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Nanosecond laser ablated metallic surfaces showed initial super-hydrophilicity, and then experienced gradual wettability conversion to super-hydrophobicity with the increase of exposing time to ambient air. Due to the presence of hierarchical structures and change of surface chemistry, the laser-induced Inconel alloy surfaces showed a stable apparent contact angle beyond 150° over 30-day air exposure. The wetting states were proposed to elucidate the initial super-hydrophilicity and the final super-hydrophobicity. The basic fundaments behind the wettability conversion was explored by analyzing surface chemistry using X-ray photoelectron spectroscopy (XPS). The results indicated that the origins of super-hydrophobicity were identified as the increase of carbon content and the dominance of C–C(H) functional group. The C–C(H) bond with excellent nonpolarity derived from the chemisorbed airborne hydrocarbons, which resulted in dramatic reduction of surface-free-energy. This study confirmed that the surface chemistry is not the only factor to determine surface super-hydrophobicity. The laser-induced super-hydrophobicity was attributed to the synergistic effect of surface topography and surface chemical compositions. In this work, the corresponding chemical reaction was particularly described to discuss how the airborne hydrocarbons were attached onto the laser ablated surfaces, which reveals the generation mechanism of air-exposed super-hydrophobic surfaces.

Laser electrochemical machining is an innovative composite processing method, achieving high surface quality and efficient shaping for difficult-to-machine materials through the combined effects of laser and electrochemical energy. Electrochemical machining adjusts the parameters of the physical field to eliminate the recast layer generated by laser ablation. In addition, the increase in electrolyte temperature caused by the laser can promote electrochemical dissolution. This work proposed a new multiphysics simulation model to explore the structure formation mechanism based on the temporal variations of temperature, electric, and flow fields during composite processing. The laser-coupled electrochemical machining used a three-current model. The temperature field variation considered not only the laser irradiation factor but also the effect of convective heat transfer induced by fluid flow. Moreover, temperature variation influences electric and flow fields, changing the physical parameters of electrolytes, such as conductivity and dynamic viscosity. Transient deformation geometry was used to uncover the material removal process during composite machining and then predict the final profile of the obtained structures. The manufacturing process could be elaborately described by the multiple physical fields using the established simulation model. Finally, an experimental study was conducted to validate the reasonability of the proposed simulation model. The role of laser effects in composite machining was also highlighted through the comparison of theoretical and experimental results.HighlightsA laser electrolytic composite processing method based on a novel electrolyte-surrounded processing electrode is proposed. A novel multiphysics simulation model based on COMSOL is proposed for laser electrolytic composite machining. The accuracy of the model has been confirmed by experiments, achieving high fitting accuracy.

This paper presented ultrasonic embossing using metal molds to replicate microstructures on polyethylene terephthalate (PET) films. The metal molds used in this study were fabricated by laser ablation processing technology. Aluminum 6061 was adopted to be mold material because of its better machinability and the optimized laser processing parameters were laser power of 10 W, scanning numbers of 20 times and scanning speed of 500 mm/s, respectively. Effects of the ultrasonic embossing parameters on replication quality, especially for replication depth were investigated. The results showed that the ultrasonic pressure F, welding time T 2 , and holding time T 3 were significant factors of replication depth. Then optimized ultrasonic parameters obtained by orthogonal experiments were determined to be ultrasonic pressure of 400 kPa, welding time of 1 s and holding time of 4 s. The corresponding maximal depth and replication rate on PET films can reach 271.7 µm and 99.74%, respectively. By using laser processed molds, the micro mixers and hydrophobic surface can be obtained successfully through ultrasonic embossing process. No leakage of blue ink in the micro mixers was observed, which meant high quality and high sealing property of the micro mixers. The instant contact angle of embossed PET films increased from 70.7° to 100.4°, which can be concluded that it was possible to change the wettability of surface and obtain the hydrophobic surface from hydrophilic surface by using laser processed molds and replicating microstructures after ultrasonic embossing. Laser ablation processing technology provides a novel way to fabricate molds and the result of this experiment offered a possibility of mass manufacture of polymer microstructure or micro device.

