Previous studies have demonstrated multiple herbicide resistance in California populations of Echinochloa phyllopogon, a noxious weed in rice (Oryza sativa) fields. It was suggested that the resistance to two classes of acetolactate synthase-inhibiting herbicides, bensulfuron-methyl (BSM) and penoxsulam (PX), may be caused by enhanced activities of herbicide-metabolizing cytochrome P450. We investigated BSM metabolism in the resistant (R) and susceptible (S) lines of E. phyllopogon, which were originally collected from different areas in California. R plants metabolized BSM through O-demethylation more rapidly than S plants. Based on available information about BSM tolerance in rice, we isolated and analyzed P450 genes of the CYP81A subfamily in E. phyllopogon. Two genes, CYP81A12 and CYP81A21, were more actively transcribed in R plants compared with S plants. Transgenic Arabidopsis (Arabidopsis thaliana) expressing either of the two genes survived in media containing BSM or PX at levels at which the wild type stopped growing. Segregation of resistances in the F2 generation from crosses of R and S plants suggested that the resistance to BSM and PX were each under the control of a single regulatory element. In F6 recombinant inbred lines, BSM and PX resistances cosegregated with increased transcript levels of CYP81A12 and CYP81A21. Heterologously produced CYP81A12 and CYP81A21 proteins in yeast (Saccharomyces cerevisiae) metabolized BSM through O-demethylation. Our results suggest that overexpression of the two P450 genes confers resistance to two classes of acetolactate synthase inhibitors to E. phyllopogon. The overexpression of the two genes could be regulated simultaneously by a single trans-acting element in the R line of E. phyllopogon.

Background: To determine the usefulness of dose volume histogram (DVH) factors for predicting the occurrence of radiation pneumonitis (RP) after application of stereotactic radiation therapy (SRT) for lung tumors, DVH factors were measured before irradiation.

The main cause of taste disorder resulting from RT was believed to be a disappearance of taste buds and not damage to the taste nerves.

Radiation oncologists are increasingly using SBRT for OM. The main reason for not using SBRT for OM is a perceived lack of evidence demonstrating clinical advantages. These data strengthen the need for robust prospective clinical trials (ongoing and in development) to demonstrate clinical efficacy given the widespread adoption of SBRT for OM.

The role of slow-mode magnetohydrodynamic (MHD) shocks in magnetic reconnection is of great importance for energy conversion and transport, but in many astrophysical plasmas the plasma is not fully ionised. In this paper, we use numerical simulations to investigate the role of collisional coupling between a proton-electron, charge-neutral fluid and a neutral hydrogen fluid for the onedimensional (1D) Riemann problem initiated in a constant pressure and density background state by a discontinuity in the magnetic field. This system, in the MHD limit, is characterised by two waves. The first is a fast-mode rarefaction wave that drives a flow towards a slow-mode MHD shock wave. The system evolves through four stages: initiation, weak coupling, intermediate coupling, and a quasisteady state. The initial stages are characterised by an over-pressured neutral region that expands with characteristics of a blast wave. In the later stages, the system tends towards a self-similar solution where the main drift velocity is concentrated in the thin region of the shock front. Because of the nature of the system, the neutral fluid is overpressured by the shock when compared to a purely hydrodynamic shock, which results in the neutral fluid expanding to form the shock precursor. Once it has formed, the thickness of the shock front is proportional to ξ −1.2 i , which is a smaller exponent than would be naively expected from simple scaling arguments. One interesting result is that the shock front is a continuous transition of the physical variables of subsonic velocity upstream of the shock front (a c-shock) to a sharp jump in the physical variables followed by a relaxation to the downstream values for supersonic upstream velocity (a j-shock). The frictional heating that results from the velocity drift across the shock front can amount to ∼2 per cent of the reference magnetic energy.

Solar flares are an explosive phenomenon where super-sonic flows and shocks are expected in and above the postflare loops. To understand the dynamics of post-flare loops, a two-dimensional magnetohydrodynamic (2D MHD) simulation of a solar flare has been carried out. We found new shock structures in and above the post-flare loops, which were not resolved in the previous work by Yokoyama & Shibata. To study the dynamics of flows along the reconnected magnetic field, the kinematics and energetics of the plasma are investigated along selected field lines. It is found that shocks are crucial to determine the thermal and flow structures in the post-flare loops. On the basis of the 2D MHD simulation, we developed a new post-flare loop model, which we defined as the pseudo-2D MHD model. The model is based on the one-dimensional (1D) MHD equations, where all variables depend on one space dimension, and all the three components of the magnetic and velocity fields are considered. Our pseudo-2D model includes many features of the multi-dimensional MHD processes related to magnetic reconnection (particularly MHD shocks), which the previous 1D hydrodynamic models are not able to include. We compared the shock formation and energetics of a specific field line in the 2D calculation with those in our pseudo-2D MHD model, and found that they give similar results. This model will allow us to study the evolution of the post-flare loops in a wide parameter space without expensive computational cost or neglecting important physics associated with magnetic reconnection.

4100 Background: Chemoradiotherapy (CRT) followed by radical surgery (S) is standard therapy for patients (pts) with locally advanced rectal cancer (LARC). Sequential use of an anti-PD-1 antibody after radiation demonstrates synergistic effects in in vivo models, and an anti-PD-1 antibody is effective in pts with microsatellite instability-high (MSI-H) metastatic colorectal cancer (mCRC). We studied nivolumab (nivo) and radical S following CRT (50.4 Gy with capecitabine 1,650 mg/m2) in T3–4 NanyM0 LARC. Methods: After the quality-assured CRT, 240 mg q2 weeks x 5 cycles of nivo and radical S were investigated. In cohort A-1, for pts with microsatellite stable (MSS) LARC, the primary endpoint was a centrally confirmed pathological complete response (pCR) rate using AJCC tumor regression grading. The estimated required sample size assuming null and alternative hypotheses pCR = 10% and 30% was 37 pts, with a 1-sided alpha of 5% and power of 90%. In Cohort A-2, 5 pts with MSI-H LARC were included in an exploratory manner. Results: From Jan/2017 to Oct/2019, a targeted number of pts was included and assessed. In cohort A-1, 30% (11/37; 90% CI 18-44%) of pCR (AJCC grade (gr) 0) rate and 38% (14/37) of major pathological response (MPR) (AJCC gr 0+1) rate were observed. Clinical CR was observed in one additional pt (3%) refusing S after nivo. In cohort A-2, 60% (3/5) of pCR rate and 60% (3/5) of MPR rate were observed. As of Jan/2020, only 2 pts (1 local and 1 metastatic) in cohort A-1 and none in cohort A-2 recurred. Immune-related severe adverse events were observed in 3 pts (gr 3 myasthenia, gr 3 interstitial nephritis, and gr 2 peripheral motor neuropathy); all fully recovered and received radical S. During the follow-up period, one additional pt with gr 2 colitis was observed. No treatment-related deaths were observed. Conclusions: Promising pCR rates of 30% and 60%, with mild toxicities, were shown in MSS and MSI-H LARC pts treated with nivo plus radical S after CRT, suggesting the candidate therapy for the future non-surgical approach. Clinical trial information: NCT02948348 .

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