Benchmark calculation of p-3H and n-3He scattering

p-3H and n-3He scattering in the energy range above the n-3He but below the d-d thresholds is studied by solving the 4-nucleon problem with a realistic nucleon-nucleon interaction. Three different methods -- Alt, Grassberger and Sandhas, Hyperspherical Harmonics, and Faddeev-Yakubovsky -- have been employed and their results for both elastic and charge-exchange processes are compared. We observe a good agreement between the three different methods, thus the obtained results may serve as a benchmark. A comparison with the available experimental data is also reported and discussed.Comment: 13 pages, 6 figures. arXiv admin note: text overlap with arXiv:1109.362

Urgent reoperative transapical valve-in-valve shortly after a transapical aortic valve implantation.

Urgent reoperative transapical aortic valve-in-valve has never been proposed as a treatment option in case of a failed transcatheter aortic valve implantation (TAVI) or in case of worsening of an existing paravalvular leak, if this complication occurs right after, or a few days after, the primary transapical aortic valve implantation. Experienced surgeons should argue that after a transapical TAVI, the apex is damaged and fragile, with a high risk of irreparable ventricular tears and life-threatening bleeding if a second transapical procedure is scheduled during the acute phase. Nevertheless, if the patient is inoperable and the vascular status, including the ascending aorta, limits alternative accesses, the urgent reoperative transapical valve-in-valve becomes an alternative. We illustrate, for the first time ever, our experience with an 81-year old female patient who underwent a transapical (TA) TAVI with a Sapien? XT 23 mm. The day after the procedure, the patient haemodynamically worsened in combination with a worsening of a known (grade 1-2) paravalvular leak. Thus, on postoperative day two, an urgent transapical valve-in-valve was performed, and a second Sapien? XT 23 mm was placed, with an excellent haemodynamic result and absence of leak. The redo apical access did not appear very complicated and the postoperative recovery was uneventful

Antibody-drug conjugates (ADC) against cancer stem-like cells (CSC) - Is there still room for optimism?

Cancer stem-like cells (CSC) represent a subpopulation of tumor cells with peculiar functionalities that distinguish them from the bulk of tumor cells, most notably their tumor-initiating potential and drug resistance. Given these properties, it appears logical that CSCs have become an important target for many pharma companies. Antibody-drug conjugates (ADC) have emerged over the last decade as one of the most promising new tools for the selective ablation of tumor cells. Three ADCs have already received regulatory approval and many others are in different phases of clinical development. Not surprisingly, also a considerable number of anti-CSC ADCs have been described in the literature and some of these have entered clinical development. Several of these ADCs, however, have yielded disappointing results in clinical studies. This is similar to the results obtained with other anti-CSC drug candidates, including native antibodies, that have been investigated in the clinic. In this article we review the anti-CSC ADCs that have been described in the literature and, in the following, we discuss reasons that may underlie the failures in clinical trials that have been observed. Possible reasons relate to the biology of CSCs themselves, including their heterogeneity, the lack of strictly CSC-specific markers, and the capacity to interconvert between CSCs and non-CSCs; second, inherent limitations of some classes of cytotoxins that have been used for the construction of ADCs; third, the inadequacy of animal models in predicting efficacy in humans. We conclude suggesting some possibilities to address these limitations

Nonlinear Gamow vectors in nonlocal optical propagation

Shock waves dominate in a wide variety of fields in physics dealing with nonlinear phenomena, nevertheless the description of their evolution is not resolved for the entire dynamics. Here we propose an analytical method based on Gamow vectors, which belong to irreversible quantum mechanics. We theoretically and experimentally show the appearance of these decaying states during shock evolution allowing to describe the whole wave propagation. These results open new ways to the control of extreme nonlinear regimes such as supercontinuum generation or in the analogies of fundamental physical theories

3D #DigitalInvasions: a crowdsourcing project for mobile user generated content

This paper introduces the #InvasioniDigitali project which is an online crowdsourcing initiative started in Italy in 2013 with the aim to promote the value of and engagement with local heritage. The paper focuses on two case studies of pilot ‘invasions’ using 3D data capture by students at museums and heritage sites in Sicily

