Ministry of Higher Education and Scientific Research
governmentCairo, Egypt
Research output, citation impact, and the most-cited recent papers from Ministry of Higher Education and Scientific Research (Egypt). Aggregated across the NobleBlocks index of 300M+ scholarly works.
Top-cited papers from Ministry of Higher Education and Scientific Research
Diarrhoea is a public health problem in developing countries. It is therefore important and useful to identify plants with antidiarrhoeal activity. Alchornea cordifolia is quoted by many traditional healers as a plant with this activity. The antidiarrhoeal activity of its leaf extract was investigated against castor oil induced diarrhoea in mice, using morphine as the standard reference drug. A significant (p < 0.01) dose related (100 mg/kg, 200 mg/kg, 400 mg/kg, 800 mg/kg) antidiarrhoeal activity of A. cordifolia leaf ethanol extract was observed with 800 mg/kg extract being the most effective. It delayed mouse intestinal transit accelerated by castor oil, inhibited the production of diarrhoeal faeces and modified the fluid and electrolyte transport across the colonic mucosa when administered intraluminally. Phytochemical screening revealed the presence of tannins and flavonoids which may account for the increased colonic water and electrolyte reabsorption, a mechanism suggested for the antidiarrhoeal activity of A. cordifolia.
Extracts of 42 medicinal plants used for the treatment of anaemia, diabetes, AIDS, malaria and obesity were screened for phytochemical substances and antioxidant potentials. The plant extracts were prepared as hydrolysed (for total antioxidant) and non-hydrolysed (for free antioxidant). Extracts were analysed using three different assay methods for antioxidant analysis: Folin (Folin Ciocalteu reagent), FRAP (Ferric Reducing Antioxidant Power) and DPPH (1,1-diphenyl-2-picrylhydrazyl). The leaves of Alchornea cordifolia showed the highest antioxidant properties as determined by both Folin and FRAP free antioxidant, followed by Dacryodes edulis and Ocimum basilicum in FRAP and by Dacryodes edulis, Harungana madagascariensis for Folin and DPPH method. For total antioxidant activity, Alchornea cordifolia was ranked first followed by Dacryodes edulis, Harungana madagascariensis, Ocimum basilicum for the FRAP method while for the Folin method Harungana madagascariensis occupied the first position followed by Cylicodiscus gabunensis, Ocimum basilicum, Coleus coprosifolius, Alchornea cordifolia, Dacryodes edulis. All the plants show some antioxidant activity irrespective of the method used. The phytochemical studies revealed the presents of important bioactive constituents with antioxidant activity that may have some medicinal properties.
The Fas system is involved in the regulation of germ cell apoptosis associated with testicular injury in experimental animals exposed to various insults. We tested the hypothesis that enhanced germ cell apoptosis mediated by the up-regulation of the Fas system and the activation of caspases may be involved in ethanol-induced testicular injury. Adult Wistar rats were fed either ethanol in Lieber-DeCarli liquid diet or an isocaloric control diet for 12 weeks. Marked Sertoli cell vacuolization and germ cell degeneration were observed in the testes of ethanol-treated rats (ETR) by both light and electron microscopy. Enhanced apoptosis of germ cells in ETR was detected by the terminal deoxynucleotidyl transferase-mediated deoxy-UTP nick end labelling (TUNEL) method, transmission electron microscopy, and was associated with elevated activity of caspase-3, -8 and -9. The expression levels of the Fas ligand (FasL) in Sertoli cells and of both Fas and caspase-3 in germ cells of ETR detected immunohistochemically were higher than those of the control testes. Furthermore, reverse transcriptase-polymerase chain reaction analysis demonstrated an increase in both Fas and FasL mRNA levels in ETR. Fas system up-regulation and the elevated activity of caspases in the testes of ETR may be a reflection of ethanol-induced testicular injury resulting in enhanced germ cells apoptosis, which may be involved in infertility associated with alcohol abuse.
