track-structure
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Track structure based simulations valuably complement experimental research on biological effects of ionizing radiation. They provide information at the highest level of detail on initial DNA damage induced by diverse types of radiation. Simulations with the biophysical Monte Carlo code PARTRAC have been used for testing working hypotheses on radiation action mechanisms, for benchmarking other damage codes and as input for modelling subsequent biological processes. To facilitate such applications and in particular to enable extending the simulations to mixed radiation field conditions, we present analytical formulas that capture PARTRAC simulation results on DNA single- and double-strand breaks and their clusters induced in cells irradiated by ions ranging from hydrogen to neon at energies from 0.5 GeV/u down to their stopping. These functions offer a means by which radiation transport codes at the macroscopic scale could easily be extended to predict biological effects, exploiting a large database of results from micro-/nanoscale simulations, without having to deal with the coupling of spatial scales and running full track-structure calculations.
- MeSH
- dvouřetězcové zlomy DNA účinky záření MeSH
- lidé MeSH
- lineární přenos energie MeSH
- metoda Monte Carlo * MeSH
- poškození DNA * MeSH
- protony * MeSH
- radioterapie * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Diverse isotopes such as 2H, 3He, 10Be, 11C and 14C occur in nuclear reactions in ion beam radiotherapy, in cosmic ray shielding, or are intentionally accelerated in dating techniques. However, only a few studies have specifically addressed the biological effects of diverse isotopes and were limited to energies of several MeV/u. A database of simulations with the PARTRAC biophysical tool is presented for H, He, Li, Be, B and C isotopes at energies from 0.5 GeV/u down to stopping. The doses deposited to a cell nucleus and also the yields per unit dose of single- and double-strand breaks and their clusters induced in cellular DNA are predicted to vary among diverse isotopes of the same element at energies < 1 MeV/u, especially for isotopes of H and He. The results may affect the risk estimates for astronauts in deep space missions or the models of biological effectiveness of ion beams and indicate that radiation protection in 14C or 10Be dating techniques may be based on knowledge gathered with 12C or 9Be.
- MeSH
- DNA MeSH
- ionty MeSH
- izotopy * MeSH
- metoda Monte Carlo MeSH
- poškození DNA * MeSH
- Publikační typ
- časopisecké články MeSH
Understanding the fundamental mechanisms involved in the induction of biological damage by ionizing radiation remains a major challenge of today's radiobiology research. The Monte Carlo simulation of physical, physicochemical and chemical processes involved may provide a powerful tool for the simulation of early damage induction. The Geant4-DNA extension of the general purpose Monte Carlo Geant4 simulation toolkit aims to provide the scientific community with an open source access platform for the mechanistic simulation of such early damage. This paper presents the most recent review of the Geant4-DNA extension, as available to Geant4 users since June 2015 (release 10.2 Beta). In particular, the review includes the description of new physical models for the description of electron elastic and inelastic interactions in liquid water, as well as new examples dedicated to the simulation of physicochemical and chemical stages of water radiolysis. Several implementations of geometrical models of biological targets are presented as well, and the list of Geant4-DNA examples is described.
- MeSH
- chemické jevy MeSH
- DNA chemie MeSH
- lidé MeSH
- metoda Monte Carlo * MeSH
- molekulární modely * MeSH
- voda chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
... I: Structural Genomics -Target Selection -- Track II: Strategic Alliances -- Networking Break in the ... ... Exhibit Hall -- Track I: Structural Genomics - Cloning, Expression, Purification, and Crystallization ... ... Exhibit Viewing & Free Time -- 1:15 pm-3:30 pm Track I: Structural Genomics - Cloning, Expression, Purification ... ... , and Crystallization (continued) Track I: Structural Genomics -Structure Solution Track II: Strategic ... ... I: Structural Genomics -Assigning Function from Structure Track II: Technology Workshops -- 5:30 pm ...
