Tokyo University of Science

About: Tokyo University of Science is a education organization based out in Tokyo, Japan. It is known for research contribution in the topics: Thin film & Enantioselective synthesis. The organization has 15800 authors who have published 24147 publications receiving 438081 citations. The organization is also known as: Tōkyō Rika Daigaku & Science University of Tokyo.

Evidence for a new nuclear ‘magic number’ from the level structure of 54 Ca

Abstract: Atomic nuclei are finite quantum systems composed of two distinct types of fermion--protons and neutrons. In a manner similar to that of electrons orbiting in an atom, protons and neutrons in a nucleus form shell structures. In the case of stable, naturally occurring nuclei, large energy gaps exist between shells that fill completely when the proton or neutron number is equal to 2, 8, 20, 28, 50, 82 or 126 (ref. 1). Away from stability, however, these so-called 'magic numbers' are known to evolve in systems with a large imbalance of protons and neutrons. Although some of the standard shell closures can disappear, new ones are known to appear. Studies aiming to identify and understand such behaviour are of major importance in the field of experimental and theoretical nuclear physics. Here we report a spectroscopic study of the neutron-rich nucleus (54)Ca (a bound system composed of 20 protons and 34 neutrons) using proton knockout reactions involving fast radioactive projectiles. The results highlight the doubly magic nature of (54)Ca and provide direct experimental evidence for the onset of a sizable subshell closure at neutron number 34 in isotopes far from stability.

Gut Microbiota Promotes Obesity-Associated Liver Cancer through PGE2-Mediated Suppression of Antitumor Immunity.

Abstract: Obesity increases the risk of cancers, including hepatocellular carcinomas (HCC). However, the precise molecular mechanisms through which obesity promotes HCC development are still unclear. Recent studies have shown that gut microbiota may influence liver diseases by transferring its metabolites and components. Here, we show that the hepatic translocation of obesity-induced lipoteichoic acid (LTA), a Gram-positive gut microbial component, promotes HCC development by creating a tumor-promoting microenvironment. LTA enhances the senescence-associated secretory phenotype (SASP) of hepatic stellate cells (HSC) collaboratively with an obesity-induced gut microbial metabolite, deoxycholic acid, to upregulate the expression of SASP factors and COX2 through Toll-like receptor 2. Interestingly, COX2-mediated prostaglandin E2 (PGE2) production suppresses the antitumor immunity through a PTGER4 receptor, thereby contributing to HCC progression. Moreover, COX2 overexpression and excess PGE2 production were detected in HSCs in human HCCs with noncirrhotic, nonalcoholic steatohepatitis (NASH), indicating that a similar mechanism could function in humans.Significance: We showed the importance of the gut-liver axis in obesity-associated HCC. The gut microbiota-driven COX2 pathway produced the lipid mediator PGE2 in senescent HSCs in the tumor microenvironment, which plays a pivotal role in suppressing antitumor immunity, suggesting that PGE2 and its receptor may be novel therapeutic targets for noncirrhotic NASH-associated HCC. Cancer Discov; 7(5); 522-38. ©2017 AACR.This article is highlighted in the In This Issue feature, p. 443.