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Institution

Linköping University

EducationLinköping, Sweden
About: Linköping University is a education organization based out in Linköping, Sweden. It is known for research contribution in the topics: Population & Thin film. The organization has 15671 authors who have published 50013 publications receiving 1542189 citations.


Papers
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Journal ArticleDOI
TL;DR: Cathepsin D and one or more cysteine proteases, such as cathepsins B or L, are important mediators of sphingosine-induced apoptosis, working upstream of the caspase cascade and mitochondrial membrane-potential changes.
Abstract: We propose a new mechanism for sphingosine-induced apoptosis, involving relocation of lysosomal hydrolases to the cytosol. Owing to its lysosomotropic properties, sphingosine, which is also a detergent, especially when protonated, accumulates by proton trapping within the acidic vacuolar apparatus, where most of its action as a detergent would be exerted. When sphingosine was added in low-to-moderate concentrations to Jurkat and J774 cells, partial lysosomal rupture occurred dose-dependently, starting within a few minutes. This phenomenon preceded caspase activation, as well as changes of mitochondrial membrane potential. High sphingosine doses rapidly caused extensive lysosomal rupture and ensuing necrosis, without antecedent apoptosis or caspase activation. The sphingosine effect was prevented by pre-treatment with another, non-toxic, lysosomotropic base, ammonium chloride, at 10 mM. The lysosomal protease inhibitors, pepstatin A and epoxysuccinyl-L-leucylamido-3-methyl-butane ethyl ester ('E-64d'), inhibited markedly sphingosine-induced caspase activity to almost the same degree as the general caspase inhibitor benzyloxycarbonyl-Val-Ala-DL-Asp-fluoromethylketone ('Z-VAD-FMK'), although they did not by themselves inhibit caspases. We conclude that cathepsin D and one or more cysteine proteases, such as cathepsins B or L, are important mediators of sphingosine-induced apoptosis, working upstream of the caspase cascade and mitochondrial membrane-potential changes.

363 citations

Journal ArticleDOI
TL;DR: This work proposes a method to choose the initial state to obtain uniqueness and to remove transients at both ends in forward-backward filtering.
Abstract: Forward-backward filtering is a common tool in off-line filtering for implementing noncausal filters. Filtering first forward and then backward or the other way around does not generally give the same result. Here, we propose a method to choose the initial state to obtain uniqueness and to remove transients at both ends.

363 citations

Journal Article
TL;DR: In this article, the optimal number of scheduled users in a massive MIMO system with arbitrary pilot reuse and random user locations is analyzed in a closed form, while simulations are used to show what happens at finite $M$, in different interference scenarios, with different pilot reuse factors, and for different processing schemes.
Abstract: Massive MIMO is a promising technique for increasing the spectral efficiency (SE) of cellular networks, by deploying antenna arrays with hundreds or thousands of active elements at the base stations and performing coherent transceiver processing. A common rule-of-thumb is that these systems should have an order of magnitude more antennas $M$ than scheduled users $K$ because the users’ channels are likely to be near-orthogonal when $M/K > 10$ . However, it has not been proved that this rule-of-thumb actually maximizes the SE. In this paper, we analyze how the optimal number of scheduled users $K^\star$ depends on $M$ and other system parameters. To this end, new SE expressions are derived to enable efficient system-level analysis with power control, arbitrary pilot reuse, and random user locations. The value of $K^\star$ in the large- $M$ regime is derived in closed form, while simulations are used to show what happens at finite $M$ , in different interference scenarios, with different pilot reuse factors, and for different processing schemes. Up to half the coherence block should be dedicated to pilots and the optimal $M/K$ is less than 10 in many cases of practical relevance. Interestingly, $K^\star$ depends strongly on the processing scheme and hence it is unfair to compare different schemes using the same $K$ .

363 citations

Journal ArticleDOI
TL;DR: In this article, the authors describe the results of a study on strategies of third-party logistics (TPL) providers and present empirical findings for a strategic segmentation of the industry.
Abstract: In this article, the authors describe the results of a study on strategies of third‐party logistics (TPL) providers. The size of the TPL industry and the different requirements placed on logistics as opposed to basic services, such as transportation or public warehousing, justify the need to treat TPL as a separate industry. The authors describe three waves of entrants into the TPL industry and a taxonomy for value creation by logistics providers. Empirical findings for a strategic segmentation of the industry are presented. The strategic segmentation is connected to the waves of entrants and the taxonomy by an evaluation of required skills of TPL players. The TPL industry will soon reach an initial stage of maturity, but further changes are to be expected.

363 citations

Journal ArticleDOI
TL;DR: The weak but omnipresent electroluminescence from several types of organic polymer is reported and interpreted to originate from interfacial charge transfer state recombination and emphasize EL as a very valuable tool to characterize the charge transferState present in donor/acceptor organic photovoltaic (OPV) cells.
Abstract: In this article we report the weak but omnipresent electroluminescence (EL) from several types of organic polymer:fullerene bulk heterojunction solar cells biased in the forward direction. The light emitted from blends of some commonly used polymers and the fullerene molecule is significantly different from that of any of the pure materials comprising the blend. The lower energy of the blend EL is found to correlate with both the voltage onset of emission and the open-circuit voltage of the photovoltaic cell under solar illumination. We accordingly interpret the emission to originate from interfacial charge transfer state recombination and emphasize EL as a very valuable tool to characterize the charge transfer state present in donor/acceptor organic photovoltaic (OPV) cells.

363 citations


Authors

Showing all 15844 results

NameH-indexPapersCitations
Rui Zhang1512625107917
Jun Lu135152699767
Jean-Luc Brédas134102685803
Lars Wallentin12476761020
S. Shankar Sastry12285886155
Gerhard Andersson11890249159
Olle Inganäs11362750562
Antonio Facchetti11160251885
Ray H. Baughman11061660009
Michel W. Barsoum10654360539
Louis J. Ignarro10633546008
Per Björntorp10538640321
Jan Lubinski10368952120
Magnus Johannesson10234240776
Barbara Riegel10150777674
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
20241
202385
2022359
20213,190
20203,210
20193,029