175 results on '"Young Ran Park"'
Search Results
2. Metabolic Profiling of Chestnut Shell (Castanea crenata) Cultivars Using UPLC-QTOF-MS and Their Antioxidant Capacity
- Author
-
Miso Nam, Ja Myung Yu, Young Ran Park, Young-Sik Kim, Jae-Ho Kim, and Min-Sun Kim
- Subjects
metabolic profiling ,Castanea crenata cultivar ,chestnut shell ,antioxidant capacity ,mass spectrometry ,Microbiology ,QR1-502 - Abstract
The inner shell of the chestnut (Castanea crenata) has long been used in Asia as a medicinal herb for improving digestion and blood circulation, and treating diarrhea. However, most chestnut shells are now treated as waste materials in industrial peeling processes. In this study, we examined the metabolite variation among major cultivars of C. crenata shells using mass spectrometry. Among five representative cultivars, Okkwang, Porotan, and Ishizuuchi had higher levels of bioactive compounds, such as ellagic acid derivatives, ellagitannins, flavonoids, and gallic acid derivatives. Their antioxidant capacity was positively correlated with their chemical composition. The byproducts (whole shells) from the industrial peeling process were re-evaluated in comparison with the inner shell, a rich source of phenolic compounds. The phenolic acids and flavonoid glucoside derivatives were significantly higher in the whole shells, whereas the levels of flavonoids were higher in the inner shells. In addition, the whole shell extracts significantly reduced cellular reactive oxygen species production compared to the inner shell extracts. This study demonstrated the different biochemical benefits of different C. crenata cultivars through metabolic profiling and suggests that the whole shell could be used as a functional ingredient, as it has the highest levels of bioactive products and antioxidant effects.
- Published
- 2022
- Full Text
- View/download PDF
3. Parthenolide promotes apoptotic cell death and inhibits the migration and invasion of SW620 cells
- Author
-
Yu Chuan Liu, Se Lim Kim, Young Ran Park, Soo-Teik Lee, and Sang Wook Kim
- Subjects
Colorectal neoplasms ,Parthenolide ,Apoptosis ,Migration ,Invasion ,Medicine ,Diseases of the digestive system. Gastroenterology ,RC799-869 - Abstract
Background/Aims: Parthenolide (PT), a principle component derived from feverfew (Tanacetum parthenium), is a promising anticancer agent and has been shown to promote apoptotic cell death in various cancer cells. In this study, we focused on its functional role in apoptosis, migration, and invasion of human colorectal cancer (CRC) cells.Methods: SW620 cells were employed as representative human CRC cells. We performed the MTT assay and cell cycle analysis to measure apoptotic cell death. The wound healing, Transwell migration, and Matrigel invasion assays were performed to investigate the effect of PT on cell migration/invasion. Western blotting was used to establish the signaling pathway of apoptosis and cell migration/invasion.Results: PT exerts antiproliferative effect and induces apoptotic cell death of SW620 cells. In addition, PT prevents cell migration and invasion in a dose-dependent manner. Moreover, PT markedly suppressed migration/invasion-related protein expression, including E-cadherin, β-catenin, vimentin, Snail, cyclooxygenase-2, matrix metalloproteinase-2 (MMP-2), and MMP-9 in SW620 cells. PT also inhibited the expression of antiapoptotic proteins (Bcl-2 and Bcl-xL) and activated apoptosis terminal factor (caspase-3) in a dose-dependent manner.Conclusions: Our results suggest that PT is a potential novel therapeutic agent for aggressive CRC treatment.
- Published
- 2017
- Full Text
- View/download PDF
4. Thickness-dependent electron mobility of single and few-layer MoS2 thin-film transistors
- Author
-
Ji Heon Kim, Tae Ho Kim, Hyunjea Lee, Young Ran Park, Woong Choi, and Cheol Jin Lee
- Subjects
Physics ,QC1-999 - Abstract
We investigated the dependence of electron mobility on the thickness of MoS2 nanosheets by fabricating bottom-gate single and few-layer MoS2 thin-film transistors with SiO2 gate dielectrics and Au electrodes. All the fabricated MoS2 transistors showed on/off-current ratio of ∼107 and saturated output characteristics without high-k capping layers. As the MoS2 thickness increased from 1 to 6 layers, the field-effect mobility of the fabricated MoS2 transistors increased from ∼10 to ∼18 cm2V−1s−1. The increased subthreshold swing of the fabricated transistors with MoS2 thickness suggests that the increase of MoS2 mobility with thickness may be related to the dependence of the contact resistance and the dielectric constant of MoS2 layer on its thickness.
- Published
- 2016
- Full Text
- View/download PDF
5. Multiple Switching Modes of NiOx Memristors for Memory-Driven Multifunctional Device Applications
- Author
-
Young Ran Park, Haein Cho, and Gunuk Wang
- Subjects
Materials Chemistry ,Electrochemistry ,Electronic, Optical and Magnetic Materials - Published
- 2022
6. Video Fingerprinting System Using Wavelet and Error Correcting Code.
- Author
-
Hyun-Ho Kang, Brian M. Kurkoski, Young-Ran Park, Hyejoo Lee, Sanguk Shin, Kazuhiko Yamaguchi, and Kingo Kobayashi
- Published
- 2005
- Full Text
- View/download PDF
7. A Steganographic Scheme in Digital Images Using Information of Neighboring Pixels.
- Author
-
Young-Ran Park, Hyun-Ho Kang, Sang-Uk Shin, and Ki-Ryong Kwon
- Published
- 2005
- Full Text
- View/download PDF
8. An Image Steganography Using Pixel Characteristics.
- Author
-
Young-Ran Park, Hyun-Ho Kang, Sang-Uk Shin, and Ki-Ryong Kwon
- Published
- 2005
- Full Text
- View/download PDF
9. Luminance efficiency roll-off mechanism in CsPbBr3−xClx mixed-halide perovskite quantum dot blue light-emitting diodes
- Author
-
Sangwon Eom, Won Kook Choi, Young Ran Park, Youngjong Kang, Hyosung Choi, Hong Hee Kim, and Bo Ram Lee
- Subjects
Quenching ,Materials science ,business.industry ,General Chemistry ,Luminance ,law.invention ,X-ray photoelectron spectroscopy ,law ,Quantum dot ,Materials Chemistry ,Optoelectronics ,Luminescence ,business ,Perovskite (structure) ,Light-emitting diode ,Diode - Abstract
Efficiency roll-off is a significant issue in blue light-emitting diodes (LEDs), but its origin still remains controversial. We report CsPbBr3−xClx/PbBry (or PbCly) (core/shell) quantum dot LEDs exhibiting the emission peak spanning from λpeak = 492 to λpeak = 435 nm by varying the Cl composition (0 ≤ x ≤ 2.21). PLQY and EQE significantly decreased with the increase of the Cl composition. Careful analyses of the composition and the energy structure using EL, PL, TRPL, UPS, XPS and STEM-EDX measurements reveal that the luminance efficiency roll-off in CsPbBr3−xClx LEDs is attributed to the following three combined effects: (1) luminescence quenching by the non-radiative trap-assisted recombination, (2) the hole transfer process at the CsPbBr3−xClx/PbBry core/shell, and (3) imbalanced charge injection caused by a high energy barrier for the hole conduction at the PVK/QD heterointerface (Δh′).
- Published
- 2021
10. Effect of Intersection Angle of Input Channels in Droplet Generators
- Author
-
Gi-Beum, Kim, Young-Ran, Park, Seong-Jong, Kim, and Kwang-Hyun, Park
- Subjects
Physics::Fluid Dynamics ,Chemistry (miscellaneous) ,Lab-On-A-Chip Devices ,Organic Chemistry ,Drug Discovery ,Molecular Medicine ,Pharmaceutical Science ,Computer Simulation ,Microfluidic Analytical Techniques ,Physical and Theoretical Chemistry ,droplet generation ,intersection angle ,flow-focusing (FF) geometries ,numerical simulation ,droplet diameter ,Analytical Chemistry - Abstract
In this paper, we studied the effects of the intersection angle between the inlet channels on the droplet diameter using a COMSOL Multiphysics® simulation. We employed the level-set method to study the droplet generation process inside a microfluidic flow device. A flow-focusing geometry was integrated into a microfluidics device and used to study droplet formation in liquid–liquid systems. Droplets formed by this flow-focusing technique are typically smaller than the upstream capillary tube and vary in size with the flow rates. Different intersection angles were modeled with a fixed width of continuous and dispersed channels, orifices, and expansion channels. Numerical simulations were performed using the incompressible Navier–Stokes equations for single-phase flow in various flow-focusing geometries. As a result of modeling, when the dispersed flow rate and the continuous flow rate were increased, the flow of the continuous flow fluid interfered with the flow of the dispersed flow fluid, which resulted in a decrease in the droplet diameter. Variations in the droplet diameter can be used to change the intersection angle and fluid flow rate. In addition, it was predicted that the smallest diameter droplet would be generated when the intersection angle was 90°.
