Characteristics of bioaerosol emissions from a municipal wastewater treatment plant: Health risk assessment and microbial composition.

Bioaerosols released from municipal wastewater treatment plants (MWWTPs) contain pathogenic microorganisms, if dispersed into the atmosphere, which pose potential health risks to humans. In this study, the concentrations and size distribution of bioaerosol, factors on the bioaerosol emission, exposure risk, and microbial composition in different treatment units of a MWWTP were investigated. The results showed that bioaerosol was released to different degrees in each treatment unit, with the concentrations of bioaerosol varied widely, ranging from 978 to 3710 CFU/m3. FG and PST were primary bioaerosol emission sources in MWWTP. COD concentration, wind speed (WS) and relative humidity (RH) significantly influenced bioaerosol concentrations. The proportion of inhalable particles (< 4.7 µm) ranged from 51.35 % to 83.33 %, and bioaerosol emitted from WWTP caused a non-carcinogenic risk to children by the exposure risk assessment (HI > 1), which need to be paid more attention. Bacterial, fungal and actinomycete aerosols were detected in each treatment unit of MWWTP. Among these bioaerosols, bacterial aerosol was dominant. Importantly, several pathogenic bacteria including Sphingobium, Brevundimonas, Romboutsia, Arcobacter, Acinetobacter, and Mycobacterium were identified within the airborne bacteria population, most of which originated from wastewater or sludge, particularly in the ambient air of AeT. Pathogenic bacteria from MWWTP should be studied further to determine their long-term behavior and possible health risks.

Combination of 308-nm excimer laser and piperine promotes melanocyte proliferation, migration, and melanin content production via the miR-328/SFRP1 axis.

OBJECTIVE: Both piperine and a 308-nm excimer laser have significant curative effects on vitiligo. This study mainly explored the molecular mechanism of a 308-nm excimer combined with piperine in regulating melanocyte proliferation. METHODS: Epidermal melanocytes were cultured in piperine solution, and the cells were irradiated by an XTRAC excimer laser treatment system at 308-nm output monochromatic light. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were for detecting the expression levels of genes or proteins. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and Transwell method was for assessing cell viability and migration capacity. The content of melanin was also detected. RESULTS: The combination of the 308-nm excimer laser and piperine enhanced the cell proliferation, migration, and melanin production of melanocytes and upregulated the level of miR-328, and restraint of miR-328 reversed the influence of the 308-nm excimer laser and piperine. Secreted frizzled-related protein 1 (SFRP1) is a direct target gene of miR-328, and miR-328 can inhibit the expression of SFRP1 and elevate the protein level of the Wnt/ß-catenin signaling pathway. CONCLUSION: The 308-nm excimer laser combined with piperine may be more efficient than piperine alone in the remedy of vitiligo, and the miR-328/SFRP1 and Wnt/ß-catenin pathways are participated in the proliferation, migration, and melanin synthesis of melanocytes.

Migration and transformation modes of microplastics in reclaimed wastewater treatment plant and sludge treatment center with thermal hydrolysis and anaerobic digestion.

Microplastics in wastewater have been investigated globally, but less research on the migration and transformation of microplastics throughout wastewater and sludge treatment. This study investigated the fate of microplastics in a reclaimed wastewater treatment plant and a centralized sludge treatment center with thermal hydrolysis and anaerobic digestion. The results exhibited that the effluent microplastics of this reclaimed wastewater treatment plant were 0.75 ± 0.26 items/L. Approximately 98 % of microplastics were adsorbed and precipitated into sludge. After thermal hydrolysis, anaerobic digestion and plate and frame dewatering, the removal rate of microplastics was 41 %. Thermal hydrolysis was the most effective method for removing microplastics. Polypropylene, polyamide and polyethylene were widely detected in wastewater and sludge. 30 million microplastics were released into the downstream river and 51.80 billion microplastics entered soil through sludge cake daily. Therefore, substantial microplastics still entered the natural environment despite the high microplastics removal rate of reclaimed wastewater and sludge treatment.

Enhancing surface sensing performance of cascaded high contrast gratings using bound states in the continuum.