BACKGROUND: Segmental mandibular resection represents a challenge to maxillofacial surgeons in terms of accurate contouring of reconstruction plates, restoration of mandibular symmetry and maintaining accurate condylar position in the glenoid fossae. METHODS: We propose a CAD/CAM technique for fabricating patient-specific templates to symmetrically prebend reconstruction plates, guide osteotomies and reposition the condylar process in the proximal edentulous segment in its preoperative position. We operated on two patients using this new technique. RESULTS: The custom-made templates showed excellent passive fit on the respective mandibles and accurately guided the reciprocating saw blade along the resection margins. The template was also capable of maintaining the spatial relation of the resected mandibles and the patients experienced excellent repeatable occlusion. Superimposition of pre- and postoperative cone-beam CT scans showed restoration of mandibular symmetry and maximum deviation of 0.4-1.4 (mean of 0.9) mm from the preoperative condylar position. The achieved resection margins using the template showed a mean distance of 1.17 mm from the virtually planned ones. CONCLUSION: We present an innovative computer-guided template that allowed for accurate guidance of mandibular resection margins and condylar positioning. The technique needs to be applied in a larger cohort of patients to verify the results. Further modifications of the design and rigidity of the template might proof beneficial.
Background: Herbs were the basis for nearly all medicinal therapy until synthetic drugs were developed in the nineteenth century. The major reasons for using medicinal herbs as a good alternative to chemical drugs, is that they have fewer side effects than synthetic drugs. Objective(s): The main objectives of this study were to investigate the antiviral activity of some popular herbal extracts in Egypt, and to determine their antioxidant activity. Methods: Experimental studies were carried out in different labs of the National Research Center in Cairo, Egypt. Ethanol extracts of three herbal plants with a history of use in traditional medicine namely; Zingiber officinale (Ginger), Nigella sativa (Black seeds) and Foeniculum vulgare (fennel) were tested for their antioxidant potency and antiviral activity against influenza virus. In vitro cytotoxicity assay was made for the extracts by 3-(4, 5-dimethylthiazol -2-yl)-2, 5-diphenyltetrazolium bromide (MTT) colorimetric assay for the determination of the concentration that causes inhibition to half of the viable cells (50% growth inhibition TC50) for each extract and selection of the safe concentration for the antiviral experiment. Antiviral activities were determined by Plaque reduction assay using Madin-Darby canine kidney (MDCK) cell line. Percentage of radical scavenging was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) method to evaluate the antioxidant activity of the extracted plants. Results: Each herb had a certain cytotoxic effect to MDCK cells at the different tested concentrations, TC50 calculated ranged from 50 to 308 μg/μl. The extracts inhibited the growth and development of H5N1 virus in a dose-dependent manner with varying antiviral activity. The most potent viral inhibitor was reported by ethanol extracts of Foeniculum vulgare. All the tested extracts showed high antioxidant activities with some variations ranged from 77.8 to 87.2 percentage scavenging activity at 30 minutes of incubation as determined by the DPPH assay. Conclusion: Some traditionally used medicinal plants are promising sources for potential antiviral and antioxidant compounds.
BACKGROUND: In effort to identify novel bacterial agents, this study was initiated to evaluate the antimicrobial properties of 17 crude extracts from 12 medicinal plants against beta-lactam-resistant bacteria. METHODOLOGY: The antimicrobial activities of plant extracts were evaluated against clinically proved beta-lactam-resistant bacteria (Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Serratia marcescens, Acinetobacter baumannii, Staphylococcus aureus and Enterococcus sp.) and reference strains of bacteria (Escherichia coli ATCC 35218, Enterobacter aerogenes ATCC 29751, E. aerogenes ATCC 13048, Pseudomonas aeruginosa ATCC 27853 and Enterococcus hirae ATCC 9790) by using disc-diffusion and agar-dilution assays. RESULTS: The crude plant extracts demonstrated broad spectrum activity against all bacteria tested with inhibition zones in the range of 8-30 mm. The minimal inhibitory concentration (MIC) values of different plant extracts against the tested bacteria were found to range from <or= 0.3 to >or= 10 mg ml(-1). The most active plant extracts were from Dortenia picta and Bridelia micrantha (MIC: 1.25-10 mg ml(-1)) on beta-lactam-resistant Gram-negative bacilli and the extracts from B. micrantha, Mallotus oppositifolius, Garcinia lucida, Garcinia. kola, Campylospermum densiflorum (leaves) and C. zenkeri (root) on beta-lactam-resistant Gram-positive cocci (MIC: <or= 0.3-5 mg ml(-1)). CONCLUSION: Of the 17 plant extracts studied, seven showed good antimicrobial activity against the tested bacteria. The stem bark of B. micrantha and the leaves of D. picta were most active towards beta-lactamase producing Gram-negative bacilli. This study shows that medicinal plants could be sources of compounds which can be used to fight against beta-lactam resistant bacteria.
