Toward high efficiency organic photovoltaic devices with enhanced thermal stability utilizing P3HT-b-P3PHT block copolymer additives

Zhu, M.,Kim, H.,Jang, Y.,Park, S.,Ryu, D.,Kim, K.,Tang, P.,Qiu, F.,Kim, D.,Peng, J. Royal Society of Chemistry 2016 Journal of Materials Chemistry A Vol.4 No.47

<P>Organic photovoltaics (OPVs) have drawn an extensive amount of attention due to their low cost, processibility and flexibility. However, a cell based on a blend of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C-61-butyric acid methyl ester (PC61BM) has a limited power conversion efficiency (PCE) due to the short exciton diffusion length of similar to 10 nm. We address this issue by designing a series of all-conjugated diblock copolymers, poly(3-hexylthiophene)-b-poly(3-(6-diethylphosphonatohexyl) thiophene) (P3HT-b-P3PHT), intended for use as additives to improve the performance of P3HT:PC61BM-based photovoltaic devices. The PCE of the devices improved from 3.30% to 4.03% with the addition of P3HT-b-P3PHT (3 : 1). The thermal stability of devices with P3HT-b-P3PHT additives improved significantly relative to that of the P3HT:PC61BM reference device, where the devices including a copolymer with a higher P3PHT content exhibited a better thermal stability. It was found that the fill factor (FF) could be regulated by simply varying the block ratio of P3HT-b-P3PHT and played a crucial role in improving both the PCE and the thermal stability. The P3HT-b-P3PHT diffused at the P3HT:PC61BM interface, improved the miscibility between P3HT and PC61BM, optimized the nanoscale morphology of the photoactive layer, and reduced the active layer roughness, all of which improved the FF and thus contributed to an improvement in device performance.</P>

p34 is a novel regulator of the oncogenic behavior of NEDD4-1 and PTEN

Hong, S-W,Moon, J-H,Kim, J-S,Shin, J-S,Jung, K-A,Lee, W-K,Jeong, S-Y,Hwang, J J,Lee, S-J,Suh, Y-A,Kim, I,Nam, K-Y,Han, S,Kim, J E,Kim, K-p,Hong, Y S,Lee, J-L,Lee, W-J,Choi, E K,Lee, J S,Jin, D-H,Kim, Macmillan Publishers Limited 2014 CELL DEATH AND DIFFERENTIATION Vol.21 No.1

PTEN is one of the most frequently mutated or deleted tumor suppressors in human cancers. NEDD4-1 was recently identified as the E3 ubiquitin ligase for PTEN; however, a number of important questions remain regarding the role of ubiquitination in regulating PTEN function and the mechanisms by which PTEN ubiquitination is regulated. In the present study, we demonstrated that p34, which was identified as a binding partner of NEDD4-1, controls PTEN ubiquitination by regulating NEDD4-1 protein stability. p34 interacts with the WW1 domain of NEDD4-1, an interaction that enhances NEDD4-1 stability. Expression of p34 promotes PTEN poly-ubiquitination, leading to PTEN protein degradation, whereas p34 knockdown results in PTEN mono-ubiquitination. Notably, an inverse correlation between PTEN and p34/NEDD4-1 levels was confirmed in tumor samples from colon cancer patients. Thus, p34 acts as a key regulator of the oncogenic behavior of NEDD4-1 and PTEN.

Feasibility of proposed single-nucleotide polymorphisms as predictive markers for targeted regimens in metastatic colorectal cancer

Kim, J C,Ha, Y J,Roh, S A,Choi, E Y,Yoon, Y S,Kim, K P,Hong, Y S,Kim, T W,Cho, D H,Kim, S Y,Kim, Y S Nature Publishing Group 2013 The British journal of cancer Vol.108 No.9

<P><B>Background:</B></P><P>Surrogate biomarkers for metastatic colorectal cancer (mCRC) are urgently needed to achieve the best outcomes for targeted therapy.</P><P><B>Methods:</B></P><P>A clinical association analysis was performed to examine the three single-nucleotide polymorphisms (SNPs) that were previously proposed as markers of chemosensitivity to the cetuximab (124 patients) and bevacizumab regimens (100 patients) in mCRC patients. In addition, biological correlations were examined for the candidate SNPs in terms of their regulatory pathway.</P><P><B>Results:</B></P><P>For cetuximab regimens, patients homozygous for the wild-type alleles (<I>GG</I>) of <I>LIFR rs3729740</I> exhibited a 1.9 times greater overall response rate (ORR) and 1.4 months longer progression-free survival (PFS) than those homozygous or heterozygous for the mutant allele (<I>GA</I> and <I>AA</I>; <I>P</I>=0.022 and 0.027, respectively). For bevacizumab regimens, patients homozygous for the minor alleles (<I>TT</I>) of <I>ANXA11 rs1049550</I> exhibited an ORR twice as high as those homozygous or heterozygous for the ancestral allele (<I>CC</I> and <I>CT</I>; <I>P</I>=0.031). Overall response rate gain was achieved up to 10% in patients with wild-type <I>LIFR rs3729740</I> patients either with wild-type <I>KRAS</I> or skin toxicity (<I>P</I>=0.001) respectively. Specifically in clones treated with cetuximab and bevacizumab regimens, active p-ERK and MMP-9 expressions were significantly reduced in clones expressing wild-type <I>LIFR rs3729740</I> (<I>P</I>=0.044) and in those expressing minor-type <I>ANXA11 rs1049550</I> (<I>P</I>=0.007), respectively.</P><P><B>Conclusion:</B></P><P><I>LIFR rs3729740</I> and possibly <I>ANXA11 rs1049550</I> may be useful as biomarkers for predicting whether mCRC patients are sensitive to relevant target regimens, although further validation in large cohorts is needed.</P>

