Showing papers by "Cairo University published in 2004"
TL;DR: In this paper, the basic conceptual framework of a new space-time theory with application to high energy particle physics is outlined, both achievements and limitations are discussed with direct reference to the mass spectrum problem.
Abstract: The essay outlines the basic conceptual framework of a new space–time theory with application to high energy particle physics. Both achievements and limitations are discussed with direct reference to the mass spectrum problem.
650 citations
TL;DR: In this article, the use of Ni as a catalyst for the electro-oxidation of methanol in alkaline medium was studied by cyclic voltammetry and it was found that only Ni dispersed on graphite shows a catalytic activity towards methanoline oxidation but massive Ni does not.
472 citations
TL;DR: DNA damage may be induced by oxidative assault in ejaculated spermatozoa and apoptosis may not contribute significantly to the DNA damage.
Abstract: BACKGROUND: The aim of this study was to examine the role of apoptosis and reactive oxygen species (ROS) in inducing DNA damage in ejaculated spermatozoa. METHODS: We examined ejaculated spermatozoa from 31 patients examined for infertility and 19 healthy donors for apoptosis, production of ROS and DNA damage using annexin V binding, chemiluminescence assay and sperm chromatin structure assay. RESULTS: The percentage of spermatozoa that underwent apoptosis in the whole ejaculate and mature fraction was higher in the patients than in the donors (P < 0.001 and P = 0.009, respectively). Levels of ROS in the whole ejaculate and immature fraction were higher in the patients than in the donors (P = 0.002 and P = 0.009). Apoptosis was significantly correlated with ROS within patients in the whole ejaculate [r (95% confidence interval) = 0.53 (0.19‐0.86)] and in the mature [0.71 (0.39‐ 1.00)] and immature spermatozoa [0.75 (0.45‐1.00)]. Only apoptosis and the DNA fragmentation index (DFI) were significantly correlated within patients in the whole ejaculate [0.57 (0.18‐0.97)]. CONCLUSIONS: DNA damage may be induced by oxidative assault. Apoptosis may not contribute significantly to the DNA damage.
416 citations
TL;DR: Two ANN-based models for prediction of BOD and SS concentrations in plant effluent are presented and are found to provide an efficient and a robust tool in predicting WWTP performance.
Abstract: Artificial neural networks (ANN) models were developed to predict the performance of a wastewater treatment plant (WWTP) based on past information. The data used in this work were obtained from a major conventional treatment plant in the Greater Cairo district, Egypt, with an average flow rate of 1 million m3/day. Daily records of biochemical oxygen demand (BOD) and suspended solids (SS) concentrations through various stages of the treatment process over 10 months were obtained from the plant laboratory. Exploratory data analysis was used to detect relationships in the data and evaluate data dependence. Two ANN-based models for prediction of BOD and SS concentrations in plant effluent are presented. The appropriate architecture of the neural network models was determined through several steps of training and testing of the models. The ANN-based models were found to provide an efficient and a robust tool in predicting WWTP performance.
409 citations
TL;DR: HoLEP and TURP are highly effective procedures for removing obstructing prostatic adenomas in a randomized, prospective clinical trial and resulted in significantly better micturition parameters and less perioperative morbidity.
332 citations
TL;DR: The analysis shows that DNA 1 components are associated with the majority of begomovirus-DNA beta complexes, being absent from only two of the complexes examined, both of which have their origins in Far East Asia.
231 citations
TL;DR: Betaine aldehyde dehydrogenase gene expression (BADH mRNA) in Salicornia europaea and Suaeda maritima leaves increased with salt stress and the expression pattern coincided with the observed betaine accumulation, which was associated with a greater capacity for osmotic adjustment.
210 citations
TL;DR: In this article, space filling curves have been used to realize a family of miniaturized hybrid couplers, and the performance of the proposed space-filling hybrids is as good as that of the corresponding conventional structures, and even better in some cases.
