Cable Corrosion Protection Mechanism Based on Impressed Current Cathodic Protection

The cable system is an important bearing element of a bridge with stay cables or slings and a matter of major concern in the safety of the bridge structure. Bridge cables are vulnerable to corrosion induced by leakage and soaking during their service life. To solve this problem, and based on the idea of proactive control by means of the impressed current cathodic protection (ICCP) of bridge cables, this study designs and develops an ICCP system device for bridge cable protection. In this study, an accelerated corrosion test was conducted to test the ICCP system of steel wires inside the cables and the cables under acid rain conditions. The corrosion protection behavior of ICCP was analyzed to reveal the corrosion protection mechanism of bridge cable ICCP. The results show that in the cable ICCP system, the impressed current generated by a more negative voltage may improve the efficiency of corrosion protection, but an excessively negative voltage may cause hydrogen embrittlement of the cable steel wire due to overprotection. The rational range of −1.13 V to −1.15 V was set as the result of the overall consideration. Within this range, the cable is subject to the joint protection of ICCP and sacrificial anode cathodic protection (SACP). Corrosive products can delay the development of cable corrosion to a certain degree; the SACP protection efficiency of the galvanized coat reduces gradually with corrosion development; and cable ICCP protection efficiency increases gradually. The ICCP for cable corrosion protection is transformed from joint protection using both a sacrificial anode and impressed current into protection, mainly using an impressed current

Preparation of Multiwalled Carbon Nanotubes/Hydroxyl-Terminated Silicone Oil Fiber and Its Application to Analysis of Crude Oils

A simple and efficient method to analyze the volatile and semivolatile organic compounds in crude oils has been developed based on direct immersion solid-phase microextraction coupled to comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (DI-SPME-GC × GC/TOFMS). A novel fiber, multiwalled carbon nanotubes/hydroxyl-terminated silicone oil (MWNTs-TSO-OH), was prepared by sol-gel technology. Using standard solutions, the extraction conditions were optimized such as extraction mode, extraction temperature, extraction time, and salts effect. With the optimized conditions, a real crude oil sample was extracted and then analyzed in detail. It shows that the proposed method is very effective in simultaneously analyzing the normal and branched alkanes, cycloalkanes, aromatic hydrocarbons, and biomarkers of crude oil such as steranes and terpanes. Furthermore, the method showed good linearity (r > 0.999), precision (RSD < 8%), and detection limits ranging from 0.2 to 1.6 ng/L

Research on the Diffusion Model of Cable Corrosion Factors Based on Optimized BP Neural Network Algorithm

Corrosion factors enter the cable via diffusion and penetration from the defect position of the cable or the connection position between the anchoring system and the cable section, seriously affecting the cable’s durability. Exploring the transmission mechanism of corrosion factors in the cable structure is essential to reveal the durability and the long-term performance of the cable structure and to judge the corrosion damage of steel wires in the cable structure. Based on the machine learning (ML) method and the analytical solution of Fick’s second law, the laws between different temperatures, humidity, cable inclinations, cable defect areas, etc., and the diffusion coefficient of corrosion factors and the concentration of surface corrosion factors are obtained, also a spatial diffusion model of corrosion factors is established. According to the research, the optimum simulation result is achieved by employing the optimized back propagation (BP) neural network algorithm, which has a faster convergence speed and better robustness. Although ambient temperature, humidity, and corrosion time all impact the diffusion rate of corrosion factors, the tilt angle of the cable and the size of cable defects are the main factors influencing the diffusion coefficient of corrosion factors and the concentration of surface corrosion factors. The error between the concentration of corrosion factors calculated by the model in this article and the measured values at each spatial point of the cable is controlled within 15%, allowing for the spatial diffusion of corrosion factors to be effectively predicted and evaluated in practical engineering

Molecularly self‐fueled nano-penetrator for nonpharmaceutical treatment of thrombosis and ischemic stroke

Thrombotic cerebro-cardiovascular diseases are the leading causes of disability and death worldwide but current drug therapeutics show important limitations. Here, the authors exploit a selfpropelling nano-penetrator with high fuel loading and controllable motion which is molecularly co-assembled using a photothermal photosensitizer and a photothermal-activable NO donor

