• Mass Spectrometry Letters
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• 제12권1호
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• pp.1-10
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• 2021

A simple, specific, and economical LC-MS/MS method was investigated for the screening of 43 prescribed antihypertensive and related drugs in human urine. The urine samples were simply prepared by diluting and mixing with internal standard before directly introduced to the LC-MS/MS system, which is fast, straightforward, and cost-effective. Fractional factorial, Box-Behnken, and I-optimal design were applied to screen and optimize the mass spectrometric and chromatographic factors. The analysis was carried out on a triple quadrupole mass spectrometer system utilizing multiple reaction monitoring with positive and negative electrospray ionization method. Chromatographic separation was performed on a Thermo Scientific Accucore RP-MS column (50 × 3.0 mm ID., 2.6 ㎛) using two separate gradient elution programs established with the same mobile phases. Chromatographic separation was performed within 12 min. The optimal method was validated based on FDA guideline. The results indicated that the assay was specific, reproducible, and sensitive with the limit of detection from 0.1 to 50.0 ㎍/L. The method was linear for all analytes with coefficient of determination ranging from 0.9870 to 0.9981. The intra-assay precision was from 1.44 to 19.87% and the inter-assay precision was between 2.69 and 18.54% with the recovery rate ranges from 84.54 to 119.78% for all drugs measured. All analytes in urine samples were stable for 24 h at 25℃, and for 2 weeks at -60℃. The developed method improves on currently existing methods by including larger number of cardiovascular medications and better sensitivity of 12 analytes.

• Preventive Nutrition and Food Science
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• 제15권1호
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• pp.74-77
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• 2010

Antibiotic-resistant Staphylococcus aureus is beginning to pose a social issue. Thus, there is an urgent need for the development of effective anti-staphylococcal agents to eradicate antibiotic-resistant S. aureus in food systems and to treat the pathogen in clinical areas. To address this need, lactic acid bacteria (LAB) from kimchi were screened for the production of anti-staphylococcal bacteriocin. From this screening, a bacteriocin generated by the MK3 strain, which was identified by 16S rRNA gene sequence analysis as Enterococcus faecium, demonstrated antimicrobial activity against an S. aureus strain, and was designated enterocin MK3. Enterocin MK3 also demonstrated activity against other gram-positive bacteria, including several LAB and Listeria monocytogenes, but not gram-negative Escherichia coli. The molecular mass of enterocin MK3 was estimated as approximately 6.5 kDa on an SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis) gel.

• Journal of Korean Vacuum Science & Technology
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• 제6권1호
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• pp.43-45
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• 2002

We have theoretically investigated steady-state carrier transport and current self-oscillation in negative-effective-mass (NEM) p$\^$+/pp$\^$+/diodes. The current self-oscillation here is a result of the formation and traveling of electric field domains in the p base having a NEM. The dependence of self-oscillating frequency on the applied dc voltage is obtained by detailed numerical simulations. In the calculations, we have considered the scatterings by carrier-impurity, carrier-acoustic phonon, carrier-polar-phonon, and carrier-nonpolar-phonon-hole interactions . This kind of NEM oscillator allows us to reach a current oscillation with terahertz frequency, thus it may be used as a broadband source of terahertz radiation.

• 분석과학
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• 제23권4호
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• pp.405-413
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• 2010

축산물(소의 근육 및 간)중에 잔류하는 합성 글루코코티코이드 6종 (betamethasone, dexamethasone, prednisone, prednisolone, methylprednisolone, flumethasone)에 대한 동시분석방법을 확립하였다. 효과적인 기기분석을 위해서 시료는 C18 고체상 카트리지를 사용하여 에틸아세테이트 용매를 사용하여 추출/정제하였다. C18 컬럼을 사용하여 분리한 후 음이온 전기분무 질량분석법의 multiple reaction monitoring 방법을 사용하여 정량 및 정성 분석을 수행하였다. 효과적이고 감도있는 HPLC-MS/MS 분석을 위해서 0.1% 포름산이 포함된 물과 아세토나이트릴이 이동상 용매로 사용되었다. 메트릭스와 약물의 종류에 따라서 검출한계(LOD)는 $0.2-0.1\;{\mu}g$/kg, 정량한계(LOQ)는 $0.8-3.4{\mu}g$/kg 이었으며, 회수율은 89.5-119.6%이었다. 확립된 기존의 방법들에 비해 6종의 글루코코티코이드의 동시분석 방법이 간소화되었고, 좋은 정확도, 정밀도 및 회수율을 나타내었으며, 축산 육류 중에 잔류하는 글루코코티코이드들 분석하는데 사용될 수 있을 것이다.