Recast layer, which has undesirable effects on the fatigue resistance and service life of components and microstructures, has been observed and analyzed from the points of surface morphology and internal microstructure by three test methods including scanning electron microscopy, metallographic corrosion analysis, and transmission electron microscopy in this study. In order to reduce the harms of these unwanted recast layers, taking ultrafast laser as a post-machining method for recast material removal is proposed based on the advantages of ultrafast laser micromachining technology, which include the wide material applicability and absence of the recast layer during processing. The feasibility of this new recast layer removal method was verified by experiments on Ti-6Al-4V. With a series of optimized processing parameters, horizontally bedded scanning processing was adopted ultimately in final recast layer removal experiment because of its higher material removal rate and better machined surface quality compared with vertically shifting scanning processing. Based on the theoretical analysis and experimental results, ultrafast laser could be widely applied in more fields of microstructures finish machining.

Wheat straw returning is widely practiced in agriculture; therefore, it is critical to determine the physicochemical and bacterial indicators in soil for the organic carbon storage, accumulative C mineralization, total nitrogen improvement, and nitrogen mineralization in various soil types after wheat straw returning. This study evaluated the influenced indicators of wheat straw addition on soil organic carbon and nitrogen transformation in diverse soil types. For this purpose, an incubation experiment was conducted to analyze the carbon and nitrogen transformation in soil from eight Chinese provinces treated with the same dry weight of wheat straw. The results indicated that the primary physicochemical and bacterial indicators that predict the carbon and nitrogen transformations in the acidic and alkaline soils were different. Of all the natural physicochemical properties of soil, cation exchange capacity and clay content were significantly correlated with organic carbon, mineralized carbon, total nitrogen, and mineralized nitrogen in the alkaline soil. In the acidic soil, the initial C/N ratio of soil was the most significant indicator of carbon and nitrogen transformation. From the perspective of the carbon- and nitrogen-relating bacterial communities, Proteobacteria were largely responsible for the accumulative C mineralization in both types of soil. Furthermore, Proteobacteria strongly regulated the organic carbon storage in the acidic soil after wheat straw addition, whereas Gemmatimonadetes was the main predicted indicator in the alkaline soil. Additionally, total nitrogen and mineralized nitrogen levels were largely explained by Bifidobacterium and Luteimonas in the alkaline soil and by Nitrospira and Bdellovibrio in the acidic soil. Soil physicochemical and biological properties significantly influence soil carbon and nitrogen transformation, which should be considered crucial indicators to guide the rational regulation of straw return in several areas.

To investigate selenium (Se) concentrations in serum of patients with rheumatoid arthritis (RA), osteoarthritis (OA), and Kashin–Beck disease (KBD), together with the effect of Se supplement (chondroitin sulfate [CS] nano-Se [SeCS]) on CS structure–modifying sulfotransferases in KBD chondrocyte. Fifty serum samples from each group with aged-matched (40–60 years), normal control (N), RA, OA, and KBD (25 males and females, respectively) were collected to determine Se concentrations. Furthermore, the KBD chondrocytes were divided into two groups following the intervention for 24 h: (a) non-treated KBD group and (b) SeCS-treated KBD group (100 ng/mL SeCS). The ultrastructural changes in chondrocytes were observed by transmission electron microscopy (TEM). Live/dead staining was used to observe cell viability. The expression of CS-modifying sulfotransferases including carbohydrate sulfotransferase 12, 13, and 15 (CHST-12, CHST-13, and CHST-15, respectively), and uronyl 2-O-sulfotransferase (UST) were examined by quantitative real-time polymerase chain reaction and western blotting analysis after SeCS intervention. The Se concentrations in serum of KBD, OA, and RA patients were lower than those in control. In OA, RA, and control, Se concentrations were higher in male than in female, while it is opposite in KBD. In the cell experiment, cell survival rate and mitochondrial density were increased in SeCS-treated KBD groups. Expressions of CHST-15, or CHST-12, and CHST-15 on the mRNA or protein level were significantly increased. Expression of UST slightly increased on the mRNA level, but no change was visible on the protein level. Se deficiency in serum of RA, OA, and KBD was observed. SeCS supplemented in KBD chondrocytes improved their survival rate, ameliorated their ultrastructure, and increased the expression of CS structure–modifying sulfotransferases.

