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Air quality is an important factor for human breathing requirements. The presence of the particulate matter which is a mixture of solid particles and liquid droplets presence in atmosphere such as PM10 and PM2.5 in the indoor air leads to fatal problems for human health. In the present investigation, two types of nanofilters (polyacrylonitrile PAN, 15wt.% and polyvinyl alcohol PVA 12wt.%) were synthesized using the electrospinning method. The polymeric solutions were prepared under high mixing conditions. The structural and morphological specifications of produced nanofibers were characterized using many measuring devices. Also, airflow characteristics across the prepared nanofilter were evaluated by designing and constructing an airflow apparatus. The apparatus consisted of two stainless steel sections and the middle zone was designed to fit the filter media. The characterization results indicated that the synthesized of PVA 12 wt.% nanofilter has uniform morphological distribution with fibers average diameter of 92 nm while the produced PAN with 15wt.% showed and an average fibers diameter of 556 nm. Moreover, the PVA nanofilter showed high-pressure values in comparison with the PAN filter. Interestingly, both filters provided high air permeability. Furthermore, the produced PAN nanofilter showed a high ability to capture the PM10 and PM2.5 due to the significant properties and specifications of nanofibers. Additionally, the produced nanofilter can be applied in air filtration processes effectively with low manufacturing costs.

Hypoparathyroidism is a rare disease that markedly reduces bone remodeling, leading to increased bone mineral density and changes in bone microarchitecture. However, it is currently unclear how these changes affect fracture risk. In this study, we investigated bone mass by dual-energy x-ray absorptiometry, the occurrence of morphometric vertebral fractures, and bone microarchitecture by assessing trabecular bone score in women with postsurgical hypoparathyroidism. We included 67 women with hypoparathyroidism aged 52.9 ± 12.3 years and 63 age- and body mass index-matched controls, which were assessed for femoral and lumbar spine bone mineral density, trabecular bone score, and vertebral fractures by dual-energy x-ray absorptiometry. Women with hypoparathyroidism had significantly higher bone mineral density at the lumbar spine, femoral neck, and total hip compared with controls despite similar trabecular bone score values. Vertebral fracture assessment indicated that two women with hypoparathyroidism presented vertebral fractures, both aged over 65 years. Conversely, no vertebral fractures were detected in control women. In a multivariate linear regression model, we found that older age, diabetes, and lower lumbar spine mineral density were significant predictors of lower trabecular bone score values. Our findings indicate that vertebral fractures are not common among women with postsurgical hypoparathyroidism aged under 65 years. Moreover, trabecular bone score values were similar in women with hypoparathyroidism and age-matched controls and were associated with traditional risk factors for fractures, such as older age, type 2 diabetes, and lower spine bone mineral density. LAY SUMMARY: Chronic parathyroid hormone deficiency decreases bone turnover and modifies skeletal properties, although the impact of these changes on fracture risk remains unclear. We studied 67 women with postsurgical hypoparathyroidism and 63 age and body mass index-matched healthy controls and found that bone mineral density is increased in women with hypoparathyroidism despite similar trabecular bone score values and a low occurrence of morphometric vertebral fractures. This suggests that the low bone turnover in hypoparathyroidism increases bone mass, but this is not accompanied by improved bone microarchitecture, indicating that trabecular bone score may be a valuable tool to complement the assessment of skeletal health and the risk of fractures in this condition., Competing Interests: Declaration of competing interest None declared., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Although high-volume online hemodiafiltration has been associated with higher clearance and lower pre-dialysis concentration of middle molecular weight toxins compared to hemodialysis, its effect on protein-bound uremic toxins has shown inconclusive results. In this study, we investigated whether hemodiafiltration impacts pre-dialysis plasma levels of the toxins indoxyl sulfate, p-cresyl sulfate, and indole-3-acetic acid compared to high-flux hemodialysis., Methods: This is a post-hoc analysis of the multicenter, randomized controlled trial HDFit (ClinicalTrials.gov: NCT02787161). Uremic toxins were determined by high performance liquid chromatography at baseline, 3, and 6 months. Mean differences in monthly changes of pre-dialysis uremic toxin concentrations between hemodiafiltration and high-flux hemodialysis were analyzed using linear mixed-effect models., Results: One hundred ninety-three patients (mean age 53 years old, 71% males) were analyzed. There were no differences between groups regarding clinical and biochemical characteristics at baseline or duration of dialysis session and blood flows throughout the follow-up. Mean differences in rates of change (μM/month, [confidence interval CI]) in high-flux hemodialysis vs. hemodiafiltration were 2.4 [0.3 to 4.56], 3.94 [- 1.54 to 9.41] and 0.06 [- 0.6 to 0.5] for indoxyl sulfate, p-cresyl sulfate and indole-3-acetic acid, respectively. In the exploratory analysis, these differences in high-flux hemodialysis vs. hemodiafiltration subgroup with convective volume > 27.5 L were 2.86 [0.43 to 5.28], 7.43 [0.7 to 14.16] and - 0.19 [- 0.88 to 0.50]., Conclusion: These exploratory findings suggest that hemodiafiltration is more effective in reducing indoxyl sulfate as compared to standard high-flux hemodialysis, and also that this effect was extended to p-cresyl sulfate in patients achieving higher convective volumes., (© 2022. The Author(s) under exclusive licence to Italian Society of Nephrology.)

