Release of phosphorus through pretreatment of waste activated sludge differs essentially from that of carbon and nitrogen resources: Comparative analysis across four wastewater treatment facilities.

The accumulation of phosphorus in activated sludge in wastewater treatment plants (WWTPs) provides potential for phosphorus recovery from sewage. This study delves into the potential for releasing phosphorus from waste activated sludge through two distinct treatment methods-thermal hydrolysis and pH adjustment. The investigation was conducted with activated sludge sourced from four WWTPs, each employing distinct phosphorus removal strategies. The findings underscore the notably superior efficacy of pH adjustment in solubilizing sludge phosphorus compared to the prevailing practice of thermal hydrolysis, widely adopted to enhance sludge digestion. The reversibility of phosphorus release within pH fluctuations spanning 2 to 12 implies that the release of sludge phosphorus can be attributed to the dissolution of phosphate precipitates. Alkaline sludge treatment induced the concurrent liberation of COD, nitrogen, and phosphorus through alkaline hydrolysis of sludge biomass and the dissolution of iron or aluminium phosphates, offering potential gains in resource recovery and energy efficiency.

Multifunctional ADM hydrogel containing endothelial cell-exosomes for diabetic wound healing.

Non-healing wound, with limited treatment options, remains a prevalent complication of diabetes mellitus. The underlying causes wherein include oxidative stress injury, bacterial infection, cellular dysfunction, and persistent inflammation. Acellular Dermal Matrix (ADM), a wound dressing composed of natural extracellular matrix and abundant bioactive factors, has been successfully developed to treat various wounds, including burns and diabetic ulcers. Protocatechualdehyde (PA) & trivalent iron ion (Fe3+) complex (Fe3+@PA) exhibits potential antioxidant and antibacterial properties. In this study, we developed a dual hydrogel network by combining Fe3+@PA complex-modified ADM with light-cured gelatin (GelMA), supplemented with exosomes derived from human umbilical vein endothelial cells (HUVEC-Exos), to create an ADM composite hydrogel system (ADM-Fe3+@PA-Exos/GelMA) with antioxidant, antibacterial, and cell-promoting functions for diabetic wound treatment. Through in vitro experiments, we investigated the biosafety, antioxidant and antibacterial properties of ADM composite hydrogel. Furthermore, we examined the protective effects of ADM composite hydrogel on diabetic wound. The above experiments collectively demonstrate that our ADM-Fe3+@PA-Exos/GelMA hydrogel promotes diabetic wound healing by eliminating bacterial infection, reduced the reactive oxygen species (ROS) levels, protecting cells against oxidative stress damage, promotingcollagen deposition and angiogenesis, which provides a promising strategy to optimize ADM for diabetic wound treatment.

Phosphate Recovery from Aqueous Solutions via Vivianite Crystallization: Interference of FeII Oxidation at Different DO Concentrations and pHs.

Vivianite (Fe3(PO4)2·8H2O) crystallization has attracted increasing attention as a promising approach for removing and recovering P from wastewaters. However, FeII is susceptible to oxygen with its oxidation inevitably influencing the crystallization of vivianite. In this study, the profile of vivianite crystallization in the presence of dissolved oxygen (DO) was investigated at pHs 5-7 in a continuous stirred-tank reactor. It is found that the influence of DO on vivianite crystallization was highly pH-related. At pH 5, the low rate of FeII oxidation at all of the investigated DO of 0-5 mg/L and the low degree of vivianite supersaturation resulted in slow crystallization with the product being highly crystalline vivianite, but the P removal efficiency was only 30-40%. The removal of P from the solution was substantially more effective (to >90%) in the DO-removed reactors at pH 6 and 7, whereas the efficiencies of P removal and especially recovery decreased by 10-20% when FeII oxidation became more severe at DO concentrations >2.5 mg/L (except at pH 6 with 2.5 mg/L DO). The elevated degree of vivianite supersaturation and enhanced rate and extent of FeII oxidation at the higher pHs led to decreases in the size and homogeneity of the products. At the same pH, amorphous ferric oxyhydroxide (AFO)─the product of FeII oxidation and FeIII hydrolysis─interferes with vivianite crystallization with the induction of aggregation of crystal fines by AFO, leading to increases in the size of the obtained solids.

