• 한국산림과학회지
• /
• 제99권1호
• /
• pp.153-162
• /
• 2010

본 연구는 경기도 용인 지역 전나무(Abies holophylla Maxim.) 임분의 구조를 분석하고, 이 지역 전나무 임분의 지속가능성을 알아보기 위하여 수행되었다. 용인시의 정수리, 대대리, 호동 지역 전나무 임분에서 매목조사를 실시하고, 관목층의 구조와 치수의 발생을 조사하였다. 산림 관리나 작업이 이루어지지 않았던 정수리와 대대리 임분에서 전나무는 중요도 40%로 임분을 우점하고 있었으며, 연속적인 연령과 직경분포를 보이고 있었다. 반면 호동 지역 임분은 간벌과 택벌 등의 산림 작업이 이루어졌던 지역으로 전나무가 흉고직경 10-45 cm 범위에 분포하나 대부분 25-30 cm 직경급에 몰려 있고, 단일수관층을 가지고 있었다. 전나무의 연령과 흉고직경의 상관 관계는 유의한 것으로 나타나긴 하였으나 높지 않았고($R^2$=0.2, P=0.03), 비슷한 연령대라도 다양한 흉고직경 값을 가졌다. 정수리 임분의 연속적인 직경 분포와 다층수관구조는 전나무가 조림 후 지속적으로 갱신이 이루어져 왔음을 보여주었다. 전나무의 치수는 ha당 2000-33000본까지 발생하였으나, 2-5 cm 직경급의 전나무는 ha당 70-150본 정도로 치수 단계에서 유령목으로 자라나는 동안의 생존율은 낮았다. 지속적인 천연갱신과 연간 약 0.6 cm의 직경생장율은 조사 지역의 환경이 전나무 서식에 비교적 적합한 지역임을 나타낸다. 또한 전나무 임분은 향후에도 지속적으로 유지될 것으로 보여 내음성 수종인 전나무를 대상으로 한 택벌림 경영의 가능성을 제시해주고 있다.

• 한국자원식물학회:학술대회논문집
• /
• 한국자원식물학회 2018년도 춘계학술발표회
• /
• pp.3-3
• /
• 2018

For centuries, Panax ginseng Meyer (Korean ginseng) has been widely used as a medicinal herb in Korea, China, and Japan. Ginsenosides are a class of triterpene saponins and recognized as the bioactive components in Korean ginseng. Ginsenosides, which can be classified broadly as protopanaxadiols (PPD), protopanaxatriols (PPT), and oleanolic acids, have been shown to flaunt a vast array of pharmacological activities such as immune-modulatory, anti-inflammatory, anti-tumor, anti-diabetic, and antioxidant effects. In recent years, a number of ginseng and ginsenoside researches have increasingly gained wide attention owing to its unique pharmacological properties. Although good efficacies of ginsenosides have been reported, lack of target specific delivery into tumor sites, low solubility, and low bioavailability due to modifications in gastro-intestinal environments limit their biomedical application in clinical trials. As a result to this major challenge, nanotechnology and drug delivery techniques play a significant role to solve this problematic issue. Thus, we reported the preparation of poly-ethylene glycol (PEG) and glycol chitosan (GC) functionalized to ginsenoside (Compound K and PPD) conjugates via hydrolysable ester bonds with improved aqueous solubility and pH-dependent drug release. In vitro cytotoxicity assays revealed that PEG-CK, and PPD-CK conjugates exhibited lower cytotoxicity compared to bare CK and PPD in HT29 cells. However, GC-CK conjugates exhibited higher and similar cytotoxicity in HT29 and HepG2 cells. Furthermore, GC-CK-treated RAW264.7 cells did not exhibit significant cell death at higher concentration of treatment which supports the biocompatibility of the polymer conjugates. They also inhibited nitric oxide production in lipopolysaccharide (LPS)-induced RAW64.7 cells. In addition to polymer-ginsenoside conjugates, silver (AgNps) and gold nanoparticles (AuNps) have been successfully synthesized by green chemistry using different m. The biosynthesized nanoparticles demonstrated antimicrobial efficacy, anticancer, anti-inflammatory, antioxidant activity, biofilm inhibition, and anticoagulant effect. Special interest on the effective delivery methods of ginsenoside to treatment sites is the focus of metal nanoparticle research.In short, nano-sizing of ginsenoside results in an increased water solubility and bioavailability. The use of nano-sized ginsenoside and P. ginseng mediated metallic nanoparticles is expected to be effective on medical platform against various diseases in the future.

