This study uses the yields of double-strand breaks (DSBs) to determine the relative biological effectiveness (RBE) of proton beams, using cell survival as a biological endpoint. DSB induction is determined when cells locate at different depths (6 positions) along the track of 62 MeV proton beams. The DNA damage yields are estimated using Monte Carlo Damage Simulation (MCDS) software. The repair outcomes are estimated using Monte Carlo excision repair (MCER) simulations. The RBE for cell survival at different oxygen concentrations is calculated using the repair-misrepair-fixation (RMF) model. Using 60Co γ-rays (linear energy transfer (LET) = 2.4 keV/μm) as the reference radiation, the RBE for DSB induction and enzymatic DSB under aerobic condition (21% O2) are in the range 1.0–1.5 and 1.0–1.6 along the track depth, respectively. In accord with RBE obtained from experimental data, RMF model-derived RBE values for cell survival are in the range of 1.0–3.0. The oxygen enhancement ratio (OER) for cell survival (10%) decreases from 3.0 to 2.5 as LET increases from 1.1 to 22.6 keV/μm. The RBE values for severe hypoxia (0.1% O2) are in the range of 1.1–4.4 as LET increases, indicating greater contributions of direct effects for protons. Compared with photon therapy, the overall effect of 62 MeV proton beams results in greater cell death and is further intensified under hypoxic conditions.

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This paper estimates the yields of DNA double-strand breaks (DSBs) induced by ultrasoft X-rays and uses the DSB yields and the repair outcomes to evaluate the relative biological effectiveness (RBE) of ultrasoft X-rays. We simulated the yields of DSB induction and predicted them in the presence and absence of oxygen, using a Monte Carlo damage simulation (MCDS) software, to calculate the RBE. Monte Carlo excision repair (MCER) simulations were also performed to calculate the repair outcomes (correct repairs, mutations, and DSB conversions). Compared to 60Co γ-rays, the RBE values for ultrasoft X-rays (titanium K-shell, aluminum K-shell, copper L-shell, and carbon K-shell) for DSB induction were respectively 1.3, 1.9, 2.3, and 2.6 under aerobic conditions and 1.3, 2.1, 2.5, and 2.9 under a hypoxic condition (2% O2). The RBE values for enzymatic DSBs were 1.6, 2.1, 2.3, and 2.4, respectively, indicating that the enzymatic DSB yields are comparable to the yields of DSB induction. The synergistic effects of DSB induction and enzymatic DSB formation further facilitate cell killing and the advantage in cancer treatment.

An energy efficient prototype for diagnostic grade mobile ECG monitoring is developed. The prototype is developed with commercial discrete components to demo a patient centric medical environment. The prototype uses a mobile phone as a gateway to transmit the measured ECG data back to the medical cloud: Bluetooth for ECG sensor to the mobile phone, while 3G/WiFi for the mobile phone to the medical cloud. Therefore, the patients are not tied to the hospital or home, and can go outside for common life. The prototype can calculate on the mobile phone the RR intervals. More accurate RR, QRS interval can be obtained from server. The platform can also analyze the non-linear analysis of heart rate variability in patients with congestive heart failure based on multi-scale entropy. The size of the developed ECG sensor node is 75mm x 35mm x 20mm which is smaller than a credit card in area. The noise density of the amplifier is 22nV/√ Hz, and the total power of the sensor frontend is below 100uA. For wireless transmission, the Bluetooth module with a micro controller consumes current less than 110mA. The prototype can monitor ECG continuously for over 24 hours or with 3 weeks standby time.

This paper develops techniques and methodologies for global path planning and navigation of a Mecanum-wheeled omnidirectional mobile robot (MWOMR). The proposed navigation system is composed of three modules: odometry, nonsingular terminal sliding-mode (NTSM) dynamic motion controller, and global path planner, which have been implemented using the SoPC technology. The odometry is constructed by using a numerical method and a kinematic model of the robot, in order to keep track of the current position and orientation of the robot over short distances. A nonsingular terminal sliding-mode dynamic controller is well derived to achieve simultaneous point stabilization and trajectory tracking. A hybrid PSO (particle swarm optimization)-RGA (real-coded genetic algorithm) algorithm is proposed to find an optimal path between a starting and ending point in a given grid environment. Simulations and experimental results are conducted which have shown the feasibility and effectiveness of the proposed global path planning and navigation methods.