| 1. |
|
|
| 2. |
|
|
| 3. |
- de la Serna, Jorge Bernardino, et al.
(författare)
-
Segregated Phases in Pulmonary Surfactant Membranes Do Not Show Coexistence of Lipid Populations with Differentiated Dynamic Properties
- 2009
-
Ingår i: Biophysical Journal. - : Elsevier Inc. - 0006-3495. ; 97:5, s. 1381-1389
-
Tidskriftsartikel (refereegranskat)abstract
- The composition of pulmonary surfactant membranes and films has evolved to support a complex lateral structure, including segregation of ordered/disordered phases maintained up to physiological temperatures. In this study, we have analyzed the temperature-dependent dynamic properties of native surfactant membranes and membranes reconstituted from two surfactant hydrophobic fractions (i.e., all the lipids plus the hydrophobic proteins SP-B and SP-C, or only the total lipid fraction). These preparations show micrometer-sized fluid ordered/disordered phase coexistence, associated with a broad endothermic transition ending close to 37°C. However, both types of membrane exhibit uniform lipid mobility when analyzed by electron paramagnetic resonance with different spin-labeled phospholipids. A similar feature is observed with pulse-field gradient NMR experiments on oriented membranes reconstituted from the two types of surfactant hydrophobic extract. These latter results suggest that lipid dynamics are similar in the coexisting fluid phases observed by fluorescence microscopy. Additionally, it is found that surfactant proteins significantly reduce the average intramolecular lipid mobility and translational diffusion of phospholipids in the membranes, and that removal of cholesterol has a profound impact on both the lateral structure and dynamics of surfactant lipid membranes. We believe that the particular lipid composition of surfactant imposes a highly dynamic framework on the membrane structure, as well as maintains a lateral organization that is poised at the edge of critical transitions occurring under physiological conditions.
|
|
| 4. |
- Fouda, Adam, et al.
(författare)
-
Influence of Selective Carbon 1s Excitation on Auger–Meitner Decay in the ESCA Molecule
- 2024
-
Ingår i: Journal of Physical Chemistry Letters. - 1948-7185. ; 15:16, s. 4286-4293
-
Tidskriftsartikel (refereegranskat)abstract
- Two-dimensional spectral mapping is used to visualize how resonant Auger–Meitner spectra are influenced by the site of the initial core–electron excitation and the symmetry of the core-excited state in the trifluoroethyl acetate molecule (ESCA). We observe a significant enhancement of electron yield for excitation of the COO 1s → π* and CF3 1s → σ* resonances unlike excitation at resonances involving the CH3 and CH2 sites. The CF3 1s → π* and CF3 1s → σ* resonance spectra are very different from each other, with the latter populating most valence states equally. Two complementary electronic structure calculations for the photoelectron cross section and Auger–Meitner intensity are shown to effectively reproduce the site- and state-selective nature of the resonant enhancement features. The site of the core–electron excitation and the respective final state hole locality increase the sensistivity of the photoelectron signal at specific functional group sites. This showcases resonant Auger–Meitner decay as a potentially powerful tool for selectively probing structural changes at specific functional group sites of polyatomic molecules.
|
|
| 5. |
- Isberg, Jan, et al.
(författare)
-
Temperature dependence of hole drift mobility in high-purity single-crystal CVD diamond
- 2005
-
Ingår i: Physica status solidi. A, Applied research. - : Wiley. - 0031-8965 .- 1521-396X. ; 202:11, s. 2194-2198
-
Tidskriftsartikel (refereegranskat)abstract
- Hole transport properties in high-purity single crystal CVD diamond samples were studied using the time of flight technique with optical excitation of the carriers. The measurements were taken at different temperatures in the interval 80-470 K. By varying the intensity of the optical excitation over several orders of magnitude, measurements at different carrier concentrations have been performed. In this way, measurements have been made both in the space charge limited and non space charge limited regimes, with consistent results. The temperature dependence of the low-field hole drift mobility shows a 7(alpha) dependence with a approximate to -1.5, below 350 K. This indicates that acoustic phonon scattering is the dominant scattering mechanism and a very low concentration of ionized impurities in this material.
|
|
| 6. |
- Jarvik, Gail P., et al.
