| 431. |
- Takook, Pegah, 1982, et al.
(författare)
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Performance evaluation of dipole versus modified bow-tie in annular phased array applicators
- 2015
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Ingår i: Progress in Electromagnetics Research Symposium. - 1559-9450 .- 1931-7360. - 9781934142301 ; 2015-January, s. 1909-1912
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Konferensbidrag (refereegranskat)abstract
- Phased arrays are the common type of applicators for deep hyperthermia systems to heat tumors selectively while keeping healthy tissues at normal temperatures. Annular array applicators with dipoles and water bolus have been improved in several studies to deposit energy efficiently in head and neck tumors. In this study we investigate the performance of a modified Bow-Tie antenna versus half-wave dipole as single elements in annular phased array applicators to heat tumors in head and neck region. Hyperthermia quality indicators have been calculated for each case to quantify the quality of treatment outcome in two different tumor positions in a head-and-neck phantom. The obtained results indicates that dipoles are appropriate phased array elements to heat superficial tumors, while modified Bow-Ties are more suitable in heating big deep-seated tumors.
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| 432. |
- Tang, Jing, et al.
(författare)
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Estimating slope from raster data : a test of eight algorithms at different resolutions in flat and steep terrain
- 2013
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Ingår i: Geodesy and Cartography. - : Vilnius Gediminas Technical University. - 2029-6991 .- 2029-7009. ; 39:2, s. 41-52
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Tidskriftsartikel (refereegranskat)abstract
- Different slope algorithms can result in totally different estimates. In the worst case, this may lead to inappropriate and useless modelling estimates. A frequent lack of awareness when choosing algorithms justifies a thorough comparison of their characteristics, making it possible for researchers to select an algorithm which is optimal for their purpose. In this study, eight frequently used slope algorithms applied to Digital Elevation Models (DEMs) are compared. The influences of the resolution of the DEM (0.5, 1, 2, and 5 metres), as well as the terrain form (flat and steep terrain), are considered. It should be noted that the focus of the study is not to compare estimates with ‘ground truth’ data, but on the comparisons between the algorithms, and the ways in which they might differ depending on resolution and terrain. Descriptive statistics are calculated in order to characterize the general characteristics of the eight tested algorithms. Eight combinations of DEM resolution and terrain form are analysed. The results show that the Maximum and Simple Difference algorithms always yield higher mean slope values than the other algorithms, while the Constrained Quadratic Surface algorithm produces the lowest values compared to the others. It is concluded that the estimated slope values are heavily dependent on the number of neighbouring cells included in the estimation. An Analysis of Variance (ANOVA) of estimated slope values strongly indicates (at the significance level of 0.01) that the tested algorithms yield statistically different results. The eight algorithms produce different estimates for all tested resolutions and terrain forms but one. The differences are more pronounced in steep terrain and at a higher resolution. More detailed pairwise comparisons between estimated slope values are also carried out. It is concluded that the smoothing effects associated with the Constrained Quadratic Surface algorithm are greater in steeper terrain, showing significantly lower estimates than other algorithms. On the other hand, the Maximum and Simple Difference algorithms show significantly higher estimates in almost all cases, except the combination of steep terrain and low resolution. With an increase in grid cell size, the loss of information contents in DEMs leads to lower estimated slope values as well as smaller relative differences between algorithms. Based on the results of this study it is concluded that the choice of algorithm results in different estimated slope values, and that resolution and terrain influences these differences significantly.
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| 433. |
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| 434. |
- Taxbro, Knut, 1973-, et al.
(författare)
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Low mortality rates among critically ill adults with COVID-19 at three non-academic intensive care units in south Sweden
- 2021
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Ingår i: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172 .- 1399-6576. ; 65:10, s. 1457-1465
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Tidskriftsartikel (refereegranskat)abstract
- Background The COVID-19 pandemic has put an exceptional strain on intensive care units worldwide. During the first year, the survival of patients with acute hypoxaemic respiratory failure appears to have improved. We aimed to describe the mortality rates, management characteristics and two pandemic waves during the first year at three non-academic rural intensive care units in Sweden. Methods We retrospectively analysed all cases of COVID-19 admitted to intensive care units in Region Jonkoping County during 1 year. The primary endpoint was 30-day mortality. Results Between 14th March 2020 and 13th March 2021, 264 patients were admitted to undergo intensive care with confirmed SARS-CoV-2 infection. The 30-day mortality rate after the initial intensive care admission was 12.9%, and this rate remained unchanged during both pandemic waves. However, we found several distinct differences between the two pandemic waves, including an increase in the use of high-flow nasal oxygen but a decrease in invasive mechanical ventilation use, biochemical markers of inflammation, continuous renal replacement therapy and length of stay in the intensive care unit. Conclusion Our study showed that critically ill patients with COVID-19 in Sweden have a low 30-day mortality rate which compares well with results published from academic centres and national cohorts throughout Scandinavia. During the second pandemic wave, the proportion of patients receiving invasive mechanical ventilation and continuous renal replacement therapy was lower than that in the first wave. This could be the result of increased knowledge and improved therapeutic options.
