Pathophysiology of Cerebral Ischemia: Role of Oxidative/Nitrosative Stress

Stroke is a devastating disease with a complex pathophysiology;it ranks second to ischemic heart disease as a cause of death and long-term disability. Tissue damage results from diverse mechanisms with central involvement of free radicals’ overproduction that results in oxidative stress and hence contributes to brain damage. Free radicals [Reactive oxygen species/Reactive nitrogen species] play central a role in the diverse normal physiological processes and as defense mechanisms against harmful substances. When the rate of their production exceeds the anti-oxidant capacity of the body, oxidative stress occurs. Oxidative stress is implicated in the pathogenesis of various diseases including hypertension, atherosclerosis, diabetes mellitus and cancer;they mediate damage to cell structures, lipid peroxidation, protein denaturation, nucleic acid and DNA damage.

Penetrating Abdominal Injuries: Pattern and Outcome of Management in Khartoum

Background: The pattern and presentation of penetrating abdominal trauma vary according to places and the structure of the present health system. As well controversies in management exist ranging from mandatory exploration to selective non-operative management. Objectives: To determine the pattern of penetrating abdominal trauma, current management practiced and outcome in Khartoum. Patients and Methods: The study was prospective, descriptive and hospital-based. It was carried out at the main three hospitals in Khartoum State. It was conducted over a period of one year from 2012 Mar to 2013 Mar. All patients who presented penetrating injury to their abdomen were included. Results: The study included 85 patients with a mean age of 28 years (SD ± 10). The male to female ratio was 11:1. Most of the patients (89.4%) were in the first four decades of their life. Twenty-three patients (27.1%) presented shock. Stab wound is the commonest mode of trauma seen in 83.5% of our patients. The majority of our patients were managed by exploratory laparotomy (81.2%), however 16 (18.8%) underwent conservative measures. Of the operated group, solid organ injuries were found in 22.9%, yet hollow viscous injuries were reported in 86.9% of the patients. Registrars operated on 78.26% of the patients. The rate of negative laparotomy of this study was 8.7%. Complications and mortality were encountered in 25.9% and 4.7% respectively. The mean hospital stay was 8.47 days (SD ± 10.6). Conclusion: This study demonstrates no difference in the pattern of intra-abdominal injuries. The rate of operative treatment is acceptable, but more laparotomies can be avoided if the haemodynamic stable patients without features of peritonitis were given a period of observation. The overall outcome was satisfactory.

Selection of Influential Microfabric Properties of Anisotropic Amphibolite Rocks on Its Uniaxial Compressive Strength (UCS): A Comprehensive Statistical Study

Occasionally, in complex inherent characteristics of certain rocks, especially anisotropic rocks it may be difficult to measure the uniaxial compressive strength UCS. However, the use of empirical relationships to evaluate the UCS of rock can be more practical and economical. Consequently, this study carried out to predict UCS from microfabrics properties of banded amphibolite rocks using multiple regression analysis. Based on statistical results, rock microfabric parameters, which adequately represent the UCS of a given rock type have been selected. The results show that grain size, shape factor and quartz content have high significant correlation with UCS at 95% confidence level. From multiple regression model, approximately 84% of the variance of the UCS can be estimated by the linear combination of these three parameters. However, according to model performance criteria: correlation coefficient (R = 0.919), variance account for (VAF = 97%) and root mean square error (RMSE = 4.16) the study clearly indicates that the developed model is reliable to predict the UCS. Finally, this approach can be easily extended to the modeling of rock strength in the absence of adequate geological information or abundant data.

