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101.
The nanomechanical properties, deformation, and shape recovery mechanism of NiTi nanowires (NWs) under torsion are studied using molecular dynamics simulations. The effects of loading rate, aspect ratio of NWs, and NW shape are evaluated in terms of atomic trajectories, potential energy, torque required for deformation, stress, shear modulus, centro-symmetry parameter, and radial distribution function. Simulation results show that dislocation nucleation starts from the surface and then extends to the interior along the {110} close-packed plane. For a high loading rate, the occurrence of torsional buckling of a NW is faster, and the buckling gradually develops near the location of the applied external loading. The critical torsional angle and critical buckling angle increase with aspect ratio of the NWs. Square NWs have better mechanical strength than that of circular NWs due to the effect of shape. Shape recovery naturally occurs before buckling. 相似文献
102.
Ming‐Der Wu Ming‐Jen Cheng Yung‐Shun Su Sung‐Yuan Hsieh Hsun‐Shuo Chang Chun‐Wei Chang Gwo‐Fang Yuan 《化学与生物多样性》2013,10(3):493-505
Cultivation of the fungal strain Annulohypoxylon ilanense, an endophytic fungus isolated from the wood of medicinal plant Cinnamomum species, resulted in the isolation of one new furanoid derivative, ilanefuranone ( 1 ), one new pyrrole alkaloid, ilanepyrrolal ( 2 ), and one new biarylpropanoid derivative, ilanenoid ( 3 ), together with 22 known compounds, of which one α‐tetralone analog, (?)‐(4R)‐3,4‐dihydro‐4,6‐dihydroxynaphthalen‐1(2H)‐one ( 4 ) was isolated for the first time from a natural source. The structures were elucidated on the basis of physicochemical evidence, in‐depth NMR spectroscopic analysis, and high‐resolution mass spectrometry, and the antimycobacterial activities were also evaluated. 相似文献
103.
Woo Young Jeon Woo Yong Shim Sung Hyeon Lee Joon Ho Choi Jung Hoe Kim 《Bioprocess and biosystems engineering》2013,36(6):809-817
Xylose utilization is inhibited by glucose uptake in xylose-assimilating yeasts, including Candida tropicalis, resulting in limitation of xylose uptake during the fermentation of glucose/xylose mixtures. In this study, a heterologous xylose transporter gene (At5g17010) from Arabidopsis thaliana was selected because of its high affinity for xylose and was codon-optimized for functional expression in C. tropicalis. The codon-optimized gene was placed under the control of the GAPDH promoter and was integrated into the genome of C. tropicalis strain LXU1 which is xyl2-disrupted and NXRG (codon-optimized Neurospora crassa xylose reductase) introduced. The xylose uptake rate was increased by 37–73 % in the transporter expression-enhanced strains depending on the glucose/xylose mixture ratio. The recombinant strain LXT2 in 500-mL flask culture using glucose/xylose mixtures showed a xylose uptake rate that was 29 % higher and a xylitol volumetric productivity (1.14 g/L/h) that was 25 % higher than the corresponding rates for control strain LXU1. Membrane protein extraction and Western blot analysis confirmed the successful heterologous expression and membrane localization of the xylose transporter in C. tropicalis. 相似文献
104.
Hoon-Ki Sung Kyung-Oh Doh Joe Eun Son Jin Gyoon Park Yunui Bae Soojeong Choi Seana Mary Lunney Nelson Rebecca Cowling Kristina Nagy Iacovos P. Michael Gou Young Koh S. Lee Adamson Tony Pawson Andras Nagy 《Cell metabolism》2013,17(1):61-72
Highlights? Two-way modulations of adipose VEGF were generated with aP2-Cre transgene ? Adipose VEGF KO reduces vasculature, increases hypoxia and inflammation in fat ? Adipose VEGF KO accelerates the development of metabolic disease in high-fat diet ? Induced adipose VEGF has opposite effect on fat and restores metabolic homeostasis 相似文献
105.
Sung Tae Kim Takafumi Tasaki Adriana Zakrzewska Young Dong Yoo Ki Sa Sung Su-Hyeon Kim Hyunjoo Cha-Molstad Joonsung Hwang Kyoung A Kim Bo Yeon Kim Yong Tae Kwon 《Autophagy》2013,9(7):1100-1103
The N-end rule pathway is a cellular proteolytic system that utilizes specific N-terminal residues as degradation determinants, called N-degrons. N-degrons are recognized and bound by specific recognition components (N-recognins) that mediate polyubiquitination of low-abundance regulators and selective proteolysis through the proteasome. Our earlier work identified UBR4/p600 as one of the N-recognins that promotes N-degron-dependent proteasomal degradation. In this study, we show that UBR4 is associated with cellular cargoes destined to autophagic vacuoles and is degraded by the lysosome. UBR4 loss causes multiple misregulations in autophagic pathways, including an increased formation of LC3 puncta. UBR4-deficient mice die during embryogenesis primarily due to defective vascular development in the yolk sac (YS), wherein UBR4 is associated with a bulk lysosomal degradation system that absorbs maternal proteins from the YS cavity and digests them into amino acids. Our results suggest that UBR4 plays a role not only in selective proteolysis of short-lived regulators through the proteasome, but also bulk degradation through the lysosome. Here, we discuss a possible mechanism of UBR4 as a regulatory component in the delivery of cargoes destined to interact with the autophagic core machinery. 相似文献
106.
