• 한국지구과학회지
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• 제34권3호
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• pp.209-223
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• 2013

이 연구의 목적은 한반도에서 $CH_4$ 농도의 수치모의 검증을 통하여 $CH_4$ 배출원의 기여 농도를 추정하는 것이고, 이 수치모의에 사용된 $CH_4$ 배출량을 상자모델로부터 추정된 $CH_4$ 배출량과 비교하는 것이다. 한반도에서 2010년 4월 1일부터 8월 22일까지 $CH_4$의 평균 농도를 추정하기 위해 WRF-CMAQ 모델이 사용되었다. 모델에서 $CH_4$ 배출량은 전지구 배출량인 EDGAR와 한국에서의 온실기체 배출량인 GHG-CAPSS로부터 인위적 배출 인벤토리와 전지구 자연적 인벤토리인 MEGAN이 적용되었다. 이들 $CH_4$ 배출량은 안면도 및 울릉도에서 측정된 $CH_4$ 농도와 모델링 농도 자료를 비교함으로써 검증되었다. 울릉도에서 국내 배출원으로부터 추정된 $CH_4$의 기여 농도는 약 20%로 나타났고, 이것은 한반도 내 농장(8%), 에너지 기여 및 산업공정(6%), 일반폐기물(5%), 생체 및 토지이용(1%) 등 $CH_4$ 배출원으로부터 기원하였다. 그리고 중국으로부터 수송된 $CH_4$의 기여 농도는 약 9%였고, 나머지 배경농도는 약 70%로 나타났다. 박스모델로 추정된 $CH_4$ 배출량은 WRF-CMAQ 모델에서 사용한 $CH_4$ 배출량과 유의미한 결과를 얻었다.

• 한국대기환경학회지
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• 제29권6호
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• pp.789-800
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• 2013

$N_2O$ and $CH_4$, Greenhouse gas emission, Forest soil, Closed chamber technique, Soil uptake $N_2O$ and $CH_4$ are important greenhouse gases (GHG) along with $CO_2$ influencing greatly on climate change. Their soil emission rates are highly affected by bio-geo-chemical processes in C and N through the land-atmosphere interface. The forest ecosystems are generally considered to be net emission for $N_2O$; however, net sinks for $CH_4$ by soil uptake. Soil $N_2O$ and $CH_4$ emissions were measured at Mt. Taewha in Gwangju, Kyeonggi, Korea. Closed chamber technique was used for surface gas emissions from forest soil during period from May to October 2012. Gas emission measurement was conducted mostly on daytime (from 09:00 to 18:00 LST) during field experiment period (total 25 days). The gas samples collected from chamber for $N_2O$ and $CH_4$ were analyzed by gas chromatography. Soil parameters were also measured at the sampling plot. GHG averages emissions during the experimental period were $3.11{\pm}16.26{\mu}g m^{-2}hr^{-1}$ for $N_2O$, $-1.36{\pm}11.3{\mu}gm^{-2}hr^{-1}$ for $CH_4$, respectively. The results indicated that forest soil acted as a source of $N_2O$, while it acted like a sink of $CH_4$ on average. On monthly base, means of $N_2O$ and $CH_4$ flux during May (spring) were $8.38{\pm}48.7{\mu}gm^{-2}hr^{-1}$, and $-3.21{\pm}31.39{\mu}gm^{-2}hr^{-1}$, respectively. During August (summer) both GHG emissions were found to be positive (averages of $2.45{\pm}20.11{\mu}gm^{-2}hr^{-1}$ for $N_2O$ and $1.36{\pm}9.09{\mu}gm^{-2}hr^{-1}$ for $CH_4$); which they were generally released from soil. During September (fall) $N_2O$ and $CH_4$ soil uptakes were observed and their means were $-1.35{\pm}12.78{\mu}gm^{-2}hr^{-1}$ and $-2.56{\pm}11.73{\mu}gm^{-2}hr^{-1}$, respectively. $N_2O$ emission was relatively higher in spring rather than other seasons. This could be due to dry soil condition during spring experimental period. It seems that soil moisture and temperature mostly influence gas production and consumption, and then emission rate in subsoil environment. Other soil parameters like soil pH and chemical composition were also discussed with respect to GHG emissions.

• 한국결정학회지
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• 제9권2호
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• pp.107-113
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• 1998

Ar하에서 trans-FeHCl(dppe)2, 1을 4-chlorobutyronitrile에 녹이면, 착물 trans-[FeH(NCCH2CH2CH2Cl)(dppe)2]Cl, 2가 생성되고, 2는 NaBF4와 반응하여 착물 trans-[FeH(NCCH2CH2CH2Cl)(dppe)2][BF4], 3로 변환된다. 착물 3의 결정학 자료: 단사정계 공간군 P21/c, a=13.540(2) , b=17.058(3) , c=21.853(4) , β=90.15(1)o, Z=4, R(wR2)=0.0524(0.1239).

