Transcriptomic profiling and discovery of key transcription factors involved in adventitious roots formation from root cuttings of mulberry.

ARs plays a crucial role in plant morphogenesis and development. The limited and inefficient rooting of scions poses a significant challenge to the efficiency and quality of clonal propagation of forest trees in silvicultural practices. Building on previous research conducted by our team, we found that applying IBA at a concentration of 1000 mg/L significantly enhanced mulberry rooting. This study aims to uncover the molecular mechanisms underlying this effect by analyzing RNA sequencing data from mulberry phloem before and after treatment with IBA over time intervals of 10, 20, 30, and 40 days. We identified 5226 DEGs, which were then classified into GO terms and KEGG pathways, showing significant enrichment in hormone signaling processes. Using WGCNA, we identified eight co-expression modules, two of which were significantly correlated with the IBA treatment. Additionally, 18 transcription factors that potentially facilitate ARs formation in mulberry were identified, and an exploratory analysis on the cis-regulatory elements associated with these transcription factors was conducted. The findings of this study provide a comprehensive understanding of the mechanisms of ARs in mulberry and offer theoretical support for the discovery and utilization of exceptional genetic resources within the species.

The Liquid-Fermentation Formulation of Sanghuangporus sanghuang Optimized by Response Surface Methodology and Evaluation of Biological Activity of Extracellular Polysaccharides.

Sanghuangporus sanghuang is a rare fungus growing on mulberry trees that has immense medicinal value. This study aimed to optimize the liquid-fermentation-media formulation and culture conditions for large-scale culturing of S. sanghuang by performing one-way testing and response surface methodology. The antioxidant and anticancer activities of the extracellular polysaccharides from S. sanghuang were also analyzed. The optimal formulation and growth conditions for S. sanghuang were as follows: glucose, 30.2 ± 0.37 g/L; yeast extract, 14.60 ± 0.05 g/L; dandelion powder, 1.24 ± 0.01 g/L; shaker speed, 150 r/min; and temperature, 25 °C. We obtained 13.99 ± 0.42 g/L of mycelium biomass by culturing S. sanghuang for 15 days with the optimized formulation. This was 2-fold higher than the mycelial mass obtained with the sub-optimal formulation. The extracellular fungal polysaccharides showed significant antioxidant activity against ABTS and DPPH free radicals, and significantly reduced the in vitro growth and survival of several cancer cell lines. The anticancer activity of the extracellular fungal polysaccharides was significantly higher in the human glioma cells than in other cancer cell lines. In summary, this study optimized the liquid media formulation and conditions for the large-scale culturing of S. sanghuang. Furthermore, the extracellular polysaccharides from S. sanghuang showed significant antioxidant and anticancer activities.

Biomineralization of phosphorus during anaerobic treatment of distillery wastewaters.

This study addresses the pressing environmental concerns associated with the rapidly growing distillery industry, which is a significant contributor to wastewater generation. By focusing on the treatment of distillery wastewater using anaerobic digestion, this research explores the potential to convert organic materials into biofuels (methane). Moreover, the study aims to recover both methane and phosphorus from distillery wastewater in a single anaerobic reactor, which represents a novel and unexplored approach. Laboratory-scale experiments were conducted using mesophilic and thermophilic upflow anaerobic sludge blanket reactors. A key aspect of the study involved the implementation of a unique strategy: the mixing of centrate and spent caustic wastewater streams. This approach was intended to enhance treatment performance, manipulate the microbial community structure, and thereby optimizing the overall treatment performance. The integration of the centrate and spent caustic streams yielded remarkable co-benefits, resulting in significant biomethane production and efficient phosphorus precipitation. The study demonstrated a phosphorus removal efficiency of ∼60 % throughout the 130-140 days operation period. The recovery of phosphorus via the reactor sludge offers exciting opportunities for its utilization as a fertilizer or as a raw material within the phosphorus refinery industry. The biomethane produced during the treatment exhibits significant energy potential, estimated at 0.5 GJ/(m3 distillery wastewater).

Antilipogenesis Effect of Rutin-Loaded Liposomes Using a Microneedle Delivery System.

