OALib Journal期刊

ISSN: 2333-9721




2018 ( 265 )

2017 ( 668 )

2016 ( 969 )

2015 ( 13769 )


匹配条件: “Mahdi M” ,找到相关结果约401275条。
Role of Arg (357) in Water Oxidation in Photosystem II
M. Mahdi Najafpour
Pakistan Journal of Biological Sciences , 2006,
Abstract: In the new structure of the PSII OEC, the guanidinium side-chain of CP43-Arg357, straddling the active face of the metal-oxo cluster. However there are a few proposal roles of Arg357. In this study three roles of Arg357 are proposed by studying model complexes: First, deprotonation of water molecules ligated to calcium and manganese (4). Second increasing positive charge on water ligated to manganese (4). Third, postulated hydrogen bonding interactions with the substrate water.
The relationship between helicobacter pylori infection and gastro-esophageal reflux disease
Batool M. Mahdi
North American Journal of Medical Sciences , 2011,
Abstract: Background: Gastro-esophageal reflux disease is a common condition, affecting 25%-40% of the population. Increasing attention has been paid to the relationship between Helicobacter pylori infection and reflux esophagitis. Aim: The aim of this study was to investigate the association between CagA+ H. pylori and endoscopically proven gastro-esophageal reflux disease. Patients and Methods: The study group included 60 hospital patients with gastro-esophageal reflux disease between 2007 and 2009 as compared with 30 healthy patients from a control group that was age and sex matched. Helicobacter pylori CagA+ was identified by an immunological test (Immunochromatography test) (ACON, USA). Results: Helicobacter pylori CagA+ was present in 42/60 (70%) of the patients with gastro-esophageal reflux disease and in 11/30 (36.6%) patients in the control group (p=0.002). The Odds ratio = 0.8004 with 95% Confidence Interval = from 0.3188 to 2.0094. The relative risk=1.35 that indicates an association between Helicobacter pylori and disease. Conclusions: The presence of Helicobacter pylori is significantly increased in patients with gastro-esophageal reflux disease as compared with the control group.
A Model for Water Oxidation Complex in Photosystem II
M. Mahdi Najafpour
Journal of Applied Sciences , 2007,
Abstract: Ruthenium complexes containing ring-substituted bipryidine ligands and related structures have longbeen known to efficiently catalyze water oxidation by strong chemical oxidants and at electrode surfaces. However, despite considerable effort, the goal of identifying the underlying molecular mechanisms has not yet been realized. In this paper, ZINDO/1 theory has been used to study a Ru complex found to react with water and Ce(NH 4)2(NO3)6 to liberate molecular oxygen (O2). The complex indicates a robust catalyst as compared to other earlier reported systems also a proposal mechanism for water oxidation is reported.
Towards Economic Single-Phase Motor  [PDF]
Mahdi Alshamasin
Energy and Power Engineering (EPE) , 2013, DOI: 10.4236/epe.2013.59058

Studying of operation balance in single-phase induction motors is an issue of interest due to the need for reducing the power consumption and increasing the motors’ life. The paper focuses on improving the motor performance by balancing the stator phase operation for the most common-used connection diagrams of single-phase capacitor-run induction motors (SPCRIMs) and three-phase induction motors (TPIMs) operating from single-phase supply (SPS). Therefore, a mathematical model is used to balance the motor operation by varying the frequency supply voltage. Characteristics of balancing parameters are investigated, various methods of motor balancing are presented and comparisons were done among these balancing methods.

Mechanical transmission of bacteria via animal agents truefly species
M. A. Habeeb,M. A. Mahdi
Advanced Studies in Biology , 2012,
Senescence process and oxidative stresses induce changes in plant genomic DNA quality  [PDF]
Sedigheh Hatami-Gigloo, S. M. Mahdi Mortazavian, Mojdeh Hatami-Gigloo, Masoud Ghorbani
Advances in Bioscience and Biotechnology (ABB) , 2013, DOI: 10.4236/abb.2013.43051

Senescence or programmed cell death is a process that interacts with many biochemical and physiological changes in living organism and is generally induced by aging. Many environmental stresses that accelerate the production of activated oxygen can also induce senescence artificially. One of the important aspects of senescence is possibly degradation of macromolecules such as DNA. It is believed that the random amplification of polymorphic DNA (RAPD) technique is a good method to compare the DNA quality of juvenile and senescence samples in which oxidative stress is induced. In this study, juvenile, senescence and plant paraquat treated leaves from tomato, tobacco and rose, as well as juvenile and senescence human tissues were processed for DNA extraction followed by RAPD technique. We discovered that plant and human genomes are influenced by senescence and environmental stresses underwent genome diversity. Using some molecular markers proved that senescence and oxidative treated samples show different DNA pattern compare to the juvenile-un- treated samples. We also concluded that RAPD technique can be used as a useful tool in genomics study to provide researchers reliable information of DNA quality and can effectively help to resolve the environment condition.

