Search Results (2,580)

Land degradation is known to alter soil properties and quality; however, its depth-dependent effects across contrasting land-use types and the key factors limiting soil recovery remain poorly quantified in tropical ecosystems. This study established a forest degradation gradient on Hainan Island, China, encompassing mature forest, secondary forest, rubber plantation, and areca plantation. Soil physical (e.g., bulk density, porosity, water content, field capacity) and chemical (e.g., organic matter, nitrogen, phosphorus, and potassium fractions) properties were measured at three depths (0–20 cm, 20–40 cm, and 40–60 cm). A soil quality index (SQI) was constructed using principal component analysis, and obstacle degree modeling was applied to identify major limiting factors. The results showed that degradation of mature forests significantly reduced topsoil (0–20 cm) quality regardless of subsequent land-use type. In contrast, changes in medium (20–40 cm) and deep (40–60 cm) soil quality were land-use dependent. Conversion to secondary forests and areca plantations resulted in negligible effects, whereas transformation into rubber plantations significantly enhanced soil quality at medium and deep depths. Obstacle degree analysis identified available phosphorus, rather than nitrogen, as the primary limiting factor for soil quality in the region, accounting for 39.7% of all limitations across land-use types. This study demonstrates that the effects of tropical forest degradation on soil quality exhibit dual dependence on both soil depth and land-use type in tropical settings. Furthermore, it highlights the essential role of available phosphorus management in guiding soil restoration and sustainable land-use strategies in these vulnerable ecosystems. Full article

Background: Hemodialysis (HD) patients are a highly vulnerable population with elevated mortality driven by comorbidities and dialysis-specific factors. While most studies focused on intra-pandemic outcomes, long-term effects remain underexplored. We aimed to evaluate 5-year mortality and the impact of COVID-19 vaccination in chronic HD patients. Methods: A retrospective study was conducted on 211 HD patients monitored between 2020 and 2024. Outcomes included overall and cardiovascular mortality, risk factors in COVID-19-positive patients, and vaccination impact. Logistic regression identified independent predictors. Results: The cohort had a mean age of 65.6 ± 13.3 years, with 55.9% males and mean dialysis vintage of 6.9 ± 5.5 years. Overall mortality reached 53.6%, while 38.4% were vaccinated. Predictors of all-cause mortality included age (OR = 1.078, p < 0.001), BMI (OR = 0.868, p < 0.001), hemoglobin (OR = 0.581, p < 0.001), phosphorus (OR = 1.351, p = 0.025), dialysis adequacy (OR = 0.138, p = 0.013), and ischemic cardiopathy (OR = 0.327, p = 0.009). In COVID-19-positive patients, mortality was associated with age (OR = 1.069, p = 0.002), low hemoglobin (OR = 0.642, p = 0.014), BMI (OR = 0.885, p = 0.009), CRP (OR = 1.015, p < 0.001), and coronary artery disease (OR = 5.68, p < 0.001). Cardiovascular disease was the leading cause of death (44.6% in COVID-19-positive vs. 73.3% in negatives, p = 0.006). Vaccination significantly reduced COVID-19-related mortality (OR = 0.023, p = 0.005) but did not influence overall or non-COVID mortality. Conclusions: Five-year mortality in HD patients remained high, mainly cardiovascular, and was strongly influenced by age, BMI, hemoglobin, dialysis adequacy, and comorbidities. COVID-19 vaccination substantially reduced COVID-related mortality but did not alter all-cause outcomes. These findings support vaccination and careful risk stratification in HD populations for future pandemics. Full article

