• The Korean Journal of Pain
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• v.22 no.1
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• pp.16-20
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• 2009

Background: Zaprinast is an inhibitor of phosphodiesterase 5, 6 and 9. Phosphodiesterase inhibitors could produce anti-nociceptive effects by promoting the accumulation of cGMP. We hypothesized that intrathecal zaprinast could attenuate the allodynia induced by chronic constriction injury of the sciatic nerve in rat. Methods: Sprague-Dawley rats were prepared with four loose ligations of the left sciatic nerve just proximal to the trifurcation into the sural, peroneal and tibial nerve branches. Tactile allodynia was measured by applying von Frey filaments to the lesioned hindpaw. The thresholds for the withdrawal responses were assessed. Zaprinast ($3-100{\mu}g$) was administered intrathecally by the direct lumbar puncture method to obtain the dose-response curve and the 50% effective dose ($ED_{50}$). Measurements were taken before and 15, 30, 45, 60, 90, 120, and 180 min after the intrathecal doses of zaprinast. The side effects were also observed. Results: Intrathecal zaprinast resulted in a dose-dependent antiallodynic effect. The maximal effects occurred within 15-30 min and then they gradually decreased down to the baseline level over time in all the groups. There was a dose dependent increase in the magnitude and duration of the effect. The $ED_{50}$ value was $17.4{\mu}g$ (95% confidence intervals; $14.7-20.5{\mu}g$). No severe motor weakness or sedation was observed in any of the rats. Conclusions: Intrathecally administered zaprinast produced a dose-dependent antiallodynic effect in the chronic constriction injury neuropathic pain model. These findings suggest that spinal phosphodiesterase 5, 6 and 9 may play an important role in the modulation of neuropathic pain.

• Korean Journal of Community Nutrition
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• v.7 no.4
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• pp.527-538
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• 2002

Body antioxidant status is an important factor in the prevention of many chronic diseases caused by oxidative stress, especially in the elderly and is affected by health-related habits, such as smoking, drinking and regular physical activity. The aim of this study was to investigate the relationship between these health-related habits and plasma antioxidant status in the elderly. Plasma antioxidant status was examined by determining plasma levels of antioxidant vitamins (vitamin C, A, E, $\beta$ -carotene), total antioxidant status (TAS) and thiobarbituric acid-reactive substance (TBARS) . The subjects included 225 elderly persons aged over 60 yews (63 males, 162 females) living in the Ulsan area. They were interviewed to collect data on their general characteristics and health behaviors such as smoking, exercise and alcohol consumption by means of questionnaires. Their dietary intakes were obtained by means of semi-quantitative food frequency questionnaires (FFQ) The study population was divided into two or three groups according to their smoking, drinking, and exercise status. The ratio of smoker, drinker and exerciser was 16.7%, 31.0% and 44.2% respectively. The dietary antioxidant vitamin intakes were not significantly different among groups of smoking and drinking status, but tended to be higher in non-smokers and non-drinkers than in smokers and drinkers. Plasma vitamin C and $\beta$ -carotene levels were significantly higher in non-smokers, but Plasma vitamin A and TBARS levels were significantly lower in non-smokers than in smokers. Plasma TAS was not significantly different among the smoking groups, but showed a tendency to decrease with an increase in the number of packyear. Plasma vitamin C and $\beta$ -carotene levels of the non-drinkers were higher than those of drinkers and past-drinkers, but plasma vitamin A, C, E, TAS and TBARS showed no difference among the groups of drinker. All vitamin intakes of the exercisers were slightly higher than those of the non-exercisers, but vitamin C intake was significantly higher in female exercisers than in non-exercisers. Plasma $\beta$ -carotene levels were significantly higher in male exercisers and plasma vitamin A, C, E, TAS and TBARS levels tended to be higher in exercisers than in non-exercisers. These results suggested that change to non-smoker, modulation of alcohol consumption and regular exercise could enhance antioxidant defences against reactive oxygen species and might increase the likelihood of a healthier life span.

