ABSTRACT
The ITER Radial Gamma-Ray Spectrometer (RGRS) consists of three gamma-ray detectors observing the plasma through three collimated, coplanar, radial lines of sight (LoS). The system was initially designed to monitor the runaway electron emission and the alpha-particle density profile [Nocente et al., Nucl. Fusion 57, 076016 (2017)]. This work presents a novel technique for measuring the fusion power during D-T operation using the RGRS. This method is based on the absolute measurement of the 17 MeV fusion gamma-rays and a semi-analytical computation of their transport from the plasma source to the detectors. This approach was initially developed and tested at JET during the second D-T campaign (DTE2) on a single LoS diagnostic [Dal Molin et al., Phys. Rev. Lett. (submitted) (2024); Rebai et al., Phys. Rev. C (submitted) (2024); and Marcer et al., Nucl. Fusion (unpublished) (2024)]. This work exploits the multiple LoS of the RGRS to create a combined virtual diagnostic whose detected fraction of the total plasma emission is less affected by variations in the plasma emission profile, reducing systematic uncertainties on the estimated total emission, compared to the individual detectors.
ABSTRACT
At present, magnetic confinement fusion devices rely solely on absolute neutron counting as a direct way of measuring fusion power. Absolute counting of deuterium-tritium gamma rays could provide the secondary neutron-independent technique required for the validation of scientific results and as a licensing tool for future power plants. However, this approach necessitates an accurate determination of the gamma-ray-to-neutron branching ratio. The gamma-ray-to-neutron branching ratio for the deuterium-tritium reaction ^{3}H(^{2}H,γ)^{5}He/^{3}H(^{2}H,n)^{4}He was determined in magnetic confinement fusion plasmas at the Joint European Torus in predominantly deuterium beam heated plasmas. The branching ratio was found to be equal to (2.4±0.5)×10^{-5} over the deuterium energy range of (80±20) keV. This accurate determination of the deuterium-tritium branching ratio paves the way for a direct and neutron-independent measurement of fusion power in magnetic confinement fusion reactors, based on the absolute counting of deuterium-tritium gamma rays.
ABSTRACT
The excited states of unstable ^{20}O were investigated via γ-ray spectroscopy following the ^{19}O(d,p)^{20}O reaction at 8 AMeV. By exploiting the Doppler shift attenuation method, the lifetimes of the 2_{2}^{+} and 3_{1}^{+} states were firmly established. From the γ-ray branching and E2/M1 mixing ratios for transitions deexciting the 2_{2}^{+} and 3_{1}^{+} states, the B(E2) and B(M1) were determined. Various chiral effective field theory Hamiltonians, describing the nuclear properties beyond ground states, along with a standard USDB interaction, were compared with the experimentally obtained data. Such a comparison for a large set of γ-ray transition probabilities with the valence space in medium similarity renormalization group ab initio calculations was performed for the first time in a nucleus far from stability. It was shown that the ab initio approaches using chiral effective field theory forces are challenged by detailed high-precision spectroscopic properties of nuclei. The reduced transition probabilities were found to be a very constraining test of the performance of the ab initio models.
ABSTRACT
Submesoscale structures fill the ocean surface, and recent numerical simulations and indirect observations suggest that they may extend to the ocean interior. It remains unclear, however, how far-reaching their impact may be-in both space and time, from weather to climate scales. Here transport pathways and the ultimate fate of the Irminger Current water from the continental slope to Labrador Sea interior are investigated through regional ocean simulations. Submesoscale processes modulate this transport and in turn the stratification of the Labrador Sea interior, by controlling the characteristics of the coherent vortices formed along West Greenland. Submesoscale circulations modify and control the Labrador Sea contribution to the global meridional overturning, with a linear relationship between time-averaged near surface vorticity and/or frontogenetic tendency along the west coast of Greenland, and volume of convected water. This research puts into contest the lesser role of the Labrador Sea in the overall control of the state of the MOC argued through the analysis of recent OSNAP (Overturning in the Subpolar North Atlantic Program) data with respect to estimates from climate models. It also confirms that submesoscale turbulence scales-up to climate relevance, pointing to the urgency of including its advective contribution in Earth systems models.
