Enhanced activation of peroxymonosulfate by a floating FeMo3Ox/C3N4 photocatalyst under visible-light assistance for oxytetracycline degradation: Performance, mechanisms and comparison with H2O2 activation

In this study, a floating FeMo₃O_x/C₃N₄-EP (FM-C-P) composite with highly stability and reusability was synthesized by an impregnation/calcination process and used to activate peroxymonosulfate (PMS) for oxytetracycline (OTC) degradation under visible light irradiation. The results demonstrated that 98.1% of OTC (50 mg/L) removal can be achieved by the activation of PMS (5 mM) using FM-C-P (1 g/L) in 30 min under visible light irradiation. The pseudo-first-order rate constant was calculated to be 0.181 min^-1. The degradation process with PMS was hardly affected by pH (3-11) and co-existing substance. ·SO₄^-, ·OH, ·O₂^- and ¹O₂ were produced in the Vis/PMS/FM-C-P system and ¹O₂ was determined to be the main reactive oxygen species (ROSs). The high efficiency of ROSs production mainly contributed to two mechanisms. Firstly, via the combination of ≡Fe (II)-·SO₅^- and free state ·SO₅^-, ¹O₂ could be generated on the Fe-N_x site. Secondly, photo-induced electrons in the FeMo₃O_x/g-C₃N₄ heterojunction could react with Fe (III) and Mo (VI) to form catalytically active species Fe (II) and Mo (IV). Moreover, the proposed degradation pathway and the toxicity of intermediated products was analyzed. Overall, this study was expected to deepen the understanding of the photo-assisted PMS activation and the generation of ¹O₂ with the presence of metal-oxide/C₃N₄ heterojunction.

Pollution characteristics of typical ARGs in the sediments of the sea area adjacent to the Yangtze Estuary, China

The pollution characteristics of the typical antibiotic resistance genes (ARGs) in the sediments of the sea area adjacent to the Yangtze Estuary, China were investigated with both seasonal and spatial insights. The positive rates of sulfonamides sul1, sul2, tetracycline tetW and quinolone gyrA resistance genes in the sediments of all sampling sites were 100%, indicating that the sea area adjacent to the Yangtze Estuary were extensively polluted by these ARGs. Occupying a dominance in most sampling sites, sul1 was found to be the dominant resistance gene in the sediments of the sea area adjacent to the Yangtze Estuary. In terms of seasonal variation characteristics, the absolute abundances of the ARGs in flood season were higher than those in dry season. In terms of spatial distribution characteristics, the absolute abundances of the ARGs in the southern sites were mostly higher than those in the northern sites, and the high abundance sites were mostly located near the coast. Different ARGs also showed different spatial distribution characteristics. The disclosure of the pollution characteristics of the typical ARGs in the sediments of the sea area adjacent to the Yangtze Estuary can provide valued information for protecting the environment of this area as well as the Yangtze River Basin.

[Clinical pathologic analysis and review of literature on 11 cases of calcifying epithelial odontogenic tumor]

Objective: To improve the understanding of histological variants of calcifying epithelial odontogenic tumor (CEOT). Methods: In this retrospective study, 11 cases of CEOT diagnosed from January 2008 to March 2022 were enrolled in the Department of Oral Pathology of Nanjing Stomatological Hospital, Medical School of Nanjing University. Among them, 10 were male and 1 was female. The patients were 19 to 58 years old [(43.0±11.9) years] and the course of disease was 2 weeks to 5 years. The clinicopathological characteristics were analyzed and the follow-up of patients ranged from 1 to 8 years, including 8 cases with follow-up data and 3 cases lost to follow-up. Furthermore, the related domestic and international literature was reviewed. Results: Eleven cases of CEOT included 6 cases of classic CEOT, 2 cases of clear cell CEOT, 2 cases of Langerhans cell-rich variant of CEOT and 1 case of non-calcified CEOT. In 6 cases of classic CEOT, the ratio of occurrence in mandible to maxilla was 2∶1, the ratio in central parts to peripheral parts was 5∶1, 2 cases were associated with unerupted teeth and 3 cases showed local aggressiveness. Histopathologically, classic CEOT showed eosinophilic epithelial cells, amyloid and calcification with Ki-67 value<5%. Among 4 cases with follow-up information, 1 case recurred after 1 year and 3 cases did not recur for 3 to 8 years. In 2 cases of clear cell CEOT, they both occurred in the periphery of mandible, pathologically showing a mix of lamellar balloon-like clear cells and typical CEOT, positive for CK5/6 and p63 in the area where the epithelial cells and clear cells were located, scattered positive for periodic acid-Schiff (PAS) in clear cells, which indicated the presence of glycogen. The maximum Ki-67 value was 5% in this type. One case lost to follow-up and the other case did not recur for 1 year follow-up after surgery. In 2 cases of Langerhans cell-rich variant of CEOT, they were cystic solid lesions and both occurred in the anterior maxilla. Langerhans cells were scattered in the epithelium and non-calcified amyloid glomeruli were present. Two cases were followed up for 1 year and 2 years without recurrence after surgery. One case of non-calcified CEOT that occurs within the jan showed invasion of surrounding soft tissues and the highest of Ki-67 value at 8% in all 11 cases without recurrence at 1 year follow-up. Conclusions: The histological pattern of classic CEOT is unique, and it is necessary to prompt the understanding of several histological variants derived from it.

