Carbon treated self-ordered TiO₂ nanotube arrays with enhanced lithium-ion intercalation performance

Kim, H.S.,Yu, S.H.,Sung, Y.E.,Kang, S.H. Elsevier Sequoia 2014 Journal of alloys and compounds Vol.597 No.-

Vertically aligned TiO<SUB>2</SUB> nanotube (TONT) arrays on titanium substrate developed by facile electrochemical anodization in an aqueous solution of 0.5M Na<SUB>2</SUB>SO<SUB>4</SUB>, 0.5M H<SUB>3</SUB>PO<SUB>4</SUB>, 0.2M sodium citrate, and 0.5wt% NaF were prepared having a pore diameter and thickness of 100nm and 1.2μm, respectively. The undoped (u-doped) TONT arrays possessing an anatase phase were again annealed at 500<SUP>o</SUP>C under a mixed gas flux of nitrogen (N<SUB>2</SUB>) and acetylene (C<SUB>2</SUB>H<SUB>2</SUB>), to induce the enhancement of electrical conductivity. It was designated as carbon-doped (c-doped) TONT arrays. Undoped and c-doped TONT arrays were compared using various characterization tools, including X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), and X-ray photoelectron spectroscopy (XPS). Furthermore, based on several electrochemical tests (galvanostatic charge/discharge tests, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS)), it was observed that c-doped TONT arrays revealed improved charge/discharge capacity, cycle stability, and rate capability, due to the enhanced electrical conductivity of c-doped TONT arrays.

Hydrogen sulfide, a gaseous signaling molecule, elongates primary cilia on kidney tubular epithelial cells by activating extracellular signal-regulated kinase

Sang Jun Han,Jee In Kim,Joshua H. Lipschutz,Kwon Moo Park 대한생리학회-대한약리학회 2021 The Korean Journal of Physiology & Pharmacology Vol.25 No.6

Primary cilia on kidney tubular cells play crucial roles in maintaining structure and physiological function. Emerging evidence indicates that the absence of primary cilia, and their length, are associated with kidney diseases. The length of primary cilia in kidney tubular epithelial cells depends, at least in part, on oxidative stress and extracellular signal-regulated kinase 1/2 (ERK) activation. Hydrogen sulfide (H2S) is involved in antioxidant systems and the ERK signaling pathway. Therefore, in this study, we investigated the role of H2S in primary cilia elongation and the downstream pathway. In cultured Madin-Darby Canine Kidney cells, the length of primary cilia gradually increased up to 4 days after the cells were grown to confluent monolayers. In addition, the expression of H2S-producing enzyme increased concomitantly with primary cilia length. Treatment with NaHS, an exogenous H2S donor, accelerated the elongation of primary cilia whereas DL-propargylglycine (a cystathionine γ-lyase inhibitor) and hydroxylamine (a cystathionine-β-synthase inhibitor) delayed their elongation. NaHS treatment increased ERK activation and Sec10 and Arl13b protein expression, both of which are involved in cilia formation and elongation. Treatment with U0126, an ERK inhibitor, delayed elongation of primary cilia and blocked the effect of NaHS-mediated primary cilia elongation and Sec10 and Arl13b upregulation. Finally, we also found that H2S accelerated primary cilia elongation after ischemic kidney injury. These results indicate that H2S lengthens primary cilia through ERK activation and a consequent increase in Sec10 and Arl13b expression, suggesting that H2S and its downstream targets could be novel molecular targets for regulating primary cilia

Breath hydrogen and methane are associated with intestinal symptoms in patients with chronic pancreatitis

Kim, D.B.,Paik, C.N.,Sung, H.J.,Chung, W.C.,Lee, K.M.,Yang, J.M.,Choi, M.G. Karger 2015 PANCREATOLOGY Vol.15 No.5