Rutin, a flavonoid glycoside phytochemical compound, has a remarkable antiobesity effect. However, its therapeutic potential is hindered by its poor water solubility and low oral bioavailability. In this study, rutin was loaded into liposomes (LR) through the self-assembly of lecithin and cholesterol. It was discovered that liposomes improved the water solubility and cellular uptake of rutin in adipocytes. These rutin-loaded liposomes were then incorporated into a microneedle patch (MP) system formed by polyvinylpyrrolidone and poly(vinyl alcohol), and the MP-LR showed an increased release percentage in the adipose tissue microenvironment of pH 6.5 and achieved local delivery of rutin into adipocytes. Next, the therapeutic potentials of rutin, LR, and MP-LR were investigated in a high-fat diet (HFD)-induced obese mouse model. The MP-LR formulation decreased the weight of the HFD mice the most significantly. The antilipogenesis mechanisms of MP-LR are downregulating the lipid synthesis-related proteins (PPAR γ and C/EBP α) in adipocytes and promoting the expression of the beige adipogenesis-related proteins (UCP 1 and Cyt C). The MP systems further promote the local penetration of LR into the adipose tissue specifically, which again elevates their antiobesity effect. Overall, this study suggests that MP-delivered liposome-based formulation is a promising approach to enhance the antiobesity efficacy of antilipogenesis bioactive compounds.

Efficient Prediction of Stability Boundaries in Milling Considering the Variation of Tool Features and Workpiece Materials.

Theoretical stability analysis is a significant approach to predicting chatter-free machining parameters. Accurate milling stability predictions highly depend on the dynamic properties of the process system. Therefore, variations in tool and workpiece attributes will require repeated and time-consuming experiments or simulations to update the tool tip dynamics and cutting force coefficients. Considering this problem, this paper proposes a transfer learning framework to efficiently predict the milling stabilities for different tool-workpiece assemblies through reducing the experiments or simulations. First, a source tool is selected to obtain the tool tip frequency response functions (FRFs) under different overhang lengths through impact tests and milling experiments on different workpiece materials conducted to identify the related cutting force coefficients. Then, theoretical milling stability analyses are developed to obtain sufficient source data to pre-train a multi-layer perceptron (MLP) for predicting the limiting axial cutting depth (aplim). For a new tool, the number of overhang lengths and workpiece materials are reduced to design and perform fewer experiments. Then, insufficient stability limits are predicted and further utilized to fine-tune the pre-trained MLP. Finally, a new regression model to predict the aplim values is obtained for target tool-workpiece assemblies. A detailed case study is developed on different tool-workpiece assemblies, and the experimental results validate that the proposed approach requires fewer training samples for obtaining an acceptable prediction accuracy compared with other previously proposed methods.

An insight into the benefits of substituting polypropylene with biodegradable polylactic acid face masks for combating environmental emissions.

Mask waste can affect the natural environment and human health. In this study, the life cycle assessment (LCA) of two types of face masks (Polylactic acid (PLA) and Polypropylene (PP)) was first performed to evaluate the environmental impacts from production to end-of-life, and then, greenhouse gas (GHG) emissions were estimated for each life stage. The GHG emissions for one functional unit of PP and PLA face masks were estimated to be 6.27E+07 and 5.06E+07 kg CO2 eq, respectively. Explicitly, PLA mask production emissions are 37 % lower as compared to those for PP masks. Packaging has been recognized as a major GHG source throughout the product's life cycle. This study may provide a new insight into the environmental benefits of reducing GHG emissions within PLA face mask life cycles. Biodegradable and environmentally friendly materials can be used in the manufacturing and packaging of face masks.

Relief of gouty arthritis in rats by total saponins from Dioscorea nipponica Makino through suppression of neutrophil extracellular trap formation via the PI3K/AKT/mTOR axis.