Introduction: Papillary thyroid cancer corresponds to approximately 1% of all carcinomas; nevertheless, it is the most prevalent endocrine neoplasm in the world. Studies reveal that the BAX (-248 G > A) polymorphism may be associated with negative regulation of BAX gene transcription activity, causing a decrease in its protein expression., Objective: The present study aimed to describe the genotype and allele frequencies of BAX single nucleotide polymorphisms (-248 G > A) (rs4645878) in the research patients, and to associate its presence with susceptibility to papillary thyroid cancer., Methods: This case-control study was conducted with 30 patients with papillary thyroid cancer. For the evaluation of genetic polymorphisms, the polymerase chain reaction-restriction fragment length polymorphism technique was employed. Allele and genotype frequencies were estimated using the SPSS program, and significant associations were considered when p < 0.05., Results: There was a significant genotypic difference between papillary thyroid cancer and the control group (p = 0.042). The GG genotype provided a protective factor for papillary thyroid cancer (p = 0.012, odds ratio (OR) = 0.313; confidence interval (CI) = 0.123-0.794). Likewise the G allele was a protective factor for papillary thyroid cancer (p = 0.009; OR = 0.360; CI = 0.163-0.793). The BAX gene polymorphism (-248 G > A) was associated with papillary thyroid cancer., Conclusion: BAX (-248 G > A) GG genotype carriers, or at least one mutated allele, was associated with papillary thyroid cancer in the Brazilian population studied, and the G allele presence is considered a protective factor against papillary thyroid cancer occurrence.

Thyroid cancer is the most common endocrine cancer in the world. Noting that the NOS3 gene polymorphism interferes with nitric oxide production, this study aims to identify and analyze the NOS3 gene polymorphism in the intron 4 region in patients with papillary thyroid cancer. A case-control study was conducted with 31 papillary thyroid cancer patients of both genders who underwent thyroidectomy and treatment with sodium iodide radiopharmaceutical (131I) compared with 81 control patients. Through papillary thyroid cancer, the results were observed, compiled, and analyzed using SPSS version 25.0. The significance level of 5% was adopted. Genotypic frequencies of healthy subjects were in the Hardy-Weinberg equilibrium ( P = 0.503). There was a significant genotypic difference between papillary thyroid cancer and healthy individuals ( P <0.001). The BB genotype conferred a protective factor for papillary thyroid cancer ( P <0.001, odds ratio (OR) 0.16; 95% confidence interval (CI) 0.06, 0.42), while the presence of the A allele appears to be a risk factor for papillary thyroid cancer ( P <0.001, OR 3.54; 95% CI 1.86, 6.73). The intron 4 polymorphism of the NOS3 gene was associated with susceptibility to papillary thyroid cancer. Thus, future research into the effects of this polymorphism is essential.

