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

An Analysis of repeated examinations in conventional film–screen radiography (FSR).

Background: X-ray is an ionising form of radiation used inconventional radiography and this can result in deleterious biologicalchanges in the body if not regulated. Radiation safety is an importantpractice in a medical facility that utilizes radiation in any form fordiagnosis, intervention or treatment. Repeat of non-diagnosticradiographs add to the radiation received by the patient and thepersonnel. The committee on quality assurance in diagnostic X-rayrecommended a repeat rate of 5 – 7% or less.Purpose: The purpose of this study was to determine image repeatrate and the causes of repeat in a University Teaching Hospital.Materials and Methods: It was a prospective study involving allroutine radiographic cases in department over a two month periodduring which 1251 examinations were carried out. Radiographs wereassessed for diagnostic quality by Radiologists following the usualclinical protocols in radiology film review. The number ofradiographs in each examination type which did not meet diagnosticcriteria and therefore required repeat, were isolated and counted.Results are presented in simple percentages.Results: The overall repeat rate was 8.6%. The highest repeat ratewas observed in radiographs of the lumbosacral region (53.06%) andthe lowest rate in the leg (2%). Under-exposure was the leadingcause of repeat (41.67%), while film fog was the least cause(0.93%). Inappropriate selection of exposure factors and poor patientpositioning by radiographers who are mainly interns (n=8) andjunior radiographers (n=4) contributed most to the repeats. Patientfaults or poor darkroom practice were the other reasons for repeats.Conclusion: The rate of repeat is above the accepted limitsrecommended by the committee on quality assurance in diagnosticX-ray (5 – 7% or less). It has increased above the 4% previouslyobtained (1992 assessment). The rate can be reduced if the juniorcadre radiographers are better supervised and a quality assuranceprogram instituted

THE USE OF CEMENT KILN DUST AS PARTIAL REPLACEMENT TO ORDINARY PORTLAND CEMENT IN HOLLOW LATERITIC BLOCKS

ABSTRACT The effect of partial replacement of cement with cement kiln dust (CKD) on the compressive strength of laterized hollow block was investigated. A total of 270 number of 450mm x 225 mm x 150mm hollow blocks using different mix were moulded and tested at 7, 14 28 days with replacement by CKD ranging from 10-50%. The results show that the compressive strength decreased with increase in CKD content. The 28 day compressive strength for 10% CKD replacement for 1:8 and 1:10 mixes were observed to exceed the minimum strength of 1.75N/mm 2 required by the Nigerian National Building Code for individual block. The strength of the laterized blocks however increases as the curing age's progresses

Tobacco use and nicotine dependence among people living with HIV who drink heavily in South Africa: a cross-sectional baseline study

Abstract

Photo-Induced Electron Transfer in P3DDT, P3OT, M3EH-PPV Conjugated Polymers Blended with Maleic Anhydride in THF Solution Under UV Flash Photolysis Studied by Means of CW TR ESR

Free-radical signals of positive polarons in conjugated polymer chains and maleic anhydride (MA) anion radicals were registered in poly(3-octylthiophene) P3OT:MA and (poly[2,5-dimethoxy-1,4-phenylene-1,2-ethenylene-2-methoxy-5-(2-ethylhexyloxy)-(1,4-phenylene-1,2-ethenylene)]) M3EH-PPV:MA blends in tetrahydrofuran (THF) solutions under ultraviolet flash photolysis (308 nm) by continuous-wave time-resolved electron spin resonance. Their emissive chemically induced dynamic electron polarization (CIDEP) originated mainly from excited triplet states (triplet mechanism of CIDEP) and partly by from the radical pair mechanism due to the singlet-triplet mixing states. The observed M3EH-PPV polaron spectrum (g0 = 2.0029) supports the supposition that the previously registered CIDEP spectra in P3DDT:MA blends (g0 = 2.0021) can be attributed to the polaron signals instead of the possible solvate electron signal one. © 2011 Springer-Verlag

Malaria Care-Seeking Behaviour Among HIV-Infected Patients Receiving Antiretroviral Treatment in South-Eastern Nigeria: A Cross-Sectional Study.

This study assesses malaria prevention and treatment behaviour among people living with HIV/AIDS (PLWHA) in Owerri, South Eastern Nigeria. Although Nigeria bears one of the world\u27s largest burdens of both malaria and HIV, there is almost no research studying how co-infected patients manage their care. We systematically sampled 398 PLWHA receiving care at Imo State Specialist Hospital and the Federal Medical Centre in Owerri to complete a structured, pre-tested questionnaire on malaria care-seeking behaviour. Descriptive statistics were reported and chi-square tests and multivariate logistic regressions were also used. The majority of HIV-infected patients (78.9%) reported having had an episode of suspected malaria quarterly or more often. There was a large variation in care-seeking patterns: on suspicion of malaria, 29.1% of participants engaged in self-medication; 39.2% went to drug shops, and only 22.6% visited HIV/AIDS care centres. Almost 40% waited more than 24 hours before initiating treatment. Most (60.3%), reported taking recommended artemisinin-based combination treatments (ACT) but a significant minority took only paracetamol (25.6%) or herbal remedies (3.5%). Most (80%) finished their chosen course of treatment; and completion of treatment was significantly associated with the frequency of suspected malaria occurrence (p = 0.03). Most (62.8%) did not take anti-malaria medication while taking antiretroviral treatment (ART) and almost all (87.6%) reported taking an ACT regimen that could potentially interact with Nigeria\u27s first-line ART regimen. Our findings suggest the need to pay more attention to malaria prevention and control as a crucial element in HIV/AIDS management in this part of Nigeria and other areas where malaria and HIV/AIDS are co-endemic. Also, more research on ART-ACT interactions, better outreach to community-level drug shops and other private sector stakeholders, and clearer guidelines for clinicians and patients on preventing and managing co-infection may be needed. This will require improved collaboration between programmes for both diseases

