Community support, social isolation and older adults' life satisfaction: evidence from a national survey in China.

OBJECTIVES: Despite the recognized importance of community social service and community built facility for enhancing older adults' life satisfaction, the mechanisms underlying their relationship have not been thoroughly examined. This study aims to complement the existing knowledge by investigating the mediating role of social disconnectedness and loneliness in the association between community support and life satisfaction among older adults. METHODS: Using data from the 2018 China Longitudinal Aging Social Survey, the study analyzes responses from 9,874 Chinese older adults (mean age = 71.30 years, SD = 7.30). We conducted descriptive statistics and Pearson's correlation to explore the variables. This study also used Mplus 8.0 to conduct a path analysis model that evaluated both the direct and indirect effects of community social service and built facility on life satisfaction. Social disconnectedness and loneliness were included as mediating variables in this model. RESULTS: The present study results show that both community social service and community built facility are positively associated with life satisfaction among older adults, and community social service is more imporatant for enhancing the life satisfaction. In addition, these associations are mediated by social disconnectedness and loneliness. CONCLUSION: Our research suggests that strengthening community social service programs and improving the built environment can reduce social disconnectedness and loneliness among older adults, ultimately enhancing their life satisfaction. Specifically, policymakers can invest in targeted interventions to enhance social connectedness and reduce loneliness, with the goal of improving the overall well-being of older adults.

Physicochemical properties and anti-diabetic ability of polysaccharides from a thinned peach fruit.

Thinned peach fruit is a by-product with abundant yields. However, it is barely utilized. This study aimed to study the physicochemical properties and anti-diabetic ability of polysaccharides (PPSs) from a thinned peach fruit to investigate its application potential. Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) characterizations were performed together with tests to determine rheology properties, monosaccharide composition, and molecular weight of the obtained polysaccharide. Moreover, the antioxidant activity, α-amylase inhibitory activity, binding abilities to bile salts, and effects on type 2 diabetic mice were analyzed. The results indicated that PPS consisted of two components with molecular weights of 287.38 kDa and 12.02 kDa, accounting for 89.83% and 10.17% of the composition, respectively. The dominant monosaccharides were galactose, galacturonic acid, and arabinose, exhibiting α-configurations. The concentration was positively related to the viscosity of PPS. As the temperature was increased from 25 °C to 37 °C and the pH from 2.0 to 7.0, the viscosity decreased. The IC50 values for scavenging DPPH and ABTS were around 0.22 and 1.47 mg mL-1. Also, PPS could inhibit α-amylase ability and bind bile salts. The administration of PPS significantly inhibited emaciation, organ damage, improved oral glucose tolerance and insulin resistance, enhanced the content of short-chain fatty acids (SCFAs), and regulated blood lipid profiles and the composition and structure of colon microbiota in type-2 diabetic mice. These results provide new evidence for the potential of PPS as a bioactive ingredient with anti-diabetic properties for use in the food industry.

In Silico Prospecting for Novel Bioactive Peptides from Seafoods: A Case Study on Pacific Oyster (Crassostrea gigas).

Pacific oyster (Crassostrea gigas), an abundant bivalve consumed across the Pacific, is known to possess a wide range of bioactivities. While there has been some work on its bioactive hydrolysates, the discovery of bioactive peptides (BAPs) remains limited due to the resource-intensive nature of the existing discovery pipeline. To overcome this constraint, in silico-based prospecting is employed to accelerate BAP discovery. Major oyster proteins were digested virtually under a simulated gastrointestinal condition to generate virtual peptide products that were screened against existing databases for peptide bioactivities, toxicity, bitterness, stability in the intestine and in the blood, and novelty. Five peptide candidates were shortlisted showing antidiabetic, anti-inflammatory, antihypertensive, antimicrobial, and anticancer potential. By employing this approach, oyster BAPs were identified at a faster rate, with a wider applicability reach. With the growing market for peptide-based nutraceuticals, this provides an efficient workflow for candidate scouting and end-use investigation for targeted functional product preparation.

Quality dependence of litter decomposition and its carbon, nitrogen and phosphorus release under simulated acid rain treatments.

Litter decomposition is of utmost importance to elemental cycling in terrestrial ecosystems, with litter quality being frequently considered to predominantly control litter decomposition. However, how acid rain (AR) would affect litter decomposition and its elements release remains inconclusive, although AR has widely occurred in Europe, North America, and East Asia. This study was conducted to observe leaf litter decomposition and release of carbon (C), nitrogen (N), and phosphorus (P) of three crops (maize, rice, and soybean) under simulated AR treatments. Results showed that the accumulated mass loss during decomposition was significantly different among species, supporting the view of litter quality predominantly controlling decomposition. Specifically, quality dependence of litter decomposition was observed in the late stage of decomposition, while mass loss of litters was comparable in the first month among species. With decomposition, the litter C/N ratio significantly increased for the three species while the C/P and N/P ratios significantly decreased or tended to decrease, suggesting that litter N was released preferentially over C and P. However, AR treatments did not significantly affect litter decomposition and its elements release in our investigation period. Moreover, litter P content appeared to strongly affect the release of C, N, and P during litter decomposition, and such P dependence could to some extent be alleviated by AR treatments. Our results suggest that AR may change the quality dependence of litter decomposition and further studies are needed to illustrate its potential mechanisms.