Ensuring the correction of heterogeneous and complex systems is an essential stage in the process... more Ensuring the correction of heterogeneous and complex systems is an essential stage in the process of engineering systems. In this paper we propose a methodology to verify and validate complex systems specified with SysML language using a combination of the two techniques of simulation and verification. We translate SysML specifications into SystemC models to validate the designed systems by simulation, then we propose to verify the derived SystemC models by using the Uppaal model checker. A case study is presented to demonstrate the effectiveness of our approach.
Le travail presente dans cette these a abouti a un systeme informatique qui realise une "in... more Le travail presente dans cette these a abouti a un systeme informatique qui realise une "integration forte" entre un systeme d'aide a la programmation et a l'utilisation des methodes d'Analyse de Donnees et un Systeme de Gestion de Bases de Donnees Relationnel "restructurable". Les modules orientes Analyse de Donnees sont structures en trois couches superposees autour du langage hote FORTRAN 77. Ils offrent au chercheur qui ecrit un programme en FORTRAN 77 des operateurs puissants de calcul statistique, d'algebre euclidienne, de calcul matriciel et de manipulation de matrices. La programmation des expressions algebriques matricielles etendues a ces operateurs est effectuee dans un langage proche de celui des mathematiques ; le programme est reconnu et traduit en FORTAN 77 par un preprocesseur. Le systeme offre egalement a l'utilisateur un pseudo-generateur de programmes. Le modele de donnees "etendu" supporte par le SGBD et son cara...
Context Parathyroid hormone-related peptide (PTHrP) is produced by many malignant tumors. It is r... more Context Parathyroid hormone-related peptide (PTHrP) is produced by many malignant tumors. It is responsible for most cases of hypercalcemia in patients with malignancy. Few published studies shed light on the relation between serum calcium levels and serum PTHrP levels in cirrhotic patients with hepatocellular carcinoma (HCC). Aim The aim of the current work was to evaluate serum PTHrP in cirrhotic patients with HCC and a possible correlation between serum PTHrP levels and albumin-corrected serum calcium levels in these patients. Patients and methods This is a cross-sectional study. The study included 35 cirrhotic patients with HCC (diagnosed depending upon α-fetoprotein and abdominal imaging studies). Data about their serum albumin and albumin-corrected serum calcium levels were collected. Sera of the studied patients were collected for determination of PTHrP levels by enzyme-linked immunosorbent assay (ELISA). Numerical data were summarized in the form of mean±SD. Strength of asso...
810 Background: Cancer treatment is a significant driver of healthcare costs worldwide, however, ... more 810 Background: Cancer treatment is a significant driver of healthcare costs worldwide, however, the economic impact of treating patients with anti-neoplastic agents is poorly elucidated. Hence, we conducted a systematic review and meta-analysis to estimate the direct costs associated with administering intravenous chemotherapy in an outpatient setting. Methods: We systematically searched four databases from 2010 to present and extracted hourly administration costs and the respective components of each estimate. Separate analyses were conducted of Canadian and United States (US) studies, respectively, to address a priori hypotheses regarding heterogeneity amongst administration cost estimates. The Drummond checklist was used to assess risk-of-bias. Data were summarized using medians with interquartile ranges and five outliers were identified; costs were presented in 2019 USD. Results: A total of 44 studies were analyzed, including sub-analyses of 19 US and seven Canadian studies. 26...
Protein-energy malnourishment is commonly encountered in patients with end-stage liver disease wh... more Protein-energy malnourishment is commonly encountered in patients with end-stage liver disease who undergo liver transplantation. Malnutrition may further increase morbidity, mortality and costs in the post-transplantation setting. The importance of carefully assessing the nutritional status during the work-up of patients who are candidates for liver replacement is widely recognized. The metabolic abnormalities induced by liver failure render the conventional assessment of nutritional status to be challenging. Preoperative loss of skeletal muscle mass, namely, sarcopenia, has a significant detrimental impact on post-transplant outcomes. It is essential to provide sufficient nutritional support during all phases of liver transplantation. Oral nutrition is preferred, but tube enteral nutrition may be required to provide the needed energy intake. Herein, the latest currently employed perioperative nutritional interventions in liver transplant recipients are thoroughly illustrated inclu...
The effect of body composition disturbances has been recently in focus. Sarcopenic obesity, a co-... more The effect of body composition disturbances has been recently in focus. Sarcopenic obesity, a co-occurrence of low muscle mass and high body fat was reportedly predictive of high mortality in patients with cirrhosis. However, the impact of the interacting sarcopenia and overweight on the outcomes after liver transplantation is still unclear. We evaluated 200 patients undergoing adult-to-adult living donor liver transplantation at our institution between January 2008 and November 2013 classified according to BMI and psoas muscle index (PMI) on admission to transplant into 4 subgroups; sarcopenic overweight (SO), sarcopenic non-overweight (SN), non-sarcopenic overweight and non-sarcopenic non-overweight (NN). Short-term outcomes and overall post-transplant survival were compared among the four subgroups. Sarcopenic patients with preoperative low PMI had higher incidence of postoperative bacteremia and major postoperative complications, and poorer overall post-transplant survival than ...