ABSTRACT
The low-spin structure of the semimagic ^{64}Ni nucleus has been considerably expanded: combining four experiments, several 0^{+} and 2^{+} excited states were identified below 4.5 MeV, and their properties established. The Monte Carlo shell model accounts for the results and unveils an unexpectedly complex landscape of coexisting shapes: a prolate 0^{+} excitation is located at a surprisingly high energy (3463 keV), with a collective 2^{+} state 286 keV above it, the first such observation in Ni isotopes. The evolution in excitation energy of the prolate minimum across the neutron N=40 subshell gap highlights the impact of the monopole interaction and its variation in strength with N.
ABSTRACT
Spectroscopic factors of neutron-hole and proton-hole states in ^{131}Sn and ^{131}In, respectively, were measured using one-nucleon removal reactions from doubly magic ^{132}Sn at relativistic energies. For ^{131}In, a 2910(50)-keV γ ray was observed for the first time and tentatively assigned to a decay from a 5/2^{-} state at 3275(50) keV to the known 1/2^{-} level at 365 keV. The spectroscopic factors determined for this new excited state and three other single-hole states provide first evidence for a strong fragmentation of single-hole strength in ^{131}Sn and ^{131}In. The experimental results are compared to theoretical calculations based on the relativistic particle-vibration coupling model and to experimental information for single-hole states in the stable doubly magic nucleus ^{208}Pb.
ABSTRACT
The discovery of new drugs to treat pathological cells in the case of aggressive liver primary cancer is imposing the identification of high-throughput screening systems to predict the in vivo response of new therapeutic molecules, in order to reduce current use of animals and drug testing costs. Recently, micro/nanostructured scaffolds have been adopted to reproduce the hepatic microenvironment due to their higher similarity to the biological niche with respect to the traditional two-dimensional culture plate, so providing novel in vitro models for reliably understanding molecular mechanisms related to cancer cells activity. Herein, we propose the study of electrospun scaffolds made of polycaprolactone as in vitro model that can mimic the morphological organization of native extracellular matrix and the co-culture of hepatic cell lines-i.e., HepG2, human healthy hepatocytes (HHH). The micro- and nano-scale morphological features of fibers with diameter equal to (3.22 ± 0.42) µm and surface roughness of (17.84 ± 4.43) nm-allow the reproduction of the in vivo scenario influencing the adhesion and proliferation rate of the cultured cells. A much lower proliferation rate is observed for the HepG2 cells compared to the HHH cells, when cultured on the fibrous scaffolds over a time course of 4 weeks. Moreover, results on oxidative stress mechanisms indicate an antioxidant effect of fibers mainly in the case of co-colture, thus suggesting a promising use as new in vitro models to explore alternative therapeutic strategies in hepatocarcinoma treatment.
Subject(s)
Extracellular Matrix/chemistry , Hepatocytes/cytology , Tissue Engineering/methods , Tissue Scaffolds/chemistry , Bromodeoxyuridine/chemistry , Cell Line , Cell Proliferation , Coculture Techniques , Hep G2 Cells , Humans , Image Processing, Computer-Assisted/methods , Liver/surgery , Polyesters/chemistry , Reactive Oxygen Species/metabolismABSTRACT
A search for shape isomers in the ^{66}Ni nucleus was performed, following old suggestions of various mean-field models and recent ones, based on state-of-the-art Monte Carlo shell model (MCSM), all considering ^{66}Ni as the lightest nuclear system with shape isomerism. By employing the two-neutron transfer reaction induced by an ^{18}O beam on a ^{64}Ni target, at the sub-Coulomb barrier energy of 39 MeV, all three lowest-excited 0^{+} states in ^{66}Ni were populated and their γ decay was observed by γ-coincidence technique. The 0^{+} states lifetimes were assessed with the plunger method, yielding for the 0_{2}^{+}, 0_{3}^{+}, and 0_{4}^{+} decay to the 2_{1}^{+} state the B(E2) values of 4.3, 0.1, and 0.2 Weisskopf units (W.u.), respectively. MCSM calculations correctly predict the existence of all three excited 0^{+} states, pointing to the oblate, spherical, and prolate nature of the consecutive excitations. In addition, they account for the hindrance of the E2 decay from the prolate 0_{4}^{+} to the spherical 2_{1}^{+} state, although overestimating its value. This result makes ^{66}Ni a unique nuclear system, apart from ^{236,238}U, in which a retarded γ transition from a 0^{+} deformed state to a spherical configuration is observed, resembling a shape-isomerlike behavior.