Rock slope stability evaluation in static and seismic conditions for left bank of Jinsha River Bridge along Lijiang-Xamgyi'nyilha railway, China

Jinsha River Bridge is located along the Lijiang-Xamgyi＇nyilha railway on the southeastern Tibet plateau; it is an area with a high prevalence of earthquakes. The bridge abutments were designed to be constructed in river bank slopes, where rocks are controlled by two sets of joint planes that significantly influence the stability of the left bank slope. According to the engineering-geological conditions and the characteristics of discontinuities, strength properties of the rock mass were obtained based on Barton model and direct shear test. Numerical analyses were performed using FLAC3D software to examine the slope＇s response to seismic loading. Then in order to evaluate the damage trends of the rock mass under the different loading conditions, a calculation model based on the geological parameters and slope stability was simulated and analyzed using the discrete element numerical simulation program UDEC （Universal Dis- tinct Element Code）, and the effect of degradation of discontinuities on the slope stability was investigated. The results show that the destruction of rock mass under the gravity, bridge foundation, and seismic load are mainly concentrated within 30 m depth of slope, and the slope under loading may slide along joint planes. In addition, the dynamic analysis by amplification of the input loading indicates that instability occurs to the bank slope at a height of about 200 m, and rock blocks will fail under seismic load. Therefore, to prevent the slope from deformation under the engineering loading and strong earthquakes, the bridge foundation should be strengthened.

The Effect of Replacement of Zn 2+ Cation with Ni 2+ Cation on the Structural Properties of Ba sub>2Zn sub>1–x Ni sub>xWO sub>6 Double Perovskite Oxides (X = 0, 0.25, 0.50, 0.75, 1)

The Ba2Zn1-xNixWO6 double perovskite oxides were synthesized using solid state reaction method. The effect of replacement of Zn2+ with Ni2+ cation on the structural properties was investigated by X-ray diffraction (XRD) at room temperature. From the X-ray diffraction and by means of standard Rietiveld method, the samples showed the same cubic crystal structure with (Fm-3m) space group and the crystallite size ranging from 71.91 nm to 148.71 nm. The unit cell volume was found to decrease as a result of the replacement, while there was no significant difference in the value of tolerance factor of the samples. This is may be due to the convergence of ionic radii of Ni2+ and Zn2+ cations. The Fourier Transform Infrared Spectroscopy (FTIR) was performed for the samples and the resultant characteristic absorption bands confirmed the double perovskite structure.

Neglected and Relapsed Clubfoot in Adults, the Functional Outcome of Acute Surgical Correction

Background: Neglected clubfoot in this series is defined as untreated equino-cavo-adducto-varus in older children or adults. Relapsed clubfoot is the residual deformity that remains after single or multiple surgical interventions. Severely neglected clubfoot rarely exists today in developed countries, except in some emigrants from low- and middle-income countries. Acute surgical management with corrective mid-foot osteotomy and elongation of the Achilles tendon has an excellent functional outcome. Objective: To assess the functional outcome of acute correction of neglected Talipes-quinoa-varus deformity in adults. Methods: This is a cross-sectional, hospital–based multi-centric study. Forty patients were included in this study. Midfoot osteotomy and elongation of the Achilles tendon were performed on all patients. Data was collected using a questionnaire and the functional outcome has been assessed using the American Orthopedic Foot and Ankle Society Score (AOFAS). This score was measured before surgery and one year after surgery. Results: the mean age was 19.9 ± 4.7 years. Males were 25 (62.5%) and females were 15 (37.5%). The mean preoperative AOFAS score was 37.7 ± 7.1 (poor). This score improved to 80.7 ± 13.7 (good to excellent), two years after surgery. However, this indicates a significant change in the functional outcome after the operation (p value Conclusion: acute correction of neglected and relapsed TEV with elongation of the Achilles tendon and single midfoot osteotomy has excellent functional outcome as assessed by AOFAS Score. The satisfaction with this procedure is impressive. The younger age population showed better outcomes with this procedure.

