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Ultrasonic Guided Insertion of Central Venous Catheter in Infants and Children
AA El Daba, YM Amr, AA Alhafez, A Hashish
Annals of Pediatric Surgery , 2010,
Abstract: Background/Purpose: ultrasound is licensed for application of regional blocks and insertion of vascular access. We aimed to compare ultrasonic guided (USG) and anatomical landmark technique (ALT) for insertion of central venous catheter (CVC) as regard success rate and rate of complications in infants and children. Materials & Methods: eighty childen (age ranged from 1-5 y) were classified into 2 groups, anatomical landmark technique was used to insert CVC in group I and ultrasonic guided technique was used in group II. Number of trials, duration of the procedure, and rate of complications were recorded. Results: There was a significant increase in success rate of insertion in group II as compared to group I (p = 0.001). Number of trials showed significant decrease in group II as compared to group I (p<0.0001). Incidence of arterial puncture was significantly decreased in group II (p = 0.028). Duration of the procedure was 21.3 ± 0.05 min in group I, and 12.5 ± 0.3 min in group II, ( p<0.0001). Conclusion: Insertion of central venous catheter in children should be guided with ultrasonography to avoid complications and failure of the procedure. Index Word: CV line insertion, ultrasonography.
Fairness Aware Group Proportional Frequency Domain Resource Allocation in L-SC-FDMA Based Uplink  [PDF]
Irfan Ahmed, Amr Mohamed
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2011, DOI: 10.4236/ijcns.2011.48060
Abstract: This paper presents virtual clusters based proportional fairness and resource allocation scheme for Localized Single Carrier Frequency Division Multiple Access (L-SC-FDMA). L-SC-FDMA has been selected as the uplink transmission scheme in 3GPP Long Term Evolution (LTE) due to its low Peak to Average Power Ratio (PAPR) over OFDMA in general and high rate-sum capacity over Interleaved SC-FDMA in particular. Virtual cluster-based proportional fairness (VCPF) scheduler exploits the link adaptation information available at MAC layer to form virtual clusters. The distributed proportional fairness scheduler ensures a minimum throughput for all users in the coverage area by assigning contiguous RBs, proportional to the throughput and the number of users in a particular cluster or group. Simulations have been performed using practical scenario of uniformly distributed users in Rayleigh faded coverage area and design formulas have been devised for network planning to get the best possible fairness with promising level of quality of service (QoS).
Simulation of small size divertor tokamak plasma edge at low density of plasma  [PDF]
Amr Hasheim Bekheit
Natural Science (NS) , 2012, DOI: 10.4236/ns.2012.41010
Abstract: A low density plasma edge of small size divertor tokamak has been modeling by “B2SOLPS0.5.2 D” fluid transport code. The results of modeling are: 1) Formation of the strong “ITB” has detected more reliable with discovery that, low density plasma is necessary and important condition for it to form. 2) Reduction of plasma density play significantly role in the formation of the strong ITB as global parameter, possibly through change in the steep density gradient which stabilize “ITG” mode. 3) The radial electric field of small size divertor tokamak plasma edge is plasma density dependence and maximum radial electric field shear is found at low plasma density. 4) In the “NBI” discharge the toroidal (parallel) velocity at low plasma density is co-current and upward direction. 5) The structure of plasma pressure and radial electric field in quiescent H-mode are obtained.
Impact of drifts in edge plasma of small size divertor tokamak  [PDF]
Amr H. Bekheit
Natural Science (NS) , 2012, DOI: 10.4236/ns.2012.42019
Abstract: The effect of poloidal E × B and diamagnetic drifts in edge plasma of Small Size Divertor (SSD) Tokamak is studied with two-dimensional B2SO- LPS-0.5.2D fluid transport code. The simulation results show the following: 1) For normal toroidal magnetic field, the increasing of core plasma density leads to large divertor asymmetries due to poloidal E × B and diamagnetic drifts. 2) Switching on the E × B and diamagnetic drifts leads to large change in poloidal distribution of radial electric field and induced counter-clockwise circulation (flow) around the x-point. 3) Switching on the E × B and diamagnetic drifts leads to the structure of poloidal distribution of radial electric field is nonmonotonic which responsible for negative spikes. 4) Switching on the E × B and diamagnetic drifts in vicinity of separatrix leads to the structure of poloidal distribution of radial electric field that has viscous layer. 5) Switching on the E × B and diamagnetic drifts results in torque generation. This torque spins up the toroidal rotation. 6) The E × B drift velocity depends on the plasma temperature heating and doesn't depend on plasma density.
