• Title/Summary/Keyword: frequency effect

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Effect of 15% Hydrogen Peroxide on Color Change and Microhardness of Bovine Teeth according to the Time (15% Hydrogen Peroxide 전문가용 치아미백 후 시간경과에 따른 색상변화와 미세경도의 변화)

  • Park, Mi-Young
    • Journal of dental hygiene science
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    • v.13 no.1
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    • pp.13-19
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    • 2013
  • This study evaluated the change of color and the microhardness according to time-out using the office bleaching with in vitro test after bleaching one time 1 day per week, total three times, for the control group and three times per 1day for the experimental group. $L^*$ was increased in both groups. Group 1 showed a significant increase statistically between before and after tooth whitening (p<0.05). Group 2 showed a significant increase statistically between before and after tooth whitening (p<0.05). ${\Delta}E^*$ was huge in both groups. In group 1, it was great in terms of statistical significance between 1 day and 7 days after tooth whitening (p<0.05). In group 2, it was the greatest between before and 1 day after tooth whitening and was significant statistically as well (p<0.05). Vickers hardness number (VHN) decreased in both groups. In group 1, VHN decreased over time and the difference was significant statistically (p<0.05). In group 2, VHN decreased over time and the difference was significant statistically (p<0.05). Percentage microhardness loss was great in both groups. In group 1, it was the greatest between 1 day and 7 days after the treatment, and it was significant statistically (p<0.05). In group 2, it was the greatest between before and 1 day after the treatment, and it was significant statistically (p<0.05). Put together, the more frequent tooth whitening a day is, the longer the period of tooth whitening when applying the same frequency, the greater color change was, however the microhardness decreased, in regard to the results over time using 15% hydrogen peroxide tooth whitening product for professionals.

Effectiveness of Multimodal Pain Control in Early Phase After Arthroscopic Rotator Cuff Repair (관절경하 회전근 개 봉합술 후 다중 통증 조절법을 이용한 초기 통증 조절의 유용성)

  • Park, Chang-Min;Kim, Jong-Hae;Kim, Suk-Jun;Choi, Chang-Hyuk
    • Clinics in Shoulder and Elbow
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    • v.15 no.1
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    • pp.1-7
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    • 2012
  • Purpose: The purpose of this study was to identify the effectiveness of multimodal pain control method in an early phase after arthroscopic rotator cuff repair, under interscalene brachial plexus block, this study was performed. Materials and Methods: The study was progressed with the 80 cases of arthroscopic rotator cuff repair. Interscalene brachial plexus block was used to all of the 80 cases and patients were divided into 2 groups. Group A consisted of patients injected with bupivacaine, through subacromial space catheter after surgery, and group B consisted of patients with additional method of multimodal pain control using oral opioids, acetaminophen-tramadol complex and selective COX2 inhibitor. Subacromial cathter was removed after injection in both groups. The pain during the day time and night time was compared on the operation day, postoperative 1st, 2nd, 3rd day and 2nd weeks, and it was measured with VAS (visual analogue scale) score. Additionally, the number of ketolorac injection and side-effect related to analgesics was compared between the 2 groups. Results : The mean VAS score of night time on the operation day and day/night time pain of the 1st, 2nd, 3rd day and 2nd weeks was 7.4, 7.0/6.8, 4.5/5.2, 4.8/5.0, 2.2/2.7 on group A and 6.5, 4.3/5.4, 3.2/4.3, 3.0/4.1, 2.4/2.5 on group B, respectively. Significant difference was observed in the night pain on the operation day, 1st, 2nd, 3rd day time and 1st night time pain (p<.05). The average number of ketololac injection was 1.1 and 0.5 in each group, and there was no difference in the frequency of side effects. Conclusion: Multimodal pain control method, after arthroscopic rotator cuff repair, showed an effective early pain control and improved patients' satisfaction.