Characteristics and Distribution of Organic Phosphorus Fractions in the Surface Sediments of the Inflow Rivers around Hongze Lake, China.

In this study, the characteristics and distribution of the organic phosphorus (Po) fractions in the surface sediments of seven inflow rivers around Hongze Lake in China were analyzed with a soil Po fraction method, as used by Ivanoff. The relationships between the Po fractions and physiochemical features of sediments were also discussed. The results showed that, the sediments of the rivers had been moderately pollution with certain ecological risk effects except the Waste Yellow River. The relative contribution order of the Po fractions in the sediments was residual Po > HCl-Po > fulvic acid-Po > humic acid-Po > labile organic phosphorus (LOP). Moderately labile organic phosphorus (MLOP) was the main part of the Po forms in the whole sediments. The risk of phosphorus released from river sediments was the highest in the western region, followed by the southwestern region, and finally the northwestern region. There were significant correlations between Po forms and total phosphorus (TP), inorganic phosphorus (Pi), and Po. Non labile organic phosphorus (NLOP) had the strongest correlation with TP. The distribution of Po forms in each region was different due to the impact of human activities, industrial and agricultural production and the land types; the heaver polluted sediments with higher Po fractions. It is suggested that most of the sediments of the inflow rivers in the regions have certain ecological risk effects and P of them have an important contributions on the eutrophication of Hongze Lake. Po forms can provide a reliable theoretical basis for dealing with the change of water quality and should be paid more attention in the lake eutrophication investigation. There was reciprocal transformation between different Po forms, especially non-bioavailable fraction can change into bio-available ones. The results can provide a basis for the earth cycle of phosphorus and a new perspective of eutrophication control of shallow lakes.

Neuroprotection of up-regulated carbon monoxide by electrical acupuncture on perinatal hypoxic-ischemic brain damage in rats.

This study investigated the neuroprotection and potential mechanism of carbon monoxide (CO) against perinatal hypoxic-ischemic brain damage in rats by electrical acupuncture (EA). Animal behavior, morphological changes, cystathionine beta-synthase (CBS), hypoxia-inducible factor-1α (HIF-1α), and heme oxygenase-1 (HO-1) expression levels, and CO content in rat cortex cells were determined. Results demonstrated that EA treatment decreased the slope behavior and increased the overhang behavior of perinatal rats. The treatment also decreased the number of positive cells. The activator and inhibitor of CBS aggravated and remitted the hypoxic damage in cortex cells, respectively. EA treatment decreased CBS expression level and increased HO-1 and HIF-1α expression levels in perinatal rat cortex cells. Compared with the control groups, the CO content of cortex cells in the EA treatment group significantly increased (**p < 0.01). We hypothesized that EA treatment increases cortical CO content to protect against hypoxic damage via the hydrogen sulfide/CBS-CO/HO-1-HIF-1α system. This study provided a significant reference for EA therapy and cued a novel protective mechanism for cerebral palsy.

Sinomenine reduces iNOS expression via inhibiting the T-bet IFN-γ pathway in experimental autoimmune encephalomyelitis in rats.

Sinomenine is a bioactive alkaloid isolated from the Chinese medicinal plant Sinomenium acutum. It is widely used as an immunosuppressive drug for treating rheumatic and arthritic diseases. In our previous studies, we found that sinomenine reduced cellular infiltration within the spinal cord and alleviated experimental autoimmune encephalomyelitis (EAE) in rats. In this study, we further investigated the mechanisms of sinomenine treatment in EAE rats. In EAE rats, treatment with sinomenine exerted an anti-inducible NO synthase (anti-iNOS) effect, which is related to the reductions of Th1 cytokine interferon-γ (IFN-γ) and its transcription factor, T-bet, in spinal cords. Moreover, sinomenine treatment of splenocytes stimulated with anti-CD3 antibody and recombinant rat interleukin 12 reduced the expression of T-bet and IFN-γ in vitro and also reduced the capability of supernatants of splenocyte culture to induce iNOS expression by primary astrocytes. However, sinomenine had no direct inhibitory effect on iNOS produced by astrocytes cultured with IFN-γ and tumor necrosis factor α in vitro. In conclusion, the anti-iNOS effect of sinomenine on EAE is mediated via the suppression of T-bet /IFN-γ pathway.

