Definitive risk factors for the development of adult T-cell leukemia (ATL) among asymptomatic human T-cell leukemia vi-

Lignin, a ubiquitous phenylpropanoid polymer in vascular plant cell walls, is derived primarily from oxidative couplings of monolignols (p-hydroxycinnamyl alcohols). It was discovered recently that a wide range of grasses, including cereals, utilize a member of the flavonoids, tricin (39,59-dimethoxyflavone), as a natural comonomer with monolignols for cell wall lignification. Previously, we established that cytochrome P450 93G1 is a flavone synthase II (OsFNSII) indispensable for the biosynthesis of soluble tricin-derived metabolites in rice (Oryza sativa). Here, our tricin-deficient fnsII mutant was analyzed further with an emphasis on its cell wall structure and properties. The mutant is similar in growth to wild-type control plants with normal vascular morphology. Chemical and nuclear magnetic resonance structural analyses demonstrated that the mutant lignin is completely devoid of tricin, indicating that FNSII activity is essential for the deposition of tricin-bound lignin in rice cell walls. The mutant also showed substantially reduced lignin content with decreased syringyl/guaiacyl lignin unit composition. Interestingly, the loss of tricin in the mutant lignin appears to be partially compensated by incorporating naringenin, which is a preferred substrate of OsFNSII. The fnsII mutant was further revealed to have enhanced enzymatic saccharification efficiency, suggesting that the cell wall recalcitrance of grass biomass may be reduced through the manipulation of the flavonoid monomer supply for lignification.

We have developed an environmentally benign large-scale (50 kg wood meal per batch) lignin production plant, operating based on acid-catalyzed polyethylene glycol (PEG) solvolysis of softwood biomass. The motivation for the proposed process was to promote technological innovation in biomass utilization systems in Japanese rural areas based on widely abundant Japanese cedar (sugi) biomass. In this study, the process was evaluated by investigating the effects of the source sugi wood meal size and the solvent PEG molecular mass on the yield, chemical structure, molecular mass, and thermal properties of the resultant PEG-modified lignin derivatives, glycol lignins (GLs). Reducing the source wood meal size and PEG solvent molecular mass not only promoted lignin PEGylation but also the subsequent acid-induced chemical rearrangements of the GLs as demonstrated by chemical analyses, 2D NMR, and size exclusion chromatography (SEC). Reducing the source wood meal size and/or increasing the solvent PEG molecular mass enhanced the thermal properties of GLs as determined by thermomechanical analysis (TMA) and thermogravimetric analysis (TGA). We considered that the proposed process can efficiently produce lignin derivatives with substantial control over the chemical structure and thermal properties to meet commercial and industrial needs for lignin-based advanced material production.

A significant linear radiation dose-response for MDS exists in atomic bomb survivors 40 to 60 years after radiation exposure. Clinicians should perform careful long-term follow-up of irradiated people to detect MDS as early as possible.