• Journal of Life Science
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• v.25 no.6
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• pp.656-662
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• 2015

Natural products and natural product structures play a general and highly significant role in drug discovery and development process because it has various merits and potentials for new drug source that have extensive clinical experience, development time contraction, excellent stability and safety. In several neurological disorders, neuronal death and excessive activation of microglia (neuro-inflammation) are observed. A number of drug discovery-related neuronal cell death and neuro-inflammation was studied from natural products, respectively. However, until now, it has not been possible to study dual-protection molecules recorded in the Natural Product library. In the present study, using the natural product-derived library of the Institute for Korea Traditional Medical Industry, we investigated dual-protective molecules against glutamate (a classical excitatory neurotransmitter)-induced oxidative stress mediated neuronal cell death and LPS-induced excessive activated microglial cells (immune cells of the brain). Chrysophanol, extracted from Rheum palmatum, had dual-protective effects against both glutamate-induced neuronal cell death and LPS-induced NO production, triggering proinflammatory cytokines and microglia activation and resulting in neuroinflammation. Flow-cytometry analysis revealed that chrysophanol had a scavenger effect, scavenging glutamate- and LPS-induced reactive oxygen species (ROS) produced by neuronal and microglial cells, respectively. Based on the present study, chrysophanol may have an important protective role against neuronal cell death and neuroinflammation in the brain. The results may be helpful for studying drug development candidates for treating central nervous system disorders.

• Journal of Life Science
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• v.26 no.9
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• pp.1088-1096
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• 2016

Despite that moderate hyperthermia can exert various antitumor activities such as direct cytotoxic effects on tumor cells, effects on tumor vasculatures and immunological effects, hyperthermia has been usually combined with radiotherapy or chemotherapy due to its limited efficacy in cancer treatment, showing some positive clinical benefits with generally well-tolerated side effects. Since heat shock responses itself can interfere with the anti-tumor effects of hyperthermia, not all of these studies might have demonstrated positive clinical outcomes in cancer patients. Therefore, the negative anti-tumor effect of hyperthermia should be reduced to enhance the effectiveness of hyperthermia. Although the responses to heat stress of tumor tissues containing vessels, immune cells, connective tissues as well as cancer cells, are very complicated, it is needed to study in the near future if some clinically available drugs, which can modulate heat stress responses, can improve the efficacy of hyperthermia in patients with cancer. In this review, the effect of clinical hyperthermia centered on non-invasive external hyperthermia using radiofrequency at moderate temperature will be discussed, since it is the state-of-the-art technology in the current clinical practice of hyperthermia, and a moderate operational temperature is used to increase the therapeutic effectiveness of conventional therapy without additional toxicity to normal tissues.

• Food Science of Animal Resources
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• v.25 no.1
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• pp.66-70
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• 2005

This study was conducted to determine the effects of MgSO₄ supplement on meat quality and serum stress hormones concentrations in late finishing pigs. Sixty castrated Landrace pigs (average weight±S.D., 106.5±8.9 kg) were assigned to a control diet (without MgSO₄ supplement) and diet with MgSO₄(10 g/kg diet) supplemented. Pigs had free access to diets and water during five-day feeding period. At the end of feeding experiment, pigs were fasted for 16 hours and transported to commercial slaughter plant (30-minute transportation distance). After 2-hour lairage time, pigs were slaughtered, and blood samples were collected at bleeding procedure of slaughter. Pigs fed the diet with MgSO₄ supplement had higher (p<0.05) serum magnesium concentrations than those in pigs fed a control diet. Serum adrenaline, noradrenaline and cortisol concentrations determined at slaughter were not significantly different between dietary groups. Carcass temperature, pH at 24h post- slaughter, drip loss and color characteristics were not influenced (p>0.05) by short-term supplement of MgSO₄. Pigs fed the diet supplemented with MgSO₄ diet had lower PSE incidence (23.3%) compared to pigs fed the control diet (33%). These results indicate that short-term supplement of dietary MgSO₄ in late finishing pigs may not be beneficial in improving pork quality, and further study needs to assess feeding regime of magnesium supplement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.1
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• pp.25-32
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• 2007

We investigated the silicide reaction stability between 10 nm-Col-xNix alloy films and silicon substrates with the existence of 4 nm-thick natural oxide layers. We thermally evaporated 10 nm-Col-xNix alloy films by varying $x=0.1{\sim}0.9$ on naturally oxidized single crystal and 70 nm-thick polycrystalline silicon substrates. The films structures were annealed by rapid thermal annealing (RTA) from $600^{\circ}C$ to $1100^{\circ}C$ for 40 seconds with the purpose of silicidation. After the removal of residual metallic residue with sulfuric acid, the sheet resistance, microstructure, composition, and surface roughness were investigated using a four-point probe, a field emission scanning electron microscope, a field ion bean4 an X-ray diffractometer, and an Auger electron depth profiling spectroscope, respectively, to confirm the silicide reaction. The residual stress of silicon substrate was also analyzed using a micro-Raman spectrometer We report that the silicide reaction does not occur if natural oxides are present. Metallic oxide residues may be present on a polysilicon substrate at high silicidation temperatures. Huge residual stress is possible on a single crystal silicon substrate at high temperature, and these may result in micro-pinholes. Our results imply that the natural oxide layer removal process is of importance to ensure the successful completion of the silicide process with CoNi alloy films.