Effects of tachykinin neuropeptide NKB and Aβ (25-35) on antioxidant enzymes status in 17β estradiol treated aging female rats  [PDF]
Rashmi Jha, Abbas Ali Mahdi, Shivani Pandey, Najma Z. Baquer, Sudha M. Cowsik
Advances in Aging Research (AAR) , 2013, DOI: 10.4236/aar.2013.24020

Aging is the leading risk factor for neurodegenerative diseases and oxidative stress involved in the pathophysiology of these diseases. These changes increase during menopausal condition in females when the level of estradiol is decreased. The aim of the present study was to determine the effect of tachykinin neuropeptide, Neurokinin B (NKB) and Amyloid beta fragment Aβ (25 - 35) on 17β estradiol (E2) treated aging female rat synaptosomes of different age groups. Aging brain functions were assayed by measuring the activities of antioxidant enzymes—superoxide dismutase (SOD) and monoamine oxidase (MAO) with neuropeptides. An in-vitro incubation of Aβ (25 - 35) in E2 treated brain synaptosomes showed toxic effects on all the parameters. However, NKB and NKB combined with Aβ (25 35) showed stimulating effects in E2 treated rat brain synaptosomes. In the present study, an increase in activity of SOD and decrease in the level of MAO, in the presence of NKB and combined NKB and Aβ in E2 treated brain synaptosomes of aging rats. This study elucidates that treatment of NKB and Aβ with E2 incombination exerts more protective influence than their individual application, against excitotoxicity in age related changes.

Neuroprotective role of 17β estradiol with tachykinin neuropeptide NKB and Aβ (25 - 35) in aging female rat brain  [PDF]
Rashmi Jha, Abbas Ali Mahdi, Shivani Pandey, Najma Z. Baquer, Sudha M. Cowsik
Advances in Aging Research (AAR) , 2013, DOI: 10.4236/aar.2013.24019

The brain experiences structural, molecular and functional alterations during aging. In aging brain tissue, the oxidative stress increases due to decreased activity of antioxidant enzymes and increased oxidative stress leading to neurodegeneration associated with excitotoxicity. In the present study, we observed the effect of tachykinin neuropeptide Neurokinin B (NKB) and amyloid beta fragment Aβ (25 - 35) on the activity of Acetylcholine esterase (AChE) and Lipid peroxidation (LPO) in brains of 17β estradiol (E2) treated aging female rat synaptosomes of different age groups. An in-vitro incubation of E2 treated brain synaptosomes with Aβ (25 - 35) showed toxic effects on all the parameters. The treatment of NKB and combined NKB and Aβ (25 - 35) increased the AChE enzyme activity and decreased the level of LPO in E2 treated aging rats. The treatment of NKB and combined NKB and Aβ (25 - 35) in a concentration dependent manner reversed the effects of aging and Aβ (25 - 35) on AChE and LPO. The present finding suggests that E2 along with NKB reverse aging and Aβ (25 - 35) induced toxicity as well as AChE and LPO levels. The results of the current study showed a possible beneficial role of NKB with E2 inthe age related neurological diseases.

An Evolutionary Algorithm for Homogeneous Grouping to Enhance Web-based Collaborative Learning
M. Mahdi Barati Jozan,Fattaneh Taghiyareh
International Journal of Computer Science Research and Application , 2013,
Abstract: Grouping of students is an important educational activity in traditional learning and e-learning environments and lots of research has been done in this area. In this paper the new algorithm is proposed for grouping of students with unlimited features. Our proposed algorithm considers the priority of features as well as their values. Priority of features is involved in the grouping by taking advantage of the Inversion concept. The results indicate that our algorithm is successful in both intra-fitness and inter-fitness grouping criteria. The discrepancy between the members of group that is called intra-group fitness and the similarity between heterogeneous formed groups that is called inter-fitness group.
Toxicity Studies of Some Inert Dusts with the Cowpea Beetle, Callosobruchus maculatus (Fabricius) (Coleoptera: Bruchidae)
Shah Hussain Ahmad Mahdi,M. Khalequzzaman
Journal of Biological Sciences , 2006,
Abstract: The present study has been undertaken to find out the effectiveness of DE and some other inert dusts like, kaolin powder, paddy husk ash, coal ash, alluvial soil, china clay and a dust formulation insecticide carbaryl on the cowpea beetles Callosobruchus maculates (F. ). The bioassay of the dusts was done on adult beetles by applying them with normal food. The LD50 of C. maculatus after 24 h was 737.15, 73305.15, 1479.29, 11449.60, 117371.50, 5171.79 and 21.49 ppm for diatomaceous earth, kaolin powder, paddy husk ash, coal ash, alluvial soil, china clay and carbaryl, respectively. The LD50 after 48 h was 385.24, 12078.10, 974.11, 7433.71, 10650.42, 1168.22 and 11.25 ppm for diatomaceous earth, kaolin powder, paddy husk ash, coal ash, alluvial soil, china clay and carbaryl respectively. The order of toxicity of the insecticides was carbaryl > diatomaceous earth > paddy husk ash > china clay > coal ash > alluvial soil> kaolin powder.

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