[Effects of Magnetic Fe3O4 Nanoparticles on the Characteristics of Anaerobic Granular Sludge and Its Interior Microbial Community].

In this study, the effects of magnetic Fe3O4 nanoparticles (Fe3O4 NPs) on soluble microbial products (SMP), loosely bound extracellular polymeric substances (LB-EPS), and tightly bound extracellular polymeric substances (TB-EPS) in anaerobic granular sludge were examined. In addition, the anaerobic granular sludge interior microbial community dynamics were investigated using high-throughput sequencing. The results demonstrated that the removal rate of COD was 83.6% after long-term exposure in the experimental reactor, namely, the anaerobic reactor containing Fe3O4 NPs. It was reduced by 5.7% in comparison with the removal rate in the control reactor. The total amount of TB-EPS in anaerobic granular sludge in the experimental and control reactors was 178.20 mg·g-1 and 138.24 mg·g-1, respectively, while the total amount of SMP in anaerobic granular sludge was 34.88 mg·L-1 and 27.44 mg·L-1, respectively. With regard to the LB-EPS in anaerobic granular sludge in the experimental reactor, the peak of humic acid disappeared and the peak intensity of coenzyme F420 decreased slightly using excitation-emission matrix (EEM) fluorescence spectra. In terms of the microbial community dynamics in the experimental reactor, the abundance of Methanobacterium was greatly augmented from 76.15% to 86.76%; whereas, the abundance of Methanothrix decreased from 17.1% to 7.51%. This indicated that Methanothrix was more sensitive to Fe3O4 NPs. Moreover, the changes in bacterial communities were evident:①the abundance of Proteobacteria dropped from 66.44% to 47.16%; ② the abundance of Actinobacteria grew from 8.97% to 17.33%; and ③ the abundance of Bacteroidetes increased from 8.07% to 17.74%. The increasing abundance of Actinobacteria and Bacteroidetes plays a positive role in the anaerobic hydrolysis of organic matter.

Transcatheter closure of congenital perimembranous ventricular septal defect using the Amplatzer duct occluder 2.

OBJECTIVE: The objective of this study was to explore the clinical effect of the transcatheter closure of congenital perimembranous ventricular septal defect using the Amplatzer duct occluder 2. METHODS: Between February 2012 and December 2016, 51 patients were subjected to Amplatzer duct occluder 2 for transcatheter closure of perimembranous ventricular septal defect. A total of 51 patients with perimembranous ventricular septal defect who underwent transcatheter closure by the conventional membranous ventricular septal occluder comprised the control group. The success rate and complications were compared, and indications of Amplatzer duct occluder 2 for perimembranous ventricular septal defect were explored. RESULTS: The success rate of the interventional procedure was 98.0% (50/51) in the group of Amplatzer duct occluder 2 versus 100% in the group of conventional membranous ventricular septal occluder. The mean age of the patients of Amplatzer duct occluder group was 5.0±3.7 years (range: 1.5-25.0), and the mean weight was 19.3±8.1 kg (range: 11.0-52.0). The mean outlet diameter of the defects was 2.8±0.6 mm (range: 1.8-5.1) as measured by transthoracic echocardiography. The device was implanted by a retrograde approach in 40 patients and antegrade approach in 10 patients. No statistical significance was observed in the incidence of complication and hospitalisation duration between the two groups; however, the Amplatzer duct occluder 2 group was cost-effective (p<0.05) and required less fluoroscopy time (p<0.05). Neither deaths nor new onset of aortic and tricuspid insufficiency occurred during the median 26.2 months (range: 3-65) of follow-up. CONCLUSIONS: Amplatzer duct occluder 2 has advantages of simple manipulation and less medical costs compared with conventional device in transcatheter closure of small type perimembranous ventricular septal defect.

Postprocedural Outcomes and Risk Factors for Arrhythmias Following Transcatheter Closure of Congenital Perimembranous Ventricular Septal Defect: A Single-center Retrospective Study.

BACKGROUND: Currently, transcatheter closure of perimembranous ventricular septal defect (pmVSD) is a widely accepted therapeutic modality. However, arrhythmias, especially postprocedural heart blocks, are a concern and outcomes are not very clear. This study explored the outcomes and risk factors of arrhythmias associated with transcatheter device closure of pmVSD. METHODS: A total of 395 patients diagnosed with pmVSD who successfully underwent transcatheter intervention between January 2010 and December 2015 in our center were retrospectively reviewed. Electrocardiographic data before and after the procedure were collected and analyzed. We first evaluated the potential risk factors including gender, age, weight, inlet and outlet diameters of defect, subaortic rim length, occluder size, corrected occluder size into body surface area, fluoroscopy time, presence of aneurysm, and deployment position. We compared the potential risk factors between arrhythmia and nonarrhythmia groups using univariate analysis, followed by logistic analysis for independent risk factors. RESULTS: Various arrhythmias were detected in 95 cases (24.1%) following transcatheter closure procedure. Logistic regression analysis revealed that eccentric (odds ratio [OR] 2.9, 95% confidence interval [CI]: 1.2-7.2) and large occluders (OR 2.0, 95% CI: 1.6-2.5), as well as long fluoroscopy time (OR 1.1, 95% CI: 1.1-1.2), were correlated with postprocedural arrhythmia. During 35.5 months (range: 9-80 months) of follow-up, most of the patients (74 out of 95) reverted to normal heart rhythm. CONCLUSIONS: The mid-term outcome of patients with arrhythmias after transcatheter closure of pmVSD was satisfactory as most of the patients recovered normal rhythm. Eccentric, large device and long fluoroscopy time increase the risk of arrhythmias after transcatheter closure of pmVSD.

Bioconjugated nanoparticle for DNA protection from ultrasound damage.

To research whether poly-L-lysine-starch nanoparticle (PLL-StNP) could protect DNA from ultrasound damage or not, a series experiments were carried out: plasmid DNA-PLL-StNP complexes were treated with ultrasound for diverse times; the electrophoresis result proved that DNA bound to the complexes all the same. To investigate whether the conjugated DNA was completely protected or not, cDNA fragments bound to PLL-StNP were treated with ultrasound, and matched molecular beacons (MBs) were added. The cDNA-MB-PLL-StNP complexes exhibited dramatically increasing fluorescence, and had the same intensity as that of those MBs that were hybridized with free cDNA fragments. After being treated by ultrasound, the pIRGFP plasmid DNA-PLL-StNP complexes were transferred into COS-7 cells mediated by ultrasound. Green fluorescence protein expressed in most of the cells. Those results indicated that PLL-StNP could completely protect DNA from ultrasound damage. Furthermore, the DNA kept the same function as untreated one.