c-Cbl-Mediated Neddylation Antagonizes Ubiquitination and Degradation of the TGF-β Type II Receptor

Zuo, W.,Huang, F.,Chiang, Y.,Li, M.,Du, J.,Ding, Y.,Zhang, T.,Lee, H.,Jeong, L.,Chen, Y.,Deng, H.,Feng, X.H.,Luo, S.,Gao, C.,Chen, Y.G. Cell Press 2013 Molecular cell Vol.49 No.3

Transforming growth factor β (TGF-β) is a potent antiproliferative factor in multiple types of cells. Deregulation of TGF-β signaling is associated with the development of many cancers, including leukemia, though the molecular mechanisms are largely unclear. Here, we show that Casitas B-lineage lymphoma (c-Cbl), a known proto-oncogene encoding an ubiquitin E3 ligase, promotes TGF-β signaling by neddylating and stabilizing the type II receptor (TβRII). Knockout of c-Cbl decreases the TβRII protein level and desensitizes hematopoietic stem or progenitor cells to TGF-β stimulation, while c-Cbl overexpression stabilizes TβRII and sensitizes leukemia cells to TGF-β. c-Cbl conjugates neural precursor cell-expressed, developmentally downregulated 8 (NEDD8), a ubiquitin-like protein, to TβRII at Lys556 and Lys567. Neddylation of TβRII promotes its endocytosis to EEA1-positive early endosomes while preventing its endocytosis to caveolin-positive compartments, therefore inhibiting TβRII ubiquitination and degradation. We have also identified a neddylation-activity-defective c-Cbl mutation from leukemia patients, implying a link between aberrant TβRII neddylation and leukemia development.

Deletion of the Lmna Gene Induces Growth Delay and Serum Biochemical Changes in C57BL/6 Mice

Ruan, J.,Liu, X.G.,Zheng, H.L.,Li, J.B.,Xiong, X.D.,Zhang, C.L.,Luo, C.Y.,Zhou, Z.J.,Shi, Q.,Weng, Y.G. Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.1

The A-type lamin deficient mouse line ($Lmna^{-/-}$) has become one of the most frequently used models for providing insights into many different aspects of A-type lamin function. To elucidate the function of Lmna in the growth and metabolism of mice, tissue growth and blood biochemistry were monitored in Lmna-deficient mice, heterozygous ($Lmna^{+/-}$) and wide-type ($Lmna^{+/+}$) backcrossed to C57BL/6 background. At 4 weeks after birth, the weight of various organs of the $Lmna^{-/-}$, $Lmna^{+/-}$ and $Lmna^{+/+}$ mice was measured. A panel of biochemical analyses consisting of 15 serological tests was examined. The results showed that Lmna deficient mice had significantly decreased body weight and increased the ratio of organ to body weight in most of tissues. Compared with $Lmna^{+/+}$ and $Lmna^{+/-}$ mice, $Lmna^{-/-}$ mice exhibited lower levels of ALP (alkaline phosphatase), Chol (cholesterol), CR (creatinine), GLU (glucose), HDL (high-density lipoprotein cholesterol) and higher levels of ALT (alanine aminotransferase) (p<0.05). $Lmna^{-/-}$ mice displayed higher AST (aspartate aminotransferase) values and lower LDL (lowdensity lipoprotein cholesterol), CK-MB (creatine kinase-MB) levels than $Lmna^{+/+}$ mice (p<0.05). There were no significant differences among the three groups of mice with respect to BUN (blood urea nitrogen), CK (creatine kinase), Cyc C (cystatin C), TP (total protein), TG (triacylglycerols) and UA (uric acid) levels (p>0.05). These changes of serological parameters may provide an experimental basis for the elucidation of Lmna gene functions.

Experimental Study of the Runaway Current in the J-TEXT Tokamak

Y. H. Luo,Z. Y. Chen,X. Q. Zhang,D. W. Huang,W. Jin,Y. H. Huang,Y. Tang,J. C. Li,R. H. Tong,W. Yan,G. Zhuang 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.64 No.3

Major plasma disruptions in tokamaks often generate runaway currents, which contain electronswith energies of several tens of megaelectron-volts (MeV). These currents can cause substantialdamage when control is lost and the current hits the limiters or the vessel wall. The interactionbetween the runaway electrons and the impurities inside the plasma results in soft X-ray emission,which can provide detailed information about the runaway generation process and the confinementof runaway electrons. A vertical soft X-ray array at the top of Joint Texas Experimental Tokamak(J-TEXT) was used to study the runaway beams resulting from major disruptions. Runawayelectron production and confinement of runaway current were observed by using soft X-ray images.

