Showing papers by "Cairo University published in 2000"
Journal Article•
TL;DR: Different crude extracts of Nigella sativa were tested for antimicrobial effectiveness against different bacterial isolates and the most effective extracts were the crude alkaloid and water extracts.
Abstract: Different crude extracts of Nigella sativa were tested for antimicrobial effectiveness against different bacterial isolates. These isolates comprised 16 gramnegative and 6 grampositive representatives. They showed multiple resistance against antibiotics, specially the gramnegative ones. Crude extracts of Nigella saliva showed a promising effect against some of the test organisms. The most effective extracts were the crude alkaloid and water extracts. Gramnegative isolates were affected more than the grampositive ones.
233 citations
TL;DR: In this paper, the results of a leaching kinetics study of low-grade zinc silicate ore with sulfuric acid were presented and the effect of particle size, reaction temperature, and acid concentration on zinc dissolution rate were determined.
196 citations
TL;DR: In this paper, a fully differential second-generation current conveyor (FDCCII) is proposed for mixed-mode applications where fully differential signal processing is required, which can operate from low supply voltages down to /spl plusmn/1.5 V.
Abstract: In this paper, a novel fully differential second-generation current conveyor (FDCCII) is presented. The proposed block is useful in mixed-mode applications where fully differential signal processing is required. Furthermore, the FDCCII can be used to realize MOSFET-C filters. The circuit has a bandwidth of about 10 MHz under heavy capacitive loads and can operate from low supply voltages down to /spl plusmn/1.5 V.
195 citations
TL;DR: This first demonstration that polymorphisms in DNA repair genes may contribute to colorectal cancer susceptibility and may increase the risk of early onset of the disease opens the door for future studies in that direction.
192 citations
TL;DR: The findings suggest that microdissection TESE is not devoid of complications, but that it is relatively safer than the conventional technique and improves sperm yield significantly in patients with non-obstructive azoospermia.
Abstract: The value of testicular sperm extraction (TESE) by microdissection was evaluated according to its physiological consequences compared with open, classic surgical biopsy in the same patient. A total of 100 patients with non-obstructive azoospermia and bilateral identical testicular histology underwent bilateral diagnostic TESE via the conventional method on one side and the microsurgical method on the other side. The spermatozoa recovery rate by microdissection TESE was significantly higher than by conventional TESE (47 and 30% respectively; P < 0.05). In order to assess the safety of this new procedure, 60 patients were followed-up ultrasonographically for 1, 3 and 6 months. Acute and chronic complications were significantly lower in the microsurgical side compared with the conventional side (15 and 58.3% respectively and 3 and 30% respectively; P < 0.05). Segmental devascularization was detected in seven testes operated on conventionally, and in two testes operated on microsurgically. However, permanent devascularization could not be detected in any patient after 6 months. These findings suggest that microdissection TESE is not devoid of complications, but that it is relatively safer than the conventional technique and improves sperm yield significantly in patients with non-obstructive azoospermia.
192 citations
TL;DR: It was only in 1880 that Charles Laveran, a French physician working in Algeria, discovered the true causative agent as being a sporozoan of the genus Plasmodium, and to map the malaria genome, identifying a huge number of genes located on 14 chromosomes.
Abstract: Malaria is an Italian word composed of “ mala ” and “ aria,” derived from malus (bad), and aeris (air). It was first used to describe a fever (miasma), which was wrongly attributed to exposure to poisonous air rising from marshes. Although the disease had been described in the Hippocratic Collection (460 to 377 BC) and its relation to mosquitoes suggested in the 5th century AD, by the Indian physician Susruta, it was only in 1880 that Charles Laveran, a French physician working in Algeria, discovered the true causative agent as being a sporozoan of the genus Plasmodium. More than a century later, we got to map the malaria genome, identifying a huge number of genes located on 14 chromosomes. Malaria is acquired through the sting of an infected Anopheles mosquito, which injects the sporozoites into the host’s dermis. These are carried with the blood stream to the liver, where they mature in the hepatocytes (extra-erythrocytic cycle) to tissue schizonts that release their merozoites into the hepatic sinusoids. The latter invade the red cells, starting the erythrocytic cycle, which comprises ring forms, trophozoites, and, subsequently, schizonts that contain a new generation of merozoites. The parasitized cells are induced by plasmodial DNA to develop a microtubular system that conveys nutrients to the parasite. They eventually rupture and release the merozoites, which repeat the same cycle. A few merozoites are sexually differentiated into male and female gametocytes, which are essential for the completion of the sexual cycle in the vector.
