oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 912 )

2018 ( 1262 )

2017 ( 1217 )

2016 ( 1729 )

Custom range...

Search Results: 1 - 10 of 714398 matches for " M. A. Abdelzaher "
All listed articles are free for downloading (OA Articles)
Page 1 /714398
Display every page Item
Differentiation Between Two Isolates of Pythium ultimum var. ultimum Isolated from Diseased Plants in Two Different Continents
H. Al-Sheikh,Hani M.A. Abdelzaher
Journal of Biological Sciences , 2010,
Abstract: This study was undertaken to investigate the differences between two distinct isolates of Pythium ultimum var. ultimum, the diseased organisms of wheat and lettuce in agricultural fields in each of Egypt and Germany, respectively. Morphological study indicated that the Egyptian and German isolates comprised a single taxon, P. ultimum var. ultimum, by the current taxonomical keys. The isolates were morphologically distinguished as having smaller or larger sexual organs by the sizes of their antheridia and oogonia. The German isolate grew faster in the lower temperature range of 4-15°C whereas the Egyptian isolate grew faster in the higher temperature range of 25-37°C. Similarities in the sequence of the r-DNA-ITS including the 5.8S rDNA demonstrated evident genetic similarity at the species level between the two isolates and should be used for confirmation of identification of species of Pythium. The two isolates were not distinguishable by their pathogenicity to cucumber seedlings. The effect of temperature, hydrogen ion concentration and osmotic potential on oospores production and germination were studied. Oospores production and germination showed a similar manner, however, the Egyptian isolate produced more oospores than the German isolate. Identification of the Egyptian and German isolates of Pythium ultimum var. ultimum to the species level can be done using sequencing of r-DNA-ITS including the 5.8S rDNA, however, some morphological and physiological differences might present within the same species. This might be attributed to the effect of environmental factors and cultural conditions.
Isolation of Aspergillus sulphureus, Penicillium islandicum and Paecilomyces variotii from Agricultural Soil and their Biological Activity Against Pythium spinosum, the Damping-Off Organism of Soybean
Hashem Al-Sheikh,H.M.A. Abdelzaher
Journal of Biological Sciences , 2010,
Abstract: This research was undertaken to study the biological control of Pythium spinosum var. spinosum, the damping-off organism of soybean using three selected soil fungi of Aspergillus sulphureus, Penicillium islandicum and Paecilomyces variotii. Pythium spinosum var. spinosum was isolated from rhizosphere soil and rhizoplane of healthy and infected soybean roots cultivated in an agricultural field located in Shahean district, Minia city, Egypt in June of 2003 and 2009 using NARM (Nystatin Ampicillin Rifampcin Miconazole) selective medium. Rhizosphere and rhizoplane mycoflora isolated from the same sites were tested for their antagonism against Pythium spinosum in agar plates. Among the isolated fungi, Aspergillus sulphureus, Penicillium islandicum and Paecilomyces variotii were proved to be potent biological agents in the plate assay. Their field effectiveness was evaluated in either autoclaved or nonsterilized soil. Coating soybean seeds and roots with spores and mycelia of these three antagonists gave germinating seeds and seedlings a very good protection from root-rot, pre- and post-emergence damping-off caused by P. spinosum. Applying these biocontrol agents to autoclaved and nonsterilized soil infested with P. spinosum provided an excellent way of protection.