• 한국환경보건학회지
• /
• 제34권4호
• /
• pp.261-270
• /
• 2008

Adjusted water fluoridation has been disputed because of its various effects on human health. Previous studies have been concerned with the difference in bone mineral density (BMD) between water fluoridated (WF) and none water fluoridated (NWF) districts. The aim of this study is to examine whether water fluoridation affects BMD. BMD was measured by dual energy X-ray absorptiometry (DXA). 386 adults(174 males and 212 females) in Ansan (WF) district and 399 adults (176 males and 223 females) in Sihwa (NWF) district, participated in this study. The Ansan and Sihwa districts are similar in residential environment and living class. The relationship between serum fluoride concentration and BMD was also examined by analysis of the serum fluoride concentrations from 402 inhabitants of the Ansan district. In females, the BMD of subjects living in Ansan ($0.457{\pm}0.008$) was a little higher than that of Sihwa subjects ($0.446{\pm}0.008$), although it is not significant, after adjusting for BMI, physical activity level, educational achievement, smoking volume, menopause status, and number of births. However, the BMD of Ansan subjects ($0.532{\pm}0.020$) in their forties was statistically higher than that of Sihwa (0.498{\pm}0.019). No relationship was found in males. In residential periods, there was significant difference (Ansan $0.467{\pm}0.013$, Sihwa $0.434{\pm}0.012$, p=0.0125) in the BMD between females of two districts, particularly in the group of over 6 year long-term inhabitants. On the contrary, there was no remarkable difference in males from the two districts. Serum fluoride concentrations in females were associated with BMD, especially in the age group of forties (p=0.0457). No relationship was observed in the male group. Analysis of adult BMD over the age of 20 in a water fluoridated and a none water fluoridated district, confirms more or less a higher BMD in the water fluoridated (WF) district, especially for females. It is assumed that the difference between two districts came somewhat from the effect of water fluoridation.

• Journal of Korean Neurosurgical Society
• /
• 제60권1호
• /
• pp.21-29
• /
• 2017

Objective : The purpose of this study was to analyze outcomes and identify prognostic factors in patients with cerebral metastases from non-small cell lung cancer (NSCLC) treated with gamma knife radiosurgery (GKS) particularly, focusing on associations of biomarkers and systemic treatments. Methods : We retrospectively reviewed the medical records of 134 patients who underwent GKS for brain metastases due to NSCLC between January 2002 and December 2012. Representative biomarkers including epidermal growth factor receptor (EGFR) mutation, K-ras mutation, and anaplastic lymphoma kinase (ALK) mutation status were investigated. Results : The median overall survival after GKS was 22.0 months (95% confidence interval [CI], 8.8-35.1 months). During follow-up, 63 patients underwent salvage treatment after GKS. The median salvage treatment-free survival was 7.9 months (95% CI, 5.2-10.6 months). Multivariate analysis revealed that lower recursive partition analysis (RPA) class, small number of brain lesions, EGFR mutation (+), and ALK mutation (+) were independent positive prognostic factors associated with longer overall survival. Patients who received target agents 30 days after GKS experienced significant improvements in overall survival and salvage treatment-free survival than patients who never received target agents and patients who received target agents before GKS or within 30 days (median overall survival: 5.0 months vs. 18.2 months, and 48.0 months with p-value=0.026; median salvage treatment-free survival: 4.3 months vs. 6.1 months and 16.6 months with p-value=0.006, respectively). To assess the influence of target agents on the pattern of progression, cases that showed local recurrence and new lesion formation were analyzed according to target agents, but no significant effects were identified. Conclusion : The prognosis of patients with brain metastases of NSCLC after GKS significantly differed according to specific biomarkers (EGFR and ALK mutations). Our results show that target agents combined with GKS was related to significantly longer overall survival, and salvage treatment-free survival. However, target agents were not specifically associated with improved local control of the lesion treated by GKS either development of new lesions. Therefore, it seems that currently popular target agents do not affect brain lesions themselves, and can prolong survival by controlling systemic disease status.