• 대한핵의학회지
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• 제28권1호
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• pp.31-36
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• 1994

$^{201}Tl-^{99m}Tc$ 감영스캔이 시행되었던 65명의 환자에서 $^{201}Tl-^{99m}Tc$ 감영스캔의 진단적 가치와 위 음성과 위 양성의 원인에 대해 조사하였다. 이들 중 21예가 부갑상선선종으로 확진되었고, 이들에서 $^{201}Tl-^{99m}Tc$ 감영스캔의 예민도는 90.5%, 특이도는 97.6%였다. 위 음성을 보인 예는 낭종성 괴사를 보인 부갑상선선종과 크기가 $1.5{\times}1{\times}0.8 cm$ 정도로 작은 종양이었다. 위 양성을 보인 1예는 무 기능성 갑상선종이었다. 결론적으로 $^{201}Tl-^{99m}Tc$ 감영스캔은 부갑상선 종괴를 찾아내는데 특이도와 예민도가 높은 검사로 생각된다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권1호
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• pp.345-349
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• 2015

Background: To determine the cut-off values of the preoperative risk of malignancy index (RMI) used in differentiating benign or malignant adnexal masses and to determine their significance in differential diagnosis by comparison of different systems. Materials and Methods: 191 operated women were assessed retrospectively. RMI of 1, 2, 3 and 4; cut-off values for an effective benign or malignant differentiation together with sensitivity, specificity, negative and positive predictive values were calculated. Results: Cut-off value for RMI 1 was found to be 250; there was significant (p<0.001) compatibility at this level with sensitivity of 60%, positive predictive value (PPV) of 75%, specificity of 93%, negative predictive value (NPV) of 88% and an overall compliance rate of 85%. When RMI 2 and 3 was obtained with a cut-off value of 200, there was significant (p<0.001) compatibility at this level for RMI 2 with sensitivity of 67%, PPV of 67%, specificity of 89%, NPV of 89%, histopathologic correlation of 84% while RMI 3 had significant (p<0.001) compatibility at the same level with sensitivity of 63%, PPV of 69%, specificity of 91%, NPV of 88% and a histopathologic correlation of 84%. Significant (p<0.001) compatibility for RMI 4 with a sensitivity of 67%, PPV of 73%, specificity of 92%, NPV of 89% and a histopathologic correlation of 86% was obtained at the cut-off level 400. Conclusions: RMI have a significant predictability in differentiating benign and malignant adnexal masses, thus can effectively be used in clinical practice.

• Journal of Nutrition and Health
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• 제34권3호
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• pp.313-321
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• 2001

