| 1. |
- Kunnus, K., et al.
(författare)
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Identification of the dominant photochemical pathways and mechanistic insights to the ultrafast ligand exchange of Fe(CO)(5) to Fe(CO)(4)EtOH
- 2016
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Ingår i: Structural Dynamics. - : AIP Publishing. - 2329-7778. ; 3:4
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Tidskriftsartikel (refereegranskat)abstract
- We utilized femtosecond time-resolved resonant inelastic X-ray scattering and ab initio theory to study the transient electronic structure and the photoinduced molecular dynamics of a model metal carbonyl photocatalyst Fe(CO)(5) in ethanol solution. We propose mechanistic explanation for the parallel ultrafast intra-molecular spin crossover and ligation of the Fe(CO)(4) which are observed following a charge transfer photoexcitation of Fe(CO)(5) as reported in our previous study [ Wernet et al., Nature 520, 78 (2015)]. We find that branching of the reaction pathway likely happens in the (1)A(1) state of Fe(CO)(4). A sub-picosecond time constant of the spin crossover from B-1(2) to B-3(2) is rationalized by the proposed B-1(2) -> (1)A(1) -> B-3(2) mechanism. Ultrafast ligation of the B-1(2) Fe(CO)(4) state is significantly faster than the spin-forbidden and diffusion limited ligation process occurring from the B-3(2) Fe(CO)(4) ground state that has been observed in the previous studies. We propose that the ultrafast ligation occurs via B-1(2) -> (1)A(1) -> (1)A'Fe(CO)(4)EtOH pathway and the time scale of the (1)A(1) Fe(CO)(4) state ligation is governed by the solute-solvent collision frequency. Our study emphasizes the importance of understanding the interaction of molecular excited states with the surrounding environment to explain the relaxation pathways of photoexcited metal carbonyls in solution.
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| 2. |
- Leitner, T., et al.
(författare)
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Time-resolved electron spectroscopy for chemical analysis of photodissociation : Photoelectron spectra of Fe(CO)(5), Fe(CO)(4), and Fe(CO)(3)
- 2018
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 149:4
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Tidskriftsartikel (refereegranskat)abstract
- The prototypical photoinduced dissociation of Fe(CO)(5) in the gas phase is used to test time-resolved x-ray photoelectron spectroscopy for studying photochemical reactions. Upon one-photon excitation at 266 nm, Fe(CO)(5) successively dissociates to Fe(CO)(4) and Fe(CO)(3) along a pathway where both fragments retain the singlet multiplicity of Fe(CO)(5). The x-ray free-electron laser FLASH is used to probe the reaction intermediates Fe(CO)(4) and Fe(CO)(3) with time-resolved valence and core-level photoelectron spectroscopy, and experimental results are interpreted with ab initio quantum chemical calculations. Changes in the valence photoelectron spectra are shown to reflect changes in the valenceorbital interactions upon Fe-CO dissociation, thereby validating fundamental theoretical concepts in Fe-CO bonding. Chemical shifts of CO 3 sigma inner-valence and Fe 3 sigma core-level binding energies are shown to correlate with changes in the coordination number of the Fe center. We interpret this with coordination-dependent charge localization and core-hole screening based on calculated changes in electron densities upon core-hole creation in the final ionic states. This extends the established capabilities of steady-state electron spectroscopy for chemical analysis to time-resolved investigations. It could also serve as a benchmark for howcharge and spin density changes in molecular dissociation and excited-state dynamics are expressed in valence and core-level photoelectron spectroscopy. Published by AIP Publishing.
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| 3. |
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| 4. |
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| 5. |
- Wernet, Ph., et al.
(författare)
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Communication : Direct evidence for sequential dissociation of gas-phase Fe(CO)(5) via a singlet pathway upon excitation at 266 nm
- 2017
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 146:21
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Tidskriftsartikel (refereegranskat)abstract
- We prove the hitherto hypothesized sequential dissociation of Fe(CO)(5) in the gas phase upon photoexcitation at 266 nm via a singlet pathway with time-resolved valence and core-level photoelectron spectroscopy with an x-ray free-electron laser. Valence photoelectron spectra are used to identify free CO molecules and to determine the time constants of stepwise dissociation to Fe(CO)(4) within the temporal resolution of the experiment and further to Fe(CO)(3) within 3 ps. Fe 3p core-level photoelectron spectra directly reflect the singlet spin state of the Fe center in Fe(CO)(5), Fe(CO)(4), and Fe(CO)(3) showing that the dissociation exclusively occurs along a singlet pathway without triplet-state contribution. Our results are important for assessing intra- and intermolecular relaxation processes in the photodissociation dynamics of the prototypical Fe(CO)(5) complex in the gas phase and in solution, and they establish time-resolved core-level photoelectron spectroscopy as a powerful tool for determining the multiplicity of transition metals in photochemical reactions of coordination complexes.
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| 6. |
- Anand, Aseem, et al.
