The Use of Carboxyfluorescein Reveals the Transport Function of MCT6/SLC16A5 Associated with CD147 as a Chloride-Sensitive Organic Anion Transporter in Mammalian Cells.

Oral drug absorption involves drug permeation across the apical and basolateral membranes of enterocytes. Although transporters mediating the influx of anionic drugs in the apical membranes have been identified, transporters responsible for efflux in the basolateral membranes remain unclear. Monocarboxylate transporter 6 (MCT6/SLC16A5) has been reported to localize to the apical and basolateral membranes of human enterocytes and to transport organic anions such as bumetanide and nateglinide in the Xenopus oocyte expression system; however, its transport functions have not been elucidated in detail. In this study, we characterized the function of MCT6 expressed in HEK293T cells and explored fluorescent probes to more easily evaluate MCT6 function. The results illustrated that MCT6 interacts with CD147 to localize at the plasma membrane. When the uptake of various fluorescein derivatives was examined in NaCl-free uptake buffer (pH 5.5), the uptake of 5-carboxyfluorescein (5-CF) was significantly greater in MCT6 and CD147-expressing cells. MCT6-mediated 5-CF uptake was saturable with a Km of 1.07 mM and inhibited by several substrates/inhibitors of organic anion transporters and extracellular Cl ion with an IC50 of 53.7 mM. These results suggest that MCT6 is a chloride-sensitive organic anion transporter that can be characterized using 5-CF as a fluorescent probe.

Improving Measurement Range of a Swellable Polymer-Clad Plastic Fiber Optic Humidity Sensor by Dye Addition.

Humidity measurement is required in various fields. We previously developed a sensor that leverages the sudden change in the transmitted light intensity when switching from leakage mode to waveguide mode. By adjusting the low-refractive-index polymer of the cladding, we achieved measurements at 60% RH. However, for practical use, measurements at low humidity are essential. Therefore, in this study, we developed a sensor using a leakage mode that enables measurements at low humidity. To measure the leakage mode, it is necessary to increase the absorbance of the cladding and the incident angle at the core-cladding interface. Therefore, we developed a sensor in which the core was stretched, and the cladding was doped with a high concentration of dye. The experimental results confirmed that a sensor with a polymer concentration of 4% and a dye concentration of 3% could measure from 0% RH to 95% RH. The sensitivity was 0.1 dB/% RH from 0% RH to 70% RH and 0.32 dB/% RH from 70% RH to 95% RH. The estimated response time for a change from 10% to 90% light transmission for a sensor with 4% polymer concentration and 0.5% dye concentration was 22 s from 45% RH to 0% RH and 50 s from 0% RH to 45% RH.

Management of flying insects on expressways through an academic-industrial collaboration: evaluation of the effect of light wavelengths and meteorological factors on insect attraction.

Insect outbreaks often occur in the absence of natural enemies and in the presence of excess suitable host materials. Outbreaks of gypsy moths are especially problematic in remote areas located in high-latitude regions in Japan because the majority of adults emerge during the short summer season and initiate synchronous mass flight toward artificial lights. The aggregation of moths in public facilities not only is an annoyance to visitors but also permits the establishment of new populations the following year. The aim of this study was to establish a method to reduce the numbers of large moths that are attracted to lights in the rest areas of expressways in Hokkaido based on the results of research on their behavioral ecology and physiology. First, we conducted extensive insect surveys using light traps that emit light at different wavelengths; the traps were set along the expressways in the summers of 2014-2018. The insects attracted to the light were roughly classified into those showing a preference for broadband light wavelengths (from UV-A to green) and short light wavelengths (from UV-A to blue). The former included aquatic insects and winged ants, and the latter included moths and beetles. Next, we analyzed correlations between moth emergence and daily meteorological data. When gypsy moths were abundant during an outbreak, the daily catch of gypsy moths was positively correlated with the highest ambient temperature on the catch day but not with the visibility range, wind speed, or moon phase. In contrast, the daily catch of oak silkmoths did not correlate with any of these parameters. Our results provide guidance for the management of forest insects inhabiting cool-temperate to subarctic regions based on light wavelengths with reference to weather variables.

Biomechanical effects of offset placement of dental implants in the edentulous posterior mandible.