<i>NOS</i>3 894G >T Gene Polymorphism: A Potential Risk Factor of Stroke in Bahraini Patients

The endothelial nitric oxide synthase (eNOS) encoded by the NOS3 gene is responsible for the synthesis of a vasoactive endothelium-derived nitric oxide (NO). The genetic polymorphism of this gene explains, in part, why some people are prone to develop stroke than others. In this study we conducted a case control study in Bahrainis to investigate “for the first time” the relationship between NOS3 894G > T (rs1799983) and 786T > C (rs2070744) polymorphisms with the stroke predisposition in Bahraini population. Detection of NOS3 polymorphism was performed by PCR RFLP genotyping method. The level of NO among cases and controls was measured using ELISA. A total of 93 unrelated stroke patients and 86 controls were included in the study. The three types of stroke;Ischemic, hemorrhagic and transient ischemic attack were reported (91.4%, 7.5% and 1.1% respectively). No significant gender difference was observed (P = 0.74). Having previous stroke was a highly significant risk factor of the disease (P = 0.001, OR = 1.4), where as a family history of stroke was not (OR = 0.11). The analysis provides evidence that the mutant 894GT + TT genotypes of NOS3 894G > T polymorphism were positively associated with stroke predisposition and it increased the risk of stroke nearly two folds (P = 0.037, OR = 1.936). Although we found an association between the mutant genotype786 TC + CC of the NOS3 786T > C polymorphism with the susceptibility to stroke (P = 0.023) suggesting that the mutant C allele might have a protective effect against stroke in this population, the strength of this association was rather low (OR = 0.484). The level of NO in stroke patients was significantly low compared to healthy controls (P 0.005). Diabetes, hypertension, heart diseases were reported in stroke patients (67%, 71.4% and 52.1% respectively). More over 50% of the cases with previous stroke are both diabetic and hypertensive. This indicates that these diseases could be considered as a significant factor in the development of stroke in this population. We concluded that the NOS3-894 G > T polymorphism is a potential risk factor of stroke in Bahraini population, whereas as the NOS3 786T > C polymorphism might have a possible protective role against the disease in this population.

Evaluation of Propolis as Intracanal Medicament against <i>Enterococcus faecalis</i>

The present study aimed to comparatively evaluate Propolis, Calcium hydroxide Ca(OH)2, Chlorhexidine gel 2% (CHX) intracanal medicaments, and a mixture of Propolis with Ca(OH)2 and CHX against Enterococcus faecalis. Material and methods: One hundred and eight single-rooted extracted human teeth were used;all teeth were cut 14 mm away from the apex and prepared until size 25 master apical file. Samples were sterilized and dipped in Brain Heart Infusion Broth (BHI) contaminated with E. faecalis for 21 days at 37°C. Samples removed, divided into six groups, injected with different medicaments as following: group A: Propolis;group B: Ca(OH)2;group C: CHX;group D: Propolis + Ca(OH)2;group E: Propolis + CHX, group F: control group with no medicament, teeth sealed with filling material and nail varnish for three times periods 2, 7 and 10 days. After each time period, samples were opened and irrigated with normal saline. H-file applied to the full length to obtain dentine chips, the files collected into test tubes containing sterile BHI and stored for 48 hours under anaerobic conditions. Samples were then removed and culture in Mueller-Hinton agar, then samples incubated for one week at 37°C after which colony forming units counted using colony counter, statistical analysis was done with ANOVA and post hoc use LSD. Results: Propolis, 2% Chlorhexidine gel, and a mixture of Propolis with Calcium hydroxide were effective against E. faecalis, Calcium hydroxide, and a mixture of Propolis Chlorhexidine was not effective against it. Conclusions: Propolis showed a promising role as an intracanal medicament.

