• 한국산학기술학회논문지
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• 제18권1호
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• pp.310-315
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• 2017

대규모 건설공사 현장에서는 발파공사에 대한 표준발파패턴과 시험발파패턴의 발파진동추정식의 상이에 따른 설계변경의 반영 문제로 시공사, 건설사업관리자, 발주처간의 갈등요인을 해소하기 위한 체계적인 자료의 수집 및 분석 과정을 통하여 효율적인 대책수립이 필요한 실정이다. 발파진동에 의한 인접 구조물에 미치는 영향을 여러 각도로 평가하려는 연구들은 계속 되어 왔으나, 노천발파를 수행하면서 현장계측의 진동파형을 분석하여 인접 건축물의 안전성을 확보하고 현장여건에 적합한 발파공법을 연구한 사례는 미미한 실정이다. 따라서 현장여건에 적합하고 경제적이며 효율적인 발파작업을 수행할 수 있도록 시험발파를 통하여 발파패턴 선정의 개선방안을 제시하는 것이 필요하다. 본 연구에서는 실제 도로확장공사 현장에서 시험발파를 통한 표준발파공법 및 진동규제기준별로 적용되는 이격 거리를 기준으로 노천 발파작업을 수행하여 발파진동 값을 계측하고 이를 통한 발파공법별 진동예측식을 회귀분석 전산프로그램을 이용하여 신뢰수준 95%의 K, n, R등을 산출하였다. 시험발파 대상지역의 발파허용진동기준을 0.3cm/sec로 설정하고 노천발파지침의 발파진동추정식과 시험발파의 발파진동추정식에 따른 이격 거리별 장약량과 발파공법을 비교분석한 결과 사업비가 증가하는 요인을 도출할 수 있었다. 또한, 노천발파 작업 중 인접 구조물에 대한 계측 및 분석을 수행하고 노천발파지점과 가장 인접한 구조물을 선정하여 발파진동 계측 및 평가를 시행하여 노천발파공사를 완료하는 과정에서 나타난 노천발파 설계 시공 지침에서의 시험발파 절차 및 해석방법에 대한 문제점을 분석하여 개선방안을 제시하였다.

• Journal of Microbiology and Biotechnology
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• 제27권8호
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• pp.1428-1440
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• 2017

Phomopsis sp. XP-8 (an endophytic fungus) was previously found to produce pinoresinol diglucoside (PDG), a major antihypertensive compound of Tu-Chung (the bark of Eucommia ulmoides Oliv.), which is widely used in Chinese traditional medicines. In the present study, two bioconversion systems were developed for the production of PDG in Tris-HCl buffer containing glucose and Phomopsis sp. XP-8 cells (both resting and freeze-dried). When other factors remained unchanged, the bioconversion time, glucose concentration, cell ages, cell dosage, pH, temperature, and stirring speed influenced PDG production in a similar and decreasing manner after an initial increase with increasing levels for each factor. Considering the simultaneous change of various factors, the optimal conditions for PDG production were established as 70 g/l cells (8-day-old), 14 g/l glucose, $28^{\circ}C$, pH 7.5, and 180 rpm for systems employing resting cells, and 3.87 g/l cells, 14.67 g/l glucose, $28^{\circ}C$, pH 7.5, and 180 rpm for systems employing freeze-dried cells. The systems employing freeze-dried cells showed lower peak PDG production ($110.28{\mu}g/l$), but at a much shorter time (12.65 h) compared with resting cells (23.62 mg/l, 91.5 h). The specific PDG production levels were 1.92 and $24{\mu}g$ per gram cells per gram glucose for freeze-dried cells and resting cells, respectively. Both systems indicated a new and potentially efficient way to produce PDG independent of microbial cell growth.

