• 공업화학
• /
• 제20권4호
• /
• pp.355-362
• /
• 2009

석유를 기반으로 한 연료는 가까운 미래에 고갈될 것이다. 디메틸에테르(Di-methyl Ether, DME)는 청정에너지이며 천연가스,석탄 및 바이오매스 등으로 생산이 가능하다.DME는 분자구조 내에 탄소-탄소 결합이 없는 함산소 연료로 연소시 그을음과 황산화물을 발생하지 않으며, 물리적 특성이 액화석유가스(Liquified Petroleum Gas, LPG)와 매우 유사하여 LPG 유통인프라를 그대로 활용할 수 있다. DME는 세탄값이 55~60 정도로 높아 디젤 자동차용 연료로도 활용이 가능하다.차세대 청정연료로 혹은 차세대 화학공업 원료물질로 전력생산,디젤 연료, 가정용 연료 및 연료전지 등에 사용이 가능하다.본 총설에서는DME의 특성, 표준화, 국내외의 기술개발현황, 대체연료로서의 활용에 대해 살펴보고자 한다.

• 생명과학회지
• /
• 제14권6호
• /
• pp.1028-1039
• /
• 2004

6500만년동안, Alu 서열은 RNA-중합효소 III에 의한 전사체를 통해 증폭해왔고, 영장류 게놈 내에 약 140만 복사의 수에 도달되었다. 그들은 가동성 인자 중에서 가장 큰 집단이며, 인간 게놈의 $10\%$를 구성한다. Alu 서열이 유전적으로 기능이 없다고 생각되었지만, 최근 많은 연구자들이 새로운 기능 및 질병과의 관련성을 증명해왔다 이들 Alu 서열은 삽입돌연변이, Alu-매개 재조합, 유전자 발현에 대해 유전자 전환 그리고 스플라이싱 사이트를 유발하고, 유전자 구조, 단백질 서열, 스플라이싱 모티프와 발현 양상에 영향을 준다. 우리는 Alu의 구조와 기원, 그들 패밀리의 컨센서스 서열, Alu의 진화와 분포 그리고 그들의 기능에 대하여 요약 정리하였다. 또한 영장류의 진화과정에 있어 질병과 관련하여 Alu 패밀리의 새로운 연구방향을 제시하였다.

• 한국식품과학회지
• /
• 제22권4호
• /
• pp.386-392
• /
• 1990

장려품종 콩 19종의 단백질 특성 비교로 추출용매에 따른 단백질 획분의 분포, 전기영동 특성 및 아미노산 조성을 조사하였다. 이들 콩에 함유된 글리시닌은 콩단백질의 $48.19{\sim}58.86%$를 차지하였으며 다른 획분에 비해 프롤라민의 비율은 콩의 품종간에 큰 차이를 보였다. 콩 단백질의 전기영동 양상은 팔달, 장백, 장엽, 단엽, 남천 및 S-138이 $21.5{\sim}31.0kd$ 범위에서 보인 단백질 분리대의 차이를 제외하고서는 품종간의 차이가 없었다. 콩에 소량 함유된 아미노산류는 시스테인 메티오닌 티로신 및 트레오닌이었으며 티로신의 비율이 다른 아미노산에 비해 품종에 따른 차이가 가장 큰 것으로 나타났다.

• BMB Reports
• /
• 제36권1호
• /
• pp.1-11
• /
• 2003

The causative role of polycyclic aromatic hydrocarbons (PAH) in human carcinogenesis is undisputed. Measurements of PAH-DNA adduct levels in easily accessible white blood cells therefore represent useful early endpoints in exposure intervention of chemoprevention studies. The successful applicability of DNA adducts as early endpoints depends on several criteria:i.adduct levels in easily accessible surrogate tissues should reflect adduct levels in target-tissues, ii. toxicokinetics and the temporal relevance should be properly defined.iii. sources of inter- and intra-individual variability must be known and controllable, and finally iv. adduct analyses must have advantages as compared to other markers of PAH-exposure. In general, higher DNA adduct levels or a higher proportion of subjects with detectable DNA adduct levels were found in exposed individuals as compared with non-exposed subjects, but saturation may occur at high exposures. Furthermore, DNA adduct levels varied according to changes in exposure, for example smoking cessation resulted in lower DNA adduct levels and adduct levels paralleled seasonal variations of air-pollution. Intra-individual variation during continuous exposure was low over a short period of time (weeks), but varied significantly when longer time periods (months) were investigated. Inter-individual variation is currently only partly explained by genetic polymorphisms in genes involved in PAH-metabolism and deserves further investigation. DNA adduct measurement may have three advantages over traditional exposure assessment: i. they can smooth the extreme variability in exposure which is typical for environmental toxicants and may integrate exposure over a longer period of time. Therefore, DNA adduct assessment may reduce the monitoring effort. ii. Biological monitoring of DNA adducts accounts for all exposure routes. iii. DNA adducts may account for inter-individual differences in uptake, elimination, distribution, metabolism and repair amongst exposed individuals. In conclusion, there is now a sufficiently large scientific basis to justify the application of DNA adduct measurement as biomarkers in exposure assessment and intervention studies. Their use in risk-assessment, however, requires further investigation.

