Twin study: genotype-dependent epigenetic factors affecting free thyroxine levels in the normal range.

Aim: To explore the clinical application of DNA methylation affecting thyroid function, we evaluated the association of DNA methylation with free thyroxine (FT4) and TSH measurements in monozygotic twins. Materials & methods: Discordant pairs for FT4 or TSH levels were examined for the relationship between the within-pair difference of each measurement and the DNA methylation levels using epigenome-wide association studies. The contribution of polymorphisms to the methylation sensitivity was also examined. Results: We found two CpG sites significantly associated with FT4 levels, and also some CpG sites showing significant differences in their methylation levels within FT4-discordant pairs depending on the polymorphism in EPHB2. Conclusion: The FT4 level may be associated with a combination of methylation and polymorphisms in the EPHB2 gene.

Electrochemistry in bicontinuous microemulsions derived from two immiscible electrolyte solutions for a membrane-free redox flow battery.

HYPOTHESES: Bicontinuous microemulsions (BMEs) have attracted attention as unique heterogeneous mixture for electrochemistry. An interface between two immiscible electrolyte solutions (ITIES) is an electrochemical system that straddles the interface between a saline and an organic solvent with a lipophilic electrolyte. Although most BMEs have been reported with nonpolar oils, such as toluene and fatty acids, it should be possible to construct a sponge-like three-dimensionally expanded ITIES comprising a BME phase. EXPERIMENTS: Dichloromethane (DCM)-water microemulsions stabilized by a surfactant were investigated in terms of the concentrations of co-surfactants and hydrophilic/lipophilic salts. A Winsor III microemulsion three-layer system, consisting of an upper saline phase, a middle BME phase, and a lower DCM phase, was prepared, and electrochemistry was conducted in each phase. FINDINGS: We found the conditions for ITIES-BME phases. Regardless of where the three electrodes were placed in the macroscopically heterogeneous three-layer system, electrochemistry was possible, as in a homogeneous electrolyte solution. This indicates that the anodic and cathodic reactions can be divided into two immiscible solution phases. A redox flow battery comprising a three-layer system with a BME as the middle phase was demonstrated, paving the way for applications such as electrolysis synthesis and secondary batteries.

Lipophilic probe behavior in microemulsions evaluated by fluorescence correlation spectroscopy.

We evaluated the dispersion and diffusion of fluorescent-labeled lipophilic vitamin E (VE) in microemulsions (MEs) including water-in-oil (W/O) type ME, oil-in-water (O/W) type ME, and bicontinuous ME (BME), using fluorescence correlation spectroscopy (FCS). We prepared a fluorescent ATTO 488 or BODIPY group labeled VE (VE-ATTO or VE-BODIPY). VE-ATTO possesses lipophilic and hydrophilic parts, while VE-BODIPY consists solely of the lipophilic part. The VE-ATTO dissolved in heptane solution as an oil phase appeared hot pink in color due to the solvatochromism effect under room light and almost no fluorescent signal, which was unlike the VE-ATTO dissolved in ME solutions and all the VE-BODIPY solutions (typical fluorescent green color). The FCS measurement proved that VE-BODIPY diffuses faster than VE-ATTO. This is presumably because the "surfactant-like" VE-ATTO is localized and trapped at the micro-water/micro-oil interface of the MEs, while the VE-BODIPY exists in the ME phase and macro-oil phase with good dispersion. These results demonstrate that FCS is a powerful tool for the rapid evaluation of the lipophilic probe behavior in heterogeneous ME solutions.

Lipophilic Vitamin E Diffusion through Bicontinuous Microemulsions.

We studied the diffusion properties of lipophilic vitamin E (VE) through bicontinuous microemulsions (BME) using both electrochemical and fluorescence correlation spectroscopy (FCS) measurements. We investigated the effect of different composition ratios of micro-water and micro-oil phases in BMEs (W/OBME). When we employed the BME with a lower W/OBME value of 40/60 (oil-rich BME) as an electrolyte solution, we obtained a larger current response from VE at a fluorinated nanocarbon film electrode. Further voltammetric studies revealed that a higher VE diffusion coefficient was observed in the oil-rich BME. The FCS results also exhibited faster diffusion through the oil-rich BME, which played a significant role in accelerating the VE diffusion probably due to the widening of the micro-oil phase pathway in the BME. Moreover, the effect of increasing the VE diffusion was pronounced at the interface between the electrode surface and the BME solution. These results indicate that controlling the conditions of the BME as the measurement electrolyte is very effective for achieving superior electrochemical measurements in a BME.

Stand-Alone Semi-Solid-State Electrochemical Systems Based on Bicontinuous Microemulsion Gel Films.

Bicontinuous microemulsion (BME)-based hydrogel films were integrated with screen-printed electrodes (SPEs) comprising working, counter, and reference electrodes to form stand-alone, semi-solid-state electrochemical systems that do not require an outer electrolyte solution. The gel network of the BME hydrogel only exists in the microaqueous phase and retains the structure of the entire BME gel. Following gelation, a microaqueous phase with sufficient ionic strength ensured effective ionic conductivity, even in thin gel films. This enabled the electrochemical reaction to proceed using a thin gel film as an electrolyte solution. However, an intact micro-oil phase with no gel network enabled efficient extraction from an external oil solution and exhibited rapid electrochemistry that was comparable to that of a BME solution. Cyclic voltammograms of lipophilic redox species in oil using the gel-integrated SPE system demonstrated successfully in the oil itself and in the air with dropped oil onto the system.