Ammonia is toxic to fish if allowed to accumulate and not-properly managed in fish production systems. Six treatments were studied to evaluate the effectiveness of applying three commercial Ammonia Removal Products (Activated Carbon, Natural Zeolite and Effective Micro-organisms (EM )). These treatments are: (1) C, Control, (2) AC5, activated carbon at 5ppt, (3) AC10, activated carbon at 10 ppt, (4) Z5, Zeolite at 5 ppt, (5) Z10, zeolite at 10 ppt, and (6) EM400, EM at 400 ppm. European Seabass fry (240.74 mg/fish IW) were stocked into glass aquaria (50 litres each) at density of 20 fry/aquarium. Water exchange rate was 20% daily and the experiment continued for 35 days. Fish were fed on experimental diet contained 51.37% crude protein, three meals daily, and six days weekly. Data of water quality, survival and growth performance were recorded weekly.
High cost has been pointed among factors that limit the promotion of geopolymers. To contribute to the reduction of the use of costly industrial sodium silicate in activators for geopolymers, a gel obtained with RHA and concentrated sodium hydroxide was used in the present study to develop an alkaline activator with 8 M NaOH and to produce geopolymers with crushed fired clay bricks wastes (FCBW). Characteristics of the gel were compared to that of commercial sodium silicate which was also mixed with 8 M NaOH in the ratio 1:1 to produce geopolymers. Chemical and mineralogical analyses were done on raw materials. Fourier Transformed Infrared Spectroscopy (FTIR) was done on the gel, commercial sodium silicate and products. Biaxial four point flexural strength, bulk density, water absorption and scanning electron microscopy (SEM) tests were also done on products. Results showed that RHA-NaOH alkaline activator has good potential in consolidating FCBW powder through geopolymerization process which gave products that had characteristics not far from that when the commercial sodium silicate was used. The gel obtained by mixing RHA and NaOH can contribute to the reduction of the use of costly commercial sodium silicate in the production process of geopolymers. However, appropriate filtration process is needed for the RHA-NaOH gel to reduce its impurities as undissolved entities, which will consequently contribute to improve the flexural strength, the density and the microstructure of its products which were low compared to when commercial sodium silicate was used.
Abstract In this study, clayey soils are characterized as backfill and potential fusible raw materials for engineering. Geotechnical tests (particle size distribution, Atterberg limits, densities) and chemico-mineralogical analyses (X-ray fluorescence, X-ray diffraction and Fourier transform infrared) were carried out on samples collected from field in the locality of Boulgou (North Cameroon) followed by the determination of mechanical properties of fired bricks (850–1200 °C). The excavations carried out have revealed a thick layer of clayey soils (~ 2 to 2.5 m) over a sandy layer. This clay formation presents some stratifications with limited influence variation in terms of mineralogy. Mean grain size distribution is dominated by sand (62–80%), clay (12–25%) and silt (6–9%). It corresponds to silty–clayey soils regarding their methylene blue values (3.3–5.6), with low plastic (13–22%) to high plastic (33%) characteristics. They are classified by USCS as clayey sand/silty clay, while one sample is a poorly graded sand (SP). Clay minerals observed are kaolinite (6–12%), montmorillonite (2–6%) and illite (8–10%). Those parameters associated with their fine nature and high compressibility make them suitable engineering applications for backfill material and barriers. From chemical analyses, relatively high contents in alkali and alkaline earth elements (~ 4 to 6%) to be used as potential fusible raw materials for fired bricks or gres ceramics were revealed. Bricks characteristics are varied: linear shrinkage (0.3 to 9%), bulk density (1.8 to 2.3 g/cm 3 ), water absorption (19.7 to 1.3%) and flexural strength (0.3 to 17.4 MPa). Overall, the requirement for fired brick (< 20%) is met up by the water absorption values. As from 1050 °C, these soils are made suitable for brick-making with good characteristics (metallic sound, good cohesion and flexural strength).