Hepatitis B Virus Infection in Pregnant Women, in Al Fashir Town, North Darfur State, Sudan

Background: Sudan is a highly endemic country for hepatitis B virus (HBV). Screening for HBV during pregnancy may help to decide on appropriate antiviral therapy and the institution of steps to minimize vertical transmission to the newborns. Of the epidemiological studies carried in different regions of Sudan, few are available regarding pregnant women. In Darfur region such data is absent, so our aim was to evaluate seroprevalence of HBV among antenatal care attendants in Al Fashir town. Method: A cross sectional study was conducted between 2013 and 2015. Blood samples were collected from 900 pregnant women attending antenatal clinics in Al Fashir town. Plasma was separated and tested for markers of HBV (HBcAb, HBsAg, HBeAg, HBeAb) using ELISA. Sociodemographic, obstetrics and medical data were collected using structured questionnaires. Results: AntiHBc was detected in 46% and HBsAg was detected in 18% of study population. HBeAg and HBeAb frequencies were found to be 2.6% and 37.7% among positive HBsAg pregnant women. There was significant association between residence, income, occupation, bloodletting and ear piercing with HBV infection (P Conclusion: The results of the study suggest that HBsAg has a high prevalence among the pregnant women in Al Fashir town, North Darfur State. So, to minimize vertical transmission, antenatal women must be routinely screened for HBV.

Determine the Optimal Density of Nile Tilapia (<i>Oreochromis niloticus</i>) Fingerlings Cultured in Floating Cages

The objective of the study was to determine the optimal density of fingerlings of the Nile tilapia (Oreochromis niloticus) culture in floating cages with respect to growth performance and to know the effect of temperature on growth during the winter period. Tilapia fingerlings (mean weight 8.5 ± 0.36 g) were stocked at densities of 120, 180 and 360 fish/m3 for 10 weeks. During culture, fish were fed a diet contains 35% protein made of peanut seed, cottonseed, wheat bran, and Sorghum. The results showed that the increase in fish density reduced the final weight of the fish. The percentage of the fish weight increased and reached 111% ± 1.45% in the lowest fish density (120 fish/m3), 79% ± 1.87% in the medium density (240 fish/m3), and 63% ± 2.03% of high fish density (360 fish/m3), therefore the daily growth rate was better in the lowest density. The rate of food conversion ratio was also better in the lowest density with 2.17 ± 0.33, followed by the medium density with 2.79 ± 0.28 and then the highest density with 3.09 ± 0.21. However, the total production in the cage increased with increasing fish density, and the return to the cost of food was better with higher fish density. According to various performance evaluation criteria, it can be concluded that the medium density 240 fish/m3 is the best for growing Nile tilapia fingerlings in floating cages. It was observed that the growth rates of the three treatments were low due to the decrease in water temperature in most of the study period, which may indicate the useless of culture in cages in the winter season.

Characterization of the Crystal Structure of Sesame Seed Cake Burned by Nd: YAG Laser

This paper reports obtaining of useful and high-value materials from sesame seed cake (SSC). For this purpose, SSC sample was burned for 30 s using Nd: YAG laser with output power 60 W. The products of this process and non-burned SSC were characterized by X-ray diffractometer (XRD), energy dispersive x-ray (EDX) and Fourier transform infrared (FTIR) so as to investigate its crystal structure and chemical components. XRD results of the SSC before burning process showed amorphous silica, rhombohedral phase of carbon, monoclinic phase of aluminum chloride, the hexagonal phase of moissanite-4H, (yellow, black) and hexagonal phase of graphite-2H, C (black). While the results of the burned SSC sample showed that the burning process using the power of Nd: YAG laser cased in appearing of crystalline hexagonal phase for silica and Carbon Nitride and converting the rhombohedral phase of Carbon into hexagonal phase. FTIR showed a number of absorbance peaks assigned to silica.

