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Coastal‐wetlands play a crucial role as carbon (C) reservoirs on Earth due to their C pool composition and functional sink, making them significant for mitigating global climate change. However, due to the development and utilization of wetland resources, many wetlands have been transformed into other land‐use types. The current study focuses on the alterations in soil organic‐C (SOC) in coastal‐wetlands following reclamation into aquaculture ponds. We conducted sampling at 11 different coastal‐wetlands along the tropical to temperate regions of the China coast. Each site included two community types, one with solely native species (Suaeda salsa, Phragmites australis and Mangroves) and the other with an adjacent reclaimed aquaculture pond. Across these 11 locations we compared SOC stock, active OC fractions, and soil physicochemical properties between coastal wetlands and aquaculture ponds. We observed that different soil uses, sampling sites, and their interaction had significant effects on SOC and its stock (p <.05). Reclamation significantly declined SOC concentration at depths of 0–15 cm and 15–30 cm by 35.5% and 30.3%, respectively, and also decreased SOC stock at 0–15 cm and 15–30 cm depths by 29.1% and 37.9%, respectively. Similar trends were evident for SOC stock, labile organic‐C, dissolved organic‐C and microbial biomass organic‐C concentrations (p <.05), indicating soil C‐destabilization and losses from soil following conversion. Soils in aquaculture ponds exhibited higher bulk density (BD; 11.3%) and lower levels of salinity (61.0%), soil water content (SWC; 11.7%), total nitrogen (TN) concentration (23.8%) and available‐nitrogen concentration (37.7%; p <.05) than coastal‐wetlands. Redundancy‐analysis revealed that pH, BD and TN concentration were the key variables most linked with temporal variations in SOC fractions and stock between two land use types. This study provides a theoretical basis for the rational utilization and management of wetland resources, the achievement of an environment‐friendly society, and the preservation of multiple service functions within wetland ecosystems. [ABSTRACT FROM AUTHOR]

Summary: Biochar is increasingly used in crop production as a fertilizer; however, its effects on nutrient cycling and stoichiometry in rice paddy soil–plant systems are unclear. We tested for effects of contrasting rates of biochar on soil and rice plant organ carbon (C), nitrogen (N), and phosphorus (P) concentrations and stoichiometry and soil physicochemical properties in early and late paddies. Overall, biochar reduced soil bulk density by an average of 7.4%, while application at 10, 20, and 40 t ha−1 increased soil C and N concentrations in early paddies by 31.6, 41.3, and 104.2%, respectively, and by 8.0, 5.0, and 21.8%, respectively; in late paddies, there were increases of 23.0, 94.1, and 117.0%, respectively, and 6.7, 15.4, and 18.0%, respectively (P < 0.05). Following biochar application at 10, 20, and 40 t ha−1, soil concentration of P decreased in early paddies by 10.9, 19.0, and 13.9%, respectively, and increased in late paddies by 4.3, 16.4, and 20.1%, respectively. Biochar increased ratios of soil C:N and C:P in early and late paddies (P < 0.05), and there was no effect on concentration and stoichiometry of soil available nutrients. Biochar reduced rice plant organ concentration of N and P in early rice and increased leaf N:P ratios. Despite the biochar application improved nutrient status in plant–soil system, we did not observe a significant increase in yield (P > 0.05). According to the N:P value of leaves between treatments, it was found that biochar alleviated the current situation of N limitation in paddy fields during the mature period and transformed the N limitation of early rice into a joint limitation of N and P. These results show that the addition of biochar to subtropical paddy soils leads to a short-term reduction in soil bulk density and increases in soil C and N concentrations and soil fertility. Thus, biochar applied at optimal rates is likely to improve the sustainability of subtropical paddy rice production. [ABSTRACT FROM AUTHOR]

Soil degradation is characterized by loss of soil organic matter, decline in fertility, imbalance in elemental content, deterioration of soil structure, and overall a deterioration of soil environment. According to the classification method of Pieri et al. (1992), the soil is classified into different degradation classes by calculating the soil structural stability index (St) of each sample point. We aimed to investigate changes in the contents, storages and stoichiometry of soil carbon (C), nitrogen (N), and phosphorus (P) together with changes in soil physical traits along a soil degradation gradient in jasmine croplands in Fuzhou area (China). The content and storage of soil C and N decreased with increasing intensity of land degradation. Soil organic C content was 15.4%, 32.3%, and 38.8% lower, respectively, in the low, medium, and high degree of degradation soils, than in the nondegraded soils. The soil C:N ratio was 18.5% higher in soils in the middle degree of degradation than in the nondegraded soils. Compared with nondegraded soils, the bulk density of the degraded soils increased and water content decreased. The decrease of soil pH coupled with salinity (conductivity) and the loss of aggregate stability are the main traits that distinguish degraded from nondegraded soils. We also detected a general N and P deficiency that is aggravated by the degradation process. Unreasonable management easily leads to degradation associated with a loss of organic C and total soil nutrients, thus impairing even more a general N and P deficiency in this area. Therefore, higher inputs of organic fertilizer should be added to alleviate the lack of organic matter, and appropriate burial should be conducted to reduce nutrient loss. Moreover, a rise of N and P fertilizer application is also advisable. [ABSTRACT FROM AUTHOR]

