ABSTRACT
Microplastics (MPs) and nanoplastics (NPs) present in wastewater can pose a negative impact to aerobic granular sludge (AGS). Herein, this study found that MPs and NPs (20 mg/L) deteriorated the sludge settleability and granule integrity, resulting in a 15.7 % and 21.9 % decrease in the total nitrogen removal efficiency of the AGS system, respectively. This was possibly due to the reduction of the extracellular polymeric substances (EPS) content. The subsequent analysis revealed that tyrosine, tryptophan, and humic acid-like substances in EPS exhibited a higher propensity for chemisorption and inhomogeneous multilayer adsorption onto NPs compared to MPs. The binding of EPS onto the surface of plastic particles increased the electronegativity of the MPs, but facilitated the aggregation of NPs through reducing the electrostatic repulsion, thereby mitigating the adverse effects of MPs/NPs on the AGS stability. Additionally, comprehensive analysis of the extended Derjaguin-Landau-Verwey-Overbeek theory indicated that the suppressed aggregation of microorganisms was the internal mechanisms contributing to the inadequate stability of AGS induced by MPs/NPs. This study provides novel insights into the detrimental mechanisms of MPs/NPs on the AGS stability, highlighting the key role of EPS in maintaining the structural stability of AGS when exposed to MPs/NPs.
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Hydroxyapatite (HAP), a mineral nucleus identified within aerobic granular sludge (AGS), plays a vital role in enhancing the AGS systems. However, the microscopic mechanism underlying their roles remains largely unexplored. Herein, a systematic investigation was carried out to elucidate the impact and enhanced mechanisms associated with HAP of different sizes, i.e. micro-HAP (mHAP) and nano-HAP (nHAP), on the aerobic granulation, nutrient removal and microbial diversity of AGS. Results showed that the presence of nHAP and mHAP significantly shortened the granulation process to 15 and 20 days, respectively. This might be ascribed to the fact that the large specific surface area of nHAP aggregates was conducive to microbial adhesion, biomass accumulation and sludge granulation. Compared with mHAP, the granules with nHAP showed better settlement performance, mechanical strength and larger diameter. The X-ray diffraction (XRD) and Raman spectrometer analysis confirmed the presence of HAP within the granules, which was found to stimulate the secretion of extracellular polymeric substance, improve the compactness of granule structure and suppress the growth of filamentous bacteria, thereby contributing to a stable AGS system. The presence of HAP, especially nHAP, effectively enriched the functional microorganisms, such as nitrifying and denitrifying bacteria (e.g. Candidatus_Competibacter) and phosphorus accumulating organisms (e.g. Flavobacterium), leading to the improved nutrient removal efficiencies (COD > 96%, TN > 76%, and TP > 74%). Further analysis revealed the up-regulation of functional enzymes (e.g. nitrite oxidoreductase and polyphosphate kinase) involved in nutrient metabolism, underlying the inherent mechanisms for the excellent nutrient removal. This study deepens the understanding of granulation mechanisms from the perspective of mineral cores, and proposes an economically feasible strategy for rapid initiation and stabilization of AGS reactors.
Subject(s)
Durapatite , Sewage , Durapatite/chemistry , Waste Disposal, Fluid/methods , Aerobiosis , Bioreactors , Phosphorus/chemistry , BiomassABSTRACT
BACKGROUND: Drug-free in vitro activation (IVA) is a new protocol to activate residual dormant follicles for fertility restoration in patients with premature ovarian insufficiency (POI). However, several deficiencies have reduced its clinical efficacy rate. Our previous studies have confirmed that the combination of adipose-derived stem cells (ADSCs) and drug-free IVA can improve the effectiveness of drug-free IVA and restore ovarian function of rats with POI. Increasing evidence has demonstrated that mesenchymal stem cell-derived exosomes have similar therapeutic effects as their source cells. Here, we performed a preclinical study to evaluate the therapeutic effects of ADSCs-derived exosomes (ADSCs-Exos) combined with drug-free IVA in the POI rats and the mechanism in restoring ovarian function. RESULTS: In vivo, the effects of ADSCs-Exos were comparable to those of ADSCs, and the ADSCs-Exos combined with drug-free IVA was better than ADSCs-Exos alone therapy in promoting follicular development. Moreover, transplantation of ADSCs/ADSCs-Exos lead to up-regulation of BCL-2 expression and down-regulation of the expression of Bax and Cleaved Caspase-3, thus reducing the apoptosis of chemotherapy-induced follicle cells, and further promoting the development of the follicles and rescuing ovarian function in POI-damaged ovary. In vitro, ovarian fragmentation could activate follicular growth and development, and in combination with ADSCs-Exos could prevent the loss of follicles, promote follicular proliferation and inhibit apoptosis. CONCLUSIONS: ADSCs-Exos combined drug-free IVA had remarkable therapeutic effects in restoring ovarian function of POI rats, and markedly promoted follicular development and inhibited apoptosis of ovarian cells in vitro. Our study confirmed that the combination therapy might be a promising and effective treatment for POI.
