Association between household size and risk of incident dementia in the UK Biobank study.

Currently, the relationship between household size and incident dementia, along with the underlying neurobiological mechanisms, remains unclear. This prospective cohort study was based on UK Biobank participants aged ≥ 50 years without a history of dementia. The linear and non-linear longitudinal association was assessed using Cox proportional hazards regression and restricted cubic spline models. Additionally, the potential mechanisms driven by brain structures were investigated by linear regression models. We included 275,629 participants (mean age at baseline 60.45 years [SD 5.39]). Over a mean follow-up of 9.5 years, 6031 individuals developed all-cause dementia. Multivariable analyses revealed that smaller household size was associated with an increased risk of all-cause dementia (HR, 1.06; 95% CI 1.02-1.09), vascular dementia (HR, 1.08; 95% CI 1.01-1.15), and non-Alzheimer's disease non-vascular dementia (HR, 1.09; 95% CI 1.03-1.14). No significant association was observed for Alzheimer's disease. Restricted cubic splines demonstrated a reversed J-shaped relationship between household size and all-cause and cause-specific dementia. Additionally, substantial associations existed between household size and brain structures. Our findings suggest that small household size is a risk factor for dementia. Additionally, brain structural differences related to household size support these associations. Household size may thus be a potential modifiable risk factor for dementia.

A newly isolated Rhizopus microsporus var. chinensis capable to secrete amyloltic enzymes with raw-starch-digesting activity.

A newly isolated active producer of raw starch digesting amyloltic enzymes, Rhizopus microsporus var. chinensis CICIM-CU F0088 was screened and identified by morphological characteristics and molecular phylogenetic analysis. This fungus was isolated from the soil of Chinese glue pudding mill, and produced high levels of amylolytic activity under solid state fermentation with supplementation of starch and wheat bran. Results of thin layer chromatography showed there are two kinds of amyloltic enzymes formed by this strain, including one alpha-amylase and two glucoamylases. It was found that the two glucoamylases can digest raw corn starch in the electron microscope experiments, and has an optimal temperature of 70 degrees Celsius. These results signified that amyloltic enzymes secreted by strain of Rhizopus microsporus var. chinensis CICIM-CU F0088 were kinds of thermostable amyloltic enzymes and able to digest raw corn starch.