We proposed the cascaded high contrast grating (CHCG) structure to enhance surface sensing capabilities through bound states in the continuum (BICs). Utilizing the finite element method (FEM) and rigorous coupled-wave analysis (RCWA), we studied the dispersion relations, far-field contribution CHCGs, and near-field distributions of BICs corresponding to resonance peaks at different wavelengths. Results demonstrate the ability to precisely control symmetry-protected BIC (SP-BIC) and Friedrich-Wintgen BIC (FW-BIC) resonance peaks by altering incident angles and structural parameters, enhancing structure robustness and tunability. Significantly, modes 1 and 2 have demonstrated substantial enhancement in surface refractive index sensing, achieving highest sensitivities at 51 nm/RIU and the figure of merit reaching 490.8 RIU-1, indicating notable advancement in detecting subtle surface changes. In contrast, mode 3 has shown robust performance in bulk refractive index sensing, achieving a sensitivity of 602 nm/RIU and a figure of merit of 5189.65 RIU-1. These findings underscore the significant potential of the structure as a high-performance integrated sensor, particularly for precise environmental and biological monitoring in surface refractive index sensing.

High-performance gas sensor with symmetry-protected quasi-bound states in the continuum.

A high-performance optical sensor with a vertical cavity structure comprising high-contrast gratings (HCGs) and a distributed Bragg reflector was designed. The structure has two peaks with different mechanisms, among which the first peak is formed by breaking the symmetry of the structure and coupling between the incident wave and the symmetric protection mode. The joint action of the HCG resonance and Fabry-Perot resonance formed a second peak. Moreover, changing the structural parameters, such as the grating width, period, and cavity length, can tune the spectral reflection dips. The sensitivity of the designed structure was as high as 674 nm/RIU, and the corresponding figure of merit was approximately 34741. The presented gas sensor provides a method for applying a vertical cavity structure to the sensing domain.

Enhancing nitrogen removal efficiency and anammox metabolism in microbial electrolysis cell coupled anammox through different voltage application.

The slow growth and difficulty in cultivating anammox bacteria limit the rapid start-up of anammox process and effective microbial enrichment. In this study, microbial electrolysis cell (MEC) was coupled with anammox to investigate the effects of different applying voltage methods on substrate removal efficiency and rates, microbial community structure, anammox metabolism and metabolic pathways. The results showed that applying voltage not only improved NH4+-N removal efficiency and removal rates, but also promoted electron transfer efficiency, key enzyme activity and extracellular polymeric substances (EPS) secretion in the systems. Step-up voltage was more conducive to the growth of Candidatus_Kuenenia in the cathode, which promoted the rapid start-up of anammox and treating wastewater with low ammonia concentration. The main metabolic pathway in step-up voltage operation was hydrazine to nitrogen, while in constant voltage operation was hydroxylamine oxidation pathway. These findings provided a new insight into the enhancement and operation of anammox system.

Dual-band refractive index sensor with cascaded asymmetric resonant compound grating based on bound states in the continuum.

We propose a cascaded asymmetric resonant compound grating (ARCG) for high-performance dual-band refractive index sensing. The physical mechanism of the sensor is investigated using a combination of temporal coupled-mode theory (TCMT) and ARCG eigenfrequency information, which is verified by rigorous coupled-wave analysis (RCWA). The reflection spectra can be tailored by changing the key structural parameters. And by altering the grating strip spacing, a dual-band quasi-bound state in the continuum can be achieved. The simulation results show that the highest sensitivity of the dual-band sensor is 480.1 nm/RIU, and its figure of merit is 4.01 × 105. The proposed ARCG has potential application prospects for high-performance integrated sensors.

Fabrication of surface ion imprinting rice husk-based polymer for selective detection and efficient adsorption of Cu2+ in lake water.