Simulation of Radial Variation of Neutral Atoms on Edge Plasma of Small Size Divertor Tokamak  [PDF]
Amr Hasheim Bekheit
Journal of Modern Physics (JMP) , 2012, DOI: 10.4236/jmp.2012.32019
Abstract: Simulations have been performed to investigate the impact of radial variation of neutral atoms (neutral puff) on the edge plasma of small size divertor tokamak. It was demonstrated that, the variation of neutral atoms (neutral puff) in edge plasma of small size divertor tokamak generates additional large radial electric field and large radial electric field shear near separatrix which can significantly influence global confinement by affecting the transition from low (L) to high (H) confinement. This simulation was performed by using B2SOLPS0.5.2D fluid transport code based on a reduced form of the transport form of transport equations. These transport equations are implemented in B2SOLPS0.5.2D fluid transport code and solved for the parameters of Small Size Divertor tokamak. The results of simulation by fluid transport B2SOLPS0.5.2D code can be summarized as follow: 1) The Plasma Parameters are significantly effect by neutral atoms puffing in the edge plasma of small size divertor tokamak; 2) Contrary to previous expectation [1] of the predominant role of neutral viscosity on toroidal flux, anomalous transport was found to be mainly effect on toroidal flux; 3) Puffing of gas (neutral) in the edge plasma of small size divertor tokamak produce strong ITB; 4) Puffing of gas (neutral) in the edge plasma of small size divertor increase plasma density especially in SOL through charge exchange and ionization processes; 5) Puffing of gas (neutral) in the edge plasma of small size divertor has significant effect on the distribution of plasma heat flux; 6) The radial electric field is affected by gas (neutral) puffing in the edge plasma of small size divertor; 7) Puffing of neutral (atoms) in the edge plasma of small size divertor tokamak produce large radial electric field shear which contribute to L-H transition; 8) The centrifugal effect has no influence on distribution of the radial profile of parallel (toroidal) velocity of edge plasma of small size divertor tokamak during gas (neutral) puffing; 9) The bootstrap current in edge plasma of small size divertor tokamak is significantly affected by gas (neutral) puffing.
Preliminary Evaluation of New Quinoa Genotypes under Sandy Soil Conditions in Egypt  [PDF]
Amr S. Shams
Agricultural Sciences (AS) , 2018, DOI: 10.4236/as.2018.911100
Abstract: Field trial was carried out at Ismailia Research Station, Ismailia Governorate, Egypt to evaluate some quinoa genotypes under arid environment of sandy soil for identifying its agronomic potentiality, chemical composition and economic opportunity. Nine quinoa genotypes including six Peruvian varieties (Amarilla Marangani, Amarilla Sacaca, Blanca de Junin, Kancolla, Salcedo INIA and Rosada de Huancayo) and three new accessions (QS14, QS16 and QS17-2) were compared in randomized complete block design with three replications. The results revealed that quinoa proved success in sandy soil with suitable grain yield under Egyptian conditions. QS17-2 accession stays only from 115 to 120 days in the field according to environmental factors and treated as short duration accession, while growth duration of the four varieties; Blanca de Junin, Kancolla, Salcedo INIA and Rosada de Huancayo, as well as, accessions of QS14 and QS16 were moderate. Amarilla Marangani and Amarilla Sacaca varieties had the longest duration genotypes. Amarilla Sacaca and Amarilla Marangani varieties, as well as, QS17-2 accession gave the highest grain yield compared with the other genotypes. The highest protein content in quinoa grains was 13.60%, which recorded from QS17-2 accession, while the lowest value (10.75%) was recorded by Blanca de Junin variety. Moreover, Salcedo INIA variety had the lowest saponins content in quinoa grains (0.07%) while QS16 accession recorded the highest content (0.22%). The economic evaluation gave a clear indicator of the lower farm prices of quinoa grains in Egypt (US$ 1000/ton), which gives a comparative advantage to Egypt in the MENA region for quinoa exportation.
Functional Outcomes of Decompressive Hemicraniectomy for Treatment of Malignant Infarctions of the Middle Cerebral Artery  [PDF]
Amr Mohsen, Waleed Abbass
Open Journal of Modern Neurosurgery (OJMN) , 2020, DOI: 10.4236/ojmn.2020.103033
Abstract: Introduction: Malignant middle cerebral artery (MCA) infarction is a devastating entity that is associated with up to 80% mortality. Decompressive Hemicraniectomy has been utilized to treat brain swelling and mass effect secondary to these infarctions in an attempt to improve functional outcome. Aim: To evaluate the functional outcome of decompressive hemicraniectomy in management of malignant MCA infarctions. Methods: The study included 30 patients with malignant MCA infarctions operated upon by decompressive hemicraniectomy and duroplasty with pericranium or fascia lata graft in the period from June 2016 to January 2019. Pre-operative neurological condition, associated morbidity, location and extent of the infarction were assessed. Surgery was performed within 48 hours of the onset of stroke or 12 hours within deterioration of conscious level. Pre-operative CT scan as well as sequential post-operative CT was done. Functional outcome was assessed by the modified Rankin Scale (mRS) at the time of discharge and 3 months following surgery. Results: The study included 18 males and 12 females with a mean age of 54.7 years. The pre-operative GCS was <8 (5 - 7) in 11 patients and 8 or higher (8 - 13) in 19 patients. Good functional outcome (mRS 0 - 3) was achieved in 13 (43.3%) cases while poor outcome (mRS 4 - 5) occurred in 8 (26.7%) cases and mortality (mRS 6) occurred in 9 (30%) cases. Conclusion: Decompressive hemicraniectomy improves functional outcome in cases of malignant MCA infarction. Pre-operative GCS, age, volume of infarction, degree of midline shift, timing of surgery and associated morbidity are the most important factors affecting the outcome.