Important role of catalase in the production of ß-carotene by recombinant Saccharomyces cerevisiae under H2O2 stress.

The effect of H(2)O(2) supplement on cell growth and ß-carotene productions in recombinant Saccharomyces cerevisiae CFW-01 and CFW-01 ctt1 deficiency in cytosolic catalase were investigated in shaking flasks. The results showed that supplement of H(2)O(2) (0.5 and 1.0 mM) can significantly stimulate the ß-carotene production. However, ß-carotene levels of CFW-01 ctt1Δ under 0.5 and 1 mM H(2)O(2) were 16.7 and 36.7% lower than those of CFW-01, respectively. Although lacking cytosolic catalase, no significant differences in cell growth were observed between CFW-01 ctt1Δ and CFW-01 under the same level of H(2)O(2) stress. These results suggest that ß-carotene can act as an antioxidant to protect the recombinant yeast from H(2)O(2) oxidative damage in the absence of cytosolic catalase. However, catalase still plays an important role in the production of ß-carotene under H(2)O(2) stress. If catalase can not timely decompose H(2)O(2), the free radicals such as OH· derived from H(2)O(2) can result in decrease of ß-carotene concentration. Therefore, in the production of ß-carotene by H(2)O(2) stress, not only the level of oxidative stress, but also the activities of catalase in cells should be considered.

[Comparative analysis of agronomic and qualitative characters in different lines of Dendrobium denneanum].

To provide theoretical basis for breeding good variety of Dendrobium denneanum, agronomic and qualitative characters of 4 different lines and relationships among them were studied. The stem length, stem diameter, leaf length, leaf width, length/ width ratio and leaf area were measured. The single fresh and dry stem was weighed and drying rate was calculated. The contents of polysaccharides and total alkaloids were determined by sulfuric acid-phenol colorimetry and acid-dye colorimetry, respectively. The correlations between characters were analyzed. The results showed that differences in major agronomic characters between four lines were significant. The plant types of dq-1 and dq-2 were higher, dq-3 was medium and dq-4 was lower. The fresh weigh of stem and content of polysaccharides were the highest in dq-2, 7.81 g and 14.33%. While the highest content of total alkaloids and was 0. 486% in dq-3. There were significant correlations between agronomic characters, but these characters had low or non correlations with qualitative characters such as polysaccharides and total alkaloids. It was shown that the content of polysaccharides and total alkaloids were significantly different among 4 lines of D. denneanum, which could be selected for different uses.

Hesperetin inhibits the maturation and function of monocyte-derived dendritic cells from patients with asthma.

Dendritic cells (DCs) are crucial regulators of allergic diseases. Hesperetin, an important bioactive compound in Chinese traditional medicine, has antioxidant and anti-allergic properties. In this study, we examined whether hesperetin influences surface molecule expression, cytokine production, the capacity to induce T cell proliferation, and the underlying signaling pathway in monocyte-derived DCs from patients with allergic asthma. The results show that hesperetin significantly suppressed Der p 1-induced HLA-DR, CD86 and CD83 expression in DCs. However, the secretion of IL-10 was not affected. Hesperetin-treated DCs exhibited a reduced ability to stimulate autologous CD4+ T cells, accompanied by less Th2 polarization. In addition, the Der p 1-induced phosphorylation of IκBα and the translocation of NF-κB p65 were inhibited in the presence of hesperetin. These novel findings provide insight into the immunopharmacological role of hesperetin in DC-based allergic diseases.