Introduction: Hypertension is multifactorial, highly prevalent in the hemodialysis (HD) population and its adequate control requires, in addition to adequate volume management, often the use of multiple antihypertensive drugs. We aimed to describe the use of antihypertensive agents in a group of HD patients and to evaluate the factors associated with the use of multiple classes (≥3) of antihypertensives., Methods: We analyzed the baseline data from the HDFit study. Clinically stable patients with HD vintage between 3 and 24 months without any severe mobility limitation were recruited from sites throughout southern Brazil. Fluid status was measured pre-dialysis with the Body Composition Monitor (BCM; Fresenius, Germany). Fluid overload (FO) was considered when the overhydration index (OH) was greater than 7% of extracellular water (OH/ECW > 7%) and overweight was defined as a body mass index (BMI) greater than 25 kg/m 2 . Prescriptions of antihypertensive drugs were obtained from participants' reports and medical records. Logistic regression was employed to determine factors associated with excessive use of antihypertensive medication (≥3 classes)., Findings: Of 195 studied patients, 171 with complete data were included (70% male, 53 ± 15 years old, 57% of them with FO). Pre-dialysis systolic blood pressure (SBP) was 150 ± 24 mmHg and patients used a median of 2 (1-3) antihypertensive drugs. Vasodilators (20%) were of lowest prevalence, use of other classes varied from 40% to 53%. Sixty-two (36%) subjects used ≥3 classes and presented a higher prevalence of diabetes and FO, lower prevalence of overweight, and higher SBP. In a logistic regression model age, BMI <25 kg/m 2 , and OH/ECW > 7% were associated with excessive drug use., Discussion: More than one-third of participants used ≥3 classes of antihypertensive drugs, and it was associated with older age, BMI <25 kg/m 2 and FO. Strategies that better manage FO may aid better blood pressure control and avoid the use of multiple antihypertensive medications., (© 2020 International Society for Hemodialysis.)

Introduction: Dialysis patients suffer from poor sleep duration and quality. We examined the self-reported sleep duration in patients randomized to either high-volume hemodiafiltration (HDF) or high flux hemodialysis (HD)., Methods: Patients from 13 Brazilian dialysis clinics were enrolled in the HDFIT randomized controlled trial (RCT) investigating the impact of HDF on physical activity and self-reported outcomes. Self-reported sleep duration was taken from patient diaries recording sleep start and end time over a week during baseline, months 3 and 6, respectively. Sleep duration was analyzed by shift and nights relative to dialysis., Results: The HDFIT study enrolled 197 patients; sleep data were available in 173 patients (87 HD; 86 HDF). Patients' age was 53 ± 15 years, 57% were white, 72% were male, 34% had diabetes, Kt/V was 1.54 ± 0.40, and albumin 3.97 ± 0.36 g/dL. Most patients reported sleeping 510-530 min/night. At 3 months, HDF patients slept 513 ± 71 min/night, HD patients 518 ± 76 min/night. At 6 months, HDF patients slept 532 ± 74 min/night, HD patients 519 ± 80 min/night. At baseline, 1st shift patients slept 406 ± 86 min the night before HD, 534 ± 64 min the night after HD, and 496 ± 99 min the night between 2 non-HD days. Compared to patients in the 2nd and 3rd shifts, patients dialyzed in the 1st shift slept less in the night before dialysis. Similar patterns were seen after 3 and 6 months., Conclusion: In our RCT, the dialysis modality (HDF vs. HD) had no effect on self-reported sleep duration. In both groups, dialysis in the 1st shift adversely affected self reported sleep duration., (© 2019 S. Karger AG, Basel.)

