心脏瓣膜置换同期行双极射频消融术治疗房颤的临床疗效

目的探讨心脏瓣膜置换同期行双极射频消融术(BRFA)治疗心房纤颤(AF)的临床疗效及安全性。方法回顾性分析2011年1月至2012年12月在瓣膜置换术同期行BRFA治疗的90例AF患者临床资料,患者在全身麻醉开胸直视体外循环下行瓣膜置换术及BRFA。术后随访患者心脏彩色超声、心电图等指标,分析比较其疗效。结果患者动脉阻断时间为65~120 min,平均(75.5±24.5)min,体外循环时间为45~200 min,平均(112.5±30.8)min;BRFA时间为13~28min,平均(21.5±7.5)min。随访结果表明91.11%患者术后3个月维持窦性心律,术后12个月左心房、左心室径线较术前明显减小,左心室射血分数较术前明显增高,差异有统计学意义(P0.05);同时房颤持续时间、术前左房径线及左室径线对手术成功有影响。结论心脏瓣膜置换术同期行BRFA治疗AF安全、简便且效果良好,值得临床推广应用。     

改良Clavien分级系统在经尿道前列腺等离子双极电切术围手术期并发症中的应用

目的采用改良的Clavien分级系统对经尿道前列腺等离子双极电切术(PKRP)围手术期的并发症进行回顾性分级。方法对2013年1~12月间171例行PKRP的良性前列腺增生(BPH)患者的临床资料进行回顾性分析,依据前列腺体积将患者分为3组:<40mL(A组)、40~79mL(B组)、≥80mL(C组),采用改良的Clavien分级系统对围手术期并发症进行分析。结果住院期间,共有34例患者发生并发症43例次,总的并发症发生率为19.9%(34/171),其中并发症发生率A组为11.5%(3/26)、B组20.7%(18/87)、C组22.4%(13/58)。3组间比较,差异无统计学意义(χ2=1.405,P>0.05)。43例次并发症中,Ⅰ级22例次、Ⅱ级16例次、Ⅲa级1例次、Ⅳa级3例次、Ⅳb级1例次,无Ⅲb级和Ⅴ级(死亡)并发症。结论采用改良的Clavien分级系统,不需要处理或不需要介入治疗的ClavienⅠ、Ⅱ级并发症占绝大多数(88.4%),而ClavienⅢ级(2.3%)及ClavienⅣ级(9.3%)并发症较少见,无ClavienⅤ级并发症。改良的Clavien分级系统是一种有效的方法,能成功地应用于PKRP术后并发症的分级。     

Atrial flutter ablation: efficacy and cost-effectiveness of a single decapolar electrode to demonstrate bidirectional isthmus block.

AIMS: To evaluate whether a single decapolar electrode is a reliable and cost-effective substitute for the 'Halo' catheter to map the circuit and detect bidirectional isthmus block during atrial flutter (AFL) ablation. METHODS AND RESULTS: Twenty-four patients underwent AFL ablation by using the decapolar electrode in the infero-lateral wall of right atrium (group A) while a 'Halo' catheter was used in 11 patients (group B). Both groups had similar clinical characteristics. Anti-clockwise rotation (20 patients), clockwise (3 patients) or both forms of AFL (1 patient) were detected in group A. All patients in group B had anti-clockwise AFL. Bidirectional isthmus block was completed in 22 patients of group A and in 9 of group B (P=NS) while incomplete isthmus block was detected in 2 patients in each group (P=NS). Mean fluoroscopy and procedure time was 27 +/- 47 min, 107 +/- 36 min in group A and 14 +/- 19 min, 114 +/- 65 min in group B (P=NS). AFL relapsed in 3 patients of group A (follow-up 7 +/- 4 months) and in 2 of group B (4 +/- 2 months). CONCLUSION: A single decapolar electrode is a reliable method to map the circuit and demonstrate bidirectional isthmus block during AFL ablation. The cost of the decapolar electrode is a quarter of that of the 'Halo' catheter. This represents a significant saving particularly for centres with a substantial number of AFL ablations.     

