Nickel-Alumina Catalysts for the Transformation of Vegetable Oils into Green Diesel: The Role of Preparation Method, Activation Temperature, and Reaction Conditions.

Two nickel alumina catalysts containing 60 wt. % Ni were synthesized by wet impregnation and co-precipitation in order to study the effect of preparation methods on the catalytic efficiency concerning the transformation of sunflower oil into green diesel. The effect of activation temperature on the catalytic efficiency of the most active catalyst was also studied. The catalysts were characterized using various techniques and which were evaluated in the aforementioned reaction using a semi-batch reactor. The catalyst prepared by co-precipitation exhibited a higher specific surface area and smaller mean crystal size of the nickel nanoparticle (higher nickel metallic surface). These justify its higher efficiency with respect to the corresponding catalyst synthesized by wet impregnation. The increase in the activation temperature from 400 to 600 °C increased the size of the nickel nanoparticles through sintering, thus destroying the small pores. These led to a decrease in the nickel surface and specific surface area and, thus, to a decrease in the catalytic efficiency. The optimization of the reaction conditions over the most active catalyst (prepared by co-precipitation and activated at 400 °C) leads to the complete transformation not only of the sunflower oil (edible oil) but also of waste cooking oil (non-edible oil) into green diesel. The liquid produced after the hydrotreatment for these two feedstocks for 7 h, at H2 pressure 40 bar and temperature 350 °C using 100 mL of oil and 1 g of catalyst was composed of 97 and 96 wt. % of green diesel, respectively.

Visualizing pore architecture and molecular transport boundaries in catalyst bodies with fluorescent nanoprobes.

The performances of porous materials are closely related to the accessibility and interconnectivity of their porous domains. Visualizing pore architecture and its role on functionality-for example, mass transport-has been a challenge so far, and traditional bulk and often non-visual pore measurements have to suffice in most cases. Here, we present an integrated, facile fluorescence microscopy approach to visualize the pore accessibility and interconnectivity of industrial-grade catalyst bodies, and link it unequivocally with their catalytic performance. Fluorescent nanoprobes of various sizes were imaged and correlated with the molecular transport of fluorescent molecules formed during a separate catalytic reaction. A direct visual relationship between the pore architecture-which depends on the pore sizes and interconnectivity of the material selected-and molecular transport was established. This approach can be applied to other porous materials, and the insight gained may prove useful in the design of more efficient heterogeneous catalysts.

Pancreatic Pseudocyst Pleural Fistula in Gallstone Pancreatitis.

Extra-abdominal complications of pancreatitis such as pancreaticopleural fistulae are rare. A pancreaticopleural fistula occurs when inflammation of the pancreas and pancreatic ductal disruption lead to leakage of secretions through a fistulous tract into the thorax. The underlying aetiology in the majority of cases is alcohol-induced chronic pancreatitis. The diagnosis is often delayed given that the majority of patients present with pulmonary symptoms and frequently have large, persistent pleural effusions. The diagnosis is confirmed through imaging and the detection of significantly elevated amylase levels in the pleural exudate. Treatment options include somatostatin analogues, thoracocentesis, endoscopic retrograde cholangiopancreatography (ERCP) with pancreatic duct stenting, and surgery. The authors present a case of pancreatic pseudocyst pleural fistula in a woman with gallstone pancreatitis presenting with recurrent pneumonias and bilateral pleural effusions.

Sex differences of continuous positive airway pressure treatment on flow-mediated dilation in patients with obstructive sleep apnea syndrome.

INTRODUCTION: There is growing research evidence suggesting the presence of endothelial dysfunction and systemic inflammation in patients with obstructive sleep apnea syndrome (OSAS). Continuous positive airway pressure (CPAP) is the most effective method for treating OSAS; nonetheless, the effects of CPAP on the aforementioned pathophysiologic pathways as well as on the systemic disease that result or coexist with the OSAS remain elusive. AIM: To assess the effect of 3-month CPAP therapy on endothelial-dependent dilation, plasma levels of inflammatory markers, blood pressure (BP), and glucose control on male and female patients with OSAS. METHODS: Our study group consisted of 40 (24 males and 16 females) patients with no prior history of cardiovascular disease, with an apnea-hypopnea index ≥15, who were assigned to receive CPAP treatment. Measurements of flow-mediated dilation (FMD), 24-hour ambulatory BP, and blood analysis were performed at baseline and 3 months after CPAP therapy. RESULTS: Baseline FMD values were negatively correlated with the apnea-hypopnea index (r=-0.55, P=0.001). After 3 months of CPAP, there was an increase in the FMD values (5.40%±2.91% vs 3.13%±3.15%, P<0.05) and a significant reduction in the patients' 24-hour systolic BP (122.82±11.88 mmHg vs 130.24±16.75 mmHg, P<0.05), diastolic BP (75.44±9.14 mmHg vs 79.68±11.09 mmHg, P<0.05), and pulse pressure (47.38±9.77 mmHg vs 52.72±11.38 mmHg, P<0.05); daytime systolic BP (125.76±12.69 mmHg vs 132.55±17.00 mmHg, P<0.05) and diastolic BP (77.88±10.39 mmHg vs 82.25±11.01 mmHg, P<0.05); nighttime systolic BP (118.17±13.16 mmHg vs 126.22±17.42 mmHg, P<0.05) and pulse pressure (46.61±10.76 mmHg vs 52.66±11.86 mmHg, P<0.05); and C-reactive protein and HbA1c levels (0.40 [0.40-0.70] mg/L vs 0.60 [0.40-0.84] mg/L and 5.45%±0.70% vs 5.95%±1.08%, respectively; P<0.05). When divided by sex, only male patients produced similar statistically significant results, while female patients failed to show such associations. CONCLUSION: Our results suggest that CPAP therapy improves the endothelial function, the BP, and the glucose control in male patients with OSAS. Further research is warranted in order to verify these results and to further elucidate the impact of CPAP on the cardiovascular risk of male and female patients with OSAS.

