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Search Results: 1 - 10 of 18776 matches for " Zaid Al Naqib "
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Neuroblastoma in Saudi Children: A Single Center Experience (2006-2014)  [PDF]
Zaid Al Naqib, Atif A. Ahmed, Musa Al Harbi, Fahad Al Manjomi, Zaheer Ullah Khan, Awatif Alanazi, Othman Mosleh, Walid Ballourah, Mohammed Rayis
Journal of Cancer Therapy (JCT) , 2015, DOI: 10.4236/jct.2015.610098
Abstract: Introduction: Neuroblastoma is the most common extracranial solid tumor in childhood and survival rate has improved during the last few decades. Only a few studies, related to Neuroblastoma in Saudi Arabian children, have been performed. We report epidemiologic data and our clinical experience from the department of Pediatric Hematology Oncology (PHO), King Fahad Medical City (KFMC), Riyadh, Saudi Arabia. Method: A retrospective observational study of all patients, with diagnosis of Neuroblastoma, who attended PHO-KFMC from July 2006 to June 2014 was performed. The survival periods (overall survival and disease-free survival) and the final outcomes for patients treated and followed at KFMC were recorded. The survival data were statistically correlated with the clinical, pathological and biological features of patients and tumors and compared to national and international cohorts. Results: Eight-year data were available for the 42 patients of which 22 (52.4%) were male and 20 (47.6%) were females. Age at diagnosis ranged 0 - 91 months with a mean and median of 26.3 and 18.5 months respectively. 16 (38.1%) patients were under one year and 26 (61.9%) above 1 year of age. The event-free survival (EFS) and overall survival (OS) rates were 66.5% and 71.5% respectively. EFS and OS among those who were <1 year age at presentation was 75% and 82%, whereas ≥1 yr age group had 59% and 62% survival rates respectively. Patients with tumors in the adrenal had considerably lower EFS (59%) and OS (63%); in comparison to patients with tumors sites other than the adrenal who had EFS and OS of 85% and 89% respectively. Both EFS and OS survival rates at the end of follow-up interval were 100.0%, in the low and intermediate risk groups. In contrast, patients in the high risk group had EFS and OS rates of 44% and 48% respectively. This difference was statistically significant (p < 0.05). Conclusion: Our results are very encouraging and comparable with known published international cohorts, and reveal an excellent outcome for stage 1, 2, 3 & 4 s. The prognosis for advanced (stage 4) disease remains rather poor. A collaborative Saudi-wide effort, with an emphasis on research in detecting clinical and biologic characteristics of aggressive disease and tailoring therapy, is needed.
Rapid and Simple Extraction Method for Volatile N-Nitrosamines in Meat Products  [PDF]
Mohammad Al-Kaseem, Zaid Al-Assaf, Franswa Karabet
Pharmacology & Pharmacy (PP) , 2013, DOI: 10.4236/pp.2013.48087
Abstract: A new methodology for extraction, pre-concentration and analysis of volatile nitrosamines in meat-derived products was developed and compared with conventional methods (Distillation and two-step solid-phase extraction). The samples (canned sausages, cured meat, luncheon and smoked meat) were treated with an aqueous sodium hydroxide (NaOH) by autoclaving at 121°C for 10 min and extracted by liquid-liquid extraction with dichloromethane, then the nitrosamines were pre-concentrated using activated silica. Then, gas chromatography coupled with flame ionization detector was used for the separation and determination of the different nitrosamines contained in a real sample and gas chromatography with mass spectrometry detection was used as the confirmation technique. The newly invented autoclaving method allowed the determination of nitrosamine compounds at trace levels with limit of detection ranged from 0.077 to 0.18 ppb and quantitation limits were from 0.26 to 0.6 ppb for all nitrosamines, and found to be superior to the conventional ones, yielding approximately about 10%-20% increasing in the recovery compared with the mean recovery obtained when applying conventional methods.
The Antioxidant Activity of Tocotrienols Compared with Some Synthetic Antioxidant  [PDF]
Housam Haj Hamdo, Warid Khayata, Zaid Al-Assaf
Pharmacology & Pharmacy (PP) , 2014, DOI: 10.4236/pp.2014.57071

The changes in content of fatty acids were studied every three months along the storage’s period, after adding an equal concentration (200 mg/Kg) of the natural antioxidant Tocotrienols (α-, β-, γ- and δ-T3) and of the synthetic one (BHT, BHA, AP) to four samples of different vegetable oils (sunflower oil, soybean oil, corn oil and olive oil). Then the oxidized and non-oxidized FAMEs were calculated to determine the antioxidant activity (AOA). The results showed that there was difference in AOA depending on the antioxidant of used. Tocotrienols were relatively weak compared with the synthetic antioxidant in all different types of oil. The AOA for each antioxidant was differed in different oil types. It was the most in the sunflower oil compared with the rest different oil types, while it was the lower for corn oil for all antioxidant. The AOA for BHA was the highest for different oil types compared with other antioxidants, and the δ-T3 had the lowest, while the rest anti-oxidants were in the following order: (BHA, BHT, AP, α-T3, β-T3, γ-T3, δ-T3).

