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- Johansson, Ann, et al.
(författare)
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System for integrated interstitial photodynamic therapy and dosimetric monitoring
- 2005
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Ingår i: Proceedings of the SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. ; 5689:1, s. 130-140
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Konferensbidrag (refereegranskat)abstract
- Photodynamic therapy for the treatment of cancer relies on the presence of light, sensitizer and oxygen. By monitoring these three parameters during the treatment a better understanding and treatment control could possibly be achieved. Here we present data from in vivo treatments of solid skin tumors using an instrument for interstitial photodynamic therapy with integrated dosimetric monitoring. By using intra-tumoral ALA-administration and interstitial light delivery solid tumors are targeted. The same fibers are used for measuring the fluence rate at the treatment wavelength, the sensitizer fluorescence and the local blood oxygen saturation during the treatment. The data presented is based on 10 treatments in 8 patients with thick basal cell carcinomas. The fluence rate measurements at 635 nm indicate a major treatment induced absorption increase, leading to a limited light penetration at the treatment wavelength. This leads to a far from optimal treatment since the absorption increase prevents peripheral tumor regions from being fully treated. An interactive treatment has been implemented assisting the physician in delivering the correct light dose. The absorption increase can be compensated for by either prolonging the treatment time or increasing the output power of each individual treatment fiber. The other parameters of importance, i.e. the sensitizer fluorescence at 705 nm and the local blood oxygen saturation, are monitored in order to get an estimate of the amount of photobleaching and oxygen consumption. Based on the oxygen saturation signal, a fractionized irradiation can be introduced in order to allow for a re-oxygenation of the tissue
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| 4. |
- Lou, X. T., et al.
(författare)
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Sulfur dioxide measurements using an ultraviolet light-emitting diode in combination with gas correlation techniques
- 2009
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Ingår i: Applied Physics B. - : Springer Science and Business Media LLC. - 0946-2171 .- 1432-0649. ; 94:4, s. 699-704
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Tidskriftsartikel (refereegranskat)abstract
- The important air pollutant sulfur dioxide has a strong structured absorption band in the ultraviolet (UV) region around 300 nm. Recently, light-emitting diodes (LEDs) with structureless emission in a band about 15-nm wide in the UV region have become available. We demonstrate that they can be ideal sources for gas absorption measurements combined with the gas correlation technique, where an absorption cell with an optically thick column of the gas under investigation is used for analysing the target gas contents in a path between the LED and the measurement device. A sensitivity of 0.4 ppm sulfur dioxide was obtained with a 19-cm optical path length and 60-s integration time. Particularly compact and cost-effective monitors especially for industrial emissions can be envisaged.
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| 5. |
- Nyman, Margareta, et al.
(författare)
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Effects of cultivar, root weight, storage and boiling on carbohydrate content in carrots (Daucus carota L)
- 2005
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Ingår i: Journal of the Science of Food and Agriculture. - : Wiley. - 1097-0010 .- 0022-5142. ; 85:3, s. 441-449
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Tidskriftsartikel (refereegranskat)abstract
- The effects of cultivar (n = 4), root weight (n = 4), storage (S months) and boiling (7 min) and their interactions on the content of dry matter and carbohydrates were studied and ranked in carrots. Boiling had the greatest effect and had an influence on all variables except the ratio between sucrose and the monosaccharides glucose and fructose. The choice of cultivar was also of great importance as regards glucose, fructose and sucrose content, while dietary fibre and dry matter were much less affected, or even unaffected, by this factor. Root weight and storage were consistently of less significance than boiling and cultivar. Thus dietary fibre solubility, fructose content and the ratio between sucrose and the monosaccharides glucose and fructose were independent of the root weight, while storage had no impact on the dry matter content. After storage the cultivar Lonto had lost more dry matter than the other cultivars (10% versus mean 1% for the others, P = 0.009) and the sugar ratio between sucrose and the monosaccharides glucose and fructose had increased in the cultivar Amarant, while it decreased in the other cultivars (P < 0.001). Furthermore, Amarant had a lower loss of sugars (35%) following boiling than the other cultivars (mean 39%, P = 0.002). Storage and boiling interacted concerning soluble and insoluble dietary fibre, fibre solubility and glucose content. It is concluded that the various factors (especially boiling and cultivar) gave rise to such differences in carbohydrate content and composition that they might be of nutritional importance. The results may thus provide a basis for selecting raw material when studying possible health effects of carrots. © 2004 Society of Chemical Industry.