- Published
- 2022
- Full Text
- View/download PDF
11. Over-expression of Anterior Gradient 3 Is Associated With Tumor Progression and Poor Survival in Gastric Cancer.
- Author
-
WAN-SIK LEE, SUN-YOUNG PARK, YOUNG-RAN PARK, and YOUNG-EUN JOO
- Subjects
CANCER invasiveness ,STOMACH cancer ,BIOMARKERS ,DISEASE progression ,MEDICAL care ,HEALTH outcome assessment - Abstract
Background/Aim: Anterior gradient (AGR) proteins, including AGR1, AGR2, and AGR3, which are members of the protein disulfide isomerase family, have been reported as biomarkers for various carcinogenesis processes. Although AGR2 and AGR1 have been demonstrated to be associated with gastric cancer (GC) progression and poor survival, the effect of AGR3 on the progression and prognosis of GC remains unknown. Therefore, our study aimed to examine the expression and prognostic significance of AGR3 in patients with GC. Patients and Methods: We investigated 271 GC patients receiving curative surgery. Formalin-fixed and paraffin-embedded tissue blocks were obtained, and long-term survival analysis was performed. The expression of AGR3 in GC tissues was investigated by quantitative reverse transcription-polymerase chain reaction, western blotting, and immunohistochemistry. Results: AGR3 was overexpressed in GC tissue compared with paired normal tissue at the mRNA and protein levels. AGR3 over-expression was significantly associated with larger tumor size, deeper tumor invasion, lymph node metastasis, and advanced tumor stage. The overall survival of patients with positive AGR3 expression was significantly lower than that of patients without positive AGR3 expression. Multivariate analysis demonstrated that AGR3 and age were independent prognostic factors associated with overall survival. Conclusion: Over-expression of AGR3 was significantly associated with tumor progression and poor survival of GC patients. Therefore, AGR3 may be a novel biomarker and prognostic factor for GC. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
12. Antioxidant and Anti-Inflammatory Effects of NCW Peptide from Clam Worm (Marphysa sanguinea)
- Author
-
Yunjo Soh, Young Ran Park, and Chan-Il Park
- Subjects
chemistry.chemical_classification ,Antioxidant ,biology ,medicine.drug_class ,medicine.medical_treatment ,Glutathione peroxidase ,Peptide ,General Medicine ,Applied Microbiology and Biotechnology ,Anti-inflammatory ,Nitric oxide ,Nitric oxide synthase ,Superoxide dismutase ,chemistry.chemical_compound ,chemistry ,Biochemistry ,Catalase ,medicine ,biology.protein ,Biotechnology - Abstract
Clam worms (Marphysa sanguinea) are a rich source of bioactive components such as the antibacterial peptide, perinerin. In the present study, we explored the physiological activities of a novel NCWPFQGVPLGFQAPP peptide (NCW peptide), which was purified from clam worm extract through high-performance liquid chromatography. Tandem mass spectrometry (MS/MS) revealed that NCW was a new peptide with a molecular weight of 1757.86 kDa. Moreover, NCW peptide exhibited significant antioxidant effects, causing a 50% inhibition of DPPH radical at a concentration of 20 μM without showing any cytotoxicity. These were associated with a reduction in the activity of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) in LPS-stimulated RAW264. 7 cells. Furthermore, NCW peptide exhibited anti-inflammatory effects in LPS-stimulated RAW264.7 macrophages via inhibition of the abnormal production of pro-inflammatory cytokines including nitric oxide (NO), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). These anti-inflammatory effects of NCW peptide were associated with the inhibition of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). Our results therefore suggest that this novel NCW peptide with antioxidant and anti-inflammatory effects could be a good therapeutic agent against inflammation-related diseases.
- Published
- 2020
13. Self-defect-passivation by Br-enrichment in FA-doped Cs1−x FA x PbBr3 quantum dots: towards high-performance quantum dot light-emitting diodes
- Author
-
Young Ran Park, Youngjong Kang, Sangwon Eom, Won Kook Choi, and Hong Hee Kim
- Subjects
Materials science ,Passivation ,Analytical chemistry ,Halide ,lcsh:Medicine ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Article ,law.invention ,law ,Vacancy defect ,Band diagram ,lcsh:Science ,Perovskite (structure) ,Nanoscale materials ,Multidisciplinary ,Doping ,lcsh:R ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Quantum dot ,lcsh:Q ,0210 nano-technology ,Materials for optics ,Light-emitting diode - Abstract
Halide vacancy defect is one of the major origins of non-radiative recombination in the lead halide perovskite light emitting devices (LEDs). Hence the defect passivation is highly demanded for the high-performance perovskite LEDs. Here, we demonstrated that FA doping led to the enrichment of Br in Cs1−xFAxPbBr3 QDs. Due to the defect passivation by the enriched Br, the trap density in Cs1−xFAxPbBr3 significantly decreased after FA doping, and which improved the optical properties of Cs1−xFAxPbBr3 QDs and their QD-LEDs. PLQY of Cs1–xFAxPbBr3 QDs increased from 76.8% (x = 0) to 85.1% (x = 0.04), and Lmax and CEmax of Cs1–xFAxPbBr3 QD-LEDs were improved from Lmax = 2880 cd m−2 and CEmax = 1.98 cd A−1 (x = 0) to Lmax = 5200 cd m−2 and CEmax = 3.87 cd A−1 (x = 0.04). Cs1–xFAxPbBr3 QD-LED device structure was optimized by using PVK as a HTL and ZnO modified with b-PEI as an ETL. The energy band diagram of Cs1–xFAxPbBr3 QD-LEDs deduced by UPS analyses.
- Published
- 2020
14. Cancer Statistics in Korea: Incidence, Mortality, Survival, and Prevalence in 2017
- Author
-
Hyun-Joo Kong, Young Ran Park, Kyu-Won Jung, Young-Joo Won, Eun Sook Lee, and Seri Hong
- Subjects
Adult ,Male ,0301 basic medicine ,Cancer Research ,Survival ,Adolescent ,Scale (ratio) ,History, 21st Century ,Special Article ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Neoplasms ,Republic of Korea ,Prevalence ,Humans ,Medicine ,Mortality ,Child ,Cancer death ,Aged ,Aged, 80 and over ,Korea ,business.industry ,Incidence ,Incidence (epidemiology) ,Infant, Newborn ,Infant ,Middle Aged ,Survival Rate ,030104 developmental biology ,Oncology ,Child, Preschool ,030220 oncology & carcinogenesis ,Female ,business ,Mortality survival ,Demography - Abstract
PurposeThis study reports the cancer statistics and temporal trends in Korea on a nationwide scale, including incidence, survival, prevalence, and mortality in 2017.Materials and MethodsThe incidence, survival, and prevalence rates of cancer were evaluated using data from the Korea National Cancer Incidence Database from 1999 to 2017 with follow-up until December 31, 2018. Deaths from cancer were assessed using cause-of-death data from 1983 to 2017, obtained from Statistics Korea. Crude and age-standardized rates (ASRs) for incidence, mortality, and prevalence, and 5-year relative survival rates were calculated and trend analysis was performed.ResultsIn 2017, newly diagnosed cancer cases and deaths from cancer numbered 232,255 (ASR, 264.4 per 100,000) and 78,863 (ASR, 76.6 per 100,000), respectively. The overall cancer incidence rates increased annually by 3.5% from 1999 to 2011 and decreased by 2.7% annually thereafter. Cancer mortality rates have been decreasing since 2002, by 2.8% annually. The 5-year relative survival rate for all patients diagnosed with cancer between 2013 and 2017 was 70.4%, which contributed to a prevalence of approximately 1.87 million cases by the end of 2017.ConclusionThe burden of cancer measured by incidence and mortality rates have improved in Korea, with the exception of a few particular cancers that are associated with increasing incidence or mortality rates. However, cancer prevalence is increasing rapidly, with the dramatic improvement in survival during the past several years. Comprehensive cancer control strategies and efforts should continue, based on the changes of cancer statistics.
- Published
- 2020
15. Watermarking for tamper detection and recovery.
- Author
-
Young-Ran Park, Hyun-Ho Kang, Kazuhiko Yamaguchi, and Kingo Kobayashi
- Published
- 2008
- Full Text
- View/download PDF
16. A Viable System for Tracing Illegal Users of Video.
- Author
-
Hyun-Ho Kang, Brian M. Kurkoski, Young-Ran Park, Sanguk Shin, Kazuhiko Yamaguchi, and Kingo Kobayashi
- Published
- 2006
- Full Text
- View/download PDF
17. 2E-Decene-4,6-diyn-1-ol-acetate inhibits osteoclastogenesis through mitogen-activated protein kinase-c-Fos-NFATc1 signalling pathways
- Author
-
Young Ran Park, Yunjo Soh, Seo Young Yang, Saroj Kuma Shrestha, and Xiang-Dong Su
- Subjects
musculoskeletal diseases ,MAPK/ERK pathway ,Physiology ,p38 mitogen-activated protein kinases ,Aster Plant ,Osteoclasts ,Bone resorption ,Mice ,Osteoclast ,Osteogenesis ,Physiology (medical) ,medicine ,Animals ,Viability assay ,Extracellular Signal-Regulated MAP Kinases ,Pharmacology ,Biological Products ,biology ,NFATC Transcription Factors ,Activator (genetics) ,Chemistry ,Macrophages ,RANK Ligand ,Genes, fos ,Cell Differentiation ,Cell biology ,medicine.anatomical_structure ,RAW 264.7 Cells ,Gene Expression Regulation ,Mitogen-activated protein kinase ,biology.protein ,Signal transduction - Abstract
An imbalance of osteoclasts and osteoblasts can result in a variety of bone-related diseases, including osteoporosis. Thus, decreasing the activity of osteoclastic bone resorption is the main therapeutic method for treating osteoporosis. 2E-Decene-4, 6-diyn-1-ol-acetate (DDA) is a natural bioactive compound with anti-inflammatory and anti-cancer properties. However, its effects on osteoclastogenesis are unknown. Murine bone marrow-derived macrophages (BMMs) or RAW264.7 cells were treated with DDA, followed by evaluation of cell viability, RANKL-induced osteoclast differentiation, and pit formation assay. Effects of DDA on RANKL-induced phosphorylation of MAPKs were assayed by western blot analysis. Expression of osteoclast-specific genes was examined with reverse transcription-PCR (RT-PCR) and western blot analysis. In this study, DDA significantly inhibited RANKL-induced osteoclast differentiation in RAW264.7 cells as well as in BMMs without cytotoxicity. DDA also strongly blocked the resorbing capacity of BMM on calcium phosphate-coated plates. DDA inhibited RANKL-induced phosphorylation of ERK, JNK and p38 MAPKs, as well as expression of c-Fos and NFATc1, which are essential transcription factors for osteoclastogenesis. In addition, DDA decreased expression levels of osteoclastogenesis-specific genes, including matrix metalloproteinase-9 (MMP-9), tartrate-resistant acid phosphatase (TRAP), and receptor activator of NF-κB (RANK) in RANKL-induced RAW264.7 cells. Collectively, these findings indicated that DDA attenuates RANKL-induced osteoclast formation by suppressing the MAPKs-c-Fos-NFATc1 signalling pathway and osteoclast-specific genes. These results indicate that DDA may be a potential candidate for bone diseases associated with abnormal osteoclast formation and function.
