Papers by mohammad maleki
Advanced Pharmaceutical Bulletin, 2019
Purpose: The increase of bacterial resistance to common antibacterial agents is one of the major ... more Purpose: The increase of bacterial resistance to common antibacterial agents is one of the major problems of health care systems and hospital infection control programs. In this study, antimicrobial activity of titanium dioxide (TiO2 ) and zinc oxide (ZnO) nanoparticles (NPs) was investigated against E. coli, Salmonella enteritidis, Listeria monocytogenes, and Staphylococcus aureus pathogenic bacteria by determining sensitivity coefficient and kinetics of bacterial death. Methods: Antimicrobial tests were performed with ~106 CFU/mL of each bacterium at baseline. At first, minimum inhibitory concentration (MIC) was concluded by the dilution method and then, death kinetic and susceptibility coefficient of NPs suspensions was determined at 0 to 360 min. treatment time. Results: The results of this study revealed that, the highest susceptibility was observed for L. monocytogenes (Z=0.025 mL/μg) to TiO2 NPs, whereas the lowest susceptibility was obtained in the reaction of ZnO NPs with S...
Journal of Neurosurgery, 2015
OBJECT The Brain Trauma Foundation has published guidelines on the surgical management of traumat... more OBJECT The Brain Trauma Foundation has published guidelines on the surgical management of traumatic subdural hematoma (SDH). However, no data exist on the proportion of patients with SDH that can be selected for conservative management and what is the outcome of these patients. The goals of this study were as follows: 1) to establish what proportion of patients are initially treated conservatively; 2) to determine what proportion of patients will deteriorate and require surgical evacuation; and 3) to identify risk factors associated with deterioration and delayed surgery. METHODS All cases of acute traumatic SDH (869 when inclusion criteria were met) presenting over a 4-year period were reviewed. For all conservatively treated SDH, the proportion of delayed surgical intervention and the Glasgow Outcome Scale score were taken as outcome measures. Multiple factors were compared between patients who required delayed surgery and patients without surgery. RESULTS Of the 869 patients with...
Decompressive laparotomy for treatment of refractory intracranial hypertension, thinking out of the box
Neurosciences (Riyadh, Saudi Arabia), 2013
I pressure management is the corner stone to the success of treatment of traumatic brain injury (... more I pressure management is the corner stone to the success of treatment of traumatic brain injury (TBI).1 The management strategy of severe TBI is variable by institution and region of practice but entails successive utilization of head elevation, sedation, paralysis, CSF drainage, hyperosmolar therapy, hyperventilation, and barbiturate coma.2 The ultimate escalation of therapy is the utilization of decompressive craniectomy in cases of refractory intracranial hypertension.3 The relationship between intracranial, intra-thoracic, and intra-abdominal pressure and pressure translocation has been known for some time.4 This is a physiological factor seldom involved in the approach to refractory intracranial hypertension, which could be secondary to abdominal compartment syndrome (ACS). We present such a concept through the following case of a polytrauma victim. A 22-year-old male who was involved in a high-speed motor vehicle crash with an initial Glasgow coma scale (GCS) of 7 and a left dilated pupil. He was intubated in the field and suffered a brief episode of ventricular fibrillation with a systolic blood pressure of 80 mm Hg en-route to our hospital. A CT of the brain showed multiple contusions in the frontal lobes bilaterally as well as the right parietal lobe. There was a small right frontotemporal subdural hematoma with effacement of the sulci. His CT abdomen showed a splenic blush for which he was submitted to endovascular angioembolization. While in the angio-suite, he sustained a generalized tonic-clonic convulsion lasting a couple of minutes for which he was started on anti-epileptic medication (phenytoin 1g loading followed by 100 mg IV TID, Phenytoin sodium, Mylan Laboratories, Morgantown, WV, USA). Additional injuries included multiple facial fractures as well as pelvic and femur fractures. He was transferred to the intensive care unit where a fiber optic intracranial pressure monitor (Codman®, The DePuy Company, Johnson & Johnson Family of Companies, Warsaw, IN, USA) was inserted. Initial intracranial pressure (ICP) was controlled by hyperosmolar therapy. Repeat imaging in 24 hours showed no interval changes, and the ICP trends were stable. On post-trama day 4, the ICP was controlled, but he was noted to have a tense abdomen. His fluid balance was positive since admission by 2.3 Lt. On post-trauma day 5, he had an ICP surge up to 40 mm Hg at 3:00 am that responded to an additional dose of mannitol. A repeat CT scan carried out urgently showed no change in the contusions, the peri-contusion edema, or the small subdural collection. The ICP was stable for the following few hours but he had a tense abdomen and was exhibiting a positive hepatojugular reflex, with an ICP rising from a baseline of 12-15 to 38-40 mm Hg, and a bladder pressure of 29 mm Hg. He had a positive fluid balance of several liters by this time, and the general surgery team was consulted to rule out an ACS. At 12:30 pm on the same day, the patient had an ICP surge to 70 mm Hg with bilateral dilated pupils. This plateau wave failed to respond to additional doses of mannitol, hypertonic saline, and hyperventilation. Given the recent CT findings of stable intracranial contusions and the objective finding of fluid overload and signs of increased intra-abdominal pressure, an emergency bedside laparotomy was performed by the general surgery team. The ICP decreased immediately to 24 mm Hg with normalization of the pupil size. A repeat CT showed no interval changes. He was then transferred to the operating room for a completion laparotomy and proper seal of the wound. By this time, the ICP was between 10 and 15 mm Hg. He had a persistent hypotensive period despite aggressive fluid resuscitation with mean arterial pressure in the 60’s with an ICP trending upwards of 20-30 mm Hg. Because of his poor hemodynamic condition, and fear of compromised cerebral perfusion, he was submitted to a left sided decompressive craniectomy with a significant drop in the ICP to 5-7 mm Hg. This expedited weaning of hyperosmolar therapy, which optimized the resuscitation protocol for his hemodynamic instability. He developed an abdominal wall hernia, which was treated by surgical closure with mesh. This developed an infection and was revised and treated with antibiotics for 8-weeks post-operatively, with eventual good wound healing. He continued to improve neurologically with no ICP derangement. He was discharged to a rehabilitation center and later returned home where he lives with his family yielding a Glasgow outcome scale of 4, and can attend to simple responsibilities in the household. He underwent an uneventful cranioplasty 11 months after his TBI.