Improving mechanical and magnetocaloric responses of amorphous melt-extracted Gd-based microwires via nanocrystallization

Belliveau, H.F.,Yu, Y.Y.,Luo, Y.,Qin, F.X.,Wang, H.,Shen, H.X.,Sun, J.F.,Yu, S.C.,Srikanth, H.,Phan, M.H. Elsevier 2017 JOURNAL OF ALLOYS AND COMPOUNDS Vol.692 No.-

<P><B>Abstract</B></P> <P>We report on the structural, mechanical, and magnetocaloric properties of annealed melt-extracted Gd<SUB>53</SUB>Al<SUB>24</SUB>Co<SUB>20</SUB>Zr<SUB>3</SUB> amorphous microwires of ∼70 μm diameter. During heat treatment small islands of nanocrystallities are generated and isolated in the amorphous region for the wires. The size of the nanocrystallities ranges from 5 nm to 10 nm. The observed lattice distortion from the nanocrystallities causes changes in the magnetic properties of the wires. The annealing temperature of 100 °C has the largest strength (1845 MPa) as compared to wires annealed at other temperatures. This is likely to trigger nanophase transformation in the amorphous region and these nanocrystals have been preserved through the increase of annealing temperature. The formulation of the nanocrystalline islands is also verified by the selected-area electron diffraction (SAED). The microwires exhibit a large and reversible magnetocaloric effect (MCE), with the maximum isothermal magnetic entropy change (−Δ<I>S</I> <SUB>M</SUB>) and refrigerant capacity (<I>RC</I>) values of 9.5 J/kg K and 689 J/kg respectively for the microwire annealed at 100 °C. This <I>RC</I> is about 35%, 67%, and 91% larger than those of bulk Gd<SUB>53</SUB>Al<SUB>24</SUB>Co<SUB>20</SUB>Zr<SUB>3</SUB> (∼509 J/kg), Gd (∼410 J/kg), and Gd<SUB>5</SUB>Si<SUB>2</SUB>Ge<SUB>1.9</SUB>Fe<SUB>0.1</SUB> (∼360 J/kg) regardless of their ordering temperatures. These results demonstrate the ability to tune the mechanical and magnetic properties of the microwires by thermal annealing.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The impact of nanocrystallization in Gd<SUB>53</SUB>Al<SUB>24</SUB>Co<SUB>20</SUB>Zr<SUB>3</SUB> microwires. </LI> <LI> Enhanced mechanical strength. </LI> <LI> Enhanced magnetocaloric response. </LI> </UL> </P>