Automatic Accompaniment to Arab Vocal Improvisation: From Technical to Commercial Perspectives  [PDF]
Fadi M. Al-Ghawanmeh, Zaid R. Shannak
Journal of Software Engineering and Applications (JSEA) , 2015, DOI: 10.4236/jsea.2015.81003
Abstract: In this multidisciplinary study, the main research question was how to improve the value of entrepreneurial initiatives that provide the web service of automatic accompaniment to Arab singing. As an example and case study, we considered the Mawaweel website that offered an automatic accompaniment to Arab vocal improvisation as a main service. After overviewing the website, we conducted a survey examining the satisfaction of its visitors in regard to presentation and quality of service. It was found that the Mawaweel website had potential to achieve success as the majority of the 22 respondents expressed general satisfaction after their first visit to the website, with an average rate of 75%. However, respondents’ ratings were strict when discussing specific aspects about the website presentation and service quality, and the means of average rates were 68.32% and 50.23% respectively. The standard deviations of average rates were 15.70% and 19.13%, respectively. This revealed a sense of inhomogeneity in the values of the different aspects of the website presentation, and an expanded sense of inhomogeneity in the quality of the different services delivered by the website. We then compared the Mawaweel website to other websites and proposed specific improvements to the aspects with average rate below 50%.
Revisión sobre métodos matemáticos para el estudio de la estabilidad del voltaje en los sistemas eléctricos de potencia
Zaid García ; et al.
Ingeniería Energética , 2010,
Abstract: In Cuba, from the seventies of the past century, different algorithms to study stationary and transientregimes of the Cuban Electric System were developed. Those algorithms and computer programs werefocused in the study of transient stability. Currently, we use widely the computer program “Power SystemExplorer” (PSX) which have a lot of facilities to make studies about stationary and transient regimes ofelectric power systems. Due to the studies about planning of electric power systems and the accumulatedexperience working with Cuban Electric System, the need of study the problems related with voltagestability of Cuban Electric System has arisen. In this paper, we make a first review about some static anddynamic mathematical methods included in bibliography about voltage stability of electric power systems.
Heavy metals pollution in sediment cores from the Gulf of Aqaba, Red Sea  [PDF]
Tariq Al-Najjar, Mohamad Rasheed, Zaid Ababneh, Anas Ababneh, Hosam Al-Omarey
Natural Science (NS) , 2011, DOI: 10.4236/ns.2011.39102
Abstract: The distribution of metals (Cd, Cr, Pb, Cu, Ni and Zn) was determined in sediment cores collected from five major areas representing different anthropogenic activities along the Jordanian coast during 27 February-11 March 2008. Metal concentrations in these sediments were relatively low compared to reported values from polluted areas. At some of the sites metal concentrations showed fluctuations with depth in the core suggesting changes in metal loading with time. The calculated contamination factors (CFs) for the suite of metals decreased in the following order Cd > Pb > Cr > Ni >Zn > Cu. The Pollution Loading Index (PLI) calculated for the different areas were highest at Phosphate Loading Berth (0.008, 0.2607, 0.0161, 0.007, 47.9375 and 0.0296 for Cu, Pb, Ni, Zn, Cd and Cr, respectively) and lowest at Hotel Area (0.0001, 0.0075, 0.0008, 0.0006, 1.0483 and 0.0005 for Cu, Pb, Ni, Zn, Cd and Cr, respectively) with others sites between these extremes. Result of this study could be used to assess the magnitude of pollution at each site and guide rational management decisions. Moreover, the data constitutes a baseline against which future anthropogenic effects can be assessed.
Determination of Seven Volatile N-Nitrosamines in Fast Food  [PDF]
Mohammad Al-Kaseem, Zaid Al-Assaf, Fran?ois Karabeet
Pharmacology & Pharmacy (PP) , 2014, DOI: 10.4236/pp.2014.52026

In this study, various fast food samples, including raw meat, cured meat, grilled meat, fried meat, smoked meat and canned meat products, were analyzed for the determination of the seven volatile N-nitrosamines. The samples were treated with an aqueous sodium hydroxide (NaOH) by autoclaving at 121°C for 10 min and extracted by liquid-liquid extraction with dichloromethane, and then the nitrosamines were pre-concentrated by using activated silica. Then, gas chromatography coupled with flame ionization detector was used for the separation and determination of the different nitrosamines contained in a real sample. The applied method allowed the determination of nitrosamine compounds at trace levels with limit of detection ranging from 0.077 to 0.18 ppb, and quantitation limits were from 0.26 to 0.60 ppb for all nitrosamines. The total concentrations of the seven nitrosamines in the studied meat samples ranged from 2.60 to 13.28 μg/kg.

