• Nutrition Research and Practice
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• 제5권4호
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• pp.357-364
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• 2011

Selenium is an antioxidant trace element linked to cardiovascular disease and cancer. Although diet is a major source, relatively little else is known about independent determinants of selenium levels in free-living humans. In this study, we aimed to investigate the independent demographic. lifestyle, and dietary determinants of selenium levels in 1,997 men and 1,905 women in two large prospective U.S. cohorts. Toenail selenium levels were quantified using neutron activation analysis. Diet, geographic residence, demographic, and environmental factors were assessed by validated self-administered questionnaires. Multivariate generalized linear models were conducted to assess the independent relations of these factors with toenail selenium levels, correcting for measurement error in the diet. In multi variable-adjusted analyses, independent predictors of higher selenium were male gender (6.3% higher levels); living in West and Northern-Midwest U.S. regions (8.9% and 7.4% higher than Southern-Midwest regions, respectively); consumption of beef and bread products (between 0.7 - 2.5% higher per daily serving); and selenium supplement use (6.9% higher than non-users); whereas cigarette smoking (5-10% lower than never smokers), older age (0.6% lower per 5 years), and consumption of eggs, white rice, dairy products, coffee, and alcohol (between 0.1 to 2.0% lower per daily serving) were associated with lower selenium. Multiple dietary and non-dietary factors independently predicted selenium levels, suggesting that both consumption and non-dietary processes (e.g.. related to oxidant status) may affect levels. Significant geographic variation in selenium levels exists in the US.

• Journal of the Korean Wood Science and Technology
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• 제40권2호
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• pp.110-122
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• 2012

This study investigated the effects of layered clay on the thermal curing behavior and tensile properties of resole phenol-formaldehyde (PF) resin/clay/cellulose nanocomposites. The thermal curing behavior of the nanocomposite was characterized using conventional differential scanning calorimetry (DSC) and temperature modulated (TMDSC). The addition of clay was found to accelerate resin curing, as measured by peak temperature ($T_p$) and heat of reaction (${\Delta}H$) of the nanocomposite’ curing reaction increasing clay addition decreased $T_p$ with a minimum at 3~5% clay. However, the reversing heat flow and heat capacity showed that the clay addition up to 3% delayed the vitrification process of the resole PF resin in the nanocomposite, indicating an inhibition effect of the clay on curing in the later stages of the reaction. Three different methods were employed to determineactivation energies for the curing reaction of the nanocomposite. Both the Ozawa and Kissinger methods showed the lowest activation energy (E) at 3% clay content. Using the isoconversional method, the activation energy ($E_{\alpha}$) as a function of the degree of conversion was measured and showed that as the degree of cure increased, the $E_{\alpha}$ showed a gradual decrease, and gave the lowest value at 3% nanoclay. The addition of clay improved the tensile strengths of the nanocomposites, although a slight decrease in the elongation at break was observed as the clay content increased. These results demonstrated that the addition of clay to resole PF resins accelerate the curing behavior of the nanocomposites with an optimum level of 3% clay based on the balance between the cure kinetics and tensile properties.

• 한국IT서비스학회지
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• 제19권4호
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• pp.31-47
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• 2020

Recently, as the COVID-19 has spread and prolonged worldwide, the 'Untact' society is becoming routinized, and various smart technologies are leading to the spread of the 'Ontact' culture. This is because the desire of consumers to purchase a product and use the service has increased while minimizing the direct contact. In order to quickly respond to this circumstance, the percentage of the companies which are adopting Chatbot in various fields such as orders, delivery, and inquiries is increasing and they are getting a positive result. However as the demand for building Chatbot increases dramatically, there are many confusions among the companies which want to introduce Chatbot to their system, due to the lack of professional technicians and difficulties in understanding AI technologies and how to build them effectively. I believe that in the post COVID-19 era, much more companies will adopt Chatbot, and this will intensify the problem. The purpose of this study was to derive the needs for a guide on the method of buiilding a Chatbot through considering the prior research on Chatbot and analysis of the recent surge in the use of Chatbot services related to COVID-19. There are implications to presenting 5 phases of universal Chatbot implementation methodology using the platform to the stakeholders who want to introduce Chatbot to their customer so that they can understand and build Chatbot more easily and use AI Chatbot actively in response to the POST COVID-19 era.

