[Research Progress on Removing Antibiotic Resistance Genes in Constructed Wetlands].

Recently, the issue of environmental pollution and emerging antibiotic resistance genes (ARGs) has gradually gained attention. Antibiotic resistant bacteria (ARB) can be effectively reduced via the conventional water treatment processes. Although the ARB are completely inactivated during the disinfection process, the free ARGs can be incorporated into other microorganisms through transformation or transduction, allowing the ARGs to spread and propagate. Therefore, ARGs in wastewater must be handled by a specific process. It has been demonstrated in several studies that treatment using constructed wetland is an effective, economical, and environmentally friendly method of removing antibiotics and resistance genes from wastewater. Here, the research progress on the removal effect of constructed wetland water treatment systems on ARGs at home and abroad was reviewed. The results revealed that the removal efficiency of ARGs in subsurface flow constructed wetland was higher than that in surface flow-constructed wetlands. The composite-constructed wetland had significantly improved removal efficiency of ARGs compared to that in the ordinarily constructed wetland; however, the parameter setting of the composite process still requires further research. Several studies have reported that the removal efficiency of ARGs using constructed wetlands varies depending on the type of constructed wetland enhancement, plant, temperature, pH, and other factors. The results of the current study revealed that cross-mixing was the best way to combine plants, whereas the selection of plant species has not yet shown a clear dominant species. Temperature and pH affected the removal of ARGs by altering the microbial community in constructed wetlands. Although longer hydraulic residence time could increase the removal efficiency of ARGs, it also increased the enrichment risk of ARGs. The selection of constructed wetland substrate type should focus on fillers with a high specific surface area; the flow direction of the up-flow type was generally more efficient than the down-flow type in removing ARGs. In conclusion, the various factors (such as, the constructed wetland type, substrate type, hydraulic retention time, ambient temperature, and plant species) need to be integrated into the design of the constructed wetland system parameters to achieve the most effective treatment effect. The application of constructed wetlands in removing ARGs from the environment has broad prospects but also faces challenges.

A Pilot Randomized Control Study on Effect Brief Heart Rate Variability Biofeedback as a Complementary Treatment in Men with Methamphetamine Use Disorder.

The aims of this study were to investigate the efficacy of heart rate variability biofeedback (HRVBFB) intervention in terms of reducing craving, severity of dependence, and rate of positive methamphetamine urine testing in men taking part in a methamphetamine use disorder outpatient treatment program. Sixty-one adult men received either HRVBFB treatment plus treatment as usual (TAU) over four weeks or TAU only. Men receiving HRVBFB showed significantly greater reductions in craving, dependence severity, and the rate of positive methamphetamine urine testing at the end of the intervention and four weeks of follow-up. The analyses further showed that the levels of craving and dependence severity at treatment entry were predictive of changes in craving and dependence severity at the end of treatment and follow-up, respectively. The baseline status of a positive methamphetamine urine test only predicted a positive methamphetamine urine test at the end of treatment, not at the end of the follow-up period. Our results showed HRVBFB intervention has merits as an adjunct treatment to ameliorate cravings and reduce the severity of dependence experienced by persons with methamphetamine use disorder. An added value of HRVBFB intervention is the fact that it can be easily and affordably implemented in everyday life.

Gender Differences in Depression and Quality of Life in Current and Abstinent Ketamine Users.

Ketamine use has become of increasing concern because it has spread in many parts of the world during the past few years. Substance users usually have depression and a lower quality of life (QoL). The aim of this study was to explore depression and QoL in ketamine users, and to further examine the role of gender in relation to differences in depression and QoL in ketamine users. This study recruited 204 current ketamine users, 102 abstinent ketamine users and 102 healthy controls. The demographic data, severity of depression and QoL were recorded. Analysis of Variance (ANOVA) was employed to compare the associations of ketamine use status with depression and QoL. Gender differences were examined by moderator analysis. The current ketamine users with and without ketamine use disorder, in addition to the abstinent ketamine users with ketamine use disorder, have more severe depression and a lower QoL than healthy controls. There were significant gender differences in depression and QoL in abstinent ketamine users with ketamine use disorder. Ketamine users have more severe depression and a lower QoL. In particular, depression and a lower QoL are still prominent in abstinent ketamine users. The gender differences in depression and QoL are significant in abstinent ketamine users.