Dissimilatory and Cytoplasmic Antimonate Reductions in a Hydrogen-Based Membrane Biofilm Reactor

A hydrogen-based membrane biofilm reactor (H₂-MBfR) was operated to investigate the bioreduction of antimonate [Sb(V)] in terms of Sb(V) removal, the fate of Sb, and the pathways of reduction metabolism. The MBfR achieved up to 80% Sb(V) removal and an Sb(V) removal flux of 0.55 g/m²·day. Sb(V) was reduced to Sb(III), which mainly formed Sb₂O₃ precipitates in the biofilm matrix, although some Sb(III) was retained intracellularly. High Sb(V) loading caused stress that deteriorated performance that was not recovered when the high Sb(V) loading was removed. The biofilm community consisted of DSbRB (dissimilatory Sb-reduction bacteria), SbRB (Sb-resistant bacteria), and DIRB (dissimilatory iron-reducing bacteria). Dissimilatory antimonate reduction, mediated by the respiratory arsenate reductase ArrAB, was the main reduction route, but respiratory reduction coexisted with cytoplasmic Sb(V)-reduction mediated by arsenate reductase ArsC. Increasing Sb(V) loading caused stress that led to increases in the expression of arsC gene and intracellular accumulation of Sb(III). By illuminating the roles of the dissimilatory and cytoplasmic Sb(V) reduction mechanism in the biofilms of the H₂-MBfR, this study reveals that the Sb(V) loading should be controlled to avoid stress that deteriorates Sb(V) reduction.

Effect of biofilm colonization on Pb(II) adsorption onto poly(butylene succinate) microplastic during its biodegradation

Few studies have mentioned the enrichment of heavy metal pollutants on microplastics derived from degradable plastics. This study investigated the adsorption behavior of Pb(II) onto biodegradable poly(butylene succinate) (PBS) microplastics during its biodegradation. The results indicated that Pb(II) adsorbed by biofilm-colonized biodegraded-PBS microplastics (B-PBS) was about 10-folds higher than that of virgin PBS (647.09 μg·g^-1 versus 64.13 μg·g^-1) due to the biofilm colonization and the degradation of PBS. After removing the biofilm, the biodegraded PBS still had high Pb(II) adsorption capacity, which was attributed to the complexation of Pb(II) and the stably adhered extracellular polymeric substances (EPS). Pb(II) adsorption onto both virgin PBS and B-PBS was highly pH-dependent, its adsorption on virgin PBS was dominated by electrostatic interaction, while as for B-PBS, the adsorption mechanisms mainly involved the coordination/complexation of Pb(II) and the EPS components on the colonized biofilm, surface complexation, and electrostatic interaction. This study suggested that the enrichment of heavy metal pollutants onto the biodegradable microplastics may pose risks to the aquatic ecosystem.

[Predictive value of plasma TMAO combined with NT-proBNP on the prognosis and length of hospitalization of patients with ischemic heart failure]

Objective: To explore the value of the assessment of plasma trimethylamine N-oxide (TMAO) combined with N-terminal pro-B-type natriuretic peptide (NT-proBNP) on predicting the all-cause mortality, length of hospitalization, and hospital cost in ischemic heart failure (IHF) patients. Methods: This prospective cohort study included 189 patients (157 males, mean age (64.0±10.5) years) with a left ventricular ejection fraction<45% caused by coronary artery disease, who hospitalized in our department from March 2016 to December 2020. Baseline data, including demographics, comorbid conditions and laboratory examination, were analyzed. The cumulative rate of all-cause mortality was evaluated using the Kaplan-Meier method and compared between the groups according to the log-rank test. Relative risks were reported as hazard ratios (HR) and 95% confidence interval (95%CI) calculated using the Cox proportional-hazards analysis, with stepwise adjustment for covariables. Spearman correlation analysis was then performed to determine the relationship between TMAO combined with NT-proBNP and length of hospitalization and hospital cost. Results: There were 50 patients in the low TMAO+low NT-proBNP group, 89 patients in high TMAO or high NT-proBNP group, 50 patients in high TMAO+high NT-proBNP group. The mean follow-up period was 3.0 years. Death occurred in 70 patients (37.0%), 27 patients (54.0%) in high TMAO+high NT-proBNP group, 29 patients (32.6%) in high TMAO or high NT-proBNP group and 14 patients (28.0%) in low TMAO+low NT-proBNP group. TMAO, in combination with NT-proBNP, improved all-cause mortality prediction in IHF patients when stratified as none, one or both biomarker(s) elevation, with the highest risk of all-cause mortality in high TMAO+high NT-proBNP group (HR=3.62, 95%CI 1.89-6.96, P<0.001). ROC curve analysis further confirmed that TMAO combined with NT-proBNP strengthened the prediction performance on the risk of all-cause death (AUC=0.727(95%CI 0.640-0.813), sensitivity 55.0%, characteristic 83.1%). Spearman correlation analysis showed that IHF patients with high TMAO and high NT-proBNP were positively associated with longer duration of hospitalization (r=0.191,P=0.009), but not associated with higher hospital cost (r=0.030, P=0.686). Conclusions: TMAO combined with NT-proBNP are valuable prediction tool on risk stratification of patients with IHF, and those with two biomarkers elevation face the highest risk of mortality during follow-up period, and are associated with the longer hospital stay.