• Bulletin of the Korean Chemical Society
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• 제33권4호
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• pp.1264-1267
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• 2012

We rationally designed and synthesized metallopolymers with organic 1,4-benzenedicarboxylic acid (BDC) linkers with different lengths of oxyethylene side chains in order to examine the influence of side chains on the coordination characteristics. While in a previous report the BDC linkers with alkyl side chains were found to form three-dimensional (3D) isoreticular metal-organic framework (IRMOF) structures or one-dimensional (1D) coordination polymeric structures with short $-O(CH_2)_6CH_3$ or long $-O(CH_2)_9CH_3$ side chains, respectively, new BDC linkers with oxyethylene side chains of the same lengths, $-(OCH_2CH_2)_2CH_3$ and $-(OCH_2CH_2)_3CH_3$, form only 3D IRMOF structures. This result is attributed to the higher flexibility and smaller volume of oxyethylene side chains compared to alkyl side chains.

• 폴리머
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• 제24권1호
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• pp.133-139
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• 2000

분자량이 200 또는 400인 poly(ethylene glycol) (PEG 200, PEG 400)을 알칼리 존재하에서 다양한 linking agent (CH$_2$C1$_2$, CH$_2$Br$_2$, CH$_2$I$_2$, Br(CH$_2$)$_3$Br)와 반응시켜 oxyalkylene-linked poly(oxyethylene) 공중합체를 합성하였다. 얻어진 공중합체의 분자량은 alkali/CH$_2$C1$_2$/PEG의 당량비를 달리하여 조절하였으며 PEG 200을 사용하였을 경우 약 500~8500, 그리고 PEG 400을 사용하였을 경우 약 1000~2000정도이었다. 말단의 -OH기 농도 적정에 의한 분자량과 GPC에 의해 얻어진 분자량은 서로 거의 일치하였다. PEG 400으로부터 얻어진 공중합체는 유리전이온도가 약 -75$^{\circ}C$정도였고, 용융온도가 1$0^{\circ}C$정도였으며 결정화도가 0~25% 정도이었다. 또한 PEG 200을 이용하여 합성된 공중합체의 경우는 분자량이 2500이하에서는 완전한 비정형 물질임을 알 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제24권1호
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• pp.60-64
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• 2003

The reactions of $[Pt(dppf)Cl_2]$ with thiophenol (PhSH), 1-propanethiol (n-PrSH), and 1,3-propanedithiol $(HSCH_2CH_2CH_2SH)$ gave the corresponding Pt-dppf-di(thiolato) compounds, $[Pt(dppf)(SPh)_2]\;(1),\;[Pt(dppf)(S-n-Pr)_2]\;(2),\;and [Pt(dppf)(SCH_2CH_2CH_2S)]\;(3)$, respectively. All products are monomeric and 4-coordinate square-planar compounds and were structurally characterized by X-ray diffraction. Electrochemical measurements (cyclovoltammograms) revealed that the oxidation potential of the dppf ligand appears to depend on the type of the group on the thiolato ligand.

• Bulletin of the Korean Chemical Society
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• 제20권11호
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• pp.1295-1298
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• 1999

Novel platinum(IV) complexes with asymmetric chiral diamine ligands cis,cis,trans-A2PtCl2(X)2 (X = OH, OCOCH3, OCOC2H5, A2 =NH2CH(CH3)CH2NH(c-C6H11)(apcha), NH2CH(CH3)CH2NH(c-C5H9)(apcpa)) have been prepared. One of the platinum(IV) complexes, (apcpa)PtCl2(OCOC2H5)2(6), was subjected to X-ray crystallographic analysis. The crystal structure of (apcpa)PtCl2(OCOC2H5)2 (monoclinic, P21 (No. 4), a = 9.1391(1), b = 22.2517(1), c = 10.0687(1)Å, β= 109.105(1)。 , V = 1934.80(3)Å3 , Z = 4, R1 = 0.0532) exhibits that the platinum atom achieves a typical octahedral arrangement with two nitrogen atoms in cis positions and two carboxylato group in trans positions. The spectroscopic data disclose that these platinum(IV) complexes are stable and their molecular structures are retained in aqueous solution. The title complexes are highly cytotoxic in vitro but do not exhibit oral anticancer activity in vivo.

