Azo dye degrading bacteria tolerant to extreme conditions inhabit nearshore ecosystems: Optimization and degradation pathways.

Nearshore ecosystems are transitional zones, and they may harbor a diverse microbial community capable of degrading azo dyes under extreme environmental conditions. In this study, thirteen bacterial strains capable of degrading eight azo dyes were isolated in nearshore environments and characterized using high throughput 16 S rRNA sequencing. The results of this study demonstrate that the biodegradability of azo dyes was influenced by their chemical structure and position of functional groups as well as the type of bacteria. The decolorization rate of Methyl Orange (95%) was double that of the heavier and sterically hindered Reactive Yellow 84 (<40%). Shewanella indica strain ST2, Oceanimonas smirnovii strain ST3, Enterococcus faecalis strain ST5, and Clostridium bufermentans strain ST12 demonstrated potential application in industrial effluent treatment as they were tolerant to a wide range of environmental parameters (pH: 5-9, NaCl: 0-70 g L-1, azo dye concentration: 100-2000 mg L-1) including exposure to metals. Analysis of the transformation products using GC-MS revealed that different bacterial strains may have different biotransformation pathways. This study provides critical insight on the in-situ biotransformation potential of azo dyes in marine environments.

Comparing biofilm reactors inoculated with Shewanella for decolorization of Reactive Black 5 using different carrier materials.

This study assessed the performance of biofilm reactors inoculated with azo dye degrading Shewanella for the decolorization of Reactive Black 5 (RB5), using three different carrier materials, namely almond shell biochar, moving bed biofilm reactor (MBBR), and polypropylene carrier (PPC). The reactors were fed with low-nutrient artificial wastewater containing RB5, and all three carriers showed good RB5 decolorization performance, with varying efficiencies. Liquid Chromatography-Mass Spectrometry analysis revealed distinct RB5 degradation pathways associated with each carrier, influenced by carrier materials and microbial communities. The MBBR carrier exhibited good stability due to its rough surface and microbial aggregates. Sequencing results highlighted differences in the microbial community structures among the carriers. Shewanella predominated the functional bacteria in the MBBR and PPC carriers, while the biochar carrier fostered highly efficient degrading microbial communities. The physicochemical properties of carrier materials significantly influenced the microbial community and RB5 degradation efficiency. These findings provide valuable insights for optimizing biofilm reactors for dye-containing wastewater treatment.

Effect of 5:2 Regimens: Energy-Restricted Diet or Low-Volume High-Intensity Interval Training Combined With Resistance Exercise on Glycemic Control and Cardiometabolic Health in Adults With Overweight/Obesity and Type 2 Diabetes: A Three-Arm Randomized Controlled Trial.

OBJECTIVE: We aimed to examine the effects of a 5:2 diet (2 days per week of energy restriction by formula diet) or an exercise (2 days per week of high-intensity interval training and resistance training) intervention compared with routine lifestyle education (control) on glycemic control and cardiometabolic health among adults with overweight/obesity and type 2 diabetes. RESEARCH DESIGN AND METHODS: This two-center, open-label, three-arm, parallel-group, randomized controlled trial recruited 326 participants with overweight/obesity and type 2 diabetes and randomized them into 12 weeks of diet intervention (n = 109), exercise intervention (n = 108), or lifestyle education (control) (n = 109). The primary outcome was the change of glycemic control measured as glycated hemoglobin (HbA1c) between the diet or exercise intervention groups and the control group after the 12-week intervention. RESULTS: The diet intervention significantly reduced HbA1c level (%) after the 12-week intervention (-0.72, 95% CI -0.95 to -0.48) compared with the control group (-0.37, 95% CI -0.60 to -0.15) (diet vs. control -0.34, 95% CI -0.58 to -0.11, P = 0.007). The reduction in HbA1c level in the exercise intervention group (-0.46, 95% CI -0.70 to -0.23) did not significantly differ from the control group (exercise vs. control -0.09, 95% CI -0.32 to 0.15, P = 0.47). The exercise intervention group was superior in maintaining lean body mass. Both diet and exercise interventions induced improvements in adiposity and hepatic steatosis. CONCLUSIONS: These findings suggest that the medically supervised 5:2 energy-restricted diet could provide an alternative strategy for improving glycemic control and that the exercise regimen could improve body composition, although it inadequately improved glycemic control.

A Study on Nonvisual Effects of Natural Light Environment in a Maternity Ward of a Hospital in Cold Area.

