RESUMEN
The biological activated carbon (BAC) process has been widely used in drinking water treatment to improve the removal of pollutants, including the precursors of nitrogenous disinfection byproducts (N-DBPs). Nevertheless, old BAC filter effluent DON concentration is heightened, increasing the highly toxic N-DBPs formation potential. Herein, the variation of dissolved organic nitrogen (DON) was comprehensively explored during one backwashing cycle, focusing on four BAC age (0.3, 2, 5, and 10 years) for BAC filters in drinking water. Comparatively, the removal rate of DON by four BAC followed the order 0.3-yr BAC (39.69%-66.96%) >2-yr BAC (10.10%-39.78%) >5-yr BAC (-4.18%-29.63%)>10-yr BAC (-20.88%-19.87%). When at day 7 after backwashing, 10-yr BAC filter effluent increased at least 13.71% of DON and considerably elevated the N-DBPs formation potential, which was attributed to the ultimate production of more various proteins/amino sugars-like compounds by microbes. In comparisons of microbial community between all BAC samples, Rhizobials were more prevalent in 10-yr BAC and could produce microbe-derived DON associated with amino acids. Moreover, microbes regulated metabolic pathways, including amino acid biosynthesis, TCA cycle, purine metabolism, and pyrimidine metabolism, to enhance the adaptive cellular machinery in response to environmental stressors, and therefore accelerated microbial secretion of microbe-derived DON. Structural equation model (SEM) analysis investigated that BAC age had bio-effects on N-DBPs formation potential, which were delivered via the linkage of " BAC age, microbial community, microbial metabolism, and DON molecular characteristics". Our findings demonstrate the necessity of reconsidering the feasibility of BAC filters for long-time operation, which has implications for future N-DBPs precursors control in drinking water.
Asunto(s)
Agua Potable , Contaminantes Químicos del Agua , Purificación del Agua , Carbón Orgánico/química , Materia Orgánica Disuelta , Agua Potable/análisis , Contaminantes Químicos del Agua/análisis , Desinfección , Nitrógeno/análisisRESUMEN
Biological activated carbon (BAC) has long been applied in China to guarantee water quality and to achieve drinking water regulations. However, a knowledge gap remains regarding the temporal dynamics of microbial communities, particularly microbe-based assembly and co-occurrence patterns. Accordingly, this study investigated the evolution of BAC microbial communities using a pilot-scale system and examined by multivariate ecological combined with high-throughput Illumina sequencing and statistical methods. The results showed that BAC microbial diversity reached its peak in 2 years and declined thereafter. Microbial communities composition was accompanied by significant temporal evolution in the BAC biofilm. Deterministic processes gained in importance along with time, especially homogeneous selection which contributed 59.09 %-75.63 % to the community assembly in 8-yr, 9-yr, and 10-yr BAC. According to co-occurrence network analysis, microbial networks have more unstable structures over time, as evidenced by higher modularity, heightened connectivity, and fewer keystones. Moreover, the interaction between microbial taxa tended to have a higher proportion of competitive relationships during the operation of the BAC tank, ranging from 13.51 % to 76.35 %. Based on these dynamic ecological processes, microbial community succession in BAC biofilm might undergo four phases: community establishment (Years 0-2); community stability (Years 2-5); community quasi-degradation (Years 5-8); community degradation (Years 8-10). The performance of BAC was greatly influenced by community development, and contaminant removal gradually decreased as community succession proceeded. These results add to our knowledge of microbial ecology and provide the basis for further research into microbial communities' regulation strategies in BAC tanks.
Asunto(s)
Carbón Orgánico , Microbiota , Carbón Orgánico/química , Consorcios Microbianos , Biodiversidad , ChinaRESUMEN
BACKGROUND/AIMS: To assess HRQL in patients with chronic hepatitis B (CHB) and investigate the relevant factors. METHODOLOGY: A cross-sectional three-center study involving 407 inpatients with CHB was conducted. Subjects completed the epidemiological questionnaire and two validated questionnaires (SF-36 and QLICD-CH). Afterwards, the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) and dopamine receptor D4 (DRD4) gene polymorphisms were assessed in all patients. RESULTS: It was found that the scores of CHB patients in SF-36 scale 8 domains were lower than those of the normal population (all p<0.001). The anti-viral therapy could improve four-area-scores (PHD (p=0.004), SOD (p=0.011), SPD (p=0.032), TOT (p=0.014)). Extraverted personality, social competence and ability to work were protective factors of HRQL, while severity of illness, better family economy and abnormal condition of liver function were risk factors. The scores in II genotype were higher than those in I/D+DD genotype of ACE polymorphisms. The scores in short repeat sequences genotypes were higher than those in long repeat sequences genotype of DRD4 polymorphisms. CONCLUSIONS: Patients with CHB had lower HRQL than normal population. Anti-viral treatments can improve their HRQL. Several health factors independently influence HRQL and ACE and DRD4 gene polymorphism is associated with HRQL of CHB patients.
