Factors Affecting Continuance Intention in Non-Face-to-Face Telemedicine Services: Trust Typology and Privacy Concern Perspectives.

As the COVID-19 pandemic progressed, the resulting demand for telemedicine services increased. This research empirically examines the role of trust, privacy concerns, and perceived usefulness in customer confirmation, satisfaction, and continuing intention in telemedicine. A typology of trust was employed to classify trust into three dimensions and explore the mediating role of the three dimensions of trust in the relationship between satisfaction, perceived usefulness, and continued intention. We also examined the moderating role of personal privacy concerns in the relationship between trust and continued intention. For this study, we developed a structural equation model based on expectation confirmation theory and analyzed 465 questionnaires from Chinese online users. The expectancy confirmation theory (ECT) was reaffirmed by empirical evidence. The results showed that the relationship between perceived usefulness and satisfaction with continued intention is moderated by the three dimensions of trust. Privacy concerns can negatively moderate the relationship between structural assurance-based trust and continued intention. This study also identified potential threats to telehealth market growth alongside new insights.

Sulfonamide-metabolizing microorganisms and mechanisms in antibiotic-contaminated wetland sediments revealed by stable isotope probing and metagenomics.

Sulfonamide (SA) antibiotics are ubiquitous pollutants in livestock breeding and aquaculture wastewaters, which increases the propagation of antibiotic resistance genes. Microbes with the ability to degrade SA play important roles in SA dissipation, but their diversity and the degradation mechanism in the field remain unclear. In the present study, we employed DNA-stable isotope probing (SIP) combined with metagenomics to explore the active microorganisms and mechanisms of SA biodegradation in antibiotic-contaminated wetland sediments. DNA-SIP revealed various SA-assimilating bacteria dominated by members of Proteobacteria, such as Bradyrhizobium, Gemmatimonas, and unclassified Burkholderiaceae. Both sulfadiazine and sulfamethoxazole were dissipated mainly through the initial ipso-hydroxylation, and were driven by similar microbes. sadA gene, which encodes an NADH-dependent monooxygenase, was enriched in the 13C heavy DNA, confirming its catalytic capacity for the initial ipso-hydroxylation of SA in sediments. In addition, some genes encoding dioxygenases were also proposed to participate in SA hydroxylation and aromatic ring cleavage based on metagenomics analysis, which might play an important role in SA metabolism in the sediment ecosystem when Proteobacteria was the dominant active bacteria. Our work elucidates the ecological roles of uncultured microorganisms in their natural habitats and gives a deeper understanding of in-situ SA biodegradation mechanisms.

Anaerobic sulfamethoxazole-degrading bacterial consortia in antibiotic-contaminated wetland sediments identified by DNA-stable isotope probing and metagenomics analysis.

Anaerobic degradation has been demonstrated as an important pathway for the removal of sulfonamide (SA) in contaminated environments, and identifying the microorganisms responsible for the degradation of SA is a key step in developing bioaugmentation approaches. In this study, we investigated the anaerobic degradation activity of three SA [sulfadiazine (SDZ), sulfamethazine (SMZ) and sulfamethoxazole (SMX)] and the associated bacterial community in wetland sediments contaminated by aquaculture (in Fujian Province, coded with FJ), livestock farming (in Sichuan Province, coded with SC), or rural wastewaters (in Guangdong Province, coded with GD). Additionally, the combination of DNA-stable isotope probing (SIP) with metagenomics was further applied to assess the active SA-degrading microbes using SMX as a model SA. Among SDZ, SMZ and SMX, only SMX could be effectively dissipated, and the degradation of SMX was relatively fast in the microcosms of sediments with higher levels of SA contamination (FJ and SC). The anaerobic biotransformation pathway of SMX was initiated by hydrogenation with the cleavage of the N-O bond on the isoxazole ring. DNA-SIP revealed that the in situ active anaerobic SMX-degraders (5, 18 and 3 genera in sediments FJ, SC and GD respectively) were dominated by Proteobacteria in sediments FJ and SC, but by Firmicutes (two Family XVIII members) in sediment GD. Mycobacterium, unclassified Burkholderiaceae and Rhodocyclaceae were identified as the dominant active SMX-degrading bacteria in both sediments FJ and SC. Higher proportions of antibiotic resistance gene and genes involved in various functional categories were observed in sediments FJ and SC.

