• 한국산림과학회지
• /
• 제99권1호
• /
• pp.125-130
• /
• 2010

식물대량증식에서 생물반응기의 이용은 규모를 대량화하고 자동화 할수 있다는 점에서 생산비를 절감할 수 있는 방법 중 하나이다. 본 연구에서는 유칼리 펠리타 선발목의 대량증식 체계를 확립하기 위해 4가지의 생물반응기 배양시스템에서 유칼리의 생장을 비교하였다. 배양기내에 지지물(net)을 설치하고 매 4시간마다 30분씩 액체배지를 공급한 TIN 배양(Temporary immersion with net)에서 식물체 생장이 가장 좋았다. TIN 시스템하에서 자란 식물체는 동일한 방식에 net가 없는 TIX 배양(Temporary immersion without net)에서 자란 식물체와 비교하여 초장이 3배 이상 증가하였다. 게다가 TIN 시스템에서 생산 된 식물체는 총 엽록소 함량, 엽록소 a/b, 그리고 건물중 등도 증가하였다. 위와 같은 결과는 기내 유칼리나무 생장에 중요한 요인이 식물체가 적당한 간격으로, 그리고 적당한 시간동안 배지에 노출되어야하고, net의 이용이 필수적임을 보여준다. TIN 시스템은 유칼리 클론묘의 대량생산을 위해 최적의 시스템으로 산업화를 위한 유칼리나무 대량생산시 유용하게 이용될 수 있을 것으로 생각된다.

• Tuberculosis and Respiratory Diseases
• /
• 제74권4호
• /
• pp.163-168
• /
• 2013

Background: In uncontrolled hemoptysis patient, bronchial arteriography and bronchial artery embolization (BAE) is a important procedure in diagnosis and treatment. The aim of this study is to assess the incidence of contrast-induced nephropathy and the risk factors of contrast-induced nephropathy (CIN) after bronchial arteriography and BAE. Methods: We retrospectively reviewed the medical records of the patients who underwent bronchial arteriography and BAE in two university hospitals from January 2003 to December 2011. CIN was defined as rise of serum creatinine more than 25% of baseline value or 0.5 mg/dL at between 48 hours and 96 hours after bronchial arteriography and BAE. We excluded patients who already had severe renal insufficiency (serum creatinine${\geq}4.0$) or had been receiving dialysis. Results: Of the total 100 screened patients, 88 patients met the enrollment criteria. CIN developed in 7 patients (8.0%). The mean duration between the exposure and development of CIN was $2.35{\pm}0.81$ days. By using multivariate analysis, serum albumin level was found to be significantly associated with the development of CIN (p=0.0219). Conclusion: These findings suggest that the incidence of CIN was higher than expected and patients with hypoalbuminemia should be monitored more carefully to prevent the development of CIN after bronchial arteriography and BAE.

• 한국수정란이식학회지
• /
• 제10권2호
• /
• pp.121-129
• /
• 1995

To examine the critical effect of oxygen concentration on embryonic development, in vitro fertilized embryos were cultured in media(TCM199 vs. SOF) supplemented sera(1O% FCS vs. 10% HS) with and without bovine oviduct epithelial cells under two gas atmosphere (5% $CO_2$ in air vs. 5% $CO_2$, 5% $O_2$, 90% $N_2$). Oocytes, obtained from abattoir ovaries, were matured in EGF containing TCM199 medium co-cultured with BOEC for 24 hours, followed by exposure to frozen-thawed, heparin4reated spermatozoa in TALP for 30 hours. And then early embryos(1~2 cell) were cultured in both TCM199 and SOF supplemented with 10% FCS or 10% RS under 5% $CO_2$ in air or 5% COi, 5% $O_2$, 90% $N_2$. Development to morulae and blastocysts was recorded on days 7, after the start of in vitro fertilization. The developmental rates of in vitro fertilized embryos to morulae and blastocysts cultured in SOF with BOEC under 5% $CO_2$, 5% $O_2$, 90% $N_2$(24.4%) were significantly(p<0.05) higher than cultured in SOF with BOEC under 5% $CO_2$ in air(14.1%) at seven days after in vitro fertilization. When early bovine embryos were cultured in TCM 199 and SOF under two different gas atmosphere, there were no significant differences in the developmental rates to morulae and blastocysts between supplements of 10% FCS and 10% HS. The rates of development to morulae and blastocysts were significantly(p<0.01) higher in TCM 199 with BOEC(24.7%) than TCM199 without BOEC(10.9%) under 5% $CO_2$ in air, otherwise SOF without BOEC(36.4%) were significantly (p<0.05) higher than in SOF with BOEC (24.4%) under 5% $CO_2$, 5% $O_2$, 90% $N_2$. In summary, these experiments have proved that the culture system in SOF supplemented 10% ES is effective on in vitro development of early bovine embryos under 5% $CO_2$, 5% $O_2$, 90% $N_2$. In addition, it is effective to development of bovine embryos that TCM 199 should be co-cultured with BOEC and SOF should be cultured without somatic cells under two different gas atmosphere.

