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Kang BH, Lee SW, Lim SW, Kim JS, Sai-Anand G, Lee SH, Kwon DH, Kang SW. Enhanced Performance of Light-Emitting Diodes by Surface Ligand Modification on Quantum Dots. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2015; 15:7169-7172. [PMID: 26716304 DOI: 10.1166/jnn.2015.10560] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The electrical characteristics of quantum dots (QDs) can vary depending on the surface modulation, which can change the luminance and efficiency of electroluminescent devices. Thus, understanding surface ligand is essential in improving the performance of QDs-based light-emitting diodes (LEDs). We analyzed the performance of QDs-based LEDs with respect to the QD surface volume. On the QD surfaces, the 1.1 nm-long tryoctylphosphine oxide (TOPO) ligand with three neck-type structure was replaced with a 1.7 nm-long oleic acid (OA) ligand with a one neck-type structure to evaluate the dependence of the LED properties on the ligand length. With all other conditions being identical, the luminance and efficiency of the QDs-based LEDs with an OA ligand were approximately 1,000 cd/m2 greater and 1.5 times higher, respectively, than those of the QDs-based LEDs with a TOPO ligand. These results show that if the physical length of the surface ligand is relatively long, decreasing the surface area would result in increased injection of electrons and holes into the QDs, increasing the luminance and efficiency.
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Kang BH, Kim JS, Lee JS, Lee SW, Sai-Anand G, Jeong HM, Lee SH, Kwon DH, Kang SW. Solution Processable CdSe/ZnS Quantum Dots Light-Emitting Diodes Using ZnO Nanocrystal as Electron Transport Layer. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2015; 15:7416-7420. [PMID: 26716347 DOI: 10.1166/jnn.2015.10542] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In this paper, we propose interface engineering between cadmium selenide/zinc sulfide (CdSe/ZnS) quantum dots (QDs) as the emissive layer (EML) and ZnO nanocrystals (NCs) as the electron transport layer (ETL) for reducing the potential barrier in QDs based light-emitting diode (QLED). The n-type ZnO NCs were effective in confining charge to the QDs EML because of their wide band gap. The ZnO NCs were synthesized using a modified sol-gel process and were applied as the ETL in QLED. For comparison, a standard QLED with Tris(8-hydroxyquinolinato)aluminium as the ETL was also fabricated. The standard QLED was shown to have a luminance of 11,240 cd/m2 and current efficiency of 2.3 cd/A. However, QLED with ZnO NCs showed a higher luminance of 28,760 cd/m2 and current efficiency of 4.9 cd/A than the reference structure, and so has more efficient charge transport. Thus, QLED with ZnO NCs not only simplified the process, but also enhanced the luminance and current efficiency by factor of two.
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Sai-Anand G, Han B, Kim SW, Lee SW, Lee JS, Jeong HM, Kang SW. Incorporation of Gold Nanodots Into Poly(3,4-ethylenedioxythiophene):Poly(styrene sulfonate) for an Efficient Anode Interfacial Layer for Improved Plasmonic Organic Photovoltaics. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2015; 15:7092-7098. [PMID: 26716289 DOI: 10.1166/jnn.2015.10537] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
UNLABELLED In this paper, we demonstrate a simple strategy for the incorporation of gold nanodots (GNDs) into poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) ( PEDOT PSS) films, towards fabrication of an efficient anode interfacial layer in order to improve the performance of bulk heterojunction (BHJ) solar cells that use a blend of poly(3-hexyl thiophene) and [6,6]-phenyl-C71 butyric acid methyl ester as the organic active layer. We synthesized citrate-stabilized GNDs, with sizes in the range of -20-30 nm, by initially blending them into PEDOT PSS by aqueous dispersion. The influence of GNDs in the PEDOT PSS layer on the photovoltaic characteristics of BHJ solar cells was investigated. Our results show that the improved performance is due to the enhanced conductivity and increased interfacial contact area between the PEDOT PSS and organic active layer, owing to the inclusion of GNDs into the PEDOT PSS. The BHJ solar cell included with GNDs (0.02 wt%) into PEDOT PSS exhibited a power conversion efficiency (PCE) of 2.92% with an open circuit voltage of 0.61 V, fill factor of 50%, and a short-circuit current density of 9.51 mA/cm2, whereas the pristine device exhibited a PCE of 2.52%.