The Electrical and Optical Properties of Zn0.5Li2xMg0.5-xFe2O4 Lithium Doped Nanoparticle Prepared by Coprecipitation Method

In this study, nano ferrite materials were produced to replace costive industrial materials [1]. Ferrite nanoparticles are the interesting material due to their rich and unique physical and chemical properties. They find applications in catalysis, bio-processing, medicine, magnetic recording, adsorption, devices etc. Using co-participation method, five nano ferrite samples Zn0.5Mg0.5-xLi2xFe2O4 (x = 0.00, 0.10, 0.20, 0.30 and 0.40) were prepared. The electrical and optical properties of the Zn0.5Mg0.5-xLi2xFe2O4 samples were studied using the Ultraviolet-visible (UV-Vis) spectroscopy. The results verified that the formation of the absorption coefficient of the five samples of Zn0.5Mg0.5-xLi2xFe2O4 increased with the increase of Lithium (Li2x). The energy band gap of the Zn0.5Mg0.5-xLi2xFe2O4 samples ranged from 3.28 to 3.12 eV [1]. The extinction coefficient (K) for five samples of Zn0.5Li2xMg0.5-xFe2O4 increased with the increase of Lithium (Li2x) at 338 nm from 0.074 to 0.207. The high magnitude of optical conductivity is (1.34 × 1012 sec-1) and the maximum value of electrical conductivity is 42 (Ω.cm)-1. This may due to the electrical and optical properties of lithium.

New Evidence of the Holokinetic Sequences around Suakin-1 and -2in the Sudanese Red Sea Area Using Integrated Geophysical Interpretation

Suakin-1 and Suakin-2 wells are in the Sudanese Red Sea segment where the hydrocarbon generation had been proved by previous studies, however, no reasonable reserve was evidenced due to the complexities of the surrounding salt structures. Six seismic lines were tied to Suakin-1 and -2 to delineate the controlling salt tectonics. The salt evacuation (Roho) and other salt bodies were recognized and matched with similar salt structures in analogous stratigraphic conditions as the Gulf of Mexico and Angola margin. While a previous inconsistent interpretation in the study area marked the high amplitude horizon of the Lower Zeit formation as the top of the Dungunab formation. Three seismic features indicated the presence of salt dome (autochthonous): velocity pull-up, dragging of the sedimentary layers forming mini basins around the third feature, which is the relative transparency of the seismic signal in two piercing like bodies. This interpretation similarly demarcated that the salt escaped east-wards, thus the mapped welded salt is believed to be formed after the salt evacuation. A 3D seismic with a far offset and wide range of azimuth is recommended for detailed imaging.

Physical Properties Study of Zn_(0.5)Mn_(0.5−x)Li_(2x)Fe_(2)O_(4) Nanoparticle Series that Prepared by Co-Precipitation Method

Co-precipitation is an important issue in chemical analysis, where it is often undesirable, but in some cases, it can be exploited. The Zn0.5Mn0.5&#8722;xLi2xFe2O4 nanomaterials (x = 0.0, 0.1, 0.2, 0.3 and 0.4) was afforded by utilizing co-precipitation method. The structural and optical characteristics were analyzed for the samples employing X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR) and Ultraviolet-visible spectrophotometer (UV-Vis). XRD revealed that the structure of certain nanoparticles is a cubic spinel with space group (Fd-3m) and crystallite size in the scale 124 - 150 nm. Lattice parameter was determined to increments with Li+1 and that may occur due to the larger ionic radius of the Li1+ ion. FTIR spectroscopy confirmed the form of spinel ferrite and explicated the properties of absorption bands approximately 593, 1111, 1385, 1640, 2922 and 3430. The energy band gap was estimated for all samples with diverse ratios and was observed in the range of 2.58 - 2.52 eV.

Estimation and Assessment of Plasma D-Dimer Levels in HIV Patients

Background: The elevation of plasma D-dimer levels is fully described and associated with the increase of the mortality of patients with HIV. The present study was aimed to estimate and assess the plasma D-dimer levels in HIV patient. Material and Methods: A case control study done in May 2015. A total of 100 subjects were enrolled in this study;50 were patients professionally diagnosed by HIV;25 (50%) were males and 25 (50%) were females;their mean age is 35 years. Further 50 normal healthy individuals as normal control group: their gender and age were matched with patient groups. The platelets poor plasma (PPP) was immediately prepared from citrated blood, then the plasma D-dimer level was measured using (MISPA-i2 Reagent) Switzerland. Data were analyzed using statistical packing for social sciences program (SPSS) 20. Results: The D-dimer levels was significantly higher in patient with HIV compared with the normal healthy control group (Mean and STD 502.2 ± 287.8 vs 251.8 ± 152.7 P. value 0.01). Conclusion: The D-dimer level was significantly higher in patient with HIV compared with those in normal healthy control group.