ABSTRACT
Poly[tetra-µ2-acetato-κ8O:O'-bis-(µ2-benzene-1,2-di-amine-κ2N:N')dicadmium], [Cd2(CH3COO)4(C6H8N2)2] n , (I), and poly[[(µ2-acetato-κ2O:O')(acetato-κ2O,O')(µ2-benzene-1,3-di-amine-κ2N:N')cadmium] hemihydrate], {[Cd(CH3COO)2(C6H8N2)]·0.5H2O} n , (II), have two-dimensional polymeric structures in which monomeric units are joined by bridging acetate and benzenedi-amine ligands. Each of the CdII ions has an O4N2 coordination environment. The coordination geometries of the symmetry-independent CdII ions are distorted octa-hedral and distorted trigonal anti-prismatic in (I) and distorted anti-prismatic in (II). Both compounds exhibit an intra-layer hydrogen-bonding network. In addition, the water of hydration in (II) is involved in inter-layer hydrogen bonding.
ABSTRACT
This is a practical report on laboratory tests for the diagnosis of antiphospholipid syndrome (APS). After a general definition of APS, this study deals with appropriateness and timing in requesting the determination of antiphospholipid (aPL) antibodies. Lupus anticoagulant (LAC), anticardiolipin (aCL), and anti ß2-glycoprotein I (aßGPI) are the mandatory tests to be performed, while other tests are not yet validated for clinical use. Interpretation of results is an important discussed issue that implies a close liaison between clinical pathologists and clinicians. Finally, a personal definition of APS according to aPL antibody profile closes the manuscript.
Subject(s)
Antiphospholipid Syndrome/diagnosis , Clinical Chemistry Tests/methods , Antibodies, Antiphospholipid/analysis , HumansABSTRACT
The isospin mixing was deduced in the compound nucleus ^{80}Zr at an excitation energy of E^{*}=54 MeV from the γ decay of the giant dipole resonance. The reaction ^{40}Ca+^{40}Ca at E_{beam}=136 MeV was used to form the compound nucleus in the isospin I=0 channel, while the reaction ^{37}Cl+^{44}Ca at E_{beam}=95 MeV was used as the reference reaction. The γ rays were detected with the AGATA demonstrator array coupled with LaBr_{3}:Ce detectors. The temperature dependence of the isospin mixing was obtained and the zero-temperature value deduced. The isospin-symmetry-breaking correction δ_{C} used for the Fermi superallowed transitions was extracted and found to be consistent with ß-decay data.
ABSTRACT
BACKGROUND: Determination of the three recommended tests for the diagnosis of antiphospholipid syndrome [Lupus Anticoagulant (LA), anticardiolipin (aCL) and anti ß2-Glycoprotein 1 (aß2GP1) antibodies] allow physicians to allocate patients into classification (risk) categories. OBJECTIVES: To measure antibodies of IgG isotype directed towards Domain 4/5 (Dm4/5) of ß2GP1. PATIENTS/METHODS: In this cross-sectional study we measured IgG aß2GP1-Dm4/5 in a group of individuals positive for IgG aß2GP1 and classified as triple (LAC+, IgG aCL+, IgG aß2GP1+, n=32), double (LAC-, IgG aCL+, IgG aß2GP1+, n=23) or single positive (LA-, IgG aCL-, IgG aß2GP1+, n=10). RESULTS: Geometric mean and standard deviation of IgG aß2GP1 values expressed as Chemiluminescent Units (CU) in triple, double, single positive groups and in 40 healthy individuals were 1795±783, 321±181, 29±8 and 5.0±1.0, respectively (ANOVA p<0.0001). Geometric mean and standard deviation of IgG aß2GP1-Dm4/5 expressed as Optical Density (OD) in triple, double and single positive groups and in 40 healthy individuals were 0.16±0.13, 0.16±0.15 and 0.26±0.15, 0.13±0,11, respectively (ANOVA p<0.002). Individuals in the single positive group, expressed significantly higher values with respect to triple (p=0.04) and double (p=0.03) positive groups. Approximate OD cut-off value (99° percentile) calculated in 40 normal control subjects is 0.404. Positivity to IgG aß2GP1-Dm4/5 according to this cutoff was found in only 5 individuals, 3 in triple positive and 2 in single positive groups and was not associated with thromboembolism. CONCLUSION: Mean level of IgG aß2GP1-Dm4/5 is higher in single positive group. There is no association between positivity to IgG aß2GP1-Dm4/5 and thromboembolic events.
