• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제2권2호
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• pp.109-114
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• 1998

The induction of crassulacean acid metabolism(CAM) characterized by day/night acid fluctuation was investigated in leaves from 10 days exposure to elevated $CO_2$ concentration(1,000 ${\mu}L\;L^{-1}CO_2).$ For Pereskia aculeata, have $C_3-like$ gas exchange pattern in well watered condition and shift into CAM-like in water stress, showed a more typical CAM-like diurnal acid fluctuation. Whereas the massive diurnal fluctuation of acidity in typical CAM of Kalanchoe rosea was declined. The effect of short-term exposure to various concentrations of $CO_2$ on titratable acidity in P. aculeata and K. rosea was also investigated. To investigate the response of various $CO_2$ concentrations, four different $CO_2$ levels(350, 700, 1,000 and 1,500 ${\mu}L\;L^{-1})$ were imposed for 24hr and measured the titratable acidity at 06:00, when the acidity was maximum, and 14:00, when the acidity was minimum. The accumulation of acid in P. aculeata was enhanced markedly by higher concentration of $CO_2,$ while the level of acidity in f rosea did not highly respond to $CO_2.$ A notable difference between P. aculeata and K. rosea was the response of de-acidification to a higher concentration of $CO_2$ Increasing with $CO_2,$ the degree of do-acidification of P. auleata was increased while that of K. rosea was depressed.

• Journal of Plant Biology
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• 제31권4호
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• pp.277-288
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• 1988

The effects of ammonium ion and glutamate on CO2 fixation abilities and related carbon metabolism were investigated in pea (Pisum sativum L. cv. Sparkle) leaf discs under conditions favoring photorespiration (21% O2, 0.03% CO2) and nonphotorespiration (5% O2, 0.03% CO2). A concentration of more than 10 mM of NH4+ decreased the photosynthetic CO2 fixation and those inhibitory effects were more remarkable in 21% O2 than in 5% O2 conditions. The effect of glutamate on CO2 fixation was found to be independent of the O2 level, as glutamate increased the CO2 fixation under both 21% and 5% O2 conditions. L-methionine-dl-sulfoximine, an irreversible inhibitor of glutamate synthetase, however, inhibited the CO2 fixation markedly under 21% O2, but did not affect it under 5% O2 conditions. The treatment with NH4+ elevated the relative amounts of 14C incorporated into soluble components from 14CO2 with no relation to O2 levels, while glutamate increased 14C into insoluble components and neutral sugars. Glutamate, especially, seemed to stmulate the biosynthesis of starch under 5% O2 condition. These results indicated that NH4+ stimulated the degradation of sugar or starch and this proposal was confirmed by the increasing of pyruvate kinase activity in leaf discs treated with ammonium ion.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.191.2-191.2
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• 2014

Cu/ZnO/$Al_2O_3$ is widely used methanol synthesis catalyst at elevated pressures P (50 to 100 bar) and temperatures T (473 to 573 K) using $CO_2$, CO, $H_2$ syngas mixture. Although Cu step and planar defects have been regarded as active sites in this catalyst, detailed $CO_2$ hydrogenation procedure has been still unknown and debated as well as initial intermediate. In this study, we investigated the mechanism of $CO_2$ hydrogenation on Cu(111) model surface at P (1 bar) and T (298 to 450 K) using reflection absorption infrared spectroscopy (RAIRS). Two distinct formates by hydrogenation of $CO_2$, on step and on terrace, show different behavior with elevating temperature. The peak intensity of on step formate was continuously decreased above 360 K up to 450K in contrast to the increase of on terrace formate. These phenomena are strong possibilities that the formate is initial intermediate and is desorbed by hydrogenation reaction because thermal desorption temperature of formate (~470 K) is much higher than desorption of on step formate. And the formate production peak of on step site was weakly correlated with CO formation.

