• 한국과학교육학회지
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• 제16권1호
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• pp.35-40
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• 1996

Teaching materials are an important aspect to decide the quality of education. Science teaching materials include textbook, workbook, worksheet, OHP materials, posters, computer softwares, experimental equipments, slides, video tapes, and other audio-vidual materials. This comparing research is based on the contemporary teaching materials used in elementary schools of the United States and Korea in 1990s. The results of this study are : 1. The United States has more elementary science teaching materials such as posters, worksheets, computer softwares, OHP materials than Korea. Both countries developed elementary science textbooks, activity books, video tapes, science reading materials, and experimental equipments. 2. The frequancy of using these science teaching materials in Korea is bigger than that in the United States. In Korean elementary science classes, most of instructions are progressed by experimental activities. Korean elementary science textbooks are mostly consisted of science activities, but those of the United States includes science information, science related jobs, STS articles and some portion of science activities. 3. Experimental equipments of the United States are stronger than those of Korea. Various and excellent elementary science teaching materials such as computer softwares, posters, audio-vidual materials, and experimental equipments should be developed and used in elementary science classes for better elementary science education.

• Molecular & Cellular Toxicology
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• 제2권2호
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• pp.134-140
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• 2006

Because shipyard workers are involved with various manufacturing process in shipyard industry, and they are exposed to many kinds of hazardous materials. Especially, painting workers were exposed polycyclic aromatic hydrocarbons (PAH). This study was conducted to assess the exposure status of PAH based on job-exposure matrix. We investigated the effect of genetic polymorphism of xenobiotic metabolism enzymes involved in PAH metabolism on levels of urinary metabolite. A total of 93 shipbuilding workers were recruited in this study. Questionnaire variables were age, sex, use of personal protective equipment, smoking, drinking, and work duration. The urinary metabolite was collected in the afternoon and corrected by urinary creatinine concentration. The genotypes of CYP1A1, CYP2E1, GSTM1, GSTT1 and UGT1A6 were investigated by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods with DNA extracted from venous blood. Urinary 1-OHP levels were significantly higher in direct exposured group (spray and touch-up) than indirect exposed group. Urinary 1-OHP, concentration of the high exposure with wild type of UGT1A6 was significantlyhigher than that of the high exposure with other UGT1A6 genotype. In multiple regression analysis of urinary 1-OHP, the regression coefficient of job grade was statistically significant (p<0.05) and UGT1A6 was not significant but a trend (p<0.1). The grade of exposure affected urinary PAH concentration was statistically significant. But genetic polymorphism of xenobiotics metabolism enzymes was not statistically significant. Further investigation of genetic polymorphism with large sample size is needed.

• Asian Pacific Journal of Cancer Prevention
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• 제16권9호
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• pp.4037-4040
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• 2015

Objective: To explore the clinical efficacy and toxic and side effects of recombinant human endostatin (rhendostatin/endostar) combined with chemotherapy in the treatment of advanced gastric cancer. Materials and Methods: A total of 70 patients with advanced gastrointestinal adenocarcioma confirmed by histopathology and/or cytological examination were divided into group A (37 patients) and group B (33 patients). Patients in group A were given intravenous drip of 15 mg endostar added into 500 mL normal saline, once every other day until the cessation of chemotherapy or patients' maximal tolerance to chemotherapy. Patients in group B received chemotherapy alone. Two groups selected the same chemotherapy regimens. FOLFIRI scheme: 90-min intravenous drip of $180mg/m^2$ irinotecan, intravenous drip of $200mg/m^2$ calcium folinate (CF) and $400mg/m^2$ 5-fluorouracil (5-Fu) on d1, and continuous intravenous pumping of 2 $400mg/m^2$ 5-Fu for 46 h. FOLFOX4 scheme: intravenous injection of $85mg/m^2$ oxaliplatin (L-OHP), $200mg/m^2$ calcium folinate (CF) and $400mg/m^2$ 5-FU on d1 for 2 h, and then continuous intravenous pumping of 2 $400mg/m^2$ 5-Fu for 46 h. XELOX scheme: oral administration of 1 $500mg/m^2$ xeloda (or tegafur 50~60 mg) in twice during d1~14 and intravenous drip of $135mg/m^2$ L-OHP on d1 for 2 h. The modified FOLFOX scheme: intravenous injection of $135mg/m^2$ L-OHP on d1 for 2 h, $200mg/m^2$ CF and 1.0 g tegafur during d1~5. Whereas, control Group B received chemotherapy regimens which were same as Group A, but no addition of endostar. Before chemotherapy, patients were given intravenous injection of 8 mg ondansetron, intramuscular injection of 10 mg metoclopramide and 20 mg diphenhydramine for prevention of vomiting, protection of liver and stomach as well as symptomatic supportive treatment. One cycle was 21 d, 4~6 cycles in total. The efficacy was evaluated every 2 cycles. Results: 32 patients in Group A could be evaluated, and the response rate (RR) and disease control rate (DCR) were 59.38% and 78.13%, respectively. 31 patients in Groups could be evaluated, and the RR and DCR were 32.26% and 54.84%, respectively. The differences between 2 groups were significant. The toxic effects include myelosuppression, gastrointestinal reaction, fatigue, cardiotoxicity and peripheral neurotoxicity. Conclusions: Preliminary observations show that endostar (once every other day) combined with chemotherapy is effective in the treatment of advanced gastrointestinal cancer, with low toxic effects, good tolerance, deserving further study.