[Prediction of trends for fine-scale spread of Oncomelania hupensis in Shanghai Municipality based on supervised machine learning models]

OBJECTIVE

To predict the trends for fine-scale spread of Oncomelania hupensis based on supervised machine learning models in Shanghai Municipality, so as to provide insights into precision O. hupensis snail control.

METHODS

Based on 2016 O. hupensis snail survey data in Shanghai Municipality and climatic, geographical, vegetation and socioeconomic data relating to O. hupensis snail distribution, seven supervised machine learning models were created to predict the risk of snail spread in Shanghai, including decision tree, random forest, generalized boosted model, support vector machine, naive Bayes, k-nearest neighbor and C5.0. The performance of seven models for predicting snail spread was evaluated with the area under the receiver operating characteristic curve (AUC), F1-score and accuracy, and optimal models were selected to identify the environmental variables affecting snail spread and predict the areas at risk of snail spread in Shanghai Municipality.

RESULTS

Seven supervised machine learning models were successfully created to predict the risk of snail spread in Shanghai Municipality, and random forest (AUC = 0.901, F1-score = 0.840, ACC = 0.797) and generalized boosted model (AUC= 0.889, F1-score = 0.869, ACC = 0.835) showed higher predictive performance than other models. Random forest analysis showed that the three most important climatic variables contributing to snail spread in Shanghai included aridity (11.87%), ≥ 0 °C annual accumulated temperature (10.19%), moisture index (10.18%) and average annual precipitation (9.86%), the two most important vegetation variables included the vegetation index of the first quarter (8.30%) and vegetation index of the second quarter (7.69%). Snails were more likely to spread at aridity of < 0.87, ≥ 0 °C annual accumulated temperature of 5 550 to 5 675 °C, moisture index of > 39% and average annual precipitation of > 1 180 mm, and with the vegetation index of the first quarter of > 0.4 and the vegetation index of the first quarter of > 0.6. According to the water resource developments and township administrative maps, the areas at risk of snail spread were mainly predicted in 10 townships/subdistricts, covering the Xipian, Dongpian and Tainan sections of southern Shanghai.

CONCLUSIONS

Supervised machine learning models are effective to predict the risk of fine-scale O. hupensis snail spread and identify the environmental determinants relating to snail spread. The areas at risk of O. hupensis snail spread are mainly located in southwestern Songjiang District, northwestern Jinshan District and southeastern Qingpu District of Shanghai Municipality.

Activation of peroxymonosulfate by a floating oxygen vacancies - CuFe2O4 photocatalyst under visible light for efficient degradation of sulfamethazine

In this study, expanded perlite supported oxygen vacancies-CuFe₂O₄ (OVs-CFEp) was synthesized via a simple method and utilized as floating catalyst to activate peroxymonosulfate (PMS) for the removal of sulfamethazine (SMT) under visible light irradiation. OVs-CFEp/Vis/PMS synergy presents much superior performance than that of OVs-CFEp/Vis system and OVs-CFEp/PMS system. PMS was efficiently activated by OVs-CFEp at a wide range of pH values, while the degrading rate of SMT was up to 95% in OVs-CFEp/Vis/PMS system. Oxygen vacancies and ·O₂^- accelerated the conversion of Fe(III)/Fe(II) and Cu(I)/Cu(II). The combination of the floating loader boosted light absorption capacity and sufficiently prevented metal ions leaching, which was all beneficial to enhance catalytic performance and recyclability. Besides, the reactive oxygen species were investigated systematically, proving that visible light and OVs-CFEp could activate PMS to produce ·SO₄^-, ·OH, O₂·^-, and ¹O₂ reactive species. Furthermore, based on intermediates identification and Density Functional Theory (DFT) calculation, three types and seven main degradation pathways involving cleavage of bond, SMT molecular rearrangement, and hydroxylation reaction were proposed. So this high photo-absorbing catalyst coupling with advanced oxidation progress was promising for extensive environmental remediation.

