212 research outputs found
Phenolics from Glycyrrhiza glabra and G. uralensis Roots and Their PPAR-γ Ligand-Binding Activity: Possible Application for Amelioration of Type 2 Diabetes
The EtOH extract of Glycyrrhiza glabra roots and the EtOAc extract of Glycyrrhiza uralensis roots exhibited considerable PPAR-γ ligand-binding activity. Bioassay-guided fractionation of these extracts resulted in the isolation of 52 phenolics, including 11 novel ones. The PPAR-γ ligand-binding activity of more than 10 isolated phenolics at 10 μg/mL was approximately three times greater than that of 0.5 μM triglitazone. Glycyrin (44), isolated from the EtOAc extract of G. uralensis roots as a PPAR-γ ligand, reduced the blood glucose levels of genetically diabetic KK-Ay mice through its PPAR-γ ligand-binding activity
Non-contact Cold Thermal Display by Controlling Low-temperature Air Flow Generated with Vortex Tube
In recent years, thermal display has been studied intensively in order to
represent a more realistic tactile quality of the object. Since human feels the
temperature of the air without touching other objects, it is necessary to
present thermal sensation in a non-contact manner. Studies on non-contact heat
display have been explored; however, few studies have reported on a device that
can display cold in a non-contact manner. In this study, we propose a
non-contact cold thermal display using a low-temperature heat source-vortex
tube, which can generate ultra-low air temperature when supplied with
compressed air. We developed a cooling model that relates the flow velocity of
cold air with the absorbed heat from skin; we implemented a prototype system
that can control the flow velocity of the generated air; and we conducted an
experiment to examine the cold sensation that the system can present. Our
results revealed that various cold sensations can be generated so that the
faster the flow velocity, the colder a user would feel
Force Rendering and Its Evaluation of a Friction-based Walking Sensation Display for a Seated User
Most existing locomotion devices that represent the sensation of walking
target a user who is actually performing a walking motion. Here, we attempted
to represent the walking sensation, especially a kinesthetic sensation and
advancing feeling (the sense of moving forward) while the user remains seated.
To represent the walking sensation using a relatively simple device, we focused
on the force rendering and its evaluation of the longitudinal friction force
applied on the sole during walking. Based on the measurement of the friction
force applied on the sole during actual walking, we developed a novel friction
force display that can present the friction force without the influence of body
weight. Using performance evaluation testing, we found that the proposed method
can stably and rapidly display friction force. Also, we developed a virtual
reality (VR) walk-through system that is able to present the friction force
through the proposed device according to the avatar's walking motion in a
virtual world. By evaluating the realism, we found that the proposed device can
represent a more realistic advancing feeling than vibration feedback
Photon correlation in GaAs self-assembled quantum dots
We report on photon coincidence measurement in a single GaAs self-assembled
quantum dot (QD) using a pulsed excitation light source. At low excitation,
when a neutral exciton line was present in the photoluminescence (PL) spectrum,
we observed nearly perfect single photon emission from an isolated QD at 670 nm
wavelength. For higher excitation, multiple PL lines appeared on the spectra,
reflecting the formation of exciton complexes. Cross-correlation functions
between these lines showed either bunching or antibunching behavior, depending
on whether the relevant emission was from a biexciton cascade or a charged
exciton recombination.Comment: 5 pages, 3 figure
Method to Develop Pseudo Three-dimensional Dental Image from Dental Panoramic Radiograph
Although three-dimensional imaging can be a powerful tool for dentists to explain treatments to patients, obtaining of three-dimensional image of teeth in general dental clinics is difficult. This paper proposed a method to develop pseudo three-dimensional dental image from conventional dental panoramic radiograph and dental impression. The method estimates imaging parameters of given panoramic radiograph through comparison with dental cast, and re-projects the radiograph into three-dimensional space. The developed pseudo three-dimensional image gives clear impression of the patient’s dental condition
Medial prefrontal cortex and anterior cingulate cortex in the generation of alpha activity induced by transcendental meditation: a magnetoencephalographic study.