전압, 공핵배 발생단계 및 체외배양액이 소의 제2세대 핵이식배 발생능에 미치는 영향

정영채,김창근,나광빈,김광식,박세영,류재원,오신애,박진서 中央大學校 遺傳工學硏究所 1998 遺傳工學硏究論集 Vol.11 No.1

소에서 체외에서 생산된 제1세대 핵이식배를 다시 공핵배로 사용하여 제2세대 핵이식배를 생산하기 위한 효과적인 방법을 개발하기 위하여 본 연구에서 세포융합시 전압, 제1세대 핵이식배의 발생단계 및 체외배양조건에 따라 제2세대 핵이식배의 발생결과를 조사한 결과는 다음과 같다. 1. 세포융합시 전압을 0.7kV/cm, 1.0kV/cm 및 1.2kV/cm로 하였을 때 세포융합율과 난할율에서 유의차는 없었으며 후기배의 발생율이 1.0kV/cm가 0.7kV/cm와 1.2kV/cm보다 다소 높게 나타났다. 2. 8-15, 16-23 및 25-32세포기의 제1세대 핵이식배를 공핵배로 이용한 제2세대 핵이식배의 융합율, 난할율 및 상실배까지의 발생율은 세포기에 따라 유의차가 없었다. 그러나 배반포배 발생율은 각각 3.4%, 6.9% 및 18.5%로서 16-23세포기와 25-32세포기간에는 유의차가 없었으나 25-32세포기는 8-15세포기보다 유의적으로 높았다(p<0.01). 3. 제2세대 핵이식배를 BOEC, BOEC-CM 및 10% FBS+BOEC-CM에서 배양한 결과 난할율과 상실배까지의 발생에서 큰 차이가 없었으나 배반포까지의 발생율은 각각 12.5%, 5.7% 및 9.6%로 BOEC 처리구에서 처리구가 가장 높은 것으로 나타났다. This study was carried out to investigate the effect of the electric pulses, donor embryo cell-stages and culture media on the 2nd generation nuclear transplant bovine embryos. Parent donor embryos were used at day 4 after IVF and 8 to 32 cell-stage embryos at day 3∼5 after the first cycle nuclear transfer were used as donor for 2nd generation. The recipient oocytes were enucleated 22 to 23 h after the onset of in vitro maturation(IVM) and preactivated 24 h after IVM. Electric fusion was performed 30 h after IVM. When a pulse of 0.7kV/cm, 1.0kV/cm or 1.2kV/cm direct current for 70μsec was applied, the fusion rates of the 2nd generation were 73.5%, 87.3% and 83.6%, respectively and the cleavage rates were 78.0%, 80.6% and 86.6%, respectively. The proportions of fusion and cleavage were lower in 0.7kV/cm than in 1.0kV/cm and 1.2kV/cm. The developmental rate to blastocyst in the 2nd generation nuclear transplant embryos was higher in 1.0kV/cm(12.9%) than in 0.7kV/cm(8.0%) and 1.2kV/cm(6.5%). The rate of fusion and cleavage and developmental rate to blastocyst in the 2nd generation embryos derived from 8 to 32 cell-stage donor embryos was 87.1%, 85.2% and 18.5%, respectively, from 25-32 cell-stage, 86.6%, 79.3% and 6.9%, respectively, from 16-23 cell-stage, and 84.1%, 77.6%, and 3.4%, respectively, from 8-15 cell-stage. These rates were not significantly different between 25-32 cell-stage and 16-23 cell-stage donor embryos, but the developmental rate was higher from 25-32 cell-stage donor embryos, than from 8-15 cell-stage. The developmental rate to blastocyst in the 2nd generation nuclear transplant embryos was higher in co-culture with bovine oviduct epithelial cells(12.5%) than in BOEC-conditioned medium with 10% FBS(9.6%) or without FBS(5.7%). The developmental rate in co-culture with BOEC was higher than in BOEC-conditioned medium.

Optical properties of amorphous $Si_xC_yN_z$ ternary thin films prepared by plasma enhanced chemical vapor deposition

Zhang, Z.H.,Fan, X.J.,Guo, H.X.,Zhang, W.,Zhang, C.Y.,Luo, F.Y. The Korean Vacuum Society 1998 Applied Science and Convergence Technology Vol.7 No.1

Amorphous ternary $Si_xC_yN-z$ thin films were obtained by plasma enhanced chemical vapor deposition(PECVD) using $N_2, SiH_4 \;and \;C_2H_4$ as the reaction sources. The chemical state were characterized by x-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy(FTIR). The optical properties of the thin films were investigated by UV-visible spectrophotometer and ellipsometer, and the optical band gaps of thin films were determined from corresponding transmittance spectra following Tauc equation.

Carrier Dynamics in Self-Assembled CdTe Stranski-Krastanow Quantum Dots Grown on ZnSe by Molecular Beam Epitaxy

C. S. Yang,K. F. Chien,J. Y. Lai,C. W. Luo,W. C. Chou,Y. T. Shih,J. S. Wang,S. R. Jian 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.5

Self-assembled CdTe/ZnSe Stranski-Krastanow quantum-dot (QD) structures, which have a CdSe-like precursor-layer (PCL) between CdTe quantum dots and ZnSe matrix, were grown by molecular beam epitaxy. The carrier dynamics of the structures was studied by photoluminescence (PL) and time-resolved photoluminescence (TRPL) measurements. The temperature-dependent PL spectra revealed that there is a carrier transformation from small dots to larger dots via the precursor layer. Temperature-dependent PL measurements verify the existence of the QD excited excitonic state in 5.0 mono-layer (ML) coverage. In 0.6 ML coverage, the TRPL spectra exhibited a double-exponential decay process, as the detection energy at PCL emission energy. The faster decay time is corresponded to the carrier lifetime in PCL, the slower decay time exhibits the carrier in small QD. However, in 5.0 ML coverage, a faster and slower decay time represents the carrier lifetime in QD excited state for larger QD and the carrier lifetime in QD ground state for smaller QD.

