Carbon-based materials for water disinfection and heavy metals removal.

The presence of heavy metals and/or harmful bacteria in drinking water represents significant risks to human health. This study aimed to develop a low-cost water treatment technology using synthesized nanocomposites with metal nanoparticles supported on activated carbon (AC) for bacteria and heavy metal removal. In addition, the performance of the developed nanomaterials was compared with that of commercial materials - carbon fibers of three different typologies. The chemical and textural properties of all tested materials were characterized. To simulate a technology to be applied in a water outlet point, removal tests were carried out in a continuous system using suspensions of Escherichia coli and/or Staphylococcus aureus, wherein the contact time with the two phases was minimal (1 min). The obtained results revealed that iron and copper oxides supported on AC with a calcination treatment (CuFeO/AC-C) was the nanocomposite with the best performance, achieving a 6 log reduction for both bacteria in the same suspension up to 9 h operation. A mix of bacteria and heavy metals, simulating a real water, was treated with CuFeO/AC-C obtaining a 6 log reduction of bacteria, a Pb2+ removal >99.9% and Cd2+ removal between 97 and 98% over 180 passage times.

In silico prediction of the enzymes involved in the degradation of the herbicide molinate by Gulosibacter molinativorax ON4T.

Gulosibacter molinativorax ON4T is the only known organism to produce molinate hydrolase (MolA), which catalyses the breakdown of the thiocarbamate herbicide into azepane-1-carboxylic acid (ACA) and ethanethiol. A combined genomic and transcriptomic strategy was used to fully characterize the strain ON4T genome, particularly the molA genetic environment, to identify the potential genes encoding ACA degradation enzymes. Genomic data revealed that molA is the only catabolic gene of a novel composite transposon (Tn6311), located in a novel low copy number plasmid (pARLON1) harbouring a putative T4SS of the class FATA. pARLON1 had an ANI value of 88.2% with contig 18 from Agrococcus casei LMG 22410T draft genome. Such results suggest that pARLON1 is related to genomic elements of other Actinobacteria, although Tn6311 was observed only in strain ON4T. Furthermore, genomic and transcriptomic data demonstrated that the genes involved in ACA degradation are chromosomal. Based on their overexpression when growing in the presence of molinate, the enzymes potentially involved in the heterocyclic ring breakdown were predicted. Among these, the activity of a protein related to caprolactone hydrolase was demonstrated using heterologous expression. However, further studies are needed to confirm the role of the other putative enzymes.

Feasibility of using magnetic nanoparticles in water disinfection.

Disinfection is a crucial step during the water treatment process due to the significant risks of water contamination with human and animal excreta. The development of innovative disinfection technologies that can be applied at water point of use, avoiding contamination problems in water distribution systems and reservoirs, are needed. Thus, the present work aimed at assessing the disinfection efficiency of iron oxide magnetic nanoparticles (MNPs) modified with different compounds, such as carbon nanotubes, copper and silver, in water solutions contaminated with bacteria. Kinetic and influence of nanoparticles concentration experiments, performed with Escherichia coli, allowed to define the optimal reaction conditions to apply in batch experiments (1 min of contact time and 50 mg/mL of MNPs). During these experiments, CuFeO/CNT, C-FeO@CVD750 and 5% Ag/FeO were selected as the most efficient presenting log reduction values of 2.99, 1.50 and 2.11, respectively; however, experiments performed with Staphylococcus aureus suspension and a mixed bacterial suspension (E. coli + S. aureus) allowed to observe a slight decrease in nanomaterials efficiency, which was more evident for C-FeO@CVD750 and 5% Ag/FeO materials achieving efficiencies of 94 and 83% (corresponding log reductions of 1.26 and 0.77, respectively). CuFeO/CNT nanoparticles proved to be the most efficient material for both bacteria removal presenting an efficiency of 99% (corresponding log reduction of 1.99) for the mixed bacterial suspension. These nanoparticles proved to have great stability over successive experiments, and the low leaching values of the metals present in their composition after reaction proved the resistance and efficiency of these magnetic nanoparticles.

Endometrioma de cicatriz após incisões cirúrgicas obstétricas: estudo retrospectivo de 33 casos e revisão de literatura / Scar endometrioma following obstetric surgical incisions: a retrospective study of 33 cases and literature review

Context and objetive:the incidence of scar endometrioma ranges from 0,03 to 3,5%. Certain factors relating to knowledge of the clinical history of the disease make correct diagnossi and treatment difficult. The aim here was to identify the clinical pattern of the disease and show surgicxal results. The literature on this topic was reviewed. Design and setting: retrospective study at hospital municipal municipal maternidade-escola dr. mário de moraes altenfelder silva. Methods: data from the medical records of patients with preoperative diagnoses of scar endometrioma who underwent operations between 2001 and 2007 were surveyed and reviewed. The postoperative diagnosis came from histopathological analysis. The main information surveyed was age, obstetric antecedents, symptoms, tumor location, size and palpation, duration of complaint, diagnosis and treatment. All patients underwent tumor excision with a safety margin. Results: there were 33 patients, of mean age 30,1+/- 5,0 years (range: 18-41 years). The total incidence was 0,11%: 0,29% in cesarean sections and 0,01% in vaginal deliveries. Twenty -nine tumors (87,9%) were located in cesarean scars, two (6,0%) in episiotomy scars and two (6,0%) in the umbilical region. the main symptom was localized cyclical pain (66,7%), of mean duration 30,5 months (+/-23). surgical treatment was successful in all cases. conclusion: this is an uncommon disease. the most important diagnostic characteristic is coincidence of painful syntoms with menstruation. patients undergoing cesarean section are at greatest risk: relative risk of 27,37 (p < 0,01). The surgical treatment of choice is excision of the endometrioma with a safety margin(au) - en