The purpose of this study is to verify the relation between vegetarian diet and the risk factors of cardiovascular disease. To do the present study the vegetarians were selected;245 Buddhist nuns(age: 23-79yrs). For control subjects, 235 healthy female adults(age: 23-79yrs) were selected. They were the teachers, the nurses and the housekeepers living in Chinju Gyeongsang Namdoo Province. Study period was from October 1996 to February 1997. The contents are consist of survey, anthropometric measurement, and clinical examination. The average ages of the subjects were 44.20yrs for vegetarians and 40.52yrs for non-vegetarians respectively. Average body mass indice(BMI) of vegetarians and non-vegetarians were 22.47 and 21.08, WHR was 0.85 and 0.84, percentage of body fat was 28.79 and 26.55 and the average duration of vegetarian diet of the vegetarians was 13.16 years. On the nutrient related lipid, fat, the energy ratio of fat, saturated fatty acid, total fatty acid, monounsaturated fatty acid and total-cholesterol were significantly lower(p<0.01) but the ratio of p/s was significantly higher(p<0.01) in vegetarians than non-vegetarians. The vegetarians were significantly higher than the non-vegetarians in intake of fiber, vitamin C. In vegetarians, variables that significant negative correlation with fiber were total-cholesterol, AI, blood sugar. In non-vegetarians, variables that significant negative correlation with fiber were TG, total-cholesterol, blood sugar, systolic blood pressure. In both subjects, the serum lipid concentration and the blood pressure were getting lower with fiber intakes. Consequently, vegetable diet can be considerably effective in making the level of the risk factors causing in cardiovascular disease lower. (Korean J Nutrition 34(3) : 313∼321, 2001)

• 한국학교수학회논문집
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• 제23권1호
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• pp.111-127
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• 2020

여러 연구에서 수학불안(MA)은 학생들의 수학교과에서의 성취도(MC)에 영향을 미치는 주요 요인이며 여학생집단에 더 크게 작용하는 것으로 보고되고 있다. 본 연구에서는 수학불안을 감소하기 위한 10차시 복합적 처치프로그램을 개발하고, 이를 비교적 MA가 높은 남녀 학생 26명에게 적용하여 그 효과를 조사하는 것이다. 이를 위해 사전, 사후에 수학불안검사지(MASS)와 성취도검사지(MCS)에 의해 수집한 두 성차집단에 대한 차이점을 분석하였다. 연구결과로서 처치프로그램을 통해 두 집단 모두 MA는 감소하였으나 MC에서는 여학생만이 효과를 나타내었다. 이 프로그램은 학생들의 수학적과 심리적 측면에 통합적으로 작용하게 되어 주 목적인 MA의 감소에서 남녀 학생 모두에게 효과적이었으며, 남학생의 MC측면에서 더 부가적인 절차와 안내가 따라야한다는 것을 내포한다.

• 대한두경부종양학회지
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• 제19권1호
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• pp.67-70
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• 2003

Out of entire salivary tumor, 1.7% are malignant lymphoma developed in salivary gland and it is usually mucosa associated lymphoid tissue (MALT) lymphoma developed in salivary gland. In the case of Non-Hodgkin lymphoma, the most frequently involved extanodal sites of diffuse large B cell lymphoma are bone, skin, thyroid, gastrointestinal tract, and lung. Development in salivary gland is very rare. A 69 years old male patient who have found Lt. submandibular gland (SMG) mass a month ago is suspected of malignancy from his FNA result, so histologic exam by SMG resection was operated. According to histopathologic exam, large B cell lymphocyte infiltratration were generally shown as diffuse and lymphoepitheliallesion were not found. In immunostaining, CD79a showed positive and CD3, CAM5.2 showed negative which diagnosed as diffuse large B cell lymphoma. As Ann Arbor stage I, CEOP-B chemotherapy was used 3 times as treatment without any recurrence. In the case of malignant lymphoma in salivary gland, it develops as painless mass in ipsilateral side. If found in parotid gland, it is rare to have facial nerve falsy and pathologically diagnosed as lymphocytes of abnormal type of monoclonal immunostaining must be provided as evidence. Combined therapy is known as most effective treatment for intermediate grade.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권3호
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• pp.262-266
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• 2009

Solitary fibrous tumor (SFT) is a neoplasm that arises most commonly in pleura. Although SFT occasionally occurs in extrapleural locations, the incidence in the oral cavity is rare. SFT is benign in almost cases and surgical excision is the effective treatment. SFT occurred in the left cheek of a 60-year-old man presented with a painless submucosal mass. The tumor was surgically removed. Immunohistochemical study showed that tumoral cells were negative for SMA, S-100, but positive for Bcl-2, CD34. SFT is easily over-diagnosed if strict criteria are not carefully applied, and strict diagnostic criteria are necessary to avoid confusion of SFT with more aggressive lesions.