Extracorporeal laparoscopically assisted resection of a perforated Meckel's diverticulum due to a chicken bone.

Meckel's diverticulum is the commonest congenital anomaly of the small intestine. It can, however, present acutely relating to a number of complications that may require emergency surgery and possible bowel resection. Perforation is a rare complication and there are only seven cases reported of an inflamed Meckel's diverticulum due to a chicken bone. Laparoscopic repair of Meckel's diverticulum-associated complications has gained popularity over the recent years. We present a case of chicken bone perforation that was treated with laparoscopic-assisted extracorporeal resection of the affected small bowel segment.

Repair of gastric defects with an equine pericardial patch.

PURPOSES: The objective of this study was to test the efficacy of an equine pericardial patch for repairing full-thickness defects of the stomach wall. METHODS: Circular defects, 1.5 cm in diameter, were created on the anterior wall of the stomach of 12 female New Zealand rabbits. The defects were repaired by an equine pericardial patch. After euthanasia at different time intervals (3 days to 8 weeks) a macroscopic evaluation of the abdominal cavity (including adhesion scoring), mechanical testing and a histological examination of the stomach were performed. RESULTS: The animals survived the surgical procedure and underwent an uneventful recovery until euthanasia. None of the patches failed. Adhesions were observed in all animals and were significant in 3/12 animals. Bursting pressure testing indicated that the repair was durable and that adequate strength to prevent patch failure was achieved by the second week. A histological examination showed gradual narrowing of the perforation site by mucosal and limited muscular regeneration. CONCLUSIONS: The equine pericardial patch was successfully used to repair a gastric defect in our experimental model, and it seems that it could have potential as a material suitable for further research concerning the repair of upper gastrointestinal defects.

Impact of continuous positive airway pressure treatment on myocardial performance in patients with obstructive sleep apnea. A conventional and tissue Doppler echocardiographic study.

INTRODUCTION: Obstructive sleep apnea (OSA) is a highly prevalent condition related to several cardiovascular complications. We assessed the effects of continuous positive airway pressure (CPAP) treatment on myocardial performance and various somatometric parameters in patients with severe OSA receiving CPAP. MATERIALS AND METHODS: This is a prospective longitudinal study of 44 patients aged 55.8 ± 10.6 years (79.5 % men), with newly diagnosed moderate and severe OSA (apnea-hypopnea index ≥15 with polysomnographic evaluation). All patients enrolled received CPAP therapy. The study protocol included a complete conventional and tissue Doppler echocardiographic study at baseline and 12 months after CPAP treatment. RESULTS: Among patients enrolled, 31 completed the prespecified study protocol. After CPAP therapy, a decrease in pulmonary artery systolic pressure (p < 0.001), right ventricular (RV) diameter (p = 0.012), inferior vena cava diameter (p = 0.005), and RV wall thickness (p = 0.006) was observed. In addition, tricuspid annular plane systolic excursion values (p = 0.048) and tissue E/A ratio at the tricuspid annulus (p = 0.01) were significantly increased. Moreover, a reduction in left ventricular (LV) mass was observed (p < 0.001). With respect to somatometric parameters, body mass index and waist diameter (p < 0.001 for both) were reduced. Importantly, the improvement in apnea-hypopnea index was associated with the improvement in pulmonary artery systolic pressure, independently from confounders such as age, gender, and the reduction in body mass index. DISCUSSION: CPAP therapy in OSA patients was found to improve right heart chambers remodeling and performance as well as somatometric characteristics. The impact of CPAP on LV performance seems less pronounced.

Intestinal Obstruction due to Bilateral Strangulated Femoral Hernias.

