Optimization of cut surface quality during CNC Plasma Arc Cutting process

Optimization of cut surface quality during CNC plasma-arc cutting (PAC) of mild steel plates is presented. Using design of experiments (DOE) the optimum process parameters are estimated. The process parameters tested include cutting speed, cutting height and arc voltage. Analysis of means (ANOM) and analysis of variances (ANOVA) were used in order for the effect of each parameter on the surface quality to be assessed

Influence of two different surgical techniques on the difficulty of impacted lower third molar extraction and their post-operative complications

Background : Post-operative complications of various degrees of severity are commonly observed in third molar impaction surgery. For this reason, a surgical procedure that decreases the trauma of bone and soft tissues should be a priority for surgeons. In the present study, we compare the efficacy and the post-operative complications of patients to whom two different surgical techniques were applied for impacted lower third molar extraction. Material and Methods : Patients of the first group underwent the classical bur technique, while patients of the second group underwent another technique, in which an elevator was placed on the buccal surface of the impacted molar in order to luxate the alveolar socket more easily. Results: Comparing the two techniques, we observed a statistically significant decrease in the duration of the procedure and in the need for tooth sectioning when applying the second surgical technique, while the post-operative complications were similar in the two groups. We also found a statistically significant lower incidence of lingual nerve lesions and only a slightly higher frequency of sharp mandibular bone irregularities in the second group, which however was not statistically significant. Conclusions: The results of our study indicate that the surgical technique using an elevator on the buccal surface of the tooth seems to be a reliable method to extract impacted third molars safely, easily, quickly and with the minimum trauma to the surrounding tissues

One-year infliximab administration for the treatment of chronic refractory pouchitis

Abstract Aim To determine the efficacy of infliximab in the treatment of chronic refractory pouchitis, following ileo-pouch anal anastomosis (IPAA) for ulcerative colitis (UC). Methods Seven patients (4 females, 3 males) with chronic refractory pouchitis were included in an open study. Pouchitis was diagnosed by clinical plus endoscopic and histological criteria. Three patients also had fistulae (pouch-bladder in 1 and perianal in 2). Extraintestinal manifestations were also present in 4 patients (erythema nodosum in 2, arthralgiae in 2). All patients were refractory to standard therapy. Crohn's disease was carefully excluded in all patients after re-evaluation of the history and examination of the small bowel with enteroclysis or small bowel capsule endoscopy. Patients received Infliximab 5 mg/kg at 0, 2 and 6 weeks and thereafter every 2 months for 1 year. Clinical response was classified as complete, partial, and no response. Fistulae closure was classified as complete, partial, and no closure. The pouchitis disease activity index (PDAI) was also used as an outcome measure. Results Clinically, all patients improved. After 1 year of follow-up, 5 of the 7 patients had a complete clinical response, and 2 of the 3 patients with a fistula had complete fistulae closure. At the end of the follow-up period the median PDAI dropped from 11 (baseline) (range, 10-14) to 5 (range, 3-8). Extraintestinal manifestations were in complete remission at the end of the followup period as well. Conclusions Our results indicate that infliximab may be recommended for the treatment of chronic refractory pouchitis complicated or not by fistulae following IPAA for UC

Plasma Arc Cutting Dimensional Accuracy Optimization employing the Parameter Design approach

Plasma Arc Cutting (PAC) is a thermal manufacturing process used for metal plates cutting. This work experimentally investigates the influence of process parameters onto the dimensional accuracy performance of the plasma arc cutting process. The cutting parameters studied were cutting speed (mm/min), torch standoff distance (mm), and arc voltage (volts). Linear dimensions of a rectangular workpiece were measured after PAC cutting following the full factorial design experimental approach. For each one of the three process parameters, three parameter levels were used. Analysis of means (ANOM) and analysis of variances (ANOVA) were performed in order for the effect of each parameter on the leaner dimensional accuracy to be assessed

