• 한국수정란이식학회지
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• 제31권2호
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• pp.117-121
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• 2016

Although piglets have been delivered by embryo transfer (ET) with in vitro produced (IVP) embryos and blastocysts, a success rate has still remained lower level. Unlike mouse, human, and bovine, it is difficult to a production of piglets by in vitro fertilization (IVF) because of an inappropriate in vitro culture (IVC) system in pig. Therefore, the present study was conducted to investigate whether minimized exposure time in IVC can improve the pregnancy and delivery rates of piglets. Immediately after IVM, the oocytes were denuded and co-incubated with freshly ejaculated boar semen for 3.5 to 4 hours at $38.5^{\circ}C$ under 5% $CO_2$ in air. To avoid long-term exposure to in vitro state, we emitted IVC step after IVF. After that the presumptive zygotes were transferred into both oviducts of the surrogate on the same day or 1 day after the onset of estrus. Pregnancy was diagnosed on day 28 after ET and then was checked regularly every month by ultrasound examination. The 3 out of 4 surrogates were determined as pregnant (75%) and a total of 5 piglets (2 females and 3 males) were delivered at $118.3{\pm}2.5$ days of pregnancy period. In conclusion, a short-term exposure time may be an important factor in the production of IVP-derived piglets. It can be apply to the in vitro production system of transgenic pig by IVF, cloning, and pronuclear microinjection methods.

• 한국환경성돌연변이발암원학회지
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• 제22권3호
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• pp.187-198
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• 2002

Chlorpyrifos is an organophosphate insecticide and one of the most commonly and widely used insecticide. However, a little known about the dermal risk of chlorpyrifos on human being. Therefore, this study was conducted for the dermal risk assessment after exposure to chlorpyrifos in Korean farmers. First, skin irritation by chlorpyrifos (10 mg/$\textrm{cm}^2$, 50 mg/$\textrm{cm}^2$, 100 mg/$\textrm{cm}^2$, 250 mg/$\textrm{cm}^2$ in acetone) was determined in rabbits for 5 days considering the usage of chlorpyrifos short term highly exposure. The index of skin irritation by chlorpyrifos was increased in each dose and length of exposure dependent manners. Next, using benchmark dose (BMD$_{5}$) approach, the dose-response relationship was assessed to calculate the reference dose (RfD). The value of RfD was 2.84 $\mu\textrm{g}$/kg/day from 142.16 $\mu\textrm{g}$/kg/day BMD5 value divided uncertainty factor 50. Finally, we assessed human dermal risk of chlorpyrifos with exposure level and RfD. Skin absorbed levels were assumed with several exposure scenarios encounting the circumstances of exposure that application method, protection equipment and cloth, exposure time and exposure frequency during chlorpyrifos spraying. By the comparison of skin absorbed dose with the reference dose, it was identified that risk values (risk index) to skin chlorpyrifos exposure were 0.958 from the point of above results and it was recommended that the occurrence of hazard effect (skin irritation toxicity) of chlorpyrifos would not be expected. Risk index was smaller than 1 in the case of spraying vehicle mounted application, 1hour exposure time and wearing protective cloth exposure. Whereas, risk index was above 1 in the case of hand-held application, 2hour exposure time and wearing common cloth. Comparing two kinds of application method, total risk index of the hand held application (1.67) was higher than vehicle mounted (0.27). Therefore, chlorpyrifos skin exposure was mainly affected by application equipment and applied form. The results of risk assessment on the human dermal toxicity of chlorpyrifos should be required to control in keeping safety rules, skin surface area available for contact, spraying time ,and spraying frequency.y.

