• Journal of Sensor Science and Technology
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• v.23 no.3
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• pp.178-184
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• 2014

Key components of implantable hearing aids are consist of an acoustic sensor that collect external sound by suppressing the body noise, a signal processor module for compensation algorithm of hearing loss, and a output transducer which has tiny size but have high efficiency, respectively. In the partial implantable hearing aids, technologies of transducer and signal processor are so matured that can be applied not too much difficulty. However, due to the difficulties in implantable acoustic sensor technology, such as minimization of masticatory sound and damage of sensor's membrane from external impact, practical use of fully implantable hearing aids have not successful so far. In this paper, we have proposed a novel implantable acoustic sensor which has trans-tympanic structure, and is verified that the proposed method can be very useful for fully implantable hearing aids by cadaveric experiments.

• Journal of the Korean Magnetics Society
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• v.10 no.5
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• pp.246-249
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• 2000

An Fe$_{49}$ Co$_{49}$ V$_2$alloy is annealed in thermal annealing furnace at 50$0^{\circ}C$, 75$0^{\circ}C$, 80$0^{\circ}C$, and 90$0^{\circ}C$. Annealed samples were cooled in air. The magnetostriction is measured by using a Michelson laser interferometer. Receiving the feedback signal of interference, a mirror attached to piezoelectric transducer (PZT) maintains the optical path length (OPL) between two arms of laser interferometer relatively constant. The feedback voltage is calibrated to the OPL variation. A magnetostriction of 2$\times$10$^{-6}$ at H = 60 Oe increases up to 33.68$\times$10$^{-6}$ at an annealing temperature of 90$0^{\circ}C$, suggesting that the magnetostrictive characteristics are improved by the microstructural modification.

• Korean Journal of Medicinal Crop Science
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• v.18 no.1
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• pp.1-8
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• 2010

Inonotus obliquus is one of the immune-regulatory substances and is recognized to play the role in the metabolic process of inflammation, allergy and immuntiy. The purpose of this study was to evaluate the effects of water extracts of Inonotus obliquus (IOW) on the liver lymphocyte immune function in the Sprague-Dawley male rats treated with carbon tetrachloride ($CCl_4$) to induce liver damage. Rats were fed with each experimental diet and water for 4 weeks. We found that effects of IOW on interferon-gamma (IFN-$\gamma$), signal transducer and activator of transcription 1 (STAT1), phospho-signal transducer and activator of transcription 1 (pSTAT1) and GATA-binding protein 3 (GATA-3) were decrease in vivo. Interleukin-4 (IL-4), STAT6, pSTAT6 and T-box expressed in T-cells (T-bet) decreased significantly lower in $CCl_4$+IOW group than the $CCl_4$ group. Our data indicated that cytokine protein production were increased in $CCl_4$ group and $CCl_4$+IOW group. As a result of this study, we assume that IOW fed could regulate the immuno-modulating functions through regulate the cytokine production capacity activated by liver damage.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.3
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• pp.211-217
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• 2014

This study analyzes the nonlinear interaction between two different vortex shedding frequencies from a cylinder with two diameters. In particular, two different vortex shedding frequencies are generated by preparing a cylinder having two diameters artificially. Flow velocity fluctuations behind the cylinder are measured three-dimensionally. Additionally, we fabricated a hole and placed a pressure transducer for measuring the pressure on the cylinder surface. The pressure signal from the pressure transducer is used as basic signal. A TSC(Trans Spectrum Coherence) is used for checking the strength of the nonlinear interaction between two different vortex shedding frequencies. As a result, the following are clarified: i) frequency distribution behind the cylinder, ii) three-dimensional flow state behind the cylinder through calculation of ensemble average, and iii) close relationship between the vertical vortex and change of low frequency by nonlinear interaction between two different vortex shedding frequencies from the cylinder with two diameters.