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| 435. |
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| 436. |
- Thalén, Lisa K., et al.
(författare)
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Enantioselective synthesis of α-methyl carboxylic acids from readily available starting materials via chemoenzymatic dynamic kinetic resolution
- 2010
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Ingår i: Journal of Organic Chemistry. - : American Chemical Society (ACS). - 0022-3263 .- 1520-6904. ; 75:20, s. 6842-6847
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Tidskriftsartikel (refereegranskat)abstract
- An enantioselective method for the synthesis of α-methyl carboxylic acids starting from trans-cinnamaldehyde, a readily available and inexpensive compound, has been developed. Allylic alcohol 1 was obtained via a standard Grignard addition to trans-cinnamaldehyde. Dynamic kinetic resolution was applied to allylic alcohol 1 utilizing a ruthenium catalyst and either an (R)-selective lipase or an (S)-selective protease to provide the corresponding allylic esters in high yield and high ee. A copper-catalyzed allylic substitution was then applied to provide the corresponding alkenes with inversion of stereochemistry. Subsequent C−C double bond cleavage afforded pharmaceutically important α-methyl substituted carboxylic acids in high ee and overall yields of up to 76%.
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| 437. |
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| 438. |
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| 439. |
- Thomasson, Marcus, et al.
(författare)
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LRIG1 and the liar paradox in prostate cancer: a study of the expression and clinical significance of LRIG1 in prostate cancer
- 2011
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 128:12, s. 2843-2852
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Tidskriftsartikel (refereegranskat)abstract
- The course of prostate cancer varies greatly, and additional prognostic markers are needed. Leucine-rich repeats and immunoglobulin-like domains protein 1 (LRIG1) is an endogenous inhibitor of growth factor signaling and a proposed tumor suppressor. Publicly available gene expression datasets indicate that LRIG1 may be overexpressed in prostate cancer. In our study, the expression of LRIG1 protein in prostate cancer was evaluated for the first time. Immunohistochemistry was performed on tissue microarrays from two different patient series: 355 Swedish patients diagnosed by transurethral resection and 293 American patients who underwent radical prostatectomy. In the Swedish series, high expression of LRIG1 correlated with Gleason score, T-stage, tumor cell proliferation, vascular density and epidermal growth factor receptor (EGFR) phosphorylation. Among the 256 Swedish patients, followed by watchful waiting, high LRIG1 expression was significantly associated with short overall and prostate cancer-specific survival. In contrast, in the US series, high LRIG1 expression was significantly associated with long overall survival. In vitro cell experiments showed that LRIG1 was induced by androgen stimulation, and its expression inhibited prostate cancer cell proliferation. Thus, LRIG1 expression was an independent marker for poor survival in the untreated patient series, perhaps as a secondary marker of androgen receptor and/or EGFR activation. On the contrary, LRIG1 was a marker for good prognosis after prostatectomy, which might be due to its growth inhibiting properties. We propose that LRIG1 is an important determinant of prostate cancer growth, and the implications of its expression on patient outcome depend on the clinical and biological circumstances.
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| 440. |
- Thoral, Elisa, et al.
(författare)
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The relationship between mitochondrial respiration, resting metabolic rate and blood cell count in great tits
- 2024
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Ingår i: Biology Open. - 2046-6390. ; 13:3
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Tidskriftsartikel (refereegranskat)abstract
- Although mitochondrial respiration is believed to explain a substantial part of the variation in resting metabolic rate (RMR), few studies have empirically studied the relationship between organismal and cellular metabolism. We therefore investigated the relationship between RMR and mitochondrial respiration of permeabilized blood cells in wild great tits (Parus major L.). We also studied the correlation between mitochondrial respiration traits and blood cell count, as normalizing mitochondrial respiration by the cell count is a method commonly used to study blood metabolism. In contrast to previous studies, our results show that there was no relationship between RMR and mitochondrial respiration in intact blood cells (i.e. with the ROUTINE respiration). However, when cells were permeabilized and interrelation re-assessed under saturating substrate availability, we found that RMR was positively related to phosphorylating respiration rates through complexes I and II (i.e. OXPHOS respiration) and to the mitochondrial efficiency to produce energy (i.e. net phosphorylation efficiency), though variation explained by the models was low (i.e. linear model: R2=0.14 to 0.21). However, unlike studies in mammals, LEAK respiration without [i.e. L(n)] and with [i.e. L(Omy)] adenylates was not significantly related to RMR. These results suggest that phosphorylating respiration in blood cells can potentially be used to predict RMR in wild birds, but that this relationship may have to be addressed in standardized conditions (permeabilized cells) and that the prediction risks being imprecise. We also showed that, in our conditions, there was no relationship between any mitochondrial respiration trait and blood cell count. Hence, we caution against normalising respiration rates using this parameter as is sometimes done. Future work should address the functional explanations for the observed relationships, and determine why these appear labile across space, time, taxon, and physiological state.
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