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匹配条件: “Osama H. Sayed” ,找到相关结果约150530条。
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A Unified Theory (I) for Neighborhood Systems and Basic Concepts on Fuzzifying Topological Spaces  [PDF]
Osama Rashed Sayed
Applied Mathematics (AM) , 2012, DOI: 10.4236/am.2012.39146
Abstract: This paper considers fuzzifying topologies, a special case of I-fuzzy topologies (bifuzzy topologies), introduced by Ying. It investigates topological notions defined by means of -open sets when these are planted into the frame-work of Ying’s fuzzifying topological spaces (by Lukasiewicz logic in [0, 1]). In this paper we introduce some sorts of operations, called general fuzzifying operations from P(X) to , where (X, τ) is a fuzzifying topological space. By making use of them we contract neighborhood structures, derived sets, closure operations and interior operations.
Development and Validation of HPLC Method for Simultaneous Determination of Amlodipine, Valsartan, Hydrochlorothiazide in Dosage Form and Spiked Human Plasma  [PDF]
Samya M. El-Gizawy, Osama H. Abdelmageed, Mahmoud A. Omar, Sayed M. Deryea, Ahmed M. Abdel-Megied
American Journal of Analytical Chemistry (AJAC) , 2012, DOI: 10.4236/ajac.2012.36055
Abstract: A simple, sensitive, and specific method was developed for simultaneous determination of Amlodipine besylate (AML), Valsartan (Vals) and Hydrochlorothiazide (HCT) by high performance liquid chromatography without previous separation. Satisfactory resolution was achieved using a RP-C18 chromatographic column, Phenomenex Kinetex (150 mm × 4.6 mm i.d) and a mobile phase consisting of acetonitrile-phosphate buffer (0.05 M) with pH 2.8 in the proportion of (40/60, v/v) at a flow rate 0.8 mL/min and the wavelength detection was 227 nm. The retention time for HCT, AML and VAls was 2.26, 3.16 and 11.19 min; respectively. The described method was linear over a range of 4-28 μg /ml, 5-40 μg /ml and 1-12 μg /ml for AML, Vals and HCT; respectively. The mean percent recoveries were 99.94%, 99.96% and 99.78% for AML, Vals and HCT; respectively. F-test and t-test at 95%con?dence level were used to check the intermediate precision data obtained under different experimental setups. The method could be used for analysis of combined dose tablet formulation containing AML, Vals, HCT as well as spiked human plasma.
Crassulacean Acid Metabolism Permutation and Survival of Caralluma Species (Apocynaceae) in Arid Habitats
Yahya S. Masrahi,Turki A. Al-Turki,Osama H. Sayed
Ecologia Balkanica , 2012,
Abstract: Several species of the stem succulent Caralluma (Apocynaceae) are abundant perennials in arid regions of the Arabian Peninsula. These arid regions have a short wet season with erratic rainfall and are characterized by harsh climatic conditions of high temperature, high evaporation and sand storms. Work presented in this paper aimed at investigating importance of Crassulacean Acid Metabolism (CAM) for survival of three Caralluma species in their natural habitat. Investigations involved studying stomatal characteristics, stomatal diffusive conductance, chlorophyll fluorescence, and CAM in three species of Caralluma, namely C. acutangula (Decne.) N.E.Br., C. edulis (Edgew.) Benth. ex Hook.f., and C. subulata (Forssk.) Decne. Microscopic examination revealed a pattern of stomatal characteristics typical of CAM plants in these three Caralluma species. Results showed that these three Caralluma species were obligate CAM plants exhibiting this mode of photosynthesis during both the wet and the dry seasons. Under protracted water stress during the long dry season very low values of stomatal diffusive conductance and dampening of CAM acidification-deacidification cycles denoted the tendency of these three Caralluma species to shift from the obligate CAM physiotype to CAM-idling mode. Chlorophyll fluorescence measurements indicated that protracted water stress induced a reduction in Photosystem II (PSII) antenna efficiency and quantum yield in the three studied Caralluma species. This reduction of PSII activity occurred in concomitance with a marked rise in non-photochemical quenching of chlorophyll fluorescence denoting operation of non-photochemical energy dissipating mechanisms known to be important for photoprotection of the photosynthetic apparatus.
