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| 2. |
- Wu, Xuping, et al.
(författare)
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Telomerase antagonist imetelstat inhibits esophageal cancer cell growth and increases radiation-induced DNA breaks
- 2012
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Ingår i: Biochimica et Biophysica Acta. Molecular Cell Research. - : Elsevier BV. - 0167-4889 .- 1879-2596. ; 1823:12, s. 2130-2135
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Tidskriftsartikel (refereegranskat)abstract
- Telomerase is mainly active in human tumor cells, which provides an opportunity for a therapeutic window on telomerase targeting. We sought to evaluate the potential of the thio-phosphoramidate oligonucleotide inhibitor of telomerase, imetelstat, as a drug candidate for treatment of esophageal cancer. Our results showed that imetelstat inhibited telomerase activity in a dose-dependent manner in esophageal cancer cells. After only 1. week of imetelstat treatment, a reduction of colony formation ability of esophageal cancer cells was observed. Furthermore, long-term treatment with imetelstat decreased cell growth of esophageal cancer cells with different kinetics regarding telomere lengths. Short-term imetelstat treatment also increased γ-H2AX and 53BP1 foci staining in the esophageal cancer cell lines indicating a possible induction of DNA double strand breaks (DSBs). We also found that pre-treatment with imetelstat led to increased number and size of 53BP1 foci after ionizing radiation. The increase of 53BP1 foci number was especially pronounced during the first 1 h of repair whereas the increase of foci size was prominent later on. This study supports the potential of imetelstat as a therapeutic agent for the treatment of esophageal cancer.
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| 3. |
- wu, xuping, et al.
(författare)
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The effect of the telomerase antagonist Imetelstat in esophageal carcinoma
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Telomerase is mainly active in human tumor cells, which provides an opportunity for a therapeutic window on telomerase targeting. We sought to evaluate the potential of the thio-phosphoramidate oligonucleotide inhibitor of telomerase, Imetelstat, as a drug candidate for treatment of esophageal cancer. Our results showed that Imetelstat inhibited telomerase activity in a dose-dependent manner in esophageal cancer cells. After only one week of Imetelstat treatment, a reduction of colony formation ability of esophageal cancer cells was observed. Furthermore, long-term treatment with Imetelstat decreased cell growth of esophageal cancer cells with different kinetics regarding telomere lengths. Cell cycle analysis demonstrated that short-term treatment with Imetelstat resulted in increased percentage of cells in G1 phase. Short-term Imetelstat treatment also increased γ-H2AX and 53BP1 foci staining in the esophageal cancer cell lines indicating a possible induction of DNA double strand breaks (DSBs). We also found that pre-treatment with Imetelstat led to increased number and size of 53BP1 foci after ionizing radiation. The increase of 53BP1 foci number was especially pronounced during the first 1 h of repair whereas the increase of foci size was prominent later on. This study supports the potential of Imetelstat as a therapeutic agent for the treatment of esophageal cancer.
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| 4. |
- Adell, Johan, 1980, et al.
(författare)
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Thermal diffusion of Mn through GaAs overlayers on (Ga, Mn)As
- 2011
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Ingår i: Journal of Physics. - : Institute of Physics Publishing (IOPP). - 0953-8984 .- 1361-648X. ; 23:8
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Tidskriftsartikel (refereegranskat)abstract
- Thermally stimulated diffusion of Mn through thin layers of GaAs has been studied by x-ray photoemission. (Ga, Mn)As samples with 5 at% Mn were capped with 4, 6 and 8 monolayer (ML) GaAs, and Mn diffusing through the GaAs was trapped on the surface by means of amorphous As. It was found that the out-diffusion is completely suppressed for an 8 ML thick GaAs film. The short diffusion length is attributed to an electrostatic barrier formed at the (Ga, Mn)As/GaAs interface.
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| 5. |
- Agui, A., et al.
