Scattering of the Exit Beam at the Patient–Cassette Front Material Interface by Ebony Wood

As part of the search for substitute materials for use asradiographic equipment accessories in developing countries,scattering of the exit beam at phantom-material (simulatingthe patient-cassette) interface has been investigated for Ebonywood and aluminium, for comparison, usingthermoluminescent detectors (TLD). Results for significanceof independent samples showed that, there was no statisticaldifference in the scattering of the exit beam towards thephantom, by the two tested materials (P = 0.3) at the 95%confidence interval, with changes in tube potential. Variationof radiation field size however produced a marked difference.This suggests the possible use of Ebony wood as a substitutefor aluminium as a radiographic accessory, subject however,to further radiographic tests and confirmation

Blindness in southern Nigeria: a review of available data

To bring up to date, existing knowledge on the prevalence and common causes of blindness in SouthernNigeria. Available publications on blindness in national and international journals, some dissertations of theNational PostgraduateMedicalCollege and the internet using MEDLINE. Data relating to the prevalence and common causes of blindness in southern Nigeria over a  20-year period (1973-2003) was reviewed. All relevant articles, full length and abstracts, were sorted by categories i.e. into global, continental (Africa), Nigeria and then southern and northern Nigeria groupings. Recent information was also obtained on the internet using MEDLINE and the “Blindness in Nigeria”. Reviewed information shows that blindness is asmuch a problemin SouthernNigeria as it is in the rest of the less developed and poor countries of the world; and that the commonest causes of blinding diseases are largely preventable and treatable. An appreciable depth of data exists on blindness in southern Nigeria. Reviewed information indicate that blindness is asmuch a problemin southernNigeria as it is in the rest of the less developed and poor countries of the world, but regrettably, the commonest causes of blinding diseases in this region are largely preventable and treatable.Keywords: Blindness, SouthernNigeria

An Evaluation of Some Common Laboratory Materials by Xray Attenuation, for use as Human Tissue Substitutes

To develop readily available laboratory materials for probableuse as imaging phantoms or test objects, Laboratory MagnesiumSulphate (MgSO4) and Table salt (NaCl) were used in the ratio80:20% by weight with paraffin wax to form test materials(MgSO4:PW1) and (NaCl:PW2). Rice powder, gelatineseparately, and a combination of gelatine (20g in 100ml of warmwater) and 100g rice powder were also made into test objects.The ratios used were confirmed by matching differentconstituents by weight of the test samples with the web basedphoton interaction software XCOM designed by the NationalInstitute of Science and Technology, USA, to obtain closematching with tissue data. Each test object was made into 1 cmblocks for exposure to narrow beam x-rays over the diagnosticenergy range (50 – 150kV) under automatic exposure conditions.Good agreement within 10%, was found between the measuredand calculated values for four of the five tested samples.Matching of the tested materials with mass attenuationcoefficients of simulated tissue showed acceptable match at highphoton energies of 0.04 – 0,05 MeV and above for gelatine, PW1(paraffin wax + MgSO4.6H2O) and Rigel (Rice + gelatine). Thesematerials can therefore be used as tissue substitutes in imagequality studies

Clay as Thermoluminescence Dosemeter in diagnostic Radiology applications

As part of efforts to isolate and utilize local and naturally occurring materials for development of thermoluminescece dosemeters and other technologies, an earlier report had shown that Nigerian clay showedprospects of utility as a thermoluminescence dosemeter (TLD). This paper reports the investigation of the basic thermoluminescence properties of clay at x-rays in the diagnostic radiology range, including dose monitoring in abdominal radiography. Clay sourced from Calabar, Nigeria, was tested for thermoluminescence response after irradiation at diagnostic radiology doses, including application in abdominal radiography dose monitoring in a clinical setting.Results show that thermoluminescence (TL) output in natural clay is very low, but demonstrates enhanced performance with the addition of common salt. Specific TL characteristics of good repeatability for individual and batched pellets (variability index of 3.08%) and a high degree of trap emptying were observed. It had a glow curve peak at 275 C; with traces of spurious thermoluminescence emission at the reader anneal temperature. There was evidence of good batch homogeneity (< 30%) and a similar pattern of dose absorption in abdominal radiography with commercialLithium Fluoride (LiF TLD-100). A high fading rate (over 30% in twelve hours) and low sensitivity (12 times less than LiF TLD-100) however, signal the unacceptability of clay as aTLD in diagnostic radiology in the forms studied. Clay demonstrates poor TL response at diagnostic radiology doses. However, it's water absorbing property offers a means of overcoming the hygroscopic nature of common salt. This could beexplored to improve the use of sodium chloride as a radiation detector.Keywords: Clay, Thermoluminescence, Dosemeter, Detector, Radiology, x-rays

Effective doses in chest and abdominal radiography following the ICRP recommendations of 1991 and 2007 in a regional hospital.