• Animal Bioscience
• /
• 제36권5호
• /
• pp.710-719
• /
• 2023

Objective: The present study investigated whether protodioscin (PD), a steroidal saponin mainly found in rhizome of Dioscorea species, alleviates oxidative stress-induced damage of porcine oocytes during in vitro maturation. Methods: Oocytes were treated with different concentrations of PD (0, 1, 10, 100, and 200 µM) in the presence of 200 µM H₂O₂ during in vitro maturation. Following maturation, spindle morphology and mitogen-activated protein kinase activity was assessed along with reactive oxygen species level, GSH activity, and mRNA expression of endogenous antioxidant genes at the MII stage. On the day 7 after parthenogenetic activation, blastocyst formation rate was calculated and the quality of embryo and mRNA expression of development-related genes was evaluated. Results: Developmental competence was significantly poorer in the 0 µM PD-treated (control) group than in the non-treated (normal) and 10 µM PD-treated (10PD) groups. Although the reactive oxygen species level did not significantly differ between these three groups, the glutathione level and mRNA expression of antioxidant genes (superoxide dismutase 1 [SOD1], SOD2, nuclear factor erythroid 2-related factor 2 [Nrf2], and hemo oxygenase-1 [HO-1]) were significantly higher in the normal and 10PD groups than in the control group. In addition, the percentage of oocytes with defective spindle and abnormal chromosomal alignment was significantly lower and the ratio of phosphorylated p44/42 to total p44/42 was significantly higher in the normal and 10PD groups than in the control group. The total cell number per blastocyst was significantly higher in the 10PD group than in the control group. The percentage of apoptotic cells in blastocysts was highest in the control group; however, the difference was not significant. mRNA expression of development-related genes (POU domain, class 5, transcription factor 1 [POU5F1], caudal type homeobox 2 [CDX2], Nanog homeobox [NANOG]) was consistently increased by addition of PD. Conclusion: The PD effectively improves the developmental competence and quality of blastocysts by protecting porcine oocytes against oxidative stress.

• 한국건축시공학회지
• /
• 제18권2호
• /
• pp.141-149
• /
• 2018

본 연구는 자기충전 콘크리트의 생산 및 시공 시 굳지 않은 상태의 안정성을 향상시킬 목적으로 유공 유리분말(GB)를 혼입한 자기충전 콘크리트에 대하여 충전성, 통과성, 재료분리 저항성 및 레올로지 특성을 평가하였다. 실험결과, GB 혼입량에 따른 충전성은 GB의 볼베어링 효과로 인해 GB $2.0kg/m^3$까지 $T_{50}$ 도달시간이 Plain에 비하여 단축되어 충전성이 개선되는 것으로 나타났다. 단, GB $4.0kg/m^3$에서는 오히려 약간 증가되었다. 통과성의 경우에는 Plain 1등급, GB $0.5{\sim}2.0kg/m^3$ 0등급, GB $4.0kg/m^3$ 1등급으로 GB 혼입량 $2.0kg/m^3$까지 '보이는 차단 없음'으로 통과성이 개선되었다. J-ring에 의한 통과성 Block step($P_J$) 값도 GB $1.0kg/m^3$에서 가장 우수한 통과성을 나타내었다. GB 혼입에 따른 재료분리 저항성은 동적 재료분리 저항성은 Plain 보다 GB을 사용하게 되면 그 혼입량에 상관없이 동적 재료분리 저항성이 증가하였다. 정적 재료분리 저항성은 GB $1.0kg/m^3$에서 재료분리도 2.5%를 나타내어 Plain(12.5%) 대비 크게 개선되었다. GB 혼입에 따른 레올로지 특성은 GB 혼입량 증가에 따른 소성 점도는 큰 차이가 발생하지 않았으나 항복응력은 $1.0kg/m^3$까지 낮아졌다. 이상을 종합하면, GB를 $1.0kg/m^3$ 사용하게 되면 자기충전 콘크리트의 충전성, 통과성, 항복응력 개선에 효과적인 것으로 나타났다. 또한 재료분리 저항성을 증가시켜 자기충전 콘크리트의 안정성에 도움이 될 것으로 판단된다.