Bioremediation of Zinc by Streptomyces aureofacienes
Osama H. EL Sayed,Hala M. Refaat,Mahmoud A. Swellam,Mahmoud M. Amer
Journal of Applied Sciences , 2011,
Abstract: Heavy metals are generally toxic to microorganisms, especially if they exist at high concentrations. Environmental pollution particularly in soil with heavy metals can stem from industrial activities or sewage discharges. In this study, twelve Streptomyces species isolated from Egyptian soil and identified by using physiological tests as Bergey’s manual was assessed quantitatively to the effects of zinc using plate diffusion method. Biosorption of zinc by biomass microorganisms is an innovative and alternative technology for removal of these pollutants due to their good performance, low cost and large available quantities. Experiments in liquid culture were used to determine concentration ranges of the metals at which the most tolerant species could grow showed that Streptomyces aureofacienes had maximum uptake of zinc (734.8 μg g-1 biomass).
Spectrophotometric Method for Determination of Five 1,4-Dihydropyridine Drugs Using N-Bromosuccinimide and Indigo Carmine Dye
Mohamed A. El Hamd,Sayed M. Derayea,Osama H. Abdelmageed,Hassan F. Askal
International Journal of Spectroscopy , 2013, DOI: 10.1155/2013/243059
Abstract: Indirect spectrophotometric method is described for quantification of five of 1,4-dihydropyridine (1,4-DHP) drugs using N-bromosuccinimide (NBS) with the aid of indigo carmine (INC) dye. The method is based on addition of known excess of NBS to an acidified solution of 1,4-DHP drugs and determining the residual of NBS through its ability to bleach the colour of the used dye; the amount of NBS that reacted corresponded to the amount of drugs. Beer’s law is obeyed in the concentration range 1.25–13.00?μg/mL. Good correlation coefficients (0.998-0.999) were found between the absorbance values and the corresponding concentrations. Limits of detections ranged from 0.141 to 0.500?μg/mL. The proposed method was successfully applied to the analysis of dosage forms; percent of recoveries ranged from 97.31 to 99.46% without interference from any common excipients. The statistical comparison by Student’s t-test and variance ratio F-test showed no significant difference between the proposed and official or reported methods. 1. Introduction 1,4-DHP derivatives are vasodilators with a great selectivity for vascular smooth muscles; they are primarily used for treatment of some of cardiovascular diseases such as hypertension, angina, and cardiac arrhythmias. Recently, they were used for the treatment of other pathological states, such as seizures and cerebral ischemic disorders [1, 2]. Many analytical methods were developed for determination of 1,4-DHP drugs, namely, nifedipine (NIF), nicardipine (NIC), nimodipine (NIM), felodipine (FEL), and amlodipine (AML) (Figure 1), in their pharmaceutical formulations and in biological fluids, such as titrimetric methods [3, 4], spectrometric methods (spectrophotometry [5–13] or spectrofluorimetry [12, 14–20]), electrochemical methods [21–23], liquid chromatographic methods [24–28], and gas chromatographic methods [29–32]. Figure 1: Chemical structure of the investigated 1,4-DHP drugs. Classical spectrophotometric measurements and their applications are considered as a routine analytical method in most quality control laboratories. Subsequently, the aim of this study to develop a simple, sensitive, and cost-effective method for determination of these drugs in pure and dosage forms using spectrophotometric technique. The method utilized NBS-INC reagents (Figure 2) and their developed offer the advantage of simplicity, sensitivity, speed, accuracy, and precision without the need for costly equipment/chemicals. Figure 2: Chemical structure of the chemical reagents. 2. Experimental 2.1. Instrumentation Absorbance measurements were
Efficient Detection of Landmines from Acoustic Images
H. Kasban;Osama Zahran;M. El-Kordy;Sayed M. S. Elaraby;El-Sayed M. El-Rabaie;Fathi El-Sayed Abd El-Samie
PIER C , 2009, DOI: 10.2528/PIERC08112002
Abstract: The Laser Doppler Vibrometer (LDV)-based Acoustic to Seismic (A/S) landmine detection system is one of the reliable and powerful landmine detection techniques. The interpretation of LDV-based A/S data is performed off-line, manually, depending heavily on the skills, experience, alertness and consistency of a trained operator. This takes a long time. The manually obtained results suffer from errors, particularly when dealing with large volumes of data. This paper proposes some techniques for the automatic detection of objects from the acoustic images which are obtained from the LDV-based A/S landmine detection system. These techniques are based on color image transformations, morphological image processing and the wavelet transform. The results obtained are optimized to select the best image type and the best morphological operation used in terms of the higher probability of detection, the lower false alarm rate, the accuracy and the processing speed.
