The interaction between water and coal is of great significance to the study of coal spontaneous combustion (CSC) in humid mine environments. Here, using an isotope tracing method to trace oxygen atoms in water, the role of water in the formation of CO, CO2, product water, and other substances during CSC was quantitatively studied through thermogravimetry coupled with mass spectrometry (TG-MS). In addition, Pearson correlation analysis was used to evaluate the relationships between the amounts of CO and CO2 generated during CSC and the different functional groups. The migration and transformation paths of oxygen atoms in water were analyzed. The results showed that water participated in the CSC reaction to produce CO, CO2, and product water in a dynamic, temperature-dependent process. CO and CO2 were formed through different reaction paths involving reactions between water and aldehyde and carboxyl groups. Further, carboxyl groups were also involved in the reaction with coal to form product water. The results from this study are helpful for understanding the influence of water in each stage of CSC, thereby aiding in its prevention and control.

This research aimed to explore the potential influence of mitochondria on the rate of anaerobic glycolysis. We hypothesized that mitochondria could reduce the rate of anaerobic glycolysis and pH decline by metabolizing a portion of glycolytic pyruvate. We utilized an in vitro model and incorporated CPI-613 and Avidin to inhibit pyruvate dehydrogenase (PDH) and pyruvate carboxylase (PC), respectively. Four treatments were tested: 400 μM CPI-613, 1.5 U/ml Avidin, 400 μM CPI-613 + 1.5 U/ml Avidin, or control. Glycolytic metabolites and pH of the in vitro model were evaluated throughout a 1440-min incubation period. CPI-613-containing treatments, with or without Avidin, decreased pH levels and increased glycogen degradation and lactate accumulation compared to the control and Avidin treatments (P < 0.05), indicating increased glycolytic flux. In a different experiment, two treatments, 400 μM CPI-613 or control, were employed to track the fates of pyruvate using [13C6]glucose. CPI-613 reduced the contribution of glucose carbon to tricarboxylic acid cycle intermediates compared to control (P < 0.05). To test whether the acceleration of acidification in reactions containing CPI-613 was due to an increase in the activity of key enzymes of glycogenolysis and glycolysis, we evaluated the activities of glycogen phosphorylase, phosphofructokinase, and pyruvate kinase in the presence or absence of 400 μM CPI-613. The CPI-613 treatment did not elicit an alteration in the activity of these three enzymes. These findings indicate that inhibiting PDH increases the rate of anaerobic glycolysis and pH decline, suggesting that mitochondria are potential regulators of postmortem metabolism.

Zinc (Zn) isotope compositions in soft mussel tissues help identify internal biological processes and track coastal Zn sources in coastal environments, thus aiding in managing marine metal pollution. This study investigated the seasonal and multi-decadal Zn isotope compositions of blue mussels (genus Mytilus) from two French coastal sites with contrasting Zn environmental contamination. Concurrently, we characterized the isotope ratios of sediments and plankton samples at each site to understand the associations between organisms and abiotic compartments. Our primary objective was to determine whether these isotope compositions trace long-term anthropogenic emission patterns or if they reflect short-term biological processes. The multi-decadal isotope profiles of mussels in the Loire Estuary and Toulon Bay showed no isotope variations, implying the enduring stability of the relative contributions of natural and anthropogenic Zn sources over time. At seasonal scales, Zn isotope ratios were also constant; hence, isotope effects related to spawning and body growth were not discernible. The multi-compartmental analysis between the sites revealed that Toulon Bay exhibits a remarkably lower Zn isotope ratio across all studied matrices, suggesting the upward transfer of anthropogenic Zn in the food web. In contrast, the Zn isotope variability observed for sediments and organisms from the Loire Estuary fell within the natural baseline of this element. In both sites, adsorptive geogenic material carrying significant amounts of Zn masks the biological isotope signature of plankton, making it difficult to determine whether the Zn isotope ratio in mussels solely reflects the planktonic diet or if it is further modified by biological homeostasis. In summary, Zn isotope ratios in mussels offer promising avenues for delineating source-specific isotope signatures, contingent upon a comprehensive understanding of the isotope fractionation processes associated with the trophic transfer of this element through the plankton.