(författare)
-
Hemochromatosis risk genotype is not associated with colorectal cancer or age at its diagnosis
- 2020
-
Ingår i: Human Genetics and Genomics Advances. - : Cell press. - 2666-2477. ; 1:1
-
Tidskriftsartikel (refereegranskat)abstract
- Homozygotes for the higher penetrance hemochromatosis risk allele, HFE c.845G>A (p.Cys282Tyr, or C282Y), have been reported to be at a 2- to 3-fold increased risk for colorectal cancer (CRC). These results have been reported for small sample size studies with no information about age at diagnosis for CRC. An association with age at diagnosis might alter CRC screening recommendations. We analyzed two large European ancestry datasets to assess the association of HFE genotype with CRC risk and age at CRC diagnosis. The first dataset included 59,733 CRC or advanced adenoma cases and 72,351 controls from a CRC epidemiological study consortium. The second dataset included 13,564 self-reported CRC cases and 2,880,218 controls from the personal genetics company, 23andMe. No association of the common hereditary hemochromatosis (HH) risk genotype and CRC was found in either dataset. The odds ratios (ORs) for the association of CRC and HFE C282Y homozygosity were 1.08 (95% confidence interval [CI], 0.91–1.29; p = 0.4) and 1.01 (95% CI, 0.78–1.31, p = 0.9) in the two cohorts, respectively. Age at CRC diagnosis also did not differ by HFE C282Y/C282Y genotype in either dataset. These results indicate no increased CRC risk in individuals with HH genotypes and suggest that persons with HH risk genotypes can follow population screening recommendations for CRC.
|
|
| 7. |
- Kolbeinsson, Ari, et al.
(författare)
-
To What Extent is Gamification an Effective Tool for Onboarding Users into a DHM Tool
- 2021
-
Ingår i: Design, User Experience, and Usability: UX Research and Design. - Cham : Springer. - 9783030782207 - 9783030782214 ; , s. 48-66
-
Konferensbidrag (refereegranskat)abstract
- Applying game-like elements to tasks or computer systems meant for serious, non-game, activities is becoming more common, and is seen as a way to support users in learning a system or to support users in performing tasks better. Applying game-like elements requires an understanding of users, the target task, and what can motivate the target users in their tasks. As in any system development, the success of the design requires validating, and this may be done multiple times in the development cycle. Some concepts, such as usability or user experience have well-established testing methods, while gamification is still a relatively immature field and evaluation methods are still being developed. This paper follows the first evaluation of a gamification system to aid with onboarding new users into the IPS IMMA digital human modelling system, offering details on the heuristic evaluation method. So early in the process, it is inevitable that problems were found, largely to do with how the motivation of users was handled, and multiple suggestions for improvements are offered.
|
|
| 8. |
|
|
| 9. |
- Lindblom, Adam, et al.
(författare)
-
An inductive 700 MW high voltage pulse generator
- 2006
-
Ingår i: IEEE Transactions on Plasma Science. - 0093-3813 .- 1939-9375. ; 34:5, s. 1838-1845
-
Tidskriftsartikel (refereegranskat)abstract
- A repetitive inductive 700-MW high-voltage pulsegenerator that delivers a 150-ns square pulse with 20-ns rise timeat 150 kV has been constructed. The pulse generator has a 1:10 aircore transformer connected to a 25-Ω pulse forming line (PFL).The transformer and the PFL are both constructed using highvoltagecables. The closing switch of the PFL is a spark gap thatis in a water tank together with the cable endings of the PFL andtransformer. The electric field at the cable endings is refractivelygraded by the high permittivity of the surrounding water. ThePFL is charged in 2.5 μs to 170 kV, and the electric field in theclosing switch of the PFL reaches 33 kV/mm until the thresholdvoltage is exceeded. The efficiency of the pulse generator is 40%.The authors believe that this concept can be up-scaled to a 25-GWgenerator operating at 500 kV. An electric circuit simulation ofa 25-GW pulse generator and an electrostatic simulation for arefractive cable ending are presented.
|
|
| 10. |
|
|