Low anterior resection (LAR) has higher risk of anastomotic leak with its attendant morbidity -mo... more Low anterior resection (LAR) has higher risk of anastomotic leak with its attendant morbidity -mortality. De-functioning loop ileostomy (DLI), claimed to mitigate the consequences of anastomotic leak, has been questioned in recent years. This study aims to evaluate the impact of ileostomy on LAR. A retrospective analysis of stoma database. 136 patients with stoma (March 2011-July 2015) were assessed. Data was analysed in respect to LAR anastomotic leak rate, impact on morbidity-mortality, short and long-term stoma complications, rate of ileostomy reversal and reasons for non-reversal. 45 patients had loop ileostomy for LAR. Male (28) to female (17) ratio was 1.65:1 with median age of 69 (IQR: 56-75.5). Only 3 anastomotic leaks (3/45, 6.5%) occurred, all treated conservatively with no mortality. 29 had reversal, average reversal time is 10 months (3-24) and 5 awaiting. Reasons for non-reversal included patients' choice (7), death from cardiac cause (1), chemotherapy (1), unfit fo...
Transanal haemorrhoidal dearterialisation and mucopexy has evolved in recent years as a popular m... more Transanal haemorrhoidal dearterialisation and mucopexy has evolved in recent years as a popular minimally invasive non-excisional surgery for symptomatic prolapsing haemorrhoids. The long-term outcome of this procedure however, remains to be established. We aim to analyse the long-term outcome of THD-mucopexy in the management of prolapsing haemorrhoids based on the evidence of a prospective data from a single institution. A prospective data was collected on 100 consecutive cases of grade 3 and 4 symptomatic haemorrhoids between the period 03/2010 and 06/2015 who underwent the procedure as a day case under general anaesthetic. Overall median follow up was for two years with average age of 54.4 ranges from 34 to 79 and gender ratio of 61% Male and 39% Female. Pre-and postoperative symptoms were assessed with a view to evaluate the nature of complications and long-term recurrence rate. [Table: see text]. THD mucopexy is a safe and effective minimally invasive modality for prolapsing s...
2015 12th International Symposium on Programming and Systems (ISPS), 2015
The objective of this paper is to propose an approach to formalize and verify the compatibility b... more The objective of this paper is to propose an approach to formalize and verify the compatibility between SysML blocks, and to help in making decision about the possibility of assembling these blocks. We specify the architecture of the system using SysML internal block diagrams. To model the interaction between blocks with a convivial manner, we propose HPSM (Hierarchical Protocol State Machine) diagram. In order to permit the verification of such interactions, we perform a translation of HPSMs into HIA-ILTs (Hierarchical Interface Automata with Inter-Level Transitions), a variant of interface automata (IA) which we propose for this purpose. Our major objective is to benefit from the hierarchy which is present in HIA-ILTs. Thus, we have adapted the existing approaches of compatibility verification based on IAs to be applicable on the HIA-ILTs. However, in order to avoid the flattening of the entire HIA-ILT, we propose a preliminary phase that allows selecting the composite states to flatten. The aim behind this is to alleviate the verification phase. Our approach is illustrated by a case study, where we demonstrate the expressiveness of the HPSM and the HIA-ILT, and we show how the hierarchy and the abstraction help to reduce the complexity of verification.
Journal of hepato-biliary-pancreatic sciences, Jan 5, 2015
Sarcopenia has been shown to be an independent predictor of lower disease-free and overall surviv... more Sarcopenia has been shown to be an independent predictor of lower disease-free and overall survival in various kinds of diseases. The quality of skeletal muscle has recently attracted much attention as a new parameter of sarcopenia. We performed a retrospective analysis of 477 patients undergoing hepatectomy for hepatocellular carcinoma (HCC) between April 2005 and August 2014. The quality of skeletal muscle was evaluated by intramuscular adipose tissue content (IMAC) using preoperative computed tomography (CT) imaging. The impact of IMAC on outcomes after hepatectomy for HCC was analyzed. Patients with high IMAC showed older age, higher body mass index, higher indocyanine green retention test at 15 min, and more operative blood loss. The overall and recurrence-free survival rates were significantly lower in patients with high IMAC than in patients with normal IMAC (P < 0.0001, P = 0.0012, respectively). Multivariate analysis showed that high IMAC was the significant risk factor ...