Abstract: In this paper, space-filling curves have been used to realize a family of miniaturized hybrids. The large surface area occupied by a conventional structure has been significantly reduced through the use of space-filling curves having the same electrical characteristics. Several space-filling curves have been studied and implemented in different designs. The second-iteration Moore rat-race coupler occupies only 12.6% of the conventional coupler's area, while the area of the second-iteration Sierpinski branch-line coupler is 24.7% of the conventional case. On the other hand, a nine-section Minkowski coupled-line balun is confined in 60% of the conventional balun's area. However, the effective size reduction depends on the used space-filling curve, compression ratio, and associated coupling between segments. The performance of the proposed space-filling hybrids is as good as that of the corresponding conventional structures, and even better in some cases. The design and simulation of the proposed space-filling hybrids have been performed using a moment-method-based full-wave electromagnetic simulator. Measurements of one fabricated coupler prototype are in good agreement with simulation results.
210 citations
TL;DR: A ganglionic blocking effect appeared to be a possible mechanism of action of Mentha microphylla and Conyza dioscoridis since a stimulant dose of nicotine could not restore the contractile response of the tissue.
186 citations
TL;DR: It was suggested that the CHL emulgel formulation prepared with HPMC with the oil phase concentration in its low level and emulsifying agent concentration inIts high level was the formula of choice since it showed the highest drug release and antifungal activity.
Abstract: This study was conducted to develop an emulgel formulation of chlorphenesin (CHL) using 2 types of gelling agents: hydroxypropylmethyl cellulose (HPMC) and Carbopol 934. The influence of the type of the gelling agent and the concentration of both the oil phase and emulsifying agent on the drug release from the prepared emulgels was investigated using a 23 factorial design. The prepared emulgels were evaluated for their physical appearance, rheological behavior, drug release, antifungal activity, and stability. Commercially available CHL topical powder was used for comparison. All the prepared emulgels showed acceptable physical properties concerning color, homogeneity, consistency, spreadability, and pH value. They also exhibited higher drug release and antifungal activity than the CHL powder. It was found that the emulsifying agent concentration had the most pronounced effect on the drug release from the emulgels followed by the oil phase concentration and finally the type of the gelling agent. The drug release from all the emulgels was found to follow diffusion-controlled mechanism. Rheological studies revealed that the CHL emulgels exhibited a shear-thinning behavior with thixotropy. Stability studies showed that the physical appearance, rheological properties, drug release, and antifungal activity in all the prepared emulgels remained unchanged upon storage for 3 months. As a general conclusion, it was suggested that the CHL emulgel formulation prepared with HPMC with the oil phase concentration in its low level and emulsifying agent concentration in its high level was the formula of choice since it showed the highest drug release and antifungal activity.
183 citations
TL;DR: The essential oil of M. armillaris exhibited a marked antioxidant effect, it improved vitamin E, vitamin C and superoxide dismutase parameters so it can be used as a free radical suppressor in carbon tetrachloride treated animals.
Abstract: The essential oils of the fresh leaves of M. ericifolia, M. leucadendron, M. armillaris and M. styphelioides were isolated by a hydrodistillation method and analysed by a gas chromatography/mass spectrometry (GC/MS) technique. The essential oil of M. ericifolia contained methyl eugenol (96.84%) as a major constituent, whereas M. leucadendron was rich in 1,8-cineole (64.30%). The essential oil of M. armillaris was rich in 1,8-cineole (33.93%) followed by terpinen-4-ol (18.79%), whereas M. styphelioides was rich in caryophyllene oxide (43.78%) and (-) spathulenol (9.65%). The essential oils of these species possessed antimicrobial and antifungal activities. M. ericifolia exhibited the highest inhibitory effects against Bacillus subtiles and Aspergillus niger. The antiviral activities of the essential oils against Herpes simplex virus type 1 (HSV-1) were studied in African green monkey kidney cells (Vero) by a plaque reduction assay. The volatile oil of M. armillaris was more effective as a virucidal (up to 99%) than that of M. leucadendron (92%) and M. ericifolia (91.5%). The effects of the essential oils on the antioxidant system status in carbon tetrachloride treated animals were studied. The essential oil of M. armillaris exhibited a marked antioxidant effect, it improved vitamin E, vitamin C and superoxide dismutase parameters so it can be used as a free radical suppressor.
