Enhanced Performance of Solution‐Processed TESPE‐ADT Thin‐Film Transistors

Chen, Liang&#x2010,Hsiang,Hu, Tarng&#x2010,Shiang,Huang, Peng&#x2010,Yi,Kim, Choongik,Yang, Ching&#x2010,Hao,Wang, Juin&#x2010,Jie,Yan, Jing&#x2010,Yi,Ho, Jia&#x2010,Chong,Lee, Cheng&#x2010,Chung,Chen WILEY‐VCH Verlag 2013 Chemphyschem Vol.14 No.12

<P><B>Abstract</B></P><P>A solution‐processed anthradithiophene derivative, 5,11‐bis(4‐triethylsilylphenylethynyl)anthradithiophene (TESPE‐ADT), is studied for use as the semiconducting material in thin‐film transistors (TFTs). To enhance the electrical performance of the devices, two different kinds of solution processing (spin‐coating and drop‐casting) on various gate dielectrics as well as additional post‐treatment are employed on thin films of TESPE‐ADT, and <I>p</I>‐channel OTFT transport with hole mobilities as high as ∼0.12 cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP> are achieved. The film morphologies and formed microstructures of the semiconductor films are characterized in terms of film processing conditions and are correlated with variations in device performance.</P>

Carbon monoxide attenuates amyloidogenesis via down‐regulation of NF‐κB‐mediated BACE1 gene expression

Kim, Hyo Jeong,Joe, Yeonsoo,Chen, Yingqing,Park, Gyu Hwan,Kim, Uh&#x2010,Hyun,Chung, Hun Taeg John Wiley and Sons Inc. 2019 Aging cell Vol.18 No.1

<P><B>Abstract</B></P><P>Amyloid‐β (Aβ) peptides, the major constituent of plaques, are generated by sequential proteolytic cleavage of the amyloid precursor protein (APP) via β‐secretase (BACE1) and the γ‐secretase complex. It has been proposed that the abnormal secretion and accumulation of Aβ are the initial causative events in the development of Alzheimer's disease (AD). Drugs modulating this pathway could be used for AD treatment. Previous studies indicated that carbon monoxide (CO), a product of heme oxygenase (HO)‐1, protects against Aβ‐induced toxicity and promotes neuroprotection. However, the mechanism underlying the mitigative effect of CO on Aβ levels and BACE1 expression is unclear. Here, we show that CO modulates cleavage of APP and Aβ production by decreasing BACE1 expression in vivo and in vitro. CO reduces Aβ levels and improves memory deficits in AD transgenic mice. The regulation of BACE1 expression by CO is dependent on nuclear factor‐kappa B (NF‐κB). Consistent with the negative role of SIRT1 in the NF‐κB activity, CO fails to evoke significant decrease in BACE1 expression in the presence of the SIRT1 inhibitor. Furthermore, CO attenuates elevation of BACE1 level in brains of 3xTg‐AD mouse model as well as mice fed high‐fat, high‐cholesterol diets. CO reduces the NF‐κB‐mediated transcription of BACE1 induced by the cholesterol oxidation product 27‐hydroxycholesterol or hydrogen peroxide. These data suggest that CO reduces the NF‐κB‐mediated BACE1 transcription and consequently decreases Aβ production. Our study provides novel mechanisms by which CO reduces BACE1 expression and Aβ production and may be an effective agent for AD treatment.</P>

Sphingosine kinase 1 pathway is involved in melatonin‐induced HIF‐1α inactivation in hypoxic PC‐3 prostate cancer cells

Cho, Sung&#x2010,Yun,Lee, Hyo&#x2010,Jeong,Jeong, Soo&#x2010,Jin,Lee, Hyo&#x2010,Jung,Kim, Hyun&#x2010,Seok,Chen, Chang Yan,Lee, Eun&#x2010,Ok,Kim, Sung&#x2010,Hoon Blackwell Publishing Ltd 2011 Journal of pineal research Vol.51 No.1

