• 한국산업보건학회지
• /
• 제25권1호
• /
• pp.27-35
• /
• 2015

Objectives: To investigate safety and health management, conditions in factories or facilities handling radiation-generating devices and radioactive isotopes were reviewed in terms of regulations of radiation safety control in Korea. Radiation exposure levels generated at those facilities were directly measured and evaluated for establishing an effective safety and health management plan. Methods: Government organizations with laws and systems of radiation safety and health were investigated and compared. There are three laws governing radiation-related employment such as occupational safety and health acts, nuclear safety acts, and medical service acts. We inspected 12 workplaces as research objects:four workplaces that manufacture and assemble semiconductor devices, three non-destructive inspection workplaces that perform inspections on radiation penetration, and five workplaces in textile and tire manufacturing. Monitoring of radiation exposure was performed through two methods. Spatial and surface monitoring using real-time radiation instruments was performed on each site handling radiation generating devices and radioactive isotopes in order to identify radiation leakage. Results: According to the occupational safety and health act, there is no legal obligation to measure ionizing radiation and set dose limits. This can cause confusion in the application of the laws, because the scopes and contents are different from each other. Surface dose rates in radiation generating devices such as implanters, thickness gages and accelerators, which were registered according to nuclear safety acts, using surveymeters, and seven of 36 facilities(19.4%) exceeded the international standards for surface radiation dose of $10{\mu}Sv/hr$. Conclusions: The results showed that occupational health and safety acts require a separate provision for measuring and assessing the radiation exposure of workers performing radiation work. Like noise, ionizing radiation will also periodically be controlled by including it in the object factors of work-environment measurement.

• 한국수정란이식학회지
• /
• 제17권3호
• /
• pp.239-249
• /
• 2002

Embryos derived from pig oocytes matured in mSOF are able to develop to blastocysts after IVF. Experiment 1 evaluated the effects of two maturation media (TCM-199 vs mSOF) on maturation rate, fertilization parameters, including penetration, polyspermy, male pronuclear formation, and the mean number of sperm penetrated per oocyte. Experiment 2 and Experiments 3 examined the effects of two maturation media on zona pellucida solubility and cortical granule distribution by transmissible electron microscopy, respectively. Experiment 4 assessed the effects of two maturation media on the in vitro embryo cleavage rate and development to blastocyst. Lastly, experiment 5 examined the cell number of blastocyst. An effect of media (P<0.05) was detected for mSOF on the mean number of sperm per oocyte. In TCM group, zona digestion time (196.5$\pm$15.5 vs 131.6$\pm$20.1 before IVF, 397.5$\pm$30.3s vs 185.3$\pm$16.4s after IVF, p<0.05) was higher in TCM-199 group. No significant effects of media was observed on cortical granule distribution between two groups by TEM. An effect (P<0.05) was observed on embryo development to blastocyst (16% vs 8%) but not on cleavage rates. No significant effects of media was observed on total cell number of blastocyst. We found that the high mean number of sperm penetrated per oocyte and the weaker zona pellucida on the basis of the digestion time was shown in pig oocytes matured in mSOF, however, porcine oocyte maturation with supplemented synthetic oviduct fluid medium (mSOF) resulted in blastocyst cell numbers comparable to those observed with Tissue Culture Medium 199.

• 한국수정란이식학회지
• /
• 제13권2호
• /
• pp.139-145
• /
• 1998

In the present study, effects of interleukin-2 (IL-2), a differentiator and proliferator of T-cells, on nuclear maturation and sperm penetration of bovine oocytes was examined in a serum-free or serum-containing medium. Basic medium was used TCM-199 supplemented with 2.2g / ι sodium bicarbonate, 100 i.u. /rnl penicillin. 100$\mu$g /ml streptomycin, 0.25$\mu$g/ml Fungizone, this medium treated with FCS and IL-2. In experiment 1, we examined the effect of the addition of 0, 1, 5, 10 or 15nM /ml IL-2 to tissue culture medium (TCM-199) on nuclear maturation of oocytes Development of oocytes to the Metaphase II (M II) stage (%) was significantly (P<0.05) higher at 1, 5,10 and 15 nM /ml IL-2(54.2, 73.5, 80.0 and 69.6%, respectively) than at 0 nM /ml IL-2(35.7%). In experiment 2, we examined the effect of the addition of l0nM /ml IL-2 or 5% FCS in oocyte maturation. Nuclear maturation rates were significantly(P<0.05) higher l0nM /ml IL-2(80%) than non-treatment(35.7%) and 5% FCS(63.6%) treatment. On the other hand, there were no significant difference in the proportion of oocytes developed to the 2-cell stage after addition of IL-2 and/or FCS. These results suggest that IL-2 supports nuclear maturation of bovine immature oocytes in vitro. Serum-free maturation system using IL-2 might be useful for evaluation of various factors on oocyte maturation.

