In this research, fully degradable elastomeric sealing materials were developed to enhance the environmental sustainability of oil and gas extraction. The modification of millable polyurethane rubber ...(MPU) with polyglycolic acid/hydrogenated nitrile butadiene rubber (PGA/HNBR) led to the synthesis of PGA@MPU/HNBR composite materials. The impact of varying monomer quantities on the mechanical properties, degradation behavior, degradation mechanisms, and thermal stability of these materials was investigated. Our findings illustrate that an increasing proportion of HNBR in the PGA@MPU/HNBR composite materials resulted in a decreased degradation rate. Simultaneously, higher HNBR content improved the thermal stability of the materials, while the inclusion of PGA reduced material hardness, rendering the composites more susceptible to swelling. At an HNBR content of 40 phr, MPU at 60 phr, and PGA at 6 phr, the composite material demonstrated the highest retention of mechanical properties at 31.3% following 168 h of hydrolysis at 100 °C. The degradation of the composite materials in 100 °C water primarily resulted from the hydrolysis of MPU's ester groups, with HNBR remaining unaffected.
Persimmon fruit quickly softens after harvest, which limits its industrial value. The hormone melatonin has been reported to delay fruit ripening and softening. However, the effect of melatonin on ...postharvest persimmon fruit remains inconclusive. In this study, we found 10 μM melatonin treatment delayed the softening of persimmon fruit, accompanying with lower levels of endogenous ethylene and abscisic acid (ABA). Further, transcriptomic and metabolomic analysis were applied to investigate the regulatory mechanism. In total, 6831 differentially expressed genes (DEGs) and 1224 differentially accumulated metabolites (DAMs) were identified. We also investigated the metabolism pathways and regulatory networks incorporating crucial structural genes and TF during persimmon fruit softening. They were involving functions of saccharides, organic acids, ethylene biosynthesis, and ABA biosynthesis. In conclusion, our results indicate that melatonin can delay the biosynthesis of ethylene and ABA during persimmon softening and provide new insights into the regulatory pathways of melatonin-maintained persimmon fruit quality.
•Melatonin delayed persimmon fruit softening and suppressed the biosynthesis of endogenous ethylene and abscisic acid.•A total of 6831 DEGs and 1224 DAMs were obtained.•Complex regulatory networks involved in pathways of saccharides and organic acids, ethylene biosynthesis and ABA biosynthesis were constructed.
As NASA pursues Artemis missions to the moon and beyond, it is essential to equip astronauts with the appropriate human-autonomy enabling technology necessary for the elevated demands of lunar ...surface exploration and extreme terrestrial access. We present MoonBuddy, an application built for the Microsoft HoloLens 2 that utilizes Augmented Reality (AR) and voice-based interaction to assist astronauts in communication, navigation, and documentation on future lunar extravehicular activities (EVAs), with the goal of reducing cognitive load and increasing task completion. User testing results for MoonBuddy under simulated lunar conditions have been positive overall, with participants indicating that the application was easy to use and helpful in completing the required tasks.
While voice user interfaces (VUIs) are becoming promising tools for users to control home appliances, the VUIs pose great challenges to the older adults. In this paper, I explored how to use ...multimedia interactions (i.e., voice+visual output) to enhance the VUI for older adults to better control home appliances. I conducted two preliminary studies with six older adults to understand the current usability problems. Given the results, I designed a smart screen prototype with visual-enhanced VUI. The evaluation showed that the participants were highly receptive to the prototype and considered its features effective and accessible.
To establish a stable production method for soft ripe ‘Saijo’ persimmon (Diospyros kaki Thunb.) fruit, the fruit were treated with fatty acids or ethylene after several weeks’ storage at 0°C. ...Softening of the fruit first occurred in the vicinity of the calyx. Partial softening was observed at 23, 16 and 3 days after the beginning of treatment in the control, and those treated with 100 μL linolenic acid and 100 ppm ethylene for 48 hours, respectively. With each treatment, the fruit soft-ripened (complete removal of astringency) 3 days after partial softening. All the ethylene treated fruit soft-ripened at one time 6 days after the beginning of treatment. Ethylene treatment was found to be the fastest and the most reliable method for producing soft ripe ‘Saijo’. Coloration in the ethylene-treated fruit was improved and fruit firmness decreased linearly. Soluble tannin concentration began to decrease 3 days after the beginning of treatment and astringency was removed completely on the sixth day. Fruit that was stored at 0°C for 2 to 8 weeks and then treated with ethylene soft-ripened 6 days after beginning of treatment. When fruit were stored for longer than 4 weeks at 0°C and then treated with ethylene, cracking occurred in the fruit during the course of soft-ripening.
In this study, we aimed to characterize which factors control ethylene production and fruit drop in persimmon (Diospyros kaki Thunb.). We determined the effects of ...3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU; a specific photosynthesis inhibitor) and defoliation treatments on the photosynthetic rate, transpiration rate, sap flow, fruit drop, and ethylene evolution. DCMU treatment, which prevented photosynthate transport but allowed water flow, promoted fruit drop by 67% 10 days after treatment. Defoliation treatment, which prevented both photosynthate and water transport, significantly hastened fruit drop. On average, fruit drop occurred 2 days earlier with defoliation treatment than DCMU treatment. Compared with the control, treated fruit attached to the tree showed an increasing trend in ethylene production, although at a low level (≤ 0.8 nL · g−1 · h−1 in the flesh; ≤ 20 nL · g−1 · h−1 in the calyx). Fruit abscission is thought to be induced by a following ethylene burst, because fruit showing an abscission trend showed high rates of ethylene production (almost 200 nL · g−1 · h−1). Thus, blocking photosynthate transport and water flow induced initial and autocatalytic increases in the production of ethylene, which plays a crucial role in triggering fruit drop. Overall, our results suggest that the transport of photosynthates, or both photosynthates and water, to fruit inhibits fruit drop by preventing the induction of ethylene synthesis in young persimmon fruit.
The fruit of the 'Hiratanenashi' persimmon (Diospyros kaki Thunb.) over-ripens on the tree by late November as a result of senescence processes. On-tree over-ripened fruits were harvested at this ...time, and the degree of fruit softening was measured. The 'softening degree' index ranged from 1.5 (firm to moderately soft) to 4 (very soft, or part of the peel ruptured). To clarify the fruit softening processes resulting from on-tree senescence, internal ethylene concentrations, gene expression of ethylene synthesis, and cell-wall-degrading enzymes were investigated in 'Hiratanenashi' persimmon. The internal ethylene concentration increased concomitantly with softening progress. The expression of two ACC synthase (ACS) genes, DkACS1 and DkACS2, and two ACC oxidase (ACO) genes, DkACO1 and DkACO2 were investigated using quantitative PCR. The ACS genes were rate limiting for ethylene production, but ACO genes were constitutive. Genes encoding three polygalacturonases (PG), two pectin methylesterases (PE), two β-galactosidases (Gal), and one α-arabinofuranosidase (Arf) were isolated from an expressed sequence tag (EST) library of on-tree softened pulp, and their expression was investigated. Among these eight isolated genes, the expression of DkPG1, DkPG2, DkGal1, and DkArf1 increased concomitantly with softening progress. In contrast, the expression of DkPG3, DkPE1, DkPE2, and DkGal2 was maintained at low levels throughout the softening progress. These results suggest that DkPG1, DkPG2, DkGal1, and DkArf1 play a coordinated role in on-tree fruit softening that follows PE action by senescence in 'Hiratanenashi'. Two of the PG genes are thought to contribute to a jelly- or soup-like texture at softening degree 4.
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