<P><B>Abstract: </B> Sphingosine kinase 1 (SPHK1) is a newly discovered modulator of hypoxia inducible factor 1α (HIF‐1α) with various biological activities such as cell growth, survival, invasion, angiogenesis, and carcinogenesis. Thus, in the present study, the biological mechanisms of melatonin were elucidated in association with SPHK1 pathway in PC‐3 prostate cancer cells under hypoxia. Melatonin inhibited the stability of HIF‐1α in a time‐ and concentration‐ dependent manners. Also, melatonin decreased SPHK1 activity in PC‐3 cells during hypoxia. Furthermore, melatonin suppressed AKT/glycogen synthase kinase‐3β (GSK‐3β) signaling pathway, which stabilizes HIF‐1α via inhibition of von Hippel‐Lindau tumor suppressor protein. Consistently, siRNA‐SPHK1 and sphingosine kinase inhibitor (SKI) effectively blocked the expression of HIF‐1α, phospho‐AKT and vascular endothelial growth factor (VEGF) production in PC‐3 cells under hypoxia, suggesting the role of SPHK1 in melatonin‐inhibited HIF‐1α accumulation. Moreover, reactive oxygen species (ROS) scavenger N‐acteylcysteine enhanced melatonin‐inhibited HIF‐1α expression and SPHK1 activity. Overall, our findings suggest that melatonin suppresses HIF‐1α accumulation via inhibition of SPHK1 pathway and ROS generation in PC‐3 cells under hypoxia.</P>

Emergent genetic oscillations in a synthetic microbial consortium

Chen, Ye,Kim, Jae Kyoung,Hirning, Andrew J.,Josi&#x107,, Kre&#x161,imir,Bennett, Matthew R. American Association for the Advancement of Scienc 2015 Science Vol.349 No.6251

<P><B>Engineering cell population behavior</B></P><P>Attaining the full promise of synthetic biology will require designing population-level behaviors of multiple interacting cell types. As a start, Chen et al. engineered two strains of the bacterium <I>Escherichia coli</I> to produce signaling molecules that regulate transcription in the complementary strain (see the Perspective by Teague and Weiss). The signaling circuit was successfully designed to produce feedback loops that produce synchronous oscillations in transcription between the two strains. A mathematical model helped determine how to modulate the oscillations and control their robustness to perturbations.</P><P><I>Science</I>, this issue p. 986; see also p. 924</P><P>A challenge of synthetic biology is the creation of cooperative microbial systems that exhibit population-level behaviors. Such systems use cellular signaling mechanisms to regulate gene expression across multiple cell types. We describe the construction of a synthetic microbial consortium consisting of two distinct cell types—an “activator” strain and a “repressor” strain. These strains produced two orthogonal cell-signaling molecules that regulate gene expression within a synthetic circuit spanning both strains. The two strains generated emergent, population-level oscillations only when cultured together. Certain network topologies of the two-strain circuit were better at maintaining robust oscillations than others. The ability to program population-level dynamics through the genetic engineering of multiple cooperative strains points the way toward engineering complex synthetic tissues and organs with multiple cell types.</P>

Femtosecond X-ray Absorption Spectroscopy at a Hard X-ray Free Electron Laser: Application to Spin Crossover Dynamics

Lemke, Henrik T.,Bressler, Christian,Chen, Lin X.,Fritz, David M.,Gaffney, Kelly J.,Galler, Andreas,Gawelda, Wojciech,Haldrup, Kristoffer,Hartsock, Robert W.,Ihee, Hyotcherl,Kim, Jeongho,Kim, Kyung Hw American Chemical Society 2013 The journal of physical chemistry. A, Molecules, s Vol.117 No.4

<P>X-ray free electron lasers (XFELs) deliver short (<100 fs) and intense (∼10<SUP>12</SUP> photons) pulses of hard X-rays, making them excellent sources for time-resolved studies. Here we show that, despite the inherent instabilities of current (SASE based) XFELs, they can be used for measuring high-quality X-ray absorption data and we report femtosecond time-resolved X-ray absorption near-edge spectroscopy (XANES) measurements of a spin-crossover system, iron(II) tris(2,2′-bipyridine) in water. The data indicate that the low-spin to high-spin transition can be modeled by single-exponential kinetics convoluted with the overall time resolution. The resulting time constant is ∼160 fs.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpcafh/2013/jpcafh.2013.117.issue-4/jp312559h/production/images/medium/jp-2012-12559h_0008.gif'></P>

p‐Type InP Nanopillar Photocathodes for Efficient Solar‐Driven Hydrogen Production