Craving for Ketamine and Its Relationship With Clinical Outcome Indicators in Males With Ketamine Use Disorder.

Background: Craving is considered a hallmark of substance use disorder and is one of the criteria of substance use disorder. The Desires for Drug Questionnaire (DDQ) is a widely used questionnaire to assess craving for heroin. This study aimed to examine the psychometric properties of the ketamine version of the DDQ (DDQ-K) and the associations between craving for ketamine as measured using the DDQ-K and clinical outcome indicators in individuals with ketamine use disorder. Methods: In total, 651 individuals with ketamine use disorder completed the DDQ-K and the Visual Analog Craving Scale (VACS). Demographic data, severity of ketamine use, money spent on ketamine, positive/negative aspects of ketamine use, and readiness to change ketamine use were also recorded. We examined the reliability (internal consistency), construct validity (factor structure), and concurrent validity of the DDQ-K. Multiple regression analysis was used to examine the relationships of craving measured using the DDQ-K with clinical outcome indicators, including money spent on ketamine, severity of ketamine use, positive/negative aspects of ketamine use, and readiness to change ketamine use. Results: The original three-factor model of the DDQ-K was acceptable for use in individuals with ketamine use disorder according to confirmatory factor analysis. The subscales of Desire and Intention and Negative Reinforcement of the DDQ-K, but not the subscale of Control, were of acceptable concurrent validity. The score on the Desire and Intention subscale was positively associated with the level of ketamine dependence, money spent on ketamine use, and positive/negative aspects of ketamine use and negatively associated with readiness to change ketamine use. Conclusion: This study supported the use of the Desire and Intention and Negative Reinforcement subscales of the DDQ-K to assess craving in patients with ketamine use.

[Status and influencing factors of polychlorinated biphenyls (PCBs) pollution in the coastal areas in China].

This review focused on the distribution, pollution status, sources and influencing factors of PCBs in the coastal areas (seawater, surface sediments and biota) in China. A few main points are listed as follows: (1) For coastal seawater, concentrations of PCBs were increasing from the north to the south and the highest concentrations of PCBs were observed in the developed east coastal areas. The concentrations of PCBs in most coastal areas were higher than the seawater standard of U. S. EPA (30 ng x L(-1)), indicating that there was a high potential risk. (2) Only a small part of surface sediments had PCBs concentrations higher than the ISQG (interim sediment quality guideline) and ERL (effects range-low) values, suggesting little probability of causing biological adverse effects and potential risk in surface sediments. (3) High-molecular-weight PCBs (4, 5 and 6 chlorinated biphenyl) were bio-accumulated in marine biota. The concentrations of PCBs in organisms were generally lower than 2000 ng x g(-1), which may have negligible effects on human health. (4) The main sources of PCBs were wastewater discharged from factories and the leakage of dismantling PCBs from electronic wastes. Factors influencing the concentrations and distribution of PCBs in the coastal areas included distance from land, flow exchange situation, water-carrying capacity, season, sediment particle size and total organic carbon content.

Computational identification and analysis of the key biosorbent characteristics for the biosorption process of reactive black 5 onto fungal biomass.

The performances of nine biosorbents derived from dead fungal biomass were investigated for their ability to remove Reactive Black 5 from aqueous solution. The biosorption data for removal of Reactive Black 5 were readily modeled using the Langmuir adsorption isotherm. Kinetic analysis based on both pseudo-second-order and Weber-Morris models indicated intraparticle diffusion was the rate limiting step for biosorption of Reactive Black 5 on to the biosorbents. Sorption capacities of the biosorbents were not correlated with the initial biosorption rates. Sensitivity analysis of the factors affecting biosorption examined by an artificial neural network model showed that pH was the most important parameter, explaining 22%, followed by nitrogen content of biosorbents (16%), initial dye concentration (15%) and carbon content of biosorbents (10%). The biosorption capacities were not proportional to surface areas of the sorbents, but were instead influenced by their chemical element composition. The main functional groups contributing to dye sorption were amine, carboxylic, and alcohol moieties. The data further suggest that differences in carbon and nitrogen contents of biosorbents may be used as a selection index for identifying effective biosorbents from dead fungal biomass.