Inhibition of growth of hepatocellular carcinoma by co-delivery of anti-PD-1 antibody and sorafenib using biomimetic nano-platelets

Abstract Background Traditional nanodrug delivery systems have some limitations, such as eliciting immune responses and inaccuracy in targeting tumor microenvironments. Materials and methods Targeted drugs (Sorafenib, Sora) nanometers (hollow mesoporous silicon, HMSN) were designed, and then coated with platelet membranes to form aPD-1-PLTM-HMSNs@Sora to enhance the precision of drug delivery systems to the tumor microenvironment, so that more effective immunotherapy was achieved. Results These biomimetic nanoparticles were validated to have the same abilities as platelet membranes (PLTM), including evading the immune system. The successful coating of HMSNs@Sora with PLTM was corroborated by transmission electron microscopy (TEM), western blot and confocal laser microscopy. The affinity of aPD-1-PLTM-HMSNs@Sora to tumor cells was stronger than that of HMSNs@Sora. After drug-loaded particles were intravenously injected into hepatocellular carcinoma model mice, they were demonstrated to not only directly activate toxic T cells, but also increase the triggering release of Sora. The combination of targeted therapy and immunotherapy was found to be of gratifying antineoplastic function on inhibiting primary tumor growth. Conclusions The aPD-1-PLTM-HMSNs@Sora nanocarriers that co-delivery of aPD-1 and Sorafenib integrates unique biomimetic properties and excellent targeting performance, and provides a neoteric idea for drug delivery of personalized therapy for primary hepatocellular carcinoma (HCC)

Biomimetic nanovaccine-mediated multivalent IL-15 self-transpresentation (MIST) for potent and safe cancer immunotherapy

Cytokine therapy, involving interleukin-15 (IL-15), is a promising strategy for cancer immunotherapy. However, clinical application has been limited due to severe toxicity and the relatively low immune response rate, caused by wide distribution of cytokine receptors, systemic immune activation and short half-life of IL-15. Here we show that a biomimetic nanovaccine, developed to co-deliver IL-15 and an antigen/major histocompatibility complex (MHC) selectively targets IL-15 to antigen-specific cytotoxic T lymphocytes (CTL), thereby reducing off-target toxicity. The biomimetic nanovaccine is composed of cytomembrane vesicles, derived from genetically engineered dendritic cells (DC), onto which IL-15/IL-15 receptor α (IL-15Rα), tumor-associated antigenic (TAA) peptide/MHC-I, and relevant costimulatory molecules are simultaneously anchored. We demonstrate that, in contrast to conventional IL-15 therapy, the biomimetic nanovaccine with multivalent IL-15 self-transpresentation (biNV-IL-15) prolonged blood circulation of the cytokine with an 8.2-fold longer half-life than free IL-15 and improved the therapeutic window. This dual targeting strategy allows for spatiotemporal manipulation of therapeutic T cells, elicits broad spectrum antigen-specific T cell responses, and promotes cures in multiple syngeneic tumor models with minimal systemic side effects.ISSN:2041-172

Highly Efficient Photothermal Conversion and Water Transport during Solar Evaporation Enabled by Amorphous Hollow Multishelled Nanocomposites

Solar evaporation, which enables water purification without consuming fossil fuels, has been considered the most promising strategy to address global scarcity of drinkable water. However, the suboptimal structure and composition designs still result in a trade-off between photothermal conversion, water transport, and tolerance to harsh environments. Here, an ultrastable amorphous Ta2O5/C nanocomposite is designed with a hollow multishelled structure (HoMS) for solar evaporation. This HoMS results in highly efficient photoabsorption and photothermal conversion, as well as a decrease of the actual water evaporation enthalpy. A superfast evaporation speed of 4.02 kg m(-2) h(-1) is achieved. More importantly, a World Health Organization standard drinkable water can be achieved from seawater, heavy-metal- and bacteria-containing water, and even from extremely acidic/alkaline or radioactive water sources. Notably, the concentration of pseudovirus SC2-P can be decreased by 6 orders of magnitude after evaporation