159 citations
TL;DR: In this paper, a room-temperature ball-milling technique has been successfully employed for fabrication of nanocrystalline powders of equiatomic WC by high-energy ball milling of elemental W and C powders.
153 citations
TL;DR: The role of the levator ani muscle (LAM) in evacuation, sexual performance and pelvic floor disorders is reviewed and levator dysfunction syndrome, which may present as pudendal canal syndrome is reviewed.
Abstract: This paper reviews the role of the levator ani muscle (LAM) in evacuation, sexual performance and pelvic floor disorders. The LAM fixes the vesical neck, anorectal junction and vaginal fornices to the side wall of the pelvis by means of the suspensory sling and hiatal ligament. On contraction it shares in the mechanism of evacuation (urination, defecation). During the sexual act vaginal distension by the erect penis evokes the vaginolevator and vaginopuborectalis reflexes, with a resulting LAM contraction. The LAM also contracts upon stimulation of the clitoris or cervix uteri, an action mediated through clitoromotor and cervicomotor reflexes. LAM contraction leads to upper vagina ballooning, which acts as receptacle for semen collection, to uterine elevation and straightening and to elongation and narrowing of the vagina. These actions enhance the sexual response and prepare the uterus and vagina for the reproductive process. During ejaculation LAM contraction facilitates semen ejection. Levator subluxation and sagging leads to levator dysfunction syndrome, which may present as pudendal canal syndrome.
137 citations
TL;DR: In this article, the main tower body is considered to be built from uniform segments where the effective design variables are chosen to be the cross-sectional area, radius of gyration and height of each segment.
116 citations
TL;DR: In this article, the electrochemical behavior of cobalt in KOH solutions of different concentrations was studied and the effects of applied potential, temperature and the presence of aggressive Cl− ions were investigated.
Abstract: The electrochemical behaviour of cobalt in KOH solutions of different concentrations was studied. The effects of applied potential, temperature and the presence of aggressive Cl− ions were investigated. Different electrochemical methods such as open-circuit potential measurements, polarisation techniques and electrochemical impedance spectroscopy (EIS) were used. The electrochemical behaviour of cobalt in naturally aerated KOH solutions is characterized by three different regions according to the alkali concentration. Corrosion behaviour was observed at high concentrations (0.3–1.0 M); passivation at lower concentrations (0.01–0.05 M), and at intermediate concentrations (0.1–0.2 M) corrosion followed by passivation was recorded. The corrosion parameters (i
corr, E
corr, and R
corr) under various conditions were calculated. Equivalent-circuit models for the electrode–electrolyte interface under different conditions were proposed. The experimental impedance data were fitted to theoretical data according to the proposed models. The relevance of the proposed models to the corrosion–passivation phenomena occurring at the electrode–solution interface was discussed. The electrochemical experimental results and discussions were supported by surface analytical techniques.
108 citations
TL;DR: A model-based approach to the detection and diagnosis of mechanical faults in rotating machinery is studied and algorithms suitable for real-time implementation are developed and evaluated using computer simulation.
Abstract: A model-based approach to the detection and diagnosis of mechanical faults in rotating machinery is studied in this paper. For certain types of faults, for example, raceway faults in rolling element bearings, an increase in mass unbalance, and changes in stiffness and damping, algorithms suitable for real-time implementation are developed and evaluated using computer simulation.
TL;DR: In this article, an n-dimensional complex Ginzburg-Landau equation is transformed to a sine-Gordon equation, sinh-Gordon equations and other equations, which depends only on one function, ζ, and can be solved.
Abstract: Applying the function transformation method, an n-dimensional complex Ginzburg–Landau equation is transformed to a sine-Gordon equation, sinh-Gordon equation and other equations, which depends only on one function, ζ, and can be solved. The general solution of the equations in ζ leads to a general soliton solution of an n-dimensional complex Ginzburg–Landau equation. It contains some interesting specific solutions such as the N multiple solitons, the propagational breathers and the quadric solitons.
TL;DR: A simple and direct analytical procedure for evaluating the ultimate flexural capacity of FRP strengthened reinforced concrete flexural members is presented and is applicable to both singly and doubly reinforced concrete rectangular sections, as well as flanged sections.
