Showing papers by "Minia University published in 2000"
TL;DR: This study, the largest community‐based survey to date, supports earlier reports of high levels of anti‐HCV among adults in rural areas of Egypt, although many of those who are seropositive will not have active liver disease.
259 citations
TL;DR: Serum nitric oxide (NO) production is increased in normal pregnancy than in the normal non‐pregnancy, which possibly represents a compensatory/protective mechanism to maintain blood flow and limit platelets aggregation in the fetal–maternal circulations.
108 citations
TL;DR: In this paper, the effect of different inorganic anions on the pitting corrosion of steel samples I and II (with different composition) was also studied in 0.1 M NaCl solution.
105 citations
TL;DR: In this article, the activation energy of the charge carriers of p-MgPc/n-Si heterojunction cells was evaluated under a monochromatic illumination of 633 nm with an input power density of 50 mW/cm2.
99 citations
TL;DR: In this paper, thin films of CdS on glass substrates have been prepared using a modified evaporation source under different preparation conditions and the structural features have been investigated using XRD.
58 citations
TL;DR: In this article, electrochromic hydrated nickel oxide films have been cathodically deposited onto ITO-coated glass substrates from a solution of nickel sulphate and urea at room temperature.
Abstract: Electrochromic hydrated nickel oxide films have been cathodically deposited onto ITO-coated glass substrates from a solution of nickel sulphate and urea at room temperature. The in situ measurements of the response time during the colouring/bleaching process are reported. The dependence of the electrochromic properties on post-deposition heat treatment have been studied. A good optical modulation has been found for un-annealed samples, while samples annealed at higher temperatures showed smaller modulation. The extinction coefficient (k) has been computed from spectrophotometrically measured transmittance and reflectance. The structural characteristics as well as the surface morphology of some nickel oxide samples were investigated using X-ray diffraction and SEM analysis.
49 citations
TL;DR: For continuing implant users, annual pregnancy rates <1.0/100 in years 6 and 7, together with low cumulative pregnancy rates, testify that Norplant capsule implants remain highly effective for 7 years.
49 citations
TL;DR: In this paper, γ-Al2O3, dried alumina gel, as well as their phosphated forms using (NH4)2HPO4 were prepared by wet impregnation and calcined at 870 K. Results indicated no detectable bulk phase changes due to phosphation.
44 citations
11 Jun 2000-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this paper, the effect of sample thickness on the measured values of the mass attenuation coefficients (μ/ρ) cm 2 / g of perspex, bakelite, paraffin, Al, Cu, Pb and Hg have been investigated at three different γ-ray energies (59.54, 661.6 and 1332.5 keV).
Abstract: Measurements have been made to determine γ-rays attenuation coefficients very accurately by using an extremely narrow-collimated-beam transmission method. The effect of the sample thickness on the measured values of the mass attenuation coefficients (μ/ρ) cm 2 / g of perspex, bakelite, paraffin, Al, Cu, Pb and Hg have been investigated at three different γ-ray energies (59.54, 661.6 and 1332.5 keV). It is seen that for these chosen materials (μ/ρ) remains constant in good agreement with the theoretical values up to 3 mean free paths and after that (μ/ρ) values for Cu, Pb and Hg decrease with further increase in the absorber thickness. This result may be attributed to the increase in the number of coherent small-angle scattering photons which reach the detector.
40 citations
TL;DR: Three new monoterpenes were isolated from an organic extract of the aerial parts of Chenopodium ambrosioides and structures were established on the basis of MS and NMR spectroscopic data.
Abstract: Three new monoterpenes (3−5) were isolated from an organic extract of the aerial parts of Chenopodium ambrosioides. Structures were established on the basis of MS and NMR spectroscopic (1H, 13C, 1H−1H COSY, HMQC and HMBC) data.
29 citations
TL;DR: In this article, the effect of gluconate (G) anion on the inhibition of chloride pitting corrosion of Delta vanadium steel has been studied using potentiodynamic and scanning electron microscopy (SEM) techniques.
TL;DR: In this article, ammonium tungsten bronze, (NH 4 ) 0.33 WO 3, was characterized in the calcination product of ammonium paratungstate at 400°C for 2 h in a static atmosphere of air.
TL;DR: Results from in vitro assays using model substrates for P450-monooxygenase, esterase, and glutathione S -transferase activities were not correlated with resistance (or with metabolism measured in pharmacokinetic assays), suggesting that activities toward thesemodel substrates were poor markers for cypermethrin metabolism and resistance.
TL;DR: In this article, an iron(III)-selective PVC membrane electrodes based on formylsalicylic acid derivatives were studied, which exhibited a good Nernstian response for FeCl3 with a slope of 20 mV per decade.