Abstract Change detection algorithms have been applied to MSS data for monitoring changes inside and outside the Lake Brullus environment. Analysis of the results reveals occurrence of erosion and accretion along both sides of the lake inlet. During the study period (1983 to 1991), the lake area decreased by an average rate of 8·6 km2 per year mainly due to drying for land reclamation. Comparison between standardized and unstandardized principal components showed that the standardized PCs are more capable of identifying occurring changes. A simple technique, such as image differencing and ratioing, comprises a powerful method to emphasize changes, especially when we use thresholding.
CONTENT: Justicia hypocrateriformis Vahl (Acanthaceae) is used as an herbal remedy for diarrhea in Cameroon folk medicine. OBJECTIVE: This study evaluates the antidiarrheal and antioxidant properties of the aqueous extract of J. hypocrateriformis (JH). MATERIALS AND METHODS: Preliminary phytochemical screening and an acute toxicity testing of the extract were carried out. The antidiarrheal activity of JH extract (100, 250, and 500 mg/kg) was assessed at curative and preventive levels in castor oil-induced diarrhea in mice. The antioxidant activity was measured by ferric reducing antioxidant power (FRAP), total phenolic content, and radical scavenging activity. RESULTS: A high lethal dose (LD50) of 14.35 g/kg obtained in acute toxicity implies the extract is not toxic. Phytochemical screening revealed the presence of phenols, tannins, flavonoids, saponins, anthraquinones, and anthocyanins. JH showed a significant protection against castor oil-induced diarrhea as evidenced by a decrease in the number of defecation and wet stool. JH (100-500 mg/kg, p.o.) produced a non-significant dose-dependent decrease in castor oil-induced intestinal transit in the preventive study. In the curative and in healthy mice study, the decrease was only significant at 500 mg/kg. JH possessed a radical scavenging activity with an IC50 of 9.93 mg/ml compared to 4.90 mg/ml for catechin. JH FRAP of 2703.77 ± 0 mg/g (catechin equiv) and phenolic concentration of 14 169.99 ± 612.39 mg/g (catechin equiv) were also obtained. CONCLUSION: Justicia hypocrateriformis extract possesses antidiarrheal activity supported by its antioxidant potential and phytochemical constituents.
This paper deals with a description of an innovative Internet of Medical Things (IoMT) system for implementing personalized health services. The proposed IoMT system has the following advantages respect to the state-of-the-art systems available in literature: (i) it fuses the data provided by several sensors, inertial measurement unit, the bio-impedance and electrocardiogram, (ii) it uses Compressed Sensing (CS) of data prior to transmission, and (iii) it adopts distributed artificial intelligence at the edge for anomaly detection. A description of the specific features and requirements of the wearable device that will be embedded on a smart T-shirt is reported. According to the delineated requirements, an architecture for the wearable device is proposed. Finally the contribution of Artificial Intelligence in the proposed IoMT system is discussed, aiming at identifying anomalies and supporting the process of decision making in the early diagnosis of diseases both at individuals level (local knowledge) or groups of individuals level (global knowledge).
This work proposes the poly(phospho-ferro-siloxo) binder resulting from the phosphoric acid activation of pozzolana (PZ) as a friendly stabilizing agent for compressed earth bricks (CEBs). Different proportions of pozzolana were incorporated into the clay soil (5, 10, 15 and 20 wt%). The CEBs were cured at 25 °C and at 70 °C. Powder X-ray diffraction (PXRD), Fourier transformed infrared spectroscopy (FTIR), water absorption as well as mechanical strength tests were used to characterize the 28 days aged CEBs. The compressive strength of CEBs varies from 9.2 to 20.6 MPa and 10.2 to 42.8 MPa at 25 °C and 70 °C, respectively. Water absorption ranges from 6 to 11% at 25 °C and 8 to 12% at 70 °C. These results indicated the possibility to use pozzolana based phosphate geopolymer binder as efficient stabilizer for the development of structural and functional CEBs. Pozzolana based phosphate geopolymer binder appears as energy-efficient and sustainable solution for the stabilization of CEB.
