Guanine has a variety of roles in chemistry, from its basic function in the storing and transferring genetic information to its usages in synthetic chemistry and other fields. Because of its distinct structure and biological importance, it is a fundamental component of contemporary study in organic chemistry and molecular biology. In this review, we focused on covering the synthetic pathways of various derivatives of guanine from the year 2000 until the present. As a result of the guanine molecule containing multiple functional groups, this gives us the ability to prepare several guanines such as O6-alkylating guanines, O6-benzylguanines, 8-aza-O6-benzylguanines, 9-substituted guanines, guanine-azo derivatives, guanine Schiff bases, guanin

This study reports on natural convection heat transfer in a square enclosure of length (L=20 cm) with a saturated porous medium (solid glass beads) having same fluid (air) at lower horizontal layer and free air fill in the rest of the cavity's space. The experimental work has been performed under the effects of heating from bottom by constant heat flux q=150,300,450,600 W/m2 for four porous layers thickness Hp (2.5,5,7.5,1) cm and three heaters length δ(20,14,7) cm. The top enclosure wall was good insulated and the two side walls were symmetrically cooled at constant temperature. Four layers of porous media with small porosity, Rayleigh number range (60.354 - 241.41) and (Da) 3.025x10-8 has been investigated. The obtained data of temperatu

The liver of marsh harrier grossly appeared as large, bi-lobed organ divided into left and right lobes, which are approximately equal in size and not divided into secondary lobes. Histologically, the liver of marsh harrier was found to contain numerous lobules which are not well defined by the connective tissue of the septa except that surrounded the portal triads. The parenchyma of liver composed of irregular branching cords of hepatocytes organized in double rows alternating with tortures path sinusoids which are lined with flattened endothelial cells and large, irregular outlined kupffer cells. Hepatic cords arranged in a radial pattern around the central vein of the liver lobule while in a subscapsular region they run parallel to the ca

The present study aims to describe the histological structure of kidney of, (Herpestes javanicus ) that inhabits Iraqi lands. Transverse sections of kidney stained with hematoxylin and eosin showed two distinct regions, the outer thin darkly stained cortex and inner thick lightly stained medulla, which further subdivided into external and internal medullary zones linked with one conical renal papilla. The lateral margin of the outer medullary tissue forms a secondary renal pyramid with a specialized fornix. All the nephrons in the kidney start with the renal corpuscle [Malpighian], which is formed from two distinct parts, these are a centrally located glomerulus, which represented by a tuft of blood capillaries and an outer Bowman’s capsu

Coronavirus disease (Covid-19) has threatened human life, so it has become necessary to study this disease from many aspects. This study aims to identify the nature of the effect of interdependence between these countries and the impact of each other on each other by designating these countries as heads for the proposed graph and measuring the distance between them using the ultrametric spanning tree. In this paper, a network of countries in the Middle East is described using the tools of graph theory.

The article aims to study the liquidity that is required to be provided optimally and the profitability that is required to be achieved by the bank, and the impact of both of them on the value of the bank, and their effect of both liquidity and profitability on the value of the bank. Hence, the research problem emerged, which indicates the extent of the effect of liquidity and profitability on the value of the bank. The importance of the research stems from the main role that commercial banks play in the economy of a country. This requires the need to identify liquidity in a broad way and its most important components, and how to

Steps were taken to obtain the Kojic acid crystals from local fungal isolation A. flavus WJF81 by separating the fermentation products from the fungus mycelium from the production plant at the centrifuge at a speed of 5000 cycles for 10 minutes. The extraction was followed by ethyl acetate then supernatant concentrate by using rotary evaporator, and dried with heat oven 37ºC. Long, yellowish, pristine acid crystals were obtained that examined the optical microscope with a magnification force of 10x and 40x. The melting point of kojic acid was determined between 152.9-153.5 °C Results of the diagnosis of Kojic acid by applying High pressure liquid chromatography HPLC technique showed that the acid was at one peak, which was close to the

Is a high degree of economic freedom an important part in the development of the economies of developing countries in the last decade of the twentieth century and the beginning of the twentieth century and the atheist. This is because a test subject (deltoid analysis of the relationship between the degree of economic freedom and foreign trade of selected developing countries for the period
( 1990 -2005) to determine the degree of economic freedom in foreign trade promotion in Singapore and Turkey. The research recommends a number of  recommendations, the most important is the responsibility of the Ministry of Planning in Iraq that is providing the necessary data for the Fraser Institute, the aim of increasing cooperation

The study consisted in the development and use of a practical method to detect and
monitor, analyze and produce maps of changes in land use and land cover in the district of
Mahmudiya in Baghdad during the period 1990-2007 using the applications of remote sensing
techniques and with the assisstant of geographic information systems (GIS),as a valuable
contribution to land degradation studies.
This study is based maiuly on the processing on two subsets of landsat5 TM images picked up
in August 1990 and 2007 respectively in order to facilitate comparision and were thengeometrically and radiometrcally calibrated ,to used for digital classification purposes using
maximum liklihoods classification or six spectral bands of