The Water Framework Directive (WFD) regulates freshwater and coastal water quality assessment in Europe. Chemical and ecological water quality status is based on measurements of chemical pollutants in water and biota together with other indicators such as temperature, nutrients, species compositions (phytoplankton, microalgae, benthos and fish) and hydromorphological conditions. However, in the current strategy a link between the chemical and the ecological status is missing. In the present WFD, no microbiological indicators are foreseen for integrating the different anthropogenic pressures, including mixtures of chemicals, nutrients and temperature changes, to provide a holistic view of the freshwater ecosystem water quality. The main aim of this work was to evaluate if natural microbial populations can be valuable indicators of multiple stressors (e.g. chemical pollutants, temperature, nutrients etc.) to guide preventive and remediation actions by water authorities. A preliminary survey was conducted to identify four sites reflecting a contamination gradient from the source to the mouth of a river suitable to the objectives of the European Marie Curie project, MicroCoKit. The River Tiber (Italy) was selected as a pilot case study to investigate the correlation between bacteria taxa and the chemical status of the river. The main physicochemical parameters, inorganic elements, organic pollutants and natural microbial community composition were assessed at four selected sites corresponding to pristine, agricultural, industrial and urban areas for three consecutive years. The overall chemical results indicated a correspondence between different groups of contaminants and the main contamination sources at the selected sampling points. Phylogenetic analysis of the microbial community analyzed by Fluorescence In Situ Hybridization method (FISH) revealed differences among the four sampling sites which could reflect an adaptive bacterial response to the different anthropogenic pressures., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: End stage renal disease (ESRD) patients require a renal replacement therapy (RRT) to filter accumulated toxins and remove excess water, which are associated with impaired physical function. Hemodialysis (HD) removes middle-molecular weight (MMW) toxins less efficiently compared to hemodiafiltration (HDF); we hypothesized HDF may improve physical function. We detailed the design and methodology of the HDFIT protocol that is testing whether changing from HD to HDF effects physical activity levels and various outcomes., Methods: HDFIT is a prospective, multi-center, unblinded, randomized control trial (RCT) investigating the impact of dialysis modality (HDF verses HD) on objectively measured physical activity levels, self-reported quality of life, and clinical/non-clinical outcomes. Clinically stable patients with HD vintage of 3 to 24 months without any severe limitation ambulation were recruited from sites throughout southern Brazil. Eligible patients were randomized in a 1:1 ratio to either: 1) be treated with high volume online HDF for 6 months, or 2) continue being treated with high-flux HD. This study includes run-in and randomization visits (baseline), 3- and 6-month study visits during the interventional period, and a 12-month observational follow up. The primary outcome is the difference in the change in steps per 24 h on dialysis days from baseline to the 6-month follow up in patients treated with HDF versus HD. Physical activity is being measured over one week at study visits with the ActiGraph ( www.actigraphcorp.com ). For assessment of peridialytic differences during the dialysis recovery period, we will analyze granular physical activity levels based on the initiation time of HD on dialysis days, or concurrent times on non-dialysis days and the long interdialytic day., Discussion: In this manuscript, we provide detailed information about the HDFIT study design and methodology. This trial will provide novel insights into peridialytic profiles of physical activity and various self-reported, clinical and laboratory outcomes in ESRD patients treated by high volume online HDF versus high-flux HD. Ultimately, this investigation will elucidate whether HDF is associated with patients having better vitality and quality of life, and less negative outcomes as compared to HD., Trial Registration: Registered on ClinicalTrials.gov on 20 April 2016 ( NCT02787161 ).

Papillary thyroid cancer (PTC) is the most common thyroid malignancy. Genetic and epigenetic alterations play a decisive role in the onset of several human neoplasms. Mutations and polymorphisms are two frequent genetic alterations. Located on chromosome 19 (19p13.11), the NIS SLC5A5 (solute carrier family 5 member 5) gene encodes a highly specialized and efficient 80-90 kDa transmembrane glycoprotein that mediates active transport of iodide from the bloodstream into the follicular cells. Given the highly significant role of NIS in the physiology and the cancer pathogenesis process, this paper's objective is to provide a comprehensive assessment of the associations between NIS gene and protein with papillary thyroid cancer.

Objective: To evaluate the performance of contrast-enhanced mammography (CEM) compared to magnetic resonance imaging (MRI) for estimating residual tumor size after neoadjuvant chemotherapy (NAC) in women with newly diagnosed breast cancer., Methods: The institutional review board approved this study. This prospective study included women with newly diagnosed breast cancer who underwent breast CEM and MRI at the end of the last cycle of NAC and before definitive surgery. Size of residual malignancy on post-NAC CEM and MRI was compared with surgical pathology. Agreements and correlations of CEM and MRI measurements with histological size were assessed., Results: Thirty-three patients were included with a mean age of 45 years (range 22-76). The sensitivity, specificity, and positive and negative predictive value for detection of residual disease of CEM were 76%, 87.5%, 95%, and 86.4%, and those of MRI were 92%, 75%, 92%, and 75%. Comparing CEM to MRI, the mean difference was -0.8 cm, concordance coefficient was 0.7, and Pearson correlation was 0.7 (p = 0.0003). The concordance coefficient between measurements of each imaging modality and pathologic tumor size was 0.7 for CEM and 0.4 for MRI. Pearson correlation was 0.8 for CEM and 0.5 for MRI. Mean differences between CEM, MRI, and residual histopathological tumor size were 0.8 cm and 1.8 cm, respectively., Conclusions: CEM has good correlation and agreement with histopathology for measuring residual disease after NAC. CEM was comparable to MRI, showing high positive predictive value and specificity for detecting residual disease.