With the deepening of the concept of recycling economy and green chemistry, selective detection and capture of Cu2+ from lake water by biosorbent are of great significance. Herein, the Cu2+ ion-imprinted polymers (RH-CIIP) with organosilane containing hydroxyl and Schiff base groups (OHSBG) as ion-receptor, fluorescent chromophores and cross-linking agent, and Cu2+ as template ion, were fabricated via surface ion imprinting technology by employing mesoporous silica MCM-41 (RH@MCM-41) as supporter. The RH-CIIP could be exploited as a fluorescent sensor for Cu2+ with high selective compared with Cu2+ non-imprinted polymers (RH-CNIP). Additionally, the LOD was calculated to be 5.62 µg/L, which is far below WHO standard for Cu2+ in drinking water of 2 mg/L, and more lower than the reported methods. Moreover, the RH-CIIP can also be utilized as an adsorbent for the effective elimination of Cu2+ from lake water with the adsorption capacity of 87.8 mg/g. Besides, the kinetic features of adsorption were well defined by the pseudo-second-order model and the sorption isotherm was in agreement with the Langmuir model. Meanwhile, the interaction of RH-CIIP and Cu2+ was investigated using theoretical calculations and XPS. Finally, RH-CIIP was able to remove almost 99 % Cu2+ in lake water samples that satisfied the drink water standard.

Structural and photoelectron spectroscopic study on the heterotrinuclear nickel-titanium dioxide carbonyl complexes Ni2TiO2(CO) n - (n = 2-4).

Herein, the configurations and intrinsic electronic properties of heteronuclear transition metal dioxide carbonyl anions Ni2TiO2(CO) n - (n = 2-4) in the gas phase were investigated using mass spectrometry coupled anionic photoelectron spectroscopy, ab initio calculations, and simulated density-of-state (DOS) spectra. The results clearly show that the binding of electrons is enhanced by the addition of CO. The ground state structures of Ni2TiO2(CO) n - (n = 2-4) are characterized to show that three transition metal atoms (one Ti atom and two Ni atoms) forming a quasi-line is favored. The interaction between Ni and C becomes weaker as the cluster size increases. The natural electron configuration shows that the extra electron is enriched on O atoms attached to Ti, and there is strong interaction between Ti and O atoms. This work gives significant insight into the configuration and electronic structures of nickel-titanium dioxide carbonyl anions, which has potential application in adsorption of carbon monoxide on the surfaces/interfaces of alloys.

Mechanisms of interaction between polystyrene nanoplastics and extracellular polymeric substances in the activated sludge cultivated by different carbon sources.

Nanoplastics (NPs) are ubiquitously present in wastewater treatment plants, which would be removed by the flocculation of extracellular polymeric substances (EPS) from activated sludge. However, the interaction mechanisms between NPs and EPS of activated sludge remain largely unexplored. This study investigated the interaction mechanisms between polystyrene nanoplastics (PS-NPs) and EPS with sodium acetate (NaAc), methanol (MeOH) and glucose (GLC) as carbon sources. The results showed that the functional group involved in the interactions between PS-NPs and EPS was the carbonyl of protein amide I region. The interaction between PS-NPs and EPS increased the ß-sheets content, decreased the ratio of α-helix to (ß-sheet + random coil), and changed the protein secondary structures to strong rigidity. This enhanced the flocculation of activated sludge cultivated by these three carbon sources. The flocculation between PS-NPs and EPS in activated sludge using NaAc as the carbon source was the strongest among these three carbon sources. Therefore, the degree of flocculation between NPs and EPS of activated sludge in wastewater treatment plants varies with carbon sources. This work provides a reference for the NPs removal mechanisms from wastewater, which will help to understand the migration behavior of MPs and NPs in wastewater treatment processes.

Double-layer symmetric gratings with bound states in the continuum for dual-band high-Q optical sensing.

Herein, we theoretically demonstrate that a double-layer symmetric gratings (DLSG) resonator consisting of a low-refractive-index layer sandwiched between two high-contrast gratings (HCG) layers, can host dual-band high-quality (Q) factor resonance. We find that the artificial bound states in the continuum (BIC) and Fabry-Pérot BIC (FP-BIC) can be induced by optimizing structural parameters of DLSG. Interestingly, the artificial BIC is governed by the spacing between the two rectangular dielectric gratings, while the FP-BIC is achieved by controlling the cavity length of the structure. Further, the two types of BIC can be converted into quasi-BIC (QBIC) by either changing the spacing between adjacent gratings or changing the distance between the upper and lower gratings. The simulation results show that the dual-band high-performance sensor is achieved with the highest sensitivity of 453 nm/RIU and a maximum figure of merit (FOM) of 9808. Such dual-band high-Q resonator is expected to have promising applications in multi-wavelength sensing and nonlinear optics.

Disease predisposition of human leukocyte antigen class II genes influences the gut microbiota composition in patients with primary biliary cholangitis.