• 과학기술학연구
• /
• 제18권1호
• /
• pp.129-175
• /
• 2018

이 논문은 한국석면운동의 지식 정치적 측면을 검토한다. 2008년 본격적으로 시작된 석면운동은 석면오염을 한국 사회의 중요한 안전보건의제로 만드는 데 앞장서 왔다. 석면오염 측정은 특히 석면오염이 광범위하고 심각한 환경보건문제라는 주요 주장을 펼치는 데 매우 중요했다. 이 활동의 특징은 공정시험방법이 아닌 '먼지 분석법'을 활용했다는 것이다. 이 논문에서는 석면운동가들의 오염 조사 보고서와 삼성 본관 주변 석면오염 논란을 통해 먼지 분석법이 대항 지식으로서 권력을 획득하는 과정을 분석한다. 석면운동가들은 먼지 분석으로 얻은 측정 데이터를 활용해 그들의 주장에 언론의 이목을 집중시키고, 정책적 변화에 필요한 자원을 동원할 수 있었다. 그러나 규제기관을 중심으로 한 전문가 집단은 먼지 분석법이 신뢰할 수 있는 석면오염 측정방법이라는 석면운동가들의 주장에 동의하지 않았다. 이와 같은 결론을 내리는 데 측정 과정에서 표준적 방법의 사용 여부와 측정 데이터의 해석적 맥락이 중요한 기준으로 작용하였다. 먼지 분석법의 권위는 부분적으로 획득되었다. 그러나 먼지 분석법은 규제과학이 내포하는 가정들을 드러내고 사회적 토론의 대상으로 전환시켰다는 점에서, 사회 운동과 과학을 결합하여 규제기관과 전문가 집단의 측정에 도전한 석면운동의 특성을 잘 보여준다.

• Journal of Radiation Protection and Research
• /
• 제25권4호
• /
• pp.191-195
• /
• 2000

현재 서울대학교병원에서 진행중인 연구의 일환으로 혈관 내 방사선치료 시 시술자의 방사선피폭 정도 및 위험성에 대해 알아보고자 연구를 시행하였다. 심장혈관 폐색으로 연구에 포함되어 방사선치료른 시행 받은 42명의 환자 중 측정이 완벽한 34명의 자료를 토대로 분석을 시행하였다. 혈관내 방사선치료는 관상동맥성형술 직후 풍선도자법을 이용하여 대상 동맥의 중막에 17 Gy를 조사하였다. 사용된 동위원소는 $^{188}Re$이었으며 GM측정기로 각기 다른 8점에서 피폭선량을 측정하였다. 환자의 심장부위에서 10cm, 40cm 떨어진 지점을 시술자의 최대피폭량, 전신피폭량의 기준으로 삼았다. 치료선량의 중앙값은 111.6 mCi이었고 중앙치료시간은 576초였다. 환자 심장부위에서 l0cm, 40cm 지점의 평균 피폭 선량율은 0.43 mSv/hr, 0.30 mSv/hr 이었고, 각 지점에서의 시술 당 평균 피폭 선량은 0.07 mSv, 0.05 mSv 이었다. 이 수치는 ICRP-60나 과학기술부 고시에서 권고하고 있는 한계 피폭선량보다 훨씬 적은 값으로 현재 저울대학교병원에서 시행하고 있는 혈관내 방사선 치료법은 방사선방어 면에서 매우 안전한 방법임을 확인할 수 있었다.

