Progress in heavy ion cancer therapy at IMP and future development

Basic research on heavy ion cancer therapy such as radiobiology, medicalphysics, and therapeutic technique has been conducted at the Institute ofModern Physics (IMP), Chinese Academy of Sciences since 1995. Based on theachievements acquired in the basic research and the requirements for a heavyion accelerator for radiotherapy purposes, a dedicated heavy ion therapy facilitynamed Heavy Ion Medical Machine (HIMM) was designed at IMP andconstructed in Wuwei, China. The HIMM facility consists of two electroncyclotron resonance ion sources, one cyclotron as the injector and onesynchrotron as the main accelerator, and four different treatment roomsequipped with passive or active beam delivery systems, and accelerates carbonions up to 400 MeV/u. After the performance inspection of HIMM organized bythe National Medical Device Inspection Center, preclinical tests like cell andanimal radiobiological experiments and dosimetric verification using anthropomorphicphantoms for elucidating the biophysical properties of the carbon ionbeams provided by HIMM were carried out. According to the Chinese medicaldevice regulations, a clinical trial in which 46 tumor patients were recruited andtwo hospitals participated was conducted in the HIMM facility, aiming atevaluating the treatment safety and short-term efficacy of the medical device.The success of the clinical trial helped the HIMM facility be authorized by theChinese government as a class III medical device. In this paper, all the aspectsmentioned above are introduced and discussed, and implications for futureimprovements are also given.

Multiple measurements of quasars acting as standard probes: Model independent calibration and exploring the dark energy equation of states

Recently, two classes of quasar samples were identified, which are promising as new cosmological probes extending to higher redshifts. The first sample uses the nonlinear relation between the ultraviolet and X-ray luminosities of quasars to derive luminosity distances, whereas the linear sizes of compact radio quasars in the second sample can serve as standardized rulers, providing angular-diameter distances. In this study, under the assumption of a flat universe, we refreshed the calibration of multiple measurements of high-redshift quasars(in the framework of a cosmological-model-independent method with the newest Hubble parameters data). Furthermore, we placed constraints on four models that characterize the cosmic equation of state(w). The obtained results show that:(1) the two quasar samples could provide promising complementary probes at much higher redshifts,whereas compact radio quasars perform better than ultraviolet and X-ray quasars at the current observational level;(2) strong degeneracy between the cosmic equation of state(w) and Hubble constant(H0) is revealed, which highlights the importance of independent determination of H0 from time-delay measurements of strongly lensed quasars;(3) together with other standard ruler probes, such as baryon acoustic oscillation distance measurements, the combined QSO+BAO measurements are consistent with the standard ΛCDM model at a constant equation of state w =-1;(4) ranking the cosmological models, the polynomial parametrization gives a rather good fit among the four cosmic-equation-of-state models, whereas the Jassal-Bagla-Padmanabhan(JBP) parametrization is substantially penalized by the Akaike Information Criterion and Bayesian Information Criterion.