• Composites Research
• /
• 제13권5호
• /
• pp.50-59
• /
• 2000

본 논문에서는 복합재료 패널 플러터를 억제할 수 있는 두 가지 방법에 대해서 연구하였다. 첫번째, 능동제어 방법에서는 선형 제어 이론을 바탕으로 제어기를 설계하였으며 제어입력이 작동기에 가해진다. 여기서 작동기로는 PZT를 사용하였다. 두 번째, 인덕터와 저항으로 구성되어진 션트회로를 사용하여 시스템의 감쇠를 증가시킴으로써 패널 플러터를 억제할 수 있는 새로운 방법인 수동감쇠기법에 대한 연구가 수행되었다. 이 수동감쇠기법은 능동적 제어보다 강건(robust)하며 커다란 전원 공급이 필요하지 않고 제어기나 감지 시스템과 같이 복잡한 주변 기기가 필요 없이도 실제 패널 플러터 억제에 쉽게 응용할 수 있는 장점을 가지고 있다. 최대의 작동력/감쇠 효과를 얻기 위해서 유전자 알고리듬을 사용하여 압전 세라믹의 형상과 위치를 결정하였다. 해밀턴 원리를 사용해서 지배 방정식을 유도하였으며, 기하학적 대변형을 고려하기 위해 von-Karman의 비선형 변형률-변위 관계식을 사용하였으며 공기력 이론으로는 준 정상 피스톤 1차 이론을 사용하였다. 4절점 4각형 평판 요소를 이용하여 이산화된 유한 요소 방정식을 유도하였다. 효율적인 플러터 억제를 위해 패널 플러터에 중요한 영향을 미치는 플러터 모드를 이용한 모드축약기법을 사용하였으며, 이를 통해 비선형 연계 모달 방정식이 얻어지게 된다. 능동적 제어 방법과 수동 감쇠 기법에 의해 수행되어진 플러터 억제 결과들을 Newmark 비선형 시분할 적분법을 통해 시간 영역에서 살펴 보았다.

• Journal of Yeungnam Medical Science
• /
• 제24권1호
• /
• pp.1-10
• /
• 2007

만성 피로증후군은 인지능력 감소, 근골격 및 수면 장애증상을 가지며 심한 피로감을 특징으로 하는 증상군을 말한다. 아직 명확한 진단기법이나 확립된 표식자가 없으며, 타질환을 배제한 후 증상기준에 따라 진단하고 있다. 병태생리도 명확한 인과관계가 증명되지 않고 있으며 치료 역시 환자의 증상개선과 삶의 질 향상을 목표로 여러 방법을 동원하고 있는 실정이다. 그러나 대조군과 비교한 많은 연구들에서 중추신경계, 신경호르몬 조절 시스템 및 만성 면역 활성 등의 이상이 보고되고 있으며, 이러한 결과들을 근거로 현재 다양한 치료방법이 동원되고 있다. 또한 이 증후군은 가족력의 가능성이 크므로 향후 유전 및 환경적 요인에 관한 연구가 활발해질 것으로 보인다. 대부분의 환자들은 우울증이나 범불안 장애 등을 동반하고 있으며, 이들이 병태생리와 관련 있을 가능성도 크다고 볼 수 있다. 결론적으로 이 증후군은 개인의 유전적 요소에 생리학적, 정신적 요인과 더불어 영양, 생활습관, 스트레스, 호르몬 등의 다양한 요인들이 복합적으로 상호 작용하여 만성적인 피로감과 다양한 증상을 나타내는 것으로 볼 수 있다. 환자-의사간 긴밀한 관계를 바탕으로 약물 및 비약물요법과 인지요법, 단계적 운동요법 등 효과가 인정된 치료방법을 꾸준히 사용하면 증상개선과 삶의 질 향상에 도움이 될 것으로 생각한다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제16권10호
• /
• pp.4409-4419
• /
• 2015