• 한국산림과학회지
• /
• 제90권1호
• /
• pp.43-54
• /
• 2001

집단의 유전적 분화는 환경요인과 유전적 소인의 복잡한 상호관계에 의해 이루어지는데, 집단내 요인으로는 종자나 화분 비산, 국소환경변이, 개체의 분포밀도 등을 들 수 있다. 점봉산의 잣나무 임분내 개체 분포와 유전적 구성에 대한 분석을 위하여 신갈나무군락내 잣나무 우접임분에 $100{\times}100m$ 조사구를 설정하였으며, 잣나무 325개체에 대한 동위효소 분석을 실시하고, 공간의 자기상관성을 계산하였다. 11개 동위효소 유전자좌에서 관찰된 평균 다형성 유전자좌 비율(P)은 72.7%, 이형접합도의 관찰치(Ho)는 0.200, 기대치(He)는 0.251로 이형접합체 과소현상을 나타내어 근연가계의 개체들이 다수 분포하는 것으로 조사되었다. 동위효소의 유전자형에 따라 325개체는 총 147 개의 그룹으로 구분되었으며, 한 개 유전자형에 최대 34개체가 포함되었다. 동위효소 유전자형의 이성성이 24~32m 구간(거리간격 8m)을 기점으로 증가하는 양상을 보였으며, 생장특성(수고와 직경)에 대한 simple block distance도 24~32m 구간에서 임의분포를 보였다. 높은 근연교배의 고정계수(F=0.204), 유전적 자기상관성, 생장특성의 분석, 동일 유전자형의 분포범위 등을 고려할 때 점봉산 잣나무 임분은 화분비산이나 숲틈 형성에 따른 종자의 집중 투입에 따른 유전자 이동(gene flow)보다는 유전적 근연(近緣)개체의 밀도(密度)에 의존(density dependent)해서 유전적 구조를 유지하는 것으로 생각되며, 유전적 동질성을 갖는 군락의 크기는 24~32m에서 결정할 수 있었다. 본 연구의 결과 유전자원보존을 위한 개체의 선정은 최소한 37m 이상의 거리를 띄어야 바람직한 것으로 조사되었다.

• 아시안잔디학회지
• /
• 제23권2호
• /
• pp.219-228
• /
• 2009

골프장은 인공적으로 건설되어 지고 관리되므로 당연히 환경의 변화가 생성된 곳이므로 건설방식이나 관리 방법에 따라 코스 내 토양 미생물 군집 구조의 특이성이 있을 것이다. 현재 제주도에서는 농약 용탈 저감방안으로 골프코스 그린지반구조에 농약 흡착층을 설치하고 그 재료로 흡착성능이 우수한 입상 활성탄 1등급을 사용할 것을 환경 영향평가서에 명시하고 있다. 본 실험은 활성탄이 처리된 제주도 A, B 골프장을 대상으로 토양에서의 화학적 특성변화와 미생물 군락변화를 분석하였다. 2007년 4월, 6월, 8월 10월에 걸쳐서 총 박테리아 수, 총 곰팡이 수, 수분함량 및 토양 이화학성(pH, EC, NO3-,NH4+ 및 P2O5)의 변화를 그린과 페어웨이에서 깊이별(표토:0-15cm, 심토: 15-30cm)로 조사되었다. 그 결과, 활성탄의 시용이 수분 보유 능력, 토양산도, 전기전도도에 긍정적인 영향을 보였으나, GAC의 물질의 수착 능력에 의하여 유효 양분들을 많이 보유하는 데 도움이 될 것이라 예상하였으나, 본 실험에서는 가용성 질산과 암모늄, 및 인산의 농도를 높이는 효과는 없었다. 토양 미생물 실험에 있어서는 총 박테리아 및 총 곰팡이의 시기적 변화가 다양성을 보였다. 이러한 현상은 농약의 시용에 따라 직접적인 관련이 있을 것으로 예상되었으나, 총 곰팡이/총 박테리아 비(F/B ration) 는 활성탄을 혼합한 토양 심토(15-30cm)에서 일정한 수치를 유지하였다. 따라서, GAC 토양층의 설치 방법이나 시비와 시약 등이 미생물군집의 변화에 영향을 주며 이는 농약의 시용이 잔디관리에 큰 변수로 작용한다는 것을 시사한다.

