목적 : 컴퓨터를 많이 사용하는 대학생을 대상으로 온라인 학습 환경과 CVS 자각증상을 조사하여 CVS 증상 예방조치를 알아보고자 하였다. 방법 : 2021년 3월부터 4월까지 온라인 설문조사에 동의한 대학생 140명을 대상으로 하였다. 대상자들의 평균 연령은 19.87±1.48세로 남학생과 여학생은 각각 70명(50.0%) 이었다. 연구 도구는 대상자의 일반적인 특성(4), 온라인 학습 환경 특성(12), CVS 자각증상(16) 총 32문항의 설문지를 이용하였다. 결과 : 대상자의 CVS 증상은 ‘건조함’(69.3%)이 가장 높은 빈도로 나타났으며, ‘시력이 나빠지는 느낌’(62.9%), ‘두통’(60.7%), ‘눈의 통증’(53.6%), ‘눈꺼풀 무거움’(50.7%)순으로 많이 나타났다. 컴퓨터 사용시간이 8시간 이상 인 그룹의 CVS 증상 발생 빈도가 높았으며, 온라인 학습동안 규칙적으로 휴식하지 않는 그룹이 휴식을 하는 그룹 보다 모든 CVS 증상에서 발생 빈도가 높았고 통계적으로 유의하였다. 결론 : 온라인 학습 환경과 CVS 자각증상을 확인하였다. 컴퓨터 사용 시간이 길수록 CVS 증상의 발생빈도는 높았으며, 온라인 학습동안 규칙적으로 휴식하는 것이 CVS 증상의 빈도를 감소시키는 것을 확인하였고, 규칙적인 눈 운동 필요 인식이 높은 결과를 확인하였다. 따라서 온라인 학습동안 올바른 눈 운동과 휴식 방법의 홍보와 교육이 필요하다고 생각한다.

목적 : 안경원 고객을 대상으로 안경원 이용 시 안경원의 고객응대 태도, 고객만족도, 변화추구성향, 전환의도 를 조사하여 안경원 고객의 전환의도에 영향을 미치는 원인을 파악하고자 하였다. 방법 : 2019년 9월부터 11월까지 온라인 설문조사에 응답한 209명을 대상으로 하였다. 안경원의 고객응대 태 도, 고객만족도, 소비자의 변화추구성향, 전환의도가 포함된 총 20개의 문항으로 설문을 구성하였다. 결과 : 안경원의 고객응대 태도는 평균 3.76점, 고객만족도는 3.18점, 소비자의 변화추구성향은 2.95점, 전환 의도는 2.63점으로 나타났다. 안경원의 고객응대 태도가 좋을수록 고객만족도는 증가하였고, 전환의도는 감소하 였다. 안경원 고객 전환의도는 소비자의 변화추구성향이 높을수록 증가하였고, 고객만족도가 높을수록 감소하였 다. 안경원의 고객응대 태도와 소비자의 변화추구성향, 고객만족도는 전환의도에 영향을 미치는 것을 확인하였다. 결론 : 안경원의 고객응대 태도는 좋았으며, 고객만족도가 높아 안경원 고객의 전환의도가 낮음을 확인하였다. 본 연구의 결과를 통해 안경원 고객의 전환의도를 줄일 수 있는 방안을 연구하는 기초자료로 사용되리라 생각한다.

A γ-aminobutyric acid (GABA) producing microorganism was isolated from Sun-Tae Jeotgal, a Korean traditional fermented seafood. Two thousand presumptive lactic acid bacteria (LAB) isolates were screened for GABA production by thin layer chromatography. One isolate, T118, produced GABA profusely, and identified as Lactobacillus brevis. Growth of Lb. brevis T118 was examined during 120 h cultivation in MRS broth under different conditions. Lb. brevis T118 grew well at 30-37℃, initial pH of 4-7, and up to 5% NaCl (w/v). A gene, gadB, encoding glutamate decarboxylase (GAD) was cloned by PCR. gadC encoding a glutamate/GABA antiporter was cloned and gadC located immediately upstream of gadB, indicating gadCB operon structure. The operon structure was confirmed by reverse transcription (RT)-PCR. gadB was overexpressed in Escherichia coli BL21 (DE3) and recombinant GAD was purified. The size of recombinant GAD was 54.4 kDa by SDS-PAGE, which matched well with the calculated size from the nucleotide sequence.

The purpose of this study was to evaluate the effect of mangosteen extract complex (MEC; Garcinia mangostana L. and propolis extracts) on the inhibition of inflammation and prevention of alveolar bone loss using a ligature-induced periodontitis model. Rat molars were ligatured with silk, and 1 μg/mL of lipopolysaccharide of Porphyromonas gingivalis was injected into the buccal and palatal gingivae of the teeth with or without treatment with the MEC. Changes in the expression levels of prostaglandin E2 (PGE2), interleukin-8 (IL-8), inducible nitric oxide synthase (iNOS), matrix metalloproteinase-8 (MMP-8), cyclooxygenase (COX)-1, and COX-2 in gingival tissues were evaluated using enzyme-linked immunosorbent assays. Alveolar bone loss around the ligated molars was examined using micro-computed tomography. The expression levels of PGE2, IL-8, iNOS, MMP-8, COX-1, and COX-2 in gingival tissues were significantly reduced in the group treated with a mixture of 16 μg of mangosteen extract powder and 544 μg of propolis extract powder (ligation [Lig] + lipopolysaccharide extracted from P. gingivalis KCOM 2804 [L] + MEC 1:34). Additionally, alveolar bone loss was significantly reduced in the Lig + L + MEC 1:34 group compared with that in other groups. These results indicate that the MEC could be useful in preventing and treating periodontitis.

