Stratifying quotient stacks and moduli stacks

Recent results in geometric invariant theory (GIT) for non-reductive linear algebraic group actions allow us to stratify quotient stacks of the form [X/H], where X is a projective scheme and H is a linear algebraic group with internally graded unipotent radical acting linearly on X, in such a way that each stratum [S/H] has a geometric quotient S/H. This leads to stratifications of moduli stacks (for example, sheaves over a projective scheme) such that each stratum has a coarse moduli space.Comment: 25 pages, submitted to the Proceedings of the Abel Symposium 201

Dihydrolipoic acid reduces cytochrome b561 proteins.

Cytochrome b561 (Cyt-b561) proteins constitute a family of trans-membrane proteins that are present in a wide variety of organisms. Two of their characteristic properties are the reducibility by ascorbate (ASC) and the presence of two distinct b-type hemes localized on two opposite sides of the membrane. Here we show that the tonoplast-localized and the putative tumor suppressor Cyt-b561 proteins can be reduced by other reductants than ASC and dithionite. A detailed spectral analysis of the ASC-dependent and dihydrolipoic acid (DHLA)-dependent reduction of these two Cyt-b561 proteins is also presented. Our results are discussed in relation to the known antioxidant capability of DHLA as well as its role in the regeneration of other antioxidant compounds of cells. These results allow us to speculate on new biological functions for the trans-membrane Cyt-b561 proteins

Safety, Clinical Outcome, and Fracture Rate of Femoropopliteal Stenting Using a 4F Compatible Delivery System.

OBJECTIVE: To determine the safety, clinical outcome, and fracture rate of femoropopliteal interventions using 4F stents. METHODS: Between January 2010 and December 2011, 112 symptomatic patients were treated by stent implantation. Ten patients were lost to follow up; therefore, 102 patients (62 men; mean age 66.4 +/- 10.1 years) were retrospectively analyzed. The indication for femoropopliteal revascularization was severe claudication (Rutherford-Becker score = 3) in 63 (62%) patients and chronic critical limb ischemia (Rutherford-Becker score = 4-6) in 39 (38%). Follow up included palpation of peripheral pulses and measurement of ankle brachial index. In patients with suspected in-stent restenosis duplex ultrasonography was performed. In 2013, patients were asked to return for a fluoroscopic examination of the stents. RESULTS: 114 lesions (Trans-Atlantic InterSociety Consensus-C and D, n = 45) were treated with 119 stents (Astron Pulsar, n = 42; Pulsar-18, n = 77). Lesions were long (>/=100 mm) in 49 cases and heavily calcified in 35. Stents were long (>/=120 mm) in 46 cases. Ten stents were partially overlapped. The technical and clinical success rates were 100%. Two puncture related complications were noted, neither of which required surgical repair. Eleven patients died (myocardial infarction, n = 4; stroke, n = 2; cancer, n = 5) and nine patients underwent major amputation (above knee, n = 4). The primary patency rate was 83% at 6 months and 80% at 12 months. The primary assisted patency rate was 97% at 6 months and 94% at 12 months. The secondary patency rate was 86% at 6 months and 85% at 12 months. The prevalence of fractures was 26% (type III and IV, 10%) after an average follow up of 25 months. CONCLUSION: Femoropopliteal stenting using a 4F compatible delivery system can be accomplished with a low complication rate, acceptable fracture rate, and with similar 12 month patency and revascularization rates as their 6F counterparts

Percutaneous Endovascular Treatment of Innominate Artery Lesions

AbstractPurposeTo assess primary success and safety of percutaneous transluminal angioplasty and/or stenting of innominate artery lesions and to compare its 30-day stroke/mortality level with the literature data.MethodsA total of 72 patients (77 stenoses, five recurrent, 58 symptomatic and 39 female) with seven innominate vessel occlusions, nine subocclusive lesions and 61 significant (>60%) stenoses of innominate artery treated between 2000 and 2009 were retrospectively reviewed. With the exception of seven, all procedures were performed using a transfemoral approach. A stent was implanted in 49 (63.6%) cases. Follow-up included neurological examination, carotid duplex scan and office/telephone interview.ResultsPrimary technical success was 93.5% (72/77). There was neither periprocedural (<48h) death, nor major neurological complication. Minor periprocedural neurological complications consisted of 2/72 (2.6%) ipsilateral TIAs. Access site complications included 4 (5.2%) access site bleedings. Follow-up was achieved in 65/72 (90.3%) of all patients and 68 (88.3%) of all procedures for a mean of 42.3 months and revealed neither major neurological complication, nor additional TIA.The cumulative primary patency rate was 100% at 12 months, 98±1.6% at 24 months, and 69.9±8.5% at 96 months. The cumulative secondary patency rate was 100% at 12 and at 24 months, and 81.5±7.7% at 96 months. Log-rank test showed no significant difference (p=0.79) in primary cumulative patencies between PTA alone (n=28) or PTA/stent (n=49).ConclusionTransfemoral PTA with or without stent appears to be a safe treatment option for innominate artery lesions

Stent-graft Treatment of Carotid Pseudoaneurysms: Case Report and Review of the Literature

Over the past decades the treatment technique for carotid aneurysms has changed. Endovascular methods have become more widespread and offer an alternative to surgery, which is often difficult in this region. Stent-graft treatment is a less invasive approach to exclude the aneurysm while maintaining patency of the carotid artery. We report two cases of internal carotid artery pseudoaneurysm which were treated using Wallgraft®. © 2005 Elsevier Ltd. All rights reserved