Subject(s)
Exosomes , Ovary , Primary Ovarian Insufficiency , Animals , Female , Primary Ovarian Insufficiency/therapy , Primary Ovarian Insufficiency/metabolism , Exosomes/metabolism , Exosomes/transplantation , Rats , Ovary/metabolism , Apoptosis , Mesenchymal Stem Cells/metabolism , Ovarian Follicle/metabolism , Adipose Tissue/cytology , Rats, Sprague-DawleyABSTRACT
Nanomaterials present in wastewater can pose a significant threat to aerobic granular sludge (AGS) systems. Herein, we found that compared to graphene nanomaterials (G-NMs), the long-term presence (95 days) of graphene oxide nanomaterials (GO-NMs) resulted in an increased proliferation of filamentous bacteria, poorer sedimentation performance (SVI30 of 74.1 mL/g) and smaller average particle size (1224.4 µm) of the AGS. In particular, the GO-NMs posed a more significant inhibitory effect to the total nitrogen removal efficiency of AGS (decreased by 14.3 %), especially for the denitrification process. The substantial accumulation of GO-NMs within the sludge matrix resulted in a higher level of reactive oxygen species in AGS compared to G-NMs, thereby inducing lactate dehydrogenase release, and enhancing superoxide oxidase and catalase activities. Such excessive oxidative stress could potentially result in a significant reduction in the activity of nitrogen metabolism enzymes (e.g., nitrate reductase and nitrite reductase) and the expression of key functional genes (e.g., nirS and nirK). Altogether, compared to G-NMs, prolonged exposure to GO-NMs had a more significant chronic toxicity effect on AGS systems. These findings implied that the presence of G-NMs and GO-NMs is a hidden danger to biological nitrogen removal and should receive more attention.
Subject(s)
Graphite , Sewage , Graphite/toxicity , Graphite/chemistry , Sewage/microbiology , Aerobiosis , Nanostructures/toxicity , Nanostructures/chemistry , Bacteria/drug effects , Bacteria/metabolism , Nitrogen/chemistry , Reactive Oxygen Species/metabolism , Oxidative Stress/drug effects , Water Pollutants, Chemical/toxicity , Water Pollutants, Chemical/chemistryABSTRACT
Research on the use of peracetic acid (PAA) activated by nonmetal solid catalysts for the removal of dissolved refractory organic compounds has gained attention recently due to its improved efficiency and suitability for advanced water treatment (AWT). Among these catalysts, nanocarbon (NC) stands out as an exceptional example. In the NC-based peroxide AWT studies, the focus on the mechanism involving multimedia coordination on the NC surface (reactive species (RS) path, electron reduction non-RS pathway, and singlet oxygen non-RS path) has been confined to the one-step electron reaction, leaving the mechanisms of multichannel or continuous electron transfer paths unexplored. Moreover, there are very few studies that have identified the nonfree radical pathway initiated by electron transfer within PAA AWT. In this study, the complete decomposition (kobs = 0.1995) and significant defluorination of perfluorooctanoic acid (PFOA, deF% = 72%) through PAA/NC has been confirmed. Through the use of multiple electrochemical monitors and the exploration of current diffusion effects, the process of electron reception and conduction stimulated by PAA activation was examined, leading to the discovery of the dynamic process from the PAA molecule â NC solid surface â target object. The vital role of prehydrated electrons (epre-) before the entry of resolvable electrons into the aqueous phase was also detailed. To the best of our knowledge, this is the first instance of identifying the nonradical mechanism of continuous electron transfer in PAA-based AWT, which deviates from the previously identified mechanisms of singlet oxygen, single-electron, or double-electron single-path transfer. The pathway, along with the strong reducibility of epre- initiated by this pathway, has been proven to be essential in reducing the need for catalysts and chemicals in AWT.
