Quantification of the radiosensitization effect of high-nanoparticles on photon irradiated cells: combining Monte Carlo simulations and an analytical approach to the local effect model.

experiments show significant reduction in the survival fraction of cells under irradiation treatments assisted with high-nanoparticles (NPs). In order to predict the radiosensitization effect of NPs, a modification of the local effect model (LEM), in which the energy deposition from NPs is assessed by Monte Carlo (MC) radiation transport codes, has been employed in the past. In this work, a combined framework that splits the consideration of the radiosensitization effect into two steps is proposed.

Identification of refractory zirconia from catalytic converters in dust: An emerging pollutant in urban environments.

Using catalytic converters is one of the most effective methods to control vehicle emissions. A washcoat of cerium oxide-zirconia (CeO-ZrO) has been used to enhance the performance of the catalytic converter device. To date, the prevalence of this material in the environment has not been assessed.

Metal bioaccessibility, particle size distribution and polydispersity of playground dust in synthetic lysosomal fluids.

Inhalation of playground dust-derived fine particles in schoolyards poses a risk from exposure to metal(oids) and minerals. In this work, we obtained the total concentration and bioaccessibility of metal(oids) with Gamble Solution (GS) and Artificial Lysosomal Fluid (ALF) synthetic solutions, simulating the extracellular neutral pH environment of the lung and the intracellular conditions of the macrophage, respectively. Scanning Electron Microscope (SEM), and Dynamic Light Scattering analysis (DLS) techniques were used to characterize particles with a size smaller than 2.

Nanoscale dose deposition in cell structures under X-ray irradiation treatment assisted with nanoparticles: An analytical approach to the relative biological effectiveness.

In this study, an analytical model for the assessment of the modification of cell culture survival under ionizing radiation assisted with nanoparticles (NPs) is presented. The model starts from the radial dose deposition around a single NP, which is used to describe the dose deposition in a cell structure with embedded NPs and, in turn, to evaluate the number of lesions formed by ionizing radiation. The model is applied to the calculation of relative biological effectiveness values for cells exposed to 0.

SERS spectroscopy and SERS imaging of Shewanella oneidensis using silver nanoparticles and nanowires.

Facile and reproducible SERS signals from Shewanella oneidensis were obtained utilizing silver nanoparticles (AgNPs) and silver nanowires (AgNWs). Additionally, SERS images identify the distribution of SERS hot-spots. One important observation is the synergistically enhanced SERS signal when AgNPs and AgNWs are used in conjunction, due to constructively enhanced electromagnetic field.

Thermoluminescence and optically stimulated luminescence properties of beta-irradiated TiO2:Yb nanoparticles.

The thermoluminescence (TL) and optically stimulated luminescenece (OSL) response of TiO2:Yb nanoparticles are studied. After beta irradiation, the materials developed a significant TL/OSL signal associated to several localized trapping states around 360-620 K. The OSL signal is mainly due to the releasing of trapped charges in the low temperature (360 and 460 K) trapping states.

Effect of Yb doping on the afterglow and thermoluminescent properties of ZnO nanophosphors.

ZnO nanophosphors prepared by a glycol mediated chemical synthesis exhibit afterglow (AG) and thermoluminescence (TL) after excitation with beta rays. These properties, which are of great interest in dose assessment of ionizing radiation fields, could be appreciably modified by Yb doping. Concentration of 1, 2 and 5% diminished the AG and TL efficiency and modified the TL glow curve shape significantly.

Thermoluminescence properties of undoped and Dy3+ doped ZrO2 nanophosphor under beta-ray irradiation.

The thermoluminescence (TL) of undoped and Dy3+ doped ZrO2 nanocrystals under beta-ray irradiation is reported. The TL glow curves are the result of the overlapping of four TL peaks produced partly by the intrinsic defect of highly asymmetrical monoclinic structure and partly due to defects produced during the synthesis process. The introduction of dopant ions induces changes in the glow curve due to the enhancement of high temperature peaks intensity.

Dose dependences of radiation induced yield in mixed radiation fields.

A theoretical model that describes dose dependences of trap filling (radiation yield) in mixed radiation fields consisting of two components is proposed. The model consists of one type of electron traps and one type of hole traps and assumes as an initial step the creation of two types of tracks, each represented by some volume with a uniform electron-hole pair density, different for each track. The relaxation process that follows comprises interband recombination, trapping of electrons and holes, and recombination of electrons with trapped holes and of holes with trapped electrons.

