• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.4
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• pp.502-506
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• 2012

In order to find the structural characteristics of the thin films of group II-VI semiconductor compounds compared with those of powder materials, films were made of 4 powders of ZnS, CdS, CdSe, and CdTe(Aldrich), each with 99.99 % purity. For the ZnS/CdS multi-layers, the ZnS layer was coated over the CdS layer on an $AlO_x$ membrane, which served as a protective layer within a vacuum at the average speed of 1 ${\AA}$/sec. After studying the structures of the group II-VI semiconductor thin films by using X-ray spectroscopy, we found that the ZnS, ZnS/CdS, CdS, and CdSe films were hexagonal and exhibited some degree of preferred orientation. Also, the particles of the thin films of II-VI semiconductor compounds proved to be more homogeneous in size compared to those of the powder materials. These results were further verified through scanning electron microscopy(SEM), EDX analysis, and powder and thin film X-ray diffraction.

• Electrical & Electronic Materials
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• v.7 no.1
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• pp.49-56
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• 1994

Polycrystalline CdS thin films were deposited by using EBE method and its crystal structure, surface morphology, electrical and optical properties as a function of annealing temperature were investigated. It was found that optimum growth conditions were substrate temperature annealing temperature 300[.deg. C]. The films were hexagonal structure preferred(002) plane and maximum grain size was 421[.angs.]. As the results, resistivity and optical transmittance of CdS thin films were $8.3{\times}{10^3}$[.ohm.cm] and 89[%] respectively.

• Journal of the Korean Chemical Society
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• v.59 no.2
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• pp.136-141
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• 2015

We have discovered that quercetin, once coated on the CdSe and CdSe-CdS quantum dots (QDs), becoming highly water soluble. In the present work, we have successfully synthesized CdSe/CdS/N-Acetyl-L-Cysteine(NAC)/Quercetin nano-composites in the aqueous solution. The products were characterized using UV-vis spectroscopy, X-ray powder diffraction, fluorescence spectroscopy, and Fourier transform infrared spectroscopy. The transmission electron microscopy (TEM) tests indicated that our nano-composite products are highly stable with homogeneous particle size and great monodispersity. Quercetin coated nano-composite CdSe/CdS/NAC/Quercetin showed different fluorescence behavior from that of CdSe/CdS/NAC. Most amazingly, the synthesized CdSe/CdS/NAC/Quercetin nano-composite exhibits strong antibacterial activity. The combination of the strong fluorescence and its antibacterial activity makes the quercetin modified quantum dots as a potential candidate for cancer targeted therapy and other cancer treatments.

• The Journal of Internal Korean Medicine
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• v.30 no.4
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• pp.674-684
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• 2009

Objectives : In conditions of brain infarction, irreversible axon damage occurs in the central nerve system (CNS), because gliosis becomes a physical and a mechanical barrier to axonal regeneration. Reactive gliosis induced by ischemic injury such as middle cerebral artery occlusion is involved with up-regulation of GFAP and CD81. This study was undertaken to examine the effect of the Gongjin-dan (GJD) on CD81 and GFAP expression and its pathway in the rat brain following middle cerebral artery occlusion (MCAO). Methods : In order to study ischemic injuries on the brain, infarction was induced by MCAO using insertion of a single nylon thread, through the internal carotid artery, into a middle cerebral artery. Cresyl violet staining, cerebral infarction size measurement, immunohistochemistry and microscopic examination were used to detect the expression of CD81 and GFAP and the effect on the infarct size and pyramidal cell death in the brain of the rat with cerebral infarction induced by MCAO. Also, c-Fos and ERK expression were measured to investigate the signaling pathway after GJD administration in MCAO rats. Results : Measuring the size of cerebral infarction induced by MCAO in the rat after injection of GJD showed the size had decreased. GJD administration showed pyramidal cell death protection in the hippocampus in the MCAO rat. GJD administration decreased GF AP expression in the MCAO rat. GJD administration decreased CD81 expression in the MCAO rat. GJD administration induced up-regulation of c-FOS expression compared with MCAO. GJD administration induced down-regulation of ERK expression compared with MCAO. Conclusion : We observed that GJD could suppress the reactive gliosis, which disturbs the axonal regeneration in the brain of a rat with cerebral infarction after MCAO by controlling the expression of CD81 and GFAP. The effect may be modulated by the regulation of c-Fos and ERK. These results suggest that GJD can be a candidate to regenerate CNS injury.

