• Korean Journal of Oriental Medicine
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• v.17 no.3
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• pp.105-114
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• 2011

Objectives : The transient inflammation has been demonstrated to alter visceral motor response (VMR) and acute mucosal inflammation may precede the manifestation of visceral hyperalgesia in animal models. The purpose of our study is to compare effects of the different frequencies applied electroacupuncture (EA) on acupoints in acute colitis induced by trinitrobenzenesulphonic acid (TNBS). Methods : In Male Sprague-Dawley rats, weighing 250~400g, a single colorectal administration of TNBS (5mg/kg) was made and electrode for electromyography (EMG) recording were stitched into the external oblique musculature. EA of either ST25 or ST36 were applied and stimulation parameter was modulated as follows: 2, 10, or 100 Hz with intensity of 2 mA and 1 ms pulse duration for 30 min. The balloon was inserted intra-anally and VMR to colorectal distension (CRD) was quantified with an EMG recording system. Results : The VMR increased significantly 3 days after TNBS intra-rectal colonic injection in rats. Both 2 Hz and 10 Hz EA on ST36 suppressed VMR to CRD in the acute colitis model but not 100 Hz. Only 10 Hz EA on ST25 suppressed VMR to CRD in the acute colitis. Conclusions : These data show that 10 Hz EA potently inhibits hypersensitivity of colorectum after TNBS induced colitis.

• Korean Journal of Optics and Photonics
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• v.10 no.5
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• pp.430-438
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• 1999

We have utilized soft-aperturing by gain media to develop a high-power tunable Ti:Sapphire laser with sub-40-fs and broad tuning range. The tunable spectral range was only limited by the bandwidth of mirrors. We made use of knife-edge slits near an intra-cavity prism controlled by micro-stepping-motors to tune the center wavelength continuously. The tunability of the center wavelength was ranged from 770 nm to 870 nm, and the measured pulsewidth was sub-40 fs throughout the above spectral range. The shortest pulsewidth was about 17 fs at the center wavelength of 820 nm and the spectral bandwidth was 72 nm. At 5 W pumping power of the Ar-ion laser we obtained average output power of 440 mW~580 mW. For the cw and Kerr-lens mode-lodking conditions, we have evaluated the value of an amplitude modulation to be ${\gamma}=2.5{\times}10^{-8}/W$ from the calculated waists of a Gaussian beam on the Ti:sapphire crystal surface. Using this result we demonstrate that the generation of sub-40-fs Kerr-lens mode-locked pulse can be described by the Ginzberg-Landau model which is a weak pulse shaping model.

• Journal of the Korean Ceramic Society
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• v.44 no.7
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• pp.343-348
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• 2007

Alumina/silver nanocomposites were fabricated using a soaking method through a sol-gel route to construct an intra-type nanostructure. The pulse electric-current sintering (PECS) technique was used to sinter the nanocomposites. Several specimens were annealed after sintering. The microstructure, mechanical properties, critical frontal process zone (FPZ) size, and thermo-mechanical properties of the nanocomposites were estimated. The relative densities of the specimens sintered at 1350 and $1450^{\circ}C$ were 95% and 99%, respectively. The maximum value of the three-point bending strength was found to be 780 MPa for the $2{\times}2{\times}10 mm$ specimen sintered at $1350^{\circ}C$. The fracture toughness of the specimen sintered at $1350^{\circ}C$ was measured to be $3.60 MPa{\cdot}m^{1/2}$ using the single-edge V-notched beam (SEVNB) technique. The fracture mode of the nanocomposites was transgranular, in contrast to the intergranular mode of monolithic alumina. The fracture morphology suggested that dislocations were generated around the silver nanoparticles dispersed within the alumina matrix. The specimens sintered at $1350^{\circ}C$ were annealed at $800^{\circ}C$ for 5 min, following which the maximum fracture strength became 810 MPa and the fracture toughness improved to $4.21 MPam^{1/2}$. The critical FPZ size was the largest for the specimen annealed at $800^{\circ}C$ for 5 min. Thermal conductivity of the alumina/silver nanocomposites sintered at $1350^{\circ}C$ was 38 W/mK at room temperature, which was higher than the value obtained with the law of mixture.

