Recent progress in the truncated Lanczos method : application to hole-doped spin ladders

The truncated Lanczos method using a variational scheme based on Hilbert space reduction as well as a local basis change is re-examined. The energy is extrapolated as a power law function of the Hamiltonian variance. This systematic extrapolation procedure is tested quantitatively on the two-leg t-J ladder with two holes. For this purpose, we have carried out calculations of the spin gap and of the pair dispersion up to size 2x15.Comment: 5 pages, 4 included eps figures, submitted to Phys. Rev. B; revised versio

Recanalization of the Native Artery in Patients with Bypass Failure

Our objective was to evaluate the possible role of endovascular recanalization of occluded native artery after a failed bypass graft in the case of either acute or chronic limb-threatening ischemia otherwise leading to amputation. In a single-center retrospective clinical analysis, from January 2004 to March 2007 we collected 31 consecutive high-surgical-risk patients (32 limbs) with critical limb ischemia following late ([30 days after surgery) failure of open surgery bypass graft reconstruction. All patients deemed unfit for surgery underwent tentative endovascular recanalization of the native occluded arterial tract. The mean follow-up period was 24 (range, 6–42) months. Technical success was achieved in 30 (93.7%) of 32 limbs. The cumulative primary assisted patency calculated by Kaplan–Meyer analysis was 92% and 88%, respectively, at 12 and 24 months. The limb salvage rate approached 90% at 30 months. In conclusion, our experience shows the feasibility of occluded native artery endovascular recanalization after a failed bypass graft, with optimal results in terms of midterm arterial patency and limb salvage. Our opinion is that successful recanalization of the arterial tract previously considered unsuitable for endovascular approach is allowed by improved competency and experience of vascular specialists, as well as the advances made in catheter and guidewire technology. This group of patients would previously have been relegated to repeat bypass grafts, with their inherently inferior patency and recognized added technical demands. We recognize previous surgical native artery disconnection and lack of pedal runoff to be the main cause of technical failure. Keywords Native artery Bypass failure Endovascular recanalizatio

Evolution of the Spin Gap Upon Doping a 2-Leg Ladder

The evolution of the spin gap of a 2-leg ladder upon doping depends upon the nature of the lowest triplet excitations in a ladder with two holes. Here we study this evolution using various numerical techniques for a t-t'-J ladder as the next-near-neighbor hopping t' is varied. We find that depending on the value of t', the spin gap can evolve continuously or discontinuously and the lowest triplet state can correspond to a magnon, a bound magnon-hole-pair, or two separate quasi-particles. Previous experimental results on the superconducting two-leg ladder Sr12Ca2Cu24O41 are discussed.Comment: 4 pages, latex, submitted to PR

Inspiratory resistance decreases limb blood flow in COPD patients with heart failure

Hosp Clin Porto Alegre, Exercise Pathophysiol Res Lab, BR-90035007 Porto Alegre, RS, BrazilHosp Clin Porto Alegre, Div Cardiol, BR-90035007 Porto Alegre, RS, BrazilSerra Gaucha Coll, Phys Therapy Dept, Caxias Do Sul, RS, BrazilHosp Clin Porto Alegre, Pulmonary Div, Porto Alegre, RS, BrazilFed Univ Rio Grande, Fac Med, Dept Med, Porto Alegre, RS, BrazilUniversidade Federal de São Paulo, Dept Med, Div Resp Dis, Pulmonary Funct & Clin Exercise Physiol Unit, São Paulo, BrazilQueens Univ, Dept Med, Div Respirol, LACEP, Kingston, ON, CanadaKingston Gen Hosp, Kingston, ON K7L 2V7, CanadaUniversidade Federal de São Paulo, Dept Med, Div Resp Dis, Pulmonary Funct & Clin Exercise Physiol Unit, São Paulo, BrazilWeb of Scienc

