Nasser Sharahili - Academia.edu (original) (raw)

Papers by Nasser Sharahili

Surgical Laparoscopy, Endoscopy & Percutaneous Techniques, 2001

The aim of this prospective comparative study was to determine the feasibility and the efficacy o... more The aim of this prospective comparative study was to determine the feasibility and the efficacy of laparoscopic cholecystectomy for acute cholecystitis in patients older than 75 years of age and to compare the results with those of open cholecystectomy. From January 1992 to December 1999, 139 patients older than 75 years of age underwent cholecystectomy for acute cholecystitis. The two groups of patients with cholecystolithiasis included 50 patients who underwent laparoscopic cholecystectomy (group 1) and 89 patients who underwent open cholecystectomy (group 2). Group 1 consisted of 30 women and 20 men, with a mean age of 81.9 years (range, 75-98). Group 2 consisted of 51 women and 38 men, with a mean age of 81.9 years (range, 75-93). There was no difference in the American Society of Anesthesiologists classification in both groups. The length of the surgery (103.3 vs. 149.7 minutes), postoperative length of stay (7.7 vs. 12.7 days), and inpatient rehabilitation (15 vs. 42 patients) were significantly shorter in group 1 than in group 2. The postoperative morbidity rate was not different between the groups. There was no mortality in group 1, but four patients died in group 2 (P ‫ס‬ 0.29). The conversion rate was 32% (n ‫ס‬ 16) in group 1. In summary, laparoscopic cholecystectomy in elderly patients with acute cholecystitis is safe and effective. Laparoscopic cholecystectomy in elderly patients restores them to the best possible quality of life with the lowest cost to them physiologically.

Atom transfer radical polymerization in aqueous media using different water-soluble initiators an... more Atom transfer radical polymerization in aqueous media using different water-soluble initiators and ligands Nasser Sharahili Styrene and methyl methacrylate have been polymerized successfully through atom transfer radical polymerization (ATRP) in aqueous dispersed media (emulsion ATRP). The thesis is divided into four experimental parts. In the first part, a water-soluble initiator was prepared for emulsion ATRP and utilized under various conditions in the presence of two ligands N, N, N', N'', N''-Pentamethyldiethylenetriamine and 2,2'-bipyridine to attain activation/deactivation only in the oil phase with Tween 20 as a non-ionic surfactant. The initiator was synthesized by the reaction of diethanolamine with α-Bromoisobutyryl bromide in anhydrous tetrahydrofuran. 1 H NMR spectroscopy (500 MHz, deuterium oxide, or chloroform-d) was performed to confirm the successful synthesis of the initiator and polystyrenes. In the second and third parts, two commercial initiators were used, poly(ethylene glycol) methyl ether 2-bromoisobutyrate (M n = 2000 g/mol), and 2hydroxyethyl 2-bromoisobutyrate (M n = 211.05 g/mol). BPY, tris(2-pyridylmethyl) amine and 4, 4'-dinonyl-2, 2'-dipyridyl were used as the ligands with various molar ratios. Polyoxyethylene (80) sorbitan monooleate, and polyoxyethylene (20) oleyl ether were used as non-ionic surfactants. In the fourth part, a macroinitiator was synthesized by the reaction of polyoxyethylene (20) stearyl ether with α-Bromoisobutyryl bromide. The formation of the macroinitiator as well as the successful synthesis of poly(ethylene glycol)-b-polystyrene, and poly(ethylene glycol)-b-poly(methyl methacrylate) block ACKNOWLEDGMENTS I would like to extend the deepest gratitude and heartfelt thankfulness to my Distinguished Professor, Nikos Hadjichristidis, for giving me a great chance to work under his supervision and his collaborative group during my thesis research period. Also, I'm very grateful to my committee members, Professor Suzana Nunes, and Professor Luigi Cavallo for their support and guidance. A great acknowledgment goes to my labmate, Ph.D. students, postdoctoral fellows, research scientists, and master students for their support and help. In particular, Dr. George Zapsas for his support, and Dr. Viko Ladelta for his valuable contributions. I would like to thank my company, Saudi Arabian Basic Industries Corporation "SABIC" top management, Human Resource (HR), and Education Department, who supported me morally and financially, in addition to granting me a great opportunity to complete my master degree. I would also like to thank KAUST Administration, Faculties, Security Department, Housing Department, and KCC members, as well as the Core Lab staff for their support and help during my study period at an unforgettable place, "KAUST". No words can express my appreciation to my family, my lovely mother, sisters, and brothers for their encouragement as well as my warm thankfulness and appreciation to my lovely daughter, Danah, and my great wife for their patience and support during my study and the research journey. 6