A kinetic model for 2,4-dichlorophenol adsorption and hydrodechlorination over a palladized biofilm

Adsorption and catalytic hydrodechlorination (HDC) of aqueous 2,4-DCP by palladium nanoparticles (Pd0NPs) associated with a biofilm (i.e., a Pd0-biofilm) was investigated in terms of the removal efficiency of 2,4-DCP, dechlorinated product selectivity, and reduction kinetics. Experiments were executed with Pd0-biofilm and with abiotic Pd0NPs-film alone. The 2,4-DCP-adsorption capacity of Pd0-biofilm was 2- to 5-fold greater than that of abiotic Pd0NPs-film, and the adsorption accelerated dechlorination by Pd0-biofilm, including selectivity to phenol instead of mono-chlorophenols. A mechanistic kinetic model was developed to represent the sequential adsorption and reduction processes. Modeling results represented well the removal of 2,4-DCP and quantified that Pd0-biofilm had a strong affinity for adsorbing 2,4-DCP. The strong adsorption increased the volume-averaged concentration of 2,4-DCP concentration inside the Pd0-biofilm, compared to the concentration in the bulk liquid. This increase in the local concentration of 2,4-DCP led to a 2- to 4-fold increase in the reduction rate of 2,4-DCP in Pd0-biofilm, compared to abiotic Pd0NPs-film. Thus, coupling Pd0NPs with the biofilm promoted 2,4-DCP removal and full dechlorination despite its low concentration in bulk water.

Enhanced visible light photo-Fenton-like degradation of tetracyclines by expanded perlite supported FeMo3Ox/g-C3N4 floating Z-scheme catalyst

In the conventional Fenton system, the relatively low efficiency of Fe (II) regeneration is a significant drawback. To address this shortcoming, a novel floating Z-scheme photo-Fenton catalyst FeMo₃O_x/g-C₃N₄/EP was prepared by a facile dip-calcination method, in which iron and molybdenum oxides with mixed valence states (FeMo₃O_x) and graphitic carbon nitride (g-C₃N₄) were loaded on the expanded perlite. The removal efficiencies reached the maximum at 98.0%, 93.1% and 97.1% for tetracycline, oxytetracycline and chlortetracycline, respectively, after 60 min dark adsorption and 60 min photo-Fenton process. The aid of dual ion (Fe and Mo) synergy system and photoreduction by Z-scheme photocatalyst enhanced the Fe (II) regeneration, resulting in the excellent performance. Radical scavenger experiment, electron spin resonance spectra (ESR) and X-ray photoelectron spectra (XPS) were used to confirm the mechanism of free radicals' formation and Fe/Mo redox cycling. ·OH, ·O₂^- and ¹O₂ played important roles in the pollutant's degradation, while the generation of ·O₂^- was enhanced due to the floatability in this system. The possible degradation pathways of TC were put forward according to the results of mass spectrum and Orbital-Weighted Fukui Function. Overall, this work provides new insights on the cooperation between iron-based mix oxides and semiconductor in the photo-Fenton system.

Simultaneous adsorption and oxidation of Sb(III) from water by the pH-sensitive superabsorbent polymer hydrogel incorporated with Fe-Mn binary oxides composite

In this work, the superabsorbent polymer hydrogel (SPH) of Poly(potassium acrylate-co-acrylamide (PPAA)) incorporated with Fe-Mn binary oxides (FMBOs) was synthesized and used for the removal of Sb(III) from water. Characterization analysis proved that FMBO₃ was successfully encapsulated into the SPH. The Fe/Mn oxide species in the composite SPH comprised FeO(OH), Fe₂O₃, MnO(OH), and MnO₂. The functional groups including N-H, -OH, carboxy as well as Fe atoms were confirmed adsorption sites through ligand exchange and inner-sphere complexes formation. Mn oxides can partially oxidize Sb(III) to Sb(V). Compared with the pseudo-first-order model, the pseudo-second-order model could better describe the adsorption kinetics. And the swelling degree of the composite SPH had a positive impact on the removal rate. The Langmuir-Freundlich model was the most suitable isotherm model to analyze the experimental data. According to thermodynamic parameters, the adsorption process was a spontaneous exothermic reaction. The maximum adsorption capacity of the composite SPH for Sb(III) could be up to 105.59 mg/g at 288 K. In addition, a stable removal rate can be achieved over a wide pH range of 3-10, with little metal leaching even under acidic conditions. Furthermore, coexisting ions and DOM displayed an insignificant influence on the adsorption of Sb(III).

Large Culprit Plaque and More Intracranial Plaques Are Associated with Recurrent Stroke: A Case-Control Study Using Vessel Wall Imaging

BACKGROUND AND PURPOSE

Intracranial atherosclerotic plaque features are potential factors associated with recurrent stroke, but previous studies only focused on a single lesion, and few studies investigated them with perfusion impairment. This study aimed to investigate the association among whole-brain plaque features, perfusion deficit, and stroke recurrence.