• 한국표면공학회:학술대회논문집
• /
• 한국표면공학회 1999년도 추계학술발표회 초록집
• /
• pp.15-15
• /
• 1999

In chip plating, several parameters must be taken into consideration. Current density, solution concentration, pH, solution temperature, components volume, chip and media ratio, barrel geometrical shape were most likely found to have an effect to the process yields. The 3 types of barrels utilized in chip plating industry are the conventional rotating barrel. vibrational barrel (vibarrel), and the centrifugal type. Conventional rotating barrel is a close type and is commonly used. The components inside the barrel are circulated by the barrel's rotation at a horizontal axis. Process yield has known to have higher thickness deviation. The vibrational barrel is an open type which offers a wide exposure to electrolyte resulting to a stable thickness deviation. It rotates in a vertical axis coupled with multi-vibration action to facilitate mixed up and easy transportation of components, The centrifugal barrel has its plated work centrifugally compacted against the cathode ring for superior electrical contact with simultaneous rotary motion. This experiment has determined the effect of barrel vibration intensity to the plating thickness distribution. The procedures carried out in the experiment involved the overall plating process., cleaning, rinse, Nickel plating, Tin-Lead plating. Plating time was adjusted to meet the required specification. All other parameters were maintained constant. Two trials were performed to confirm the consistency of the result. The thickness data of the experiment conducted showed that the average mean value obtained from higher vibrational intensity is nearer to the standard mean. The distribution curve shown has a narrower specification limits and it has a reduced variation around the target value, Generally, intensity control in vi-barrel facilitates mixed up and easy transportation of components, However, it is desirable to maintain an optimum vibration intensity to prevent solution intrusion into the chips' internal electrode. A cathodic reaction can occur in the interface of the external and internal electrode. $2HD{\;}+{\;}e{\;}{\rightarrow}20H{\;}+{\;}H_2$ Hydrogen can penetrate into the body and create pressure which can cause cracks. At high intensity, the chip's motion becomes stronger, its contact between each other is delayed and so plating action is being controlled. However, the strong impact created by its collision can damage the external electrode's structure thereby resulting to bad plating condition. 1 lot of chip was divided into two equal partion. Each portion was loaded to the same barrel one after the other. Nickel plating and tin-lead plating was performed in the same station. Portion A maintained the normal barrel vibration intensity and portion B vibration intensity was increased two steps higher. All other parameters, current, solution condition were maintained constant. Generally, plating method find procedures were carried out in a best way to maintained the best plating condition. After plating, samples were taken out from each portion. molded and polished. Plating thickness was investigated for both. To check consistency of results. 2nd trial was done now using different lot of another characteristics.

• Journal of Periodontal and Implant Science
• /
• 제29권4호
• /
• pp.821-838
• /
• 1999

On the basis of the evidences that electrical stimulation could enhance proliferation and differentiation of bone cells and promote healing and regeneration of bone, this study was performed to investigate the effects of electrical stimulation on human periodontal ligament cells and gingival fibroblasts in vitro, which also have important roles in regeneration of periodontium, and to evaluate the potential of clinical application of electrical stimulation. Human periodontal ligament cells and gingival fibroblasts were primarily cultured from the root surface of extracted premolar and the adjacent gingiva without periodontal diseases. In control group, the cells ($5{\times}10^4$ cells/ml)were incubated only in Dulbecco's Modified Eagle's Medium contained with 10% fetal bovine serum. In test groups, electrical stimulation was given at the current intensity of $0.25{\mu]A$(test group 1), $1.0{\mu}A$(test group 2), and $2.5{\mu}A$(test group 3) for 12 hours to the same culture media with the control group. After 12 hour exposure of electrical stimulation, the cells were incubated for 2 and a half days(60 hours), and then each group of cells was analyzed for cell proliferation, protein level, and activity of alkaline phosphatase. The results were as follows ; 1. The Rate of cell proliferation of every test group increased significantly in both periodontal ligament cells and gingival fibroblasts, and in periodontal ligament cells, test group 3 showed significantly increased proliferation compared to the other test groups(p<0.05). 2. In the protein levels, neither periodontal ligament cell nor gingival fibroblast showed statistically significant differences between control and test groups. 3. The activity of alkaline phosphatase in periodontal ligament cells increased significantly in all test groups(p<0.05), but there were no significant differences between 3 test groups. In gingival fibroblasts, the activity of alkaline phosphatase increased significantly only in test group 3(p<0.05). From the above results, it is concluded that electrical stimulation may have beneficial effects on the regeneration of destructed periodontal tissue in regard of the stimulation of periodontal ligament cells and gingival fibroblasts as well as electrically stimulated bone formation that has been known, and that electrical stimulation may have the potential of clinical application.

• 한국산업보건학회지
• /
• 제9권1호
• /
• pp.99-111
• /
• 1999

The purpose of this study was to evaluate crystalline silica contents in airborne respirable dusts from various manufacturing industries and to compare analytical ability of two different methods of quantifying crystalline silica, X-ray diffraction(XRD) and Fourie transform infrared spectroscopy(FTIR). Various manufacturing industries with a history of having pneumoconiosis cases and also known to generate dusts containing crystalline silica were investigated. These industries include: ceramics, brick, concrete, and abrasive material etc. The personal respirable dust samples were collected using l0mm, Dorr-Oliver nylon cyclone equipped with 37mm, $5{\mu}m$ pore size. polyvinylchloride (PVC) filters as collection media. All samples were weighed before and after sampling and were pretreated according to the NIOSH sampling and analytical methods 7500, and 7602 for dust collection and quartz analysis. A total of 48 samples were collected from these industries. Initial analyses of these samples showed log-normal distributions for dust and quartz concentrations. Some results from ceramics and stone exceeded current Korean Occupational Exposure Limits. The average concentrations of personal respirable dust by cyclone were 0.43, 0.24, 0.26, 0.42, 0.53 and $0.29mg/m^3$ in ceramics, stone, concrete, glass, briquets, and others, respectively. A comparison of performance of two analytical methods for quantifying crystalline silica was performed using data from ceramics. The results showed that no significant difference was found between two methods for ceramics. The mean crystalline silica contents determined by XRD were 3.41 % of samples from briquets and 7.18 % from ceramics and were 2.58 % from concrete and 10.33 % from ceramics by FTIR. For crystalline silica analysis, two analytical techniques were highly correlated with $r^2=0.81$ from ceramics. Both cristobalite and tridymite were not detected by XRD and FTIR.

