505 research outputs found

    Hematopoietic Functions of the Bone Marrow in the Cases Irradiated with Ultra-short Waves on the Diencephalon Part 3 Therapeutic Effects of the Irradiation of Ultra-short Waves in the Rabbits with Experimental Anemia and in the Patients with Hypoplastic Anemia

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    The following results were obtained in the study of the rabbits with experimental anemia and the patients with hypoplastic anemia both treated with ultra-short waves in the Diencephalon. 1) In the rabbits with experimental anemia induced by the venesection of blood, the phenylhydrazine and benzol intoxication, the period of time for the recovery of anemia was shortened in the cases with the treatment of ultra-short waves faster than in the cases without treatment. 2) In the rabbits with anemia induced by the venesection of blood and the phenylhydrazine intoxication, the bone marrow function were accelerated by successive irradiations sooner than by a single irradiation. 3) In one of three Patients with hypoplastic anemia some effect from the treatment was observable

    Aspergillus niger Spores Are Highly Resistant to Space Radiation

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    The filamentous fungus Aspergillus niger is one of the main contaminants of the International Space Station (ISS). It forms highly pigmented, airborne spores that have thick cell walls and low metabolic activity, enabling them to withstand harsh conditions and colonize spacecraft surfaces. Whether A. niger spores are resistant to space radiation, and to what extent, is not yet known. In this study, spore suspensions of a wild-type and three mutant strains (with defects in pigmentation, DNA repair, and polar growth control) were exposed to X-rays, cosmic radiation (helium- and iron-ions) and UV-C (254 nm). To assess the level of resistance and survival limits of fungal spores in a long-term interplanetary mission scenario, we tested radiation doses up to 1000 Gy and 4000 J/m2. For comparison, a 360-day round-trip to Mars yields a dose of 0.66 ± 0.12 Gy. Overall, wild-type spores of A. niger were able to withstand high doses of X-ray (LD90 = 360 Gy) and cosmic radiation (helium-ion LD90 = 500 Gy; and iron-ion LD90 = 100 Gy). Drying the spores before irradiation made them more susceptible toward X-ray radiation. Notably, A. niger spores are highly resistant to UV-C radiation (LD90 = 1038 J/m2), which is significantly higher than that of other radiation-resistant microorganisms (e.g., Deinococcus radiodurans). In all strains, UV-C treated spores (1000 J/m2) were shown to have decreased biofilm formation (81% reduction in wild-type spores). This study suggests that A. niger spores might not be easily inactivated by exposure to space radiation alone and that current planetary protection guidelines should be revisited, considering the high resistance of fungal spores

    Studying the effects of galactic cosmic radiation on astro- and microbiological model systems

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    In-depth knowledge regarding the biological effects of the radiation field in space is required for assessing the radiation risks in space. Within the last 50 years, space technology has provided tools for transporting terrestrial life beyond this protective magnetic field in order to study in situ responses to selected conditions of space (reviewed in Horneck et al., 2010). From a biological perspective applicable to simple and complex organisms (ranging from biomolecules and microorganisms to humans) various influential physical modifications such as increased radiation exposure were experienced onboard an orbiting spacecraft in low Earth orbit (LEO), out- and inside the International Space Station (ISS), orbiting Moon or on the way to other astrobiological-interesting targets (Mars or icy moons of Saturn or Jupiter). The majority of experiments on microorganisms in space were performed using Earth-orbiting robotic spacecraft, e.g., the Russian Foton satellites (FOTON) and the European Retrievable Carrier (EURECA), or human-tended spacecraft, such as space shuttles and space stations, e.g., MIR and ISS (reviewed in Nicholson, 2009; Nicholson et al., 2009; Horneck et al., 2010)

    In vitro characterization of cells derived from chordoma cell line U-CH1 following treatment with X-rays, heavy ions and chemotherapeutic drugs

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    <p>Abstract</p> <p>Background</p> <p>Chordoma, a rare cancer, is usually treated with surgery and/or radiation. However, very limited characterizations of chordoma cells are available due to a minimal availability (only two lines validated by now) and the extremely long doubling time. In order to overcome this situation, we successfully derived a cell line with a shorter doubling time from the first validated chordoma line U-CH1 and obtained invaluable cell biological data.</p> <p>Method</p> <p>After isolating a subpopulation of U-CH1 cells with a short doubling time (U-CH1-N), cell growth, cell cycle distribution, DNA content, chromosome number, p53 status, and cell survival were examined after exposure to X-rays, heavy ions, camptothecin, mitomycin C, cisplatin and bleocin. These data were compared with those of HeLa (cervical cancer) and U87-MG (glioblastoma) cells.</p> <p>Results</p> <p>The cell doubling times for HeLa, U87-MG and U-CH1-N were approximately 18 h, 24 h and 3 days respectively. Heavy ion irradiation resulted in more efficient cell killing than x-rays in all three cell lines. Relative biological effectiveness (RBE) at 10% survival for U-CH1-N was about 2.45 for 70 keV/ÎŒm carbon and 3.86 for 200 keV/ÎŒm iron ions. Of the four chemicals, bleocin showed the most marked cytotoxic effect on U-CH1-N.</p> <p>Conclusion</p> <p>Our data provide the first comprehensive cellular characterization using cells of chordoma origin and furnish the biological basis for successful clinical results of chordoma treatment by heavy ions.</p

    Pollution of Polyaromatic Hydrocarbons in the Airborne Particles in the Developing Countries in Asia Region

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    Joint Research on Environmental Science and Technology for the Eart

    Chemical, Thermal, and Radiation Resistance of an Iron Porphyrin: A Model Study of Biosignature Stability

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    Metal complexes of porphyrins and porphyrin-type compounds are ubiquitous in all three domains of life, with hemes and chlorophylls being the best-known examples. Their diagenetic transformation products are found as geoporphyrins, in which the characteristic porphyrin core structure is retained and which can be up to 1.1 billion years old. Because of this, and their relative ease of detection, metalloporphyrins appear attractive as chemical biosignatures in the search for extraterrestrial life. In this study, we investigated the stability of solid chlorido(2,3,7,8,12,13,17,18-octaethylporphyrinato)iron(III) [FeCl(oep)], which served as a model for heme-like molecules and iron geoporphyrins. [FeCl(oep)] was exposed to a variety of astrobiologically relevant extreme conditions, namely: aqueous acids and bases, oxidants, heat, and radiation. Key results are: (1) the [Fe(oep)]âș core is stable over the pH range 0.0–13.5 even at 80°C; (2) the oxidizing power follows the order ClO⁻ > H₂O₂ > ClO₃⁻ > HNO₃ > ClO₄⁻; (3) in an inert atmosphere, the iron porphyrin is thermally stable to near 250°C; (4) at high temperatures, carbon dioxide gas is not inert but acts as an oxidant, forming carbon monoxide; (5) a decomposition layer is formed on ultraviolet irradiation and protects the [FeCl(oep)] underneath; (6) an NaCl/NaHCO₃ salt mixture has a protective effect against X-rays; and (7) no such effect is observed when [FeCl(oep)] is exposed to iron ion particle radiation. The relevance to potential iron porphyrin biosignatures on Mars, Europa, and Enceladus is discussed
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