ABSTRACT
Strontium was used for the first time as an activator agent for magnesium tetraborate (MBO) and photoluminescence (PL) and thermoluminescence (TL) properties were determined using a spectrophotometer and a TL reader, respectively. The results proved that 0.25wt% Sr ratio played an important role in prolonging the afterglow and the phosphor gave the main TL peak with the highest intensity at 200°C like an ideal case. Therefore, it is worthwhile to carry out continuous and systematic research on it.
ABSTRACT
In this paper, the thermoluminescence (TL) dosimetric characteristics of MgO doped natural amethyst samples (Mg-NA) are presented. The morphologies and chemical structures of the powder form samples were identified using XRD, FTIR, SEM, SEM mapping and EDX. Comparison of the TL intensities showed that 10wt% Mg-NA was nearly 150 times more sensitive than undoped amethyst and the main dosimetric properties proved that 10wt% Mg-NA may be a promising phosphor for clinical and radiotherapy purposes.
ABSTRACT
There are limited data about false-positive reactions against hepatitis C virus (HCV) in syphilitic patients and false-positive reactions against syphilis in the patients with HCV infection. The aim of this study was to demonstrate the false-positivity of syphilis in patients with HCV infection, the false-positivity of anti-HCV in patients with syphilis and the validity of the serological tests in such patients. Fifty patients with positive anti-HCV, 21 patients with positive VDRL and 50 healthy subjects were studied. Syphilis serology was determined by the Venereal Disease Research Laboratory (VDRL) test and microhemagglutination for T. pallidum (MHA-TP) test. Hepatitis C serology was determined by a second generation ELISA (Ortho Diagnostics) test for HCV antibody, and anti-HCV positive patients were tested for HCV RNA by polymerase chain reaction (PCR). All assays were performed on all subjects. Not only the false-positive VDRL reaction in the patients with HCV infection but also false-positive anti-HCV tests in syphilitic patients have been observed. Four patients with syphilis had positive anti-HCV and negative HCV-RNA, whereas 10% (5 of 50) of patients with hepatitis C infection had positive VDRL and these patients were negative for MHA-TP test. The rates of false-positivity of VDRL and anti-HCV were higher than within the control group (p < 0.05). According to these data, positive anti-HCV in syphilitic patients and positive VDRL in chronic hepatitis C may be false-positive results with regard to the reaginic tests. Therefore, therapeutic measures should not be initiated without confirmation with a treponemal test or PCR. VDRL and HCV-ELISA tests may be interacted with IgM or IgG antibodies. This relationship should be investigated in further studies.
