Kyushu University

About: Kyushu University is a education organization based out in Fukuoka, Japan. It is known for research contribution in the topics: Population & Catalysis. The organization has 68284 authors who have published 135190 publications receiving 3055928 citations. The organization is also known as: Kyūshū Daigaku.

Dynamics of cancer progression

Abstract: Evolutionary concepts such as mutation and selection can be best described when formulated as mathematical equations. Cancer arises as a consequence of somatic evolution. Therefore, a mathematical approach can be used to understand the process of cancer initiation and progression. But what are the fundamental principles that govern the dynamics of activating oncogenes and inactivating tumour-suppressor genes in populations of reproducing cells? Also, how does a quantitative theory of somatic mutation and selection help us to evaluate the role of genetic instability?

A novel cytochrome P450 is implicated in brassinosteroid biosynthesis via the characterization of a rice dwarf mutant, dwarf11, with reduced seed length.

Abstract: We have characterized a rice (Oryza sativa) dwarf mutant, dwarf11 (d11), that bears seeds of reduced length. To understand the mechanism by which seed length is regulated, the D11 gene was isolated by a map-based cloning method. The gene was found to encode a novel cytochrome P450 (CYP724B1), which showed homology to enzymes involved in brassinosteroid (BR) biosynthesis. The dwarf phenotype of d11 mutants was restored by the application of the brassinolide (BL). Compared with wild-type plants, the aberrant D11 mRNA accumulated at higher levels in d11 mutants and was dramatically reduced by treatment with BL, implying that the gene is feedback-regulated by BL. Precise determination of the defective step(s) in BR synthesis in d11 mutants proved intractable because of tissue specificity and the complex control of BR accumulation in plants. However, 6-deoxotyphasterol (6-DeoxoTY) and typhasterol (TY), but not any upstream intermediates before these compounds, effectively restored BR response in d11 mutants in a lamina joint bending assay. Multiple lines of evidence together suggest that the D11/CYP724B1 gene plays a role in BR synthesis and may be involved in the supply of 6-DeoxoTY and TY in the BR biosynthesis network in rice.

Nearly 100% Internal Quantum Efficiency in Undoped Electroluminescent Devices Employing Pure Organic Emitters

Abstract: The design of efficient and concentration-insensitive metal-free thermally activateddelayed fluorescence (TADF) materials is reported. Blue and green organic light-emitting diodes (OLEDs) containing a hole-transport layer, an undoped TADF emissive layer, and an electron-transport layer achieve maximum external quantum efficiencies of 19%, which is comparable to the best doped OLEDs.