Clinical relevance of incomplete device endothelialization after left atrial appendage closure.

PURPOSE: This study aimed to assess the incidence, potential risk factors and clinical impact of incomplete device endothelialization(IDE) after left atrial appendage closure (LAAC). METHODS: A total of 101 consecutive patients with nonvalvular atrial fibrillation (AF) who underwent successful LAAC and received antithrombotic treatment using a standard regimen were prospectively followed up to 6 months after the procedure. The status of device endothelialization and device-related thrombus (DRT) were evaluated using cardiac computed tomography (CT). Major adverse cardio-cerebral events (MACCE) including all-cause death, heart failure(HF) hospitalization, acute ischemic stroke, transient ischemic attack(TIA), peripheral vascular embolism, and major bleeding were recorded. RESULTS: IDE was detected in 65 (64.4%) patients. Patients with IDE or complete device endothelialization (CDE) did not significantly differ with respect to baseline clinical characteristics and interventional procedure features. Multivariate analysis model revealed that persistent AF, left atrial appendage ostial diameter and left atrial size were independent risk factors for IDE. During 6-month follow-up, the incidence of DRT was 4.6% in patients with IDE and 2.8% in those with CDE, respectively (p > 0.05), and the overall rate of MACCE was non-significantly higher in the IDE group (7.7% vs. 2.8%, p = 0.32). CONCLUSION: IDE is common after LAAC, especially in patients with persistent AF, higher left atrial appendage ostial diameter and left atrial size. IDE confers an increased risk for DRT, but may be not necessarily associated with thromboembolic events and poor clinical outcome, providing careful monitoring and continued antithrombotic therapy are given.

Instantly Detecting Catalysts' Hot Spots Temperature In Situ during Photocatalysis by Operando Raman Spectroscopy.

Precisely detecting the catalysts' hot spots temperature in situ instantly during photocatalysis is a great challenge but extremely important for chemical reactions. However, no efficient method has been developed to instantly detect the hot spots temperature in situ during photocatalysis. Herein, we designed a simple and convenient method to measure the instant hot spots temperature in situ on the nanostructure surface during photocatalysis by operando Raman spectroscopy using 4-methoxyphenyl isocyanide (MI) as the probe molecule. The νN≡C frequency of MI varied linearly with temperature, which is caused by the orientation change of the MI induced by temperature, leading to the change in the frequency of the νN≡C bond that directly interacts with the nanostructure surface. Using in situ surface-enhanced Raman spectroscopy (SERS), the surface temperature of the catalysts illuminating for each time can be measured instantly. Interestingly, the catalytic activity of the hydrogen evolution reaction (HER) for the Au-Ag/Ag2S heterojunction nanorods (HJNRs) are higher than that for the Ag-Au-Ag HJNRs, although they have a lower surface temperature during photocatalysis; therefore, hot carriers and electronic structure contributed more to the catalytic activity of the Au-Ag/Ag2S HJNRs than that of the Ag-Au-Ag HJNRs. Such an instant hot spots temperature detecting method of catalysts can greatly facilitate the analysis of the mechanism of catalytic processes.

Research on the Influence of Cosolvent on the Determination of the Contamination Degree of Jet Fuel.

The effect of cosolvent on trace free water in the determination of the contamination degree of jet fuel was investigated. The interference of trace free water on the automatic particle counter can be eliminated by adding isopropanol as a cosolvent to the measured oil sample. Isopropanol can dissolve trace free water in oil. Addition of isopropanol could stabilize the pollution grade of particles with size ≥30 µm (c) at the same level, which is most obviously affected by free water without isopropanol. The standard uncertainty u(X 1) is slightly reduced with the addition of isopropanol, and the repeatability and accuracy of the automatic particle counting method are obviously improved. The results show that isopropanol should be added as a cosolvent to eliminate the interference of free water when the contamination degree of jet fuel oil samples with obvious free water is determined by the automatic particle counting method.

I2-Mediated Iodobenzannulation of Yne-Allenones toward 1-Naphthols and Their Synthetic Application.

