• Safety and Health at Work
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• 제10권4호
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• pp.428-436
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• 2019

Background: Metalworking fluids (MWFs) are mixtures with inhalation exposures as mists, dusts, and vapors, and dermal exposure in the dispersed and bulk liquid phase. A quantitative risk assessment was performed for exposure to MWF and respiratory disease. Methods: Risks associated with MWF were derived from published studies and NIOSH Health Hazard Evaluations, and lifetime risks were calculated. The outcomes analyzed included adult onset asthma, hypersensitivity pneumonitis, pulmonary function impairment, and reported symptoms. Incidence rates were compiled or estimated, and annual proportional loss of respiratory capacity was derived from cross-sectional assessments. Results: A strong healthy worker survivor effect was present. New-onset asthma and hypersensitivity pneumonitis, at 0.1 mg/㎥ MWF under continuous outbreak conditions, had a lifetime risk of 45%; if the associated microbiological conditions occur with only 5% prevalence, then the lifetime risk would be about 3%. At 0.1 mg/㎥, the estimate of excess lifetime risk of attributable pulmonary impairment was 0.25%, which may have been underestimated by a factor of 5 or more by a strong healthy worker survivor effect. The symptom prevalence associated with respiratory impairment at 0.1 mg/㎥ MWF was estimated to be 5% (published studies) and 21% (Health Hazard Evaluations). Conclusion: Significant risks of impairment and chronic disease occurred at 0.1 mg/㎥ for MWFs in use mostly before 2000. Evolving MWFs contain new ingredients with uncharacterized long-term hazards.

• Radiation Oncology Journal
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• 제2권2호
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• pp.221-228
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• 1984

The recogition that the vast majority of patients with small cell lung cancer have distant metastatic disease at the time of diagnosis lead to the use of systemic chemotherapy and consequent major improvement in survival, but recently evaulated treatment strategies, integration of large field chest irradiation with chemotherapy lead to the improved the local control and relapse free survival in limited SCLC. Therefore, it is logical to combine the two modalities in an effort to maximize the therapeutic effect. Authors performed the combination chemotherapy of CAV (Cyclophosphamide, Adriamycin, an6 Vincristine) and radiotherapy of primary tumor and regional lymphatics with prophylatic cranial irradiation in 42 patients of limited SCLC, from Mar. 1978 to Dec. 1982 Seoul National University Hospital. The results are as follows : 1. CR and PR after 2 cycles chemotherapy is $7\%$ and $43\%$, respectively however, subsequent response to radiotherapy is $38\%$ and $43\%$ in CR and PR. 2. Overall median survival peroid is 8.6 months. 3. 1 year and 2 years survival rate is $46.3\%$ and $20.5\%$, respectively. 4. Incidence of proven brain metastasis is $5\%$.

• 환경영향평가
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• 제11권4호
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• pp.289-309
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• 2002

Solutions of many landscape problems depend on area-wide assessment and interpretation of spatial and physical characteristics over the study area. The authors argue that the public awareness for an area-wide urban landscape appears to be very low due to limited chance to the information. Acknowledging these constraints, an operational, user-friendly information system has been developed by combining internet technology with GIS. In particular, integration among satellite data and digital maps takes advantage of each component, and enables the landscape structure to be visualized, interacted with and deployed all on the Web. The 1m resolution IKONOS data realistically identified the major type of landscape by large scale spatial precision while TM data revealed successfully the major parameters that influence an area-wide spatial structure in the study area. This system would play a crucial role in improving the public awareness for area-wide landscape information if it is operationally introduced into the Government since the highly user-friendly interface based on image maps provides a completely new means for disseminating information for area-wide landscape in a visual and interactive manner to the general public.