Lee, Min Hyung,Takei, Kuniharu,Zhang, Junjun,Kapadia, Rehan,Zheng, Maxwell,Chen, Yu&#x2010,Ze,Nah, Junghyo,Matthews, Tyler S.,Chueh, Yu&#x2010,Lun,Ager, Joel W.,Javey, Ali WILEY‐VCH Verlag 2012 Angewandte Chemie Vol.124 No.43

<P><B>Perfekte Textur</B>: Der Einfluss der Oberflächen‐Nanotexturierung, der TiO<SUB>2</SUB>‐Passivierung und des Ru‐Cokatalysators auf die photoelektrochemische Wasserstoffentwicklung durch p‐InP‐Photokathoden wurde untersucht. Höhere Stromdichten und günstigere Onset‐Potentiale werden nach Oberflächen‐Nanotexturierung beobachtet. NHE=Normalwasserstoffelektrode.</P>

Suppressive effect of docosahexaenoyl‐lysophosphatidylcholine and 17‐hydroxydocosahexaenoyl‐lysophosphatidylcholine on levels of cytokines in spleen of mice treated with lipopolysaccharide

Jim, Mei Chen,Hung, Nguyen Dang,Yoo, Jae Myung,Kim, Mee Ree,Sok, Dai&#x2010,Eun WILEY‐VCH Verlag 2012 European journal of lipid science and technology Vol.114 No.2

<P><B>Abstract</B></P><P>Lysophosphatidylcholine (lysoPC) with polyunsaturated fatty acyl chains has been known to be anti‐inflammatory in vivo. In the present study, we examined the effect of docosahexaenoyl‐lysophosphatidylcholine (DHE‐lysoPC) and 17‐hydroxydocosahexaenoyl‐lysophosphatidylcholine (17‐HDHE‐lysoPC) on spleen weight and cytokine level in spleen of mice treated with lipopolysaccharide (LPS). For this purpose, mice were administrated i.p. with DHE‐lysoPC or 17‐HDHE‐lysoPC 1 h before i.p. injection of LPS. First, DHE‐lysoPC (50–400 µg/kg) was found to suppress the LPS‐induced increase of spleen weight dose‐dependently, and such a suppressive effect was greater for 17‐HDHE‐lysoPC, compared to DHE‐lysoPC. Next, in an attempt to see the effect of DHE‐lysoPC on cytokine levels in spleen of mice treated with LPS, DHE‐lysoPC was found to suppress LPS‐induced increase in the levels of cytokines such as TNF‐α, IL‐1β, or IL‐6 in a dose dependent manner (50–400 µg/kg), in contrast to DHA showing a significant action at a high dose (400 µg/kg) only. The greater suppressive effect of 17‐HDHE‐lysoPC (15–150 µg/kg) than DHE‐lysoPC suggested that action of DHE‐lysoPC may be enhanced through lipoxygenation process. Presumably in support of this, when the interval time between 17‐HDHE‐lysoPC administration and LPS challenge was varied, the cytokine‐suppressing effect was found to be augmented in a time‐dependent manner. Taken all together, it is suggested that DHE‐lysoPC and 17‐HDHE‐lysoPC may be beneficial in suppressing the inflammation in spleen tissue.</P>

Development of a bone reconstruction technique using a solid free‐form fabrication (SFF)‐based drug releasing scaffold and adipose‐derived stem cells

Lee, Jin Woo,Kim, Ki&#x2010,Joo,Kang, Kyung Shin,Chen, Shaochen,Rhie, Jong&#x2010,Won,Cho, Dong&#x2010,Woo Wiley Subscription Services, Inc., A Wiley Company 2013 Journal of biomedical materials research. Part A Vol.101 No.7