TL;DR: Aims: To study the interactions between Candida albicans and 12 other species of Candida and bacteria in biofilms.
Abstract: Aims: To study the interactions between Candida albicans and 12 other species of Candida and bacteria in biofilms.
Methods and Results: The number of cells within growing biofilms in a polystyrene tube model was measured after adding C. albicans to preformed biofilms of other micro-organisms and vice versa. It was also measured after simultaneous biofilm formation of C. albicans and other micro-organisms. The number of cells of C. albicans within the growing biofilms decreased significantly (P < 0·05) when the fungus was added to preformed biofilms of Candida spp. and bacteria except, with C. parapsilosis, Torulopsis glabrata and the glycocalyx producer Pseudomonas aeruginosa. When C. parapsilosis, Staphylococcus epidermidis (nonglycocalyx producer) or Serratia marcescens was added to preformed biofilms of C. albicans, the number of cells of these micro-organisms increased in the growing biofilms.
Conclusions: Biofilms of C. albicans are capable of holding other micro-organisms and more likely to be heterogeneous with other bacteria and fungi in the environment and on medical devices.
Significance and Impact of the Study: Recognition of the heterogeneity of biofilm-associated organisms can influence treatment decisions, particularly in patients who do not respond to initial appropriate therapy.
TL;DR: A clinical trial with increased numbers of subjects is indicated to evaluate the potential of topical therapy to reduce infections and save newborn lives in developing countries.
Abstract: Because the therapeutic options for managing infections in neonates in developing countries are often limited innovative approaches to preventing infections are needed. Topical therapy with skin barrier-enhancing products may be an effective strategy for improving neonatal outcomes particularly among preterm low birth weight infants whose skin barrier is temporarily but critically compromised as a result of immaturity. We tested the impact of topical application of sunflower seed oil 3 times daily to preterm infants <34 weeks gestational age at the Kasr El-Aini neonatal intensive care unit at Cairo University on skin condition rates of nosocomial infections and mortality. Treatment with sunflower seed oil (n = 51) resulted in a significant improvement in skin condition (P = 0.037) and a highly significant reduction in the incidence of nosocomial infections (adjusted incidence ratio 0.46; 95% confidence interval 0.26–0.81; P = 0.007) compared with infants not receiving topical prophylaxis (n = 52). There were no reported adverse events as a result of topical therapy. Given the low cost (~$.20 for a course of therapy) and technologic simplicity of the intervention and the effect size observed in this study a clinical trial with increased numbers of subjects is indicated to evaluate the potential of topical therapy to reduce infections and save newborn lives in developing countries. (authors)
TL;DR: The main concepts of E Infinity theory and some of the principle results have been explained in this article, and the problem of the mass spectrum of the standard model from various viewpoints, in particular, from that of gravitational instanton.
Abstract: The paper is an elementary introduction to the concepts of E Infinity of quantum physics. In the first two paragraphs the main concepts of E Infinity theory and some of the principle results have been explained. Subsequently we address the problem of the mass spectrum of the standard model from various viewpoints, in particular, from that of gravitational instanton. Particular attention is paid throughout the paper to giving an intuitive grasp for an extended theory of vacuum fluctuation based on Dirac's hole theory and E Infinity theory. It is further shown how the golden mean and logarithmic scalings can be used to understand quantum gravity and how the new transfinite Dirac's theory can explain certain anomalous positron production which was observed by several experimental groups worldwide.
TL;DR: Although these results are preliminary, interactive MR imaging-guided RF ITA for treatment of primary renal tumors has a high success rate and no intra- or postprocedural complications were observed.
