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Latest Paper:
Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
Scalable fabrication of carbon nanotube (CNT) bundles is essential to future advances in several applications. Here, we report on the development of a simple, two-step method for fabricating vertically aligned and periodically distributed CNT bundles and periodically porous CNT films at the sub-micron scale. The method involves laser interference ablation (LIA) of an iron film followed by CNT growth via iron-catalyzed chemical vapor deposition. CNT bundles with square widths ranging from 0.5 to 1.5 µm in width, and 50-200 µm in length, are grown atop the patterned catalyst over areas spanning 8 cm(2). The CNT bundles exhibit a high degree of control over square width, orientation, uniformity, and periodicity. This simple scalable method of producing well-placed and oriented CNT bundles demonstrates a high application potential for wafer-scale integration of CNT structures into various device applications, including IC interconnects, field emitters, sensors, batteries, and optoelectronics, etc.
Poult Sci. 2012 Apr ;91 (4):936-42
22399733
Feed Science Institute, College of Animal Science, Zhejiang University, No. 388, Yuhangtang Road, Hangzhou 310058, People's Republic of China.
In total, 180 Lingnan Yellow broiler breeders were used to investigate the effect of different sources of selenium (Se) on the expression of cellular glutathione peroxidase (GPx1) and cytoplasmic thioredoxin reductase (TrxR1) in the liver and kidney of broiler breeders and their offspring by quantitative real-time PCR. There were 6 replicates of 3 dietary treatments. Broiler breeders were fed corn-soy-based diets supplemented with 0.15 mg/kg of Se from sodium selenite, Se-enriched yeast (SY), or selenomethionine (SM). At the end of the feeding trial, liver and kidney mRNA levels of GPx1 and TrxR1 were determined by quantitative real-time PCR, as well as the activity of GPx1 and TrxR1 in liver and kidney of breeders and their offspring. The results showed that, compared with sodium selenite, SY or SM significantly increased (P < 0.05) the activity of TrxR1 in the liver and kidney of broiler breeders and their offspring but not the GPx1 activity. The liver GPx1 and TrxR1 mRNA levels in SY or SM groups were higher (P < 0.05) than that in the sodium selenite group. And the kidney TrxR1 mRNA levels were also significantly increased (P < 0.05) by using SY or SM, whereas there was no significant difference in the kidney GPx1 mRNA levels between the organic or inorganic sources of Se used.
Department of Obstetrics and Gynecology, The Second Affiliated Hospital of Harbin Medical University , Harbin , China.
Context: Integrin-linked kinase (ILK), a multidomain focal adhesion protein serine/threonine kinase, plays an essential role in ovarian carcinoma. There are reports that the expression and activity of ILK are increased in ovarian cancer. Objective: To test the hypothesis that ILK pathway mediates the apoptosis of ovarian carcinoma SKOV3 cell influencing the cell survival, we performed these studies. Materials and methods: We applied lentivirus transfection, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide (MTT), apoptotic proteins expressions assay, and Hoechst to study our hypothesis. Results: We found that silencing of the ILK increases the cell cytotoxic, growth inhibition, and apoptosis. Moreover, after blocking the activation of ILK with ILK shRNA, up-regulation of pro-apoptotic bax expression and down-regulation of the anti-apoptotic bcl-2 expression were found in ovarian cancer SKOV3 cell line. These were associated with an increasing cleaved caspase-3 activity and chromatin condensation of cell nuclear. Furthermore, the expressions of fas and fas ligand (fasL), belonging to the tumor necrosis factor family and controlling the cell apoptosis, were also enhanced. Conclusions: Thus, these findings indicate that both the intrinsic pathway and the extrinsic death receptor pathway are involved in the process that silencing of the ILK gene induces the apoptosis in ovarian carcinoma SKOV3 cell.
Molecules. 2012 ;17 (3):2491-517
22382527
Department of Chemistry, 3 Science Drive 3, National University of Singapore, 117543, Singapore. chmhhv@nus.edu.sg.
N-heterocyclic carbenes (NHCs) can be easily modified by introducing functional groups at the nitrogen atoms, which leads to versatile coordination chemistry as well as diverse catalytic applications of the resulting complexes. This article summarizes our contributions to the field of NHCs bearing different types of sulfur functions, i.e., thioether, sulfoxide, thiophene, and thiolato. The experimental evidence for the truly hemilabile coordination behavior of a Pd(II) thioether-NHC complex has been reported as well. In addition, complexes bearing rigid CSC-pincer ligands have been synthesized and the reasons for pincer versus pseudo-pincer formation investigated. Incorporation of the electron-rich thiolato function resulted in the isolation of structurally diverse complexes. The catalytic activities of selected complexes have been tested in Suzuki-Miyaura, Mizoroki-Heck and hydroamination reactions.
Inorg Chem. 2012 Feb 23;:
22360431
Kecai Xiong,
Feilong Jiang,
Yanli Gai,
Youfu Zhou,
Daqiang Yuan,
Kongzhao Su,
Xinyi Wang,
Maochun Hong
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences , Fuzhou, 350002, China.
