110 research outputs found
On the deployment of Mobile Trusted Modules
In its recently published TCG Mobile Reference Architecture, the TCG Mobile
Phone Work Group specifies a new concept to enable trust into future mobile
devices. For this purpose, the TCG devises a trusted mobile platform as a set
of trusted engines on behalf of different stakeholders supported by a physical
trust-anchor. In this paper, we present our perception on this emerging
specification. We propose an approach for the practical design and
implementation of this concept and how to deploy it to a trustworthy operating
platform. In particular we propose a method for the take-ownership of a device
by the user and the migration (i.e., portability) of user credentials between
devices.Comment: To appear in: Proceedings of the Wireless Communications and
Networking Conference, IEEE WCNC 2008, Las Vegas, USA, 31 March - 2 April
200
Mechanical thrombectomy in acute ischemic stroke—experience from 6 years of practice
INTRODUCTION: We present our results from the first 6 years with mechanical thrombectomy in the treatment of ischemic stroke. METHODS: Every patient treated with mechanical thrombectomy for acute ischemic stroke from September 2005 to December 2011 was consecutively included in this retrospective analysis. Baseline and outcome data were retrieved from computerized records at the hospital. National Institute of Health Stroke Scale (NIHSS) score and the modified Rankin Scale (mRS) score were used as outcome parameters. Favorable outcome was defined as a mRS score of 0–2, corresponding to independence in activities of daily living. We also evaluated revascularization and severe adverse events, with focus on symptomatic intracranial hemorrhage. RESULTS: Good functional outcome (mRS 0–2) was achieved in 50 % (120/240) of all patients. For patients with no neurological deficit prior to stroke onset (i.e., mRS = 0 before stroke), the proportion with good functional outcome was 54 %. Symptomatic hemorrhages occurred in 4.6 % of the cases (5.7 % in the anterior circulation). CONCLUSION: In summary, our results supports that mechanical thrombectomy is a safe and effective method to restore blood flow in selected patients suffering from an acute ischemic stroke
[Ni(NHC)2] as a scaffold for structurally characterized trans [H-Ni-PR2] and trans [R2P-Ni-PR2] complexes
The addition of PPh2H, PPhMeH, PPhH2, P(para-Tol)H2, PMesH2 and PH3 to the two-coordinate Ni0 N-heterocyclic carbene species [Ni(NHC)2] (NHC=IiPr2, IMe4, IEt2Me2) affords a series of mononuclear, terminal phosphido nickel complexes. Structural characterisation of nine of these compounds shows that they have unusual trans [H−Ni−PR2] or novel trans [R2P−Ni−PR2] geometries. The bis-phosphido complexes are more accessible when smaller NHCs (IMe4>IEt2Me2>IiPr2) and phosphines are employed. P−P activation of the diphosphines R2P−PR2 (R2=Ph2, PhMe) provides an alternative route to some of the [Ni(NHC)2(PR2)2] complexes. DFT calculations capture these trends with P−H bond activation proceeding from unconventional phosphine adducts in which the H substituent bridges the Ni−P bond. P−P bond activation from [Ni(NHC)2(Ph2P−PPh2)] adducts proceeds with computed barriers below 10 kcal mol−1. The ability of the [Ni(NHC)2] moiety to afford isolable terminal phosphido products reflects the stability of the Ni−NHC bond that prevents ligand dissociation and onward reaction
ITER coaxial gyrotron development - final report
ITER KOAXIALGYROTRONENTWICKLUNG - Schlußbericht -
Kurzfasssung:
Eine 4,5 MW Elektronenkanone (Diode) für Gyrotrons mit koaxialem Resonator, deren auf nahezu Erdpotential liegender zentraler Leiter vom Kathodenring umgeben ist (Inverse Magnetron Injection Gun, IMIG) wurde ausgelegt und hergestellt (Uc = 90 kV, Ib = 50 A, Geschwindigkeitsverhältnis 1,4 und Stromdichte am Emitter je=2,8 A/cm²). Der Emitter besteht aus LaB6 mit einem mittleren Radius von 56 mm. Die Eigenschaften des Elektronenstrahls wurden mittels der Gegenfeldmethode gemessen. Der mittlere Wert von ist in guter Übereinstimmung mit numerischen Vorhersagen. Die gemessene Geschwindigkeitsstreuung rms 9 % ist zwar relativ groß, aber immer noch klein genug, um einen verläßlichen Betrieb bei den Designparametern zu erlauben.
