Measurement of Natural Radioactivity in Beach Sand of Akkuyu Mersin, Turkey

Distribution of natural radionuclide gamma rays produced by 232Th, 226Ra and 40K, were determined for the sand collected along the cost of Mersin in Akkuyu. Gamma radiation in beach sand samples collected from Akkuyu nuclear power plant region has been measured by NaI(Tl) gamma ray spectrometer. Gamma spectrometer has been calibrated with IAEA reference set which were RGK, RGU and RGTH. The radioactivity concentration of were calculated and expressed in Bqkg-1. The source of  cause for the total doses of beach sand was formed due to three primordial radionuclide which were 232Th, 226Ra and 40K. The activity of radionuclide were between 3.96-17.18, 15.82-39.48 and 133.54-287.06Bqkg-1 respectively. Radiological hazard, radium equivalent, external hazard and total dose rate were also calculated. Results were discussed with UNCEAR reports. Keywords: Natural Radioactivity, Sand, Gamma-Ray Spectrometry, Dose Rate, Akkuy

Thermoluminescence study of Mn doped lithium tetraborate powder and pellet samples synthesized by solution combustion synthesis

In this paper, the thermoluminescence (TL) dosimetric characteristics under beta-ray, x-ray and gamma-ray excitations of powder and pellet Mn-doped lithium tetraborates (LTB) which were produced by solution combustion synthesis technique were investigated, and the results were compared with that of TLD-100 chips. The chemical composition and morphologies of the obtained LTB and Mn-doped LTB (LTB:Mn) were confirmed by X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) and scanning electron microscopy (SEM) with EDX. LTB:Mn was studied using luminescence spectroscopy. In addition, the effects of sintering and annealing temperatures and times on the thermoluminescence (TL) properties of LTB:Mn were investigated. The glow curves of powder samples as well as pellet samples exposed to different beta doses exhibited a low temperature peak at about 100 °C followed by an intense principal high temperature peak at about 260 °C. The kinetic parameters (E, b, s) associated with the prominent glow peaks were estimated using Tm-Tstop, initial rise (IR) and computerized glow curve deconvolution (CGCD) methods. The TL response of integral TL output increased linearly with increasing the dose in the range of 0.1-10 Gy and was followed by a superlinearity up to 100 Gy both for powder and pellet samples using beta-rays. Powder and pellet LTB:Mn were irradiated to a known dose by a linear accelerator with 6 and 18 MV photon beams, 6-15 MeV electron beams and a traceable 137Cs beam to investigate energy response. Further, TL sensitivity, fading properties and recycling effects related with beta exposure of LTB:Mn phosphor were evaluated and its relative energy response was also compared with that of TLD-100 chips. The comparison of the results showed that the obtained phosphors have good TL dose response with adequate sensitivity and linearity for the measurement of medical doses

Characterization and some fundamental features of Optically Stimulated Luminescence measurements of silver activated lithium tetraborate

A new lithium tetraborate (Li2B4O7 or abbreviated as LTB) material was produced by adding various concentrations of Ag impurities to allow better luminescent properties using the solution combustion synthesis (SCS) method. The formation of single phase LTB was confirmed using X-ray Diffraction (XRD) data and Scanning Electron Microscopy (SEM) analysis indicated the existence of a tetragonal crystalline domain. Two broad band emissions located at similar to 272 nm (near UV region) and 526 nm (green region) were observed from room temperature photoluminescence (PL) under 205 nm excitation The synthesized material consisted of polycrystalline LTB with 1 wt% Ag (abbreviated herein as LTB: Ag) exhibits considerable thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) which is several times more sensitive to beta radiation than the other concentrations attempted. It was determined that the OSL signal has been a collection of three component signals. A step-preheating procedure to investigate the depth of the trapping centers associated with the OSL signal was carried out. We suggest that the TL peak at 200 degrees C mainly contributes to the OSL signal. It was observed that the total OSL area shows a linear dose response for beta doses ranging from 1 to 100 Gy. The minimum detectable dose (MDD) value was found to be around 3 mGy using the total OSL area. Under optimum conditions (irradiation with beta-rays), the reproducibility of total OSL area was determined with a - 3% deviation at the end of the 9th irradiation-blue light stimulation-readout cycle. The dark storage stability of the total OSL signals was investigated and fading of the total OSL area was found to be approximately 25% after one week. The trap depth corresponding to the OSL signal was found to be 0.99 eV and 0.94 eV using various heating rate and isothermal annealing methods, respectively. Finally, silver doped lithium tetraborate is shown to have promise as an optically stimulated luminescent dosimeter, particularly in medical and personal applications