• Journal of Environmental Impact Assessment
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• v.25 no.6
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• pp.514-524
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• 2016

The Bio-Climatic impact Assessment System, BioCAS was utilized to produce analysis maps of daily maximum perceived temperature ($PT_{max}$) and excess mortality ($r_{EM}$) over the entire Seoul area on a heat wave event. The spatial resolution was 25 m and the Aug. 5, 2012 was the selected heat event date. The analyzed results were evaluated by comparing with observed health impact data - mortality and morbidity - during heat waves in 2004-2013 and 2006-2011,respectively. They were aggregated for 25 districts in Seoul. Spatial resolution of the comparison was equalized to district to match the lower data resolution of mortality and morbidity. Spatial maximum, minimum, average, and total of $PT_{max}$ and $r_{EM}$ were generated and correlated to the health impact data of mortality and morbidity. Correlation results show that the spatial averages of $PT_{max}$ and $r_{EM}$ were not able to explain the observed health impact. Instead, spatial minimum and maximum of $PT_{max}$ were correlated with mortality (r=0.53) and morbidity (r=0.42),respectively. Spatial maximum of $PT_{max}$, determined by building density, affected increasing morbidity at daytime by heat-related diseases such as sunstroke, whereas spatial minimum, determined by vegetation, affected decreasing mortality at nighttime by reducing heat stress. On the other hand, spatial maximum of $r_{EM}$ was correlated with morbidity (r=0.52) but not with mortality. It may have been affected by the limit of district-level irregularity such as difference in base-line heat vulnerability due to the age structure of the population. Areal distribution of the heat impact by local building and vegetation, such as spatial maximum and minimum, was more important than spatial mean. Such high resolution analyses are able to produce quantitative results in health impact and can also be used for economic analyses of localized urban development.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.5
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• pp.321-327
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• 2006

In Korea, there is a growing competitive for water resources between industrial, domestic and agricultural consumer, and the environment as many other OECD countries. The demand on water use is also affecting aquatic ecosystems particularly where withdrawals are in excess of minimum environmental needs for rivers, lakes and wetland habits. OECD developed three indicators related to water use by the agriculture in above contexts : the first is a water use intensity indicator, which is expressed as the quantity or share of agricultural water use in total national water utilization; the second is a water stress indicator, which is expressed as the proportion of rivers (in length) subject to diversion or regulation for irrigation without reserving a minimum of limiting reference flow; and the third is a water use efficiency indicator designated as the technical and the economic efficiency. These indicators have different meanings in the aspect of water resource conservation and sustainable water use. So, it will be more significant that the indicators should reflect the intrinsic meanings of them. The problem is that the aspect of an overall water flow in the agro-ecosystem and recycling of water use not considered in the assessment of agricultural water use needed for calculation of these water use indicators. Namely, regional or meteorological characteristics and site-specific farming practices were not considered in the calculation of these indicators. In this paper, we tried to calculate water use indicators suggested in OECD and to modify some other indicators considering our situation because water use pattern and water cycling in Korea where paddy rice farming is dominant in the monsoon region are quite different from those of semi-arid regions. In the calculation of water use intensity, we excluded the amount of water restored through the ground from the total agricultural water use because a large amount of water supplied to the farm was discharged into the stream or the ground water. The resultant water use intensity was 22.9% in 2001. As for water stress indicator, Korea has not defined nor monitored reference levels of minimum flow rate for rivers subject to diversion of water for irrigation. So, we calculated the water stress indicator in a different way from OECD method. The water stress indicator was calculated using data on the degree of water storage in agricultural water reservoirs because 87% of water for irrigation was taken from the agricultural water reservoirs. Water use technical efficiency was calculated as the reverse of the ratio of irrigation water to a standard water requirement of the paddy rice. The efficiency in 2001 was better than in 1990 and 1998. As for the economic efficiency for water use, we think that there are a lot of things to be taken into considerations to make a useful indicator to reflect socio-economic values of agricultural products resulted from the water use. Conclusively, site-specific, regional or meteorogical characteristics as in Korea were not considered in the calculation of water use indicators by methods suggested in OECD(Volume 3, 2001). So, it is needed to develop a new indicators for the indicators to be more widely applicable in the world.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.3
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• pp.145-152
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• 2013