• 한국초지조사료학회지
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• 제15권3호
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• pp.222-230
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• 1995

This study was canied out to ddermine optimum areas for various sizes of land coverage of the farm machinery utilization in 1993-1994. A kind of machinery size and work systems were classed as the power tiller of 10HP+man power, the tractor of 35~46HP (tractor of 64~86HP and attachment were leased to harvest work), 64-86HP+ attachment and 90- 105HP+ attachment, respectively. \ulcornerhe results are summarized as follows: 1. The optimum areas of tractors of 90~105HP, 64~86HP and the power tiller of lOHP were estimated as 21.9 (corn-rye cropping system)- 26.9ha (sorghum $\times$ sudangrass - rye cropping system), 14.7 - 22.8ha and 1.2 - 1.61ha, respectively. The break-even-point areas of the tractors of 90-105HP. 64-86HP and the power tiller of lOHP were 16.6 (corn-rye cropping system)- 19.9ha (sorghum $\times$ sudangrass - rye cropping system), 12.5 - 16.lha and 0.12-0.13ha, respectively. 2. The optimum areas (land sizes, annual field capacity) for 50 cows by feeding rate(%) of roughage to concentrate were 6.8ha, 13.6ha in the 4060, 8.5ha, 17.0ha in the 5050 and 10.2ha, 20.4ha in the 60:40, and in case of 30 cows, it were 4.lha, 8.2ha in the 40:60, respectively. In the former case for the form of work system was the trador of 90-105HP+attachment and 64~86HP+ attachment, and the latter was the tractor of 35~46HP (tractor of 64~86HP and attachment were leased to harvest work) and 64-86HP+ attachment. 3. Productiori cost for corn-rye cropping system reducted to 51.8% in 102.9 wonkg dry matter the tractor of 90~ 105HP+ attachment with 213.4 wonkg dry matter the power tiller of 10HP+ man power.

• 한국발생생물학회지:발생과생식
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• 제17권4호
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• pp.421-426
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• 2013

In this study, oocyte steroidogenesis are investigated in relation to oocyte development in the starry flounder, Platichthys stellatus, a marine multiple spawner. Vitellogenic (0.52 and 0.55 mm oocyte diameter) and mature oocytes (0.63, 0.66 and 0.71 mm oocyte diameter) were incubated in vitro in the presence of $[^3H]17{\alpha}$-hydroxyprogesterone ($[^3H]17{\alpha}$-OHP) as a precursor. Steroid metabolites were extracted from the incubated media and oocytes, the extracts were separated and identified by thin-layer chromatography (TLC), high performance liquid chromatography (HPLC) and gas chromatographymass spectrometry (GC-MS). The major metabolites produced from $[^3H]17{\alpha}$-OHP were androgens [androstenedione ($A_4$) and testosterone (T)] and estrogens [$17{\beta}$-estradiol ($E_2$) and estrone ($E_1$)] and progestins [$17{\alpha},20{\alpha}$-dihydroxy-4-pregnen-3-one ($17{\alpha}20{\alpha}P$) and $17{\alpha},20{\beta}$-dihydroxy-4-pregnen-3-one ($17{\alpha}20{\beta}P$)] in vitellogenic and mature oocytes. The results from this study suggest the potential roles of $E_1$ in the oocytes with diameter 0.52-0.71 mm, $17{\alpha}20{\alpha}P$ and $17{\alpha}20{\beta}P$ at the oocytes of 0.63, 0.66 and 0.71 mm.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제35회 추계학술대회논문집
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• pp.177-180
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• 2010