MATERIALS AND METHODS

Patients with ischemic stroke due to intracranial atherosclerosis were retrospectively collected and categorized into first-time and recurrent-stroke groups. Patients underwent high-resolution vessel wall imaging and DSC-PWI. Intracranial plaque number, culprit plaque features (such as plaque volume/burden, degree of stenosis, enhancement ratio), and perfusion deficit variables were recorded. Logistic regression analyses were performed to determine the independent factors associated with recurrent stroke.

RESULTS

One hundred seventy-five patients (mean age, 59 [SD, 12] years; 115 men) were included. Compared with the first-time stroke group (n = 100), the recurrent-stroke group (n = 75) had a larger culprit volume (P = .006) and showed more intracranial plaques (P < .001) and more enhanced plaques (P = .003). After we adjusted for other factors, culprit plaque volume (OR, 1.16 per 10-mm³ increase; 95% CI, 1.03-1.30; P = .015) and total plaque number (OR, 1.31; 95% CI, 1.13-1.52; P < .001) were independently associated with recurrent stroke. Combining these factors increased the area under the curve to 0.71.

CONCLUSIONS

Large culprit plaque and more intracranial plaques were independently associated with recurrent stroke. Performing whole-brain vessel wall imaging may help identify patients with a higher risk of recurrent stroke.

The influent COD/N ratio controlled the linear alkylbenzene sulfonate biodegradation and extracellular polymeric substances accumulation in an oxygen-based membrane biofilm reactor

This work evaluated the fates of linear alkylbenzene sulfonate (LAS), chemical oxygen demand (COD), ammonia nitrogen (NH₄⁺-N), and total nitrogen (TN) when treating greywater (GW) in an oxygen-based membrane biofilm reactor (O₂-MBfR). An influent ratio of chemical oxygen demand to total nitrogen (COD/TN) of 20 g COD/g N gave the best removals of LAS, COD, NH₄⁺-N and TN, and it also had the greatest EPS accumulation in the biofilm. Higher EPS and improved performance were linked to increases in the relative abundances of bacteria able to biodegrade LAS (Zoogloea, Pseudomonas, Parvibaculum, Magnetospirillum and Mycobacterium) and to nitrify (Nitrosomonas and Nitrospira), as well as to ammonia oxidation related enzyme (ammonia monooxygenase). The EPS was dominated by protein, which played a key role in adsorbing LAS, achieving short-time protection from LAS toxicity and allowed LAS biodegradation. Continuous high-efficiency removal of LAS alleviated LAS toxicity to microbial physiological functions, including nitrification, nitrate respiration, the tricarboxylic acid (TCA) cycle, and adenosine triphosphate (ATP) production, achieving the stable high-efficient simultaneous removal of organics and nitrogen in the O₂-MBfR.

Co-removal of 2,4-dichlorophenol and nitrate using a palladized biofilm: Denitrification-promoted microbial mineralization following catalytic dechlorination

The effects of nitrate on 2,4-dichlorophenol (2,4-DCP) dechlorination and biodegradation in a hydrogen (H₂)-based palladized membrane biofilm reactor (Pd-MBfR) were studied. The Pd-MBfR was created by synthesizing palladium nanoparticle (Pd⁰NPs) that spontaneously associated with the biofilm to form a Pd⁰-biofilm. Without input of nitrate, the Pd-MBfR had rapid and stable catalytic hydrodechlorination: 93% of the 100-μM influent 2,4-DCP was continuously converted to phenol, part of which was then fermented via acetogenesis and methanogenesis. Introduction of nitrate enabled phenol mineralization via denitrification with only a minor decrease in catalytic hydrodechlorination. Phenol-degrading bacteria capable of nitrate respiration were enriched in the Pd⁰-biofilm, which was dominated by the heterotrophic genera Thauera and Azospira. Because the heterotrophic denitrifiers had greater yields than autotrophic denitrifiers, phenol was a more favorable electron donor than H₂ for denitrification. This feature facilitated phenol mineralization and ameliorated denitrification inhibition of catalytic dechlorination through competition for H₂. Increased nitrite loading eventually led to deterioration of the dechlorination flux and selectivity toward phenol. This study documents simultaneous removal of 2,4-DCP and nitrate in the Pd-MBfR and interactions between the two reductions.