This study aimed to investigate the growth and physiological characters of Liriodendron tulipifera seedlings in responses to two different levels of elevated air temperature and $CO_2$ concentration. The seedlings were grown in environment-controlled growth chambers with two combinations of air temperature and $CO_2$ conditions: (1) $22^{\circ}C$ + ambient $CO_2$ $380{\mu}mol\;mol^{-1}$ and (2) $27^{\circ}C$ + $770{\mu}mol\;mol^{-1}$. Physiological characters such as growth, photosynthesis, and water use efficiency, were monitored for 85 days. The seedlings under the elevated treatment showed a greater amount of growth in tree height, compared with those under the control. Regarding the characteristics of assimilatory organs, the elevated treatment resulted in a greater amount of total leaf area, leaf unfolding, and dry weight per leaf area. No significant differences were found in photosynthesis capacity between the two treatments. The increase in water use efficiency with increased intercellular $CO_2$ partial pressure appeared overall lower in the seedling under the elevated treatment, compared with those under the control. The total leaf area of the seedlings under the elevated treatment was larger than that under the control, indicating a higher amount of photosynthesis. In addition, an increase of root growth was noted under the elevated treatment. A resistance mechanism of water stress may be attributed to a higher amount of organ growth as well as the tree height under the elevated treatment than the control.

• Horticultural Science & Technology
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• v.33 no.6
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• pp.820-828
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• 2015

This study was carried out to determine the effects of vernalization, temperature, and soil water deficit (SD) on mesophyll cells, growth, and yield of Chinese cabbage (Brassica campestris L). The palisade parenchyma and spongy tissues of Chinese cabbage were observed under full irrigation and two weeks of SD treatment. These cells were severely collapsed by four weeks SD treatment. The SD treatment had the greatest influence on the growth of Chinese cabbage among the tested treatment factors (vernalization, temperature, and SD), growth significantly decreased by severe drought treatment (four weeks SD treatment). In addition, the relative growth rate, unit leaf rate, leaf area ratio, specific leaf area, and leaf weight ratio were significantly affected by SD treatment; however, other individual factors and their combined treatments did not influence the analyzed growth parameters. The yield under vernalization after high temperature and full irrigation treatments was 3,056 kg/10 a, which was the greatest among all the tested treatments, while four-week SD treatment significantly reduced the yield. Head formation of Chinese cabbage was not altered under SD treatment, and vernalization treatments did not induce bolting. Our results indicated that collapsing mesophyll cells and reduced growth and yield were induced by SD treatment. Thus we suggest that optimal irrigation system should be install to avoid or overcome crippling drought conditions in the open field.

• Journal of Plant Biotechnology
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• v.44 no.4
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• pp.409-415
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• 2017

The vegetation period of trees might be prolonged by the delay of the leaf senescence in autumn. Thus, we focused on the generation of senescence-delayed transgenic trees to enhance biomass production. The PagMYC2, a gene containing the basic helix-loop-helix domain, was selected as a candidate for a senescence-delayed transgenic tree. The PagMYC2 gene was specifically induced after treatment with phytohormone jasmonic acid, and upregulated by abiotic stresses such as salinity, osmotic pressure and a low temperature. The constitutive overexpression of the PagMYC2 delayed the leaf senescence and inhibited chlorophyll degradation in the transgenic poplars. Leaf senescence analysis was performed in the leaf tissues of the PagMYC2-over-expression transgenic poplars. The transgenic poplars exhibited higher photochemical efficiency than did a wild type plant under a short-day condition (6 hours light/18 hours darkness) or a low temperature condition ($15^{\circ}C$) that was similar to the weather conditions of autumn. These results suggest that the PagMYC2 is a useful genetic resource to improve biomass production, which is able to sustain growth with senescence-delayed leaves for a long time in autumn.

• Journal of the Korean Vacuum Society
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• v.22 no.5
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• pp.245-249
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• 2013

The $HfO_X$ thin film was deposited what it has been paid attention to the next generation oxide thin layer of MOSFET (metal-Oxide semiconductor field-effect-transistor) by rf magnetron sputter on Si (100) substrate. The $HfO_X$ thin film was deposited using a various oxygen gas flows (5, 10, 15 sccm). After deposition, $HfO_X$ thin films were annealed from 400 to $800^{\circ}C$ for 20 min in nitrogen ambient. The electrical characteristics of the $HfO_X$ thin film was improved by leakage current properties, depending on the increase of oxygen gas flow and annealing temperature. In particular, the properties of nano-mechanics of $HfO_X$ thin films were measured by AFM and Nano-indenter. From the results, the maximum indentation depth at the basis of maximum indentation force was increased from 24.9 to 38.8 nm according to increase the annealing temperature. Especially, the indentation depth was increased rapidly at $800^{\circ}C$. The rapid increasement of indentation depth was expected to be due to the change of residual stress in the $HfO_X$ thin film, and this result was caused by relative flux of oxygen outgasing during the annealing process.