Ensuring the correction of heterogeneous and complex systems is an essential stage in the process... more Ensuring the correction of heterogeneous and complex systems is an essential stage in the process of engineering systems. In this paper we propose a methodology to verify and validate complex systems specified with SysML language using a combination of the two techniques of simulation and verification. We translate SysML specifications into SystemC models to validate the designed systems by simulation, then we propose to verify the derived SystemC models by using the Uppaal model checker. A case study is presented to demonstrate the effectiveness of our approach.
Le travail presente dans cette these a abouti a un systeme informatique qui realise une "in... more Le travail presente dans cette these a abouti a un systeme informatique qui realise une "integration forte" entre un systeme d'aide a la programmation et a l'utilisation des methodes d'Analyse de Donnees et un Systeme de Gestion de Bases de Donnees Relationnel "restructurable". Les modules orientes Analyse de Donnees sont structures en trois couches superposees autour du langage hote FORTRAN 77. Ils offrent au chercheur qui ecrit un programme en FORTRAN 77 des operateurs puissants de calcul statistique, d'algebre euclidienne, de calcul matriciel et de manipulation de matrices. La programmation des expressions algebriques matricielles etendues a ces operateurs est effectuee dans un langage proche de celui des mathematiques ; le programme est reconnu et traduit en FORTAN 77 par un preprocesseur. Le systeme offre egalement a l'utilisateur un pseudo-generateur de programmes. Le modele de donnees "etendu" supporte par le SGBD et son cara...
Context Parathyroid hormone-related peptide (PTHrP) is produced by many malignant tumors. It is r... more Context Parathyroid hormone-related peptide (PTHrP) is produced by many malignant tumors. It is responsible for most cases of hypercalcemia in patients with malignancy. Few published studies shed light on the relation between serum calcium levels and serum PTHrP levels in cirrhotic patients with hepatocellular carcinoma (HCC). Aim The aim of the current work was to evaluate serum PTHrP in cirrhotic patients with HCC and a possible correlation between serum PTHrP levels and albumin-corrected serum calcium levels in these patients. Patients and methods This is a cross-sectional study. The study included 35 cirrhotic patients with HCC (diagnosed depending upon α-fetoprotein and abdominal imaging studies). Data about their serum albumin and albumin-corrected serum calcium levels were collected. Sera of the studied patients were collected for determination of PTHrP levels by enzyme-linked immunosorbent assay (ELISA). Numerical data were summarized in the form of mean±SD. Strength of asso...
810 Background: Cancer treatment is a significant driver of healthcare costs worldwide, however, ... more 810 Background: Cancer treatment is a significant driver of healthcare costs worldwide, however, the economic impact of treating patients with anti-neoplastic agents is poorly elucidated. Hence, we conducted a systematic review and meta-analysis to estimate the direct costs associated with administering intravenous chemotherapy in an outpatient setting. Methods: We systematically searched four databases from 2010 to present and extracted hourly administration costs and the respective components of each estimate. Separate analyses were conducted of Canadian and United States (US) studies, respectively, to address a priori hypotheses regarding heterogeneity amongst administration cost estimates. The Drummond checklist was used to assess risk-of-bias. Data were summarized using medians with interquartile ranges and five outliers were identified; costs were presented in 2019 USD. Results: A total of 44 studies were analyzed, including sub-analyses of 19 US and seven Canadian studies. 26...
Protein-energy malnourishment is commonly encountered in patients with end-stage liver disease wh... more Protein-energy malnourishment is commonly encountered in patients with end-stage liver disease who undergo liver transplantation. Malnutrition may further increase morbidity, mortality and costs in the post-transplantation setting. The importance of carefully assessing the nutritional status during the work-up of patients who are candidates for liver replacement is widely recognized. The metabolic abnormalities induced by liver failure render the conventional assessment of nutritional status to be challenging. Preoperative loss of skeletal muscle mass, namely, sarcopenia, has a significant detrimental impact on post-transplant outcomes. It is essential to provide sufficient nutritional support during all phases of liver transplantation. Oral nutrition is preferred, but tube enteral nutrition may be required to provide the needed energy intake. Herein, the latest currently employed perioperative nutritional interventions in liver transplant recipients are thoroughly illustrated inclu...
The effect of body composition disturbances has been recently in focus. Sarcopenic obesity, a co-... more The effect of body composition disturbances has been recently in focus. Sarcopenic obesity, a co-occurrence of low muscle mass and high body fat was reportedly predictive of high mortality in patients with cirrhosis. However, the impact of the interacting sarcopenia and overweight on the outcomes after liver transplantation is still unclear. We evaluated 200 patients undergoing adult-to-adult living donor liver transplantation at our institution between January 2008 and November 2013 classified according to BMI and psoas muscle index (PMI) on admission to transplant into 4 subgroups; sarcopenic overweight (SO), sarcopenic non-overweight (SN), non-sarcopenic overweight and non-sarcopenic non-overweight (NN). Short-term outcomes and overall post-transplant survival were compared among the four subgroups. Sarcopenic patients with preoperative low PMI had higher incidence of postoperative bacteremia and major postoperative complications, and poorer overall post-transplant survival than ...