Abstract: PURPOSE: To perform a phase II clinical trial to evaluate efficacy and safety of interactive magnetic resonance (MR) imaging–guided radiofrequency (RF) interstitial thermal ablation (ITA) of primary renal tumors. MATERIALS AND METHODS: Ten male patients (age range, 25–83 years) with peripheral renal cell carcinoma and contraindications to surgery were treated with percutaneous RF ITA entirely guided and monitored with a 0.2-T MR imaging unit. By using a 200-W RF ablation system and custom-fabricated MR imaging–compatible cool-tip electrodes, pulsed RF current was applied for single or multiple ablation cycle(s) of 12–15 minutes until the entire tumor was replaced by an enlarging zone of low signal intensity on T2-weighted and/or short inversion time inversion-recovery images acquired intermittently during the procedure. Kidney MR images were acquired before, immediately after, and 2 weeks after ablation and then every 3 months for 1 year and every 6 months thereafter. Intra- and postprocedural complicatio...
TL;DR: The suggested method, which is called multistage Adomian's decomposition method (MADM), can be considered as an extension of the ADM which is very efficient in solving a variety of differential and algebraic equations.
TL;DR: A new hybrid Genetic-algorithm/heuristic coding scheme is developed for the problem of simultaneous scheduling of machines and identical automated guided vehicles in flexible manufacturing systems with the objective of minimizing the makespan.
Abstract: In this paper, the problem of simultaneous scheduling of machines and identical automated guided vehicles (AGVs) in flexible manufacturing systems is addressed with the objective of minimizing the makespan. This problem is composed of two interrelated decision problems: the scheduling of machines, and the scheduling of AGVs. Both problems are known to be NP-complete, resulting in a more complicated NP-complete problem when they are considered simultaneously. A new hybrid Genetic-algorithm/heuristic coding scheme is developed for the studied problem. The developed coding scheme is combined with a set of genetic algorithm (GA) operators selected from the literature of the applications of GAs to the scheduling problems. The algorithm is applied to a set of 82 test problems, which was constructed by other researchers, and the comparison of the results indicates the superior performance of the developed coding.
TL;DR: Multivariate analysis shows that cyclin D1 and A are two independent prognostic factors in colorectal cancer patients that may help in predicting the clinical outcome of patients on an individual basis and could be considered important therapeutic targets.
Abstract: Background
Colorectal cancer is a common cancer all over the world. Aberrations in the cell cycle checkpoints have been shown to be of prognostic significance in colorectal cancer.
TL;DR: In this article, the results of a leaching kinetics study of spent nickel oxide catalyst with sulfuric acid were presented and the effects of spent catalyst particle size and reaction temperature on Ni extraction rate were determined.
TL;DR: In this article, a detailed study has been performed on the effect of the matrix on the limit of detection (LOD) and the plasma parameters of the laser induced breakdown spectroscopy (LIBS) technique.
Abstract: In the present work a detailed study has been performed on the effect of the matrix on the limit of detection (LOD) and the plasma parameters of the laser induced breakdown spectroscopy (LIBS) technique The LOD of magnesium, silicon, manganese and copper as minor elements was evaluated in aluminium standard sample alloys compared to the values of the LOD of the same elements in standard steel alloys The effect of changing the matrix on the laser induced plasma plume parameters, namely the plasma temperature Te and the electron density Ne, has been also studied Calibrations were achieved for the four elements with linear regression coefficients between 98–99% on average According to the obtained results Mn and Cu have the lowest LOD in the steel alloy matrix, while Mg has much lower LOD in the aluminium alloy matrix These results may be interpreted in view of the compatibility of the physical properties of the elements existing in the same matrix Approximately similar electronic structure and values of melting point, density, atomic weight, etc, may facilitate better conditions for energy transfer within the matrix From the application view point, it is possible for LIBS in the on-line industrial process control to follow up only a single element (that with the lowest LOD in such matrix) as a marker for the correct alloying in metals and mixing in pharmaceuticals
TL;DR: One-stage TEPT technique is both feasible and safe technique in properly selected children with rectosigmoid HD in all ages and is associated with excellent clinical results.