• 국제초고층학회논문집
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• 제9권3호
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• pp.283-300
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• 2020

The Lakhta Center is a Multifunction Complex Development (MFCD) consisting of 1) an 86 story office tower rising 462 m above the ground to provide high-end offices for Gazprom Neft and Gazprom Group affiliates 2) a Multi-Function Building (MFB) that includes, a scientific/educational center, a sport center, a children's technopark, a planetarium, a multi-transformable hall, an exhibition center, shops, restaurants, and other public facilities 3) a Stylobate 4) "The Arch, which forms the main entrance to the tower, restaurants, and cafes 5) underground parking and 6) a wide range of large public plazas. While each of the MFCD buildings is technically challenging in its own right, the focus of the paper is to present the development and integration of the structural and foundation systems of the bowed, tapered, and twisted shape of the tower into the fabric of the tallest Tower in Europe.

• Journal of Periodontal and Implant Science
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• 제35권4호
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• pp.839-850
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• 2005

The success of an implant is determined by its integration into the tissue surrounding the biomaterial. Surface roughness is considered to influence the behavior of adherent cells. The aim of this in vitro study was to determine the effect of surface roughness on Saos-2 osteoblast-like cells. Titanium disks blasted with 75 ${/mu}m$ aluminum oxide particles and machined titanium disks were prepared. Saos-2 were plated on the disks at a density of 50,000 cells per well in 48-well dishes. After 1 hour, 1 day, 6 days cell numbers were counted. One day, 6 days after plating, alkaline phosphatase(ALPase) activity was determined. Compared to experimental group, the number of cells was significantly higher on control group. The stimulatory effect of surface roughness on ALPase was more pronounced on the experimental group than on control group. These results demonstrate that surface roughness alters proliferation and differentiation of osteoblasts. The results also suggest that implant surface roughness may play a role in determining phenotypic expression of cells.

• Bulletin of the Korean Chemical Society
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• 제26권6호
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• pp.939-942
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• 2005

For the detection of cyanobacterial toxin, an Enzyme-linked immunosorbent assay (ELISA) was integrated into a PDMS microchip. The conjugates of microcystin-LR (MCLR) and keyhole limpet hemocyanin (KLH) were adsorbed on the surface of polystyrene beads and these MCLR-KLH polystyrene beads were introduced into a microchamber. MCLR on the surface of polystyrene beads reacted with horseradish peroxides (HRP) conjugated anti-MCLR monoclonal antibody (mAb) which had a competitive reaction with MCLR in water sample. After the enzyme substrate 3,3,5,5-tetramethyl benzidine (TMB) was injected into the chamber and catalyzed by HRP, the color change was detected with a liquid-cord waveguide. This integration shortened the conventional ELISA analysis time from several hours to about 30 min with only 4.2 $\mu$L MCLR sample consuming which was useful for the environmental analysis. More over, troublesome operations required for ELISA could be replaced by simple operations. The microchip based detection system showed a good sensitivity of 0.05 $\mu$g/L and maintained good reliability through its quantitative range with low coefficients of variation (2.5-10.5%).

• ETRI Journal
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• 제35권4호
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• pp.697-705
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• 2013

Emerging trends in the area of digital very large scale integration (VLSI) signal processing can lead to a reduction in the cost of the cochlear implant. Digital signal processing algorithms are repetitively used in speech processors for filtering and encoding operations. The critical paths in these algorithms limit the performance of the speech processors. These algorithms must be transformed to accommodate processors designed to be high speed and have less area and low power. This can be realized by basing the design of the auditory filter banks for the processors on digital VLSI signal processing concepts. By applying a folding algorithm to the second-order digital gammatone filter (GTF), the number of multipliers is reduced from five to one and the number of adders is reduced from three to one, without changing the characteristics of the filter. Folded second-order filter sections are cascaded with three similar structures to realize the eighth-order digital GTF whose response is a close match to the human cochlea response. The silicon area is reduced from twenty to four multipliers and from twelve to four adders by using the folding architecture.