(författare)
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Automated Bone Scan Index as a quantitative imaging biomarker in metastatic castration-resistant prostate cancer patients being treated with enzalutamide
- 2016
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Ingår i: EJNMMI Research. - : Springer. - 2191-219X. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Having performed analytical validation studies, we are now assessing the clinical utility of the upgraded automated Bone Scan Index (BSI) in metastatic castration-resistant prostate cancer (mCRPC). In the present study, we retrospectively evaluated the discriminatory strength of the automated BSI in predicting overall survival (OS) in mCRPC patients being treated with enzalutamide.METHODS: Retrospectively, we included patients who received enzalutamide as a clinically approved therapy for mCRPC and had undergone bone scan prior to starting therapy. Automated BSI, prostate-specific antigen (PSA), hemoglobin (HgB), and alkaline phosphatase (ALP) were obtained at baseline. Change in automated BSI and PSA were obtained from patients who have had bone scan at week 12 of treatment follow-up. Automated BSI was obtained using the analytically validated EXINI Bone(BSI) version 2. Kendall's tau (τ) was used to assess the correlation of BSI with other blood-based biomarkers. Concordance index (C-index) was used to evaluate the discriminating strength of automated BSI in predicting OS.RESULTS: Eighty mCRPC patients with baseline bone scans were included in the study. There was a weak correlation of automated BSI with PSA (τ = 0.30), with HgB (τ = -0.17), and with ALP (τ = 0.56). At baseline, the automated BSI was observed to be predictive of OS (C-index 0.72, standard error (SE) 0.03). Adding automated BSI to the blood-based model significantly improved the C-index from 0.67 to 0.72, p = 0.017. Treatment follow-up bone scans were available from 62 patients. Both change in BSI and percent change in PSA were predictive of OS. However, the combined predictive model of percent PSA change and change in automated BSI (C-index 0.77) was significantly higher than that of percent PSA change alone (C-index 0.73), p = 0.041.CONCLUSIONS: The upgraded and analytically validated automated BSI was found to be a strong predictor of OS in mCRPC patients. Additionally, the change in automated BSI demonstrated an additive clinical value to the change in PSA in mCRPC patients being treated with enzalutamide.
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| 7. |
- Au, A. E., et al.
(författare)
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Altered B-lymphopoiesis in mice with deregulated thrombopoietin signaling
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Thrombopoietin (TPO) is the master cytokine regulator of megakaryopoiesis. In addition to regulation of megakaryocyte and platelet number, TPO is important for maintaining proper hematopoietic stem cell (HSC) function. It was previously shown that a number of lymphoid genes were upregulated in HSCs from Tpo(-/-)mice. We investigated if absent or enhanced TPO signaling would influence normal B-lymphopoiesis. Absent TPO signaling in Mpl(-/-)mice led to enrichment of a common lymphoid progenitor (CLP) signature in multipotential lineage-negative Sca-1(+)c-Kit(+) (LSK) cells and an increase in CLP formation. Moreover, Mpl(-/-)mice exhibited increased numbers of PreB2 and immature B-cells in bone marrow and spleen, with an increased proportion of B-lymphoid cells in the G1 phase of the cell cycle. Conversely, elevated TPO signaling in Tpo(Tg) mice was associated with reduced B-lymphopoiesis. Although at steady state, peripheral blood lymphocyte counts were normal in both models, Mpl(-/-)E mu-myc mice showed an enhanced preneoplastic phase with increased numbers of splenic PreB2 and immature B-cells, a reduced quiescent fraction, and augmented blood lymphocyte counts. Thus, although Mpl is not expressed on lymphoid cells, TPO signaling may indirectly influence B-lymphopoiesis and the preneoplastic state in Myc-driven B-cell lymphomagenesis by lineage priming in multipotential progenitor cells.
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| 8. |
- Bratt, Ola, 1963, et al.