A new I2-mediated iodobenzannulation of yne-allenones has been established, enabling breaking/rearranging of C≡C bonds to selectively access 4-iodonaphthalen-1-ols with generally good yields. The resulting 4-iodonaphthalen-1-ols could serve as a new and reliable coupling reagent, which further reacted with H2O under the oxygen conditions to generate unexpected 1,2-carbonyls with good yields through Pd-catalyzed deiodinated carbonylation, whereas employment of benzene-1,2-diamine as the nucleophile rendered 3-(quinoxalin-2-yl)naphthalen-1-ols through Pd-catalyzed [4 + 2] heterocyclization. On the basis of the controlled experiments, the mechanism for forming 1,2-carbonyls was proposed, including an oxidative addition, 1,3-palladium migration, reductive elimination, and oxidative dehydrogenation sequence.

Atom-economic synthesis of cyclobuta[a]naphthalen-4-ols via a base-promoted [2 + 2] cycloaddition/1,6-nucleophilic addition cascade.

A first atom-economic [2 + 2] cycloaddition/1,6-conjugate addition cascade of yne-allenones with C-nucleophiles including 1,3-dicarbonyls and α,α-dicyanoolefins under base-promoted conditions has been established, enabling the direct construction of C(sp3)-C(sp3) bonds to generate cyclobuta[a]naphthalen-1-ols with generally good yields. These resulting products have a cyclobutene unit that contains both an aryl and alkyl group.

Understanding Mechanisms of Synergy between Acidification and Ultrasound Treatments for Activated Sludge Dewatering: From Bench to Pilot-Scale Investigation.

Enhancing activated sludge dewaterability is of scientific and engineering importance in the face of accelerated urbanization and stringent environmental regulations. In this study, we investigated the integration of acidification and ultrasound (A/US) treatment for improving sludge dewaterability at both bench- and pilot-scales. Our results showed that the A/US process exhibited significantly improved sludge dewatering performance, characterized by capillary suction time, cake moisture, and water/solid content of sludge cake. Synergistic dewatering mechanisms were elucidated with a suite of macro and spectroscopic evidence. Characterization of treated sludge revealed that US-induced thermal, mechanical shearing force, and radical oxidation effects disrupts floc cells and accelerates the decomposition of extracellular polymeric substances (EPS), releasing bound water into the bulk phase. In addition to enhancing hydrolysis of EPS, the acidic pH environment caused the protonation of functional groups on EPS, facilitating the reflocculation of US decomposed sludge for improved filterability. Our bench-scale and pilot-scale investigations provide a mechanistic basis for better understanding of the A/US process, and enable development of a viable and economical dewatering technology.

Rapid decolorization of dye Orange G by microwave enhanced Fenton-like reaction with delafossite-type CuFeO2.

Bimetallic oxide CuFeO2 as a new heterogeneous catalyst has shown much higher catalytic ability for activating peroxide than single-metal oxides. The present work demonstrated a synergistic microwave (MW) enhanced Fenton-like process with CuFeO2 for rapid decolorization of azo dye Orange G (OG). The MW irradiation dramatically enhanced the OG degradation efficiency, achieving 99.9% decolorization within 15min at pH5. The XRD analysis of reused CuFeO2, together with metal leaching tests, indicated merits of recycling for CuFeO2. The subsequent surface element analysis by XPS for fresh and used CuFeO2 showed a complex network for reactions between copper-iron redox pairs and surface hydroxyl groups, leading to a synergistic Fenton-like system accelerated by MW irradiation. In the CuFeO2 initiated Fenton-like reactions, several oxidant species (i.e., OH, O2-, electron hole, and FeIVO) responsible to the OG oxidation were identified by quenching experiments, showing the MW generated high temperature and "hot spots" enhanced the yield of OH by generation of electron-hole pairs. Further, the 26 detected degradation products confirmed the OH dominant oxidation of OG. This study shows that the MW-enhanced Fenton-like reaction using CuFeO2 has potential applications for rapid decolorization of dye effluent.

Planar graphene oxide-based magnetic ionic liquid nanomaterial for extraction of chlorophenols from environmental water samples coupled with liquid chromatography-tandem mass spectrometry.