Assessments of Elastic Anisotropy of Banded Amphibolite as a Function of Cleavage Orientation Using S- and P-Wave Velocity

As most rocks are of an anisotropic nature, the measurement elastic modulus of anistropic rocks is of general interest. Nevertheless, uniaxial compression test is common method to measure the dynamic elastic constants of anisotropic rocks;the use of ultrasonic pulse test is attractive, because the test is non-destructive and easy to apply. This study aimed to demonstrate the influence of orientation of foliation planes of banded amphibolite rocks on the compressional (Vp), shear wave (Vs) velocities propagating and elastic modules using ultrasonic pulse test. The result showed that the planes of foliation have a major effect on the wave velocity, where the Vp and Vs were taken parallel to the foliation plane show higher values than those obtained in the other directions (β = 30。, 60。 and 90。). The preliminary conclusions are developed concerning that the elastic modulus is vary continuously as a function of cleavage orientation with respect to the direction of wave propagations, where Poisson’s ratio having the smallest relative change. The highest values of Young’s modulus and shear modulus are observed for foliation dip angles of 0? and the lowest values are for foliation dip angles of 90。. This indicates that the observed intrinsic anisotropy and the close relations of the directional dependent seismic anisotropy to the foliation planes are mainly a result of crystallographic preferred orientation of major minerals (e.g. horn- blende and elongated quarts grains).

Hyperfibrinogenemia and Reduced Plasma Protein C Levels in HIV-Infected Patients

Background: Heamatological problems have been associated with human immunodeficiency virus infection. Hypercoagulability, in particular, thrombosis is becoming more common in HIV-positive patients. Aim: The goals of this study were to determine levels of plasma fibrinogen, protein C, Hemoglobin, and ESR among Sudanese HIV-positive patients. Materials and Methods: This is a case-control study, for this investigation, a total of 100 participants were recruited for this study. Fifty people were diagnosed with HIV, 25 of whom were males (50 percent) and 25 of whom were females (50 percent), with an average age of 35.5 years. Further fifty healthy people, 26 (52%) of whom were men and 24 (48%) of whom were women, with a mean age of 37.1 years, matched the case group. Fresh Poor Plasma was obtained by centrifuging citrated venous blood samples at 3000 rpm for 15 minutes. The fibrinogen level was determined using an automated coagulation analyzer. Total protein C level was measured by a fully-automated blood coagulation analyzer (SYSMEX CA-500’JAPAN). The haemoglobin parameter was measured from EDTA anticoagulant samples using the Sysmex KX 21-N automated haematological analyzer. In one hour, the ESR was done using a Westergren tube. Data was collected using a structured direct questionnaire. SPSS version 21 was used to analyse the data. Results: The current study discovered that in Sudanese HIV infection, the mean and standard deviation of plasma fibrinogen levels were statistically substantially higher than in the normal control group (370.5 ± 67 vs 214.7 ± 21 with P value 0.001). Protein C levels were statistically significantly lower in HIV positive patients compared with control group (0.6 ± 0.1 vs 1.3 ± 0.2 with P value 0.001). In HIV positive patients, haemoglobin was statistically substantially lower than in healthy people (10.8 ± 1.8 vs 13.7 ± 1.9, P value 0.01). The erythrocyte sedimentation rate was statistically significantly higher in HIV positive patients than in the control group, with (58.00 ± 27 vs 7.68 ± 3 with P value 0.00). Conclusions: HIV infected patients had higher plasma fibrinogen levels and lower haemoglobin levels than normal healthy control groups. In 16 percent of HIV positive patients, protein C deficiency was discovered. HIV-positive patients had significantly greater ESR.