Gouty arthritis (GA) is an inflammatory disorder that is associated with elevated serum levels of uric acid. Total saponins from Dioscorea nipponica Makino (TSDN) are a natural component that ameliorates inflammation while also decreasing uric acid levels. The aim of the present study was to unravel the mechanism of TSDN in gouty rats in regard to regulation of the formation of neutrophil extracellular traps (NETs) via the PI3K/AKT/mTOR axis. A total of 40 Wistar rats were divided into 4 groups: normal, model, TSDN and rapamycin groups. Reverse-transcription-quantitative PCR (RT-qPCR) and western blot analysis were used to assess the mRNA and protein expression levels of the PI3K/AKT/mTOR axis. The formation of NETs was detected by immunohistochemical and immunofluorescent methods. ELISA was used to measure the levels of IL-1ß and TNF-α. RT-qPCR and western blotting demonstrated that TSDN compromised the mRNA and protein expression levels of activated protein kinase (AMPK) and mTOR, as well as the mRNA expression levels of AKT and PTEN. Furthermore, it increased the protein expression levels of phosphorylated (p-) PI3K, p-AKT and p-AMPK. Immunohistochemical and immunofluorescent analyses revealed that TSDN decreased the protein expression levels of neutrophil elastase, proteinase 3, cathepsin G, lactoferrin and myeloperoxidase, as well as the number of citrullinated histone 3+ cells. TSDN also reduced the release of IL-1ß and TNF-α. Overall, the anti-inflammatory action of TSDN in gouty rats may be realized by suppressing the formation of NETs by regulating the PI3K/AKT/mTOR axis.

Apolipoprotein A-I attenuates peritoneal fibrosis associated with peritoneal dialysis by inhibiting oxidative stress and inflammation.

Apolipoprotein A-I (apoA-I), 90% of which is present in high-density lipoprotein (HDL), is the main constituent of HDL, has anti-inflammatory and anti-oxidant properties, and has received extensive attention in anti-atherosclerosis. Yet little is known about apoA-I 's role in peritoneal dialysis. In this study, by analyzing PD patients (n = 81), we found that decreased apoA/HDL-C ratio is significantly associated with rapid decline in peritoneal function. Further studies were performed in animal experiments to determine the ascendancy of apolipoprotein A-I mimetic peptide (D-4F) on peritoneum, we found that D-4F administration reduced peritoneal fibrosis and peritoneal endothelial mesenchymal transformation (EMT) induced by high glucose peritoneal dialysate, such as N-cadherin, Fibronectin, Vimentin, and α-smooth muscle actin (α-SMA) expression decreased. In mechanism, D-4F can significantly inhibit Smad2/3 phosphorylation, which is the major pathway leading to fibrosis. Furthermore, D-4F treatment inhibited NADPH oxidase and thiobarbituric acid reactive substances (TBARS) expression, increased the activity of certain enzymes, such as superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Finally, treatment with D-4F inhibits the expression of interleukins-6(IL-6), Interleukin-1ß(IL-1ß), and tumor necrosis factor-α(TNF-α). Taken together, based on the above research evidence, apoA-I and its peptide mimic may regulate the oxidative stress, TGF- ß1/Smads signaling pathway and inflammatory response to reduce peritoneal fibrosis due to peritoneal dialysis.

Total Saponin Fraction of Dioscorea Nipponica Makino Improves Gouty Arthritis Symptoms in Rats via M1/M2 Polarization of Monocytes and Macrophages Mediated by Arachidonic Acid Signaling.

