Effective closure of a tracheal incision by BioGlue in natural orifice transluminal endoscopic surgery performed for thoracic exploration

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Continuous Production of Lipase-Catalyzed Biodiesel in a Packed-Bed Reactor: Optimization and Enzyme Reuse Study

An optimal continuous production of biodiesel by methanolysis of soybean oil in a packed-bed reactor was developed using immobilized lipase (Novozym 435) as a catalyst in a tert-butanol solvent system. Response surface methodology (RSM) and Box-Behnken design were employed to evaluate the effects of reaction temperature, flow rate, and substrate molar ratio on the molar conversion of biodiesel. The results showed that flow rate and temperature have significant effects on the percentage of molar conversion. On the basis of ridge max analysis, the optimum conditions were as follows: flow rate 0.1 mL/min, temperature 52.1°C, and substrate molar ratio 1 : 4. The predicted and experimental values of molar conversion were 83.31 ± 2.07% and 82.81 ± .98%, respectively. Furthermore, the continuous process over 30 days showed no appreciable decrease in the molar conversion. The paper demonstrates the applicability of using immobilized lipase and a packed-bed reactor for continuous biodiesel synthesis

Natural orifice transluminal endoscopic surgery: A transtracheal approach for the thoracic cavity in a live canine model

BackgroundThe present study aimed to evaluate the performance of transtracheal thoracic exploration and pericardial window creation in a canine survival model.MethodsTransthoracic exploration was performed in 14 dogs. Under general anesthesia, after an incision in the right lateral wall of the middle–lower portion of the trachea was made, a 9-mm metal tube was advanced into the thoracic cavity. For thoracic cavity exploration and pericardial window creation, a flexible bronchoscope was introduced through the metal tube into the thoracic cavity. After thoracoscopy, a Dumon stent (Novatech, Grasse, France) was used to cover the tracheal incision site and facilitate healing. Animals were evaluated by endoscopy 1 and 2 weeks later. Animals were humanely killed, and necropsy was performed 2 weeks after the transtracheal natural orifice transluminal endoscopic surgery.ResultsFourteen dogs underwent transtracheal thoracic exploration lasting for an average of 110 minutes (range, 80–150), with 3 perioperative deaths. At 2 weeks after pericardial window creation, endoscopy revealed normal healing of the tracheal incision sites in all 11 surviving animals. Necropsy on the 11 animals at 2 weeks showed 9 adhesions around the pericardial window and 5 adhesions around the tracheal incision region. No mediastinitis or abscesses could be identified.ConclusionsTranstracheal thoracic exploration is technically feasible. Increasing surgical experience together with improvement in endoscopic techniques will further facilitate the development of natural orifice transluminal endoscopic surgery for thoracic diseases

Feasibility of transumbilical anatomic “Lung” segmentectomy in a canine model

Summary: Background: Transumbilical approach has been shown to be feasible to perform lung wedge resection and anatomic lobectomy. This study uses a canine model to assess the feasibility of transumbilical segmentectomy. Methods: Transumbilical segmentectomy was performed in 10 beagle dogs using a 3-cm umbilical incision combined with a 2.5-cm diaphragmatic incision. We evaluated the surgical outcomes, operative complications, physiologic changes, hemodynamic changes, and inflammatory changes of the procedures. Results: Transumbilical segmentectomy was successfully completed in eight of ten animals. There was one mortality complication related to lung injury causing hemodynamic collapse. Another animal required conventional thoracotomy to complete the surgery due to limited working space. There were no notable events in the postoperative period for all eight dogs that completed the segmentectomy via the transumbilical approach. Conclusion: This animal study demonstrates that the pulmonary segmentectomy can be performed with current standard endoscopic instruments via a single transumbilical incision.We believe that advancing surgical innovation and good collaboration between multi-disciplinary research teams will further establish clearer roles for transumbilical segmentectomy in thoracic surgery. Keywords: Animal study, Transumbilical lung segmentectomy, Video assisted thoracic surger

Continuous Production of Lipase-Catalyzed Biodiesel in a Packed-Bed Reactor: Optimization and Enzyme Reuse Study

An optimal continuous production of biodiesel by methanolysis of soybean oil in a packed-bed reactor was developed using immobilized lipase (Novozym 435) as a catalyst in a tert-butanol solvent system. Response surface methodology (RSM) and Box-Behnken design were employed to evaluate the effects of reaction temperature, flow rate, and substrate molar ratio on the molar conversion of biodiesel. The results showed that flow rate and temperature have significant effects on the percentage of molar conversion. On the basis of ridge max analysis, the optimum conditions were as follows: flow rate 0.1 mL/min, temperature 52.1 degrees C, and substrate molar ratio 1 : 4. The predicted and experimental values of molar conversion were 83.31 +/- 2.07% and 82.81 +/- 98%, respectively. Furthermore, the continuous process over 30 days showed no appreciable decrease in the molar conversion. The paper demonstrates the applicability of using immobilized lipase and a packed-bed reactor for continuous biodiesel synthesis

Enzymatic synthesis of rose aromatic ester (2-phenylethyl acetate) by lipase

BACKGROUND: 2-Phenylethyl acetate (2-PEAc) is a highly valued natural volatile ester with a rose-like odour that is widely used to add scent or flavour to cosmetics, soaps, foods and drinks. In this study, 2-PEAc was synthesised enzymatically by transesterification of vinyl acetate with 2-phenethyl alcohol catalysed by immobilised lipase (Novozym 435) from Candida antarctica. RESULTS: Response surface methodology and a three-level/three-factor Box–Behnken design were used to evaluate the effects of time, temperature and enzyme amount on the molar conversion % of 2-PEAc. The results showed that temperature was the most important variable. Based on the ridge max analysis results, optimum enzymatic synthesis conditions were predicted as a reaction time of 79 min, a temperature of 57.8 ◦C and an enzyme amount of 122.5 mg. The predicted and experimental yields were 86.4 and 85.4% respectively. CONCLUSION: Three immobilised lipases were screened and 15 reaction conditions were tested in order to find the combination for maximum yield. The optimisation of 2-PEAc synthesis catalysed by Novozym 435 was successfully developed. The kinetic study of this transesterification reaction showed that it followed an ordered ping-pong bi-bimechanism without any inhibition by reactants