- Published
- 2021
18. A novel steganographic system with information integrity.
- Author
-
Young-Ran Park, Hyun-Ho Kang, Kazuhiko Yamaguchi, and Kingo Kobayashi
- Published
- 2007
- Full Text
- View/download PDF
19. Comparing and Evaluating two English versions of Samguk Yusa
- Author
-
Young-Ran Park
- Published
- 2019
20. Resistive switching functional quantum-dot light-emitting diodes
- Author
-
Won Kook Choi, Young Joon Hong, and Young Ran Park
- Subjects
010302 applied physics ,Materials science ,Annealing (metallurgy) ,business.industry ,General Physics and Astronomy ,02 engineering and technology ,021001 nanoscience & nanotechnology ,medicine.disease_cause ,01 natural sciences ,Capacitance ,law.invention ,Chemical state ,law ,Quantum dot ,Vacancy defect ,0103 physical sciences ,medicine ,Optoelectronics ,General Materials Science ,0210 nano-technology ,business ,Ultraviolet ,Diode ,Light-emitting diode - Abstract
This study demonstrates quantum-dot light-emitting diodes (QD-LEDs) with a function of resistive switching memory, capable of on/off operation at the same driving current depending on reset/set state. The QD-LEDs were fabricated by spin-coating process and experienced two different annealing conditions, which yielded defective or less-defective V2O5–x layer. One of the annealing conditions produced QD-LEDs with the unusual electrical behaviors of negative differential resistance (NDR), capacitance oscillation, and voltage–current hysteresis curves, signifying so-called resistive switching characteristics. X-ray and ultraviolet photoelectron spectroscopies were used to examine the chemical state of the differently annealed V2O5–x layers. The less stoichiometric V2O5–x layer was found to be responsible for the resistive switching behaviors of the NDR and the low and high resistance states (LRS and HRS, respectively). We discuss the LRS/HRS of V2O5–x for resistive switching in terms of a conductive filament effect, induced by microstructural changes caused by oxygen drift and vacancy annihilation processes in the high defect density V2O5–x layer.
- Published
- 2019
21. Ran, Ras-related nuclear protein, regulates chondrogenic differentiation of ATDC5 cells
- Author
-
Yunjo Soh, Sift Desk, Se-woong Kim, Young Ran Park, and Mahesh Sapkota
- Subjects
Collagen ii ,Chemistry ,Ran GTP-Binding Protein ,Ran ,Chondrogenesis ,Bone morphogenetic protein 2 ,Cell biology - Published
- 2019
22. Comparing survival outcomes for cervical cancer based on the 2014 and 2018 International Federation of Gynecology and Obstetrics staging systems
- Author
-
Myong Cheol Lim, Wonkyo Shin, Tae Young Ham, Young Ran Park, and Young-Joo Won
- Subjects
0301 basic medicine ,Adult ,medicine.medical_specialty ,Science ,Uterine Cervical Neoplasms ,Cervix Uteri ,Article ,Stage ib ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,Stage IIIC ,Stage (cooking) ,Lymph node ,Data collection system ,Cancer ,Aged ,Neoplasm Staging ,Retrospective Studies ,Gynecology ,Cervical cancer ,Multidisciplinary ,business.industry ,Obstetrics ,Middle Aged ,medicine.disease ,Prognosis ,Cervical cancer staging ,Cancer registry ,030104 developmental biology ,medicine.anatomical_structure ,Oncology ,030220 oncology & carcinogenesis ,Medicine ,Female ,Lymph Nodes ,business - Abstract
The International Federation of Gynecology and Obstetrics (FIGO) cervical cancer staging system was modified in 2018, introducing new stage IB subdivisions and new lymph node status considerations in stage IIIC. We compared cervical cancer survival outcomes according to the 2014 and 2018 FIGO staging systems. We selected 10% of cervical cancer cases (2010–2015) from the Korean national cancer registry (2010–2015) through a systematic sampling method. We collected information using a collaborative stage data collection system and evaluated the results according to both staging systems. The log-rank test was used to analyze overall survival differences. No significant difference in survival was observed between 2018 subdivisions IB1/IB2/IB3 (P = 0.069), whereas a considerable difference was observed between these subdivisions according to histological subtypes. In the 2018 FIGO staging system, stage IIIC had better survival than stage IIIA/IIIB (P
- Published
- 2021
23. Suppression of Inflammation, Osteoclastogenesis and Bone Loss by PZRAS Extract
- Author
-
Young Ran Park, Hyoung-Kwon Cho, Saroj Kumar Shrestha, Liang Li, and Yunjo Soh
- Subjects
0106 biological sciences ,Lipopolysaccharides ,Glutathione reductase ,Cathepsin K ,Interleukin-1beta ,Pharmacology ,01 natural sciences ,Applied Microbiology and Biotechnology ,Bone resorption ,Bone remodeling ,Ginseng ,Mice ,Osteoclast ,Osteogenesis ,010608 biotechnology ,medicine ,Animals ,Bone Resorption ,chemistry.chemical_classification ,Cathepsin ,Inflammation ,Mice, Inbred ICR ,biology ,NFATC Transcription Factors ,Plant Extracts ,Tartrate-Resistant Acid Phosphatase ,Tumor Necrosis Factor-alpha ,Glutathione peroxidase ,RANK Ligand ,Cell Differentiation ,General Medicine ,biology.organism_classification ,medicine.anatomical_structure ,RAW 264.7 Cells ,chemistry ,Matrix Metalloproteinase 9 ,Scutellaria baicalensis ,Matrix Metalloproteinase 2 ,Proto-Oncogene Proteins c-fos ,Biotechnology - Abstract
Panax ginseng has a wide range of activities including a neuroprotective effect, skin protective effects, enhanced DNA repairing, anti-diabetic activity, and protective effects against vascular inflammation. In the present study, we sought to discover the inhibitory effects of a mixture of natural products containing Panax ginseng, Ziziphus jujube, Rubi fructus, Artemisiae asiaticae and Scutellaria baicalensis (PZRAS) on osteoclastogenesis and bone remodeling, as neither the effects of a mixture containing Panax ginseng extract, nor its molecular mechanism on bone inflammation, have been clarified yet. PZRAS upregulated the levels of catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GSH-R) and glutathione peroxidase (GSH-Px) and reduced malondialdehyde (MDA) in LPS-treated RAW264.7 cells. Moreover, treatment with PZRAS decreased the production of IL-1β and TNF-α. PZRAS also inhibited osteoclast differentiation through inhibiting osteoclastspecific genes like MMP-2, 9, cathepsin K, and TRAP in RANKL-treated RAW264.7 cells. Additionally, PZRAS has inhibitory functions on the RANKL-stimulated activation of ERK and JNK, which lead to a decrease in the expression of NFATc1 and c-Fos. In an in vivo study, bone resorption induced by LPS was recovered by treatment with PZRAS in bone volume per tissue volume (BV/TV) compared to control. Furthermore, the ratio of eroded bone surface of femurs was significantly increased in LPS-treated mice compared to vehicle group, but this ratio was significantly reversed in PZRAS-treated mice. These results suggest that PZRAS could prevent or treat disorders with abnormal bone loss.
