Swelling-Induced Quaternized Anthrone-Containing Poly(aryl ether ketone) Membranes with Low Area Resistance and High Ion Selectivity for Vanadium Flow Batteries.

A vanadium flow battery (VFB) is one of the most promising electrochemical energy storage technologies. However, membranes for VFBs still suffer from high cost or low conductivity and poor stability. Here, we report new quaternized anthrone-containing poly(aryl ether ketone) (QAnPEK) membranes for VFBs. QAnPEK membranes with moderate ion exchange capacity (1.26 mmol g-1) were swelling-induced in H3PO4 (50 wt %) to form wider ion transport pathways that significantly enhanced membrane conductivity (e.g., 0.49 Ω cm2 for the QAnPEK-virgin membrane and 0.12 Ω cm2 for the swelling-induced QAnPEK-90 membrane). The bulky rigid anthrone-containing backbone provided high swelling resistance and enabled QAnPEK membranes to have high ion selectivity. As a result, QAnPEK membranes displayed low area resistance, high ion selectivity, and robust mechanical strength. The QAnPEK-90 membrane yielded excellent energy efficiencies (92.4% at 80 mA cm-2, 85.1% at 200 mA cm-2, and 80.3% at 280 mA cm-2). Moreover, QAnPEK membranes exhibited outstanding in situ and ex situ stability, for example, the VFB with the QAnPEK-40 membrane demonstrated highly stable battery performance for 3000 cycles at 160 mA cm-2. QAnPEK membranes are attractive candidates for VFB application.

Robust Adamantane-Based Membranes with Enhanced Conductivity for Vanadium Flow Battery Application.

Membranes with high conductivity, high selectivity, and high stability are urgently needed for high-power-density vanadium flow batteries (VFBs). Enhancing membrane conductivity presents many challenges, often resulting in sacrificing membrane selectivity and mechanical strength. To overcome this, new robust adamantane-based membranes with enhanced conductivity are constructed for VFB. Low-content basic piperazine (IEC = 0.78 mmol g-1) and hydrophilic hydroxyl groups are introduced into highly rigid, hydrophobic adamantane containing poly(aryl ether ketone) backbone (PAPEK) and then selectively swelled to induce microphase separation and form ion transport pathways. The highly rigid and hydrophobic PAPEK exhibits high swelling resistance and provides the membranes with slight swelling, high selectivity, and high mechanical strength. The selective swelling temperature has a significant influence on the areal resistance of the resulting membrane, e.g., the PAPEK-130 membrane, when selectively swelled at 130 °C, has low areal resistance (0.22 Ω∙cm2), which is approximately two-fifths that of the PAEKK-60 membrane (treated at 60 °C, 0.57 Ω∙cm2). Consequently, the resulting PAPEK membranes exhibit low swelling, high selectivity, and low areal resistance, with the VFB constructed with a PAPEK-90 membrane exhibiting excellent energy efficiency (91.7%, at 80 mA∙cm-2, and 80.0% at 240 mA∙cm-2) and stable cycling performance for 2000 cycles.

Transapical Transcatheter Aortic Valve Implantation Using a New TAVI System for High-Risk Patients With Severe Aortic Stenosis.

BACKGROUND: To evaluate the safety and efficacy of transcatheter aortic valve implantation (TAVI) for high-risk patients with aortic stenosis using the J-Valve system. METHODS: 30 high-risk patients with severe AS underwent TAVI procedure were enrolled with mean age 74.5±4.5 years and mean logistic Euro-SCORE-I of 28.4±9.6%. All patients were followed up for 6 months. Outcomes were analysed in accordance with the updated standardised endpoints defined by the Valve Academic Research Consortium -2 (VRAC-2) criteria. RESULTS: VARC-2 defined device success was obtained in 93% (28 of 30 patients). No operative mortality was noted. No major complications such as third-degree AV-block, myocardium infraction or cerebrovascular events were noted during procedure and follow-up. Transvalvular PG was decreased at 6 months compared with preoperative state (PG mean: 55.4±14.9 vs 14.6±6.9mmHg p<0.01). No moderate or above degree paravalvular leakage (PVL) was noted. All patients with successful valve implantation were alive with improved exercise tolerance. CONCLUSIONS: Our initial result has demonstrated that the J-Valve system has the potential to become a feasible treatment option for high-risk patients with severe AS.

