• Title/Summary/Keyword: Elevated $CO_2$

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Ecophysiology of Photosynthesis 3: Photosynthetic responses to elevated atmospheric $CO_2$ concentration and temperature (광합성의 생리생태 (3) - $CO_2$ 농도와 온도 상승에 대한 광합성 반응 -)

  • 김판기;이은주
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.3 no.4
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    • pp.238-243
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    • 2001
  • 대기중의 $CO_2$ 농도 상승은 지구온난화의 주원인이 되고 있는데, 1960년대 전반에 320$\mu$㏖ㆍ㏖$^{-1}$ 이하 였던 $CO_2$농도가 화석연료의 사용량 증가, 삼림 벌채 등의 영향으로 근년에는 360 $\mu$㏖ㆍ㏖$^{-1}$ 이상으로 상승하였다(Bagastow et al., 1985). 이러한 추세로 대기중의 $CO_2$ 농도가 증가한다면 21세기 말에는 $CO_2$ 농도가 현재의 약 2배로 상승되고, 2~6$^{\circ}C$의 기온 상승이 예측되어 (Burroughs, 2001) 지구차원의 환경문제로 대두되고 있다.(중략)

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Changes in photosynthesis and carbohydrate synthesis in response to elevated UV-B environment (고 자외선 환경에서 식물의 광합성, 기공조절 및 탄수화물 합성)

  • Yun, Hyejin;Sung, Jwakyung;Lee, Suyeon;Lee, Yejin;Ha, Sangkeun;Sonn, Yeonkyu
    • Korean Journal of Agricultural Science
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    • v.41 no.4
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    • pp.275-281
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    • 2014
  • The ozone depletion has caused plants to be exposed to an increased penetration of solar ultraviolet-B (UV-B) radiation. Enhanced UV-B radiation may have influence on biological functions of plant in many aspects including inhibition of photosynthesis. It is evident that UV-B can potentially impair the performance of all three main component processes of photosynthesis, the photophosphorylation reactions of the thylakoid membrane, the $CO_2$-fixation reactions of the Calvin cycle and stomatal control of $CO_2$ supply. Owing to these depressed reactions, the production and allocation of carbohydrates might be markedly affected, and therefore, the growth and development of plant are distinctly reduced. In this review paper, we provide basic theory and further researches in terms of photosynthesis and carbohydrate synthesis in response to elevated UV-B radiation.

Ecological study on effects of heavy metal accumulation on pillbugs (토양 내 서식하는 공벌레의 중금속 축적에 따른 생태적 연구)

  • Lee, Sang-Don
    • Journal of Environmental Impact Assessment
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    • v.20 no.5
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    • pp.675-684
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    • 2011
  • In nature, the overall effect of heavy metals on the biota can be influenced by a number of environmental factors like soil characteristics and air pollution by elevated $CO_2$. Pillbugs (Isopoda, Armadillium vulgare) take up heavy metals with their food and store them mainly in the vesicles of hepatopancreas. They accumulate certain metals, occur in relatively large numbers, are easily collected and identified, and provide sufficient material for analysis. The species are decomposing litter well and soil impurities into N and P. Therefore, it has been suggested that total body concentration of metals in pillbugs could be positively correlated to the levels of environmental exposure and that pillbugs could be used as biological indicators of metal pollution and global change by $CO_2$. The aim of the study is to determine effects of heavy metal concentrations in soil and elevated $CO_2$ on pillbugs' body accumulation of heavy metal and growth rate. In this study, the concentrations of six metals (Fe, Mg Cu, Zn, Pb, Cd) have been determined. Pillbugs (N=287) were collected at five sites during Jul-Aug, 2006. Cu and Zn concentrations in the body were much higher than in the soils(1.39-41.70 times). This indicated that bioaccumulation of some of the heavy metals were increasing in the food-chain. The high bioconcentration of lead in Sangam may be partly associated with reclaimed land uses.

Blood test results from simultaneous infection of other respiratory viruses in COVID-19 patients

  • In Soo, Rheem;Jung Min, Park;Seung Keun, Ham;Jae Kyung, Kim
    • International Journal of Advanced Culture Technology
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    • v.10 no.4
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    • pp.316-321
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    • 2022
  • Since 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread rapidly, infecting millions of people worldwide. On March 11, 2020, the World Health Organization declared coronavirus disease (COVID-19) a pandemic owing to the worldwide spread of SARS-CoV-2, which created an unprecedented burden on the global healthcare system. In this context, there are increasing concerns regarding co-infections with other respiratory viruses, such as the influenza virus. In this study, clinical data of patients infected with SARS-CoV-2 and other respiratory viruses were compared with patients infected with SARS-CoV-2 alone. The hematology and blood biochemistry results of 178 patients infected with SARS-CoV-2 , who were tested on admission, were retrospectively reviewed. In patients with SARS-CoV-2 and adenovirus co-infection, C-reactive protein levels were elevated on admission, whereas lactate dehydrogenase (LDH), prothrombin time, international normalized ratio, activated partial thromboplastin clotting time, and bilirubin values were all within the normal range. Moreover, patients with SARS-CoV-2 and human bocavirus co-infection had low LDH and high bilirubin levels on admission. These findings reveal the clinical features of respiratory virus and SARS-CoV-2 co-infections and support the development of appropriate approaches for treating patients with SARS-CoV-2 and other respiratory virus co-infections.