• 대한조선학회지
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• 제27권3호
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• pp.107-116
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• 1990

구조물의 탄성을 고려한 탱크내 유동은 자유수면을 갖는 유체와 탄성변형하는 구조물이 연성된 시스템으로서 유체유동으로 인한 과도한 구조물변형, 유체의 부가질량 및 부가감쇠력에 의한 구조물의 동특성변화, 구조물 진동으로 인한 유체유동의 왜곡 등이 복합된 비선형 해석이 요구된다. 본 논문에서는 탱크 벽을 1자유도 수평운동하는 강체로 가정하였으며 Lagrangian 유한요소법을 이용하여 유동해석을 수행하였고 유체-구조물 연성문제의 수치적분을 위하여 조합된 implicit-explicit 알고리듬을 도입하였다. 탱크벽의 동특성 변화에 따른 유체-구조물연성 탱크의 동특성변화를 관찰하였으며 파도생성 문제에 관한 수치계산을 수행하였다.

• Clinical and Experimental Reproductive Medicine
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• 제37권3호
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• pp.207-216
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• 2010

목 적: Small interfering RNA (siRNA)를 이용하여 homeobox (HOXA) 10 유전자의 발현이 억제된 일차배양 자궁내막 세포를 이용하여 자궁내막 탈락막화 (decidualization)에 HOXA유전자를 포함한 세포 내 신호전달기전을 분석하고자 하였다. 연구방법: 본원 산부인과에서 자궁내막 질환 이외의 이유로 전자궁 적출술을 받은 환자의 자궁내막 조직을 채취한다. $37^{\circ}C$에서 20분간 Trypsin-EDTA를 처리하여 단일세포로 분리한 후 10% fetal bovine serum이 첨가된 DMEM/F12 배지를 이용하여 24시간 동안 $37^{\circ}C$ 5% $CO_2$ 배양기 안에서 배양한다. 배양된 자궁내막 세포를 HOXA10 siRNA로 첨가한 후 TGF-${\beta}1$을 10 ng/mL 농도로 48시간 첨가하여 탈락막화를 유도한다. 배양된 자궁내막 세포에서 reverse transcription polymerase chain reaction을 이용하여 HOXA10, prolactin, cyclooxygenase (COX)-2, peroxisome proliferator-activated receptor (PPAR)-$\gamma$ 및 wingless-type MMTV integration site family (Wnt)의 발현을 관찰하였다. 결 과: HOXA10의 경우 transforming growth factor (TGF)-${\bata}1$과 HOXA10 siRNA를 처리하지 않은 대조군에 비하여 TGF-${\beta}1$을 처리한 군에서 약 1.8배 가량 발현양의 증가를 보였다. 자궁내막 탈락막 표지인자로 알려져 있는 prolactin의 경우 TGF-${\beta}1$을 처리한 경우 대조군에 비하여 유의한 발현의 증가를 보였으며 HOXA10 siRNA를 처리한 군에 있어서는 TGF-${\beta}1$을 첨가하더라도 prolactin mRNA의 발현양의 증가를 관찰할 수 없었다. 또한 자궁내막 세포의 분화인자로 알려져 있는 COX-2의 발현 역시 HOXA10 siRNA를 처리한 군에 있어서 mRNA 발현양이 유의하게 감소하였으며 TGF-${\beta}1$을 처리하여도 발현의 증가를 관찰할 수 없었다. Wnt4의 경우 HOXA10 siRNA를 이용하여 HOXA10의 발현을 억제한 경우 대조군에 비하여 유의하게 mRNA의 발현양이 감소하였으며 이러한 발현양의 감소는 TGF-${\beta}1$을 처리하여도 증가됨을 관찰할 수 없었다. PPAR$\gamma$의 발현은 HOXA10 siRNA의 처리와 관계없이 TGF-${\beta}1$에 의하여 감소하는 것을 관찰할 수 있었다. 결 론: Progesterone에 의하여 자궁내막 상피세포에서 분비되는 것으로 알려져 있는 TGF-${\beta}1$에 의한 자궁내막 기질세포의 분화 (탈락막화)는 HOXA10 및 Wnt에 의하여 조절되는 것으로 생각된다.

