| 1. |
- Han, Y., et al.
(författare)
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X-Radiation Induces Non-Small-Cell Lung Cancer Apoptosis by Upregulation of Axin Expression
- 2009
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Ingår i: International Journal of Radiation Oncology Biology Physics. - : Elsevier BV. - 0360-3016. ; 75:2, s. 518-526
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Axis inhibition (Axin) is an important negative regulator of the Wnt pathway. This study investigated the relationship between Axin expression and sensitivity to X-rays in non-small-cell lung cancer (NSCLC) to find a useful indicator of radiosensitivity. Methods and Materials: Tissue from NSCLC patients, A549 cells, and BE1 cells expressing Axin were exposed to 1-Gy of X-radiation. Axin and p53 expression levels were detected by immunohistochemistry and reverse transcription-PCR. Apoptosis was determined by TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling) assay and FACS (fluorescence-activate cell sorter) analysis. Caspase-3 activity was determined by Western blotting. Phospho-JNK expression was determined by immunofluorescence. Results: The expression of Axin was significantly lower in NSCLC tissues than in normal lung tissues (p less than 0.05). Axin expression correlates with differentiation, TNM staging, and lymph node metastasis of NSCLC (p less than 0.05). Its expression negatively correlates with the expression of p53(mt) (p=0.000) and positively correlates with apoptosis (p=0.002). The prognosis of patients with high expression of Axin was better than those with low expression. X-radiation increases Axin expression in NSCLC tissue, and caspase-3 is significantly higher in samples in which Axin is increased (p less than 0.05). Both X-radiation and Axin induce apoptosis of A549 and BE1 cells; however, the combination of the two enhances the apoptotic effect (p less than 0.05). In A549 cells, inhibition of p53 blocks Axin-induced apoptosis, whereas in BE1 cells, the JNK pathway is required. Conclusions: Axin induces the p53 apoptotic pathway in cells where this pathway is intact; however, in cells expressing p53(mt), Axin induces apoptosis via the JNK pathway. Elevated Axin expression following X-ray exposure is a reliable indicator for determining the radiosensitivity of NSCLC.
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| 2. |
- Deng, R., et al.
(författare)
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Surface morphology, structural and optical properties of polar and non-polar ZnO thin films : A comparative study
- 2009
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Ingår i: Journal of Crystal Growth. - : Elsevier BV. - 0022-0248. ; 311:19, s. 4398-4401
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Tidskriftsartikel (refereegranskat)abstract
- The polar and non-polar ZnO thin films were fabricated on cubic MgO (1 1 1) and (0 0 1) substrates by plasma-assisted molecular beam epitaxy. Based on X-ray diffraction analysis, the ZnO thin films grown on MgO (1 1 1) and (1 0 0) substrates exhibit the polar c-plane and non-polar m-plane orientation, respectively. Comparing with the c-plane ZnO film, the non-polar m-plane ZnO film shows cross-hatched stripes-like morphology, lower surface roughness and slower growth rate. However, low-temperature photoluminescence measurement indicates the m-plane ZnO film has a stronger 3.31 eV emission, which is considered to be related to stacking faults. Meanwhile, stronger band tails absorbance of the m-plane ZnO film is observed in optical absorption spectrum.
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| 3. |
- Schaap, M., et al.
(författare)
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Standardized evaluation methodology and reference database for evaluating coronary artery centerline extraction algorithms
- 2009
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Ingår i: Medical Image Analysis. - : Elsevier. - 1361-8415 .- 1361-8423. ; 13:5, s. 701-714
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Tidskriftsartikel (refereegranskat)abstract
- Efficiently obtaining a reliable coronary artery centerline from computed tomography angiography data is relevant in clinical practice. Whereas numerous methods have been presented for this purpose, up to now no standardized evaluation methodology has been published to reliably evaluate and compare the performance of the existing or newly developed coronary artery centerline extraction algorithms. This paper describes a standardized evaluation methodology and reference database for the quantitative evaluation of coronary artery centerline extraction algorithms. The contribution of this work is fourfold: (1) a method is described to create a consensus centerline with multiple observers, (2) well-defined measures are presented for the evaluation of coronary artery centerline extraction algorithms, (3) a database containing 32 cardiac CTA datasets with corresponding reference standard is described and made available, and (4) 13 coronary artery centerline extraction algorithms, implemented by different research groups, are quantitatively evaluated and compared. The presented evaluation framework is made available to the medical imaging community for benchmarking existing or newly developed coronary centerline extraction algorithms.