Thanks to the discovery of human eye photoreceptor cells, ipGRC and human nonvisual channels, the nonvisual effects of light have gradually come to our vision and been rationally utilized. Along with this trend, people have expanded their demand for the light environment to both visual and nonvisual needs from only visual needs. With a good natural daylighting, parturients will find their psychological pressure and physiological pain relieved, their rehabilitation rate increased, and they get rehabilitated more quickly. This study was carried out in a representative maternity ward in Harbin based on the latest research results on nonvisual effects at home and abroad. Specifically, the nonvisual effects on the natural light environment in the ward throughout the year were simulated and analyzed from the aspects of equivalent melanopic lux (EML), stimulus frequency (Stim.freq), and circadian effective area (CEA). During the study, natural light in the ward was measured on site, and the evaluation tool and workflow of nonvisual effects were created with the aid of Grasshopper modeling platform, Ladybug+Honeybee, and VB script editor. The results show that the nonvisual effects of natural light on the body of parturients gradually weaken as they further go inside the ward. What is worse, in the most unfavorable all-overcast condition, daylighting on beds far away from the window does not meet the stimulus of human circadian rhythm from April to August. Therefore, additional light is required. The wards have the best nonvisual natural light environment when they are south facing and have a window to floor ratio of 0.3.

Research on Carbon Emission Efficiency Space Relations and Network Structure of the Yellow River Basin City Cluster.

The Yellow River Basin serves as China's primary ecological barrier and economic belt. The achievement of the Yellow River Basin's "double carbon" objective is crucial to China's green and low-carbon development. This study examines the spatial link and network structure of city cluster carbon emission efficiency in the Yellow River Basin, as well as the complexity of the network structure. It focuses not only on the density and centrality of the carbon emission efficiency network from the standpoint of city clusters, but also on the excellent cities and concentration of the city cluster 's internal carbon emission efficiency network. The results show that: (1) The carbon emission efficiency of the Yellow River Basin has been dramatically improved, and the gap between city clusters is narrowing. However, gradient differentiation characteristics between city clusters show the Matthew effect. (2) The distribution of carbon emission efficiency in the Yellow River Basin is unbalanced, roughly showing a decreasing trend from east to west. Lower-level efficiency cities have played a significant role in the evolution of carbon emissions efficiency space. (3) The strength of the carbon emission efficiency network structure in the Yellow River Basin gradually transitions from weakly correlated dominant to weakly and averagely correlated dominant. Among them, the Shandong Peninsula city cluster has the most significant number of connected nodes in the carbon emission efficiency network. In contrast, the emission efficiency network density of the seven city clusters shows different changing trends. Finally, this study suggests recommendations to improve carbon emission efficiency by adopting differentiated governance measures from the perspective of local adaptation and using positive spatial spillover effects.

[Celastrol inhibits neurotoxicity induced by Cd2].

Cadmium (Cd) is a common heavy metal in the environment. Cd2+ may penetrate the blood-brain barrier and produce neurotoxicity, thus inducing various neurodegenerative diseases. Celastrol is an effective component of Tripterygium wilfordii Hook. F., which has many pharmacological effects such as anti-cancer and anti-inflammatory. Here we explored the effect of celastrol on the corresponding neurotoxicity induced by Cd2+. Cell proliferation test, cell membrane integrity test, and cell morphology were observed to analyze the effect of Cd2+ on the viability of HMC3. The neurotoxicity of Cd2+ and the effect of celastrol on the corresponding neurotoxicity induced by Cd2+ were analyzed by nitric oxide (NO) test, lipid peroxidation (MDA) test, and Western blotting. When the concentration of Cd2+ reached 40 µmol/L, the inhibition rate of HMC3 cell proliferation was (57.17±8.23)% (P < 0.01, n=5), compared with the control group. The cell activity continued to reduce when the Cd2+ concentration further increased. When the concentration of Cd2+ was higher than 40 µmol/L, the cell membrane of HMC3 was significantly damaged, and the damage was dose-dependent. Upon increasing the Cd2+ concentration, the cell morphology began to change and the adhesion also became worse. Cd2+ significantly increased the amount of NO released by HMC3 cells, while celastrol effectively inhibited the NO release of HMC3 cells induced by Cd2+. Cd2+ greatly increased the release of MDA in HMC3 cells, and the level of MDA decreased rapidly upon the addition of 10-7 mol/L celastrol. Cd2+ increased the expression of p-PI3K protein, and the levels of p-PI3K protein and p-AKT protein were inhibited by the addition of celastrol (10‒7 mol/L, 10‒6 mol/L), thus preventing cell apoptosis. In conclusion, celastrol inhibits Cd2+ induced microglial cytotoxicity and plays a neuroprotective role.