• 한국수자원학회논문집
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• 제47권4호
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• pp.397-409
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• 2014

본 연구에서는 과거 자연하천에서 개수 후 현재 정비하천으로 변화된 하천공간의 생태기능을 비교 평가할 수 있는 방법을 제안하고 그 적용성을 검토하였다. 생태기능 평가는 하도 중심의 물리구조와 하천공간의 생태연결성으로 구성하였고, 각각 4개와 2개 평가항목을 토대로 평가기준에 따라 정량화 하였다. 평가방법의 적용은 하천개수 전인 1918년과 대규모 하천개수사업이 종료된 현재의 만경강 하천공간에 204개 격자와 7개 하도구간을 설정하고 GIS 분석기능을 활용하여 수행하였다. 그 결과, 물리구조와 생태연결성은 각각 평균 2등급에서 4등급, 2등급에서 3등급으로 감소한 것으로 나타났다. 물리구조의 주된 악화 원인은 직강화와 그에 따른 하천 횡단구조물의 건설에 의한 것으로 파악되었고, 생태연결성 악화는 도로와 철도 등에 의한 선적 단절요인이 토지이용에 의한 면적 단절요인보다 비교적 더 크게 작용한 것으로 확인되었다. 특히, 생태기능이 높은 격자들을 기준으로 하천공간을 살펴볼 때, 1918년의 생태 연결성은 하천을 축으로 분포되어 있었음을 알 수 있으나, 2007년은 제방 축조와 도시화된 지역의 증가로 산포하는 경향을 나타났다.

• 한국환경보건학회지
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• 제38권1호
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• pp.51-56
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• 2012

Objectives: High concentrations of airborne particulate matters (PM) can affect the health of passengers using public transportation. The objectives of this research were to develop a PM control system for a railway cabin and to evaluate the performance of the device under conditions of an actual journey. Methods: This study measured the concentrations of $PM_{10}$ and $PM_{2.5}$ simultaneously in a reference cabin and a cabin with the PM control device. Results: The average $PM_{10}$ concentration in the reference cabin was 100 ${\mu}g/m^3$, and the $PM_{10}$ concentration in the cabin with the control device was 79 ${\mu}g/m^3$. While the overall control efficiency of the control device was 15.4%, reduction was more effective for peak $PM_{10}$ concentration. However, $PM_{2.5}$ levels did not differ greatly between the reference cabin and the cabin with the control device. The ratio of $PM_{2.5}$ to $PM_{10}$ was 0.37. $PM_{10}$ concentrations in cabins were not associated with ambient concentrations, indicating that the main sources of $PM_{10}$ were present in cabins. Additionally, average $CO_2$ concentration in the cabins was 1,359 ppm, less than the maximum of 2,000 ppm set out by the Korean Ministry of Environment's guideline. The $CO_2$ concentration in cabins was significantly associated with the number of passengers: the in-cabin concentration = $23.4{\times}N+460.2$, where N is the number of passengers. Conclusions: Application of the PM control device can improve $PM_{10}$ concentration, especially at peak levels but not $PM_{2.5}$ concentration.

• 생물정신의학
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• 제24권2호
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• pp.59-67
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• 2017

Shift workers experience a disruption in the circadian sleep-wake rhythm, which brings upon adverse health effects such as fatigue, insomnia and decreased sleep quality. Moreover, shift work has deleterious effects on both work productivity and safety. In this review, we present a brief overview of the current literature on the consequences of shift work, especially focusing on attention-associated cognitive decline and related behavioral changes. We searched two electronic databases, PubMed and RISS, using key search terms related to cognitive domains, deleterious effects, and shift work. Twenty studies were eligible for the final review. The consequences of shift work can be classified into the following three categories extracted from the literature review : 1) work accidents ; 2) commuting accidents such as car accidents that occur on the way to and from work ; and 3) attendance management at work (i.e., absenteeism, tardiness, and unscheduled early departure). These cognitive and behavioral consequences of shift work were also found to be associated with sleep disorders in shift workers. Thus, improvements in the shift work system are necessary in order to enhance workers' health conditions, work productivity, and safety.