• 생명과학회지
• /
• 제24권12호
• /
• pp.1330-1338
• /
• 2014

결핵균인 Mycobacterium tuberculosis H37Rv에서는 16개의 adenylyl cyclase (AC) 유전자가, 비병원성인 M. smegmatis에서는 10개의 AC 유전자가 발견되었다. M. smegmatis에서 발견된 10개의 AC 유전자들 중 MSMEG_0228, MSMEG_3243, MSMEG_3780, MSMEG_4279, MSMEG_4477, MSMEG_6154 유전자들의 발현은 저산소 조건에서 유도되었다. 반면에 M. smegmatis가 nitric oxide (NO)에 노출이 되면 MSMEG_3780과 MSMEG_4279 유전자의 발현이 유도되었다. 유산소 조건에서 키운 M. smegmatis와 비교할 때, 저산소 조건에서 성장한 M. smegmatis 세포 내부와 성장 배지 내의 cAMP 양은 각각 450배와 9.8배 증가하였다. M. smegamtis가 NO에 노출이 되면 세포 내의 cAMP 농도는 5.8배 증가하였다. DevSR two-component system은 M. smegmatis가 저산소 조건이나 NO에 노출되었을 때 많은 유전자의 발현을 유도하는 주요 조절계로 알려져 있는데, 저산소 조건에서 발현이 유도된 6개의 AC 유전자의 발현이 M. smegmatis devR mutant에서도 wild type에서와 마찬가지로 저산소 조건에서 유도됨이 관찰되었다. 이 결과는 저산소 조건에서 발현이 유도되는 6개의 AC 유전자들이 DevSR two-component system에 의해 조절되지 않음을 나타내고 있다. 저산소 조건에서 발현이 가장 많이 유도된 MSMEG_3780 유전자의 발현조절에 관련이 있는 조절자를 발굴하기 위해 ligand fishing 분석을 수행하였고, 후보 조절자로서 MSMEG_5136을 발굴하였다.

• 대한수의학회지
• /
• 제35권1호
• /
• pp.187-195
• /
• 1995

The present study carried out to determine the developmental capacity of bovine oocytes matured in epidermal growth factor(EGF)-containing medium, the developmental competence of bovine embryos using synthetic oviduct fluid(SOF) and the effect of glucose on the development of bovine embryos. In experiment 1, oocytes, obtained from abattoir ovaries, were matured in EGF-containing medium for 24 hours, followed by exposure to Korean native cattle spermatozoa for 18 hours and cultured by utilizing co-culture system with bovine oviduct epithelial cells(BOEC) in TCM199. In experiment 2, early bovine embryos were cultured in SOF with or without BOEC and compared with those in TCM199 with BOEC. In experiment 3, bovine embryos were cultured in the presence or absence of glucose. Seven and ten days after in vitro fertilization, developmental competence of embryos were evaluated. The rate of cleavage was significantly(P<0.05) higher in EGF-containing maturation medium(70.0%) than in control(57.7%). The rates of development to morulae and blastocysts were 30.6% and 23.3% there was no significant difference between them. The rates of in vitro fertilized embryos to morulae and blastocysts cultured in SOF with BOEC(30.4%) and in TCM199 with BOEC(38.0%) were significantly(P<0.01) higher than cultured in SOF without BOEC(13.4%) at seven days after in vitro fertilization. The rates of embryos to blastocysts cultured in SOF with BOEC(29.4%) and in TCM199 with BOEC(35.9%) were significantly(P<0.05) higher than cultured in SOF without BOEC(13.4%) at ten days after in vitro fertilization. The rates of early embryos to morulae and blastocysts cultured in the presence or absence of glucose were 12.2% and 17.5% each other, there was no significant difference between them. The results show that bovine oocytes matured in the presence of EGF can cleave better, SOF with BOEC can replace serum containing complex media, TCM199 with BOEC in bovine embryo culture and glucose have little effect on the culture of early bovine embryos.