Photo-induced charge separation process in (PCBM-C120O)/(M3EH-PPV) blend solid film studied by means of X and K-bands ESR at 77 and 120 K

The new fullerene dimer adduct PCBM-C120O was studied as an electron acceptor by light-induced ESR (LESR) when blended with the electron donor-conjugated polymer M3EH-PPV in a thin solid film. ESR parameters for the PCBM-C120O anion radical and the M3EH-PPV polaron (triaxial gx,y,z factors) were determined by X- and K-band ESR techniques at temperatures of 77 and 120 K. It was found that isotropic g0 of PCBM-C120O anion radical ESR spectra obtained in this blend under illumination is close to g-factors of electrochemically reduced (C120-O)-{radical dot} and does not coincide with the analogous parameter of (C120-O)2-{radical dot}{radical dot} (reported in literature). Spin relaxation parameters (T1 and T2) of the PCBM-C120O anion radical and M3EH-PPV positive polaron are similar to T1, T2 for light-induced ion radicals in the P3HT/PCBM blend. © 2010 Elsevier B.V. All rights reserved

Bovine tuberculosis epidemiology in Cameroon, Central Africa, based on the interferon gamma assay

Despite sub-Saharan Africa (SSA) accounting for ~20% of the global cattle population, prevalence estimates and related risk factors of bovine tuberculosis (bTB) are still poorly described. The increased sensitivity of the IFN-γ assay and its practical benefits suggest the test could be useful to investigate bTB epidemiology in SSA. This study used a population-based sample to estimate bTB prevalence, identify risk factors and estimate the effective reproductive rate in Cameroonian cattle populations. A cross-sectional study was conducted in the North West Region (NWR) and the Vina Division (VIN) of Cameroon in 2013. A regional stratified sampling frame of pastoral cattle herds produced a sample of 1,448 cattle from 100 herds. In addition, a smaller cross-sectional study sampled 60 dairy cattle from 46 small-holder co-operative dairy farmers in the NWR. Collected blood samples were stimulated with bovine and avian purified protein derivatives, with extracted plasma screened using the IFN-γ enzyme-linked immunosorbent assay (Prionics Bovigam®). Design-adjusted population prevalences were estimated, and multivariable mixed-effects logistic regression models using Bayesian inference techniques identified the risk factors for IFN-γ positivity. Using the IFN-γ assay, the prevalence of bTB in the dairy cattle was 21.7% (95% CI: 11.2–32.2). The design-adjusted prevalence of bTB in cattle kept by pastoralists was 11.4% (95% CI: 7.6–17.0) in the NWR and 8.0% (95% CI: 4.7–13.0) in the VIN. A within-herd prevalence estimate for pastoralist cattle also supported that the NWR had higher prevalence herds than the VIN. Additionally, the estimates of the effective reproductive rate Rt were 1.12 for the NWR and 1.06 for the VIN, suggesting different transmission rates within regional cattle populations in Cameroon. For pastoral cattle, an increased risk of IFN-γ assay positivity was associated with being male (OR = 1.89; 95% CI:1.15–3.09), increasing herd size (OR = 1.02; 95% CI:1.01–1.03), exposure to the bovine leucosis virus (OR = 2.45; 95% CI: 1.19–4.84) and paratuberculosis (OR = 9.01; 95% CI: 4.17–20.08). Decreased odds were associated with contacts at grazing, buffalo (OR = 0.20; 95% CI: 0.03–0.97) and increased contact with other herds [1–5 herds: OR = 0.16 (95% CI: 0.04–0.55); 6+ herds: OR = 0.18 (95% CI: 0.05–0.64)]. Few studies have used the IFN-γ assay to describe bTB epidemiology in SSA. This study highlights the endemic situation of bTB in Cameroon and potential public health risks from dairy herds. Further work is needed to understand the IFN-γ assay performance, particularly in the presence of co-infections, and how this information can be used to develop control strategies in the SSA contexts

Multifrequency X,W-band ESR study on photo-induced ion radical formation in solid films of mono- and di-fullerenes embedded in conjugated polymers

Anion-cation radical formation in solid films of M3EH-PPV blended with C60-PCBM, C120-O-PCBM and C60-MDHE, C 120-O-MDHE under diode laser (532 nm) and Xe-lamp light excitation studied by means of X,W-band at temperatures 30-80 K is reported. Subsequent high frequency W-band ESR data demonstrate the reproducible, but variable effect of appreciable dispersion (D) contribution in the ESR spectral line for the di-fullerene anion radicals. It is suggested that the increase of the D part relative to the absorption (A) in the summarized ESR absorption line in blends with difullerenes is caused by the higher value of difullerene medium conductivity. The obtained data are quantitatively discussed by the D/A ∼ F(d/δ) functional dependence in approach of plane film geometry, where d is the film thickness and δ is the skin-depth. The influence of ν-dependent δ at D/A value has been checked using X-band LESR. © 2014 Elsevier Ltd. All rights reserved