• 운동영양학회지
• /
• 제16권2호
• /
• pp.65-71
• /
• 2012

Oxygen is the final acceptor of electron transport from fat and carbohydrate oxidation, which is the rate-limiting factor for cellular ATP production. Under altitude hypoxia condition, energy reliance on anaerobic glycolysis increases to compensate for the shortfall caused by reduced fatty acid oxidation [1]. Therefore, training at altitude is expected to strongly influence the human metabolic system, and has the potential to be designed as a non-pharmacological or recreational intervention regimen for correcting diabetes or related metabolic problems. However, most people cannot accommodate high altitude exposure above 4500 M due to acute mountain sickness (AMS) and insulin resistance corresponding to a increased levels of the stress hormones cortisol and catecholamine [2]. Thus, less stringent conditions were evaluated to determine whether glucose tolerance and insulin sensitivity could be improved by moderate altitude exposure (below 4000 M). In 2003, we and another group in Austria reported that short-term moderate altitude exposure plus endurance-related physical activity significantly improves glucose tolerance (not fasting glucose) in humans [3,4], which is associated with the improvement in the whole-body insulin sensitivity [5]. With daily hiking at an altitude of approximately 4000 M, glucose tolerance can still be improved but fasting glucose was slightly elevated. Individuals vary widely in their response to altitude challenge. In particular, the improvement in glucose tolerance and insulin sensitivity by prolonged altitude hiking activity is not apparent in those individuals with low baseline DHEA-S concentration [6]. In addition, hematopoietic adaptation against altitude hypoxia can also be impaired in individuals with low DHEA-S. In short-lived mammals like rodents, the DHEA-S level is barely detectable since their adrenal cortex does not appear to produce this steroid [7]. In this model, exercise training recovery under prolonged hypoxia exposure (14-15% oxygen, 8 h per day for 6 weeks) can still improve insulin sensitivity, secondary to an effective suppression of adiposity [8]. Genetically obese rats exhibit hyperinsulinemia (sign of insulin resistance) with up-regulated baseline levels of AMP-activated protein kinase and AS160 phosphorylation in skeletal muscle compared to lean rats. After prolonged hypoxia training, this abnormality can be reversed concomitant with an approximately 50% increase in GLUT4 protein expression. Additionally, prolonged moderate hypoxia training results in decreased diffusion distance of muscle fiber (reduced cross-sectional area) without affecting muscle weight. In humans, moderate hypoxia increases postprandial blood distribution towards skeletal muscle during a training recovery. This physiological response plays a role in the redistribution of fuel storage among important energy storage sites and may explain its potent effect on changing body composition. Conclusion: Prolonged moderate altitude hypoxia (rangingfrom 1700 to 2400 M), but not acute high attitude hypoxia (above 4000 M), can effectively improve insulin sensitivity and glucose tolerance for humans and antagonizes the obese phenotype in animals with a genetic defect. In humans, the magnitude of the improvementvaries widely and correlates with baseline plasma DHEA-S levels. Compared to training at sea-level, training at altitude effectively decreases fat mass in parallel with increased muscle mass. This change may be associated with increased perfusion of insulin and fuel towards skeletal muscle that favors muscle competing postprandial fuel in circulation against adipose tissues.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2022년도 추계학술대회
• /
• pp.95-95
• /
• 2022

Maize is one of the world's three largest crops and has a long cultivation history, and is an important crop used for various purposes such as food, feed, and industrial raw materials. Recently, the agricultural environment is changing, in which the limit of cultivation of crops is shifted to the north due to the rise in temperature due to climate change. This study was conducted in experimental field of Suwon in 2022 by setting a seeding period earlier than the sowing time to establish the North Korean agricultural climatic zone and meteorological conditions. The test cultivars were silage cultivars, Kwangpyeongok and Dacheongok. As a priming test method, it was used to directly plant seeds in the field through immersion using 4mM zinc (Zn) and 2.5mM manganese (Mn), which are trace elements for seeds. The planting season was early on March 15th, April 1st, and April 15th. The number of days from sowing to silk stage of the two cultivars sown on March 15, April 1, and April 15 was 107, 93, and 85 days for Kwangpyeongok and 109, 95, and 87 days for Dacheongok, respectively. The seed priming test did not show any difference from the control group in the growth survey up to the middle stage of growth. In another test, low-temperature recovery was confirmed through nitrogen (2-5%) foliar fertilization after 3 days, 5 days, and 7 days in refrigeration (0 degrees), a selective low temperature treatment for com in the third leaf stage. As a result of this study, it was confirmed that the low-temperature damaged com treated at 0℃ showed the same growth as that of the untreated com through nitrogen foliar fertilization. These results suggest that urea foliar fertilization for low-temperature damage reduction of corn for silage in high-latitude climates will be helpful. In addition, through the results of the study, additional studies are needed on the recovery mechanism and field application through urea foliar fertilization.