A planar graphene oxide-based magnetic ionic liquid nanomaterial (PGO-MILN) was synthesized. The prepared PGO-MILN was characterized by transmission electronmicroscopy (TEM) and Fourier-transform infrared spectrometry (FTIR). The results of adsorption experiments showed that the PGO-MILN had great adsorption capacity for 2-chlorophenol (2-CP), 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP), 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP) and pentachlorophenol (PCP). Based on the adsorption experimental data, a sensitive magnetic method for determination of the five CPs in environmental water samples was developed by an effective magnetic solid-phase extraction (MSPE) procedure coupled with high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). The effects of main MSPE parameters including the solution pH, extraction time, desorption time, and volume of desorption solution on the extraction efficiencies had been investigated in detail. The recoveries ranged from 85.3 to 99.3% with correlation coefficients (r) higher than 0.9994 and the linear ranges were between 10 and 500ngL(-1). The limits of detection (LODs) and limits of quantification (LOQs) of the five CPs ranged from 0.2 to 2.6ngL(-1) and 0.6 to 8.7ngL(-1), respectively. The intra- and inter- day relative standard deviations (RSDs) were in the range from 0.6% to 7.4% and from 0.7% to 8.4%, respectively. It was confirmed that the PGO-MILN was a kind of highly effective MSPE materials used for enrichment of trace CPs in the environmental water.

Symptomatic sinus tachycardia with perpetuating slow pathway: successful treatment with radiofrequency ablation.

We report a case of sinus tachycardia with perpetuating slow pathway (SP) conduction in a 42-year-old woman who developed severe symptoms as a result of atrioventricular (AV) desynchronization. The restoration of an AV synchrony, achieved with selective radiofrequency ablation of the SP, eliminated the symptomatic arrhythmia and may represent a reasonable therapeutic option despite the fact that the patient has no AV-node reentrant tachycardia. This case demonstrates the importance of AV timing.

Identification and functional analysis of a novel PRKAG2 mutation responsible for Chinese PRKAG2 cardiac syndrome reveal an important role of non-CBS domains in regulating the AMPK pathway.

BACKGROUND: PRKAG2 gene encodes the γ2 regulatory subunit of AMP-activated protein kinase (AMPK) that acts as a sensor of cellular energy status, and its germline mutations are responsible for PRKAG2 cardiac syndrome (PCS). The majority of missense mutations of cystathionine beta-synthase (CBS) domains found in PCS impair the binding activity of PRKAG2 to adenosine derivatives, and therefore lead to PRKAG2 function impairment and AMPK activity alteration, resulting in a familial syndrome of ventricular preexcitation, conduction defects, and cardiac hypertrophy. However, it is unclear about the PRKAG2 mutation in the non-CBS domain. Here, a Chinese family exhibiting the cardiac syndrome associated with a novel heterozygous PRKAG2 mutation (Gly100Ser) mapped to exon 3 encoding a non-CBS domain is described and the function of this novel mutation was investigated in vitro. METHODS: The PRKAG2 G100S and R302Q mutations were constructed by a two-step polymerase chain reaction and then transfected into CCL13 cells by lentivirus vectors. Wild-type PRKAG2 gene transfection was used as a negative control. PRKAG2 expression was determined by Western blot. Immunofluorescence was used to localize the intracellular PRKAG2 proteins. MTT assay was performed to explore the effect of mutations on cell proliferation. Periodic acid-Schiff staining was used for detecting glycogen accumulation. AMPK concentration was measured with enzyme-linked immunosorbent assay. RESULTS: Our results showed neither intracellular localization of PRKAG2 nor cell growth was altered. In contrast, PRKAG2 protein expression levels were significantly reduced by this mutation. Furthermore, PRKAG2-mediated activity of AMPK was attenuated, resulting in glycogen metabolism dysregulation. These findings revealed that non-CBS domains of PRKAG2 were essential to the regulation of AMPK activity, similar to CBS. CONCLUSIONS: Our study ascribes a crucial regulatory role to the novel PRKAG2 G100S mutation, and reiterates that PCS occurs as a consequence of AMPK signaling abnormality caused by PRKAG2 gene mutations.

Development and preclinical evaluation of a biodegradable ventricular septal defect occluder.