Bi-polar radiofrequency ablation for rheumatic heart disease with atrial fibrillation / 中国胸心血管外科临床杂志

@#Objective    To evaluate the clinical effects of bi-polar radiofrequency ablation (BRFA) for the surgical treatment of atrial fibrillation (AF) in rheumatic heart disease (RHD) patients. Methods    We involved 96 RHD patients who underwent valve replacement in Department of Cardiovascular Surgery, West China Hospital from July 2014 through May 2015. There were 74 patients with AF, 22 in sinus rhythm. All patients with AF were fully informed of BRFA, in which 40 of the 74 patients received while the other 34 patients refused. The 40 patients with AF who received BRFA were classified into a treatment group and the other 34 patients were classified into a control group. The 20 patients with sinus rhythm were classified into a blank group as well. The clinical effect and quality of life of the patients were analyzed. Results    Left atrial diameter (LAD), pulmonary arterial systolic pressure (PASP), and conversion rate of sinus rhythm at discharge, maintenance rate of sinus rhythm during follow-up in patients with AF were significantly higher than those in the patients in sinus rhythm. No difference was found in terms of survival rate, mortality, major complications among the three groups. The treatment group experienced higher scores in physical functioning (PF), role-physical (RP), general health (GH), vitality (VT), social functioning (SF), mental health (MH), physical component summary (PCS), mental component summary(MCS) and total score compared with the control group both at postoperative 3-month and 6-month . At postoperative 12-month, the treatment group experienced higher scores in PF, RP, GH, PCS, and total score compared with the control group. Conclusion    AF would enhance the negative impact on structure remodeling in RHD patients. BRFA is beneficial for the conversion and maintaining of sinus rhythm in RHD patients and the decreasing of LAD & PASP parameter as well. BRFA is more beneficial for the improvement of quality of life in RHD patients with AF during one-year follow-up.

Efficient Fenton Oxidation of Congo Red Dye by Magnetic MgFe2O4 Nanorods.

We reported a highly active magnetic MgFe2O4 nanorods catalyst by annealing Mg(OH)2 deposited α-FeOOH nanorods. The catalyst was fully characterized by X-ray diffraction (XRD), High Resolution Transmission Electron Microscopy (HRTEM), and Vibrating Sample Magnetometer (VSM), and the results showed that the magnetic MgFe2O4 nanorods were a diameter of 50 nm. The as-prepared MgFe2O4 nanorods were used to catalyze Fenton oxidation of Congo red (CR) solution, and the degradation rate of CR reached 95% after 2 h. The catalytic activity remained high after five cycles. The magnetic MgFe2O4 nanorods could be easily separated from organic solvent. The effects of parameters such as temperature, dosage of catalyst, and H2O2 were also analyzed. This opens new perspectives for the synthesis of one-dimensional magnetic catalyst based on a template method and effective treatment of aqueous hazardous dye.

A modified Cox maze IV procedure: a simpler technique for the surgical treatment of atrial fibrillation.

OBJECTIVES: To determine the effectiveness of a simplified surgical treatment method for atrial fibrillation (AF). METHODS: Between September 2012 and October 2013, 120 patients (mean age, 52.3 ± 8.8 years) underwent valve surgery and concomitant bipolar radiofrequency ablation for the treatment of AF. Patients were randomized to a Cox maze IV procedure (CMP-IV) group (n = 60) or a modified CMP-IV (MCMP-IV) group (n = 60). Freedom from AF was defined as freedom from any left atrial arrhythmia lasting <30 s and no requirement of antiarrhythmic drugs after 6 months. Data were recorded at postoperative follow-up examinations, which were scheduled at 1, 3, 6 and 12 months, and annually thereafter. RESULTS: No ablation-related complications occurred in either group. The mean ablation time was longer in the CMP-IV group than in the MCMP-IV group (18.5 ± 1.7 vs 16.6 ± 1.6 min, P < 0.001). The mean follow-up time was 32.4 ± 3.6 months (range, 26-39 months). Freedom from AF tended to be higher, but not significantly so, among the MCMP-IV group than among the CMP-IV group over the entire follow-up period. CONCLUSIONS: The MCMP-IV is an effective surgical procedure for the treatment of AF. In certain patients, such as those with anatomic variations of the pulmonary veins, the MCMP-IV is simpler than the CMP-IV. CLINICAL TRIALS REGISTRATION ID: ChiCTR-TRC-12002742.

Papillary fibroelastoma of the aortic valve in association with rheumatic heart disease: a case report.

BACKGROUND: Papillary fibroelastoma (PFE) is a rare primary cardiac neoplasm that is usually discovered incidentally at autopsy or during cardiac surgery. PFE combined with rheumatic heart disease (RHD) is extremely rare, and only a few cases have been reported. Additionally, the growth rate of the tumor is unknown. CASE PRESENTATION: Here, we present a very rare case of PFE of the aortic valve combined with RHD, which were identified in a female patient who survived for 5 years without surgical intervention, and who subsequently underwent successful surgical treatment. CONCLUSIONS: PFEs may be generally slow-growing tumors, however, the better treatment of choice may be surgery because it produces good curative effects with very low risk of complications, while preventing serious disease consequences.

