The Development of a Measuring System for Intraoral SpO2.

Blood oxygen saturation (SpO2) is an essential indicator of a patient's general condition. However, conventional measurement methods have some issues such as time delay and interference by ambient light. Improved measurement methods must be developed, and there are no reports on intraoral measurements of SpO2 using wearable devices. Therefore, we aimed to establish an intraoral SpO2 measurement method for the first time. Twelve healthy adults participated in this study. The following steps were taken: (1) to identify the optimal measurement location, mid-perfusion index (PI) values were measured at six places on the mucosa of the maxilla, (2) to validate the optimal measurement pressure, PI values were obtained at different pressures, and (3) using the proposed mouthpiece device, SpO2 values in the oral cavity and on the finger were analyzed during breath-holding. The highest PI values were observed in the palatal gingiva of the maxillary canine teeth, with high PI values at pressures ranging from 0.3 to 0.8 N. In addition, changes in SpO2 were detected approximately 7 s faster in the oral cavity than those on the finger, which is attributed to their proximity to the heart. This study demonstrates the advantage of the oral cavity for acquiring biological information using a novel device.

A New Intraoral Six-Degrees-of-Freedom Jaw Movement Tracking Method Using Magnetic Fingerprints.

We proposed a novel jaw movement tracking method that can measure in six degrees of freedom. The magnetic field generated by a permanent magnet paired with a small, low-power-consumption Hall effect magnetic sensor is used to estimate the relative distance between two objects-in this instance, the lower and upper jaws. By installing a microelectromechanical system (MEMS) orientation sensor in the device, we developed a mouthpiece-type sensing device that can measure voluntary mandibular movements in three-dimensional orientation and position. An evaluation of individuals wearing this device demonstrated its ability to measure mandibular movement with an accuracy of approximately 3 mm. Using the movement recording feature with six degrees of freedom also enabled the evaluation of an individual's jaw movements over time in three dimensions. In this method, all sensors are built onto the mouthpiece and the sensing is completed in the oral cavity. It does not require the fixation of a large-scale device to the head or of a jig to the teeth, unlike existing mandibular movement tracking devices. These novel features are expected to increase the accessibility of routine measurements of natural jaw movement, unrestricted by an individual's physiological movement and posture.

Visualization of orthodontic forces generated by aligner-type appliances.

Recently, the number of patients who request esthetically pleasing aligner-type orthodontic appliances (referred to as aligners) has been increasing. However, the orthodontic forces generated by these aligners are still unknown. This study aimed to verify whether the orthodontic force in aligners can be estimated by measuring near infrared 2D birefringence, and to visualize the orthodontic force. We measured the mechanical and photoelastic properties of transparent orthodontic thermoplastic specimens to correlate the optical retardation with the applied load. The results confirmed equivalence between the mechanical properties and the photoelasticity. In addition, the 2D retardation distribution that occurred when stress was applied to the sample was mapped and visualized. This indicates that it is possible to estimate and visualize the orthodontic force using the retardation obtained by near infrared 2D birefringence measurement.

Diversity of Adenostemma lavenia, multi-potential herbs, and its kaurenoic acid composition between Japan and Taiwan.

Adenostemma lavenia (L.) Kuntze (Asteraceae) is widely distributed in tropical regions of East Asia, and both A. lavenia and A. madurense (DC) are distributed in Japan. In China and Taiwan, A. lavenia is used as a folk medicine for treating lung congestion, pneumonia, and hepatitis. However, neither phylogenic nor biochemical analysis of this plants has been performed to date. We have reported that the aqueous extract of Japanese A. lavenia contained high levels of ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic acid (11αOH-KA; a kaurenoic acid), which is a potent anti-melanogenic compound. Comparison of chloroplast DNA sequences suggested that A. lavenia is originated from A. madurense. Analyses of kaurenoic acids revealed that Japanese A. lavenia and A. madurense contained high levels of 11αOH-KA and moderate levels of 11α,15OH-KA, while Taiwanese A. lavenia mainly contained 9,11αOH-KA. The diverse biological activities (downregulation of Tyr, tyrosinase, gene expression [anti-melanogenic] and iNOS, inducible nitric oxide synthase, gene expression [anti-inflammatory], and upregulation of HO-1, heme-oxygenase, gene expression [anti-oxidative]) were associated with 11αOH-KA and 9,11αOH-KA but not with 11α,15OH-KA. Additionally, 11αOH-KA and 9,11αOH-KA decreased Keap1 (Kelch-like ECH-associated protein 1) protein levels, which was accompanied by upregulation of protein level and transcriptional activity of Nrf2 (NF-E2-related factor-2) followed by HO-1 gene expression. 11αOH-KA and 9,11αOH-KA differ from 11α,15OH-KA in terms of the presence of a ketone (αß-unsaturated carbonyl group, a thiol modulator) at the 15th position; therefore, thiol moieties on the target proteins, including Keap1, may be important for the biological activities of 11αOH-KA and 9,11αOH-KA and A. lavenia extract.