The Bhopal gas tragedy involving methyl isocyanate (MIC) is one of the most horrific industrial accidents in recent decades. We investigated the genotoxic effects of MIC in long-term survivors and their offspring born after the 1984 occurrence. There are a few cytogenetic reports showing genetic damage in the MIC-exposed survivors, but there is no information about the associated cancer risk. The same is true about offspring. For the first time, we here assessed the micronucleus (MN) frequency using cytokinesis-blocked micronucleus (CBMN) assay to predict cancer risk in the MIC-affected population of Bhopal. A total of 92 healthy volunteers (46 MIC-affected and 46 controls) from Bhopal and various regions of India were studied taking gender and age into consideration. Binucleated lymphocytes with micronuclei (BNMN), total number of micronuclei in lymphocytes (MNL), and nuclear division index (NDI) frequencies and their relationship to age, gender and several lifestyle variabilities (smoking, alcohol consumption and tobacco-chewing) were investigated. Our observations showed relatively higher BNMN and MNL (P<0.05) in the MIC-affected than in the controls. Exposed females (EF) exhibited significantly higher BNMN and MNL (P<0.01) than their unexposed counterparts. Similarly, female offspring of the exposed (FOE) also suffered higher BNMN and MNL (P<0.05) than in controls. A significant reduction in NDI (P<0.05) was found only in EF. The affected group of non-smokers and non-alcoholics featured a higher frequency of BNMN and MNL than the control group of non-smokers and non-alcoholics (P<0.01). Similarly, the affected group of tobacco chewers showed significantly higher BNMN and MNL (P<0.001) than the non-chewers. Amongst the affected, smoking and alcohol consumption were not associated with statistically significant differences in BNMN, MNL and NDI. Nevertheless, tobacco-chewing had a preponderant effect with respect to MNL. A reasonable correlation between MNL and lifestyle habits (smoking, alcohol consumption and tobacco-chewing) was observed only in the controls. Our results suggest that EF and FOE are more susceptible to cancer development, as compared to EM and MOE. The genotoxic outcome detected in FOE reflects their parental exposure to MIC. Briefly, the observed cytogenetic damage to the MIC-affected could contribute to cancer risk, especially in the EF and FOE.

• Asian Pacific Journal of Cancer Prevention
• /
• 제16권3호
• /
• pp.889-896
• /
• 2015

Matrix metalloproteinase-2 (MMP2) is an endopeptidase, mainly responsible for degradation of extracellular matrix components, which plays an important role in cancer disease. A single nucleotide polymorphism (SNP) at -1306 disrupts a Sp1-type promoter site. The results from the published studies on the association between MMP2 -1306 C>T polymorphism and cancer risk are contradictory and inconclusive. In the present study, a meta-analysis was therefore performed to evaluate the strength of any association between the MMP2 -1306 C>T polymorphism and risk of cancer. We searched all eligible studies published on association between MMP2 -1306 C>T polymorphism and cancer risk in PubMed (Medline), EMBASE and Google Scholar online web databases until December 2013. Genotype distribution data were collected to calculate the pooled odds ratios (ORs) and 95% confidence intervals (95%CIs) to examine the strength of the association. A total of 8,590 cancer cases and 9,601 controls were included from twenty nine eligible case control studies. Overall pooled analysis suggested significantly reduced risk associated with heterozygous genotype (CT vs CC: OR=0.758, 95%CI=0.637 to 0.902, p=0.002) and dominant model (TT+CT vs CC: OR=0.816, 95%CI=0.678 to 0.982, p=0.032) genetic models. However, allelic (T vs C: OR=0.882, 95%CI=0.738 to 1.055, p=0.169), homozygous (TT vs CC: OR=1.185, 95%CI=0.825 to 1.700, p=0.358) and recessive (TT vs CC+CT: OR=1.268, 95%CI=0.897 to 1.793, p=0.179) models did not show any risk. No evidence of publication bias was detected during the analysis. The results of present meta-analysis suggest that the MMP2 -1306 C>T polymorphism is significantly associated with reduced risk of cancer. However, further studies with consideration of different populations will be required to evaluate this relationship in more detail.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권5호
• /
• pp.2349-2354
• /
• 2012

Objective: Individual studies of the associations between P53 codon 72 polymorphism (rs1042522) and bladder cancer susceptibility have shown inconclusive results. To derive a more precise estimation of the relationship, we performed this systemic review and meta-analysis based on 15 publications. Methods: We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association. Results: We found that there was no association between P53 codon 72 polymorphism and bladder cancer risk in the comparisons of Pro/Pro vs Arg/Arg; Pro/Arg vs. Arg/Arg; Pro/Pro plus Pro/Arg vs. Arg/Arg; Arg/Arg vs. Pro/Arg plus Arg/Arg (OR=1.06 95%CI 0.81-1.39; OR=1.06 95%CI 0.83-1.36; OR=0.98 95%CI 0.78-1.23; OR=1.06 95%CI 0.84-1.32). However, a significantly increased risk of bladder cancer was found among Asians in the homozygote comparison (Pro/Pro vs. Arg/Arg, OR=1.36 95%CI 1.05-1.75, P=0.790 for heterogeneity) and the dominant model (Arg/Pro plus Pro/Pro vs. Arg/Arg, OR=1.26 95%CI 1.05-1.52, P=0.564 for heterogeneity). In contrast, no evidence of an association between bladder cancer risk and P53 genotype was observed among Caucasian population in any genetic model. When stratifying for the stage of bladder, no statistical association were found (Pro/Pro vs. Arg/Arg, OR=0.45 95%CI 0.17-1.21; Pro/Arg vs. Arg/Arg, OR=0.60 95%CI 0.28-1.27; Dominant model, OR=0.56 95%CI 0.26-1.20; Recessive model, OR=0.62 95%CI0.35-1.08) between P53 codon 72 polymorphism and bladder cancer in all comparisons. Conclusions: Despite the limitations, the results of the present meta-analysis suggest that, in the P53 codon 72, Pro/Pro type and dominant mode might increase the susceptibility to bladder cancer in Asians; and there are no association between genotype distribution and the stage of bladder cancer.