• Archives of Pharmacal Research
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• v.29 no.8
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• pp.633-644
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• 2006

In last couple of decades the use of natural compounds like flavonoids as chemopreventive agents has gained much attention. Our current study focuses on identifying chemopreventive flavonoids and their mechanism of action on human prostate cancer cells. Human prostate cancer cells (PC3), stably transfected with activator protein 1 (AP-1) luciferase reporter gene were treated with four main classes of flavonoids namely flavonols, flavones, flavonones, and isoflavones. The maximum AP-1 luciferase induction of about 3 fold over control was observed with $20\;{\mu}M$ concentrations of quercetin, chrysin and genistein and $50\;{\mu}M$ concentration of kaempferol. At higher concentrations, most of the flavonoids demonstrated inhibition of AP-1 activity. The MTS assay for cell viability at 24 h showed that even at a very high concentration $(500\;{\mu}M)$, cell death was minimal for most of the flavonoids. To determine the role of MAPK pathway in the induction of AP-1 by flavonoids, Western blot of phospho MAPK proteins was performed. Four out of the eight flavonoids namely kaempferol, apigenin, genistein and naringenin were used for the Western Blot analysis. Induction of phospho-JNK and phospho-ERK activity was observed after two hour incubation of PC3-AP1 cells with flavonoids. However no induction of phospho-p38 activity was observed. Furthermore, pretreating the cells with specific inhibitors of JNK reduced the AP-1 luciferase activity that was induced by genistein while pretreatment with MEK inhibitor reduced the AP-1 luciferase activity induced by kaempferol. The pharmacological inhibitors did not affect the AP-1 luciferase activity induced by apigenin and naringenin. These results suggest the possible involvement of JNK pathway in genistein induced AP-1 activity while the ERK pathway seems to play an important role in kaempferol induced AP-1 activity.

• The Journal of Korean Academy of Sensory Integration
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• v.18 no.2
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• pp.55-68
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• 2020

Objective : The purpose of this study is to summarize the best-available intervention evidence for children's sensory integration therapy, drawn from studies published domestically in Korea over the last 10 years. Methods : The articles evaluated in this study were collected from the RISS and DBpia databases using the search terms "sensory integration," "sensory processing," and "Ayres Sensory Integration (ASI)". A total of 19 papers were analyzed. The selected studies were then assessed using the Population, Intervention, Outcomes, and Comparison method, the International Classification of Functioning, Disability and Health (ICF) method, and the modified Evidence Alert Traffic Light Grading System. Results : Development delay was the most commonly applied diagnosis for children's sensory integration therapy and individual sensory integration therapy was the most frequently used intervention method. The intervention effect was 91 percent in the body structure and function of ICF. The areas concentrated on were sensory modulation, sensory processing, fine and gross motor, body scheme, body-self concept, balance, basic movement, postural control and hand function, attention, and self-esteem. Conclusion : This simple overview of the efficacy of children's sensory integration therapy provides a basis for easy understanding and use by therapists, researchers and families with children.

• Applied Biological Chemistry
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• v.22 no.3
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• pp.173-180
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• 1979

SDS gel electrophoresis has been employed to examine the changes in distribution of three major classes of nuclear proteins extracted from isolated liver nuclei in response to refeeding of starved rats with a fat-free high carbohydrate diet and following insulin injection into streptozotocin-diabetic rats. The relative quantity of electrophoretically separated proteins in the fraction showed marked changes with 0.14 NaCl extracts, but not with histones and phenol soluble non-histone proteins. During 48h starvation at least five proteins ranging in molecular weight from 50,000 to 180,000 daltons decreased relative to normal controls while a protein with 36,000 daltons was increased. Refeeding the starved rats with a high carbohydrate diet reversed these changes over 24 h. Insulin injection into streptozotocin-diabetic rats increased levels of the set of five 0.14 M NaCl soluble proteins identified from refeeding experiment of starved rats. The 36,000 daltons protein was also diminished. These results indicate that changes in distribution of certain nuclear proteins in 0.14M NaCl extracts are associated with the control of nuclear activity ralated to known insulin-signalled modulation and induction of cytosolic lipogenic enzymes.