• 한국심리학회지ㆍ건강
• /
• 제14권2호
• /
• pp.277-292
• /
• 2009

급성 스트레스 상황에 따른 Type D 성격의 자율신경계 반응을 심박률 변동성을 중심으로 조사하였다. Type DS-14의 점수에 근거하여 Type D 집단(n=23명)과 non-Type D 집단(n=23명)을 구성하였다. 심박률 변동성(heart rate variability, HRV)을 이용하여 기저선, 스트레스 단계 및 회복 단계 동안의 심박활동을 측정하였으며 스트레스 과제로는 Stroop 색채단어 검사가 사용되었다. 반복측정 변랑분석을 통해 두 집단의 심박활동을 비교하였으며, 회귀분석을 통해 Type D 척도와 스트레스 취약성 척도가 기저선 상태에서의 심박활동의 변화를 예측할 수 있는지를 알아보았다. 연구 결과, Type D 집단은 non-Type D 집단보다 고주파수(high frequency, HF) 활성화가 더 낮았고 저주파수(low frequency, LF) 활성화는 더 높았다. 스트레스 과제 수행 시, non-Type D 집단에서는 교감신경계 활성화 지표(LF component, LF/HF)가 증가하고 부교감신경계 활성화 지표(HF component)가 감소하는 것이 관찰된 반면, Type D 집단에서는 심박활동 비율상의 유의한 변화가 나타나지 않았다. 또한, Type D 척도의 총점수, 부정적 정서 소척도와 사회적 억제 소척도는 기저선 상태에서의 심박활동 반응에 대한 유의한 예측인자로 나타났다. 이러한 결과는 Type D 성격이 non-Type D 성격에 비해 교감신경계 활성화 비율이 높거나 또는 부교감신경계 활성화비율이 낮음을 시사한다. 즉, Type D가 스트레스에 취약한 성격임을 시사하며, Type D에서 관찰된 심박 활동 양상, 즉 높은 교감신경계 혹은 낮은 부교감신경계 활성화는 Type D 성격이 심장혈관 장애 등을 포함한 정신신체 질환과 관련될 수 있음을 시사한다.

• 한국산학기술학회논문지
• /
• 제16권7호
• /
• pp.4450-4458
• /
• 2015

본 연구의 목적은 Yoga와 Pilates 운동 수행이 자율신경계에 미치는 영향을 분석하여 운동처방의 임상적 기초 자료를 제공하고자 하였다. 피험자는 체육전공 대학생 20명을 요가운동군(Yoga Group)과 필라테스운동군(Pilates Group)에 각각 10명씩 배정하였고, 자율신경계 측정은 운동 전, 운동 직후, 회복기 30분 후에 이루어졌다. 그 결과 첫째, 요가는 스트레스 지수와 평균맥박이 시기의 주효과와 시기와 집단의 상호작용효과의 유의한 차이를 보였다. 둘째, 요가는 교감활성과 자율신경균형이 시기의 주효과, 시기와 집단의 상호작용효과, 집단의 주효과 모두 유의한 차이를 보였다. 셋째, 맥박다양성, 부교감활성도, SDNN, RMSSD는 시기의 주효과는 유의한 차이를 보였고, 시기와 집단의 상호작용효과와 집단의 주효과는 통계적으로 유의한 차이를 나타내지 않았다. 따라서 요가는 스트레스 지수를 낮추고 평균맥박 감소의 효과를 얻을 수 있으며, 특히 요가 운동이 필라테스 운동보다 교감활성 감소와 자율신경균형에 더 긍정적인 영향을 미치는 것으로 사료된다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제29권3호
• /
• pp.419-427
• /
• 2016

There is a high association of heat shock on the alteration of energy and lipid metabolism. The alterations associated with thermal stress are composed of gene expression changes and adaptation through biochemical responses. Previous study showed that Angelica gigas Nakai (AGN) root extract promoted adipogenic differentiation in murine 3T3-L1 preadipocytes under the normal temperature condition. However, its effect in heat shocked 3T3-L1 cells has not been established. In this study, we investigated the effect of AGN root hot water extract in the adipogenic differentiation of murine 3T3-L1 preadipocytes following heat shock and its possible mechanism of action. Thermal stress procedure was executed within the same stage of preadipocyte confluence (G0) through incubation at $42^{\circ}C$ for one hour and then allowed to recover at normal incubation temperature of $37^{\circ}C$ for another hour before AGN treatment for both cell viability assay and Oil Red O. Cell viability assay showed that AGN was able to dose dependently (0 to $400{\mu}g/mL$) increase cell proliferation under normal incubation temperature and also was able to prevent cytotoxicity due to heat shock accompanied by cell proliferation. Confluent preadipocytes were subjected into heat shock procedure, recovery and then AGN treatment prior to stimulation with the differentiation solution. Heat shocked preadipocytes exhibited reduced differentiation as supported by decreased amount of lipid accumulation in Oil Red O staining and triglyceride measurement. However, those heat shocked preadipocytes that then were given AGN extract showed a dose dependent increase in lipid accumulation as shown by both evaluation procedures. In line with these results, real-time polymerase chain reaction (RT-PCR) and Western blot analysis showed that AGN increased adipogenic differentiation by upregulating heat shock protection related genes and proteins together with the adipogenic markers. These findings imply the potential of AGN in heat shock amelioration among 3T3-L1 preadipocytes through heat shock factor and proteins augmentation and enhanced adipogenic marker expression.