• 대한간호학회지
• /
• 제20권3호
• /
• pp.414-429
• /
• 1990

Numerous research reports have substantiated the role of stressful life events in relation to the onset of health changes. The relationship tends to hold across different age groups. Theoretically, adolescence has been considered a developmental crisis period of great stress, impoverished coping skills and high vulnerability to biological, social and psychological demands. The research problem addressed by this study was to examine the relationships between stressful life events and health symptom patterns, and the effect of two variables, coping and social, support, theoretically considered to mediate the relationship between stress and health symptoms in adolescents. The following five hypotheses were tested in this research : 1. Health symptoms are positively related to stressful life events in adolescents, 2. Health symptoms are negatively related to coping in adolescents, 3. Health symptoms are negatively related to social support in adolescents, 4. When coping is controlled, the relationship between health symptoms and stressful life events will decrease, and 5. When social support is controlled, the relationship between health symptoms and stressful life events will increase. The study subjects consisted of 1090 high school students of the metropolitan city of Seoul. The following sampling procedure was used : 1. Of the 169 high schools in nine school administrative districts in the city, a proportional sample of ten schools was selected. 2. One class from each of the freshman and sophomore was randomly selected and all the students who were in the sampled class were used as the study sample. The study was limited to freshman and sophomore adolescents, aged 15 to 18(mean＝16.6). Of the 1090 subjects 688(63%) were boys and 402(37%) were girls. An Adolescent Inventory of Stressful Life Events, a Health Symptom Questionnaire and an Adolescent Coping Inventory were adapted for this study. The Norbeck Social Support questionnaire was utilized to collect the data on perceived social support. Five high school teachers in the areas of school health and counselling reviewed the items of each questionnaire for content validity. A pilot study was undertaken to ascertain reliability. Fifty three high school students responded to the questionnaires and gave their opinions on the items. For stressful life events, health symptoms, coping, and social support, the Cronbach's alpha's on the study were .70, .94, .77, and .76, respectively. Research assistants attended all the sampled classes with the school proctor to explain the purpose and procedures of the study to the students. The questionnaires along with a ballpoint pen were distributed to the students who were asked to complete each item. The research assistants left the ballpoint pen with the students as a gift for their cooperation. An average of 50 minutes was required to complete the questionnaires. Using an SPSS, the first, three hypotheses were tested using Gamma, a measure of association for ordinal variables. Partial gamma was used to test the fourth and fifth hypotheses. Patterns of elaboration described by Babbie were selected to interpret the relationship of the three variable analyses. The significance of gamma was determined by Chisquare at a .05 level of significance. There was a positive relationship between health symptoms and stressful life events(Gamma＝.35, p＝.000). Thus the first hypothesis was supported. Unexpectedly, coping was positively related with health symptoms(Gamma＝.13, p＝.000). That is, the higher the coping levels, the greater number of health problems. The third hypothesis, the higher the level of social support, the fewer the health symptoms, was not accepted in this adolescent study group. When coping was controlled, under the condition of low coping the association between health symptoms and stressful life events increased significantly to a partial gamma of .39, and under the condition of high coping it was .30. According to the elaboration model, when one partial relationship is the same or greater than the original and the other is smaller, the control variable should be considered to be specifying the conditions. When social support was controlled the relationship between stressful life events and health symptoms increased under the condition of low social support, but with high social support, the relationship decreased. Both partial gamma were statistically significant at .05 level(.43 and .26 relatively). It can be interpreted that stressful life events are strongly and positively related to health symptoms under the condition of low social support, however this relationship can not be expected with high social support. Thus, the last two hypotheses were conditionally sustained. In this study, the relationships between stressful life events and health symptoms, and the specified me diating roles of coping and social support were found to have statistical interaction. This finding supports the theoretical position of this study. It suggests that stressful life events would create high susceptability to biological social and psychological health symptoms and coping and social support buffering the relationship between stressful life events and health symptom. The findings of this study have implications for nursing practice. When adolescents are confronted with non-developmental life events that are perceived as stressful, nurses should recognize the evidence of the stress-buffering effect of coping and social support on health symptoms and utilize the diverse sources of social support that are readily available to adolescents.

