• Title/Summary/Keyword: Korean Medical school

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THE POLYMERIZATION RATE AND THE DEGREE OF CONVERSION OF COMPOSITE RESINS BY DIFFERENT LIGHT SOURCES (광원의 종류에 따른 복합레진의 중합거동 및 중합률에 관한 연구)

  • Ryoo, Joo-Hee;Lee, In-Bog;Yoo, Hyun-Mee;Kim, Mi-Ja;Seok, Chang-In;Kwon, Hyuk-Choon
    • Restorative Dentistry and Endodontics
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    • v.29 no.4
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    • pp.386-398
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    • 2004
  • Objectives: The purpose of this study was to observe the reaction kinetics and the degree of polymerization of composite resins when cured by different light sources and to evaluate the effectiveness of the blue Light Emitting Diode Light Curing Units (LED LCUs) compared with conventional halogen LCUs. Materials and Methods: First, thermal analysis was performed by a differential scanning calorimeter (DSC). The LED LCU (Elipar Freelight, $320{\;}mW/\textrm{cm}^2$) and the conventional halogen LCU (XL3000, $400{\;}mV/\textrm{cm}^2$) were used in this study for curing three composite resins (SureFil, Z-250 and AEliteFLO). Second. the degree of conversion was obtained in the composite resins cured according to the above curing mode with a FTIR. Third, the measurements of depth of cure were carried out in accordance with ISO 4049 standards. Statistical analysis was performed by two-way ANOVA test at 95% levels of confidence and Duncan's procedure for multiple comparisons. Results: The heat of cure was not statistically different among the LCUs (p > 0.05). The composites cured by the LED (Exp) LCUs were statistically more slowly polymerized than by the halogen LCU and the LED (Std) LCU (p < 0.05). The composite resin groups cured by the LED (Exp) LCUs had significantly greater degree of conversion value than by the halogen LCU and the LED (Std) LCU (p =0.0002). The composite resin groups cured by the LED (Std) LCUs showed significantly greater depth of cure value than by the halogen LCU and the LED (Exp) LCU (p < 0.05).

Study on Antioxidant Potency of Cuscutae Semen, Psoraleae Fructus, Cnidii Fructus and Epimedii Herba by DPPH Method (DPPH 방법을 통한 토사자, 보골지(補骨脂), 사상자(蛇床子), 음양곽(淫羊藿)의 항산화 활성에 대한 연구)

  • Oh, Myung-Sook;Kim, Do-Rim;Kang, Ji-Ung;Kim, San-Woong;Yu, Tae-Weon;Park, Jung-Yeul;Kim, Dong-Min;Park, Wan-Su;Chang, Mun-Seog;Park, Soo-Yeon;Park, Seong-Kyu
    • Herbal Formula Science
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    • v.13 no.2
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    • pp.101-110
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    • 2005
  • The present study was conducted to compare antioxidant activity of Cuscutae Semen, Psoraleae Fructus, Cnidii Fructus and Epimedii Herba by DPPH radical scavenging activity. The extract was studied using diphenyl-picryl-hydrazyl (DPPH) for DPPH method. DPPH radical scavenging activity was measured after. .10, 20 and 30 minutes. The extract was tested by 1, 5, 10, 50, 100, 500 and $1000{\mu}g/ml$ concentrations. The results showed that the extract scavenged DPPH radical with time-dependent manner. Also, the extract showed dose-dependent DPPH radical scavenging activity. The extract of Cuscutae Semen, Psoraleae Fructus, Cnidii Fructus and Epimedii Herba scavenged DPPH radical with the IC50 being 2.7, 3.2, 2.9 and 1.1 mg/ml, respectively. In conclusion, the extract of Epimedii Herba, Cuscutae Semen, Cnidii Fructus and Psoraleae Fructus have antioxidant activity for the treatment of male sterility.