• 대한의생명과학회지
• /
• 제12권2호
• /
• pp.81-89
• /
• 2006

The ischemia-responsive 94 gene (irp94) encoding a 94 kDa endoplasmic reticulum resident protein was investigated its molecular properties associated with unfoled protein responses. First, the expression of irp94 mRNA was tested after the reperfusion of the transient forebrain ischemia induction at the central nervous system in three Mongolian gerbils. Second, irp94 expression in PC12 cells, which are derived from transplantable rat pheochromocytoma cultured in the DMEM media, was tested at transcriptional and translational levels. The half life of irp94 mRNA was also determined In PC12 cells. Last, the changes of irp94 mRNA expression were investigated by the addition of various ER stress inducible chemicals (A23187, BFA, tunicamycin, DTT and $H_2O_2$) and proteasome inhibitors, and heat shock. High level expression of irp94 mRNA was detected after 3 hours reperfusion in the both sites of the cerebral cortex and hippocampus of the gerbil brain. The main regulation of irp94 mRNA expression in PC 12 cells was determined at the transcriptional level. The half life of irp94 mRNA in PC12 cells was approximately 5 hours after the initial translation. The remarkable expression of irp94 mRNA was detected by the treatment of tunicamycin, which blocks glycosylation of newly synthesized polypeptides, and $H_2O_2$, which induces apoptosis. When PC12 cells were treated with the cytosol proteasome inhibitors such as ALLN (N-acetyl-leucyl-norleucinal) and MG 132 (methylguanidine), irp94 mRNA expression was increased. These results indicate that expression of irp94 was induced by ER stress including oxidation condition and glycosylation blocking in proteins. Expression of irp94 was increased when the cells were chased after heat shock, suggesting that irp94 may be involved in recovery rather than protection against ER stresses. In addition, irp94 expression was remarkably increased when cytosol proteasomes were inhibited by ALLN and MG 132, suggesting that irp94 plays an important role for maintaining the ERAD (endoplasmic reticulum associated degradation) function.

• Ecology and Resilient Infrastructure
• /
• 제7권1호
• /
• pp.26-42
• /
• 2020

토양은 식물들이 뿌리 내려 생태계를 조성할 수 있게 하는 근간이자 인류의 삶의 터전으로, 그 생성에 많은 시간을 필요로 하기 때문에 토양의 보존과 관리가 중요하다. 토양 리질리언스는 다양한 종류의 교란으로부터 토양이 본래의 구조와 기능을 유지하는 능력으로, 불확실성과 예측불가능성이 높은 미래에 대비할 수 있는 연구 분야이다. 따라서 본 연구는 국내에서 아직 널리 알려지지 않은 토양 리질리언스의 개념과 필요성, 그리고 기존에 수행된 국외 연구 내용들을 정리함으로써, 토양리질리언스를 처음 접하는 국내·외 연구자들에게 리질리어스 연구의 진입 문턱 (threshold)을 낮추는데 기여할 것을 목적으로 수행되었다. 본 연구 전반부에는 리질리언스와 토양 리질리언스에 대해 소개하였으며, 후반부에는 많은 토양 리질리언스 선행연구들이 관심을 가진 주요 스트레스 원인을 자연적 요인과 인위적 요인으로 구분하여 정리하였다. 지구상에는 모암, 기후, 인간의 활동, 문화가 모두 동일한 지역은 없기 때문에 각 토양마다 고유의 특수성을 갖고 있다. 따라서 본 연구 결과 활용하고자 하는 연구자는 토양 리질리언스를 도입하고자 하는 지역의 특수성을 고려하여 활용해야 할 것이다. 또한 토양 리질리언스 연구자들의 네트워크를 강화하여 연구결과를 공유하고 적극 활용할 수 있는 기반을 만드는 데 노력해야 할 것이다.

