Microplastic pollution promotes soil respiration: A global-scale meta-analysis.

Microplastic (MP) pollution likely affects global soil carbon (C) dynamics, yet it remains uncertain how and to what extent MP influences soil respiration. Here, we report on a global meta-analysis to determine the effects of MP pollution on the soil microbiome and CO2 emission. We found that MP pollution significantly increased the contents of soil organic C (SOC) (21%) and dissolved organic C (DOC) (12%), the activity of fluorescein diacetate hydrolase (FDAse) (10%), and microbial biomass (17%), but led to a decrease in microbial diversity (3%). In particular, increases in soil C components and microbial biomass further promote CO2 emission (25%) from soil, but with a much higher effect of MPs on these emissions than on soil C components and microbial biomass. The effect could be attributed to the opposite effects of MPs on microbial biomass vs. diversity, as soil MP accumulation recruited some functionally important bacteria and provided additional C substrates for specific heterotrophic microorganisms, while inhibiting the growth of autotrophic taxa (e.g., Chloroflexi, Cyanobacteria). This study reveals that MP pollution can increase soil CO2 emission by causing shifts in the soil microbiome. These results underscore the potential importance of plastic pollution for terrestrial C fluxes, and thus climate feedbacks.

Normothermic Machine Perfusion versus Cold Storage of Liver in Pig Model: A Meta-Analysis.

BACKGROUND Normothermic machine perfusion (NMP) is a novel strategy used for organ preservation. We aimed to determine the overall efficacy of NMP for liver preservation versus traditional static cold storage (CS). MATERIAL AND METHODS We performed a meta-analysis of the literature to evaluate the efficacy of NMP in experimental pig models of liver preservation. We use the standardized mean difference and 95% confidence intervals (CI) to calculate statistics and used the random effects model for the combined analysis of the results. RESULTS A total of 16 studies from 12 published articles were included. The combined results showed that NMP significantly decreased alanine aminotransferase (ALT), aspartate aminotransferase (AST), and hyaluronic acid levels in serum or perfusate, significantly increased bile production, and had a similar 5-7-days survival rate after liver transplantation compared with the CS group. CONCLUSIONS NMP provides superior graft preservation compared with CS in the pig model.