269 research outputs found

    Characterization of red-fleshed pear accessions from Emilia-Romagna region

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    Germplasm collections represent a reservoir of traits and genes that might be used in breeding programs to cope with the evolving market demand. Some old pear accessions still cultivated in the Apennine Mountains in Italy possess a red flesh fruit. This paper reports the molecular analysis of 33 red-fleshed pear accessions, collected in different areas of the Emilia-Romagna region and genotyped with 18 simple sequence repeat (SSR) markers with the aim of improving germplasm conservation strategies for old red-fleshed pears and for supporting ongoing breeding programs. The molecular profiles revealed both cases of synonymy and homonymy and only 6 unique genotypes were identified. S-genotypes were also established in order to highlight the genetic relationships among these landraces. Four of the unique genotypes have been clustered based on pomological data

    Transient magnetic domain wall ac dynamics by means of magneto-optical Kerr effect microscopy

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    The domain wall response under constant external magnetic fields reveals a complex behavior where sample disorder plays a key role. Furthermore, the response to alternating magnetic fields has only been explored in limited cases and analyzed in terms of the constant field solution. Here we unveil phenomena in the evolution of magnetic domain walls under the application of alternating magnetic fields within the creep regime, well beyond a small fuctuation limit of the domain wall position. Magnetic field pulses were applied in ultra-thin ferromagnetic films with perpendicular anisotropy, and the resulting domain wall evolution was characterized by polar magneto-optical Kerr effect microscopy. Whereas the DC characterization is well predicted by the elastic interface model, striking unexpected features are observed under the application of alternating square pulses: magneto-optical images show that after a transient number of cycles, domain walls evolve toward strongly distorted shapes concomitantly with a modification of domain area. The morphology of domain walls is characterized with a roughness exponent when possible and contrasted with alternative observables which result to be more suitable for the characterization of this transient evolution. The final stationary convergence as well as the underlying physics is discussed.Comment: 9 pages, 8 figure

    Multi-catheter cryotherapy for the treatment of resistant accessory pathways.

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    OBJECTIVE: To investigate the utility of simultaneous multi-catheter cryotherapy for the treatment of APs that were previously resistant to standard radiofrequency (RF) catheter ablation. BACKGROUND: Catheter ablation is established in the treatment of accessory pathways (AP), with high rates of permanent procedural success with a single attempt. However, there are still instances of acute procedural failure and AP recurrences with standard RF and cryotherapy methods. METHODS: Seven consecutive cases of pre-excitation syndromes with prior failed RF catheter ablation had the novel treatment. Cryotherapy was delivered using two 8 mm tip focal cryoablation catheters (Freezor® Max, Medtronic, Minneapolis, Minnesota, USA). RESULTS: Accessory pathway localisation was septal in 5 cases, left posterolateral in 1, right lateral in 1. In all cases, ablation of the AP was acutely successful with no procedural complications. Median procedure and fluoroscopy durations were 199 and 35 min, sequentially. Median Procedure duration fell significantly in the second half of series (174 min) compared to the first half (233 min, P = 0.05). One patient had evidence of a recurring AP conduction with pre-excitation at 5-week follow up. After a median follow up of 66.8+-6.5 months, 6 out of 7 patients remained asymptomatic and free of pre-excitation. CONCLUSION: Simultaneous multi-catheter cryotherapy is feasible, safe and can provide definitive cure of accessory pathways that were previously resistant to standard radiofrequency ablation. Further study is required in the assessment of this novel form of advanced cryotherapy to treat complex and resistant arrhythmias

    Results of the Patient-Related Outcomes of Mechanical lead Extraction Techniques (PROMET) study: a multicentre retrospective study on advanced mechanical lead extraction techniques.

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    AIMS: Several large studies have documented the outcome of transvenous lead extraction (TLE), focusing on laser and mechanical methods. To date there has been no large series addressing the results obtained with rotational lead extraction tools. This retrospective multicentre study was designed to investigate the outcomes of mechanical and rotational techniques. METHODS AND RESULTS: Data were collected on a total of 2205 patients (age 66.0 ± 15.7 years) with 3849 leads targeted for extraction in six European lead extraction centres. The commonest indication was infection (46%). The targeted leads included 2879 pacemaker leads (74.8%), 949 implantable cardioverter-defibrillator leads (24.6%), and 21 leads for which details were unknown; 46.6% of leads were passive fixation leads. The median lead dwell time was 74 months [interquartile range (IQR) 41-112]. Clinical success was obtained in 97.0% of procedures, and complete extraction was achieved for 96.5% of leads. Major complications occurred in 22/2205 procedures (1%), with a peri-operative or procedure-related mortality rate of 4/2205 (0.18%). Minor complications occurred in 3.1% of procedures. A total of 1552 leads (in 992 patients) with a median dwell time of 106 months (IQR 66-145) were extracted using the Evolution rotational TLE tool. In this subgroup, complete success was obtained for 95.2% of leads with a procedural mortality rate of 0.4%. CONCLUSION: Patient outcomes in the PROMET study compare favourably with other large TLE trials, underlining the capability of rotational TLE tools and techniques to match laser methods in efficacy and surpass them in safety
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