• The Journal of Advanced Prosthodontics
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• 제12권3호
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• pp.157-166
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• 2020

PURPOSE. The aim of this study was to evaluate the clinical performance and reliability of plasma sprayed nanostructured zirconia (NSZ) coating. MATERIALS AND METHODS. This study consisted of three areas of analysis: (1) Mechanical property: surface roughness of NSZ coating and bond strength between NSZ coating and titanium specimens were measured, and the microstructure of bonding interface was also observed by scanning election microscope (SEM). (2) Biocompatibility: hemolysis tests, cell proliferation tests, and rat subcutaneous implant test were conducted to evaluate the biocompatibility of NSZ coating. (3) Mechanical compatibility: fracture and artificial aging tests were performed to measure the mechanical compatibility of NSZ-coated titanium abutments. RESULTS. In the mechanical study, 400 ㎛ thick NSZ coatings had the highest bond strength (71.22 ± 1.02 MPa), and a compact transition layer could be observed. In addition, NSZ coating showed excellent biocompatibility in both hemolysis tests and cell proliferation tests. In subcutaneous implant test, NSZ-coated plates showed similar inflammation elimination and fibrous tissue formation processes with that of titanium specimens. Regarding fatigue tests, all NSZ-coated abutments survived in the five-year fatigue test and showed sufficient fracture strength (407.65-663.7 N) for incisor teeth. CONCLUSION. In this study, the plasmasprayed NSZ-coated titanium abutments presented sufficient fracture strength and biocompatibility, and it was demonstrated that plasma spray was a reliable method to prepare high-quality zirconia coating.

• 한국도서관정보학회지
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• 제42권4호
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• pp.203-221
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• 2011

이 연구는 작은도서관에서 이루어지고 있는 장서개발 과정을 조사하여 그 문제점을 분석하고 개선방안을 제안하고자 한 조사연구이다. 장서의 중요성과 주로 소규모장서로 운영되는 작은도서관의 특성에 비추어 볼때 특히 작은도서관에 있어서 장서개발의 중요성은 재론할 필요가 없다. 그럼에도 불구하고 현재의 작은도서관은 자료구입 예산의 부족, 전문사서의 부재, 운영자의 비전문성과 과다한 업무, 잦은 이직 등으로 인하여 효과적인 장서구성에 어려움이 있으며 소장 자료의 질도 높지 않다는 것이 일반적인 관찰이다. 이러한 문제인식에 바탕하여 이 연구에서는 현재 급속히 증가하고 있는 작은도서관의 장서가 실제로 어떻게 개발되고 관리되는지 장서개발 과정을 파악하고, 업무과정에서 발생하는 제반 상황을 분석하여 실천적 문제들을 제기하고자 하였다. 이를 기반으로 작은도서관 현장에서 체계적인 장서개발이 이루어지기 위한 시사점을 제공하고자 하였다.

• 대한한의학회지
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• 제29권1호
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• pp.106-116
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• 2008

Objectives : Peroxynitrite $(ONOO^-)$, superoxide anion radical $({\cdot}O_2^-)$ and nitric oxide (NO) are cytotoxic because they can oxidize several cellular components such as proteins, lipids and DNA. They have been implicated in the aging processes, and age-related diseases such as Alzheimer's disease, rheumatoid arthritis, cancer and atherosclerosis. The aim of this study was to investigate the $ONOO^-$, NO, and $({\cdot}O_2^-)$ scavenging and anti-inflammatory activities of Mori Fructus in ob/ob mice. Methods : Mice were grouped and treated for 5 weeks as follows. Both the normal lean (C57/BL6J black mice) and control obese (ob/ob mice) groups received the standard chow. The experimental groups were fed a diet of chow supplemented with 7.5, 15 and 30 mg Mori Fructus per 1 kg of body weight for 14 days. For this study, the fluorescent probes, namely 2',7'-dichlorodihydrofluorescein diacetate (DCFDA), 4,5-diaminofluorescein (DAF-2) and dihydrorhodamine 123 (DHR 123) were used. Western blotting was performed using anti-phospho $I{\kappa}B-\alpha$, anti-IKK-$\alpha$, anti-NF-${\kappa}B$ (p50, p65), anti-COX-2 and anti-iNOS respectively. Results : Mori Fructus inhibited the generation of $ONOO^-$, NO and $({\cdot}O_2^-)$ in the lipopolysaccharide (LPS)-treated mouse kidney postmitochondria in vitro. The generation of $ONOO^-$, NO and $({\cdot}O2^-)$ were inhibited in the Mori Fructus-administered ob/ob mice groups. The GSH/GSSG ratio decreased in the ob/ob mice, whereas they improved in the Mori Fructus-administered groups. Mori Fructus inhibited the expression of phospho $I{\kappa}B-\alpha$, IKK-$\alpha$, COX-2, iNOS genes, and thereby the activation of NF-$I{\kappa}B$. Conclusions : These results suggest that Mori Fructus is an effective $ONOO^-$, $({\cdot}O_2^-)$ and NO scavenger, and therefore it might be a potential therapeutic drug against the inflammation process and inflammation-related diseases.

