Graded Hecke algebras for disconnected reductive groups

We introduce graded Hecke algebras H based on a (possibly disconnected) complex reductive group G and a cuspidal local system L on a unipotent orbit of a Levi subgroup M of G. These generalize the graded Hecke algebras defined and investigated by Lusztig for connected G. We develop the representation theory of the algebras H. obtaining complete and canonical parametrizations of the irreducible, the irreducible tempered and the discrete series representations. All the modules are constructed in terms of perverse sheaves and equivariant homology, relying on work of Lusztig. The parameters come directly from the data (G,M,L) and they are closely related to Langlands parameters. Our main motivation for considering these graded Hecke algebras is that the space of irreducible H-representations is canonically in bijection with a certain set of "logarithms" of enhanced L-parameters. Therefore we expect these algebras to play a role in the local Langlands program. We will make their relation with the local Langlands correspondence, which goes via affine Hecke algebras, precise in a sequel to this paper.Comment: Theorem 3.4 and Proposition 3.22 in version 1 were not entirely correct as stated. This is repaired in a new appendi

Temperature dependence of electrical properties of electrodeposited Ni-based nanowires

The influence of annealing on the microstructure and the electrical properties of cylindrical nickel-based nanowires has been investigated. Nanowires of nickel of nominally 200 nm diameter and of permalloy (Py) of nominally 70 nm were fabricated by electrochemical deposition into nanoporous templates of polycarbonate and anodic alumina, respectively. Characterization was carried out on as-grown nanowires and nanowires heat treated at 650°C. Transmission electron microscopy and diffraction imaging of as-grown and annealed nanowires showed temperature-correlated grain growth of an initially nano-crystalline structure with ≤8 nm (Ni) and ≤20 nm (Py) grains towards coarser poly-crystallinity with grain sizes up to about 160 nm (Ni) and 70 nm (Py), latter being limited by the nanowire width. The electrical conductivity of individual as-grown and annealed Ni nanowires was measured in situ within a scanning electron microscope environment. At low current densities, the conductivity of annealed nanowires was estimated to have risen by a factor of about two over as-grown nanowires. We attribute this increase, at least in part, to the observed grain growth. The annealed nanowire was subsequently subjected to increasing current densities. Above 120 kA mm -2 the nanowire resistance started to rise. At 450 kA mm -2 the nanowire melted and current flow ceased

Optimizing surgical techniques in extra-anatomical ilio-femoral bypasses

Scopul lucrării. Bypass-ul extraanatomic ilio-femural crossover este o procedura chirurgicala utilizată pentru revascularizarea segmentului aorto-femural, când intervențiile endovasculare nu sunt posibile, iar aplicarea unui bypass aorto sau ilio-femural este dificilă sau chiar imposibilă din cauza condițiilor tehnice sau a stării pacientului. Scopul este studierea rezultatelor precoce și tardive pentru favorizarea unor schimbări și implementarea unor gesturi tehnice în aplicarea bypass-urilor crossover ilio-femural, pentru a crea o geometrie cât mai fiziologică ce poate oferi o soluție durabilă pe termen lung. Materiale și metode. Pe parcursul anilor 2001-2022 au fost efectuate 142 bypass-uri crossover ilio-femurale. Rezultate. În perioada postoperatorie a fost un singur deces și s-au efectuat 3 amputații. Au fost analizate duplex scanările și CT angiografiile în primele 12 luni postoperatorii, pentru aprecierea altor leziuni aterosclerotice, care ar necesita revascularizare deschisă s-au endovasculară atît in bazinul recipient cât și cel donator. Totodată, a fost apreciata poziția și forma bypass-ului ce a dus la folosirea ulterioară a unor noi procedee tehnice ce diferă de cele descrise anterior. Concluzii. Optimizarea tehnicilor chirurgicale creând o geometrie cât mai fiziologică, excluderea maximală a angulărilor stenozante ale grefei poate oferi bypass-ului extraanatomic crossover ilio-femural o durabilitate îndelungată. Acest lucru poate favoriza creșterea frecvenței indicațiilor la folosirea bypass-urilor crossover ilio-femural.Aim of study. The extra-anatomic ilio-femoral crossover bypass is a surgical procedure used for revascularizing the aorto-femoral segment when endovascular interventions are not possible, and when applying an aorto- or ilio-femoral bypass is difficult or even impossible due to technical conditions or the patient's condition. The aim was to study the early and late outcomes to promote changes and implement technical gestures in the application of ilio-femoral crossover bypasses, aiming to create a more physiological geometry that can provide a durable long-term solution. Materials and methods. Between 2001 and 2022, a total of 142 ilio-femoral crossover bypasses were performed. Results. There was one death and three amputations in the postoperative period. Duplex scans and CT angiography were analyzed in the first 12 months postoperatively to assess other atherosclerotic lesions that would require open or endovascular revascularization in both the recipient and donor areas. Additionally, the position and shape of the bypass were evaluated, leading to the subsequent use of new technical procedures that differ from those previously described. Conclusions. Optimizing surgical techniques by creating a more physiological geometry and minimizing stenotic angles of the graft can provide the extra-anatomic ilio-femoral crossover bypass with long-lasting durability. This may increase the frequency of indications for using ilio-femoral crossover bypasses

