• Anatomy and Cell Biology
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• v.57 no.2
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• pp.256-270
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• 2024

The antidepressant drug trazodone (TRZ) is commonly used for treating depression, anxiety, and insomnia, however, it causes cardiotoxicity, which is one of its limitations. The objective of this work was to investigate the impact of sage (Salvia officinalis) in rats against cardiotoxicity induced by TRZ and to investigate the mechanisms involved in its cardio-protective properties through autophagy and oxidative stress. Fifty male albino rats were split randomly into five experimental groups: control group, sage oil group (100 mg/kg), TRZ group (20 mg/kg), protective group, and curative group. Cardiac function biomarkers (aspartate aminotransferase [AST], creatine kinase-MB [CK-MB], and cardiac troponin T [cTnI]) were assessed in serum. Oxidative stress and inflammatory biomarkers in cardiac tissue (total antioxidant capacity, malondialdehyde, and tumor necrosis factor-α) were evaluated. Heart tissues were subjected to histological, immunohistochemical, and ultrastructural evaluations. DNA damage also evaluated. Significant rise in the levels of AST, CK-MB, and cTnI were observed with enhanced autophagy along with marked histopathological changes in the form of interrupted muscle fibers with wide interstitial spaces with areas of hemorrhage and extravasated blood and interstitial mononuclear cellular infiltration in TRZ group. DNA damage was also significantly increased in TRZ group. However, administration of sage in both protective and curative groups show marked improvement of the cardiac alterations. In conclusion, sage ameliorated the alterations in the heart induced by trazadone through modulation of autophagy and oxidative stress.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.8
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• pp.1818-1826
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• 2014

Time-variant sea surface causes a forward scattering and Doppler spreading in received signal on underwater acoustic communication system. This results in time-varying amplitude, frequency and phase variation of the received signal. In such a way the channel coherence bandwidth and fading feature also change with time. Consequently, the system performance is degraded and high-speed coherent digital communication is disrupted. In this paper, quadrature phase shift keying (QPSK) performance is examined in two different sea surface conditions. The impact of sea surface scattering on performance is analyzed on basis of the channel impulse response and temporal coherence using linear frequency modulation (LFM) signal. The impulse response and the temporal coherence of the rough sea surface condition were more unstable and less than that of the calm sea surface condition, respectively. By relating these with time variant envelope, amplitude and phase of received signal, it was found that the bit error rate (BER) of QPSK are closely related to time variation of sea surface state.

• JSTS:Journal of Semiconductor Technology and Science
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• v.11 no.3
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• pp.169-181
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• 2011

In this present paper, a comprehensive drain current model incorporating the effects of channel length modulation has been presented for multi-layered gate material engineered trapezoidal recessed channel (MLGME-TRC) MOSFET and the expression for linearity performance metrics, i.e. higher order transconductance coefficients: $g_{m1}$, $g_{m2}$, $g_{m3}$, and figure-of-merit (FOM) metrics; $V_{IP2}$, $V_{IP3}$, IIP3 and 1-dB compression point, has been obtained. It is shown that, the incorporation of multi-layered architecture on gate material engineered trapezoidal recessed channel (GME-TRC) MOSFET leads to improved linearity performance in comparison to its conventional counterparts trapezoidal recessed channel (TRC) and rectangular recessed channel (RRC) MOSFETs, proving its efficiency for low-noise applications and future ULSI production. The impact of various structural parameters such as variation of work function, substrate doping and source/drain junction depth ($X_j$) or negative junction depth (NJD) have been examined for GME-TRC MOSFET and compared its effectiveness with MLGME-TRC MOSFET. The results obtained from proposed model are verified with simulated and experimental results. A good agreement between the results is obtained, thus validating the model.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.10
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• pp.1-8
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• 2013

Wireless Visible Light Communication is the technology that enables communication using LED illumination Infrastructure instead of existing illumination such as incandescent lamp or fluorescent light. Because VLC uses light for communication, it has no problem of frequency permission and is harmless to human body. It is also possible to check the communication through eye. So VLC can be used as a supplement to the Radio Frequency communication, Infrared in indoor environment. So far, researchers on the LED Visible light communication have focused on the increasing transmission speed, transmission distance, modulation method. However, there is few research of main factors that influence on system performance. System performance has been mainly predicted through simulation. In this paper, I recognized that these factors such as outside light noise, obstacle, LED panel position or emitted angle have a great impact on wireless communication system. So I experimented VLC system by changing distance and position to discover location suitable for BER regulation.

• Journal of Power Electronics
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• v.14 no.6
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• pp.1322-1333
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• 2014

To track the sinusoidal current under stationary frame and suppress the effects of low-order grid harmonics, the multi-resonant quasi-proportional plus resonant (PR) controller has been extensively used for digitally controlled LCL-type pulse-width modulation (PWM) converters with capacitor-current-feedback active damping. However, designing the controller is difficult because of its high order and large number of parameters. Moreover, the computation and PWM delays of the digitally controlled system significantly affect damping performance. In this study, the delay effect is analyzed by using the Nyquist diagrams and the system stability constraint condition can be obtained based on the Nyquist stability criterion. Moreover, impact analysis of the control parameters on the current loop performance, that is, steady-state error and stability margin, identifies that different control parameters play different decisive roles in current loop performance. Based on the analysis, a simplified controller design method based on the system specifications is proposed. Following the method, two design examples are given, and the experimental results verify the practicability and feasibility of the proposed design method.