- Published
- 2020
24. Antioxidant and Anti-Inflammatory Effects of NCW Peptide from Clam Worm (
- Author
-
Young Ran, Park, Chan-Il, Park, and Yunjo, Soh
- Subjects
Inflammation ,Cell Survival ,Macrophages ,Anti-Inflammatory Agents ,Nitric Oxide Synthase Type II ,Polychaeta ,Antioxidants ,Molecular Weight ,Mice ,RAW 264.7 Cells ,Cyclooxygenase 2 ,Animals ,Cytokines ,Amino Acid Sequence ,Inflammation Mediators ,Peptides ,Nitrites - Abstract
Clam worms (
- Published
- 2020
25. Analyses of English Proverbs translated from Translation Machines
- Author
-
Young Ran Park
- Subjects
Computer science ,Translation (geometry) ,Linguistics - Published
- 2018
26. MicroRNA 196B Regulates HOXA5, HOXB6 and GLTP Expression Levels in Colorectal Cancer Cells
- Author
-
Young-Ran Park, Ji-Su Mo, and Soo-Cheon Chae
- Subjects
0301 basic medicine ,Cancer Research ,Colorectal cancer ,Down-Regulation ,Biology ,Protein expression ,Pathology and Forensic Medicine ,Pathogenesis ,03 medical and health sciences ,0302 clinical medicine ,Cell Movement ,Cell Line, Tumor ,microRNA ,medicine ,Humans ,RNA, Messenger ,Gene ,Aged ,Homeodomain Proteins ,Messenger RNA ,General Medicine ,Middle Aged ,Colorectal carcinogenesis ,medicine.disease ,Up-Regulation ,Gene Expression Regulation, Neoplastic ,MicroRNAs ,030104 developmental biology ,Oncology ,030220 oncology & carcinogenesis ,Cancer research ,Target gene ,Carrier Proteins ,Colorectal Neoplasms - Abstract
MiRNAs are non-coding RNAs that play important roles in the pathogenesis of human diseases by regulating target gene expression in specific cells or tissues. Previously we identified colorectal cancer (CRC) associated MIR196B, which was specifically up-regulated in CRC cells and tissue. We also identified 18 putative MIR196B target genes by comparing the mRNAs down-regulated in MIR196B-overexpressed cells with MIR196B target genes predicted by public bioinformatics tools. In this study, we verified the association between MIR196B and three genes, HOXA5, HOXB6 and GLTP. HOXA5, HOXB6 and GLTP transcripts were directly down-regulated by MIR196B. The mRNA and proteins levels of HOXA5, HOXB6 and GLTP were also down-regulated in CRC cells by the up-regulated MIR196B. GLTP protein expression was decreased in CRC tissues compared to adjacent non-tumor tissues. These results suggest that HOXA5, HOXB6, and GLTP were direct target genes of MIR196B in CRC cells, and that the up-regulated MIR196B in CRC tissue regulates the expression levels of HOXA5, HOXB6, and GLTP during colorectal carcinogenesis.
- Published
- 2018
27. Nanoparticle intercalation-induced interlayer-gap-opened graphene–polyaniline nanocomposite for enhanced supercapacitive performances
- Author
-
TaeYoung Kim, Won G. Hong, Kyungjung Kwon, Sanghyuk Park, Sungjin Im, Ji Hoon Doh, Young Joon Hong, Hyeong Jin Kim, Woo Seok Yang, Young Ran Park, and Byung-Nam Kim
- Subjects
Materials science ,Nanocomposite ,Graphene ,Intercalation (chemistry) ,General Physics and Astronomy ,Nanotechnology ,02 engineering and technology ,Surfaces and Interfaces ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,law.invention ,Silver chloride ,chemistry.chemical_compound ,chemistry ,law ,Electrode ,Polyaniline ,Pseudocapacitor ,0210 nano-technology ,Nanosheet - Abstract
This study demonstrates a method for improving supercapacitive performance of two-dimensional nanosheet-based composite electrode. As a hybridized electrostatic double layer capacitor–electrochemical pseudocapacitor (EDLC–PC) electrode, we synthesized reduced graphene oxide–polyaniline nanofibers (rGO–PANi NFs) composite electrode. For the enhanced supercapacitive performances, insulator silver chloride nanoparticles (AgCl NPs) were intercalated into the interlayer gap of rGO. The AgCl NP intercalation (i) exfoliated rGO layers and (ii) prevented rGO-self-agglomeration that makes it difficult to utilize the high surface-to-volume ratio of ideal mono- (or few-) atomic-thick rGO layers. As a result, (iii) the specific capacitance was improved in accordance with the enlarged specific surface area of rGO. Furthermore, (iv) the well-developed rGO edges, which were opened by the AgCl intercalation, enabled formation of more bonds between PANi and rGO by selective grafting of PANi to the rGO edges. Hence, the bonds of PANi–rGO, as conducting paths, substantially reduced the total electrical resistance. Enhanced specific capacitance, ion diffusion efficiency, and reduced electrical resistance indicated the bi-functional roles of AgCl NP insertion for high performance hybridized EDLC–PC electrodes.
- Published
- 2017
28. Parthenolide promotes apoptotic cell death and inhibits the migration and invasion of SW620 cells
- Author
-
Sang Wook Kim, Young Ran Park, Soo-Teik Lee, Se Lim Kim, and Yu Chuan Liu
- Subjects
0301 basic medicine ,lcsh:Medicine ,Vimentin ,Apoptosis ,Colorectal neoplasms ,Parthenolide ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Invasion ,Medicine ,MTT assay ,lcsh:RC799-869 ,Migration ,biology ,business.industry ,lcsh:R ,Gastroenterology ,Cell migration ,030104 developmental biology ,chemistry ,030220 oncology & carcinogenesis ,Cancer cell ,biology.protein ,Cancer research ,Original Article ,lcsh:Diseases of the digestive system. Gastroenterology ,Signal transduction ,Wound healing ,business - Abstract
Background/aims Parthenolide (PT), a principle component derived from feverfew (Tanacetum parthenium), is a promising anticancer agent and has been shown to promote apoptotic cell death in various cancer cells. In this study, we focused on its functional role in apoptosis, migration, and invasion of human colorectal cancer (CRC) cells. Methods SW620 cells were employed as representative human CRC cells. We performed the MTT assay and cell cycle analysis to measure apoptotic cell death. The wound healing, Transwell migration, and Matrigel invasion assays were performed to investigate the effect of PT on cell migration/invasion. Western blotting was used to establish the signaling pathway of apoptosis and cell migration/invasion. Results PT exerts antiproliferative effect and induces apoptotic cell death of SW620 cells. In addition, PT prevents cell migration and invasion in a dose-dependent manner. Moreover, PT markedly suppressed migration/invasion-related protein expression, including E-cadherin, β-catenin, vimentin, Snail, cyclooxygenase-2, matrix metalloproteinase-2 (MMP-2), and MMP-9 in SW620 cells. PT also inhibited the expression of antiapoptotic proteins (Bcl-2 and Bcl-xL) and activated apoptosis terminal factor (caspase-3) in a dose-dependent manner. Conclusions Our results suggest that PT is a potential novel therapeutic agent for aggressive CRC treatment.
- Published
- 2017
29. Combined Parthenolide and Balsalazide Have Enhanced Antitumor Efficacy Through Blockade of NF-κB Activation
- Author
-
Young Ran Park, Yu Chuan Liu, Se Lim Kim, Hwan-Jeong Jeong, Eun-Mi Kim, Seung Young Seo, In Hee Kim, Sang Wook Kim, Yo Na Kim, Seong Hun Kim, Soo Teik Lee, and Seung Ok Lee
- Subjects
0301 basic medicine ,Cancer Research ,Combination therapy ,Carcinogenesis ,Colorectal cancer ,Apoptosis ,medicine.disease_cause ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Antineoplastic Combined Chemotherapy Protocols ,Animals ,Humans ,Medicine ,Parthenolide ,Mesalamine ,Molecular Biology ,Cell Proliferation ,Mice, Inbred BALB C ,business.industry ,Anti-Inflammatory Agents, Non-Steroidal ,NF-kappa B ,Cancer ,Drug Synergism ,Balsalazide ,Colitis ,medicine.disease ,Phenylhydrazines ,030104 developmental biology ,Oncology ,chemistry ,030220 oncology & carcinogenesis ,Cancer cell ,Cancer research ,Female ,Colorectal Neoplasms ,business ,Sesquiterpenes ,Signal Transduction - Abstract
Balsalazide is a colon-specific prodrug of 5-aminosalicylate that is associated with a reduced risk of colon cancer in patients with ulcerative colitis. Parthenolide, a strong NF-κB inhibitor, has recently been demonstrated to be a promising therapeutic agent, promoting apoptosis of cancer cells. In the current study, the antitumor effect of balsalazide combined with parthenolide in human colorectal cancer cells and colitis-associated colon cancers (CAC) was investigated. The results demonstrate that the combination of balsalazide and parthenolide markedly suppress proliferation, nuclear translocation of NF-κB, IκB-α phosphorylation, NF-κB DNA binding, and expression of NF-κB targets. Apoptosis via NF-κB signaling was confirmed by detecting expression of caspases, p53 and PARP. Moreover, treatment of a CAC murine model with parthenolide and balsalazide together resulted in significant recovery of body weight and improvement in histologic severity. Administration of parthenolide and balsalazide to CAC mice also suppressed carcinogenesis as demonstrated by uptake of 18F-fluoro-2-deoxy-D-glucose (FDG) using micro-PET/CT scans. These results demonstrate that parthenolide potentiates the efficacy of balsalazide through synergistic inhibition of NF-κB activation and the combination of dual agents prevents colon carcinogenesis from chronic inflammation. Implications: This study represents the first evidence that combination therapy with balsalazide and parthenolide could be a new regimen for colorectal cancer treatment. Mol Cancer Res; 15(2); 141–51. ©2016 AACR.