Plasma Arc Cutting Dimensional Accuracy Optimization employing the Parameter Design approach

Plasma Arc Cutting (PAC) is a thermal manufacturing process used for metal plates cutting. This work experimentally investigates the influence of process parameters onto the dimensional accuracy performance of the plasma arc cutting process. The cutting parameters studied were cutting speed (mm/min), torch standoff distance (mm), and arc voltage (volts). Linear dimensions of a rectangular workpiece were measured after PAC cutting following the full factorial design experimental approach. For each one of the three process parameters, three parameter levels were used. Analysis of means (ANOM) and analysis of variances (ANOVA) were performed in order for the effect of each parameter on the leaner dimensional accuracy to be assessed

Hepatic resection for large hepatocellular carcinoma in the era of UCSF criteria

Background: Treating patients with hepatocellular carcinoma (HCC) remains a challenge, especially when the disease presents at an advanced stage. The aim of this retrospective study was to determine the efficacy of liver resection in patients who fulfil or exceed University of California San Francisco (UCSF) criteria by assessing longterm outcome. Methods: Between 2002 and 2008, 59 patients with large HCC (>5 cm) underwent hepatectomy. Thirty-two of these patients fulfilled UCSF criteria for transplantation (group A) and 27 did not (group B). Disease-free survival and overall survival rates were compared between the two groups after resection and were critically evaluated with regard to patient eligibility for transplant. Results: In all patients major or extended hepatectomies were performed. There was no perioperative mortality. Morbidity consisted of biliary fistula, abscess, pleural effusion and pneumonia and was significantly higher in patient group B. Disease-free survival rates at 1, 3 and 5 years were 66%, 37% and 34% in group A and 56%, 29% and 26% in group B, respectively (P < 0.01). Survival rates at 1, 3 and 5 years were 73%, 39% and 35% in group A and 64%, 35% and 29% in group B, respectively (P = 0.04). The recurrence rate was higher in group B (P = 0.002). Conclusions: Surgical resection, if feasible, is suggested in patients with large HCC and can be performed with acceptable overall and disease-free survival and morbidity rates. In patients eligible for transplantation, resection may also have a place in the management strategy when waiting list time is prolonged for reasons of organ shortage or when the candidate has low priority as a result of a low MELD (model for end-stage liver disease) score

Hepatic resection for large hepatocellular carcinoma in the era of UCSF criteria

AbstractBackgroundTreating patients with hepatocellular carcinoma (HCC) remains a challenge, especially when the disease presents at an advanced stage. The aim of this retrospective study was to determine the efficacy of liver resection in patients who fulfil or exceed University of California San Francisco (UCSF) criteria by assessing longterm outcome.MethodsBetween 2002 and 2008, 59 patients with large HCC (>5cm) underwent hepatectomy. Thirty-two of these patients fulfilled UCSF criteria for transplantation (group A) and 27 did not (group B). Disease-free survival and overall survival rates were compared between the two groups after resection and were critically evaluated with regard to patient eligibility for transplant.ResultsIn all patients major or extended hepatectomies were performed. There was no perioperative mortality. Morbidity consisted of biliary fistula, abscess, pleural effusion and pneumonia and was significantly higher in patient group B. Disease-free survival rates at 1, 3 and 5 years were 66%, 37% and 34% in group A and 56%, 29% and 26% in group B, respectively (P < 0.01). Survival rates at 1, 3 and 5 years were 73%, 39% and 35% in group A and 64%, 35% and 29% in group B, respectively (P= 0.04). The recurrence rate was higher in group B (P= 0.002).ConclusionsSurgical resection, if feasible, is suggested in patients with large HCC and can be performed with acceptable overall and disease-free survival and morbidity rates. In patients eligible for transplantation, resection may also have a place in the management strategy when waiting list time is prolonged for reasons of organ shortage or when the candidate has low priority as a result of a low MELD (model for end-stage liver disease) score