Comparative Investigation of Activated Carbon Electrode and a Novel Activated Carbon/Graphene Oxide Composite Electrode for an Enhanced Capacitive Deionization

Capacitive deionization is an emerging brackish water desalination technology whose principle lies in the utilization of porous electrodes (activated carbon materials) to temporarily store ions. Improving the properties of carbon material used as electrodes have been the focus of recent research, as this is beneficial for overall efficiency of this technology. Herein, we have synthesized a composite of activated carbon/graphene oxide electrodes by using a simple blending process in order to improve the hydrophilic property of activated carbon. Graphene oxide (GO) of different weight ratios was blended with commercial Activated carbon (AC) and out of all the composites, AC/GO-15 (15 wt.% of GO) exhibited the best electrochemical and salt adsorption performance in all operating conditions. The as prepared AC and AC/GO-x (x = 5, 10, 15 and 20 wt.% of GO) were characterized by cyclic voltammetry and their physical properties were also studied. The salt adsorption capacity (SAC) of AC/GO-15 at an operating window of 1.0 V is 5.70 mg/g with an average salt adsorption rate (ASAR) of 0.34 mg/g/min at a 400 mg/L salt initial concentration and has a capacitance of 75 F/g in comparison to AC with 3.74 mg/g of SAC, ASAR of 0.23 mg/g/min and a capacitance of 56 F/g at the same condition. This approach could pave a new way to produce a highly hydrophilic carbon based electrode material in CDI.     

Comparison of Properties of Hardfaced Layers Made by a Metal-Core-Covered Tubular Electrode with a Special Chemical Composition

In this article, the results of research on the metal-mineral-type abrasive wear of a wear-resistant plate made by a tubular electrode with a metallic core and an innovative chemical composition using the manual metal arc hardfacing process were presented. The properties of the new layer were compared to the results of eleven wear plates manufactured by global suppliers, including flux-cored arc welding gas-shielded (FCAW-GS, Deposition Process Reference Number: 138), flux-cored arc welding self-shielded (FCAW-SS, Deposition Process Reference Number: 114), automated hardfacing, and manual metal arc welding (MMAW, Deposition Process Reference Number: 111) hardfacing T Fe15 and T Fe16 alloys, according to EN 14700:2014. Characterization of the hardfaced layers was achieved by using hardness tests, optical microscopy, confocal microscopy, scanning electron microscopy, and EDS (Energy Dispersive Spectroscopy) and X-ray diffraction analyses. Based on wear resistance tests in laboratory conditions, in accordance with ASTM G65-00: Procedure A, and surface layer hardness tests, in accordance with PN-EN ISO 6508-1, the wear plates most suitable for use in metal-mineral conditions were chosen. The results demonstrated the high metal-mineral abrasive wear resistance of the deposit weld metal produced by the new covered tubular electrode. The tubular electrode demonstrated a high linear correlation between the surface wear resistance and the hardness of the metal matrix of the tested abrasive wear plates. In addition to hardness, size, shape, the dispersion of strengthening phases, and the base metal content, depending on hardfacing technology and technological parameters, impact wear resistance is represented by volumetric loss caused by effect-free or constrained dry abrasive medium contact. The presented results can be used in machine part material selection and wear planning for applications in inspection, conservation, and regeneration interval determination. The obtained results will be applied in a real-time wear rate prediction system based on the measurement of the working parameters.     

All-Carbon Electrode Consisting of Carbon Nanotubes on Graphite Foil for Flexible Electrochemical Applications

We demonstrate the fabrication of an all-carbon electrode by plasma-enhanced chemical vapor deposition for use in flexible electrochemical applications. The electrode is composed of vertically aligned carbon nanotubes that are grown directly on a flexible graphite foil. Being all-carbon, the simple fabrication process and the excellent electrochemical characteristics present an approach through which high-performance, highly-stable and cost-effective electrochemical applications can be achieved.     

Electrochemical,spectroscopic, and molecular docking studies of the interaction between the anti-retroviral drug indinavir and dsDNA

In this study, an electrochemical DNA biosensor was developed using a straightforward methodology to investigate the interaction of indinavir with calf thymus double-stranded deoxyribonucleic acid (ct-dsDNA) for the first time. The decrease in the oxidation signals of deoxyguanosine (dGuo) and deoxyadenosine (dAdo), measured by differential pulse voltammetry, upon incubation with different concentrations of indinavir can be attributed to the binding mode of indinavir to ct-dsDNA. The currents of the dGuo and dAdo peaks decreased linearly with the concentration of indinavir in the range of 1.0–10.0 μg/mL. The limit of detection and limit of quantification for indinavir were 0.29 and 0.98 μg/mL, respectively, based on the dGuo signal, and 0.23 and 0.78 μg/mL, respectively, based on the dAdo signal. To gain further insights into the interaction mechanism between indinavir and ct-dsDNA, spectroscopic measurements and molecular docking simulations were performed. The binding constant (K_b) between indinavir and ct-dsDNA was calculated to be 1.64 × 10⁸ M⁻¹, based on spectrofluorometric measurements. The obtained results can offer insights into the inhibitory activity of indinavir, which could help to broaden its applications. That is, indinavir can be used to inhibit other mechanisms and/or hallmarks of viral diseases.