This study evaluated the effects of dietary potassium diformate supplementation on growth performance, nutrient digestibility, gastrointestinal pH, jejunal morphology, digestive enzyme activity, and antioxidant status of weaned piglets in a 28-day trial. Twenty-four weaned piglets were selected and, after a 4-day adaptation period, randomly assigned to 4 treatment groups (n = 6). The dietary treatments included a control diet (basal diet) and 3 diets supplemented with 0.6%, 1.2%, or 1.8% potassium diformate in the basal diet. The results indicated that the feed conversion ratio (FCR) of piglets was reduced by all three potassium diformate supplementation levels compared to the control group (p < 0.05). Additionally, the FCR was decreased in piglets fed the 1.8% potassium diformate-supplemented diet compared to those fed the 1.2% potassium diformate-supplemented diet (p < 0.05). Piglets fed the three potassium diformate-supplemented diets exhibited higher apparent total tract digestibility (ATTD) of dry matter and crude protein than the control group (p < 0.05). The 1.8% potassium diformate groups also showed increased ATTD of calcium and phosphorus compared to the control group (p < 0.05). Supplementation with 1.2% or 1.8% potassium diformate reduced the digesta pH in the proximal stomach, distal stomach, and duodenum, while increased jejunal villus height (VH), VH/crypt depth (VH/CD) ratio, and catalase and total superoxide dismutase activities in the jejunal mucosa compared to the control group (p < 0.05). The 1.2% potassium diformate group showed higher α-amylase activity than the control group (p < 0.05). Correlation analysis revealed that FCR negatively correlated with ATTD of dry matter, crude protein, calcium, phosphorus, and jejunal VH, while positively correlating with digesta pH in the proximal stomach (p < 0.05). The ATTD of dry matter negatively correlated with digesta pH in the proximal stomach, distal stomach, and duodenum, and positively correlated with jejunal VH/CD ratio and catalase activity (p < 0.05). The ATTD of crude protein negatively correlated with digesta pH in the proximal stomach, distal stomach, and duodenum (p < 0.05). Collectively, dietary supplementation with 1.8% potassium diformate reduced FCR of weaned piglets, which was associated with enhanced nutrient digestibility, reduced pH in the anterior gastrointestinal tract, and improved jejunal morphology. Full article

The aim of this study was to evaluate and compare dried apple (A), chokeberry (C), grape (G), raspberry (R), and red currant (RC) pomace as potential additives to food, beverages, and cosmetics. Their physicochemical properties and nutritional composition were examined. The fruit pomace was characterised by significant differences in acidity ranging 1.41 (G) to 7.96 g·100 g⁻¹_d.w. (R), water holding capacity (2.36–4.25 g·g⁻¹, C-A), and oil holding capacity (1.86–2.41 g·g⁻¹, C-G). The colour parameters of the pomace differed significantly. The highest lightness L* was recorded for the apple pomace (66.29). Samples RC and R were characterised by the highest redness (32.99; 26.76), while A, G, and R showed high b* values, amounting to 28.54, 22.84, and 20.40 (yellowness), respectively. The highest protein (13.01%), fat (6.82%), and fibre (67.38%) contents were recorded in the redcurrant pomace. The mineral analysis revealed high potassium, phosphorus, and calcium contents in all pomace samples, with the grape and redcurrant pomace containing the highest mineral content. These results highlight the potential of fruit pomace as a sustainable, nutritionally enriching ingredient, primarily for food products, and the potential to reduce food waste. Full article

The remediation of contaminated soils is essential for restoring land productivity and soil health. Pteris vittata L., an arsenic hyperaccumulator, has been widely used for phytoremediation, yet its ecological effects on soil systems remain insufficiently understood. In this field study, we evaluated the influence of Pteris vittata L. remediation on soil physico-chemical properties, microbial diversity, and molecular ecological networks. The results showed that long-term arsenic contamination significantly reduced soil total carbon, total nitrogen, and available phosphorus, simplified bacterial network structures, and markedly altered the keystone taxa that maintain microbial interactions. In contrast, soils under Pteris vittata L. remediation exhibited higher nutrient availability, greater bacterial diversity, and more complex microbial networks than contaminated soils, indicating partial recovery of ecosystem functions. These findings demonstrate that Pteris vittata L. remediation can mitigate arsenic-induced soil degradation and provide an important scientific basis for assessing the long-term impacts of arsenic contamination and the role of remediation measures in soil health evolution. Full article