OBJECTIVE: To explore the mechanism of effects of total saponin fraction from Dioscorea Nipponica Makino (TSDN) on M1/M2 polarization of monocytes/macrophages and arachidonic acid (AA) pathway in rats with gouty arthritis (GA). METHODS: Seventy-two Sprague Dawley rats were randomly divided into 4 groups (n=18 in each): normal, model, TSDN at 160 mg/kg, and celecoxib at 43.3 mg/kg. Monosodium urate crystal (MSU) was injected into the rats' ankle joints to induce an experimental GA model. Blood and tissue samples were collected on the 3rd, 5th, and 8th days of drug administration. Histopathological changes in the synovium of joints were observed via hematoxylin and eosin (HE) staining. The expression levels of arachidonic acid (AA) signaling pathway were assessed via real-time polymerase chain reaction (qPCR) and Western blot. Flow cytometry was used to determine the proportion of M1 and M2 macrophages in the peripheral blood. An enzyme-linked immunosorbent assay (ELISA) was used to detect interleukine (IL)-1 ß, tumor necrosis factor-alpha (TNF-α), IL-4, IL-10, prostaglandin E2 (PGE2), and leukotriene B4 (LTB4). RESULTS: HE staining showed that TSDN improved the synovial tissue. qPCR and Western blot showed that on the 3rd, 5th and 8th days of drug administration, TSDN reduced the mRNA and protein expressions of cyclooxygenase (COX)2, microsomal prostaglandin E synthase-1 derived eicosanoids (mPGES-1), 5-lipoxygenase (5-LOX), recombinant human mothers against decapentaplegic homolog 3 (Smad3), nucleotide-binding oligomerization domain-like receptor protein 3 (NALP3), and inducible nitric oxide synthase (iNOS) in rats' ankle synovial tissues (P<0.01). TSDN decreased COX1 mRNA and protein expression on 3rd and 5th day of drug administration and raised it on the 8th day (both P<0.01). It lowered CD68 protein expression on days 3 (P<0.01), as well as mRNA and protein expression on days 5 and 8 (P<0.01). On the 3rd, 5th, and 8th days of drug administration, TSDN elevated the mRNA and protein expression of Arg1 and CD163 (P<0.01). Flow cytometry results showed that TSDN decreased the percentage of M1 macrophages while increasing the percentage of M2 in peripheral blood (P<0.05 or P<0.01). ELISA results showed that on the 3rd, 5th, and 8th days of drug administration, TSDN decreased serum levels of IL-1 ß, TNF-α, and LTB4 (P<0.01), as well as PGE2 levels on days 3rd and 8th days (P<0.05 or P<0.01); on day 8 of administration, TSDN increased IL-4 serum levels and enhanced IL-10 contents on days 5 and 8 (P<0.05 or P<0.01). CONCLUSION: The anti-inflammatory effect of TSDN on rats with GA may be achieved by influencing M1/M2 polarization through AA signaling pathway.

Simiao Yong'an decoction ameliorates murine collagen-induced arthritis by modulating neutrophil activities: An in vitro and in vivo study.

ETHNOPHARMACOLOGICAL RELEVANCE: Rheumatoid arthritis (RA) is a common systemic autoimmune disease with high morbidity and disability rate. Currently, there is no effective allopathic treatment for RA, and most of the drugs provoke many adverse effects. Simiao Yong'an decoction (SMYAD) is a traditional Chinese prescription for the treatment of sore and gangrene caused by hot poison. With the development of pharmacology and clinical research, SMYAD has remarkable anti-inflammatory properties and has been used for RA treatments for years. AIM OF THE STUDY: This study aimed to investigate the anti-arthritic effect of SMYAD and further explore the immunopharmacological mechanisms. MATERIALS AND METHODS: Arthritis was induced in DBA/1 mice by two-time immunizations. Collagen-induced rheumatoid arthritis (CIA) mice were divided into 4 groups: control, model, methotrexate (MTX), and SMYAD group (n = 6). The administration groups were given MTX (0.5 mg/kg/3 d) and SMYAD (4.5 g/kg/d) by gavage from day 14. The arthritis index (AI) score was evaluated every 3 days after the second immunization. Hematoxylin and eosin (H&E) staining, Safranin-O fast green staining, Trap staining, and Micro-CT were used to measure the histopathology injuries and bone destruction of joints. Granulocyte changes in the spleen, bone marrow, and period blood were analyzed by flow cytometry. The expression of inflammatory cytokines and chemokines in joints were detected by qRT-PCR. SMYAD-containing serum was obtained from SD rats gavaged with SMYAD. Neutrophils were isolated from peripheral blood and bone marrow for the in vitro experiments of transwell cell assay, apoptosis assay, reactive oxygen species (ROS) generation and neutrophil extracellular traps (NETs) formation. RESULTS: SMYAD significantly relieved arthritis severity in CIA mice. The AI score was significantly decreased in the SMYAD group compared with the model group. Additionally, SMYAD alleviated inflammatory infiltration, cartilage damage, osteoclast formation, and bone damage in the ankle joints. In the flow cytometry assay, SMYAD significantly reduced granulocytes number in the spleen and bone marrow, while increased in peripheral blood. Furthermore, compared with the CIA group, SMYAD suppressed the mRNA levels of inflammatory factors including TNF-α, IL-1ß, IL-6 and chemokines CXCL1, CXCL2, and IL-8 in the inflamed joints. In the in vitro studies, 20% SMYAD-containing serum effectively inhibited the migration of neutrophils, promoted neutrophils apoptosis, reduced ROS production and NETs formation. CONCLUSION: Collectively, our results demonstrated that SMYAD effectively restrained arthritis in CIA mice by modulating neutrophil activities.