Developing Business Management Students' Persuasive Writing Through Blog-based Peer-Feedback
Osama Hassanein Sayed
English Language Teaching , 2010, DOI: 10.5539/elt.v3n3p54
Abstract: The present study attempted to investigate the effect of using blog-based peer feedback on the persuasive writing of EFL business management students at the community college in Bisha, King Khalid University, Saudi Arabia. The study used a pre-test/post-test experimental and control group design. An experimental group and a control group were exposed to pre-post means of getting data (a pre-post test of persuasive writing). Results of the analysis of the differences between means of scores of the study subjects in the pre-post-measurements revealed a significant improvement in the experimental group students' persuasive writing.
Pharmacist Role in Pharmaceutical Care during Ramadan  [PDF]
Osama H. Mohamed Ibrahim
Pharmacology & Pharmacy (PP) , 2015, DOI: 10.4236/pp.2015.612061
Abstract: Introduction: Ramadan is the ninth month in the Islamic Hijri calendar where Muslims are ex-pected to fast every day from dawn to sunset. The eating behavior changes during Ramadan and the abstinence of food affects the oral drugs administration and other convenience dosage forms. There is a need to highlight and illustrate the role of the pharmacists in medication adjustment challenges that the patients conquer in the Holy month of Ramadan. Objectives: To estimate the awareness of pharmacists’ role in providing pharmaceutical care during Ramadan; moreover, to explore pharmacists’ perspective on the importance of medication regimen adjustment along with the proper counseling required to optimize patients’ health throughout fasting. Method: This is an observational study that was done through dissemination of a cross-sectional survey among 130 pharmacists covering Abu Dhabi, Dubai, Sharjah, Ajman, and Northern Emirates regions. The targeted population consisted of practicing community pharmacists and hospital pharmacists across UAE. Results: Among pharmacists participated in the study 115 pharmacists (88.5%) were Muslims and 79 pharmacists (60.8%) were Arabs. 126 pharmacists (97%) reported performing one or more kinds of medication regimen adjustment around Ramadan for at least one patient. Changing the frequency had the highest percentage by the pharmacist compared to other methods of regimen adjustment (39%). Moreover, the results revealed that 46.9% of the pharmacists chose not to change the medication itself. Nineteen percent of Muslim pharmacists initiated the conversation about medication regimen adjustment (P = 0.0448) compared to non-Muslims, while14% of pharmacists were Arabs who showed no statistically significant difference. Conclusion: In conclusion, pharmacists are more qualified to adjust and manage medication regimens than what they are presently performing. Utilization of such skill is required to adjust patients’ medication regimen during fasting the Holy month of Ramadan and to ensure safe transition for fasting patients into and out of Ramadan.
A Novel Spectrophotometric Method for Determination of Five 1,4-Dihydropyridine Drugs in Their Tablets and Capsules Using Vanillin Reagent  [PDF]
Mohamed A. El Hamd, Sayed M. Derayea, Osama Hassan Abdelmageed, Hassan F. Askal
American Journal of Analytical Chemistry (AJAC) , 2013, DOI: 10.4236/ajac.2013.43020
Abstract:
A selective and new spectrophotometric method is described for determination of five 1,4 dihydropyridine drugs (1,4- DHP); namely nifedipine (NIF), nicardipine (NIC), nimodipine (NIM), felodipine (FEL) and amlodipine (AML). The method is based on a coupling reaction between the cited drugs and vanillin reagent in acidic condition. Under optimized conditions, the red coloured products were measured at 500 nm for NIF, NIC, NIM and FEL or at 479 nm for AML. Molar absorptivities were ranged from 0.575 × 104 1.065 × 104 l·mol-1·cm-1, Beers law was obeyed at 5 - 70 μg/mL concentration range and the limit of detection was ranged from 0.150 - 1.500 μg/mL. The proposed method was successfully extended to pharmaceutical preparations tablets and capsules and comparison by Student’s t-test and variance ratio F-test showed no significant difference.
Studies on the Immunomodulatory Effects of Lactoferrin in Rats Infected with E. coli  [PDF]
Mohamed El-Sayed El-Boshy, Osama Ali Abdalla, Adal Hassan
Journal of Immune Based Therapies, Vaccines and Antimicrobials (JIBTVA) , 2013, DOI: 10.4236/jibtva.2013.24005
Abstract:

Eighty male albino rats of Westar strain (350 ± 10 g), 10 to 12 weeks old were divided into four groups. The groups treated are as following. The first control group (Gp. I) was given intraperitoneally in normal saline (1 mL). The second group (Gp. II) was orally infected with 3 × 1012 CFU of E. coli /Kg. BW. The third group (Gp. III) was infected with

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