• Asian Pacific Journal of Cancer Prevention
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• 제13권5호
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• pp.1881-1886
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• 2012

Breast cancer is a heterogeneous disease that is affected by ethnicity of patients. According to hormone receptor status and gene expression profiling, breast cancers are classified into four molecular subtypes, each showing distinct clinical behavior. Lack of sufficient data on molecular subtypes of breast cancer in Iran, prompted us to investigate the prevalence and the clinicopathological features of each subtype among Iranian women. A total of 428 women diagnosed with breast cancer from 2002 to 2011 were included and categorized into four molecular subtypes using immunohistochemistry. Prevalence of each subtype and its association with patients' demographics and tumor characteristics, such as size, grade, lymph-node involvement and vascular invasion, were investigated using Chi-square, analysis of variance and multivariate logistic regression. Luminal A was the most common molecular subtype (63.8%) followed by Luminal B (8.4%), basal-like (15.9%) and HER-2 (11.9%). Basal-like and HER-2 subtypes were mostly of higher grades while luminal A tumors were more of grade 1 (P<0.001). Vascular invasion was more prevalent in HER-2 subtype, and HER-2 positive tumors were significantly associated with vascular invasion (P=0.013). Using muti-variate analysis, tumor size greater than 5 cm and vascular invasion were significant predictors of 3 or more nodal metastases. Breast cancer was most commonly diagnosed in women around 50 years of age and the majority of patients had lymph node metastasis at the time of diagnosis. This points to the necessity for devising an efficient screening program for breast cancer in Iran. Further, prospective surveys are suggested to evaluate prognosis of different subtypes in Iranian patients.

• 한국물환경학회지
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• 제39권6호
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• pp.465-474
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• 2023

The chemical composition and molecular weight characteristics of dissolved organic matter (DOM) exert a profound influence on the efficiency of organic matter removal in water treatment systems, acting as efficiency predictive indicators. This research evaluated the primary chemical and molecular weight properties of DOM derived from diverse sources, including rivers, lakes, and biomasses, and assessed their relationship with the efficiency of coagulation/flocculation treatments. Dissolved organic carbon (DOC) removal efficiency through coagulation/flocculation exhibited significant correlations with DOM's hydrophobic distribution, the ratio of humic-like to protein-like fluorescence, and the molecular weight associated with humic substances (HS). These findings suggest that the DOC removal rate in coagulation/flocculation processes is enhanced by a higher presence of HS in DOM, an increased influence of externally sourced DOM, and more presence of high molecular weight compounds. The results of this study further posit that the efficacy of water treatment processes can be more accurately predicted when considering multiple DOM characteristics rather than relying on a singular trait. Based on major results from this study, a predictive model for DOC removal efficiency by coagulation/flocculation was formulated as: 24.3 - 7.83 × (fluorescence index) + 0.089 × (hydrophilic distribution) + 0.102 × (HS molecular weight). This proposed model, coupled with supplementary monitoring of influent organic matter, has the potential to enhance the design and predictive accuracy for coagulation/flocculation treatments targeting DOC removal in future applications.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2725-2730
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• 2007

Turbo-type molecular drag pumps ( MDPs ) are used in the liquid crystal display ( LCD ), semiconductor and other thin film industries. Siegbahn ( disk-type ) molecular drag pumps are used as high-pressure stages in the hybrid-type turbomolecular pumps, where they can operate in the viscous, the transition and the free molecular flow regime. In this study is performed to investigate the pumping characteristics of three-stage disk-type molecular drag pump ( DTDP ) in the molecular transition flow region. The experiments are measured using five vacuum pressure gauges in the positions for rotors of DTDP. The test is performed with nitrogen gas ( $N_2$ ).

• 한국인쇄학회지
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• 제12권1호
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• pp.13-27
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• 1994

Litho printing ink vehicles based on rosin modified phenolic are faster drying, have better durability, are harder and glosser and have greater resistance to water than ones based on ester gums. Ink-Water balance and rheological properties are important in litho printing process. These physical properties is concerned with molecular weight of Resin to use vehicle. So this paper was studied about the effects of changing molecular weight of Rosin modified phenolic on surface tension, viscosity, pseudoplasticity and printablility of Litho Inks. The results were as follows. 1) The surface tension of model inks depended on the molecular weight of the resin : Dispersion componnent of ink increase but non dispersion component decrease as molecular weight of Resin increase. 2) Water pick-up of litho ink is more fast balance, using low molecular weight of Resin. 3) Viscosity, Yield value and Newtonian value of model inks increase as molecular weight of Resin increase. 4) The litho ink prepared with the modified phenolic of which molecular weight is about 20000 showed the highest printing density and gloss.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.27-27
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• 2011