Background: In 2007, the International Commission for Radiological Protection (ICRP), published a new set of tissues and tissue weighting factors as recommendations in the ICRP publication 103. This altered the parameters contributing to the calculation of effective dose, which is normally used as a single indicator of risk. Purpose: To assess the effect of the 2007 review of tissue weighting factors on measured doses in a clinical setting, using patient doses for chest (CXR) and abdominal (AXR) radiography. Materials &amp; Methods: Patient entrance surface doses(ESD) obtained in a dose audit for chest (CXR) and abdomen (AXR) examinations with Harshaw type Lithium Fluoride thermoluminescent dosemeters (LiF-TLD 100) were used in a Monte Carlo calculation software, XDOSE, developed by the National Radiation Protection Board (NRPB) to calculate organ doses. Effective doses (E mSv) were calculated with both the ICRP 1991 and 2007 recommendations of tissue weighting factors. A 2-sample t-statistic was used to test for differences between the results for both recommendations. Tests were at the 95% confidence interval. Results: The mean effective doses for CXR were found to be 0.04 (range 0.019 to 0.092) mSv and 0.03 (range 0.011 to 0.069) mSv for the 1991 and 2007 recommendations, respectively. Mean abdominal effective dose values were 0.78 (range 0.16 to 2.98) mSv for the 1991 wƮ factors, and 0.49 (range 0.099 to 1.97) mSv for the 2007 recommended factors. The mean percentage difference between the effective doses calculated with wƮ recommendations of 1991 and 2007 respectively came to 1.7 ± 0.6 % with a range between 0.8 and 3.3 % for CXR (p &lt; 0.05) and 35.9 ± 5.6 with a range of 20.8 to 42.3%, for AXR (p = 0.05). Conclusion: Effective doses showed statistically significant differences between the values calculated from the 1991 and 2007 wƮ values for chest radiography. There is however, insufficient evidence to accept a difference for the abdominal effective doses. Wider studies are required to confirm this result

Prevalence of Refractive Error in a Rural Ogoni Community in Southern Nigeria

Background: Refractive error, though not life-threatening, can negatively affect the quality of the socio-economic life of an individual, especially in a poor-resource setting.Objective: To determine the prevalence and pattern of the distribution of refractive error in Kegbara-Dere community in Gokana local government area of Rivers State, Nigeria.Methods: This study forms part of a baseline ocular health survey among the residents of Kegbara Dere (K-Dere), a community designated for community eye outreach in Gokana local government area of Rivers State, Nigeria. Visual acuity was tested outdoors using the Snellen chart and near vision with a near vision chart. Objective refraction was done in a darkened area with a streak retinoscope, and subjectively refined to determine therefractive status of the subject. For this study, refractive error is defined aspresenting vision &lt; 6/6 and improved by one or more lines on the Snellen chart when looking through the pinhole or with the aid of a minimum of 0.25D lens. Myopia was diagnosed when the correction of the eye was more than minus 0.25DS; hypermetropia, when the correction of the eye was &gt; + 0.25DS. All astigmatic refractions were recorded at their spherical equivalent.Results: The prevalence of refractive error was 28.5%. Of this,  hypermetropia was seen in 19.2%, while myopia was seen in 9.3% of the cases. Most of the study population (71.5%) were emmetropic. The  highest number of emmetropes and hypermetropes occurred in the 20-29 year age group, while most myopes were seen in the 50-59 year age group.Conclusion: Refractive error constitutes a significant cause of ocular morbidity in Kegbara community.Key words: refractive error, rural communit

Citric acid Production from Agricultural Wastes using Aspergillus niger Isolated from some Locations within Kaduna Metropolis, Nigeria

This investigation was carried out to assess citric acid production by Aspergillus species isolated in some locations within Kaduna metropolis Nigeria using standard methods. Fungal isolates identified as Aspergillus niger were obtained from samples collected from four (4) different locations.&nbsp; Isolates were subjected to substrate preference test using local substrates such as wheat straw, rice straw and potato peel powder. Wheat straw supported the highest growth value of 41%. Screening of A. niger isolates for the production of citric acid showed that the isolate from Kawo (Kw) gave the highest yield of citric acid (0.38g/100ml) on basal screening media. Optimization of pH and temperature were carried out and the optimum temperature and pH for citric acid production by isolate Kw was 30OC (0.65g/100ml) and pH 6.0. The wheat straw treated with 5 N HCl produced a high yield of citric acid with a value of 25.60g/kg while the untreated wheat straw produced a yield of 13.3g/kg. Molecular characterization to confirm the identity of the fungal isolates was carried out by the amplification and sequencing of the 5.8S gene of the ribosomal RNA and the two intergenic spacers ITS1 and ITS2 of the strains. By comparison (BLAST) of Aspergillus niger isolate to reference sequence in the gene bank, a sequence similarity of 99% to 100% of other Aspergillus niger strain was obtained. Various methods of strain improvement techniques could be adopted to increase citric acid production by the A. niger isolates obtained from this study

Glycemic control, micronutrients and some metabolic enzyme activity in type 2 diabetes

Background: Alterations in the metabolism of some essential micronutrients and activities of some metabolic enzymes have been reported in diabetes mellitus. These changes have been attributed to hyperglycemia and increased protein glycosylation associated with diabetes and seems to be more pronounced in poor glycemic states. The influence of glycemic control on serum levels of calcium (Ca), Iron (Fe), phosphorus (P), vitamin C, and lactate dehydrogenase (LDH) and amylase activity in type 2 diabetes were determined in this study.Methods: Fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), serum calcium (Ca), Iron (Fe), phosphorus (P), vitamin C, LDH and amylase activity were determined in fifty type 2 diabetic subjects aged between 40-70 years and fifty age matched apparently healthy non-diabetic subjects in Calabar, Nigeria using colorimetric methods. Socio-demographic characteristics, anthropometric indices (body mass indices (BMI), waist to hip ratio (WHR)) and blood pressure were determined using standard methods. Data was analyzed using t-test, ANOVA and Pearson correlation analysis at p = 0.05.Results: The FPG, HbA1c, serum vitamin C, Iron and calcium levels were significantly higher and serum phosphorus lower in diabetics than in non-diabetics. Diabetics with poor glycemic control (HbA1c >8.0%) have higher serum calcium and LDH activity compared to those with good glycemic control (HbA1c <8.0%).Conclusions: Diabetes may alter the metabolism of vitamin C, Iron, calcium and phosphorus while poor glycemic control may be associated with changes in calcium and LDH activity.