• Journal of Pharmaceutical Investigation
• /
• 제35권6호
• /
• pp.403-409
• /
• 2005

For transdermal delivery of large molecular drugs such as vaccine and protein drugs, novel microneedle treatment device with roll was designed. The roll dimension is 1.43 cm diameter and 2.8 cm perimeter. Total number of microneedle on the roll is 3,360 with $230\;{\mu}m$ height and $740\;{\mu}m$ distance. The pore with $150\;{\mu}m$ depth and $35\;{\mu}m$ diameter on the skin was made by the designed microneedle device. This system could be achieved without pain. The permeation rates of FITC labelled ovalbumin (FITC-OVA, molecular weight: 45,000 g/mol) as a model protein were determined by modified Franz diffusion cells using skins of hairless mice or SD rats which were treated by using microneedle device two or four times. The average penetration fluxes of model protein increased from 674 to $872\;{\mu}g/cm^{2}{\cdot}hr$ as the number of treatment to make pore increased from two to four times. In conclusion, we confirmed the possibility of using the designed microneedle treatment device for transdermal delivery of the large molecular drugs.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권6호
• /
• pp.2765-2769
• /
• 2014

Background: Oesophageal cancer presents high incidence rates in the so-called Brazilian-Uruguayan belt. Materials and Methods: The present study included 1,170 participants (234 cases and 936 controls) which were analyzed by unconditional multiple logistic regression in order to examine risk of oesophageal squamous cell carcinoma (OESCC) associated with several food groups. Results: Boiled red meat (OR 2.59, 95%CI 1.69-3.97), lamb meat (OR 1.64, 95%CI 1.07-2.51), processed meat (OR 1.49, 95%CI 1.01-2.21), whole milk (OR 1.78, 1.19-1.68), fresh vegetables and fruits (OR 0.42, 95%CI 0.27-0.63), mate consumption (OR 2.04, 95%CI 1.32-3.16), and black tea (OR 0.10, 95%CI 0.04-0.28) were significantly associated with risk of OESCC. Conclusions: Hot beverages (mate) and hot foods (boiled meat) appear to be important determinants in the risk of OESCC, allowing the penetration of carcinogens in tobacco and alcohol into the oesophageal mucosa.

• 대한치과보철학회지
• /
• 제32권2호
• /
• pp.225-233
• /
• 1994

The restorations of the severely damaged teeth by post core have been increased with the developement of endodontic procedures. But high failure rates of these procedures being reported, various restorative modifications were induced for successful treatments. Cast post-core and prefabricated post with core buildups are choice of treatment. The main causes of failure of the restorations are the fracture of post and core, root fracture, and recurrent caries due to microleakage. Recently, the acid etching technique and the use of dentin bonding agent at tooth surface to reduce the possible microleakage at the tooth-restoration interfaces were introduced. The object of this study was to measure and compare the microleakage by the types and cementation methods of post-core. For this study, forty extracted human anterior teeth were selected for specimen. After cleansing and routine endodontic procedures, anatomic crowns of each specimen were removed at the level of 2mm above the cementoenamel junction. Canals were preparated for post insertion and specimens were divided into four groups randomly. Post-cores were fabricated according to method for each group. Microleakage was measured by length of dye penetration at the tooth-restoration interfaces with measuring microscope at 50 magnification. Oneway ANOVA and t-test were performed for statistical analysis of resulting data. The following results were obtained from this study. 1. There wert significant statistical differences in degree of microleakage between each group (p<0.01). 2. Cast post-core cemented with ZPC (Group I) showed the most severe microleakage pattern$(1.5547{\pm}0.0872mm)$, and cast post-core cemented with adhesive resin cement after tooth surface treatment with dentin bonding agent (Group II) showed the least microleakage $(0.1497{\pm}0.0872mm)$. 3. Group IV revealed less dye penetrations than group III, but no statistical significance was seen between two groups.

• 한국건설관리학회:학술대회논문집
• /
• 한국건설관리학회 2004년도 제5회 정기학술발표대회 논문집
• /
• pp.571-574
• /
• 2004

최근 건설업체는 주택상품 기획시 홈네트워크를 차별화 요소로 사용하고 있으나 공급자로서의 역할만 하고 있을 뿐 앞으로 창출될 거대한 규모의 홈네트워크 시장에 대한 적절한 수익모델을 발견하지 못하고 있는 실정이다. 관련업계에서는 유비쿼터스(Ubiquitous)시대를 대비하여 국가성장동력으로 삼으려는 정부의 정책하에 관련 가전, 통신, 방송업계의 시장선점을 위한 각축이 진행중이다 한편 인구구조 및 라이프스타일의 변화 등으로 인해 디지털화된 주거환경에 대한 소비자의 요구도 높아지고 있다 그러나 현재 거주자들에게 제공되고 있는 대부분의 홈디지털 서비스는 정책적 뒷받침의 부족과 분양가상승 우려 등으로 초보적인 수준에 머물러 있는 것으로 조사되었다. 미래주거환경을 선도해야할 건설사들에게 고객특성별 수요분석을 통한 품목 개발과 적극적인 수용의지가 요구되고 있다.