A Rapid, Validated RP-HPLC Method for the Determination of Seven Volatile N-Nitrosamines in Meat  [PDF]
Mohammad Al-Kaseem, Zaid Al-Assaf, Fran?ois Karabeet
Pharmacology & Pharmacy (PP) , 2014, DOI: 10.4236/pp.2014.53037

The present work reports a rapid reversed-phase high-performance liquid chromatography (RP-HPLC) method for the determination of seven volatile N-nitrosamines namely N-nitrosodimethylamine (NDMA), N-nitrosomethylethylamine (NMEA), N-nitrosodiethylamine (NDEA), N-nitrosodiproylamine (NDPA), N-nitrosodi butylamine (NDBA), N-nitrosopiperidine (NPIP) and N-nitrosopyrrolidine (NPYR) for monitoring food safety. A strategic experimental approach was implemented for the method development. The desired chromatographic separation was achieved on a Symmetry C18 (4.6 × 150 mm, 5 μm) column using gradient elution. The optimized mobile phase consisted of the 10 mM ammonium hydroxide pH = 8.9 and acetonitrile. The eluted compounds were monitored at 231 nm wavelength using spectrophotometric detector. The developed method separated seven compounds from each other within a run time of 10 min. The method is effective for the determination of presence of these carcinogenic compounds. The average extraction recovery of seven nitrosamines was found 84.5%; the precision of method was found less than 2.7% and accuracy was found between 95%-102.5%. The assay could be applied in food monitoring safety.

Comparative Study on Methods for Preparation of Gold Nanoparticles  [PDF]
Khalida S. Merza, Hadi D. Al-Attabi, Zaid M. Abbas, Hashim A. Yusr
Green and Sustainable Chemistry (GSC) , 2012, DOI: 10.4236/gsc.2012.21005
Abstract: The gold nanoparticles were prepared in many methods, differed in reducing and dispersion agents and stability. The first solution was prepared by using potassium bitartrate as reducing agent and Polyethylene glycol as a dispersion factor. We got a solution of colloid gold with wine-red color that has been measured the particle size; it was between 50 - 200 nanometers. The second gold colloidal solution was prepared by using sodium citrate as a reducing agent and without adding a dispersion agent, the color of the final solution is dark grey, but this solution did not remain stable, deposition happened quickly and crystals separated from the solution. The third one was prepared by using sodium citrate as a reducing agent and the solution was heated to a certain temperature, and the color of the solution became dark red after several minutes. Either the fourth method has been prepared gold colloid solution by using potassium bitartrate as a reductant for the gold ion. We have noted that no reaction under normal conditions, while the reaction by heating the solution to high temperature, and when added poly vinyl pyrrolidone will lead to a solution of colloild gold with dark purple-red color and stable under normal conditions for a long time. We measured the particles size in this experiment; it was less than 100 nanometers. We conclude from the above that all the reducing agent needs to appropriate conditions to complete the process of reduction of gold ion, and to get the nano gold particles, therefore; these particles in the colloid solution need to dispersion factor to the survival of the particles widespread so that the solutions with certain concentrations of poly vinyl pyrrolidone can be proven in the process of stability of the gold colloid solution.
Cultural Eating Practices among Jordanians  [PDF]
Hiba Bawadi, Zaid Al-Hamdan, Hala Bawadi, Omar Ershidat, Fwzieh Hammad, Lana Agraib
Food and Nutrition Sciences (FNS) , 2012, DOI: 10.4236/fns.2012.36106
Abstract: Culture has an enormous impact on individuals’ food choices and practices. This research aimed to screen cultural eating practices among Jordanians. Jordanian adults (N = 4750) completed a survey with regard to common eating practices in Jordan. Practices were classified into 4 themes, namely regular eating practices (7 practices), seasonal eating practices (4 practices), eating practices in social occasions (6 practices), and eating practices in religious occasions (10 practices). Interestingly, most nutritional practices during Ramadan and Eids (religious occasions) were agreed upon from 100% of the participating sample. In conclusion, culture in Jordan has a huge influences eating practices and food choice. Negative culture’s influence over eating practices may exist, thus increasing awareness about unhealthy eating practices related to culture is necessary.
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