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Development and Validation of an HPLC Method for the Pharmacokinetic Study of Dipyridamole in Human (디피리다몰 체내동태 연구를 위한 혈청 중 디피리다몰의 HPLC 정량법 개발 및 검증)

  • Cho, Hea-Young;Kang, Hyun-Ah;Moon, Jae-Dong;Choi, Hoo-Kyun;Lee, Yong-Bok
    • Journal of Pharmaceutical Investigation
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    • v.36 no.1
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    • pp.45-51
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    • 2006
  • A rapid, selective and sensitive reversed-phase HPLC method for the determination of dipyridamole in human serum was developed, validated, and applied to the pharmacokinetic study of dipyridamole. Dipyridamole and internal standard, loxapine, were extracted from human serum by liquid-liquid extraction with diethyl ether and analyzed on a Nova Pak $C_{I8}$ column with the mobile phase of 40 mM ammonium acetate:methanol:acetonitrile (35:35:30)(v/v/v, pH 7.8). Detection wavelength of 280 nm and flow rate of 1.0 mL/min were fixed for the study. The assay robustness for the changes of mobile phase pH, organic solvent content, and flow rate was confirmed by $3^3$ factorial design using a fixed dipyridamole concentration (50 ng/mL) with respect to its peak area and retention time. And also, the ruggedness of this method was investigated at three different laboratories using same quality control (QC) samples. This method showed linear response over the concentration range of 2-2000 ng/mL with correlation coefficients greater than 0.999. The lower limit of quantification using 0.5 mL of serum was 2 ng/mL, which was sensitive enough for pharmacokinetic studies of dipyridamole. The overall accuracy of the quality control samples ranged from 103.94 to 105.86% for dipyridamole with overall precision (% C.V.) being 4.60-11.49%. The relative mean recovery of dipyridamole for human serum was 97.64%. Stability studies showed that dipyridamole was stable during storage, or during the assay procedure in human serum. The peak area and retention time of dipyridamole were not significantly affected by the changes of mobile phase pH, organic solvent content, and flow rate under the conditions studied. This method showed good ruggedness (within 15% C.V.) and was successfully used for the analysis of dipyridamole in human serum samples for the pharmacokinetic studies of orally administered Dimor tablet (75 mg as dipyridamole) at three different laboratories, demonstrating the suitability of the method.

Bioequivalence of Neurocetil Tablet to Nicetile Tablet (Acetyl-L-Carnitine 500 mg) (니세틸 정(아세틸-엘-카르니틴 500 mg)에 대한 뉴로세틸 정의 생물학적 동등성)

  • Cho, Hea-Young;Kim, Eun-A;Jeong, Hyun-Cheol;Shim, Young-Sun;Lim, Dong-Koo;Oh, In-Joon;Moon, Jai-Dong;Lee, Yong-Bok
    • Journal of Pharmaceutical Investigation
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    • v.31 no.1
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    • pp.49-55
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    • 2001
  • Acetyl-L-carnitine (ALC), an endogenous component of the L-carnitine family, is naturally occurring molecule synthesized from L-carnitine (LC) by carnitine acetyl transferase. ALC has been shown to improve the cognitive performance of patients suffering from dementia of the Alzheimer's type and proposed for treating Alzheimer's disease in pharmacological doses. The purpose of the present study was to evaluate the bioequivalence of two ALC tablets, $Nicetile^{TM}$ (Dong-A pharmaceutical Co., Ltd.) and $Neurocetil^{TM}$ (Kyung-Dong Pharmaceutical Co., Ltd.), according to the guidelines of Korea Food and Drug Administration. Twenty six normal male volunteers, $22.80{\pm}2.76$ year in age and $63.07{\pm}7.98\;kg$ in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After one tablet containing 500 mg of ALC was orally administered, blood was taken at predetermined time intervals and the concentrations of ALC in serum were determined using HPLC with fluorescence detector. Because of the presence of endogenous ALC, the calibration was performed using dialyzed serum. Pharmacokinetic parameters such as $AUC_t$, $C_{max}\;and\;T_{max}$ were calculated and ANOVA was utilized for the statistical analysis of the parameters. The results showed that the differences in $AUC_t$, $C_{max}\;and\;T_{max}$ between two tablets were 2.72%, -0.65% and -8.42%, respectively, when calculated against the $Nicetile^{TM}$ tablet. The powers $(1-{\beta})$ for $AUC_t\;and\;C_{max}$ were 94.87% and 87.17%, respectively. Minimum detectable differences $({\Delta})$ at ${\alpha}=0.05$ and $1-{\beta}=0.8$ were less than 20% (e.g., 15.58% and 19.16% $AUC_t\;C_{max}$, respectively). The 90% confidence intervals were within ${\pm}20%$ (e.g., $-11.84{\sim}6.41$ and $-10.57{\sim}11.88$for $AUC_t\;and\;C_{max}$, respectively). Two parameters met the criteria of KFDA for bioequivalence, indicating that $Neurocetil^{TM}$ tablet is bioequivalent to $Nicetile^{TM}$ tablet.