• E2M - 전기 전자와 첨단 소재
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• 제12권7호
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• pp.7-11
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• 1999

Fully sealed field emission display in size of 4.5 inch has been fabricated using single-wall carbon nanotubes-organic vehicle com-posite. The fabricated display were fully scalable at low temperature below 415$^{\circ}C$ and CNTs were vertically aligned using paste squeeze and surface rubbing techniques. The turn-on fields of 1V/${\mu}{\textrm}{m}$ and field emis-sion current of 1.5mA at 3V/${\mu}{\textrm}{m}$ (J=90${\mu}{\textrm}{m}$/$\textrm{cm}^2$)were observed. Brightness of 1800cd/$m^2$ at 3.7V/${\mu}{\textrm}{m}$ was observed on the entire area of 4.5-inch panel from the green phosphor-ITO glass. The fluctuation of the current was found to be about 7% over a 4.5-inch cath-ode area. This reliable result enables us to produce large area full-color flat panel dis-play in the near future. Carbon nanotubes (CNTs) have attracted much attention because of their unique elec-trical properties and their potential applica-tions [1, 2]. Large aspect ratio of CNTs together with high chemical stability. ther-mal conductivity, and high mechanical strength are advantageous for applications to the field emitter [3]. Several results have been reported on the field emissions from multi-walled nanotubes (MWNTs) and single-walled nanotubes (SWNTs) grown from arc discharge [4, 5]. De Heer et al. have reported the field emission from nan-otubes aligned by the suspension-filtering method. This approach is too difficult to be fully adopted in integration process. Recently, there have been efforts to make applications to field emission devices using nanotubes. Saito et al. demonstrated a car-bon nanotube-based lamp, which was oper-ated at high voltage (10KV) [8]. Aproto-type diode structure was tested by the size of 100mm $\times$ 10mm in vacuum chamber [9]. the difficulties arise from the arrangement of vertically aligned nanotubes after the growth. Recently vertically aligned carbon nanotubes have been synthesized using plasma-enhanced chemical vapor deposition(CVD) [6, 7]. Yet, control of a large area synthesis is still not easily accessible with such approaches. Here we report integra-tion processes of fully sealed 4.5-inch CNT-field emission displays (FEDs). Low turn-on voltage with high brightness, and stabili-ty clearly demonstrate the potential applica-bility of carbon nanotubes to full color dis-plays in near future. For flat panel display in a large area, car-bon nanotubes-based field emitters were fabricated by using nanotubes-organic vehi-cles. The purified SWNTs, which were syn-thesized by dc arc discharge, were dispersed in iso propyl alcohol, and then mixed with on organic binder. The paste of well-dis-persed carbon nanotubes was squeezed onto the metal-patterned sodalime glass throuhg the metal mesh of 20${\mu}{\textrm}{m}$ in size and subse-quently heat-treated in order to remove the organic binder. The insulating spacers in thickness of 200${\mu}{\textrm}{m}$ are inserted between the lower and upper glasses. The Y\ulcornerO\ulcornerS:Eu, ZnS:Cu, Al, and ZnS:Ag, Cl, phosphors are electrically deposited on the upper glass for red, green, and blue colors, respectively. The typical sizes of each phosphor are 2~3 micron. The assembled structure was sealed in an atmosphere of highly purified Ar gas by means of a glass frit. The display plate was evacuated down to the pressure level of 1$\times$10\ulcorner Torr. Three non-evaporable getters of Ti-Zr-V-Fe were activated during the final heat-exhausting procedure. Finally, the active area of 4.5-inch panel with fully sealed carbon nanotubes was pro-duced. Emission currents were character-ized by the DC-mode and pulse-modulating mode at the voltage up to 800 volts. The brightness of field emission was measured by the Luminance calorimeter (BM-7, Topcon).