• The Journal of Internal Korean Medicine
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• v.27 no.3
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• pp.639-652
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• 2006

Objective : The etiology of chronic prostatitis is likely multifactorial, resulting from either a cascade of events after an initiating factor or from a variety of etiologic mechanisms. There is substantiating evidence to support the role of the inflammatory responses in its pathogenesis, and the clinical value in the evaluation of therapeutic efficacy. Forsythiae Frucus has been traditionally used in treatment of inflammatory diseases, including of prostatitis and urinary tract inflammation. In this study, we investigated the effects of Forsythiae Frucus on inflammatory cytokines and cyto-pathological alternation in the rat model of chronic non-bacterial prostatitis induced by castration and $17{\beta}$-estradiol treatment. Methods : Two-month-old rats were treated with $17{\beta}$-estradiol after castration for induction of experimental non-bacterial prostatitis. which is similar to human chronic prostatitis in histopathological profiles. Forsythiae Frucus as an experimental specimen, and testosterone as a positive control, were administered orally. The prostates were evaluated by histopathologlcal parameters including the epithelial score and epithelio-stromal ratio for glandular damage. and the expression of inflammatory cytokine genes including interleukin (IL)-$1{\beta}$, IL-5, IL-12, tumor necrosis factor (TNF)-$\alpha$. eotaxin, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2(cox-2). Results : While prostates of control rats revealed severe acinar gland atrophy and stromal proliferation. the rats treated with Forsythiae Frucus showed a diminished range of tissue damage. Epithelial score was improved in the Forsythiae Frucus group over that of the control (P<0.05). The epithelia-stromal ratio was lower in the Forsythiae Frucus group when compared to that of the control (P<0.05). In the reverse transcription-polymerase chain reaction (RT-PCR) of inflammatory cytosine genes. Forsythiae Frucus inhibited the expression of IL-$1{\beta}$, TNF-$\alpha$, iNOS, cox-2 genes, while it modulated the expression of IL-5, which is an anti-inflammatory cytokine. Conclusions : These findings suggest that Forsythiae Frucus may protect the glandular epithelial cells and also inhibit stromal proliferation in association with the immune modulation including the suppression of inflammatory cytokines and increase of anti-inflammatory cytokines. From theses results. we suggest that Forsythiae Frucus could be a useful remedy agents for treating chronic non-bacterial prostatitis.

• Korean Journal of Acupuncture
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• v.26 no.4
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• pp.195-209
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• 2009

Objectives : Transient inflammation has been demonstrated to alter visceral sensory function in animal models and acute mucosal inflammation may precede the manifestation of visceral hyperalgesia. Thus in this study we compared effects of herbal acupuncture of Nidus Vespae (NV) applied to the different acupoints in the acute colitis induced by trinitrobenzenesulphonic acid (TNBS) intracolonic injection in rats. Methods : In Male Sprague-Dawley rats, weighing 250 ~ 400 g, TNBS (5 mg/kg) was infused intrarectally through a silicon rubber catheter into the anus under isoflurane anaesthesia. Under general anesthesia, acupoints of LI4 (Hapkok), SI25 (Cheonchu), ST36 (Joksamni), BL25 (Daejangsu) were intramuscularly injected by NV. Expressions of cFos protein in the periaqueductal gray (PAG), locus coeruleus (LC), nucleus of solitary tract (Sol), and the 6th lumbar spinal cord (L6 s.c.) were observed at 24 hrs after TNBS induced colitis by immunohistochemistry. Results : The expression of c-Fos protein in L6 s.c., Sol, LC and PAG increased 24 hrs after TNBS injection into colorectum as compared to normal group. NV herbal acupuncture also inhibited the expression of c-Fos protein in Sol but not L6 s.c., LC, and PAG. NV to ST36 inhibited significantly the c-Fos expression in Sol and PAG. NV to ST25 inhibited the c-Fos protein expression all over the observation area. NV to BL25 showed the inhibitory effects in the areas except LC. Whether or not a role of endogenous opioids, intrathecal injection of naltrexone (30 ug / 30 ul) was applied before the 2nd herbal acupuncture treatment 24 hrs after TNBS-induced colitis in rat. Naltrexone reversed the inhibition of c-Fos protein expression in the spinal cord and brainstem under different conditions such as type of herbal acupuncture compound and choice of acupoint. Conclusions : In summary, these data show that herbal acupuncture of NV inhibits signal pathways such as spinal cord and brain stem ascending hypersensitivity of colorectum after TNBS induced colitis. This effect may be mediated by acupoints through the endogenous opioid system involving the pain modulation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.21-26
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• 2016