Optical absorption and thermoluminescence in single NaCl:Cu crystals exposed to 60Co and UV light.

Optical absorption (OA) and thermally stimulated luminescence measurements were performed on NaCl:Cu+(0.04 and 0.08%) crystals blocks grown by the Czochralski technique.

Optically stimulated luminescence dosimetry performance of natural Brazilian topaz exposed to beta radiation.

Optically stimulated luminescence (OSL) has become the technique of choice in many areas of dosimetry. Natural materials like topaz are available in large quantities in Brazil and other countries. They have been studied to investigate the possibility of use its thermoluminescence (TL) properties for dosimetric applications.

Thermoluminescence response of new KCl(X)Br(1-X):EuCl3 sintered phosphors exposed to beta and gamma radiation.

Alkali halides crystals have been the subject of intense research for an understanding of their radiation-induced defects and luminescence properties. They exhibit noteworthy thermoluminescence (TL) properties when exposed to ionising radiation. Currently, these materials are grown employing expensive and rather complicated techniques.

Thermoluminescence behaviour of KCL(1-x)Br(x):Pb2+ exposed to gamma radiation.

The thermoluminescence (TL) behaviour of solid solutions of lead doped KCl(1-x)Br(x) (X = 0.02, 0.35, 0.

Optical absorption, TL and IRSL of basic plagioclase megacrysts from the pinacate (Sonora, Mexico) quaternary alkalic volcanics.

The paper presents the first results of an investigation on optical absorption (OA), thermally and infrared stimulated luminescence (TL and IRSL) of the Pinacate plagioclase (labradorite). The OA spectra reveal two bands with maxima at 1.0 and 3.

Performance of CVD diamond as an optically and thermally stimulated luminescence dosemeter.

Diamond is a material with extreme physical properties. Its radiation hardness, chemical inertness and tissue equivalence qualify it as an ideal material for radiation dosimetry. In the present work, the optically stimulated luminescence (OSL) and thermoluminescence (TL) characteristics of a 10 microm thick CVD diamond (polycrystalline diamond films prepared by chemical vapor deposition) film were studied in order to test its performance as a beta radiation dosemeter.

Thermoluminescence properties of KCl(1-X)KBrX:Pb2+ mixed crystals.

A study is presented of the thermoluminescence (TL) of phosphors based on potassium halides doped with divalent lead, such as KCl:Pb2+, KBr:Pb2+ and the crystalline series KCl(1-X)Br(X):Pb2+. The defects in the crystals generated by irradiation have been investigated as well as the trapping and room temperature recombination mechanisms. The samples were gamma irradiated to a dose of 10 kGy.

Thermoluminescence in CVD diamond films: application to actinometric dosimetry.

Diamond is considered a tissue-equivalent material since its atomic number (Z =6) is close to the effective atomic number of biological tissue (Z =7.42). Such a situation makes it suitable for radiation detection purposes in medical applications.

Ultraviolet thermoluminscent dosimetry using high temperature peaks in KCl:Eu2+ crystals.

The thermoluminescence (TL) characteristics of KCl:Eu2+ irradiated with solar and monochromatic ultraviolet (UV) light have been investigated. The glow curves exhibit at least five TL peaks between room temperature and 673 K. The low temperature peaks (<500 K) are very sensitive to the UV radiation, but their intensities practically do not depend on the duration of solar irradiation and are determined by the ratio between the creation rate by UV and the bleaching rate by visible light.

Study of the phototransferred thermoluminescence in KCl:Eu2+ phosphors.

The phototransferred thermoluminescence (PITL) processes play an important role in the optical stimulated luminescence (OSL) and thermoluminescence (TL) dosimetric properties in KCl:Eu2+ crystals. In the present work, experimental evidence is presented about the participation of F and Fz centres in the associated recombination luminescence mechanisms involved with all three phenomena. An analysis of the TL glow curve of KCl:Eu2+ exposed to X ray ionising radiation shows three main thermoluminescence peaks around 370, 390 and 470 K.

Application of a thermoluminescence method for the detection of irradiated spices.

Food irradiation is extremely effective at reducing food-borne illness as well as losses caused by infestation and contamination. Despite the well-established regulations that permit irradiation to control pathogens in spices, there are no widespread methods to detect previously irradiated food. Therefore, it has become necessary to develop new detection and dose determination methods for food subjected previously to irradiation.