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Kim SK, Chung JH, Park HJ, Kang SW, Lim DJ, Byun SH, Baek DG, Ko HY, Lew BL, Baik HH, Sim WY. Polymorphisms in the promoter regions of the CXCL1 and CXCL2 genes contribute to increased risk of alopecia areata in the Korean population. GENETICS AND MOLECULAR RESEARCH 2015; 14:9667-74. [PMID: 26345899 DOI: 10.4238/2015.august.14.29] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Alopecia areata (AA) is a common disease, which causes hair loss in humans. AA has a genetically complex inheritance. This study investigated the possible correlations between single nucleotide polymorphisms (SNPs) in the promoter regions of the chemokine (C-X-C motif) ligand 1 (melanoma growth stimulating activity, alpha) (CXCL1) and chemokine (C-X-C motif) ligand 2 (CXCL2) genes and the development of AA in the Korean population. Two hundred and thirty-five AA patients and 240 control subjects were recruited. The specific SNPs occurring in the promoter regions of the CXCL1 and CXCL2 genes (rs3117604, -429C/T and rs3806792, -264T/C, respectively) were genotyped. All data obtained was evaluated using the SNPStats, SPSS 18.0, and the Haploview v.4.2 software platforms. The Odd's ratios (OR), 95% confidence intervals (CI), and P values were calculated using multiple logistic regression models. Analyses of the genetic sequences obtained revealed a significant correlation between the two SNPs and the development of AA (rs3117604, P = 0.0009 in co-dominant model 1, P = 0.01 in co-dominant model 2, P = 0.004 in the dominant model, P = 0.005 in the log-additive model, P = 0.012 in allele distribution; rs3806792, P = 0.036 in co-dominant model 2, P = 0.0046 in the log-additive model). The TT and CC haplotypes were also observed to show a significant association with increased risk of AA (TT haplotype, P = 0.0018; CC haplotype, P = 0.0349). Our data suggests that the CXCL1 and CXCL2 genes may be associated with AA susceptibility.
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Kim JH, Kang SW, Lee EJ, Kim J, Kim SJ, Ahn J. Temporal changes in foveal contour after macular hole surgery. Eye (Lond) 2014; 28:1355-63. [PMID: 25233817 DOI: 10.1038/eye.2014.217] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 08/11/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND To investigate the changes in inner foveal contour after surgery for macular hole (MH) and its clinical implications. METHODS This retrospective observational case series included 66 eyes from 66 patients who underwent surgery for MH. Notching of tissue was defined as an abrupt alteration in the inner contour of the parafoveal tissue based on postoperative optical coherence tomography (OCT) image. The distance between the parafoveal edges of the outer plexiform layer (OPL) was defined as the inter-OPL distance. The inter-OPL distance was divided into nasal, temporal, superior, and inferior lengths. The difference in the lengths of each direction between the early and late postoperative period was compared between directions with and without notching. RESULTS The early and late postoperative examination was performed at 4.6±2.9 weeks and 6.2±0.6 months, respectively. Notching of tissue was noted in 54 eyes (81.8%). In 53 eyes with a measurable inter-OPL distance, the notching of tissue was noted in 45 eyes (84.9%) regardless of preoperative MH size. The mean amount of foveal tissue elongation that occurred during the designated period was 104.6±68.8 and 78.4±72.9 μm in the directions with and without the notching of tissue (P<0.001), respectively. CONCLUSIONS The changes in the inner foveal contour, including notching of tissue and elongation of foveal tissue, were noted in the majority of eyes after MH surgery. Notching of tissue on OCT image could be a clinical marker for the development of foveal tissue elongation after MH surgery.