Three types of bauxites containing aluminum hydroxide of 58.1% gibbsite and 19.3% boehmite for BX3, 95.5% of gibbsite for BX55 and 84.5% of gibbsite for BX8 were used with lime at 95% of CaO through solid state sintering in one stage to prepare a refractory clinker at 1550 °C. The powder obtained after grinding the clinker showed in the XRD curves the presence of CaO·2Al2O3 and CaO·TiO2 phases in the cement samples. The density of cement powder varied between 2.95 and 3.17 g/cm3 and the specific area of powder obtained after grinding was between 0.72 and 0.85 m2/g. The properties of hydrated cement, W/C = 0.33, after stabilization of cement components for 48 h at 105 °C were showed by XRD, DTA, DTG and SEM (C3AH6, AH3, CA2 and CaO·TiO2). The Young's modulus of the cement made varied between 35.5 and 39.4 GPa, and these Young's moduli were compared to conventional CA14M cement.
BACKGROUND: When heavy metals accumulate in air, soil, and water, the risk of human exposure increases among industrial workers, as well as in people living near polluted areas. Heavy metals adversely affect a variety of bodily systems such as the cardiovascular, respiratory, endocrine, immune, and reproductive systems. In addition, long-term exposure and accumulation of heavy metals in the body may disturb oxidative stress genes and thus increase the susceptibility to various diseases. OBJECTIVES: The aim of this study is to estimate the metallothionein concentration in both mussel samples from Abu Qir Bay, Egypt and the blood of local fishermen as a biomarker of exposure to metal pollution. METHODS: Levels of metallothionein and heavy metals were measured in mussels. Blood levels of metallothionein and heavy metals of local fishermen were measured and compared with a control group. The effect of heavy metal exposure on oxidative stress status was investigated through the determination of malondialdehyde (MDA), catalase and glutathione content. RESULTS: The results of this study showed high concentrations of metallothionein in mussels and in fishermen's blood, accompanied by high concentrations of metals such as cadmium (Cd), copper (Cu), lead (Pb), chromium (Cr), and zinc (Zn). At the same time, a significant decrease in glutathione content and catalase enzyme activity was associated with a significant increase in the malondialdehyde concentrations in sera of fishermen. CONCLUSIONS: The present study found that the El Maadiya region is polluted with heavy metals, inducing oxidative stress in fishermen in the vicinity. These results reveal the necessity of further environmental monitoring in the study area in order to evaluate other types of pollutants and their effects on human health.
In this study, an ecofriendly binder was developed by using rice husk ash (RHA) and sodium hydroxide as the activator alongside fly ash (FA) as the aluminosilicate precursor at ambient conditions. The developed binder was used in the production of mortars with varying proportions of sand. A total of three mortar mixtures were developed with sand to binder ratios of 0.55, 0.83 and 1.11. The corresponding behaviour of the mortars and influence of the sand proportions was assessed in terms of the compressive strength, water absorption, density, porosity. Microstructural investigations such as scanning electron microscopy, energy dispersive x-ray spectroscopy, infrared spectrum analysis and mercury intrusion porosimetry were also used to validate the physical properties. The findings from this study demonstrated that RHA can be used successfully as an activator component in the production of mortars. In terms of the sand content, it was found out that increasing the sand to binder ratio has detrimental effects on the performance of the mortars due to the reduction in the binder content primarily. The microstructure analysis of the mortars made with sand to binder ratio of 0.55 showed a compact and strong structure justifying the higher compressive strength achieved. The MIP analysis confirmed that the formation of C-A-S-H gel at the advanced ages allowed the pores refinement with a significant decrease in the fraction of the capillary and macroscopic pores within the geopolymer mortars.