Nowadays in all countries, public resources of health care may be inadequate to meet health care ... more Nowadays in all countries, public resources of health care may be inadequate to meet health care demands. Hence, the policy makers and providers of health care should provide citizens with most effective methods when available resources are limited. During the past decades, a large number of research efforts in the issue of health care and its applicable mathematical models have been considered by researchers and practitioners. In this regard, location and redeployment of ambulances is one of the main issues considered in which an attempt is made to maximally cover desired regions and service patients in emergency situations. This paper presents the issue of locating available ambulances with regards to demand pattern and redeploying the located ambulances. Toward this end, after locating the ambulances, a new mathematical model is developed with the aim of minimizing the expected value of total traveled distance by the ambulances. In addition, to shed light on the merit of proposed model, a set of numerical experiments is presented. By the end of the paper, the corresponding conclusions are presented.
Computers & Industrial Engineering, 2014
Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques, 2011
Craniectomie décompressive primaire ou secondaire : des indications et des résultats différents. ... more Craniectomie décompressive primaire ou secondaire : des indications et des résultats différents. Contexte : L'hypertension inracrânienne peut causer des dommages secondaires après un traumatisme crânien. Il se peut qu'un traitement médical agressif ne soit pas suffisant pour diminuer la pression intracrânienne (PIC) qui augmente et une craniectomie de décompression (CD) est alors envisagée. La CD peut être divisée en deux catégories selon le moment et la raison pour laquelle l'intervention est faite : primaire (effectuée au moment de l'évacuation de la lésion à effet de masse) et secondaire (effectuée pour traiter une PIC réfractaire). La plupart des études ont analysé ensemble la CD primaire et la CD secondaire. Nous avons émis l'hypothèse que ces deux groupes de patients sont différents et le but de cette étude rétrospective était d'évaluer leurs différences afin de mieux prédire le résultat après une CD. Méthode : Soixante-dix patients ont subi une CD au cours d'une période de quatre ans dans notre centre. Ils ont été divisés en deux groupes selon le moment où la CD a été effectuée. La CD primaire a été faite dans les 24 heures suivant l'accident pour évacuer une lésion à effet de masse chez 44 patients. Vingt-six patients ont subi une CD secondaire au delà des 24 premières heures pour traiter une PIC réfractaire. Nous avons comparé les caractéristiques préopératoires et l'issue postopératoire de ces deux groupes de patients. Résultats : Nous avons observé des différences significatives quant au mécanisme ayant provoqué la lésion, aux anomalies pupillaires et au score de Marshall entre la CD primaire et la CD secondaire ainsi qu'une différence significative quant au résultat : 45,5% des patients ayant subi une CD primaire ont eu un bon résultat et la mortalité chez ces patients a été de 40,9%, alors que dans le groupe de patients qui ont subi une CD secondaire 73,1% ont eu un bon résultat avec 15,4% de mortalité. Conclusions : Les indications de la CD primaire et de la CD secondaire ainsi que les caractéristiques des patients sont différentes. La prédiction du résultat de la CD devrait tenir compte de l'indication chirurgicale.
Modélisation hiérarchisée du comportement des sols
Revue Française de Génie Civil, 2000
Dans cette étude est proposée la mise en place d'un outil permettant de mieux maîtriser la q... more Dans cette étude est proposée la mise en place d'un outil permettant de mieux maîtriser la qualité des modèles de comportement intégrés dans les codes de calcul utilisés en géotechnique. Pour cela un modèle de comportement est développé, sur la base du modèle CJS. Ce modèle ...
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Papers by mohammad maleki