• 생명과학회지
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• 제13권6호
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• pp.896-902
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• 2003

본 연구는 도라지 추출물의 항 비만 효과를 관찰하기 위하여 비만 흰쥐에 도라지 추출물을 투여 한 후, 비만 흰쥐의 체중 변화와 혈청 중의 지질 프로파일을 측정하였다. 그 결과 도라지 추출물의 투여는 실험 시작 후 1주부터 8주까지 대조군에 비하여 감소하는 경향을 보였다. 고지방식이로 비만을 유도하였을 때, 정상군 보다 total cholesterol, triglyceride, fatty acid, total lipid의 함량이 증가되던 것이 도라지 추출물의 투여로 total cholesterol, triglyceride, fatty acid, total lipid의 함량이 현저히 감소하는 경향을 나타냈다. PG군의 total cholesterol$(77.2\pm3.3mg/dl)$은 대조군에 비해 약 7.0% 감소되었으며, PG군의 triglyceride$(103.6\pm9.0 mg/dl)$은 대조군에 비해 약 21.1% 감소되었다. 아울러 PG군의 fatty acid$(630.1\pm45.9 uEq/L)$함량은 대조군에 비해 약 19.6% 감소하였다. 또한 PC군의 경우 총 지질 함량은 $396\pm23.7mg/dl$ 이며, 이는 대조군에 비해 약 9.1% 감소하는 경향을 나타냈다. 이상의 결과로 미루어 보아 도라지 추출물은 비만의 개선 효과가 있을 것으로 생각되며, 앞으로 많은 연구가 병행하여야 할 것으로 사료된다.

• Journal of Radiation Protection and Research
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• 제48권4호
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• pp.197-203
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• 2023

Background: The thermoluminescent dosimeter (TLD) and Monte Carlo (MC) dosimetry are carried out to determine the occupational dose for personnel in the handling of ¹²⁵I seed sources. Materials and Methods: TLDs were placed in different layers of the Alderson-Rando phantom in the thyroid, lung and also eyes and skin surface. An ¹²⁵I seed source was prepared and its activity was measured using a dose calibrator and was placed at two distances of 20 and 50 cm from the Alderson-Rando phantom. In addition, the Monte Carlo N-Particle Extended (MCNPX 2.6.0) code and a computational phantom with a lattice-based geometry were used for organ dose calculations. Results and Discussion: The comparison of TLD and MC results in the thyroid and lung is consistent. Although the relative difference of MC dosimetry to TLD for the eyes was between 4% and 13% and for the skin between 19% and 23%, because of the existence of a higher uncertainty regarding TLD positioning in the eye and skin, these inaccuracies can also be acceptable. The isodose distribution was calculated in the cross-section of the head phantom when the ¹²⁵I seed was at two distances of 20 and 50 cm and it showed that the greatest dose reduction was observed for the eyes, skin, thyroid, and lungs, respectively. The results of MC dosimetry indicated that for near the head positions (distance of 20 cm) the absorbed dose rates for the eye lens, eye and skin were 78.1±2.3, 59.0±1.8, and 10.7±0.7 µGy/mCi/hr, respectively. Furthermore, we found that a 30 cm displacement for the ¹²⁵I seed reduced the eye and skin doses by at least 3- and 2-fold, respectively. Conclusion: Using a computational phantom to monitor the dose to the sensitive organs (eye and skin) for personnel involved in the handling of ¹²⁵I seed sources can be an accurate and inexpensive method.

• Journal of Gastric Cancer
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• 제13권1호
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• pp.26-33
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• 2013

Purpose: The aims are to: (i) display the multidimensional learning curve of totally laparoscopic distal gastrectomy, and (ii) verify the feasibility of totally laparoscopic distal gastrectomy after learning curve completion by comparing it with laparoscopy-assisted distal gastrectomy. Materials and Methods: From January 2005 to June 2012, 247 patients who underwent laparoscopy-assisted distal gastrectomy (n=136) and totally laparoscopic distal gastrectomy (n=111) for early gastric cancer were enrolled. Their clinicopathological characteristics and early surgical outcomes were analyzed. Analysis of the totally laparoscopic distal gastrectomy learning curve was conducted using the moving average method and the cumulative sum method on 180 patients who underwent totally laparoscopic distal gastrectomy. Results: Our study indicated that experience with 40 and 20 totally laparoscopic distal gastrectomy cases, is required in order to achieve optimum proficiency by two surgeons. There were no remarkable differences in the clinicopathological characteristics between laparoscopy-assisted distal gastrectomy and totally laparoscopic distal gastrectomy groups. The two groups were comparable in terms of open conversion, combined resection, morbidities, reoperation rate, hospital stay and time to first flatus (P>0.05). However, totally laparoscopic distal gastrectomy had a significantly shorter mean operation time than laparoscopy-assisted distal gastrectomy (P<0.01). We also found that intra-abdominal abscess and overall complication rates were significantly higher before the learning curve than after the learning curve (P<0.05). Conclusions: Experience with 20~40 cases of totally laparoscopic distal gastrectomy is required to complete the learning curve. The use of totally laparoscopic distal gastrectomy after learning curve completion is a feasible and timesaving method compared to laparoscopy-assisted distal gastrectomy.