• Journal of Biomedical Engineering Research
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• v.19 no.2
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• pp.143-152
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• 1998

In this paper, we present the performances of a Doppler system using single channel RF(Radio Frequency) sampling. This technique consists of undersampling the ultrasonic blood backscattered RF signal on a single channel. Conventional undersampling method in Doppler imaging system have to use a minimum of two identical parallel demodulation channels to reconstruct the multigate analytic Doppler signal. However, this system suffers from hardware complexity and problem of unbalance(gain and phase) between the channels. In order to reduce these problems, we have realized a multigate pulsed Doppler system using undersampling on a single channel, It requires sampling frequency at $4f_o$(where $f_o$ is the center frequency of the transducer) and 12bits A/D converter. The proposed " single-Channel RF Sampling" method aims to decrease the required sampling frequency proportionally to $4f_o$/(2k+1). To show the influence of the factor k on the measurements, we have compared the velocity profiles obtained in vitro and in vivo for different intersequence delays time (k=0 to 10). We have used a 4MHz center frequency transducer and a Phantom Doppler system with a laminar stationary flow. The axial and volumetric velocity profiles in the vessel have been computed according to factor k and have been compared. The influence of the angle between the ultrasonic beam and the flow axis direction, and the fluid viscosity on the velocity profiles obtained for different values of k factor is presented. For experiment in vivo on the carotid, we have used a data acquisition system with a sampling frequency of 20MHz and a dynamic range of 12bits. We have compared the axial velocity profiles in systole and diastole phase obtained for single channel RF sampling factor.ng factor.

• Food Science of Animal Resources
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• v.43 no.5
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• pp.859-876
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• 2023

It is known that animal-origin medicine could be one of effective treatment to remedy atopic dermatitis (AD) by controlling the cytokines. Cicadidae Periostracum (CP), the slough of Cryptotympana pustulata, has been frequently used for treating AD and skin affliction in traditional Korean Medicine. This study is aimed at investigating the ameliorating effects of CP on AD and its potential mechanism. The dinitrochlorobenzene sensitized mice were treated with CP for 2 weeks. The various biomarkers and the dermatitis scores presented that CP treatment can induce the visual and biological improvements of AD model. Pruritus, the most serious symptom of AD, which can cause repeated scratching behaviors and finally lead to lichenification, was reduced with CP treatment by regulating the inflammatory reactions. In addition, CP treatment diminished the number of mast cells that are known for causing inflammatory reactions. Moreover, it is proven that CP can decline secretion of interleukin-22, which means CP treatment has anti-inflammatory effects. CP treatment can correct the imbalance of helper T (Th)1 and Th2, downregulating thymic stromal lymphopoietin that leads to decrease of mRNA level of inflammatory cytokines. The crucial role of CP treatment is controlling of the Janus kinase 1/signal transducer and activator of transcription 3 pathway. In addition, CP treatment has the inhibitory effects on kallikrein related peptidase (KLK) 5 and KLK7. Taken together, CP treatment can ameliorate most symptoms and problems caused by AD disease, improving the AD patients' life quality.

• Journal of the Korean Geotechnical Society
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• v.23 no.1
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• pp.51-65
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• 2007

The purpose of this study is the development and application of a high resolution ultrasonic wave imaging system to detect discontinuity plane in lab-scale rock models. This technique is based on received time series which capture the multiple reflections at interface. This study includes the fundamental aspects of ultrasonic wave propagation in rock mass, the selection of the optimal ultrasonic wave transducer, data gathering, a signal processing, imaging methods, and experiments. Experiments are carried out by the horizontal movement and rotation devices. Experimental studies show the discontinuity is well detected by the horizontal movement and rotation devices under water. Furthermore, the discontinuity and the cavity on the plaster block are identified by the rotation device. This study suggests that the new method may be an economical and effective tool for the detection of the discontinuity on rock mass.

• Animal Bioscience
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• v.37 no.8
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• pp.1377-1386
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• 2024

