ABSTRACT
Objective: The present study aims to investigate the incidence and predictors of atrial high-rate events (AHREs) in patients with permanent pacemaker implants. Methods: A total of 289 patients who were implanted with a dual-chamber pacemaker due to complete atrioventricular block or symptomatic sick sinus syndrome (SSS) and had no previous history of atrial fibrillation were included in the present study. AHREs are defined as events with an atrial frequency of ≥175 bpm and a duration of ≥5 min. The patients were divided into two groups according to whether or not AHREs were detected during the follow-up: group A (AHRE+, n = 91) and group N (AHRE-, n = 198). Results: During the 12-month follow-up period, AHREs were detected in 91 patients (31.5%). The multivariate Cox regression analysis revealed that patient age [odds ratio [OR] = 1.041; 95% confidence interval [CI], 1.018-1.064; and P < 0.001], pacemaker implantation due to symptomatic SSS (OR = 2.225; 95% CI, 1.227-4.036; and P = 0.008), and the percentage of atrial pacing after pacemaker implantation (OR = 1.010; 95% CI, 1.002-1.017; and P = 0.016) were independent AHRE predictors. Conclusion: The AHRE detection rate in patients with pacemaker implants was 31.5%. Patient age, pacemaker implantation due to symptomatic SSS, and the percentage of atrial pacing after pacemaker implantation were independent AHRE predictors.
ABSTRACT
An aerobic denitrifier was isolated from the activated sludge of landfill leachate through traditional microbiological methods. Based on its morphological feature, physiological and biochemical properties, and 16S rDNA sequence analysis, this strain was identified as Pseudomonas sp., named as GL19 with an accession number of KC710974 in GenBank. Its aerobic denitrification characteristics and nitrification function were studied to show that the factors including carbon source, C/N, pH and cultivation temperature were important for denitrification. The optimized condition for aerobic denitrification was as follows: sodium citrate as the carbon resource, C/N no less than 15, pH of 6-10, DO of 4.8-7.7 mg x L(-1), culture temperature of 15-34 degrees C and the initial nitrate nitrogen of 140 mg x L(-1). Combining these conditions, the removal rate of nitrate nitrogen and average removal rate of TN reached 100% and 96.5%, respectively, without the accumulation of nitrite nitrogen. The strain had the capability to utilize nitrite nitrogen or ammonia nitrogen to achieve high nitrogen removal efficiency: the nitrite nitrogen removal rate reached 100% in 20 hours with an initial nitrite nitrogen of 140 mg x L(-1); the ammonia nitrogen was efficiently removed from 280 mg x L(-1) to 3.11 mg x L(-1) in 28 hours with the removal rate of up to 98.9%. These results suggested that strain GL19 with the function of cold resistance and highly effective aerobic denitrification could achieve simultaneous nitrification and denitrification. Hence, GL19 could have high potential in practical wastewater treatment in winter of south area.
Subject(s)
Denitrification , Nitrification , Pseudomonas/classification , Sewage/microbiology , Carbon/chemistry , Nitrates/chemistry , Nitrites/chemistry , Nitrogen/chemistry , Pseudomonas/isolation & purification , Pseudomonas/metabolism , RNA, Ribosomal, 16S/genetics , Wastewater/microbiology , Water Pollutants, Chemical/chemistryABSTRACT
<p><b>OBJECTIVE</b>To evaluate the efficacy of energy controllable steep pulses (ECSP) in the treatment of rabbit VX2 cancer implanted in livers.</p><p><b>METHODS</b>A tumor model was successfully established using 30 rabbits. ECSP were applied to liver cancer in half of these rabbits and the rest were used as controls. After exposure to ECSP, tissues were obtained and subjected by routine HE and transmission electron microscopic (TEM) observation. The survival time of the animals and the statuses of each group were recorded.</p><p><b>RESULTS</b>From pathological observations, ECSP showed effectively destructive action compared with that of the unexposed group. A clear borderline can be seen between necrotic cancer and its surrounding normal tissue. Irreversible cell changes were present under TEM. The survival periods of the experimental and control group were 83.1 days and 39.0 days respectively, and there was a significant difference between the two groups (Z = -2.943, P < 0.01).</p><p><b>CONCLUSION</b>ECSP can effectively treat rabbit VX2 cancer implanted in the liver; also it is safe for its surrounding normal tissues. ECSP can be a useful method for local treatment of liver cancer.</p>