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| 7. |
- Svanberg, Magnus, et al.
(författare)
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Prediction of shape distortions for a curved composite C-spar
- 2005
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Ingår i: Journal of reinforced plastics and composites (Print). - : SAGE Publications. - 0731-6844 .- 1530-7964. ; 24:3, s. 323-339
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents predictions and validations of shape distortions of a curved C-spar, using a simulation tool developed in the general purpose FE-program ABAQUS. The simulation tool is based on a simplified mechanical constitutive model that accounts for the mechanisms identified in a previous experimental study concerning the influence from the cure schedule on shape distortions. The main objective of the present paper is to validate the simplified constitutive model and a simplified simulation approach. The feasibility for simulation of shape distortions of a component with relatively complex shape has also been investigated. © 2005 Sage Publications.
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| 8. |
- Svensson, Jenny, et al.
(författare)
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Tumor selectivity at short times following systemic administration of a liposomal temoporfin formulation in a murine tumor model
- 2007
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Ingår i: Photochemistry and Photobiology. - 0031-8655. ; 83:5, s. 1211-1219
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Tidskriftsartikel (refereegranskat)abstract
- Meso-tetra(hydroxyphenyl)chlorin (mTHPC) (INN: Temoporfin) is one of the most potent photodynamically active substances in clinical use. Treatment protocols for Temoporfin-mediated photodynamic therapy often rely on drug-light intervals of several days in order for the photosensitizer to accumulate within the target tissue, though tumor selectivity is limited. Here, the mTHPC localization was studied at 2-8 h following systemic administration of a liposomal Temoporfin formulation (0.15 mg kg(-1) b.w.) in HT29 human colon adermcarcinoma in NMRI nu/nu mice. Photosensitizer distribution within tumor and internal organs was investigated by means of high performance liquid chromatography following chemical extraction, as well as in situ fluorescence imaging and point-monitoring fluorescence spectroscopy. For tumor tissue, the Temoporfin concentrations at 4 h (0.16 +/- 0.024 ng mg(-1)) and 8 h (0.18 +/- 0.064 ng mg(-1)) were significantly higher than at 2 It (0.08 +/- 0.026 ng mg(-1)). The average tumor-to-muscle and the tumor-to-skin selectivity were 6.6 and 2, respectively, and did not vary significantly with time after photosensitizer injection. In plasma, the Temoporfin concentration was low (0.07 +/- 0.07 ng mg(-1)) and showed no significant variation with time. Our results indicate a rapid biodistribution and clearance from the bloodstream. Within the same type of organ, data from both fluorescence methods generally exhibited a significant correlation with the extraction results.
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| 9. |
- Thomsen, J, et al.
(författare)
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Optical Doppler tomography for monitoring vascularization during photodynamic therapy of skin cancer lesions
- 2008
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Ingår i: BIOPHOTONICS: PHOTONIC SOLUTIONS FOR BETTER HEALTH CARE. - : SPIE. - 1996-756X .- 0277-786X. - 9780819471895 ; 6991
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Konferensbidrag (refereegranskat)abstract
- We investigate vascular changes during Photodynamic therapy (PDT) of skin tumors using optical Doppler tomography (ODT). The effect of vascular shut down on tumor destruction is currently not known, and to optimize treatment it is relevant to investigate this issue further. Optical Doppler tomography is capable of measuring blood flow in biological tissue down to 1-2 mm with sub-mm/s velocity sensitivity and micrometer spatial resolution making it suitable for blood flow measurements in the skin. We demonstrate the ability of detecting blood flow in the human skin using non-interstitial ODT to preserve the non-invasiveness. In general a very limited blood flow activity was observed in normal skin and around skin tumors making monitoring of changes difficult. We suggest solutions to a number of practical issues such as sampling errors and natural fluctuations in flow activity for future work.
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