• 과학교육연구지
• /
• 제38권2호
• /
• pp.356-375
• /
• 2014

본 연구의 목적은 비형식 과학학습의 개념인 자발적 학습, 다양한 장소에서의 학습 등의 학습측면을 담고 있는 학교 밖 영재 프로그램을 개발하여 초등 단위학교 5학년 영재학급 학생들에게 적용 후 창의적 문제해결력, 과학탐구능력, 과학적 태도에 어떤 영향을 주었는지 알아보고자 하였다. 이 연구를 위하여 영흥도 내 초등 단위학교 5학년 영재학급 학생 15명을 대상으로 적용하였고 그 결과는 다음과 같다. 첫째, 본 연구를 위해 개발한 영흥도 지역자원을 활용한 학교 밖 영재 프로그램을 단위학급에 투여한 후 창의적 문제해결력의 변화를 알아본 결과 학생들의 창의적 문제해결력 신장에 효과가 있었다(p<.05). 창의적 문제해결력 하위 요소별로 살펴보면 다양한 문제 제안하기, 적절한 탐구문제 선택하기, 실험계획 세우기, 해결방법 확인하기 영역에서 유의미한 차이를 보였다(p<.05). 반면, 해결책 생각하기 영역에서는 유의미한 차이를 보이지 못하였다. 본 프로그램의 특성상 영흥도에 국한된 체험위주의 수업이 바탕을 이루고 있어 지역 확산적인 사고 위주의 해결책 제시가 쉽지 않은 것으로 해석할 수 있다. 둘째, 본 연구에서 개발한 프로그램은 학생들의 과학적 탐구능력의 신장에 효과가 있었다. 하위요소별로 살펴보면, 기초탐구과정에서는 관찰, 예상영역을 제외한 영역에서 유의미한 변화를 주지 못하였다. 반면에 통합탐구능력에는 자료변환에 유의미한 차이를 보였다. 이는 본 프로그램 중 생각넓히기, 더 나아가기 영역에서 이야기 만드는 과정, 활용방안 등의 활동이 긍정적인 영향을 미친 것이라고 생각되었다. 셋째, 본 연구에서 개발한 프로그램은 학생들의 과학적 태도 변화에는 판단유보를 제외한 영역에서는 통계적으로 유의미한 차이가 나타나지 않았다. 과학적 태도는 인지적인 방법의 학습보다는 정의적인 방법에 의해 훨씬 더 효과적으로 변화할 수 있는데, 본 연구에서는 45일이라는 비교적 짧은 실험기간과 체험학습 장소에서의 탐구활동이 제한된 시간 안에 이루어져야 했으므로 그 부담감이 전체적으로 과학적 태도 변화의 긍정적인 부분에 영향을 주지 못하였다고 할 수 있다. 넷째, 학교 밖 영재 프로그램의 효과성을 알아보기 위한 설문 및 면담결과에서는 운영, 인식에서 긍정에 가까운 평가 결과를 나타내었으며 특히, 운영에서는 시설, 준비, 복지 영역에서 인식에서는 흥미도와 활용도 영역에서 긍정적인 효과를 거두었다. 이러한 결과는 일반 학급에서 접하기 힘든 시설과 체험활동들로 이루어져 있었고 학생들 스스로 계획한 탐구활동을 실행할 수 있는 기회가 적었기 때문으로 분석되어 졌다. 또한 면담을 통해 체험활동이 학습자로 하여금 흥미와 만족도 등을 높일 수 있는 방법이 될 수 있다는 결과를 도출하여 그동안의 선행연구와 같은 결과를 얻을 수 있었다. 위와 같은 연구 결과를 바탕으로 후속연구에서는 도서지역 뿐 아니라 다양한 지역적 특성을 갖고 있는 현장에서 좀 더 많은 학생들을 표본집단으로 하여 학교 밖 영재 프로그램을 연구할 필요성이 있으며, 각 지역적 특성에 맞는 실제적이고, 적절한 프로그램 안 개발이 동반되어야 되어야 할 것이다. 아울러 정의적인 학습 방법과 단기간이 아닌 장기간에 걸친 프로그램을 준비할 수 있도록 해야 할 것이다.