• Journal of Animal Science and Technology
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• 제62권2호
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• pp.208-217
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• 2020

Heat stress negatively affects cattle productivity by reducing feed intake. In the present study, we assessed if the rumen microbiome composition of Hanwoo steers was altered by exposure to heat stress. Rumen samples were collected from four Hanwoo steers that were individually housed in climate-controlled chambers with 60% humidity and environmental temperatures of: 1) 15℃ (0-day group), 2) 35℃ for 3 days (3-day group), and 3) 35℃ for 6 days (6-day group). The total community DNA of samples was extracted, and 997,843 bacterial and 1,508,770 archaeal sequences were analyzed using next-generation sequencing. Assessment of the relative abundances revealed 15 major phyla of which Bacteroidetes was found to be the most dominant. After 3 days of heat stress exposure there were no significant changes in the rumen microbiome composition, except for a decrease in the Planctomycetes. However, after 6 days of heat stress exposure, we found that the relative abundance of fibrolytic Ruminococcaceae had decreased while that of lactate-producing Lactobacillaceae and amylolytic Prevotella and Ruminobacter had increased. The normal rumen microbiome of Hanwoo cattle was shown to be disrupted after 6 days of heat stress, which led to the decrease in fibrolytic bacteria that are sensitive to low pH and the increase in both lactate-producing and amylolytic bacteria. We have demonstrated that the microbiome composition of the rumen is affected by acute heat stress. Our findings may contribute to the development of different feeding strategies to restore heat stress-induced disruption of the rumen microbiome.

• Safety and Health at Work
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• 제14권3호
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• pp.303-308
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• 2023

Background: Occupational workers at altitudes are more prone to falls, leading to catastrophic outcomes. Acrophobia, height-related anxiety, and affected executive functions lead to postural instabilities, causing falls. This study investigated the effects of repeated virtual height exposure and training on cognitive processing and height-related anxiety. Methods: Twenty-eight healthy volunteers (age 20.48 ± 1.26 years; mass 69.52 ± 13.78 kg) were recruited and tested in seven virtual environments (VE) [ground (G), 2-story altitude (A1), 2-story edge (E1), 4-story altitude (A2), 4-story edge (E2), 6-story altitude (A3), and 6-story edge (E3)] over three days. At each VE, participants identified occupational hazards present in the VE and completed an Attitude Towards Heights Questionnaire (ATHQ) and a modified State-Trait Anxiety Inventory Questionnaire (mSTAIQ). The number of hazards identified and the ATHQ and mSTAIQ scores were analyzed using a 7 (VE; G, A1, A2, A3, E1, E2, E3) x 3 (DAY; DAY 1, DAY 2, DAY 3) factorial repeated measures analysis of variance. Results: The participants identified the lowest number of hazards at A3 and E3 VEs and on DAY 1 compared to other VEs and DAYs. ATHQ scores were lowest at G, A1, and E1 VEs. Conclusion: Cognitive processing is negatively affected by virtual altitudes, while it improves with short-term training. The features of virtual reality, such as higher involvement, engagement, and reliability, make it a better training tool to be considered in ergonomic settings. The findings of this study will provide insights into cognitive dual-tasking at altitude and its challenges, which will aid in minimizing occupational falls.

• Environmental Analysis Health and Toxicology
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• 제17권1호
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• pp.81-93
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• 2002

There were no specific effects for test materials on Sprague-Dawiey (S.D.) rats in clinical symptoms, amounts of food intakes, weight changes, laboratory findings, and pathology after whole body 1, 1-Dichloro-1-fluoroethane (used as coolant, metal cleaner and solvents) exposure (0, 1,500, 3,000, and 6,000 ppm) for 13 weeks (6 hour/day, 5 days/week). However, the loss of capillary vessels in eyeball (pupil) was observed in a female rat among 6,000 ppm group. Though there was a tendency for MCHC (Mean Corpuscular Hemoglobin Concentration) in rat to be decreased (p<0.05), it was not regarded as abnormal because the values were within normal limits. In asthma-stimulation related evaluations. there was also a tendency for inflammatory cell counts in bronchoalveolar lavages to be increased. But it had no statistical significance, and also no dependency on sex and the exposed concentration . Based on this result, the non observed effect level (NOEL) induced by 1, 1-Dichloro-1-fluoroethane inhalation was evaluated in groups with 3,000 ppm below (S.D. Rats, 13 weeks). Finally, it was concluded that the short term exposal of 1, 1-Dichloro-1-fluoroethane is not considered as a asthma stimulant by inhalation despite of some study limitations such as test animals use and short-term exposure.