• 한국산림과학회지
• /
• 제87권3호
• /
• pp.422-428
• /
• 1998

구상나무 개체목으로부터 채취한 48개의 배유조직을 이용해서 PCR 방법에 의해 생성된 inter-simple sequence repeats(I-SSR) 표지자를 분석했다. 예비실험에서 6개의 배유조직을 이용해서 35개의 primer를 검색했으며, 그들 중에서 PCR 반응이 가장 잘되는 19개 primer를 선정해서 48개 배유조직을 이용한 본 실험에 사용했다. 카이자승 검정 결과, 19개 primer에 의해 증폭된 51개의 증폭산물이 5% 유의 수준에서 멘델의 분리비(1:1)에 따라 차대에 유전됨을 확인할 수 있었다. 멘델 유전자좌로 확인된 51개 표지자들의 게놈내 분포양상을 확인하기 위해서 연관분석을 수행한 결과, 51개 유전자좌들이 상호간에 서로 연관되어있지 않은 것으로 확인되어 이들이 전체 게놈상에 고르게 분포하고 있음을 확인할 수 있었다. 본 연구에서 관찰된 51개 유전자좌들이 게놈상에 고르게 분포하고 있다는 특성 때문에 게놈상의 특정부위에 편중되지 않은 유전정보를 얻을 수 있다는 장점이 있다. 즉, 기존의 RAPD 표지자들 중 상당수가 독립적인 연관군을 형성하는 것으로 알려져 있기 때문에 이들 연관군이 위치한 특정 부위의 DNA를 증폭하여 분석하는 RAPD 표지자에 비해서 I-SSR 표지자들이 유전 다양성을 추정하는데 더 유용한 표지자로 활용될 수 있을 것으로 생각되며, 이들 표지자들이 독립적인 진화의 과정을 겪을 것으로 기대되기 때문에 cladistic 방법에 의해 진화적 유연관계를 추정하는데 더 적합한 표지자로 생각된다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제19권2호
• /
• pp.153-159
• /
• 2006

A 2,656 bp fragment of chicken ghrelin gene was cloned and SNPs were detected by PCR-RFLP and Allele Specific PCR (ASP) in 12 Chinese indigenous chicken breeds and a commercial chicken population. The results showed that there were 23 base variations and an amino acid change ($Gln{\rightarrow}Arg$) in cloned chicken ghrelin gene. Three SNPs were confirmed in 13 populations and associations between this gene and growth traits of Tibetan chicken (TC) and Recessive White chicken (RW) were investigated. The results of haplotype analysis revealed that 26 haplotype genotypes were composed of eight haplotypes. The results of $x^2$ tests indicated that there were significant differences between genotypes or haplotype genotype frequencies in some of the breeds or sexes at 0.05 or 0.01 levels. The results of ANOVA revealed that there were significant differences between genotypes or haplotype genotypes on some growth traits of TC and RW chicken breeds at 0.05 or 0.01 levels. Multiple comparisons showed that there were significant associations between genotype CT at site 71 and some growth traits of two chicken breeds and between genotype AG at site 1,215 and body weight at 16 wk of two chicken breeds, and there was a significant association between haplotype genotype CAA/CAG and body weight and shank girth at 16 wk of two chicken breeds.

• Asian-Australasian Journal of Animal Sciences
• /
• 제31권4호
• /
• pp.473-479
• /
• 2018