Local chiral potentials and the structure of light nuclei

We present fully local versions of the minimally non-local nucleon-nucleon potentials constructed in a previous paper [M.\ Piarulli {\it et al.}, Phys.\ Rev.\ C {\bf 91}, 024003 (2015)], and use them in hypersperical-harmonics and quantum Monte Carlo calculations of ground and excited states of $^3$H, $^3$He, $^4$He, $^6$He, and $^6$Li nuclei. The long-range part of these local potentials includes one- and two-pion exchange contributions without and with $\Delta$-isobars in the intermediate states up to order $Q^3$ ($Q$ denotes generically the low momentum scale) in the chiral expansion, while the short-range part consists of contact interactions up to order $Q^4$. The low-energy constants multiplying these contact interactions are fitted to the 2013 Granada database in two different ranges of laboratory energies, either 0--125 MeV or 0--200 MeV, and to the deuteron binding energy and $nn$ singlet scattering length. Fits to these data are performed for three models characterized by long- and short-range cutoffs, $R_{\rm L}$ and $R_{\rm S}$ respectively, ranging from $(R_{\rm L},R_{\rm S})=(1.2,0.8)$ fm down to $(0.8,0.6)$ fm. The long-range (short-range) cutoff regularizes the one- and two-pion exchange (contact) part of the potential.Comment: 29 pages, 3 figure

Observation of Fermi-Pasta-Ulam-Tsingou Recurrence and Its Exact Dynamics

One of the most controversial phenomena in nonlinear dynamics is the reappearance of initial conditions. Celebrated as the Fermi-Pasta-Ulam-Tsingou problem, the attempt to understand how these recurrences form during the complex evolution that leads to equilibrium has deeply influenced the entire development of nonlinear science. The enigma is rendered even more intriguing by the fact that integrable models predict recurrence as exact solutions, but the difficulties involved in upholding integrability for a sufficiently long dynamic has not allowed a quantitative experimental validation. In natural processes, coupling with the environment rapidly leads to thermalization, and finding nonlinear multimodal systems presenting multiple returns is a long-standing open challenge. Here, we report the observation of more than three Fermi-Pasta-Ulam-Tsingou recurrences for nonlinear optical spatial waves and demonstrate the control of the recurrent behavior through the phase and amplitude of the initial field. The recurrence period and phase shift are found to be in remarkable agreement with the exact recurrent solution of the nonlinear Schrödinger equation, while the recurrent behavior disappears as integrability is lost. These results identify the origin of the recurrence in the integrability of the underlying dynamics and allow us to achieve one of the basic aspirations of nonlinear dynamics: the reconstruction, after several return cycles, of the exact initial condition of the system, ultimately proving that the complex evolution can be accurately predicted in experimental conditions

Local chiral interactions and magnetic structure of few-nucleon systems

The magnetic form factors of $^2$H, $^3$H, and $^3$He, deuteron photodisintegration cross sections at low energies, and deuteron threshold electrodisintegration cross sections at backward angles in a wide range of momentum transfers, are calculated with the chiral two-nucleon (and three-nucleon) interactions including $\Delta$ intermediate states that have recently been constructed in configuration space. The $A\,$=$\,$3 wave functions are obtained from hyperspherical-harmonics solutions of the Schr\"odinger equation. The electromagnetic current includes one- and two-body terms, the latter induced by one- and two-pion exchange (OPE and TPE, respectively) mechanisms and contact interactions. The contributions associated with $\Delta$ intermediate states are only retained at the OPE level, and are neglected in TPE loop (tree-level) corrections to two-body (three-body) current operators. Expressions for these currents are derived and regularized in configuration space for consistency with the interactions. The low-energy constants that enter the contact few-nucleon systems. The predicted form factors and deuteron electrodisintegration cross section are in excellent agreement with experiment for momentum transfers up to 2--3 fm$^{-1}$. However, the experimental values for the deuteron photodisintegration cross section are consistently underestimated by theory, unless use is made of the Siegert form of the electric dipole transition operator. A complete analysis of the results is provided, including the clarification of the origin of the aforementioned discrepancy.Comment: 24 pages, 13 figure