The High Content of Ent-11α-hydroxy-15-oxo-kaur- 16-en-19-oic Acid in Adenostemma lavenia (L.) O. Kuntze Leaf Extract: With Preliminary in Vivo Assays.

BACKGROUND: Ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic acid (11αOH-KA) is a multifunctional biochemical found in some ferns, Pteris semipinnata, and its congeneric species. Although a number of therapeutic applications of 11αOH-KA have been proposed (e.g., anti-cancer, anti-inflammation, and skin whitening), the content of 11αOH-KA in these ferns is not high. Adenostemma lavenia (L.) O. Kuntze, an Asteraceae, has also been reported to contain 11αOH-KA. The decoction (hot water extract) of whole plants of A. lavenia is used as a folk remedy for inflammatory disorders, such as hepatitis and pneumonia, suggesting that 11αOH-KA may be the ingredient responsible for the medicinal properties of this plant. METHODS: The anti-melanogenic activities of the water extracts of A. lavenia leaves and Pteris dispar Kunze (a cognate of P. semipinnata) leaves were compared in mouse B16F10 melanoma cells. The amount of 11αOH-KA was measured by using liquid chromatography spectrometry. C57BL/6J mice were treated with the water extract of A. lavenia leaf, and the blood concentration of 11αOH-KA was measured. The in vivo efficacy of the water extract of A. lavenia leaf was evaluated according to tis anti-melanogenic activity by monitoring hair color. RESULTS: Although both the extracts (A. lavenia and P. dispar Kunze) showed high anti-melanogenic activities, only A. lavenia contained a high amount of 11αOH-KA, approximately 2.5% of the dry leaf weight. 11αOH-KA can be purified from A. lavenia leaves in two steps: water extraction followed by chloroform distribution. The treatment of mice with the water extract of A. lavenia leaf suppresses pigmentation in their hairs. CONCLUSIONS: Despite the small number of mice examined, the present preliminary result of the suppressed hair pigmentation suggests that the water extract of A. lavenia leaf and the ingredient that is possibly responsible for this-11αOH-KA-are new materials for oral cosmetics. The results may also be helpful in the future development of functional foods and methods to treat patients suffering from hyperpigmentation disorders, such as melasma.

Magnetophotonic crystal with cerium substituted yttrium iron garnet and enhanced Faraday rotation angle.

Magnetophotonic crystals (MPCs) comprising cerium-substituted yttrium iron garnet (CeYIG) sandwiched by two Bragg mirrors were fabricated by vacuum annealing. CeYIG was deposited on Bragg mirrors at room temperature and annealed in 5 Pa of residual air. No ceria or other non-garnet phases were detected. Cerium 3 + ions substituted on the yttrium sites and no cerium 4 + ions were found. The Faraday rotation angle of the MPC was -2.92° at a wavelength of λ = 1570 nm was 30 times larger than that of the CeYIG film. These results showed good agreement with calculated values derived using a matrix approach.

Thermomagnetic writing into magnetophotonic microcavities controlling thermal diffusion for volumetric magnetic holography.

Holographic memory is expected to become a high-capacity data storage. Magnetic volumetric holograms are rewritable holograms that are recorded as magnetization directions through thermomagnetic recording. However, the effective depth of magnetic holograms is limited by thermal diffusion that causes merging of magnetic fringes. In this study, we propose the insertion of heat-sink layers (HSLs) for retaining well-defined magnetic fringes during volumetric writing. Magnetophotonic microcavity media were used for demonstrating the HSL effect, and the structural design principle was established in numerical calculations. The results indicate that deep and clear magnetic fringes and an improvement in the diffraction efficiency can be achieved by the insertion of HSLs.

Collinear volumetric magnetic holography with magnetophotonic microcavities.

Hologram memory is a candidate for high-capacity data storage. Magnetic holograms formed as magnetization directions have been studied to realize rewritable hologram media. Recently, we reported that the magnetophotonic microcavity (MPM) can improve diffraction efficiency because of enhanced Faraday rotation angle and deep hologram writing. In this study, we demonstrated a clear reconstructed image from magnetic holograms in an MPM medium. The structural condition of MPMs for high diffraction efficiency was investigated, and the MPM medium was actually fabricated. The image reconstructed from the MPM medium had approximately twice the brightness of that reconstructed using a monolayer film.

Para-magneto- and electro-optic microcavities for blue wavelength modulation.

We report on microcavities comprising para-magnetic garnet and electro-optic films (MPMEO) for modulation of the polarization rotation angle of light at near-UV wavelengths with a slight intensity change, with applying a low voltage. The MPMEO are composed of para-magnetic garnet and electro-optic films sandwiched between two Bragg mirrors. The microcavity states in MPMEO are split and yield both the large rotation angle and high optical efficiency. Significant enhancement and modulation by applied voltages are verified through a conventional matrix calculation approach. High optical efficiency (>90%) and large modulation (~90 degree) of the polarization rotation are proved.