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Influence of Smoking on Short-Term Clinical Results of Periodontal Bone Defects Treated with Regenerative Therapy Using Bioabsorbable Membranes (흡연이 흡수성 차폐막을 이용한 조직유도재생술의 치유에 미치는 영향)

  • Kang, Tae-Heon;Seol, Yang-Jo;Lee, Yong-Moo;Kye, Seung-Beom;Kim, Weon-Kyeong;Chung, Chong-Pyoung;Han, Soo-Boo
    • Journal of Periodontal and Implant Science
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    • v.30 no.2
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    • pp.305-324
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    • 2000
  • This study compared the short-term(4 months) clinical results of regenerative therapy with bioabsorbable membranes($BioMesh^{(R)}$) and bone allograft for the treatment of periodontal(intrabony and furcation) defects in smokers and nonsmokers.(16 smokers) 32 subjects with 92 defects participated in the study(46 in smokers and 46 in non-smokers). This study also evaluated a bioresorbable barrier with and without decalcified freeze-dried bone allograft(DFDBA). The 92 periodontal defects were randomly treated with either the resorbable barrier alone or resorbable barrier in combination with DFDBA following thorough defect debridement and root preparation with tetracycline. Each patient received both types of treatment modalities. Clinical examinations(probing depth, gingival recession, clinical attachment level, plaque index and gingival index) were carried out immediately before and 4 months after surgery. Significant(p<0.001) gains in mean attachment level were observed for both smokers(2.93mm) and non-smokers(3.30mm) but there were not significant difference between two groups. Similarly, significant reductions in mean probing depthshowed for smokers(4.52mm) and non-smokers(4.26mm). However, when comparing gingival recession, smokers were found to exhibit significantly poorer treatment results(1.59mm vs 0.96mm, p<0.05). Using the split-mouth-design, no statistically significant difference between the two modalities could be detected with regard to pocket depth reduction, gingival recession, or attachment gain. These results illustrate that the attachment gain is better in the non-smoker and the best in the non-smoker with the combination therapy of resorbable barrier and DFDBA than with resorbable barrier alone but smoking had no significant effect on clinical treatment outcome, even though smokers show more significant gingival recession. In addition, both treatments, either resorbable barrier plus DFDBA or resorbable barrier alone, promoted significant resolution of periodontal defects but the addition of DFDBA with a bioabsorbable membrane appears to add no extra benefit to the only membrane treatment.