Surgical Laparoscopy, Endoscopy & Percutaneous Techniques, 2001

The aim of this prospective comparative study was to determine the feasibility and the efficacy o... more The aim of this prospective comparative study was to determine the feasibility and the efficacy of laparoscopic cholecystectomy for acute cholecystitis in patients older than 75 years of age and to compare the results with those of open cholecystectomy. From January 1992 to December 1999, 139 patients older than 75 years of age underwent cholecystectomy for acute cholecystitis. The two groups of patients with cholecystolithiasis included 50 patients who underwent laparoscopic cholecystectomy (group 1) and 89 patients who underwent open cholecystectomy (group 2). Group 1 consisted of 30 women and 20 men, with a mean age of 81.9 years (range, 75-98). Group 2 consisted of 51 women and 38 men, with a mean age of 81.9 years (range, 75-93). There was no difference in the American Society of Anesthesiologists classification in both groups. The length of the surgery (103.3 vs. 149.7 minutes), postoperative length of stay (7.7 vs. 12.7 days), and inpatient rehabilitation (15 vs. 42 patients) were significantly shorter in group 1 than in group 2. The postoperative morbidity rate was not different between the groups. There was no mortality in group 1, but four patients died in group 2 (P ‫ס‬ 0.29). The conversion rate was 32% (n ‫ס‬ 16) in group 1. In summary, laparoscopic cholecystectomy in elderly patients with acute cholecystitis is safe and effective. Laparoscopic cholecystectomy in elderly patients restores them to the best possible quality of life with the lowest cost to them physiologically.

Atom transfer radical polymerization in aqueous media using different water-soluble initiators an... more Atom transfer radical polymerization in aqueous media using different water-soluble initiators and ligands Nasser Sharahili Styrene and methyl methacrylate have been polymerized successfully through atom transfer radical polymerization (ATRP) in aqueous dispersed media (emulsion ATRP). The thesis is divided into four experimental parts. In the first part, a water-soluble initiator was prepared for emulsion ATRP and utilized under various conditions in the presence of two ligands N, N, N', N'', N''-Pentamethyldiethylenetriamine and 2,2'-bipyridine to attain activation/deactivation only in the oil phase with Tween 20 as a non-ionic surfactant. The initiator was synthesized by the reaction of diethanolamine with α-Bromoisobutyryl bromide in anhydrous tetrahydrofuran. 1 H NMR spectroscopy (500 MHz, deuterium oxide, or chloroform-d) was performed to confirm the successful synthesis of the initiator and polystyrenes. In the second and third parts, two commercial initiators were used, poly(ethylene glycol) methyl ether 2-bromoisobutyrate (M n = 2000 g/mol), and 2hydroxyethyl 2-bromoisobutyrate (M n = 211.05 g/mol). BPY, tris(2-pyridylmethyl) amine and 4, 4'-dinonyl-2, 2'-dipyridyl were used as the ligands with various molar ratios. Polyoxyethylene (80) sorbitan monooleate, and polyoxyethylene (20) oleyl ether were used as non-ionic surfactants. In the fourth part, a macroinitiator was synthesized by the reaction of polyoxyethylene (20) stearyl ether with α-Bromoisobutyryl bromide. The formation of the macroinitiator as well as the successful synthesis of poly(ethylene glycol)-b-polystyrene, and poly(ethylene glycol)-b-poly(methyl methacrylate) block ACKNOWLEDGMENTS I would like to extend the deepest gratitude and heartfelt thankfulness to my Distinguished Professor, Nikos Hadjichristidis, for giving me a great chance to work under his supervision and his collaborative group during my thesis research period. Also, I'm very grateful to my committee members, Professor Suzana Nunes, and Professor Luigi Cavallo for their support and guidance. A great acknowledgment goes to my labmate, Ph.D. students, postdoctoral fellows, research scientists, and master students for their support and help. In particular, Dr. George Zapsas for his support, and Dr. Viko Ladelta for his valuable contributions. I would like to thank my company, Saudi Arabian Basic Industries Corporation "SABIC" top management, Human Resource (HR), and Education Department, who supported me morally and financially, in addition to granting me a great opportunity to complete my master degree. I would also like to thank KAUST Administration, Faculties, Security Department, Housing Department, and KCC members, as well as the Core Lab staff for their support and help during my study period at an unforgettable place, "KAUST". No words can express my appreciation to my family, my lovely mother, sisters, and brothers for their encouragement as well as my warm thankfulness and appreciation to my lovely daughter, Danah, and my great wife for their patience and support during my study and the research journey. 6