| 61. |
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| 62. |
- Sun, Aijun, et al.
(author)
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Imaging Tumor Perfusion and Oxidative Metabolism in Patients With Head-and-Neck Cancer Using 1- [11C]-Acetate PET During Radiotherapy : Preliminary Results
- 2012
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In: International Journal of Radiation Oncology, Biology, Physics. - : Elsevier BV. - 0360-3016 .- 1879-355X. ; 82:2, s. 554-560
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Journal article (peer-reviewed)abstract
- Background A growing body of in vitro evidence links alterations of the intermediary metabolism in cancer to treatment outcome. This study aimed to characterize tumor oxidative metabolism and perfusion in vivo using dynamic positron emission tomography (PET) with 1- [11C]-acetate (ACE) during radiotherapy. Methods and Materials Nine patients with head-and-neck cancer were studied. Oxidative metabolic rate (kmono) and perfusion (rF) of the primary tumors were assessed by dynamic ACE-PET at baseline and after 15, 30, and 55 Gy was delivered. Tumor glucose uptake (Tglu) was evaluated with [18F]-fluorodeoxyglucose PET at baseline. Patients were grouped into complete (CR, n = 6) and partial responders (PR, n = 3) to radiotherapy. Results The 3 PR patients died within a median follow-up period of 33 months. Baseline kmono was almost twice as high in CR as in PR (p = 0.02) and Tglu was lower in CR than in PR (p = 0.04). kmono increased during radiotherapy in PR (p = 0.004) but remained unchanged in CR. There were no differences in rF between CR and PR at any dosage. kmono and rF were coupled in CR (p = 0.001), but not in PR. Conclusions This study shows that radiosensitive tumors might rely predominantly on oxidative metabolism for their bioenergetic needs. The impairment of oxidative metabolism in radioresistant tumors is potentially reversible, suggesting that therapies targeting the intermediary metabolism might improve treatment outcome.
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| 63. |
- Sun, Aijun, 1973-
(author)
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Radiolabeled acetate PET in oncology imaging : studies on head and neck cancer, prostate cancer and normal distribution
- 2010
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Doctoral thesis (other academic/artistic)abstract
- The use of positron emission tomography (PET) for imaging in oncology has grown rapidly in recent years. 2-[18F]-fluorodeoxyglucose (FDG) is the most common tracer of PET, although drawbacks exist. Radiolabeled 1-[11C]-acetate (C-AC) is a simple probe for evaluation of perfusion, anabolism (lipogenesis) and catabolism (oxidative metabolism) in all living tissues. This study explored the potential of AC PET in head and neck cancer, benign and malignant lymph nodes in prostate cancer and normal distribution. In head and neck cancer, C-AC PET detected more primaries and lymph node metastases than FDG PET. The mean primary tumor volumes delineated by C-AC was 51% larger than that of FDG before radiotherapy (RT). Both FDG and C-AC PET tumor volumes must be carefully validated before used in clinical routine. Baseline tumor clearance rate (kmono) was higher in complete responders (CR) than that in partial responders (PR). kmono tended to correlate inversely with FDG SUV at baseline. Radiosensitive tumors might rely predominantly on oxidative metabolism for their biogenetic needs. kmono increased in PR during RT. The potential reversibility of impaired kmono in radioresistant tumors imply that treatment targeting the intermediary metabolism might improve the outcome. Tumor relative perfusion index (rF) and kmono were coupled in CR throughout the RT, but not in PR. Dynamic C-AC PET provides a new non-invasive method to simultaneously evaluate the tumor oxidative metabolism and perfusion which link the RT response in patients by a single tracer injection. In prostate cancer, elevated C-AC accumulation is common in benign inguinal lymph nodes, probably due to increased lipogenesis rather than lymphatic drainage. CT Hounsfield unit of benign nodes was lower than that of metastases, suggesting that density measurement using CT might improve the specificity of nodal staging of prostate cancer. A novel tracer 2-[18F]-fluoroacetate (F-AC) was synthesized and used for dynamic PET-CT imaging in animals. Compared with C-AC PET-CT, F-AC showed prolonged blood retention, no detectable trapping in myocardium and salivary glands, rapid excretion from liver to bile and urine and de-fluorination resulting in intensive skeletal activity. F-AC does not mimic the normal physiologic path of C-AC and appears to be of little use for assessment of perfusion, intermediary metabolism or lipogenesis.
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| 64. |
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| 65. |
- Söderbaum, Fredrik, 1968, et al.
(author)
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Introduction: The End of the Development-Security Nexus?