Effects of potassium loading and thermal aging on K/Pt/Al₂O₃ high-temperature lean NO_x trap catalysts

Luo, J.,Gao, F.,Kim, D.H.,Peden, C.H.F. Elsevier Science Publishers 2014 CATALYSIS TODAY - Vol.231 No.-

The effects of K loading and thermal aging on the structural properties and high temperature performance of Pt/K/Al<SUB>2</SUB>O<SUB>3</SUB> lean NO<SUB>x</SUB> trap (LNT) catalysts were investigated using in situ X-ray diffraction (XRD), temperature-programmed decomposition/desorption of NO<SUB>x</SUB> (NO<SUB>x</SUB>-TPD), transmission electron microscopy (TEM), NO oxidation, and NO<SUB>x</SUB> storage tests. In situ XRD results demonstrate that KNO<SUB>3</SUB> becomes extremely mobile on the Al<SUB>2</SUB>O<SUB>3</SUB> surface, and experiences complex transformations between orthorhombic and rhombohedral structures, accompanied by sintering, melting and thermal decomposition upon heating. NO<SUB>x</SUB> storage results show an optimum K loading around 10% for the best performance at high temperatures. At lower K loadings where the majority of KNO<SUB>3</SUB> stays as a surface layer, the strong interaction between KNO<SUB>3</SUB> and Al<SUB>2</SUB>O<SUB>3</SUB> promotes KNO<SUB>3</SUB> decomposition and deteriorates high-temperature performance. At K loadings higher than 10%, the performance drop is not caused by NO<SUB>x</SUB> diffusion limitations as for the case of barium-based LNTs, but rather from the blocking of Pt sites by K species, which adversely affects NO oxidation. Thermal aging at 800<SUP>o</SUP>C severely deactivates the Pt/K/Al<SUB>2</SUB>O<SUB>3</SUB> catalysts due to Pt sintering. However, in the presence of potassium, some Pt remains in a dispersed and oxidized form. These Pt species interact strongly with K and, therefore, do not sinter. After a reduction treatment, these Pt species remain finely dispersed, contributing to a partial recovery of NO<SUB>x</SUB> storage performance.

Progress in Novel Oxides for Gate Dielectrics and Surface Passivation of GaN/AlGaN Heterostructure Field Effect Transistors

C.R.Abernathy,B.P.Gila,A.H.Onstine,S.J.Pearton,Jihyun Kim,B.Luo,R.Mehandru,F.Ren,J. K. Gillespie,R. C. Fitch,J. Sewell,R. Dettmer,G.D. Via,A. Crespo,T.J. Jenkins,Y. Irokawa 대한전자공학회 2003 Journal of semiconductor technology and science Vol.3 No.1

Hardness of Porous Nanocrystalline Co-Ni Electrodeposits

C. Ma,S. C. Wang,R. J. K. Wood,J. Zekonyte,Q. Luo,F. C. Walsh 대한금속·재료학회 2013 METALS AND MATERIALS International Vol.19 No.6

The Hall-Petch relationship can fail when the grain size is below a critical value of tens of nanometres. This occurs particularly for coatings having porous surfaces. In this study, electrodeposited nanostructured Co-Ni coatings from four different nickel electroplating baths having grain sizes in the range of 11-23 nm have been investigated. The finest grain size, approximately 11 nm, was obtained from a coating developed from the nickel sulphate bath. The Co-Ni coatings have a mixed face centred cubic and hexagonal close-packed structures with varying surface morphologies and different porosities. A cluster-pore mixture model has been proposed by considering no contribution from pores to the hardness. As the porosity effect was taken into consideration, the calculated pore-free hardness is in agreement with the ordinary Hall- Petch relationship even when the grain size is reduced to 11 nm for the Co-Ni coatings with 77±2 at% cobalt. The present model was applied to other porous nanocrystalline coatings, and the Hall-Petch relationship was maintained.