Metagenomic insights into the profile of antibiotic resistomes in sediments of aquaculture wastewater treatment system.

To meet the rapidly growing global demand for aquaculture products, large amounts of antibiotics were used in aquaculture, which might accelerate the evolution of antibiotic-resistant bacteria (ARB) and the propagation of antibiotic genes (ARGs). In our research, we revealed the ARGs profiles, their co-occurrence with mobile genetic elements (MGEs), and potential hosts in sediments of a crab pond wastewater purification system based on metagenomic analysis. The residual antibiotic seems to increase the propagation of ARGs in the crab pond, but there was no clear relationship between a given antibiotic type and the corresponding resistance genes. The effect of aquaculture on sediment was not as profound as that of other anthropogentic activities, but increased the relative abundance of sulfonamide resistance gene. A higher abundance of MGEs, especially plasmid, increased the potential ARGs dissemination risk in crab and purification ponds. Multidrug and sulfonamide resistance genes had greater potential to transfer because they were more frequently carried by MGEs. The horizontal gene transfer was likely to occur among a variety of microorganisms, and various ARGs hosts including Pseudomonas, Acinetobacter, Escherichia, and Klebsiella were identified. Bacterial community influenced the composition of ARG hosts, and Proteobacteria was the predominant hosts. Overall, our study provides novel insights into the environmental risk of ARGs in sediments of aquaculture wastewater treatment system.

Antibiotic resistance genes and mobile genetic elements in a rural river in Southeast China: Occurrence, seasonal variation and association with the antibiotics.

Human activities in rural areas, such as livestock farming, aquaculture, and rural domestic sewage discharge, may result in antibiotic resistance genes (ARGs) pollution in rural rivers. A systematic monitoring in different seasons was conducted in a typical agriculture-polluted river with Real-Time Quantitative PCR. A total of 11 ARGs and 2 related mobile genetic elements (MGEs) were detected at all sites with relative abundances of 6.9 × 10-10-0.2 copies/16S rRNA copies. Among them, sul1, sul2 and int1 were the dominant target genes in water samples. tetW, ermB, and floR were more abundant in November (the dry season), while other ARGs, MGEs and 16s rRNA were at a higher absolute abundance in warm seasons. There was less spatial variation of ARGs in the dry season than in the other two seasons. Furthermore, the relative abundance of ARGs was higher at sampling sites adjoining pollution sources. In addition, cluster analysis implied that ARGs in upstream sediments may be released into surface water and migrate downstream in the direction of river flow. There was no significant correlation between ARGs and their corresponding antibiotics. However, the total concentration of tetracycline was significantly correlated with the non-paired ARGs, including sul3, floR, and ermB. At the same time, heavy metals (Zn, Pb, Cd, Cr6+, As) and other environmental parameters (permanganate index, pH, DO) may apply selective pressure on the spread of ARGs, according to redundancy and Pearson's correlation analysis.

Occurrence and variations of pharmaceuticals and personal-care products in rural water bodies: A case study of the Taige Canal (2018-2019).