Objective: The study was designed to perform a genome-wide association (GWA) and partitioning of genome using Illumina's PorcineSNP60 Beadchip in order to identify variants and determine the explained heritability for the total number of teats in Yorkshire pig. Methods: After screening with the following criteria: minor allele frequency, $MAF{\leq}0.01$; Hardy-Weinberg equilibrium, $HWE{\leq}0.000001$, a pair-wise genomic relationship matrix was produced using 42,953 single nucleotide polymorphisms (SNPs). A genome-wide mixed linear model-based association analysis (MLMA) was conducted. And for estimating the explained heritability with genome- or chromosome-wide SNPs the genetic relatedness estimation through maximum likelihood approach was used in our study. Results: The MLMA analysis and false discovery rate p-values identified three significant SNPs on two different chromosomes (rs81476910 and rs81405825 on SSC8; rs81332615 on SSC13) for total number of teats. Besides, we estimated that 30% of variance could be explained by all of the common SNPs on the autosomal chromosomes for the trait. The maximum amount of heritability obtained by partitioning the genome were $0.22{\pm}0.05$, $0.16{\pm}0.05$, $0.10{\pm}0.03$ and $0.08{\pm}0.03$ on SSC7, SSC13, SSC1, and SSC8, respectively. Of them, SSC7 explained the amount of estimated heritability along with a SNP (rs80805264) identified by genome-wide association studies at the empirical p value significance level of 2.35E-05 in our study. Interestingly, rs80805264 was found in a nearby quantitative trait loci (QTL) on SSC7 for the teat number trait as identified in a recent study. Moreover, all other significant SNPs were found within and/or close to some QTLs related to ovary weight, total number of born alive and age at puberty in pigs. Conclusion: The SNPs we identified unquestionably represent some of the important QTL regions as well as genes of interest in the genome for various physiological functions responsible for reproduction in pigs.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권24호
• /
• pp.10937-10941
• /
• 2015

Pathogenesis of lung cancer is a complicated biological process including multiple genetic and epigenetic changes. Since cigarette smoking is confirmed as the most main risk factor of non-small cell lung cancer (NSCLC), the aim of this study was to determine whether tobacco exposure plays a role in gene methylation. Methylation of the RAR-${\beta}$ gene were detected using methylation-specific polymerase chain reaction in DNA from 167 newly diagnosed cases with NSCLC and corresponding 105 controls. A significant statistical association was found in the detection rate of the promoter methylation of RAR-${\beta}$ gene between NSCLC and controls ($x^2$=166.01; p<0.01), and hypermethylation of the RAR-${\beta}$ gene was significantly associated with smoking status (p=0.038, p<0.05). No relationship was found between RAR-${\beta}$ gene methylation and pathologic staging including clinical stage, cell type, gender and drinking (p>0.05), and the methylation of RAR-${\beta}$ gene rate of NSCLC was slightly higher in stages III+IV (80.0%) than in I+II (70.8%). Similar results were obtained for methylation of the RAR-${\beta}$ gene between squamous cell carcinoma (77.9%) and other cell type lung cancer (73.9%). These results showed that the frequency of methylation increased gradually with the development of clinical stage in smoking-associated lung cancer patients, and tobacco smoke may be play a potential role in RAR-${\beta}$ gene methylation in the early pathogenesis and process in lung cancer, particularly squamous cell carcinoma. Aberrant promoter methylation is considered to be a promising marker of previous carcinogen exposure and cancer risk.

• 한국약용작물학회지
• /
• 제13권1호
• /
• pp.21-29
• /
• 2005

경남지역의 자생 둥굴레속 47개 수집종의 유연관계를 분석하기 위한 기초자료로서 수집종의 생장 몇 형태 관련 형질, 잎마름병 감염정도, 이들 형질간 상관관계를 분석하였던 바 그 결과는 다음과 같다. 1. 초장은 산둥굴레에서 가장 길었던 반면, 용둥굴레에서 가장 짧았다. 한편 줄기의 생장형태는 직립형을 포함한 3개군으로, 줄기색깔은 녹색을 포함한 3개군으로 분류하였다. 2. 염의 형태로는 타원형을 포함한 5개군으로, 엽병은 존재 유무로부터 2개군으로, 엽병의 색깔은 녹색을 포함한 3개군으로 분류되었으며, 그 중에 특이하게 피침 형태로 엽연이 자색인 1개종이 수집되었다. 3. 꽃은 화형이 항아리형, 통형, 조롱박형의 3개군으로, 화색은 흰색을 포함한 3개군으로 분류되었으며, 특별하게 조롱박형인 1개 수집종은 연녹색을 띄고 있었다. 화사는 실린더형과 편평형으로, 화경의 색깔은 자색을 포함한 4개군으로 분류되었으며, 포의 존재 유무와 형태에 따라 4개군으로 분류하였다. 4. 과실은 둥근형 등 3개군으로 분류되었으며, 백과중은 둥굴레에서 가장 무거웠던 반면, 용둥굴레에서 가장 가벼웠다. 5. 둥굴레 잎마름병에 대한 저항성이 아주 강한 것은 2종, 이병율이 7% 이하인 것은 7개종으로 조사되어서 근경수량을 증대할 수 있는 저항성 유전자원이 자생하고 있음을 알 수 있었다. 6. 제형질의 상관관계에서 근경수량과 관련된 근경중은 초장, 경직경, 엽수, 엽장, 엽폭, 지하경 직경과 정의상관을 보였으나 근경수량에 가장 큰 영향을 미치는 잎마름병 이병율은 초장, 경직경, 엽수, 엽장, 백립중, 근경중, 지하경 직경과 부의상관을 보였다.