• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.654-660
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• 2001

Dentinogenesis imperfecta is an example of an inheritable dentinal defect originating during the histodifferentiation stage of tooth development, with involvement of the primary and permanent teeth. Shields, Bixler and El-Kafrawy proposed three types of Dentinogenesis imperfecta : Type I, II, III. Witkop reported a prevalence of 1 in 8000 with the trait, and no significant difference between male and female. Affected teeth have red-brown discoloration often with distinctive wearness of occlusal surface of posterior teeth and incisal surface of anterior teeth. Once enamel seperated from underlying defective dentin, the dentin demonstrates significantly acclerated attrision. Radiographically, the teeth have thin roots, bulbous crown, cervical constriction, and obliteration of the root canals and pulp chambers. In primary dentition periapical lesions or multiple root fractures are often observed. In successive generations the phenotypes of discoloration and wearness of teeth occurred, and one of the patient's subships, 10 year-old sister, showed general discoloration of her teeth and mild wearness. In this case, a 4 year-old male reported to the Yonsei University Pedodontics clinic, with a chief complaint of discolored teeth. The teeth showed generally yellowish-brown discoloration and moderate wearness. In radiographic features, obliteration of pulp, bulbous crown, and short roots were observed. It was diagnosed as Dentinogenesis imperfecta. The posterior teeth were restored with Stainless Steel Crown, and defective incisors including left upper primary central incisor which was extracted due to a root fracture with Open-faced Stainless Steel crown.

• Journal of Radiation Protection and Research
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• v.31 no.3
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• pp.141-148
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• 2006

Surveys of radioactive contamination were performed for imported foodstuffs in 2003. The following samples among imported foodstuffs were selected from markets and Korea Food and Drug Administration(KFDA); the imported samples from country associated with the Chernobyl nuclear accident, the samples produced around the nuclear power plants or nuclear tests, the foodstuffs reported as radioacitive contamination materials in foreign country. After pretreatments such as drying and homogenization, samples were analyzed. The $^{137}Cs$ radionuclide was only measured among the regulation radionuclides($^{137}Cs,\;^{134}Cs,\;^{131}I$) of food code. All foodstuffs except Inonotus Obliquus(Chaga mushooms) are less than 17.0 Bq/kg or below the minimum detectable activity(MDA). The activity concentrations of Chaga mushrooms from Russia ranged up to 131.25 Bq/ltg which is almost 35 % of the maximum permitted level of food code. The fraction of imported foodstuffs having meaningful radioactivity is small, however, the radioactive contamination survey of imported foodstuffs is still needed.

• Journal of Life Science
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• v.23 no.12
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• pp.1525-1531
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• 2013

Baegilju is a famous traditional Korean wine made over the course of 100 days. The physiological functionalities of Baegilju were evaluated using different tests. The spectrophotometric method was used to determine the total concentration of polyphenolics and flavonoids and DPPH and ABTS radicals. A nitrite scavenging assay was used to evaluate antioxidant activity. The fibrin plate method was used for fibrinolysis and to evaluate angiotensin I converting enzyme (ACE) inhibitory activity; finally, the colorimetric determination method was used to evaluate acetylcholinesterase (AChE) inhibitory activity. The total polyphenolic content of non-sterilized Baegilju and sterilized Baegilju were 391.59 ${\mu}g$ and 401.33 ${\mu}g$ tannic acid equivalents/ml, respectively; and the flavonoids contents were 284.75 ${\mu}g$ and 308.35 ${\mu}g$ quercetin equivalents/ml, respectively. Baegilju exhibited more excellent antioxidant activities (DPPH and ABTS radicals, nitrite scavenging activity) than did Cheongju. In addition, the fibrinolytic activity and AChE inhibitory activity were found to be higher in Baegilju than they were in Cheongju. The ACE inhibitory activity of non-sterilized Baegilju, sterilized Baegilju, and Cheongju were 23.62%, 19.99%, and 38.91%, respectively. Therefore, these results suggest that Baegilju has potential as an antioxidant agent and anti-thrombosis agent.

