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β-hydroxybutyrate, a ketone body metabolite, has been shown to suppress depression-like behavior in rodents. In this study, we examined its antidepressive property in acute and chronic administration modes in mice by using forced swim test and tail suspension test. Results showed that the decrease effect of β-hydroxybutyrate (300 mg/kg) on immobility time in the tail suspension test and forced swim test in stress-naive mice began to be significant at day 11. In a dose-dependent experiment, β-hydroxybutyrate treatment (11 days) showed significant antidepressant activities at the dose of 200 and 300 mg/kg. Unlike fluoxetine, β-hydroxybutyrate treatment (300 mg/kg) showed no antidepressant activities in the acute (1 hour before the test) and three times administration mode within 24 hours (1, 5, and 24 hours before the test). But in a co-administration mode, β-hydroxybutyrate (100 mg/kg) -fluoxetine (2.5 mg/kg) co-administration exhibited an obvious antidepressant activity in the tail suspension test and forced swim test. Further analysis showed that the antidepressant effects of β-hydroxybutyrate and fluoxetine were not associated with the change in mouse locomotor activity. Furthermore, both chronic β-hydroxybutyrate treatment and β-hydroxybutyrate-fluoxetine co-treatment suppressed chronic unpredictable stress-induced increase in immobility time in the tail suspension test and forced swim test as well as chronic unpredictable stress-induced decrease in mouse body weight. Taken together, these results indicate that β-hydroxybutyrate (1) needs a relatively long time to show comparable behavioral activity to that of fluoxetine in assays that are sensitive to the behavioral effects of established antidepressant compounds and (2) can augment the antidepressant action of a sub-therapeutic dose of fluoxetine.

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：In order to achieve the densification of the structure of the flexible guided three-dimensional weaving composite prefabricated component during the weaving process, a digital compaction system is used to study the compaction characteristics of the three-dimensional woven composite component, and the compaction displacement and compaction during the compaction process are measured and recorded. The relationship between the load and the spring-back of the component and the forming process parameters reveals the relationship between fiber volume fraction and compressive stress. It shows that the densification and compaction process of digital flexible oriented three-dimensional weaving composites can be divided into three stages: low-stress linear pre-compaction, non-linear transitional compaction and high-stress compaction, and the densification of the composite preform structure are established. The theoretical formula of the characteristic, in the process of compaction and densification, the components are subjected to pressure maintaining treatment, and the relationship between compaction load and holding time is analyzed. It shows that the compressibility of the flexible guided three-dimensional weaving components gradually decreases with the increase of the number of layers, the rebound amount and weaving. The number of layers is positively correlated, and the average fiber rebound per layer gradually decreases and tends to be stable.