The X17 boson and the 3^3H(p,e+e−)4(p,e^+ e^-)^4He and 3^3He(n,e+e−)4(n,e^+ e^-)^4He processes: a theoretical analysis

The present work deals with $e^+$-$e^-$ pair production in the four-nucleon system. We first analyze the process as a purely electromagnetic one in the context of a state-of-the-art approach to nuclear strong-interaction dynamics and nuclear electromagnetic currents, derived from chiral effective field theory ($\chi$EFT). Next, we examine how the exchange of a hypothetical low-mass boson would impact the cross section for such a process. We consider several possibilities, that this boson is either a scalar, pseudoscalar, vector, or axial particle. The ab initio calculations use exact hyperspherical-harmonics methods to describe the bound state and low-energy spectrum of the $A\,$=$\,4$ continuum, and fully account for initial state interaction effects in the $3+1$ clusters. While electromagnetic interactions are treated to high orders in the chiral expansion, the interactions of the hypothetical boson with nucleons are modeled in leading-order $\chi$EFT (albeit, in some instances, selected subleading contributions are also accounted for). We also provide an overview of possible future experiments probing pair production in the $A\,$=$\,4$ system at a number of candidate facilities.facilities.Comment: 32 pages, 17 figures. Corrected version, having fixed a problem with a phase in the multipolar expansions. Only Figs. 4 and 10 change significantly, the rest only marginally. The conclusions are unchanged. We include also a number of improvements: 1) better wave functions, 2) the isoscalar pseudoscalar case, and 3) the comparison with the new ATOMKI data (see new Fig. 17

Identification of High Platelet Reactivity Despite ADP P2Y12 Inhibitor Treatment: Two Populations in the Vasodilator-Stimulated Phosphoprotein Assay and Variable PFA-P2Y Shapes of Curve.

Introduction Response to ADP P2Y <sub>12</sub> receptor inhibition by clopidogrel can be evaluated by various techniques. Here, we compared a functional rapid point-of-care technique (PFA-P2Y) with the degree of biochemical inhibition assessed by the VASP/P2Y <sub>12</sub> assay. Methods Platelet response to clopidogrel was investigated in 173 patients undergoing elective intracerebral stenting (derivation cohort n = 117; validation cohort n = 56). High platelet reactivity (HPR) was defined as PFA-P2Y occlusion time <106 seconds or VASP/P2Y <sub>12</sub> platelet reactivity index (PRI) >50%. Results In the derivation cohort, receiver operator characteristics analysis for the ability of PFA-P2Y to detect biochemical HPR showed high specificity (98.4%) but poor sensitivity (20.0%) and a very low area under the curve (0.59). The VASP/P2Y <sub>12</sub> assay revealed two coexisting platelet populations with different levels of vasodilator-stimulated phosphoprotein (VASP) phosphorylation: a fraction of highly phosphorylated, inhibited platelets and another of poorly phosphorylated, reactive platelets. Analysis of the PFA-P2Y curve shape revealed different types, categorized by time of occlusion (<106 seconds, 106 to 300 seconds, >300 seconds), and pattern (regular, irregular, and atypical). Noteworthy, curves with late occlusion and permeable curves with an irregular or atypical pattern correlated with VASP-PRI >50% and smaller sizes of the inhibited platelet subpopulation. Considering the PFA-P2Y shape of the curve for the detection of HPR improved sensitivity (72.7%) and preserved specificity (91.9%), with a rather high AUC (0.823). The validation cohort confirmed the VASP/P2Y <sub>12</sub> assay data and the usefulness of considering the PFA-P2Y curve shape. Conclusion In patients treated with acetylsalicylic acid and clopidogrel for 7-10 days, the VASP/P2Y <sub>12</sub> assay reveals two coexisting subpopulations of differentially inhibited platelets, whose relative sizes predict global PRI and distinct PFA-P2Y curve patterns, indicating incomplete clopidogrel efficacy. The detailed analysis of both VASP/P2Y <sub>12</sub> and PFA-P2Y is necessary for optimal detection of HPR