• Korean Journal of Medicinal Crop Science
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• v.15 no.6
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• pp.391-397
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• 2007

To develop new high valuable Gugija (Lycium chinensis), biofunctionalities of Gugija standard species and its hybrids were investigated and compared with each water extracts and methanol extracts from Lycii Fructus, Lycii Folium and buds and Lycii Cortex Radicis. Among various biofunctionalities of Gugija standard species, antioxidant activity was showed the highest in methanol extracts from buds of Cheongwoon species (93%) and antihypertensive angiotensin I-converting enzyme (ACE) inhibitory activity was 84.1% in the water extracts from Lycii Cortex Radicis of Cheongyang NO.7. Futhermore, methanol extracts from Lycii Cortex Radicis of Myungan A-2 hybrid showed 93.1% of antioxidant activity and 96.9% of ACE inhibitory activity was also showed in the methanol extracts from Lycii Fructus of DO148-72(A11) hybrid. However, fibrinolytic activity and anticholesteromia HMG-CoA reductase inhibitory activity were weak or not detected in almost of Gugija standard species and its hybrids. Therefore, we finally selected Cheongwoon Gugija standard species (buds) and Myungan A-2 hybrid (Lycii Cortex Radicis) as good antioxidant sources and also DO148-72 (A11) hybrid (Lycii Fructus) as excellent antihypertensive ACE inhibitior sources for manufacturing functional food product.

• Korean Journal of Materials Research
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• v.10 no.4
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• pp.295-300
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• 2000

Uniform silicon tip arrays were fabricated using the reactive ion etching followed by the reoxidation sharpening, and the effect of Pd-coated layer on electron emission characteristics was studied. The electron emission from Si field emitter arrays(FEAs) was a little, but improved by removing surface oxide on the FEA, but pronounced drastically by coating a $100-{\AA}-thick$ Pd metal layer. The turn-on voltage in the Pd-coated Si FEAs was reduced by 30 V in comparison with that in uncoated ones. This results from the increase of surface roughness at the tip apex by the Pd coating on Si FEA, via the decrease of the apex radius at which electrons are emitting. The Pd-coated emitters showed superior operating stability over a wide current range to that of the uncoated ones. This suggests that Pd coating enhances the high temperature stability and the surface inertness Si FEA.

• Korean Chemical Engineering Research
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• v.56 no.2
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• pp.204-211
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• 2018

In this study, densities of water + N-Methyldiethanolamine (MDEA), Water + 2-Amino-2-Methyl-1-Propanol (AMP), MDEA + AMP binary systems and Water+MDEA+AMP ternary system were measured over the full range of composition at temperatures from 303.15 K to 333.15 K by using an Anton Paar digital vibrating tube densimeter (DMA4500). The experimental excess volumes have been obtained from the experimental density results and have been fitted using the Redlich-Kister-Muggianu expression. The parameters obtained from the binary excess volume data were used for the correlation of ternary system with one additional ternary parameter for each isotherm. All investigated binary and ternary systems are completely miscible, because the values of excess volume are negative under the examined conditions.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.6
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• pp.1341-1348
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• 2009

Hoechunyanggyeok-san (HYS) is a traditional oriental herbal medicine widely used for treating inflammatory disorders. Although there are numerous clinical results of HYS reported in the literature of oriental hebal medicine, it has been rarely conducted to evaluate the immuno-biological activity. The present study was conducted to examine the anti-inflammatory effects of HYS extract (HYSE) in vivo and in vitro. To determine the cytotoxic concentration of HYSE, cell viability was tested by MTT assay. All four doses of HYSE (0.01, 0.03, 0.10 and 0.30 mg/ml) had no significant cytotoxicity during the entire experimental period. In order to measure NO levels in culture medium, the cells were treated with $1\;{\mu}g/ml$ of LPS 1h before adding HYSE for 24 h and then culture medium were reacted with Griess reagent. Increased NO production and iNOS expression were detected in LPS-activated cells compared to control. However, these increases were dose-dependently attenuated by treatment with HYSE. LPS plays a key role in leading to the massive production of pro-inflammatory cytokines such as TNF-$\alpha$, IL-$1{\beta}$ and IL-6 in macrophages. Thus, we next determined the levels of these cytokines. HYSE reduced the elevated production of TNF-$\alpha$, IL-$1{\beta}$ and IL-6 by LPS. Moreover, the effects of HYSE were in a dose-dependent manner. In vivo, histopathological study, HYSE effectively inheefed the increases of hind paw skin thicknesses and inflammatory cell infiltrations induced by carrageenan treatment. It, therefore, considered that HYSE will be favorably inheefed the acute edematous inanner. In s. These findings showed that HYSE could have anti-inflammatory effects through the reduction of NO and inflammatory cytokines in macrophage. Furthermore, the reduction of carrageenan-induced paw oedema by HYSE helps to understand its actions on inflammatory conditions.