Subject(s)
Diamond , Electrons , Peracetic Acid , Peracetic Acid/chemistry , Diamond/chemistry , Electron Transport , Fluorocarbons/chemistry , Caprylates/chemistry , Surface Properties , Water Purification , Water Pollutants, Chemical/chemistryABSTRACT
The structural variances of adsorbents play a crucial role in determining the number of effective adsorption sites and pretreatment performance. However, there is still a gap in comprehending the impact of different carbon structural adsorbents on membrane fouling. Therefore, this study aimed to compare the efficacy of granular activated carbon (GAC), powdered activated carbon (PAC), and activated carbon fiber (ACF) in mitigating membrane fouling during municipal sewage reclamation using an aerobic granular sludge membrane bioreactor (AGMBR). The results demonstrated that the utilization of PAC significantly enhanced the normalized flux and reduced fouling resistance in comparison to GAC and ACF systems. PAC effectively adsorbed low and medium-molecular-weight pollutants present in raw sewage, resulting in an increase in average particle size and a decrease in foulant content on the membrane surface. The Hermia model indicated that adsorption pretreatment minimized standard blocking while promoting the formation of a sparse and porous cake layer. Moreover, according to the extended Derjaguin-Landau-Verwey-Overbeek theory, PAC has been demonstrated as the optimal antifouling system owing to its enhanced repulsion between membrane-foulant and foulant-foulant interactions. Correlation analysis revealed that the exceptional antifouling performance of the PAC system was due to its high removal rates of chemical oxygen demand (~78 %) and suspended solids (~97 %). This research offers valuable insights into the mitigation of membrane fouling through the utilization of adsorbents featuring diverse carbon structures.
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BACKGROUND: 3D-printing is widely used in regenerative medicine and is expected to achieve vaginal morphological restoration and true functional reconstruction. Mesenchymal stem cells-derived exosomes (MSCs-Exos) were applyed in the regeneration of various tissues. The current study aimed to explore the effctive of MSCs-Exos in vaginal reconstruction. METHODS: In this work, hydrogel was designed using decellularized extracellular matrix (dECM) and gelatin methacrylate (GelMA) and silk fibroin (SF). The biological scaffolds were constructed using desktop-stereolithography. The physicochemical properties of the hydrogels were evaluated; Some experiments have been conducted to evaluate exosomes' effect of promotion vaginal reconstruction and to explore the mechanism in this process. RESULTS: It was observed that the sustained release property of exosomes in the hydrogel both in vitro and in vitro.The results revealed that 3D scaffold encapsulating exosomes expressed significant effects on the vascularization and musule regeneration of the regenerative vagina tissue. Also, MSCs-Exos strongly promoted vascularization in the vaginal reconstruction of rats, which may through the PI3K/AKT signaling pathway. CONCLUSION: The use of exosome-hydrogel composites improved the epithelial regeneration of vaginal tissue, increased angiogenesis, and promoted smooth muscle tissue regeneration. 3D-printed, lumenal scaffold encapsulating exosomes might be used as a cell-free alternative treatment strategy for vaginal reconstruction.
Subject(s)
Decellularized Extracellular Matrix , Exosomes , Mesenchymal Stem Cells , Printing, Three-Dimensional , Tissue Scaffolds , Vagina , Female , Exosomes/metabolism , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/metabolism , Animals , Vagina/cytology , Tissue Scaffolds/chemistry , Decellularized Extracellular Matrix/chemistry , Stereolithography , Rats , Hydrogels/chemistry , Rats, Sprague-Dawley , Regeneration , Plastic Surgery Procedures/methods , Gelatin/chemistry , Humans , Tissue Engineering/methods , Extracellular Matrix/metabolismABSTRACT
BACKGROUND: The adoption of digitization has emerged as a new trend in the advancement of healthcare systems. To ensure high-quality care, nurses should possess sufficient skills to assist in the digital transformation of healthcare practices. Suitable tools have seldom been developed to assess nurses' skills in digital applications. This study aimed to develop the Nursing Digital Application Skill Scale (NDASS) and test its psychometric properties. METHODS: The Nursing Digital Application Skill Scale was developed in three phases. In Phase 1, an item pool was developed based on previous literature and the actual situation of nursing work. Phase 2 included 14 experts' assessment of content validity and a focus group interview with 30 nurses to pretest the scale. In phase 3, 429 registered nurses were selected from March to June 2023, and item analysis, exploratory factor analysis, and confirmatory factor analysis were used to refine the number of items and explore the factor structure of the scale. Additionally, reliability was determined by internal consistency and test-retest reliability. RESULTS: The final version of the NDASS consisted of 12 items. The content validity index of NDASS reached 0.975 at an acceptable level. The convergent validity test showed that the average variance extracted value was 0.694 (> 0.5) and the composite reliability value was 0.964 (> 0.7), both of which met the requirements. The principal component analysis resulted in a single-factor structure explaining 74.794% of the total variance. All the fitting indices satisfied the standard based upon confirmatory factor analyses, indicating that the single-factor structure contributed to an ideal model fit. The internal consistency appeared high for the NDASS, reaching a Cronbach's alpha value of 0.968. The test-retest reliability was 0.740, and the split-half coefficient was 0.935. CONCLUSION: The final version of the NDASS, which possesses adequate psychometric properties, is a reliable and effective instrument for nurses to self-assess digital skills in nursing work and for nursing managers in designing nursing digital skill training.