Dirac cohomology, elliptic representations and endoscopy

The first part (Sections 1-6) of this paper is a survey of some of the recent developments in the theory of Dirac cohomology, especially the relationship of Dirac cohomology with (g,K)-cohomology and nilpotent Lie algebra cohomology; the second part (Sections 7-12) is devoted to understanding the unitary elliptic representations and endoscopic transfer by using the techniques in Dirac cohomology. A few problems and conjectures are proposed for further investigations.Comment: This paper will appear in `Representations of Reductive Groups, in Honor of 60th Birthday of David Vogan', edited by M. Nervins and P. Trapa, published by Springe

On the elliptic nonabelian Fourier transform for unipotent representations of p-adic groups

In this paper, we consider the relation between two nonabelian Fourier transforms. The first one is defined in terms of the Langlands-Kazhdan-Lusztig parameters for unipotent elliptic representations of a split p-adic group and the second is defined in terms of the pseudocoefficients of these representations and Lusztig's nonabelian Fourier transform for characters of finite groups of Lie type. We exemplify this relation in the case of the p-adic group of type G_2.Comment: 17 pages; v2: several minor corrections, references added; v3: corrections in the table with unipotent discrete series of G

Pathological elongation of the internal carotid artery: surgical treatment and immediate postoperative results

Scopul lucrării. În structura cauzelor dezvoltării insuficienței cerebrovasculare, elongarea patologică a arterei carotide interne ocupă locul 2, după afectarea aterosclerotică. Prevalența dolicoarteriopatiei la populația generală se estimează a fi de la 10 la 40 %, iar de la 16% până la 56 % din pacienți au în anamnestic deficit neurologic tranzitor sau permanent. Scopul lucrării este optimizarea tehnicilor chirurgicale și aprecierea eficienței postoperatorii imediate la pacienții cu elongare patologică a arterei carotide interne. Materiale și metode. Studiul efectuat reprezintă o analiză retrospectivă a 243 pacienți, tratați în cadrul IMSP SCR ,,Timofei Moșneaga”, secția de Chirurgie Vasculară în perioada 2002-2022. Rezultate. La pacienții supuși studiului s-a efectuat 258 intervenții chirurgicale. Rezultatele imediate au fost: la 230 pacienți (89.14 %) a dispărut simptomatologia preoperatorie, AVC ischemic s-a înregistrat la 1 pacient, sindrom coronarian acut sau deces nu s-a înregistrat la nici un pacient din lotul studiat. Concluzii. Luând în considerare rata mică de complicații periprocedurale precum și eficacitatea postoperatorie imediată evidentă, putem spune că intervenția chirurgicală în tratamentul elongărilor patologice ale arterelor carotide interne reprezintă o metoda sigură și eficientă pentru prevenirea accidentelor vasculare cerebrale acute și îmbunătățirea calității vieții pacienților.Aim of study. Among the causes contributing to the development of cerebrovascular insufficiency, pathological elongation of the internal carotid artery ranks second after atherosclerotic involvement. The prevalence of dolichoarteriopathy in the general population is estimated to range from 10% to 40%, and between 16% and 56% of patients have a history of transient or permanent neurological deficits. The aim of this study was to optimize surgical techniques and assess immediate postoperative efficacy in patients with pathological elongation of the internal carotid artery. Materials and methods. This study represents a retrospective analysis of 243 patients treated at the State Medical and Pharmaceutical University "Timofei Moșneaga", Department of Vascular Surgery, between 2002 and 2022. Results. A total of 258 surgical interventions were performed in the study group. The immediate results were as follows: symptomatology disappeared in 230 patients (89.14%), one patient experienced an ischemic stroke, and no cases of acute coronary syndrome or death were recorded among the studied patients. Conclusions. Considering the low rate of periprocedural complications and the evident immediate postoperative effectiveness, it can be concluded that surgical intervention for the treatment of pathological elongation of the internal carotid artery is a safe and efficient method for preventing acute cerebrovascular accidents and improving the quality of life for patients