Low anterior resection (LAR) has higher risk of anastomotic leak with its attendant morbidity -mo... more Low anterior resection (LAR) has higher risk of anastomotic leak with its attendant morbidity -mortality. De-functioning loop ileostomy (DLI), claimed to mitigate the consequences of anastomotic leak, has been questioned in recent years. This study aims to evaluate the impact of ileostomy on LAR. A retrospective analysis of stoma database. 136 patients with stoma (March 2011-July 2015) were assessed. Data was analysed in respect to LAR anastomotic leak rate, impact on morbidity-mortality, short and long-term stoma complications, rate of ileostomy reversal and reasons for non-reversal. 45 patients had loop ileostomy for LAR. Male (28) to female (17) ratio was 1.65:1 with median age of 69 (IQR: 56-75.5). Only 3 anastomotic leaks (3/45, 6.5%) occurred, all treated conservatively with no mortality. 29 had reversal, average reversal time is 10 months (3-24) and 5 awaiting. Reasons for non-reversal included patients' choice (7), death from cardiac cause (1), chemotherapy (1), unfit fo...
Transanal haemorrhoidal dearterialisation and mucopexy has evolved in recent years as a popular m... more Transanal haemorrhoidal dearterialisation and mucopexy has evolved in recent years as a popular minimally invasive non-excisional surgery for symptomatic prolapsing haemorrhoids. The long-term outcome of this procedure however, remains to be established. We aim to analyse the long-term outcome of THD-mucopexy in the management of prolapsing haemorrhoids based on the evidence of a prospective data from a single institution. A prospective data was collected on 100 consecutive cases of grade 3 and 4 symptomatic haemorrhoids between the period 03/2010 and 06/2015 who underwent the procedure as a day case under general anaesthetic. Overall median follow up was for two years with average age of 54.4 ranges from 34 to 79 and gender ratio of 61% Male and 39% Female. Pre-and postoperative symptoms were assessed with a view to evaluate the nature of complications and long-term recurrence rate. [Table: see text]. THD mucopexy is a safe and effective minimally invasive modality for prolapsing s...
2015 12th International Symposium on Programming and Systems (ISPS), 2015
The objective of this paper is to propose an approach to formalize and verify the compatibility b... more The objective of this paper is to propose an approach to formalize and verify the compatibility between SysML blocks, and to help in making decision about the possibility of assembling these blocks. We specify the architecture of the system using SysML internal block diagrams. To model the interaction between blocks with a convivial manner, we propose HPSM (Hierarchical Protocol State Machine) diagram. In order to permit the verification of such interactions, we perform a translation of HPSMs into HIA-ILTs (Hierarchical Interface Automata with Inter-Level Transitions), a variant of interface automata (IA) which we propose for this purpose. Our major objective is to benefit from the hierarchy which is present in HIA-ILTs. Thus, we have adapted the existing approaches of compatibility verification based on IAs to be applicable on the HIA-ILTs. However, in order to avoid the flattening of the entire HIA-ILT, we propose a preliminary phase that allows selecting the composite states to flatten. The aim behind this is to alleviate the verification phase. Our approach is illustrated by a case study, where we demonstrate the expressiveness of the HPSM and the HIA-ILT, and we show how the hierarchy and the abstraction help to reduce the complexity of verification.
Journal of hepato-biliary-pancreatic sciences, Jan 5, 2015
Sarcopenia has been shown to be an independent predictor of lower disease-free and overall surviv... more Sarcopenia has been shown to be an independent predictor of lower disease-free and overall survival in various kinds of diseases. The quality of skeletal muscle has recently attracted much attention as a new parameter of sarcopenia. We performed a retrospective analysis of 477 patients undergoing hepatectomy for hepatocellular carcinoma (HCC) between April 2005 and August 2014. The quality of skeletal muscle was evaluated by intramuscular adipose tissue content (IMAC) using preoperative computed tomography (CT) imaging. The impact of IMAC on outcomes after hepatectomy for HCC was analyzed. Patients with high IMAC showed older age, higher body mass index, higher indocyanine green retention test at 15 min, and more operative blood loss. The overall and recurrence-free survival rates were significantly lower in patients with high IMAC than in patients with normal IMAC (P < 0.0001, P = 0.0012, respectively). Multivariate analysis showed that high IMAC was the significant risk factor ...
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Papers by Ahmed Hammad