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This study developed a cell model of oxidative damage by treating PC12 cells for 24 h with 200 µmol/L H2O2 and determined the degree of oxidative stress by assaying the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and lactate dehydrogenase (LDH) and the level of malondialdehyde (MDA). Moreover, cell apoptosis and reactive oxygen species (ROS) levels were evaluated. Western blot and real-time polymerase chain reaction (PCR) were used to detect the protein and mRNA expression levels of B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax), caspase-3, nuclear factor E2 related factor 2 (Nrf2), kelch-like ECH-associated protein 1 (Keap1), and heme oxygenase-1 (HO-1). The results showed that after being treated with 200 µmol/L H2O2 for 24 h, the survival rate of PC12 cells was 60.12%. Cytotoxicity experiments showed that nervonic acid could significantly reduce the contents of LDH and MDA, inhibit excessive production of ROS, and enhance the activities of SOD and GSH-Px in H2O2-injuried cells. In addition, it significantly upregulated the expression of Bcl-2, Nrf2 and HO-1, and downregulated the expression of caspase-3, Bax, and Keap1. In summary, nervonic acid has a protective effect on H2O2-induced oxidative damage in PC12 cells by a mechanism associated with the activation of the Nrf2/HO-1 signaling pathway.

Innate immune systems are key defenses of animals and particularly important in species that lack the sophisticated adaptive immune systems as found in vertebrates. Here, we were interested to quantify variation in innate immune responses of insects in hosts that differ in their parasite susceptibility. To do this, we studied immune responses in honey bees, which can host a remarkable number of different parasites, which are major contributors of declining bee health and colony losses. The most significant parasite of honey bees is the mite Varroa destructor, which has infested the majority of global honey bee populations, and its control remains a major challenge for beekeepers. However, a number of nonmanaged honey bees seem able to control Varroa infections, for example, the Eastern honey bee Apis ceranacerana or the African honey bee Apis mellifera scutellata. These bees therefore make interesting study subjects to identify underlaying resistance traits, for example, by comparing them to more susceptible bee genotypes such as Western honey bees (A. melliferaligustica). We conducted a series of interlinked experiments and started with behavioral assays to compare the attractiveness of bee larvae to mites using different honey bee genotypes and castes. We found that 6-day-old larvae are always most attractive to mites, independently of genotype or castes. In a next step, we compared volatile profiles of the most attractive larvae to test whether they could be used by mites for host selection. We found that the abundance of volatile compounds differed between larval ages, but we also found significant differences between genotypes and castes. To further study the expected underlaying physiological differences between potentially resistant and susceptible host larvae, we compared the larval hemolymph proteomes of the three honey bee genotypes and two castes in response to mite exposure. We identified consistent upregulation of immune and stress-related genes in Varroa-exposed larvae, which differed between genotypes and castes. Tolerant honey bee castes and genotypes were characterized by stronger or more distinct immune esponses. In summary, we provide first insights into the complex involvement of the innate immune system of tolerant honey bees against mite infestations, which could be used for future breeding purposes.

At present, in order to improve the performance of spiral groove mechanical seals, the structural parameters of seals are mostly adjusted based on the experience of designers. The integration degree of existing mechanical seal performance research examples is low, and the whole performance optimization process lacks of scientific theoretical framework to guide. In order to solve this problem, combining the axiomatic design theory with the existing mechanical seal performance research, a structural optimization method of spiral groove mechanical seal based on axiomatic design theory was put forward. This method defines the mapping relationship between the three-level functional requirement domain and the design parameter domain of the spiral groove mechanical seal, and thus develops 14×14 diagonal optimization matrix. The research results show that the introduction of axiomatic design provides a basic theoretical framework for the performance optimization of spiral groove mechanical seals and decomposes the optimization process into several design modules, which improves the efficiency and accuracy of the optimization design of spiral groove mechanical seals and has good application value.