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Lee HG, Sai-Anand G, Komathi S, Gopalan AI, Kang SW, Lee KP. Efficient visible-light-driven photocatalytic degradation of nitrophenol by using graphene-encapsulated TiO₂ nanowires. JOURNAL OF HAZARDOUS MATERIALS 2014; 283:400-409. [PMID: 25310598 DOI: 10.1016/j.jhazmat.2014.09.014] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 08/28/2014] [Accepted: 09/01/2014] [Indexed: 06/04/2023]
Abstract
In this work, a new hybrid nanocatalyst, namely titanium dioxide (TiO2) composite nanowires, encapsulated with graphene (G) and palladium nanoparticles (Pd NPs) (designated as G-Pd@TiO2-CNWs), was prepared. In preparing the nanowires, a combination of electrospinning and hydrothermal approaches was employed. The visible-light-driven photocatalytic performance of G-Pd@TiO2-CNWs was investigated using the reduction of 4-nitrophenol (4-NP) as a model reaction. The results showed that G-Pd@TiO2-CNWs converted nearly 100% of 4-NP under visible light irradiation. The reaction kinetics of the photocatalytic reduction of 4-NP was studied by UV-vis spectrophotometry and the apparent rate constant was determined and compared with those for other supported TiO2 catalysts. Furthermore, the spent G-Pd@TiO2-CNWs could be recovered by simple centrifugation and reused. The work is expected to shed new light on the development of G-incorporated hybrid nanostructures for harvesting light energy and on the development of new photocatalysts for the removal of environmental pollutants.
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Sai-Anand G, Philips MF, Lee KP, Kang SW, Gopalan AL. Facile electrodeposition of flower like gold nanostructures on a conducting polymer support. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2014; 14:3256-3261. [PMID: 24734764 DOI: 10.1166/jnn.2014.8576] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Herein, we report an attractive, simple and templateless synthetic method for the formation of anisotropic gold nanostructures. Gold 'mesoflowers' consisting of arrays of nanoplatelets were synthesized by electrochemical gold deposition on/off conditions onto a conducting poly(diphenylamine) (PDPA) support matrix. A possible forming mechanism of anisotropic gold nanostructures is presented. The electronic and electrochemical properties of gold nanoflower decorated PDPA in an assembled diode configuration were evaluated.
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Kwon SJ, Park JH, Park EJ, Lee SA, Lee HS, Kang SW, Kwon J. ATM-mediated phosphorylation of the chromatin remodeling enzyme BRG1 modulates DNA double-strand break repair. Oncogene 2014; 34:303-13. [PMID: 24413084 DOI: 10.1038/onc.2013.556] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Revised: 11/15/2013] [Accepted: 11/18/2013] [Indexed: 12/25/2022]
Abstract
ATP-dependent chromatin remodeling complexes such as SWI/SNF (SWItch/Sucrose NonFermentable) have been implicated in DNA double-strand break (DSB) repair and damage responses. However, the regulatory mechanisms that control the function of chromatin remodelers in DNA damage response are largely unknown. Here, we show that ataxia telangiectasia mutated (ATM) mediates the phosphorylation of BRG1, the catalytic ATPase of the SWI/SNF complex that contributes to DSB repair by binding γ-H2AX-containing nucleosomes via interaction with acetylated histone H3 and stimulating γ-H2AX formation, at Ser-721 in response to DNA damage. ATM-mediated phosphorylation of BRG1 occurs rapidly and transiently after DNA damage. Phosphorylated BRG1 binds γ-H2AX-containing nucleosomes to form the repair foci. The Ser-721 phosphorylation of BRG1 is critical for binding γ-H2AX-containing nucleosomes and stimulating γ-H2AX formation and DSB repair. BRG1 binds to acetylated H3 peptides much better after phosphorylation at Ser-721 by DNA damage. However, the phosphorylation of Ser-721 does not significantly affect the ATPase and transcriptional activities of BRG1. These results, establishing BRG1 as a novel and functional ATM substrate, suggest that the ATM-mediated phosphorylation of BRG1 facilitates DSB repair by stimulating the association of this remodeler with γ-H2AX nucleosomes via enhancing the affinity to acetylated H3. Our work also suggests that the mechanism of BRG1 stimulation of DNA repair is independent of the remodeler's enzymatic or transcriptional activities.