• Asian-Australasian Journal of Animal Sciences
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• 제12권1호
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• pp.84-92
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• 1999

The rumen microbial ecosystem is coming to be recognized as a rich alternative source of genes for industrially useful enzymes. Recent advances in biotechnology are enabling development of novel strategies for effective delivery and enhancement of these gene products. One particularly promising avenue for industrial application of rumen enzymes is as feed supplements for nonruminant and ruminant animal diets. Increasing competition in the livestock industry has forced producers to cut costs by adopting new technologies aimed at increasing production efficiency. Cellulases, xylanases, ${\beta}$-glucanases, pectinases, and phytases have been shown to increase the efficiency of feedstuff utilization (e.g., degradation of cellulose, xylan and ${\beta}$-glucan) and to decrease pollutants (e.g., phytic acid). These enzymes enhance the availability of feed components to the animal and eliminate some of their naturally occurring antinutritional effects. In the past, the cost and inconvenience of enzyme production and delivery has hampered widespread application of this promising technology. Over the last decade, however, advances in recombinant DNA technology have significantly improved microbial production systems. Novel strategies for delivery and enhancement of genes and gene products from the rumen include expression of seed proteins, oleosin proteins in canola and transgenic animals secreting digestive enzymes from the pancreas. Thus, the biotechnological framework is in place to achieve substantial improvements in animal production through enzyme supplementation. On the other hand, the rumen ecosystem provides ongoing enrichment and natural selection of microbes adapted to specific conditions, and represents a virtually untapped resource of novel products such as enzymes, detoxificants and antibiotics.

• Journal of Preventive Medicine and Public Health
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• 제49권4호
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• pp.249-251
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• 2016

Objectives: Nail salon owners in New York City (NYC) are required to provide their workers with gloves and it is their responsibility to maintain healthy, safe working spaces for their employees. The purpose of this study was to determine the frequency with which nail salon workers wear protective gloves. Methods: A Freedom of Information Law request was submitted to New York Department of State's Division of Licensing Services for a full list of nail salons in Manhattan, NYC. A sample population of 800 nail salons was identified and a simple random sample (without replacement) of 30% (n=240) was selected using a random number generator. Researchers visited each nail salon from October to December of 2015, posing as a potential customer to determine if nail salon workers were wearing gloves. Results: Among the 169 salons in which one or more workers was observed providng services, a total of 562 workers were observed. For 149 salons, in which one or more worker was observed providing services, none of the workers were wearing gloves. In contrast, in six of the salons observed, in which one or more workers was providing services, all of the workers (1 in 2 sites, 2 in 1 site, 3 in 2 sites, and 4 in 1 site) were wearing gloves. Almost three-quarters of the total number of workers observed (n=415, 73.8%) were not wearing gloves. Conclusions: The findings of this study indicate that, despite recent media attention and legislation, the majority of nail salon workers we observed were not wearing protective gloves when providing services.

• Genomics & Informatics
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• 제7권3호
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• pp.152-158
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• 2009

Although the genetic basis for bone mineral density (BMD) has been studied by many groups so far, genes responsible for this complex trait has not been completely revealed. In order to localize quantitative trait loci (QTLs) for BMD variation in Asian population, the study was designed using a group of Mongolian population, a genetically closed population with a homogeneous lifestyle. BMD was measured at the left and right wrists and ankles using DEXA in 1,082 participants from 142 families. Genotyping of 13 polymorphic microsatellite markers on chromosome 13 (average spacing 8-9 cM) and two-point and multipoint linkage analysis were performed. In two-point linkage analysis, we identified two markers, D13S175 (6.03 cM) and D13S265 (68.73 cM) that had LOD scores greater than 1 for left ankle (LOD=2.09, LOD=1.49, respectively). We also found a marker D13S175 (6.03 cM) with a high LOD for left wrist (LOD=1.49) and the markers D13S265 (68.73 cM) and D13S217 (17.21 cM) for the right wrist (LOD= 1.82, LOD= 1.62, respectively). Among these significant marker regions, only two regions at 17 cM (13p11) and 65 cM (13q21) for the right wrist overlapped with major QTLs reported in following multipoint linkage analysis (LOD= 1.7549, LOD=1.4462, respectively). This study provides the possible evidence of the presence of QTLs affecting right wrist BMD in Mongolian populations on 13p11 and 13q21. Modest evidence was also found for genes affecting left ankle and left wrist BMD on 13p13.

• 대한치과교정학회지
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• 제27권6호
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• pp.865-870
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• 1997

폐쇄성 수면무호흡(이하 OSA)환자의 일반적 특징의 하나로 다소 비대한 Submental부위를 든다. 따라서 근간에는 경부 주위의 측정을 임상적 진단의 한 보조방법으로 채택하는 경우도 있다. 본 연구는 80명의 환자로 부터 직접위와 앙와위의 두 자세에서 각각 두 장의 측모두부방서선사진을 채득하여 OSA환자의 안면과 혀의 크기를 일반인의 그것과 비교 하였다. 채득된 실험자료는 각각 증상의 심한 정도에 따라 무증상군, 경미군 중증군 그리고 중중근으로 나누었다. 크기 측정의 방법으로는 각각의 두 계측점간의 거리를 측정하여 모든 계측치의 합으로 해부학적 크기를 대신하였다. 결과로서, 안면의 크기가 혀의 크기보다 체중과 더 높은 상관관계를 보였으나, 증상의 심한 정도와는 혀의 크기가 더 중요한 측정치 임을 알수 있었다. 혀의 크기가 증상의 정도에 비례함에 있어서 $1\%$의 유의차를 보였다.