Background: The human leukocyte antigen (HLA) susceptibility gene is the main genetic risk factor for primary biliary cholangitis (PBC). The prognosis of patients with PBC is linked to gut microbiota dysbiosis. However, whether the HLA alleles are associated with the gut microbiota distribution and disease severity remains unknown. Methods: A cohort of 964 Chinese patients with PBC was enrolled at Beijing YouAn Hospital, Beijing, China. High-resolution genotyping of the HLA class I and class II loci from 151 of these patients was performed using sequence-based PCR. Stool samples were collected from 43 of the 151 fully HLA-typed patients to analyze their microbiota compositions via 16S RNA gene sequencing. Results: Of the 964 patients, the male:female ratio was 114:850, and 342 of these patients (35.5%) had already developed liver cirrhosis (LC) before enrollment. Patients with PBC showed a significantly higher frequency of HLA DRB1*08:03 than did the controls (21.2% vs. 9.0%, P=0.0001). HLA-DRB1*03:01, DRB1*07:01, DRB1*14:05, and DRB1*14:54 frequencies were also increased but did not reach significance after Bonferroni's correction. Conversely, the DQB1*03:01 frequency was significantly lower in patients with PBC than in the controls (24.5% vs. 39.2%, P=0.0010). The patients' gut microbiota were analyzed from four perspectives. The microbial community abundances were significantly lower in FHRAC-positive patients (patients with a combination of five HLA DRB1 high-risk alleles) than in FHRAC-negative patients (P<0.05). Of the top 10 microbial genera, Lachnospiraceae_incertae_sedis was higher in the FHRAC-positive patients than in the FHRAC-negative patients (P<0.05). linear discriminant analysis (LDA) effect-size (LEfSe) analysis showed different microbes at different levels in the FHRAC-negative patients but not in the FHRAC-positive patients. DQB1*03:01-positive patients contained mostly Lactobacillaceae at the family level. A comparison of the FHRAC-positive patients with and without liver cirrhosis showed that the abundances of Veillonella were significantly higher in patients with cirrhosis and FHRAC than in those without cirrhosis and are FHRAC-negative. Conclusion: The HLA class II genes may influence the gut microbiota compositions in patients with PBC. Differential gut microbiota were expressed at different taxonomic levels. Some bacterial abundances may be increased in FHRAC-positive patients with PBC and cirrhosis.

Achieving mainstream anammox in biological aerated filter by regulating bacteria community structure.

Although mainstream partial nitrification-anammox (PN-A) is a highly efficient and sustainable wastewater treatment process, it is difficult to achieve and stabilize due to the competition among functional bacteria. In this study, achieving one-stage mainstream anammox via regulating bacteria community structure was studied in a lab-scale biological aerated filter (BAF). The results showed that high free ammonia with 89.57 mg/L, nitrite nitrogen (NO2--N) competition between anammox bacteria (AnAOB) and nitrite oxidizing bacteria (NOB), and backwash regulated the bacteria community structure. After backwash, Candidatus Kuenenia became the dominant bacteria and the relative abundance increased to 5.56 %. In BAF, one-stage mainstream anammox with total nitrogen (TN) being lower than 15 mg/L in the effluent was achieved using lag-time of bacteria activity recovery caused by alternating operation of high and low ammonia nitrogen (NH4+-N), which have great potential applied in municipal wastewater treatment plants (MWWTPs).

N2O production and emission pathways in anammox biofilter for treating wastewater with low nitrogen concentrations.