• 한국토양비료학회지
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• 제35권2호
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• pp.105-111
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• 2002

현재 채소류에 대한 질소시비량 추천식은 육지부토양에서 시험한결과를 이용하여 설정된 것으로 이를 화산회토양에서도 활용하는 문제가 있어 이를 검토하기위하여 제주도 토양을 중심으로 1999년에는 pot와 2000년에는 포장에서 몇개의 질소시비량수준을 두고 배추를 재배한 시험결과는 다음과 같다. 1. Pot와 포장시험에서 배추의 질소 최고시비량은 $294{\sim}331kg\;ha^{-1}$이었고 토양의 유기물함량과 최고시비량과의 관계를 이용하여 화산회토양에 알맞는 새로 질소시 비량 추천식을 설정하였다. 2. 배추의 질소시비량시험을 통한 화산회토의 실제 질소시비적량은 기존의 추천식을 이용한 시비량과는 큰차이를 보였고 개선된 질소시비 추천식으로부터 산출된 질소 시비량과는 근소한 차이를 보였다. 3. 수화기 T-N 함량 및 질소흡수량은 질소시비량이 증가할수록 많았으나 질소이용 율은 질소시비량이 증가할수록 낮아지는 경향이었다. 4. 화산회토양에서 재배하는 양배추 대한 토양유기물함량에 따른 질소 시비량은 배추대비 질소흡수량을 흡수량비교 계수로 하고 이를 이용하여 양배추의 새로운 질소시비 추천식을 도출하였다.

• 한국수자원학회논문집
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• 제36권6호
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• pp.1013-1023
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• 2003

본 연구에서는 최근 환경재료로서 관심이 모아지고 있는 다공성 콘크리트를 하천구조물(보 및 하상재료)에 적용함으로써 수질을 개선하고자 수행하였다. 먼저, 물리ㆍ화학적 특징을 평가해 본 결과, 공극률 10% 및 30%의 다공성 콘크리트의 압축강도는 일반 콘크리트의 최저 압축강도(180 kgf/$cm^2$)를 상회하여 하천구조물에 적용 가능하였고, 알칼리 용출에 의한 부착 미생물에의 영향도 거의 없을 것으로 판단되었다. 또한, 일반 콘크리트와 다공성 콘크리트로 하천구조물을 제작하여 부착물의 성상을 비교ㆍ검토한 결과, 같은 유속조건에서 부착물의 DW량은 일반 콘크리트에 비해 다공성 콘크리트가 1.6배 높은 것으로 나타났으며, 반면에 유속을 10배 달리한 실험의 결과에서는 거의 같은 부착물의 DW량을 보여 부착매질에 의한 영향이 유속에 의한 영향보다도 더 크게 작용한 것을 알 수 있었다. 부착물의 성상에서도 건조물중 AFDM의 비가 다공성 콘크리트에서 더 큰 것으로 나타났으며, 특히 N, P의 비가 높은 것은 부착 생물에 의한 흡수 및 흡착, 물질대사에 의해 유기물 제거가 더 컸기 때문으로 사료된다. 수질개선 효과에 있어서 전 구간을 종합한 결과, 다공성 콘크리트를 적용한 하천구조물에서의 SS, BOD, COD, T-N, T-P의 제거효율은 일반 콘크리트 보다 각각 34.6%, 36.9%, 33.9%, 18.3%, 21.6% 씩 증가하여 하천 수질개선에 크게 기여한 것으로 평가되었다.

• 한국수정란이식학회지
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• 제11권3호
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• pp.249-258
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• 1996

