Nitrogen deposition is one of the most important factors affecting carbon (C) and nitrogen (N) cycling in terrestrial ecosystem. A six-year N addition experiment was carried out to explore how N deposition affected C and N fractions in soil aggregates in the secondary aspen forest (YHL) and primary Korean pine broad-leaved forest (HSL). We investigagted the effects of N addition on dissolved organic carbon and nitrogen (DOC and DON), microbial biomass carbon and nitrogen (MBC and MBN), particulate organic carbon and nitrogen (POC and PON) in soil aggregates with different particle sizes. The results showed that the contents of carbon and nitrogen fractions generally increased with the decrease of particle sizes of soil aggregates except for POC and PON. In soil aggregates of HSL, POC and PON significantly decreased by 20.7% and 22.6% in N treatment, respectively, but DOC increased by 11.6%. In YHL, N addition treatment had no signi-ficant effect on C and N fractions in soil aggregates. Total carbon or nitrogen correlated well with the active C and N fractions in soil aggregates, with a great significant negative correlation between POC and DOC in HSL (r=-0.503) and a significant positive correlation between DOC and MBC (r=0.462). In HSL, the negative effect of N treatment on POC and PON and the positive effect on DOC was mainly attributed to the accelerated decomposition of POM by stimulating microbial activity. Soil C and N pools in HSL were more vulnerable to N deposition than that in YHL.
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http://dx.doi.org/10.13287/j.1001-9332.201905.025 | DOI Listing |
iScience
January 2025
Key Laboratory for Environmental Factors Control of Agro-product Quality Safety (Ministry of Agriculture and Rural Affairs), Tianjin Key Laboratory of Agro-environment and Safe-product, Institute of Agro-environmental Protection, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China.
Nitrogen-fixing microorganisms (NFMs) are important components of soil N sinks and are influenced by multiple environmental factors. We established a random forest model optimized by the distributed delayed particle swarm optimization (RODDPSO) algorithm to analyze the global NFM data. Soil pH, organic carbon (OC), mean annual precipitation (MAP), altitude, and total phosphorus (TP) are factors with contributions greater than 10% to NFMs.
View Article and Find Full Text PDFMater Today Bio
February 2025
State Key Laboratory of Ophthalmology, Optometry and Visual Science, School of Ophthalmology and Optometry, School of Biomedical Engineering, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China.
The widespread antibiotic resistance has called for alternative antimicrobial agents. Carbon nanomaterials, especially carbon quantum dots (CQDs), may be promising alternatives due to their desirable physicochemical properties and potential antimicrobial activity, but their antimicrobial mechanism remains to be investigated. In this study, nitrogen-doped carbon quantum dots (N-CQDs) were synthesized to inactivate antibiotic-resistant bacteria and treat bacterial keratitis.
View Article and Find Full Text PDFNano Lett
January 2025
The Institute for Advanced Studies, Wuhan University, Wuhan 430072, China.
Robust interfaces in anodes play a crucial role in boosting sodium-ion battery (SIB) performance. However, the fragile interfaces constructed by a two-step synthesis or artificial stack are prone to be destroyed during the charging/discharging processes, which significantly reduces the lifetime of SIBs. Here, a facile construction strategy is developed to produce robust interfaces in hollow sphere-like CoSe/nitrogen-doped carbon (HS-CoSe/NC) using intrinsic Co, N, C in metal-organic framework as precursors, which enhance the electron/ion diffusion kinetics.
View Article and Find Full Text PDFActa Biochim Biophys Sin (Shanghai)
January 2025
CAS Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences (CAS), Shanghai 200032, China.
U32 is an industrial strain capable of producing therapeutically useful rifamycin SV. In early days of fermentation studies, nitrate was found to increase the yield of rifamycin along with globally, affecting both carbon and nitrogen metabolism in favor of antibiotic biosynthesis; thus, the (NSE) hypothesis was proposed. Although GlnR is likely the master regulator of the pleotropic effect of NSE, the global metabolism affected by NSE has never been systematically examined.
View Article and Find Full Text PDFFood Res Int
February 2025
Fondazione Edmund Mach, Via E. Mach 1, 38098 San Michele all'Adige, TN, Italy. Electronic address:
Isotope Ratio Mass Spectrometry (IRMS) is a promising tool in organic authentication cases. Premium-priced Italian rice varieties (Carnaroli, Arborio, Baldo) are used in cuisines worldwide for their unique qualitative properties. Organic authentication of rice by morphological assessment is unfeasible, while its market availability at different refining stages (brown, white) further increases the data variability.
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