TL;DR: In this paper, the authors present a framework for optimizing earthmoving operations using computer simulation and genetic algorithms, which aims at minimizing time and cost of earthmoving operation, including equipment availability and project indirect cost.
Abstract: This paper presents a framework for optimizing earthmoving operations using computer simulation and genetic algorithms. It provides a multiobjective optimization tool geared towards selection of near-optimum fleet configurations. The optimization aims at minimizing time and cost of earthmoving operations. The proposed framework considers factors that influence earthmoving operations including equipment availability and project indirect cost. The simulation process, in the proposed methodology, utilizes discrete event simulation and object oriented modeling. The optimization process uses a recently developed genetic algorithm to search for a near-optimum fleet configuration employing Pareto optimality to account for multiobjective optimization. The algorithm considers a set of qualitative and quantitative variables that influence the production of earthmoving operations. The developed framework supports time.cost tradeoff analysis and can assist users in considering what if scenarios with respect to fleet configurations. A numerical example is presented to illustrate a number of practical features of the proposed framework and to demonstrate its capabilities in selecting near-optimum fleet configurations.
TL;DR: In this paper, the physicochemical properties of new metal complexes with salicylidine-2-aminobenzimidazole (SABI) were investigated using elemental and thermal analyses, IR, conductometric, solid reflectance and magnetic susceptibility measurements.
Abstract: New metal complexes of Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) with salicylidine-2-aminobenzimidazole (SABI) are synthesized and their physicochemical properties are investigated using elemental and thermal analyses, IR, conductometric, solid reflectance and magnetic susceptibility measurements. The base reacts with these metal ions to give 1:1 (Metal:SABI) complexes; in cases of Fe(III), Co(II), Cu(II), Zn(II) and Cd(II) ions; and 1:2 (Metal:SABI) complexes; in case of Ni(II) ion. The conductance data reveal that Fe(III) complex is 2:1 electrolyte, Co(II) is 1:2 electrolyte, Cu(II), Zn(II) and Cd(II) complexes are 1:1 electrolytes while Ni(II) is non-electrolyte. IR spectra showed that the ligand is coordinated to the metal ions in a terdentate mannar with O, N, N donor sites of the phenloic -OH, azomethine -N and benzimidazole -N3. Magnetic and solid reflectance spectra are used to infer the coordinating capacity of the ligand and the geometrical structure of these complexes. The thermal decomposition of the complexes is studied and indicates that not only the coordinated and/or crystallization water is lost but also that the decomposition of the ligand from the complexes is necessary to interpret the successive mass loss. Different thermodynamic activation parameters are also reported, using Coats-Redfern method.
TL;DR: Concomitant administration of alpha-tocopherol and simvastatin to hypercholesterolemic male rats improved their reproductive efficiency and produced additional protection against reduced fertility induced by hypercholesterololemia.
TL;DR: In this article, the devitrification behavior of different sizes of slag-derived glass was investigated using differential thermal analysis, X-ray diffraction and scanning electron microscopy to determine the possibility of preparing glass-ceramic materials.
Abstract: The devitrification behavior of different sizes of slag-derived glass was investigated using differential thermal analysis, X-ray diffraction and scanning electron microscopy to determine the possibility of preparing glass-ceramic materials. The crystalline phases were identified as gehlenite, diopside pyroxene and barium aluminium silicate. The degree of crystallization was determined by evaluation the changes of density at different temperatures where a maximum density was achieved at 900 °C. A remarkable difference in the glass-ceramic texture was observed by treating the sample at different crystallization temperatures. Both acicular and dendritic morphology have been identified in the sample heat-treated at 1050 °C. A slight variation in peak crystallization temperature with particle size indicated a bulk crystallization mechanism.
TL;DR: In this article, the passivity and its breakdown reactions have been studied on Mo-containing stainless steel specimens using different electrochemical techniques and the results of potentiodynamic polarization showed that icorr and ic increases with increasing either Cl− or SO42− concentration indicating the decrease in passivity of the formed film.
TL;DR: Guar gum-enriched enteral nutrition was related to a decrease of diarrheal episodes in ICU patients with preexisting diarrhea; and to a trend for lower plasma glucose and cholesterol levels.