A systematic monitoring campaign of pharmaceuticals and personal-care products (PPCPs) was performed in the Taige Canal basin, which is located in a rural area of the Yangtze River Delta. A total of 55 out of 61 monitored PPCPs were detected, with concentrations up to 647 ng/L. The maximum concentrations of 75% of monitored antibiotics and 80% of non-antibiotics were above the median values of previously reported maximum concentrations in China, indicating that the basin is heavily contaminated. It is estimated that the PPCP mass flow of the Taige Canal (0.06-0.58 kg/day) entering into Lake Taihu is similar to that of the influent of a wastewater treatment plant. Analysis of the seasonal variation shows that, during the wet season, the average total concentration of sulfonamides was 8 and 11 times that of the normal season and dry season, respectively. The concentration of sulfachlorpyridazine accounted for 40.37% of total antibiotics, suggesting heavy pollution from the animal-breeding industry in this area. The PPCP mass flow rates observed in 2019 were lower than those of 2018 in the same season, and this interannual variation is mainly attributable to water pollution controls in the watershed. Combined analysis of ordination and clustering indicates that the distribution of PPCPs in the Taige Canal is affected by the confluence with Yong'an River and human activities such as water pollution control. Water-sediment distribution analysis demonstrates that the sediment-water distribution coefficients of quinolone and macrolide were higher than those of sulfonamide, lincosamide and chloramphenicol.

Biodegradation of sulfonamides in both oxic and anoxic zones of vertical flow constructed wetland and the potential degraders.

The pollution of wastewater with antibiotics and antibiotics resistance genes has attracted public concerns about ecosystem and global health. Swine wastewater can contain high concentrations of antibiotics, especially sulfonamides, even after full-scale wastewater treatment. In this study, mesocosm-scale vertical flow constructed wetlands (VF-CWs) were applied to abate nutrients and antibiotics in swine wastewater containing sulfonamides. VF-CWs performed well in the removal of both nutrients and antibiotics. Sulfonamides did not influence total organic carbon (TOC) and total phosphorus (TP) removal, and even slightly enhanced NH4+-N removal. High removal efficiencies (26.42-84.05%) were achieved for sulfadiazine (SDZ), sulfamethoxazole (SMX) and sulfamethazine (SMZ). Together with lab-scale sorption and biodegradation experiments, microbial degradation was found to be the most important removal mechanism for sulfonamides in VF-CWs. Sulfonamides addition increased bacterial alpha-diversity and changed microbial community structure. Moreover, antibiotics promoted antibiotic-resistant or -degrading bacteria. Bacillus, Geobacter and other seven genera were correlated with sulfonamides reduction under either aerobic or anaerobic condition. In summary, VF-CW is a suitable alternative for swine wastewater treatment, and biodegradation plays the key role in sulfonamides abatement. Main findings of the work. This was the first work to combine bacterial community analysis with microcosm experiments to uncover the major removal mechanism of sulfonamides in constructed wetlands.

Sulfadiazine degradation in soils: Dynamics, functional gene, antibiotic resistance genes and microbial community.

Sulfonamides and their corresponding antibiotic resistance genes (ARGs) are widespread in the environment, which leads to a major threat to global health crisis. Biodegradation plays a major role in sulfonamides removal in soil ecosystem, but the degradation dynamics and the associated functional bacteria in situ remain unclear. In this study, aerobic degradation of sulfadiazine (SDZ) at two dosages (1 and 10 mg/kg) was explored for up to 70 days in two different agricultural soils. The removal of SDZ in all treatments followed first-order multi-compartment model with half-life times of 0.96-2.57 days, and DT50 prolonged with the increase of initial dosage. A total of seven bacterial genera, namely Gaiella, Clostrium_sensu_stricto_1, Tumebacillus, Roseiflexus, Variocorax, Nocardioide and Bacillus, were proposed as the potential SDZ-degraders. sadA gene was for the first time detected in soil samples, but other functional genes might also participate in SDZ degradation. The enrichment of sulfonamide resistance genes was found after 70 days' incubation, which might result in the spread of ARGs in soil. This study can add some new insights towards SDZ degradation in soil ecosystem and provide a potential resource for the bioremediation of SDZ-contaminated soil.

Seasonal and spatial variations of pharmaceuticals and personal care products occurrence and human health risk in drinking water - A case study of China.