Backgrounds: The bacterial overgrowth might be associated with chronic pancreatitis. This study was to evaluate the prevalence and characteristics of small intestinal bacterial overgrowth (SIBO) in patients with chronic pancreatitis. Methods: 36 patients with chronic pancreatitis and 49 healthy controls undergoing the hydrogen (H<SUB>2</SUB>)-methane (CH<SUB>4</SUB>) lactulose breath test (LBT) were reviewed. The LBT positivity (+) indicating the presence of SIBO, gas types, bowel symptom questionnaire, laboratory and radiologic results were surveyed. The LBT+ was (1) an increase in the breath H<SUB>2</SUB> (≥20 ppm) or CH<SUB>4</SUB> (≥10 ppm) over the baseline or (2) a baseline H<SUB>2</SUB> (≥20 ppm) or CH<SUB>4</SUB> (≥10 ppm) within 90 min after lactulose load. Results: LBT+ was significantly higher in the patients (17/36) than in controls (1¾9) (47.2% vs. 26.5%, P < 0.05). During LBT, the H<SUB>2</SUB> levels between 0 and 105 min were significantly higher in patients than in controls. Among LBT+ patients, 11 (64.7%), 1 (5.9%), 5 (29.4%) were in the LBT (H<SUB>2</SUB>)+, (CH<SUB>4</SUB>)+, (mixed)+ groups, respectively. The LBT+ group had significantly higher scores of flatus than those of the LBT- group. Considering the subtypes of LBT, the LBT (mixed)+ group had higher symptom scores of significance or tendency in hard stool, strain, urgency, and flatus than LBT- group The laboratory and radiologic features were not significantly different between LBT+ and LBT- groups. Conclusions: SIBO is common in patients in chronic pancreatitis. Especially, excretions of mixed H<SUB>2</SUB> and CH<SUB>4</SUB> appear to be related with deterioration of intestinal symptoms.

ASIP Instructions and Their Hardware Architecture for H.264/AVC

Lee, Jung-H.,Kim, Sung-D.,Sunwoo, Myung-H. The Institute of Electronics and Information Engin 2005 Journal of semiconductor technology and science Vol.5 No.4

H.264/AVC adopts new features compared with previous multimedia algorithms. It is inefficient to implement some of the new blocks using existing DSP instructions. Hence, new instructions are required to implement H.264/AVC. This paper proposes novel instructions for intra-prediction, in-loop deblocking filter, entropy coding and integer transform. Performance comparisons show that the required computation cycles for the in-loop deblocking filter can be reduced about $20{\sim}25%$. This paper also proposes new instructions for the integer transform. The proposed instructions can execute one dimension forward/inverse integer transform. The integer transform can be implemented using much smaller hardware size than existing DSPs.

ASIP Instructions and Their Hardware Architecture for H.264 / AVC

Jung H. Lee,Sung D. Kim,Myung H. Sunwoo 대한전자공학회 2005 Journal of semiconductor technology and science Vol.5 No.4

H.264/AVC adopts new features compared with previous multimedia algorithms. It is inefficient to implement some of the new blocks using existing DSP instructions. Hence, new instructions are required to implement H.264/AVC. This paper proposes novel instructions for intra-prediction, in-loop deblocking filter, entropy coding and integer transform. Performance comparisons show that the required computation cycles for the in-loop deblocking filter can be reduced about 20 ~ 25%. This paper also proposes new instructions for the integer transform. The proposed instructions can execute one dimension forward/inverse integer transform. The integer transform can be implemented using much smaller hardware size than existing DSPs.

Siberian Sturgeon Oocyte Extract Induces Epigenetic Modifications of Porcine Somatic Cells and Improves Developmental Competence of SCNT Embryos

Kim, So-Young,Kim, Tae-Suk,Park, Sang-Hoon,Lee, Mi-Ran,Eun, Hye-Ju,Baek, Sang-Ki,Ko, Yeoung-Gyu,Kim, Sung-Woo,Seong, Hwan-Hoo,Campbell, Keith H.S.,Lee, Joon-Hee Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.2