Atomic Diffusion and Electric Conductivity of Gum Arabic/Graphite Composite

In this work, we had adopted solid states reaction kinetic model to calculate diffusion coefficient of graphite Gr in Gum Arabic (GA) as the function of temperatures and concentration? D(t, C). From the calculations we have found that the diffusion coefficient D increases with increasing temperature. At higher temperature the Gr atoms might get enough thermal energy to overcome the activation energy (Ea) barrier and hence can easily be transported to a new atomic position. Diffusion coefficient of Gr at high concentrations had exceeded that at low concentrations by more than two to three orders of magnitude. Such increase can be attributed to the large number of jumps or jump frequency which found to be directly proportion to the Gr concentration. Electric conductivity, calculated by Nernst-Einstein equation, at high concentration Gr had exceeded that at lower concentration. The decrease in conductivity with decreasing Gr concentration might be attributed to the effective charges interactions, which lead to enhance the recombination of charge carriers.

The Influence of Cu on the Dielectric Properties of NiZnFe₂O₄Synthesized by Solid State Reaction Method

The phase pure Copper Ferrite, Zinc Ferrite, and Nickel Ferrite were prepared from oxides of Ni, Cu, Zn, and Fe using traditional ceramic method. X-ray diffraction data were collected and the formation of the spinal phase structure was found. The lattice parameter was found to be 8.441 Å for ZnFe2O4, 8.35 Å for NiFe2O4, and 8.349 Å for CuFe2O4. The Ni0.4Zn0.6Fe2O4 ferrite was sintered at three different temperatures: namely 1100°C, 1200°C, and 1300°C and similar temperature control was applied to Cu0.2Ni0.2Zn0.4Fe2O4 ferrite group. The energy band gap was calculated for Ni0.4Zn0.6Fe2O4 and Cu0.2Ni0.2Zn0.4Fe2O4 and was found to be 3.657 eV and 4.889 eV, respectively. The dielectric properties were investigated over a wide range using impedance spectroscopy and were found to decrease with the increase of frequency. Similar behavior was observed with the sintering temperature. In the same manner, the electric conductivity was found to decrease with the increase of frequency and sintering temperature as well. On the other hand, the electric resistivity was found to increase with both frequency and the sintering temperature.

Assessment of ESAK and ED for Adult’s Patients Examined by Computed Radiography

This study designed to evaluate the entrance surface air kerma (ESAK) to the patient during X-ray examination to the skull antero-posterior (AP), skull Lateral (LAT), chest postero-anterior (PA), Lumber spine AP/LAT and Pelvis AP. Totally, 408 patients were included in this study using computed radiography (CR) in different three hospitals in Khartoum;five X-ray machines were covered. The entrance surface air kerma (ESAK) was calculated for each patient from the exposure parameters using different peak tube voltages. Patient’s data such as (age and weight) and exposure parameters (kVp) and (mAs) were recorded. The result obtained showed that, the entrance surface air kerma ranged from 0.88 to 3.30 mGy for Skull (AP), 0.588 to 1.87 mGy for skull (LAT), 0.03 to 2 mGy for chest PA, 1.50 to 3.40 mGy Lumbar spine AP, 2.60 to 5.15 mGy for Lumbar spine (LAT), and 1.05 to 4.40 mGy for Pelvis. This study provides additional data that can help the regulatory authority to establish reference dose level for diagnostic radiology in Sudan. This study recommends that the CR operator must be used to optimize the patient dose by using the best strategies available for reducing radiation dose. Computed radiography must be used with high level training for medical staff to reduce the dose;each radiology department should implement a patient dose measurement quality assurance programme. Doses to the patients should be regularly monitored and the proposed national DRLs should be taken as guidance for optimization.