| 1. |
- Iacopetta, B, et al.
(författare)
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Functional categories of TP53 mutation in colorectal cancer: results of an International Collaborative Study.
- 2006
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Ingår i: Annals of oncology : official journal of the European Society for Medical Oncology / ESMO. - : Elsevier BV. - 0923-7534. ; 17:5, s. 842-7
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Loss of TP53 function through gene mutation is a critical event in the development and progression of many tumour types including colorectal cancer (CRC). In vitro studies have found considerable heterogeneity amongst different TP53 mutants in terms of their transactivating abilities. The aim of this work was to evaluate whether TP53 mutations classified as functionally inactive (< or=20% of wildtype transactivation ability) had different prognostic and predictive values in CRC compared with mutations that retained significant activity. MATERIALS AND METHODS: TP53 mutations within a large, international database of CRC (n = 3583) were classified according to functional status for transactivation. RESULTS: Inactive TP53 mutations were found in 29% of all CRCs and were more frequent in rectal (32%) than proximal colon (22%) tumours (P < 0.001). Higher frequencies of inactive TP53 mutations were also seen in advanced stage tumours (P = 0.0003) and in tumours with the poor prognostic features of vascular (P = 0.006) and lymphatic invasion (P = 0.002). Inactive TP53 mutations were associated with significantly worse outcome only in patients with Dukes' stage D tumours (RR = 1.71, 95%CI 1.25-2.33, P < 0.001). Patients with Dukes' C stage tumours appeared to gain a survival benefit from 5-fluorouracil-based chemotherapy regardless of TP53 functional status for transactivation ability. CONCLUSIONS: Mutations that inactivate the transactivational ability of TP53 are more frequent in advanced CRC and are associated with worse prognosis in this stage of disease.
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| 2. |
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| 3. |
- Carlsson, Ella, et al.
(författare)
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Mass composition of the escaping plasma at Mars
- 2006
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Ingår i: Icarus. - : Elsevier BV. - 0019-1035 .- 1090-2643. ; 182:2, s. 320-328
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Tidskriftsartikel (refereegranskat)abstract
- Data from the Ion Mass Analyzer (IMA) sensor of the ASPERA-3 instrument suite on Mars Express have been analyzed to determine the mass composition of the escaping ion species at Mars. We have examined 77 different ion-beam events and we present the results in terms of flux ratios between the following ion species: CO2+/O+ and O-2(+)/O+. The following ratios averaged over all events and energies were identified: CO2+/O+ = 0.2 and O-2(+)/O+ = 0.9. The values measured are significantly higher, by a factor of 10 for O-2(+)/O+, than a contemporary modeled ratio for the maximum fluxes which the martian ionosphere can supply. The most abundant ion species was found to be O+, followed by O-2(+) and CO2+. We estimate the loss of CO2+ to be 4.0 x 10(24) s(-1) (0.29 kg s(-1)) by using the previous measurements of Phobos-2 in our calculations. The dependence of the ion ratios in relation to their energy ranges we studied, 0.3-3.0 keV, indicated that no clear correlation was found.
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| 4. |
- Hsieh, Y S Y, et al.
(författare)
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Structural diversity, functions and biosynthesis of xyloglucans in angiosperm cell walls.
- 2009
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Ingår i: New Zealand Journal of Forestry Science. - : Scion. ; 39, s. 187-196
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Tidskriftsartikel (refereegranskat)abstract
- Xyloglucans occur in the primary cell walls of all angiosperms where they are thought to have a structural role and be involved in the control of cell expansion. They also occur in the thick, non-lignified secondary cell walls of seeds of some species ofeudicotyledons where they serve as reserve carbohydrates. The xyloglucans in the primary cell walls of most eudicotyledons have similar structures with side chains containing galactose and fucose. However, in one group of eudicotyledons, the asterids, there is considerable structural variability in the xyloglucans, with many containing arabinose. There is also variability in the xyloglucans of the monocotyledons, with those in the family Poaceae containing no fucose and only small proportions ofgalactose. The xyloglucans of the thick, secondary cell walls of seeds are similar to those in the primary walls of most eudicotyledons, but contain no fucose. The functional significance of these structural variations is unknown. A number of genes and their encoded glycosyltransferases have been identified as being involved in the biosynthesis of the xyloglucans of the model eudicotyledon Arabidopsis thaliana.
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| 5. |
- Andersson, Thorvald, 1946, et al.
(författare)
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Macroscopic defects in GaN/AlN multiple quantum well structures grown by MBE on GaN templates
- 2009
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Ingår i: Microelectronics Journal. - : Elsevier BV. - 0026-2692. ; 40:2, s. 360-362
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Tidskriftsartikel (refereegranskat)abstract
- We have used MBE to grow in AlN/GaN superlattices, with different number of periods, on 2.5-mu m-thick MOVPE-GaN templates to study the development of defects such as surface deformation due to strain. After growth the samples were studied by atomic force microscopy (AFM), transmission electron microscopy (TEM), XRD and Fourier transform infrared spectroscopy (FT-IR). The strain increased with the number of quantum wells (QWs) and eventually caused defects such as microcracks visible by optical microscopy at four or more QW periods. High-resolution TEM images showed shallow recessions on the surface (surface deformation) indicating formation of microcracks in the MQW region. The measured intersubband (IS) absorption linewidth from a four period structure was 97 meV, which is comparable with the spectrum from a 10 period structure at an absorption energy of similar to 700 meV. This indicates that the interface quality of the MQW is not substantially affected by the presence of cracks.
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