Subject(s)
Antibodies, Antiphospholipid/immunology , Antiphospholipid Syndrome/immunology , Immunoglobulin G/immunology , beta 2-Glycoprotein I/immunology , Antibodies, Antiphospholipid/blood , Antiphospholipid Syndrome/blood , Cross-Sectional Studies , Epitopes/chemistry , Epitopes/immunology , Humans , Immunoglobulin G/blood , Protein Structure, Tertiary , beta 2-Glycoprotein I/chemistryABSTRACT
Search for a new kind of superfluidity built on collective proton-neutron pairs with aligned spin is performed studying the Gamow-Teller decay of the T=1, J(π)=0+ ground state of (62)Ge into excited states of the odd-odd N=Z nucleus (62)Ga. The experiment is performed at GSI Helmholtzzentrum für Shwerionenforshung with the (62)Ge ions selected by the fragment separator and implanted in a stack of Si-strip detectors, surrounded by the RISING Ge array. A half-life of T1/2=82.9(14) ms is measured for the (62)Ge ground state. Six excited states of (62)Ga, populated below 2.5 MeV through Gamow-Teller transitions, are identified. Individual Gamow-Teller transition strengths agree well with theoretical predictions of the interacting shell model and the quasiparticle random phase approximation. The absence of any sizable low-lying Gamow-Teller strength in the reported beta-decay experiment supports the hypothesis of a negligible role of coherent T=0 proton-neutron correlations in (62)Ga.
ABSTRACT
The properties of pygmy dipole states in 208Pb were investigated using the 208Pb(17O, 17O'γ) reaction at 340 MeV and measuring the γ decay with high resolution with the AGATA demonstrator array. Cross sections and angular distributions of the emitted γ rays and of the scattered particles were measured. The results are compared with (γ, γ') and (p, p') data. The data analysis with the distorted wave Born approximation approach gives a good description of the elastic scattering and of the inelastic excitation of the 2+ and 3- states. For the dipole transitions a form factor obtained by folding a microscopically calculated transition density was used for the first time. This has allowed us to extract the isoscalar component of the 1- excited states from 4 to 8 MeV.
ABSTRACT
BACKGROUND: The revised classification criteria for the antiphospholipid syndrome state that antiphospholipid (aPL) antibodies (lupus anticoagulant [LAC] and/or anticardiolipin [aCL] and/or anti-ß2 -glycoprotein I [aß2 GPI] antibodies) should be detected on two or more occasions at least 12 weeks apart. Consequently, classification of patient risk and adequacy of treatment may be deferred by 3 months. OBJECTIVES: In order to early classify patient risk, we evaluated whether aPL positivity confirmation is related to aPL antibody profiles. PATIENTS AND METHODS: Consecutive patients referred to our center who were initially positive in one or more tests exploring the presence of aPL were tested after 3 months. During a 4-year period, 225 patients were initially positive in one or more tests, and 161 were available for confirmation after 3 months. Patients were classified as triple-positive (n = 54: LAC(+) , aCL(+) , aß2 GPI(+) , same isotype), double-positive (n = 50: LAC(-) , aCL(+) , aß2 GPI(+) , same isotype) and single-positive (n = 53: LAC or aCL or aß2 GPI antibodies as the sole positive test). RESULTS: Among subjects with triple positivity at initial testing, 98% (53 of 54) had their aPL profile confirmed after 12 weeks. The double-positive and single-positive groups had data confirmed in 42 of 50 (84%) and 23 of 57 (40%) subjects, respectively. CONCLUSIONS: Our results show that high-risk subjects with triple-positive aPL profiles are identified early, at the time of the initial screening tests.
