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Objective: To explore the effects of organic acids on tobacco pH and flue gas pH. Methods: 34 kinds of single-grade tobacco and 11 kinds of finished cigarettes were taken as the research objects, and their non-volatile organic acids, tobacco pH, and the pH of mainstream smoke total particulate matter were measured respectively. Grey correlation analysis and principal component analysis were used to analyze the correlation between organic acids and pH. Results: The results of grey correlation analysis show that oxalic acid, palmitic acid, malic acid and oleic acid have a relatively large influence on the pH of single-grade tobacco; Palmitic acid, malic acid, linolenic acid and oxalic acid have a relatively large impact on the pH of cigarette cut tobacco; Malic acid, palmitic acid, linolenic acid and oxalic acid have relatively large effects on the pH of mainstream smoke total particulate matter of the cigarettes. Conclusion: Comprehensive analysis shows that malic acid and oxalic acid have a greater influence on the pH of single-grade tobacco, and malic acid and palmitic acid have a greater influence on the pH of cigarette cut tobacco and the pH of mainstream smoke total particulate matter.

The mammalian pituitary gland drives highly conserved physiological processes such as somatic cell growth, pubertal transformation, fertility, and metabolism by secreting a variety of hormones. Recently, single-cell transcriptomics techniques have been used in pituitary gland research. However, more studies have focused on adult pituitary gland tissues from different species or different sexes, and no research has yet resolved cellular differences in pituitary gland tissue before and after sexual maturation. Here, we identified a total of 15 cell clusters and constructed single-cell transcriptional profiles of rats before and after sexual maturation. Furthermore, focusing on the gonadotrope cluster, 106 genes were found to be differentially expressed before and after sexual maturation. It was verified that Spp1, which is specifically expressed in gonadotrope cells, could serve as a novel marker for this cell cluster and has a promotional effect on the synthesis and secretion of follicle-stimulating hormone. The results provide a new resource for further resolving the regulatory mechanism of pituitary gland development and pituitary hormone synthesis and secretion. [ABSTRACT FROM AUTHOR]

Background: Gonadotropin precisely controls mammalian reproductive activities. Systematic analysis of the mechanisms by which epigenetic modifications regulate the synthesis and secretion of gonadotropin can be useful for more precise regulation of the animal reproductive process. Previous studies have identified many differential m6A modifications in the GnRH-treated adenohypophysis. However, the molecular mechanism by which m6A modification regulates gonadotropin synthesis and secretion remains unclear. Results: Herein, it was found that GnRH can promote gonadotropin synthesis and secretion by promoting the expression of FTO. Highly expressed FTO binds to Foxp2 mRNA in the nucleus, exerting a demethylation function and reducing m6A modification. After Foxp2 mRNA exits the nucleus, the lack of m6A modification prevents YTHDF3 from binding to it, resulting in increased stability and upregulation of Foxp2 mRNA expression, which activates the cAMP/PKA signaling pathway to promote gonadotropin synthesis and secretion. Conclusions: Overall, the study reveals the molecular mechanism of GnRH regulating the gonadotropin synthesis and secretion through FTO-mediated m6A modification. The results of this study allow systematic interpretation of the regulatory mechanism of gonadotropin synthesis and secretion in the pituitary at the epigenetic level and provide a theoretical basis for the application of reproductive hormones in the regulation of animal artificial reproduction. [ABSTRACT FROM AUTHOR]

Dark microbial CO2 fixation plays a crucial role in soil organic carbon (SOC) sequestration, but the fungus contributions to this process in varying agroecosystems remain unclear. This study investigated fungal CO2 fixation in 29 soil samples collected from the major agricultural regions across China. Phospholipid fatty analysis-stable isotope probing revealed variations in fungal fixation by 2.2 to 65.5% of the total microbial CO2 fixation. CO2 assimilation of ten fungal strains belonging to the phyla Ascomycota and Basidiomycota was determined in three different media using an isotope labeling experiment. Trichocladium uniseriatum had the highest CO2 fixation capacity. T. uniseriatum had the reductive tricarboxylic acid cycle (rTCA) for CO2 assimilation associated with sulfite metabolism. T. uniseriatum was thus selected for use in soil inoculation experiments, aimed to trace the fractionation of its fixed carbon in SOC. The CO2 fixation rate of T. uniseriatum was 0.07–0.09 μg C per g of soil per day. Notably, 77–82% of the fixed C was partitioned into the mineral-associated soil organic carbon. This study highlights the significance of fungal CO2 fixation in soil carbon sequestration. [ABSTRACT FROM AUTHOR]