Effect of biostimulation on biodegradation of dissolved organic carbon in biological filters

The addition of labile organic carbon (LOC) to enhance the biodegradation rate of dissolved organic carbon (DOC) in biological columns was studied. Acetate standard solution (NaAc) and Luria Bertrani (LB) medium were used as LOC as biostimulants in glass column system used for measurements of biodegradable dissolved organic carbon (BDOC). The addition of LOC related with the increase of total DOC in sample. The concentration of BDOC increased up to 7 and 5 times and was utilized after 24 min. contact time. The biodegradation rate constant was increased at least 26 times during adaptation-biostimulation period. There was a strong positive correlation between the biodegradation rate constant and the concentration of BDOC. Biostimulation period ranged from 24 to 53 h for NaAc biostimulant and from 20 to 168 h for LB. The study has shown that LOC could be used as stimulator to enhance the biodegradation rate of DOC during biofiltration

The association of spatial T wave axis deviation with incident coronary events. The ARIC cohort

BACKGROUND: Although current evidence suggests that the spatial T wave axis captures important information about ventricular repolarization abnormalities, there are only a few and discordant epidemiologic studies addressing the ability of the spatial T wave axis to predict coronary heart disease (CHD) occurrence. METHODS: This prospective study analyzed data from 12,256 middle-aged African American and white men and women, from the Atherosclerosis Risk in Communities Study (ARIC). Following a standardized protocol, resting standard 12-lead, 10-second electrocardiograms were digitized and analyzed with the Marquette GE program. The median follow-up time was 12.1 years; incident coronary heart disease comprised fatal and non-fatal CHD events. RESULTS: The incidence rate of CHD was 4.26, 4.18, 4.28 and 5.62 per 1000 person-years respectively, across the spatial T wave axis quartiles. Among women for every 10 degrees increase in the spatial T wave axis deviation, there was an estimated increase in the risk of CHD of 1.16 (95% CI 1.04–1.28). After adjustment for age, height, weight, smoking, hypertension, diabetes, QRS axis and minor T wave abnormalities, this hazard rate ratio for women fell to 1.03 (0.92–1.14). The corresponding crude and adjusted hazard ratios for men were 1.05 (95% CI 0.96–1.15) and 0.95 (0.86–1.04) respectively. CONCLUSIONS: In conclusion, this prospective, population-based, bi-ethnic study of men and women free of coronary heart disease at baseline shows that spatial T wave axis deviation is not associated with incident coronary events during long-term follow up. It is doubtful that spatial T wave axis deviation would add benefit in the prediction of CHD events above and beyond the current traditional risk factors

Idiopathic ventricular fibrillation – Long term prognosis in relation to clinical findings and ECG patterns in a Swedish cohort

Background: Idiopathic ventricular fibrillation (IVF) is a rare cause of sudden cardiac arrest which may pose therapeutic and prognostic challenges. To date, the only effective treatment for survivors of cardiac arrest is the insertion of an implantable cardioverter-defibrillator (ICD). We sought to review the long-term outcome of a Swedish cohort with IVF. Methods and results: Fifty patients with IVF diagnosis between 1988 and 2016 (mean age at index 34.3, 56% male), were followed for a median 13.8 years in this retrospective multicenter observational study. No cardiac mortality was reported. 32% (n = 16) of patients had recurrence of ventricular fibrillation or sustained ventricular tachycardia, requiring ICD therapy, at a median time of 1.9 years (range 0.1–20.3) from the index event. Annual incidence rate of ventricular tachyarrhythmia was 3.1%. Abnormal ECG at baseline did not predict appropriate ICD therapy (p = 0.56). During the follow-up period, 14% (n = 7) patients received a cardiac diagnosis. Follow-up genetic testing was low (26%), however did confirm pathogenic mutations in three cases. Conclusion: Idiopathic VF is a rare diagnosis with a relatively good prognosis provided ICD therapy is initiated. Routine clinical follow-up is recommended due to potential late emerging cardiac pathology. ECG changes are common, but have no prognostic value in determining the risk of ventricular arrhythmias recurrence. Screening for genetic diseases has previously been low, and this calls for improvement, especially since cheaper and more comprehensive genetic panels are now readily available