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Soil multifunctionality is essential for the enhancement of soil carbon sequestration, but disturbances such as thinning practices can influence soil microbial activity and carbon cycling. Microbial residues, particularly microbial residue carbon (MRC), are important contributors to soil organic carbon (SOC), but the effects of thinning intensity on MRC accumulation remain poorly understood. This study evaluated the impact of four thinning treatments—control (CK, 0%), light-intensity thinning (LIT, 20%), medium-intensity thinning (MIT, 30%), and high-intensity thinning (HIT, 45%)—on soil multifunctionality in Chinese fir plantations five years after thinning. Soil nutrient provision, microbial biomass, enzyme activity, and microbial residue carbon were assessed. The results showed that thinning intensity significantly affected soil nutrient provision and microbial biomass, with MIT and HIT showing higher nutrient levels than CK and LIT. Specifically, MIT's and HIT's total nutrient provision increased by 0.04 and 0.15 compared to that of CK. Enzyme activity was highest in LIT (+0.89), followed by MIT (+0.07), with HIT showing a decline (−0.84). Microbial biomass, including bacterial PLFAs (B-PLFAs), fungal PLFAs (F-PLFAs), microbial biomass carbon (MBC), and nitrogen (MBN), was highest in CK and MIT, and lowest in HIT, with MIT showing a 0.13 increase compared to CK. Microbial residue carbon (MRC) accumulation was positively correlated with soil organic carbon (SOC), total nitrogen (TN), available nitrogen (AN), and easily oxidized organic carbon (EOC). The highest MRC content in the 0–20 cm soil layer was observed in MIT and CK (10.46 and 11.66 g/kg, respectively), while the MRC in LIT and HIT was significantly lower, reduced by 24% and 12%, respectively. These findings highlight the significant role of thinning intensity in microbial activity and carbon cycling. Medium-intensity thinning (MIT, 30%) was identified as the most effective approach for promoting microbial biomass and enhancing carbon cycling in Chinese fir forest soils, making it an optimal approach for forest management aimed at increasing soil carbon sequestration. [ABSTRACT FROM AUTHOR]

Dipeptidyl peptidase 4 (DPP4) is a serine protease widely distributed in membrane-bound and soluble forms in various tissues and organs throughout the body. DPP4 plays a role in inflammation, immune regulation, cell growth, migration and differentiation. The role of DPP4 in tumors has garnered increasing attention. Previous research has demonstrated that DPP4 contributes to the promotion of cancer in most cancers, and it may play a specific biological function through the variation in tumor cell types and expression forms. However, the expression of DDP4 in different tumor types and its specific mechanism remains unclear. In this review, we describe the structure of DPP4, summarize the recent research progress of its expression and potential mechanisms in common tumors, and discuss the development prospects of DPP4 inhibitors in tumor therapy. Although current research emphasizes the potential of DPP4 as a drug target, the incomplete understanding of its regulatory mechanisms impedes the discovery and development of new therapies against it. Further research on DPP4-related tumors is anticipated to promote its clinical application as a potential therapeutic target. [ABSTRACT FROM AUTHOR]