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| 4. |
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| 5. |
- Thinh, N.Q., et al.
(författare)
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Properties of Ga-interstitial defects in AlxGa 1-xNyP1-y
- 2005
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 71:12
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Tidskriftsartikel (refereegranskat)abstract
- A detailed account of the experimental results from optically detected magnetic resonance (ODMR) studies of grown-in defects in (Al)GaNP alloys, prepared by molecular beam epitaxy, is presented. The experimental procedure and an in-depth analysis by a spin Hamiltonian lead to the identification of two Gai defects (Gai-A and Gai-B). New information on the electronic properties of these defects and the recombination processes leading to the observation of the ODMR signals will be provided. These defects are deep-level defects. In conditions when the defect is directly involved in radiative recombination of the near-infrared photoluminescence band, the energy level of the Gai-B defect was estimated to be deeper than ~1.2 eV from either the conduction or valence band edge. In most cases, however, these defects act as nonradiative recombination centers, reducing the efficiency of light emission from the alloys. They can thus undermine the performance of potential photonic devices. High thermal stability is observed for these defects. ©2005 The American Physical Society.
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| 6. |
- Chen, X. Y., et al.
(författare)
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Application of weak ferromagnetic BiFeO3 films as the photoelectrode material under visible-light irradiation
- 2007
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Ingår i: Applied Physics Letters. - : American Institute of Physics (AIP). - 0003-6951 .- 1077-3118. ; 91:2, s. 022114-
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Tidskriftsartikel (refereegranskat)abstract
- BiFeO3 films prepared by pulsed laser deposition on Pt/TiO2/SiO2/Si substrates were studied as photoelectrode for water splitting. Under visible-light irradiation, the photocurrent intensity of the polycrystalline BiFeO3 film was found to double that of the amorphous one in a three-electrode cell. The incident photon to current conversion efficiency for the polycrystalline BiFeO3 electrode was approximately 16% at 350 nm and 7% at 530 nm at 1.5 V (versus saturated calomel electrode). The ferromagnetism of the amorphous BiFeO3 film was an order of magnitude weaker than that of the polycrystalline one, supporting the "size effect" explanation for magnetic origin. (C) 2007 American Institute of Physics.
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| 7. |
- Okamoto, H., et al.
(författare)
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Mutation analysis of the human 5-lipoxygenase C-terminus : Support for a stabilizing C-terminal loop
- 2005
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Ingår i: Biochimica et Biophysica Acta - Proteins and Proteomics. - : Elsevier BV. - 1570-9639 .- 1878-1454. ; 1749:1, s. 123-131
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Tidskriftsartikel (refereegranskat)abstract
- Lipoxygenases contain prosthetic iron, in human 5-lipoxygenase (5LO) the C-terminal isoleucine carboxylate constitutes one of five identified ligands. ATP is one of several factors determining 5LO activity. We compared properties of a series of 5LO C-terminal deletion mutants (one to six amino acid residues deleted). All mutants were enzymatically inactive (expected due to loss of iron), but expression yield (in E. coli) and affinity to ATP-agarose was markedly different. Deletion of up to four C-terminal residues was compatible with good expression and retained affinity to the ATP-column, as for wild-type 5LO. However when also the fifth residue was deleted (Asn-669) expression yield decreased and the affinity to ATP was markedly diminished. This was interpreted as a result of deranged structure and stability, due to loss of a hydrogen bond between Asn-669 and His-399. Mutagenesis of these residues supported this conclusion. In the structure of soybean lipoxygenase-1, a C-terminal loop was pointed out as important for correct orientation of the C-terminus. Accordingly, a hydrogen bond appears to stabilize such a C-terminal loop also in 5LO. © 2005 Elsevier B.V. All rights reserved.
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