Asunto(s)
Hepatitis B Crónica/psicología , Calidad de Vida , Adulto , Anciano , Estudios Transversales , Femenino , Estado de Salud , Hepatitis B Crónica/tratamiento farmacológico , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Peptidil-Dipeptidasa A/genética , Polimorfismo Genético , Receptores de Dopamina D4/genéticaRESUMEN
OBJECTIVE: The NAD(P)H:quinone oxidoreductase 1 (NQO1) rs1800566 polymorphism, leading to proline- toserine amino-acid and enzyme activity changes, has been implicated in bladder cancer risk, but individually published studies showed inconsistent results. We therefore here conducted a meta-analysis to summarize the possible association. METHODS: A systematic literature search up to August 27, 2012 was carried out in PubMed, EMBASE and Wanfang databases, and the references of retrieved articles were screened. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were analyzed for homozygote contrast (TT vs. CC), additive model (T vs. C), dominant model (TT+CT vs. CC), and recessive model (TT vs. CC+CT) to assess the association using fixed- or random-effect models. RESULTS: We identified 12 case-control studies including 3,041 cases and 3,128 controls for the present meta-analysis. Significant association between NQO1 rs1800566 genetic polymorphism and risk of bladder cancer was observed in the additive model (OR = 1.15, 95% CI = 1.01-1.30, p = 0.030). Moreover, in the subgroup analysis stratified by ethnicity, significant associations were observed in Asians (OR = 1.26, 95% CI = 1.08-1.47, p = 0.003 for T vs. C; OR = 1.68, 95% CI = 1.21-2.32, p = 0.002 for TT vs. CC; OR = 1.50, 95% CI = 1.13-1.98, p = 0.005 for TT vs. CT+CC) but not in Caucasians. CONCLUSIONS: The results suggest that NQO1 rs1800566 genetic polymorphism may contribute to bladder cancer development, especially in Asians.
Asunto(s)
Predisposición Genética a la Enfermedad/genética , NAD(P)H Deshidrogenasa (Quinona)/genética , Polimorfismo Genético/genética , Neoplasias de la Vejiga Urinaria/genética , Pueblo Asiatico/genética , Estudios de Casos y Controles , Genotipo , Humanos , Riesgo , Factores de RiesgoRESUMEN
OBJECTIVE: To assess the nutritional status of iodine in school children of Wuqiao County in Hebei Province. METHODS: 1209 school children aged 8-12 years were selected by multistage random sampling. Thyroid size estimated by inspection and palpation was graded according to the criteria recommended by WHO. The concentration of urinary iodine and iodine in salt was also measured. RESULTS: There were 74 goiter cases, accounted for 6.1% of total students investigated. The median of urinary iodine was 208 microg/L and the median of iodine intake was 312 microg/d. The excretion of urinary iodine at <100 microg/L, <50 microg/L, 200-300 microg/L and 300 microg/L accounted for 18.5%, 4.6%, 27.2% and 26.5% of total detected samples respectively. The coverage of iodized salt in the area was 77% and the iodine in iodized salt was at a median of 26.96 mg/kg. CONCLUSION: Goiter is endemic in Wuqiao County of Hebei Provinee. Urinary iodine of school children was more than the optimal range, and the iodine nutrition was excessive in this area.
Asunto(s)
Bocio/epidemiología , Yodo/orina , Niño , China/epidemiología , Femenino , Bocio/prevención & control , Humanos , Yodo/administración & dosificación , Yodo/química , Masculino , Tamizaje Masivo , Prevalencia , Cloruro de Sodio DietéticoRESUMEN
OBJECTIVE: To explore the clustering character of overweight and obesity with multiple cardiovascular disease risk factors such as blood pressure, serum lipids and glucose, and to provide evidence for intervention in childhood. METHODS: A cross-sectional study was conducted on 913 children aged 7-13 years in urban area of Shijiazhuang. Measurements included height, weight, systolic blood pressure (SBP), diastolic blood pressure (DBP) and fasting serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and serum glucose (GLU). RESULTS: Overall prevalence rate of overweight and obesity was 29.24% (boys: 34.98% vs. girls: 24.23%). When compared with normal children, children with overweight or obesity had significantly higher levels of SBP, DBP, TC, TG but low HDL-C. The prevalence rates of high SBP, DBP, TC, TG, GLU and low HDL-C in overweight and obese children were higher than in normal children. After adjusted for gender and age, the odds ratios of overweight and obese children for high SBP, DBP, TC, TG, GLU and low HDL-C were 6.77, 3.22, 2.55, 6.42, 3.85 and 2.94 (95% CI: 4.15-11.04, 1.38-7.49, 1.59-4.11, 3.46-11.92, 1.69-8.78 and 1.83-4.73), respectively. Odds ratios of overweight and obese children holding any one, two or three of the selected six risk factors appeared to be 2.74, 13.15 and 15.33 (95% CI : 1.92-3.92, 6.69-25.87 and 4.17-56.39), respectively. CONCLUSION: Childhood overweight and obesity increased the clustering of children's risk factors on cardiovascular diseases, as well as increasing the risk of children acquiring multiple cardiovascular disease risk factors. Controlling overweight and obesity would help early prevention on children from getting cardiovascular diseases.