Somatic cell nuclear transfer (SCNT) has generally demonstrated that a differentiated cell can convert into a undifferentiated or pluripotent state. In the SCNT experiment, nuclear reprogramming is induced by exposure of introduced donor nuclei to the recipient cytoplasm of matured oocytes. However, because the efficiency of SCNT still remains low, a combination of SCNT technique with the ex-ovo method may improve the normal development of SCNT embryos. Here we hypothesized that treatment of somatic cells with extracts prepared from the germinal vesicle (GV) stage Siberian sturgeon oocytes prior to their use as nuclear donor for SCNT would improve in vitro development. A reversible permeability protocol with $4{\mu}g/mL$ of digitonin for 2 min at $4^{\circ}C$ in order to deliver Siberian sturgeon oocyte extract (SOE) to porcine fetal fibroblasts (PFFs) was carried out. As results, the intensity of H3K9ac staining in PFFs following treatment of SOE for 7 h at $18^{\circ}C$ was significantly increased but the intensity of H3K9me3 staining in PFFs was significantly decreased as compared with the control (p<0.05). Additionally, the level of histone acetylation in SCNT embryos at the zygote stage was significantly increased when reconstructed using SOE-treated cells (p<0.05), similar to that of IVF embryos at the zygote stage. The number of apoptotic cells was significantly decreased and pluripotency markers (Nanog, Oct4 and Sox2) were highly expressed in the blastocyst stage of SCNT embryos reconstructed using SOE-treated cells as nuclear donor (p<0.05). And there was observed a better development to the blastocyst stage in the SOE-treated group (p<0.05). Our results suggested that pre-treatment of cells with SOE could improve epigenetic reprogramming and the quality of porcine SCNT embryos.

Mucosal immunization with recombinant influenza hemagglutinin protein and poly gamma-glutamate/chitosan nanoparticles induces protection against highly pathogenic influenza A virus

Moon, H.J.,Lee, J.S.,Talactac, M.R.,Chowdhury, M.Y.E.,Kim, J.H.,Park, M.E.,Choi, Y.K.,Sung, M.H.,Kim, C.J. Elsevier Scientific Pub. Co 2012 Veterinary microbiology Vol.160 No.3

Intranasal administration of recombinant influenza hemagglutinin (rHA) antigen or inactivated virus with nanoparticles (NPs) composed of poly-γ-glutamic acid (γ-PGA) and chitosan which are safe, natural materials, and able to target the mucosal membrane as a mucosal adjuvant, could induce a high degree of protective mucosal immunity in the respiratory tract. Intranasal immunization with mixture of rHA antigen or inactivated virus and γ-PGA/chitosan nanoparticles (PC NPs) induced not only a high anti-HA immunoglobulin A (IgA) response in lung and IgG response in serum, including anti-HA neutralizing antibodies, but also an influenza virus-specific cell-mediated immune response. Also, PC NPs could function as a potential mucosal adjuvant when it was compared with the well-known mucosal adjuvant, cholera toxin (CT). Intranasal administration of rHA antigen or inactivated virus with PC NPs protected mice against challenge with a lethal dose of the highly pathogenic influenza A H5N1 virus. These results suggested that application of PC NPs with a subunit antigen of influenza produced by prokaryotic expression system provides several solutions to the current problems of the influenza vaccines using inactivated influenza virus. Moreover, our finding about a sufficient function of PC NPs to elevate vaccine efficacy led us to consider that it can be useful in clinical applications as a potent mucosal adjuvant with safety.

PHF2 histone demethylase acts as a tumor suppressor in association with p53 in cancer

Lee, K-H,Park, J-W,Sung, H-S,Choi, Y-J,Kim, W H,Lee, H S,Chung, H-J,Shin, H-W,Cho, C-H,Kim, T-Y,Li, S-H,Youn, H-D,Kim, S J,Chun, Y-S Macmillan Publishers Limited 2015 Oncogene Vol.34 No.22

Plant homeodomain finger 2 (PHF2) has a role in epigenetic regulation of gene expression by demethylating H3K9-Me2. Several genome-wide studies have demonstrated that the chromosomal region including the PHF2 gene is often deleted in some cancers including colorectal cancer, and this finding encouraged us to investigate the tumor suppressive role of PHF2. As p53 is a critical tumor suppressor in colon cancer, we tested the possibility that PHF2 is an epigenetic regulator of p53. PHF2 was associated with p53, and thereby, promoted p53-driven gene expression in cancer cells under genotoxic stress. PHF2 converted the chromatin that is favorable for transcription by demethylating the repressive H3K9-Me2 mark. In an HCT116 xenograft model, PHF2 was found to be required for the anticancer effects of oxaliplatin and doxorubicin. In PHF2-deficient xenografts, p53 expression was profoundly induced by both drugs, but its downstream product p21 was not, suggesting that p53 cannot be activated in the absence of PHF2. To find clinical evidence about the role of PHF2, we analyzed the expressions of PHF2, p53 and p21 in human colon cancer tissues and adjacent normal tissues from patients. PHF2 was downregulated in cancer tissues and PHF2 correlated with p21 in cancers expressing functional p53. Colon and stomach cancer tissue arrays showed a positive correlation between PHF2 and p21 expressions. Informatics analyses using the Oncomine database also supported our notion that PHF2 is downregulated in colon and stomach cancers. On the basis of these findings, we propose that PHF2 acts as a tumor suppressor in association with p53 in cancer development and ensures p53-mediated cell death in response to chemotherapy.