In-situ remediation of zinc contaminated soil using phosphorus recovery product: Hydroxyapatite/calcium silicate hydrate (HAP/C-S-H)

This work discussed the feasibility and stability of utilizing C-S-H phosphorus recovered products, HAP/C-S-H, to remove Zn(Ⅱ) from aqueous solution and in-situ immobilize Zn(Ⅱ) in contaminated soil. The removal mechanisms of Zn(Ⅱ) by HAP/C-S-H were relatively complex, combining multiple reactions including electrostatic attraction, ion exchange, surface complexation and (co-)precipitation. The removal rate of Zn(Ⅱ) by HAP/C-S-H raised with the increase of pH value, reaching 99.47% at pH of 8 in aqueous solution. The ion strength of background solution negatively affected the adsorption efficiency. The pseudo-second-order model and Langmuir model were more suitable to fit the Zn(Ⅱ) adsorption experimental data for the adsorbent. The adsorption process was endothermic and spontaneous naturally according to thermodynamic parameter. The maximum adsorption capacity of HAP/C-S-H can reach 114.0 mg/g at 308 K. After 28 days of immobilization, the release of Zn(Ⅱ) in soil with HAP/C-S-H remarkably decreased to 0.6 mg/L, compared with control group (2.9 mg/L). BCR sequential extraction results indicated that HAP/C-S-H could convert acid-soluble Zn(Ⅱ) into reducible and residual Zn(Ⅱ), reducing the bioavailability and ecotoxicity of Zn(Ⅱ) in contaminated soil. pH-dependent leaching tests revealed that the soil with HAP/C-S-H had stronger resistance to acid impact.

Assessing effects of Ca2+ addition on membrane bioreactor performance and macro-floc sludge characteristics

Calcium ions (Ca²⁺) can trigger coagulation-flocculation process to form macro-flocculated sludge (MFS). Thus, dosing Ca²⁺-containing reagents into membrane bioreactors (MBRs) is considered as a promising approach to mitigate membrane biofouling. However, a mechanistic understanding of Ca²⁺ addition to MBR performance remains elucidated, such as physicochemical characteristics of MFS and their functionality variations. Consequently, this study was sought to understand the interplays of Ca²⁺ addition and MBR performance with a focus on characterizing MFS in detail. Three parallel MBRs were amended with 82, 208 and 410 mg-Ca²⁺/L final concentrations. Particle size analyses revealed that MFS formation was overall enhanced by the Ca²⁺ addition and granular sludge with diameters of up to 900 μm was formed in the 410 mg-Ca²⁺/L scenario. We believed that cationic bridges facilitated by elevated Ca²⁺ concentrations in conjunction with coagulation-flocculation were primary mechanisms of the formation of large flocs. Moreover, significant portions of soluble proteins and polysaccharides were flocculated and precipitated by Ca²⁺, which demonstrated a negative correlation between extracellular polymeric substances (EPS) concentrations and the formation of MFS. Furthermore, the population abundancies of Thiotrichaceae, Sphingomonadales and Hyphomicrobiaceae decreased in the sludge with Ca²⁺ addition resulted in profound changes of the microbial communities in the MBRs. But MBR performance, such as chemical oxygen demand removal (over 90%), showed no variation during the MBR operation. On the contrary, total nitrogen removal was inhibited in the MBRs. It was because the enlarging MFS formed diffusion barriers to prevent organic component from entering into the sludge flocs to be consumed.

Effects of coexistence of tetracycline, copper and microplastics on the fate of antibiotic resistance genes in manured soil

The coexistence of antibiotics, heavy metals and microplastics is becoming commonplace and may affect antibiotic resistance in manured soil. The current understanding of the role of microplastics in soil with combined pollution of antibiotics, heavy metals and antibiotic resistance genes (ARGs) is limited. Here, the effects of the coexistence of tetracycline (TC), Cu and environmental microplastics (EM) on the fate of nine ARGs and three heavy metal resistance genes in agricultural soil were investigated by batch and microcosm experiments. EM were obtained by exposing virgin microplastics to soil environments for 80 days, which exhibited higher adsorption affinity for Cu and TC than soil particles and virgin microplastics. 1% EM in soil increased bioavailable concentrations of TC and Cu by 79-138% and 88-135%, respectively, and decreased TC dissipation from 11.79 mg kg^-1 to 3.08 mg kg^-1. Correspondingly, the total relative abundances of target ARGs increased by 219-348%. The significant correlations of tetG, tetB, tetQ, sul2, sul1 and intl1 with bioavailable fractions of TC and Cu in soil environments were revealed by network analysis. Moreover, scanning electron micrographs showed the special plastisphere around EM. Attributed to the biofilm generation and higher pollutant accumulation in the plastisphere, EM could be the source of antibiotic-resistant bacteria and ARGs in soil environments. Structure equation models further identified that indirect effects of EM acted a major role in the propagation of ARGs by altering soil properties, soil microbial diversity and intl1 abundance. This study revealed that EM could increase the stimulative effects of Cu and TC on antibiotic resistance and magnify the environmental risk of manure application in soil environments.