고압관, 가압관, 발사관으로 구성된 Ballistic Range의 일종인 2단식 경가스 총을 사용하여 초음속 액체 제트의 분무 특성을 연구하였다. 135 bar의 압축공기는 고압관과 가압관 사이에 OHP필름으로 구성된 격막을 파열시킨 후 가압관의 발사체를 약 250 m/s의 속도로 가속하였다. 가속된 발사체는 액체 저장부에 충돌하여 액체를 초고압으로 가압한 후 초음속으로 분사시키며, 특히 초음속 액체 제트는 미립화된 다중 제트의 형태를 나타내고 액체 제트 전방 영역에서 충격파를 수반한다. 다양한 분사 노즐의 기하학적 형상에 대한 분무시험결과 초음속 액체 제트의 속도와 충격파 각도가 각각 다르게 생성되었으며, L/d가 9.9, 11.9, 23.8의 조건에 대하여 L/d가 23.8의 경우에 액체 제트의 분사속도가 마하수 1.53으로 가장 낮게 측정되었다.

• 한국발생생물학회지:발생과생식
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• 제12권1호
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• pp.107-112
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• 2008

점망둑의 난모세포 성숙과정에서 생성되는 주요 성 스테로이드 호르몬, $C_{21}$-스테로이드를 분석하고자 전구물질 $^3H-17{\alpha}hydroxyprogesterone$ ($^3H-17{\alpha}OHP$)를 성숙기 난모세포(난경 $0.74{\sim}0.97\;mm$) 배양초기에 첨가하여 24시간 배양하였다. 스테로이드 대사물질 분석과 동정은 thin layer chromatography와 gaschromatography-mass spectrometry로 이루어졌다. $^3H-17{\alpha}20{\alpha}P$로부터 생성된 주요 성 스테로이드 대사물질은 $17{\alpha}$-hydroxy, $20{\alpha}$-dihydroprogesterone ($17{\alpha}20{\alpha}P$)와 $17{\alpha}$-hydroxy, $20{\beta}$-dihydroprogesterone ($17{\alpha}20{\beta}P$)로 확인되었다. 이들 대사물질은 난경 0.80 mm 이상에서 관찰되었으며, GVBD (germinal vesicle breakdown) 유도 효능 테스트에서 점망둑의 난모세포는 $17{\alpha}20{\beta}P$에 더 민감하게 반응하였다. 이러한 결과는 점망둑의 난소성숙 과정에 $17{\alpha}20{\alpha}P$와 $17{\alpha}20{\beta}P$이 모두 관여하나, MIS (maturation inducing steroid)로서의 가능성은 $17{\alpha}20{\beta}P$이 더 큰 것으로 관찰되었다.

• 한국수산과학회지
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• 제48권4호
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• pp.483-488
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• 2015

We studied oocyte steroidogenesis in the blackfin flounder Glyptocephalus stelleri as a region-specific species, in the East Sea of Korea during the spawning season. Maturing oocytes (0.76, 0.82, 0.88, and 0.91 mm in oocyte diameter) were incubated in vitro in the presence of [$^3H$] $17{\alpha}$-hydroxyprogesterone ($[^3H]17{\alpha}$-OHP) as a precursor. Steroid metabolites were extracted from the incubated medium and oocytes, and the extracts were separated and identified by thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC) and gas chromatographymass spectrometry (GC/MS). The major metabolites produced from $[^3H]17{\alpha}$-OHP were androgens [androstenedione (A4) and testosterone (T)] and estrogens [$17{\beta}$-estradiol (E2) and estrone (E1)] and progestins [$17{\alpha},20{\alpha}$-dihydroxy-4-pregen-3-one ($17{\alpha}20{\alpha}P$) and $17{\alpha}20{\beta}$-dihydroxy-4-pregnen-3-one ($17{\alpha}20{\beta}P$)] in maturing oocytes. The metabolic rate of $17{\alpha}20{\beta}$ was elevated (29.04%) in oocytes measuring 0.88 mm (nucleus migration stage following the induction of germinal vesicle breakdown), but was very low in oocytes measuring 0.76, 0.82, and 0.91 mm (0.42, 0.67, and 2.62%, respectively). From these results, we suggest that $17{\alpha}20{\beta}P$ acts as a maturation-inducing steroid in the blackfin flounder.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 추계학술대회
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• pp.356-359
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• 2017