Introduction. Femoral hernias are at high risk of strangulation due to the narrow femoral canal and femoral ring. This can lead to symptoms of obstruction or strangulation requiring emergency surgery and possible bowel resection. To our knowledge, there is only one previous published report of bilateral strangulated femoral hernia. We present our case of this phenomenon. Case Report. An 86-year-old woman presented with symptoms of small bowel obstruction. Examination revealed two tender lumps in the area of the femoral triangle. CT scan revealed bilateral femoral hernias. Both hernias were repaired and a small bowel resection on the right side was performed with side to side anastomosis. She made an uneventful recovery. Conclusion. Bilateral femoral hernias are a rare occurrence with only one reported case of bilateral strangulation. Our case highlights the importance of meticulous history taking and clinical examination as any delay in diagnosis will increase the risk of mortality and morbidity for the patient. Hernias should always be considered as a cause if one presents with symptoms of abdominal pain or obstruction.

Laparoscopically assisted repair of vaginal evisceration after hysterectomy.

Vaginal evisceration is a rare condition most commonly associated with previous vaginal surgery. It usually presents with vaginal bleeding, lower abdominal pain and a protruding mass, and requires immediate assessment and surgical management to salvage the prolapsed bowel. Any delay in the treatment may result in bowel ischaemia and perforation which is associated with higher morbidity and mortality. We report a case of spontaneous vaginal evisceration during defaecation in a 56-year-old postmenopausal women 11 months post hysterectomy. This case highlights the benefits of a combined laparoscopic and transvaginal approach in the successful management of this surgical emergency.

Gallbladder volvulus: a case of mimicry.

Torsion of the gallbladder resulting in a volvulus is a rare clinical finding that poses a diagnostic challenge preoperatively to both surgeons and radiologists. It is thought to occur secondary to a redundant mesentery where rotation of the gallbladder occurs along the axis of the cystic duct and cystic artery. Gallbladder volvulus commonly presents as acute cholecystitis and is rarely diagnosed preoperatively. An early emergency laparoscopic cholecystectomy is the preferred treatment. Early consideration of this diagnosis enables prompt surgical intervention and quick postoperative recovery periods.

Effect of CPAP treatment on endothelial function and plasma CRP levels in patients with sleep apnea.

BACKGROUND: Continuous positive airway pressure (CPAP) is the most effective method for treating obstructive sleep apnea syndrome (OSAS) and alleviating symptoms. Improved sleep quality with effective CPAP therapy might also contribute to attenuated systemic inflammation and improved endothelial function, with subsequent reduction of cardiovascular risk. The aim of this study was to assess the effect of 3-month CPAP therapy on brachial artery flow-mediated dilation (FMD) and plasma C-reactive protein (CRP) levels in patients with OSAS. MATERIAL/METHODS: Our study group consisted of 38 male patients with no prior history of cardiovascular disease. Twenty patients with an Apnea-Hypopnea Index (AHI) ≥15 were assigned to receive CPAP treatment and 18 subjects with an AHI<5 were included in the control group. Six patients failed to comply with the CPAP treatment. Measurement of FMD and blood analysis was performed at baseline and 3 months after CPAP therapy. RESULTS: Baseline FMD values were negatively correlated with age, BMI, AHI, DSI,% of time <90% Sa02, and CRP (p<0.05). Plasma CRP values were positively correlated with BMI, AHI, DSI and% of time <90% Sa02 (p<0.05). In the group of patients who complied with the CPAP treatment, there was a significant increase in the FMD values (9.18 ± 0.55 vs. 6.27 ± 0.50) and a decrease in the levels of CRP (0.67 ± 0.15 vs. 0.84 ± 0.18) (p<0.05). CONCLUSIONS: Appropriate CPAP therapy improved both CRP and FMD values, suggesting its potentially beneficial role in reducing cardiovascular risk in OSAS patients.

Large infrapatellar ganglionic cyst of the knee fat pad: a case report and review of the literature.

INTRODUCTION: Large ganglionic cystic formations arising from the infrapatellar fat pad are quite uncommon and only a few are mentioned in the literature. An open excision in these cases is mandatory. CASE PRESENTATION: We report the case of a large infrapatellar fat pad ganglion in a 37-year-old Greek man with chronic knee discomfort. The ganglionic cyst originated from the infrapatellar fat pad and had no intrasynovial extension. The final diagnosis was determined with magnetic resonance imaging of the knee, and the lesion was treated with surgery. CONCLUSIONS: These lesions are asymptomatic in most cases but often are misdiagnosed as meniscal or ligamentous lesions of the knee joint. Nowadays, the therapeutic trend for such lesions is arthroscopic excision, but when there is a large ganglion, as in this case report, the treatment should be an open and thorough resection. This report is intended mostly but not exclusively for clinical physicians and radiologists.