• Asian Journal of Atmospheric Environment
• /
• 제11권2호
• /
• pp.131-137
• /
• 2017

A cyclone is an effective tool to facilitate the collection of aerosol particles without using filters, and in cell exposure studies is able to collect a sufficient amount of aerosol particles to evaluate their adverse health effect. In this study, we examined two different methods to improve the aerosol particle collection efficiency of a cyclone. The individual and combined effects of reducing the surface roughness of the inner wall of the cyclone and of using a circular cone attachment were tested. The collection efficiency of particles of diameter $0.2{\mu}m$ was improved by approximately 10% when using a cyclone with a smoothened inner wall (average roughness $Ra=0.08{\mu}m$) compared with the original cyclone ($Ra=5.1{\mu}m$). A circular cone attachment placed between the bottom section of the cyclone and the top section of a collection bottle, resulted in improved collection of smaller particles without the attachment. The 50% cutoff diameter of the modified cyclone (combined use of smoothened inner wall and attachment) was $0.23{\mu}m$ compared to $0.28{\mu}m$ in the original model. The combined use of these two techniques resulted in improved collection efficiency of aerosol particles.

• Journal of Computing Science and Engineering
• /
• 제11권4호
• /
• pp.111-120
• /
• 2017

Post-translational modifications (PTMs) of proteins play substantial roles in the gene regulation of cell physiological functions and in the generation of major diseases. However, the majority of existing studies only explored a certain PTM of proteins, while very few have investigated the PTMs of two or more domains and the effects of their interactions. In this study, after collecting data regarding a large number of breast cancer-related and validated PTMs, a sequence and domain analysis of breast cancer proteins was carried out using bioinformatics methods. Then, protein-protein interaction network-related tools were applied in order to determine the crosstalks between the PTMs of the proteins. Finally, statistical and functional analyses were conducted to identify more modification sites of domains and proteins that may interact with at least two or more PTMs. In addition to exploring the associations between the interactive effects of PTMs, the present study also provides important information that would allow biologists to further explore the regulatory pathways of biological functions and related diseases.

• 한국태양에너지학회 논문집
• /
• 제32권2호
• /
• pp.35-41
• /
• 2012

Knowledge of the solar radiation components and classified wavelength data are essential for modeling many solar photovoltaic systems. This is particularly the case for applications that concentrate the incident energy to attain high photo-dynamic efficiency achievable only at the higher intensities. In order to estimate the performance of concentrating PV systems, it is necessary to know the intensity of the beam radiation, as only this components can be concentrated, and The new PV cell can generate electricity from ultraviolet and infrared light as well as visible light. The Korea Institute of Energy Research(KIER) has began collecting solar radiation components data since January, 1988, and solar radiation classified wavelength data since November, 2008. KIER's solar radiation components and classified wavelength data will be extensively used by concentrating PV system users or designers as well as by research institutes. It is essential to utilize the solar radiation data as application and development of solar energy system increase. Consider able efforts have been made constructing a standard data base system from measure data.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
• /
• pp.91-91
• /
• 2012

We aim in synthesizing various functional thin films thinner than ~ 10 nm for environmental applications and photovoltaic devices. Atomic layer deposition is used for synthesizing inorganic thin films with a precise control of the film thickness. Several examples about application of our thin films for removing volatile organic compounds (VOC) will be highlighted, which are summarized in the below. 1) $TiO_2$ thin films prepared by ALD at low temperature ($<100^{\circ}C$) show high adsorption capacity for toluene. In combination with nanostructured templates, $TiO_2$ thin films can be used as building-block of high-performing VOC filter. 2) $TiO_2$ thin films on carbon fibers and nanodiamonds annealed at high temperatures are active for photocatalytic oxidation of VOCs, i.e. photocatalytic filter can be created by atomic layer deposition. 3) NiO can catalyze oxidation of toluene to $CO_2$ and $H_2O$ at $<300^{\circ}C$. $TiO_2$ thin films on NiO can reduce poisoning of NiO surfaces by reaction intermediates below $200^{\circ}C$. We also fabricated inverted organic solar cell based on ZnO electron collecting layers on ITO. $TiO_2$ thin films with a mean diameter less than 3 nm on ZnO can enhance photovoltaic performance by reducing electron-hole recombination on ZnO surfaces.

