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.
The continued acceleration in the business environment has led to the need for organizations great attention to quality applied in organizations to meet the needs of customers and stay in the market for as long as possible.
Search launched from the underlying problem is the presence of concentrations of defects and waste plaguing the company and to achieve the goal of the study detects the level of quality applied in the factory vessels and reservoirs of the General Company for Heavy Engineering Equipment, As well as calculate wastage rates occurring in the production process and find a relationship between the level of quality and ratios defective in each type of waste, it has been used quantitative meas
... Show MoreThe first known use of the term conspiracy theory dated back to the nineteenth century. It is defined as a theory that explains an event or set of circumstances as the result of a secret plot by usually powerful conspirators. It is commonly used, but by no means limited to, extreme political groups. Since the emergence of COVID-19 as a global pandemic in December 2019, the conspiracy theory was present at all stages of the pandemic.
The first known use of the term conspiracy theory dated back to the nineteenth century. It is defined as a theory that explains an event or set of circumstances as the result of a secret plot by usually powerful conspirators. It is commonly used, but by no means limited to, extreme political groups. Since the emergence of COVID-19 as a global pandemic in December 2019, the conspiracy theory was present at all stages of the pandemic.
We notice that the issue of development is one of the most important issues in ourepoch especially in our country which classify within back ward countries.
When we talk here about the development we don’t mean only the development of capitals or the development of products.but the most important thing is the development of mind .if we notice the experience of developits economy and it didn’t reach to the wanted aim.because these sides . The highness of the meutal rate of the nation is the standard of of the nation is the standard of the sentific and cultural advance for this nation .And that is what we have noticed in human societies ingenerall .
We noticed that
... Show MoreThis study found that one of the constructive, necessary, beneficial, most effective, and cost-effective ways to meet the great challenge of rising energy prices is to develop and improve energy quality and efficiency. The process of improving the quality of energy and its means has been carried out in many buildings and around the world. It was found that the thermal insulation process in buildings and educational facilities has become the primary tool for improving energy efficiency, enabling us to improve and develop the internal thermal environment quality processes recommended for users (student - teacher). An excellent and essential empirical study has been conducted to calculate the fundamental values of the
... Show MoreA seasonal study of periphytic algae attached to the surface of river boats was conducted in Tigris river in Al Aadhamiya site for the period from October 2016 to May 2017. A total of 107 taxa of periphytic algae were identified belonging to the four classes of algae. The periphytic algae community dominated by Bacillariophyceae was (60.7%) followed by Chlorophyceae (20.5%) and Cyanophyceae (17.7%) Chrysophyceae was constituted (0.9%) of the total number. During the whole period of study filamentous taxa such as Oscillatoria amphibian, Phormidium spp., Spirulinagigantean, Cladophoreglomerata and Melosira roeseana remained the dominant colonizer which may be reflect the ability of this species to grow multiplies under different environmental
... Show MoreThe purpose of this work was to study the effects of the Nd:YAG laser on exposed dentinal
tubules of human extracted teeth using a scanning electron microscope (SEM). Eighty 2.5mm-thick
slices were cut at the cementoenamel junction from 20 extracted human teeth with an electric saw. A
diamond bur was used to remove the cementum layer to expose the dentinal tubules. Each slice was
sectioned into four equal quadrants and the specimens were randomly divided into four groups (A to D ).
Groups B to D were lased for 2 mins using an Nd:YAG laser at 6 pulses per second at energy outputs of
80 , 100 and 120 mJ. Group A served as control. Under SEM observation, nonlased specimens showed
numerous exposed dentinal tubules. SEM o