Effects of Total Saponins from Dioscorea Nipponica Makino on Monosodium Urate-Induced M1-Polarized Macrophages through Arachidonic Acid Signaling Pathway: An in vitro Study.

OBJECTIVE: To investigate and reveal the underlying mechanism of the effect of total saponins from Dioscoreae nipponica Makino (TSDN) on the arachidonic acid pathway in monosodium urate (MSU) crystal-induced M1-polarized macrophages. METHODS: M1 polarization of RAW264.7 cells were induced by 1 µ g/mL lipopolysaccharide (LPS). The methylthiazolyldiphenyl-tetrazolium bromide method was then used to screen the concentration of TSDN. MSU (500 µ g/mL) was used to induce the gouty arthritis model. Afterwards, 10 µ g/L TSDN and 8 µ mol/L celecoxib, which was used as a positive control, were added to the above LPS and MSU-induced cells for 24 h. The mRNA and protein expressions of cyclooxygenase (COX) 2, 5-lipoxygenase (5-LOX), microsomal prostaglandin E synthase derived eicosanoids (mPGES)-1, leukotriene B (LTB)4, cytochrome P450 (CYP) 4A, and prostaglandin E2 (PGE2) were tested by real-time polymerase chain reaction and Western blotting, respectively. The enzyme-linked immunosorbent assay was used to test the contents of M1 markers, including inducible nitric oxid synthase (NOS) 2, CD80, and CD86. RESULTS: TSDN inhibited the proliferation of M1 macrophages and decreased both the mRNA and protein expressions of COX2, 5-LOX, CYP4A, LTB4, and PGE2 (P<0.01) while increased the mRNA and protein expression of mPGES-1 (P<0.05 or P<0.01). TSDN could also significantly decrease the contents of NOS2, CD80, and CD86 (P<0.01). CONCLUSION: TSDN has an anti-inflammation effect on gouty arthritis in an in vitro model by regulating arachidonic acid signaling pathway.

Stoichiometric homeostasis of N:P ratio drives species-specific symbiotic N fixation inhibition under N addition.

Introduction: Symbiotic N fixation inhibition induced by N supply to legumes is potentially regulated by the relative N and P availability in soil. However, the specific responses of different legume species to changes in N:P availability remain unclear, and must be better understood to optimize symbiotic N fixation inputs under N enrichment. This study investigated mechanisms by which soil N and P supply influence the symbiotic N fixation of eight legume species, to quantify the inter-specific differences, and to demonstrate how these differences can be determined by the stoichiometric homeostasis in N:P ratios (HN:P). Methods: Eight herbaceous legume species were grown separately in outdoor pots and treated with either no fertilizer (control), N fertilizer (14 g N m-2), P fertilizer (3.5 g P m-2) or both N and P fertilizer. Plant nutrients, stoichiometric characteristics, root biomass, non-structural carbohydrates (NSC), rhizosphere chemistry, P mobilization, root nodulation and symbiotic N fixation were measured. Results: N addition enhanced rhizosphere P mobilization but drove a loss of root biomass and root NSC via exudation of P mobilization compound (organic acid), especially so in treatments without P addition. N addition also induced a 2-14% or 14-36% decline in symbiotic N fixation per plant biomass by legumes in treatments with or without P addition, as a result of decreasing root biomass and root NSC. The changes in symbiotic N fixation were positively correlated with stoichiometric homeostasis of N:P ratios in intact plants without root nodules, regardless of P additions. Discussion: This study indicates that N addition can induce relative P limitations for growth, which can stimulate rhizosphere P mobilization at the expense of root biomass and carbohydrate concentrations, reducing symbiotic N fixation in legumes. Legume species that had less changes in plant N:P ratio, such as Lespedeza daurica and Medicago varia maintained symbiotic N fixation to a greater extent under N addition.