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Lim SM, Chang H, Yoon MJ, Hong YK, Kim H, Chung WY, Park CS, Nam KH, Kang SW, Kim MK, Kim SB, Lee SH, Kim HG, Na II, Kim YS, Choi MY, Kim JG, Park KU, Yun HJ, Kim JH, Cho BC. A multicenter, phase II trial of everolimus in locally advanced or metastatic thyroid cancer of all histologic subtypes. Ann Oncol 2013; 24:3089-94. [PMID: 24050953 DOI: 10.1093/annonc/mdt379] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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Kim HR, Lee MJ, Song JE, Han JH, Yoo TH, Kang SW, Choi KH, Han SH. Drainage failure because of spontaneous fracture of the peritoneal dialysis catheter. Perit Dial Int 2013; 33:218-20. [PMID: 23478378 DOI: 10.3747/pdi.2012.00045] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Khan MRR, Kang BH, Lee SW, Kim SH, Yeom SH, Lee SH, Kang SW. Fiber-optic multi-sensor array for detection of low concentration volatile organic compounds. OPTICS EXPRESS 2013; 21:20119-20130. [PMID: 24105558 DOI: 10.1364/oe.21.020119] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In this paper, we proposed a new type high sensitive volatile organic compounds (VOCs) gas sensor array that is based on the pulse width modulation technique. Four different types of solvatochromic dyes and two different types of polymers, were used to make the five different types of sensing membranes. These were deposited on the five side-polished optical fibers by a spin coater to make the five different sensing elements of the array. In order to ascertain the effectiveness of the sensors, five VOC gases were tested. Finally, principal component analysis (PCA) has been used to discriminates different types of VOCs.
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Kim JH, Kang SW, Kim YT, Kim SJ, Chung SE. Partial posterior hyaloidectomy for macular disorders. Eye (Lond) 2013; 27:946-51. [PMID: 23743531 DOI: 10.1038/eye.2013.117] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Accepted: 04/16/2013] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To evaluate the effect of partial posterior hyaloidectomy (PPH) in preventing iatrogenic retinal breaks related to the induction of a posterior vitreous detachment (IPVD). METHODS Fifty-nine patients who necessitated IPVD for an epiretinal membrane or macular hole were included in this prospective, interventional case series. Extensive removal of vitreous gel, close to the retina, was conducted before IPVD under 23 G (gauge)-vitrectomy system. The PPH involved the limited extent of IPVD and limited removal of the outermost vitreous cortex to an area slightly beyond the margin of the temporal major vascular arcade. The incidence of retinal breaks related to the surgery was compared with 57 eyes that had undergone conventional 23-G total vitrectomy accompanied by extensive IPVD using χ(2)-test. RESULTS Patients were followed-up for a mean of 14.3 months (6-30 months) after the surgery. The incidence of peripheral retinal breaks after the PPH was 3.4% (2/59 eyes), which was significantly lower than that in the eyes that underwent conventional 23 G vitrectomy (15.8%, 9/57 eyes, P=0.023) for the same disorders that required an IPVD. No patient complained of postoperative floaters, postoperatively. CONCLUSIONS PPH would be an efficient procedure to prevent iatrogenic peripheral retinal breaks related to an IPVD.
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Yoon H, Oh D, Park HC, Kang SW, Han Y, Lim DH, Paik SW. Predictive factors for gastroduodenal toxicity based on endoscopy following radiotherapy in patients with hepatocellular carcinoma. Strahlenther Onkol 2013; 189:541-6. [PMID: 23703401 DOI: 10.1007/s00066-013-0343-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Accepted: 03/06/2013] [Indexed: 12/25/2022]
Abstract
PURPOSE The aim of this work was to determine predictive factors for gastroduodenal (GD) toxicity in hepatocellular carcinoma (HCC) patients who were treated with radiotherapy (RT). PATIENTS AND METHODS A total of 90 HCC patients who underwent esophagogastroduodenoscopy (EGD) before and after RT were enrolled. RT was delivered as 30-50 Gy (median 37.5 Gy) in 2-5 Gy (median 3.5 Gy) per fraction. All endoscopic findings were reviewed and GD toxicities related to RT were graded by the Common Toxicity Criteria for Adverse Events, version 3.0. The predictive factors for the ≥ grade 2 GD toxicity were investigated. RESULTS Endoscopic findings showed erosive gastritis in 14 patients (16 %), gastric ulcers in 8 patients (9 %), erosive duodenitis in 15 patients (17 %), and duodenal ulcers in 14 patients (16 %). Grade 2 toxicity developed in 19 patients (21 %) and grade 3 toxicity developed in 8 patients (9 %). V25 for stomach and V35 for duodenum (volume receiving a RT dose of more than x Gy) were the most predictive factors for ≥ grade 2 toxicity. The gastric toxicity rate at 6 months was 2.9 % for V25 ≤ 6.3 % and 57.1 % for V25 > 6.3 %. The duodenal toxicity rate at 6 months was 9.4 % for V35 ≤ 5.4 % and 45.9 % for V35 > 5.4 %. By multivariate analysis including the clinical factors, V25 for stomach and V35 for duodenum were the significant factors. CONCLUSION EGD revealed that GD toxicity is common following RT for HCC. V25 for the stomach and V35 for the duodenum were the significant factors to predict ≥ grade 2 GD toxicity.