Although anaerobic ammonia oxidation (anammox) is a cost-effective nitrogen removal process, nitrous oxide (N2O) production will greatly reduce the advantages of this process. It is important to identify the N2O emission pathways and then reduce the N2O production in anammox system. To date, very limited research has been done to investigate the N2O production and N2O emission pathways in anammox biofilter. In this study, N2O production were investigated under different filtration rates in anammox biofilter for treating wastewater with low nitrogen concentrations, and N2O emission pathways were analyzed with batch tests using N2O microsensor and stable isotope mass spectrometry. The results showed N2O production increased with the increase of filtration rates in anammox biofilter, where the N2O emission factor increased from 0.012 % at 1.0 m/h to 0.496 % at 3.0 m/h. And the optimal operation condition was at filtration rate of 1.5 m/h, where NH4+-N and NO2--N removal efficiencies reached 99 % and N2O concentration was the lowest. qPCR showed that anammox bacteria, nitrifying bacteria and denitrifying bacteria were all present in anammox biofilter, with anammox bacteria in the highest abundance. And nitrifying bacteria and denitrifying bacteria provided the possibility of N2O production. The batch tests and stable isotope mass spectrometry analysis indicated that nitrifier denitrification, hydroxylamine oxidation and endogenous heterotrophic denitrification were N2O production pathways in aerobic zone and anoxic zone of anammox biofilter, respectively. In addition, batch tests under different conditions showed no oxygen environment could reduce N2O production. Therefore, the production of N2O in anammox system is a problem that cannot be ignored and should be paid more attention to.

A reasonably constructed fluorescent chemosensor based on the dicyanoisophorone skeleton for the discriminative sensing of Fe3+ and Hg2+ as well as imaging in HeLa cells and zebrafish.

In this study, a new fluorescent sensor dicyanoisophorone Rhodanine-3-acetic acid (DCI-RDA) (DCI-RDA) has been developed by employing a DCI-based push-pull dye as the fluorophore and RDA as the recognition moiety for the simultaneous sensing of Fe3+ and Hg2+ with a large Stokes Shift (162 nm), high selectivity and sensitivity, and low LOD (1.468 µM for Fe3+ and 0.305 µM for Hg2+). In particular, DCI-RDA has a short response time (30 s). The Job's plot method in combination with 1H NMR titration and theoretical calculations was used to determine the stoichiometry of both DCI-RDA-Fe3+/Hg2+ complexes to be 1 : 1. Moreover, DCI-RDA is applied as a fluorescent probe for imaging in HeLa cells and zebrafish, indicating that it can be potentially applied for Fe3+/Hg2+ sensing in the field of biology.

Benzobisthiadiazole and Its Derivative-Based Semiconducting Polymer Nanoparticles for Second Near-Infrared Photoacoustic Imaging.

Photoacoustic (PA) imaging has received more and more attention on disease diagnosis and fundamental scientific research. It is still challenging to amplify their imaging ability and reduce the toxicity of inorganic materials and exogenous contrast agents. Semiconducting polymer nanoparticles (SPNs), as a new type of contrast agent, have the advantages of low toxicity, flexible structure adjustment, good photostability, and excellent photothermal conversion efficiency. SPNs containing benzo(1,2-c;4,5-c')bis(1,2,5)thiadiazole (BBT) units, as the most classic second near-infrared window (NIR-II, 1,000-1700 nm) PA contrast agents, can achieve light absorption in the NIR-II region, thereby effectively reducing light loss in biological tissues and improving imaging resolution. This mini review summarizes the recent advances in the design strategy of BBT and its derivative-based semiconducting polymer nanoparticles for second near-infrared photoacoustic imaging. The evolution process of BBT blocks provides a unique perspective for the design of high-performance NIR-II PA contrast agents.

Using two-step cluster analysis to classify inpatients with primary biliary cholangitis based on autoantibodies: A real-world retrospective study of 537 patients in China.

Background: A variety of autoantibodies have been detected in primary biliary cholangitis (PBC), while the presence of autoantibody clusters and their clinical significance have not been fully understood. We aimed at defining autoantibody clusters and to better understand the clinical features and prognosis of PBC patients based on autoantibody clusters under real-world conditions. Methods: We retrospectively analyzed 788 inpatients with PBC evaluated between October 2008 and July 2019, and included 537 patients. Nineteen autoantibodies which were measured routinely were investigated for cluster analysis. Two-step clustering, Kaplan-Meier survival, and Cox regression analyses were used. Results: Five clusters were defined. A cluster of antinuclear antibodies (ANA) and anti-gp210 positive patients were identified with a high rate of cirrhosis at baseline and low survival rate; a cluster of ANA, anti-centromere antibodies (ACA) and/or anti-CENP-B female dominant patients with older disease onset, low level of platelet count at baseline, high rate of hepatic decompensation, and low survival rate was also characterized; and another cluster of anti-mitochondrial antibodies (AMA) and/or AMA-M2, anti-Ro52 and a high rate of anti-gp210 positive patients were identified with a high proportion of male patients and low survival rate. A subgroup of patients with anti-SSA and/or anti-SSB coexists with SjS was also identified; patients with only AMA and/or AMA-M2-positive with a benign clinical outcome and relatively high complication of non-alcoholic fatty liver disease (NAFLD) were also identified. Only anti-gp210 was considered as a significant predictor for poor outcomes especially in patients with cirrhosis. Conclusion: Clustering methods allow the identification of distinct autoantibody profiles of PBC that form clinical subsets and can be useful for personalized approaches to diagnosis, clinical management, and the prediction of clinical outcomes. Anti-gp210 was the strongest predictive factor for poor outcomes especially in PBC patients with cirrhosis under real-world conditions.

