| 41. |
- Abrahamsson, M. L. A., et al.
(författare)
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Ruthenium-manganese complexes for artificial photosynthesis : Factors controlling intramolecular electron transfer and excited-state quenching reactions
- 2002
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Ingår i: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 41:6, s. 1534-1544
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Tidskriftsartikel (refereegranskat)abstract
- Continuing our work toward a system mimicking the electron-transfer steps from manganese to P-680(+) in photosystem II (PS II), we report a series of ruthenium(II)-manganese(II) complexes that display intramolecular electron transfer from manganese(II) to photooxidized ruthenium(III). The electron-transfer rate constant (k(ET)) values span a large range, 1 X 10(5)-2 x 10(7) s(-1), and we have investigated different factors that are responsible for the variation. The reorganization energies determined experimentally (lambda = 1.5-2.0 eV) are larger than expected for solvent reorganization in complexes of similar size in polar solvents (typically lambda approximate to 1.0 eV). This result indicates that the inner reorganization energy is relatively large and, consequently, that at moderate driving force values manganese complexes are not fast donors. Both the type of manganese ligand and the link between the two metals are shown to be of great importance to the electron-transfer rate. In contrast, we show that the quenching of the excited state of the ruthenium(II) moiety by manganese(II) in this series of complexes mainly depends on the distance between the metals. However, by synthetically modifying the sensitizer so that the lowest metal-to-ligand charge transfer state was localized on the nonbridging ruthenium(II) ligands, we could reduce the quenching rate constant in one complex by a factor of 700 without changing the bridging ligand. Still, the manganese(II)-ruthenium (III) electrontransfer rate constant was not reduced. Consequently, the modification resulted in a complex with very favorable properties.
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| 42. |
- Ackesjö, Helena, 1973-
(författare)
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Barns övergångar till och från förskoleklass : Gränser, identiteter och (dis-)kontinuiteter
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The overall aim of this study is to gain knowledge of how the transitions to and from preschool class are described and understood by children. Previous research has indicated that transitions between different school forms can be seen as both problematic and threatening. Transitions should be facilitated and "smooth", something that indicates that continuity is important. Of interest for this study is to gain knowledge of children's perspective of continuities: which continuities and discontinuities children express intransitions.Transitions are theoretically considered as social processes that are constructed, shared and reconstructed together with others. In these processes, children mark and construct borders through speech and action. Their border markings (for example, expression of differences and/or similarities between different communities and between different school forms) also become part of a child's identity constructions.The thesis is based upon the research described in three articles. The empirical data underlying these studies was constructed in a longitudinal ethnographic inspired field work where children have been observed in two transitions between three different school forms: preschool, preschool class and compulsory school.Results suggest that from children’s perspectives the transitions between different school forms contain challenges, opportunities, limitations, changes and preservation. However, the transitions also involve expressions concerning security, risk-taking and include visual markings between the different school forms.One of the conclusions that can be drawn from this work is that it isn’t enough to turn to policy level, such as curricula or even teachers’ aims or aspirations to facilitate these transitions. The child’s perspectives need to be taken into account. Through children's narratives, we have gained knowledge about the opportunities transitions can offer, but also how transitions can be considered as threats or be difficult to interpret for children. This study has also increased our understanding of the importance of continuity as well as discontinuity to mark borders between different school forms.
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| 43. |
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| 44. |
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| 45. |
- Ahlberg, Mats Steinholtz, et al.
(författare)
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PCASTt/SPCG-17-A randomised trial of active surveillance in prostate cancer: Rationale and design
- 2019
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Ingår i: BMJ Open. - : BMJ. - 2044-6055. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Introduction Overtreatment of localised prostate cancer is substantial despite increased use of active surveillance. No randomised trials help define how to monitor patients or when to initiate treatment with curative intent. Methods and analysis A randomised, multicentre, intervention trial designed to evaluate the safety of an MRI-based active surveillance protocol, with standardised triggers for repeated biopsies and radical treatment. The aim is to reduce overtreatment of prostate cancer. 2000 men will be randomly allocated to either surveillance according to current practice or to standardised triggers at centres in Sweden, Norway, Finland and the UK. Men diagnosed in the past 12 months with prostate cancer, ≤T2a, prostate-specific antigen (PSA) <15 ng/mL, PSA density ≤0.2 ng/mL/cc, any International Society of Urological Pathology (ISUP) grade 1 are eligible. Men with ISUP grade 2 in <30% of cores on systematic biopsy and <10 mm cancer in one core on systematic or targeted biopsy are also eligible. Men diagnosed on systematic biopsy should have an MRI and targeted biopsies against Prostate Imaging and Reporting Data System V.2 3-5 lesions before inclusion. Identical follow-up in the two study arms: biannual PSA testing, yearly clinical examination and MRI every second year. In the experimental arm, standardised triggers based on MRI and PSA density elicit repeated biopsies. MRI and histopathological progression trigger radical treatment. Primary outcome measure is progression-free survival. Secondary outcome measures are cumulative incidence of metastatic disease, treatments with curative intent, pT3-4 at radical prostatectomy, switch to watchful waiting, prostate cancer mortality and quality of life. Inclusion started in October 2016 and in October 2018; 275 patients have been enrolled. Ethics and dissemination Ethical approval was obtained in each participating country. Results for the primary and secondary outcome measures will be submitted for publication in peer-reviewed journals. Trial registration number NCT02914873.
