Breaking the DNA by soft X-rays in the water window reveals the scavenging and temporal behaviour of OH radicals.

A laser-plasma source emitting photons with energies in the water window spectral range has been used to reveal the radiation chemical yields of single-strand breaks in plasmid DNA as a function of OH radical scavenger concentration. Direct and indirect effects were investigated separately using DNA samples with various levels of hydration. We experimentally determined the value of the efficiency factor for strand cleavage in DNA caused by the reaction with OH radicals at 0.

Unraveling the role of human microglia in tick-borne encephalitis virus infection: insights into neuroinflammation and viral pathogenesis.

Tick-borne encephalitis virus (TBEV) is a neurotropic orthoflavivirus responsible for severe infections of the central nervous system. Although neurons are predominantly targeted, specific involvement of microglia in pathogenesis of TBE is not yet fully understood. In this study, the susceptibility of human microglia to TBEV is investigated, focusing on productive infection and different immune responses of different viral strains.

Effect of elevated temperature and hydrocortisone addition on the proliferation of fibroblasts.

Hyperthermia along with hydrocortisone (HC) are proven teratogens that can negatively influence embryo development during early pregnancy. Proliferation of cells is one of the main developmental processes during the early embryogenesis. This study was focused on testing the effect of elevated temperature and HC addition on proliferation of cells in in vitro cultures.

Applicability of Gene Expression in Saliva as an Alternative to Blood for Biodosimetry and Prediction of Radiation-induced Health Effects.

As the great majority of gene expression (GE) biodosimetry studies have been performed using blood as the preferred source of tissue, searching for simple and less-invasive sampling methods is important when considering biodosimetry approaches. Knowing that whole saliva contains an ultrafiltrate of blood and white blood cells, it is expected that the findings in blood can also be found in saliva. This human in vivo study aims to examine radiation-induced GE changes in saliva for biodosimetry purposes and to predict radiation-induced disease, which is yet poorly characterized.

RADIATION DAMAGE TO DNA PLASMIDS IN THE PRESENCE OF BOROCAPTATES.

Boron derivatives have great potential in cancer diagnostics and treatment. Borocaptates are used in boron neutron capture therapy and potentially in proton boron fusion therapy. This work examines modulation effects of two borocaptate compounds on radiation-induced DNA damage.

EXPERIMENTAL IN VITRO DOSIMETRY OF 223RA AND 177LU.

Targeted alpha therapy with radionuclides undergoing multiple alpha-particle decays is a promising method of nuclear medicine. To study the effectiveness of alpha versus beta emitters, survival of DU145 prostate cancer cells exposed to 223Ra or 177Lu was assessed. Per decay, the cells were much more sensitive to the alpha than beta emitter.

MONTE CARLO SIMULATIONS OF OUT-OF-FIELD LET SPECTRA IN WATER PHANTOM IRRADIATED BY SCANNING PENCIL PROTON BEAM.

LET spectra can be measured by track-etched detectors. However, these detectors are not able to identify the type of interacting particles. Monte Carlo simulations can provide this missing information.

BORON-ENHANCED BIOLOGICAL EFFECTIVENESS OF PROTON IRRADIATION: STRATEGY TO ASSESS THE UNDERPINNING MECHANISM.

Proton radiotherapy for the treatment of cancer offers an excellent dose distribution. Cellular experiments have shown that in terms of biological effects, the sharp dose distribution is further amplified, by as much as 75%, in the presence of boron. It is a matter of debate whether the underlying physical processes involve the nuclear reaction of 11B with protons or 10B with secondary neutrons, both producing densely ionizing short-ranged particles.

Out-of-Field Doses Produced by a Proton Scanning Beam Inside Pediatric Anthropomorphic Phantoms and Their Comparison With Different Photon Modalities.