• Journal of Forest and Environmental Science
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• 제33권2호
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• pp.113-121
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• 2017

In flight particulate matter particularly emissions generated by incomplete combustion processes has become a subject of global concern due to the health problems and environmental impacts associated with them. This has compelled most countries to set standards for coarse and fine particles due to their conspicuous impacts on environment and public health. This contribution therefore explores forest fire emissions and how its particulates affects air quality, damage to vegetation, water bodies and biological functions as architects for lung diseases and other degenerative illnesses such as oxidative stress and aging. Soot was collected from simulated forest fire using a clean glass surface and carefully transferred into amber vials for analysis. Volatile components of soot were collected over 10 mL dichloromethane and analyzed using a QTOF Premier-Water Corp Liquid Chromatography hyphenated to a mass selective detector (MSD), and Gas Chromatograph coupled to a mass spectrometer (GC-MS). To characterize the size and surface morphology of soot, a scanning electron microscope (SEM) was used. The characterization of molecular volatiles from simulated forest fire emissions revealed long chain compounds including octadec-9-enoic acid, octadec-6-enoic acid, cyclotetracosane, cyclotetradecane, and a few aromatic hydrocarbons (benzene and naphthalene). Special classes of organics (dibenzo-p-dioxin and 2H-benzopyran) were also detected as minor products. Dibenzo-p-dioxin for instance in chlorinated form is one of the deadliest environmental organic toxins. The average particulate size of emissions using SEM was found to be $11.51{\pm}4.91{\mu}m$. This study has shown that most of the emissions from simulated forest fire fall within $PM_{10}$ particulate size. The molecular by-products of forest fire and particulate emissions may be toxic to both human and natural ecosystems, and are possible precursors for various respiratory ailments and cancers. The burning of a forest by natural disasters or man-made fires results in the destruction of natural habitats and serious air pollution.

• The Korean Journal of Ecology
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• 제23권2호
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• pp.83-88
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• 2000

When interpreting change over time in forest ecosystems, distinguishing the effects of forest succession from the effects of environmental stress can be difficult. The result may be a simplistic interpretation. citing a specific successional or environmental cause of forest change when both types may be occurring. We present two case studies of changes in the forest floor in northern hardwoods. First, the belief that 50% of soil organic matter is lost in the first 20 years after logging was based on a study comparing northern hardwood stands of different ages. We resampled a series of 13 such stands after an interval of 15 years, and found that the young stands were not, in fact. losing organic matter as rapidly as predicted from the original chronosequence study. The pattern of higher organic matter content in the forest floors of older stands compared to young stands could be equally well explained by changes in logging practices over the last century as by the aging of the stand. The observed pattern of forest floor organic matter as a function of stand age was previously interpreted as a successional pattern, ignoring changes in treatment history. In the second case study, observed losses of base cations from the forest floor were attributed to cation depletion caused by acid rain and declining calcium deposition. We found that young stands were gaining base cations in the forest floor; losses of base cations were restricted to older stands. Differences in litter chemistry in stands of different ages may explain some of the pattern in cation gains and losses. In this case, the contribution of successional processes to cation loss had been overlooked in favor of environmental stress as the dominant mechanism behind the observed changes. Studies of environmental stress use repeated measures over time. but often don't consider stand age as a factor. Studies of successional change often assume that environmental factors remain constant. We were able to consider both forest succession and external factors because we repeatedly sampled stands of different ages.

• BMB Reports
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• 제53권10호
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• pp.539-544
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• 2020

Skin aging appears to be the result of overlapping intrinsic (including genetic and hormonal factors) and extrinsic (external environment including chronic light exposure, chemicals, and toxins) processes. These factors cause decreases in the synthesis of collagen type I and elastin in fibroblasts and increases in the melanin in melanocytes. Collagen Type I is the most abundant type of collagen and is a major structural protein in human body tissues. In previous studies, many products containing collagen derived from land and marine animals as well as other sources have been used for a wide range of purposes in cosmetics and food. However, to our knowledge, the effects of human collagen-derived peptides on improvements in skin condition have not been investigated. Here we isolate and identify the domain of a human COL1A2-derived protein which promotes fibroblast cell proliferation and collagen type I synthesis. This human COL 1A2-derived peptide enhances wound healing and elastin production. Finally, the human collagen alpha-2 type I-derived peptide (SMM) ameliorates collagen type I synthesis, cell proliferation, cell migration, and elastin synthesis, supporting a significant anti-wrinkle effect. Collectively, these results demonstrate that human collagen alpha-2 type I-derived peptides is practically accessible in both cosmetics and food, with the goal of improving skin condition.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2010년도 춘계 종합학술대회 논문집
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• pp.594-600
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• 2010