Abstract: Novel iron(III)-selective PVC membrane electrodes
based on formylsalicylic acid derivatives were studied The electrode based
on p-chloroaniline-3-formylsalicylic acid as a sensor, containing
potassium tetrakis(4-chlorophenyl)borate as a lipophilic salt and
o-nitrophenyl octyl ether as a plasticizer, gave the best
performance The electrode exhibits a good Nernstian response for
10−1–50 × 10−5 mol
l−1 FeCl3 with a slope of 20 mV per decade It
shows a high selectivity for iron(III) in comparison with
alkali, alkaline earth and heavy metal ions The electrode response and
selectivity remained almost unchanged for at least 1 month The effects of
plasticizers, membrane supports, lipophilic salts and pH on the potential
response of the electrode were also studied The electrode was successfully
applied to the determination of iron(III) contents in some
rocks
TL;DR: In this paper, the interaction of Ca(II), Cu(II, Zn, Pb, and La(III) ions with the antibiotics cephalexin, cefadroxil, cephaloridine, and cefoperazone as secondary ligands was investigated potentiometrically.
Abstract: The interaction of Ca(II), Cu(II), Zn(II), Pb(II), and La(III) ions with the antibiotics cephalexin, cefadroxil, cephaloridine, and cefoperazone as secondary ligands was investigated potentiometrically. The formation constants were determined for a ligand-to-metal ratio of 1:1 at 25°C and KNO3. The protonation constants of the complexes were evaluated for the system . The order of stability of the binary and ternary complexes were examined. It was found that glycine adds preferably [M(II)-cephalosporin] rather than to the aqueous complexes of M(II). In all cases 1:1:1 complexes were formed.
TL;DR: In this article, the thermal decomposition course of ammonium paratungstate (APT) in hydrogen was studied using thermogravimetric and differential thermal analyses X-ray diffractometry, infrared spectroscopy and diffuse reflectance spectrography were used to characterize and identify the intermediate solid products.
TL;DR: Reagent strip-detected hematuria and proteinuria were highly associated, particularly in children, with S. haematobium infection, confirming spread of this species up the Nile River and its focality in Minya.
Abstract: Risk factors, prevalence, and intensity of infection with Schistosoma sp. and prevalence and magnitude of morbidity caused by schistosomiasis was assessed in a stratified random sample of 16,433 subjects from 2,409 households in 33 rural communities in Minya Governorate, Egypt. The prevalence of S. haematobium ranged from 1.9% to 32.7% among the communities and averaged 8.9%. The average intensity of infection was a geometric mean egg count (GMEC) of 8.5 per 10 ml of urine and ranged from 1.6 to 30.9. Prevalence was maximum (18-20%) in those 10-20 years of age and higher in males than in females. Intensity of infection followed the same pattern. Infection with S. mansoni was present almost exclusively in a single village, confirming spread of this species up the Nile River and its focality in Minya. Risk factors for S. haematobium infection were an age from 11 to 20; male gender; males bathing in, women washing clothing or utensils in, and children swimming or playing in canals; and a history of, or treatment for, schistosomiasis. Recent history of burning micturition was associated with infection in children but not in adults, while a history of blood in urine correlated with S. haematobium infection in both age groups. Reagent strip-detected hematuria and proteinuria were highly associated, particularly in children, with S. haematobium infection. The presence of hepatomegaly or splenomegaly on physical examination was not associated with S. haematobium ova in the urine. Hepatomegaly, as measured by ultrasonography in the midclavicular line or the midsternal line, or ultrasonography-detected splenomegaly were not present more frequently in infected subjects than in uninfected subjects. Schistosoma ova were not detected more frequently in urine of subjects with ultrasonography-detected periportal fibrosis than in the urine from subjects without this finding. Ultrasonography-detected urinary bladder wall lesions were detected in only 6 (0.3%) subjects and obstructive uropathy was observed in 54 (2.7%) subjects. The absence of an association between prevalence of urinary tract morbidity and S. haematobium infections was surprising. Two possible explanations are 1) that repeated chemotherapy has reduced the prevalence of urinary tract morbidity and 2) that morbidity was not being detected by the ultrasonographic operators.
24 Jul 2000
TL;DR: In this paper, the effect of various deterministic and probabilistic models on the calculated slope reliability index varies with slope geometry and soil strength parameters, and the shape of the failure surface can significantly affect the slope reliability.
