Decrease of inhibitory effect of 2-chlorophenol on nitrification in sequencing batch reactors.

The metabolic and kinetic behaviour of a nitrification process in the presence of 2-chlorophenol (2-CP) was evaluated in two sequencing batch reactors (SBR1, SBR2) inoculated with nitrifying sludge previously exposed to phenolic compounds. The SBR1 was inoculated with sludge previously exposed to 2-CP, while the SBR2 was inoculated with sludge previously exposed to p-cresol. An inhibitory effect of 20 mg 2-CP-C/L on both nitrification processes was observed, as specific rates decreased according to a control assay in the absence of 2-CP. However, the inhibitory effect decreased throughout the cycles. At the end of cycle 6, a stable nitrifying process was observed with the sludge previously exposed to 2-CP (SBR1), as an ammonium consumption efficiency and a nitrate production yield close to 99.6 ± 0.3% and 0.99 ± 0.02 were respectively achieved. Despite a complete ammonium consumption being achieved with the sludge previously exposed to p-cresol (SBR2), partial nitrification was observed as nitrate production yield accounted for 0.28 ± 0.08 and nitrite was accumulated within the culture. Nevertheless, both nitrifying sludges had the ability to completely consume 2-CP. The use of SBR systems with nitrifying sludge previously exposed to 2-CP resulted in a better nitrification performance, thus it may be a good alternative for achieving a stable nitrifying respiratory process where complete and simultaneous ammonium and 2-CP consumption can be acquired.

Effect of low-frequency repetitive transcranial magnetic stimulation on sleep pattern and quality of life in patients with focal epilepsy.

OBJECTIVE: In this study we analyzed the effects of transcranial magnetic stimulation (TMS) on sleep and on the self-perceived quality of life in epileptic patients. METHODS: A total of 24 male patients diagnosed with focal epilepsy were included in the study. Pharmacological treatment with levetiracetam was standardized at 2 g daily. Before TMS onset, all-night polysomnographic recording (PSG) was performed, and the Quality of Life in Epilepsy Inventory (QOLIE-31) was administered. Thereafter, patients underwent low-frequency repetitive TMS (1000 pulses/1 Hz) daily for 10 days. After the end of the treatment, a second polysomnographic study was performed, and the QOLIE-31 questionnaire was administered again. RESULTS: TMS induced a significant increase in sleep efficiency and in total sleep time, along with a decrease in sleep latency and the number of awakenings. In addition, the number of interictal discharges during sleep decreased significantly. Concerning the QOLIE-31 scale values, the patients showed great improvement in the self-perceived quality of life. CONCLUSION: The present results indicate that TMS may mediate therapeutic effects in the treatment of patients with focal epilepsy, and that TMS treatment is accompanied by improvement of sleep patterns as well as improvement in self-perceived quality of life. However, a study that includes a control group undergoing sham stimulation is needed to confirm these findings.

Polysomnographic features in infants with early diagnosis of congenital hypothyroidism.

Thyroid hormones play a major role in the maturation process of the brain. Currently, congenital hypothyroidism is detected by mass screening. The impact of this early hormonal deficiency on the organization of the sleep pattern is not known. In this study, the polysomnographic features in children diagnosed with congenital hypothyroidism were analyzed. Children were detected by mass population screening and the hormonal replacement therapy starts immediately. Children's age ranged between 1.5 and 18 months of age. The duration of hormonal treatment before sleep recordings varied between 8 days and 17 months. Children were polysomnographically recorded in the morning, for at least 2h, obtaining more than one sleep cycle. Results showed a high prevalence of females (5/1) in the group studied. A high proportion of infants (43%) displayed central apnea in different degrees (mild, moderate and severe) as well as hypopnea (83%), mainly in subjects around 4 and 8 months of age. The proportion of infants displaying central apnea decreases as age increases. In addition, indeterminate (light) sleep increase and quiet (slow wave) sleep decrease significantly regardless of age and treatment. The percentage of REM sleep correlated positively with the age of the child at the beginning of the treatment, and negatively with their age at the time of the study. These data indicate that congenital hypothyroidism facilitates the presence of central sleep apnea. The decrease of these respiratory alterations correlates with the increase of the hormonal replacement therapy. It seems that sleep respiratory alterations in congenital hypothyroidism are linked to brain maturation processes in which thyroid hormones play a major role.