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| 2. |
- Bravo, L, et al.
(författare)
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- 2021
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swepub:Mat__t
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| 3. |
- Tabiri, S, et al.
(författare)
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- 2021
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swepub:Mat__t
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| 4. |
- Thijssen, E. H., et al.
(författare)
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Diagnostic value of plasma phosphorylated tau181 in Alzheimer's disease and frontotemporal lobar degeneration
- 2020
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Ingår i: Nature Medicine. - : Springer Science and Business Media LLC. - 1078-8956 .- 1546-170X. ; 26, s. 387-397
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Tidskriftsartikel (refereegranskat)abstract
- Plasma pTau181 concentrations are elevated specifically in patients diagnosed with Alzheimer's disease compared to those diagnosed with frontotemporal lobar degeneration or elderly controls, supporting its further development as a blood-based biomarker for AD. With the potential development of new disease-modifying Alzheimer's disease (AD) therapies, simple, widely available screening tests are needed to identify which individuals, who are experiencing symptoms of cognitive or behavioral decline, should be further evaluated for initiation of treatment. A blood-based test for AD would be a less invasive and less expensive screening tool than the currently approved cerebrospinal fluid or amyloid beta positron emission tomography (PET) diagnostic tests. We examined whether plasma tau phosphorylated at residue 181 (pTau181) could differentiate between clinically diagnosed or autopsy-confirmed AD and frontotemporal lobar degeneration. Plasma pTau181 concentrations were increased by 3.5-fold in AD compared to controls and differentiated AD from both clinically diagnosed (receiver operating characteristic area under the curve of 0.894) and autopsy-confirmed frontotemporal lobar degeneration (area under the curve of 0.878). Plasma pTau181 identified individuals who were amyloid beta-PET-positive regardless of clinical diagnosis and correlated with cortical tau protein deposition measured by F-18-flortaucipir PET. Plasma pTau181 may be useful to screen for tau pathology associated with AD.
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| 5. |
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| 6. |
- Nelander, Rikard, et al.
(författare)
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Fingerprints of spatial charge transfer in Quantum Cascade Lasers
- 2007
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 102, s. 1-113104
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Tidskriftsartikel (refereegranskat)abstract
- We show that mid-infrared transmission spectroscopy of a quantum cascade laser provides clear-cut information on changes in charge location at different bias. Theoretical simulations of the evolution of the gain/absorption spectrum for a lambda~7.4 µm InGaAs/AlInAs/InP quantum cascade laser have been compared with the experimental findings. Transfer of electrons between the ground states in the active region and the states in the injector goes hand in hand with a decrease of discrete intersubband absorption peaks and an increase of broad, high-energy absorption toward the continuum delocalized states above the barriers.
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| 7. |
- Pereira, M. F., Jr., et al.
(författare)
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Characterization of intersubband devices combining a nonequilibrium many body theory with transmission spectroscopy experiments
- 2007
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Ingår i: Journal of Materials Science: Materials in Electronics. - : Springer Science and Business Media LLC. - 0957-4522 .- 1573-482X. ; 18:7, s. 689-694
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we apply a microscopic nonequilibrium many body Keldysh Green's functions approach to an analysis of complex intersubband optical materials and devices. The calculated absorption/gain spectra are in very good agreement with transmission spectroscopy measurements of quantum cascade laser structures operating in the mid-infrared (midIR). The very good agreement reached between theoretical results and experimental measurements benchmarks the predictive power of our algorithms and its potential as a design tool for efficient intersubband designs.
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| 8. |
- Revin, D.G., et al.
(författare)
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Probing the electronic and optical properties of quantum cascade lasers under operating conditions
- 2006
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Ingår i: Proceedings of SPIE, the International Society for Optical Engineering. - : SPIE. ; 6386, s. 1-63860
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- We report the realisation of spectroscopic broadband transmission experiments on quantum cascade lasers (QCLs) under continuous wave operating conditions for drive currents up to laser threshold. This technique allows, for the first time, spectroscopic study of light transmission through the waveguide of QCLs in a very broad spectral range (λ~1.5-12 μm), limited only by the detector response and by interband absorption in the materials used in the QCL cladding regions. Waveguide transmittance spectra have been studied for both TE and TM polarization, for InGaAs/InAlAs/InP QCLs with different active region designs emitting at 7.4 and 10μm. The transmission measurements clearly show the depopulation of the lower laser levels as bias is increased, the onset and growth of optical amplification at the energy corresponding to the laser transitions as current is increased towards threshold, and the thermal filling of the second laser level and decrease of material gain at high temperatures. This technique also allows direct determination of key parameters such as the exact temperature of the laser core region under operating conditions, as well as the modal gain and waveguide loss coefficients.
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