Surgical treatment tactics in renal cell carcinoma with metastatic thrombus in the inferior cava vein

Secția Chirurgie Vasculară, Laboratorul de Cardiologie Intervențională și Endochirurgie, IMSP Spitalul Clinic Republican”Timofei Moșneaga”, Chișinău, Republica Moldova, Al XIII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” și al III-lea Congres al Societății de Endoscopie, Chirurgie miniminvazivă și Ultrasonografie ”V.M.Guțu” din Republica MoldovaIntroducere: Pacienții cu cancer renal reprezintă 15.3 cazuri noi per 100,000 populație anual raportate în Statele Unite ale Americii. Material și metode: Pe parcursul anilor 2010-2019, în secția de chirurgie vasculară a IMSP SCR “Timofei Mosneaga”, au fost operați 34 pacienti cu diagnosticul de cancer renal cu concreștere și tromb metastatic în vena cavă inferioară. În dependență de tipul trombului metastatic in vena cava inferioara au fost abordate diferite metode de acces, mobilizare și trombectomie cu sau fară plastie a defectului parietal. Rezultate: Histologic a fost descoperit cancerul renal cu celule clare la toți pacienții, ce reprezintă 80-90% din cancerele renale. Durata medie de spitalizare a pacienților a fost de 9 zile. Concluzii: Nefrectomia si trombectomia din vena cava inferioara în cazul hipernefroamelor cu tromb metastatic în vena cava inferioară pot fi efectuate în siguranță cu o rata înaltă de supraviețuire la distanță a pacienților. Tipul de acces și mobilizare a venei cave depinde de nivelul extinderii trombului metastatic. Suportul de circulație extracorporeală este necesar doar în cazurile de extindere intracardiacă a trombului metastatic.Introduction: Patients suffering from renal cancer, represent 15.3 new cases per 100,000 populations, annualy reported in the United States of America. Materials and methods: During 2010-2019, 34 patients with renal cancer involving ingrow and the inferior cava vein metatstatic thrombus underwent surgery in Vascular Surgery Department PBI CRH “Timofei Mosneaga”. Depending on the inferior cava vein metastatic thrombus type, were used different access, mobilization and thrombectomy types, with or without parietal defect plastics. Results: Clear cell renal cancer was confirmed histologically in all patients, that represents 80-90 % of the total amount of renal cancers. Average hospital stay represented 9 days after surgery. Conclusions: Nephrectomy and inferior cava vein thrombectomy, in renal cancer with inferior cava vein metastatic thrombus, can be performed safely, with a high rate of survival, also at distance in time. The type of access and mobilization of the cava vein depends on the level of metastatic thrombus enlargement. Extracorporeal circulation is necessary only in cases that include intracardiac thrombus extension

A European study on decellularized homografts for pulmonary valve replacement: initial results from the prospective ESPOIR Trial and ESPOIR Registry data\u2020

OBJECTIVES: Decellularized pulmonary homografts (DPH) have shown excellent results for pulmonary valve replacement. However, controlled multicentre studies are lacking to date.METHODS: Prospective European multicentre trial evaluating DPH for pulmonary valve replacement. Matched comparison of DPH to bovine jugular vein (BJV) conduits and cryopreserved homografts (CH) considering patient age, type of heart defect and previous procedures.RESULTS: In total, 121 patients (59 female) were prospectively enrolled (August 2014-December 2016), age 21.3 +/- 14.4 years, DPH diameter 24.4 +/- 2.8 mm. No adverse events occurred with respect to surgical handling; there were 2 early deaths (30 + 59 years) due to myocardial failure after multi-valve procedures and no late mortality (1.7% mortality). After a mean follow-up of 2.2 +/- 0.6 years, the primary efficacy end points mean peak gradient (16.1 +/- 12.1 mmHg) and regurgitation (mean 0.25 +/- 0.48, grade 0-3) were excellent. One reoperation was required for recurrent subvalvular stenosis caused by a pericardial patch and 1 balloon dilatation was performed on a previously stented LPA. 100% follow-up for DPH patients operated before or outside the trial (n = 114) included in the ESPOIR Registry, age 16.6 +/- 10.4 years, diameter 24.1 +/- 4.2 mm, follow-up 5.1 +/- 3.0 years. The combined DPH cohort, n = 235, comprising both Trial and Registry data showed significantly better freedom from explantation (DPH 96.7 +/- 2.1%, CH 84.4 +/- 3.2%, P = 0.029 and BJV 82.7 +/- 3.2%, P = 0.012) and less structural valve degeneration at 10 years when matched to CH, n = 235 and BJV, n = 235 (DPH 61.4 +/- 6.6%, CH 39.9 +/- 4.4%, n.s., BJV 47.5 +/- 4.5%, P = 0.029).CONCLUSIONS: Initial results of the prospective multicentre ESPOIR Trial showed DPH to be safe and efficient. Current DPH results including Registry data were superior to BJV and CH.Thoracic Surger