• 대한지리학회지
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• 제38권5호
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• pp.667-685
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• 2003

미국 캔자스주 정부와 연방정부가 필요로 하는 상세한 지표피복 수치지도제작을 위해, Landsat Thematic Mapper 자료를 이용하여 캔자스주 전체를 대상으로 43가지로 분류된 식생군단(vegetation alliance) 수준의 자연식 생지도를 제작하였다. 지도제작 방법으로는 봄, 여름, 가을의 계절별 위성자료를 이용하여 두 단계 분류절차를 거치는 이른바 '하이브리드(hybrid)' 방식을 채택하였다. 이 접근 방법은 첫 단계로 unsupervised classification을 이용, 자연녹지를 농경지로부터 분리해 낸 다음. 두 번째 단계에서 supervised classification, 현장확인조사. 그리고 분류 후 다양한 보강자료를 이용하여 최종적으로 자연식생을 구분ㆍ분류해 내는 것이다. 정확도 평가는 세 가지 분류 수준에서 실행되었는데, 이는 앤더슨 분류단계 I(Anderson level I), 식생군계(vegetation formation), 그리고 식생군단 수준을 포함한다. 확인결과 전반적인 정확도는 51.7%에서 89.4%에 이르는 것으로 조사되었다.

• 대한치과교정학회지
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• 제48권4호
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• pp.236-244
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• 2018

Objective: The aim of this study is to compare the adaptation of a straight wire between brackets positioned at the mid-lingual surface and those placed gingivally by using a three-dimensional simulation software. Methods: This cross-sectional study was performed using OrthoAid, an in-house software. The subjects were 36 adolescents with normal Class I occlusion. For each dental cast, two bracket positioning approaches, namely the middle and gingival, were examined. In the middle group, the reference points were placed on the mid-lingual surface of each tooth, while in the gingival group, the reference points were positioned lingually on the anterior teeth. A 4th degree polynomial was adopted, and the in-plane and off-plane root mean squares (RMSs) of the distances between the reference points and the fitted polynomial curve were calculated using the software. Statistical analysis was performed using the paired-samples t-test (${\alpha}=0.05$). Results: The mean in-plane RMS of the polynomial curve to the bracket distance in the gingival group was significantly lower than that in the middle group (p < 0.001). The off-plane RMS was higher in the gingivally positioned brackets in the maxilla than in the middle group (p < 0.001). However, the off-plane RMS in mandible was not statistically significantly different between the two groups (p = 0.274). Conclusions: The results demonstrated that the gingival placement of lingual brackets on the anterior teeth could decrease the distance between a tooth and the straight wire.

• Childhood Kidney Diseases
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• 제16권1호
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• pp.21-31
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• 2012

초점성 분절성 사구체 경화증(focal segmental glomerulosclerosis; FSGS)은 경화증을 주 병변으로 하는 질환으로서 일차성 사구체 질환의 하나이면서 진행된 사구체 질환의 형태적 변화를 기술하는 단어로도 사용되고 있다. 사구체에는 경화증, 유리질 형성, 거품세포의 출현, 발세포의 공포화, 광륜형성 등이 보이고, 간질의 섬유화와 염증세포의 침윤, 세뇨관의 위축, 혈관의 비후 및 내막 섬유화 등을 특징으로 한다. 면역형광검사에서 부분적으로 IgM과 C3 등의 침착을 보이지만 면역관련 질환은 아니다. 전자현미경 검사에서는 발세포의 손상 현상으로 세포질 내의 공포화와 족돌기가 상실되는 것이 중요 소견이다. 2004년 표준화 된 FSGS의 분류는 과거의 형태학적 변형들을 모아서 임상과의 상관관계를 지웠다. 그 결과 tip형이 가장 예후가 좋으며, collapsing형이 가장 나쁜 것으로 알려졌다. 그러나 이 분류가 증례에 따라서는 적용하기가 애매한 경우가 많고, collapsing형을 FSGS에 분류하는 것에 대한 반론 등이 제기되고 있다. 한편, 임상적으로는 FSGS를 원인에 따라 분류하여 거꾸로 형태학적 공통점을 찾으려는 노력을 하고 있다. 사구체의 수가 적어서 일어나는 과여과로 인한 FSGS는 perihilar형이 많고 유전적 질환에 의한 것은 diffuse mesangial sclerosis가 특징인 것으로 주장되고 있다. FSGS는 이와 같이 아직도 밝혀져야 할 것이 많은 질환이며, 계속적인 연구가 이루어져야 할 필요가 있다.