- Published
- 2017
30. Impact of Job Stress, Depression and Perceived Health Status on Job Satisfaction among Child Care Teachers
- Author
-
Lee, Mi-Ran, Sun-Nam · Lee, and Young-Ran · Park
- Subjects
Child care ,Job stress ,030504 nursing ,business.industry ,05 social sciences ,Job attitude ,Perceived health ,03 medical and health sciences ,Medicine ,0501 psychology and cognitive sciences ,Job satisfaction ,Gainful employment ,0305 other medical science ,business ,Depression (differential diagnoses) ,050104 developmental & child psychology ,Clinical psychology - Published
- 2016
31. Aloe-emodin inhibits osteogenic differentiation and calcification of mouse vascular smooth muscle cells
- Author
-
Young Ran Park, Yunjo Soh, Saroj Kumar Shrestha, Ming Yang, and Mahesh Sapkota
- Subjects
Male ,0301 basic medicine ,medicine.medical_specialty ,Vascular smooth muscle ,Myocytes, Smooth Muscle ,Bone Morphogenetic Protein 2 ,chemistry.chemical_element ,Anthraquinones ,Aorta, Thoracic ,Calcium ,Muscle, Smooth, Vascular ,03 medical and health sciences ,Calcification, Physiologic ,0302 clinical medicine ,Osteogenesis ,Internal medicine ,medicine.artery ,medicine ,Animals ,Thoracic aorta ,Osteopontin ,Von Kossa stain ,Smad4 Protein ,Pharmacology ,Mice, Inbred ICR ,biology ,Chemistry ,Osteoblast ,medicine.disease ,030104 developmental biology ,medicine.anatomical_structure ,Endocrinology ,biology.protein ,030217 neurology & neurosurgery ,Ex vivo ,Calcification - Abstract
Vascular calcification increases the risk of morbidity and mortality in patients with cardiovascular diseases, chronic kidney diseases, and diabetes. However, viable therapeutic methods to target vascular calcification are limited. Aloe-emodin (AE), an anthraquinone is a natural compound found in the leaves of Aloe-vera. In this study, we investigated the underlying mechanism of AE in the calcification of vascular smooth muscle cells (VSMCs) and murine thoracic aorta. We demonstrate that AE repressed not only the phenotypes of Ca2+ induced calcification but also level of calcium in VSMCs. AE has no effect on cell viability in VSMC cells. Alizarin red, von Kossa stainings and calcium quantification showed that Ca2+ induced vascular calcification is significantly decreased by AE in a concentration-dependent manner. In contrast, AE attenuated Ca2+ induced calcification through inhibiting osteoblast differentiation genes such as SMAD4, collagen 1α, osteopontin (OPN), Runt-related transcription factor (RUNX-2) and Osterix. AE also suppressed Ca2+ induced osteoblast-related protein expression including collagen 1α, bone morphogenic protein 2 (BMP-2), RUNX-2 and smooth muscle actin (SMA). Furthermore, Alizarin red, von Kossa stainings and calcium quantification showed that AE significantly inhibited the calcification of ex vivo ring formation in murine thoracic aorta, and markedly inhibited vitamin D3 induced medial aorta calcification in vivo. Taken together, our findings suggest that AE may have therapeutic potential for the prevention of vascular calcification program.
- Published
- 2019
32. [Corrigendum] Lipocalin 2 inversely regulates TRAIL sensitivity through p38 MAPK‑mediated DR5 regulation in colorectal cancer
- Author
-
Soo Teik Lee, In Suk Min, Young Ran Park, Sang Wook Kim, and Se-Lim Kim
- Subjects
0301 basic medicine ,Regulation of gene expression ,Cancer Research ,Gene knockdown ,Oncogene ,Biology ,Cell cycle ,Molecular medicine ,03 medical and health sciences ,030104 developmental biology ,Oncology ,Downregulation and upregulation ,Apoptosis ,Cancer research ,Gene silencing - Abstract
TNF-related apoptosis-inducing ligand (TRAIL) induces apoptosis through death receptors (DRs)4 and/or 5 expressed on the cell surface. Multiple clinical trials are underway to evaluate the antitumor activity of recombinant human TRAIL and agonistic antibodies to DR4 or DR5. However, their therapeutic potential is limited by the high frequency of cancer resistance. In this study, we provide evidence demonstrating the role of lipocalin 2 (LCN2) in the TRAIL-mediated apoptosis of human colorectal cancer (CRC). By analyzing the mRNA expression data of 71 CRC tissues from patients, we found that DR5 was preferentially expressed in CRC tissues with a low LCN2 expression level compared to tissues with a high LCN2 expression level. Moreover, we analyzed the association between DR5 and LCN2 expression and this analysis revealed that DR5 expression in CRC tended to be inversely associated with LCN2 expression. By contrast, no association was found between the DR4 and LCN2 expression levels. The expression patterns of LCN2 in human CRC cell lines also exhibited an inverse association with DR5 expression. The knockdown of LCN2 by siRNA in the TRAIL‑resistant CRC cells expressing high levels of LCN2 led to a significant increase in TRAIL-induced apoptosis through the upregulation of DR5 protein and mRNA expression. The mechanism through which LCN2 silencing sensitized the CRC cells to TRAIL was dependent on the extrinsic pathway of apoptosis. In addition, we identified that the knockdown of LCN2 enhanced the sensitivity of the cells to TRAIL through the p38 MAPK/CHOP-dependent upregulation of DR5. Taken together, the findings of this study suggest that LCN2 is responsible for TRAIL sensitivity and LCN2 may thus prove to be a promising target protein in DR-targeted CRC therapy.
- Published
- 2018
33. Down-regulation of miR-9 promotes epithelial mesenchymal transition via regulating anoctamin-1 (ANO1) in CRC cells
- Author
-
Soo Teik Lee, Se Lim Kim, Sang Wook Kim, In Hee Kim, Seung Young Seo, Min Ro Lee, Young Ran Park, Shi Mao Zhu, Seong Hun Kim, and Seung Ok Lee
- Subjects
Male ,Cancer Research ,Epithelial-Mesenchymal Transition ,Down-Regulation ,Apoptosis ,Biology ,ANO1 ,03 medical and health sciences ,0302 clinical medicine ,Cyclin D1 ,Gentamicin protection assay ,Downregulation and upregulation ,Cell Movement ,Cell Line, Tumor ,Genetics ,Humans ,Neoplasm Invasiveness ,Epithelial–mesenchymal transition ,RNA, Messenger ,Phosphorylation ,Extracellular Signal-Regulated MAP Kinases ,Molecular Biology ,Anoctamin-1 ,Cell Proliferation ,Neoplasm Staging ,Base Sequence ,Cell growth ,Cell migration ,Transfection ,Cell Cycle Checkpoints ,Middle Aged ,digestive system diseases ,Neoplasm Proteins ,Up-Regulation ,Gene Expression Regulation, Neoplastic ,MicroRNAs ,030220 oncology & carcinogenesis ,Lymphatic Metastasis ,biology.protein ,Cancer research ,Female ,Colorectal Neoplasms ,Proto-Oncogene Proteins c-akt - Abstract
MicroRNA-9 (miR-9) has been reported to play a suppressive or promoting role according to cancer type. In this study, we investigated the effects of anoctamin-1 (ANO1) and miR-9 on colorectal cancer (CRC) cell proliferation, migration, and invasion and determined the underlying molecular mechanisms. Thirty-two paired CRC tissues and adjacent normal tissues were analyzed for ANO1 expression using quantitative real-time PCR (qRT-PCR). HCT116 cells were transiently transfected with miR-9 mimic, miR-9 inhibitor, or si-ANO1. Cell proliferation was determined by MTT, and flow cytometric analysis, while cell migration and invasion were assayed by trans-well migration and invasion assay in HCT116 cells. ANO1 was validated as a target of miR-9 using luciferase reporter assay and bioinformatics algorithms. We found that ANO1 expression was up-regulated in CRC tissues compared with adjacent normal tissues. ANO1 expression was associated with advanced tumor stage and lymph node metastasis, and there was an inverse relationship between miR-9 and ANO1 mRNA expression in CRC specimens, but no significant difference was found between miR-9 and ANO1 expression. ANO1 is a direct target of miR-9, and overexpression of miR-9 suppressed both mRNA and protein expression of ANO1 and inhibited cell proliferation, migration, and invasion of HCT116 cells. We also showed that overexpression of miR-9 suppressed expression of p-AKT, cyclin D1, and p-ERK in HCT116 cells. We conclude that miR-9 inhibits CRC cell proliferation, migration, and invasion by directly targeting ANO1, and miR-9/ANO1 could be a potential therapeutic target for CRC.