<P><B>Abstract</B></P><P>For tissue regeneration, three essential components of scaffolds, signals (biomolecules), and cells are required. Moreover, because bony defects are three‐dimensional in many clinical circumstances, an exact 3D scaffold is important. Therefore, we proposed an effective reconstruction tool for cranial defects using human adipose‐derived stem cells (hADSCs) and a 3D functional scaffold fabricated by solid free‐form fabrication (SFF) technology that secretes biomolecules. We fabricated poly(propylene fumarate)‐based 3D scaffolds with embedded microsphere‐deliverable bone morphogenetic protein‐2 (BMP‐2) by microstereolithography. BMP‐2‐loaded SFF scaffolds with/without hADSCs (SFF/BMP/hADSCs scaffolds and SFF/BMP scaffolds, respectively) and BMP‐2‐unloaded SFF scaffolds (SFF scaffolds) were then implanted in rat crania, and <I>in vivo</I> bone formation was observed. Analyses of bone formation areas using micro‐computed tomography (micro‐CT) showed the superiority of SFF/BMP/hADSCs scaffolds. Hematoxylin and eosin stain, Masson's trichrome stain, and collagen type‐I stain supported the results of the micro‐CT scan. And human leukocyte antigen‐ABC showed that seeded, differentiated hADSCs were well grown and changed to the bone tissue at the inside of the scaffold. Results showed that our combination of a functional 3D scaffold and hADSCs may be a useful tool for improving the reconstruction quality of severe bony defects in which thick bone is required. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.</P>

A model study for an Oceania watershed: spatio‐temporal changes of mesozooplankton in riverine and estuarine parts of the Lanyang River in Taiwan

Dahms, Hans&#x2010,Uwe,Tseng, Li&#x2010,Chun,Hsiao, Shih&#x2010,Hui,Chen, Qing&#x2010,Chao,Hwang, Jiang&#x2010,Shiou Springer Japan 2013 Ecological research Vol.28 No.2

<P><B>Abstract</B></P><P>The mesozooplankton of a river tributary in Oceania is evaluated and is correlated against environmental, abiotic, and biological attributes of this lotic system. Abundance, distribution, and the diversity of mesozooplankton was studied at nine stations including one estuarine station during ten sampling campaigns from June 2004 to December 2005 along the Lanyang River, the largest river and estuarine ecosystem in northeastern Taiwan. Mesozooplankton was dominated by copepods, cladocerans, and fish larvae. Among all samples, the highest abundances of mesozooplankton (5,049.36 individuals m<SUP>−3</SUP>) occurred in the estuary station in August 2004, which also corresponds to the highest salinities (37.0), indicating the marine role in shaping the estuarine planktonic assemblages. The abundance of mesozooplankton and number of mesozooplankton taxa were significantly higher in samples of the estuarine station than in the riverine stations (<I>p</I> < 0.05, one‐way ANOVA). The number of mesozooplankton taxa number was affected by water temperature (<I>r</I> = 0.697; <I>p</I> = 0.025, Pearson's correlation) that was primarily influenced by the weather that was in turn affected by seasonal monsoons.</P>

FOXO protects against age‐progressive axonal degeneration

Hwang, Inah,Oh, Hwanhee,Santo, Evan,Kim, Do&#x2010,Yeon,Chen, John W.,Bronson, Roderick T.,Locasale, Jason W.,Na, Yoonmi,Lee, Jaclyn,Reed, Stewart,Toth, Miklos,Yu, Wai H.,Muller, Florian L.,Paik, Jihy John Wiley and Sons Inc. 2018 AGING CELL Vol.17 No.1

<P><B>Summary</B></P><P>Neurodegeneration resulting in cognitive and motor impairment is an inevitable consequence of aging. Little is known about the genetic regulation of this process despite its overriding importance in normal aging. Here, we identify the Forkhead Box O (FOXO) transcription factor 1, 3, and 4 isoforms as a guardian of neuronal integrity by inhibiting age‐progressive axonal degeneration in mammals. FOXO expression progressively increased in aging human and mouse brains. The nervous system‐specific deletion of <I>Foxo</I> transcription factors in mice accelerates aging‐related axonal tract degeneration, which is followed by motor dysfunction. This accelerated neurodegeneration is accompanied by levels of white matter astrogliosis and microgliosis in middle‐aged <I>Foxo</I> knockout mice that are typically only observed in very old wild‐type mice and other aged mammals, including humans. Mechanistically, axonal degeneration in nerve‐specific <I>Foxo</I> knockout mice is associated with elevated mTORC1 activity and accompanying proteotoxic stress due to decreased Sestrin3 expression. Inhibition of mTORC1 by rapamycin treatment mimics FOXO action and prevented axonal degeneration in <I>Foxo</I> knockout mice with accelerated nervous system aging. Defining this central role for FOXO in neuroprotection during mammalian aging offers an invaluable window into the aging process itself.</P>