(författare)
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The Value of an Extensive Transrectal Repeat Biopsy with Anterior Sampling in Men on Active Surveillance for Low-risk Prostate Cancer: A Comparison from the Randomised Study of Active Monitoring in Sweden (SAMS)
- 2019
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Ingår i: European Urology. - : Elsevier BV. - 0302-2838 .- 1873-7560. ; 76:4, s. 461-466
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Tidskriftsartikel (refereegranskat)abstract
- Background: A systematic repeat biopsy is recommended for men starting on active surveillance for prostate cancer, but the optimal number and distribution of cores are unknown. Objective: To evaluate an extensive repeat transrectal biopsy with anterior sampling in men starting on active surveillance. Design, setting, and participants: Randomised multicentre trial. From 2012 to 2016, 340 Swedish men, aged 40-75 yr, with recently diagnosed low-volume Gleason grade group 1 prostate cancer were included. Intervention: Either an extensive transrectal biopsy with anterior sampling (median 19 cores) or a standard transrectal biopsy (median 12 cores). Outcome measurements and statistical analysis: Primary outcome measure: Gleason grade group >= 2 cancer. Secondary outcomes: Cancer in anteriorly directed biopsy cores and postbiopsy infection. Nonparametric statistical tests were applied. Results and limitations: Gleason grade group >= 2 cancer was detected in 16% of 156 men who had an extensive biopsy and in 10% of 164 men who had a standard biopsy, a 5.7% difference (95% confidence interval [CI]-0.2% to 13%, p = 0.09). There was a strong linear association between prostate-specific antigen (PSA) density and cancer in the anteriorly directed biopsy cores. The odds ratios for cancer in the anteriorly directed cores were for any cancer 2.2 (95% CI 1.3-3.9, p = 0.004) and for Gleason grade group >= 2 cancer 2.3 (95% CI 1.2-4.4, p = 0.015) per 0.1-ng/ml/cm(3) increments. Postbiopsy infections were equally common in the two groups. A limitation is that magnetic resonance imaging was not used. Conclusions: The trial did not support general use of the extensive transrectal repeat biopsy template, but cancer in the anteriorly directed cores was common, particularly in men with high PSA density. The higher the PSA density, the stronger the reason to include anterior sampling at a systematic repeat biopsy. Patient summary: This trial compared two different templates for transrectal prostate biopsy in men starting on active surveillance for low-risk prostate cancer. Cancer was often found in the front part of the prostate, which is not sampled on a standard prostate biopsy. (C) 2019 European Association of Urology. Published by Elsevier B.V. All rights reserved.
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| 9. |
- Ebenhag, Sven-Christian, 1976, et al.
(författare)
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Two-way coherent frequency transfer in a commercial DWDM communication network in Sweden
- 2015
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Ingår i: 2015 Joint Conference of the IEEE International Frequency Control Symposium and the European Frequency and Time Forum, FCS 2015 - Proceedings. - 1075-6787. - 9781479988662 ; , s. 276-279
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Konferensbidrag (refereegranskat)abstract
- An experimental fiber link is being established between SP Technical Research Institute of Sweden in Boras and Chalmers University of Gothenburg in Sweden. The one way fiber length is about 60 km and implemented in SUNET (Swedish University Network). The aim of the project is to evaluate the signal quality when sending a stable optical frequency utilizing a wavelength in a DWDM (Dense Wavelength Division Multiplexing) system fiber pair. The experiment uses a channel in the DWDM with the wavelength of 1542.14 nm. This wavelength is within the C band and is therefore compatible with common Erbium doped amplifiers in this network. Another aim of the system is to be ultra-stable which corresponds to a stability of 1×10-13 for τ = 1 s as well as providing the ability to distribute monitored ultra-stable frequency with a future traceability to UTC (SP) (National realization of Universal Time Coordinated within Sweden) to multiple users within the network. Measurements of an optical frequency transfer using a fiber-link based on unidirectional light signals in parallel fibers have shown promising results in a free-running setup and in a lab environment. The fractional frequency stability, analyzed as the Overlapping Allan deviation, is approximately 3×10-13 at τ = 10 s and almost 1×10-14 at 105 s.
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| 10. |
- Flejmer, Anna M., 1971-, et al.
(författare)
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Impact of physiological breathing motion for breast cancer radiotherapy with proton beam scanning - An in silico study
- 2017
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Ingår i: Physica medica (Testo stampato). - : Elsevier BV. - 1120-1797 .- 1724-191X. ; 39, s. 88-94
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Tidskriftsartikel (refereegranskat)abstract
- This study investigates the impact of breathing motion on proton breast treatment plans. Twelve patients with CT datasets acquired during breath-hold-at-inhalation (BHI), breath-hold-at-exhalation (BHE) and in free-breathing (FB) were included in the study. Proton plans were designed for the left breast for BHI and subsequently recalculated for BHE or designed for FB and recalculated for the extreme breath-hold phases. The plans were compared from the point of view of their target coverage and doses to organs-at-risk. The median amplitude of breathing motion determined from the positions of the sternum was 4.7 mm (range 0.5-14.6 mm). Breathing motion led to a degradation of the dose coverage of the target (heterogeneity index increased from 4-7% to 8-11%), but the degraded values of the dosimetric parameters of interest fulfilled the clinical criteria for plan acceptance. Exhalation decreased the lung burden [average dose 3.1-4.5 Gy (RBE)], while inhalation increased it [average dose 5.8-6.8 Gy (RBE)]. The individual values depended on the field arrangement. Smaller differences were seen for the heart [average dose 0.1-0.2 Gy (RBE)] and the LAD [1.9-4.6 Gy (RBE)]. Weak correlations were generally found between changes in dosimetric parameters and respiratory motion. The differences between dosimetric parameters for various breathing phases were small and their expected clinical impact is consequently quite small. The results indicated that the dosimetric parameters of the plans corresponding to the extreme breathing phases are little affected by breathing motion, thus suggesting that this motion might have little impact for the chosen beam orientations with scanned proton beams.
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