- 2012
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In: Development Dialogue. - 0345-2328. ; 2012:No 58, s. 7-20
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Journal article (other academic/artistic)abstract
- Thinking and policy on ‘development’ and ‘security’ have undergone paradigmatic shifts in recent decades. The well-known merger of development and security into a ‘development-security nexus’ is now shifting towards an increasingly institutionalised securitisation. Security is everywhere, and development is security. A new discourse and practice is arising as the meaning of these concepts shift and the referents and objects of development and security are changing. Gradually we are moving beyond the development-security nexus into the reign of continuous global disaster management. These new articulations of the development-security nexus and global disaster management have served to legitimise a more radical interventionist agenda – first and foremost carried out by the West in the Global South. With thought-provoking contributions by leading authorities in this burgeoning field, this volume makes sense of the aforementioned paradigmatic shift. The articles explore the rationale and forces behind the institutionalisation of interventionism and intrusive disaster management as well as the consequences thereof in a number of policy domains and cases.
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| 66. |
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| 67. |
- Sörensen, Jens, et al.
(author)
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Akademisk ofrihet
- 2014
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In: Uppsala Nya Tidning. - 1104-0173.
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Journal article (pop. science, debate, etc.)
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| 68. |
- Sörensen, Jens, et al.
(author)
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Aningslöst om SLU-tvång
- 2014
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In: Uppsala Nya Tidning. - 1104-0173.
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Journal article (pop. science, debate, etc.)
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| 69. |
- Sörensen, Jens, et al.
(author)
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Determination of wind turbine near-wake length based on stability analysis
- 2014
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In: Journal of Physics, Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 524:1
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Journal article (peer-reviewed)abstract
- A numerical study on the wake behind a wind turbine is carried out focusing on determining the length of the near-wake based on the instability onset of the trailing tip vortices shed from the turbine blades. The numerical model is based on large-eddy simulations (LES) of the Navier-Stokes equations using the actuator line (ACL) method. The wake is perturbed by applying stochastic or harmonic excitations in the neighborhood of the tips of the blades. The flow field is then analyzed to obtain the stability properties of the tip vortices in the wake of the wind turbine. As a main outcome of the study it is found that the amplification of specific waves (traveling structures) along the tip vortex spirals is responsible for triggering the instability leading to wake breakdown. The presence of unstable modes in the wake is related to the mutual inductance (vortex pairing) instability where there is an out-of-phase displacement of successive helix turns. Furthermore, using the non-dimensional growth rate, it is found that the pairing instability has a universal growth rate equal to π/2. Using this relationship, and the assumption that breakdown to turbulence occurs once a vortex has experienced sufficient growth, we provide an analytical relationship between the turbulence intensity and the stable wake length. The analysis leads to a simple expression for determining the length of the near wake. This expression shows that the near wake length is inversely proportional to thrust, tip speed ratio and the logarithmic of the turbulence intensity.
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| 70. |
- Sörensen, Jens, et al.
(author)
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First-in-Human Molecular Imaging of HER2 Expression in Breast Cancer Metastases Using the In-111-ABY-025 Affibody Molecule
- 2014
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In: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 1535-5667 .- 2159-662X. ; 55:5, s. 730-735
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Journal article (peer-reviewed)abstract
- The expression status of human epidermal growth factor receptor type 2 (HER2) predicts the response of HER2-targeted therapy in breast cancer. ABY-025 is a small reengineered Affibody molecule targeting a unique epitope of the HER2 receptor, not occupied by current therapeutic agents. This study evaluated the distribution, safety, dosimetry, and efficacy of In-111-ABY-025 for determining the HER2 status in metastatic breast cancer. Methods: Seven patients with metastatic breast cancer and HER2-positive (n = 5) or - negative (n 5 2) primary tumors received an intravenous injection of approximately 100 mu g (similar to 140 MBq) of In-111-ABY-025. Planar gamma-camera imaging was performed after 30 min, followed by SPECT/CT after 4, 24, and 48 h. Blood levels of radioactivity, antibodies, shed serum HER2, and toxicity markers were evaluated. Lesional HER2 status was verified by biopsies. The metastases were located by F-18-FDG PET/CT 5 d before In-111-ABY-025 imaging. Results: Injection of In-111-ABY-025 yielded a mean effective dose of 0.15 mSv/MBq and was safe, well tolerated, and without drug-related adverse events. Fast blood clearance allowed high-contrast HER2 images within 4-24 h. No anti-ABY025 antibodies were observed. When metastatic uptake at 24 h was normalized to uptake at 4 h, the ratio increased in HER2-positive metastases and decreased in negative ones (P, < 0.05), with no overlap and confirmation by biopsies. In 1 patient, with HER2- positive primary tumor, In-111-ABY-025 imaging correctly suggested a HER2negative status of the metastases. The highest normal-tissue uptake was in the kidneys, followed by the liver and spleen. Conclusion: In-111-ABY- 025 appears safe for use in humans and is a promising noninvasive tool for discriminating HER2 status in metastatic breast cancer, regardless of ongoing HER2-targeted antibody treatment.
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