교육부의 운영계획에 따라서 학교당 1~2개 교실에 전자칠판(IWB, Interactive White Board)이 보급되었다. 따라서, 두상투영기(OHP, Overhead Projector)와 스크린 대신에 실물화상기와 전자칠판이 그 역할을 대신하게 되었다. 하지만 촬상소자와 디스플레이 장치의 발전 속도를 따라가지 못하고, 활용도가 떨어지는 경우가 많았다. 본 연구에서는 스마트폰의 카메라를 이용하여 고해상도의 이미지를 획득할 수 있도록 연구한다. 획득한 고해상도의 이미지를 전자칠판이나 대형 TV로 무선 통신으로 지연시간 없이 전송할 수 있도록 와이기그(WiGig, Wireless Gigabit) 기술을 이용한다. 또한 스마트폰 카메라에 넓은 화각(FOV, Field of View)의 렌즈를 탑재하여 출시하는 것에 반하여, 현미경 렌즈를 이용하여 스마트폰으로 특정 부분을 400배까지 확대하여 관찰할 수 있도록 한다. 본 연구결과로 교육 및 연구 현장에서 실시간 400배 확대의 활성화 자료로서 사용될 것이다.

• Annals of Occupational and Environmental Medicine
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• 제35권
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• pp.6.1-6.15
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• 2023

Background: Polycyclic aromatic hydrocarbons (PAHs) are occupational and environmental pollutants generated by the incomplete combustion of organic matter. Exposure to PAHs can occur in various occupations. In this study, we compared PAH exposure levels among occupations based on 4 urinary PAH metabolites in a Korean adult population. Methods: The evaluation of occupational exposure to PAHs was conducted using Second Korean National Environmental Health Survey data. The occupational groups were classified based on skill types. Four urinary PAH metabolites were used to evaluate PAH exposure: 1-hydroxypyrene (1-OHP), 2-naphthol (2-NAP), 1-hydroxyphenanthrene (1-OHPHE), and 2-hydroxyfluorene (2-OHFLU). The fraction exceeding the third quartile of urinary concentration for each PAH metabolite was assessed for each occupational group. Adjusted odds ratios (ORs) for exceeding the third quartile of urinary PAH metabolite concentration were calculated for each occupational group compared to the "business, administrative, clerical, financial, and insurance" group using multiple logistic regression analyses. Results: The "guard and security" (OR: 2.949; 95% confidence interval [CI]: 1.300-6.691), "driving and transportation" (OR: 2.487; 95% CI: 1.418-4.364), "construction and mining" (OR: 2.683; 95% CI: 1.547-4.655), and "agriculture, forestry, and fisheries" (OR: 1.973; 95% CI: 1.220-3.191) groups had significantly higher ORs for 1-OHP compared to the reference group. No group showed significantly higher ORs than the reference group for 2-NAP. The groups with significantly higher ORs for 1-OHPHE than the reference group were "cooking and food service" (OR: 2.073; 95% CI: 1.208-3.556), "driving and transportation" (OR: 1.724; 95% CI: 1.059-2.808), and "printing, wood, and craft manufacturing" (OR: 2.255; 95% CI: 1.022-4.974). The OR for 2-OHFLU was significantly higher in the "printing, wood, and craft manufacturing" group (OR: 3.109; 95% CI: 1.335-7.241) than in the reference group. Conclusions: The types and levels of PAH exposure differed among occupational groups in a Korean adult population.