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| 46. |
- Ahlstedt, Jonas, et al.
(författare)
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Non-invasive imaging methodologies for assessment of radiation damage to bone marrow and kidneys from peptide receptor radionuclide therapy. : -
- 2019
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Ingår i: Neuroendocrinology. - : S. Karger AG. - 1423-0194 .- 0028-3835. ; 110:1-2, s. 130-138
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Tidskriftsartikel (refereegranskat)abstract
- Background/Aims: Peptide receptor radionuclide therapy (PRRT) is becoming clinical routine for management of neuroendocrine tumours. The number of PRRT cycles is correlated with treatment effect but theoretically limited by off-target radiation damage to kidneys and bone marrow. New imaging biomarkers for assessment of PRRT tissue damage would enable evaluation of novel renal and bone marrow protective agents, as well as personalised PRRT treatment regiments. Methods: Mice treated with [177Lu]Lu-DOTA-TATE PRRT or vehicle were examined at baseline and following treatment with [18F]fluorothymidine (FLT) positron emission tomography (PET) and technetium-99m-mercapto-acetyl-tri-glycine ([99mTc]Tc-Mag3) single-photon emission tomography (SPECT) to assess dynamic changes in bone marrow proliferation and renal function, respectively. Results: Bone marrow proliferation as assessed by [18F]FLT was decreased 2 days after PRRT treatment, but not vehicle, compared to baseline (target-to-background ratio [TBRmax] baseline:1.69 ± 0.29 vs. TBRmax PRRT: 0.91 ± 0.02, p < 0.01). Renal function as assessed by [99mTc]Tc-Mag3 SPECT was similarly decreased 2 days following PRRT compared to vehicle (fractional uptake rate [FUR] vehicle: 0.030 ± 0.014 s–1 vs. FUR PRRT: 0.0051 ± 0.0028 s–1, p < 0.01). Conclusion: [18F]FLT PET and [99mTc]Tc-Mag3 SPECT are promising techniques for assessing bone marrow and renal injury from [177Lu]Lu-DOTA-TATE PRRT and may potentially improve patient management by allowing evaluation of protective interventions as well as enabling personalised PRRT treatments.
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| 47. |
- Ahmed, Istaq, 1972, et al.
(författare)
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Structural study and proton conductivity in Yb-doped BaZrO3
- 2007
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Ingår i: Solid State Ionics. - 0167-2738. ; 178:(7-10), s. 515-520
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Tidskriftsartikel (refereegranskat)abstract
- Traditional solid state sintering has been used to prepare the perovskite BaZr0.9Yb0.1O3-delta. Analysis of X-ray powder diffraction data shows that an increase of the unit cell parameter, a, was observed compared to undoped BaZrO3. Rietveld analysis of room temperature neutron powder diffraction data confirmed cubic symmetry (space group Pm-3m). Dynamic thermogravimetric analysis (TGA) indicates that the hydration process occurs below 200 degrees C. The strong O-H stretch band, 2500-3500 cm(-1), in the infrared absorbance spectrum clearly manifests the presence of protons in the hydrated material. Proton conductivity was investigated on hydrated and as-prepared samples under dry and wet atmospheres, respectively. Keywords: X-ray diffraction; neutron diffraction; Rietveld refinement; proton conductor; perovskite
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| 48. |
- Aineskog, Helena, et al.