Subject(s)
Antibodies, Antiphospholipid/blood , Antiphospholipid Syndrome/diagnosis , Lupus Coagulation Inhibitor/blood , Thrombosis/blood , beta 2-Glycoprotein I/chemistry , Adult , Antibodies, Anticardiolipin/immunology , Antibodies, Antiphospholipid/immunology , Antiphospholipid Syndrome/blood , Antiphospholipid Syndrome/immunology , Cohort Studies , Female , Humans , Lupus Coagulation Inhibitor/immunology , Male , Middle Aged , Predictive Value of Tests , Reproducibility of Results , Risk , Time FactorsABSTRACT
The combination of oral anticoagulants with dual antiplatelet therapy (DAT) in patients undergoing percutaneous coronary intervention with stent implantation (PCI-stenting) is subject to controversy due to the high risk of bleeding. In this multicenter retrospective parallel-group study, we compared the rate of adverse events in chronically anticoagulated patients who underwent PCI-stenting and were discharged on aspirin, clopidogrel and warfarin (triple antithrombotic therapy [TT] group) and were followed in Italian anticoagulation centers, with a parallel cohort of patients who underwent PCI-stenting and were discharged on DAT group. The primary endpoint was the incidence of major bleeding while the patients were in TT and DAT. A secondary endpoint was the occurrence of major ischemic adverse events (MACEs). The final cohort consisted of 229 TT patients and 231 DAT patients followed up for 6 and 7 months, respectively. There were 11 (4.8%; 9.1% patient/years) major bleeding events in the TT group (1 was fatal) as compared to 1 (0.4%; 0.7% patient/years) event in the DAT group (p = 0.003). Of the 28 (6.1%) MACE recorded during the follow-up, 12 (5.2%) occurred in the TT group and 16 (6.9%) in the DAT group. In conclusion, despite close monitoring of anticoagulated patients in dedicated centers, the major bleeding incidence remains high among unselected patients undergoing PCI-stenting and treated with TT. Any efforts to minimize these events should be pursued.
Subject(s)
Fibrinolytic Agents/administration & dosage , Fibrinolytic Agents/adverse effects , Hemorrhage/chemically induced , Hemorrhage/epidemiology , Percutaneous Coronary Intervention/adverse effects , Adult , Aged , Cohort Studies , Drug Therapy, Combination , Female , Follow-Up Studies , Hemorrhage/diagnosis , Humans , Male , Middle Aged , Retrospective StudiesABSTRACT
The γ-ray strength function of 56Fe has been measured from proton-γ coincidences for excitation energies up to ≈11 MeV. The low-energy enhancement in the γ-ray strength function, which was first discovered in the (3He,αγ)56Fe reaction, is confirmed with the (p,p'γ)56Fe experiment reported here. Angular distributions of the γ rays give for the first time evidence that the enhancement is dominated by dipole transitions.
ABSTRACT
The neutron-rich lead isotopes, up to (216)Pb, have been studied for the first time, exploiting the fragmentation of a primary uranium beam at the FRS-RISING setup at GSI. The observed isomeric states exhibit electromagnetic transition strengths which deviate from state-of-the-art shell-model calculations. It is shown that their complete description demands the introduction of effective three-body interactions and two-body transition operators in the conventional neutron valence space beyond (208)Pb.
ABSTRACT
A single positive laboratory test among those exploring the presence of antiphospholipid antibodies is not associated with thromboembolic events and does not identify patients with antiphospholipid syndrome. On the other hand, more than one laboratory test positive, and in particular all three tests positive, is strongly associated to thromboembolic events and identifies high risk patients. Triple positivity is in fact related to the presence of a specific anti-ß2-glycoprotein I (anti-Domain I) antibody, also able to prolong coagulation tests. Monoclonal antibodies against Domain I with Lupus Anticoagulant activity might be candidate material for standardization of antiphospholipid assays. Much work remains to be done in this field.
Subject(s)
Antiphospholipid Syndrome/diagnosis , Blood Coagulation Tests , Enzyme-Linked Immunosorbent Assay , Humans , Reference StandardsABSTRACT
Secondary prevention of venous thromboembolism in antiphospholipid syndrome (APS) is usually made using vitamin K antagonists (VKAs) to maintain an international normalized ratio (INR) between 2.0 and 3.0. The optimal intensity of anticoagulation was determined in two prospective randomized controlled trials, both excluding the benefit of more intense anticoagulation. The same regimen is also recommended in patients with APS and arterial thromboembolism as aspirin does not appear to protect against recurrences. The duration of treatment is usually indefinite because of a substantial risk of recurrence.