• 대한화학회지
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• 제24권1호
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• pp.1-7
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• 1980

메탄올, 에탄올 및 에탄올-물 혼합용매중에서 메틸클로로휘메이트, 메틸티올클로로휘메이트, 메틸티오노클로로휘메이트 및 메틸디티오클로로휘메이트의 가용매분해반응에 대한 속도상수를 전기전도도법으로 구하고 활성화 파라미터를 계산하였다. 결과로 메틸클로로휘메이트는 항상 $S_N2$ 메카니즘으로 반응하며, 가수분해 순위는 $CH_3S(CS)Cl>CH_3S(CO)Cl>CH_3O(CS)Cl>CH_3O(CO)Cl$ 로 $S_N1$ 반응성이 감소하고, 메탄올에서는 $CH_3S(CS)Cl$은 $S_N1$으로, 기타는 $S_N2$로 반응하고, 에탄올에서는 모두 $S_N2$로 반응하나 아직도 메틸클로로디티오휘메이트는 $S_N1$ 반응성이 어느정도 작용함을 알았다. 또한 에탄올-물 혼합용매에서 물함량이 큰 부분에서는 티오치환체의 $S_N1$ 반응성이 증가하며 메틸클로로디티오휘메이트는 $S_N1$으로 반응함을 알았다. 에탄올-물 혼합용매중에서 $S_N1$ 반응성의 순위는 가수분해속도의 순위와 같았다.

• 한국육종학회지
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• 제42권1호
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• pp.50-55
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• 2010

옥수수 R 유전자의 대립인자 중 하나인 R-r:standard (R-r:std)는 종자 호분층의 안토시아닌 합성을 조절하는 S subcomplex와 종자 이외 식물체부위의 안토시아닌 합성을 조절하는 P component로 구성되어 있으며, S subcomplex는 S1 및 S2 component로 구성되어 있다. R 유전자의 대립인자 중 일부는 Pl 유전자가 존재할 경우 종피의 안토시아닌 합성을 유도한다. 따라서 Pl 유전자가 존재할 경우 옥수수 종피의 안토시아닌 합성을 유도하는 R 유전자의 구성요소를 구명하고자 종피의 안토시아닌 합성에 미치는 서로 다른 R 인자들의 효과를 분석하였다. R-ch와 r-ch 인자는 유사한 정도의 착색 효과를 보였으며, R-r:Ecuador (R-r:Ec)는 이들보다 짙은 착색효과를 나타내었다. S subcomplex의 기능은 상실하였으나 정상적인 P component를 보유하고 있는 것으로 추정되는 r-ch는 Pl 유전자가 존재할 경우 종피의 색소합성 기능을 유지하고 있으나, S subcomplex의 기능은 정상이나 P component의 기능은 잃어버린 것으로 추정되는 R-r:Ec 유래 인자 R-g:g1111는 Pl 유전자가 존재할 경우에도 종피가 착색되지 않았다. 더욱이 R-ch와 r-ch 인자의 PCR 분석 결과, R-ch는 P와 S1 component를 보유하고 있으나, r-ch는 S1을 보유하고 있지 않는 것으로 나타났다. 따라서 R 유전자의 구성요소 중 P component가 종피의 안토시아닌 합성에 관여하는 구성요소로 추정되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권12호
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• pp.1942-1949
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• 2019

Objective: Leukocyte cell-derived chemotaxin 2 (LECT2) is associated with several physiological processes including inflammation, tumorigenesis, and natural killer T cell generation. Chicken LECT2 (chLECT2) gene was originally identified as one of the differentially expressed genes in chicken kidney tissue, where the chickens were fed with different calcium doses. In this study, the molecular characteristics and gene expression of chLECT2 were analyzed under the stimulation of toll-like receptor 3 (TLR3) ligand to understand the involvement of chLECT2 expression in chicken metabolic disorders. Methods: Amino acid sequence of LECT2 proteins from various species including fowl, fish, and mammal were retrieved from the Ensembl database and subjected to Insilco analyses. In addition, the time- and dose-dependent expression of chLECT2 was examined in DF-1 cells which were stimulated with polyinosinic:polycytidylic acid (poly [I:C]), a TLR3 ligand. Further, to explore the transcription factors required for the transcription of chLECT2, DF-1 cells were treated with poly (I:C) in the presence or absence of the nuclear factor ${\kappa}B$ ($NF{\kappa}B$) and activated protein 1 (AP-1) inhibitors. Results: The amino acid sequence prediction of chLECT2 protein revealed that along with duck LECT2 (duLECT2), it has unique signal peptide different from other vertebrate orthologs, and only chLECT2 and duLECT2 have an additional 157 and 161 amino acids on their carboxyl terminus, respectively. Phylogenetic analysis suggested that chLECT2 is evolved from a common ancestor along with the actinopterygii hence, more closely related than to the mammals. Our quantitative polymerase chain reaction results showed that, the expression of chLECT2 was up-regulated significantly in DF-1 cells under the stimulation of poly (I:C) (p<0.05). However, in the presence of $NF{\kappa}B$ or AP-1 inhibitors, the expression of chLECT2 is suppressed suggesting that both $NF{\kappa}B$ and AP-1 transcription factors are required for the induction of chLECT2 expression. Conclusion: The present results suggest that chLECT2 gene might be a target gene of TLR3 signaling. For the future, the expression pattern or molecular mechanism of chLECT2 under stimulation of other innate immune receptors shall be studied. The protein function of chLECT2 will be more clearly understood if further investigation about the mechanism of LECT2 in TLR pathways is conducted.