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The primary aim of the present study was to investigate the effect of dexmedetomidine (DEX) on postoperative pain and early cognitive impairment in old male patients, who underwent laparoscopic cholecystectomy (LC). A total of 97 old patients, subjected to LC at the 980 Hospital of the Joint Service Support Force of the People's Liberation Army of China, were randomly divided into two groups, namely the DEX and normal saline groups. Patients in the DEX group received an intravenous infusion of 0.8 µg/kg DEX within 10 min following general anesthesia, followed by a maintenance infusion of 0.5 µg/(kg/h). Furthermore, patients in the normal saline group were treated with an equivalent volume of normal saline. Cognitive function was assessed using the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA) tests at 6 h, 1, 2 and 3 days, postoperatively. The incidence of postoperative cognitive dysfunction (POCD) and postoperative adverse events were recorded for both groups. In addition, the Visual Analogue Scale (VAS) pain score was utilized to assess the pain level of all patients, while the Quality of Recovery-15 (QoR-15) scale was employed to analyze the postoperative recovery results. Therefore, the MoCA score was higher in the DEX group compared with the normal saline group at 6 h and day 1 postoperatively. Additionally, the MMSE score was higher at 6 h postoperatively in the DEX group compared with the normal saline group. Correspondingly, the incidence of POCD was lower in the DEX group compared with the normal saline group at 6 h and day 1, after LC (P<0.05). VAS score in resting state for patients in the DEX group was significantly lower compared with the normal-saline group (P<0.05). Furthermore, the QoR-15 scale score in patients in the DEX group was notably increased compared with the normal saline group on the first and second days after the operation (P<0.05). Overall, the present study verified that the continuous infusion of DEX at a rate of 0.5 µg/(kg/h) during LC could effectively reduce the incidence of early POCD and alleviate postoperative pain in old male patients, thus facilitating postoperative recovery.
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AIMS: The aims of the study were to explore the experiences of women with gestational diabetes mellitus (GDM) and their partners and examine the factors influencing partner involvement in GDM management, seeking to inform a targeted couple-based intervention. DESIGN: A descriptive qualitative study. METHODS: We conducted semi-structured interviews with 14 women with GDM and their partners. Participants were recruited through convenience sampling from a tertiary hospital in Xi'an, China. Data were analysed using thematic analysis. RESULTS: Three themes and 12 subthemes were identified. Theme I: Women's expectations of their partner's involvement in GDM management-practical support and emotional support. Theme II: Partner involvement in GDM management-constructive involvement, unhelpful involvement with good intentions and insufficient involvement. Theme III: Factors that influence partner involvement in GDM-knowledge of GDM, GDM risk perception, health consciousness, attitudes towards the treatment plan, couple communication regarding GDM management, family roles and appraisal of GDM management responsibility. CONCLUSION: Women desired practical and emotional support from partners. The types of partner involvement in GDM management varied. Some partners provided constructive support, while some partners' involvement was limited, non-existent or actively unhelpful. By combining these results with the factors influencing partner involvement, our findings may help healthcare professionals develop strategies to involve partners in GDM care and enhance women's ability to manage GDM. IMPLICATIONS FOR THE PROFESSION AND PATIENT CARE: Partner involvement in GDM care may help them understand and better attend to women's needs, thus improving their experience and potential outcomes. This study highlights novel factors that need to be considered in developing couple-based interventions for this population. REPORTING METHOD: The reporting follows the COREQ checklist. PATIENT OR PUBLIC CONTRIBUTION: Some patients were involved in data interpretation. There is no public contribution.