One-stage hybrid surgery for acute Stanford type A aortic dissection with David operation, aortic arch debranching, and endovascular graft: a case report.

Acute Stanford type A aortic dissection requires an extremely complex surgical strategy and presents high risk of complications. Although many different procedures were reported to treat this aortic dissection, high mortality rate and incidences of complications still exist. This study presents a 59-year-old lady with acute Stanford type A aortic dissection, which originated from the aortic root to proximal part of right external iliac artery and involved the brachiocephalic trunk, left carotid artery, celiac trunk, and left renal artery. The patient underwent one-stage hybrid surgery of David procedures, debranching, and endovascular aortic repair under ultrasound-guided aortic arch cannulation cardiopulmonary bypass (CPB). The surgery was successfully performed, and the patient showed no post-operative complication. The one-staged hybrid surgery of David procedures, debranching, and endovascular aortic repair provides novel and well-designed combined techniques for treating complex acute Stanford type A aortic dissection. Our techniques significantly lowered the risks, thereby expanding the indications of surgical intervention for acute Stanford type A aortic dissection.

Outcomes of tricuspid annuloplasty with and without prosthetic rings: a retrospective follow-up study.

BACKGROUND: The efficacies of tricuspid valve repair, risk factors for treatment failure and postoperative quality of life have not been thoroughly evaluated in patients with tricuspid insufficiency associated with rheumatic heart disease (RHD). We therefore reviewed our experience with ring and non-ring tricuspid annuloplasty for the treatment of functional tricuspid insufficiency (TI) in RHD. METHODS: This retrospective, follow-up study involved 74 RHD patients who underwent either non-ring annuloplasty (De Vega procedure; 34 patients, 45.95 %) or ring annuloplasty (40 patients, 54.05 %) along with concurrent mitral or/and aortic valve replacement. Operation time, cardiopulmonary bypass time, aortic clamping time, intensive care unit stay and extubation time were recorded. Echocardiographic findings and Short Form (SF)-36 scores were compared between the two groups. RESULTS: In hospital mortality and complications were similar in the two study groups (P = 0.6755). At 1 week, 1 month, 6 months, 1 year, 2 years and even longer after the operation, the Kaplan-Meier curve of freedom from mild and above recurrent TI showed significantly better efficacy in the ring annuloplasty group than the De Vega procedure group (log rank P = 0.0377). Risk factors for recurrent TI included high pulmonary artery systolic pressure (PASP) and non-ring annuloplasty (PASP: hazard ratio = 1.52; non-ring: hazard ratio = 1.42). The mental component summary score at 1 year after the operation did not significantly differ between the two groups (P = 0.6446), but the physical component summary score was significantly better in the ring annuloplasty group (P = 0.0037). CONCLUSION: Compared with non-ring annuloplasty, ring annuloplasty was associated with improved survival, decreased TI recurrence and higher quality of life in RHD patients undergoing tricuspid valve repair combined with mitral and/or aortic valve replacement.

[A systemic review of low intensity anticoagulation therapy for Chinese population with heart valve replacement].

OBJECTIVE: To investigate the safety and efficacy of low intensity anticogulation therapy for chinese population underwent heart valve replacemnt. METHODS: From January 1999 to October 2010, the literatures concering anticoagulation therapy for chinese population with heart valve replacement were researched in following databases: CBM, CNKI, VIP, Pubmed as well as cochrane library. Screening and quality evaluation was conducted according to the inclusion and exclusion criteria. Meta-analysis of control studies and descriptive analysis of descriptive studies were conducted. RESULTS: Total 61 articles were reviewed, including 4 control studies and 57 descriptive studies. Both Meta analysis and descriptive analysis results showed also that the rates of total anticoagulation-related complications as well as bleeding events were significantly decreased in patients receiving low intensity anticoagulation therapy in compared with classical intensity strategy (RR = -0.06, 95%CI: -0.08--0.03, P < 0.001;RR = -0.06 , 95%CI:-0.08-0.04, P < 0.001), while no significant differeces were noted as for risk of thrmoboembolic events among two different intensity groups (RR = 0.01, 95%CI:-0.01-0.03, P > 0.05). CONCLUSIONS: Low intensity anticoagulation therapy (INR ≤ 2.5) could effectively miminze the anticoagulation-related hemorrhage and mortality rates and while without increasing the rates of thrmoboembolic event. This therapy was safe, effective and suitable for the coagulation characteristics of Chinese population.

Rare early prosthesis obstruction after mitral valve replacement: a case report and literature review.