목적 : 폭주부족안과 정상안의 컬러렌즈 착용 전과 후의 시기능과 읽기능력을 측정하여 컬러렌즈 착용이 폭주부족안에게 미치는 영향을 알아보고자 하였다. 방법 : 색각이상이 없고 안질환이 없는 39명을 대상으로 CISS 설문을 실시하여 폭주부족군과 대조군을 분 류하였다. 굴절검사를 실시하여 최대교정시력이 1.0 이상으로 완전교정을 한 후, 시기능 검사와 Intuitive Colorimeter Mk.3을 이용하여 근거리 독서 시 선호하는 컬러렌즈 색상을 선택한 후, 읽기능력을 검사하였다. 분석 방법은 SPSS 18.0 통계프로그램을 사용하였으며, 통계적으로 유의수준은 p<0.05을 기준으로 하였다. 결과 : CISS 점수는 폭주부족안이 정상안 보다 높았다. 폭주부족안의 근거리 외사위량이 더 크게 나타났 으며, 폭주근점도 더 길게 나타났다. 양성상대조절력과 조절래그값은 폭주부족안이 정상안보다 더 큰 값을 보였으며, 조절용이성은 정상안보다 속도가 느렸다. 폭주부족안은 컬러렌즈를 사용했을 때의 맞은 단어의 개수와 읽기 속도가 증가하였다. 반면, 정상안에서는 컬러렌즈의 사용 전과 후의 읽기 능력 변화에 큰 차이 를 나타내지 않았다. 결론 : 본 연구 결과, 컬러렌즈가 폭주부족안의 근거리 읽기 능력에 긍정적인 영향을 주는 것을 확인하였 다. 추후 컬러렌즈 착용 후의 자각증상에 대한 설문과 폭주 및 조절 검사의 결과를 추가적으로 진행한다면 더 다양한 결과로 분석할 수 있을 것으로 기대된다.

Anopheles sinensis is an important vector for Plasmodium vivax and thus has been targeted with pyrethroids in Republic of Korea. Using the direct contact mortality bioassay, two field populations of An. sinensis from Ganghwa-gun and Goyang-si were characterized for their resistance to pyrethroids with RR ratio values (Resistant ratio to imidacloprid) of 125.6 to 203.8 folds and 80.0 to 120 folds, respectively. Genomic DNA was used for Allele-specific PCR (AS-PCR) genotyping of the sodium channel genes to detect L1014S mutations. The homozygous susceptible Leu/Leu genotype in Ganghwa-gun and Goyang-si was 5.0% and 11.3% and the resistance genotypes were 95.0% and 88.7%, respectively. The homozygous Phe/Phe resistance genotype was the most prevalent as 35.4% in Ganghwa-gun and 44.0% in Goyang-si. Hence, this study suggests that malaria vector control programs should be prepared for the management of pyrethroid insecticide resistance.

This study is focused on the synthesis of urea and amide derivatives particularly, since the amide moiety is an essential binding group at the binding site. Urea derivatives 3-7 and 13-14 were obtained by reaction of 2-aminopyrimidines and other amines with diverse isocyanates in pyridine as a solvent under reflux. The urea derivatives were obtained in low yield because of the highly electron deficient nature of the amino group of the 2-aminopyrimidine. Amide derivatives 8-10 were obtained in moderate yields by reaction of compound 1 with aryl chloride derivatives. Also, arylamine 11 was synthesized by Buchwald-Hartwig amination in moderate yields. Most of the compound did not show good activity against A375P melanoma cells, compared with Sorafenib as control compound.

In order to improve the thermal stability of PAN-based electrospun fibers, AP-PER-MEL and TiO2 were added in to the fibers as additives. The polymer composite with uniformly mixed additional agents was obtained. In case of non-treated sample, the fibers were burn off completely with high rate within 620℃. But in case of treated samples (EF-M and EF-MT), it is sure that the thermal stability was improved by studying TGA data and ISO flammability test about 20 and 30%, respectively. A synergy effect of adding two kinds of agents (AP-PER-MEL and TiO2) into PAN-based electrospun fibers was confirmed. Through SEM images, it is confirmed that the fiber shape can be kept even after addition of agents (AP-PER-MEL and TiO2). Finally the thermal stability of fibers was largely developed with keeping the nature of PAN-based fibers effectively.

A nanocomposite consisting of Fe3O4 and MWCNT was produced via sol-gel technique using FeCl3 along with MWCNT by calcination at 300℃. The degradation effect of rhodamine B dye has been investigated under UV illumination in a darkroom. The degradation reaction was studied by monitoring the discoloration of dye as a function of irradiation time using UV-visible spectrophotometeric technique. The Fe3O4-MWCNT samples have continuous degradation ability under the UV illumination with the first order kinetics and the dye removal was better than in the pristine Fe3O4. The resultant composite catalyst was found to be efficient for the photo-Fenton reaction of the dye.

Development of white light emitting materials has been an interesting area for scientists and scientists have developed many organic, polymer and inorganic materials for white electroluminescent devices. Among them, single component small molecules gave best results in terms of efficiency, simplicity of device fabrication, and CIE values. Therefore, this review covers detailed discussion about syntheses of small compounds used in white organic light emitting devices until 2007.