1,5 MW-Gyrotronoszillatoren mit koaxialem Resonator für die Moden TE28,16 und TE31,17 bei 140 bzw. 165 GHz wurde entwickelt und getestet. Eine maximale Ausgangsleistung von 1,17 MW bei einem Wirkungsgrad von 27.2 % wurde im Designmodus bei 140 GHz gemessen (Pulslänge 0,15 - 0,5 ms). In einem weiten Betriebsparameterbereich wurde Einmodenoszillation gefunden. Die experimentellen Ergebnisse stimmen gut mit Vielmodenrechnungen überein. Stufenweise Frequenzdurchstimmung wurde erfolgreich durchgeführt. Mit konstanter Magnetfeldkompression wurden im Frequenzbereich von 115,6 bis 164,2 GHz zwanzig Moden im Einmodenbetrieb angeregt. So wurden z.B. 0,9 MW im TE25,14 bei 123,0 GHz und 1,16 MW im TE32,18 bei 158,9 GHz gemessen.
Die Auswahl von Betriebsfrequenz und Betriebsmodus der 165 GHz-Version wird durch die obere Grenze des verfügbaren supraleitenden Magneten und durch den Gebrauch der IMIG des 140 GHz \- TE28,16 - Koaxialgyrotrons bestimmt. Eine maximale Ausgangsleistung von 1,17 MW bei einem Wirkungsgrad von 26,7 % wurde im Designmodus TE31,17 gemessen. Der maximale Wirkungsgrad von 28,2 % wurde bei einer Ausgangsleistung von 0,9 MW beobachtet. Einmodenbetrieb wurde auch im TE32,17 bei 167,1 GHz, im TE33,17 bei 169,46 GHz und im TE34,17-Modus bei 171,8 GHz erreicht und zwar mit Ausgangsleistungen von 1,02 MW, 0,63 MW bzw. 0,35 MW. Die Leistungs- und Wirkungsgradbegrenzung zu hohen Frequenzen hin ist durch das maximal erreichbare Magnetfeld von 6.6 T bedingt.
Optimierung und Auslegung eines quasioptischen Modenwandlersystems, das mit einem Zweistrahlauskoppelprinzip für koaxiale Gyrotrons mit zwei Ausgangsfenstern verträglich ist, werden auch vorgestellt. Die Zweistufen-Modenwandler-Sequenzen TE-28,16 nach TE+76,2 nach TEM00 bei 140 GHz und TE-31,17 nach TE+83,2 nach TEM00 bei 165 GHz, die beide jeweils zwei enggebündelte (60° an der Hohlleiterantenne) Ausgangsstrahlen erzeugen, wurden untersucht. Es werden hohe Konversionswirkungsgrade erwartet (94 % bzw. 92 %)
[Ni(NHC)2] as a scaffold for structurally characterized trans [H-Ni-PR2] and trans [R2P-Ni-PR2] complexes
The addition of PPh(2)H, PPhMeH, PPhH(2), P(para‐Tol)H(2), PMesH(2) and PH(3) to the two‐coordinate Ni(0) N‐heterocyclic carbene species [Ni(NHC)(2)] (NHC=IiPr(2), IMe(4), IEt(2)Me(2)) affords a series of mononuclear, terminal phosphido nickel complexes. Structural characterisation of nine of these compounds shows that they have unusual trans [H−Ni−PR(2)] or novel trans [R(2)P−Ni−PR(2)] geometries. The bis‐phosphido complexes are more accessible when smaller NHCs (IMe(4)>IEt(2)Me(2)>IiPr(2)) and phosphines are employed. P−P activation of the diphosphines R(2)P−PR(2) (R(2)=Ph(2), PhMe) provides an alternative route to some of the [Ni(NHC)(2)(PR(2))(2)] complexes. DFT calculations capture these trends with P−H bond activation proceeding from unconventional phosphine adducts in which the H substituent bridges the Ni−P bond. P−P bond activation from [Ni(NHC)(2)(Ph(2)P−PPh(2))] adducts proceeds with computed barriers below 10 kcal mol(−1). The ability of the [Ni(NHC)(2)] moiety to afford isolable terminal phosphido products reflects the stability of the Ni−NHC bond that prevents ligand dissociation and onward reaction
The genera Melanothamnus Bornet & Falkenberg and Vertebrata S.F. Gray constitute well-defined clades of the red algal tribe Polysiphonieae (Rhodomelaceae, Ceramiales).
