• Environmental Analysis Health and Toxicology
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• v.19 no.3
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• pp.261-269
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• 2004

Although the biological functions of metallothioneins (MTs) are still being investigated, they have been suggested to be involved in detoxification of heavy metals, scavenging of free radicals, and protection against alkylating agents. MTs have been reported to be induced in most of animal tissues by heavy metals such as zinc, copper, mercury and cadmium, and the proteins have binding affinities to the metals. However, the presence or induction of MTs was reported not to be clear in leydig cells, which produce testosterone for the maturation of spermatozoa in male testes. In this study, we investigated the inducibility of metallothionein isomers by cadmium in cultured mouse leydig cells. Total RNA was extracted from the near confluent grown leydig cells and RT-PCR was Performed using the Primers which were synthesized on the basis of MT-1, 2, 3 and 4 cDNA from GenBank database. As results, MT-1 and MT-2 mRNA were found to be expressed in cadmium non-treated control cells and MT 1 mRNA expression was dose-dependent when leydig cells were treated with cadmium chloride. But MT-3 which is known to be brain specific and MT-4 which is another isoform of metallothionein, were not expressed. Other genes induced or depressed in cadmium treated leydig cells were also identified by microarray techniques.

• Applied Chemistry for Engineering
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• v.10 no.6
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• pp.881-884
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• 1999

We have studied the other unit which is partial element in fullerene $C_{90}$. The energy of the higher fullerene increased by 5.6 kcal/mol for each $1.0{\beta}$ of planarity for the other units and increased by 11.0 kcal/mol for each $2C_1$ other unit at RHF/AM1 method. Therefore, we have known that the stable $C_{90}$ isomer do not have $C_1$ unit in other unit and have small planarity. The confirmable $C_{90}$ isomers by experiment satisfies these two conditions.

• Applied Chemistry for Engineering
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• v.21 no.5
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• pp.481-487
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• 2010

Recently membrane-based gas separation has attracted a great deal of research interests due to the growing demands on greener technologies. Current membrane-based gas separation is dominant by polymer membranes and limited mostly to non-condensable gases even though condensable gases such hydrocarbon isomers are much more attractive. This is primarily due to the limitations of polymer materials. Zeolites and their composites with polymer can offer alternative to current polymeric membranes owing to their superior separation and chemical/thermal properties. This review is intended to provide a brief overview on zeolite and zeolite/polymer composite membranes for gas separation applications.

• Korean Journal of Materials Research
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• v.2 no.2
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• pp.101-109
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• 1992

Polyethylene terephthalate(PET) is a well known commercial polymer widely available as fibre and as a major polymer with diverse applications. In this experiment, for the modification of PET, the pentanediol isomers, 1,5-pentanediol(1,5-PD) and neopentyl glycol(NPG), were introduced as third monomers. Crystallization rate decreased by the added NPG of PET modified by NPG units. In the case of PET modified by 1,5-PD, crystallization rate had been slightly increased at all temperatures until the 1,5-PD was added about 10 mol%. The decreased crystallization rate is thought to be due to branched from methyl group of neopentyl, which greatly retards the crystallization by growing onto the crystal surface of the diffused polymer chain.

• Analytical Science and Technology
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• v.17 no.3
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• pp.282-288
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• 2004

Inclusion selectivities of the cyanocadmate host complexes with ammonium oniums, $[Cd_x(CN)_{2x}][onium{\cdot}zG]$ (onium = $NMe_3Et^+$, $NMeEt{_3}^+$ and $NEt{_4}^+$, G = guest), have been investigated for $C_6H_6$ (B), PhMe (T), PhEt (E), ortho (O), meta (M), and para (P) isomers of $C_6H_4Me_2$ as the aromatic guest molecules. From the binary, ternary, quaternary and quinary mixed guests of B, T, E, O, M and P, the order of preference in the $NMe_3Et+$-host is $B{\gg}$T>P${\fallingdotseq}O{\fallingdotseq}M$ and E>O${\gg}P{\fallingdotseq}M$; in the $NMeEt{_3}^+$-host is T>B>P${\gg}O{\fallingdotseq}M$ and E>P${\gg}$M>O; in the $NEt{_4}^+$-host is $B{\gg}T{\fallingdotseq}O{\fallingdotseq}M{\fallingdotseq}P$. However, the $NEt{_4}^+$-host complexes of E, O, M and P mixed-guests were not obtained. These inclusion selectivities were compared to our previous results of the $NMe{_4}^+$-host; T>B>P${\gg}$M>O and E>P${\gg}$M>O.