Opportunistic pathogens exhibit distinct growth dynamics in rainwater and tap water storage systems

Opportunistic pathogens (OPs) are emerging microbial contaminants in engineered water systems, yet their growth potential in rainwater systems has not been evaluated. The purpose of this study was to compare the growth dynamics of bacterial OPs and related genera (Pseudomonas aeruginosa, Legionella spp., L. pneumophila, Mycobacterium spp., and M. avium), two amoebal hosts (Acanthamoeba spp. and Vermamoeba vermiformis), and the fecal indicator Escherichia coli in simulated rainwater and tap water storage systems (SWSSs). Quantitative polymerase chain reaction (q-PCR) analysis of target microorganisms in SWSS influents and effluents demonstrated that P. aeruginosa and Legionella thrived in rainwater, but not in tap water. V. vermiformis proliferated in both rainwater and tap water polyvinyl chloride (PVC) SWSSs, while mycobacteria were largely absent in rainwater SWSSs. Tank materials exerted stronger influence on target microorganisms in rainwater SWSSs relative to tap water SWSSs, with species-specific responses noted in bulk water and biofilm. For instance, P. aeruginosa and V. vermiformis had the highest gene copy numbers in PVC rainwater SWSS effluents and biofilm, while Legionella peaked in stainless steel rainwater SWSS effluents and PVC rainwater SWSS biofilm. These results highlighted the OP contamination risks in rainwater storage systems and provided insights into rainwater system design and operation in terms of OP control.

[Clinical features of primary isolated chylopericardium: a retrospective review study]

Objective: To examine the clinical characteristics and abnormal reflux branches of primary isolated chylopericardium. Methods: Totally 43 patients with primary isolated chylopericardium at Department of Lymphatic Surgery, Affiliated Beijing Shijitan Hospital,Capital Medical University from June 2007 to January 2018 were recruited in this study. There were 21 males and 22 females, aging (23.0±15.9) years (range: 2 to 57 years). The levels of triglyceride, total cholesterol, total protein and albumin in pericardial effusion and blood were compared by paired-t test, and the characteristics of lymphatic system in direct lymphangiography and postoperative CT were analyzed. Results: Pericardial effusion was mainly milky white and monocytes, and 95.3%(41/43) were positive for Rivalta test. The level of triglyceride in pericardial effusion was significantly higher than that of blood ((9.67±5.11) mmol/L vs. (1.28±0.89) mmol/L, t=10.557, P<0.01), and the levels of total cholesterol ((2.19±0.52) mmol/L vs. (4.12±1.06) mmol/L, t=-3.732, P<0.01), total protein ((61.25±16.17) g/L vs. (68.26±8.30) g/L, t=-2.958, P=0.005) and albumin ((36.63±7.06) g/L vs. (42.32±4.73) g/L, t=-5.747, P<0.01) were significantly lower than that of blood. In the direct lymphangiography, the imaging of iliac and retroperitoneal lymphatics showed dilated or tortuous in 90.7% (39/43), the thoracoabdominal segment of thoracic duct showed dilation in 46.5% (20/43), and cervical thoracic duct imaging showed dilation in 44.2% (19/43) and stenosis in 55.8% (24/43). The image of lipiodol flowing into the vein showed obstruction at the venous angle. There were 60.5%(26/43) of the patients with lipiodol reflux through the bronchomediastinal trunk (type Ⅰ), 11.6%(5/43) with lipiodol diffusion to the pericardium through the abnormal pathway from the thoracic segment of the thoracic duct (type Ⅱ), while no communication pathway between the thoracic duct and the pericardial cavity (type Ⅲ) found in 27.9%(12/43). CT images obtained after the direct lymphangiography showed 34.9%(15/43) had abnormal distribution of lipiodol in pericardium, mediastinal lymph nodes and lung hilar lymph nodes, 46.5%(20/43) in mediastinal lymph nodes and lung hilar lymph nodes, 14.0%(6/43) only mediastinal lymph nodes, 4.6%(2/43) had no lipiodol in the above areas. Conclusions: Pericardial effusion compared with same period blood, has higher triglyceride, lower total cholesterol, total protein and albumin. The obstruction of the cervical segment of the thoracic duct and the formation of abnormal reflux branches would be corelative to primary isolated chylopericardium.

Prognostic value of late gadolinium enhancement in arrhythmogenic right ventricular cardiomyopathy: a meta-analysis

AIM

To assess systematically the prognostic value of cardiac magnetic resonance imaging (CMRI) in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC).

MATERIALS AND METHODS

The full text of studies of the clinical efficacy of late gadolinium enhancement (LGE) in ARVC was retrieved in multiple databases. Stata 14 was adopted for meta-analysis and bias analysis. Heterogeneity was assessed with the I² statistic.

RESULTS

After exclusions, 561 patients were included in five studies, and the eligibility criteria were met. The meta-analysis suggested that there was a significant difference between LGE positive and negative patients with ARVC in all-cause mortality (relative risk [RR] = 4.78, 95% confidence interval [CI] = 1.41, 16.23, p=0.012; p for heterogeneity = 0.692, I² = 0%); major adverse cardiovascular events (MACE) (RR=2.48, 95% CI = 1.24, 4.96, p=0.010; p for heterogeneity = 0.596, I² = 0%); ventricular tachycardia (RR=3.13, 95% CI = 1.69, 5.78, p<0.001; p for heterogeneity = 0.825, I² = 0%); implanted cardiac defibrillators (RR=3.15, 95% CI = 1.69, 5.87], p<0.001; p for heterogeneity = 0.353, I² = 9.4%).

