Endothelin-1 (ET-1) is a potent vasoconstrictor hormone that has been identified as an important factor
responsible for the development of cardiovascular dysfunctions. ET-1 exerts its vasoconstrictor activity
through two pharmacologically distinct receptors, ETA and ETB that are found in vascular smooth muscle
cells (VSMCs) and the vasodilator activity through an ETB receptor located on endothelial cells. This study
aimed to show the impact of 1µM L-arginine (LA), 100µM tetrahydrobiopterin (BH4), and their combined
effect on ET-1 activity in both lead-treated and lead-untreated rat aortic rings. This means, investigating how
endothelial dysfunction reverses the role of nitric oxide precursor and cofactor. In this study, Rat aortic rings
have been pre-incubated with BH4, LA and their combination. Subsequently, the aortic rings were preincubated with 200µM N-Nitro-L-arginine methyl ester (L-NAME) and 0.5µM BQ-123. Then, the vascular
response to cumulative doses of rat ET-1 was analyzed in each of the above-mentioned groups (LA, BH4, LA
& BH4, L-NAME, BQ-123), in the presence and absence of lead acetate 1µM Pb (C2H3O2)2. ET-1 efficacy and
potency were significantly decreased in the presence of LA, BH4, and LA and BH4 combination in the untreated
group, while it significantly increased in the presence of lead. In the second trial of experiments ET-1 efficacy
markedly decreased in BQ-123- incubated cells in both lead-treated and untreated aortic rings. In the presence
of lead, the efficacy of ET-1 was raised with the use of L-NAME. In conclusion, LA and BH4 can be considered
pharmacological agents to alter the potency of ET-1-induced vasoconstriction and concomitantly lower blood
pressure.
Preparation of epoxy/ TiO2 and epoxy/ Al2O3 nanocomposites is studed and investigated in this paper. The nano composites are processed by different nano fillers concentrations (0, 0.01, 0.02 ,0.03, 0.04 ,0.05 ,0.07 and 0.1 wt%). The particles sized of TiO2,Al2O3 are about 20–50 nm.Epoxy resin and nano composites containing different shape nano fillers of (TiO2:Al2O3 composites),are shear mixing with ratio 1 to 1,with different nano hybrid fillers concentrations( 0.025 ,0.0 5 ,0.15 ,0.2, and 0.25 wt%) to Preparation of epoxy/ TiO2- Al2O3 hybrid composites. The mechanical properties of nanocomposites such as bending ,wearing, and fatigue are investigated as mechanical properties.
This study evaluates the performance of magnetic abrasive finishing (MAF) of aluminum alloy in terms of achieving materials removal (MR). A vertical milling machine is used to perform the finishing process using a developed MAF unit that consists of an inductor made out of a 150 mm long and 20 mm diameter iron core wound with 1500 turns and 0.5 mm copper wire. The commutator and magnetic pole are attached at the top and bottom of the inductor, respectively. The required current is supplied using a DC power supply. The South Pole workpiece is a 100×50×3 mm3 plate of AA 1100 aluminum alloy, whereas the magnetic pole represented the North Pole. Pole rotational speed, applied current, and abrasive finishing time was selected as
... Show MoreAn investigation was conducted for dewaxing of lubricating oil fraction by urea to reduce the pour point.In this study mixture of 45 % methyl ethyl ketone (MEK) and 55 % toluene was used as a solvent. The studied variables are mixing time (10-70 min), solvent to oil volume ratio (0.5:1- 2:1), urea to wax weight ratio (2- 6) and constant mixing speed 1500 rpm. By analysis of the experimental results, the best operating conditions achieved are mixing time 40 min, solvent/oil 2:1 volume ratio, and urea/wax 4:1 weight ratio. At these conditions the pour point of the lubricating oil decreases from 24 ° C to -13 °C.
This paper discusses the role of Auditors' Technological Maturity in reinforcing the quality of auditing profession, through focusing on the concepts of Technological Maturity and quality of auditing profession, as well as designing a proposed model for Technological Maturity which includes five evolutionary and sequential stages, and this proposed model would contribute to reinforce the quality of auditing. This proposed model will be employed in the field of auditing profession because the importance of the development and investment in this profession and the importance of the need for specialized knowledge in Information Technology, and the result of a proposed model is development of technological knowledge for the auditor to reach
... Show MoreThe world went through turmoil before the sixth century AD, and human societies were in conflict and rivalry, each strong state is a weak state-dependent, but the dominant societies made the slave societies to them .. And thus made many societies or civilizations system of classes, and differentiation between members of one community, Weakened its strength and go alone. As the Islamic society in the present weak and weak and falling to the lowest levels of civilizational underdevelopment in the organization of society and social security contrary to what it was Islamic civilization, because of our distance from the heavenly instructions, and this prompted many to walk behind Western ideas aimed at the demolition of Islamic civilization,
... Show MoreMany urban and rural areas fall under the impact of disasters, whether natural or industrial, and with increasing complexity in urban areas, with diversity of economic, social and political components, and technological and cognitive development, the effects of disasters and wars have increased with the time, where disasters are affecting all aspects of life, causing great waste of property and lives, also displacement of populations and disruption of economic life, these effects are multiplied if they are not dealt with in sound curricula and scientific strategies.
The research aims to identify the experiences of some countries and their strategies and effective programs in reconstruction after exposure to disasters and wars wit
... Show MorePraise be to God, Lord of the worlds, and prayers and peace be upon our master Muhammad and upon his family and companions.
We see human societies differ from one society to another in organizing social life, and each according to the foundations and rules prepared by the main thing in the welfare and prosperity.
That is why we see eastern societies differ from western societies in many patterns and various ways of reaching that sophistication, until Islam came and gave the proper model in raising society at that time to the best and highest social levels, because it is based on heavenly rules and foundations and not status as in previous civilizations.
And when the Islamic community has
Museum education is of great importance to an appropriate representation of museums’ collections and exhibits, including traditional fashion. Therefore, museum educators/curators need to be equipped with the most essential skills in their profession in order to adequately present the museum’s history and holdings. This could be achieved through specialized training programs. However, Arab countries are still behind in terms of museum education. Therefore, this article aims to shed light on this issue by assessing the knowledge and skills possessed by museum educators/curators and how training programs could affect them
This study included 50 blood serum samples that collected from children with age ranged between 7-12 years. Thirty five samples collected from children with Type 1 Diabetes Mellitus (T1D), and 15 blood serum samples collected from healthy children as a control sample. The polymorphism of IL-4 -590 (C>T) gene, which amplified by using amplification refractory mutation system (ARMS-PCR) was showed high percentage of C allele frequency in T1D patients sample in comparison with T allele frequency, and the C allele revealed as etiological faction with risk by having T1D disease, whereas the T allele showed high frequency from the C allele frequency in control sample, and the T allele revealed as preventive faction from infection by this disease.
... Show MoreBackground: One common undesirable side effect of orthodontic treatment with fixed appliances is the development of incipient caries lesions around brackets, particularly in patients with poor oral hygiene. Different methods have been used to prevent demineralization; the recent effort to improve the resistance against the demineralization is by the application of lasers. Materials and method: Thirty human premolars extracted for orthodontic purposes were used to test the effect of two energy level of ER-YAG laser on enamel resistance to demineralization. The brackets were bonded on the teeth and all the labial surface excluding 2 mm area gingival to the brackets were painted with acid resistance varnish. Three groups were generated. The fi
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