• The Korean Journal of Pain
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• v.8 no.1
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• pp.159-163
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• 1995

Accidental high epidural block is a rare but serious complication. It can result from many factors, which include the volume and concentration of drug, posture, puncture site, age, pregnancy or intra-abdominal mass, and patients' height and weight. We had a case of accidental high epidural block recently. This is a case report which was confirmed by an epiduragram. A healthy 50-year-old woman with a huge uterine myoma was scheduled for a total abdominal hysterectomy under continous epidural analgesia. Epidural catheterization was carried out smoothly. However, an unexpected hypotension was noticed after an epidural injection of 2% lidocaine 25 ml. Thereafter, the patient was intubated and her respiration was controlled during the operation. Using the 5mg of ephedrine, her blood pressure and pulse were well maintained. The scheduled operation was carried out for one hour uneventfully, but after the operation, she felt paresthesia on her hands in the recovery room. To differentiate between the high epidural and the subdural blocks. We injected 5 ml of a water soluble Niopam 300 through the catheter postoperatively. It was observed on the epiduragram that the catheter was placed in the epidural space. It was suggested that the high epidural block was induced from the widespread diffusion through the narrowed epidural space due to the engorgement of the epidural venous plexus by the patient's huge uterine myoma.

• Korean Chemical Engineering Research
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• v.53 no.6
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• pp.723-729
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• 2015

The moment analysis of cyclic adenosine monophosphate (cAMP) was performed using chromatograms that were obtained with the pulse input method from an octadecyl silica (ODS) high-performance liquid chromatography (HPLC) column. The general rate (GR) model was employed to calculate the first absolute moment and the second central moment. Three important coefficients for moment analysis, which are molecular diffusivity ($D_m$), external mass transfer coefficient ($k_f$), and intra-particle diffusivity ($D_e$), were estimated by the Wilke-Chang equation, Wilson-Geankoplis equation, and comparing van Deemter equation to theoretical plate number equation, respectively. Experiments were conducted by various conditions of flow rates, methanol volume ratio of the mobile phase, and solute concentration. After the moment analysis, results were organized by van Deemter plots. Also van Deemter coefficients were compared each other to effect $H_{ax}$, $H_f$, and $H_d$ on height equivalent to a theoretical plate (HETP, $H_{total}$). The value of intraparticle diffusion ($H_d$) was the primary factor which makes for HETP whereas external mass transfer ($H_f$) was disregardable factor.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.4
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• pp.39-50
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• 2011

In this paper, we presents a CDR circuit for $2^{nd}$-generation AiPi+, one of the Intra-panel Interface. The speed of the proposed clock and data recovery is increased to 1.25 Gbps compared with that of AiPi+. The DLL-based CDR architecture is used to generate the multi-phase clocks. We propose the simple scheme for frequency detector (FD) to mitigate the harmonic-locking and reduce the complexity. In addition, the duty cycle corrector that limits the maximum pulse width is used to avoid the problem of missing clock edges due to the mismatch between rising and falling time of VCDL's delay cells. The proposed CDR is implemented in 0.18 um technology with the supply voltage of 1.8 V. The active die area is $660\;{\mu}m\;{\times}\;250\;{\mu}m$, and supply voltage is 1.8 V. Peak-to-Peak jitter is less than 15 ps and the power consumption of the CDR except input buffer, equalizer, and de-serializer is 5.94 mW.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.7
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• pp.137-144
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• 2019

For the structures near the seismogenic fault, the evaluation of seismic performance against near-fault ground motions is important as well as for design ground motions. In this study, characteristics of seismic behaviors and seismic performance of the pile-bent bridge constructed on the thick soft soil site with various weak soil layers were analyzed. The input ground motions were synthesized by the directivity pulse parameters for intra-plate regions. The ground motion acceleration histories of each layer were obtained by one-dimensional site response analysis. Each soil layer was modeled by equivalent linear springs, and multi-support excitations with different input ground motions at each soil spring were applied for nonlinear seismic analyses. The analysis result by the near-fault ground motions and ground motions matched to design spectra were compared. In case of the near fault ground motion input, the bridge behaved within the elastic range but the location of the maximum moment occurred was different from the result of design ground motion input.