(författare)
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Serum S100B correlates with health-related quality of life and functional outcome in patients at 1 year after aneurysmal subarachnoid haemorrhage
- 2022
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Ingår i: Acta Neurochirurgica. - : Springer Nature. - 0001-6268 .- 0942-0940. ; 164:8, s. 2209-2218
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Early, objective prognostication after aneurysmal subarachnoid haemorrhage (aSAH) is difficult. A biochemical marker would be desirable. Correlation has been found between levels of the protein S100 beta (S100B) and outcome after aSAH. Timing and clinical usefulness are under investigation.METHODS: Eighty-nine patients admitted within 48 h of aSAH were included. Modified ranking scale (mRS), EuroQoL health-related quality of life measure (EQ-5Dindex) and EuroQoL visual analogue scale (EQ-VAS) values were evaluated after 1 year. S100B was measured in blood samples collected at admission and up to day 10.RESULTS: S100B correlated significantly with EQ-5Dindex and mRS, but not EQ-VAS at 1 year after aSAH. A receiver operating characteristic analysis for peak S100B values (area under the curve 0.898, 95% confidence interval 0.828-0.968, p < 0.0001), with a cutoff of 0.4 μg/l, yielded 95.3% specificity and 68% sensitivity for predicting unfavourable outcome. Dichotomized S100B (> 0.4 μg/l vs ≤ 0.4 μg/l), age and Hunt and Hess grading scale score (HH) were associated with unfavourable mRS outcome in univariate logistic regression analysis. Dichotomized S100B was the only variable independently correlated with unfavourable mRS outcome in a multivariate logistic regression analysis.CONCLUSIONS: For the first time, S100B was shown to correlate with mRS and health-related quality of life at 1 year after aSAH. Peak S100B can be used as a prognostic factor for unfavourable outcome measured as dichotomized mRS after aSAH. A peak value cutoff of 0.4 μg/l is suggested. Ethical approval no: 2013/366-31, 4th of February 2014.
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| 49. |
- Al-Amin, Rasel A., Researcher, 1983-, et al.
(författare)
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Monitoring drug–target interactions through target engagement-mediated amplification on arrays and in situ
- 2022
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Ingår i: Nucleic Acids Research. - : Oxford University Press. - 0305-1048 .- 1362-4962. ; 50:22, s. e129-e129
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Tidskriftsartikel (refereegranskat)abstract
- Drugs are designed to bind their target proteins in physiologically relevant tissues and organs to modulate biological functions and elicit desirable clinical outcomes. Information about target engagement at cellular and subcellular resolution is therefore critical for guiding compound optimization in drug discovery, and for probing resistance mechanisms to targeted therapies in clinical samples. We describe a target engagement-mediated amplification (TEMA) technology, where oligonucleotide-conjugated drugs are used to visualize and measure target engagement in situ, amplified via rolling-circle replication of circularized oligonucleotide probes. We illustrate the TEMA technique using dasatinib and gefitinib, two kinase inhibitors with distinct selectivity profiles. In vitro binding by the dasatinib probe to arrays of displayed proteins accurately reproduced known selectivity profiles, while their differential binding to fixed adherent cells agreed with expectations from expression profiles of the cells. We also introduce a proximity ligation variant of TEMA to selectively investigate binding to specific target proteins of interest. This form of the assay serves to improve resolution of binding to on- and off-target proteins. In conclusion, TEMA has the potential to aid in drug development and clinical routine by conferring valuable insights in drug–target interactions at spatial resolution in protein arrays, cells and in tissues.
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| 50. |
- Al-Amin, Rasel A., 1983-, et al.
(författare)
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Target Engagement-Mediated Amplification for Monitoring Drug-Target Interactions in Situ
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- It is important to determine the localization of drugs or drug candidates at cellular and subcellular resolution in relevant clinical specimens. This is necessary to evaluate drug candidates from early stages of drug development to clinical evaluation of mutations potentially causing resistance to targeted therapy. We describe a technology where oligonucleotide-conjugated drug molecules are used to visualize and measure target engagement in situ via rolling-circle amplification (RCA) of circularized oligonucleotide probes (padlock probes). We established this target engagement-mediated amplification (TEMA) technique using kinase inhibitor precursor compounds, and we applied the assay to investigate target interactions by microscopy in pathology tissue sections and using flow cytometry for blood samples from patients, as well as in commercial arrays including almost half of all human proteins. In the variant proxTEMAtechnique, in situ proximity ligation assays were performed by combining drug-DNA conjugates with antibody-DNA conjugates to specifically reveal drug binding to particular on- or off-targets in pathological tissues sections. In conclusion, the TEMA methods successfully visualize drug-target interaction by experimental and clinically approved kinase inhibitors in situ and with kinases among a large collection of arrayed proteins.
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