To improve the efficiency of in vitro production of embryos with follicular oocytes in Korean Native cows, the recovery rates, in vitro maturation, fertilization and development, and the time required for collecting and processing oocytes by aspiration with or without slicing were evaluated comparatively. The ovaries were obtained from a local abattoir and placed in physiological saline at 25~28$^{\circ}C$ and brought to the laboratory within 3 hrs. The oocytes were collected by aspiration of follicles(2~6mm) with or without slicing ovaries after aspiration, and classified into Grade I, Grade II, Denuded, Expanded oocytes by the morphology of cumulus cells attached and the homogeneity of cytoplasmic granules. Also the time required for each step of collecting and processing oocytes were measured. The cumulus cells were removed in some Grade I oocytes to measure their size and nuclear configuration before and after in vitro maturation. The Grade I oocytes were matured in vitro(IVM) for 24 hrs. in TGM-199 supplemented with 35$\mu$g /ml FSH, 10$\mu$g /ml LH, 1 $\mu$g /ml at 39$^{\circ}C$ under 5% C02 in air. They were fertilized in vitro(IVF) by epididymal spermatozoa treated with heparin for 24hrs. and then the zygotes were cocultured in vitro (IVC) with bovine oviductal epithelial cells for 10 days. The results obtained were as follows: The number of oocytes recovered per ovary was averaged 6.6 by aspiration and 11.2 by slicing post aspiration, which summed to 17.8. The number of Grade I oocytes recovered per ovary was averaged 3.1 by aspiration and 3.6 by slicing, which summed to 6.7. The percentage of Grade I to total oocytes recovered was significantly(P<0.05) higher as 48.0 % in aspiration than 31.6% in slicing post aspiration. The time requlred for recovering a Grade I oocyte by aspiration and slicing was 1.1 and 2.5 min, respectively. The mean diameter of Grade I oocytes by aspiration and slicing was similar as 148.7 and 151.5$\mu$m, respectively. The percentage of Metaphase II stage oocytes after IVM for 24 hours was significantly (P

• Clinical and Experimental Reproductive Medicine
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• 제26권2호
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• pp.257-263
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• 1999

It is well known that discard of seminal plasma from the semen and separation of motile sperm should be preceded before insemination for IUI or IVF. Till now, more than ten kinds of semen treatment methods have been developed. Of those, swim-up and Percoll methods have been used widely in ART laboratories as a routine semen treatment methods because of its advantages. However, there are reports that Percoll can make a genetic trouble because of its chemical structure and therefore the necessity has been arisen to substitute Percoll for other equivalent materials. This study was performed to evaluate the effects of three different sperm preparation methods (swim-up, Percoll and Sil-Select) on sperm motility, sperm recovery rate and fertilization rate. Also, the feasibility of using Sil-Select instead of Percoll in ART was evaluated. Each semen samples were divided into three fractions and motile sperm were recovered by swim-up, Percoll and Sil-Select gradient centrifugation methods. Normal and sub-normal criteria of fifteen semen samples and seventeen IVF cycles were included in these study. As results, no significant difference was found in sperm recovery rate in normal semen treated by a Swim-up, Percoll and Sil-Select method ($13.2{\times}10^6,\;17.5{\times}10^6\;and\;17.7{\times}10^6$ respectively). The initial sperm motility was 61.9% and this increased to 87.1%, 92.6% and 89.5% through Swim-up, Percoll and Sil-Select treatment, respectively. Higher motility was observed in Percoll and Sil-Select treated groups (81.5%, 79.2%, respectively) than swim-up group (66.8%) after incubation for 24hrs. In sub-normal group, sperm recovery rates were higher in Sil-Select group $(2.9{\times}10^6)$ than Percoll gradients group $(1.8{\times}10^6)$. In IVF cycles, the outcomes of fertilization using sperm treated by swim-up and Sil-Select group were similar (82.2%, 79.7% respectively). In conclusion, our results indicate that Sil-Select can be used as a substitute material for sperm preparation instead of Percoll.

• 한국산림과학회지
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• 제97권1호
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• pp.102-112
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• 2008

이 연구의 목적은 한-중 임산물 관세구조를 비교분석하여 향후 예상되는 양국간 FTA 협상을 대비하기 위한 기초 자료를 제공하는데 있다. 중국은 우리나라의 최대 임산물 교역국으로 2007년 전체 임산물 교역액의 33%에 달한다. 그러나 대중 교역액의 대부분은 수입이며, 지속적으로 늘어나고 있는 추세여서 FTA 협상 결과에 따라 국내임산업에 미칠 영향은 매우 클 것으로 보인다. 관세구조를 비교분석해본 결과 중국은 우리나라보다 품목이 더 세분화되어 있고 무관세 품목이 많으며 석재류를 제외하고는 단기소득임산물과 목재류에서 모두 우리나라보다 관세가 낮은 것으로 나타났다. 또한 중국은 가공도가 낮을수록 무관세 또는 저율 관세를 부과하는 한편 가공도가 높을수록 높아지는 누진관세 체계를 가지고 있으나 동일부류 내에서도 다시 가공도에 따라 차등 관세를 부과하는 등 복잡한 관세구조를 가지고 있다. 특히 합판, 보드류의 경우 한국은 자국 산업을 보호하기 위해 양허하지 않고 조정관세를 적용하고 있으나 중국은 모두 양허하였으며 대신 가공도에 따라 차등 관세를 부과하여 자국 산업을 보호하는 특징이 있다. FTA체결을 위해 예외 없는 관세철폐 원칙이 적용될 경우 실행관세 세율이 높은 한국의 수입 증가폭이 더 클 것으로 예상되며, 관세철폐에 따른 충격은 무관세 품목이 적은 한국이 상대적으로 더 클 것으로 보인다.