• Journal of Microbiology
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• v.43 no.4
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• pp.375-380
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• 2005

Autonomous ultradian metabolic oscillation (T$\simeq$50 min) was detected in an aerobic chemostat culture of Saccharomyces cerevisiae. A pulse injection of GSH (a reduced form of glutathione) into the culture induced a perturbation in metabolic oscillation, with respiratory inhibition caused by $H_2S$ burst pro-duction. As the production of $H_2S$ in the culture was controlled by different amino acids, we attempted to characterize the effects of GSH on amino acid metabolism, particularly with regard to branched chain and sulfur-containing amino acids. During stable metabolic oscillation, concentrations of intra-cellular glutamate, aspartate, threonine, valine, leucine, isoleucine, and cysteine were observed to oscil-late with the same periods of dissolved $O_2$ oscillation, although the oscillation amplitudes and maximal phases were shown to differ. The methionine concentration was stably maintained at 0.05 mM. When GSH (100 $\mu$M) was injected into the culture, cellular levels of branched chain amino acids increased dramatically with continuous $H_2S$production, whereas the cysteine and methionine concentrations were noticeably reduced. These results indicate that GSH-dependent perturbation occurs as the result of the promotion of branched chain amino acid synthesis and an attenuation of cysteine and methionine synthesis, both of which activate the generation of $H_2S$. In a low sulfate medium containing 2.5 mM sulfate, the GSH injections did not result in perturbations of dissolved $O_2$ NAD(P)H redox oscillations without burst $H_2S$ production. This suggests that GSH-dependent perturbation is intimately linked with the metabolism of branched-chain amino acids and $H_2S$ generation, rather than with direct GSH-GSSG redox control.

• Journal of Dental Anesthesia and Pain Medicine
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• v.22 no.4
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• pp.295-304
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• 2022

Background: The first dental experience is vital in molding a child's attitude towards dentistry and dental outcomes. The cooperation of a child during dental treatment is essential to render successful and high-quality treatment. Dental anxiety is common in children undergoing dental treatment. The success of pediatric dental treatments and patient comfort depends on controlling the levels of patient anxiety in clinical settings. This study aimed to compare the effectiveness of the recorded maternal voice and virtual cognitive tool (Roogies application) in the management of pediatric dental patients. Methods: The study was carried out with children aged of 4-7 years [n = 80, (40 male and 40 female)], without any past dental history, and were randomly allocated into two groups. After informed consent was obtained, the entire procedure was explained to the parents. Anxiety was assessed pre-, during, and post-treatment by measuring pulse rate, and recording Venham Picture Test (VPT) scores. Group A [n = 40; 20 boys and 20 girls)] was provided with a headphone that played a recorded maternal voice. Group B [n = 40; 20 boys and 20 girls)] was administered the virtual cognitive tool. After conditioning the children, oral prophylaxis was performed for both groups. A comparative evaluation was conducted for each treatment session. Results: The intra-group comparison of VPT scores and heart rate for patients assigned to the recorded maternal voice showed a statistically significant difference in dental anxiety (P-value ≤0.001). Conclusion: This study demonstrated that a reduction in dental anxiety with the help of recorded maternal voice forms an important component of non-pharmacological behavior management. Alternatively, the use of a virtual cognitive tool as an anxiety-reducing technique can also be advocated.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.1
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• pp.1-8
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• 2011

The objective of this study was to determine the effectiveness of topical 5% EMLA cream versus 20% Benzocaine gel in reducing pain from intra oral needle insertion alone as well as injection of anesthetic. The 2 topical anesthetics were tested against each other bilaterally using a randomized, controlled, single blinded, split mouth design. Phase I was conducted to find out the rapidity of onset action of the two agents on anterior/posterior vestibules and anterior/posterior palatal mucosa. Phase II was conducted to evaluate the efficacy of the two topical anaesthetic agents in reducing the pain of intraoral injections. The agents were left in anterior/posterior vestibules and anterior/posterior palatal mucosa for the amount of time recorded in phase I. Subjects recorded pain on a 100-mm modified visual analog scale(VAS). A pulse oximeter was used to recorded the preoperative and postoperative pulse rates. In phase I of the study, two topical agents showed the longer onset of action at anterior part and vestibules than posterior part and palatal mucosa. EMLA cream showed the rapidest onset of action compared to benzocaine gel except on anterior palatal mucosa. In phase II of the study, the VAS grading of the pain for anesthetic administration showed EMLA cream was significantly(P<.05) better in elimination or reducing the pain on the anterior/posterior palatal mucosa. In conclusion, EMLA cream showed the rapidest onset of action compared to benzocaine gel except on anterior palatal mucosa. EMLA cream was found to be superior to Benzocaine gel with regards to pain reduction for anesthetic administration especially on anterior and posterior palatal mucosa.