• Journal of Power Electronics
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• v.14 no.6
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• pp.1081-1092
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• 2014

Renewable energy is being spotlighted as the electric power generating source for the next generation. Due to an increase in renewable energy systems in the grid system, their impact on the grid has become non-negligible. Thus, many countries in the world, including Europe, present their own grid codes for grid power conversion devices. In order to experiment with these grid codes, grid fault test equipment is required. This paper proposes both equipment and a control method, which are constructed with a 7-level cascaded H-bridge converter, that are capable of generating various grid faults. In addition, the Pulse Width Modulation (PWM) method for multilevel converters is compared and analyzed. The proposed structure, the control method, and the PWM method are verified through simulation and experimental results.

• YAKHAK HOEJI
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• v.48 no.4
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• pp.241-246
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• 2004

Mercury is a widespread metal and consequently there are large populations that currently exposed to low levels of mercury. Endotoxin is a component of the gram-negative bacteria and promotes inflammatory responses. The present study was designed to determine the impact of mercury on lymphocytes phenotype populations and endotoxin-induced inflammatory cytokine expressions in immune organ, spleen and thymus. Male BALB/c mice were exposed continuously to 0, 0.3, 1.5, 7.5, or 37.5 ppm of mercuric chloride in drinking water for 14 days and at the end of the treatment period, lipopolysaccharide (LPS, 0.5 mg/kg) was injected intraperitoneally 2 h prior to euthanasia. The dose-range of mercury used did not cause hepatotoxicity. Mercury at 7.5 and 37.5 ppm dose-dependently decreased CD3$^{+}$ T lymphocytes in spleen; both CD4$^{+}$ and CD8$^{+}$ single positive lymphocyte populations were decreased. Exposure to 7.5 and 37.5 ppm of mercury decreased the CD8$^{+}$ T lymphocyte population in the thymus, whereas double positive CD4$^{+}$ / CD8$^{+}$ and CD4$^{+}$ thymocytes were not altered. Mercury altered LPS-induced inflammatory cytokine gene expressions such as, tumor necrosis factor $\alpha$, interferon ${\gamma}$, and interleukin-12 in spleen and thymus. Results indicated that decreases in T lymphocyte populations in immune organs and altered cytokine gene expression may contribute to the immune-modulative effects of inorganic mercury.ganic mercury.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.12 no.1
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• pp.42-46
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• 2012

With the development of industry, more large-scale non-linear loads are added to existing power systems and they cause the serious power quality (PQ) problems to the nearby sensitive installations more and more. To protect the important loads and mitigate the impact of PQ disturbances on them, various compensating devices are installed. One of the most important control skills used in the compensating equipment at the load side is how fast they can recognize or detect the discontinuous abnormal PQ events from the normal voltage signal. This paper deals with two estimation methods for the fast detection and tracking of general PQ disturbances: Teager Energy Operator (TEO), which is a non-linear operator and used for a short time energy calculation, and Kalman Filter (KF), which is one of the most universally used estimation techniques. And it is also shown how to apply the TEO and the KF to detect the PQ disturbances such as voltage sag, swell, interruption, harmonics and voltage fluctuation.

• Molecular & Cellular Toxicology
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• v.1 no.2
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• pp.124-129
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• 2005

Pro-inflammatory cytokines, such as tumor necrosis factor $(TNF)-{\alpha}$, interleukin-12 (IL-12) and interleukin $(IL-1)-{\beta}$, play a key role in causing inflammatory diseases, which are rheumatoid arthritis, Crohn's disease and sepsis. Accumulating evidences suggest that low level laser irradiation (LLLI) may have an anti-inflammatory action. However, there are few data regarding down regulation of Th1 immune response by using the diod typed laser emitting device for human patients. As a fundamental step in order to address this issue, we investigated immunological impact of the low level laser irradiation (10 mw laser diode with a wavelength of 630 nm) on expression of pro-inflammatory cytokines in murine immunocytes (splenocytes and peritoneal macrophages) in vitro. The LLLI on lipopolysaccharide (LPS 100 ng/ml)-stimulated murine splenocytes and macrophages, clearly down regulated mRNA expression of $TNF-{\alpha}$ and IL-12 in dose-dependent manner. In addition, LLLI significantly inhibits the NO production in the LPS-stimulated murine macrophages. This data suggests that LLLI (wavelength of 630 nm) may exert an anti-inflammatory action via modulation of pro-inflammatory cytokine and NO production pathway.

• Korean Journal of Optics and Photonics
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• v.5 no.2
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• pp.319-325
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• 1994

The performance of Manchester-coded DPSK optical wavelength division multiplexing (WDM) systems using a stochastic approach is evaluated taking into account the shot noise and the four-wave mixing (FWM) caused by fiber nonlinearities. The result of Manchester-coded system is compared to conventional non-return-to-zero (NRZ) systems for DPSK modulation formats. Further, the dynamic range, defined as the ratio of the maximum input power (limited by the FWM), to the minimum input power (limited by receiver sensitivity), is evaluated. For $1.55.{\mu}m$16 channel WDM systems, the dynamic range of DPSK Manchester coded systems shows a 2.1 dB improvement with respect to the NRZ. This result holds true for both dispersion-shifted fiber and conventional fiber; it has been obtained for 10 GHz channel spacing, 1 Gbps/channel bit rate.t rate.