Abstract: A significant percentage of the bridges in North America were built after the Second World War. Most of them were originally designed for smaller vehicles, lighter loads, and a lower traffic volume than commonly experienced today. A study reported by Klaiber and colleagues (1987) indicates that over 50% of all bridges in the United States were built before 1940, and approximately 42% of these bridges are considered to be structurally deficient. This alarming statistic underscores the importance of developing reliable and cost-effective repair and strengthening techniques for existing bridge structures. A particularly challenging problem in this area is the rehabilitation of reinforced concrete structures. In recent years, the repair of understrengthened or damaged reinforced concrete members by the external bonding of fiber-reinforced polymer (FRP) laminates has received considerable attention. This paper investigates the flexural behavior of reinforced concrete beams strengthened with externally bonded FRP laminates. A simple and direct analytical procedure for evaluating the ultimate flexural capacity of FRP strengthened reinforced concrete flexural members is presented. The procedure is derived from equilibrium equations and compatibility of strains and is applicable to both singly and doubly reinforced concrete rectangular sections, as well as flanged sections. The procedure is validated by comparisons with results of experimental data available in the literature. Upper and lower limits of FRP that may be bonded to a reinforced concrete cross section to ensure ductile behavior are established, and design nomographs to facilitate implementation of the procedure are presented.
TL;DR: The proposed methods have been applied successfully to the analysis of the cited drugs either in pure form or in pharmaceutical formulations, with good accuracy and precision, compared statistically with those given by the reported methods.
TL;DR: In this article, a monitoring of pesticide residues was conducted at different locations in the El-Haram region Giza, Egypt, where water samples were obtained by solid phase extraction (SPE) and soil samples by gel permeation chromatography (GPC).
TL;DR: Presoaking seeds in 10 −2 mM putrescine can alleviate the adverse effect of NaCl during germination and early seedling growth of Atropa belladonna and increase alkaloids as well as endogenous putRescine.
TL;DR: This paper introduces several novel active RC oscillator circuits using the operational transresistance amplifier (OTRA) as the basic active building block.
TL;DR: The results show that liposomes encapsulating pilocarpine HCl have kept their integrity and physicochemical properties for at least 15 months, which makes them suitable for commercial use.
TL;DR: In this article, the authors demonstrate the practicality of the current feedback operational amplifier (CFOA) in realizing grounded capacitor (or grounded resistor) oscillator circuits using one or two CFOAs.
Abstract: This paper demonstrates the practicality of the current feedback operational amplifier (CFOA) in realizing grounded capacitor (or grounded resistor) oscillator circuits. The paper begins with a description of the minimum passive component oscillators, using one or two CFOAs. Next, two new single CFOA oscillators with independent control on the condition of oscillation are generated from the single CFOA minimum component oscillator. Three new oscillator circuits using two CFOAs are introduced. Grounded capacitor and grounded resistor oscillators using three CFOAs with independent control on the condition of oscillation and on the frequency of oscillation are also included. The proposed grounded component oscillators are suitable for VLSI implementation. PSpice simulations and experimental results demonstrating the performance of some of the proposed oscillators are given.
05 Jun 2000
TL;DR: A set of preprocessing and segmentation algorithms along with a set of features that are able to recognize and classify different categories of normal white blood cells based on the morphological characteristics of their outer contour and nuclei are presented.
Abstract: Automated medical image processing and analysis offers a powerful tool for medical diagnosis. In this work we tackle the problem of white blood cell shape analysis based on the morphological characteristics of their outer contour and nuclei. The paper presents a set of preprocessing and segmentation algorithms along with a set of features that are able to recognize and classify different categories of normal white blood cells. The system was tested on gray level images obtained from a CCD camera through a microscope and produced a correct classification rate close to 91%.
TL;DR: The results obtained by the proposed scoring system matched well with other classifications regarding grade I and III IUA, but in the cases with moderate IUA (grade II), there was overlap between the classifications which can be attributed to considering the menstrual and reproductive history.
Abstract: We propose a new scoring system for intrauterine adhesions (IUA) that may predict the prognosis after hysteroscopic adhesiolysis. We analyzed hysteroscopic findings and clinical data of patients diagnosed as having IUA by reviewing previously published hysteroscopic classifications of IUA. The data were subjected to evaluation according to the most popular classifications in addition to the proposed classification using a scoring system for different parameters. The results obtained by the proposed scoring system matched well with other classifications regarding grade I and III IUA. But in the cases with moderate IUA (grade II), there was overlap between the classifications (sensitivity 58.3%) which can be attributed to considering the menstrual and reproductive history. Further studies are needed to assess its prognostic value.
TL;DR: In this article, an ethanolic extract (antioxidative extract, AOE) from wheat germ that was roasted at 160°C for 20 min was used to stabilize stripped corn oil.
