| 1. |
- Laukkanen, P., et al.
(författare)
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Ultrathin (1x2)-Sn layer on GaAs(100) and InAs(100) substrates : A catalyst for removal of amorphous surface oxides
- 2011
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 98:23, s. 231908-1-231908-3
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Tidskriftsartikel (refereegranskat)abstract
- Amorphous surface oxides of III-V semiconductors are harmful in many contexts of device development. Using low-energy electron diffraction and photoelectron spectroscopy, we demonstrate that surface oxides formed at Sn-capped GaAs(100) and InAs(100) surfaces in air are effectively removed by heating. This Sn-mediated oxide desorption procedure results in the initial well-defined Sn-stabilized (1x2) surface even for samples exposed to air for a prolonged time. Based on ab initio calculations we propose that the phenomenon is due to indirect and direct effects of Sn. The Sn-induced surface composition weakens oxygen adsorption.
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| 2. |
- Laukkanen, P., et al.
(författare)
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Core-level shifts of the c(8 x 2)-reconstructed InAs(100) and InSb(100) surfaces
- 2010
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Ingår i: Journal of Electron Spectroscopy and Related Phenomena. - : Elsevier BV. - 0368-2048 .- 1873-2526. ; 177:1, s. 52-57
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Tidskriftsartikel (refereegranskat)abstract
- We have studied In-stabilized c(8 2)-reconstructed InAs(1 0 0) and InSb(1 0 0) semiconductor surfaces, which play a key role in growing improved III-V interfaces for electronics devices, by core-level photoelectron spectroscopy and first-principles calculations. The calculated surface core-level shifts (SCLSs) for the zeta and zeta a models, which have been previously established to describe the atomic structures of the III-V(1 00)c(8 x 2) surfaces, yield hitherto not reported interpretation for the As 3d, In 4d, and Sb 4d core-level spectra of the III-V(1 00)c(8 x 2) surfaces, concerning the number and origins of SCLSs. The fitting analysis of the measured spectra with the calculated zeta and zeta a SCLS values shows that the InSb spectra are reproduced by the zeta SCLSs better than by the zeta a SCLSs. Interestingly, the zeta a fits agree better with the InAs spectra than the zeta fits do, indicating that the zeta a model describes the InAs surface better than the InSb surface. These results are in agreement with previous X-ray diffraction data. Furthermore, an introduction of the complete-screening model, which includes both the initial and final state effects, does not improve the fitting of the InSb spectra, proposing the suitability of the initial-state model for the SCLSs of the III-V(1 0 0)c(8 x 2) surfaces. The found SCLSs are discussed with the ab initio on-site charges.
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| 5. |
- Lång, P, et al.
(författare)
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Expression and secretion of the novel adipokine tartrate-resistant acid phosphatase from adipose tissues of obese and lean women
- 2011
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Ingår i: International Journal of Obesity. - : Springer Science and Business Media LLC. - 0307-0565 .- 1476-5497. ; 35:12, s. 1502-1510
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Tartrate-resistant acid phosphatase (TRAP) expressed by adipose tissue macrophages (ATMs) induces mice obesity and human adipocyte differentiation in vitro. This study aimed to investigate whether TRAP was secreted differently from human obese versus lean adipose tissues and to identify the cellular source of adipose tissue TRAP.Design: Subcutaneous adipose tissues obtained from healthy subjects. Enzyme-linked immunosorbent assays (ELISAs) for total (5a+5b) and cleaved TRAP (5b) were used. TRAP secretion was determined in adipose tissue biopsies, and mRNA expression was studied in cell types isolated from the same.Subjects: Results of 24 lean and 24 obese women (in vitro) and 8 subjects (in vivo) were compared. The main outcome measurements were TRAP expression and secretion in vitro and in vivo.Results: In-house total TRAP ELISA showed high sensitivity and a coefficient of variance of 11%. Adipose secretion of total TRAP was linear in vitro with time and was evident in vivo. Total TRAP secretion in vitro was similar in lean and obese women expressed per unit weight of the adipose tissue but correlated positively with the number/size of adipocytes (P≤0.01) and with adipose secretion of tumor necrosis factor-α and interleukin-6 (P<0.01). TRAP 5b was not secreted from the adipose tissue. ATMs displayed highest cellular expression of TRAP mRNA in adipose tissue cells derived from lean or obese women.Conclusions: TRAP is a novel human adipokine produced by macrophages and secreted from the subcutaneous adipose tissue in vivo and in vitro. Secretion is linked to the size and number of adipocytes, as well as to concomitant secretion of inflammatory mediators, suggesting that TRAP is involved in fat accumulation and adipose inflammation. International Journal of Obesity advance online publication, 8 March 2011; doi:10.1038/ijo.2011.17.
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| 6. |
- Olsson, Malin, 1972-, et al.
(författare)
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Mitochondrial haplogroup is associated with the phenotype of familial amyloidosis with polyneuropathy in Swedish and French patients
- 2009
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Ingår i: Clinical Genetics. - : Wiley. - 0009-9163 .- 1399-0004. ; 75:2, s. 163-168
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Tidskriftsartikel (refereegranskat)abstract
- Familial amyloidotic polyneuropathy (FAP) is a monogenic disease caused by mutations in the transthyretin (TTR) gene. The phenotype of the most common TTR mutation, V30M, varies within and between populations. Oxidative stress and protein misfolding are cellular processes involved in the development of FAP. Because the mitochondria are important for both these processes, we investigated if mitochondrial haplogroups are related to age at onset of the disease in Swedish and French FAP patients. Mitochondrial haplogroup analysis was performed on 25 early-onset (below 40 years) and 29 late-onset (above 51 years) Swedish FAP patients. DNA from 249 Swedish individuals served as controls. In addition, 6 early-onset and 17 late-onset French FAP patients were examined with 25 French controls. The haplogroup distribution among late-onset Swedish and French cases was similar to that found in the general populations, whereas among early-onset cases a different haplogroup distribution was seen. The relatively rare haplogroup K was significantly more common among early-onset cases. Our findings substantiate the suggestion that a genetic component, still to be found, affecting mitochondrial function has an impact on the amyloid generating process in transthyretin amyloidosis.
