Superconducting proximity effect in interacting quantum dots revealed by shot noise

We study the full counting statistics of charge transport through a quantum dot tunnel-coupled to one normal and one superconducting lead with a large superconducting gap. As function of the level detuning, there is a crossover from a regime with strong superconducting correlations in the quantum dot to a regime in which the proximity effect on the quantum dot is suppressed. We analyze the current fluctuations of this crossover in the shot-noise regime. In particular, we predict that the full counting statistics changes from Poissonian with charge 2e, typical for Cooper pairs, to Poissonian with charge e, when the superconducting proximity effect is present. Thus, the onset of the superconducting proximity effect is revealed by the reduction of the Fano factor from 2 to 1.Comment: 5 pages, 3 figure

Higher and lower active circulating VWF levels: different facets of von Willebrand disease

Most circulating von Willebrand factor (VWF) is normally inactive and incapable of binding platelets, but numerous disorders may modify the proportion of active VWF. We explored active VWF levels in patients with von Willebrand disease (VWD) whose VWF had a higher affinity for platelet glycoprotein (GP)Ib, but different susceptibilities to ADAMTS13 and multimer patterns (9 patients lacking large multimers, 10 with a normal pattern); 12 patients with VWF C2362F and R1819_C1948delinsS mutations, which make VWF resistant to ADAMTS13 were also studied. Type 2B patients with abnormal or normal multimers had significantly more active VWF (3\ub733 \ub1 1\ub76 and 3\ub774 \ub1 0\ub774, respectively; normal 0\ub799 \ub1 0\ub723). The type of VWF mutation influenced VWF activation: V1316M was associated with the highest levels in patients with abnormal multimers, and R1341W in those with normal multimers. Pregnancy induced gradually rising active VWF levels and declining platelet counts in one type 2B VWD patient without large multimers. Active VWF levels dropped significantly in patients homozygous for the C2362F mutation or heterozygous for R1819_C1948delinsS mutations (0\ub72 \ub1 0\ub703 and 0\ub723 \ub1 0\ub71, respectively), and less in cases heterozygous for the VWF C2362F mutation (0\ub755 \ub1 0\ub717). We demonstrate that VWF may be more or less activated, with or without any direct involvement of the A1 domain, and regardless of ADAMTS1

Higher and lower active circulating VWF levels : Different facets of von Willebrand disease

Most circulating von Willebrand factor (VWF) is normally inactive and incapable of binding platelets, but numerous disorders may modify the proportion of active VWF. We explored active VWF levels in patients with von Willebrand disease (VWD) whose VWF had a higher affinity for platelet glycoprotein (GP)Ib, but different susceptibilities to ADAMTS13 and multimer patterns (9 patients lacking large multimers, 10 with a normal pattern); 12 patients with VWF C2362F and R1819_C1948delinsS mutations, which make VWF resistant to ADAMTS13 were also studied. Type 2B patients with abnormal or normal multimers had significantly more active VWF (3·33 ± 1·6 and 3·74 ± 0·74, respectively; normal 0·99 ± 0·23). The type of VWF mutation influenced VWF activation: V1316M was associated with the highest levels in patients with abnormal multimers, and R1341W in those with normal multimers. Pregnancy induced gradually rising active VWF levels and declining platelet counts in one type 2B VWD patient without large multimers. Active VWF levels dropped significantly in patients homozygous for the C2362F mutation or heterozygous for R1819_C1948delinsS mutations (0·2 ± 0·03 and 0·23 ± 0·1, respectively), and less in cases heterozygous for the VWF C2362F mutation (0·55 ± 0·17). We demonstrate that VWF may be more or less activated, with or without any direct involvement of the A1 domain, and regardless of ADAMTS13

C2362F mutation gives rise to an ADAMTS13-resistant von Willebrand factor

Von Willebrand factor (VWF) multimers result from proteolysis by the metalloprotease ADAMTS13. Since C2362F-VWF features abnormally large multimers with their triplet oligomer structure replaced by a diffuse smear, we explored the susceptibility of C2362F-VWF to ADAMTS13. VWF-enriched blood samples, obtained by cryoethanol precipitation of plasma from a patient with von Willebrand disease (VWD) homozygous for the C2362F mutation and a normal subject, were submitted to cleavage by recombinant ADAMTS13 under static conditions in the presence of urea. C2362F-VWF proved completely ADAMTS13-resistant in vitro . At any concentration of recombinant ADAMTS13 (from 0.1 \ub5M to 1 \ub5M), there was no evidence of the abnormally large VWF multimers of C2362F-VWF disappearing, nor any increased representation of triplet multimer bands, unlike the situation seen in normal VWF. This is due partly to a defective ADAMTS13 binding to C2362F-VWF under static conditions, as seen in both the patient's and recombinant mutated VWF proteins. These findings were associated with a significantly shorter than normal survival of C2362F-VWF after DDAVP, demonstrating that proteolysis and VWF survival may be independent phenomena. Our findings clearly demonstrate that the loss of cysteine 2362 makes VWF resistant to proteolysis by ADAMTS13, at least partly due to an impaired ADAMTS13 binding to VWF. This suggests that the B2 domain of VWF is involved in modulating ADAMTS13 binding to VWF and the consequent proteolytic process. The C2362F-VWF mutation also enables a new abnormality to be identified in the VWF-ADAMTS13 relationship, i.e. an ADAMTS13-resistant VWF

SICE national survey: current status on the adoption of laparoscopic approach to the treatment of colorectal disease in italy

The real di usion of laparoscopy for the treatment of colorectal diseases in Italy is largely unknown. The main purpose of the present study is to investigate among surgeons dedicated to minimally invasive surgery, the volume of laparoscopic colorectal procedures, the type of operation performed in comparison to traditional approach, the indication for surgery (benign and malignant) and to evaluate the di erent types of technologies used. A structured questionnaire was developed in collaboration with an international market research institute and the survey was published online; invitation to participate to the survey was issued among the members of the Italian Society of Endoscopic Surgery (SICE). 211 surgeons working in 57 surgical departments in Italy ful lled and answered the online survey. A total of 6357 colorectal procedures were recorded during the year 2015 of which 4104 (64.1%) were performed using a minimally invasive approach. Colon and rectal cancer were the most common indications for laparoscopic approach (83.1%). Left colectomy was the operation most commonly performed (41.8%), while rectal resection accounted for 23.5% of the cases. Overall conversion rate was 5.9% (242/4104). Full HD standard technology was available and routinely used in all the responders’ centers. The proportion of colorectal resec- tions that are carried out laparoscopically in dedicated centers has now reached valuable levels with a low conversion ra

Determining the phase diagram of atomically thin layered antiferromagnet CrCl3

Changes in the spin configuration of atomically thin, magnetic van der Waals multilayers can cause drastic modifications in their opto-electronic properties. Conversely, the opto-electronic response of these systems provides information about the magnetic state, which is very difficult to obtain otherwise. Here, we show that in CrCl3 multilayers, the dependence of the tunnelling conductance on applied magnetic field, temperature and number of layers tracks the evolution of the magnetic state, enabling the magnetic phase diagram to be determined experimentally. Besides a high-field spin-flip transition occurring for all thicknesses, the in-plane magnetoconductance exhibits an even\u2013odd effect due to a low-field spin-flop transition. Through a quantitative analysis of the phenomena, we determine the interlayer exchange coupling as well as the layer magnetization and show that in CrCl3 shape anisotropy dominates. Our results reveal the rich behaviour of atomically thin layered antiferromagnets with weak magnetic anisotropy