Yuan-Fong Chau Wei-Hsiang Lin Min-Jer Sung Ci-Yao Jheng San-Cai Jheng Din Ping Tsai 《Plasmonics (Norwell, Mass.)》2013,8(2):755-761
We propose a new design of a plasmonic nanoantenna and numerically study its optical properties by means of the 3D finite element method. The nanoantenna is composed of two identical castle-like contour nanometal-filled dielectric media inside the hollows. We examine the influence of the contour thickness, gap width, and dielectric media filled inside the hollows on the antenna resonance conditions. Through these simulations, we show that it is possible to tune an antenna with a constant length over a broad spectral range (ranging in ultraviolet–visible, visible light, and infrared light). 相似文献
107.
Shin Jung Park Sun-Hee Hyun Hyo Won Suh Seok-Young Lee Gi-Ho Sung Seong Hwan Kim Hyung-Kyoon Choi 《Metabolomics : Official journal of the Metabolomic Society》2013,9(1):236-246
In this study, nuclear magnetic resonance techniques coupled with multivariate data analysis were used for the metabolic profiling of mycelia and fruiting bodies of the entomopathogenic fungi, Cordyceps bassiana according to developmental stages. A direct extraction method using two deuterated solvents of D2O and CDCl3 was used to investigate the relative levels of identified metabolites in each extraction condition in the mycelium and fruiting body formation stages. There was a clear separation among mycelia and fruiting bodies with various developmental stages in partial least-squares discriminant analysis (PLS-DA) derived score plots. During the transition from mycelia to fruiting bodies, the major metabolic change observed was the conversion of glucose to mannitol, and beauvericin to phenylalanine and 1-hydroxyisovaleric acid. In the developmental stages of fruiting bodies studied, there was a clear separation between stage 3 and the other stages in PLS-DA derived score plots. Nineteen compounds including 13 amino acids, 2 nucleosides, 3 organic acids, and glucose showed the highest levels in stage 3 fruiting bodies. The flavonoid content in the fruiting bodies showed similar levels during stages 1, 2, and 3, whereas the level at stage 4 was significantly decreased compared to the other stages. Results suggest that the fruiting body of C. bassiana is richer in natural resources at stage 3 compared to the other fruiting body stages due to its high abundance of compounds including total flavonoids. The metabolome information acquired in this study can be useful criteria for the quality control of commercial use of C. bassiana. 相似文献
108.
Sung‐Hae Park Jongchul Lim Young Soo Kwon In Young Song Jong Min Choi Seulki Song Taiho Park 《Liver Transplantation》2013,3(2):184-192
Nanoporous network polymer nanocomposites with tunable pore size for size‐dependent selective ion transport are successfully prepared via the surface‐induced cross‐linking polymerization of methyl methacrylate (MMA) and 1,6‐hexanediol diacrylate (HDDA) on the surfaces of nanocrystalline TiO2 particles. The morphologies of the porous network polymer layer and nanopores were investigated by transmission electron microscopy (TEM), field emission scanning electron microscopy (FE‐SEM), and Brunauer–Emmett–Teller (BET) experiments. The porous layer size‐selectively screened the ions that contacted the nanocrystalline TiO2 particles, as demonstrated by ion conductivity measurements, electrochemical impedance spectroscopy (EIS), and transient absorption spectroscopy (TAS). 相似文献
109.
Jong-Seok Kim Woo Sik Kim Keehoon Lee Choul-Jae Won Jin Man Kim Seok-Yong Eum Won-Jung Koh Sung Jae Shin 《PloS one》2013,8(3)
Two closely related bacterial species, Segniliparus rotundus and Segniliparus rugosus, have emerged as important human pathogens, but little is known about the immune responses they elicit or their comparative pathophysiologies. To determine the virulence and immune responses of the two species, we compared their abilities to grow in phagocytic and non-phagocytic cells. Both species maintained non-replicating states within A549 epithelial cells. S. rugosus persisted longer and multiplied more rapidly inside murine bone marrow-derived macrophages (BMDMs), induced more pro-inflammatory cytokines, and induced higher levels of macrophage necrosis. Activation of BMDMs by both species was mediated by toll-like receptor 2 (TLR2), followed by mitogen-activated protein kinases (MAPK) and nuclear factor κB (NF-κB) signaling pathways, indicating a critical role for TLR2 in Segniliparus-induced macrophage activation. S. rugosus triggered faster and stronger activation of MAPK signaling and IκB degradation, indicating that S. rugosus induces more pro-inflammatory cytokines than S. rotundus. Multifocal granulomatous inflammations in the liver and lung were observed in mice infected with S. rugosus, but S. rotundus was rapidly cleared from all organs tested within 15 days post-infection. Furthermore, S. rugosus induced faster infiltration of innate immune cells such as neutrophils and macrophages to the lung than S. rotundus. Our results suggest that S. rugosus is more virulent and induces a stronger immune response than S. rotundus. 相似文献
110.
Taylor J. Jensen Tricia Zwiefelhofer Roger C. Tim ?eljko D?akula Sung K. Kim Amin R. Mazloom Zhanyang Zhu John Tynan Tim Lu Graham McLennan Glenn E. Palomaki Jacob A. Canick Paul Oeth Cosmin Deciu Dirk van den Boom Mathias Ehrich 《PloS one》2013,8(3)