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Design and analysis of a lower limb assistive exoskeleton robot.

In recent years, exoskeleton robot technology has developed rapidly. Exoskeleton robots that can be worn on a human body and provide additional strength, speed or other abilities. Exoskeleton robots have a wide range of applications, such as medical rehabilitation, logistics and disaster relief and other fields. The study goal is to propose a lower limb assistive exoskeleton robot to provide extra power for wearers. The mechanical structure of the exoskeleton robot was designed by using bionics principle to imitate human body shape, so as to satisfy the coordination of man-machine movement and the comfort of wearing. Then a gait prediction method based on neural network was designed. In addition, a control strategy according to iterative learning control was designed. The experiment results showed that the proposed exoskeleton robot can produce effective assistance and reduce the wearer's muscle force output. A lower limb assistive exoskeleton robot was introduced in this paper. The kinematics model and dynamic model of the exoskeleton robot were established. Tracking effects of joint angle displacement and velocity were analyzed to verify feasibility of the control strategy. The learning error of joint angle can be improved with increase of the number of iterations. The error of trajectory tracking is acceptable.

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Tripartite interactions of an endophytic entomopathogenic fungus, Asian corn borer, and host maize under elevated carbon dioxide.

Biological control of insect pests is encountering an unprecedented challenge in agricultural systems due to the ongoing rise in carbon dioxide (CO2) level. The use of entomopathogenic fungi (EPF) in these systems is gaining increased attention, and EPF as crop endophytes hold the potential for combining insect pest control and yield enhancement of crops, but the effects of increased CO2 concentration on this interaction are poorly understood. Here, the introduction of endophytic EPF was explored as an alternative sustainable management strategy benefiting crops under elevated CO2, using maize (Zea mays), Asian corn borer (Ostrinia furnacalis), and EPF (Beauveria bassiana) to test changes in damage to maize plants from O. furnacalis, and the nutritional status (content of carbon, nitrogen, phosphorus, potassium), biomass, and yield of maize. The results showed that endophytic B. bassiana could alleviate the damage caused by O. furnacalis larvae for maize plants under ambient CO2 concentration, and this effect was enhanced under higher CO2 concentration. Inoculation with B. bassiana effectively counteracted the adverse impact of elevated CO2 on maize plants by preserving the nitrogen content at its baseline level (comparable with ambient CO2 conditions without B. bassiana). Both simultaneous effects could explain the improvement of biomass and yield of maize under B. bassiana inoculation and elevated CO2. This finding provides key information about the multifaceted benefits of B. bassiana as a maize endophyte. Our results highlight the promising potential of incorporating EPF as endophytes into integrated pest management strategies, particularly under elevated CO2 concentrations. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

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Changes in the Glucose Concentration Affect the Formation of Humic-like Substances in Polyphenol-Maillard Reactions Involving Gibbsite.

The polyphenol-Maillard reaction is considered one of the important pathways in the formation of humic-like substances (HLSs). Glucose serves as a microbial energy source that drives the humification process. However, the effects of changes in glucose, particularly its concentration, on abiotic pathways remain unclear. Given that the polyphenol-Maillard reaction requires high precursor concentrations and elevated temperatures (which are not present in soil), gibbsite was used as a catalyst to overcome energetic barriers. Catechol and glycine were introduced in fixed concentrations into a phosphate-buffered solution containing gibbsite using the liquid shake-flask incubation method, while the concentration of glucose was controlled in a sterile incubation system. The supernatant fluid and HLS components were dynamically extracted over a period of 360 h for analysis, thus revealing the influence of different glucose concentrations on abiotic humification pathways. The results showed the following: (1) The addition of glucose led to a higher degree of aromatic condensation in the supernatant fluid. In contrast, the supernatant fluid without glucose (Glu0) and the control group without any Maillard precursor (CK control group) exhibited lower degrees of aromatic condensation. Although the total organic C (TOC) content in the supernatant fluid decreased in all treatments during the incubation period, the addition of Maillard precursors effectively mitigated the decreasing trend of TOC content. (2) While the C content of humic-like acid (CHLA) and the CHLA/CFLA ratio (the ratio of humic-like acid to fulvic-like acid) showed varying increases after incubation, the addition of Maillard precursors resulted in a more noticeable increase in CHLA content and the CHLA/CFLA ratio compared to the CK control group. This indicated that more FLA was converted into HLA, which exhibited a higher degree of condensation and humification, thus improving the quality of HLS. The addition of glycine and catechol without glucose or with a glucose concentration of 0.06 mol/L was particularly beneficial in enhancing the degree of HLA humification. Furthermore, the presence of glycine and catechol, as well as higher concentrations of glucose, promoted the production of N-containing compounds in HLA. (3) The presence of Maillard precursors enhanced the stretching vibration of the hydroxyl group (-OH) of HLA. After the polyphenol-Maillard reaction of glycine and catechol with glucose concentrations of 0, 0.03, 0.06, 0.12, or 0.24 mol/L, the aromatic C structure in HLA products increased, while the carboxyl group decreased. The presence of Maillard precursors facilitated the accumulation of polysaccharides in HLA with higher glucose concentrations, ultimately promoting the formation of Al-O bonds. However, the quantities of phenolic groups and phenols in HLA decreased to varying extents.

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Chlorogenic acid improves the development of porcine parthenogenetic embryos by regulating oxidative stress and ameliorating mitochondrial function.