Abstract: Many deterministic and probabilistic models can be applied to reliability analysis of earth slopes. This paper investigates the effect of commonly used models by a set of comparative studies based on three prototype embankments. The deterministic models considered are the simplified Bishop method, the modified Swedish method, and Spencer's method. For Spencer's method, both circular and non-circular failure surfaces are considered. The probabilistic models considered are the mean-value first order second moment method (MFOSM), the point estimate method (PEM), and the advanced first order second moment method (AFOSM). The results indicate that the effect of these different models on the calculated slope reliability index varies with slope geometry and soil strength parameters. The effect of deterministic slope stability method is not significant; but the shape of the failure surface can significantly affect the slope reliability, especially for layered embankments. No practical difference was observed between the results of reliability analyses done by the mean-value First Order Second Moment method (MFOSM) and Point Estimate Method (PEM). For the cases studied the AFOSM gave a more conservative reliability index, but it requires more computational effort due to the iterative nature of slope stability problems and numerical problems may occur.
TL;DR: In this article, a parent compound, Ho(NO 3 ) 3 ·5H 2 O (HoNit), was used as a parent for the formation of Ho 2 O 3 at up to 800°C in atmosphere of air.
TL;DR: In this paper, Tm2O3 was obtained as a final product of the thermal decomposition of Tm(CH3COO)3·4H2O. The results revealed that the oxide obtained at 600°C has a higher surface area with larger pores than that obtained at 800°C (SBET=32.8 m2 g−1).
Abstract: Thulium oxide, Tm2O3, was obtained as a final product of the thermal decomposition of Tm(CH3COO)3·4H2O. The decomposition steps up to 800°C were characterized by TG, DTA, XRD, SEM, GC-MS and gas- and solid-phase IR spectroscopy. The results showed that Tm(CH3COO)3
·4H2O dehydrates completely in two overlapping steps at 90 and 110°C and decomposes to Tm2O3 at 540°C through a non-crystalline intermediate Tm(OH)(CH3COO)2 at 350°C, Tm(O)(CH3COO) at 375°C and Tm2O2CO3 at 400°C. The oxides obtained at 600 and 800°C were subjected to texture analysis and pyridine adsorption. The results revealed that the oxide obtained at 600°C has a higher surface area of 49.7 m2 g−1 with larger pores than that obtained at 800°C (SBET=32.8 m2 g−1). On the other hand, the oxide obtained at 600°C has a basic surface character and contains at least two different Lewis acid sites as indicated from pyridine adsorption. The gaseous decomposition products as identified by gas-phase IR and GC-MS are water vapour, acetic acid, ketene, acetone and methane.
TL;DR: The thermal decomposition of erbium oxalate hydrate (Er 2 (C 2 O 4 ) 3 ·6H 2 O) till 900°C, in air and nitrogen, was investigated by nonisothermal gravimetry and differential thermal analyses as mentioned in this paper.
TL;DR: Two new norditerpenoid acids of the labdane type (norgrindelic acids), 4,5-dehydro-6-oxo-18-nor-grindelsic acid (1) and 4β-hydroxyl 6-oxopoxy 19-nor grindelics (2) were isolated from the aerial parts of Grindelia nana as mentioned in this paper.
Abstract: Two new norditerpenoid acids of the labdane-type (norgrindelic acids), 4,5-dehydro-6-oxo-18-norgrindelic acid (1) and 4β-hydroxy-6-oxo-19-norgrindelic acid (2), as well as a new grindelic acid derivative, 18-hydroxy-6-oxogrindelic acid (3), were isolated from the aerial parts of Grindelia nana. In addition, the known compounds, 6-oxogrindelic acid, grindelic acid, methyl grindeloate, 7α,8α-epoxygrindelic acid, and 4α-carboxygrindelic acid were also isolated. The structures of the new compounds were characterized on the basis of spectroscopic analysis.
TL;DR: A series of fused and spiropyrazolones, pyrimidinthiones, thiazolidinones and β-lactams incorporating benzoindole derivatives have been synthesised by cyclocondensation addition reaction and cycloaddition reaction of hydrazine hydrate, hydroxylamine, thiourea, mercapto acetic acid and monochloroacetyl chloride as mentioned in this paper.
Abstract: A series of fused and spiropyrazolones, pyrimidinthiones, thiazolidinones and β-lactams incorporating benzoindole derivatives have been synthesised by cyclocondensation addition reaction and cycloaddition reaction of hydrazine hydrate, hydroxylamine, thiourea, mercapto acetic acid and monochloroacetyl chloride. The pre pared com pounds were tested for anti bacterial and fungicidal activity. Gram-negative bacteria (Bacilluscereus), as well as the fun gus was used for this purpose. The biological assay was determined according to the filter paper disc method. Assay plates were incubated at 30°C one day for the bacteria and three days for the fun gus (British pharmacopoeia commisson, 1102m, London 1963). The test results show that the components have a strong and sat is factory effect.