Stricter requirements on nutrient removal in wastewater treatment are being imposed by rapid urbanization and tightening water-quality standards. Despite their excellent solid–liquid separation and effective biological treatment, MBRs in conventional operation remain hindered by membrane fouling, limited robustness to influent variability, and elevated energy consumption. In recent years, precise process control and resource-oriented operation have been enabled by the integration of artificial intelligence (AI) with MBRs. Advances in four areas are synthesized in this review: optimization of MBR control architectures, intelligent adaptation to multi-source wastewater, regulation of membrane operating parameters, and enhancement of nitrogen and phosphorus removal. According to reported studies, increases in total nitrogen and total phosphorus removal have been achieved by AI-driven strategies while energy use and operating costs have been reduced; under heterogeneous influent and dynamic operating conditions, stronger generalization and more effective real-time regulation have been demonstrated relative to traditional approaches. For large-scale deployment, key challenges are identified as improvements in model interpretability and applicability, the overcoming of data silos, and the realization of multi-objective collaborative optimization. Addressing these challenges is regarded as central to the realization of robust, scalable, and low-carbon intelligent wastewater treatment. Full article

As one of the key vectors for the transmission of Dengue fever, Aedes albopictus is highly ecologically adaptable. The development of environmentally compatible biological defence and control technologies has therefore become an urgent need for vector biological control worldwide. This study constructed and used double-stranded RNA (dsRNA) expression vectors targeting the cyp314a1 and cyp315a1 genes of Ae. albopictus to transform Chlamydomonas reinhardtii and Chlorella vulgaris, achieving RNA interference (RNAi)-mediated gene silencing. The efficacy of the RNAi recombinant algal strain biocide against Ae. albopictus was evaluated by administering it to Ae. albopictus larvae. The results showed that the oral administration of the cyp314a1 and cyp315a1 RNAi recombinant C. reinhardtii/C. vulgaris strains was lethal to Ae. albopictus larvae and severely affected their pupation and emergence. The recombinant algal strains triggered a burst of ROS (Reactive Oxygen Species) in the mosquitoes’ bodies, resulting in significant increases in the activities of the superoxide dismutase (SOD), peroxiredoxin (POD) and catalase (CAT), as well as significant upregulation of the mRNA levels of the CME pathway genes in larvae. In the simulated field experiment, the number of Ae. albopictus was reduced from 1000 to 0 in 16 weeks by the RNAi recombinant Chlorella, which effectively controlled the population of mosquitoes. Meanwhile, the levels of nitrogen (N), phosphorus (P), nitrate, nitrite, ammonia and COD (Chemical Oxygen Demand) in the test water decreased significantly. High-throughput sequencing analyses of 18S rDNA and 16S rDNA showed that, with the release of RNAi recombinant Chlorella into the test water, the biotic community restructuring dominated by resource competition caused by algal bloom, as well as the proliferation of anaerobic bacteria and the decline of aerobic bacteria triggered by anaerobic conditions, are the main trends in the changes in the test water. This study is an important addition to the use of RNAi recombinant microalgae as a biocide. Full article