Chlorogenic acid (CGA) is an effective phenolic antioxidant that can scavenge hydroxyl radicals and superoxide anions. Herein, the protective effects and mechanisms leading to CGA-induced porcine parthenogenetic activation (PA) in early-stage embryos were investigated. Our results showed that 50 μM CGA treatment during the invitro culture (IVC) period significantly increased the cleavage and blastocyst formation rates and improved the blastocyst quality of porcine early-stage embryos derived from PAs. Then, genes related to zygotic genome activation (ZGA) were identified and investigated, revealing that CGA can promote ZGA in porcine PA early-stage embryos. Further analysis revealed that CGA treatment during the IVC period decreased the abundance of reactive oxygen species (ROS), increased the abundance of glutathione and enhanced the activity of catalase and superoxide dismutase in porcine PA early-stage embryos. Mitochondrial function analysis revealed that CGA increased mitochondrial membrane potential and ATP levels and upregulated the mitochondrial homeostasis-related gene NRF-1 in porcine PA early-stage embryos. In summary, our results suggest that CGA treatment during the IVC period helps porcine PA early-stage embryos by regulating oxidative stress and improving mitochondrial function.

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Stable fabrication of S-step photocatalyst assembled from Cu-doped SnO2 yolk-shell hollow spheres capsulated by MnCo2O4 nanoparticles for enhancing antibiotic photodegradation

Despite the exceptional capability of photocatalytic systems, the development of highly-oxidative materials for the decontamination of tenacious pollutants is still vacant. The brilliance oxidation potential of tin-oxide which is much higher than that of TiO2 together with its astounding stability in harsh oxidative reactions introduces a prospective candidate. However, the insufficient photoactivation of tin-oxide resulting from its wide bandgap energy prevented from the full exploitation of its intrinsic capability. Herein, the metal-glycerate-assisted metal–organic framework engineered yolk-shelled copper-doped SnO2 (YS-(5)CSO) hollow spheres. The multi-level hollow spheres not only benefit from vase surface area, but also take the advantages of trapping photons by multi-reflation/scattering effect and effective charge dissociation by minimized ion diffusion path. The well-coordination of the dopant element in SnO2 lattice induced enormous mid-gap defects to construct a visible-light-driven SnO2. Moreover, the exterior shell of as-synthesized YS-(5)CSO was amalgamated with the MnCo2O4 nanoparticles (Np-MCO@YS-(5)CSO) to construct S-scheme heterojunction. Under optimized operational conditions, the promising capability of Np-MCO@YS-(5)CSO was realized in total photodegradation of levofloxacin (LFC) (60 mg/L), which was 31.2 and 5.3 times kinetically greater than that of the pristine Np-MCO and YS-(5)CSO, respectively. Additionally, the engineered photocatalytic system presented exceptional capability in the decontamination of real pharmaceutical effluent under visible-light irradiation. In the term of stability matter, the photocatalytic performance of as-synthesized Np-MCO@YS-(5)CSO preserved under six successive cycling runs. The elemental leaching and post-characterization analyses after reusability tests revealed the high stability of Np-MCO@YS-(5)CSO nanocomposite, which endured during long-runs and vicious oxidative reactions without any failure. Generally, the combination of simultaneous Z-scheme heterojunction with the electronic modification of doping strategy bridges the gap between experimental investigations and industrial photocatalyst application.

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Transcriptomic and Metabolomic Research on the Germination Process of Panax ginseng Overwintering Buds.

Ginseng (Panax ginseng C. A. Meyer) is a perennial plant with a long dormancy period. While some researchers employ gibberellin and other substances to stimulate premature germination, this method is limited to laboratory settings and cannot be applied to the field cultivation of ginseng. The mechanism underlying the germination of ginseng overwintering buds remains largely unexplored. Understanding the internal changes during the dormancy release process in the overwintering buds would facilitate the discovery of potential genes, metabolites, or regulatory pathways associated with it. In this study, we approximately determined the onset of dormancy release through morphological observations and investigated the process of dormancy release in ginseng overwintering buds using transcriptomic and metabolomic approaches. Our analyses revealed that the germination process of ginseng overwintering buds is regulated by multiple plant hormones, each acting at different times. Among these, abscisic acid (ABA) and gibberellic acid (GA) serve as classical signaling molecules regulating the dormancy process, while other hormones may promote the subsequent growth of overwintering buds. Additionally, metabolic pathways associated with arginine may be involved in the dormancy release process. Polyamines synthesized downstream may promote the growth of overwintering buds after dormancy release and participate in subsequent reproductive growth. This study provides insights into the germination process of ginseng overwintering buds at the molecular level and serves as a reference for further exploration of the detailed mechanism underlying ginseng overwintering germination in the future.

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Effect of ultrasonic vibration on the pores and properties of the laser-arc hybrid welding joint of high nitrogen steel

High nitrogen steel welded joints are prone to problems such as porosity defects and coarse grain size. To address these issues, ultrasonic-assisted laser-arc hybrid welding experiments were conducted on 8 mm-thick high nitrogen steel plates. The effect of ultrasonic vibration on the porosity defects, microstructure, and properties of welded joints was studied. The results indicate that with the increase of ultrasonic power, the pore ratio of the weld first decreases and then increases. The effects generated due to ultrasound such as cavitation and sound flow caused grain refinement while weakening the directionality of grain growth. The refined microstructure of the weld increased the microhardness. However, when the ultrasonic power was 240 W, the microhardness of the welded joint decreased due to the low nitrogen content. As the ultrasonic power was increased, the tensile strength and impact toughness initially exhibited an enhancement followed by a declining trend. The best mechanical properties were obtained when the ultrasonic power was 180 W. In contrast, the worst performance was obtained when the ultrasonic power was 240 W, which was due to higher porosity and severe nitrogen loss. Ultrasonic impact can reduce welding residual stress and improve the corrosion resistance of welds, and the effect becomes more pronounced with the increase of ultrasound power.

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