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Selvam R, Jurkevich A, Kang SW, Mikhailova MV, Cornett LE, Kuenzel WJ. Distribution of the Vasotocin Subtype Four Receptor (VT4R) in the Anterior Pituitary Gland of the Chicken, Gallus gallus, and its Possible Role in the Avian Stress Response. J Neuroendocrinol 2013; 25:56-66. [PMID: 22849330 DOI: 10.1111/j.1365-2826.2012.02370.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Revised: 05/29/2012] [Accepted: 07/27/2012] [Indexed: 11/29/2022]
Abstract
The neurohormone arginine vasotocin (AVT) in non mammalian vertebrates is homologous to arginine vasopressin (AVP) in mammals. Its actions are mediated via G protein-coupled receptors that belong to the vasotocin/mesotocin family. Because of the known regulatory effects of nonapeptide hormones on anterior pituitary functions, receptor subtypes in that family have been proposed to be located in anterior pituitary cells. Recently, an avian vasotocin receptor subtype designated VT4R has been cloned, which shares 69% sequence homology with a human vasopressin receptor, the V1aR. In the present study, a polyclonal antibody to the VT4R was developed and validated to confirm its specificity to the VT4R. The antibody was used to test the hypothesis that the VT4R is present in the avian anterior pituitary and is specifically associated with certain cell types, where its expression is modulated by acute stress. Western blotting of membrane protein extracts from pituitary tissue, the use of HeLa cells transfected with the VT4R and peptide competition assays all confirmed the specificity of the antibody to the VT4R. Dual-labelling immunofluorescence microscopy was utilised to identify pituitary cell types that contained immunoreactive VT4R. The receptor was found to be widely distributed throughout the cephalic lobe but not in the caudal lobe of the anterior pituitary. Immunoreactive VT4R was associated with corticotrophs. Approximately 89% of immunolabelled corticotrophs were shown to contain the VT4R. The immunoreactive VT4R was not found in gonadotrophs, somatotrophs or lactotrophs. To determine a possible functional role of the VT4R and previously characterised VT2R, gene expression levels in the anterior pituitary were determined after acute immobilisation stress by quantitative reverse transcriptase-polymerase chain reaction. The results showed a significant increase in plasma corticosterone levels (three- to four-fold), a significant reduction of VT4R mRNA and an increase of VT2R mRNA (P < 0.05) in acutely immobilised chicks compared to controls. The data suggest a role of the VT4R in the avian stress response.
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Ahn MJ, Murugan RN, Kim EJ, Lee JH, Cheong CJ, Kang SW, Park HJ, Shin SY, Kim HJ, Bang JK. Studies on the Effect of Number of Sugar Moiety in the Antifreeze Activity of Homodimeric AFGPs. B KOREAN CHEM SOC 2012. [DOI: 10.5012/bkcs.2012.33.7.2411] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Kim DK, Nam BY, Li JJ, Park JT, Lee SH, Kim DH, Kim JY, Kang HY, Han SH, Yoo TH, Han DS, Kang SW. Translationally controlled tumour protein is associated with podocyte hypertrophy in a mouse model of type 1 diabetes. Diabetologia 2012; 55:1205-17. [PMID: 22311416 DOI: 10.1007/s00125-012-2467-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 12/31/2011] [Indexed: 02/06/2023]
Abstract
AIMS/HYPOTHESIS Translationally controlled tumour protein (TCTP) is thought to be involved in cell growth by regulating mTOR complex 1 (mTORC1) signalling. As diabetes characteristically induces podocyte hypertrophy and mTORC1 has been implicated in this process, TCTP may have a role in the pathogenesis of diabetes-induced podocyte hypertrophy. METHODS We investigated the effects and molecular mechanisms of TCTP in diabetic mice and in high glucose-stimulated cultured podocytes. To characterise the role of TCTP, we conducted lentivirus-mediated gene silencing of TCTP both in vivo and in vitro. RESULTS Glomerular production of TCTP was significantly higher in streptozotocin induced-diabetic DBA/2J mice than in control animals. Double-immunofluorescence staining for TCTP and synaptopodin revealed that podocyte was the principal cell responsible for this increase. TCTP knockdown attenuated the activation of mTORC1 downstream effectors and the overproduction of cyclin-dependent kinase inhibitors (CKIs) in diabetic glomeruli, along with a reduction in proteinuria and a decrease in the sizes of podocytes as well as glomeruli. In addition, knockdown of TCTP in db/db mice prevented the development of diabetic nephropathy, as indicated by the amelioration of proteinuria, mesangial expansion, podocytopenia and glomerulosclerosis. In accordance with the in vivo data, TCTP inhibition abrogated high glucose-induced hypertrophy in cultured podocytes, which was accompanied by the downregulation of mTORC1 effectors and CKIs. CONCLUSIONS/INTERPRETATION These findings suggest that TCTP might play an important role in the process of podocyte hypertrophy under diabetic conditions via the regulation of mTORC1 activity and the induction of cell-cycle arrest.