Sulfamethoxazole and ciprofloxacin are among the most prescribed antibiotics and are frequently detected in surface water ecosystems. The aim of this study was to assess the role of a riverine natural microbial community in sulfamethoxazole (SMX) degradation in presence and absence of ciprofloxacin (CIP). River samples were collected from a stretch of the Tiber River highly impacted by human pressure. An experimental set up was performed varying some abiotic (dark/UV-light) and biotic (presence/absence of microorganisms) conditions that can affect antibiotic degradation. The residual concentrations of SMX and CIP were measured (HPLC-MS or HPLC-UV/FLD) and the effects on the natural microbial community were assessed in terms of microbial number (N. live cells/mL) and structure (Fluorescence In Situ Hybridization - FISH). Finally, the occurrence of the antibiotic resistance sul1 gene was also verified using quantitative PCR (qPCR). In 28 days, in the presence of both UV-light and microorganisms SMX disappeared (

Background: Chronic kidney disease (CKD) patients develop metabolic acidosis when approaching stages 3 and 4, a period in which accelerated atherogenesis may ensue. Studies in vitro show that low pH may increase low-density lipoprotein (LDL) oxidation, suggesting a role for chronic metabolic acidosis in atherosclerosis. The present study attempted to evaluate the effects of conservative care using oral sodium bicarbonate (NaHCO 3 ) supplementation on the electronegative LDL [LDL(-)], a minimally oxidized LDL, plasma levels in CKD patients., Methods: Thirty-one CKD patients were followed by a multidisciplinary team during 15 months of care in which 1.0 mmol/kg/day oral NaHCO 3 supplementation was first given in the third month. Blood samples were collected 3 months before the initiation of oral NaHCO 3 supplementation (T1), at the time of the beginning of supplementation (T2), and thereafter, each 4 months (T3, T4 and T5) until month 15 of care. Blood parameters and LDL(-) were measured from these collections., Results: After 12 months of conservative care, creatinine clearance (MDRD) was kept stable, and serum bicarbonate (HCO 3 - ) increased from 20.5 ± 2.9 to 22.6 ± 1.1 mM ( p < 0.003). LDL(-) plasma levels declined from 4.5 ± 3.3 to 2.1 ± 0.9 U/L ( p < 0.007) after reaching mean serum HCO 3 - levels of 22.6 ± 1.1 mM., Conclusions: Conservative care using oral NaHCO 3 supplementation was able to stabilize renal function and decrease serum levels of LDL(-), a modified proatherogenic lipoprotein, only when mean serum HCO 3 - levels approached 22 mM. This study constitutes evidence that alkali therapy, in addition to its beneficial effect on renal disease progression, might serve as a preventive strategy to attenuate atherogenesis in CKD patients.

Polychlorobiphenyl (PCB) biodegradation was followed for 1 year in microcosms containing marine sediments collected from Mar Piccolo (Taranto, Italy) chronically contaminated by this class of hazardous compounds. The microcosms were performed under strictly anaerobic conditions with or without the addition of Dehalococcoides mccartyi, the main microorganism known to degrade PCBs through the anaerobic reductive dechlorination process. Thirty PCB congeners were monitored during the experiments revealing that the biodegradation occurred in all microcosms with a decrease in hepta-, hexa-, and penta-chlorobiphenyls (CBs) and a parallel increase in low chlorinated PCBs (tri-CBs and tetra-CBs). The concentrations of the most representative congeners detected in the original sediment, such as 245-245-CB and 2345-245-CB, and of the mixture 2356-34-CB+234-245-CB, decreased by 32.5, 23.8, and 46.7 %, respectively, after only 70 days of anaerobic incubation without any bioaugmentation treatment. Additionally, the structure and population dynamics of the microbial key players involved in the biodegradative process and of the entire mixed microbial community were accurately defined by Catalyzed Reporter Deposition Fluorescence In Situ Hybridization (CARD-FISH) in both the original sediment and during the operation of the microcosm. The reductive dehalogenase genes of D. mccartyi, specifically involved in PCB dechlorination, were also quantified using real-time PCR (qPCR). Our results demonstrated that the autochthonous microbial community living in the marine sediment, including D. mccartyi (6.32E+06 16S rRNA gene copy numbers g(-1) sediment), was able to efficiently sustain the biodegradation of PCBs when controlled anaerobic conditions were imposed.