Severe SARS-CoV-2 Infection With Multiorgan Involvement Followed by MIS-C in an Adolescent

  • Bomi Lim;Su-Mi Shin;Mi Seon Han
    • Pediatric Infection and Vaccine
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    • v.29 no.3
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    • pp.155-160
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    • 2022
  • Children and adolescents with coronavirus disease 2019 (COVID-19) generally have mild symptoms. Severe infection due to severe acute respiratory syndrome coronavirus 2 (SARSCoV-2) involving multiorgan dysfunction is rare in this population. Herein, we present an unusual case of severe SARS-CoV-2 infection with multiorgan involvement followed by multisystem inflammatory syndrome in children (MIS-C) in a vaccinated 16-year-old boy. The patient was unconscious on initial presentation, and had severe paralytic ileus. On laboratory examination, there was severe metabolic acidosis, lymphocytopenia, thrombocytopenia, elevated inflammatory markers, elevated liver enzymes, and evidence of acute kidney injury with proteinuria and hematuria. His symptoms improved with the administration of remdesivir and dexamethasone. The patient briefly experienced MIS-C 2 weeks after the diagnosis of COVID-19, but the patient was discharged without any complications.

Kinetics and Mechanism of Substitution Reaction of $PPN^+(\eta^n-MeCp)Mn(CO)_2\;Cl^-$ with $PR_3$(R=Me, Et, OEt, $C_6H_5$)

  • Park, Yong Gwang;Lee, Yong Gu;Kim, Gyu Sik
    • Bulletin of the Korean Chemical Society
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    • v.17 no.2
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    • pp.138-142
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    • 1996
  • The transition metal carbonylate, PPN+(${\eta}^5-MeCp)Mn(CO)_2Cl^-$ undergoes a novel ligand substitution reaction with PR3 (R=Me, Et, OEt, $C_6H_5$ in THF at elevated temperatures (40 $^{\circ}C$ up to 60 $^{\circ}C)$ under the pseudo-first-order reaction conditions (usually 20-fold excess of PR3 with respect to metal carbonylate concentrations) where chloride is displaced by PR3. The reaction follows overall first order dependence on [(${\eta}^5-MeCp)Mn(CO)_2Cl^-$]; however, the negative entropy changes of activation (${\Delta}S^{\neq}$=-19.3 e.u. for $P(OEt)_3$; ${\Delta}S^{\neq}$=-16.4 e.u. for $PPh_3$) suggest the existence of the intermediate, ((η3-MeCp)Mn(CO)2(THF)Cl-, which eventually transforms to the product (${\eta}^5-MeCp)Mn(CO)_2(PR_3)$.

Studies on the Development of Antihyperlipidemic Drugs from Oriental Herbal Medicines(II) - Antihyperlipidemic Effects of Oriental Herbal Medicines - (한방약물로부터 항고지혈증 치료약물개발(2) - 수종 한약재의 항고지혈증 효과 -)

  • Jung, Eun-Ah;Kim, Dong-Hyun;Lee, Sang-In;Kim, Nam-Jae
    • Korean Journal of Pharmacognosy
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    • v.31 no.2
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    • pp.190-195
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    • 2000
  • In the previous reports, we selected 80% MeOH extract of 7 herbs including Scutellariae Radix(SR), Paeoniae Radix Rubra(PRR), Moutan Cortex(MC), Angelicae Gigantis Radix(AGR), Crataegi Fructus(CF), Bambusae Caulis in Taeniam(BCT) and Cinnamomi Ramulus(CR), which exhibited the inhibitory effect on HMG-CoA reductase and DPPH free radical scavenging effect in vitro, and antihyperlipidemic effects on antihyperlipidemic rats induced by Triton WR 1339 in vivo. Among them, SR, MC, AGR and BCT showed significant suppression of elevated serum LDL-cholesterol level, and AGR and CF showed significant liver weight increase on high cholesterol diet induced hyperlipidemic mice. And, SR, PRR, AGR, BCT and CR significantly suppressed the elevated serum total cholesterol and triglyceride levels on corn oil induced hyperlipidemic rats. Then, in order to research new antihyperlipidemic agents from the oriental medicinal herbs, we chose SR, AGR, CR and BCT which have the antihyperlipidemic effect in vitro and in vivo, and those herbs were systematically fractionated with organic solvent. EtOAc fraction of SR, hexane fraction of BCT, AGR and chloroform fraction of CR exhibited remarkably inhibitory effect on HMG-CoA reductase activity.

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Synthesis and Equilibria of Octahedral and Tetrahedral Complexes of Cobalt (II) 2,2'-Dipyridylamine

  • Paik Suh Myunghyun;Oh Young-Hee
    • Bulletin of the Korean Chemical Society
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    • v.3 no.1
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    • pp.5-9
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    • 1982
  • Reactions of cobalt(II) chloride with 2,2'-dipyridylamine (dpa) in alcoholic solutions afford the complex of octahedral $Co(dpa)_2Cl_2{\cdot}CH_3OH$. The octahedral complex is converted to tetrahedral $Co(dpa)Cl_2$ in certain solvents or at the elevated temperature, and the tetrahedral complex is changed to the octahedral one with added dpa. The electronic spectra of the complexes in DMF, measured with various concentrations of 2,2'-dipyridylamine, establish the equilibrium; $td-Co(dpa)Cl_2+dpa_\rightleftarrows^Koh-Co(dpa)_2Cl_2$. The equilibrium constants determined by the analysis of the visible spectra are 6.4, 3.6 and 2.0 $M^{-1}$, respectively, at 25.5, 38.0 and $49.0^{\circ}C,\;with\;{\Delta}H^{\circ}\;and\;{\Delta}S^{\circ}$being -9.5 kcal/mole and -28 eu.