• Journal of Plant Biotechnology
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• 제34권1호
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• pp.37-45
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• 2007

수박은 형질전환이 매우 어렵고 직접적인 신초 유도방법으로는 안정된 형질전환을 기대할 수 없어서, 다른 여러 작물에서 높은 효율을 보였던 캘러스 유래 신초 유도 방법을 도입하고자 하였다. 수박의 최적 캘러스 유도조건은 자엽 절편체의 경우 2.0 mg/L zeatin과 0.1 mg/L IAA이었으며 뿌리 절편체의 경우 2.0 mg/L BA와 0.1 mg/L 2,4-D이었다. NptII 유전자의 선발 항생제는 kanamycin보다는 paromomycin 빠르고 효과적이었으며, 수박의 절편체에 Agrobacterium을 접종 한 후 paromomycin을 125 mg/L 첨가한 배지에서 선발하였다. pmGFP5-ER vector로 형질전환한 후 캘러스 상태에서 형광현미경을 통해 GFP 유전자의 도입을 확인하였으며, 딱딱한 초록색의 캘러스에서 강한 GFP 발현을 관찰하였고, 자엽유래 캘러스의 경우 WM8에서 9.0%, 뿌리유래 캘러스의 경우 WM6에서 8.3%의 가장 높은 GFP 발현 효율을 보였다. GFP 유전자 도입과 같은 방법으로 WMV-CP 유전자가 있는 pWMV2300 vector로 형질전환한 후 캘러스 상태에서 PCR 및 Southern blot 분석을 한 결과, 두 점의 캘러스에서 WMV-CP 유전자가 도입되었음을 확인하였다. 본 연구를 통하여 확립된 수박의 캘러스 유도 시스템은 안정된 수박 형질전환 방법에 기초 자료로서 이용될 것이다.

• Clinical and Experimental Reproductive Medicine
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• 제21권2호
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• pp.183-190
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• 1994

Purpose of the present study was to find the optimal culture conditions for the maturation and fertilization of immature oocytes by the use human body fluids and gonadotropins (Gn) in the mouse model. Cumulus-enclosed mouse immature oocytes were incubated in the medium containing various human body fluids with or without Gn in vitro, and examined to confirm nuclear maturation (NM) and fertilization. Female ICR mice were stimulated with 7.5 IU pregnant mares' serum gonadotropin (PMSG). Cumulus-enclosed immature oocytes were isolated at 48-52 hr post PMSG injection and cultured in TCM 199 supplemented with various concentrations (20, 50, and 70%) of human body fluids such as fetal cord serum (hCS), follicular fluid (hFF), peritoneal fluid (hPF) and amniotic fluid (hAF) in the presence or absence of 10 IU/ml PMSG and 10 IU/ml human chorionic gonadotropin (hCG) for 18 hr. Fetal calf serum (FCS) was used as a control for the supplements. Matured oocytes were fertilized with sperm collected from the epididymis of male mice. Fertilization was conducted in T6 medium containing 15 mgl ml bovine serum albumin, and confirmed at 6 hr post-insemination. Evaluation of nucler maturation and fertilization was carried out by rapid staining using fuchin. There was no significant difference between the effects of human body fluids and FCS supplements on nuclear maturation of cumulus enclosed mouse immature oocytes. When maturation medium was supplemented with 20% hPF or 20% hAF, fertilization rates were significantly (P<0.01) lower than that of 20% FCS, hCS and hFF groups. However, higher concentrations of body fluids during IVM were not more beneficial on fertilizability of oocytes. The addition of Gn significantly increased the fertilization rates in hPF and hAF groups (hPF without Gn; 51.5%, compared with 85.1% for addition of Gn, and hAF without Gn; 30.1% compared with 85.8% for addition of Gn) at 20% concentration. These results suggest that human body fluids at 20% concentration and gonadotropins can be used as supplements for the maturation of mouse immature oocytes in vitro. When gonadotropins supplemented with the human body fluids in the maturation medium, fertilizability of mouse immature oocytes was increased in hPF and hAF groups. These results can be applied to maturation of human immature oocytes in vitro.