Unraveling the Atomistic Sodiation Mechanism of Black Phosphorus for Sodium Ion Batteries by First-Principles Calculations

Hembram, K. P. S. S.,Jung, Hyun,Yeo, Byung Chul,Pai, Sung Jin,Kim, Seungchul,Lee, Kwang-Ryeol,Han, Sang Soo American Chemical Society 2015 The Journal of Physical Chemistry Part C Vol.119 No.27

<P>As opposed to the standard graphite anode used for lithium (Li) ion batteries (LIBs), a standard anode material for sodium (Na) ion batteries (NIBs) has not yet been reported. Black phosphorus is potentially very attractive as an anode material for NIBs, as it has a layered structure similar to graphite but a greater interlayer distance. In this work, we propose an atomistic mechanism for the sodiation of black phosphorus, based on first-principles calculations. The layered structure of black phosphorus is maintained up to the composition of Na<SUB>0.25</SUB>P, with <I>one-dimensional</I> sodiation (an intercalation process) occurring in the interlayer spaces of the black phosphorus, resulting in sliding of the phosphorene layers because one Na atom tends to bind to four P atoms. At Na levels beyond Na<SUB>0.25</SUB>P, the intercalation process changes to an alloying process. Sodiation exceeding the critical composition leads to breaking of P–P bonds and eventual formation of an amorphous phase from the layered Na<SUB><I>x</I></SUB>P structure. After the P–P bonds in the layered Na<SUB><I>x</I></SUB>P structure are broken, in a progress in which staggered P–P bonds are preferentially broken rather than planar P–P bonds, P<SUB>2</SUB> dumbbells are generated. As sodiation proceeds further, most of the P<SUB>2</SUB> dumbbells become isolated P atoms. Thus, in the amorphous Na<SUB>3</SUB>P phase, only low-coordinate P components such as isolated atoms (primarily) and dumbbells are found. We expect that our comprehensive understanding of the sodiation mechanism in black phosphorus will provide helpful guidelines in designing new types of black phosphorus anodes to obtain better performing NIBs.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpccck/2015/jpccck.2015.119.issue-27/acs.jpcc.5b05482/production/images/medium/jp-2015-054822_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jp5b05482'>ACS Electronic Supporting Info</A></P>

Efficient long-term amplification of hepatitis B virus isolates after infection of slow proliferating HepG2-NTCP cells

Kö,nig, Alexander,Yang, Jaewon,Jo, Eunji,Park, Kyu Ho Paul,Kim, Hyun,Than, Thoa Thi,Song, Xiyong,Qi, Xiaoxuan,Dai, Xinghong,Park, Soonju,Shum, David,Ryu, Wang-Shick,Kim, Jung-Hee,Yoon, Seung Kew,P Elsevier 2019 Journal of hepatology Vol.71 No.2