Tidal and Sub-tidal Current Characteristics in the Central part of Chunsu Bay, Yellow Sea, Korea during the Summer Season (서해 천수만 중앙부의 하계 조류/비조류 특성)

  • Jung, Kwang Young;Ro, Young Jae;Kim, Baek Jin
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.18 no.2
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    • pp.53-64
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    • 2013
  • This study analyzed the ADCP records along with wind by KMA and discharge records at Seosan A-, B-district tide embankment by KRC for 33 days obtained in the Chunsu Bay, Yellow Sea, Korea spanning from July 29 to August 30, 2010. Various analyses include descriptive statistics, harmonic analysis of tidal constituents, spectra and coherence, complex correlation, progressive vector diagram and cumulative curves to understand the tidal and sub-tidal current characteristics caused by local wind and discharge effect. Observed current speed ranges from -30 to 40 (cm/sec), with standard deviation from 1.7 (cm/sec) at bottom to 18.7 (cm/sec) at surface. According to the harmonic analysis results, the tidal current direction show NNW-SSE. The magnitudes of semi-major axes range from 9.4 to 14.8 (cm/sec) for M2 harmonic constituent and from 4.4 to 7.0 (cm/sec) for S2, respectively. And the magnitudes of semi-minor axes range from 0.1 to 0.5 (cm/sec) for M2 and from 0.4 to 1.4 (cm/sec) for S2, respectively. In the spectral analysis results in the frequency domain, we found 3~6 significant spectral peaks for band-passed wind and residual current of all depth. These peak periods represent various periodicities ranging from 2 to 8 (days). In the coherency analysis results between band-passed wind and residual current of all depth, several significant coherencies could be resolved in 3~5 periodicities within 2.8 (days). Highest coherency peak occurred at 4.6 (day) with 1.2-day phase lag of discharge to band-passed residual current. The progressive vector of wind and residual current travelled to northward at all layers, and the travel distance at middle layer was greater than surface layer distance. The Northward residual current was caused by a seasonal southern wind, and the density-driven current formed by fresh water input effected southward residual current. The sub-tidal current characteristics is determined by seasonal wind force and fresh water inflow in the Chunsu Bay, Yellow Sea, Korea.

Efficiency of microspore embryogenesis in Brassica rapa using different genotypes and culture conditions (배추 유전자원의 소포자 유래 배 발생 효율에 미치는 배양 조건 구명)

  • Seo, Mi-Suk;Sohn, Seong-Han;Park, Beom-Seok;Ko, Ho-Cheol;Jin, Mina
    • Journal of Plant Biotechnology
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    • v.41 no.3
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    • pp.116-122
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    • 2014
  • Total of fifty accessions of Brassica rapa with various morphological characteristics were used for production of double haploid plants though microspore culture in Brassica rapa. Among them, only 30 accessions induced embryos from microspores. The highest efficiency of embryo induction of 1.194 per bud was obtained from IT135449 of turnip type, while 3 accessions of sarson (winter oil) type did not generate embryo. The effect of heat shock periods for embryogenesis was also investigated with 4 accessions (IT135449; Turnip type, IT199710; Chinese cabbage type, IT212886; Pak choi type, IT218043; Summer oil type). The high productions of embryos were observed in IT135449, IT199710 and IT212886 when microspores were pre-cultured to $32^{\circ}C$ for 2 days. In IT218043, high embryogenesis was observed at the 3 days of heat shock treatment. The optimal condition of shoot regeneration for IT199710 was observed in MS medium supplemented with NAA $0.5mg{\cdot}L^{-1}$ and BAP $1mg{\cdot}L^{-1}$. In contrast, the IT135449 and IT212886 were observed high regeneration frequency in MS medium without plant growth regulators. All the plantlets regenerated from microspore-derived embryos have been successfully transplanted to soil, and bud self-pollinated seeds were produced from doubled haploid plants. This indicated that double-haploid genotype was likely generated naturally during embryogenesis process.