OBJECTIVES: This study evaluated the feasibility, effectiveness, and safety of a biodegradable (BD) occluder for closure of ventricular septal defect (VSD) in an acute canine model. BACKGROUND: All current available VSD occluders are permanent implants which consist of a metal framework and synthetic fabrics. However, the septal occluder in vivo plays the role of a temporary bridge that facilitates the ingrowth of fibrous connective tissue and endothelialization. The ideal occluder may be a temporary scaffold which can be gradually absorbed in vivo and replaced by "native" tissue. METHODS: The BD VSD occluder consists of a polydioxanone (PDO) framework and two pieces of poly-L-lactic acid (PLLA) fabrics. Percutaneous transcatheter closure of interventionally created VSDs was performed in 16 dogs using the BD occluders. Follow-up consisted of electrocardiography, transthoracic echocardiography, and fluoroscopy from 1 week to 24 weeks post-implantation. Gross pathology and histopathology were obtained at 6, 12, and 24 weeks follow-up. RESULTS: Implantation of the BD occluders was successful in 15 animals. The devices became well integrated into the ventricular septum with complete endothelialization at 12 weeks after implantation. After 24 weeks in vivo, the PDO framework of devices was largely absorbed and replaced by the ingrowth of collagenous fibers, and the PLLA fabric within disks was partly degraded. Neither occluder dislocation nor VSD recanalization occurred during follow-up. CONCLUSIONS: The BD occluder proved safe and effective for VSD closure. This device is characterized by compatible mechanical properties, a fully BD property, and a good match between the degradation of occluder and the healing response of organism.

Animal experimental study of the fully biodegradable atrial septal defect (ASD) occluder.

This study was conducted to evaluate the feasibility, safety, biocompatibility, and degradation features of a fully biodegradable occluder for closure of atrial septal defect (ASD) in an acute canine model. The ASD was created in 20 healthy mongrel dogs by the brockenbrough needle, and the fully biodegradable occluders were implanted by self-made delivery system. The success rate and complications were observed. Acute ASD models were successfully created in 18 dogs, and 16 occluders were successfully implanted in the ASD models. Animals were sacrificed at different times after procedure. The cardiac gross anatomy showed that all occluders were stable in the interatrial septum, no vegetation or thrombus formation was observed on the surface of all occluders. They were embedded into endogenous host tissue gradually at 12-week follow-up. Different periods of pathological observations suggested that the occluders degraded gradually over about 24 weeks and essentially became an integral part of the septum. Transcatheter closure of ASD in acute canine model using the fully biodegradable ASD occluder has the potential of a high successful rate of technique, excellent biocompatibility, and fewer complications with adequate, immediate, and short-term results.

Intracoronary infusion of bone marrow-derived mononuclear cells contributes to longstanding improvements of left ventricular performance and remodelling after acute myocardial infarction: a meta-analysis.

BACKGROUND: Conflicting results exist now on the sustained effects of intracoronary bone marrow-derived mononuclear cells (BMMNCs) infusion in patients with acute myocardial infarction (AMI). METHODS: Systematical literature search of PubMed, ISI Web of Science, and Cochrane databases was conducted. We included the randomised controlled trials with at least 12-month follow-up data for AMI patients receiving primary percutaneous coronary intervention in addition to intracoronary BMMNCs transfer or not (the control). Summary statistics were calculated using random-effects models. RESULTS: A total of 10 trials with 757 patients were available for analysis. The pooled statistics showed intracoronary administration of BMMNCs significantly improved post-infarction left ventricular ejection fraction (weight mean differences [WMD]=4.04%, 95% confidence intervals [CI], 3.01-5.07%; p<0.01), and attenuated the enlargement of left ventricular end-diastolic volume (WMD=-6.13 ml, 95%CI, -10.56 ml to -1.69 ml; p=0.007) as well as infarct size (WMD=-2.47%, 95%CI, -3.79% to -1.15%; p=0.0002). However, for the major adverse clinical events (MACEs), there appeared to be neutral results (between-group differences of p>0.10). CONCLUSIONS: Intracoronary BMMNCs infusion leads to longstanding and moderate improvements of post-infarction left ventricular performance as well as remodelling. Meanwhile, the procedure did not increase the risk of MACEs.

Identifying mass transfer influences on Au nanoparticles growth process by centrifugation.

