A new mathematical model for radiation cell killing mechanism: Target cumulating model

There are numerous mathematical or statistical models have been given out for radiation cell killing mechanism. Unfortunately, none of the model could explain the mechanism perfectly. The more advanced model for it is still necessary to be researched. Following common assumption, a new theoretical model named "target cumulating" model is induced from the molecular and particle physics level. The result of theoretical calculation gives the equation of cell survival rate corresponding to delivered dose and other sensitivity parameters. In addition to fit the cell survival curve well, the new model showed advantages with comparing to previous models. Also, the new model predicts or explains some phenomenon that had been observed in laboratory (e.g. dose rate effect and low dose hypersensitivity)

Bimodal waveguide interferometer RI sensor fabricated on low-cost polymer platform

A refractive index sensor based on bimodal waveguide interferometer is demonstrated on the low-cost polymer platform for the first time. Different from conventional interferometers which make use of the interference between the light from two arms, bimodal waveguide interferometers utilize the interference between the two different internal modes in the waveguide. Since the utilized first higher mode has a wide evanescent tail which interacts with the external environment, the interferometer can reach a high sensitivity. Instead of vertical bimodal structure which is normally employed, the lateral bimodal waveguide is adopted in order to simplify the fabrication process. A unique offset between the centers of single mode waveguide and bimodal waveguide is designed to excite the two different modes with equal power which contributes to the maximum fringe visibility. The bimodal waveguide interferometer is finally fabricated on optical polymer (Ormocore) which is transparent at both infrared and visible wavelengths. It is fabricated using the UV-based soft imprint technique which is simple and reproductive. The bulk sensitivity of fabricated interferometer sensor with a 5 mm sensing length is characterized using different mass concentration sodium chloride solutions. The sensitivity is obtained as 316 pi rad/RIU and the extinction ratio can reach 18 dB

Palladium and silver abundances in stars with [Fe/H] > -2.6

Palladium (Pd) and silver (Ag) are the key elements for probing the weak component in the rapid neutron-capture process (r-process) of stellar nucleosynthesis. We performed a detailed analysis of the high-resolution and high signal-to-noise ratio near-UV spectra from the archive of HIRES on the Keck telescope, UVES on the VLT, and HDS on the Subaru Telescope, to determine the Pd and Ag abundances of 95 stars. This sample covers a wide metallicity range with -2.6 $\lesssim$ [Fe/H] $\lesssim$ +0.1, and most of them are dwarfs. The plane-parallel LTE MAFAGS-OS model atmosphere was adopted, and the spectral synthesis method was used to derive the Pd and Ag abundances from Pd I {\lambda} 3404 {\AA} and Ag I {\lambda} 3280/3382 {\AA} lines. We found that both elements are enhanced in metal-poor stars, and their ratios to iron show flat trends at -0.6 < [Fe/H] < +0.1. The abundance ratios of [Ag/H] and [Pd/H] are well correlated over the whole abundance range. This implies that Pd and Ag have similar formation mechanisms during the Galactic evolution.Comment: 15 pages, 12 figures, accepted to A&