Fundamental physics activities with pulsed neutron at J-PARC(BL05)

"Neutron Optics and Physics (NOP/ BL05)" at MLF in J-PARC is a beamline for studies of fundamental physics. The beamline is divided into three branches so that different experiments can be performed in parallel. These beam branches are being used to develop a variety of new projects. We are developing an experimental project to measure the neutron lifetime with total uncertainty of 1 s (0.1%). The neutron lifetime is an important parameter in elementary particle and astrophysics. Thus far, the neutron lifetime has been measured by several groups; however, different values are obtained from different measurement methods. This experiment is using a method with different sources of systematic uncertainty than measurements conducted to date. We are also developing a source of pulsed ultra-cold neutrons (UCNs) produced from a Doppler shifter are available at the unpolarized beam branch. We are developing a time focusing device for UCNs, a so called "rebuncher", which can increase UCN density from a pulsed UCN source. At the low divergence beam branch, an experiment to search an unknown intermediate force with nanometer range is performed by measuring the angular dependence of neutron scattering by noble gases. Finally the beamline is also used for the research and development of optical elements and detectors. For example, a position sensitive neutron detector that uses emulsion to achieve sub-micrometer resolution is currently under development. We have succeeded in detecting cold and ultra-cold neutrons using the emulsion detector.Comment: 9 pages, 5 figures, Proceedings of International Conference on Neutron Optics (NOP2017

Multiple osteoblastomas in a child with Cushing syndrome due to bilateral adrenal micronodular hyperplasias

Adrenocorticotropin-independent adrenal hyperplasias are rare diseases, which are classified into macronodular (>1 cm) and micronodular (≤1 cm) hyperplasia. Micronodular adrenal hyperplasia is subdivided into primary pigmented adrenocortical disease and a limited or nonpigmented form 'micronodular adrenocortical disease (MAD)', although considerable morphological and genetic overlap is observed between the 2 groups. We present an unusual case of a 44-month-old girl who was diagnosed with Cushing syndrome due to MAD. She had presented with spotty pigmentation on her oral mucosa, lips and conjunctivae and was diagnosed with multiple bone tumors in her femur, pelvis and skull base at the age of 8 years. Her bone tumor biopsies were compatible with osteoblastoma. This case highlights the importance of verifying the clinicopathologic correlation in Cushing syndrome and careful follow-up and screening for associated diseases

New project for precise neutron lifetime measurement at J-PARC

The decay lifetime of free neutrons (∼880 s) is an important parameter of the weak interaction and for Big Bang Nucleosynthesis. However, results of measurements currently show discrepancies depending on the method used. As most experiments nowadays employ ultra cold neutrons, we have developed a new cold-beam experiment which we perform at the Japan Proton Accelerator Research Complex. As a special feature, a polarized neutron beam is bunched by a spin flip chopper. A time projection chamber operated with He and CO2 gas, including a well-controlled amount of 3He, is used for detection of the beta-decays and simultaneous determination of the beam intensity. Using the data between 2014 and 2016, we evaluated our first, preliminary result of the neutron lifetime as 896 ± 10(stat.) −10+14(sys.) s. We plan several upgrades to achieve our precision goal of 1 s

New project for precise neutron lifetime measurement at J-PARC

The decay lifetime of free neutrons (∼880 s) is an important parameter of the weak interaction and for Big Bang Nucleosynthesis. However, results of measurements currently show discrepancies depending on the method used. As most experiments nowadays employ ultra cold neutrons, we have developed a new cold-beam experiment which we perform at the Japan Proton Accelerator Research Complex. As a special feature, a polarized neutron beam is bunched by a spin flip chopper. A time projection chamber operated with He and CO2 gas, including a well-controlled amount of 3He, is used for detection of the beta-decays and simultaneous determination of the beam intensity. Using the data between 2014 and 2016, we evaluated our first, preliminary result of the neutron lifetime as 896 ± 10(stat.) −10+14(sys.) s. We plan several upgrades to achieve our precision goal of 1 s

Design and Synthesis of Potent Inhibitor of Apoptosis (IAP) Proteins Antagonists Bearing an Octahydropyrrolo[1,2‑<i>a</i>]pyrazine Scaffold as a Novel Proline Mimetic

To develop novel inhibitor of apoptosis (IAP) proteins antagonists, we designed a bicyclic octahydropyrrolo­[1,2-<i>a</i>]­pyrazine scaffold as a novel proline bioisostere. This design was based on the X-ray co-crystal structure of four N-terminal amino acid residues (AVPI) of the second mitochondria-derived activator of caspase (Smac) with the X-chromosome-linked IAP (XIAP) protein. Lead optimization of this scaffold to improve oral absorption yielded compound <b>45</b>, which showed potent cellular IAP1 (cIAP1 IC₅₀: 1.3 nM) and XIAP (IC₅₀: 200 nM) inhibitory activity, in addition to potent tumor growth inhibitory activity (GI₅₀: 1.8 nM) in MDA-MB-231 breast cancer cells. X-ray crystallographic analysis of compound <b>45</b> bound to XIAP and to cIAP1 was achieved, revealing the various key interactions that contribute to the higher cIAPI affinity of compound <b>45</b> over XIAP. Because of its potent IAP inhibitory activities, compound <b>45</b> (T-3256336) caused tumor regression in a MDA-MB-231 tumor xenograft model (T/C: −53% at 30 mg/kg)