Expanded Endoscopic Endonasal Approach (EEEA) for Clival Chordomas  [PDF]
Waleed Abbass, Amr Mohsen
Open Journal of Modern Neurosurgery (OJMN) , 2020, DOI: 10.4236/ojmn.2020.103036
Abstract: Objective: To evaluate the role of expanded endoscopic endonasal approach in removal of clival chordomas. Patients & Methods: Nine patients with clival chordomas were operated upon in Cairo University hospital from September 2015 to September 2018 using the EEEA a recurrent case and seven new cases were involved in these study and ten operations were done. All patients had preoperative neurological and radiological examination. The study was focusing on the approach, efficacy of tumor removal, reconstruction of the base and complications related to this approach. Results: Nine patients were operated in this study in which ten operations were done. It included six males (66.6%) and three females (33.3%) with age ranging from 4 years to 63 years with average age 40.7 years. Headache and diplopia were the most common symptoms found in six patients (66.6%). Brainstem affection was found in two patients (22.2%). Lower cranial nerves affection was found in two patients (22.2%). One case developed CSF leakage postoperatively (11.1%). Two patients underwent tracheostomy. We achieve total removal in four patients (44.4%), near total removal in one patient (11.1%) and subtotal tumor resection in four patients (44.4%). Conclusion: EEEA for clival chordomas is safe and effective approach regarding the results of the incidence of complications, and the percentage of tumor resection.
Endoscopic Assisted Microscopic Surgical Removal of Craniopharyngioma  [PDF]
Waleed Abbass, Amr Mohsen
Open Journal of Modern Neurosurgery (OJMN) , 2020, DOI: 10.4236/ojmn.2020.104048
Abstract: Background: Craniopharyngioma is a benign tumor which represents 2% - 3% of all intracranial tumors, there are two types: childhood type which affects children between 5 and 10 years and adulthood type which affects patients 50 - 60 years old. The presenting symptoms develop over years and include visual, endocrine, hypothalamic, neurological and neurophysiological manifestations. Surgery is the treatment of choice. Postoperative radiotherapy, gamma-knife and intra tumoral injection of chemotherapeutic drugs have been used as an adjuvant therapy in some cases. Objectives: In this study, we evaluated the role of endoscopy in assisting microscopic surgical removal of craniopharyngioma. Methods: Eleven patients were operated upon in Cairo University Hospitals, Egypt. All operations were done using microscope through the subfrontal approach. At the end of surgery, the endoscope was used to detect any residual tumor in the subchiasmatic and retrochiasmatic areas and to visualize the posterior part of the tumor which couldn’t be seen by the microscope to check if it was adherent to the hypothalamus and to evaluate whether to be removed or not. Results: The study included eleven cases, four of which were childhood type and seven adult type craniopharyngiomas. Total removal was achieved in six cases (five cases of adulthood type). Oumaya reservoir was inserted in five cases; ventriculoperitoneal shunt was needed in five cases. All cases suffered from temporary diabetes insipidus postoperatively, while only two cases developed permanent diabetes insipidus. Three cases presented preoperatively with pituitary hypofunction and two cases developed postoperative pituitary hypofunction, which necessitated hormone replacement therapy. Conclusion: Craniopharyngioma is one of the most difficult and challenging tumors for neurosurgeons due to its relation to optic nerve, hypothalamus and vascular system formed by Willis circle and its perforating branches. Endoscopy has a role in decision making after microscopic removal of craniopharyngioma.
Understanding Consumer Digital Consumption Behaviour in the Edge of Social Media Platforms  [PDF]
Cherouk Amr Yassin
Open Journal of Social Sciences (JSS) , 2021, DOI: 10.4236/jss.2021.910028
Abstract: This study aims at providing insights to the understanding of consumer behaviour which has become very complicated with the existence of the world of social media. Although research on consumer behaviour field has been seeking lately to understand the digital behaviour of the consumers. Marketers and academics risk offloading their market understanding to the algorithms, keeping marketers out of the loop, and losing the ability in understanding their consumer and their reactions. The lack of a well understanding of the consumer’s perception and attitude towards social media recommended Ads generated from the Recommender Systems, may impede the ability of organizations to build a marketing orientation and may negatively influence predicted consumer response. Previous studies were restricted to explaining the evolving role of perception and attitude of Facebook recommended advertisements in the context of impulse buying behaviour. Thus, structural equational modelling was done to understand the effects of the variables under investigation. The findings revealed that impulse buying is affected by the positive attitude towards the recommended advertisings, which are influenced by both informativeness and credibility as values perceived from the recommended advertisings. This study provides some useful practical implications for the F-commerce administrators, advertisers, promoters, and consumers.
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