• 대한치과보철학회지
• /
• 제31권2호
• /
• pp.219-235
• /
• 1993

To determine the compatibilities of soft liming materials with denture cleansers by measuring the flexibility and elasticity and investigating the surface changes, 4 self-curing acrylic resin soft lining materials and 1 heat-curing silicone soft lining material were evaluated. 3mm thick x 20mm diameter discs of soft lining materials were individually bonded to a hard acrylic resin base as per manufacturers’instructions. Using an Instron universal testing machine, a static stress of $2kg/cm^2$ was applied for 30secs., the strain in compression was measured, giving an indication of the material’s flexibility. Elastic recovery was measured at 10secs. After removal of stress. Surface changes were investigated with Stereomicroscope. Then the specimens were immersed in 4alkaline peroxide denture cleansers and water as control group, tests were carried out at 1 day, 2 days, 7 days, 14 days and 30 days. The results were as follows : 1. Alkaline peroxide denture cleansers caused considerable porosity on the surface of selfcuring acrylic resin soft lining materials, and the most affected by the cleansers were Viscogel, Coe-Soft, Coe-Comfort, Lynal, in that order. 2. There was significant difference in flexibility between each soft lining material except for Coe-Comfort and Visco-gel, and every soft lining material was significant difference in elasticity. Especially Molloplast-B and Lynal were less flexible and more elastic than other soft lining materials(p<0.05). 3. The denture cleansers increased the flexibility and elasticity of the soft lining materials compared with control group(p<0.05), and Denalan, Polident, Kleenite, Efferdent affected the soft lining materials in that order. 4. There was significant difference in flexibility between each denture cleanser except for Denalan and Polident(p<0.05). Though Denalan and Polident, Denalan and Kleenite did not show significant difference in elasticity, other denture cleansers showed significant difference among each other(p<0.05). 5. Clinically Coe-Comfort, Coe-Soft and Visco-gel were incompatible with alkaline peroxide denture cleansers, and Lynal would be used within only 2 weeks. But Molloplast-B was compatible with alkaline peroxide denture cleansers.

• 한국전산구조공학회논문집
• /
• 제19권4호
• /
• pp.407-418
• /
• 2006

본 논문에서는 일차전단변형이론(FSDT)을 이용한 복합재료 적층평판의 고정밀 해석기법을 소개한다. 전단수정계수가 자동적으로 포함되도록 횡방향 전단 변형에너지를 혼합변분이론(mixed variational theorem)을 이용하여 개선하였다. 혼합변분이론에서는 변분을 횡방향 응력들에 대해서만 취하였다. 가정된 횡방향 전단응력은 효율적인 고차이론(Cho and Parmerter, 1993)으로부터 구하였다 횡방향 수직응력은 3차 다항식으로 가정하였고, 무전단 응력조건과 평판의 윗면과 아랫면에서의 응력을 만족하는 조건을 부과함으로써 얻었다. 한편, 변위들에 대해서는 일차전단변형이론의 변위장을 사용하였다. 이렇게 해서 얻어진 변형 에너지를 본 논문에서는 EFSDTM3D이라고 명명 하였다. 본 논문에서 개발된 EFSDTM3D는 변위와 응력의 계산에서 고전적인 FSDT와 같은 정도의 계산 효율을 가지면서, 동시에 변위와 응력의 두께방향의 정확도를 면내 방향 응력들에 대한 최소오차자승법에 기초하여 응력 회복 과정을 적용함으로써 개선하였다. 계산된 결과는 고전적인 FSDT, 3차원 탄성해, 그리고 참고문헌 중에서 이용 가능한 결과들과 비교하여 검증하였다.

• 한국전산구조공학회논문집
• /
• 제19권4호
• /
• pp.429-440
• /
• 2006

이 연구의 목적은 두 가지로 대별할 수 있다. 첫째는, 베리오그램 모델링에 기초를 둔 정규크리깅 보간법의 p-적응적 유한요소법으로의 적용성이다. 둘째는, 수정된 초수렴 팻취복구 기법을 사용한 사후오차평가기와 연계된 계층적 p-체눈 세분화의 적응적 유한요소 과정을 제시하는 것이다. 가중치를 부여한 보간기법중의 하나인 정규크리깅 방법은 가우스 적분점에서의 응력데이타로 부터 소위 준정해를 얻는데 적용된다. 가중치를 동일하게 가정하는 종래의 보간기법과는 달리 실험적 및 이론적 베리오그램을 작성한 후 보간을 위한 가중치를 결정하게 된다. 한편, 적응적 p-체눈 세분화는 해석영역의 각 체눈에서 p-차수를 만족할만한 정확도를 얻을 수 있도록 프로그램내에서 자동으로 사후오차평가를 통해 불균등 또는 선택적으로 증가시킨다. 수정된 초수렴 팻취복구기법을 검증하기 위해 극한치를 사용한 새로운 오차평가기가 제안된다. 제안된 알고리즘의 정당성은 선형탄성파괴역학의 대표적 문제들인 중앙균열판, 일변균열 및 양변균열 해석을 통해 테스트되었다.