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.

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.

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.

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.

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.

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.

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.