A comparative study of gold nanoparticles (Au NPs) growth employing cetyltrimethylammonium bromide (CTAB) adsorbent was performed. Au nanooctahedrons transformed into slightly truncated nanocubes without centrifugation, whereas they transformed into nanocubes with centrifugation. Our results indicate that the mass transfer of Au monomers can influence the shape evolution of NPs.

Potential candidate genes for alveolar hypoxia identified by transcriptome network analysis.

BACKGROUND. Alveolar hypoxia is an important condition related to many disorders such as chronic pulmonary hypertension, pulmonary vasoconstriction, and pulmonary vascular remodeling. The aim of present study was to disclose the biological response and the potential transcriptome networks regulating the hypoxia response in the lungs. MATERIALS AND METHODS. In this study, the microarray dataset GSE11341 was used to construct a regulatory network and identify the potential genes related to alveolar hypoxia. In addition, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Gene Ontology (GO) term enrichment analyses were also performed. RESULTS. Hypoxia inducible factor 1 alpha (HIF-1α), peroxisome proliferator-activated receptor gamma (PPARγ), and nuclear factor of kappa light polypeptide gene enhancer in B cells (NF-кB) were to be the hub nodes in the transcriptome network. HIF-1α may regulate potassium voltage-gated channel, shaker-related subfamily, member (5KCNA5), solute carrier family 2 (facilitated glucose transporter), member (1SLC2A1), and heme oxygenase (decycling) 1 (HMOX1) expression through the regulation of membrane potential, glucose metabolism, and anti-inflammation pathways. HMOX-1 mediates signaling pathways that relate to NF-кB. CCND1 (cyclin D1) expression could be regulated by PPARγ and HIF-1α via the cell cycle pathway. In addition, new transcriptional factors and target genes, such as phosphofructokinase (PFKL, liver), aldolase A (ALDOA, fructose-bisphosphate), and trefoil factor 3 (intestinal) (TFF3), were also identified. CONCLUSIONS. Transcriptome network analysis is a helpful method for the identification of the candidate genes in alveolar hypoxia. The KEGG pathway and GO term analysis are beneficial in the prediction of the underlying molecular mechanism of these identified genes in alveolar hypoxia.

Early diagnosis and rescue pericardiocentesis for acute cardiac tamponade during radiofrequency ablation for arrhythmias. Is fluoroscopy enough?

BACKGROUND: With the number of complex catheter ablation procedures increasing, procedure-related acute cardiac tamponade is encountered more frequently in the cardiac catheterization laboratory. Survival depends on prompt recognition and rescue pericardiocentesis. OBJECTIVE: The aim of this report was to validate fluoroscopic heart silhouette characteristics associated with cardiac tamponade as a diagnostic method, and evaluate the safety and effectiveness of fluoroscopy-guided pericardiocentesis during catheter ablation. METHODS: All cases of acute cardiac tamponade that occurred in the cardiac catheterization laboratory during radiofrequency catheter ablation from March 2004 to November 2009 were reviewed retrospectively. RESULTS: Of 1,832 catheter ablation procedures performed during a 5-year period, 10 (0.55%) were complicated by cardiac tamponade. Fluoroscopic examination confirmed the diagnosis in all 10 patients and demonstrated effusions before hypotension in four patients. All patients were stabilized by fluoroscopy-guided pericardiocentesis with placement of an indwelling catheter and autologous transfusion. The time interval between recognition of cardiac tamponade and completion of pericardiocentesis was 6.0 ± 1.8 minutes (range 3-9 minutes). The mean aspirated blood volume was 437 mL (range 110-1,400 mL), and the mean autotransfused blood volume was 425 mL (range 100-1,384 mL). Surgical repair of the cardiac perforation was needed in one patient. No procedure-related death occurred. CONCLUSION: A reduction in the excursion of cardiac silhouette on fluoroscopy is an early diagnostic sign of cardiac tamponade during radiofrequency ablation. Fluoroscopy-guided pericardiocentesis is a safe and effective management strategy for cardiac tamponade developed in the cardiac catheterization laboratory.

[Outcome of transcatheter closure of perimembranous ventricular septal defect with modified double-disk occluder device].