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Park CS, Joo KI, Kang SW, Kim HR. A PDMS-Coated Optical Fiber Bragg Grating Sensor for Enhancing Temperature Sensitivity. ACTA ACUST UNITED AC 2011. [DOI: 10.3807/josk.2011.15.4.329] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Yeom SH, Kim OG, Kang BH, Kim KJ, Yuan H, Kwon DH, Kim HR, Kang SW. Highly sensitive nano-porous lattice biosensor based on localized surface plasmon resonance and interference. OPTICS EXPRESS 2011; 19:22882-22891. [PMID: 22109166 DOI: 10.1364/oe.19.022882] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We propose a design for a highly sensitive biosensor based on nanostructured anodized aluminum oxide (AAO) substrates. A gold-deposited AAO substrate exhibits both optical interference and localized surface plasmon resonance (LSPR). In our sensor, application of these disparate optical properties overcomes problems of limited sensitivity, selectivity, and dynamic range seen in similar biosensors. We fabricated uniform periodic nanopore lattice AAO templates by two-step anodizing and assessed their suitability for application in biosensors by characterizing the change in optical response on addition of biomolecules to the AAO template. To determine the suitability of such structures for biosensing applications, we immobilized a layer of C-reactive protein (CRP) antibody on a gold coating atop an AAO template. We then applied a CRP antigen (Ag) atop the immobilized antibody (Ab) layer. The shift in reflectance is interpreted as being caused by the change in refractive index with membrane thickness. Our results confirm that our proposed AAO-based biosensor is highly selective toward detection of CRP antigen, and can measure a change in CRP antigen concentration of 1 fg/ml. This method can provide a simple, fast, and sensitive analysis for protein detection in real-time.
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Song S, Choi K, Ryu SW, Kang SW, Choi C. TRAIL promotes caspase-dependent pro-inflammatory responses via PKCδ activation by vascular smooth muscle cells. Cell Death Dis 2011; 2:e223. [PMID: 22048166 PMCID: PMC3223690 DOI: 10.1038/cddis.2011.103] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is best known for its selective cytotoxicity against transformed tumor cells. Most non-transformed primary cells and several cancer cell lines are not only resistant to death receptor-induced apoptosis, but also subject to inflammatory responses in a nuclear factor-κB (NF-κB)-dependent manner. Although the involvement of TRAIL in a variety of vascular disorders has been proposed, the exact molecular mechanisms are unclear. Here, we aimed to delineate the role of TRAIL in inflammatory vascular response. We also sought possible molecular mechanisms to identify potential targets for the prevention and treatment of post-angioplastic restenosis and atherosclerosis. Treatment with TRAIL increased the expression of intercellular adhesion molecule-1 by primary human vascular smooth muscle cells via protein kinase C (PKC)δ and NF-κB activation. Following detailed analysis using various PKCδ mutants, we determined that PKCδ activation was mediated by caspase-dependent proteolysis. The protective role of PKCδ was further confirmed in post-traumatic vascular remodeling in vivo. We propose that the TRAIL/TRAIL receptor system has a critical role in the pathogenesis of inflammatory vascular disorders by transducing pro-inflammatory signals via caspase-mediated PKCδ cleavage and subsequent NF-κB activation.