Subject(s)
Diabetes, Gestational , Pregnancy , Female , Humans , Diabetes, Gestational/therapy , Diabetes, Gestational/psychology , Qualitative Research , Attitude , Communication , IntentionABSTRACT
The algal-bacterial granular sludge (ABGS) system is a prospective wastewater treatment technology, but few studies focused on the effects of different inoculum types on the establishment of the ABGS system under low aeration conditions (step-decrease superficial gas velocity from 1.4 to 0.5 cm/s). Results from this study indicated that compared with other inocula, the ABGS formed by co-inoculating aerobic granular sludge (AGS) and targeted algae (Chlorella) exhibited a shorter granulation period (shortened by 15 days), higher total nitrogen (89.4%) and PO43--P (95.0%) removal efficiencies, and a greater yield of fatty acid methyl esters (FAMEs) (9.04 mg/g MLSS). This was possibly attributed to that the functional bacteria (e.g. Thauera, Gemmobacter and Rhodobacter) in the inoculated AGS facilitated the ABGS granulation. The inoculated algae promoted their effective enrichment under illumination conditions and enhanced the production of extracellular polymeric substances, thus improving the stability of ABGS. The enriched algae were attached to the outer layer of the granules, which could provide sufficient oxygen for bacterial metabolism, revealing the inherent mechanisms for the good stability of ABGS under low aeration intensity. Overall, the rapid granulation of ABGS can be achieved by inoculating optimal inocula under low aeration conditions, which is convenient and economically feasible, and motivates the application of algal-bacterial consortia.
Subject(s)
Chlorella , Sewage , Sewage/microbiology , Biofuels , Chlorella/metabolism , Prospective Studies , Bioreactors/microbiology , Bacteria/metabolism , Waste Disposal, Fluid/methods , Nitrogen/metabolism , AerobiosisABSTRACT
AIMS: To estimate the effectiveness of the Couples Coping with Gestational Diabetes Mellitus (GDM) Programme on GDM self-management and pregnancy outcomes. METHODS: A randomised controlled trial among pregnant women with suboptimal GDM self-management and their partners was undertaken. Couples recruited from three hospitals in China were randomly allocated to either intervention (n = 70) or control (n = 70) conditions. Couples in the intervention group underwent the couple-based intervention (GDM education, shared illness appraisals, initiation of collaborative action and consolidation of collaborative action). Women in the control group received individual GDM education. Data were analysed using the independent samples t-test, chi-square test, and generalised estimating equations. RESULTS: GDM knowledge for the women and their partners and GDM self-management significantly improved in both the intervention and control groups, with stronger improvement in the intervention group. Women in the intervention group gained significantly less weight than those in the control group (11.2 kg ± 2.8 kg vs 13.1 kg ± 2.6 kg, p = 0.008). Infant birth weights were significantly lower in the intervention group (3.2 kg ± 0.3 kg vs 3.4 kg ± 0.4 kg, p = 0.008). There were no significant differences in other pregnancy outcomes. CONCLUSIONS: The Couples Coping with GDM Programme was associated with improvements in GDM knowledge of women and their partners and in women's self-management, and with lower gestational weight gain and infant birth weight.
Subject(s)
Diabetes, Gestational , Self-Management , Pregnancy , Female , Humans , Diabetes, Gestational/therapy , Birth Weight , Pregnant Women , Pregnancy OutcomeABSTRACT
Prolonging the reproductive lifespan is beneficial for preserving the physical and psychological health of women. The transplantation of mesenchymal stem cell (MSC)derived exosomes (MSCExos) has been reported to be a promising regenerative therapeutic strategy for restoring the function of aging ovaries. The present study thus evaluated the therapeutic efficacy of exosomes derived from human umbilical cordMSCs (hUCMSCExos) in a mouse model of natural ovarian aging (NOA), and further investigated the role of exosomal microRNAs (miRNAs/miRs) in the mechanisms of this creative therapy. Specifically, following the administration of hUCMSCExos in mice with NOA, ovarian function was found to improve, as indicated by the restoration of follicle numbers and hormone levels. These exosomes were found to exhibit the ability to inhibit PTEN expression and suppress apoptosis both in vivo and in vitro. Subsequently, miRNA sequencing of the exosomes was performed, following which bioinformatics analysis was used to identify the highly expressed miRNAs that are capable of targeting PTEN expression. Through highthroughput sequencing and molecular analyses, miR215p was found to be the highest in ranking in terms of expression, suggesting that hUCMSCExos can preserve ovarian function by suppressing PTEN expression to inhibit apoptosis by delivering miR215p. On the whole, the results of the present study suggest that the application of exosomes can be used to restore ovarian function in mice with NOA. These positive findings also suggest that the transplantation of exosomes derived from MSCs holds promise as an agent against ovarian aging.