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The Effect of Bioresorbable Membrane on the Bone Regeneration of Streptozotocin Induced Diabetic Rats (스트렙토조토신 유도 당뇨백서의 골조직 재생에 흡수성 차폐막이 미치는 영향)

  • Yang, Byung-Kun;Lee, Hak-Churl;Lee, Ji-Young;Son, Kang-Bae;Seol, Yang-Jo;Lee, Sang-Cheol;Kye, Seung-Beom;Chung, Chong-Pyoung;Han, Soo-Boo
    • Journal of Periodontal and Implant Science
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    • v.30 no.2
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    • pp.287-305
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    • 2000
  • The purpose of this study is to evaluate the effects of bioresorbable membranes in guided bone regeneration of streptozotocin induced diabetic rats. 50 Sprague-Dawley rats were randomly categorized into 4 groups: Group 1 & 2 had 10 normal rats each and group 3 & 4 included 15 streptozotocin induced diabetic rats each. Defect measuring 7mm in diameter was formed on every rat calvarium. No membrane was used in groups 1 & 3 and membranes were used in groups 2 & 4. The rates were sacrificed at 2 and 4 weeks after defect formation. Routine histological specimens were prepared. Masson-trichrome and HE stain were done before light microscopy. Guided regenerative potential was evaluated by measuring the amount of new bone formation in the calvarial defect by histomorphometry. Following results were obtained. 1. New bone formation in the diabetic groups was significantly less that than in the normal groups regardless of membrane use(p<0.05). 2. In the comparison of new bone formation in the normal groups, membrane group showed significantly more bone formation(p<0.1). 3. When the amount of new bone formation was compared in the diabetic groups, more bone was formed in the membrane groups but the difference was not statistically significant.4. In the normal groups the amount of new bone formation was significantly greater at 4 weeks compared to that at2 weeks(p<0.05) but amount of bone regeneration at 4 weeks was not significantly greater than that at 2 weeks in both diabetic groups.

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Production and Characterization of Ethanol- and Protease-Tolerant and Xylooligosaccharides-Producing Endoxylanase from Humicola sp. Ly01

  • Zhou, Junpei;Wu, Qian;Zhang, Rui;Yang, Yuying;Tang, Xianghua;Li, Junjun;Ding, Junmei;Dong, Yanyan;Huang, Zunxi
    • Journal of Microbiology and Biotechnology
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    • v.23 no.6
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    • pp.794-801
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    • 2013
  • This paper reports the production and characterization of crude xylanase from the newly isolated Humicola sp. Ly01. The highest (41.8 U/ml) production of the crude xylanase was obtained under the optimized conditions (w/v): 0.5% wheat bran, 0.2% $KH_2PO_4$, and 0.5% peptone; initial pH 7.0; incubation time 72 h; $30^{\circ}C$; and 150 rpm. A considerable amount of the crude xylanase was induced using hulless barley bran or soybean meal as the carbon source, but a small amount of the enzyme was produced when supplementary urea was used as the nitrogen source to wheat bran. The crude xylanase showed apparent optimal cellulase-free xylanase activity at $60^{\circ}C$ and pH 6.0, more than 71.8% of the maximum xylanase activity in 3.0-30.0% (v/v) ethanol and more than 82.3% of the initial xylanase activity after incubation in 3.0-30.0% (v/v) ethanol at $30^{\circ}C$ for 2 h. The crude xylanase was moderately resistant to both acid and neutral protease digestion, and released 7.9 and 10.9 ${\mu}mol/ml$ reducing sugar from xylan in the simulated gastric and intestinal fluids, respectively. The xylooligosaccharides were the main products of the hydrolysis of xylan by the crude xylanase. These properties suggested the potential of the crude enzyme for being applied in the animal feed industry, xylooligosaccharides production, and high-alcohol conditions such as ethanol production and brewing.