• Parasites, Hosts and Diseases
• /
• 제51권4호
• /
• pp.449-452
• /
• 2013

Taenia pisiformis is one of the most important parasites of canines and rabbits. T. pisiformis cysticercus (the larval stage) causes severe damage to rabbit breeding, which results in huge economic losses. In this study, the genetic variation of T. pisiformis was determined in Sichuan Province, China. Fragments of the mitochondrial cytochrome b (cytb) (922 bp) gene were amplified in 53 isolates from 8 regions of T. pisiformis. Overall, 12 haplotypes were found in these 53 cytb sequences. Molecular genetic variations showed 98.4% genetic variation derived from intra-region. $F_{ST}$ and Nm values suggested that 53 isolates were not genetically differentiated and had low levels of genetic diversity. Neutrality indices of the cytb sequences showed the evolution of T. pisiformis followed a neutral mode. Phylogenetic analysis revealed no correlation between phylogeny and geographic distribution. These findings indicate that 53 isolates of T. pisiformis keep a low genetic variation, which provide useful knowledge for monitoring changes in parasite populations for future control strategies.

• Parasites, Hosts and Diseases
• /
• 제51권4호
• /
• pp.401-412
• /
• 2013

Because of an increased number of Acanthamoeba keratitis (AK) along with associated disease burdens, medical professionals have become more aware of this pathogen in recent years. In this study, by analyzing both the nuclear 18S small subunit ribosomal RNA (18S rRNA) and mitochondrial 16S rRNA gene loci, 27 clinical Acanthamoeba strains that caused AK in Japan were classified into 3 genotypes, T3 (3 strains), T4 (23 strains), and T5 (one strain). Most haplotypes were identical to the reference haplotypes reported from all over the world, and thus no specificity of the haplotype distribution in Japan was found. The T4 sub-genotype analysis using the 16S rRNA gene locus also revealed a clear subconformation within the T4 cluster, and lead to the recognition of a new sub-genotype T4i, in addition to the previously reported sub-genotypes T4a-T4h. Furthermore, 9 out of 23 strains in the T4 genotype were identified to a specific haplotype (AF479533), which seems to be a causal haplotype of AK. While heterozygous nuclear haplotypes were observed from 2 strains, the mitochondrial haplotypes were homozygous as T4 genotype in the both strains, and suggested a possibility of nuclear hybridization (mating reproduction) between different strains in Acanthamoeba. The nuclear 18S rRNA gene and mitochondrial 16S rRNA gene loci of Acanthamoeba spp. possess different unique characteristics usable for the genotyping analyses, and those specific features could contribute to the establishment of molecular taxonomy for the species complex of Acanthamoeba.

• Molecular & Cellular Toxicology
• /
• 제4권1호
• /
• pp.1-4
• /
• 2008

The 5-HTT gene is a candidate gene for influencing the clinical response to antidepressant treatment. The purpose of this gene study was to determine the relationship between serotonin transporter gene polymorphism at the SLC6A4 and the response to citalopram in a Korean population with major depressive disorder (MDD). Citalopram was administered for 8 weeks to the 80 patients who completed this study. The severity of depression was assessed with the 21-item Hamilton Depression Rating scale, and the 5-HTTLPR genotypes in the patients were determined using the polymerase chain reaction. Our result did not showed significant differences in, allele, and carrier distribution between the normal group and MDD patients. This study suggest that polymorphism of the 5HTT gene was not associated with citalopram response to MDD in the Korean population.