To further our understanding of the change in association between lignin and carbohydrates after kraft pulping, isotope-labeled kraft pulp (KP) was prepared using 13C and D double-isotope-labeled wheat straw, and it was subjected to enzymatic hydrolysis and ionic liquid treatment to explore the linkages between lignin and carbohydrate complexes in wheat straw. Isotope abundance determination showed that 13C and D abundances in the experimental groups were substantially higher than those in the control group, indicating that the injected exogenous coniferin-[α-13C], coniferin-[γ-13C], and d-glucose-[6-D2] were effectively absorbed and metabolized during wheat internode growth. Solid-state CP/MAS 13C-NMR spectroscopy showed that lignin was mainly linked to polysaccharides via acetal, benzyl ether, and benzyl ester bonds. Kraft pulp (KP) from the labeled wheat straw was degraded by cellulase. The obtained residue was fractionated using the ionic liquid DMSO/TBAH to separate the cellulose-lignin complex (KP-CLC) and xylan-lignin complex (KP-XLC). X-ray diffractometer determination showed that the KP-CLC regenerated cellulose type II from type I after the ionic liquid conversion. The 13C-NMR spectrum of Ac-En-KP-CLC showed that the cellulose-lignin complex structure was chemically bonded between the lignin and cellulose through acetal and benzyl ether bonds. The 13C-NMR spectrum of En-KP-XLC showed a lignin-hemicellulose complex structure, wherein lignin and xylan were chemically bonded by benzyl ether and acetal bonds. These results indicate that the cross-linking between lignin and carbohydrates exists in lignocellulosic fibers even after kraft pulping.

This study investigates the chronology of copper (Cu) contamination and its stable isotopes within an emblematic Brazilian mangrove impacted by multiple urban and industrial Cu sources, deforestation, and eutrophication. In particular, it tests Cu isotopes as tracers of anthropogenic inputs into an anthropized watershed impacted by multiple sources. To do so, we used multi-isotopic approaches (δ65Cu, δ13C, and δ15N), elemental analyses (Al, Ca, Fe, P, Cu, C, and N), and selective and sequential extractions in a210Pb-dated sediment core. This geochemical \"toolbox\" allowed identifying two main stages of Cu evolution in the sediment core. In the first stage, before 1965, Cu isotope fingerprints responded to landscape changes, indicating a shift from marine to geogenic dominance due to the remobilization and erosion of terrestrial materials. In the second stage, after 1965, the sediment geochemical profile showed increased Cu total concentrations with a higher bioavailability (as reflected by sequential extraction data) accompanying changes in Cu isotope signatures towards anthropogenic values. The findings evidence that local industrial sources, possibly combined with diffuse urban sources, export Cu into downstream mangroves with a distinguishable isotope signature compared to natural values. This study demonstrates the applicability of Cu isotopes as new environmental forensic tools to trace anthropogenic sources in mangrove sediments. Incorporated into a robust geochemical toolbox that combines inorganic and organic proxies for sedimentary materials, this new tool provides a comprehensive understanding of Cu dynamics in mangrove ecosystems, shedding light on the historical and current sources of Cu.

Arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) are able to provide key ecosystem services, protecting plants against biotic and abiotic stresses. Here, we hypothesized that a combination of AMF (Rhizophagus clarus) and PGPR (Bacillus sp.) could enhance 33P uptake in maize plants under soil water stress. A microcosm experiment using mesh exclusion and a radiolabeled phosphorus tracer (33P) was installed using three types of inoculation: i) only AMF, ii) only PGPR, and iii) a consortium of AMF and PGPR, alongside a control treatment without inoculation. For all treatments, a gradient of three water-holding capacities (WHC) was considered i) 30% (severe drought), ii) 50% (moderate drought), and iii) 80% (optimal condition, no water stress). In severe drought conditions, AMF root colonization of dual-inoculated plants was significantly lower compared to individual inoculation of the AMF, whilst 33P uptake by dual-inoculated plants or plants inoculated with bacteria was 2.4-fold greater than the uninoculated treatment. Under moderate drought conditions the use of AMF promoted the highest 33P uptake by plants, increasing it by 2.1-fold, when compared to the uninoculated treatment. Without drought stress, AMF showed the lowest 33P uptake and, overall, plant P acquisition was lower for all inoculation types when compared to the severe and moderate drought treatments. The total shoot P content was modulated by the water-holding capacity and inoculation type, with the lowest values observed under severe drought and the highest values under moderate drought. The highest soil electrical conductivity (EC) values were found under severe drought in AMF-inoculated plants and the lowest EC for no drought in single or dual-inoculated plants. Furthermore, water-holding capacity influenced the total soil bacterial and mycorrhizal abundance over time, with the highest abundances being found under severe and moderate drought. This study demonstrates that the positive influence of microbial inoculation on 33P uptake by plants varied with soil water gradient. Furthermore, under severe stress conditions, AMF invested more in the production of hyphae, vesicles and spore production, indicating a significant carbon drain from the host plant as evidenced by the lack of translation of increased 33P uptake into biomass. Therefore, under severe drought the use of bacteria or dual-inoculation seems to be more effective than individual AMF inoculation in terms of 33P uptake by plants, while under moderate drought, the use of AMF stood out.

