Search

The term “differently-abled” refers to people with mobility difficulties, including the disabled and the elderly. In order to explore the optimal evacuation efficiency, in emergencies, of different floors in multi-layered buildings where differently-abled people reside, this study has established a mixed evacuation model based on the characteristics of the evacuation behavior of differently-abled people and non-differently-abled people. This model simulated the impact of evacuation strategies on different floors for differently-abled people at various assistance ratios. Through the comparative analysis of various evacuation strategies, an evacuation efficiency analysis model was constructed, which is suitable for multi-layered buildings where differently-abled people reside. The research indicates that, for stair-determined evacuation strategies, when the proportion of assisting personnel exceeds 70%, there is a noticeable improvement in overall evacuation efficiency. For elevator-determined evacuation strategies, evacuating middle floors with unrestricted methods can enhance evacuation efficiency. The analysis model for optimal evacuation efficiency on each floor that is presented in this study, using a five-story building as an example, can clearly and accurately determine evacuation strategies for multi-layered buildings where differently-abled people reside.

During hepatitis B virus (HBV) infection, the host immune response, including the presence of functional HBV-specific T cells and HBV-specific antibody-producing B cells, ultimately determines the HBV infection outcome: either the virus is cleared, or infection persists. Functional exhaustion of HBV-specific CD8+ cytotoxic T cells is the most important immune feature in chronic HBV infection. However, chronic HBV infection also re-writes humoral immunity, whereby B cells are the leading participants. In this review, we highlight HBV-specific B cell responses and propose future directions for research aimed at the generation of more efficient immunotherapeutic strategies.

Radio-fluorogenic (RFG) gels become permanently fluorescent when exposed to high-energy radiation with the intensity of the emission proportional to the local dose of radiation absorbed. An apparatus is described, FluoroTome 1, that is capable of taking a series of tomographic images (thin slices) of the fluorescence of such an irradiated RFG gel on-site and within minutes of radiation exposure. These images can then be compiled to construct a 3D movie of the dose distribution within the gel. The historical development via a laboratory-bench prototype to a readily transportable, user-friendly apparatus is described. Instrumental details and performance tests are presented.

We have filled a 24 mm diameter glass sphere with a transparent polymer-gel that is radio-fluorogenic, i.e., it becomes (permanently) fluorescent when irradiated, with an intensity proportional to the local dose deposited. The gel consists of >99.9% tertiary-butyl acrylate (TBA), pre-polymerized to ~15% conversion, and ~100 ppm maleimido-pyrene (MPy). Its dimensions and physical properties are close to those of the vitreous body of the human eye. We have irradiated the gel with a 3 mm diameter, 200 kVp X-ray beam with a dose rate of ~1 Gy/min. A three-dimensional (3D) (video) view of the beam within the gel has been constructed from tomographic images obtained by scanning the sample through a thin sheet of UV light. To minimize optical artefacts, the cell was immersed in a square tank containing a refractive-index-matching medium. The 20⁻80% penumbra of the beam was determined to be ~0.4 mm. This research was a preparatory investigation of the possibility of using this method to monitor the millimetre diameter proton pencil beams used in ocular radiotherapy.

We review the development and application of an organic polymer-gel capable of producing fixed, three-dimensional fluorescent images of complex radiation fields. The gel consists for more than 99% of γ-ray-polymerized (~15% conversion) tertiary-butyl acrylate (TBA) containing ~100 ppm of a fluorogenic compound, e.g., maleimido-pyrene (MPy). The radio-fluorogenic effect depends on copolymerization of the MPy into growing chains of TBA on radiation-induced polymerization. This converts the maleimido residue, which quenches the pyrene fluorescence, into a succinimido moeity (SPy), which does not. The intensity of the fluorescence is proportional to the yield of free-radicals formed and hence to the local dose deposited. Because the SPy moieties are built into the polymer network, the image is fixed. The method of preparing the gel and imaging the radiation-induced fluorescence are presented and discussed. The effect is illustrated with fluorescent images of the energy deposited in the gel by beams of X-rays, electrons, and protons as well as a radioactive isotope.