TL;DR: The Arabic version of the abridged International Index of Erectile Function administered to 136 Egyptian men proved to be reliable and valid and showed a high degree of specificity and sensitivity among the Egyptian population.
Abstract: The objective of this study is to assess the validity of Arabic version of the abridged International Index of Erectile Function among a sample from the Egyptian populace. Two groups were included in this study. Group A included 68 patients complaining of erectile dysfunction (ED) >1 y, who failed oral treatment and accepted intracavernous self-injection. All patients of group A were previously clinically diagnosed as having ED. Group B included 68 men not complaining of ED and not suffering from any major chronic or acute illness. The mean (s.d.) age of all 136 patients was 52+/-5.7 y. Candidates of both groups were requested to complete the Sexual Health Inventory for Men (SHIM) questionnaire. Cronbach's alpha coefficient was used to assess the internal consistency of the SHIM. The items of maintenance ability, erection confidence, maintenance frequency, erection firmness and intercourse satisfaction showed an overall ICC of 0.92. Internal consistency for the whole scale was 0.91. In conclusion, the Arabic version of the SHIM administered to 136 Egyptian men proved to be reliable and valid. It also showed a high degree of specificity and sensitivity among the Egyptian population.
TL;DR: BVDV vaccines and their future development continue to be an enigma in the control of BVDV.
Abstract: Bovine viral diarrhea virus (BVDV) is one of the major immuno-suppressive viruses of cattle. The effect on the innate and acquired immune system is unique and results in dramatic immune dysfunction. BVDV infection also has the ability to cause persistent infection (PI) in the developing fetus. This Pl syndrome creates a requirement for high levels of BVDV immunity from vaccines to prevent these infections. BVDV vaccines and their future development continue to be an enigma in the control of BVDV.
TL;DR: The addition of fibers to provisional resin increased both fracture toughness and flexural strength and the mean Flexural strength values were significantly increased by different combinations of fiber and resin.
Abstract: Statement of problem Fracture of provisional restorations is of concern, especially with long-span fixed partial dentures or areas of heavy occlusal stress. A number of different techniques for reinforcement of provisional restorations have been suggested; however, the effect of these techniques is largely unclear. Purpose The aim of this study was to determine the fracture toughness and flexural strength of different types of provisional restoration resins reinforced with different commercially available fibers. Material and methods A total of 105 specimens were prepared in this study for each test; compact tensile specimens for the fracture toughness test and rectangular specimens for the flexural strength test. The specimens were divided into 3 groups according to the type of resin used, Jet, Trim, or Temphase (n=35), and then each group was divided into 7 subgroups (n=5) according to the type of fiber reinforcement, Construct, Fibrestick, Ribbond normal, Ribbond THM, Ribbond triaxial, or Fibrenet. Unreinforced specimens served as the control. Specimens were loaded in a universal testing machine until fracture. The mean fracture toughness (MPa·m 1/2 ) and mean flexural strength (MPa) were compared by 1-way analysis of variance, followed by the Tukey standardized range test (α=.05). Results Fibrestick and Construct reinforcements showed a significant increase ( P 1/2 to 2.74±0.12 MPa·m 1/2 ; polyethyl methacrylate from 0.67±0.07 MPa·m 1/2 to 1.64±0.13 MPa·m 1/2 ; and bis-acryl from 0.87±0.05 MPa·m 1/2 to 1.39±0.11 MPa·m 1/2 . Construct increased polymethyl methacrylate to 2.59±0.28 MPa·m 1/2 ; polyethyl methacrylate to 1.53±0.22 MPa·m 1/2 ; and bis-acryl to 1.30±0.13 MPa·m 1/2 ; however, there was no significant difference between Fibrestick and Construct reinforcements in the degree of reinforcement. Similarly the mean flexural strength values were significantly increased by different combinations of fiber and resin ( P Conclusion The addition of fibers to provisional resin increased both fracture toughness and flexural strength.