A series of discrete complexes,[Ni(8)(BTC4A)(2)(μ(6)-CO(3))(2)(μ-CH(3)COO)(4)(dma)(4)]·H(2)O (1),[Ni(8)(BTC4A)(2)(μ(6)-CO(3))(2)(μ-Cl)(2)(μ-HCOO)(2)(dma)(4)]·2DMF·2CH(3)CN (2),[Ni(8)(PTC4A)(2)(μ(6)-CO(3))(2)(μ-CH(3)COO)(4)(dma)(4)]·DMF (3), and [Ni(8)(PTC4A)(2)(μ(6)-CO(3))(2)(μ-OH)(μ-HCOO)(3)(dma)(4)](4)(p-tert-butylthiacalix[4]arene = H(4)BTC4A, p-phenylthiacalix[4]arene = H(4)PTC4A, dma = dimethylamine, and DMF = N,N'-dimethylformamide), have been prepared under solvothermal conditions and structurally characterized by single-crystal X-ray diffraction analyses, powder XRD, and IR spectroscopy. These four complexes are stacked by dumbbell-like building blocks with one chairlike octanuclear-nickel(II) core, which is capped by two thiacalix[4]arene molecules and connected by two in situ generated carbonato anions and different auxiliary anions. This work implied that not only the solvent molecules but also the upper-rim groups of thiacalix[4]arenes have significant effects on the self-assembly of the dumbbell-like building blocks. The magnetic properties of complexes 1-4 were examined, indicating strong antiferromagnetic interactions between the nickel(II) ions in the temperature range of 50-300 K.
Chem Commun (Camb). 2012 Feb 22;:
22358259
Department of Chemistry, Texas A&M University, College Station, TX 77843, USA. zhou@mail.chem.tamu.edu.
Stepwise adsorption in a metal-organic framework with both micro- and meso-pores is caused by adsorbates first filling the micropores, then adsorbing along the mesopore walls, and finally filling the mesopores.
Transgenic Res. 2012 Feb 2;:
22297392
Qingjie Yang,
Dawei Yuan,
Lianxuan Shi,
Teresa Capell,
Chao Bai,
Nuan Wen,
Xiaodan Lu,
Gerhard Sandmann,
Paul Christou,
Changfu Zhu
School of Life Sciences, Northeast Normal University, Changchun, 130024, China.
The accumulation of carotenoids in plants depends critically on the spatiotemporal expression profiles of the genes encoding enzymes in the carotenogenic pathway. We cloned and characterized the Gentiana lutea zeaxanthin epoxidase (GlZEP) promoter to determine its role in the regulation of carotenogenesis, because the native gene is expressed at high levels in petals, which contain abundant chromoplasts. We transformed tomato (Solanum lycopersicum cv. Micro-Tom) plants with the gusA gene encoding the reporter enzyme β-glucuronidase (GUS) under the control of the GlZEP promoter, and investigated the reporter expression profile at the mRNA and protein levels. We detected high levels of gusA expression and GUS activity in chromoplast-containing flowers and fruits, but minimal levels in immature fruits containing green chloroplasts, in sepals, leaves, stems and roots. GlZEP-gusA expression was strictly associated with fruit development and chromoplast differentiation, suggesting an evolutionarily-conserved link between ZEP and the differentiation of organelles that store carotenoid pigments. The impact of our results on current models for the regulation of carotenogenesis in plants is discussed.
Department of Traditional Chinese Medicines, Shenyang Pharmaceutical University, Shenyang, China.
Two novel flavonoid glycosides, 6"'-dihydrophaseoylspinosin (1) and 6″,6"'-diferuloylspinosin (2), were isolated from the MeOH extract of Semen Ziziphi Spinosae, together with six known flavonoids, isovitexin-2″-O-β-(6-O-E-feruloyl)glucopyranoside (3), spinosin (4), isospinosin (5), 6"'-feruloylspinosin (6), swertisin (7), and isovitexin-2″-O-β-d-glucopyranoside (8). The structures of 1 and 2 were elucidated by spectroscopic methods including UV, IR, ESI-TOF-MS, 1D NMR, and 2D NMR experiments.
State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871, China. yuandan@pku.edu.cn
The blend morphology and vertical arrangement are critical to the performance of organic bulk-heterojunction photovoltaic devices. In the present paper, the authors proposed a new annealing method that controls the blend morphology and vertical arrangement of two materials by means of simultaneously applying external electrical field and violet irradiation on the active layer of poly(3-hexylthiophene)(P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) during annealing process. By using this annealing method, the power conversion efficiency increased by 36%, which was caused by vertical phased-separated blend of crystalline P3HT and PCBM and better charge extraction of electrodes. X-ray photoelectron spectroscopy (XPS) was measured to prove more fullerene derivatives at the organic/cathode interfaces by using this annealing method. The X-ray diffraction (XRD) analysis and UV-Vis absorption spectrum analysis also revealed more ordered polymer crystallization.
Institute of Radiation Medicine, Fudan University, No.2094 Xie-Tu Road, Shanghai 200032, China.
BACKGROUND Radiation-induced bystander effect (RIBE) has important implication in tumour radiotherapy, but the bystander signals are still not well known. METHODS The role of cytochrome-c (cyt-c) and free radicals in RIBE on human hepatoma cells HepG2 was investigated by detecting the formation of bystander micronuclei (MN) and the generation of endogenous cyt-c, inducible nitric oxide (NO) synthase (iNOS), NO, and reactive oxygen species (ROS) molecules. RESULTS When HepG2 cells were cocultured with an equal number of irradiated HepG2 cells, the yield of MN in the nonirradiated bystander cells was increased in a manner depended on radiation dose and cell coculture time, but it was diminished when the cells were treated with cyclosporin A (CsA), an inhibitor of cyt-c release. Meanwhile the CsA treatment inhibited radiation-induced NO but not ROS. Both of the depressed bystander effect and NO generation in the CsA-treated cells were reversed when 5 μM cyt-c was added in the cell coculture medium. But these exogenous cyt-c-mediated overproductions of NO and bystander MN were abolished when the cells were pretreated with s-methylisothiourea sulphate, an iNOS inhibitor. CONCLUSION Radiation-induced cyt-c has a profound role in regulating bystander response through an iNOS-triggered NO signal but not ROS in HepG2 cells.
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