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Ahn MJ, Sohn HI, Nan YH, Murugan RN, Cheong CJ, Ryu EK, Kim EH, Kang SW, Kim EJ, Shin SY, Bang JK. Functional and Structural Characterization of Drosocin and its Derivatives Linked O-GalNAc at Thr 11Residue. B KOREAN CHEM SOC 2011. [DOI: 10.5012/bkcs.2011.32.9.3327] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Thayananuphat A, Youngren OM, Kang SW, Bakken T, Kosonsiriluk S, Chaiseha Y, El Halawani ME. Dopamine and mesotocin neurotransmission during the transition from incubation to brooding in the turkey. Horm Behav 2011; 60:327-35. [PMID: 21741977 DOI: 10.1016/j.yhbeh.2011.06.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 06/17/2011] [Accepted: 06/20/2011] [Indexed: 11/17/2022]
Abstract
We investigated the neuroendocrine changes involved in the transition from incubating eggs to brooding of the young in turkeys. Numbers of mesotocin (MT; the avian analog of mammalian oxytocin) immunoreactive (ir) neurons were higher in the nucleus paraventricularis magnocellularis (PVN) and nucleus supraopticus, pars ventralis (SOv) of late stage incubating hens compared to the layers. When incubating and laying hens were presented with poults, all incubating hens displayed brooding behavior. c-fos mRNA expression was found in several brain areas in brooding hens. The majority of c-fos mRNA expression by MT-ir neurons was observed in the PVN and SOv while the majority of c-fos mRNA expression in dopaminergic (DAergic) neurons was observed in the ventral part of the nucleus preopticus medialis (POM). Following intracerebroventricular injection of DA or oxytocin (OT) receptor antagonists, hens incubating eggs were introduced to poults. Over 80% of those injected with vehicle or the D1 DA receptor antagonist brooded poults, while over 80% of those receiving the D2 DA receptor antagonist or the OT receptor antagonist failed to brood the poults. The D2 DA/OT antagonist groups also displayed less c-fos mRNA in the dorsal part of POM and the medial part of the bed nucleus of the stria terminalis (BSTM) areas than did the D1 DA/vehicle groups. These data indicate that numerous brain areas are activated when incubating hens initially transition to poult brooding behavior. They also indicate that DAergic, through its D2 receptor, and MTergic systems may play a role in regulating brooding behaviors in birds.
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Kim YH, Hur ST, Park CS, Park KW, Choi SW, Kang SW, Kim HR. A vertical-field-driven polymer-stabilized blue phase liquid crystal mode to obtain a higher transmittance and lower driving voltage. OPTICS EXPRESS 2011; 19:17427-17438. [PMID: 21935109 DOI: 10.1364/oe.19.017427] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We demonstrate a vertical-field-driven polymer-stabilized blue phase liquid crystal (PS-BPLC) mode for solving low transmittance and high driving voltage problems in conventional in-plane-switching (IPS) PS-BPLC modes. By controlling the ray directions of incident beams by means of two prism sheets attached to the top and bottom substrates, continuous grayscale properties can be achieved with a vertical field, where the transmittance of the proposed structure can be increased to become twice as high as that of a IPS PS-BPLC cell, and its driving voltage can also be lowered by about 20 V. With the vertical-field-driven PS-BPLC mode, the hysteresis problem of the IPS PS-BPLC mode can also be solved due to a reduction of the electric field required to achieve sufficient field-induced retardation.
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Yuan H, Kwon HC, Yeom SH, Kwon DH, Kang SW. MOSFET-BJT hybrid mode of the gated lateral bipolar junction transistor for C-reactive protein detection. Biosens Bioelectron 2011; 28:434-7. [PMID: 21835604 DOI: 10.1016/j.bios.2011.07.062] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 07/25/2011] [Accepted: 07/25/2011] [Indexed: 12/21/2022]
Abstract
In this study, we propose a novel biosensor based on a gated lateral bipolar junction transistor (BJT) for biomaterial detection. The gated lateral BJT can function as both a BJT and a metal-oxide-semiconductor field-effect transistor (MOSFET) with both the emitter and source, and the collector and drain, coupled. C-reactive protein (CRP), which is an important disease marker in clinical examinations, can be detected using the proposed device. In the MOSFET-BJT hybrid mode, the sensitivity, selectivity, and reproducibility of the gated lateral BJT for biosensors were evaluated in this study. According to the results, in the MOSFET-BJT hybrid mode, the gated lateral BJT shows good selectivity and reproducibility. Changes in the emitter (source) current of the device for CRP antigen detection were approximately 0.65, 0.72, and 0.80 μA/decade at base currents of -50, -30, and -10 μA, respectively. The proposed device has significant application in the detection of certain biomaterials that require a dilution process using a common biosensor, such as a MOSFET-based biosensor.