Introduction/objective: We evaluated the predictability of early changes in serum albumin (sAlb) on the two-year mortality of incident hemodialysis patients., Methods: Observational, longitudinal retrospective study using the database of Fresenius Medical Care of Latin America. Adult patients starting dialysis from January/2000 to June/2004, from 25 centers were included. Changes in sAlb during the first 3 months on hemodialysis were used as the main predictor. The outcome was death from any cause., Results: 1,679 incident patients were included. They were 52 ± 15 years old, 58.7% male and 21.5% diabetic, with a median sAlb of 38 g/L (bromocresol green). 923 patients had sAlb < 38 g/L (Low sAlb Group) and 756 ones had sAlb > 38.0 g/L (Adequate sAlb Group). The mortality was significantly higher in Low sAlb Group (17% vs. 11%, p < 0.001). Early changes in sAlb significantly affected two-year mortality. Factoring the Kaplan Meier curve of Low sAlb Group by the presence of an increase in sAlb uncovered of a statistically significant difference in mortality favoring the ones whose sAlb went up (19% vs. 15%, p = 0.043). Differently, patients from Adequate sAlb Group with a decrease in their sAlb had a statistically higher mortality rate (13% vs. 8%, p = 0.029)., Conclusions: Early sAlb changes showed a significant predictive power on mortality at 2 years in incident hemodialysis patients. Those with low initial sAlb may have a better prognosis if their sAlb rises. In contrast, patients with satisfactory initial levels can have a worsening of their prognosis in the case of an early reduction in sAlb.

New concerns about biodiversity, ecosystem services and human health triggered several new regulations increasing the need for sound ecotoxicological risk assessment. The PEER network aims to share its view on the research issues that this challenges. PEER scientists call for an improved biologically relevant exposure assessment. They promote comprehensive effect assessment at several biological levels. Biological traits should be used for Environmental risk assessment (ERA) as promising tools to better understand relationships between structure and functioning of ecosystems. The use of modern high throughput methods could also enhance the amount of data for a better risk assessment. Improved models coping with multiple stressors or biological levels are necessary to answer for a more scientifically based risk assessment. Those methods must be embedded within life cycle analysis or economical models for efficient regulations. Joint research programmes involving humanities with ecological sciences should be developed for a sound risk management., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Brazil has the third largest contingent of patients on maintenance hemodialysis (HD) worldwide. However, little is known regarding survival rate and predictors of mortality risk in that population, which are the purposes of this study. A total of 3,082 patients incident on HD, from 2000 to 2004, at 25 dialysis facilities distributed among 7 out of 26 states of Brazil were followed-up until 2009. Patients were 52 ± 16 years-old, 57.8% men, and 20.4%, diabetics. The primary outcome was all causes of mortality. Data were censored at five years of follow-up. The global five-year survival rate was 58.2%. In the Cox proportional model, variables associated with risk of death were: age (hazard ratio - HR = 1.44 per decade, p < 0.0001), diabetes (HR = 1.51, p < 0.0001), serum albumin (HR = 0.76 per g/dL, p = 0.001), creatinine (HR = 0.92 per mg/dL, p < 0.0001), and phosphorus (HR = 1.06 per mg/dL, p = 0.04). The present results show that the mortality rate on HD in this Brazilian cohort was relatively low, but the population is younger and with a lower prevalence of diabetes than the ones reported for developed countries.