Abstract Sensible thermal energy storage using concrete as a storage medium is a promising technology that helps minimize energy in power plant. The purpose of this study is to evaluate the potential benefits of metakaolin (MK) as a partial substitute for fly ash-based geopolymer for heat resistance. As a partial substitute (5 and 20 wt.%) for fly ash (FA), nine metakaolins containing different alumina contents were selected. In order to assess their potential for storing high-temperature thermal energy, physical and microstructural analyses were performed before and after heat exposure up to 500 °C. Low packing density limits the workability of some metakaolins and increases water demand in pastes. The mechanical properties of geopolymer weaken as the temperature is raised (< 500 °C). The high alumina content of some metakaolins, however, helps to mitigate strength loss during high temperatures. A higher dosage of metakaolin has also shown to prevent this deterioration of strength. A reduction in strength under heating is caused by both dehydration and dehydroxylation. The higher fineness and alumina content of MK have demonstrated significant potential to enhance the heat resistance of FA-based geopolymers. As a result, the geopolymer paste developed is suitable for being used in heat-resistant applications. Article Highlights Fly ash was the main precursor of as prepared alkali-activated binders. Adding metakaolin enhances the resistance of hardened materials under thermal load. The higher the alumina content inside metakaolin is, the higher the performance is.
Easy manipulation and preservation of cells in suspension through the different steps of sample processing for electron microscopy examination is essential for proper diagnosis. The author used agarose gel as an embedding media for processing cells in suspension for electron microscopic examination. The AgarCyto cell block procedure of Kerstens et al. (J Histochem Cytochem. 2000; 48: 709--718) was used to begin electron microscopic processing of exfoliated urothelial cells in voided urine or cells in suspension. Processing of agarose cell block simultaneously for light and electron microscopic examination represents a great advantage offered by this innovated technique.
BACKGROUND: Despite vast improvements in transfusion services in sub-Saharan Africa over the last decade, there remain serious concerns on the safety and adequacy of the blood supply across the region. OBJECTIVE: This review paper ascertains the role of pathogen reduction technology (PRT) in improving blood safety and supply adequacy in the region. METHOD: The state of blood safety in sub-Saharan Africa was reviewed. Meetings, seminars and correspondence were undertaken with key clinicians, scientists and professional bodies in the region, including the World Health Organization's Regional Office for Africa, to examine the suitability of PRT for improving the safety of whole blood transfusion, a prevalent transfusion format in the region. RESULTS: Existing literature suggests that combining PRT with current blood safety measures (such as serology) would improve the safety and adequacy of the blood supply for transfusions in sub-Saharan Africa. This was echoed by the findings of the stakeholder meetings. CONCLUSION: PRT System and the Cerus S-303 System, we suggest that companies conduct comprehensive toxicological evaluation of the agents used for PRT and publish this in the scientific literature. We also recommend that the safety and efficacy of these technologies should be established in a randomised clinical trial conducted in sub-Saharan Africa.
ABSTRACT Five clay deposits in Foumban, west Cameroon, were studied for their morphological, mineralogical and geochemical properties to determine their suitability for ceramics. The clays were examined with X-ray diffraction, X-ray fluorescence, thermal gravimetric analysis and Fourier-transform infrared spectroscopy. Field studies showed that a homogeneous clayey layer occurs at the upper part of the laterite cover of the interfluves, while the valleys are occupied by a clayey heterogeneous hydromorphic material. The clays are composed of kaolinite, illite, smectite and chlorite, associated with quartz, K-feldspars, plagioclase, goethite, traces of rutile and hematite. Geochemical analyses of these samples show a relatively large amount of SiO 2 (45–71%), Al 2 O 3 (14–31%) and relatively little Fe 2 O 3 (up to 11%), suggesting weathering of mainly granitic and rhyolitic parent rocks. The majority of these clays may be used in the production of structural ceramics such as bricks (refractory or not) and tiles. The relatively high proportion of the alkalis (K 2 O + Na 2 O; 6–8%) in some samples from Marom and Njindare areas might be responsible for the low firing temperatures. The abundance of smectite limits the application of some Koutaba and Marom clays for structural ceramics, while the high Fe 2 O 3 contents (>8%) in some Bangourain clays indicate that some pre-treatment might be necessary prior to use.