Subject(s)
Exosomes , Mesenchymal Stem Cells , MicroRNAs , Humans , Female , Animals , Mice , MicroRNAs/genetics , Aging , Apoptosis , Immunologic FactorsABSTRACT
BACKGROUND: Evidence-based practice (EBP) is an essential approach of optimizing patient outcomes and driving progress in clinical practice. As an important reserve talent of medical staff and researchers, the clinical postgraduates are expected to become the backbones of supporting the implementation of EBP in clinical units after graduation. The assessment of their EBP learning outcomes is an important issue, yet few tools have been developed specifically in Mainland China. The purpose of this study is to adapt the Evidence-Based Practice Profile Questionnaire (EBP2Q) to Mainland China's cultural context and to evaluate the psychometric properties of the Chinese EBP2Q in clinical postgraduates. METHODS: Cross-cultural modification, including translating the original EBP2Q into Chinese was implemented according to established guidelines. A pilot study was carried out in Mainland China among 30 clinical postgraduates. A subsequent validation study was conducted among 633 clinical postgraduates majoring in clinical medicine, stomatology and nursing from Mainland China. Construct validity was assessed by exploratory factor analysis (n = 313), together with confirmatory factor analysis (n = 320). Reliability was determined by internal consistency and test-retest reliability. RESULTS: The Chinese EBP2Q consisted of 40 items. The content validity index of the Chinese EBP2Q achieved 0.938 at an acceptable level. Principal component analysis resulted in a four-factor structure explaining 61.586% of the total variance. All fitting indices satisfied the standard based upon confirmatory factor analyses, indicating that the four-factor structure contributed to an ideal model fit. The internal consistency appeared high for the Chinese EBP2Q, reaching a Cronbach's alpha value of 0.926. Test-retest reliability was 0.868 and the split-half coefficient was 0.925. CONCLUSION: Chinese version of EBP2Q possesses adequate validity, test-retest reliability and internal consistency. It is a promising questionnaire to be adopted by Chinese medical educators in designing their course and curriculum, or by clinical postgraduates for self-assessment of EBP learning.
Subject(s)
Evidence-Based Practice , Humans , China , Pilot Projects , Reproducibility of Results , East Asian PeopleABSTRACT
In this study, a novel membrane bioreactor (MBR) inoculated with algal-bacterial granular sludge (ABGMBR) was established to improve pollutant removal and alleviate membrane fouling. The ABGMBR system showed higher pollutant removal rate and longer operation time (152 day) compared to the control MBR (AGMBR). Moreover, the contents of the pollutants such as granular sludges, extracellular polymeric substances (EPS), and soluble microbial products on the membrane were remarkably reduced, leading to the formation of a porous and loose cake layer on the membrane and a slow increase in transmembrane pressure. Standard blocking was the main mechanism of membrane fouling; however, the membrane pore blockage was significantly reduced in ABGMBR. The extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory suggested that the aggregation and adhesion of foulants on the membrane were greatly inhibited in ABGMBR. Furthermore, correlation analysis showed significant differences in membrane fouling characteristics between AGMBR and ABGMBR. The ABGMBR system effectively retarded sludge disintegration and increased the repulsion between the sludge and membrane owing to the favorable mixed liquor characteristics. This study showcases the superior operational efficiency and anti-fouling performance of ABGMBR, offering a novel perspective on sewage reuse and membrane fouling mitigation.
