A Scalable and Robust Water Management Strategy for PEMFCs: Operando Electrothermal Mapping and Neutron Imaging Study.

Effective water management is crucial for the optimal operation of low-temperature polymer electrolyte membrane fuel cells (PEMFCs). Excessive liquid water production can cause flooding in the gas diffusion electrodes and flow channels, limiting mass transfer and reducing PEMFC performance. To tackle this issue, a nature-inspired chemical engineering (NICE) approach has been adopted that takes cues from the integument structure of desert-dwelling lizards for passive water transport. By incorporating engraved, capillary microchannels into conventional flow fields, PEMFC performance improves significantly, including a 15% increase in maximum power density for a 25 cm2 cell and 13% for a 100 cm2 cell. Electro-thermal maps of the lizard-inspired flow field demonstrate a more uniform spatial distribution of current density and temperature than the conventional design. Neutron radiography provides evidence that capillary microchannels in the lizard-inspired flow field facilitate the efficient transport and removal of generated liquid water, thereby preventing blockages in the reactant channels. These findings present a universally applicable and highly efficient water management strategy for PEMFCs, with the potential for widespread practical implementation for other electrochemical devices.

Effects of Spermidine on Mouse Gut Morphology, Metabolites, and Microbial Diversity.

Spermidine is a class of biologically active organic small molecules that play an important role in maintaining intestinal homeostasis. The specific objective of this study was to explore the effects of spermidine on intestinal morphology, metabolites, and microbial diversity in mice. We showed that 0.3 mmol/L of spermidine significantly promoted the growth of ileal villi (p < 0.05), and 3.0 mmol/L of spermidine significantly increased the body weight of mice and promoted the growth of jejunum villi (p < 0.05). The 16S rDNA sequencing results indicated that 3.0 mmol/L of spermidine affected the balance of the intestinal flora by increasing the abundance of intestinal Lactic acid bacteria and reducing the abundance of harmful bacteria (Turicibacter and Alistipes). Additionally, spermidine affects the levels of microbial metabolites such as succinic acid and Pantetheine. In summary, spermidine affects intestinal morphology and regulates intestinal flora and metabolites, and this study has provided a new understanding of spermidine's effects on the intestinal tract.

[Phytoestrogen-like effect of Siwu Decoction and molecular mechanism: based on network pharmacology and in vivo experiment].

This study explored the phytoestrogen-like effect of Siwu Decoction(SWD) and the estrogen receptor(ER)-mediated molecular mechanism based on network pharmacology and in vivo experiment. The active components and targets of SWD were retrieved from Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP), and related targets of "estrogen" from GeneCards and Online Mendelian Inheritance in Man(OMIM). Cytoscape and STRING were employed to construct the protein-protein interaction(PPI) network and "chemical component-target-disease" network and core targets were identified, followed by Gene Ontology(GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment of the core targets by R software. For the in vivo experiment, the 22-day-old SD female rats were treated(ig) with SWD for 4 days. Via hematoxylin-eosin(HE) staining, the morphological changes of rat uterus were observed. Reverse transcriptase-polymerase chain reaction(RT-PCR) was performed to detect mRNA expression of ER subtypes, estrogen-related targets, and the main regulatory factors in the estrogen signaling pathway. The results indicated 74 targets of SWD exerted phytoestrogen-like effect. KEGG pathway enrichment result suggested that estrogen signaling pathway was closely related to the phytoestrogen-like effect of SWD. Rats in SWD group demonstrated significantly thickened endometrium and significantly decreased expression of ERα, ERß, and G protein-coupled estrogen receptor(GPER) mRNA in ovarian tissue. In addition, significant lowering of ERα and ERß mRNA expression and significant rise of GPER mRNA expression in uterine tissue were observed in the SWD group. The expression of mitogen-activated protein kinase(MAPK) p38, MEK1/2 and extracellular signal-regulated kinase(ERK)1/2 mRNA was significantly low while that of epidermal growth factor receptor(EGFR) mRNA was significantly high in both ovarian and uterine tissues of SWD group compared with those in the control group. In conclusion, the phytoestrogen-like effect of SWD is closely related to the estrogen signaling pathway. The result lays a basis for revealing molecular mechanism of SWD in the treatment of gynecological diseases.