BACKGROUND: Proper implant placement is very important for long-term implant stability. Recently, numerous biomechanical studies have been conducted to clarify the relationship between implant placement and peri-implant stress. The placement of multiple implants in the edentulous posterior mandible has been studied by geometric analysis, three-dimensional finite element analysis (FEA), model experimentation, etc. Offset placement is a technique that reduces peri-implant load. However, few studies have used multiple analyses to clarify the value of the offset placement under identical conditions. The present study aimed to clarify the biomechanical effects of offset placement on the peri-implant bone in edentulous posterior mandibles by comparative investigation using FEA and model experimentation with strain gauges. METHODS: Three implants were embedded in an artificial mandible in the parts corresponding to the first premolar, the second premolar, and the first molar. A titanium superstructure was mounted to prepare models (experimental models). Three load points (buccal, central, and lingual) were established on the part of the superstructure corresponding to the first molar. Three types of experimental models, each with a different implant placement, were prepared. In one model, the implants were placed in a straight line; in the other two, the implants in the parts corresponding to the second premolar and the first molar were offset each by a 1-mm increment to the buccal or lingual side. Four strain gauges were applied to the peri-implant bone corresponding to the first molar. The experimental models were imaged by micro-computed tomography (CT), and FEA models were constructed from the CT data. A vertical load of 100 N was applied on the three load points in the experimental models and in the FEA models. The extent of compressed displacement and the strain in the peri-implant bone were compared between the experimental models and the FEA models. RESULTS: Both experimental and FEA models suffered the least compressed displacement during central loading in all placements. The greatest stress and compressive strain was on the load side in all types of placements. CONCLUSIONS: Offset placement may not necessarily be more biomechanically effective than straight placement in edentulous posterior mandibles.

A biomechanical investigation of mandibular molar implants: reproducibility and validity of a finite element analysis model.

BACKGROUND: Three-dimensional finite element analysis (FEA) is effective in analyzing stress distributions around dental implants. However, FEA of living tissue involves many conditions, and the structures and behaviors are complex; thus, it is difficult to ensure the validity of the results. To verify reproducibility and validity, we embedded implants in experimental models and constructed FEA models; implant displacements were compared under various loading conditions. METHODS: Implants were embedded in the molar regions of artificial mandibles to fabricate three experimental models. A titanium superstructure was fabricated and three loading points (buccal, central, and lingual) were placed on a first molar. A vertical load of 100 N was applied to each loading point and implant displacements were measured. Next, the experimental models were scanned on micro-computed tomography (CT) and three-dimensional FEA software was used to construct two model types. A model where a contact condition was assumed for the implant and artificial mandible (a contact model) was constructed, as was a model where a fixation condition was assumed (a fixation model). The FEA models were analyzed under similar conditions as the experimental models; implant displacements under loading conditions were compared between the experimental and FEA models. Reproducibility of the models was assessed using the coefficient of variation (CV), and validity was assessed using a correlation coefficient. RESULTS: The CV of implant displacement was 5% to 10% in the experimental and FEA models under loading conditions. Absolute values of implant displacement under loading were smaller in FEA models than the experimental model, but the displacement tendency at each loading site was similar. The correlation coefficient between the experimental and contact models for implant displacement under loading was 0.925 (p < 0.01). The CVs of equivalent stress values in the FEA models were 0.52% to 45.99%. CONCLUSIONS: Three-dimensional FEA models were reflective of experimental model displacements and produced highly valid results. Three-dimensional FEA is effective for investigating the behavioral tendencies of implants under loading conditions. However, the validity of the absolute values was low and the reproducibility of the equivalent stresses was inferior; thus, the results should be interpreted with caution.

Catalytic enantioselective fluorination of oxindoles.

We have developed a highly efficient catalytic enantioselective fluorination of oxindole derivatives. In the presence of a catalytic amount of chiral Pd complex 2 (2.5 mol %), various substrates, including aryl- and alkyl-substituted oxindoles, were fluorinated in a highly enantioselective manner (up to 96% ee). In addition, when R was a hydrogen atom, enantioselective fluorination followed by solvolysis gave a monofluorinated ester with up to 93% ee. To our knowledge, this is the first example of catalytic enantioselective fluorination of oxindoles.

Amine-salt-controlled, catalytic asymmetric conjugate addition of various amines and asymmetric protonation.

The combined use of chiral Pd complex 2 and amine salt enabled completely regulated release of free nucleophilic amine. Under these conditions, an efficient catalytic asymmetric conjugate addition of various amines was achieved to afford beta-amino acid derivatives in high chemical yields with up to 98% ee. Furthermore, a highly enantioselective protonation in 1,4-addition of amine was also developed. [reaction: see text]