Wheat straw returning is a common agronomic measure in the farmland. Understanding organic carbon transformation is of great significance for carbon budget under the premise of widespread distribution of cadmium (Cd) contaminated soils. An incubation experiment was conducted to assess the influence of Cd contamination on the decomposition and accumulation of total organic carbon (TOC) as well as the composition and abundance of bacterial communities in eight soil types with wheat straw addition. The results showed that inhibition of Cd contamination on microbially mediated organic carbon decomposition was affected by soil types. The lower cumulative C mineralization and higher TOC content could be observed in the acidic soils relative to that in the alkaline soils. The content of Cd in soil exhibits different effects on the inhibition in decomposition of TOC. The high dosage level of Cd had stronger inhibitory impact due to its high toxicity. The decomposition of TOC was restricted by a reduction in soil bacterial abundance and weakening of bacterial activities. Redundancy analysis (RDA) indicated that Proteobacteria and Gemmatimonadetes were abundant in alkaline Cd-contaminated soils with wheat straw addition, while Bacteroidetes dominated cumulative C mineralization in acidic Cd-contamination soils. Moreover, the abundance of predicted functional bacteria indicated that high-dose Cd-contamination and acid environment all inhibited the decomposition of TOC. The present study suggested that pH played an important role on carbon dynamics in the Cd-contaminated soils with wheat straw addition.

Climate change is predicted to increase the occurrence of extreme weather events such as heatwaves, which may thereby impact the outcome of plant-herbivore interactions. While elevated temperature is known to directly affect herbivore growth, it remains largely unclear if it indirectly influences herbivore performance by affecting the host plant they feed on. In this study, we investigated how transient exposure to high temperature influences plant herbivory-induced defenses at the transcript and metabolic level. To this end, we studied the interaction between potato ( Solanum tuberosum ) plants and the larvae of the potato tuber moth ( Phthorimaea operculella ) under different temperature regimes. We found that P. operculella larvae grew heavier on leaves co-stressed by high temperature and insect herbivory than on leaves pre-stressed by herbivory alone. We also observed that high temperature treatments altered phylotranscriptomic patterns upon herbivory, which changed from an evolutionary hourglass pattern, in which transcriptomic responses at early and late time points after elicitation are more variable than the ones in the middle, to a vase pattern. Specifically, transcripts of many herbivory-induced genes in the early and late defense stage were suppressed by HT treatment, whereas those in the intermediate stage peaked earlier. Additionally, we observed that high temperature impaired the induction of jasmonates and defense compounds upon herbivory. Moreover, using jasmonate-reduced (JA-reduced, irAOC ) and -elevated (JA-Ile-elevated, irCYP94B3s ) potato plants, we showed that high temperature suppresses JA signaling mediated plant-induced defense to herbivore attack. Thus, our study provides evidences on how temperature reprograms plant-induced defense to herbivores.

Edible insects are a highly nutritious source of protein and are enjoyed by people all over the world. Insects contain various other nutrients and beneficial compounds, such as lipids, vitamins and minerals, chitin, phenolic compounds, and antimicrobial peptides, which contribute to good health. The practice of insect farming is far more resource-efficient compared to traditional agriculture and animal husbandry, requiring less land, energy, and water, and resulting in a significantly lower carbon footprint. In fact, insects are 12 to 25 times more efficient than animals in converting low-protein feed into protein. When it comes to protein production per unit area, insect farming only requires about one-eighth of the land needed for beef production. Moreover, insect farming generates minimal waste, as insects can consume food and biomass that would otherwise go to waste, contributing to a circular economy that promotes resource recycling and reuse. Insects can be fed with agricultural waste, such as unused plant stems and food scraps. Additionally, the excrement produced by insects can be used as fertilizer for crops, completing the circular chain. Despite the undeniable sustainability and nutritional benefits of consuming insects, widespread acceptance of incorporating insects into our daily diets still has a long way to go. This paper provides a comprehensive overview of the nutritional value of edible insects, the development of farming and processing technologies, and the problems faced in the marketing of edible insect products and insect foods to improve the reference for how people choose edible insects.

Selenium, an essential trace element for human health, exerts an indispensable effect in maintaining physiological homeostasis and functions in the body. Selenium deficiency is associated with arthropathies, such as Kashin-Beck disease, rheumatoid arthritis, osteoarthritis, and osteoporosis. Selenium deficiency mainly affects the normal physiological state of bone and cartilage through oxidative stress reaction and immune reaction. This review aims to explore the role of selenium deficiency and its mechanisms existed in the pathogenesis of arthropathies. Meanwhile, this review also summarized various experiments to highlight the crucial functions of selenium in maintaining the homeostasis of bone and cartilage.