Previous EEG studies have shown that transcendental meditation (TM) increases frontal and central alpha activity. The present study was aimed at identifying the source of this alpha activity using magnetoencephalography (MEG) and electroencephalography (EEG) simultaneously on eight TM practitioners before, during, and after TM. The magnetic field potentials corresponding to TM-induced alpha activities on EEG recordings were extracted, and we attempted to localize the dipole sources using the multiple signal classification (MUSIC) algorithm, equivalent current dipole source analysis, and the multiple spatio-temporal dipole model. Since the dipoles were mapped to both the medial prefrontal cortex (mPFC) and anterior cingulate cortex (ACC), it is suggested that the mPFC and ACC play an important role in brain activity induced by TM.</p
Spatially Continuous Non-Contact Cold Sensation Presentation Based on Low-Temperature Airflows
Our perception of cold enriches our understanding of the world and allows us
to interact with it. Therefore, the presentation of cold sensations will be
beneficial in improving the sense of immersion and presence in virtual reality
and the metaverse. This study proposed a novel method for spatially continuous
cold sensation presentation based on low-temperature airflows. We defined the
shortest distance between two airflows perceived as different cold stimuli as a
local cold stimulus group discrimination threshold (LCSGDT). By setting the
distance between airflows within the LCSGDT, spatially continuous cold
sensations can be achieved with an optimal number of cold airflows. We
hypothesized that the LCSGDTs are related to the heat-transfer capability of
airflows and developed a model to relate them. We investigated the LCSGDTs at a
flow rate of 25 L/min and presentation distances ranging from 10 to 50 mm. The
results showed that under these conditions, the LCSGDTs are 131.4 1.9 mm,
and the heat-transfer capacity of the airflow corresponding to these LCSGDTs is
an almost constant value, that is, 0.92.Comment: 7 page
Integration of Independent Heat Transfer Mechanisms for Non-Contact Cold Sensation Presentation With Low Residual Heat
Thermal sensation is crucial to enhancing our comprehension of the world and
enhancing our ability to interact with it. Therefore, the development of
thermal sensation presentation technologies holds significant potential,
providing a novel method of interaction. Traditional technologies often leave
residual heat in the system or the skin, affecting subsequent presentations.
Our study focuses on presenting thermal sensations with low residual heat,
especially cold sensations. To mitigate the impact of residual heat in the
presentation system, we opted for a non-contact method, and to address the
influence of residual heat on the skin, we present thermal sensations without
significantly altering skin temperature. Specifically, we integrated two highly
responsive and independent heat transfer mechanisms: convection via cold air
and radiation via visible light, providing non-contact thermal stimuli. By
rapidly alternating between perceptible decreases and imperceptible increases
in temperature on the same skin area, we maintained near-constant skin
temperature while presenting continuous cold sensations. In our experiments
involving 15 participants, we observed that when the cooling rate was -0.2 to
-0.24 degree celsius per second and the cooling time ratio was 30 to 50 %, more
than 86.67 % of the participants perceived only persistent cold without any
warmth
Measurement of intracellular pH by flow cytometry using pH sensitive fluorescence dye, and influence of hyperthermia and amiloride derivatives on the intracellular pH
エールリッヒ腹水癌細胞とそのアドリアマイシン耐性細胞において蛍光pH指示薬2'、7'-bis-(2-carboxyethyl) carboxyfluorescein] (BCECF) の蛍光量をフローサイトメトリーで測定することによって細胞内pHの検量曲線を作成することができた。このことより、これらの細胞においてBCECFの蛍光量で細胞内pHの変化を簡易に比較できることを示唆した。さらに、温熱、Na(+)/H(+) exchanger の阻害例であるアミロライド[3,5-diamino-6-chloro-N-(diaminomethylene) pyrazinecarboxamide]、およびアミロライド誘導隊MH-12-43[N-amidino-3-amino-6-chloro-5-(N-ethyliso-propylamino) pyrazinecarboxyamide] の細胞内pHへの影響をエールリッヒ腹水癌細胞で観察した。37℃では、0.5mMアミロライド、0.05mM MH-12-43により細胞内pHは減少し、42℃処理によりさらに減少した。42℃において、0.05mM MH-12-43による細胞内pHの減少は、0.5mMアミロライドによる減少より大きかった。We examined relationship between intensity of intracellular fluorescence of [2', 7'-bis-(2'-carboxyethyl) carboxyfluorescein] (BCECF) and intracellular pH in Ehrlich ascites tumor cells and their adriamycin-resistant strain, and found a good correlation between them at both strains. This suggests that changes in the intracellular pH on these strains may be obtained through measurement of intracellular fluorescence of BCECF by flow cytometry. Further, we examined influence of hyperthermia, 3, 5-diamino-6-chloro-N-(diaminomethylene)pyrazinecarboxamide (amiloride), an inhibitor of Na(+)/H(+) exchanger, and its derivative; N-amidino-3-amino-6-chloro-5-(N-ethylisopropylamino) pyrazinecarboxyamide (MH-12-43) on the intracellular pH in Ehrlich ascites tumor cells. The treatment of 0.5mM amiloride or 0.05mM MH-12-43 reduced intracellular pH at 37℃, while the more reduction was observed by the treatment at 42℃. The reduction of intracellular pH by 0.05mM MH-12-43 was more substantial than that of 0.5mM amiloride at 42℃
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