Cadmium (Cd), a pervasive and highly phytotoxic metal pollutant, poses severe threats to agricultural productivity, ecosystem stability, and human health through its entry into the food chain. Plants have evolved intricate defense mechanisms, among which the strategic manipulation of nutrient elements emerges as a critical physiological and biochemical strategy for mitigating Cd stress. This comprehensive review delves deeply into the multifaceted roles of essential macronutrient elements (nitrogen, phosphorus, potassium, calcium, magnesium, sulfur), essential micronutrient elements (zinc, iron, manganese, copper) and non-essential beneficial elements (silicon, selenium) in modulating plant responses to Cd toxicity. We meticulously dissect the physiological, biochemical, and molecular underpinnings of how these nutrients influence Cd bioavailability in the rhizosphere, Cd uptake and translocation pathways, sequestration and compartmentalization within plant tissues, and the activation of antioxidant defense systems. Nutrient elements exert their influence through diverse mechanisms: competing with Cd for root uptake transporters, promoting the synthesis of complexes that reduce Cd mobility, stabilizing cell walls and plasma membranes to restrict apoplastic flow and symplastic influx, modulating redox homeostasis by enhancing antioxidant enzyme activities and non-enzymatic antioxidant pools, regulating signal transduction pathways, and influencing gene expression profiles related to metal transport, chelation, and detoxification. The complex interactions between nutrients themselves further shape the plant’s capacity to withstand Cd stress. Recent advances elucidating nutrient-mediated epigenetic regulation, microRNA involvement, and the role of nutrient-sensing signaling hubs in Cd responses are critically evaluated. Furthermore, we synthesize the practical implications of nutrient management strategies, including optimized fertilization regimes, selection of nutrient-efficient genotypes, and utilization of nutrient-enriched amendments, for enhancing phytoremediation efficiency and developing low-Cd-accumulating crops, thereby contributing to safer food production and environmental restoration in Cd-contaminated soils. The intricate interplay between plant nutritional status and Cd stress resilience underscores the necessity for a holistic, nutrient-centric approach in managing Cd toxicity in agroecosystems. Full article

The main aim of this study was to analyze the excessive biomass of invasive alien aquatic plants reducing the water quality of a lake which was restored in the past. This study was conducted on Długie Lake (26.8 ha, 17.3 m, Masurian Lake District, northeastern Poland), which was completely degraded by raw wastewater inflow. After the long-term restoration (1987–2003) and recovery of submerged macrophyte meadows, the invasion of Elodea nuttallii—an invasive alien aquatic plant (IAAP)—was observed due to the increasing water temperature in recent years, impairing the functioning, biodiversity, and ecosystem services of this urban lake, as well as causing the deterioration of lake water quality. Therefore, an excessive biomass of E. nuttallii has been removed from the lake since 2022. The analysis of physico-chemical water quality parameters showed that consecutive excessive biomass macrophyte gradual removal (three times during the growing season) helps to limit the excessive growth of E. nuttallii and also removes nutrient loads from the ecosystem. Removing excess aquatic vegetation also helps maintain the lake’s aesthetic and recreational value. Currently, the total phosphorus concentration in lake water did not exceed 0.3 mg P/L and total nitrogen did not exceed 2.0 mg N/L. Chlorophyll a contents oscillated in the range of 5 to 9 µg/L, and Secchi disk visibility exceeded 3 m. Full article

Developing sustainable and high-performance sorbents for efficient CO₂ capture is essential for mitigating climate change and reducing industrial emissions. In this study, phosphorus-doped porous carbons (LPSP-T) were synthesized via a one-step activation–doping strategy using lotus petiole biomass as a precursor and sodium phytate as a dual-function activating and phosphorus-doping agent. The simultaneous activation and phosphorus incorporation at various temperatures (650–850 °C) under a nitrogen atmosphere produced carbons with tailored textural properties and surface functionalities. Among them, LPSP-700 exhibited the highest specific surface area (525 m²/g) and a hierarchical porous structure, with abundant narrow micropores (<1 nm) and phosphorus-containing surface groups that synergistically enhanced CO₂ capture performance. The introduction of P functionalities not only improved the surface polarity and binding affinity toward CO₂ but also promoted the formation of a well-connected pore network. As a result, LPSP-700 delivered a CO₂ uptake of 2.51 mmol/g at 25 °C and 1 bar (3.34 mmol/g at 0 °C), along with a high CO₂/N₂ selectivity, fast CO₂ adsorption kinetics and moderate isosteric heat of adsorption (Q_st). Furthermore, the dynamic CO₂ adsorption capacity (0.81 mmol/g) was validated by breakthrough experiments, and cyclic adsorption–desorption tests revealed excellent stability with negligible loss in performance over five cycles. Correlation analysis revealed pores < 2.02 nm as the dominant contributors to CO₂ uptake. Overall, this work highlights sodium phytate as an effective dual-role agent for simultaneous activation and phosphorus doping and validates LPSP-700 as a sustainable and high-performance sorbent for CO₂ capture under post-combustion conditions. Full article