4 svazky : ilustrace ; 28 cm
- MeSH
- metody pro přípravu analytických vzorků MeSH
- proteiny analýza MeSH
- proteomika metody MeSH
- Publikační typ
- abstrakty MeSH
- kongresy MeSH
- souborné dílo MeSH
- Konspekt
- Biologické vědy
- NLK Obory
- biologie
... catastrophes to the evolution of biosystems 58 -- [Jaroslav Valenta) -- 2.4 On some aspects of the structure ... ... bone tissue and its remodelling 63 -- 2.4.1 Introduction 63 -- [Jaroslav Valenta) -- 2.4.2 Periodic structure ... ... A mathematical model of a transversely isotropic medium 82 -- 2.5.4 Examples of the loading of structures ... ... system of features of a set of tracks of locomotion 514 -- 6.2.3 The mechanism of the origin of a track ... ... identification of a criminal by his tracks in a dispersive environment 542 -- 6.4.1 Simulation of a track ...
347 s. : obr., tab., přeruš.bibliogr.
Biomechanics is one of the branches of science contributing significantly not only to increasing our knowledge of the development of living systems but also to our understanding of the relevant laws of mechanics and their mechanical functions. Important anatomical and biomechanical data as related to the individual functions of the organism and their biomechanical significance are focussed on in this publication. The locomotor and circulatory apparatus and the identification of the mechanical properties of living tissue and materials used in osteosynthesis and alloarthroplasty are among the fields covered. The phenomena observed in the cardiovascular system are described using the basic equation of motion of viscous fluids. Suitable hydraulic models are proposed for investigation and testing of vascular grafts, artificial cardiac valves and artificial heart. Important research data are presented about biomechanical structures of the locomotoric apparatus, and joint rheology. A section is included presenting the fundamentals of the biomechanical analysis in criminology and in bioballistics.
Advances in fluorescent probe design and synthesis have allowed the uniform in situ labeling of individual RNA molecules. In a technique referred to as single molecule RNA FISH (smRNA FISH), the labeled RNA molecules can be imaged as diffraction-limited spots and counted using image analysis algorithms. Single RNA counting has provided valuable insights into the process of gene regulation. This microscopy-based method has often revealed a high cell-to-cell variability in expression levels, which has in turn led to a growing interest in investigating the biological significance of gene expression noise. Here we describe the application of the smRNA FISH technique to samples of Caenorhabditis elegans, a well-characterized model organism.
- MeSH
- algoritmy MeSH
- Caenorhabditis elegans genetika růst a vývoj metabolismus MeSH
- embryo nesavčí metabolismus ultrastruktura MeSH
- fixace tkání metody MeSH
- fluorescenční barviva chemie MeSH
- genetická transkripce MeSH
- hybridizace in situ fluorescenční metody MeSH
- messenger RNA chemie genetika metabolismus MeSH
- poměr signál - šum MeSH
- vývojová regulace genové exprese MeSH
- zobrazení jednotlivé molekuly metody MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The article deals with the measurement of dynamic effects that are transmitted to the driver (passenger) when driving in a car over obstacles. The measurements were performed in a real environment on a defined track at different driving speeds and different distributions of obstacles on the road. The reaction of the human organism, respectively the load of the cervical vertebrae and the heads of the driver and passenger, was measured. Experimental measurements were performed for different variants of driving conditions on a 28-year-old and healthy man. The measurement's main objective was to determine the acceleration values of the seats in the vehicle in the vertical movement of parts of the vehicle cabin and to determine the dynamic effects that are transmitted to the driver and passenger in a car when driving over obstacles. The measurements were performed in a real environment on a defined track at various driving speeds and diverse distributions of obstacles on the road. The acceleration values on the vehicle's axles and the structure of the driver's and front passenger's seats, under the buttocks, at the top of the head (Vertex Parietal Bone) and the C7 cervical vertebra (Vertebra Cervicales), were measured. The result of the experiment was to determine the maximum magnitudes of acceleration in the vertical direction on the body of the driver and the passenger of the vehicle when passing a passenger vehicle over obstacles. The analysis of the experiment's results is the basis for determining the future direction of the research.
- MeSH
- automobily * MeSH
- dopravní nehody MeSH
- dospělí MeSH
- krční obratle MeSH
- lidé MeSH
- řízení motorových vozidel * MeSH
- zrychlení MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