Carbohydrates are expected to replace petroleum and to become the base of industrial chemistry. Chirality is one particular area in which carbohydrates have a special potential advantage over petroleum resources. Herein, we report a catalytic approach for the direct production of d-tetroses [i.e., d-(−)-erythrose and d-(+)-erythrulose] from d-hexoses through a fast retro-aldol process at 190 °C that achieves a yield of 46 % and completely retains the chiral centers in the final chiral synthon. The d-tetrose products were further converted into their derivatives, thereby accomplishing transfer of chirality from natural chiral hexoses to high-value-added chiral chemicals. Our results also suggest that the product distribution for the conversion of d-hexoses was determined by their isomerization and epimerization trends that competed with their corresponding retro-aldol condensation processes. [ABSTRACT FROM AUTHOR]

Applying industrial waste amendments, such as steel slag and biochar, to soils is an increasingly common practice to improve soil fertility, crop yield, and soil carbon (C) pool storage and stability. However, the effects of separate and combined applications of slag and biochar on total and active soil organic C (SOC) pools and the associated relationships between soil microorganisms and C cycling are unclear. Therefore, this study examined the effects of steel slag, rice straw biochar, and slag+biochar amendments to subtropical early and late rice paddy soils on total and active SOC concentrations and microbial abundance and diversity. The results showed that slag+biochar increased SOC content in early and late rice, with increases in dissolved organic C of 28.7 and 52.6 % in the early and late rice jointing stages, respectively. Soil organic C was positively correlated with soil C:N ratios in the two crop seasons. Applications of slag and biochar alone increased the diversity of soil bacteria in early rice but decreased in late rice. Meanwhile, the combined application of slag and biochar decreased diversity of soil bacterial community diversity and increased the relative abundance of some beneficial bacterial taxa, such as Pseudomonas, Bacillus, Flavisolibacter , and Ferruginibacte which are related to SOC cycling and sequestration. The results highlight that the combined slag and biochar amendments can improve soil specific properties, such as pH and SOC stocks, which elicit alterations in soil bacterial composition, especially of some keystone genera, altogether resulting in enhanced soil C sequestration and C pool stability. [Display omitted] • Combined slag and biochar amendment increased soil pH and SOC concentrations. • Combined amendment altered soil bacterial community composition. • Combined slag and biochar amendment can maintain the stability of soil C pool. • Soil properties and bacterial community influenced soil C sequestration. [ABSTRACT FROM AUTHOR]

This study investigates the utility of plant δ¹3C natural labeling in predicting the impacts of environmental shifts on carbon cycling within ecosystems, particularly focusing on paddy fields treated with maize (Zea mays L.) residues and biochar. Specifically, it examines how soil δ¹3C and the sources of soil organic carbon (SOC), respond in paddy fields (which cultivate C3 plants like rice) when amended with maize residues, maize biochar, and silica‐enriched biochar (derived from C4 plants). Conducted in the Fuzhou paddy fields, the experiment included control groups and treatment groups with maize residue (4 t ha⁻¹), maize biochar (4 t ha⁻¹), and silicon‐modified maize biochar (4 t ha⁻¹) during both the early and late rice growth periods. The results indicate that all soil treatments increased soil δ¹3C. The application of maize residues notably affected the δ¹3C of the upper soil profile (0–15 cm) differently from the deeper layers (15–30 cm), and it increased soil organic C more than biochar or silicon‐modified maize biochar. Soil available P (AP) and pH emerged as significant factors linking δ¹3C, influencing rice yield through changes in soil physicochemical properties. Unlike maize residues, which reduced rice yields, applications of biochar and silicon‐modified maize biochar increased rice yields. The latter, which was particularly effective in lowering SOC decomposition rates and addressing rice's silica needs, emerged as the preferred option. The study highlights maize biochar and silicon‐modified maize biochar as sustainable alternatives to maize residues for rice cultivation, enhancing soil fertility, carbon pool stability, and yields. [ABSTRACT FROM AUTHOR]

Background: Numerous studies have evaluated the association between the angiotensinogen (AGT) T174M polymorphism and ischemic stroke(IS) risk. However, the specific association is still controversial., Materials and Methods: In order to explore this association more deeply, we performed a meta-analysis. All of the relevant studies were identified from PubMed, Embase, and Chinese National Knowledge Infrastructure database up to October 2014. Statistical analyses were conducted with STATA 12.0 software. Odds ratio (OR) with 95% confidence interval (CI) values were applied to evaluate the strength of the association., Results: Six studies with 1290 cases and 1125 controls were included. No significant variation in IS risk was detected in any of the genetic models in the overall (MM vs. TT: OR = 1.64, 95% CI = 0.51-5.28; MT vs. TT: OR = 0.93, 95% CI = 0.66-1.31; dominant model: OR = 1.08, 95% CI = 0.69-1.72; recessive model: OR = 0.61,95% CI = 0.20-1.91). Taking into account the effect of ethnicity, further stratified analyses were performed. The results showed that AGT gene T174M polymorphism might be associated with IS risk in Asians (MM vs. TT: OR = 3.28, 95% CI = 1.79-6.02; recessive model: OR = 0.31, 95% CI = 0.17-0.57)., Conclusion: In conclusion, the AGT T174M polymorphism may be a susceptible predictor of the risk of IS in Asians. Further, large and well-designed studies are needed to confirm this conclusion.