• The Korean Journal of Pain
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• 제13권1호
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• pp.1-7
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• 2000

Background: Intraarticular local anesthetic injection has been therapeutically applied for pain control in various arthritis patients. However, little physiologic effects of local anesthetics on their tissue were known. This study was conducted to determine its effects on the cell proliferation and matrix metalloproteinases (MMP) production of cultured fibroblast like synoviocytes (FLS) derived from synovial tissues of rheumatoid arthritis patients. Methods: Bupivacaine with varying concentrations 0 (control), 0.1, 0.25, 0.5% was applied to experimental cell groups growing as monolayers in culture plates for varying durations 0 (control), 30, 90, 180 seconds in the presence and absence of interleukin-$1\beta$. Results: No statistical significances were noted in thymidine incorporation between 0, 30, 90 and 180 seconds exposure groups with 0.5% bupivacaine after 1 day and 2 days. Thymidine incorporation between 0, 0.1, 0.25, 0.5% exposure groups 1 day and 2 days after 90 seconds exposure did not show any differences. After exposure to bupivacaine, there were statistically significant increases in MMP-1 (p=0.025) and MMP-3 productions (p=0.000) of FLS in the absence of IL-$1\beta$, but no differences among the groups in the presence of IL-$1\beta$. Conclusion: We concluded that in this short-term in vitro study, bupivacaine does not have injurious effect on cultured rheumatoid arthritic joint tissues. The long-term effect cannot be known from this investigation.

• 원예과학기술지
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• 제29권3호
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• pp.187-194
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• 2011

광강도와 배양액 농도에 따른 칼랑코에(Kalanchoe blossfeldiana 'Marlene')의 생육단계별 양수분 흡수율과 작물생육을 조사하였다. 광강도는 일적산 광합성유효광양자속(PPF)이 6.5, 10.3, $18.2mol{\cdot}m^{-2}{\cdot}d^{-1}$의 3수준으로, 배양액의 농도는 유묘기 EC 0.5, 1.0, 1.5, $2.0dS{\cdot}m^{-1}$의 4수준, 단일처리 후 EC 1.0, 1.5, 2.0, $3.0dS{\cdot}m^{-1}$의 4수준으로 처리하였다. 유묘기 초장은 저광 조건에서 가장 길었고, 엽면적과 건물중은 PPF $10.3mol{\cdot}m^{-2}{\cdot}d^{-1}$에서 가장 높았다. 유묘기 모든 광조건에서 EC $1.5dS{\cdot}m^{-1}$일 경우에 최대 건물중과 엽면적이 나타났다. 단일처리기 초장 역시 저광 조건에서 길었고, 엽면적, 건물 중, 분지수는 광강도가 증가함에 따라 현저하게 증가하였다. 모든 광조건에서 엽면적, 건물중, 분지수는 배양액농도가 EC 1.0-$2.0dS{\cdot}m^{-1}$까지 증가하다가 EC $3.0dS{\cdot}m^{-1}$에서 현저히 감소하였고, EC $2.0dS{\cdot}m^{-1}$에서 가장 높았다. 생육이 양호하였던 EC 처리구(유묘기 EC $1.5dS{\cdot}m^{-1}$, 단일처리기 EC $2.0dS{\cdot}m^{-1}$)의 $NO_3$-N, $H_2PO_4{^-}$, $K^+$, $Ca^{2+}$, $Mg^{2+}$ 이온간의 상호간 비율을 분석한 결과 육묘단계에서는 광강도에 따라 큰 차이가 없었지만, 단일처리기에서는 큰 차이가 확인되었다. 따라서 작물의 최적의 생장을 위해 유묘기에는 광도 별 EC 조절로 충분하지만, 단일처리기에는 광강도에 따른 배양액 조성과 EC조절이 필요하다.