为准确、快速地测定植物油中8种维生素E异构体，建立了均质快速提取法结合反相高效液相色谱法同时测定植物油中8种维生素E异构体的方法，并采用该方法对14种常见植物油进行测定。结果表明：与传统的皂化法和固相萃取法比较，均质快速提取法前处理快速简便，测定准确度和精密度高，重现性好；8种维生素E异构体在15 min内可以实现良好分离；在0.5~10 μg/mL质量浓度范围内8种维生素E异构体线性关系良好(R2＞0.999)，检出限为0.02~0.05 μg/mL，定量限为0.07~0.17 μg/mL，相对标准偏差在2.48%~5.79%之间，加标回收率在90.00%~110.00%之间；不同食用植物油中生育酚和生育三烯酚的种类和含量存在明显差异。建立的均质快速提取法结合反相高效液相色谱法适用于植物油中8种维生素E异构体的同时测定。 In order to accurately and quickly determine eight vitamin E isomers in vegetable oils，a method for simultaneous determination of eight vitamin E isomers in vegetable oils by homogeneous rapid extraction combined with RP-HPLC was established, and the method was used to determine 14 common vegetable oils. The results showed that compared with the conventional saponification method and solid-phase extraction method, the homogeneous rapid extraction method was fast and simple, with high accuracy, precision and good reproducibility. Eight kinds of vitamin E isomers could be well separated within 15 min. The linearities of eight vitamin E isomers were well in the range of 0.5-10 μg/mL(R2>0.999). The detection limits, quantitation limits, relative standard deviations and spiked recoveries were 0.02-0.05 μg/mL, 0.07-0.17 μg/mL, 2.48%-5.79% and 90.00%-110.00%, respectively. There were obvious differences in the types and contents of tocopherols and tocotrienols in different edible vegetable oils. The established homogeneous rapid extraction combined with RP-HPLC is suitable for the simultaneous determination of eight vitamin E isomers in vegetable oils.

Based on the test site at the Qinghai�Tibet Plateau with an altitude of 4 300 m, atmospheric neutron single event effects of a 65 nm high�speed large�area static random access memory (SRAM) array were measured in real�time. By breaking through key technologies such as effect screening, intelligent remote measurement and control, a total of 39 single�event upset were observed during the 153 d test period, of which multiple�cell upset (MCU) accounts for 23%, and the largest MCU is 9 bits. The contribution ratios of high�energy neutron, thermal neutron and alpha particle were analyzed in detail, and based on the multi�ground neutron flux data, the single�bit upset (SBU) and MCU failure in time (FIT) at Beijing ground and 10 km high�altitude application were deduced. It is found that the main cause of soft error on the ground is the alpha particle. As the altitude increases, the contribution of atmospheric neutron to soft error increases significantly. All MCUs are caused by high�energy neutron, and the MCU FIT value at an altitude of 10 km in Beijing is obviously increased. Its proportion increases from 8% of the ground to 26%. In combination with the device layout, an in�depth analysis of the MCU generation mechanism was carried out. Finally, a goal�oriented optimization method of memory soft error hardening strategy was proposed.

Nervonic acid (NA) is a kind of ultra‐long‐chain monounsaturated fatty acid, which can repair nerve cell damage caused by oxidative stress. Alzheimer's disease (AD) is a nervous system disease and often accompanied by the decline of learning and memory capacity. In this study, the combined dose of D‐galactose/AlCl3 was used to establish a mouse model of AD. Meanwhile, the mice were treated with different doses of NA (10.95 and 43.93 mg/kg). The results showed that NA delayed the decline of locomotion and learning ability caused by D‐galactose/AlCl3, increased the activity of total superoxide dismutase, catalase, glutathione peroxidase, and reduced the content of malondialdehyde in vivo. Besides, NA reduced the levels of interleukin‐6 (IL‐6), tumor necrosis factor‐α (TNF‐α), interleukin‐1β (IL‐1β), aspartate aminotransferase, alanine aminotransferase, increased the levels of 5‐hydroxytryptamine, dopamine, γ‐aminobutyric acid, alleviated the cell morphology damage induced by D‐galactose/AlCl3 in hippocampus and liver tissue. Furthermore, the intervention of NA upregulated the expression levels of PI3K, AKT, and mTOR genes and downregulated the expression levels of TNF‐α, IL‐6, and IL‐1β genes. Therefore, we speculate the intervention of NA could be an effective way in improving cognitive impairment through the activation of PI3K signaling pathway. These results suggest that NA has the potential to be developed as antioxidant drug for the prevention and early therapy of AD. [ABSTRACT FROM AUTHOR]