Polysiphonia is the largest genus of red algae, and several schemes subdividing it into smaller taxa have been proposed since its original description. Most of these proposals were not generally accepted, and currently the tribe Polysiphonieae consists of the large genus Polysiphonia (190 species), the segregate genus Neosiphonia (43 species), and 13 smaller genera (< 10 species each). In this paper, phylogenetic relationships of the tribe Polysiphonieae are analysed, with particular emphasis on the genera Carradoriella, Fernandosiphonia, Melanothamnus, Neosiphonia, Polysiphonia sensu stricto, Streblocladia and Vertebrata. We evaluated the consistency of 14 selected morphological characters in the identified clades. Based on molecular phylogenetic (rbcL and 18S genes) and morphological evidence, two speciose genera are recognized: Vertebrata (including the type species of the genera Ctenosiphonia, Enelittosiphonia, Boergeseniella and Brongniartella) and Melanothamnus (including the type species of the genera Fernandosiphonia and Neosiphonia). Both genera are distinguished from other members of the Polysiphonieae by synapomorphic characters, the emergence of which could have provided evolutionarily selective advantages for these two lineages. In Vertebrata trichoblast cells are multinucleate, possibly associated with the development of extraordinarily long, photoprotective, trichoblasts. Melanothamnus has 3-celled carpogonial branches and plastids lying exclusively on radial walls of the pericentral cells, which similarly may improve resistance to damage caused by excessive light. Other relevant characters that are constant in each genus are also shared with other clades. The evolutionary origin of the genera Melanothamnus and Vertebrata is estimated as 75.7-95.78 and 90.7-138.66 Ma, respectively. Despite arising in the Cretaceous, before the closure of the Tethys Seaway, Melanothamnus is a predominantly Indo-Pacific genus and its near-absence from the northeastern Atlantic is enigmatic. The nomenclatural implications of this work are that 46 species are here transferred to Melanothamnus, six species are transferred to Vertebrata and 13 names are resurrected for Vertebrata
Consensus statements and recommendations from the ESO-Karolinska Stroke Update Conference, Stockholm 11–13 November 2018
The purpose of the European Stroke Organisation–Karolinska Stroke Update Conference is to provide updates on recent stroke therapy research and to give an opportunity for the participants to discuss how these results may be implemented into clinical routine. The meeting started 22 years ago as Karolinska Stroke Update, but since 2014 it is a joint conference with European Stroke Organisation. Importantly, it provides a platform for discussion on the European Stroke Organisation guidelines process and on recommendations to the European Stroke Organisation guidelines committee on specific topics. By this, it adds a direct influence from stroke professionals otherwise not involved in committees and work groups on the guideline procedure. The discussions at the conference may also inspire new guidelines when motivated. The topics raised at the meeting are selected by the scientific programme committee mainly based on recent important scientific publications. This year’s European Stroke Organisation–Karolinska Stroke Update Meeting was held in Stockholm on 11–13 November 2018. There were 11 scientific sessions discussed in the meeting including two short sessions. Each session except the short sessions produced a consensus statement (Full version with background, issues, conclusions and references are published as web-material and at www.eso-karolinska.org and http://eso-stroke.org) and recommendations which were prepared by a writing committee consisting of session chair(s), scientific secretary and speakers. These statements were presented to the 250 participants of the meeting. In the open meeting, general participants commented on the consensus statement and recommendations and the final document were adjusted based on the discussion from the general participants Recommendations (grade of evidence) were graded according to the 1998 Karolinska Stroke Update meeting with regard to the strength of evidence. Grade A Evidence: Strong support from randomised controlled trials and statistical reviews (at least one randomised controlled trial plus one statistical review). Grade B Evidence: Support from randomised controlled trials and statistical reviews (one randomised controlled trial or one statistical review). Grade C Evidence: No reasonable support from randomised controlled trials, recommendations based on small randomised and/or non-randomised controlled trials evidence
Consensus statements and recommendations from the ESO-Karolinska Stroke Update Conference, Stockholm 11-13 November 2018
The purpose of the European Stroke Organisation-Karolinska Stroke Update Conference is to provide updates on recent stroke therapy research and to give an opportunity for the participants to discuss how these results may be implemented into clinical routine. The meeting started 22 years ago as Karolinska Stroke Update, but since 2014 it is a joint conference with European Stroke Organisation. Importantly, it provides a platform for discussion on the European Stroke Organisation guidelines process and on recommendations to the European Stroke Organisation guidelines committee on specific topics. By this, it adds a direct influence from stroke professionals otherwise not involved in committees and work groups on the guideline procedure. The discussions at the conference may also inspire new guidelines when motivated. The topics raised at the meeting are selected by the scientific programme committee mainly based on recent important scientific publications. This year's European Stroke Organisation-Karolinska Stroke Update Meeting was held in Stockholm on 11-13 November 2018. There were 11 scientific sessions discussed in the meeting including two short sessions. Each session except the short sessions produced a consensus statement (Full version with background, issues, conclusions and references are published as web-material and at and ) and recommendations which were prepared by a writing committee consisting of session chair(s), scientific secretary and speakers. These statements were presented to the 250 participants of the meeting. In the open meeting, general participants commented on the consensus statement and recommendations and the final document were adjusted based on the discussion from the general participants Recommendations (grade of evidence) were graded according to the 1998 Karolinska Stroke Update meeting with regard to the strength of evidence. Grade A Evidence: Strong support from randomised controlled trials and statistical reviews (at least one randomised controlled trial plus one statistical review). Grade B Evidence: Support from randomised controlled trials and statistical reviews (one randomised controlled trial or one statistical review). Grade C Evidence: No reasonable support from randomised controlled trials, recommendations based on small randomised and/or non-randomised controlled trials evidence.Peer reviewe
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