- Published
- 2018
34. MiRNA-206 suppresses PGE2-induced colorectal cancer cell proliferation, migration, and invasion by targetting TM4SF1
- Author
-
Sungkun Chun, Shi Mao Zhu, Soo Teik Lee, Seung Young Seo, Jung Mi Oh, Seung Ok Lee, In Hee Kim, Min Ro Lee, Se Lim Kim, Seong Hun Kim, Young Ran Park, and Sang Wook Kim
- Subjects
0301 basic medicine ,Male ,Epithelial-Mesenchymal Transition ,Biophysics ,Apoptosis ,Biochemistry ,Dinoprostone ,Flow cytometry ,03 medical and health sciences ,0302 clinical medicine ,Cell Movement ,Cell Line, Tumor ,microRNA ,medicine ,Humans ,MTT assay ,Neoplasm Invasiveness ,Molecular Biology ,Aged ,Cell Proliferation ,Neoplasm Staging ,medicine.diagnostic_test ,Chemistry ,Cell growth ,Cell migration ,Cell Biology ,Transfection ,Middle Aged ,Cadherins ,Neoplasm Proteins ,Gene Expression Regulation, Neoplastic ,MicroRNAs ,030104 developmental biology ,Cell culture ,030220 oncology & carcinogenesis ,Antigens, Surface ,Cancer research ,Female ,Colorectal Neoplasms - Abstract
MiRNA (miR)-206 plays a tumor suppressor role in various cancer types. Here, we investigated whether miR-206 is involved in prostaglandin E2 (PGE2)-induced epithelial–mesenchymal transition (EMT) in colorectal cancer (CRC) cells through the targetting of transmembrane 4 L six family member 1 (TM4SF1).The effect of PGE2 on growth and apoptosis of CRC cells was evaluated using the MTT assay and flow cytometry analysis, respectively. TM4SF1 and miR-206 expression levels were determined with quantitative polymerase chain reaction (qRT-PCR) in CRC tissues and cell lines. The concentration of PGE2 in the serum of CRC patients and healthy controls was measured with an ELISA kit. A miR-206 or TM4SF1 construct was transfected into cells with PGE2. Transwell migration and invasion assays were used to examine cell migration and invasion properties. Additionally, a luciferase assay was performed to determine whether TM4SF1 was directly targetted by miR-206.We found that miR-206 was down-regulated and TM4SF1 was up-regulated in human CRC tissues and cell lines. Moreover, miR-206 was negatively correlated with TM4SF1 expression. Bioinformatics analysis and a luciferase reporter assay revealed that miR-206 directly targetted the 3′-untranslated region (UTR) of TM4SF1, and TM4SF1 expression was reduced by miR-206 overexpression at both the mRNA and protein levels. Additionally, PGE2 significantly suppressed the expression of miR-206 and increased the expression of TM4SF1 in CRC cells. PGE2 induction led to enhanced CRC cell proliferation, migration, and invasion. Moreover, the overexpression of miR-206 decreased CRC cell proliferation, migration, and invasion compared with control group in PGE2-induced cells, and these effects could be recovered by the overexpression of TM4SF1. Overexpression of miR-206 also suppressed the expression of β-catenin, VEGF, MMP-9, Snail, and Vimentin and enhanced E-cadherin expression in PGE2-induced cells. These results could be reversed by the overexpression of TM4SF1. At last, up-regulation of miR-206 suppressed expression of p-AKT and p-ERK by targetting TM4SF1 in PGE2-induced cells.Our results provide further evidence that miR-206 has a protective effect on PGE2-induced colon carcinogenesis.
- Published
- 2018
35. Solution-processed quantum dot light-emitting diodes with PANI:PSS hole-transport interlayers
- Author
-
Koo Shin, Young-Soo Seo, Ji Hoon Doh, Soo Young Kim, Yunseok Kim, Young Ran Park, Young Joon Hong, and Won Kook Choi
- Subjects
Materials science ,business.industry ,General Chemistry ,Electroluminescence ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,law.invention ,Biomaterials ,chemistry.chemical_compound ,chemistry ,PEDOT:PSS ,Quantum dot ,law ,Polyaniline ,Materials Chemistry ,Optoelectronics ,Work function ,Electrical and Electronic Engineering ,business ,Solution process ,Ultraviolet photoelectron spectroscopy ,Light-emitting diode - Abstract
For solution-processed quantum dot light-emitting devices (QD-LEDs), poly(3,4-ethylenedioxythiophene) polystyrene sulfonate/poly(N-vinylcarbozole) (PEDOT:PSS/PVK) bilayers have been widely used as the hole injection/transport layer. The high work function of the hole transport layer is crucial for high electroluminescence efficiency with balanced electron/hole charge injection. Herein, we report improvement of the performance of QD-LEDs by inserting a polyaniline (PANI)-poly (p-styrenesulfonic acid) (PSS) (PANI:PSS) hole-transport layer between the PVK and PEDOT:PSS layers. The insertion of the PANI:PSS layer significantly shifted the electronic energy levels of the PVK layers to lower values, which reduced the energy barrier of holes traveling to the QD layer by 0.22 eV. The QD-LEDs with PANI:PSS interlayer exhibited superior electric and electroluminescent characteristics. The hole-only devices with PANI:PSS interlayer also presented high hole injection and transport capability. Ultraviolet photoelectron spectroscopy (UPS) was used to investigate the electronic energy level alignment of the QD-LEDs with/without the PANI:PSS interlayer. The device performance results of QD-LEDs and hole-only devices indicated enhanced electric and electroluminescent characteristics for the PANI:PSS-inserted QD-LEDs with high hole conduction capability, in agreement with UPS findings.
- Published
- 2015
36. Light-Emitting Diodes: Graphene Oxide Inserted Poly(N -Vinylcarbazole)/Vanadium Oxide Hole Transport Heterojunctions for High-Efficiency Quantum-Dot Light-Emitting Diodes (Adv. Mater. Interfaces 15/2017)
- Author
-
Woo Seok Yang, Young Ran Park, Hu Young Jeong, Won Kook Choi, Kyoung Soon Choi, Soo Young Kim, Jong Chan Kim, Yong-Jin Kim, Young Joon Hong, and Young-Soo Seo
- Subjects
Materials science ,Graphene ,business.industry ,Mechanical Engineering ,Oxide ,Heterojunction ,Vanadium oxide ,Poly-N-vinylcarbazole ,law.invention ,chemistry.chemical_compound ,chemistry ,Mechanics of Materials ,law ,Quantum dot ,Optoelectronics ,business ,Light-emitting diode ,Graphene oxide paper - Published
- 2017
37. Parthenolide suppresses hypoxia-inducible factor-1α signaling and hypoxia induced epithelial-mesenchymal transition in colorectal cancer
- Author
-
Young Ran Park, Soo Teik Lee, Sang Wook Kim, and Se Lim Kim
- Subjects
0301 basic medicine ,Oncology ,Cancer Research ,medicine.medical_specialty ,Epithelial-Mesenchymal Transition ,Angiogenesis ,Cell ,Down-Regulation ,Mice, Nude ,Biology ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,Internal medicine ,medicine ,Human Umbilical Vein Endothelial Cells ,Animals ,Humans ,Parthenolide ,Neoplasm Invasiveness ,Epithelial–mesenchymal transition ,Tube formation ,Neovascularization, Pathologic ,NF-kappa B ,Cell cycle ,HCT116 Cells ,Hypoxia-Inducible Factor 1, alpha Subunit ,Xenograft Model Antitumor Assays ,Cell Hypoxia ,030104 developmental biology ,medicine.anatomical_structure ,Hypoxia-inducible factors ,chemistry ,030220 oncology & carcinogenesis ,Colonic Neoplasms ,Cancer research ,Female ,Signal transduction ,HT29 Cells ,Sesquiterpenes ,Signal Transduction - Abstract
Activation of hypoxia-inducible factor 1α (HIF‑1α) is frequently observed in solid tumors and it has been associated with various pathophysiological processes, including epithelial‑mesenchymal transition (EMT). Previously, we reported that parthenolide (PT), an inhibitor of nuclear factor-κB (NF-κB), is a promising anticancer agent because it promotes apoptosis of human colorectal cancer (CRC). Here, we investigated a new molecular mechanism by which PT acts on HIF‑1α and hypoxia contributing to EMT by NF‑κB inhibition. Cell viability, DNA binding activity, vascular cell tube formation and cell motility were studied after treatment of PT in hypoxic or normoxic condition. Moreover, effects of PT on hypoxia signaling and hypoxia-induced EMT signaling were investigated. We also examined the inhibitory effect of PT on CRC progression in xenografts. We demonstrated that PT markedly inhibits hypoxia dependent HIF‑1α activity and angiogenesis by preventing NF-κB activation. We also report that PT decreases the level of proteins associated with glucose metabolism, angiogenesis, development and survival that are regulated by HIF‑1α. Furthermore, we verified that PT protects the morphological change from epithelial to mesenchymal state, inhibits matrix metalloproteinase (MMP) enzyme activity and decreases cell motility involved in the -regulation of the hypoxia-induced EMT markers. In addition, PT inhibits growth in CRC xenograft models and regulates NF‑κB, HIF‑1α and EMT specific marker in tissue specimens. Our data demonstrated that PT can inhibit HIF‑1α signaling and hypoxia-induced EMT, suggesting a novel molecular mechanism for HIF‑1α mediated cancer progression and metastasis.
- Published
- 2017
38. Quantum-Dot Light-Emitting Diodes with Nitrogen-Doped Carbon Nanodot Hole Transport and Electronic Energy Transfer Layer
- Author
-
Hu Young Jeong, Young-Soo Seo, Young Ran Park, Won Kook Choi, and Young Joon Hong
- Subjects
Multidisciplinary ,Materials science ,Photoluminescence ,business.industry ,Heterojunction ,02 engineering and technology ,Electroluminescence ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Article ,0104 chemical sciences ,law.invention ,Quantum dot ,law ,Optoelectronics ,Nanodot ,0210 nano-technology ,business ,Ultraviolet photoelectron spectroscopy ,Light-emitting diode ,Diode - Abstract
Electroluminescence efficiency is crucial for the application of quantum-dot light-emitting diodes (QD-LEDs) in practical devices. We demonstrate that nitrogen-doped carbon nanodot (N-CD) interlayer improves electrical and luminescent properties of QD-LEDs. The N-CDs were prepared by solution-based bottom up synthesis and were inserted as a hole transport layer (HTL) between other multilayer HTL heterojunction and the red-QD layer. The QD-LEDs with N-CD interlayer represented superior electrical rectification and electroluminescent efficiency than those without the N-CD interlayer. The insertion of N-CD layer was found to provoke the Förster resonance energy transfer (FRET) from N-CD to QD layer, as confirmed by time-integrated and -resolved photoluminescence spectroscopy. Moreover, hole-only devices (HODs) with N-CD interlayer presented high hole transport capability, and ultraviolet photoelectron spectroscopy also revealed that the N-CD interlayer reduced the highest hole barrier height. Thus, more balanced carrier injection with sufficient hole carrier transport feasibly lead to the superior electrical and electroluminescent properties of the QD-LEDs with N-CD interlayer. We further studied effect of N-CD interlayer thickness on electrical and luminescent performances for high-brightness QD-LEDs. The ability of the N-CD interlayer to improve both the electrical and luminescent characteristics of the QD-LEDs would be readily exploited as an emerging photoactive material for high-efficiency optoelectronic devices.
