PubMed Health⌕ Search

Biomedical subjects

Yun Xu

Publications and source records attributed to Yun Xu.

3 recordsLinked to original sources
PubMed2026

Divergent responses of the rhizosphere microbiome to organic amendments sustain cadmium immobilization and low crop Cd accumulation after remediation.

This study integrated a two-stage immobilization-cultivation experiment to evaluate the effects of three immobilization strategies (inorganic, organic, and organo-mineral amendments) and two fertilization modes (mineral fertilizer alone and partial substitution with organic fertilizer) on soil cadmium (Cd) immobilization and plant Cd accumulation. During the immobilization phase, the organo-mineral strategy achieved the highest Cd immobilization efficiency of 69.5%. In the cultivation phase, the use of mineral fertilizer alone led to Cd remobilization, whereas organic substitution maintained or even enhanced immobilization, reducing shoot Cd accumulation in pak choi by up to 58.3%. Notably, the combined organic immobilization and organic substitution treatment (OP) was particularly effective: despite not having the lowest soil available Cd, it achieved the lowest plant Cd accumulation (2.83 mg·kg-1). Genomic analysis indicated that the OP treatment enriched core metagenome-assembled genomes (MAGs), including MAG8/Pelagerythrobacter, MAG13/Sphingomicrobium, and MAG30/VAYN01, which contained the highest abundances of genes related to extracellular polymeric substance (EPS) synthesis, phosphorus mobilization, and complexation-precipitation, suggesting the potential of these microbes to enhance EPS secretion and phosphate precipitation for rhizospheric Cd interception. This functional potential, along with the measured high EPS content (259.88 mg·kg-1) and low plant Cd accumulation in the OP group, provides coherent correlative evidence supporting the hypothesis that an "EPS barrier-chemical precipitation" mechanism synergistically reduces Cd migration to root surfaces. Collectively, continuous organic management can maintain soil fertility, enhance Cd immobilization, and promote low-Cd crop production, offering an efficient strategy for the safe utilization of remediated farmland.

Cadmium contamination↗
PubMed2026

Ethanol pretreatment drives microbial community adaptation to overcome acidification in high-solid anaerobic digestion of food waste under rapid organic loading shock.

This study investigated how ethanol pretreatment (EP) enhances the resilience of high-solid anaerobic digestion against rapid organic loading shocks. Semi-continuous reactors fed with either untreated or EP-treated food waste were compared, and the underlying mechanisms were elucidated by integrating thermodynamic calculations with metagenomic analyses. At an organic loading rate of 6.0 g VS/(Lˑd), the control group (untreated) collapsed due to the accumulation of propionate and other longer-chain volatile fatty acids (VFAs), resulting in a methane yield decrease exceeding 70%. In contrast, the EP group maintained stability, exhibiting a methane yield decrease of less than 5%, with VFAs dominated by readily degradable acetate. Thermodynamic analysis confirmed that EP significantly lowered the energy barriers for VFA degradation. Metagenomic analysis revealed that both propionate/butyrate activation pathways (with lower energy cost or independence from acetyl-CoA) and syntrophic acetate oxidation were activated in the EP group, thereby avoiding the VFA metabolic stress observed in the control group. Furthermore, higher abundances of conductive type IV pili genes, Complex II, and archaeal V/A-type ATPase were detected in the EP group, suggesting the establishment of direct interspecies electron transfer and enhanced electron flux and energy capture efficiency. Moreover, under high loading conditions, only a few high-abundance metagenome-assembled genomes (MAGs) were detected in the control group, while multiple MAGs carrying identical VFA-degrading enzyme systems were identified in the EP group. The functionally redundant microbiota, unobstructed VFA metabolic pathways, and efficient electron transfer and energy supply collectively sustained the stability of the EP group under loading shocks.

Anaerobic digestion↗
PubMed2025

The Effect of APOE ε4 Allele on Dynamic Local Spontaneous Brain Activity and Functional Integration in Alzheimer's Disease.

The apolipoprotein E (APOE) ε4 allele is the most important genetic risk factor for sporadic Alzheimer's disease (AD), yet its mechanisms in AD pathology and cognitive decline remain unclear. Using a sliding-time window approach to directly quantify the instantaneous fluctuations of various local metrics based on continuous time series and calculate voxel-wise concordance of these metrics, we explored the impact of APOE ε4 on dynamic local brain activity and functional integration in AD, and its interrelations with plasma biomarkers and cognition. Results showed that APOE ε4 widely affected dALFF, dReHo, dGSCorr, and voxel-wise concordance. For AD patients, APOE ε4 carriers uniquely exhibited correlations between dALFF in the right angular gyrus/supramarginal gyrus and MoCA scores and orientation function, and between voxel-wise concordance in the right caudate nucleus (CAU) and general cognition, attention, language function, orientation function, plasma Aβ42. Critically, APOE ε4-related altered voxel-wise concordance in the right CAU mediated the relationship between plasma Aβ and language cognition in AD. Moreover, the combined model incorporating dynamic metrics, plasma AD biomarkers, and demographic data effectively distinguished AD from NC (AUC = 0.94, sensitivity = 87.69%, specificity = 86.84%). In conclusion, the APOE ε4 allele might play a pivotal role in modulating brain dynamic functional activities in AD, which may contribute to the association between Aβ pathology and cognitive decline. Our findings may provide imaging markers and targets for the diagnosis and treatment of AD.

Humans↗