Carotid-brachial bypass in severe upper limb ischemia

Scopul lucrării. În ocluziile axului arterial subclavio-axilar cu ischemie severă a membrului superior s-ar impune folosirea metodelor endovasculare sau aplicarea unui bypass ortotop. În cazul imposibilității din motive tehnice sau stării pacientului drept alternativă servește bypass-ul carotido-brahial. Scopul studiului este aprecierea posibilității utilizării bypass-ului extraanatomic carotido-brahial în revascularizarea membrului superior în ischemia severă. Materiale și metode. Studiul cuprinde 5 pacienți cu ocluzia axului subclavio-axilar cu ischemie severă a membrului superior, dintre care 3 cu ocluzie acută pe fondal de stenoze aterosclerotice, la care intervenția inițială de trombectomie (embolectomie) a eșuat, un pacient cu tromboza anevrismului a. subclaviculare și un pacient cu ocluzie aterosclerotică de gradul IV cu gangrena degetului II, la care intervenția endovasculară a eșuat. La toți pacienții s-a aplicat un bypass carotido-brahial cu grefon safen intern inversat. Grefele au fost amplasate suprafascial supraclavicular. Rezultate. La toți 5 pacienți ischemia a cedat complet. La 4 din ei s-a restabilit pulsul distal. La pacientul cu ateroscleroză cronică de gradul IV, cu afectarea concomitentă a arterelor antebrațului, pulsul s-a restabilit la bifurcația arterei brahiale. La acest pacient s-a efectuat amputația degetului. Complicații nu s-au înregistrat. Incomodități subiective din cauza amplasării suprafasciale și supraclaviculare a bypass-urilor deasemenea n-au fost înregistrate. Concluzii. Bypass-urile carotido-brahiale localizate suprafascial și supraclavicular servesc o alternativă a bypass-urilor ortotope inclusiv în cazurile eșecurilor sau contraindicațiilor metodelor endovasculare.Aim of study. In cases of occlusion of the subclavian-axillary arterial axis with severe upper limb ischemia, the use of endovascular methods or the application of an orthotopic bypass may be necessary. In case of technical impossibility or patient condition, carotidbrachial bypass serves as an alternative. The objective of the study is to evaluate the possibility of using extra-anatomic carotidbrachial bypass for revascularization of the upper limb in severe ischemia Materials and methods. The study includes 5 patients with occlusion of the subclavian-axillary axis and severe upper limb ischemia, of which 3 had acute occlusion due to atherosclerotic stenosis, with initial thrombectomy (embolectomy) being unsuccessful. One patient had subclavian artery aneurysm thrombosis, and one patient had grade IV atherosclerotic occlusion with gangrene of the second digit, in whom endovascular intervention was unsuccessful. Carotid-brachial bypass with an inverted internal saphenous vein graft was performed in all patients. The grafts were placed in a suprafascial supraclavicular position. Results. Complete resolution of ischemia was achieved in all 5 patients. Distal pulses were restored in 4 of them. In the patient with chronic grade IV atherosclerosis and concomitant involvement of the forearm arteries, the pulse was restored at the brachial artery bifurcation. Digit amputation was performed in this patient. No complications were recorded, and there were no subjective discomforts related to the suprafascial and supraclavicular placement of the bypasses. Conclusions. Suprafascial and supraclavicular carotid-brachial bypasses serve as an alternative to orthotopic bypasses, including in cases of failure or contraindications to endovascular methods