A case study was implemented to investigate the seasonal and spatial variations of 43 kinds of pharmaceuticals and personal care products (PPCPs) in the water supply system of Changzhou in China. The source water, water samples in each unit along the drinking water treatment process, as well as the drinking water product in both urban and rural area in different seasons have been included. The total concentrations of detected PPCPs range from 6.37 ng/L to 809.28 ng/L, the level of which is higher than other reports in China. In summer, more kinds of PPCPs were at higher concentrations in drinking water in urban area in spite of that fewer kinds of PPCPs were detected in raw water than in winter. It mainly because some kinds of PPCPs, which can be still detected under higher temperature and stronger irradiation in summer, were hardly removed by the drinking water treatment plant (DWTP). Therefore, people are at relatively higher health risk by PPCPs exposure through the intake of drinking water during summer than winter. The advanced treatment which applied GAC (granular activated carbon) filtration improved 2% to 46% of removal efficiency on PPCPs compared with conventional process, for which advanced treatment processes should be advocated in more DWTPs in China. In rural private wells, the situation is more worrying. Twelve more kinds of PPCPs were detected in rural drinking water than in urban, of which the max concentration reached 107 ng/L. The total concentrations of PPCPs in drinking water in rural area were obviously higher than in urban area, which lead to risk quotient (RQ) values of 4-6 times higher.

Degradation of PFOA Substitute: GenX (HFPO-DA Ammonium Salt): Oxidation with UV/Persulfate or Reduction with UV/Sulfite?

Hexafluoropropylene oxide dimer acid (HFPO-DA, ammonium salt with trade name: GenX) has been recently detected in river water worldwide. There are significant concerns about its persistence, and potential adverse effects to the biota. In this study, the degradability of GenX by typical advanced redox technologies (UV/persulfate and UV/sulfate) is investigated. Results demonstrate that <5% GenX is oxidized after 3 h in UV/persulfate system, which is much lower than ∼27% for PFOA. In comparison, GenX can be readily degraded and defluorinated by hydrated electron (eaq-) generated by UV/sulfite system. Specifically, GenX is not detectable after 2 h, and >90% of fluoride ion is recovered 6 h later. This is attributed to the accumulation and subsequent degradation of CF3CF2COOH and CF3COOH, which are stable intermediates of GenX degradation. Mechanistic investigations suggest that the etheric bond in the molecule is a favorable attack point for the eaq-. Such finding is corroborated by quantum chemical calculations. The side CF3- at the α-carbon probably acts as an effective barrier that prevents GenX from being cleaved by SO4-• or OH• at its most sensible point (i.e. the carboxyl group). This study illustrates that reduction by UV/sulfite might be a promising technology to remove GenX from contaminated water.

The mutual influence of speciation and combination of Cu and Pb on the photodegradation of dimethyl o-phthalate.

Specific industrial application of dimethyl o-phthalate (DMP) in ore flotation has led to DMP-heavy metals combined pollution, which causes the abiotic degradation of DMP in the environment more complex. This study focused on the effect of Cu and Pb on photodegradation of DMP. The major mechanism of inhibiting effect of Cu and Pb on degradation of DMP involved their speciation and combination. It was found that the Cu (5 mg/L, I = 95.4%) and Pb (5 mg/L, I = 100%) could inhibit the photodegradation of DMP. The main species that inhibit the DMP degradation were Cu(OH)+ and Pb(OH)+, respectively. The intensity of the UV-Vis absorbance of DMP was obviously related to the concentration of Cu2+ (R2 = 0.8655) or Pb2+ (R2 = 0.9019) ions. Fluorescence quenching effect of Cu2+ (R2 > 0.9946), Pb2+ (R2 > 0.6879) on DMP is strongly correlated with the concentration of ions. And the equilibrium membrane dialysis experiment has also verified the combination of DMP and Cu, Pb. These results are useful to understand the effect mechanism of metal species on the photodegradation of organic chemicals.