TL;DR: Conscious pain mapping can be done with reasonable success in women with prior surgical evaluations and treatments for chronic pelvic pain, and chronic visceral pain syndrome, adhesions, and endometriosis were the most common diagnoses.
TL;DR: In this article, the hydrodynamic properties of a long rigid floating pontoon interacting with linear oblique waves in water of finite arbitrary depth are examined theoretically, and the flow is idealized as linearized, velocity potentials are expressed in the form of eigen-function expansions with unknown coefficients.
TL;DR: In this paper, the authors provided quantitative estimates of soil, vegetation structure and species distribution in 144 stands along two transects in two extreme desert zones of western Egypt, and classified the samples into eight twinspan groups.
Abstract: 1
The present study provides quantitative estimates of soil, vegetation structure and species distribution in 144 stands along two transects in two extreme desert zones of western Egypt. This study had two aims: (1) to describe the floristic composition of the accidental type of vegetation growing in parts of the Western Desert of Egypt; and (2) to analyse the distribution of species in relation to certain environmental factors by multivariate data analysis.
2
Eight environmental variables were recorded: salinity, pH, calcium carbonate, soil moisture, organic matter content, and percentages of sand, silt and clay. A total of 60 species belonging to 19 families of the angiosperms and Ephedra alata was recorded. Chamaephytes and therophytes were the most frequent, denoting a typical desert life-form spectrum, mainly of Saharo-Arabian distribution.
3
The samples were classified into eight twinspan groups. Detrended correspondence analysis (DCA) showed that these groups could be distinguished by the first two DCA axes. They could also be effectively interpreted and explained with canonical correspondence analysis (CCA). Based on forward regression, salinity, fine sediments, organic matter and soil moisture content related closely to the first three canonical axes, and accounted for 84.1% of the species–environment relationship among the stands.
4
Both classification and ordination resulted in a clear demonstration of the vegetation pattern in the study area. Other twinspan groups were characterized in addition to those identified previously. In conclusion, the study area has a transitional character where the Nubian Desert and the Northern Mediterranean vegetation meet.
TL;DR: In this article, an automated, systematic, and computationally efficient methodology to estimate the material parameters for characterizing general nonlinear material models for large strain analysis (e.g., hyperelastic and hyper foam materials) is presented.
Abstract: An automated, systematic, and computationally efficient methodology to estimate the material parameters for characterizing general nonlinear material models for large strain analysis (e.g., hyperelastic and hyper foam materials) is presented. Such constitutive material models often require a large number of material constants to describe a host of physical phenomena and complicated deformation mechanisms. Extracting such material constants for a model from the volumes of data generated in the test laboratory is usually a very difficult, and frustrating. The integrated code COMPARE (that is an acronym of Constitutive Material PARameter Estimator) is being developed to enable the determination of an “optimum” set material parameters by minimizing the errors between the experimental test data and the predicted response. The key ingredients of COMPARE are listed as follows: (i) primal analysis tools (response functionals) for differential form of constitutive models; (ii) sensitivity analysis; (iii) optimization technique of an error/cost function; and (iv) graphical user interface. The code COMPARE casts the estimation of the material parameters as a minimum-error, weighted-multiobjective, optimization problem. Detailed derivations and results generated by applying the proposed technique to a comprehensive set of test data are given. These results have clearly demonstrated the great practical utility of the automated scheme developed.
TL;DR: In this article, a higher-order displacement model for the study of the behavior of concentrically and eccentrically stiffened laminated plates based on C0 finite element discretization is presented.
TL;DR: In this paper, X-ray diffraction patterns and XPS analysis of the annealed BaTiO3 thin films were used to obtain high crystallinity, the desired stoichiometry, and less Ti+3 defects.
TL;DR: Sera from 173 turkeys, 108 chickens, and 48 ducks from Giza, Egypt, were tested for the presence of anti-Toxoplasma gondii antibodies by means of the modified agglutination test using mercaptoethanol and formalin-fixed tachyzoites.
Abstract: Sera from 173 turkeys, 108 chickens, and 48 ducks from Giza, Egypt, were tested for the presence of anti-Toxoplasma gondii antibodies by means of the modified agglutination test using mercaptoethanol and formalin-fixed tachyzoites. The prevalence of anti-T. gondii antibodies (>1:25) among turkeys, chickens, and ducks was 59.5%, 47.2%, and 50%, respectively.
TL;DR: Different flotation strategies to separate both calcite and silica from a sedimentary phosphate ore are studied in this article, and the results reveal better selectivity when phosphoric acid is used as depressant for phosphate.