Impact of visit-to-visit fasting plasma glucose variability on the development of diabetes: The mediation by insulin resistance.

BACKGROUND: Little is known about the risk of diabetes due to higher glycemic variability and the underlying mechanisms. We aimed to examine the association of visit-to-visit variability (VVV) in fasting plasma glucose (FPG) with incident diabetes in Chinese adults and whether the association was mediated by changes in insulin resistance (IR). METHODS: We included 1856 community residents without a history of diabetes and having attended 3 examinations in 2008, 2009, and 2013 respectively. The SD, the average successive variability (ASV), the coefficient of variation (CV), and the variability independent of the mean (VIM) of three recorded FPG measurements were calculated for each participant, and SD, ASV, CV, and VIM were used as a measure of VVV in FPG. Incident diabetes was defined according to the 1999 World Health Organization criteria. IR was evaluated using the homeostatic model assessment (HOMA). RESULTS: A total of 153 (8.2%) participants developed incident diabetes at the third visit. Compared with the lowest tertile (0-5.83 mg/dl) of FPG-SD, the highest tertile (9.55-74.17 mg/dl) was associated with a 148% increased risk of diabetes (odds ratio [OR], 2.48; 95% confidence interval [CI], 1.36-4.49), after adjustment for covariates including mean FPG at 3 visits. Mediation analyses suggested that changes in IR (ΔHOMA-IR) might mediate 17.3% of the association between increased FPG-SD and elevated diabetes risk. Similar results were found for FPG-CV, FPG-ASV, and FPG-VIM. CONCLUSIONS: The VVV in FPG was significantly associated with risks of diabetes in Chinese adults, which was partially mediated by changes in IR.

Sorption and biodegradation of propylparaben in greywater by aerobic attached-growth biomass.

Greywater (GW) is becoming an important alternative water source for non-potable purposes, but requires treatment to remove contaminants, including micropollutants that in GW mainly originate from personal care products. Biofilters are commonly used for onsite GW treatment, but there are still significant knowledge gaps regarding their ability and mechanism of micropollutants removal. This study investigates the removal of propylparaben (PPB) by aerobic attached-growth biomass, quantifying the kinetics and the interplay between sorption and biodegradation. The ability of biomass, collected from a pilot scale biofilter treating real GW, to eliminate PPB from both synthetic greywater (SGW) and deionized (DI) water was studied in laboratory batch experiments. Elimination of PPB was found to proceed via sorption to biomass followed by biodegradation. Sorption of PPB by biomass in SGW and in DI water exhibited similar kinetics, fitting Langmuir isotherm with the maximum adsorbed amount of 9.8mgPPB gbiomass-1. PPB biodegradation exhibited first-order kinetics in both SGW and DI water, with a 30h lag-phase in SGW and no lag-phase in DI water. This difference is attributed to presence of readily-biodegradable organic matter in the SGW. Actual PPB degradation rate in both cases (excluding the lag phase in SGW) was very similar, 62mgPPB gbiomass-1d-1, yielding almost full mineralization. These findings show the relative contribution of the major processes involved in PPB elimination by biofilters and can be applied for designing GW treatment units.

An outbreak of acute GII.17 norovirus gastroenteritis in a long-term care facility in China: The role of nursing assistants.

More than 30 residents and nursing assistants in a geriatric nursing hospital developed acute gastroenteritis from December 7th to December 18th, 2014 in Shanghai, China. An immediate epidemiological investigation was conducted to identify the etiological agent of the outbreak, mode of transmission and the risk factors. Cases were investigated according to an epidemiological questionnaire. Samples from cases, highly transmissible environmental surfaces and drinking water were collected for pathogens detection. A retrospective cohort study was conducted to explore the transmission mode. A total of 34 cases were affected in this acute gastroenteritis outbreak, including 23 residents, 9 nursing assistants and 2 doctors. 13 out of 30 samples were positive for GII.17 norovirus, no other pathogen was detected. Nursing assistants who developed gastroenteritis symptoms had a higher attack rate in residents they cared than those who did not develop any gastroenteritis symptoms (p<0.001). The acute gastroenteritis outbreak was caused by GII.17 norovirus. Person-to-person close contact and contaminated environmental surfaces were the probable transmission route. Nursing assistants were considered to play an important role in the secondary spread of norovirus. The poor medical skill and personal hygiene habits of nursing assistants in China should be paid attention and improved urgently which is critically important to prevent hospital infections.