Radionuclides in environmental ecosystems have ecotoxicity and health impact on human and environment, so radioactive contamination has always been one of the global concerns. This study mainly focused on the radioactivity of mosses collected from the Leye Tiankeng Group in Guangxi. The activities of 239+240Pu measured by SF-ICP-MS and 137Cs measured by HPGe in moss and soil samples are as follows: 0-2.29 Bq/kg in mosses and 1.5-11.9 Bq/kg in soils for 137Cs, and 0.025-0.25Bq/kg in mosses and 0.07-0.51Bq/kg in soils for 239+240Pu. The range of 240Pu/239Pu atom ratios (0.201 in mosses and 0.184 in soils) and 239+240Pu/137Cs activity ratios (0.128 in mosses and 0.044 in soils) indicated that the 137Cs and 239+240Pu in study area were mainly contributed by global fallout. 137Cs and 239+240Pu showed similar distribution in soils. However, their behaviors in mosses were quite different due to the differences in the growth environment of mosses. The transfer factors of 137Cs and 239+240Pu from soil to moss varied in different growth stages and specific environments. A weak positive correlation among 137Cs, 239+240Pu in mosses and soil-derived radionuclides suggested that resettlement was predominant here. The negative correlation between 7Be, 210Pb and soil-derived radionuclides indicated that 7Be and 210Pb came from atmospheric components, while the weak correlation between them suggested that their specific sources were different. The Cu and Ni were moderately enriched in mosses here due to the use of agricultural fertilizers, At the same time, Zn was at a high level in the Lilang area, where transportation was more developed.

Isotope-labeled four polycyclic aromatic hydrocarbons (PAH4-d12) were applied to study the migration and distribution of PAH4 in oil to French fries during frying. The results showed that the mobilities of PAH4-d12 showed a downtrend within 0-6 h and then an uptrend, and PAH4-d12 were mainly distributed in the crust of the French fries, especially five-ring PAHs-d12. The correlation analysis showed that PAH4-d12 migration was mainly caused by oil absorption of French fries. The low fluidity of the oil slowed down the PAH4-d12 migration, which was accelerated as the total polar component increased (higher than 15-20%). Additionally, higher frying temperature enhanced the crust ratio and porous structure of French fries, which explained the abundant five-ring PAHs-d12 distributed in the crust. This study provided references for optimizing the frying parameters: the exposure of PAH4 in French fries to humans can be reduced by controlling the oil quality and weakening the crust of the French fries.

UNASSIGNED: Due to their widespread use, sulfonamide antibiotics (SAs) have become ubiquitous environmental contaminants and thus a cause of public concern. However, a complete understanding of the behavior of these pollutants in complex environmental systems has been hampered by the unavailability and high cost of isotopically labeled SAs.
UNASSIGNED: Using commercially available uniformly [14C]- and [13C]-labeled aniline as starting materials, we synthesized [phenyl-ring-14C]- and [phenyl-ring-13C]-labeled sulfamethoxazole (SMX), sulfamonomethoxine (SMM), and sulfadiazine (SDZ) in four-step (via the condensation of labeled N-acetylsulfanilyl chloride and aminoheterocycles) or five-step (via the condensation of labeled N-acetylsulfonamide and chloroheterocycles) reactions, with good yields (5.0-22.5% and 28.1-54.1% for [14C]- and [13C]-labeled SAs, respectively) and high purities (> 98.0%).
UNASSIGNED: The synthesis of [14C]-labeled SAs in milligram amounts enables the preparation of labeled SAs with high specific radioactivity. The efficient and feasible methods described herein can be applied to the production of a variety of [14C]- or [13C]-labeled SAs for studies on their environmental behavior, including the fate, transformation, and bioaccumulation of these antibiotics in soils and aqueous systems.
UNASSIGNED: The online version contains supplementary material available at 10.1186/s12302-022-00598-z.

The advent of Multicollector ICP-MS inaugurated the analysis of new metal isotope systems, the so-called \"non-traditional\" isotopes. They are now available tools to study geochemical and ecotoxicological aspects of marine metal contamination and hence, to push the frontiers of our knowledge. However, such applications are still in their infancy, and an accessible state-of-the-art describing main applications, obstacles, gaps, and directions for further development was missing from the literature. This paper fills this gap and aims to encourage the marine scientific community to explore the contributions of this newly available information for the fields of chemical risk assessment, biomonitoring, and trophic transfer of metal contaminants. In the current \"Anthropocene\" epoch, metal contamination will continue to threaten marine aquatic ecosystems, and \"non-traditional\" isotopes can be a valuable tool to detect human-induced changes across time-space involving metal contaminants, and their interaction with marine biota.