• Journal of Powder Materials
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• v.23 no.2
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• pp.91-94
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• 2016

High-quality colloidal CdSe/ZnS (core/shell) is synthesized using a continuous microreactor. The particle size of the synthesized quantum dots (QDs) is a function of the precursor flow rate; as the precursor flow rate increases, the size of the QDs decreases and the band gap energy increases. The photoluminescence properties are found to depend strongly on the flow rate of the CdSe precursor owing to the change in the core size. In addition, a gradual shift in the maximum luminescent wave (${\lambda}_{max}$) to shorter wavelengths (blue shift) is found owing to the decrease in the QD size in accordance with the quantum confinement effect. The ZnS shell decreases the surface defect concentration of CdSe. It also lowers the thermal energy dissipation by increasing the concentration of recombination. Thus, a relatively high emission and quantum yield occur because of an increase in the optical energy emitted at equal concentration. In addition, the maximum quantum yield is derived for process conditions of 0.35 ml/min and is related to the optimum thickness of the shell material.

• Journal of Sensor Science and Technology
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• v.22 no.3
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• pp.185-190
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• 2013

We report on direct finding of how the morphology (i.e. filopodia width) of $CD4^+$ T lymphocytes correlates with the size of the quartz nanohohole arrays (QNHAs, 140, 200, 270, and 550 nm in diameter) via scanning electron microscopy (SEM). This research exhibits that the filopodia of $CD4^+$ T-lymphocytes extended on the QNHA substrates were observed to increase in width by increasing the size of QNHA in diameter from 140 to 550 nm. This strong linear response ($R^2$=0.988, n = 6) in filopodia's width of surface-bound $CD4^+$ T-cells with topographical structures of QNHA can be explained by contact guidance between the cells and solid-state substrates. Furthermore, this research suggests that the protruded filopodia of surface-bound T-lymphocytes can be used as a biosensor for sensing the topographical information of the nano-patterned substrates.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7491-7496
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• 2015

Background: Biomarkers in breast neoplasms provide invaluable information regarding prognosis and help determining the optimal treatment. We investigated the possible correlation between cancer stem cell (CSC) markers (CD133, and ALDH1) in invasive ductal breast carcinomas with some clinicopathological parameters. Aim: To assess the correlation between expression of cancer stem cell (CSC) markers (CD133, and ALDH1) and clinicopathological parameters of invasive ductal breast carcinomas. Materials and Methods: Immunohistochemical analysis of CD133 and ALDH1 was performed on a series of 120 modified radical mastectomy (MRM) specimens diagnosed as invasive ductal breast carcinoma. Results: Expression of both CD133 and ALDH1 was significantly changed and related to tumor size, tumor stage (TNM), and lymph node metastasis. A negative correlation between CD133 and ALDH1 was found. Conclusions: Detecting the expression of CD133 and ALDH1 in invasive ductal breast carcinomas may be of help in more accurately predicting the aggressive properties and determining the optimal treatment.

• Journal of Surface Science and Engineering
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• v.38 no.3
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• pp.112-117
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• 2005

In this paper, CdS thin films, which were widely used as a window layer of the CdS/CdTe and the $CdS/CuInSe_2$heterojunction solar cell, were grown by chemical bath deposition, and the structural, optical and electrical properties of the films on reaction temperatures were investigated. Cadmium acetate and thiourea were used as cadmium and sulfur source, respectively. And Ammonium acetate was used as the buffer solution. As the reaction temperatures were increased, the deposition rate of CdS fllms prepared by CBD was increased and the grain size was large due to increasing reaction rate in solution, also optical transmittance of the films in visible lights was increased on rising reaction temperatures.

• Proceedings of the KWS Conference
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• 2005.11a
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• pp.55-57
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• 2005

In this study, modeling of the CD stud welding system was conducted considering mechanical and electrical components. The electrical components such as arc resistance, cable resistance, capacitance, internal resistance and cable inductance were found to affect the output waveform significantly. The calculated results showed food agreements with the experiment results within 20% error. The main defect of CD stud welding with 1010 steel stud and SS400 steel plate was the void trapped between stud and base metal. The effect of the spring force and stud tip size on void formation was investigated.

• Korean Chemical Engineering Research
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• v.53 no.6
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• pp.798-801
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• 2015

Nanomaterials (NMs) based on cadmium telluride (CdTe) are the theme of numerous research areas due to their unique chemical and physical properties. NM synthesis via a size-controlled procedure has become an intriguing research topic because NMs exhibit novel optical and physical properties depending on their size and shape. In this study, we prepared CdTe nanowires (NWs) via self-assembly from individual Nanoparticles (NPs). Thioglycolic acid (TGA)-to-Cd ion ratio of 1.3 was used instead of the traditional value of 2.4 and the reduced amount of stabilizer resulted in reorganization from individual NPs into NWs consisting of multi-layers of individual NPs. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were performed to characterize NWs. The produced nanowires were straight and long in shape and their length ranged from 500 nm to tens of micrometers.