• 한국표면공학회:학술대회논문집
• /
• 한국표면공학회 2012년도 춘계학술발표회 논문집
• /
• pp.301-302
• /
• 2012

본 연구에서는 ripple 형태의 ZnO 박막을 역구조 태양전지의 전자 수집층으로 사용하였으며, 원자층 증착법 (Atomic Layer Deposition, ALD)을 이용하여 $TiO_2$ 박막을 ZnO 표면에 증착하였다. $TiO_2$가 ZnO 표면 위에 약 <3nm 정도 두께의 초미세 박막으로 형성되었을 경우 태양전지의 성능이 향상되었다. 특히 Jsc (short-circuit current)와 전환효율 값의 향상을 보였다. 반면 $TiO_2$를 더 두껍게 증착되었을 경우 오히려 태양전지 성능이 떨어지는 결과를 얻었다. 이와 같은 결과 전자를 수집하는 ZnO 위에서 $TiO_2$가 장벽으로 작용함으로써 전자의 이동을 억제하기 때문으로 풀이된다. 반면 $TiO_2$가 초미세 박막으로 형성되었을 때 ZnO 표면에 존재하는 결함자리, 즉 전자와 정공이 재결합하는 자리를 덮어줌으로써 오히려 태양전지의 성능을 향상시키게 된다. 본 연구에서는 ALD 방법을 이용하여 $TiO_2$의 미세한 두께조절을 통해 태양전지 성능향상이 가능함을 확인하였다.

• 한국양봉학회지
• /
• 제32권4호
• /
• pp.391-394
• /
• 2017

Propolis is made by bees collecting protective material or essence of plants and mixing with saliva and enzymes produced by the salivary glands. It is used to repair the inside of the honeycomb, keep it sterile, and adjust the temperature and humidity. Propolis is a natural antibiotic substance that it is used to make a clean room by coating the cell before the queen bee lay eggs, and preventing the bacteria from invading by using with wax when sealing the nursery room. Propolis extract is a health functional food with antioxidant and oral antimicrobial effects. In order to use propolis in food, its active ingredients are extracted with ethanol. Water-soluble propolis was prepared by mixing and stirring honey and ethanol extracted propolis (EEP) solution. When 1kg of honey and 100ml of ethanol extracted propolis solution were mixed and stirred, the total flavonoid content of water-soluble propolis was $6.6{\pm}1.1mg/10g$, and the free radical scavenging effects of water-soluble propolis were 54 to 74%.

• International Journal of Precision Engineering and Manufacturing-Green Technology
• /
• 제5권5호
• /
• pp.637-642
• /
• 2018

The impact of the sintering process, especially in terms of sintering temperature and sintering aid concentration, on the ohmic transport and electrode performance of $(La_{0.80}Sr_{0.20})_{0.95}CoO_{3-{\delta}}$-gadolinia-doped ceria (LSCF-GDC) cathodes is studied. The ohmic and charge-transfer kinetics exhibit a highly coupled $Co_3O_4$ concentration dependency, showing the best performances at an optimum range of 4-5 wt%. This is ascribed to small grain sizes and improved connection between particles. The addition of $Co_3O_4$ was also found to have a dominant impact on charge-transfer kinetics in the LSCF-GDC composite layer and a moderate impact on the electronic transport in the current-collecting LSCF layer. Care should be taken to avoid a formation of excessive thermal stresses between layers when adding $Co_3O_4$.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권11호
• /
• pp.5551-5556
• /
• 2012

Cytological examination is widely used as a diagnostic tool because of the ease of collecting cells from the involved area. However, the diagnostic yield of cytological examination is unsatisfactory; the reasons include sampling error, poorly prepared samples, small numbers of malignant cells, and low grades of cellular atypia. In this study, we focused on the high infectivity of adenovirus towards epithelial cells and applied the luciferase-expressing adenoviral vector to a new cancer cell detection tool. In addition, adenoviral infectivity was enhanced by modifying viral fiber proteins. The sensitivity of the diagnostic tool was tested using the NCI-H1299 lung cancer cell line, and validated in body fluid samples from cancer patients with a variety of etiology. Results showed that the adenovirus efficiently transfected NCI-H1299 with high sensitivity. Only 10 cancer cells were sufficient for detection of luciferase signals. In body fluid samples, the adenovirus confirmed the diagnosis for malignant and benign cancer, but not in non-epithelial cell derived samples. This study provides proof-of-concept for a more reliable and sensitive diagnostic tool for epithelium-derived cancer.