As a dreadful complication after the mechanical heart valve replacement, prosthetic valve obstruction caused by pannus formation occurs increasingly with time. The authors here present a case of 42-year-old woman who was urgently admitted to hospital with acute heart failure symptoms due to the mechanical mitral valve failure only 3 months after surgery. Transthoracic and transesophageal echocardiography demonstrated that the bileaflet of the mitral prosthesis were completely immobilized with only a small transvalvular jet remained. During the reoperation, the reason of the prosthetic valve obstruction was attributed to the noncircular pannus ingrowth extending from the atrioventricular side. For a better understanding of the prosthetic valve dysfunction caused by pannus formation, the authors then compile a literature review to briefly discuss the status quo of the clinical characteristics of this uncommon complication.

[Stimulative and regulative functions of osteoblasts loaded under the titanium particles on osteoclasts].

Our previous studies on the function of the osteoblasts (OBs) have shown that worn titanium particles decrease osteoblast function and promot secretion of bone resorption cytokines of OBs surrounding the synovium-like interface membrane of loosening implants. The current study was aimed to test the hypothesis that osteoclasts (OCs) bone absorption function is induced by conditioned media (CM) prepared from OBs loaded in the presence or absence of titanium particles (with three mean diameters 6.9 microm, 2.7 microm, and 0.9 microm, respectively). The effects of CM on OCs function were examined using a combination of the morphological characteristics tests, i.e., TRAP dyeing, scanning electron microscopy, F-actin immunofluorescence protocol for confocal microscopy, bone resorption lacunae assay, osteoclastic calcium tracking, with biochemical evaluation, i.e., C-terminal cross-linked telopeptides of type I collagen evaluated with ABC-ELISA method. The results showed that CM from 0.9 microm titanium particles could induce osteoclastic differentiation and formation, could partially influence the survival of the OCs; while CM of 2.7 microm and 6.9 microm titanium particles, especially the latter, could obviously augmented osteoclastic activity, survival, or differentiation. The stimulation of osteoclast function may be due to a parallel increase in the intracellular free calcium concentration. The present study provides strong support for the hypothesis that osteoclastic activity, survival, or differentiation are very important in the development of aseptic loosening. The development of therapeutic interventions to reduce osteoclastic function and optimization of biomaterials may be useful approaches for improving the performance of orthopaedic implants.

[Comparison of adhesion of different endothelial cells under shear stress load in the flow field in vitro].

This study was aimed to compare the differences of adhesion properties of endothelial cells (EC) from arteries (AEC), veins (VEC) and capillaries (MVEC) under shear stress condition, and to explore whether they can get the same adhesive ability as graft in similar shear stress conditions. With mended parallel plate flow apparatus and peristalsis pump providing fluid shear stress used, endothelial culture models were established in vitro with the same environmental factors as steady culture. To compare the adhesion among three kinds of endothelial cells under dynamic condition and static condition, the dynamic change of cytoskeletal actin filaments and the effects of different adhesive proteins coated on the adhesion of EC to the glass were studied. The cultured endothelial cells under flow conditions were extended and arranged along the direction of flow. The adhesive ability from high to low under static condition were AEC, MVEC and VEC (VEC compared with AEC or MVEC, P < 0.05), sequentially. The adhesion of endothelial cells from variety sources under dynamic culture condition was significantly increased than that of the static groups. The ratio of cell retention was not significantly different between AEC and MVEC. But VEC was significantly different (P < 0.05) compared with AEC or MVEC. The actin filaments (F-actin) were bundled together and arranged along the direction of flow after fluid culture. Dense peripheral band (DPB) gradually disappeared and distinct stress fibers were formed, which even interconnected to form a whole in the MVEC. The adhesion of AEC, VEC and MVEC under shear stress conditions are more significantly increased than those under the static culture conditions, and the MVEC can achieve the same adhesion as AEC.

[Pressure change-mediated effects on vasoactive protein of endothelial cells in the flow field in vitro].

Lining the inner surface of the walls of blood vessels, Endothelial cells (ECs) go beyond providing selective membrane to maintain the natural structure and function of vessels; they also synthesize varieties of vasoactive proteins to modify the pressure shift in the local flow field and hence they adapt the physiological activities of vessels. In this experiment, ELISA and RT-PCR technologies were adopted. We set up five different pressure loaded ECs groups,one non-activated cultured ECs group and one single shear stress loaded ECs group. Such a design was intended to demonstrate the effects of pressure shift on the expression of vasoactive protein synthesized by ECs [Endothelin-1(ET-1), endothelial Nitric Oxide Synthase (eNOS), Cyclooxygenase-2(COX-2) and Vascular Endothelial Growth Factor(VEGF)]. Our aim was to elucidate the mechanism of the pressure shift mediated dysfunction in ECs and the related dose-effect relationship. Based on these data, we suggest that ECs could modify the expression of vasoactive protein for adapting to the pressure shift in the local flow field; while in the process of--40 cmH2O induced ECs' dysfunction, the vasoactive proteins eNOS, COX-2 and VEGF play an important role in protecting ECs.