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Lee DY, Song SB, Moon JY, Jeong KH, Park SJ, Kim HJ, Kang SW, Lee SH, Kim YH, Chung JH, Ihm CG, Lee TW. Association between interleukin-3 gene polymorphism and acute rejection after kidney transplantation. Transplant Proc 2011; 42:4501-4. [PMID: 21168724 DOI: 10.1016/j.transproceed.2010.09.153] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Accepted: 09/28/2010] [Indexed: 11/26/2022]
Abstract
BACKGROUND Acute rejection (AR) after kidney transplantation resulting from alloimmune responses has a negative effect on graft survival. AR is mainly caused by T-cell immune responses activated by cytokines, including interleukin (IL)-2, -4, and -7. Many reports have shown that single nucleotide polymorphisms (SNPs) of these cytokines can affect the occurrence of AR. IL-3, which is secreted by activated T cells, can mediate AR. Our study sought to investigate the association between SNPs of the IL3 gene and the occurrence of an AR episode (ARE). METHODS We analyzed 3 SNPs of IL3 (rs181781, rs2073506, and rs40401) among 330 renal recipients, 60 of whom had developed an ARE. SNPs of the IL3 gene, including 1 exonic SNP (rs40401) and 2 regulatory thought to be promoter SNPs (rs181781 and rs2073506). RESULTS The genotypes of 60 ARE subjects and the 270 patients without AR demonstrated a significant relationship between genotype frequencies and the SNPs. The occurrence of an ARE was associated with rs181781 (P = .041, dominant model), rs2073506 (P = .009, codominant 1 model; P = .003, dominant model), and rs40401 (P = .014, recessive model). Among haplotypes, AAT showed a significant association with ARE. (P = .0033). CONCLUSION Our results suggest that IL3 gene polymorphisms were associated with this event.
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Kang SW, Park HJ, Ban JY, Chung JH, Chun GS, Cho JO. Effects of nicotine on apoptosis in human gingival fibroblasts. Arch Oral Biol 2011; 56:1091-7. [PMID: 21497792 DOI: 10.1016/j.archoralbio.2011.03.016] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 02/25/2011] [Accepted: 03/26/2011] [Indexed: 02/03/2023]
Abstract
AIM Cigarette smoke is a complex mixture of more than 4700 chemical compounds including free radicals and oxidants and it is a world widely known problem to health. Nicotine is the major compound of tobacco and known as the cause of gingivitis and periodontitis. It induces intracellular oxidative stress recognized as the important agent in the damage of biological molecules. The aim of this study is to clarify the cytotoxic pathway of nicotine in human gingival fibroblasts (HGFs). METHODS Human gingival fibroblasts stimulated by nicotine were used as an in vitro model. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to detect cell viability and reactive oxygen species (ROS) generation was assessed with 2,7-dichlorofluoroscein diacetate (DCF-DA). Morphological change was detected by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) nick end labelling (TUNEL) assay, stained with 4,6-diamidino-2-phenylindole (DAPI). To delineate the roles of extracellular signal-regulated kinase (ERK), P38 and c-Jun N-terminal kinase (JNK), Western blot and caspase-3 (CASP3) activity assay were performed. RESULTS Exposure of the human gingival fibroblasts to nicotine reduced cell viability by time and dose dependent and increased the generation of ROS. It also showed morphological evidence of increased apoptosis, resulted in transient activation of JNK and ERK concomitant with activation of P38, and stimulated apoptosis as evidenced by CASP3 activation and Poly ADP ribose polymerase (PARP) cleavage. CONCLUSION These results suggest that nicotine induces apoptosis through the ROS generation and CASP3 dependent pathways in HGFs.
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