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| 7. |
- Polikarpov, M., et al.
(författare)
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Towards virtual histology with X-ray grating interferometry
- 2023
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Ingår i: Scientific Reports. - 2045-2322. ; 13, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Breast cancer is the most common type of cancer worldwide. Diagnosing breast cancer relies on clinical examination, imaging and biopsy. A core-needle biopsy enables a morphological and biochemical characterization of the cancer and is considered the gold standard for breast cancer diagnosis. A histopathological examination uses high-resolution microscopes with outstanding contrast in the 2D plane, but the spatial resolution in the third, Z-direction, is reduced. In the present paper, we propose two high-resolution table-top systems for phase-contrast X-ray tomography of soft-tissue samples. The first system implements a classical Talbot–Lau interferometer and allows to perform ex-vivo imaging of human breast samples with a voxel size of 5.57 μm. The second system with a comparable voxel size relies on a Sigray MAAST X-ray source with structured anode. For the first time, we demonstrate the applicability of the latter to perform X-ray imaging of human breast specimens with ductal carcinoma in-situ. We assessed image quality of both setups and compared it to histology. We showed that both setups made it possible to target internal features of breast specimens with better resolution and contrast than previously achieved, demonstrating that grating-based phase-contrast X-ray CT could be a complementary tool for clinical histopathology.
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| 8. |
- Rodriguez-Ruiz, Alejandro, et al.
(författare)
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One-view digital breast tomosynthesis as a stand-alone modality for breast cancer detection : do we need more?
- 2018
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 28:5, s. 1938-1948
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To compare the performance of one-view digital breast tomosynthesis (1v-DBT) to that of three other protocols combining DBT and mammography (DM) for breast cancer detection. Materials and methods: Six radiologists, three experienced with 1v-DBT in screening, retrospectively reviewed 181 cases (76 malignant, 50 benign, 55 normal) in two sessions. First, they scored sequentially: 1v-DBT (medio-lateral oblique, MLO), 1v-DBT (MLO) + 1v-DM (cranio-caudal, CC) and two-view DM + DBT (2v-DM+2v-DBT). The second session involved only 2v-DM. Lesions were scored using BI-RADS® and level of suspiciousness (1–10). Sensitivity, specificity, receiver operating characteristic (ROC) and jack-knife alternative free-response ROC (JAFROC) were computed. Results: On average, 1v-DBT was non-inferior to any of the other protocols in terms of JAFROC figure-of-merit, area under ROC curve, sensitivity or specificity (p>0.391). While readers inexperienced with 1v-DBT screening improved their sensitivity when adding more images (69–79 %, p=0.019), experienced readers showed similar sensitivity (76 %) and specificity (70 %) between 1v-DBT and 2v-DM+2v-DBT (p=0.482). Subanalysis by lesion type and breast density showed no difference among modalities. Conclusion: Detection performance with 1v-DBT is not statistically inferior to 2v-DM or to 2v-DM+2v-DBT; its use as a stand-alone modality might be sufficient for readers experienced with this protocol. Key points: • One-view breast tomosynthesis is not inferior to two-view digital mammography.• One-view DBT is not inferior to 2-view DM plus 2-view DBT.• Training may lead to 1v-DBT being sufficient for screening.
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| 9. |
- Sjöstrand, Karin, et al.
(författare)
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Combining cost benefit analysis with multi criteria analysis for sustainability assessment of regional water supply policies
- 2016
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Ingår i: Society For Risk Analysis Annual Meeting 2016.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The provision of safe drinking water is of primary importance in society and a prerequisite for public health and economic development. This provision is however threatened by a variety of risks due to e.g. climate change and societal development. To manage these risks the water utilities are facing complex decision situations. Today, decisions on costly investments are being made with limited knowledge of which choices are the most sustainable. In order to achieve a safe and sustainable water supply, a regional perspective on the environmental, social and economic effects of the decisions is increasingly promoted in Sweden. There are, however, few decision support tools adapted to the regional level. Hence, this study focuses on the development of a decision support framework for assessing the sustainability of risk reducing measures by adapting Cost-Benefit Analysis (CBA) and Multi Criteria Analysis (MCA) to a regional perspective. The Gothenburg region serves as a case study for which five measures are evaluated: (1) centralization of water supply production; (2) centralization of water supply organization; (3) shift of the main raw water source (4) maximization of groundwater usage; and (5) use of additional raw water sources. All measures aim to enhance safety by reducing risks. Uncertainties concerning the net present values are analyzed using statistical simulation (Monte Carlo). The CBA results are complemented with environmental and social effects in an MCA, including criteria such as intrinsic values, equity and health. The case study results are then used to design a decision support framework that allows for non-market valuations and economic and ecological tradeoffs under uncertainty, a novelty on the regional scale. In conclusion, it is expected that the results of this study will provide decision makers with a framework that can improve their ability to make well-informed decisions and ensure the society a safe water supply for generations to come.
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