• 천문학논총
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• 제27권4호
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• pp.177-179
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• 2012

We present Spitzer IRS spectroscopy of $CO_2$ ice toward 19 young stellar objects (YSOs) with luminosity lower than $1L_{\odot}$. Pure $CO_2$ ice forms only at elevated temperatures, T > 20 K, and thus at higher luminosities. Current internal luminosities of YSOs with L < $1L_{\odot}$ do not provide such conditions out to radii of typical envelopes. Significant amounts of pure $CO_2$ ice would signify a higher past luminosity. We analyze $15.2{\mu}m$ $CO_2$ ice bending mode absorption lines in comparison to the laboratory data. We decompose pure $CO_2$ ice from 12 out of 19 young low luminosity sources. The presence of the pure $CO_2$ ice component indicates high dust temperature and hence high luminosity in the past. The sum of all the ice components (total $CO_2$ ice amount) can be explained by a long period of low luminosity stage between episodic accretion bursts as predicted in an episodic accretion scenario. Chemical modeling shows that the episodic accretion scenario explains the observed total $CO_2$ ice amount best.

• BMB Reports
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• 제56권12호
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• pp.669-674
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• 2023

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection leads to various clinical symptoms including anemia. Lipocalin-2 has various biological functions, including defense against bacterial infections through iron sequestration, and it serves as a biomarker for kidney injury. In a human protein array, we observed increased lipocalin-2 expression due to parental SARS-CoV-2 infection in the Calu-3 human lung cancer cell line. The secretion of lipocalin-2 was also elevated in response to parental SARS-CoV-2 infection, and the SARS-CoV-2 Alpha, Beta, and Delta variants similarly induced this phenomenon. In a Calu-3 implanted mouse xenograft model, parental SARSCoV-2 and Delta variant induced lipocalin-2 expression and secretion. Additionally, the iron concentration increased in the Calu-3 tumor tissues and decreased in the serum due to infection. In conclusion, SARS-CoV-2 infection induces the production and secretion of lipocalin-2, potentially resulting in a decrease in iron concentration in serum. Because the concentration of iron ions in the blood is associated with anemia, this phenomenon could contribute to developing anemia in COVID-19 patients.

• 한국재료학회지
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• 제11권12호
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• pp.1042-1046
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• 2001

Co-22%Cr alloy films are promising for high-density perpendicular magnetic recording media with their perpendicular anisotropy and large coercivity of 3000 Oe. We observed that a self organized nano structure(SONS) of fine ferromagnetic Co-enriched phase and paramagnetic Cr-enriched phase appears inside the grain of Co-Cr magnetic alloy thin films at the elevated substrate temperature after do-sputtering. We prepared 1000 $\AA$-thick Co-22%Cr films on 2000 $\AA$- SiO$_2$/Si(100) substrates at the deposition rate of 100 $\AA$/min with substrate temperatures of 3$0^{\circ}C$, 10$0^{\circ}C$, 15$0^{\circ}C$, 20$0^{\circ}C$, 30$0^{\circ}C$, and 40$0^{\circ}C$, respectively. We employed a vibrating sample magnetometer(VSM) to measure the B-H loops showing the saturation magnetifation, coercivity, remanence in in- plane and out- of- plane modes. In- plane coercivity, perpendicular coercivity, and perpendicular remanence increased as substrate temperature increased, how-ever they decreased after 30$0^{\circ}C$ slowly. Transmission electron microscope (TEM) characterization revealed that the self organized nano structure (SONS) appears at the elevated substrate temperature, which forms fine Co-enriched phases inside a grain, then it eventually affect the perpendicular magnetic property. Our results imply that we may tune the perpendicular magnetic properties with SONS obtained at appropriate substrate temperature.

• 한국농림기상학회지
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• 제20권2호
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• pp.149-158
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• 2018

본 연구는 지구온난화에 따른 봄 감자에 대한 상승된 $CO_2$농도, 온도 그리고 한발에 미치는 영향을 평가를 위해 국립식량과학원 옥외환경시설에서 수행을 하였다. 감자는 C3식물로 상승된 $CO_2$농도와 적정 온도에 효과적인 생육 반응을 하지만, 괴경비대기의 한발은 수량 증가를 억제 시킨다. 괴경 수량은 상승된 $CO_2$농도와 온도 그리고 한발 처리에 따라 상당히 유의한 차이를 보여 주었다. SAPR 2는 SPAR 1에 비하여 수량이 28% 증가 되었는데, 생육기간 동안 SPAR 2는 $CO_2$ 효과와 적정온도로 주당 괴경수의 증가보다는 개체당 괴경의 크기에 의해 수량이 결정 된 것으로 판단된다. 한편 SPAR 3은 SPAR 2에 비하여 약 56% 수량 감소를 하였다. 괴경비대기의 한발은 형태적으로 간장과 측지수의 감소와 건물중 생산에 저해를 주었다. 생리적으로 엽록소와 질소 양분흡수을 감소시켜 결국 광합성률 감소와 괴경으로 전류 되는 동화산물이 낮아지면서 수량 감소 원인이 된 것으로 판단되었다. 따라서 향후 이상 기후 대응을 위해, 다양한 기후 조건에서 재배되는 감자의 생육을 파악하기 위한 기후변화 시나리오 및 봄 감자의 작부체계 개선이 필요할 것으로 판단된다.