Financial Impact of Off-Pump Coronary Artery Bypass (체외순환 없이 시행하는 관상동맥우회술의 경제성 분석)

  • Lim, Cheong;Chang, Woo-Ik;Kim, Ki-Bong;Kim, Yoon
    • Journal of Chest Surgery
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    • v.35 no.5
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    • pp.365-368
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    • 2002
  • Background: Coronary artery bypass grafting(CABG) imposes large amount of medical costs, which are greatly affected by the surgical approach, quality of perioperative care and associated co-morbidities. Recently, off-pump CABG(OPCAB) has been introduced and performed with increasing frequency. To evaluate the efficacy of OPCAB in view of financial impact, we analyzed the costs and medical resources of OPCAB and compared with conventional CABG. Material and Method: From January 1998 to July 1999, 184 patients underwent CABG operation; 111 patients with OPCAB(group I) and 73 patients with conventional CABG(group II). We prospectively collected clinical data including risk factors and retrospectively reviewed the hospital resources. Result: Preoperative parameters including risk factors, postoperative mortality, morbidity and length of hospital stay were not different between the two groups, Duration of stay in the intensive care unit(ICU) (51.3 vs 128.3 hours, p<0.01) and ventilator, support time(14.9 vs 56.2 hours, p<0.01) were significantly shorter in the OPCAB group. Total hospital coats were 17,220,000 add 21,250,000(Korean Won) in group I and II, respectively(p<0.01). There were significant differences in operation fee, costs for operative materials, transfusion and diagnostic radiology between two groups. In group I, all the resources except diagnostic radiology were significantly decreased compared with group II. Conclusion: OPCAB has a beneficial effect on hospital charge and resource utilization. Shorter duration of the ICU stay and ventilatory support time may reduce the total hospital costs.

Effect of the Vessel Vibration Noise to the Underwater Ambient Noise (선박진동소음이 해중환경소음에 미치는 영향에 관한 연구)

  • 박중희
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.23 no.4
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    • pp.163-168
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    • 1987
  • The underwater observation of the ambient noise and the noise generated by the engine revolution in a ship was carried out in July to August, 1984, 1985 and 1987, near around some ports and in the Eastern Sea of Korea. Vertical distribution of the sound pressure of both noises were observed and the spectrum characteristics were analysed and compared. The results obtained are summarized as follows: 1. Sound pressure level of the ambient noise at 5m deep layer in calm sea condition (wind speed 0-2m/s) near around the ports were observed as 108dB at the eastern part of Pusan port, 106dB at the southern part of Pusan port and 101dB at Kuryongpo port. It shows that the level near around the large port which contains much noisy resources is higher than the small port. The level at 5m deep layer in the open sea, in the mid-region between Korean Peninsula and Ulnung Island was observed as 100dB. It mean that the level in the open sea is lower than that around the ports. The level at 20m and 70m deep layer were 1-2dB lower than that at 5m deep layer, and that at deeper layer than 100m was almost constantly 100dB around. 2. Sound pressure level of the ambient noise at 5m deep layer in windy open sea condition (wind speed 10-15m/s) was 108dB, and was gradually decreased in accordance with the increase of depth with representing 100dB at 70m deep layer and that at deeper layer was almost constantly 100dB. The level of the noise generated by engine revolution was 146, 125, 112, 110, 104dB at 5, 50, 100, 150 and 200m deep layer respectively. It means that the level decrease with the depth. 3. Spectrum level of the ambient noise at 5m deep layer with the frequency band of 10 Hz, 100 Hz, 1 KHz, 10 KHz, in the windy sea condition were 86, 75, 61, 32dB respectively and the level of the noise generated by engine revolution was 105, 95, 86, 55dB respectively. It means that the latter are about 20dB higher than the former. The level of the former at 200m deep layer was 80, 68, 47, 26dB and the latter 82, 70, 59, 31dB. It means that the latter are about 4dB higher than the former.