TL;DR: The activity size distribution of unattached and attached 212 Pb to aerosol particles was measured in the open air of El-Minia City, Egypt as mentioned in this paper, where the samples were collected using a wire screen diffusion battery technique and a low pressure cascade impactor.
TL;DR: In this article, the pore volume was calculated from the adsorption branch to explore the modification of porosity for pure and phosphated zirconia catalysts by impregnating two precursors (zirconium hydroxide and crystalline ZrO2) with an aqueous solution of diammonium hydrogen phosphate.
TL;DR: The synthesis and structural characterization of 2-thioxopyrido[2,3d]pynmidinethiones 5,9,12 and 4,4′-(1,4-phenylene)-di-(2,thioxo-1, 2,3,4tetrahydropyrimidines) 16-22 are described in this paper.
Abstract: The synthesis and structural characterization of 2-thioxopyrido[2,3-d]pynmidinethiones 5,9,12 and 4,4′-(1,4-phenylene)-di-(2-thioxo-1,2,3,4-tetrahydropyrimidines) 16-22 are described.
TL;DR: Histological and SEM observations showed that themaxillae act as the primary grasping organ and that the maxillipeds scrape off the host tissue for food.
Abstract: A parasitic copepod, Lamproglena monodi Capart, 1944, is re-described on the basis of specimens collected on the gill filaments of three species of Tilapia freshwater fish (Cichlidae) obtained at El-Minia, Nile river system, Egypt. Infection rate was 20% in Oreochromis niloticus niloticus, 16% in Sarotherodon galilaeus galilaeus and 20% in Tilapia zilli. Histological and SEM observations showed that the maxillae act as the primary grasping organ and that the maxillipeds scrape off the host tissue for food. The bilobed oral apparatus is considered to be homologous with the labrum.
TL;DR: In this paper, the thermal behavior of CrO3 on heating up to 600°C in dynamic atmospheres of air, N2 and H2 was examined by thermogravimetry (TG), differential thermal analysis (DTA), IR spectroscopy and diffuse reflectance spectraopy (DRS).
Abstract: The thermal behaviour of CrO3 on heating up to 600°C in dynamic atmospheres of air, N2 and H2 was examined by thermogravimetry (TG), differential thermal analysis (DTA), IR spectroscopy and diffuse reflectance spectroscopy (DRS). The results revealed three major thermal events, depending to different extents on the surrounding atmosphere: (i) melting of CrO3 near 215°C (independent of the atmosphere), (ii) decomposition into Cr2(CrO4)3 at 340–360°C (insignificantly dependent), and (iii) decomposition of the chromate into Cr2O3 at 415–490°C (significantly dependent). The decomposition CrO3 → Cr2(CrO4)3 is largely thermal and involves exothermic deoxygenation and polymerization reactions, whereas the decomposition Cr2(CrO4)3 → Cr2O3 involves endothermic reductive deoxygenation reactions in air (or N2) which are greatly accelerated and rendered exothermic in the presence of H2. TG measurements as a function of heating rate (2–50°C min−1) demonstrated the acceleratory role of H2, which extended to the formation of Cr(II) species. This could sustain a mechanism whereby H2 molecules are considered to chemisorb dissociatively, and then spillover to induce the reduction. DTA measurements as a function of the heating rate (2–50°C min−1) helped in the derivation of non-isothermal kinetic parameters strongly supportive of the mechanism envisaged.
TL;DR: In this paper, the thermal decomposition of Ni(II)-carboxylate-imidazole complexes in a nitrogen atmosphere was studied non-isothermally.
Abstract: The thermal decomposition of some Ni(II)-carboxylate-imidazole complexes in a nitrogen atmosphere was studied non-isothermally. From the non-isothermal thermoanalytical data, it was found that these complexes decompose through a stepwise release of imidazole molecules and/or CO ones forming unstable intermediates which produce metal oxide or the metal as a final decomposition product. TG in conjunction with DTG were used to evaluate the kinetic and thermodynamic parameters of the decomposition reaction. The kinetic studies were performed employing a computer-oriented kinetic analysis of each set of W-T data obtained under constant heating rate. The diffusion processes are the decisive mechanisms for the decomposition. The values of ΔE, A, ΔH, ΔS and ΔG for activation were calculated for the complexes and correlated to variation in their structure.
TL;DR: In this paper, the authors measured the positron annihilation lifetimes (PAL) for two viscosity-average molecular weights of poly(methyl methacrylate), PMMA, as a function of temperature.