<P><B>Background & Aims</B></P> <P>As hepatitis B virus (HBV) spreads through the infected liver it is simultaneously secreted into the blood. HBV-susceptible <I>in vitro</I> infection models do not efficiently amplify viral progeny or support cell-to-cell spread. We sought to establish a cell culture system for the amplification of infectious HBV from clinical specimens.</P> <P><B>Methods</B></P> <P>An HBV-susceptible sodium-taurocholate cotransporting polypeptide-overexpressing HepG2 cell clone (HepG2-NTCPsec+) producing high titers of infectious progeny was selected. Secreted HBV progeny were characterized by native gel electrophoresis and electron microscopy. Comparative RNA-seq transcriptomics was performed to quantify the expression of host proviral and restriction factors. Viral spread routes were evaluated using HBV entry- or replication inhibitors, visualization of viral cell-to-cell spread in reporter cells, and nearest neighbor infection determination. Amplification kinetics of HBV genotypes B-D were analyzed.</P> <P><B>Results</B></P> <P>Infected HepG2-NTCPsec+ secreted high levels of large HBV surface protein-enveloped infectious HBV progeny with typical appearance under electron microscopy. RNA-seq transcriptomics revealed that HBV does not induce significant gene expression changes in HepG2-NTCPsec+, however, transcription factors favoring HBV amplification were more strongly expressed than in less permissive HepG2-NTCPsec−. Upon inoculation with HBV-containing patient sera, rates of infected cells increased from 10% initially to 70% by viral spread to adjacent cells, and viral progeny and antigens were efficiently secreted. HepG2-NTCPsec+ supported up to 1,300-fold net amplification of HBV genomes depending on the source of virus. Viral spread and amplification were abolished by entry and replication inhibitors; viral rebound was observed after inhibitor discontinuation.</P> <P><B>Conclusions</B></P> <P>The novel HepG2-NTCPsec+ cells efficiently support the complete HBV life cycle, long-term viral spread and amplification of HBV derived from patients or cell culture, resembling relevant features of HBV-infected patients.</P> <P><B>Lay summary</B></P> <P>Currently available laboratory systems are unable to reproduce the dynamics of hepatitis B virus (HBV) spread through the infected liver and release into the blood. We developed a slowly dividing liver-derived cell line which multiplies infectious viral particles upon inoculation with patient- or cell culture-derived HBV. This new infection model can improve therapy by measuring, in advance, the sensitivity of a patient’s HBV strain to specific antiviral drugs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Cell culture system that mimicks complete HBV life cycle from entry to egress. </LI> <LI> Efficient <I>in vitro</I> infection with crude HBV patient sera. </LI> <LI> Up to 50- and 1,300-fold net amplification of patient- and cell culture-derived input HBV in the supernatant. </LI> <LI> Polyethylene glycol-independent HBV spread to adjacent cells, forming infected cell clusters. </LI> <LI> Evaluation of patient- and cell culture-derived HBV amplification w/wo antivirals over 8 weeks. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Identification of a novel <i>FAM83H</i> mutation and microhardness of an affected molar in autosomal dominant hypocalcified amelogenesis imperfecta

Hyun, H.-K.,Lee, S.-K.,Lee, K.-E.,Kang, H.-Y.,Kim, E.-J.,Choung, P.-H.,Kim, J.-W. Blackwell Publishing Ltd 2009 International endodontic journal Vol.42 No.11

<P>Abstract</P><P>Aim </P><P>To determine the underlying molecular genetic aetiology of a family with the hypocalcified form of amelogenesis imperfecta and to investigate the hardness of the enamel and dentine of a known <I>FAM83H</I> mutation.</P><P>Methodology </P><P>Mutational screening of the <I>FAM83H</I> on the basis of candidate gene approach was performed. All exons and exon–intron boundaries was amplified and sequenced. A microhardness test was performed to measure the Vickers microhardness value.</P><P>Results </P><P>A novel nonsense mutation (c.1354C>T, p.Q452X) was identified in the last exon of <I>FAM83H</I>, which resulted in soft, uncalcified enamel. The affected enamel was extremely soft (about 17% of the normal control), but the underlying dentine was as hard as the normal control.</P><P>Conclusions </P><P>Mutational analysis revealed a novel mutation in <I>FAM83H</I> gene. Hardness of dentine was not affected by the mutation, whilst the enamel was extremely soft.</P>

Foxp3 is a key downstream regulator of p53-mediated cellular senescence

Kim, J-E,Shin, J-S,Moon, J-H,Hong, S-W,Jung, D-J,Kim, J H,Hwang, I-Y,Shin, Y J,Gong, E-Y,Lee, D H,Kim, S-M,Lee, E Y,Kim, Y S,Kim, D,Hur, D,Kim, T W,Kim, K-p,Jin, D-H,Lee, W-J Macmillan Publishers Limited 2017 Oncogene Vol.36 No.2

<P>The downstream events and target genes of p53 in the process of senescence are not fully understood. Here, we report a novel function of the forkhead transcription factor Foxp3, which is a key player in mediating T-cell inhibitory functions, in p53-mediated cellular senescence. The overexpression of Foxp3 in mouse embryonic fibroblasts (MEFs) accelerates senescence, whereas Foxp3 knockdown leads to escape from p53-mediated senescence in p53-expressing MEFs. Consistent with these results, Foxp3 expression resulted in the induction of senescence in epithelial cancer cells, including MCF7 and HCT116 cells. Foxp3 overexpression also increased the intracellular levels of reactive oxygen species (ROS). The ROS inhibitor N-acetyl-L-cysteine rescued cells from Foxp3-expression-induced senescence. Furthermore, the elevated ROS levels that accompanied Foxp3 overexpression were paralleled by an increase in p21 expression. Knockdown of p21 in Foxp3-expressing MEFs abrogated the Foxp3-dependent increase in ROS levels, indicating that Foxp3 acts through the induction of p21 and the subsequent ROS elevation to trigger senescence. Collectively, these results suggest that Foxp3 is a downstream target of p53 that is sufficient to induce p21 expression, ROS production and p53-mediated senescence.</P>