• 한국생물환경조절학회:학술대회논문집
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• 한국생물환경조절학회 1995년도 특강 및 학술논문발표요지
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• pp.87-88
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• 1995

양액재배에서는 토양재배와는 달리 $CO_2$ 농도의 급격한 감소가 나타나게 된다. 또한 엽채류는 질소 공급원에 대한 생육 반응이 민감하며, 그 양상도 다양하게 나타므로 배양액의 NO$_3$ : NH$_4$ 비는 작물의 생육, 수량, 품질 등에 큰 영향을 미치게 된다. 본 실험은 결구상추의 수경재배에서 $CO_2$시용에 따른 질소동화 촉진작용을 검토하고, 배양액 내 질소원의 형태별 비율이 작물생육에 미치는 영향을 구명하여, 결구 상추의 생산성을 극대화하고자 실시하였다. (중략)

• ALGAE
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• 제29권3호
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• pp.203-215
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• 2014

As global warming continues over the coming century, marine organisms will experience a warmer, more acidic ocean. Although these stressors may behave antagonistically or synergistically and will impact organisms both directly (i.e., physiologically) and indirectly (i.e., through altered species interactions), few studies have examined the complexities of these effects in combination. To address these uncertainties, we examined the independent and combined effects of elevated temperature and $pCO_2$ on the physiology of the adult sporophyte stage of giant kelp, Macrocystis pyrifera, and the grazing of the purple sea urchin Strongylocentrotus purpuratus. While elevating $pCO_2$ alone had no effect on M. pyrifera growth or photosynthetic carbon uptake, elevating temperature alone resulted in a significant reduction in both. However, when M. pyrifera was grown under elevated temperature and $pCO_2$ together, growth and photosynthetic carbon uptake significantly increased relative to ambient conditions, suggesting an interaction of these factors on photosynthetic physiology. S. purpuratus held under future conditions generally exhibited reduced growth, and smaller gonads than urchins held under present-day conditions. However, urchins fed kelp grown under future conditions showed higher growth rates, partially ameliorating this effect. Feeding rates were variable over the course of the experiment, with only the first feeding rate experiment showing significantly lower rates for urchins held under future conditions. Together, these data suggest that M. pyrifera may benefit physiologically from a warmer, more acidic (i.e., higher $pCO_2$) ocean while S. purpuratus will likely be impacted negatively. Given that kelp-urchin interactions can be important to kelp forest structure, changes to either of these populations may have serious consequences for many coastal environments.

• 생태와환경
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• 제55권4호
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• pp.341-351
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• 2022

The physiological characteristics, growth, and yield of each regional rice variety ('Odaebyeo', 'Saechucheong', 'Ilmibyeo') were investigated depending on the impact of changes in temperature and CO₂ concentration. Experiments were conducted with a control group, which reflected atmospheric CO₂ concentration and temperature, and treatment groups, in which the CO₂ concentration and temperature were increased by 250 ppm and 2.0℃ from those in the control group. The results showed that the increase in CO₂ concentration and temperature reduced the growth and yield of the rice 'Odaebyeo', but did not substantially change the productivity of the 'Saechucheong' and 'Ilmibyeo'. The increase in CO₂ concentration and temperature increased stomatal conductance and rate of transpiration of the 'Odaebyeo' variety, thereby decreasing its water use efficiency (WUE). In contrast, the increase in CO₂ concentration and temperature increased the photosynthetic rate and WUE of the 'Saechucheong' and 'Ilmibyeo' varieties. The gradual change in climate is considered to directly affect growth and development of rice and diversely affect the productivity of each variety. Therefore, it is necessary to implement technological development, select regionally optimal rice varieties, develop new rice varieties, as well as conduct long-term monitoring of each rice variety for climate adaptation to counter global warming.