Evaluation of the Pozzolanic Activity of Sewage Sludge Ash
M. A. Tantawy,A. M. El-Roudi,Elham M. Abdalla,M. A. Abdelzaher
ISRN Chemical Engineering , 2012, DOI: 10.5402/2012/487037
Abstract:
Fire Resistance of Sewage Sludge Ash Blended Cement Pastes
M. A. Tantawy,A. M. El-Roudi,Elham M. Abdalla,M. A. Abdelzaher
Journal of Engineering , 2013, DOI: 10.1155/2013/361582
Abstract: The aim of the present study is to investigate the hydration characteristics and the fire resistance of sewage sludge ash blended cement pastes by the determination of compressive strength, bulk density, and total porosity in addition to XRD and SEM techniques. Sewage sludge ash modifies the hydration of cement because of its pozzolanic reaction with portlandite favoring the formation of crosslinked fibrous calcium silicate of low Ca/Si ratio. Hence, it was concluded that thermal damage of cement pastes after the exposure to high treatment temperatures (i.e., crack formation and loss of mechanical properties) was effectively reduced with sewage sludge as content up to 20?wt% because of that the presence of crosslinked fibrous calcium silicate strengthens the cement matrix. 1. Introduction Sewage water is the collection of wastewater effluents from domestic, hospital, commercial, and industrial establishments. The objective of the sewage treatment is to produce treated sewage water and sewage sludge suitable for safe discharge into the environment or reuse [1]. International environmental protection agencies recommended that incineration is an attractive disposal method of sewage sludge [2]. Sewage sludge ash has been used as an additive in the production of construction materials [3], mortars [4], and concrete [5]. The exposure of concrete to high temperatures as in an accidental fire of buildings leads to an undesirable structural quality deterioration [6]. Previous studies illustrate that hardened cement paste plays a key role in high temperatures deterioration process. The main damage mechanisms that discuss the deterioration of concrete at elevated temperatures are thermal mismatch, decomposition of hydrates, coarsening of pore structure, and pore pressure effects [7]. Siliceous aggregates expand around 575°C as a result of the α-β quartz inversion, whereas cement paste shrinks above 200°C [8]. This thermal mismatch (i.e., expansion of siliceous aggregate and shrinkage of cement paste matrix) causes a considerable tension at the aggregate-matrix interface leading eventually to interface fracture and cracking [9]. The decomposition of hydrates occurs during the thermal damage of cementitious materials including the decomposition of ettringite, C-S-H, and carboaluminate hydrates at 180–450°C and portlandite at 425–580°C [10]. The decomposition of portlandite damages the C-S-H. The decomposition of hydrates decreases stiffness and strength of cementitious materials. Volume reduction of the hydrated phases because of the loss of bound water leads to air
Evaluation of the Pozzolanic Activity of Sewage Sludge Ash
M. A. Tantawy,A. M. El-Roudi,Elham M. Abdalla,M. A. Abdelzaher
ISRN Chemical Engineering , 2012, DOI: 10.5402/2012/487037
Abstract: Raw sewage sludge was characterized by XRD, FTIR, SEM, and TGA techniques and incinerated in temperature range 650–950°C for 2?h. The effect of incineration temperature on the microstructure and pozzolanic activity of the resultant ash was investigated by techniques mentioned above as well as Chapelle test. It was concluded that incineration of sewage sludge affects the microstructure and pozzolanic activity of the resultant ash. During incineration at temperatures lower than 800°C, amorphous silica captures fixed carbon resulting from incomplete combustion conditions whereas at higher temperatures crystallization of amorphous silica was enhanced. Hydration products formed from hydrothermal treatment of silica fume with lime is amorphous whereas that of sewage sludge ash is fibrous. Hence, incineration of sewage sludge ash must be optimized at 800°C to preserve the pozzolanic activity of the resultant ash. 1. Introduction Sewage is the collection of wastewater effluents from domestic, hospital, commercial, industrial establishments, and rain water. The objective of sewage treatment is to produce treated sewage water and sewage sludge suitable for safe discharge into the environment or reuse [1]. The most common treatment options for sewage sludge include anaerobic digestion, aerobic digestion, and composting. Choice of the treatment method depends on the amount of sludge and other site-specific conditions [2]. Sewage sludge tends to accumulate heavy metals existing in the wastewater. The composition of sewage sludge and its content of heavy metals vary widely depending on the sludge origins and treatment options [3]. In past decades, sewage sludge was primarily disposed to landfills and seawaters [4]. Space limitations on existing landfills and increasing environmental concerns such as groundwater pollution from landfill leachate, odor emission and soil contamination have prompted the investigation of alternative disposal routes [5]. Sewage sludge has been used in agriculture as fertilizer and soil amendment [6]. However heavy metals such as Zn, Cu, Ni, Cd, Pb, Hg, and Cr are principal elements restricting the use of sludge for agricultural purposes [3]. The solidification/stabilization of sewage sludge in cementitious matrix has been evaluated [7]. Sewage sludge adversely affects durability of concrete, mainly due to the organic material which retards setting and heavy metals which interfere with the hardening reactions [8]. Hence, sewage sludge addition in concrete was limited to 10?wt.% and the solidified concrete was recommended for use in certain
Eeffects of angiotensin converting ensyme inhibitors, peroxisome prolieferators activated receptor-α and γ agonists, and statins on a rat model of hypertension
