Prevention of quality of life (QOL) deterioration is associated with the inhibition of geriatric diseases and the regulation of brain function. However, no substance is known that prevents the aging of both body and brain. It is known that polyamine concentrations in somatic tissues (including the brain) decrease with increasing age, and polyamine-rich foods enhance longevity in yeast, worms, flies, and mice, and protect flies from age-induced memory impairment. A main source of exogenous polyamines is the intestinal lumen, where they are produced by intestinal bacteria. We found that arginine intake increased the concentration of putrescine in the colon and increased levels of spermidine and spermine in the blood. Mice orally administered with arginine in combination with the probiotic bifidobacteria LKM512 long-term showed suppressed inflammation, improved longevity, and protection from age-induced memory impairment. This study shows that intake of arginine and LKM512 may prevent aging-dependent declines in QOL via the upregulation of polyamines.

Background: Polyamines play roles in bacterial cell-to-cell signaling processes. Results: In Proteus mirabilis, PlaP is important for putrescine uptake, swarming motility, and urothelial cell invasion, and the putrescine transport inhibitor Triamide-44 inhibits these processes. Conclusion: PlaP is the primary putrescine transporter in P. mirabilis. Significance: This research suggests that novel drug cocktails that target both microbial putrescine uptake and biosynthesis can be developed.

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Staging laser wake-field acceleration is considered to be a necessary technique for developing full-optical jitter-free high energy electron accelerators. Splitting of the acceleration length into several technical parts and with independent laser drivers allows not only the generation of stable, reproducible acceleration fields but also overcoming the dephasing length while maintaining an overall high acceleration gradient and a compact footprint. Temporal and spatial coupling of pre-accelerated electron bunches for their injection in the acceleration phase of a successive laser pulse wake field is the key part of the staging laser-driven acceleration. Here, characterization of the coupling is performed with a dense, stable, narrow energy band of <3% and energy-selectable electron beams with a charge of ~1.6 pC and energy of ~10 MeV generated from a laser plasma cathode. Cumulative focusing of electron bunches in a low-density preplasma, exhibiting the Budker–Bennett effect, is shown to result in the efficient injection of electrons, even with a long distance between the injector and the booster in the laser pulse wake. The measured characteristics of electron beams modified by the booster wake field agree well with those obtained by multidimensional particle-in-cell simulations.

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The effect of the poly(oxyethylene) (POE) chain length of ionic surfactants, expressed as C12H25-(OCH2CH2)-nOCH2C6H3(OH)(NO2) (n = 2—9), on the extraction of monovalent cations, including alkali metal and tetraalkylammonium (TAA) ions, was investigated. The extraction constants (Kex) with surfactants having a POE chain of n ≥ 6 were almost constant for each alkali metal ion. The Kex sequence was Li+ &lt; Na+ &lt; Cs+ ≤ K+ = Rb+. The extractability and selectivity largely decreased as n in the surfactant decreased (n &lt; 6). The effect of the POE chain length was related to the stability of the alkali metal-POE complex. Unlike an alkali metal ion, the Kex values for all TAA ions were almost constant with surfactants of n = 2—8. These facts indicated that the surfactant extracts alkali metal ions by both complex formation with its POE chain and ion-pair formation with a terminal p-nitrophenolate anion. On the other hand, TAA ions were extracted simply by ion-pair formation with a p-nitrophenolate anion of the surfactant. The proposed structures are discussed from the viewpoint of the spectrum shift of the extracted species.