Development and application of Compton scattering hard X-ray source based on X-band electron linear accelerator.

Compton scattering hard X-ray source which consists of an X-band (11.424 GHz) electron linear accelerator (linac) and YAG laser is under construction at Nuclear Professional School, the University of Tokyo (UTNS). Monochromatic hard X-rays are required for variety of medical and biological applications. Main advantage of our scheme is to produce monochromatic tunable hard (10-40 keV) X-rays with the intensities of 108-109 photons/sec. In addition, X-ray energy can be changed with rapidly by 40 msec by introducing two different wavelength lasers (YAG fundamental (1064 nm), 2nd harmonic (532 nm)) and optical switch. This quick energy change is indispensable to living specimens and very difficult by a large SR light source and others. Dual-energy X-ray CT and subtraction X-ray CT are available to determine 3D distribution of atomic number density and electron density, and specified atomic distribution, respectively. Here, the construction status of the X-band beam line and the application plan of the hard X-ray will be reported.NanoBeam200

Development of the high resolution electron beam profile monitor for medical use X-band linac

Compact hard X-ray source using the X-band linear accelerator to which is developed in Nuclear Engineering Research Laboratory the University of Tokyo makes beam size 100micrometer pulse laser and an electronic beam collide, and generates X-rays by Compton scattering. In order to collide a laser electronic beam efficiently, the beam profile monitor that can measure a beam profile with sufficient accuracy is indispensable. As a beam profile monitor which has resolution between the altitude which can measure 100 micro meters, it is focused on Wire scanner, OTR(Optical Transition Radiation) monitor and Screen monitor(alumina ceramics), and the research and development are done. Moreover, since it has the angular distribution decided by the energy of electron beam also besides measuring a beam profile. The angular distribution of optical transition radiation is asking for the electron beam dispersion angle and beam size in the beam waist simultaneously, it can expect measuring beam emittance. The measurement comparison with the QUAD scan method shows the emittance measurement possibility. If this measurement method is success the emittance measurement is done only 1 shot measurement. Supposing the X-band linear accelerator, some verification experiments are performed with S-band linear accelerator (E=20MeV) in this institution. From last experiment, we have observed the blots of Screen monitor about 75 micro meters. From the thickness of the screen was 100 micro meters, we can determine the blots of the screen monitor are depend on the thickness of screen. So the screen monitor cannot measure the beam size less than 100 micro meters. Measuring the beam profile using these three (OTR, Wire Scanner, Screen monitor) beam profile monitors repeatedly, we have achieved the resolution within statistically 10 micrometers. From the experiment of the OTR angular distribution measurement, we have achieved to measure the electron beam energy within the resolution 1MeV and the beam emittance was measured about 20 [pi mm mrad], this result shows the agreement with the result from QUAD scan method. In this poster presentation, we report the result of the verification experiments.Korea-Japan Seminar on Advanced Utilization of Particle Accelerato

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APAC0

Synthesis and structure-activity relationship study of aldose reductase inhibiting marine alkaloid lukianol A and its derivatives

Lukianol A (1a) and its six derivatives 1b-1g, in which each hydroxyl groups of 1a was individually modified, were synthesized via the common intermediate 7a, which was obtained by condensation of the styryl carbazate 10 with p-hydroxyphenylpyruvic acid and subsequent [3,3]-sigmatropic rearrangement. The synthesized lukianol derivatives were evaluated for their ability to inhibit human aldose reductase. 4′-O-methyl (1b) and 4′-dehydroxy (1g) derivatives showed the same level of inhibitory activity as 1a (IC50 2.2 µM), indicating that the 4′-OH is irrelevant for the activity. In contrast, methylation of the hydroxyl group at the 4″′-position (1d) resulted in the loss of activity at a concentration of 10 µM, and masking the hydroxyl group at the 4″-position (1e) caused a 9-fold decrease in activity compared with that of 1b, suggesting that the 4″-OH is an essential group, and the 4″′-OH is required for higher activity

Conditional inference tree models to perceive depth of invasion in T1 colorectal cancer

Background and aim: accurate diagnosis of invasion depth for T1 colorectal cancer is of critical importance as it decides optimal resection technique. Few reports have previously covered the effects of endoscopic morphology on depth assessment. We developed and validated a novel diagnostic algorithm that accurately predicts the depth of early colorectal cancer.Methods: we examined large pathological and endoscopic databases compiled between Jan 2015 and Dec 2018. Training and validation data cohorts were derived and real-world diagnostic performance of two conditional interference tree algorithms (Models 1 and 2) was evaluated against that of the Japan NBI-Expert Team (JNET) classification used by both expert and non-expert endoscopists.Results: model 1 had higher sensitivity in deep submucosal invasion than that of JNET alone in both training (45.1% vs. 28.6%, p < 0.01) and validation sets (52.3% vs. 40.0%, p < 0.01). Model 2 demonstrated higher sensitivity than Model 1 (66.2% vs. 52.3%, p < 0.01) in excluding deeper invasion of suspected Tis/T1a lesions.Conclusion: we discovered that machine-learning classifiers, including JNET and macroscopic features, provide the best non-invasive screen to exclude deeper invasion for suspected Tis/T1 lesions. Adding this algorithm improves depth diagnosis of T1 colorectal lesions for both expert and non-expert endoscopists