For the design of real applicable molecular devices, current-voltage properties through molecular nanostructures such as metal-molecule-metal junctions (molecular junctions) have been studied extensively. In thiolate monolayers on the gold electrode, the chemical bonding of sulfur to gold and the van der Waals interactions between the alkyl chains of neighboring molecules are important factors in the formation of well-defined monolayers and in the control of the electron transport rate. Charge transport through the molecular junctions depends significantly on the energy levels of molecules relative to the Fermi levels of the contacts and the electronic structure of the molecule. It is important to understand the interfacial electron transport in accordance with the increased film thickness of alkyl chains that are known as an insulating layer, but are required for molecular device fabrication. Thiol-tethered RuII terpyridine complexes were synthesized for a voltage-driven molecular switch and used to understand the switch-on mechanism of the molecular switches of single metal complexes in the solid-state molecular junction in a vacuum. Electrochemical voltammetry and current-voltage (I-V) characteristics are measured to elucidate electron transport processes in the bistable conducting states of single molecular junctions of a molecular switch, Ru(II) terpyridine complexes. (1) On the basis of the Ru-centered electrochemical reaction data, the electron transport rate increases in the mixed self-assembled monolayer (SAM) of Ru(II) terpyridine complexes, indicating strong electronic coupling between the redox center and the substrate, along the molecules. (2) In a low-conducting state before switch-on, I-V characteristics are fitted to a direct tunneling model, and the estimated tunneling decay constant across the Ru(II) terpyridine complex is found to be smaller than that of alkanethiol. (3) The threshold voltages for the switch-on from low- to high-conducting states are identical, corresponding to the electron affinity of the molecules. (4) A high-conducting state after switch-on remains in the reverse voltage sweep, and a linear relationship of the current to the voltage is obtained. These results reveal electron transport paths via the redox centers of the Ru(II) terpyridine complexes, a molecular switch.

• 한국식품과학회지
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• 제53권6호
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• pp.695-700
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• 2021

본 연구에서는 단백질 가수분해효소 0.1%와 1% Protamex를 사용하여 저분자 콜라겐을 제조하였다. 토종 닭발의 조단백질과 콜라겐의 함량은 일반 육계에 비해 높은 함량이 나타났다. 단백질 가수분해 효소농도와 반응시간이 증가할수록 낮은 분자량의 콜라겐을 얻을 수 있는 것으로 나타났다. 특히 1% Protamex로 7시간 처리한 시료가 1,000-5,000 Da의 저분자 콜라겐 함량이 55.6%로 나타났으며, 평균 분자량은 5,390 Da로 가장 낮은 분자량이 나타났다. 이는 단백질 가수분해효소 Protamex가 고분자 펩타이드 결합을 저분자 펩타이드로 분해했기 때문이다. 효소처리 콜라겐의 조직감은 고분자 펩타이드의 콜라겐이 저분자 펩타이드로 분해되어 gel을 형성하지 못하고 sol의 형태를 유지하였다. 효소농도와 효소반응시간이 증가할수록 콜라겐의 평균분자량은 작아지나 효소반응 5시간부터 평균분자량의 감소가 미미해지는 경향이 나타났다. 따라서 저분자 콜라겐 효소반응시간은 경제적으로 볼 때 5시간에서 7시간 사이가 적합하다고 할 수 있다. 이 연구결과는 향후 산업적 효소를 이용한 저분자 콜라겐 제조 및 식품 소재 활용의 기초자료로 이용할 수 있을 것이다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
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• pp.55-56
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• 2000

We report the fabrication of carbon nanostureture films with excellent electron-emission characteristics on chrome electrodes using a pre-deposited transition metal catalyst layer. The emission current densities of 1 ${\mu}A/cm^2$ and 1 $mA/cm^2$ were measured at the electric field of 2.5 and 4.8 $V/{\mu}m$, respectively, and the current fluctuation of less than 2.5% was observed at the average current density 211 ${\mu}A/cm^2$ for the measurement duration of 20 minutes. We counted more than ${\sim}10^4$ emission sites per $cm^2$ from the emission images, and also noticed good mechanical stability. Moreover, we were able to fabricate good electron-emitting carbon films on chrome electrodes on Corning glass substrates at the nominal temperature below $650^{\circ}C$.

• 한국환경보건학회지
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• 제27권2호
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• pp.92-99
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• 2001

This present study was aimed to investigate the characteristics of dissoloved organic matter (DOC) in sewage. The results are summarized as follows ; The plateaux reached in 3~4 days by the biodegradability test on sewage samples based on DOC. 쏭 rations of BDOC to DOC were 48, 21, 13 and 11% for raw sewage, primary treatment effluent, secondary treatment effluent and final treatment effluent, respectively. As the SUVA values ranged less 3L/m.mg for the effluent of sewage treatment plant, the DOC is composed largely of non-humic materials, hydrophilic, less aromatic as compared to waters with higher SUVA values. Through the biodegradability test, Dissolved organics showed that the quantity of LMW(Low Molecular Weight) less than 1,000 daltons was decreased, HMW(High Molecular Weight) more than 30,000 daltons had a tendency to increase. Large portion of UV$^{254}$ in final treatment effluent was increased of MMW(Medium Molecular Weight). Also, average removal efficiency of DOC was 32% during sewage treatment.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2004년도 제28회 KOSCO SYMPOSIUM 논문집
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• pp.133-137
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• 2004

The present study is focused on the small scale turbulent mixing processes in the scalar field. In order to deal with molecular mixing in turbulent flow, the linear eddy model is addressed. In each realization, the molecular mixing term is implemented deterministically, and turbulent stirring is represented by a sequence of instantaneous, statistically independent rearrangement event called by triplet map. The LEM approach is applied with relatively simple conditions. The characteristics of scalar mixing and PDF profiles are addressed in detail.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.1912-1915
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• 2007

The disjoining pressure is critical in modeling the transport phenomena in small scales. They are very useful in characterizing the non-continuum effects that are not negligible in heat and mass transports in the film of less than submicro-scales. We present he disjoining pressure of thin film absorbed on solid substrate using Molecular Dynamics Simulation (MD). The disjoining pressure with respect to the film thickness is accurately calculated in the resolution of a molecular scale. The characteristics of the pressure are discussed regarding the molecular nature of the fluid system like molecular diameter and intermolecular interaction. Also, the MD results are compared with those based on the macroscopic approximation of the slab-like density profile. Significant discrepancy is observed when the effective film thickness is less than several molecular diameter