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A Study on Life Styles, Dietary Attitudes and Dietary Behaviors According to Extracurricular Activities of Elementary Students in Sejong (세종시 일부 초등학생의 과외수강에 따른 생활습관, 식태도 및 식행동에 대한 연구)

  • Oh, Keun-Jeong;Kim, Mi-Hyun;Kim, Myung-Hee;Choi, Mi-Kyeong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.8
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    • pp.1335-1343
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    • 2013
  • Parents in South Korea are known for their high level of educational zeal for their children. As a result, their children usually take extra classes in institutions as well as participate in other extracurricular activities such as sports and music. The purpose of this study was to examine the lifestyle and dietary behaviors of Korean elementary students involved in such activities. The total number of subjects was 550 fourth to sixth graders in elementary schools in Sejong, Korea. Of the total subjects, 88.0% were involved in extracurricular classes or other activities for an average of 7.34 hours/week. The subjects were assigned to one of four groups based on the degree of extracurricular activities: No extra-class (n=66), Low extra-class (1${\leq}$taking time<5 hours/week, n=118), Medium extra-class (5${\leq}$taking time<10 hours/week, n=184), and High extra-class (taking time${\geq}$10 hours/week, n=182). More subjects in the High extra-class group went to bed late (P<0.01), were under stress (P<0.01), and skipped breakfast, compared with those in the other groups. The ratio of students who answered 'I go to an institute without a meal' (P<0.01), 'I prepare a meal for myself' (P=0.053), or 'I eat out before going to an institute' (P<0.01) was higher in the High extra-class group than in the Low extra-class group. The frequency of eating fast food was higher in the High extra-class group, compared with the other groups. These results indicate that a high amount of extracurricular studies may have a negative effect on the children's lifestyles and dietary behaviors. Therefore, this study alerts parents to the potential harm of excessive extracurricular activities to their children's health.

Radiation Adaptive Response Induced by I-131 Therapy in Patients with Differentiated Thyroid Cancer (분화 갑상선암 환자에서 I-131 치료에 의해 유도되는 방사선적응반응)

  • Li, Ming-Hao;Bom, Hee-Seung
    • The Korean Journal of Nuclear Medicine
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    • v.35 no.2
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    • pp.83-88
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    • 2001
  • Purpose: The purpose of this study was to ascertain whether radiation adaptive response could be induced by high dose I-131 therapy in patients with differentiated thyroid cancer. Materials and Methods: Lymphocytes from 21 patients (7 males, 14 females, mean age $55{\pm}12$ years) were collected before and after administration of 5,550 MBq (150 mCi) I-131. They were exposed to a challenge dose of 1 Gy gamma rays using a Cs-137 cell irradiator. The number of ring-form (R) and dicentric (D) chromosomes was counted under the light microscope, and used to calculate the frequency of chromosomal aberration. Ydr, which was defined as the sum of R and D divided by the total number of counted lymphocytes. Results: Ydr in patients before I-131 therapy ($0.09{\pm}0.01$) was not different from that of controls ($0.08{\pm}0.01$). Ydr was significantly increased to $0.13{\pm}0.02$ (p<0.0001) after I-131 therapy. Increase of Ydr after the challenge irradiation of 1 Gy was significantly lower in patients after I-131 therapy than before I-131 therapy ($0.17{\pm}0.03\;vs\;0.21{\pm}0.02$, p<0.0001). Cycloheximide (CHM), an inhibitor of protein synthesis, abolished this effect. Ydr after CHM ($0.20{\pm}0.01$) was significantly higher than Ydr after I-131 therapy ($0.17{\pm}0.03$, p<0.0001), but was not different from Ydr before I-131 therapy ($0.21{\pm}0.02$).Conclusion: High dose I-131 therapy induces an adaptive response in peripheral lymphocytes of patients with well-differentiated thyroid cancer, which is associated with protein synthesis.

