Numerous research studies have been done for exosomes, particularly focusing on membrane proteins and included nucleic acids, and the volume of the knowledge about the lipids in the exosomal membrane has been increasing. However, the dynamic property of the exosomal membrane is hardly studied. By employing milk exosome as an example, herein the exosomal membrane was characterized focusing on the membrane fluidity and polarity. The lipid composition and phase state of milk exosome (exosome from bovine milk) were estimated. The milk exosome contained enriched Chol (43.6 mol % in total lipid extracts), which made the membrane in the liquid-ordered (l o) phase by interacting with phospholipids. To suggest a model of exosomal vesicle cargo, the liposome compositions that mimic milk exosome were studied: liposomes were made of cholesterol (Chol), milk sphingomyelin (milk SM), and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). By using fluorescent probes 1,6-diphenyl-1,3,5-hexatriene and 6-dodecanoyl-2-dimethylaminonaphthalene, the microenvironments of submicron-sized membranes of exosome and model liposomes were investigated. The membrane fluidity of milk exosome was slightly higher than those of Chol/milk SM/POPC liposomes with a similar content of Chol, suggesting the presence of enriched unsaturated lipids. The most purposeful membrane property was obtained by the liposome composition of Chol/milk SM/POPC = 40/15/45. From the above, it is concluded that Chol is a fundamental component of the milk exosomal membrane to construct the enriched l o phase, which could increase the membrane rigidity and contribute to the function of exosome.

We fabricated pentacene-based memory field-effect transistors (FETs) in which a monolayer of semiconductor colloidal nano-dots (NDs) is embedded as a floating gate. After a sufficiently large writing voltage was applied on the control gate, the fabricated FETs showed a large positive threshold voltage (V th) shift that was attributed to electrons trapped in embedded NDs. The V th shift was measured as a function of the writing voltage, and it was shown that the minimum writing voltage for memory FETs with small NDs is significantly larger than that for FETs with large ones. This result supports the proposed model of the memory effect in which electrons that tunneled from nearby pentacene molecules are trapped in embedded NDs because the electron energy level in small NDs is higher than that in large ones.

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We propose herein a method for estimating the mixing state of the contents of a peristaltic continuous mixing conveyor simulating the intestine, developed for mixing and conveying powders and liquids. This study serves to improve a previously proposed method for estimating the mixing state using a logistic regression model with the pressure and flow rate sensors installed in the device as inputs. Moreover, the estimation accuracy of the proposed method is better than that of the previous method. The generalizability of the proposed method is evaluated for four conditions in which the feeding order of the contents, powder, and liquid are changed. The feeding order is as follows: powder first, liquid first, and powder and liquid alternately. As a result, a highly accurate estimation of mixing is achieved under the condition wherein the powder component is in the unit adjacent to the lid, but not under the condition wherein the liquid component is fed first. It is speculated that this is because the movement of the powder component inside the device is more easily reflected by the pressure and flow rate sensors installed in the device than in the liquid component.