CONCLUSION

LGE in ARVC patients is a predictor of all-cause mortality and MACE.

Lumen air pressure (LAP) affecting greywater treatment in an oxygen-based membrane biofilm reactor (O2-MBfR)

Several technologies have been employed to treat greywater (GW) for domestic use. Aerobic biological treatment has achieved high efficiency, the main cost being the necessary source of oxygen (O₂). This study explores the effects of lumen air pressure (LAP) on reactor performance and microbial community succession in an O₂-based membrane biofilm reactor (O₂-MBfR) treating GW. At high LAP (≥0.8 psi), the dissolved oxygen (DO) concentration inside the reactor was higher than 0.38 ± 0.02 mg/L, leading to removal efficiencies of 90%, 98%, and 80%, of total chemical oxygen demand, total linear alkylbenzene sulfonate (LAS), and total nitrogen, respectively. Lower LAP (<0.8 psi) led to a decrease in DO inside the system, and a less effective GW treatment. Low O₂ pressure decreased organic biodegradation and ammoniation, and caused LAS accumulation in the biofilm, leading to the solubilization of extracellular polymeric substances and cell lysis. Comprehensive consideration of reactor performance and energy input, DO inside the MBfR at 0.38 ± 0.02 mg/L could be selected as the optimized condition for GW treatment. Microbial community analyses results also revealed that improved LAP was favorable for the enrichment of LAS-biodegradation related genus (Pseudomonas, Parvibaculum, Magnetospirillum, Clostridium, Zoogloea, Dechloromonas and Mycobacterium), nitrifiers (Nitrosomonas and Sphingomonas) and facultative microorganisms (Dechloromonas, Flavobacterium, Pseudomonas, Aeromonas and Zoogloea) that can carry out denitrification under relatively high DO conditions (>0.38 mg/L), but led to the reduction of the relative abundance of heterotrophs (Acidovorax, Thermomonas, Brevundimonas and Enterobacter) that are more sensitive towards high DO conditions.

[Construction of a forecast system for prediction of schistosomiasis risk in China based on the flood information]

OBJECTIVE

To create a model based on meteorological data to predict the regions at risk of schistosomiasis during the flood season, so as to provide insights into the surveillance and forecast of schistosomiasis.

METHODS

An interactive schistosomiasis forecast system was created using the open-access R software. The schistosomiasis risk index was used as a basic parameter, and the species distribution model of Oncomelania hupensis snails was generated according to the cumulative rainfall and temperature to predict the probability of O. hupensis snail distribution, so as to identify the regions at risk of schistosomiasis transmission during the flood season.

RESULTS

The framework of the web page was built using the Shiny package in the R program, and an interactive and visualization system was successfully created to predict the distribution of O. hupensis snails, containing O. hupensis snail surveillance site database, meteorological and environmental data. In this system, the snail distribution area may be displayed and the regions at risk of schistosomiasis transmission may be predicted using the species distribution model. This predictive system may rapidly generate the schistosomiasis transmission risk map, which is simple and easy to perform. In addition, the regions at risk of schistosomiasis transmission were predicted to be concentrated in the middle and lower reaches of the Yangtze River during the flood period.

CONCLUSIONS

A schistosomiasis forecast system is successfully created, which is accurate and rapid to utilize meteorological data to predict the regions at risk of schistosomiasis transmission during the flood period.

Key role of soluble microbial products in waste activated sludge reduction by synergetic combination of cocoamidopropyl betaine and alkalinity in the short-time aerobic digestion system

As a widely used ampholytic surfactant, cocoamidopropyl betaine (CAPB) has been improved to enhance waste activated sludge (WAS) reduction in the short-time aerobic digestion (STAD) system, but how system pH value affects the synergetic combined process has not been discussed. This research evaluated how alkalinity affects soluble microbial products (SMP) dynamics and WAS reduction in the synergetic system. After adding CAPB, the biodegradation rate constant of VSS (k_VSS), TCOD (k_TCOD) and CAPB (k_CAPB) were much higher than that of without adding CAPB; pH value at 7.0-8.0 showed the maximum specific oxygen uptake rate (SOUR) of WAS, leading to the highest WAS reduction efficiency. Further study indicated that CAPB can significantly improve the release of extracellular polymeric substances (EPS), leading to the increased SMP concentrations and low molecular weight fractions (MWF) proportions in SMP; more SMP with low MWF fraction led to the increased SOUR, thus further accelerate the WAS reduction; increasing pH could improve the foaminess and solubility of CAPB, thus further improve the organics release and SMP accumulation, which could be quickly removed in the system. This findings lay the foundation of the practical application of the synergetic combination system in WAS reduction.