노인 인구의 급격한 증가와 더불어 노인성질환도 증가함에 따라 일상적인 생활을 하지 못하는 노인에 대한 요양과 치료는 노인장기요양보험제도의 실시로 어느 정도 효과를 거두고 있지만 치매 예방을 통한 유병률 감소는 사회적 비용을 감소시킬 수 있음에도 불구하고 그 중요성이 간과되고 있다. 특히 요양시설이나 복지기관 현장에서는 경증 치매 및 치매 예방에 대한 프로그램은 전무하거나 일시적이고 단편적인 기법만을 활용하고 있는 실정이다. 이에 본 논문에서는 치매에 관심이 있는 노인을 대상으로 복지 전문가가 현장에서 비교적 손쉽게 적용할 수 있는 손운동법(촉각), 회상요법(시각), 치료레크리에이션(미각), 음악요법(청각), 원예치료(후각) 등 오감을 자극하는 기법들을 적절히 조화시켜 체계적으로 적용할 수 있는 치매 예방 프로그램을 제안한다.

• 생물정신의학
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• 제11권2호
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• pp.104-109
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• 2004

Objectives:Abnormalities in neurotrophic factors that regulate neuronal development and synaptic plasticity are often implicated as some causes of schizophrenia. In previous studies, researchers reported that brain and serum BDNF levels underwent similar changes during maturation and aging processes in rats. They also found a positive correlation between serum and cortical BDNF levels. In this study, we investigated whether the serum levels of BDNF in Korean schizophrenic patients would be different from those of healthy controls. Methods:Using an ELISA kit, serum BDNF levels were assessed in schizophrenic group(N=49) and control group(N=50). Results:Serum BDNF levels in the schizophrenic group($36.29{\pm}19.78$ng/ml) were significantly higher than those in control group($22.4{\pm}14.4$ng/ml). The BDNF levels did not correlate with duration of treatment, age or daily dose of antipsychotics in patients with schizophrenia. Conclusions:This result suggests that schizophrenia is characterized by high serum BDNF levels and supports the hypothesis of neurotrophic factor involvement in psychotic disorder. Serum BDNF level is likely to be one of the possible biological markers for schizophrenia.

• 한국포장학회지
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• 제26권2호
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• pp.61-69
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• 2020

As post-harvest processes of onions are carried by a 20 kg-net package which results in high-cost and low-efficiency, especially, the insufficient drying and physical damage of onions after harvesting leads to a huge second loss in storage, we had developed a low-cost, high-efficiency post-harvest bulk handling machinery system by collecting onions on a farm using ton-bags, drying with forced air circulation, and sorting/packaging. The post-harvest bulk handling machinery system consisted of 6 devices, and this study designed an automatic feed hopper with a feeding rate control device, an inclined belt conveyor with a two-step chute, and an automatic pallet unloading device for feeding onions into the sorting/packing line. This study also analyzed the performance and control of the total system. The device had 1-ton handling capacity, but the operational condition was set to increase the capacity. The three-step filling method of pallet by the velocity control of the inclined belt conveyor was applied in the post-harvest bulk handling machinery system for the prevention of physical damage. If one worker was set to operate the total system, the time required to complete one palletized load was approximately 5 minutes and 5 seconds. The calculated daily handling capacity was approximately 94 tons, when the daily actual working time was 8 hours. When the developed system was applied to the managerial size of 2,000 ton, the processing cost per ton of the system was decreased by 19.5%, compared with the existing 20 kg-net package-based handling. The developed post-harvest bulk handling machinery system would be a good substitute for the rapid decline and aging of rural labor.

• 한국식품영양과학회지
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• 제39권2호
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• pp.186-192
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• 2010

피부의 주름은 노화과정의 결과로 유도되어지는데, 비효소적 glycation 반응은 주름생성의 원인 중에 하나로 단백질의 비가역적 가교결합에 의해 생성된 최종당화산물(AGEs)이라고 불리는 갈색화합물을 생성한다. 비교적 반감기가 긴 collagen은 쉽게 glycation이 일어나고 collagen의 가교결합(cross-linking)이 일어나면서 여러 단계의 반응을 거쳐 최종적으로 생성된 AGEs가 피부에 축적되어 피부의 탄력감소 및 주름을 일으킨다고 알려져 있다. 피부 내에 glycation된 collagen의 축척은 피부의 탄력성을 유지하는 것을 방해한다. 수종의 식용작물로부터 항주름소재를 개발하기 위하여 메탄올 및 열수추출물을 조제한 후 AGEs 형성을 억제하는 활성을 검색하였다. 먼저 서양향신료 중에서는 월계수잎, 계피, 정향, 오레가노, 로즈마리, 사보리, 팔각과 한약재 중에서는 복분자, 달개비, 삼지구엽초, 가자와 해당화의 메탄올 및 열수추출물에서 최종당화산물 생성 억제활성이 높았다. 그러나 국내 식물 중에서는 단지 참취 및 녹차 추출물의 메탄올과 열수추출물만이 높은 활성을 보였으며 해조류 중에서는 활성이 높은 시료는 없었다.