• Analytical Science and Technology
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• v.23 no.4
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• pp.363-370
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• 2010

This study was performed to validate reference materials (RMs) for proficiency testing (PT) in waste inter-laboratories. Dioxin RMs were prepared from fly ash in industrial incinerators. The relative standard deviations (RSDs) of analytical results were 2.6~15.7% for the dioxin RMs in 10 replicates (between and withinbottles). Data were collected and statistical analysis was performed by the One-way ANOVA test. The combined uncertainties of target isomers in dioxin analysis were 0.114~7.091.

• Mass Spectrometry Letters
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• v.6 no.3
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• pp.53-58
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• 2015

Recombinant erythropoietins (EPOs) are an important class of biotherapeutics that stimulate red blood cell production. The quality, safety, and potency of EPO variants are determined largely by their glycosylation, which makes up nearly half their mass. Thus, detailed glycomic analyses are important to assess biotherapeutic quality and establish the equivalency of biosimilar EPOs now coming to market. High-resolution mass spectrometry (MS) has recently emerged as the premier tool for glycan analysis in EPOs. Using the accurate mass measurements provided by high-resolution MS, the compositions of even large, complex glycans can easily be determined. When combined with a nano-LC separation, differentiation of structural isomers also becomes a possibility. These components, together, provide a comprehensive picture of biotherapeutic glycosylation. In this review, we provide an overview of MS-based analytical platform for glycomic characterization of EPO biotherapeutics and biosimilars.

• Analytical Science and Technology
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• v.13 no.6
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• pp.789-801
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• 2000

This analysis was conducted for PCDDs/PCDFs in sediment by isotope dilution HRGC/HRMS method. From the result, the mean recovery of surrogate standard was in the range of 70.1-80.8%. Among the distribution of 2, 3, 7, 8-substituted isomers, the concentration of OCDD represented almost 40.6-78.5% of total concentration and that of OCDF showed 6.6-14.7% and 1, 2, 3, 4, 6, 7, 8-HpCDD showed 5.1-7.7%. The portion of PCDDs represented 62.4-86.9% of total PCDDs/PCDFs. In the TEQ concentration 1, 2, 3, 4, 7, 8-PeCDF concentration represented 22.7-35.6 % of total TEQ concentration.

• Korean Journal of Environmental Agriculture
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• v.30 no.2
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• pp.202-208
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• 2011

BACKGROUD: ${\alpha}$- and ${\beta}$- Endosulfan isomers of endosulfan, an endocrine disrupting chemical, are widely used cyclodiene organochlorine pesticide in worldwide, and it has widespread application in agriculture and can contaminate river-system as runoff from soil or aerial deposition METHOD AND RESULTS: In this study, an attempt was made to isolate an endosulfan degrading fungus from endosulfan-polluted agricultural soil. Through repetitive enrichment and successive subculture in media containing endosulfan and its metabolites as the sole carbon source, a fungus designated KEF-1 was isolated. Based on phylogenetic analysis, strain KEF-1 was assigned to the genus Eutypella. Also, the ITS (internal transcribed spacer) sequences of KEF-1 were submitted to GenBank under accession number EF581006. In potato dextrose broth containing 8 ${\mu}g$/mL endosulfan, strain KEF-1 completely degraded the endosulfanin 12 days. CONCLUSION: These results suggested that Eutypella sp. KEF-1 has potential as a biocatalyst for endosulfan bioremediation

• Journal of the Korean Chemical Society
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• v.32 no.6
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• pp.536-542
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• 1988

A nickel(Ⅱ) complex, Ni(IAA-NBz) (IAA-NBz') with ligand, N-benzylisonitrosoacetyl acetone imine (H-IAA-NBz) has been synthesized. This complex is very stable at room temperature and has cis-form and trans-form isomers. The ratio of nickel (Ⅱ) ion and ligand combined is 1 : 2. The elemental analysis, ir, nmr. electronic spectra and mass spectra have been studied. It is suggested from these studies that the isonitroso group of one ligand, H-IAA-NBz coordinates to nickel(Ⅱ)ion through the nitrogen atom to form five-membered ring, while that of the other ligand, H-IAA-NBz coordinates to nickel (Ⅱ) ion through the oxygen atom to form six-membered ring in square-planar complex.