This paper presents a step-down DC-DC buck converter with a CCM/DCM dual-mode function for the internal power stage of portable electronic device. The proposed converter that is operated with a high frequency of 1 MHz consists of a power stage and a control block. The power stage has a power MOS transistor, inductor, capacitor, and feedback resistors for the control loop. The control part has a pulse width modulation (PWM) block, error amplifier, ramp generator, and oscillator. In this paper, an external capacitor for compensation has been replaced with a multiplier equivalent CMOS circuit for area reduction of integrated circuits. In addition, the circuit includes protection block, such as over voltage protection (OVP), under voltage lock out (UVLO), and thermal shutdown (TSD) block. The proposed circuit was designed and verified using a $0.18{\mu}m$ CMOS process parameter by Cadence Spectra circuit design program. The SPICE simulation results showed a peak efficiency of 94.8 %, a ripple voltage of 3.29 mV ripple, and a 1.8 V output voltage with supply voltages ranging from 2.7 to 3.3 V.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.3
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• pp.517-526
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• 2008

A one-chip DC-DC converter circuit for OLED(Organic Light-Emitting Diode) display module of automotive clusters is newly proposed. OLED panel driving voltage circuit, which is a charge-pump type, has improved characteristics in miniaturization, low cost and EMI(Electro-Magnetic Interference) compared with DC-DC converter of PWM(Pulse Width Modulator) type. By using bulk-potential biasing circuit, charge loss due to parasitic PNP BJT formed in charge pumping, is prevented. In addition, the current dissipation in start-up circuit of band-gap reference voltage generator is reduced by 42% and the layout area of ring oscillator is reduced by using a logic voltage VLP in ring oscillator circuit using VDD supply voltage. The driving current of VDD, OLED driving voltage, is over 40mA, which is required in OLED panels. The test chip is being manufactured using $0.25{\mu}m$ high-voltage process and the layout area is $477{\mu}m{\times}653{\mu}m$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.3
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• pp.201-206
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• 2019

This report constitutes the first demonstration in Korea of single-crystal lateral gallium oxide ($Ga_2O_3$) as a metal-oxide-semiconductor field-effect-transistor (MOSFET), with a breakdown voltage in excess of 480 V. A Si-doped channel layer was grown on a Fe-doped semi-insulating ${\beta}-Ga_2O_3$ (010) substrate by molecular beam epitaxy. The single-crystal substrate was grown by the edge-defined film-fed growth method and wafered to a size of $10{\times}15mm^2$. Although we fabricated several types of power devices using the same process, we only report the characterization of a finger-type MOSFET with a gate length ($L_g$) of $2{\mu}m$ and a gate-drain spacing ($L_{gd}$) of $5{\mu}m$. The MOSFET showed a favorable drain current modulation according to the gate voltage swing. A complete drain current pinch-off feature was also obtained for $V_{gs}<-6V$, and the three-terminal off-state breakdown voltage was over 482 V in a $L_{gd}=5{\mu}m$ device measured in Fluorinert ambient at $V_{gs}=-10V$. A low drain leakage current of 4.7 nA at the off-state led to a high on/off drain current ratio of approximately $5.3{\times}10^5$. These device characteristics indicate the promising potential of $Ga_2O_3$-based electrical devices for next-generation high-power device applications, such as electrical autonomous vehicles, railroads, photovoltaics, renewable energy, and industry.