OBJECTIVE: To evaluate the efficacy and adverse effects of transcatheter closure of perimembranous ventricular septal defect (pmVSD) with modified double-disk occluder device (MDVO). METHODS: Clinical data including clinical examination, electrocardiography daily after the procedure for a week, chest-X-rays and TTE before discharge and at 3-5 days after the procedure were analyzed from 604 patients underwent percutaneous closure of a pmVSD with MDVO at our department between December 2001 and December 2008. RESULTS: Procedure was successful in 576 out of 604 patients (95.4%) and 583 VSD occluders were placed. Endocarditis, thromboembolism, or deaths were not observed after procedure. Conduction block occurred in 81 patients (56 RBBB, 14 LBBB) and transient nonparoxysmal ventricular tachycardia in 31 patients after the procedure. Complete heart block occurred in 11 patients, 9 of them recovered in 3 weeks, permanent pacemaker was implanted in 2 patients (one had transient III degrees AVB before the procedure, the other underwent simultaneous closure of ventricular septal defect and atrial septal defect). Trivial/small residual shunts were found in 69 patients (12.0%). The residual shunts disappeared in 31 patients and remained unchanged in 38 patients (6.6%) 7 days after procedures. Aortic regurgitation developed in 5 patients (2 trivial/small, 3 small/moderate), and tricuspid regurgitation was present in 35 patients (32 trivial/small, 3 moderate). Five patients developed haemolysis (device retrieved via catheter in 1 patient due to persistent haemolysis, the other 4 patients recovered 3-14 days post procedure). Pseudoaneurysm of femoral artery occurred in 1 patient, and disappeared by pressure dressing. Device was successfully replaced in 2 patients with either device embolization (n = 1) or device misplacement (n = 1) after device retrieval by catheter. CONCLUSION: It is safe and effective to close congenital perimembranous ventricular septal defect with domestic-made occluder device.

Plasma ghrelin and obestatin levels are increased in spontaneously hypertensive rats.

Obestatin, encoded by the same gene as ghrelin, was first described as a physiological opponent of ghrelin. We investigated fasting plasma ghrelin and obestatin levels in spontaneously hypertensive rats and Wistar-Kyoto rats. We found that ghrelin levels, obestatin levels and the ratio of ghrelin to obestatin were significantly higher in spontaneously hypertensive rats than Wistar-Kyoto rats. Systolic blood pressure and diastolic blood pressure were positively correlated; however, heart period and baroreflex sensitivity were negatively correlated with ghrelin levels. Systolic blood pressure was positively correlated, whereas baroreflex sensitivity was negatively correlated with obestatin levels. In addition, systolic blood pressure was a significantly independent variable of ghrelin levels, obestatin levels, and the ghrelin to obestatin ratio in a multiple regression analysis. Our data suggests that there is a disturbance of ghrelin and obestatin in the circulation of spontaneously hypertensive rats and the ghrelin/obestatin system might play a role in blood pressure regulation.

A new pan-nitinol occluder for transcatheter closure of ventricular septal defects in a canine model.

BACKGROUND: The Amplatzer ventricular septal defect (VSD) occluder has a fixed stainless steel pin bottom protruding out of the surface at the center of the discs on both sides. Theoretically, this protruding bottom may interfere with epithelialization or, in some cases, cause thrombosis. OBJECTIVE: To evaluate a new type of pan-nitinol VSD occluder without the protruding stainless steel pin bottom on both sides in a canine VSD model designed to ensure safety, effectiveness, and feasibility. METHODS AND RESULTS: VSDs were successfully created by transseptal ventricular septal puncture with a Brockenbrough needle and dilation with an 8-mm-diameter balloon via the right jugular vein in 9 out of 12 canines. The new type VSD occluder was successfully implanted in 8 of the 9 modeled canines. No procedure- or device-related complication was observed. Transthoracic echocardiography and MRI 2 months after device implantations showed that there was no device dislocation or heart valve dysfunction in 6 of the 8 tested canines. In addition, gross and pathological examinations 3-6 months after implantation showed no corrosion of the devices or serious inflammatory reactions in the modeled animals. Complete endothelialization was seen over the surface of the discs. CONCLUSIONS: The new pan-nitinol VSD device can be successfully implanted in a canine VSD model via a transcatheter approach featuring high success rate, low risk of procedure-related complications, and sound biocompatibility. The result suggests that this new VSD occluder could be used safely in future clinical trials for further test.