한국에서 지역에 따른 Helicobacter pylori 균주 내성

김재연 ( Jae Yeon Kim ),김나영 ( Na Young Kim ),김성중 ( Sung Jung Kim ),백광호 ( Gwang Ho Baik ),김광하 ( Gwang Ha Kim ),김정목 ( Jung Mogg Kim ),남령희 ( Ryoung Hee Nam ),김홍빈 ( Hong Bin Kim ),이동호 ( Dong Ho Lee ),정현채 ( H 대한소화기학회 2011 대한소화기학회지 Vol.57 No.4

Background/Aims: This study was performed to compare the prevalence rates of primary antibiotic resistance in Helicobacter pylori (H. pylori) isolates among different regions of Korea. Methods: H. pylori were isolated from gastric mucosal biopsy specimens of 99 Koreans who lived in Gyeonggi (n=40), Kangwon province (n=40) and Busan (n=19) from April to August in 2008. All the patients had no history of H. pylori eradication therapy. The susceptibilities of the H. pylori isolates to amoxicillin, clarithromycin, metronidazole, tetracycline, azithromycin, ciprofloxacin, levofloxacin, and moxifloxacin were tested according to the agar dilution method. Results: There was a difference in resistance to clarithromycin in three institutes located among Gyeonggi (32.5%), Kangwon province (12.5%) and Busan (42.1%) by One way ANOVA test (p=0.027) and nonparametric Kruskal Wallis test (p=0.027). However, by post-hoc analysis, there was no statistically significant difference among three regions. Similarly, the other 7 antibiotics (amoxicillin, metronidazole, tetracycline, azithromycin, ciprofloxacin, levofloxacin and moxifloxacin) did not show any significant difference. Conclusions: There was no significant regional difference of the primary antibiotic resistance of H. pylori. However, the included patient number might not be enough for this conclusion demanding further evaluations. (Korean J Gastroenterol 2011;57:221-229)

Roles of AKT1 and AKT2 in non-small cell lung cancer cell survival, growth, and migration.

Lee, Myoung W,Kim, Dae S,Lee, Joo H,Lee, Bum S,Lee, Soo H,Jung, Hye L,Sung, Ki W,Kim, Heung T,Yoo, Keon H,Koo, Hong H Japanese Cancer Association 2011 Cancer Science Vol.102 No.10

<P>Although AKT ? protein kinase B is constitutively active in nonsmall cell lung cancer (NSCLC) cells and is an attractive target for enhancing the cytotoxicity of therapeutic agents, the distinct roles of the AKT isoforms in NSCLC are largely unknown. In the present study, we investigated the roles of AKT1 and AKT2 in NSCLC cells using RNAi. The siRNA targeting of AKT1 or AKT2 effectively decreased protein levels of AKT1 and AKT2, respectively, in A549 and H460 cells. Cisplatin treatment of these cells increased apoptotic cell death compared with control. The siRNA-induced knockdown of AKT1 in H460 cells significantly decreased basal MEK? ERK1 ? 2 activity, resulting in nuclear factor-κB activation, whereas knockdown of AKT2 resulted in anti-apoptotic Bcl-2 family protein MCL-1 (MCL-1) cleavage, the collapse of mitochondrial membrane potential, cytochrome c release, and activation of the caspase cascade. Consequently, both siRNA treatments enhanced the chemosensitivity of H460 cells to cisplatin. However, neither AKT1 nor AKT2 siRNA treatment had any effect of p27 expression, and although both treatments tended to induced G2 ?M phase arrest, the effect was not statistically significant. Treatment with AKT1 siRNA markedly decreased colony formation growth and migration, but AKT2 siRNA had no significant effects on these parameters. These data suggest that AKT1 and AKT2 both contribute to cell survival, albeit via different mechanisms, and that the effects on cell growth and migration are predominantly regulated by AKT1. These findings may aid in refining targeted strategies for the inhibition of AKT isoforms towards the sensitization of NSCLC cells to therapeutic agents.</P>