Studying CaSO4:Eu as an OSL phosphor

This study was carried out to investigate the properties of the OSL signal from Eu-doped calcium sulfate (CaSO4:Eu) phosphor and study on its thermal behavior as a function of temperature under a series of luminescence experiments. The suitability of its usage as an optically stimulated luminescence (OSL) dosimeter was also checked. CaSO4:Eu was synthesized using the precipitation method and prepared in pellet form. The dopant concentration value was performed as 0.1 mol%. The synthesized CaSO4:Eu was analyzed by X-ray diffraction (XRD) method to confirm the product. To have an idea about the crystallography and microstructure morphology of the material, scanning electron microscope (SEM) analysis were carried out. It was found that the OSL signal is a resultant signal having three components and exhibits thermal quenching above 150 degrees C. The excitation spectrum of CaSO4:Eu showed, different peaks in the region 220-360 nm with the highest one at 269 nm. Thermoluminescence (TL) signals of CaSO4:Eu pellets were obtained and compared with the TL signals obtained after OSL measurements of the same pellets by blue light stimulation. The low temperature, peak near 180 degrees C did not show any significant change in TL after OSL measurement whereas the high temperature peak at 240 degrees C was bleached with the blue light illumination and might be responsible for the observed OSL signal. The dosimetric properties such as dose response, minimum detectable dose, energy response, reusability, fading properties, thermal stability and effect of reading temperatures on OSL signals were examined. OSL signals of CaSO4:Eu pellets were decreased by approximately 8% at the end of the 24 h and by about 7% at the end of 28 days when compared with the first readout. The thermal stability of the 240 degrees C TL peak and OSL signal using isothermal decay measurements were used to determine the trap parameters. The CaSO4:Eu OSL dosimeter in accordance with the presented study allows a high-sensitivity OSL phosphor whose host material was previously known as conventional synthetic CaSO4 TLD material. (C) 2017 Elsevier B.V. All rights reserved

Investigation of in vitro PDT activities of zinc phthalocyanine immobilised TiO2 nanoparticles

WOS: 000401108500044PubMed ID: 28365390Phthalocyanines (Pcs) are commonly used as Photosensors (PSs) in Photodynamic Therapy (PDT) applications due to their intense absorption in the far red-near IR spectral region with a high extinction coefficient and high ability for generating singlet oxygen. Pcs targetspecifically tumors, and do not show any considerable toxic effects under the absence of light. In particular, their chemical versatility has allowed the introducion a number of substituent at the periferal or axial positions which provide modulating photophysical properties, increases the solubility of these compounds in organic solvents. Nanoparticles increase the bioavailability, stability, and transport of PSs to target tissue. TiO2 nanoparticles are prefered in these applications because of their non toxic, low cost and high chemical stability properties. In our study, a Zinc Phthalocyanine (ZnPc) was used as a photosensor. The design of ZnPc integrated TiO2 nanoparticles is intended to make PSs a more effective PDT agent. With the aim to examine the nuclear imaging/treatment potentials of ZnPc and ZnPc-TiO2 in hepatocellular carcinoma (HepG2), colorectal adenocarcinoma (HT29) tumor and human healthy lung (WI38) cell lines in vitro study ZnPc and TiO2-ZnPc were also labeled with I-131. It is determined that I-131-ZnPc-TiO2 nanoparticle show a potential as an agent for the imaging/treatment of hepatocellular cancer by in vitro. The toxicity studies revealed that TiO2 nanoparticle decreases the toxicity of ZnPc. In vitro PDT results show that TiO2-ZnPc has a potential as a PDT agent in colon tumor treatment. Consequently, synthesized ZnPc and ZnPc-TiO2 could be promising candidates as theranostic agents. (C) 2017 Elsevier B.V. All rights reserved.Scientific and Technological Research Council of Turkey, TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [114Z430]The authors gratefully acknowledge the financial support by The Scientific and Technological Research Council of Turkey, TUBITAK (Grant no: 114Z430)

Photodynamic therapy and nuclear imaging activities of zinc phthalocyanine-integrated TiO2 nanoparticles in breast and cervical tumors