Biodegradation of bensulfuron-methyl and its effect on bacterial community in paddy soils.

Bensulfuron-methyl (BSM) is a new kind of sulfonylurea herbicide widely used to control broad-leaf weeds in rice paddies. The aim of this work was to study BSM biodegradation in paddy soils with BSM-degrading bacteria Bacillus megaterium L1 and Brevibacterium sp. BH and its effect on the structures of soil bacterial community. More than 90 % of BSM could be degraded in paddy soils with 0.0355 mg kg⁻¹ BSM concentration. Addition of BSM-degrading bacterial strains Bacillus megaterium L1 into BSM contaminated paddy soil could have the half-life time of BSM compared to treatment without Bacillus megaterium L1 inoculation. Denaturing gradient gel electrophoresis and principle component analysis indicated that the diversity of the soil microbial community structure changed along with the addition of BSM, which recovered at the end of the experiment (5 weeks). Addition of BSM-degrading bacteria Bacillus megaterium L1 enriched the diversity of soil microbial community structure in paddy soils. This study provides information on the biodegradation of BSM and BSM's influences on the soil bacteria microbial community structures.

Ecofriendly decolorisation of Cr-complex dye Acid Black 172 by a newly isolated Pseudomonas sp. strain DY1.

Pseudomonas sp. strain DY1 was newly isolated from soil with rotten wood and identified as a member of the genus Pseudomonas based on 16S rDNA and biochemical tests. Acid Black 172, a water soluble Cr-complex dye, was then selected as a model dye to investigate the decolorisation ability of the strain. It was observed that the growth of the strain was not inhibited by high dose of metal ions (10 mM), and efficient decolorisation was still observed when high concentrations of Fe(2+), Fe(3+) and Ca(2+) existed. The optimal decolorising conditions obtained from Taguchi design were as follows: temperature 37˚C, pH 7.0, Fe(3+) and proline concentrations of 7 mM and 3.0 g/L, respectively. Under the optimal conditions, 94.5% of Acid Black 172 (100 mg/L) could be decolorised by the strain in 24 h. The kinetics of the decolorisation best fitted the first order kinetic model (R(2)=0.981). Besides, the phytotoxicity study demonstrated a good detoxification by the strain. This work has a certain practical value in microbial decolorisation of textile wastewater.

[Magnetic fields ameliorates high-fat and high-protein diet-induced fatty liver in rats].

OBJECTIVE: To study the mechanism of the effect of low-frequency rotary constant magnetic field on high-fat and high-protein diet-induced fatty liver in rats. METHODS: Fatty liver model was established in SD rats by feeding on a high-fat and high-protein diet daily. The enzyme activity changes in the serum and liver homogenate were detected at 10, 14, and 18 weeks, and the pathological changes of the liver were observed with optical and electron microscopy. RESULTS: In magnetic field intervention group, the concentration of alanine aminotransferase and aspartate transaminase were significantly decreased, and the activity of lipoprotein lipase, hepatic lipase, superoxide dismutase and the concentration of malondialdehyde in the liver homogenate were significantly increased. Under optical microscope and electron microscope, the rats in the model group showed diffusive adipose degeneration in the hepatic cells with large lipid droplets, which became large vacuoles after fat extraction, indicating fatty necrosis. In magnetic field intervention group, remarkably smaller lipid droplets and lessened hepatic cell adipose degeneration were observed. CONCLUSION: Low-frequency rotary constant magnetic field has beneficial effect on fat metabolism, leading to reduced lipid peroxidation and structural recovery of the degenerated hepatic cells.