Nitrogen (N) and phosphorus (P) play vital roles in crop growth. However, conventional fertilizers exhibit low utilization efficiency, making them prone to causing resource wastage and water eutrophication. Although metal–organic frameworks (MOFs) have shown great potential for application in controlled-release fertilizers (CRFs), currently reported MOF-based CRFs suffer from low nutrient content, which limits their further application. To address this issue, this study synthesized a series of hierarchically porous MOFs, denoted as MIL-156(X), using sodium acetate as a modulator under hydrothermal conditions. These materials were subsequently loaded with urea and phosphate from aqueous solution to form MOFs-based CRFs (N-P-MIL-156(X)). Results indicate that MIL-156(X) retain microporous integrity while incorporating abundant mesopores. Increasing modulator content reduced particle size and average pore diameter but increased specific surface area and adsorption capacity for urea and phosphate. MIL-156-H (with a high modulator content addition) exhibited the highest adsorption capacity, conforming to Langmuir isotherm and pseudo-second-order kinetics. The adsorption mechanisms of urea and phosphate involved hydrogen bonding and the formation of Ca intra-spherical complexes, respectively. N-P-MIL-156-H contained 10.8% N and 16.3% P₂O₅, with sustained release durations exceeding 42 days (N) and 56 days (P₂O₅) in an aqueous solution. Pot trials demonstrated significantly higher nutrient use efficiency (N-44.8%, P₂O₅-16.56%) and a 12.22% yield increase compared to conventional fertilization (N-35.6%, P₂O₅-13.32%). Thus, N-P-MIL-156-H-based fertilization significantly promotes rice growth and N/P utilization efficiency, offering a promising strategy for developing controlled-release fertilizers and improving nutrient management. Full article

The effects of soil acidification on the phoD-harboring microbial community and the fractions of soil phosphorus in tea plantation soils are still unclear. In this study, tea plantations with different soil pH were used as the research object to analyze changes in soil phosphorus fractions, phoD gene abundance, phoD-harboring microbial community composition, and their relationship with tea yield and quality. The results showed that the content of tea polyphenols, caffeine, free amino acids, theanine, and tea yield decreased significantly after acidification. Moreover, the content of total phosphorus in the acidified soil also decreased significantly. Further analysis of soil phosphorus fractions showed that the acidification of the tea plantation soil resulted in a significant decrease in the content of different types of labile and moderately labile phosphorus, whereas the content of non-labile phosphorus exhibited the opposite trend. As the content of soil NaHCO₃-Po, NaOH-Po, Resin-Pi, NaHCO₃-Pi, NaOH-Pi, and HCl-Pi decreased significantly after acidification, its organic and inorganic phosphorus content also decreased significantly. Its phosphorus activation capacity decreased by 4.75% after soil acidification. Soil acidification significantly reduced the diversity of phoD-harboring microbial communities by 61.89%. Analysis of the phoD-harboring microbial community composition suggested that the microbial abundance of Acidobacteria and Proteobacteria showed a decreasing trend in acidified soils, while for Nitrospirae, Verrucomicrobia, Actinobacteria, and Planctomycetes, it showed an increasing trend. Correlation analysis showed that microorganisms with significantly decreasing abundance in tea plantation soils were significantly and positively correlated with soil pH, labile phosphorus, moderately labile phosphorus, phosphorus activation coefficients, and tea yield and quality after soil acidification. It is evident that soil acidification inhibited soil phosphorus availability by shifting phoD-harboring microbial community composition in tea plantation soils, thus affecting the yield and quality of above-ground tea leaves. Full article