WOS: 000425729000014PubMed ID: 29136341In recent years, phthalocyanines (Pcs) have been widely used as photosensitizer in photodynamic therapy applications. Because of their strong absorptions in the near-infrared region (640-700nm). The integration of phthalocyanine derivatives to a nanoparticle is expected to be efficient way to improve the activity of the photosensitizer on the targeted tissue. It is known that the integrated molecules not only show better accumulation on tumor tissue but also reduce toxicity in healthy tissues. In this study, the ZnPc molecule was synthesized and integrated to the TiO2 nanoparticle, to investigate the potential of PDT and its cytotoxicity. Additionally, ZnPc and ZnPc-TiO2 molecules were labeled with I-131 and it was aimed to put forth the nuclear imaging/therapy potentials of I-131 labeled ZnPc/ZnPc-TiO2 by determining in vitro uptakes in mouse mammary carcinoma (EMT6), human cervical adenocarcinoma (HeLa). In result of our study, it was observed that the radiolabeling yields of the synthesized ZnPc and ZnPc-TiO2 with I-131 were quite high. In vitro uptake studies shown that I-131-ZnPc-TiO2 could be a potential agent for nuclear imaging/treatment of breast and cervical cancers. According to PDT results, ZnPc-TiO2 might have as to be a potential PDT agent in the treatment of cervical tumor. ZnPc and ZnPc-TiO2 might be used as theranostic agents.Scientific and Technological Research Council of Turkey, TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [114Z430]The Scientific and Technological Research Council of Turkey, TUBITAK, Grant/Award Number: 114Z43

Evaluation of photodynamic therapy and nuclear imaging potential of subphthalocyanine integrated TiO2 nanoparticles in mammary and cervical tumor cells

###EgeUn###This study, subphthalocyanines (SubPc) and SubPc integrated TiO2 nanoparticles (SubPc-TiO2) were synthesized as novel photosensitizers. Their PDT effects were evaluated. Furthermore, nuclear imaging potential of I-131-labelled SubPc/SubPc-TiO2 were examined in mouse mammary carcinoma (EMT6) and cervix adenocarcinoma (HeLa) cell lines. The uptake results show that SubPc labelled with I-131 radionuclide ((131) I-SubPc) in EMT6 and HeLa cell lines was found to be approximately the same as in the WI38 cell line. However, the uptake values of SubPc-TiO2 labelled with I-131(I-131-SubPc- TiO2) in EMT6 and HeLa cell lines were determined to be two times higher than in the WI38 cell line. In other words, the target/non-target tissue ratio was identified as two in the EMT6 and HeLa cell lines. I-131-SubPc-TiO2 is promising for imaging or treatment of breast and cervix tumors. In vitro photodynamic therapy studies have shown that SubPc and SubPc-TiO2 are suitable agents for PDT. In addition, SubPc-TiO2 has higher phototoxicity than SubPc. As a future study, in vivo experiments will be held and performed in tumor-bearing nude mice.Scientific and Technological Research Council of Turkey, TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [114Z430]The authors gratefully acknowledge financial support by The Scientific and Technological Research Council of Turkey, TUBITAK (Grant no: 114Z430)

Illness perception of dropout patients followed up at bipolar outpatient clinic, Turkey

Dropout is a common problem in the treatment of psychiatric illnesses including bipolar disorders (BD). The aim of the present study is to investigate illness perceptions of dropout patients with BD. A cross sectional study was done on the participants who attended the Mood Disorder Outpatient Clinic at least 3 times from January 2003 through June 2008, and then failed to attend clinic till to the last one year, 2009, determined as dropout. Thirty-nine dropout patients and 39 attendent patients with BD were recruited for this study. A sociodemographic form and brief illness perception questionnaire were used to capture data. The main reasons of patients with BD for dropout were difficulties of transport (31%), to visit another doctor (26%), giving up drugs (13%) and low education level (59%) is significant for dropout patients. The dropout patients reported that their illness did not critically influence their lives, their treatment had failed to control their illnesses, they had no symptoms, and that their illness did not emotionally affect them. In conclusion, the nonattendance of patients with serious mental illness can result in non-compliance of therapeutic drug regimens, and a recurrence of the appearance symptoms. The perception of illness in dropout patients with BD may be important for understanding and preventing nonattendance. (C) 2015 Elsevier B.V. All rights reserved