Subject(s)
Membranes, Artificial , Sewage , Bioreactors , Bacteria , Extracellular Polymeric Substance MatrixABSTRACT
Microplastics (MPs) and nanoplastics (NPs) are prevalent in sewage and pose a potential threat to nitrogen biotransformation in wastewater treatment systems. However, investigations on how MPs and NPs affect the microbial nitrogen conversion and metabolism of the activated sludge are still scanty. Herein, the responses of microbiomes and functional genes to polystyrene MPs and NPs in activated sludge systems were investigated by metagenomic analysis. Results indicated that 1 mg/L MPs and NPs had marginal impacts on the nitrogen removal performance of the activated sludge systems, whereas high concentrations of MPs and NPs (20 and 100 mg/L) decreased the total nitrogen removal efficiency (13.4%-30.6%) by suppressing the nitrogen transformation processes. Excessive reactive oxygen species induced by MPs and NPs caused cytotoxicity, as evidenced by impaired cytomembranes and decreased bioactivity. Metagenomic analysis revealed that MPs and NPs diminished the abundance of denitrifiers (e.g. Mesorhizobium, Rhodobacter and Thauera), and concurrently reduced the abundance of functional genes (e.g. napA, napB and nirS) encoding for key enzymes involved in the nitrogen transformations, as well as the genes (e.g. mdh) related to the electron donor production, thereby declining the nitrogen removal efficiency. Network analysis further clarified the attenuate association between denitrifiers and denitrification-related genes in the plastic-exposed systems, elucidating that MPs and NPs restrained the nitrogen removal by inhibiting the contributions of microorganisms to nitrogen transformation processes. This study provides vital insights into the responses of the microbial community structure and nitrogen conversion processes to micro(nano)plastics disturbance in activated sludge systems.
Subject(s)
Microbiota , Sewage , Sewage/chemistry , Plastics , Polystyrenes , Waste Disposal, Fluid/methods , Nitrogen/metabolism , Microplastics , Metabolic Networks and PathwaysABSTRACT
Cyanobacteria and their metabolites are one of the primary precursors of disinfection by-products (DBPs) in natural water environments. However, few studies have investigated whether the production of DBPs by cyanobacteria changes under complex environmental conditions and possible mechanisms underlying these changes. Therefore, we investigated the effects of algal growth phase, water temperature, pH, illumination and nutrients on the production of trihalomethane formation potential (THMFPs) by Microcystis aeruginosa in four algal metabolic fractions, that is, hydrophilic extracellular organic matter (HPI-EOM), hydrophobic EOM (HPO-EOM), hydrophilic intracellular organic matter (HPI-IOM) and hydrophobic IOM (HPO-IOM). Additionally, correlations between THMFPs and some typical algal metabolite surrogates were analyzed. The results showed that the productivity of THMFPs by M. aeruginosa in EOM could be affected significantly by the algal growth phase and incubation conditions, while the IOM productivity varied insignificantly. M. aeruginosa in the death phase could secrete more EOM and have a higher THMFP productivity than those in the exponential or stationary phases. Cyanobacteria grown under harsh conditions could have increased THMFP productivity in EOM by increasing the reactivity of algal metabolites with chlorine, for example, under low pH conditions, and secreting more metabolites in EOM, for example, under low temperature or nutrient limitation conditions. Polysaccharides were responsible for the enhanced THMFP productivity in HPI-EOM fraction, and a significant linear correlation was found between the concentration of polysaccharides and THMFPs (r = 0.8307). However, THMFPs in HPO-EOM did not correlate with dissolved organic carbon (DOC), ultraviolet absorbance at 254 nm (UV254), specific UV absorbance (SUVA) and cell density. Thus, we could not specify the kind of algal metabolites that contribute to the increased THMFPs in the HPO-EOM fraction under harsh growth conditions. Compared with the case in EOM, the THMFPs in IOM were more stable and correlated with the cell density and total amount of IOM. The results implied that the THMFPs in the EOM were sensitive to growth conditions and were independent of algal density. Considering the fact that traditional water treatment plants cannot remove dissolved organics as efficiently as algal cells, the increased THMFP productivity in EOM by M. aeruginosa under harsh growth conditions could be a potentially serious threat to the safety of the water supply.