E Abdelzaher, I AbdelReheem, M Hassan, A Abd-Elhameed, D Kamal
Alexandria Journal of Medicine , 2010,
Abstract: Background: Hypertension is a common and complex human disease that causes significant morbidity and mortality worldwide. The role of endothelial dysfunction as an early event of pathophysiologic importance has been recently delineated. Nitric oxide (NO) is an important vasodilator and a potent regulator of inflammation, and mitogenesis. Therefore, inhibition of NO synthesis provided an interesting model of hypertension with specific cardiovascular alterations in which different events of the disease process could be traced. Aim: The aim of this work was to study the cardiovascular abnormalities in a rat model of hypertension induced by administration of the NO synthase inhibitor, N?-nitro-L-arginine methyl ester (L-NAME). In addition, the effects of short and long term administration of an angiotensin converting enzyme inhibitor (Lisinopril), a peroxisome proliferators activated receptor (PPAR)-a agonist (Fenofibrate), a PPAR-? agonist (Pioglitazone) and a statin (Atorvastatin) were studied. Methods: The study was conducted on 128 rats divided into groups and received the studied drugs. Arterial blood pressure and TGF- 1 were recorded. The animals were then sacrificed and the heart weight/body weight (HW/BW) ratio was calculated. Routinely processed hearts and aortae were examined to assess degree of inflammation or fibrosis. This was followed by immunohistochemical detection of CD68 and PCNA and histochemical staining using Masson trichrome stain. Evaluation was done by computerized image analysis. Results: Short term administration of L-NAME was associated with a significant increase in blood pressure associated with marked myocardial inflammatory response (mostly CD68 positives macrophages) and increased proliferative activity. Long term administration of L-NAME resulted in a significant aggravation of hypertension accompanied by myocardial hypertrophy and significant increase in HW/BW ratio. Extensive fibrosis and a significant increase in plasma TGF- 1 level were noted. Short term administration of the studied drugs showed that only Lisinopril showed a significant decrease in blood pressure. The inflammatory and proliferative changes were attenuated by short term administration of the studied drugs, yet with different degrees. Long term administration of all drugs except Fenofibrate led to a significant reduction of blood pressure, HW/BW ratio, fibrosis and plasma TGF- 1. Conclusions: Disturbances of NO production are likely to be major determinants of endothelial dysfunction, hypertension and their pathological consequences; hence, directing therapy towards conserving endothelial NO bioavailability seems to be of paramount importance. The tested drugs were capable of modulating the different aspects of the disease whether the early or late changes, though their profiles were different. Among the studied classes of drugs, Lisinopril was superior in modulating alterations associated with hypertension.
Is the use of gonadotrophin-releasing hormone agonists facilitates vaginal hysterectomy in moderate enlarged uterus?
Mohamed AbdElzaher,dAshraf Moawad, Mohamed Ali, Wael A. Ismail
Egyptian Journal of Hospital Medicine , 2012,
Abstract: Introduction: Vaginal hysterectomy is considered to be the method of choice for removal of the uterus but most gynecologists still prefer the abdominal route for removal of benign large uteri >14 weeks. GnRH agonists such as goserelin can reduce uterine bulk by up to 60% and was initially used to convert a midline to Pfannenstiel incision in abdominal hysterectomy. The conversion of an abdominal to a potential vaginal hysterectomy by uterine size reduction would prove advantageous.Objective: To evaluate the efficacy of the preoperative administration of GnRH agonist for women with enlarged uteri without prolapse in order to facilitate vaginal hysterectomy; in comparison with patients with enlarged uteri who underwent to direct Total abdominal hysterectomy for a similar indication (i.e. Menorrhagia).Design: Prospective multicentre randomized controlled trialSetting: Tertiary Center HospitalsMethods: Women scheduled for hysterectomy for menorrhagia with non-prolapsing clinical uterine size of >14 weeks were offered an attempt for vaginal hysterectomy after pre-treatment with Goserelin for 3 months (Study group= 30). A group of women with comparable uterine size who underwent abdominal hysterectomy for similar indication served as (Control group=30). Pre- and postoperative data such as hemoglobin, myoma size, uterine weight, duration of procedure and complications, pain score, and length of hospital stay were collected prospectively.Results: Both groups had comparable preoperative hemoglobin, body mass index and subjective preoperative uterine bulk (16.7±2.4 vs16.9±2.2 weeks). The uterine weight was lower in the study group (507.6±211 g) compared to the control group (728.8±189 g), P<0.001.The subjective mean decrease in clinical uterine bulk was 20%. The duration of surgery was nearly twice as long in vaginal (123.3±34.9 min) compared to abdominal hysterectomy (73.9±23.9 min), P< 0.001, but analgesia use and the length of inpatient stay were lower in the study group (2.4±1 days) compared to control group (4.97±1.5 days), P<0.001. No significant difference between the two groups as regards the rate of occurrence of surgical complications.Conclusions: In women with >14 week size uteri, treatment with gonadotrophin agonists reduces uterine size sufficiently to allow safe vaginal hysterectomy. Although duration of surgery was longer, women who underwent vaginal hysterectomy required less analgesia and had shorter inpatient stay.