• Radiation Oncology Journal
• /
• 제11권1호
• /
• pp.133-141
• /
• 1993

From Jan.1982 to Dec.1990, 77 patients with rectal cancer were treated with curative surgical resection followed by postoperative adjuvant irradiation alone or combined with chemotherapy at the Department of Radiation Oncology, Korea University Hospital (KUH). Fifty-four (54/77, $70.1{\%}$) patients underwent abdominoperineal resection , 20 (20/77, $26{\%}$) patients underwent low anterior resection, and 3 (3/77, $3.9{\%}$,) patients had wide excision only. Thirty-nine (39/77, $50.5{\%}$) received sequential chemotherapy (2 cycles to 12 cycles). The 5-year survival rate for the entire group was $43{\%}:\;78.2{\%}$ in B2+B3, $39.4{\%}$ in stage C1+C2+C3. Survival rates decreased with increasing penetration of the bowel wall by tumor and the presence of regional lymph node metastasis. Those patients survival who underwent an abdominoperineal resection also experienced a significant decrease in compared to low anterior resection ($23.1{\%}$ vs. $63.8{\%}$ in 5-year survival, p <0.05). Local failure occurred in 15 ($19.5{\%}$) out of the 77 patients overall, 1($5.3{\%}$) of 19 in stage B2+B3, and 14 ($24.1{\%}$,) of 58 in stage C1+C2+C3. Presacral area was most common site of local failufre (8/17, $47.1{\%}$). Distant failure occurred in 13 ($16.9{\%}$) of 77 patients. The most frequent site of distant failure was the lung followed by the liver, the bone, and the brain. Combined locoregional and distant failure occurred in 2 ($2.6{\%}$) of 77 patients. Pathological confirmation of perirectal fat and/or regional lymph node involvement resulted in a singificant decrease in survival and local control.

• 한국가축번식학회지
• /
• 제10권1호
• /
• pp.91-99
• /
• 1986

This experiment was undertaken to examine the effects of HIS treatment on the motility and acrosome reaction of frozen bovine spermatozoa and to test their abilities to interact with zona-free hamster eggs in vitro. Also, in vitro results were compared with those of bull's fertility in AI. The frozen semen from four Holstein bulls were exposed to HIS-DM for 5 minutes after thawing and then preincubated for 60 minutes in DM prior to insemination. The hamster eggs were mounted, fixed and stained 6 hours after exposure to boving spermatozoa and examined under a phase-contrast microscope. 1. The sperm motility expressed as a mobility index dro, pp.d significantly from 60-75 to 12-24 after exposure to HIS-DM, but increased in 32 to 41 at insemination. Bull C showed a low motility index than those of the orher bulls. The percentage of acrosome reaction by staining procedure were increased by HIS-DM treatment but did not change during 7 hours incubation period in DM. 2. The overall percentage of hamster eggs interacting with bull spermatozoa was 56.3%, 58.3%, 66.6% and 70.0%, respectively. Although there was no significant difference among bulls in the penetration rate of spermatozoa into hamster eggs, high proportions of eggs interacted with spermatozoa from Bull C and D than those from Bull A and B. 3. The conception rates (60-90 day RP) resulting from AI were 62.5%, 67.5% and 70.9% for Bull A, B and C, respectively. These results were in good agreement with the invitro results that the proportions of bull sperm-egg interction were greater for Bull C than for Bull A and B.

• Composites Research
• /
• 제28권6호
• /
• pp.378-382
• /
• 2015

인구밀도가 증가하고 매년 고층건물의 수가 늘어나고, 대부분의 사람들이 하루에 엘리베이터를 이용하는 시간이 많아짐에 따라 일상생활 속에서 엘리베이터는 중요한 역할을 하고 있다. 매년 고층건물이 늘어남에 따라 고속 고층 승강기의 기술 요구 수준도 높아져 가고 있다. Carbon-fiber-reinforced plastics (CFRPs)는 높은 강성과 경량화 및 낮은 마찰력 등을 장점으로 하고 있으며, 엘리베이터용 wire rope에 매우 적합한 재료이다. 본 논문에서는 CFRP의 특성을 분석하기 위하여, wire rope와 CFRP UD의 인장 강도 및 수치 해석을 통한 벤딩 해석 비교를 진행하였다.