Background: Background : Patients with non-rheumatic atrial fibrillation have high risk of thromboembolism especially ischemic stroke usually arising from left atrial appendage .Transoesophageal echocardiography provides useful information for risk stratification in these patients as it detects thrombus in the left atrial or left atrial appendage. Objective : This study was conducted at Al-Kadhimiya Teaching Hospital to assess the prevalence of left atrial chamber thrombi in patients with chronic non-rheumatic atrial fibrillation using transoesophageal echocardiography and its clinical significance as well as to verify the superiority of transoesophageal over transthoracic echocardiography in the detection of these abnormalities. Type of

In this paper extensive examples and related counterexamples of the category of -skew -Armendariz rings are given. This category of rings regards a new generalization for the concepts of -skew Armendariz and skew -Armendariz rings. A ring is called -skew -Armendariz if for any ( ) Σ and ( ) Σ such that ( ) ( ) ( ), then ( ) ( ) for each and . First some general properties of -skew -Armendariz rings are studied and then relations between -skew -Armendariz rings and other related rings are investigated. Also various examples of non -skew -Armendariz rings are established.

In this paper we study necessary and sufficient conditions for a reverse- centralizer of a semiprime ring R to be orthogonal. We also prove that a reverse- centralizer T of a semiprime ring R having a commuting generalized inverse is orthogonal

The strong cryptography employed by PGP (Pretty Good Privacy) is one of the best available today. The PGP protocol is a hybrid cryptosystem that combines some of the best features of both conventional and public-key cryptography. This paper aim to improve PGP protocol by combined between the Random Genetic algorithm, NTRU (N-th degree Truncated polynomial Ring Unit) algorithm with PGP protocol stages in order to increase PGP protocol speed, security, and make it more difficult in front of the counterfeiter. This can be achieved by use the Genetic algorithm that only generates the keys according to the Random Genetic equations. The final keys that obtained from Genetic algorithm were observed to be purely random (according to the randomne

The main purpose of this paper is to investigate some results. When h is  -( ,δ) – Derivation on prime Γ-near-ring G and K is a nonzero semi-group ideal of G, then G is commutative .

This study includes isolation, purification, and identification of algae from the canal around Baghdad university Al-jadriah. Four unialgal cultures were obtained. These algal cultures included 3 species of cyanophyta ( Nostoc carneum, Westillopesis prolifica, Chroococcus turgidus), 1 species of chlorophyta (Chlorella vulgaris) . Different plants belonging to different families were collected and extracted for their oils which were Ricinus communis and Sesamum indicum (seeds), Matricaria chamomilla (flowers) .However, antialgal activity of the extracted oils were evaluated the isolated algae with 7 concentrations (0.09, 0.3, 0.5, 1, 10, 20 , 30) % using the agar wells diffusion method. Results showed that R. communis oil was more effecti

This research includes synthesis of new heterocyclic derivatives of N-benzyl-5-bromoisatin. New 1, 2, 4-triazole, oxazoline and thiazoline derivatives of [N-benzyl-5-bromo-3-(Ethyliminoacetate)-indole-2-one] (2) have been synthesized. The preparation process started by the reaction of 5-bromoisatin with sodium hydride in dimethylformamide (DMF) at 0°C, gave suspension of sodium salt of 5-bromoisatin and subsequent reaction with benzylchloride to give N-benzyl-5-bromoisatin (1). Compound (1) reacted with ethylglycinate (Schiff base) obtained the intermediate compound (2) which reacted with different reagents in two ways. The first way, compound (2) reacted with (hydrazine hydrate, semicarbazide, phenylsemicarbazide and thiosemicarbazide)

In this paper a new method is proposed to perform the N-Radon orthogonal frequency division multiplexing (OFDM), which are equivalent to 4-quadrature amplitude modulation (QAM), 16-QAM, 64-QAM, 256-QAM, ... etc. in spectral efficiency. This non conventional method is proposed in order to reduce the constellation energy and increase spectral efficiency. The proposed method gives a significant improvement in Bit Error Rate performance, and keeps bandwidth efficiency and spectrum shape as good as conventional Fast Fourier Transform based OFDM. The new structure was tested and compared with conventional OFDM for Additive White Gaussian Noise, flat, and multi-path selective fading channels. Simulation tests were generated for different channels

PM3 and DFT (B3LYP) with a 6-311++G (2d, 2p) level of theoretical quantum mechanical calculations were employed to give investigation into the inhibition efficiency of the two new N-phenyl-ethylidene-5-bromo isatin derivatives which are N-phenyl-ethylidene-5-bromo-3[(imine aceto) urea]-2-oxo indole (NPEO) and N-phenyl-ethyeidine-5-bromo-3[(imine aceto) thiourea]-2-oxo indole (NPES). The calculated physical properties and quantum chemical parameters correlated to the inhibition efficiency all are studied and discussed at the equilibrium geometry in a vacuum, dimethyl sulfoxide and aqueous at their correct symmetry.

        This paper is concerned with the solution of the nanoscale structures consisting of the   with an effective mass envelope function theory, the electronic states of the  quantum ring are studied.  In calculations, the effects due to the different effective masses of electrons in and out the rings are included. The energy levels of the electron are calculated in the different shapes of rings, i.e., that the inner radius of rings sensitively change the electronic states. The energy levels of the electron are not sensitively dependent on the outer radius for large rings. The structures of  quantum rings are studied by the one electronic band Hamiltonian effective mass approximati