108 research outputs found

    Comparison of photon volumetric modulated arc therapy, intensity-modulated proton therapy, and intensity-modulated carbon ion therapy for delivery of hypo-fractionated thoracic radiotherapy

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    Purpose The aim of the present study was to compare the dose distribution generated from photon volumetric modulated arc therapy (VMAT), intensity modulated proton therapy (IMPT), and intensity modulated carbon ion therapy (IMCIT) in the delivery of hypo-fractionated thoracic radiotherapy. Methods and materials Ten selected patients who underwent thoracic particle therapy between 2015 and 2016 were re-planned to receive a relative biological effectiveness (RBE) weighted dose of 60 Gy (i.e., GyE) in 15 fractions delivered with VMAT, IMPT, or IMCIT with the same optimization criteria. Treatment plans were then compared. Results There were no significant differences in target volume dose coverage or dose conformity, except improved D95 was found with IMCIT compared with VMAT (p = 0.01), and IMCIT was significantly better than IMPT in all target volume dose parameters. Particle therapy led to more prominent lung sparing at low doses, and this result was most prominent with IMCIT (p \u3c 0.05). Improved sparing of other thoracic organs at risk (OARs) was observed with particle therapy, and IMCIT further lowered the D1cc and D5cc for major blood vessels, as compared with IMPT (p = 0.01). Conclusion Although it was comparable to VMAT, IMCIT led to significantly better tumor target dose coverage and conformity than did IMPT. Particle therapy, compared with VMAT, improved thoracic OAR sparing. IMCIT, compared with IMPT, may further improve normal lung and major blood vessel sparing under limited respiratory motion

    Strain-induced high ferromagnetic transition temperature of MnAs epilayer grown on GaAs (110)

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    MnAs films are grown on GaAs surfaces by molecular beam epitaxy. Specular and grazing incidence X-ray diffractions are used to study the influence of different strain states of MnAs/GaAs (110) and MnAs/GaAs (001) on the first-order magnetostructural phase transition. It comes out that the first-order magnetostructural phase transition temperature Tt, at which the remnant magnetization becomes zero, is strongly affected by the strain constraint from different oriented GaAs substrates. Our results show an elevated Tt of 350 K for MnAs films grown on GaAs (110) surface, which is attributed to the effect of strain constraint from different directions

    Floral response to the Late Triassic Carnian Pluvial Episode

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    The Late Triassic Carnian Pluvial Episode (CPE; ca. 234–232 Ma) was characterized by dramatic global temperature and humidity increases, which in many terrestrial settings was accompanied by changes from arid to humid vegetation types. This study reviews current evidence of terrestrial floral composition and distribution during the CPE and analyzes spatial and temporal variation with relation to potential environmental driving mechanisms. Available evidence suggests the CPE was a globally significant event that triggered significant increases in the abundance of ferns and hygrophytes in terrestrial floras and freshwater algae in fluvial and lacustrine settings. These changes ended a long interval of relatively arid terrestrial climatic conditions since the early Triassic and are linked temporally with eruptions of the oceanic plateau Wrangellia Large Igneous Province (LIP). The massive release of greenhouse gasses including isotopically light CO2 during 3–4 distinct pulses of Wrangellia volcanism appears to have been the main driver of CPE climate change. Each pulse enhanced global atmospheric circulation and the hydrological cycle and resulted in changes from arid to humid conditions that affected floral abundance and composition. Higher terrestrial primary productivity in humid phases facilitated increased burial of terrestrial organic carbon and led to the recommencement of peat accumulation, ending the coal gap that had persisted since the earliest Triassic times. Enhanced movement of carbon from the atmosphere through the biosphere into the geosphere may have counteracted the warming effects of Wrangellia volcanic greenhouse gas emissions and ultimately led to the return of a steady climate state that terminated the warm and humid conditions of the CPE

    Scale-Up Production of Chicken Myoblasts in Microcarrier-Based System

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    With the rapid development of the cultivated meat industry, large-scale cell culture technology applied to cultivated meat production has received extensive attention. In this study, two microcarriers, Cytodex 1 and 3D TableTrix™, were used for suspension culture of myoblasts in spinner flasks to select a more suitable one for large-scale culture of myoblasts, and then the effects of different culture conditions on the large-scale culture of cells were explored. The microscopic results showed that Cytodex 1 was spheres with a smooth surface and no macroporous structure, and 3D TableTrix™ was irregular spheres with a porous surface and large pores. The results of cell culture in spinner flasks showed that the cells grew on 3D TableTrix™ more efficiently, and after 10 days of culture, the cell yield was 8.97 × 105 cells/mL. The optimal conditions for cell attachment were intermittent stirring at 40 r/min for 10 min with intervals of 50 min. The best cell culture efficiency was obtained by using cell inoculation density of 1 × 105 cells/mL, microcarrier density of 2 mg/mL, agitation speed of 40 r/min, and initial culture serum concentration of 20% as well as replacing the medium with a new one containing 10% serum (V/V) after 24 h of culture, and replacing 50% of the medium with a new one with every other day. By bead to bead transfer of the microcarriers, the cells were transferred to a 2 L spinner flask. Finally, 1.07 × 109 cells were harvested with a survival rate of more than 95%. Microcarriers loaded with cells could be cryopreserved and resuscitated, and no significant differences in proliferation status and morphology were observed compared with thawed cells. The optimized microcarrier based culture process will have promising applications in the industrial scale production of cultivated meat
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