An Alternative Approach to Water Regulations for Public Health Protection at Bathing Beaches
Amir M. Abdelzaher,Helena M. Solo-Gabriele,Matthew C. Phillips,Samir M. Elmir
Journal of Environmental and Public Health , 2013, DOI: 10.1155/2013/138521
Abstract:
An Alternative Approach to Water Regulations for Public Health Protection at Bathing Beaches
Amir M. Abdelzaher,Helena M. Solo-Gabriele,Matthew C. Phillips,Samir M. Elmir,Lora E. Fleming
Journal of Environmental and Public Health , 2013, DOI: 10.1155/2013/138521
Abstract: New approaches should be considered as the US Environmental Protection Agency (EPA) moves rapidly to develop new beach monitoring guidelines by the end of 2012, as these guidelines serve as the basis by which states and territories with coasts along the oceans and Great Lakes can then develop and implement monitoring programs for recreational waters. We describe and illustrate one possible approach to beach regulation termed as the “Comprehensive Toolbox within an Approval Process (CTBAP).” The CTBAP consists of three components. The first is a “toolbox” consisting of an inventory of guidelines on monitoring targets, a series of measurement techniques, and guidance to improve water quality through source identification and prevention methods. The second two components are principles of implementation. These include first, “flexibility” to encourage and develop an individualized beach management plan tailored to local conditions and second, “consistency” of this management plan to ensure a consistent national level of public health protection. The results of this approach are illustrated through a case study at a well-studied South Florida recreational marine beach. This case study explores different monitoring targets based on two different health endpoints (skin versus gastrointestinal illness) and recommends a beach regulation program for the study beach that focuses predominately on source prevention. 1. Introduction There is a growing health concern related to swimming in contaminated waters. Globally, each year, there are in excess of an estimated 120 million cases of gastrointestinal disease and in excess of an estimated 50 million cases of more severe respiratory diseases associated with swimming and bathing in wastewater-polluted coastal waters [1]. Since the 1950s, epidemiologic studies have been designed to evaluate the relationship between swimming in point source-impacted beaches and health risks (i.e., gastrointestinal disease, respiratory, eye, nose, and throat illnesses); they have concluded that symptoms for all these illnesses were increased in swimmers compared to nonswimmers [2, 3]. Outbreak reports from the CDC also confirm that illnesses in the USA are occurring from swimming in contaminated waters [4]. The excess illnesses associated with coastal water pollution can also result in substantial economic burdens. A study in Orange County, CA, estimated 3.3 million US dollars per year in excess illness costs for Newport and Huntington Beaches associated with bathing in marine waters [5]. Swimming-related illness is predominately
Study on Parasexual Recombination between Pyricularia oryzae and Pyricularia grisea  [PDF]
M. A. Monsur, M. Kusaba
Agricultural Sciences (AS) , 2018, DOI: 10.4236/as.2018.93023
Abstract: Rice blast fungus is notorious for changeability in pathogenicity, but it lacks sexual life cycle. It can be postulated that such an imperfect fungus has another mechanism for generating genetic variations. Recent studies concerning comparative genomics reveal that parasexual recombination may play important role in the evolution of rice blast fungus. To observe the parasexualism of rice blast (Pyricularia oryzae) and crabgrass blast (Pyricularia grisea) fungus double inoculation and punch method were applied in this experiment. A total of 520 isolates collected from the double inoculated lesions was subjected to PCR-RFLP analysis of the ITS region to identify subcultures of the inoculated rice blast isolates. As a result, four isolates from the three double inoculated lesions with SA13-1ME and TP106 were identified as subcultures of TP106. To access the recombination genotypes, a total of 17 isolates from the three lesions was subjected to MAGGY-DNA fingerprint analysis. However, recombinant DNA fingerprint patterns between TP106 and SA13-1ME were not detected among the 17 isolates. Although TP022 was not recovered from the double inoculated lesions, the fact that TP106 was recovered from the double inoculated lesion indicates that rice blast fungus can invade and colonized in blast lesion on crabgrass. The opportunistic infection on the double inoculated lesions observed in this study potentially provides new insight into the life cycle of rice blast pathogen.
Page 1 /714398
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.