To explore the coupling between agricultural farming models and surface water environmental in central China’s irrigation districts, this study focuses on the Four Lakes Basin within Jianghan Plain, a key grain-producing and ecological protection area. Integrating remote sensing images, statistical yearbooks, and on-site monitoring data, the study analyzed the phased characteristics of the basin’s agricultural pattern transformation, the changes in non-point source nitrogen and phosphorus loads, and the responses of water quality in main canals and Honghu Lake to agricultural adjustments during the period 2010~2023. The results showed that the basin underwent a significant transformation in agricultural patterns from 2016 to 2023: the area of rice-crayfish increased by 14%, while the areas of dryland crops and freshwater aquaculture decreased by 11% and 4%, respectively. Correspondingly, the non-point source nitrogen and phosphorus loads in the Four Lakes Basin decreased by 11~13%, and the nitrogen and phosphorus concentrations in main canals decreased slightly by approximately 2 mg/L and 0.04 mg/L, respectively; however, the water quality of Honghu Lake continued to deteriorate, with nitrogen and phosphorus concentrations increasing by approximately 0.46 mg/L and 0.06 mg/L, respectively. This indicated that the adjustment of agricultural farming models was beneficial to improving the water quality of main canals, but it did not bring about a substantial improvement in the sustainable development of Honghu Lake. This may be related to various factors that undermine the sustainability of the lake’s aquatic ecological environment, such as climate change, natural disasters, internal nutrient release from sediments, and the decline in water environment carrying capacity. Therefore, to advance sustainability in this basin and similar irrigation districts, future efforts should continue optimizing agricultural models to reduce nitrogen/phosphorus inputs, while further mitigating internal nutrient release and climate disaster risks, restoring aquatic vegetation, and enhancing water environment carrying capacity. Full article

Background: Chronic kidney disease (CKD) in companion animals leads to progressive renal deterioration and metabolic complications such as hyperphosphatemia and metabolic acidosis, particularly in advanced stages. Methods: This 90-day, double-blind, randomized controlled study evaluated the effects of a renal supplement (Renal Combi, Candioli srl, Beinasco, Turin, Italy) in 30 dogs diagnosed with CKD. Dogs were randomly assigned to a treatment group (TRT, n = 15), receiving a commercial renal diet plus the supplement (once daily), or a control group (CTR, n = 15), receiving the same diet and a placebo. Results: Results showed that supplementation effectively reduced proteinuria, blood urea, and phosphorus levels, stabilized creatinine and SDMA, and maintained blood pressure. It also improved markers of systemic inflammation and oxidative stress. Conclusions: The once-daily dosage simplified administration and was especially beneficial for hyporexic dogs or those on multiple medications. This study supports the use of the tested supplement as an effective adjunctive therapy for managing CKD in dogs, offering metabolic, renal, and nutritional benefits while enhancing compliance through convenient dosing. Full article

Harnessing solar energy is crucial for applications such as water desalination through solar collectors, where efficient conversion of solar radiation into thermal energy is required. In this study, electroless nickel–phosphorus (Ni-P) coatings and their carbon black (CB) nanoparticle composites were successfully deposited and evaluated as selective solar absorbers. The coatings exhibited compact, crack-free, and amorphous structures composed mainly of Ni(OH)₂ and NiOOH, as confirmed by SEM-EDS, XRD, FTIR, and Raman analyses. Increasing the pH enhanced the deposition rate and coating thickness while reducing the phosphorus content. Incorporation of CB nanoparticles was confirmed, though it slightly decreased coating thickness. Optical characterization revealed high absorptance and low emissivity across all samples, with the Ni-P coating produced at higher pH (C1) achieving the best performance (brightness L* = 29.0; figure of merit α − ε = 0.84). Aging tests further demonstrated the resilience of this sample, maintaining a figure of merit of 0.81. These findings establish Ni-P coatings, particularly at higher pH, as promising and safer alternatives to conventional chromium-based solar selective coatings. Full article