• 사물인터넷융복합논문지
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• 제6권4호
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• pp.7-14
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• 2020

본 연구는 2010년 1월부터 2018년 12월까지 일산화탄소의 12일 단기 노출에 따른 순환계통 질환 사망자 수의 영향관계를 분석하였고, 일산화탄소 농도 증가에 따른 미래의 순환계통 질환의 진료비용을 예측하였다. 한국환경공단의 대기환경정보(Airkorea)와 한국 통계청에서 자료를 추출하였고, 포아송 회귀분석과 ARIMA 개입 모형을 사용하여 분석하였다. 통계처리는 SPSS Ver. 21.0 프로그램을 이용하였다. 연구 결과는 다음과 같다. 첫째, 일산화탄소의 단기 노출에 따른 순환계통 질환 사망에 영향관계를 당일부터 이전 11일 전까지 분석한 결과는 이전 11일에서 가장 높은 영향력이 있는 것으로 나타났다. 둘째, 일산화탄소 농도 증가에 따라 미래의 순환계통 질환 진료비용은 2019년 예측값이 10,123십억원으로 2018년 12월 말의 관측값 9,443십억원보다 높게 나타났다. 또한 월별로 정리해 보면 순환계통 질환 진료비용은 계절변동이 반영되어 1월 보다 12월로 갈수록 높아진다는 것을 알 수 있었다. 이러한 연구를 통하여 일산화탄소와 같은 대기오염물질 증가에 따른 선제적 대응을 위하여 IoT를 활용한 다양한 기기 및 장비를 보급함으로써 모든 국민의 건강한 삶을 위한 미래가 실현될 수 있을 것이다.

• 한국작물학회지
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• 제8권1호
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• pp.91-97
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• 1970

안성지방에서 8월말경 마령서의 추작을 할때 남작을 2pm의 Gibberellin 용액에 10분간 침적해서 파종할 경우 종서의 취급방식이 파종후의 종서부패와 발아생육에 미치는 영향에 관해서 실험한 성적을 요약하면 다음과 같다. (1) 절단종서의 절단면을 직사일광에 조사하면 파종후의 종서부패와 발아생육의 지연을 초래하였는데 조사시간이 3시간이상 되면 피해는 막심하다. (2) 토양수분이 넉넉하고 직사일광에 오래 쏘이지만 ？\ulcorner으면 직파를 해도 최아정식하는 것 보다 종서부패가 많지 않다. (3) 종서부패가 적으면 직파하는 것이 최아정식하는 것보다 본포에서의 호착기간이 필요없기 때문에 생육이 빠르다. (4) 종서절편을 파종전 3일간 독속에 넣고 대하여 절구의 유상조직형성을 촉진해보려는 시도는 실해하였는데 이는 독속의 고습도유지가 안되었기 때문이라고 추측된다. (5) 처리 및 파종작업이 단기간에 끝인다면 일기의 영향은 청천이나 담천이나 다름이 없다. (6) 포장수분이 부족하지 않으면 관수를 해도 부패경감이나 발아촉진의 효과가 나타나지 않았다.

• 한국임상약학회지
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• 제2권1호
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• pp.11-22
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• 1992

Thymic extract showed antitumor effect to sarcoma mice with higher dose$(200{\mu}g/mouse/day$ i.p., 4weeks) but not with low dose$(5{\mu}g/mouse/day$ i.p., 6 weeks). Direct cytotoxicities were exhibited against sarcoma 180, L1210 and MOLT-4 by MTT assay. The spleen weight of mice were increased but the number of circulating lymphocytes were not increased after long-term(2 weeks) administration of thymic extract. Evaluating the mitogenesis by MTT assay. $\%$ absorbance of human lymphocytes was not increased by thymic extract. Cell cycle statistics of S phase and $G_2/M$ phase was not increased in the presence of that by PI staining. The formation of rosette was induced, irrespectively of exposure time short-term(l hour) and long-term(2 weeks). The population of mouse blood T-cell to bind Lyt2-antimonoclonal antibody and to $L_2T_4$ were increased after administration of thymic extract$(2-200{\mu}g/mouse/day)$. From the above results, it is suggested that thymic extract exerts antitumor activity by stimulating T cells to differeniate in vivo but not in vitro.