• 대한수의학회지
• /
• 제29권3호
• /
• pp.303-313
• /
• 1989

To investigate the epidemiological trait of intestinal diseases of animals caused by thermophilic Campyllobacter spp., isolation of etiological agent was carried out and the profiles of plasmids and the transfer of resistance plasmid in the isolated Campylobacter spp. were examined. The results were as follows. 1. A total of 110 isolates of C jejuni and C coli were subjected to the test for the presence of plasmid DNA. Of the isolates examined, 60% of the isolates were noted to harbor plasmid DNA. Plasmid occurrencer ate from pigs, chickens and cattle were 76.2%, 61.7% and 37.7%, respectively. The plasmids of a large molecular weight, ranging from 36 Md to 86Md, were identified with the strains of tetracycline resistant. 2. Transfer frequency of tetracycline resistant plasmids was higher in the case of the filter mating method than in the broth mating method by the factor of 10~1,000. 3. Tetracycline resistant plasmids of C jejuni were transferrable to C jejuni and C coli by conjugation. In a low frequency, the transfer of tetracycline plasmid was also possible to Vibrio parahemolyticus. However, it was impossible to transfer to Streptococcus fecalis, E coli and Vibrio cholerae. 4. Tetracycline resistant plasmids of C jejuni were impossible to transfer to Campylobacter spp. and related bacteria by transformation.

• 한국물환경학회지
• /
• 제23권3호
• /
• pp.397-402
• /
• 2007

Anammox reactor seeded with sewage sludge from RBC reactor and anaerobic granule from full-scale UASB reactor treating distillery wastewater was operated. Mixed granule and suspended sludge in the ammonium oxidizing process were taken and analyzed to investigate microbial community structure by molecular methods such as gene cloning and phylogenetic tree analysis after 250 days of continuous cultivation. The average nitrogen removal rate showed $0.9kg\;N/m^3-day$ after 250 days of continuous operation, then the maximum nitrogen removal rate showd $1.9kg\;N/m^3-day$ when $2.1kg\;N/m^3-day$ of nitrogen loading rate was applied. As results of gene cloning and phylogenetic tree analysis, Three kinds of phylum were found to be Proteobacteria, Acidobacteria and Planctomycetes (anammox bacteria) in mixed granule. Five kinds of phylum were found to be Proteobacteria, Chlorobi, Planctomycetes, Nitrospirae and Verrucomicrobia in suspended sludge. We found planctomycete KSU-1 and putative new anammox bacteria in the reactor. Microbial structure represented different consortia depending on the types of sludge in the anammox reactor.

• 한국약용작물학회지
• /
• 제14권2호
• /
• pp.96-100
• /
• 2006

Regions of allelic loss on chromosomes in many tumors of human and some experimental animals are generally considered to harbor tumor-suppressor genes involved in tumorigenesis. Allelotype analyses have greatly improved our under-standing of the molecular mechanism of radiation lymphomagenesis. Previously, we and others found frequent loss of heterozygosity (LOH) on chromosomes 4, 11, 12, 16 and 19 in radiation-induced lymphomas from several $F_1$, hybrid mice. To examine possible contributions of individual tumor-suppressor genes to tumorigenesis in p53 heterozygous deficiency, we investigated the genome-wide distribution and status of LOH in radiation-induced lymphomas from $F_1$ mice with different p53 status. In this study, we found frequent LOH (more than 20%) on chromosomes 4 and 12 and on chromosomes 11, 12, 16 and 19 in radiation-induced lymphomas from $(STS/A{\times}MSM/Ms)F_1$ mice and $(STS/A{\times}MSM/Ms)F_1-p53^{KO/+}$ mice, respectively. Low incidences of LOH (10-20%) were also observed on chromosomes 11 in mice with wild-type p53, and chromosomes 1, 2, 9, 17 and X in p53 heterozygous-deficient mice. The frequency of LOH on chromosomes 9 and 11 increased in the $(STS/A{\times}MSM/Ms)F_1-p53^{KO/+}$ mice. Preferential losses of the STS-derived allele on chromosome 9 and wild-type p53 allele on chromosome 11 were also found in the p53 heterozygous-deficient mice. Thus, the putative tumor-suppressor gene regions responsible for lymphomagenesis might considerably differ due to the p53 status.