• Journal of Biomedical Engineering Research
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• v.25 no.6
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• pp.605-609
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• 2004

Blood pressure (BP) is one of the important physiological parameters for diagnosing cardiovascula diseases by means of noninvasive method. Existing noninvasive methods for measuring arterial BP have to use cuff and difficult in measuring arterial BP continuously. Systolic blood pressure (SBP) and pulse transit time (PTT) have a kind of inverse relationship. We acquired PTT data when subjects were in relaxation and also after exercise. We performed the linear regression analysis for making the regression equations for each subject and the regression equation for all subjects. We compared the estimated SBP with the measured SBP to check the accuracy of our regression equations. From the result, the regression equations for each subject was appropriate according to the American National Standards Institute of the Association of the Advancement of Medical Instrument (ANSI/AAMI) which says that BP devices should have ±5mmHg mean of error and 8mmHg standard deviation of error. However, the regression equation for all subjects was not proper to ANSI/AAMI recommendation. The result means that, without cuff, we can continuously estimate each subject's SBP through PTT and indivisual calibration.

• Journal of Biomedical Engineering Research
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• v.20 no.1
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• pp.107-113
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• 1999

The purpose of this study was to develop a miniature imaging gamma probe with high performance that can detect small or residual tumors after surgery. Gamma probe detector system consists of NaI(Tl) scintillator, position sensitive photomultiplier tube (PSPMT), and collimator. PSPMT was optically coupled with 6.5 mm thick, 7.62 cm diameter of NaI(Tl) crystal and supplied with -1000V for high voltage. Parallel hexagonal hole collimator was manufactured for characteristics of 40-mm hole length, 1.3-mm hole diameter, and 0.22 mm septal thickness. Electronics consist of position and trigger signal readout systems. Position signals were obtained with summing, subtracting, and dividing circuit using preamplifer and amplifier. Trigger signals were obtained using summing amplifier, constant fraction discriminator, and gate and delay generator module with preamplifer. Data acquisition and processing were performed by Gamma-PF interface board inserted into pentium PC and PIP software. For imaging studies, flood and slit mask images were acquired using a point source. Two hole phantom images were also acquired with collimator. Intrinsic and system spatial resolutions were measured as 3.97 mm and 5.97 mm, respectively. In conclusion, Miniature gamma probe images based on the PSPMT showed good image quality, we conclude that the miniature imaging gamma probe was successfully developed and good image data were obtained. However, further studies will be required to optimize imaging characteristics.

• Journal of Sensor Science and Technology
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• v.5 no.5
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• pp.21-29
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• 1996

A piezoresistive silicon acceleration sensor with 8 beams, utilized by an unique silicon micromachining technique using porous silicon etching method which was fabricated on the selectively diffused (111)-oriented $n/n^{+}/n$ silicon subtrates. The width, length, and thickness of the beam was $100\;{\mu}m$, $500\;{\mu}m$, and $7\;{\mu}m$, respectively, and the diameter of the mass paddle (the region suspended by the eight beams) was 1.4 mm. The seismic mass on the mass paddle was formed about 2 mg so as to measure accelerations of the range of 50g for automotive applications. For the formation of the mass, the solder mass was loaded on the mass paddle by dispensing Pb/Sn/Ag solder paste. After the solder paste is deposited, Heat treatment was carried out on the 3-zone reflow equipment. The decay time of the output signal to impulse excitation of the fabricated sensor was observed for approximately 30 ms. The sensitivity measured through summing circuit was 2.9 mV/g and the nonlinearity of the sensor was less than 2% of the full scale output. The output deviation of each bridge was ${\pm}4%$. The cross-axis sensitivity was within 4% and the resonant frequency was found to be 2.15 KHz from the FEM simulation results.