• 한국환경복원기술학회지
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• 제12권1호
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• pp.111-122
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• 2009

Abatements of TN and ${NO_3}^-$-N in a horizontal subsurface-flow wetland with litter layer on its surface were compared with those without one. The wetland was constructed in 2001 on floodplain of the Gwangju Stream which flows through Gwangju City in Korea. Its dimensions were 29m in length, 9m in width and 0.65m in depth. A bottom layer of 45cm was filled with crushed granites (15~40mm in diameter) and a middle layer of 10cm had pea pebbles. An upper layer of 5cm contained coarse sands. Reeds (Phragmites australis) growing in natural wetlands were transplanted on its surface. Water of the stream was channelled into the wetland by gravity flow and its effluent was discharged back into the stream. Average Litter layer of 12.2cm was formed on its surface in 2007. The layer and above-ground parts of reeds were eliminated in April 2008. Volumes and water quality of influent and effluent of the wetland were analyzed from May to November in 2007 and 2008, respectively. Inflow into the wetland both in 2007 and 2008 averaged approximately 40$m^3$/day and hydraulic residence time both in 2007 and 2008 was about 1.5days. Influent TN concentration in 2007 and 2008 averaged 3.96 and 3.89mg/L, respectively and average influent ${NO_3}^-$-N concentration in 2007 and 2008 was 2.11 and 2.05mg/L, respectively. With a 0.05 significance level, influent concentrations of TN and ${NO_3}^-$-N, temperatures and pH of effluent, and heights and stem numbers of reeds showed no difference between the wetland with litter layer and without one. TN retention in the wetland with litter layer and without one averaged 64,76 and 54.69%, respectively and ${NO_3}^-$-N removal averaged 60.83 and 50.61%, respectively. Both TN and ${NO_3}^-$-N abatement rates in the wetland with litter layer were significantly high (TN abatement: p<0,001, ${NO_3}^-$-N abatement: p=0.001) when compared with those without one. The subsurface-flow wetland having litter layer on its surface was more efficient for TN and ${NO_3}^-$-N removal.

• Toxicological Research
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• 제23권3호
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• pp.279-287
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• 2007

Copper (Cu) is an essential trace element indispensable for brain development and function; either excess or deficiency in Cu can cause brain malfunction. While it is known that Cu and Fe homeostasis are strictly regulated in the brain, the question as to how systemic Fe status may influence brain Cu distribution was poorly understood. This study was designed to test the hypothesis that dietary Fe condition affects Cu transport into the brain, leading to an altered brain distribution of Cu. Rats were divided into 3 groups; an Fe-deficient (Fe-D) group which received an Fe-D diet ($3{\sim}5 mg$ Fe/kg), a control group that was fed with normal diet (35mg Fe/kg), and an Fe-overload group whose diet contained an Fe-O diet (20g carbonyl Fe/kg). Following a 4-week treatment, the concentration of Cu/Fe in serum, CSF (cerebrospinal fluid) and brain were determined by AAS, and the uptake rates of Cu into choroids plexus (CP), CSF, brain capillary and parenchyma were determined by an in situ brain perfusion, followed by capillary depletion. In Fe-D and Fe-O, serum Fe level decreased by 91% (p<0.01) and increased by 131% (p<0.01), respectively, in comparison to controls. Fe concentrations in all brain regions tested (frontal cortex, striatum, hippocampus, mid brain, and cerebellum) were lower than those of controls in Fe-D rats (p<0.05), but not changed in Fe-O rats. In Fe-D animals, serum and CSF Cu were not affected, while brain Cu levels in all tested regions (frontal cortex, striatum, hippocampus, mid brain, and cerebellum) were significantly increased (p<0.05). Likewise, the unidirectional transport rate constants $(K_{in})$ of Cu in CP, CSF, brain capillary and parenchyma were significantly increased (p<0.05) in the Fe-D rats. In contrast, with Fe-O, serum, CSF and brain Cu concentrations were significantly decreased as compared to controls (p<0.05). Cu transport was no significant change of Cu transport of serum in Fe-O rats. The mRNA levels of five Cu-related transporters were not affected by Fe status except DMT1 in the CP, which was increased in Fe-D and decreased in Fe-O. Our data suggest that Cu transport into brain and ensuing brain Cu levels are regulated by systemic Fe status. Fe deficiency appears to augment Cu transport by brain barriers, leading to an accumulation of Cu in brain parenchyma.