Social media use and impact during the holiday travel planning process

Through an empirical study among holiday travellers, residing in the Former Soviet Union Republics, this paper presents a comprehensive view of role and impact of social media on the whole holiday travel planning process: Before, during and after the trip, providing insights on usage levels, scope of use, level of influence and trust. Findings suggest that social media are predominantly used after holidays for experience sharing. It is also shown that there is a strong correlation between perceived level of influence from social media and changes made in holiday plans prior to final decisions. Moreover, it is revealed that user-generated content is perceived as more trustworthy when compared to official tourism websites, travel agents and mass media advertising

Synchronous mucinous adenocarcinoma of the rectosigmoid seeding onto a pre-existing anal fistula

Carcinoma within a long-standing fistula-in-ano is rare and may be defined by specific neoplastic involvement of the fistulous track in the absence of rectal mucosal carcinoma. The presence of a carcinoma of mucinous histology occurring synchronously in the perianal region and the colon is exceptionally rare. We present a case with a review of the literature concerning its aetiopathogenesis and treatment. A 72-year-old man with a 2 months history of dark red rectal bleeding and mucus per rectum with alternating constipation and diarrhoea, was observed. Clinical examination and a barium enema showed a perianal fistula and an annular stenosing lesion of the rectosigmoid. Preoperative CT scan confirmed the colonic lesion. Colonic resection and wide fistula excision were performed. Histology showed an adenocarcinoma with a clear resection margins. The fistula also showed a similar histology. Chemoradiation (5-Fluorouracil (425 mg/m(2)) and Leucovorin (20 mg/m(2)) with 4500 cGy external beam radiotherapy was utilized. Subsequent clinical follow-up and CT examination of the patient has not revealed recurrent disease at 14 months

A Decisive Role of [18F] Fdg PET/CT for Diagnosis of Neoplastic Vascular Thrombosis: Report of A Case

The combined use of PET scan with CT and fluorodeoxyglucose ([18F]FDG) can modify, in selected oncologic patients, the clinical management and care. We report here the case of a 63-year old female who showed increase serum level of CEA 3 years following left colectomy for cancer. Ultrasound and CT (computed tomography) of the abdomen showed a single lesion in the segment II of the liver with portal thrombosis. [18F] FDG PET/CT revealed two lesions (the first area was histologically proven to be a colorectal carcinoma metastasis, the second one corresponded to the portal thrombosis). No antithrombotic drugs were administered and patient underwent chemotherapy for 4 courses (eloxatin plus 5-fluorouracil anf leucovorin). Liver resection was performed 2 weeks after the end of chemotherapy, and intraoperative ultrasound revealed a normal portal flow

EEG-based BCI Systems and IDIAP EEG Database

After giving an overview of the current BCI systems that use non-invasive techniques, we describe in details the database that has been acquired at IDIAP, under the Brain Machine Interface project

Mechanical analysis of the ENEA TF coil proposal for the EU DEMO fusion reactor

The design of the superconducting magnet system of the European DEMO fusion reactor is currently being pursued in the framework of the EUROfusion Magnets Work Package (WPMAG). Three alternative winding pack (WP) options for the Toroidal Field Coils (TFCs) are being proposed by different research units, each featuring a different conductor manufacturing technology (react-and-wind vs. wind-and-react) or winding layout (layer vs. pancake). One of the options (namely, WP#2), proposed by Italian ENEA, features a layer-wound WP design adopting a wind-and-react conductor with rectangular cross section with high aspect ratio, obtained squeezing an initially circular conductor. In order to assess the capability of all the TFC components to withstand the electromagnetic loads due to the huge Lorentz forces without any structural failure during the magnet lifetime, the mechanical analysis of the 2016 version of the WP#2 design option is performed here applying a hierarchical approach herein defined as the Stress Recovery Tool (SRT): the Finite Element Analysis (FEA) of a whole magnet (including the casing) is performed at a low computational cost adopting a coarse WP model with smeared (homogenized) properties. The displacements computed on the smeared WP are then used as boundary conditions for a refined FEA of some WP slices, located in selected (critical) poloidal positions, where all the conductors detailed features (jacket, insulations) are properly accounted for