| 1. |
- Amloy, Supaluck, et al.
(författare)
-
Excitons and biexcitons in InGaN quantum dot like localization centers
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Indium segregation in a narrow InGaN single quantum well creates quantum dot (QD) like exciton localization centers. Cross section transmission electron microscopy reveals varying shapes and lateral sizes in the range ~1-5 nm of the QD-like features, while scanning near field optical microscopy demonstrates a highly inhomogeneous spatial distribution of optically active individual localization centers. Microphotoluminescence spectroscopy confirms the spectrally inhomogeneous distribution of localization centers, in which the exciton and the biexciton related emissions from single centers of varying geometry could be identified by means of excitation power dependencies. Interestingly, the biexciton binding energy (Ebxx) was found to vary from center to center, between 3 to -22 meV, in correlation with the exciton emission energy. Negative binding energies justify the three-dimensional quantum confinement, which confirms QD-like properties of the localization centers.! The observed energy correlation is proposed to be understood as variations of the lateral extension of the confinement potential, which would yield smaller values of Ebxx for reduced lateral extension and higher exciton emission energy. The proposed relation between lateral extension and Ebxx is further supported by the exciton and the biexciton recombination lifetimes of a single QD, which suggest a lateral extension of merely ~3 nm for a QD with strongly negative Ebxx = -15.5 meV.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
- Braunerhjelm, Pontus, 1953-, et al.
(författare)
-
Rädda våra företagare nu!
- 2020
-
Ingår i: Dagens Juridik. - Stockholm : Blendow Publishing AB. ; 6 maj
-
Annan publikation (populärvet., debatt m.m.)
|
|
| 7. |
- Chaireti, Roza, et al.
(författare)
-
Thrombin generation and levels of factor VII activity measured in the presence of rabbit and human thromboplastins in patients with mild factor VII deficiency – effects of mutations in factor VII
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Background/Aim: It is known that spontaneous prolonged prothrombin time-international normalized ratio may be caused by deficiency of factor VII (FVII). The activity of FVII in the presence of thromboplastins of different origin is affected by the presence of specific mutations in the F7 gene. The present study aims to evaluate patients with mild FVII deficiency and somewhat discrepant FVII activity depending on the use of human or rabbit thromboplastin in relation to mutations in the FVII gene and markers of thrombin generation.Patients and methods: A cohort of 10 patients with mild deficiency of FVII and discrepant FVII activity was investigated. The median ratio of the FVII activity in the presence of human/rabbit thromboplastin was 1.4. All but 1 patient had mild to no bleeding symptoms. A genetic analysis of the F7 gene was performed. Thrombin generation was measured by the calibrated automated thrombogram in platelet poor plasma in the presence of human recombinant and different dilutions of rabbit thromboplastin and compared with thrombin generation in healthy controls (n=12). Thrombin generation was measured in 9 patients as 1 was treated with warfarin at the time of the blood sampling.Results: Six previously described mutations were found. Two of those (FVII Padua and FVII Shinjo) are known to affect the results for FVII activity dependent on the species origin of the thromboplastin. Nine out of 10 patients had one mutation in common (Arg353Gln), which however does not affect the binding site of FVII to tissue factor. Lagtime and ttpeak increased with decreasing concentrations of thromboplastin and total and maximum thrombin concentrations increased with increasing thromboplastin concentrations in the patients with FVII deficiency. ETP in patients with FVII deficiency was 86% of ETP in controls.Discussion: The Arg353Gln mutation was very common, however it does not appear to affect the reactivity towards thromboplastins of different origins. Although ETP was higher in the healthy controls, thrombin generation in FVII deficient patients was enough to sustain normal haemostasis. The expected thrombin generation patterns with increasing thromboplastin concentrations were confirmed for the patients in this study.
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
- Johnson, Lars, et al.
(författare)
-
Phase Transformation of Ti(B,N) into TiB2 and TiN Studied by Atom Probe Tomography
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The phase transformation of supersaturated solid-solution cubic (c) Ti0.57(B0.28N0.72)0.43 thin films into the equilibrium phases TiN and TiB2 has been studied by a combination of X-ray diffraction, transmission electron microscopy, and atom probe tomography. The transformation was found to progress through nucleation and growth, first of TiN and c-TiB0.5N0.5, followed by transformation of the B-rich precipitates to TiB2. The two-step process is interpreted as Guinier-Preston zone formation due to the incoherency between c-TiN and hexagonal TiB2. The nucleation was furthermore observed to be unclassical, with non-equilibrium compositions and extensive interfacial regions in the nuclei.
|
|