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Therapeutic Use of Music for Stuttering Children (말더듬 아동을 위한 음악치료적 접근)

  • Cho, Jung Min
    • Journal of Music and Human Behavior
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    • v.4 no.1
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    • pp.21-30
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    • 2007
  • Unlike other common forms of speech disorder, such as phonological disorder or dysphonia, stuttering has not been studied within the context of music therapy. Most cases of stuttering display no difficulty in singing, and fluency within the musical structure does not translate to fluency in speech. Hence, musical approach has been generally considered to be ineffective to the treatment of stuttering. However, the fundamentals of music therapy assume its extensive application in treating variety of speech disorders, including the case of stuttering. Presented in this paper are the case studies designed to validate the efficacy of music therapy as a remedy for stuttering. This study enrolled 6 children with stuttering and conducted 20 individual sessions over a period of 10 weeks. The sessions focused on the Melodic Intonation Therapy, Reinforcement of speech rhythm, song writing and singing. Musical elements were structured to enhance the verbal expression and rhythmic senses, as well as to facilitate the initiation of verbal communication. The result is as follows. First, it was noticed that the disfluency had been decreased in before and after of the music therapy in every child although the result was somewhat different depending the child. The overall result of the investigation shows the significant difference statistically. And categorically speaking, the significant difference was checked in the frequency of the stuttering. In the steps of the session, the increase and decrease was happened repeatedly, and then after it was decreased little by little. Secondly, the Communication Attitude was decreased in before and after of the music therapy, and also there was significant difference statistically. although the avoidance behavior was decreased in before and after of the music therapy, the increase and the decrease was repeated irregularly in the steps of session. All the results described above shows that music therapy gives positive effect to decrease in disfluency of stuttering child and also to develop the Communication Attitude. And new possibility and effectiveness can be proposed in the musical approach to the stuttering.

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Repetition of Apoptosis Induced by Amiloride Derivatives in Human Umbilical Vein Endothelial Cells (제대정맥 내피세포에서 Amiloride 유도체에 의한 Apoptosis 반복)

  • Park, Kyu Chang;Park, Kyu Sang;Moon, Soo Jee
    • Clinical and Experimental Pediatrics
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    • v.46 no.1
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    • pp.56-66
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    • 2003
  • Purpose : Human umbilical vein endothelial cells(HUVECs) play an important role in regulating blood flow by releasing vasoactive substances. It has been reported that endothelial impairment and dysfunction might be a primary cause of placental vascular disease, which is manifested clinically as preeclampsia in mother and intrauterine growth restriction in fetus. Furthermore, the frequency of apoptotic changes is increased in umbilical and placental tissues from growth-restricted pregnancies. However, the various mechanisms of umbilical endothelial cell apoptosis have not been broadly proposed. We investigate the effects of amiloride derivatives on apoptotic death of HUVECs and identify their ionic mechanism. Methods : HUVECs were purchased from Clonetics, and cultured on endothelial cell growth medium. MTT assay and flow cytometry were used for assessing cytotoxic effect and confirming the apoptosis. Changes in intracellular ion concentrations were measured with specific fluorescent dyes and fluorescence imaging analysis system. Results : Amiloride derivatives elicited cytotoxic effects on HUVECs with dose-dependent manners and the rank order of potency is HMA($IC_{50}\;11.2{\mu}M$), MIA>EIPA>>amiloride. HMA-induced cytotoxicity is dependent on extra- and intracellular pH, that is, increase extra- and intracellular pH augmented the cytotoxic effects of HMA. HMA dose-dependently reduced intracellular major ions, such as $K^+$ and $Cl^-$. Interestingly, the depletion of intracellular ions induced by HMA was also significantly enhanced at alkaline extracellular pH. Conclusion : Amiloride derivatives induce apoptosis of HUVECs with dose and pH dependent manners. They reduce intracellular $K^+$ and $Cl^-$ concentration, which is also extracellular pH dependent.