Since 2010, EURADOS Working Group 9 (Radiation Dosimetry in Radiotherapy) has been involved in the investigation of secondary and scattered radiation doses in X-ray and proton therapy, especially in the case of pediatric patients. The main goal of this paper is to analyze and compare out-of-field neutron and non-neutron organ doses inside 5- and 10-year-old pediatric anthropomorphic phantoms for the treatment of a 5-cm-diameter brain tumor. Proton irradiations were carried out at the Cyclotron Centre Bronowice in IFJ PAN Krakow Poland using a pencil beam scanning technique (PBS) at a gantry with a dedicated scanning nozzle (IBA Proton Therapy System, Proteus 235).

Examining potential confounding factors in gene expression analysis of human saliva and identifying potential housekeeping genes.

Isolation of RNA from whole saliva, a non-invasive and easily accessible biofluid that is an attractive alternative to blood for high-throughput biodosimetry of radiological/nuclear victims might be of clinical significance for prediction and diagnosis of disease. In a previous analysis of 12 human samples we identified two challenges to measuring gene expression from total RNA: (1) the fraction of human RNA in whole saliva was low and (2) the bacterial contamination was overwhelming. To overcome these challenges, we performed selective cDNA synthesis for human RNA species only by employing poly(A)+-tail primers followed by qRT-PCR.

Out-of-field doses in pediatric craniospinal irradiations with 3D-CRT, VMAT, and scanning proton radiotherapy: A phantom study.

Purpose: Craniospinal irradiation (CSI) has greatly increased survival rates for patients with a diagnosis of medulloblastoma and other primitive neuroectodermal tumors. However, as it includes exposure of a large volume of healthy tissue to unwanted doses, there is a strong concern about the complications of the treatment, especially for the children. To estimate the risk of second cancers and other unwanted effects, out-of-field dose assessment is necessary.

Folding DNA into origami nanostructures enhances resistance to ionizing radiation.

We report experimental results on damage induced by ionizing radiation to DNA origami triangles which are commonly used prototypes for scaffolded DNA origami nanostructures. We demonstrate extreme stability of DNA origami upon irradiation, which is caused by (i) the multi-row design holding the shape of the origami even after severe damage to the scaffold DNA and (ii) the reduction of damage to the scaffold DNA due to the protective effect of the folded structure. With respect to damage induced by ionizing radiation, the protective effect of the structure is superior to that of a naturally paired DNA double helix.

Adult Feeding Preference and Fecundity in the Large Pine Weevil, (Coleoptera: Curculionidae).

Adult feeding preferences of on , , , , and were tested in outdoor conditions. The preferred food source was , and the mean bark area consumed per seedling was 440.8 ± 147.

Gamma radiation effects on diamond field-effect biosensors with fibroblasts and extracellular matrix.

Due to high biocompatibility, miniaturization, optical transparency and low production cost together with high radiation hardness the diamond-based sensors are considered promising for radiation medicine and biomedicine in general. Here we present detection of fibroblast cell culture properties by nanocrystalline diamond solution-gated field-effect transistors (SG-FET), including effects of gamma irradiation. We show that blank nanocrystalline diamond field-effect biosensors are stable at least up to 300 Gy of γ irradiation.

Assessment of DNA damage with an adapted independent reaction time approach implemented in Geant4-DNA for the simulation of diffusion-controlled reactions between radio-induced reactive species and a chromatin fiber.

Purpose: Simulation of indirect damage originating from the attack of free radical species produced by ionizing radiation on biological molecules based on the independent pair approximation is investigated in this work. In addition, a new approach, relying on the independent pair approximation that is at the origin of the independent reaction time (IRT) method, is proposed in the chemical stage of Geant4-DNA.

Methods: This new approach has been designed to respect the current Geant4-DNA chemistry framework while proposing a variant IRT method.

Out-of-field doses for scanning proton radiotherapy of shallowly located paediatric tumours-a comparison of range shifter and 3D printed compensator.