The antiviral drug Tamiflu has received particular attention because of its recommended use against the influenza A H5N1 and H1N1 viruses. Given its resistance to degradation and its hydrophilicity the active metabolite, Oseltamivir Carboxylate (OC), is expected to enter the aquatic ecosystem from sewage treatment plants. In the present paper the bacterial community of surface water samples, treated with OC (1.5 mg L⁻¹), was characterized by Fluorescence In Situ Hybridization (FISH) in microcosm experiments. The α-, β- and γ-Proteobacteria increased in OC-treated versus non-treated water samples during the incubation period, suggesting these bacterial groups had an active role in OC degradation.

A bacterial community in an aquifer contaminated by s-triazines was studied. Groundwater microcosms were treated with terbuthylazine at a concentration of 100 microg L(-1) and degradation of the herbicide was assessed. The bacterial community structure (abundance and phylogenetic composition) and function (carbon production and cell viability) were analysed. The bacterial community was able to degrade the terbuthylazine; in particular, Betaproteobacteria were involved in the herbicide biotransformation. Identification of some bacterial isolates by PCR amplification of the 16S rRNA gene revealed the presence of two Betaproteobacteria species able to degrade the herbicide: Advenella incenata and Janthinobacterium lividum. PCR detection of the genes encoding s-triazine-degrading enzymes indicated the presence of the atzA and atzB genes in A. incenata and the atzB and atzC genes in J. lividum. The nucleotide sequences of the PCR fragments of the atz genes from these strains were 100% identical to the homologous genes of the Pseudomonas sp. strain ADP. In conclusion, the results show the potential for the use of a natural attenuation strategy in the treatment of aquifers polluted with the terbuthylazine. The two bacteria isolated could facilitate the implementation of effective bioremediation protocols, especially in the case of the significant amounts of herbicide that can be found in groundwater as a result of accidental spills.

Pesticide and nitrate contamination of soil and groundwater from agriculture is an environmental and public health concern worldwide. Simazine, 6-chloro-N2,N4-diethyl-1,3,5-triazine-2,4-diamine, is a triazine herbicide used in agriculture for selective weed control with several types of crops and it is frequently applied to soils receiving N-fertilizers. Degradation experiments were performed in the laboratory to assess whether the biodegradation of simazine in soil may be influenced by the presence of urea. Simazine degradation rates under different experimental conditions (presence/absence of urea, microbiologically active/sterilized soil) were assessed together with the formation, degradation and transformation of its main metabolites in soil. Simazine degradation was affected by the presence of urea, in terms both of a smaller half-life (t(1/2)) and of a higher amount of desethyl-simazine formed. The soil bacterial community was also studied. Microbial abundances were determined by epifluorescence direct counting. Moreover in situ hybridization with rRNA-targeted fluorescent oligonucleotide probes was used to analyze the bacterial community structure. Fluorescent in situ hybridization (FISH) was used to detect specific groups of bacteria such as the alpha,beta,gamma-subdivisions of Proteobacteria, Gram-positive bacteria with a high G + C DNA content, Planctomycetes, Betaproteobacterial ammonia-oxidizing bacteria and nitrifying bacteria. The presence of the herbicide and/or urea affected the bacterial community structure, showing that FISH is a valuable tool for determining the response of bacterial populations to different environmental conditions., (Copyright 2005 Society of Chemical Industry)

Pesticide and nitrate contamination of soil and groundwater from agriculture is an environmental and public health concern worldwide. The herbicide terbuthylazine (CBET) has replaced atrazine in Italy and in many other countries because the use of the latter has been banned because of its adverse environmental impacts. Unlike atrazine, knowledge about the fate of CBET in soil is still not extensive, especially regarding its transformation products, but recent monitoring data show its occurrence and that of its main metabolite, desethyl-terbuthylazine (CBAT), in groundwater above the limit of 0.1 microg/L established by European Union Directive and Italian legislation. The objective of this work was to investigate if the presence of the fertilizer urea affects CBET degradation in the soil. Laboratory CBET degradation experiments in the presence/absence of urea were performed with microbiologically active soil and sterilized soil. Terbuthylazine degradation rates under the different experimental conditions were assessed, and the formation, degradation, and transformation of the metabolite CBAT were also studied. Terbuthylazine degradation was affected by the presence of urea, in terms both of a higher disappearance time of 50% of the initial concentration and of a lower amount of CBAT formed. These findings have practical implications for the real-life assessment of the environmental fate of triazine herbicides in agricultural areas since these herbicides are frequently applied to soils receiving ureic fertilizers.