Transcript Profiling of Toll-Like Receptor mRNAs in Selected Tissues of Mink (Neovison vison)

  • Tong, Mingwei;Yi, Li;Cheng, Yuening;Zhang, Miao;Cao, Zhigang;Wang, Jianke;Zhao, Hang;Lin, Peng;Yang, Yong;Cheng, Shipeng
    • Journal of Microbiology and Biotechnology
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    • v.26 no.12
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    • pp.2214-2223
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    • 2016
  • Toll-like receptors (TLRs) can recognize conserved molecular patterns and initiate a wide range of innate and adaptive immune responses against invading infectious agents. The aim of this study was to assess the transcript profile of mink TLRs (mTLRs) in mink peripheral blood mononuclear cells (PBMCs) and a range of tissues, and to explore the potential role of mTLRs in the antiviral immune response process. The results indicated that the mTLR partial nucleotide sequences had a high degree of nucleotide identity with ferret sequences (95-98%). Phylogenetic analysis showed that mammalian TLRs grouped into five TLR families, with a closer relationship of the mTLRs with those of ferret than the other mammalian sequences. Moreover, all the mTLRs were ubiquitously expressed in lymphoid organs (spleen and lymph nodes) and PBMCs. Interestingly, the mTLR expression patterns in lung, uterus, and heart showed quite a lot of similarity. Another remarkable observation was the wide expression of mTLR1-3 mRNAs in all tissues. Among the analyzed tissues, skeletal muscle was revealed to being the lowest repertoire of mTLR expression. Additionally, mink PBMCs exposed to the canine distemper virus revealed significant upregulation of mTLR2, mTLR4, mTLR7, and mTLR8 mRNAs, indicating that mTLRs have a role in innate immunity in the mink. Collectively, our results are the first to establish the basic expression patterns of mTLRs and the relationship between mTLRs and a virus, which will contribute to better understanding of the evolution and the functions of mTLRs in the innate immune system in minks.

Investigation of Physical Imaging Properties in Various Digital Radiography Systems (다양한 디지털 방사선 시스템의 물리적 영상 특성 조사)

  • Jeong, Hoi-Woun;Min, Jung-Hwan;Yoon, Yong-Su;Kim, Jung-Min
    • Journal of radiological science and technology
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    • v.40 no.3
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    • pp.363-370
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    • 2017
  • We aimed to evaluate the physical imaging properties in various digital radiography systems with charged coupled device (CCD), computed radiography (CR), and indirect flat panel detector (FPD). The imaging properties measured in this study were modulation transfer function (MTF) wiener spectrum (WS), and detective quantum efficiency (DQE) to compare the performance of each digital radiography system. The system response of CCD were in a linear relationship with exposure and that of CR and FPD were proportional to the logarithm of exposure. The MTF of both CR and FPD indicated a similar tendency but in case of CCD, it showed lower MTF than that of CR and FPD. FPD showed the lowest WS and also indicated the highest DQE among three systems. According to the results, digital radiography system with different type of image receptor had its own image characteristics. Therefore, it is important to know the physical imaging characteristics of the digital radiography system accurately to obtain proper image quality.

A Case Study on the Occupational Therapy Evaluation and Intervention Plan of a Community Asperger Syndrome Child Receiving Coping Model (지역사회 아스퍼거 장애 아동을 대상으로 대처모델(coping model)을 적용한 작업치료 평가 및 중재계획수립: 사례연구)

  • Lee, Mi Ji
    • Therapeutic Science for Rehabilitation
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    • v.2 no.1
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    • pp.87-91
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    • 2013
  • Objective : This case study examined the evaluation of occupational therapy and plan to intervention of community asperger syndrome child receiving coping model. Methods : We selected child which 7-year-old boy. Evaluation periods were 2weeks which consisted of external factors and internal factors. External factors were made up interaction of subject, environments and participation of school and community. Internal factors were made up observation and structured evaluation about development state and medical conditions. Also it included observation of appropriate mood and emotions. Results : After evaluation receiving coping model, we planed to intervention. First, subject able to use his time effectively. Second, we'll have intervention program about delayed fine motor areas. Third, we'll educate self-control skills and coping skills of subject's action which not controlled himself. Fourth, we'll find the personal and physical sources to care subject. Conclusion : Our research has planed occupational therapy intervention receiving coping model of asperger syndrome subject. Future research need to practical applications.