- Published
- 2017
- Full Text
- View/download PDF
39. Polymorphisms of interleukin-31 are associated with anti-CCP levels in females with rheumatoid arthritis
- Author
-
Shin-Seok Lee, Soo-Cheon Chae, Ji-In Yu, and Young-Ran Park
- Subjects
Adult ,Male ,medicine.medical_treatment ,Inflammation ,Biology ,Peptides, Cyclic ,Polymorphism, Single Nucleotide ,Arthritis, Rheumatoid ,Immune system ,Genetics ,medicine ,Humans ,Cytotoxic T cell ,Genetic Association Studies ,Haplotype ,Receptors, Interleukin ,Middle Aged ,medicine.disease ,Interleukin 31 ,Cytokine ,Lymphotoxin ,Haplotypes ,Rheumatoid arthritis ,Immunology ,Female ,medicine.symptom - Abstract
Cytokines play important roles in a wide range of different cell types, tissues and organs. Interleukin-31 (IL-31) is a member of the IL-6 family of cytokines. IL-31 is a T helper type 2 (Th2) effecter cytokine that plays an important role in atopic and allergic diseases. It was found that genotype and allele frequencies of the IL-31 SNPs in rheumatoid arthritis (RA) patients were not significantly different from those in the healthy controls. The haplotype frequencies of IL-31 SNPs were also not significantly different between the RA patients and the healthy controls. The g.-1066G>A, g.586C>A and g.1449C>G polymorphisms of IL-31 were significantly associated with the anti-CCP levels in the female RA patients (P = 0.010, 0.012 and 0.025, respectively). The results indicate that in RA patients, IL-31 SNPs may play a role in anti-CCP production, and suggest that SNPs in the IL-31 gene could be associated with susceptibility to RA. RA is one of the most common autoimmune diseases worldwide and is characterized by the inflammation of synovial tissues and the formation of rheumatoid pannus, which is capable of eroding adjacent cartilage and bone and cause subsequent joint destruction (Goldring and Gravallese 2000). RA comes about through a complex interaction betweenmultiple genetic and environmental factors (Gregersen 1999). The activated T helper (Th) cells during the developing stage are differentiated phenotypically and functionally into two distinct types of cells, Th1 and Th2 (Abbas et al. 1996). Th1 cells produce cytokines such as interferonγ (IFN-γ ), IL-12 and the cytotoxic factor lymphotoxin. They are commonly associated with cell-mediated immune
- Published
- 2014
40. The Change of Ultrasonic Transmission Velocity by Wood Decay
- Author
-
Won-Joung Hwang, Young Ran Park, Dong-Heub Lee, and Hyun-Mi Lee
- Subjects
Materials science ,Materials Science (miscellaneous) ,Ultrasonic velocity ,technology, industry, and agriculture ,food and beverages ,Ultrasonic transmission ,Bending ,White rot fungus ,Composite material ,complex mixtures ,Industrial and Manufacturing Engineering ,Fungal exposure - Abstract
The deterioration in wood by the brown-rot fungus (Fomitopsispalustris) and the white-rot fungus (Trametesversicolor) were measured using ultrasonic velocity. Those were used for the decay exposure and 4 wood species of wood as the test specimens, Pinusdensiflora, Larixkaempferi, Pinuskoraiensis and Pinusrigida, were chosen with both the brown- and white-rot culture petridish during 12 weeks. After 12 weeks, the decrease rate of ultrasonic velocity was measured at 10~15%. In both brown- and white-rot exposure experiments, P. rigida showed significant decrease in ultrasonic velocity (20%), L. kaempferi on the other hand did not show decrease in ultrasonic velocity. After the fungal exposure experiment, the inside of specimens was investigated by computer tomography (C/T). After C/T investigation, bending tests were performed.
- Published
- 2014
41. Pressure distribution and wall shear stress in stenosis and abdominal aortic aneurysm by computational fluid dynamics modeling (CFD)
- Author
-
Hyung-Sub Kang, Yeong-Seok Yang, Young Ran Park, Shang-Jin Kim, In-Shik Kim, Byung-Yong Park, Jong-Beum Choi, and Gi-Beum Kim
- Subjects
Materials science ,General Chemical Engineering ,Hemodynamics ,Reynolds number ,General Chemistry ,Blood flow ,medicine.disease ,Abdominal aortic aneurysm ,Stenosis ,symbols.namesake ,medicine.anatomical_structure ,cardiovascular system ,medicine ,Shear stress ,symbols ,Elasticity (economics) ,Blood vessel ,Biomedical engineering - Abstract
sThe models of stenosed blood vessel with three different types of stenosis types have been modeled to investigate blood flow characteristics. The study was performed to investigate various hemodynamics, such as pressure and wall shear stress (WSS), with the change of stenosis ratio and Reynolds numbers (Re). The results of modeling, the minimum WSS occurred in different regions according to the stenosis types. The change of the diameter of blood vessel showed up in the pre-stenotic region by elastic behavior characteristics of blood vessels. Also, when the thickness of wall of blood vessel is 2 mm, the radius of blood vessel is increased by approximately two-times. As atherosclerosis progresses, the wall of blood vessels gradually loses elasticity and then the thickness of blood vessels gets thinner.
- Published
- 2013
42. Analyses on Attitudes to Smart Education-related Variables Based on Parents' Age, Levels of Education and Income
- Author
-
Jae-Hoon Kim, Young Ran Park, and Keol Lim
- Subjects
Medical education ,Educational method ,media_common.quotation_subject ,Political science ,Pedagogy ,Household income ,Creativity ,Mobile device ,Tablet pc ,media_common - Abstract
This research was conducted to analyze parents` attitudes on the issues related to the Smart Education Initiative Korea. The questions included the usefulness of major digital tools for educational purposes, knowledge on the Smart Education, necessity for better educational methods, and Bring Your Own Devices (BYOD) policy. A total of 432 response cases from the parents were analyzed considering the parents` age, academic level, and income. As a result, parents regarded desktop PCs as more effective tools for learning when compared to tablet PCs. Meanwhile, mobile devices and SNSs were hardly considered as instructional tools. Second, familarity and understanding of the Smart Education were proportional to household income and mothers` education levels. Third, parents needed for the change in educational methods and agreed with the importance of students` self-regulated learning, collaboration, inquiry ability and creativity. Fourth, regarding BYOD, parents were willing to buy devices with a reasonable price. In conclusion, it is required to reflect the results of the study when implementing the Smart Education throughout the nation.
- Published
- 2013
43. Photoluminescence enhancement from hybrid structures of metallic single-walled carbon nanotube/ZnO films
- Author
-
Young Ran Park, Na Liu, and Cheol Jin Lee
- Subjects
Spin coating ,Photoluminescence ,Materials science ,business.industry ,General Physics and Astronomy ,Nanotechnology ,Carbon nanotube ,law.invention ,Metal ,law ,visual_art ,visual_art.visual_art_medium ,Optoelectronics ,General Materials Science ,Surface plasmon resonance ,business ,Spin (physics) ,Excitation ,Localized surface plasmon - Abstract
We investigated the dependence of localized surface plasmon resonance (LSPR) coupled photoluminescence (PL) emission on the density of a metallic single-walled carbon nanotube (m-SWCNT). The m-SWCNTs of various densities were deposited on top of ZnO films by spin coating and filtration transfer method to form the hybrid structures. We observed PL enhancement from ZnO films deposited with spin coated m-SWCNT, comparing with pure ZnO film. The m-SWCNT acts as absorbers for the light emitted due to SPR. After resonant excitation, hot electrons in m-SWCNT are created in high energy states, which can then transfer from the m-SWCNT to the conduction band of the ZnO films. We discuss the relationship between the hot electron flow generated by internal photoemission and LSPR.