Subject(s)
Cyanobacteria , Microcystis , Water Purification , Microcystis/metabolism , Trihalomethanes/metabolism , Disinfection , Chlorine/metabolism , Water Purification/methodsABSTRACT
Vaginal reconstruction has incorporated the use of gastrointestinal segments for decades, but the technique is inevitably associated with complications. Tissue-engineering techniques, however, have brought great hope for vaginal reconstruction. This study aimed to evaluate the utility of small intestinal submucosa (SIS) in reconstructing clinically significant large vaginal defects in a porcine model and to investigate the role of the Hippo pathway in the vascular remodeling process. The composition and mechanical properties of SIS were characterized. Full-thickness vaginal defects were established in 10 minipig donors, with 4 cm lengths removed and replaced by an equal sized SIS scaffolds. The neovaginas were subjected to macroscopic, histological, immunohistochemical and molecular evaluations at 4 and 12 weeks after the surgery. Four weeks after the operation, extracellular matrix reorganization and complete coverage of the surface of the luminal matrix by vaginal epithelium were observed, accompanied by the formation of a microvascular network and the regeneration of smooth muscles, albeit disorderly arranged. Twelve weeks after implantation, enhancements were seen in the formation of the multi-layered squamous epithelium, angiogenesis, and large muscle bundle formation in the vagina. Additionally, the expression levels of angiogenesis-related proteins, proliferation-related proteins and Hippo pathway-related proteins in the neovagina were significantly increased. These results indicate that SIS could be used to reconstruct large vaginal defects and that the vascular remodeling process is potentially regulated by the Hippo pathway.
Subject(s)
Intestine, Small , Vascular Remodeling , Female , Animals , Swine , Hippo Signaling Pathway , Swine, Miniature , Vagina/surgeryABSTRACT
OBJECTIVE: This study aims to explore the ability of adenosine deaminase (ADA) to discriminate atypical Epstein Barr virus (EBV) infection in children from acute febrile illness. METHODS: All children admitted to the Children's Hospital of Soochow University between 2018 and 2019, who were acute febrile patients and subjected to the plasma EBV-DNA polymerase chain reaction (PCR) and indirect immunofluorescence (IIF) assay for EBV-specific antibodies assays. The diagnostic value of each detection index was compared by the area under the ROC curve. RESULTS: In children with atypical Epstein Barr virus infection, the sensitivity, specificity, positive predictive value, negative predictive value and Youden index were 62.87%, 100.00%,100.00%, 61.73% and 0.63 for EBV-DNA PCR assay, 80.84%, 100.00%, 100.00%, 75.76% and 0.81 for VCA-IgG avidity and 89.22%, 87.00%, 91.98%, 82.86% and 0.76 for ADA. VCA-IgG avidity (AUC=0.904, P<0.01) and ADA (AUC=0.881, P<0.01) assays had the great diagnostic efficiency. In addition, the sensitivity, specificity and AUC were 92.75%,91.43% and 0.921(95%CI: 0.856-0.985) for ADA in the course≤3 days group, respectively. CONCLUSIONS: ADA has a good diagnostic value in the early stage of atypical EBV infection, and is not affected by primary EBV infection and reactivation. SCHLüSSELWöRTER: Adenosine deaminase, Epstein -Barr virus, Biomarker, children.
Subject(s)
Epstein-Barr Virus Infections , Humans , Child , Epstein-Barr Virus Infections/diagnosis , Herpesvirus 4, Human/genetics , Adenosine Deaminase , Antibodies, Viral , Immunoglobulin G , Biomarkers , DNAABSTRACT
Light-driven algal-bacterial granular sludge (ABGS) is an innovative low-carbon technology with significant merits in treating municipal wastewater, but how to shorten the photogranulation process, especially under low aeration conditions, is largely unknown. Herein, two strategies were proposed to accelerate the start-up of the ABGS system in photo-sequencing batch reactors (PSBRs) with a low superficial gas velocity of 0.5 cm/s. Compared to directly dosing mycelial pellets (MPs), applying MPs to flocculate algae and using the formed algal-mycelial pellets (AMPs) as carriers enhanced the establishment of the algal-bacterial symbiosis. The ABGS system developed rapidly within 20 days, with a large particle diameter (mean diameter of 321 µm) and excellent settleability (SVI30 of 55.4 mL/g). More importantly, this system could be stably operated for at least 100 days, mainly attributed to the reinforced secretion of protein with unique secondary structure and elevated hydrophobic functional groups. As for the reactor performance, the average removal efficiencies of the ABGS system were 97.8% for organic matter, 80.0% for total nitrogen, and 84.4% for phosphorus. The enrichment of functional bacteria and algae, and the up-regulation of functional genes and enzymes involved in electron production and transport processes likely drove the transformation of the pollutants, underlining the inherent mechanism for the excellent nutrient removal performance. This study provides a promising approach to solve the problem of a long ABGS start-up period and unstable granular structure under low aeration conditions, which is significant for achieving effective wastewater treatment without energy intensive aeration.