Shape transformations of lipid vesicles by insertion of bulky-head lipids

Lipid vesicles, in particular Giant Unilamellar Vesicles (GUVs), have been increasingly important as compartments of artificial cells to reconstruct living cell-like systems in a bottom-up fashion. Here, we report shape transformations of lipid vesicles induced by polyethylene glycol-lipid conjugate (PEG lipids). Statistical analysis of deformed vesicle shapes revealed that shapes vesicles tend to deform into depended on the concentration of the PEG lipids. When compared with theoretically simulated vesicle shapes, those shapes were found to be more energetically favorable, with lower membrane bending energies than other shapes. This result suggests that the vesicle shape transformations can be controlled by externally added membrane molecules, which can serve as a potential method to control the replications of artificial cells

Liposome-based liquid handling platform featuring addition, mixing, and aliquoting of femtoliter volumes

This paper describes the utilization of giant unilamellar vesicles (GUVs) as a platform for handling chemical and biochemical reagents. GUVs with diameters of 5 to 10 µm and containing chemical/biochemical reagents together with inert polymers were fused with electric pulses (electrofusion). After reagent mixing, the fused GUVs spontaneously deformed to a budding shape, separating the mixed solution into sub-volumes. We utilized a microfluidic channel and optical tweezers to select GUVs of interest, bring them into contact, and fuse them together to mix and aliquot the reaction product. We also show that, by lowering the ambient temperature close to the phase transition temperature Tm of the lipid used, daughter GUVs completely detached (fission). This process performs all the liquid-handing features used in bench-top biochemistry using the GUV, which could be advantageous for the membrane-related biochemical assays

Ambipolar transport in bulk crystals of a topological insulator by gating with ionic liquid

We report that the ionic-liquid gating of bulk single crystals of a topological insulator can control the type of the surface carriers and even results in ambipolar transport. This was made possible by the use of a highly bulk-insulating BiSbTeSe2 system where the chemical potential is located close to both the surface Dirac point and the middle of the bulk band gap. Thanks to the use of ionic liquid, the control of the surface chemical potential by gating was possible on the whole surface of a bulk three-dimensional sample, opening new experimental opportunities for topological insulators. In addition, our data suggest the existence of a nearly reversible electrochemical reaction that causes bulk carrier doping into the crystal during the ionic-liquid gating process.Comment: 7 pages, 6 figures, 2 tables; significantly expanded version to fully discuss the gating process and its side effects; published in PR

加齢またはアルツハイマー病が語彙・意味機能に及ぼす影響 : 意味的プライミング法による検討

This study aims to clarify the influences of aging and AD on lexical-semantics by assigning a semantic priming paradigm. The following participants are included in the study: 30 young students, 22 early elderly, 19 late elderly, and 14 AD patients. The participants are asked to perform lexical decision tasks. Targets are high-frequency concrete words or nonwords. The primes are controlled with regard to their semantic relevance to the targets as follows: Association (e.g., king - lion), Superordination (beast - lion), Coordination (tiger - lion), Shared feature (eyes - lion), Distinctive feature (mane - lion), or Neutral (XXXX – lion). The participants have to decide whether the stimulus is a real word or not as correctly and as quickly as possible when the targets appeared on a monitor. As the Results, the mean reaction times (RTs) of the elderly groups are significantly longer than those of the young group, and the RTs of the AD group are even longer than those of the elderly groups. In the young and the elderly groups, the RTs for all the related-prime conditions are significantly shorter than those for the neutral-prime conditions (priming effects). The priming effects appears to be greater in the elderly groups. However, when the RTs are taken into consideration (priming rates), the gains are equivalent among young and elderly groups. In the AD group, priming effects are not observed, and noticeable individual differences in the priming rate are seen. The above findings suggest that lexical-semantics are generally preserved from aging. We also discusses that lexical-semantics are impaired in AD, and the diversity of the impairments may be the essence of AD

Ionic Liquid Fluorohydrogenates and Their Applications

The recent results are described on the developments of ionic liquid (IL) fluorohydrogenates with high ionic conductivities and wide electrochemical windows. Several cyclic ammonium cations have been found to be combined with fluorohydrogenate anions giving a vacuum stable ionic liquid fluorohydrogenates, Cat+[(FH)2.3F]−. N-ethyl-N-methylpyrrolidinium fluorohydrogenate, EMPyrro(FH)2.3F, and N-allylpyrridinium fluorohydrogenate, APyrrid(FH)2.3F, exhibit wide electrochemical windows of around 5 V. A fluorohydrogenate fuel cell (FHFC) using HF-deficient IL, 1-ethyl-3-methyl- imidazolium fluorohydrogenate, EMIm(FH)1.3F, as the electrolyte operates at 120{degree sign}C without humidification. The maximum output power so far obtained in the preliminary cell test is 41 mWcm-2 (0.41 V and 100 mA cm-2) at 40{degree sign}C without humidification

Study of laser frequency stability from the observed vertical wind velocity by the Na lidar at Troms*

The Tenth Symposium on Polar Science/Ordinary sessions: [OS] Space and upper atmospheric sciences, Wed. 4 Dec. /Entrance Hall (1st floor) at National Institute of Polar Research (NIPR