Objective: Embryonic interferon-tau (IFNT) and progesterone affect expression of interferon-stimulated genes (ISGs), progesterone receptor (PGR) and progesterone-induced blocking factor (PIBF) in the ovine thyroid. Methods: Thyroids of ewes were sampled at day 16 of nonpregnancy, days 13, 16, and 25 of pregnancy, and real-time quantitative polymerase chain reaction assay, western blot and immunohistochemistry were used to detect expression of ISGs, PGR, and PIBF. Results: Free ISG15 protein was undetected, but ISG15 conjugated proteins upregulated at day 16 of pregnancy, and expression levels of ISG15 conjugated proteins, PGR isoform (70 kDa), PIBF, interferon-gamma-inducible protein 10 and myxovirusresistance protein 1 peaked, but expression level of signal transducer and activator of transcription 1 was the lowest at day 16 of pregnancy. In addition, the expression levels of PGR isoform (70 kDa) and signal transducer and activator of transcription 1 (STAT1) decreased, but levels of PGR isoform (43 kDa), 2',5'-oligoadenylate synthetase, IP-10 and MX1 increased at day 25 of pregnancy comparing with day 16 of the estrous cycle. Conclusion: Early pregnancy affects expression of ISGs, PGR, and PIBF in maternal thyroid through IFNT and progesterone, which may regulate thyroid autoimmunity and thyroid hormone secretion in ewes.

• Parasites, Hosts and Diseases
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• v.62 no.1
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• pp.30-41
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• 2024

The dense granule protein of Toxoplasma gondii, inhibitor of signal transducer and activator of transcription 1 (IST) is an inhibitor of signal transducer and activator of transcription 1 (STAT1) transcriptional activity that binds to STAT1 and regulates the expression of inflammatory molecules in host cells. A sterile inflammatory liver injury in pathological acute liver failures occurs when excessive innate immune function, such as the massive release of IFN-γ and TNF-α, is activated without infection. In relation to inflammatory liver injury, we hypothesized that Toxoplasma gondii inhibitor of STAT1 transcription (TgIST) can inhibit the inflammatory response induced by activating the STAT1/IRF-1 mechanism in liver inflammation. This study used IFN-γ and TNF-α as inflammatory inducers at the cellular level of murine hepatocytes (Hepa-1c1c7) to determine whether TgIST inhibits the STAT1/IRF-1 axis. In stable cells transfected with TgIST, STAT1 expression decreased with a decrease in interferon regulatory factor (IRF)-1 levels. Furthermore, STAT1 inhibition of TgIST resulted in lower levels of NF-κB and COX2, as well as significantly lower levels of class II transactivator (CIITA), iNOS, and chemokines (CLXCL9/10/11). TgIST also significantly reduced the expression of hepatocyte proapoptotic markers (Caspase3/8/9, P53, and BAX), which are linked to sterile inflammatory liver injury. TgIST also reduced the expression of adhesion (ICAM-1 and VCAM-1) and infiltration markers of programmed death-ligand 1 (PD-L1) induced by hepatocyte and tissue damage. TgIST restored the cell apoptosis induced by IFN-γ/TNF-α stimulation. These results suggest that TgIST can inhibit STAT1-mediated inflammatory and apoptotic responses in hepatocytes stimulated with proinflammatory cytokines.

• Oncology Letters
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• v.17 no.5
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• pp.4735-4741
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• 2019

Fms-like tyrosine kinase 3 (FLT3) is a valuable pharmacological target in the treatment of acute myeloid leukemia (AML). LDD-1075 and LDD-1076 are indirubin derivatives, and LDD-1075 is the ester form of LDD-1076. LDD-1076 exhibited a potent in vitro FLT3 kinase activity inhibition with an IC₅₀ of 7.89 nM, whereas, LDD-1075 demonstrated a relatively weak activity against FLT3 (IC₅₀ of 3.19 µM). In contrast with the results of the FLT3 kinase activity inhibition assay, the LDD-1076 did not affect the growth of the MV4-11 cell line, which harbors the constitutively activated form of the FLT3 mutation. Notably, LDD-1075 exhibited a strong cytotoxic effect against the MV4-11 cells. When LDD-1075 was incubated with the MV4-11 cell lysate, the formation of LDD-1076 was observed. Treatment with LDD-1075 inhibited the FLT3 phosphorylation along with the phosphorylation of the signal transducer and activator of transcription 5 protein, which is a downstream signal transducer of FLT3. Treatment with LDD-1075 induced apoptosis and cell cycle arrest at the G1 phase. The present study demonstrated that the LDD-1076 formed by the bioconversion of LDD-1075 is a potent FLT3 inhibitor with anti-leukemic activity.