Disruption of a regulatory loop between DUSP1 and p53 contributes to hepatocellular carcinoma development and progression

Hao, P.P.,Li, H.,Lee, M.J.,Wang, Y.P.,Kim, J.H.,Yu, G.R.,Lee, S.Y.,Leem, S.H.,Jang, K.Y.,Kim, D.G. Elsevier Science Publishers 2015 Journal of hepatology Vol.62 No.6

Background & Aims: Altered expression of dual specificity phosphatase 1 (DUSP1) is common in tumors including hepatocellular carcinoma (HCC), and is predictive of tumor progression and poor prognosis. However, the tumor suppressive role of DUSP1 has yet to be clearly elucidated. Methods: The molecular mechanisms of tumor suppression that were investigated were induction of apoptosis, cell cycle inhibition, and regulation of p53. Additionally, the antitumor effect of DUSP1 was assessed using a mouse model. Associated signaling pathways in HCC cells and tissues were examined. Results: Downregulation of DUSP1 expression was significantly correlated with poor differentiation (p<0.001) and advanced HCC stage (p=0.023). DUSP1 expression resulted in HCC suppression and longer survival (p=0.0002) in a xenoplant mice model. DUSP1 inhibited p38 MAPK phosphorylation and subsequently suppressed HSP27 activation, resulting in enhanced p53 phosphorylation at sites S15, S20, and S46 in HCC cells. Enhanced p53 activation induced the expression of target genes p21 and p27, which are linked to cell cycle arrest and apoptosis. Thus, DUSP1 was potentially linked to p53 activation via the p38 MAPK/HSP27 pathway. Wild-type but not mutant p53 transcriptionally upregulated DUSP1 via its DNA-binding domain. DUSP1 and p53 might collaborate to suppress tumors in hepatocarcinogenesis via a positive regulatory loop. Conclusions: Our results revealed that disruption of a positive regulatory loop between DUSP1 and p53 promoted HCC development and progression, providing a rationale for a therapeutic agent that restores DUSP1 in HCC.

국내이용 말사료의 영양적 가치와 YEAST CULTURE 첨가시 소화율 , 광물질 이용율 및 혈액성상에 미치는 영향

김성민(S . M . Kim),김종민(C . M . Kim),이현기(H . K . Lee),박원표(W . P . Park),임영재(Y . J . Lim),김병진(B . J . Kim),정태영(T . Y . Chung) 한국영양사료학회 1991 韓國營養飼料學會誌 Vol.15 No.5

Reproductive Performance, Milk Composition, Blood Metabolites and Hormone Profiles of Lactating Sows Fed Diets with Different Cereal and Fat Sources

Park, M.S.,Shinde, P.L.,Yang, Y.X.,Kim, J.S.,Choi, J.Y.,Yun, K.,Kim, Y.W.,Lohakare, J.D.,Yang, B.K.,Lee, J.K.,Chae, Byung-Jo Asian Australasian Association of Animal Productio 2010 Animal Bioscience Vol.23 No.2

Different dietary cereal sources and fat types in the lactation diet were evaluated to investigate their effects on reproductive performance, milk composition, blood metabolites and hormones in multiparous sows. Twenty-four sows were randomly assigned to one of four treatments according to a 2${\times}$2 factorial arrangement of treatments. Each treatment had 6 replicates comprising 1 sow. Two cereal (corn or wheat) and two fat (tallow or soybean oil) sources were used to prepare iso-caloric and iso-nitrogenous diets. Sows fed corn-based diets lost less body weight (p = 0.003) and backfat thickness (p = 0.034), consumed more feed (p = 0.032) and had shorter wean-to-estrus interval (p = 0.016) than sows fed wheat-based diets. Fewer piglets and lower body weight of piglets (p<0.05) at weaning were noted in sows fed wheat-based diets than in sows fed corn-based diets. However, no significant effects (p>0.05) of dietary fat source and its interaction with dietary cereal source on sow body condition and reproductive performance were observed during lactation. Feeding of a corn-based diet improved (p<0.05) sow milk total solid, protein and fat, increased blood urea nitrogen (p = 0.032) and triglyceride (p = 0.018), and decreased blood creatinine (p = 0.011) concentration at weaning when compared with sows fed wheatbased diets. Sows fed corn-based diets had higher concentration of insulin (p = 0.048) and LH (p<0.05) at weaning than sows fed wheatbased diets. The results indicate that feeding corn-based diets to lactating sows improved sow body condition and reproductive performance compared with wheat-based diets regardless of fat sources.