(författare)
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Direct observation of interface effects of thin AlAs(100) layers buried in GaAs
- 2000
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Ingår i: Applied Surface Science. - : Elsevier. - 0169-4332 .- 1873-5584. ; 166:1-4, s. 309-312
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Tidskriftsartikel (refereegranskat)abstract
- A study of the electronic structure of ultrathin AlAs layers buried in GaAs(100) and their interfaces is presented. Al L2,3 soft-X-ray-emission (SXE) spectra from the AlAs layers were measured. The spectra show distinct thickness-dependent features, which are reproduced using ab initio calculations.
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| 6. |
- Aryasetiawan, F., et al.
(författare)
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Calculations of Hubbard U from first-principles
- 2006
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - : The American Physical Society. - 1098-0121 .- 1550-235X. ; 74:12, s. Article number 125106-
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Tidskriftsartikel (refereegranskat)abstract
- The Hubbard U of the 3d transition metal series as well as SrVO3, YTiO3, Ce, and Gd has been estimated using a recently proposed scheme based on the random-phase approximation. The values obtained are generally in good accord with the values often used in model calculations but for some cases the estimated values are somewhat smaller than those used in the literature. We have also calculated the frequency-dependent U for some of the materials. The strong frequency dependence of U in some of the cases considered in this paper suggests that the static value of U may not be the most appropriate one to use in model calculations. We have also made comparison with the constrained local density approximation (LDA) method and found some discrepancies in a number of cases. We emphasize that our scheme and the constrained local density approximation LDA method theoretically ought to give similar results and the discrepancies may be attributed to technical difficulties in performing calculations based on currently implemented constrained LDA schemes.
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| 7. |
- Aryasetiawan, F., et al.
(författare)
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Energy loss spectra and plasmon dispersions in alkali metals : Negative plasmon dispersion in Cs
- 1994
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Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 73:12, s. 1679-1682
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Tidskriftsartikel (refereegranskat)abstract
- We present ab initio calculations of the energy loss spectra and plasmon dispersions of the alkali metals Na, K, Rb, and Cs within the random phase approximation, including band structure effects and core electrons as well as local field effects, due to inhomogeneity in the induced charge density. Band structure effects are found to cause a negative dispersion in Cs.
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| 8. |
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| 9. |
- Aryasetiawan, F., et al.
(författare)
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GW approximation with self-screening correction
- 2012
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - : American Physical Society. - 1098-0121 .- 1550-235X. ; 85:3, s. 035106-
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Tidskriftsartikel (refereegranskat)abstract
- The GW approximation takes into account electrostatic self-interaction contained in the Hartree potential through the exchange potential. However, it has been known for a long time that the approximation contains self-screening error, as is evident in the case of the hydrogen atom. When applied to the hydrogen atom, the GW approximation does not yield the exact result for the electron removal spectra because of the presence of self-screening: the hole left behind is erroneously screened by the only electron in the system that is no longer present. We present a scheme to take into account self-screening and show that the removal of self-screening is equivalent to including exchange diagrams, as far as self-screening is concerned. The scheme is tested on a model hydrogen dimer and it is shown that the scheme yields the exact result to second order in (Uο-Uι)/2t, where Uο and Uι are, respectively, the on-site and off-site Hubbard interaction parameters and t is the hopping parameter.
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| 10. |
- Aryasetiawan, F., et al.
(författare)
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GW spectral functions of Gd and NiO
- 1996
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Ingår i: Physical Review B Condensed Matter. - : American Physical Society. - 0163-1829 .- 1095-3795. ; 54:8, s. 5353-5357
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Tidskriftsartikel (refereegranskat)abstract
- The spectral functions of highly correlated systems Gd and NiO have been calculated within the GW approximation. In the case of Gd, satellites are found at the positions of the experimental main peaks. However, some quasiparticle weight remains at the local density eigenvalue but its weight is unusually small (0.3). In NiO, satellite structure is observed at around -10 eV when starting from the local density Hamiltonian. It is found, however, that the satellite intensity is reduced towards self-consistency and almost disappears. © 1996 The American Physical Society.
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