The importance of lake sediments as a pathway for microcystin dynamics in shallow eutrophic lakes.

Microcystins are toxins produced by cyanobacteria. They occur in aquatic systems across the world and their occurrence is expected to increase in frequency and magnitude. As microcystins are hazardous to humans and animals, it is essential to understand their fate in aquatic systems in order to control health risks. While the occurrence of microcystins in sediments has been widely reported, the factors influencing their occurrence, variability, and spatial distribution are not yet well understood. Especially in shallow lakes, which often develop large cyanobacterial blooms, the spatial variability of toxins in the sediments is a complex interplay between the spatial distribution of toxin producing cyanobacteria, local biological, physical and chemical processes, and the re-distribution of toxins in sediments through wind mixing. In this study, microcystin occurrence in lake sediment, and their relationship with biological and physicochemical variables were investigated in a shallow, eutrophic lake over five months. We found no significant difference in cyanobacterial biomass, temperature, pH, and salinity between the surface water and the water directly overlying the sediment (hereafter 'overlying water'), indicating that the water column was well mixed. Microcystins were detected in all sediment samples, with concentrations ranging from 0.06 to 0.78 µg equivalent microcystin-LR/g sediments (dry mass). Microcystin concentration and cyanobacterial biomass in the sediment was different between sites in three out of five months, indicating that the spatial distribution was a complex interaction between local and mixing processes. A combination of total microcystins in the water, depth integrated cyanobacterial biomass in the water, cyanobacterial biomass in the sediment, and pH explained only 21.1% of the spatial variability of microcystins in the sediments. A more in-depth analysis that included variables representative of processes on smaller vertical or local scales, such as cyanobacterial biomass in the different layers and the two fractions of microcystins, increased the explained variability to 51.7%. This highlights that even in a well-mixed lake, local processes are important drivers of toxin variability. The present study emphasises the role of the interaction between water and sediments in the distribution of microcystins in aquatic systems as an important pathway which deserves further consideration.

Contribution of sediments in the removal of microcystin-LR from water.

Microcystins are produced by several species of cyanobacteria and can harm aquatic organisms and human beings. Sediments have the potential to contribute to the removal of dissolved microcystins from the water body through either adsorption to sediment particles or biodegradation by the sediment's bacterial community. However, the relative contribution of these two removal processes remains unclear and little is known about the significance of sediment's overall contribution. To study this, changes in the concentration of microcystin-LR (MCLR) in the presence of sediment, sediment with microbial inhibitor, and non-sterile lake water were quantified in a laboratory experiment. Our results show that, in the presence of sediment, MCLR concentration decreased significantly in an exponential way without a lag phase, with an average degradation rate of 9 µg d(-1) in the first 24 h. This indicates that sediment can contribute to the removal of MCLR from the water immediately and effectively. Whilst both, the biodegradation and adsorption ability of the sediment contributed significantly to the removal of MCLR from the water body, biodegradation was shown to be the dominant removal process. Also, the sediment's ability to degrade MCLR from the water was shown to be faster than the biodegradation through the bacterial community in the water. The present study emphasizes the importance of sediments for the removal of microcystins from a water body. This will be especially relevant in shallow systems where the interaction between the water and the sediment is naturally high. Our results are also useful for the application of sediments to remove microcystins at water treatment facilities.

Effects of the Distribution of a Toxic Microcystis Bloom on the Small Scale Patchiness of Zooplankton.

Toxic cyanobacterial blooms can strongly affect freshwater food web structures. However, little is known about how the patchy occurrence of blooms within systems affects the spatial distribution of zooplankton communities. We studied this by analysing zooplankton community structures in comparison with the spatially distinct distribution of a toxic Microcystis bloom in a small, shallow, eutrophic lake. While toxic Microcystis was present at all sites, there were large spatial differences in the level of cyanobacterial biomass and in the zooplankton communities; sites with persistently low cyanobacterial biomass displayed a higher biomass of adult Daphnia and higher zooplankton diversity than sites with persistently high cyanobacterial biomass. While wind was the most likely reason for the spatially distinct occurrence of the bloom, our data indicate that it was the differences in cyanobacterial biomass that caused spatial differences in the zooplankton community structures. Overall, our study suggests that even in small systems with extensive blooms 'refuge sites' exist that allow large grazers to persist, which can be an important mechanism for a successful re-establishment of the biodiversity in an ecosystem after periods of cyanobacterial blooms.