The lowest possible energy of proton scanning beam in cyclotron proton therapy facilities is typically between 60 and 100 MeV. Treatment of superficial lesions requires a pre-absorber to deliver doses to shallower volumes. In most of the cases a range shifter (RS) is used, but as an alternative solution, a patient-specific 3D printed proton beam compensator (BC) can be applied.

In Vivo Validation of Alternative FDXR Transcripts in Human Blood in Response to Ionizing Radiation.

Following cell stress such as ionising radiation (IR) exposure, multiple cellular pathways are activated. We recently demonstrated that ferredoxin reductase (FDXR) has a remarkable IR-induced transcriptional responsiveness in blood. Here, we provided a first comprehensive FDXR variant profile following DNA damage.

In Vitro Comparison of Passive and Active Clinical Proton Beams.

Nowadays, the irradiation methodology in proton therapy is switching from the use of passively scattered beams to active pencil beams due to the possibility of more conformal dose distributions. The dose rates of active pencil beams are much higher than those of passive beams. The purpose of this study was to investigate whether there is any difference in the biological effectiveness of these passive and active irradiation modes.

Overcoming challenges in human saliva gene expression measurements.

Saliva, as a non-invasive and easily accessible biofluid, has been shown to contain RNA biomarkers for prediction and diagnosis of several diseases. However, systematic analysis done by our group identified two problematic issues not coherently described before: (1) most of the isolated RNA originates from the oral microbiome and (2) the amount of isolated human RNA is comparatively low. The degree of bacterial contamination showed ratios up to 1:900,000, so that only about one out of 900,000 RNA copies was of human origin, but the RNA quality (average RIN 6.

RADIOPROTECTIVE EFFECT OF HYDROXYL RADICAL SCAVENGERS ON PROKARYOTIC AND EUKARYOTIC CELLS UNDER VARIOUS GAMMA IRRADIATION CONDITIONS.

The influence of various hydroxyl radical scavengers such as methanol, ethanol and dimethyl sulfoxide on radiation sensitivity of prokaryotic cells (bacteria Escherichia coli) and eukaryotic cells (yeast Saccharomyces cerevisiae and V79 cells-Chinese hamster pulmonary fibroblasts) irradiated by 60Co gamma radiation was investigated. The dependence of radiation sensitivity on dose rate in range from 1.8 to 100 Gy h-1 was evaluated.

RADIATION-INDUCED PLASMID DNA DAMAGE: EFFECT OF CONCENTRATION AND LENGTH.

Plasmid DNA is commonly used as a simpler substitute for a cell in studies of early effects of ionizing radiation because it allows to determine yields of primary DNA lesions. Experimental studies often employ plasmids of different lengths, in different concentrations in the aqueous solution. Influence of these parameters on the heavy-ion induced yields of primary DNA damage has been studied, using plasmids pUC19 (2686 bp), pBR322 (4361 bp) and pKLAC2 (9107 bp) in 10 and 50 ng/μl concentration.

COMPARISON OF THE RADIATION SENSITIVITY OF THE BREAST CANCER CELL LINE MCF7 AND HUMAN ADIPOSE-DERIVED STEM CELLS.

A comparison between breast cancer cell line MCF7 and human adipose-derived stem cells (ADSC) after irradiation by the same doses of megavoltage X-rays was performed. The cell growth, the induction of apoptosis and the expression of selected genes were analyzed. Irradiated MCF7 related to its control sample grows slower than ADSC and it undergoes apoptosis in much higher levels than ADSC.

OVERVIEW OF AIRCREW EXPOSURE TO COSMIC RADIATION IN THE CZECH REPUBLIC.

Monitoring of exposures of aircrew members of airline operators registered in the Czech Republic has been performed since 1998. The individual effective doses are calculated using the computer code CARI annually. The calculations are based on information about participation of aircrew members on the specific flights and on the parameters describing the typical flight profiles of the flights; the latter is regularly verified with control measurements performed onboard aircraft.