Spatial distributions of granular activated carbon in up-flow anaerobic sludge blanket reactors influence methane production treating low and high solid-content wastewater.

The impacts of granular activated carbon (GAC) spatial distributions in up-flow anaerobic sludge blanket (UASB) reactors treating different solid-content wastewater were evaluated in the present study. When treating high solid-content wastewater, the highest methane yield was observed for UASB supplemented with self-floating GAC (74.2 ± 3.7 %), which was followed by settled + self-floating GAC reactor (65.1 ± 3.8 %), then settled GAC reactor (58.3 ± 1.4 %). When treating low solid-content wastewater, all UASBs achieved improved methane yield, and settled + self-floating GAC reactor achieved the highest methane yield (83.4 ± 3.3 %). Self-floating GAC amended reactor showed the best performance for treating high solid-content wastewater, while settled + self-floating GAC amended reactor was optimal for treating medium and low solid-content wastewater. The spatial distributions of microbial communities differed in the reactors with settled GAC and floating GAC. This study underlines the importance of considering feedwater characteristics when adopting GAC-based UASB processes.

Single layer aligned semiconducting single-walled carbon nanotube array with high linear density.

Highly ordered semiconducting single-walled carbon nanotubes(sc-SWCNTs) array with high purity, high linear density and controllable manner is strongly desired for carbon-based integrated circuits, yet it remains a big challenge. Herein, close-packed single layered and controllably aligned sc-SWCNTs arrays were obtained through dielectrophoresis using a high purity sc-SWCNT dispersion. Under optimized condition of length and average number of interconnecting junctions across the channel full of aligned sc-SWCNTs, field effect transistors (FETs) with high performance were achieved with both a high on/off current ratio and large carrier mobility. Based on the optimized channel length, by systematically optimizing the dielectrophoresis parameters of the frequency and duration of applied AC voltage (Vpp), the highly ordered sc-SWCNTs arrays with an ultra-high linear density of 54 ± 2 tubesµm-1showed relatively high device performance of FET. The fabrication process optimized in this report can be further extended and applied in large-area, low-cost carbon-based integrated circuits.

Stable structures and superconducting properties of Ca-La-H compounds under pressure.

The calcium hydrides and lanthanum hydrides under high pressures have been reported to have good superconducting properties with high-TC. In this work, the structures and superconductivities of Ca-La-H ternary hydrides have been studied by genetic algorithm and density functional theory calculations. Our results show that at the pressure range of 100-300 GPa, the most stable structure of CaLaH12has aCmmmsymmetry, in which there is a H24hydrogen cage. It can be expected to have high possibility to be synthesized due to its large stability. Furthermore, the predictedTCof theCmmm-CaLaH12structure is about 140 K at 150 GPa, and when the pressure decreases to 30 GPa, the CaLaH12structure with aC2/msymmetry has a predictedTCof about 49 K. The CaLaH12is suggested to be a stable good superconductor with large stability and performs well at relatively low pressures.

Electrochemical Preparation of Porous Organic Polymer Films for High-Performance Memristors.

Porous organic polymer films (PFs) with intrinsical porosity and tuneable pore environment are ideally suited for application in electronic devices. However, the huge challenges still exist for construction of electronic devices based on PFs owing to lack of robustness, processability, and controllable preparation. Herein, we report the electrochemical preparation of carbazole-based porous organic polymer films (eCPFs) as switchable materials for the memristors. These eCPFs possess the characteristics of controllable thickness/size, high stability, and excellent porosity. Carbazole and cyano groups are introduced into the eCPFs to constructing electron transfer systems. Thus, the memristors constructed based on these eCPFs exhibit excellent switching performance, reliability, and reproducibility. The electrochemically controllable preparation method of porous organic polymer membranes proposed in this paper provides a feasible idea for the developments of electronic devices.

Network of Tourism-Industrial Complex in Cities: Typologies and Implications through a Critical Literature Review.