Enhanced optical sensing performance in stacked resonant compound gratings.

We proposed a high-performance integrated optical sensor based on a stacked resonant compound grating (SRCG). The transmission spectrum of a SRCG is investigated by the theoretical model that combines the coupled mode theory with the eigenmode information of the grating structures. It is found that the spectral width of the SRCG is controlled by changing its structural parameters such as the strip depth, the period of the grating, and cavity length. The simulation results, which are verified by finite element method (FEM), show that the sensitivity of the sensor is 401.8 nm/RIU with its figure of merit (FOM) as high as 57404. The presented sensor is a promising application for high-performance biosensing.

Achieving and control of partial denitrification in anoxic-oxic process of real municipal wastewater treatment plant.

Partial denitrification is an alternative process to provide stable nitrite for anammox. In this study, based on full-scale and lab-scale experiments, achieving and control of partial denitrification and the microbial mechanism were studied for 17 months in municipal wastewater treatment plant (MWWTP). Using glucose (GLC) as sole carbon source, partial denitrification was successfully achieved with nitrite accumulation percentage (NAP) higher than 90%; whereas, using sodium acetate (NaAc) as sole carbon source, nitrite accumulation was effectively controlled with economic and efficient carbon usage. Candidatus Competibacter and Thaurea were the dominant communities for partial denitrification. Denitrifying glycogen accumulating organisms (DGAOs), Thauera, denitrifying phosphorus accumulating organisms (DPAOs), GAOs, PAOs and denitrifiers coexisted in MWWTP, resulting in COD specific removal rate (CODSRR) of 883.10 ~ 1188.92mgN/gMLVSS/h during partial denitrification. Through adjustment of Anoxic-Oxic (A/O) operation to anoxic operation, the growth of GAOs and PAOs could be limited.

The protective role of miR-132 targeting HMGA2 through the PI3K/AKT pathway in mice with Alzheimer's disease.

OBJECTIVE: To explore the role and of miR-132, HMGA2 and PI3K/AKT pathway in mice with Alzheimer's disease (AD). METHODS: The mice were divided into 7 groups: the normal group, the model group (AD model mice), the NC group (AD mice injected with negative control (NC) vector), the miR-132 mimic group (AD mice injected with miR-132 mimics), the miR-132 inhibitor group (AD mice injected with miR-132 inhibitor), the si-HMGA2 group (AD mice injected with HMGA2 silencing vector), and the miR-132 inhibitor + si-HMGA2 group (model mice treated with miR-132 inhibitor and si-HMGA2). Y-maze experiment and related molecular biology experiments were performed. RESULTS: The double-luciferase reporter assay verified that miR-132 could target and inhibit the expression of HMGA2A. Compared with the NC group, model mice had decreased learning and memory ability, reduced miR-132, p-PI3K/PI3K, p-AKT/AKT, AQP4 expression as well as GFAP GSH-Px, SOD, ATP, and T-AOC levels, but increased expression of HMGA2 and the levels of TNF-α, IL-6, NO, IL-1ß, MAO, and MDA (P<0.017). Up-regulation of miR-132 or silencing HMGA2 could partly reverse the changes, but inhibition of miR-132 would exaggerate the brain injury and these molecular changes (P<0.017). The combination uses of si-HMGA2 and miR-132 inhibitor could reverse the changes caused by miR-132 inhibitor (P<0.017). CONCLUSION: miR-132 could downregulate the expression of HMGA2 and promote the expression of the PI3K/AKT pathway, so as to achieve a protective effect on brain in AD mice.