Linkage between temperature sensitivity of SOM decomposition and microbial communities depends on soil fractions.

The magnitude of terrestrial carbon (C)-climate feedback largely depends on the temperature sensitivity of soil organic matter (SOM) decomposition (Q10). However, our understanding of determinants of Q10 for SOM fractions such as particulate and mineral-associated organic matter (POM and MAOM, respectively) is still inadequate. Particularly, it remains unclear whether microbial effects on Q10 are fraction-dependent, which induces large uncertainties in projecting soil C dynamics. Here, we conducted large-scale topsoil sampling on the Tibetan Plateau, in combination with SOM fractionation and 300-day laboratory incubation to assess SOM fraction-dependent linkages between Q10 and microbial properties. We found that compared with MAOM, POM had larger Q10 and greater microbial diversity, and also structured distinct microbial communities as well as their co-occurrence patterns. Furthermore, associations of Q10 with microbial properties differed between the two SOM fractions. Bacterial community composition and relative abundance of bacterial keystone taxa affected Q10 for POM and MAOM respectively, while bacterial alpha diversity showed opposite relationships with Q10 for POM and MAOM. These findings highlight the necessity of incorporating SOM fraction-dependent microbial properties and their linkages with Q10 into Earth system models to accurately predict terrestrial C-climate feedback.

Construction of the prognostic nomogram and treatment recommendation in patients with mixed endometrial carcinoma treated with hysterectomy.

The study aimed to identify the independent prognostic factors of mixed endometrial carcinoma (MEC) patients treated with hysterectomy and to explore the optimal treatment modalities for overall survival (OS) and cancer-specific survival (CSS). Using the Surveillance, Epidemiology, and End Results (SEER) database, a total of 12,848 MEC patients treated with hysterectomy were screened out. Independent prognostic factors were identified by Cox regression analysis and used to construct the nomogram. The concordance index (C-index) of OS and CSS were 0.807 and 0.834 in the training set. Validation of the nomogram revealed that the receiver operating curve (ROC) maintained good discrimination, the decision curve analysis (DCA) had a high net benefit rate, and the calibration curves showed high consistency. Patients were grouped by the nomogram formula and the number of positive regional lymph nodes (NPR-Lymph node) to evaluate the therapeutic outcomes of chemotherapy, radiotherapy, neoadjuvant treatment and lymph node operation. Survival analysis revealed that chemotherapy could improve the prognosis for OS and CSS in the high-risk group and in the group with NPR-Lymph node counts above 1 (P < 0.05). Radiotherapy was associated with better OS and CSS in the intermediate-risk and high-risk groups, and in the group with NPR-Lymph node counts above 0 (P < 0.05). Lymphadenectomy was found to prolong OS and CSS in the high-risk group (P < 0.05), while neoadjuvant treatment did not prolong OS and CSS in any group. Thus, in this study, the nomogram for MEC patients treated with hysterectomy was successfully built and validated which could effectively predict the prognosis and identify at-risk population to guide clinical decision-making. The NPR-Lymph node was identified as a potentially strong prognostic indicator with good clinical value.

Metagenomic insights into microbial community structure and metabolism in alpine permafrost on the Tibetan Plateau.

Permafrost, characterized by its frozen soil, serves as a unique habitat for diverse microorganisms. Understanding these microbial communities is crucial for predicting the response of permafrost ecosystems to climate change. However, large-scale evidence regarding stratigraphic variations in microbial profiles remains limited. Here, we analyze microbial community structure and functional potential based on 16S rRNA gene amplicon sequencing and metagenomic data obtained from an ∼1000 km permafrost transect on the Tibetan Plateau. We find that microbial alpha diversity declines but beta diversity increases down the soil profile. Microbial assemblages are primarily governed by dispersal limitation and drift, with the importance of drift decreasing but that of dispersal limitation increasing with soil depth. Moreover, genes related to reduction reactions (e.g., ferric iron reduction, dissimilatory nitrate reduction, and denitrification) are enriched in the subsurface and permafrost layers. In addition, microbial groups involved in alternative electron accepting processes are more diverse and contribute highly to community-level metabolic profiles in the subsurface and permafrost layers, likely reflecting the lower redox potential and more complicated trophic strategies for microorganisms in deeper soils. Overall, these findings provide comprehensive insights into large-scale stratigraphic profiles of microbial community structure and functional potentials in permafrost regions.