• BMB Reports
• /
• 제40권4호
• /
• pp.467-474
• /
• 2007

Autosomal recessive polycystic kidney disease (ARPKD) is one of the important genetic disorders in pediatric practice. Mutation of the polycystic kidney and hepatic disease gene 1 (PKHD1) was identified as the cause of ARPKD. The gene encodes a 67-exon transcript for a large protein of 4074 amino acids termed fibrocystin, but its function remains unknown. The neoplastic-like in cystic epithelial proliferation and the epidermal growth factor/epidermal growth factor receptor (EGF/EGFR) axis overactivity are known as the most important characteristics of ARPKD. Since the misregulation of $Ca^{2+}$ signaling may lead to aberrant structure and function of the collecting ducts in kidney of rat with ARPKD, present study aimed to investigate the further mechanisms of abnormal proliferation of cystic cells by inhibition of PKHD1 expression. For this, a stable PKHD1-silenced HEK-293T cell line was established. Then cell proliferation rates, intracellular $Ca^{2+}$ concentration and extracellular signal-regulated kinase 1/2 (ERK1/2) activity were assessed after treatment with EGF, a calcium channel blocker and agonist, verapamil and Bay K8644. It was found that PKHD1-silenced HEK-293T cell lines were hyperproliferative to EGF stimulation. Also PKHD1-silencing lowered the intracellular $Ca^{2+}$ and caused EGF-induced ERK1/2 overactivation in the cells. An increase of intracellular $Ca^{2+}$ in PKHD1-silenced cells repressed the EGF-dependent ERK1/2 activation and the hyperproliferative response to EGF stimulation. Thus, inhibition of PKHD1 can cause EGF-induced excessive proliferation through decreasing intracellular $Ca^{2+}$ resulting in EGF-induced ERK1/2 activation. Our results suggest that the loss of fibrocystin may lead to abnormal proliferation in kidney epithelial cells and cyst formation in ARPKD by modulation of intracellular $Ca^{2+}$.

• 한국어병학회지
• /
• 제25권3호
• /
• pp.249-256
• /
• 2012

본 연구는 서천해역 김 양식장의 월별, 어장별 김 갯병 발생 현황 및 김 엽체 사세포 비율을 관찰하고 결과를 분석하여 우리나라 양식 김 갯병에 관한 자료를 축적하고자 시도되었다. 서천해역의 12개 김 양식장에서 2008년 11월부터 2009년 3월까지 5개월 동안 매월 1회씩 김발을 채취하였다. 연구 결과 갯병 발병율은 거의 대부분의 정점에서 양식 초기에는 낮았지만 후반기로 갈수록 높아졌다. 이 해역에서 가장 빈발하는 질병은 규조류 부착증이었으며, 그 다음으로는 의사흰갯병이었다. 규조류 부착증이 가장 높게 발병한 시기는 양식 초기인 11월이었으며, 12월에는 발병율이 가장 낮았고 이어 점차 증가하는 양상을 보였다. 김 엽체에 부착된 규조류는 대부분이 Licmophora sp. 이었다. 양식 초기인 11월에는 녹반병과 의사흰갯병의 빈도가 높았지만, 양식 후반기로 갈수록 두 질병의 발생율이 점차 감소하는 대신에 호상균병 발생 빈도가 높아졌다. 연구 해역 사세포율은 지점에 따라 다소차이가 있었지만 전체적으로는 양식 후기에 높았고, 예외적으로 양식장 거의 정중앙에 위치한 St. 9와 내만에 위치한 St. 11, St. 12는 양식 초기에 사세포 비율이 높았다. 이러한 김 엽체의 사세포율 변화는 영양분 공급과 조류소통 등 여러 가지 요인이 관계하고 있지만 보다 더 정확한 요인은 환경 요인 조사를 통하여 밝혀질 수 있을 것으로 판단된다.