Although tourism has increasingly become an important activity with wide influences on the economic, social, and spatial development of a city, knowledge and interest mostly remain on its industrial performance and promotion. The synergy between tourism and city development is largely overlooked in many cases, resulting in suboptimal design and planning of city tourism activities and unfledged potentials of city development. The aim of the paper is to propose a view of tourism-industrial complex based on a synergistic perspective in order to clarify the systematic characteristics of urban tourism in an integrated, sustainable manner. Availing of bibliometric methods and drawing on city/urban tourism literature, this paper proposes a concept of tourism-industrial complex to cover current complicated and various tourism activities that are embedded in cities at diverse levels regardless of social, economic, and spatial factors. Then, four types of tourism-industrial complexes are proposed, including demand-driven, resource-dependent, externally forced, and hybrid-driven models. Due to the networked connectivity of urban tourism, urban backgrounds, tourism industry, and external circumstances all contribute to a coupling the tourism city development system. The results provide theoretical constructs and policy recommendations for optimization and sustainable city and tourism development.

Anaerobic digestion of thickened waste activated sludge under calcium hypochlorite stress: Performance stability and microbial communities.

Hypochlorite pretreatment has been proven effective in enhancing waste activated sludge (WAS) anaerobic digestion performances recently. In this study, two semi-continuous anaerobic sequencing batch reactors (ASBRs), one fed with Ca(ClO)2 pretreated thickened WAS (TWAS) and one with raw TWAS, were operated at mesophilic conditions (35 °C) for 145 days. Three loading shocks were introduced to each reactor to compare the performance stability and resilience between the digestion of Ca(ClO)2 pretreated TWAS and untreated TWAS. Microbial community shifts were quantified to reveal the microbiome responses to disturbances. The results suggested that 1% Ca(ClO)2 enhanced the digestion of TWAS by inactivating and transforming the biomass to more easily digested substrates. Co-occurrence network analysis revealed that the strongest interactions in the microbial community occurred in the steady state of TWAS anaerobic digestion.

Effect of phosphate and ammonium concentrations, total suspended solids and alkalinity on lignin-induced struvite precipitation.

To solve the problems of eutrophication and resource crisis, the recovery of phosphorus by struvite (NH4MgPO4·6H2O) precipitation has become a focus of recent research. The feasibility of using Kraft lignin powder as a seed to promote struvite precipitation has been demonstrated in the previous study. In this study, the effect of lignin in promoting struvite precipitation in synthetic wastewater with different characteristics was investigated. Lignin-induced struvite crystallization was tested under various initial concentrations of PO4-P and NH4-N, total suspended solids (TSS) and alkalinity. At pH 7.9, the enhancement of PO4-P recovery remains around 45% under different PO4-P and NH4-N concentrations. Moreover, lignin is more effective under relatively lower alkalinity and still workable to reduce co-precipitates potential under higher alkalinity. Also, the effect of TSS on PO4-P recovery is not significant. Overall, the effect of lignin in promoting phosphorus recovery is relatively stable and can be used in synthetic wastewater with different characteristics.

Microbial co-occurrence network topological properties link with reactor parameters and reveal importance of low-abundance genera.

Operational factors and microbial interactions affect the ecology in anaerobic digestion systems. From 12 lab-scale reactors operated under distinct engineering conditions, bacterial communities were found driven by temperature, while archaeal communities by both temperature and substrate properties. Combining the bacterial and archaeal community clustering patterns led to five sample groups (ambient, mesophilic low-solid-substrate, mesophilic, mesophilic co-digestion and thermophilic) for co-occurrence network analysis. Network topological properties were associated with substrate characteristics and hydrolysis-methanogenesis balance. The hydrolysis efficiency correlated (p < 0.05) with clustering coefficient positively and with normalized betweenness negatively. The influent particulate COD ratio and the relative differential hydrolysis-methanogenesis efficiency (Defficiency) correlated negatively with the average path length (p < 0.05). Individual genera's topological properties showed more connector genera in thermophilic network, representing stronger inter-module communication. Individual genera's normalized degree and betweenness revealed that lower-abundance genera (as low as 0.1%) could perform central hub roles and communication roles, maintaining the stability and functionality of the microbial community.