- Published
- 2013
44. Cancer Statistics in Korea: Incidence, Mortality, Survival, and Prevalence in 2017.
- Author
-
Seri Hong, Young-Joo Won, Young Ran Park, Kyu-Won Jung, Hyun-Joo Kong, and Eun Sook Lee
- Subjects
CANCER statistics ,CANCER-related mortality ,MORTALITY ,TREND analysis - Abstract
Purpose This study reports the cancer statistics and temporal trends in Korea on a nationwide scale, including incidence, survival, prevalence, and mortality in 2017. Materials and Methods The incidence, survival, and prevalence rates of cancer were evaluated using data from the Korea National Cancer Incidence Database from 1999 to 2017 with follow-up until December 31, 2018. Deaths from cancer were assessed using cause-of-death data from 1983 to 2017, obtained from Statistics Korea. Crude and age-standardized rates (ASRs) for incidence, mortality, and prevalence, and 5-year relative survival rates were calculated and trend analysis was performed. Results In 2017, newly diagnosed cancer cases and deaths from cancer numbered 232,255 (ASR, 264.4 per 100,000) and 78,863 (ASR, 76.6 per 100,000), respectively. The overall cancer incidence rates increased annually by 3.5% from 1999 to 2011 and decreased by 2.7% annually thereafter. Cancer mortality rates have been decreasing since 2002, by 2.8% annually. The 5-year relative survival rate for all patients diagnosed with cancer between 2013 and 2017 was 70.4%, which contributed to a prevalence of approximately 1.87 million cases by the end of 2017. Conclusion The burden of cancer measured by incidence and mortality rates have improved in Korea, with the exception of a few particular cancers that are associated with increasing incidence or mortality rates. However, cancer prevalence is increasing rapidly, with the dramatic improvement in survival during the past several years. Comprehensive cancer control strategies and efforts should continue, based on the changes of cancer statistics. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
45. Investigations of the polymer alignment, the nonradiative resonant energy transfer, and the photovoltaic response of poly(3-hexylthiophene)/TiO2 hybrid solar cells.
- Author
-
Young Ran Park, You-Jin Lee, Chang-Jae Yu, and Jae-Hoon Kim
- Subjects
- *
ANNEALING of metals , *PHOTOVOLTAIC cells , *TITANIUM dioxide , *EMISSIONS (Air pollution) , *PHOTONS - Abstract
We report the effects of annealing on the performance of hybrid photovoltaic (PV) cells containing poly(3-hexylthiophene) (P3HT) coated onto TiO2/Sn doped In2O3 (ITO) and ITO substrates. In the optimized device, which exhibits a higher efficiency, the backbone axes of the P3HT chains were found to lie within the substrate plane, their conjugated planes are slightly tilted, and their side chains are substantially tilted. The carboxylate group is attached via bidentate or bridging coordination to the TiO2 surface and enables photoinduced charge transfer between TiO2 and P3HT. The observed large quenching (with excitation at 488 nm) and enhanced emission (with excitation at 325 nm) indicates that efficient Förster resonance energy transfer occurs between TiO2 and P3HT. Thus, the main influences on the high efficiency of the hybrid PV cells are the photon-mediated electronic transition and the photoinduced charge transfer. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
46. Optical investigation of Zn1-xFexO films grown on Al2O3(0001) by radio-frequency sputtering.
- Author
-
Kwang Joo Kim and Young Ran Park
- Subjects
- *
THIN films , *PHOTOEMISSION , *RADIO frequency , *MAGNETRONS , *SPUTTERING (Physics) , *ALLOYS - Abstract
Zn1-xFexO thin films were grown on Al2O3(0001) substrates by radio-frequency magnetron sputtering. The alloys show wurtzite crystal structure up to x=0.24 with reduced c-axis lattice constant compared to that of pure ZnO. Fe 2p core-level photoemission measurements reveal the evidence for the coexistence of the Fe3+ and Fe2+ ions substituting the tetrahedral the Zn2+ sites. The optical properties of the samples were measured by the spectroscopic ellipsometry at room temperature in the 1.5–5 eV photon energy region. With increasing x, the optical band-gap (E0) absorption edge is found to shift slightly to lower energies (70 meV for x=0.24) than that of the pure ZnO. Below the E0 edge, optical absorption structures are observed at about 1.7, 2.4, and 2.8 eV. These structures are interpreted as due to the d-d transitions from the 6A1 ground state to the excited states, 4T1 (1.7 eV), 4T2 (2.4 eV), and 4E and 4A1 (2.8 eV), of the crystal-field-split 3d5 multiplets of the tetrahedral Fe3+ ion. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
47. Optical properties of normal spinel MxCo3-xO4 (M=Cr and Cu): Coexistence of charge-transfer and crystal-field transitions.
- Author
-
Kwang Joo Kim, Young Ran Park, Dong Hoon Hyun, and Sung Ho Lee
- Subjects
- *
METALLIC films , *OPTICAL properties , *ELLIPSOMETRY , *CRYSTAL lattices , *CHARGE transfer , *SPECTRUM analysis - Abstract
Optical properties of normal spinel MxCo3-xO4 (M=Cr and Cu) films grown by sol-gel method have been investigated by the spectroscopic ellipsometry (SE) in the 1.5–4 eV region. For x<1.0, the cubic lattice constant of CrxCo3-xO4 is found to increase linearly with x while that of CuxCo3-xO4 decreases slightly. By comparing the optical constants of the ternary oxides measured by SE with those of Co3O4, Mott-Hubbard, charge-transfer (CT) and crystal-field (CF) transitions are found to coexist in the same energy region. The changes in the optical absorption spectrum by Cr and Cu alloying into Co3O4 are explained in terms of the changes in the electronic structure of Co3O4 through the substitution of the octahedral Co3+ and the tetrahedral Co2+ sites of the spinel structure by Cr3+ and Cu2+ ions, respectively. The CT transitions are explained in terms of d states of the Co3+ and Co2+ ions and p states of O2- ion. The CF transitions are interpreted as originating from the CF multiplets of the octahedral Co3+ and Cr3+ ions. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
48. Sputtering growth and optical properties of [100]-oriented tetragonal SnO[sub 2] and its Mn alloy films.
- Author
-
Young Ran Park, Hideaki and Kwang Joo Kima, Hideaki
- Subjects
- *
THIN films , *MANGANESE alloys , *RADIO frequency , *STOICHIOMETRY , *TITANIUM ores - Abstract
SnO[sub 2] and its Mn alloy thin films have been grown on Al[sub 2]O[sub 3](0001) substrates by reactive radio-frequency magnetron sputtering performed in the presence of O[sub 2] gas. The prepared films showed preferred orientation in the [100] direction of the rutile structure of SnO[sub 2]. The O[sub 2]/Ar gas-flow ratio maintained during the sputtering was found to significantly affect the crystalline quality and stoichiometry of the films. The optical constants of the SnO[sub 2] and Sn[sub 1-x]Mn[sub x]O[sub 2] (x<=0.27) films were measured by spectroscopic ellipsometry in the 2–5 eV photon energy region. The band-gap energy of SnO[sub 2] is determined to be 3.86 eV and that of Sn[sub 1-x]Mn[sub x]O[sub 2] increases for x<=0.11 and then decreases for the higher x, exhibiting a negative bowing. The initial increase of the band-gap energy is attributable to the hybridization between localized Mn d states located near the band gap and O p-like valence bands. The decrease of the band-gap energy is interpreted as due to the SnO[sub 2]–MnO[sub 2] alloying effects. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
49. A Study on Hemodynamic Characteristics at the Stenosed Blood Vessel Using Computational Fluid Dynamics Simulations
- Author
-
Hyung-Sub Kang, Gi-Beum Kim, Seong-Jong Kim, Young Ran Park, Shang-Jin Kim, and Jin-Shang Kim
- Subjects
Materials science ,Biomedical Engineering ,Pulsatile flow ,Pharmaceutical Science ,Medicine (miscellaneous) ,Hemodynamics ,Arterial Occlusive Diseases ,Bioengineering ,Aneurysm, Ruptured ,Computational fluid dynamics ,symbols.namesake ,Shear stress ,medicine ,Animals ,Humans ,Arterial Pressure ,Computer Simulation ,General Materials Science ,business.industry ,Models, Cardiovascular ,Reynolds number ,Arteries ,Mechanics ,Blood flow ,medicine.disease ,Stenosis ,Axial compressor ,symbols ,Vascular Resistance ,Rheology ,Shear Strength ,business ,Blood Flow Velocity - Abstract
In this study, we have used computational fluid dynamics to investigate the blood flow in the stenosed blood vessels. The numerical simulation using commercial software ADINA 8.6 were solved about the stenosed blood vessel according to the percent of stenosis and Reynolds number. The blood flow in the normal and stenosed blood vessel was grasped for the validity of the model. The characteristic of the pulsatile flow changed through the steady state flow and analysis of the pulsatile flow according to the time was grasped. The computational model with the characteristics of the fluid-structure interaction is introduced to investigate the wall shear stress, pressure distribution and axial flow velocity. The results show that axial flow velocity and wall shear stress in the region of stenosis was increased by increasing percent of stenosis and Reynolds number. Also, we can know that in the stenosed blood vessel the possibility of the generation of the aneurysm was increased by increasing Reynolds number and percent of stenosis.
- Published
- 2013
50. Investigations of the polymer alignment, the nonradiative resonant energy transfer, and the photovoltaic response of poly(3-hexylthiophene)/Ti[O.sub.2] hybrid solar cells
- Author
-
Young Ran Park, You-Jin Lee, Chang-Jae Yu, and Jae-Hoon Kim
- Subjects
Annealing -- Usage ,Organometallic compounds -- Structure ,Organometallic compounds -- Electric properties ,Organometallic compounds -- Optical properties ,Solar batteries -- Composition ,Solar cells -- Composition ,Thiophene -- Structure ,Thiophene -- Electric properties ,Titanium dioxide -- Electric properties ,Titanium dioxide -- Optical properties ,Titanium dioxide -- Thermal properties ,Physics - Abstract
Several studies are conducted to explain the different effects of annealing on the polymer alignment and performance of the different poly(3-hexylthiophene)/Ti[O.sub.2] hybrid solar cells. The photon-mediated electronic transition is shown to be the main factor leading to high efficiency in these cells.
- Published
- 2010
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.