• Wind and Structures
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• 제20권4호
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• pp.549-564
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• 2015

The three-dimensional unsteady incompressible Reynolds-averaged Navier-Stokes equations and k-${\varepsilon}$ double equations turbulent model were used to investigate the effect on the measurements of anemometers due to a passing high-speed train. Sliding mesh technology in Fluent was utilized to treat the moving boundary problem. The high-speed train considered in this paper was with bogies and inter-carriage gaps. Combined with the results of the wind tunnel test in a published paper, the accuracy of the present numerical method was validated to be used for further study. In addition, the difference of slipstream between three-car and eight-car grouping models was analyzed, and a series of numerical simulations were carried out to study the influences of the anemometer heights, the train speeds, the crosswind speeds and the directions of the induced slipstream on the measurements of the anemometers. The results show that the influence factors of the train-induced slipstream are the passing head car and tail car. Using the three-car grouping model to analyze the train-induced flow is reasonable. The maxima of horizontal slipstream velocity tend to reduce as the height of the anemometer increases. With the train speed increasing, the relationship between $V_{train}$ and $V_{induced\;slipstream}$ can be expressed with linear increment. In the absence of natural wind conditions, from the head car arriving to the tail car leaving, the induced wind direction changes about $330^{\circ}$, while under the crosswind condition the wind direction fluctuates around $-90^{\circ}$. With the crosswind speed increasing, the peaks of $V_X,{\mid}V_{XY}-V_{wind}{\mid}$ of the head car and that of $V_X$ of the tail car tend to enlarge. Thus, when anemometers are installed along high-speed railways, it is important to study the effect on the measurements of anemometers due to the train-induced slipstream.

• Asian Pacific Journal of Cancer Prevention
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• 제16권15호
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• pp.6463-6468
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• 2015

Background: Chemotherapy is one of the common approaches in treatment of cancers, especially leukemia. However, drug resistance phenomena reduce the likelihood of treatment success. Resveratrol is a herbal compound which through complicated processes makes some selected cells sensitive to treatment and induction of apoptosis. In the present study, the effects of resveratrol on the expression of miR 15a and miR16-1 and apoptosis in the CCRF-CEM cell line were investigated. Materials and Methods: The CCRF-CEM cell line was cultured under standard conditions and changes in miR 15a and miR 16-1 expression were analyzed by real time-PCR technique, with attention to reveratrol dose and time dependence. Also, apoptosis is evaluated by flow cytometry using annexin V and PI. Results: CCRF-CEM cells underwent dose-dependent apoptotic cell death in response to resveratrol. MiR 15a and miR 16-1 expression was up-regulated after 24 and 48 hours resveratrol treatment (p<0.05). Conclusions: The results of our study indicate that resveratrol induces apoptosis in a time and dose-dependent manner in CCRF-CEM cells. Also, increased expression level of miR 16-1 and miR 15a by means of resveratrol in CCRF-CEM cells might have a role in apoptosis induction and predisposition. According to our results resveratrol can be regarded as a dietary supplement to improve efficacy of anti-leukemia therapies.

• 생태와환경
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• 제41권3호
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• pp.367-373
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• 2008

유해남조의 생물학적 제어를 위한 연구의 일환으로 북한강수계(가평)에 서식하는 이매패 말조개(Unio douglasiae)의 섭식특성을 조사하였다. 섭식실험은 크게 시간별, 개체크기, 동물밀도, 먹이밀도 (엽록소-a 농도) 등에 따라 패류의 여과율 및 배설물 생산량을 각각 측정하였다. 말조개의 여과율은 섭식 후 적용 7시간째 (0.21 L $g^{-1}h^{-1}$, 0.54 mg $g^{-1}h^{-1}$), 크기 5 cm보다 작은 개체에서 최고 여과율 및 배설물 생산량 (5.89 L $g^{-1}h^{-1}$, 16.38 mg $g^{-1}h^{-1}$)을 각각 나타냈다. 또한 가장 낮은 먹이밀도 (엽록소-a 88.5 ${\mu}gL^{-1}$)에서 0.41 L $g^{-1}h^{-1}$로 최고 여과율을 보였으며, 일정 먹이농도 이상에서는 배설물 생산량이 증가하지 않는 것으로 나타났다. 또한 패류의 조류 제어효과는 개체 밀도가 증가할수록 뚜렷한 효과를 나타냈다. 결국 이상의 결과들은 북한강에 서식하는 이매패 말조개가 부영양호수의 남조류 제어의 유용생물로서 적용 가능성을 입증하였다.